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LeafOS / LeafOS-Devices / android_kernel_samsung_gta4xl / 3b0228656dcb07a1c9fc81e8516475c2d7c4300e / . / net / core / dev.c
blob: ef9fe60ee294b0e2503456f68136440646c86344 [file] [log] [blame]
/*
* NET3 Protocol independent device support routines.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Derived from the non IP parts of dev.c 1.0.19
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Mark Evans, <evansmp@uhura.aston.ac.uk>
*
* Additional Authors:
* Florian la Roche <rzsfl@rz.uni-sb.de>
* Alan Cox <gw4pts@gw4pts.ampr.org>
* David Hinds <dahinds@users.sourceforge.net>
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
* Adam Sulmicki <adam@cfar.umd.edu>
* Pekka Riikonen <priikone@poesidon.pspt.fi>
*
* Changes:
* D.J. Barrow : Fixed bug where dev->refcnt gets set
* to 2 if register_netdev gets called
* before net_dev_init & also removed a
* few lines of code in the process.
* Alan Cox : device private ioctl copies fields back.
* Alan Cox : Transmit queue code does relevant
* stunts to keep the queue safe.
* Alan Cox : Fixed double lock.
* Alan Cox : Fixed promisc NULL pointer trap
* ???????? : Support the full private ioctl range
* Alan Cox : Moved ioctl permission check into
* drivers
* Tim Kordas : SIOCADDMULTI/SIOCDELMULTI
* Alan Cox : 100 backlog just doesn't cut it when
* you start doing multicast video 8)
* Alan Cox : Rewrote net_bh and list manager.
* Alan Cox : Fix ETH_P_ALL echoback lengths.
* Alan Cox : Took out transmit every packet pass
* Saved a few bytes in the ioctl handler
* Alan Cox : Network driver sets packet type before
* calling netif_rx. Saves a function
* call a packet.
* Alan Cox : Hashed net_bh()
* Richard Kooijman: Timestamp fixes.
* Alan Cox : Wrong field in SIOCGIFDSTADDR
* Alan Cox : Device lock protection.
* Alan Cox : Fixed nasty side effect of device close
* changes.
* Rudi Cilibrasi : Pass the right thing to
* set_mac_address()
* Dave Miller : 32bit quantity for the device lock to
* make it work out on a Sparc.
* Bjorn Ekwall : Added KERNELD hack.
* Alan Cox : Cleaned up the backlog initialise.
* Craig Metz : SIOCGIFCONF fix if space for under
* 1 device.
* Thomas Bogendoerfer : Return ENODEV for dev_open, if there
* is no device open function.
* Andi Kleen : Fix error reporting for SIOCGIFCONF
* Michael Chastain : Fix signed/unsigned for SIOCGIFCONF
* Cyrus Durgin : Cleaned for KMOD
* Adam Sulmicki : Bug Fix : Network Device Unload
* A network device unload needs to purge
* the backlog queue.
* Paul Rusty Russell : SIOCSIFNAME
* Pekka Riikonen : Netdev boot-time settings code
* Andrew Morton : Make unregister_netdevice wait
* indefinitely on dev->refcnt
* J Hadi Salim : - Backlog queue sampling
* - netif_rx() feedback
*/
#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/capability.h>
#include <linux/cpu.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/notifier.h>
#include <linux/skbuff.h>
#include <linux/bpf.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/busy_poll.h>
#include <linux/rtnetlink.h>
#include <linux/stat.h>
#include <net/dst.h>
#include <net/dst_metadata.h>
#include <net/pkt_sched.h>
#include <net/checksum.h>
#include <net/xfrm.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netpoll.h>
#include <linux/rcupdate.h>
#include <linux/delay.h>
#include <net/iw_handler.h>
#include <asm/current.h>
#include <linux/audit.h>
#include <linux/dmaengine.h>
#include <linux/err.h>
#include <linux/ctype.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <net/ip.h>
#include <net/mpls.h>
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <trace/events/napi.h>
#include <trace/events/net.h>
#include <trace/events/skb.h>
#include <linux/pci.h>
#include <linux/inetdevice.h>
#include <linux/cpu_rmap.h>
#include <linux/static_key.h>
#include <linux/hashtable.h>
#include <linux/vmalloc.h>
#include <linux/if_macvlan.h>
#include <linux/errqueue.h>
#include <linux/hrtimer.h>
#include <linux/netfilter_ingress.h>
#include <linux/crash_dump.h>
#include "net-sysfs.h"
/* Instead of increasing this, you should create a hash table. */
#define MAX_GRO_SKBS 8
/* This should be increased if a protocol with a bigger head is added. */
#define GRO_MAX_HEAD (MAX_HEADER + 128)
static DEFINE_SPINLOCK(ptype_lock);
static DEFINE_SPINLOCK(offload_lock);
struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
struct list_head ptype_all __read_mostly; /* Taps */
static struct list_head offload_base __read_mostly;
static int netif_rx_internal(struct sk_buff *skb);
static int call_netdevice_notifiers_info(unsigned long val,
struct net_device *dev,
struct netdev_notifier_info *info);
/*
* The @dev_base_head list is protected by @dev_base_lock and the rtnl
* semaphore.
*
* Pure readers hold dev_base_lock for reading, or rcu_read_lock()
*
* Writers must hold the rtnl semaphore while they loop through the
* dev_base_head list, and hold dev_base_lock for writing when they do the
* actual updates. This allows pure readers to access the list even
* while a writer is preparing to update it.
*
* To put it another way, dev_base_lock is held for writing only to
* protect against pure readers; the rtnl semaphore provides the
* protection against other writers.
*
* See, for example usages, register_netdevice() and
* unregister_netdevice(), which must be called with the rtnl
* semaphore held.
*/
DEFINE_RWLOCK(dev_base_lock);
EXPORT_SYMBOL(dev_base_lock);
/* protects napi_hash addition/deletion and napi_gen_id */
static DEFINE_SPINLOCK(napi_hash_lock);
static unsigned int napi_gen_id = NR_CPUS;
static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
static seqcount_t devnet_rename_seq;
static inline void dev_base_seq_inc(struct net *net)
{
while (++net->dev_base_seq == 0)
;
}
static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
{
unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
}
static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
{
return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
}
static inline void rps_lock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
spin_lock(&sd->input_pkt_queue.lock);
#endif
}
static inline void rps_unlock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
spin_unlock(&sd->input_pkt_queue.lock);
#endif
}
/* Device list insertion */
static void list_netdevice(struct net_device *dev)
{
struct net *net = dev_net(dev);
ASSERT_RTNL();
write_lock_bh(&dev_base_lock);
list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
hlist_add_head_rcu(&dev->index_hlist,
dev_index_hash(net, dev->ifindex));
write_unlock_bh(&dev_base_lock);
dev_base_seq_inc(net);
}
/* Device list removal
* caller must respect a RCU grace period before freeing/reusing dev
*/
static void unlist_netdevice(struct net_device *dev)
{
ASSERT_RTNL();
/* Unlink dev from the device chain */
write_lock_bh(&dev_base_lock);
list_del_rcu(&dev->dev_list);
hlist_del_rcu(&dev->name_hlist);
hlist_del_rcu(&dev->index_hlist);
write_unlock_bh(&dev_base_lock);
dev_base_seq_inc(dev_net(dev));
}
/*
* Our notifier list
*/
static RAW_NOTIFIER_HEAD(netdev_chain);
/*
* Device drivers call our routines to queue packets here. We empty the
* queue in the local softnet handler.
*/
DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
EXPORT_PER_CPU_SYMBOL(softnet_data);
#ifdef CONFIG_LOCKDEP
/*
* register_netdevice() inits txq->_xmit_lock and sets lockdep class
* according to dev->type
*/
static const unsigned short netdev_lock_type[] = {
ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
static const char *const netdev_lock_name[] = {
"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
static inline unsigned short netdev_lock_pos(unsigned short dev_type)
{
int i;
for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
if (netdev_lock_type[i] == dev_type)
return i;
/* the last key is used by default */
return ARRAY_SIZE(netdev_lock_type) - 1;
}
static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
unsigned short dev_type)
{
int i;
i = netdev_lock_pos(dev_type);
lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
netdev_lock_name[i]);
}
static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
{
int i;
i = netdev_lock_pos(dev->type);
lockdep_set_class_and_name(&dev->addr_list_lock,
&netdev_addr_lock_key[i],
netdev_lock_name[i]);
}
#else
static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
unsigned short dev_type)
{
}
static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
{
}
#endif
/*******************************************************************************
*
* Protocol management and registration routines
*
*******************************************************************************/
/*
* Add a protocol ID to the list. Now that the input handler is
* smarter we can dispense with all the messy stuff that used to be
* here.
*
* BEWARE!!! Protocol handlers, mangling input packets,
* MUST BE last in hash buckets and checking protocol handlers
* MUST start from promiscuous ptype_all chain in net_bh.
* It is true now, do not change it.
* Explanation follows: if protocol handler, mangling packet, will
* be the first on list, it is not able to sense, that packet
* is cloned and should be copied-on-write, so that it will
* change it and subsequent readers will get broken packet.
* --ANK (980803)
*/
static inline struct list_head *ptype_head(const struct packet_type *pt)
{
if (pt->type == htons(ETH_P_ALL))
return pt->dev ? &pt->dev->ptype_all : &ptype_all;
else
return pt->dev ? &pt->dev->ptype_specific :
&ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
}
/**
* dev_add_pack - add packet handler
* @pt: packet type declaration
*
* Add a protocol handler to the networking stack. The passed &packet_type
* is linked into kernel lists and may not be freed until it has been
* removed from the kernel lists.
*
* This call does not sleep therefore it can not
* guarantee all CPU's that are in middle of receiving packets
* will see the new packet type (until the next received packet).
*/
void dev_add_pack(struct packet_type *pt)
{
struct list_head *head = ptype_head(pt);
spin_lock(&ptype_lock);
list_add_rcu(&pt->list, head);
spin_unlock(&ptype_lock);
}
EXPORT_SYMBOL(dev_add_pack);
/**
* __dev_remove_pack - remove packet handler
* @pt: packet type declaration
*
* Remove a protocol handler that was previously added to the kernel
* protocol handlers by dev_add_pack(). The passed &packet_type is removed
* from the kernel lists and can be freed or reused once this function
* returns.
*
* The packet type might still be in use by receivers
* and must not be freed until after all the CPU's have gone
* through a quiescent state.
*/
void __dev_remove_pack(struct packet_type *pt)
{
struct list_head *head = ptype_head(pt);
struct packet_type *pt1;
spin_lock(&ptype_lock);
list_for_each_entry(pt1, head, list) {
if (pt == pt1) {
list_del_rcu(&pt->list);
goto out;
}
}
pr_warn("dev_remove_pack: %p not found\n", pt);
out:
spin_unlock(&ptype_lock);
}
EXPORT_SYMBOL(__dev_remove_pack);
/**
* dev_remove_pack - remove packet handler
* @pt: packet type declaration
*
* Remove a protocol handler that was previously added to the kernel
* protocol handlers by dev_add_pack(). The passed &packet_type is removed
* from the kernel lists and can be freed or reused once this function
* returns.
*
* This call sleeps to guarantee that no CPU is looking at the packet
* type after return.
*/
void dev_remove_pack(struct packet_type *pt)
{
__dev_remove_pack(pt);
synchronize_net();
}
EXPORT_SYMBOL(dev_remove_pack);
/**
* dev_add_offload - register offload handlers
* @po: protocol offload declaration
*
* Add protocol offload handlers to the networking stack. The passed
* &proto_offload is linked into kernel lists and may not be freed until
* it has been removed from the kernel lists.
*
* This call does not sleep therefore it can not
* guarantee all CPU's that are in middle of receiving packets
* will see the new offload handlers (until the next received packet).
*/
void dev_add_offload(struct packet_offload *po)
{
struct packet_offload *elem;
spin_lock(&offload_lock);
list_for_each_entry(elem, &offload_base, list) {
if (po->priority < elem->priority)
break;
}
list_add_rcu(&po->list, elem->list.prev);
spin_unlock(&offload_lock);
}
EXPORT_SYMBOL(dev_add_offload);
/**
* __dev_remove_offload - remove offload handler
* @po: packet offload declaration
*
* Remove a protocol offload handler that was previously added to the
* kernel offload handlers by dev_add_offload(). The passed &offload_type
* is removed from the kernel lists and can be freed or reused once this
* function returns.
*
* The packet type might still be in use by receivers
* and must not be freed until after all the CPU's have gone
* through a quiescent state.
*/
static void __dev_remove_offload(struct packet_offload *po)
{
struct list_head *head = &offload_base;
struct packet_offload *po1;
spin_lock(&offload_lock);
list_for_each_entry(po1, head, list) {
if (po == po1) {
list_del_rcu(&po->list);
goto out;
}
}
pr_warn("dev_remove_offload: %p not found\n", po);
out:
spin_unlock(&offload_lock);
}
/**
* dev_remove_offload - remove packet offload handler
* @po: packet offload declaration
*
* Remove a packet offload handler that was previously added to the kernel
* offload handlers by dev_add_offload(). The passed &offload_type is
* removed from the kernel lists and can be freed or reused once this
* function returns.
*
* This call sleeps to guarantee that no CPU is looking at the packet
* type after return.
*/
void dev_remove_offload(struct packet_offload *po)
{
__dev_remove_offload(po);
synchronize_net();
}
EXPORT_SYMBOL(dev_remove_offload);
/******************************************************************************
*
* Device Boot-time Settings Routines
*
******************************************************************************/
/* Boot time configuration table */
static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
/**
* netdev_boot_setup_add - add new setup entry
* @name: name of the device
* @map: configured settings for the device
*
* Adds new setup entry to the dev_boot_setup list. The function
* returns 0 on error and 1 on success. This is a generic routine to
* all netdevices.
*/
static int netdev_boot_setup_add(char *name, struct ifmap *map)
{
struct netdev_boot_setup *s;
int i;
s = dev_boot_setup;
for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
memset(s[i].name, 0, sizeof(s[i].name));
strlcpy(s[i].name, name, IFNAMSIZ);
memcpy(&s[i].map, map, sizeof(s[i].map));
break;
}
}
return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
}
/**
* netdev_boot_setup_check - check boot time settings
* @dev: the netdevice
*
* Check boot time settings for the device.
* The found settings are set for the device to be used
* later in the device probing.
* Returns 0 if no settings found, 1 if they are.
*/
int netdev_boot_setup_check(struct net_device *dev)
{
struct netdev_boot_setup *s = dev_boot_setup;
int i;
for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
!strcmp(dev->name, s[i].name)) {
dev->irq = s[i].map.irq;
dev->base_addr = s[i].map.base_addr;
dev->mem_start = s[i].map.mem_start;
dev->mem_end = s[i].map.mem_end;
return 1;
}
}
return 0;
}
EXPORT_SYMBOL(netdev_boot_setup_check);
/**
* netdev_boot_base - get address from boot time settings
* @prefix: prefix for network device
* @unit: id for network device
*
* Check boot time settings for the base address of device.
* The found settings are set for the device to be used
* later in the device probing.
* Returns 0 if no settings found.
*/
unsigned long netdev_boot_base(const char *prefix, int unit)
{
const struct netdev_boot_setup *s = dev_boot_setup;
char name[IFNAMSIZ];
int i;
sprintf(name, "%s%d", prefix, unit);
/*
* If device already registered then return base of 1
* to indicate not to probe for this interface
*/
if (__dev_get_by_name(&init_net, name))
return 1;
for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
if (!strcmp(name, s[i].name))
return s[i].map.base_addr;
return 0;
}
/*
* Saves at boot time configured settings for any netdevice.
*/
int __init netdev_boot_setup(char *str)
{
int ints[5];
struct ifmap map;
str = get_options(str, ARRAY_SIZE(ints), ints);
if (!str || !*str)
return 0;
/* Save settings */
memset(&map, 0, sizeof(map));
if (ints[0] > 0)
map.irq = ints[1];
if (ints[0] > 1)
map.base_addr = ints[2];
if (ints[0] > 2)
map.mem_start = ints[3];
if (ints[0] > 3)
map.mem_end = ints[4];
/* Add new entry to the list */
return netdev_boot_setup_add(str, &map);
}
__setup("netdev=", netdev_boot_setup);
/*******************************************************************************
*
* Device Interface Subroutines
*
*******************************************************************************/
/**
* dev_get_iflink - get 'iflink' value of a interface
* @dev: targeted interface
*
* Indicates the ifindex the interface is linked to.
* Physical interfaces have the same 'ifindex' and 'iflink' values.
*/
int dev_get_iflink(const struct net_device *dev)
{
if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
return dev->netdev_ops->ndo_get_iflink(dev);
return dev->ifindex;
}
EXPORT_SYMBOL(dev_get_iflink);
/**
* dev_fill_metadata_dst - Retrieve tunnel egress information.
* @dev: targeted interface
* @skb: The packet.
*
* For better visibility of tunnel traffic OVS needs to retrieve
* egress tunnel information for a packet. Following API allows
* user to get this info.
*/
int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
struct ip_tunnel_info *info;
if (!dev->netdev_ops || !dev->netdev_ops->ndo_fill_metadata_dst)
return -EINVAL;
info = skb_tunnel_info_unclone(skb);
if (!info)
return -ENOMEM;
if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
return -EINVAL;
return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
}
EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
/**
* __dev_get_by_name - find a device by its name
* @net: the applicable net namespace
* @name: name to find
*
* Find an interface by name. Must be called under RTNL semaphore
* or @dev_base_lock. If the name is found a pointer to the device
* is returned. If the name is not found then %NULL is returned. The
* reference counters are not incremented so the caller must be
* careful with locks.
*/
struct net_device *__dev_get_by_name(struct net *net, const char *name)
{
struct net_device *dev;
struct hlist_head *head = dev_name_hash(net, name);
hlist_for_each_entry(dev, head, name_hlist)
if (!strncmp(dev->name, name, IFNAMSIZ))
return dev;
return NULL;
}
EXPORT_SYMBOL(__dev_get_by_name);
/**
* dev_get_by_name_rcu - find a device by its name
* @net: the applicable net namespace
* @name: name to find
*
* Find an interface by name.
* If the name is found a pointer to the device is returned.
* If the name is not found then %NULL is returned.
* The reference counters are not incremented so the caller must be
* careful with locks. The caller must hold RCU lock.
*/
struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
{
struct net_device *dev;
struct hlist_head *head = dev_name_hash(net, name);
hlist_for_each_entry_rcu(dev, head, name_hlist)
if (!strncmp(dev->name, name, IFNAMSIZ))
return dev;
return NULL;
}
EXPORT_SYMBOL(dev_get_by_name_rcu);
/**
* dev_get_by_name - find a device by its name
* @net: the applicable net namespace
* @name: name to find
*
* Find an interface by name. This can be called from any
* context and does its own locking. The returned handle has
* the usage count incremented and the caller must use dev_put() to
* release it when it is no longer needed. %NULL is returned if no
* matching device is found.
*/
struct net_device *dev_get_by_name(struct net *net, const char *name)
{
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_name_rcu(net, name);
if (dev)
dev_hold(dev);
rcu_read_unlock();
return dev;
}
EXPORT_SYMBOL(dev_get_by_name);
/**
* __dev_get_by_index - find a device by its ifindex
* @net: the applicable net namespace
* @ifindex: index of device
*
* Search for an interface by index. Returns %NULL if the device
* is not found or a pointer to the device. The device has not
* had its reference counter increased so the caller must be careful
* about locking. The caller must hold either the RTNL semaphore
* or @dev_base_lock.
*/
struct net_device *__dev_get_by_index(struct net *net, int ifindex)
{
struct net_device *dev;
struct hlist_head *head = dev_index_hash(net, ifindex);
hlist_for_each_entry(dev, head, index_hlist)
if (dev->ifindex == ifindex)
return dev;
return NULL;
}
EXPORT_SYMBOL(__dev_get_by_index);
/**
* dev_get_by_index_rcu - find a device by its ifindex
* @net: the applicable net namespace
* @ifindex: index of device
*
* Search for an interface by index. Returns %NULL if the device
* is not found or a pointer to the device. The device has not
* had its reference counter increased so the caller must be careful
* about locking. The caller must hold RCU lock.
*/
struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
{
struct net_device *dev;
struct hlist_head *head = dev_index_hash(net, ifindex);
hlist_for_each_entry_rcu(dev, head, index_hlist)
if (dev->ifindex == ifindex)
return dev;
return NULL;
}
EXPORT_SYMBOL(dev_get_by_index_rcu);
/**
* dev_get_by_index - find a device by its ifindex
* @net: the applicable net namespace
* @ifindex: index of device
*
* Search for an interface by index. Returns NULL if the device
* is not found or a pointer to the device. The device returned has
* had a reference added and the pointer is safe until the user calls
* dev_put to indicate they have finished with it.
*/
struct net_device *dev_get_by_index(struct net *net, int ifindex)
{
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (dev)
dev_hold(dev);
rcu_read_unlock();
return dev;
}
EXPORT_SYMBOL(dev_get_by_index);
/**
* netdev_get_name - get a netdevice name, knowing its ifindex.
* @net: network namespace
* @name: a pointer to the buffer where the name will be stored.
* @ifindex: the ifindex of the interface to get the name from.
*
* The use of raw_seqcount_begin() and cond_resched() before
* retrying is required as we want to give the writers a chance
* to complete when CONFIG_PREEMPT is not set.
*/
int netdev_get_name(struct net *net, char *name, int ifindex)
{
struct net_device *dev;
unsigned int seq;
retry:
seq = raw_seqcount_begin(&devnet_rename_seq);
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (!dev) {
rcu_read_unlock();
return -ENODEV;
}
strcpy(name, dev->name);
rcu_read_unlock();
if (read_seqcount_retry(&devnet_rename_seq, seq)) {
cond_resched();
goto retry;
}
return 0;
}
/**
* dev_getbyhwaddr_rcu - find a device by its hardware address
* @net: the applicable net namespace
* @type: media type of device
* @ha: hardware address
*
* Search for an interface by MAC address. Returns NULL if the device
* is not found or a pointer to the device.
* The caller must hold RCU or RTNL.
* The returned device has not had its ref count increased
* and the caller must therefore be careful about locking
*
*/
struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
const char *ha)
{
struct net_device *dev;
for_each_netdev_rcu(net, dev)
if (dev->type == type &&
!memcmp(dev->dev_addr, ha, dev->addr_len))
return dev;
return NULL;
}
EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
{
struct net_device *dev;
ASSERT_RTNL();
for_each_netdev(net, dev)
if (dev->type == type)
return dev;
return NULL;
}
EXPORT_SYMBOL(__dev_getfirstbyhwtype);
struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
{
struct net_device *dev, *ret = NULL;
rcu_read_lock();
for_each_netdev_rcu(net, dev)
if (dev->type == type) {
dev_hold(dev);
ret = dev;
break;
}
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(dev_getfirstbyhwtype);
/**
* __dev_get_by_flags - find any device with given flags
* @net: the applicable net namespace
* @if_flags: IFF_* values
* @mask: bitmask of bits in if_flags to check
*
* Search for any interface with the given flags. Returns NULL if a device
* is not found or a pointer to the device. Must be called inside
* rtnl_lock(), and result refcount is unchanged.
*/
struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
unsigned short mask)
{
struct net_device *dev, *ret;
ASSERT_RTNL();
ret = NULL;
for_each_netdev(net, dev) {
if (((dev->flags ^ if_flags) & mask) == 0) {
ret = dev;
break;
}
}
return ret;
}
EXPORT_SYMBOL(__dev_get_by_flags);
/**
* dev_valid_name - check if name is okay for network device
* @name: name string
*
* Network device names need to be valid file names to
* to allow sysfs to work. We also disallow any kind of
* whitespace.
*/
bool dev_valid_name(const char *name)
{
if (*name == '\0')
return false;
if (strlen(name) >= IFNAMSIZ)
return false;
if (!strcmp(name, ".") || !strcmp(name, ".."))
return false;
while (*name) {
if (*name == '/' || *name == ':' || isspace(*name))
return false;
name++;
}
return true;
}
EXPORT_SYMBOL(dev_valid_name);
/**
* __dev_alloc_name - allocate a name for a device
* @net: network namespace to allocate the device name in
* @name: name format string
* @buf: scratch buffer and result name string
*
* Passed a format string - eg "lt%d" it will try and find a suitable
* id. It scans list of devices to build up a free map, then chooses
* the first empty slot. The caller must hold the dev_base or rtnl lock
* while allocating the name and adding the device in order to avoid
* duplicates.
* Limited to bits_per_byte * page size devices (ie 32K on most platforms).
* Returns the number of the unit assigned or a negative errno code.
*/
static int __dev_alloc_name(struct net *net, const char *name, char *buf)
{
int i = 0;
const char *p;
const int max_netdevices = 8*PAGE_SIZE;
unsigned long *inuse;
struct net_device *d;
p = strnchr(name, IFNAMSIZ-1, '%');
if (p) {
/*
* Verify the string as this thing may have come from
* the user. There must be either one "%d" and no other "%"
* characters.
*/
if (p[1] != 'd' || strchr(p + 2, '%'))
return -EINVAL;
/* Use one page as a bit array of possible slots */
inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
if (!inuse)
return -ENOMEM;
for_each_netdev(net, d) {
if (!sscanf(d->name, name, &i))
continue;
if (i < 0 || i >= max_netdevices)
continue;
/* avoid cases where sscanf is not exact inverse of printf */
snprintf(buf, IFNAMSIZ, name, i);
if (!strncmp(buf, d->name, IFNAMSIZ))
set_bit(i, inuse);
}
i = find_first_zero_bit(inuse, max_netdevices);
free_page((unsigned long) inuse);
}
if (buf != name)
snprintf(buf, IFNAMSIZ, name, i);
if (!__dev_get_by_name(net, buf))
return i;
/* It is possible to run out of possible slots
* when the name is long and there isn't enough space left
* for the digits, or if all bits are used.
*/
return -ENFILE;
}
/**
* dev_alloc_name - allocate a name for a device
* @dev: device
* @name: name format string
*
* Passed a format string - eg "lt%d" it will try and find a suitable
* id. It scans list of devices to build up a free map, then chooses
* the first empty slot. The caller must hold the dev_base or rtnl lock
* while allocating the name and adding the device in order to avoid
* duplicates.
* Limited to bits_per_byte * page size devices (ie 32K on most platforms).
* Returns the number of the unit assigned or a negative errno code.
*/
int dev_alloc_name(struct net_device *dev, const char *name)
{
char buf[IFNAMSIZ];
struct net *net;
int ret;
BUG_ON(!dev_net(dev));
net = dev_net(dev);
ret = __dev_alloc_name(net, name, buf);
if (ret >= 0)
strlcpy(dev->name, buf, IFNAMSIZ);
return ret;
}
EXPORT_SYMBOL(dev_alloc_name);
static int dev_alloc_name_ns(struct net *net,
struct net_device *dev,
const char *name)
{
char buf[IFNAMSIZ];
int ret;
ret = __dev_alloc_name(net, name, buf);
if (ret >= 0)
strlcpy(dev->name, buf, IFNAMSIZ);
return ret;
}
static int dev_get_valid_name(struct net *net,
struct net_device *dev,
const char *name)
{
BUG_ON(!net);
if (!dev_valid_name(name))
return -EINVAL;
if (strchr(name, '%'))
return dev_alloc_name_ns(net, dev, name);
else if (__dev_get_by_name(net, name))
return -EEXIST;
else if (dev->name != name)
strlcpy(dev->name, name, IFNAMSIZ);
return 0;
}
/**
* dev_change_name - change name of a device
* @dev: device
* @newname: name (or format string) must be at least IFNAMSIZ
*
* Change name of a device, can pass format strings "eth%d".
* for wildcarding.
*/
int dev_change_name(struct net_device *dev, const char *newname)
{
unsigned char old_assign_type;
char oldname[IFNAMSIZ];
int err = 0;
int ret;
struct net *net;
ASSERT_RTNL();
BUG_ON(!dev_net(dev));
net = dev_net(dev);
if (dev->flags & IFF_UP)
return -EBUSY;
write_seqcount_begin(&devnet_rename_seq);
if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
write_seqcount_end(&devnet_rename_seq);
return 0;
}
memcpy(oldname, dev->name, IFNAMSIZ);
err = dev_get_valid_name(net, dev, newname);
if (err < 0) {
write_seqcount_end(&devnet_rename_seq);
return err;
}
if (oldname[0] && !strchr(oldname, '%'))
netdev_info(dev, "renamed from %s\n", oldname);
old_assign_type = dev->name_assign_type;
dev->name_assign_type = NET_NAME_RENAMED;
rollback:
ret = device_rename(&dev->dev, dev->name);
if (ret) {
memcpy(dev->name, oldname, IFNAMSIZ);
dev->name_assign_type = old_assign_type;
write_seqcount_end(&devnet_rename_seq);
return ret;
}
write_seqcount_end(&devnet_rename_seq);
netdev_adjacent_rename_links(dev, oldname);
write_lock_bh(&dev_base_lock);
hlist_del_rcu(&dev->name_hlist);
write_unlock_bh(&dev_base_lock);
synchronize_rcu();
write_lock_bh(&dev_base_lock);
hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
write_unlock_bh(&dev_base_lock);
ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
ret = notifier_to_errno(ret);
if (ret) {
/* err >= 0 after dev_alloc_name() or stores the first errno */
if (err >= 0) {
err = ret;
write_seqcount_begin(&devnet_rename_seq);
memcpy(dev->name, oldname, IFNAMSIZ);
memcpy(oldname, newname, IFNAMSIZ);
dev->name_assign_type = old_assign_type;
old_assign_type = NET_NAME_RENAMED;
goto rollback;
} else {
pr_err("%s: name change rollback failed: %d\n",
dev->name, ret);
}
}
return err;
}
/**
* dev_set_alias - change ifalias of a device
* @dev: device
* @alias: name up to IFALIASZ
* @len: limit of bytes to copy from info
*
* Set ifalias for a device,
*/
int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
{
char *new_ifalias;
ASSERT_RTNL();
if (len >= IFALIASZ)
return -EINVAL;
if (!len) {
kfree(dev->ifalias);
dev->ifalias = NULL;
return 0;
}
new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
if (!new_ifalias)
return -ENOMEM;
dev->ifalias = new_ifalias;
strlcpy(dev->ifalias, alias, len+1);
return len;
}
/**
* netdev_features_change - device changes features
* @dev: device to cause notification
*
* Called to indicate a device has changed features.
*/
void netdev_features_change(struct net_device *dev)
{
call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
}
EXPORT_SYMBOL(netdev_features_change);
/**
* netdev_state_change - device changes state
* @dev: device to cause notification
*
* Called to indicate a device has changed state. This function calls
* the notifier chains for netdev_chain and sends a NEWLINK message
* to the routing socket.
*/
void netdev_state_change(struct net_device *dev)
{
if (dev->flags & IFF_UP) {
struct netdev_notifier_change_info change_info;
change_info.flags_changed = 0;
call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
&change_info.info);
rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
}
}
EXPORT_SYMBOL(netdev_state_change);
/**
* netdev_notify_peers - notify network peers about existence of @dev
* @dev: network device
*
* Generate traffic such that interested network peers are aware of
* @dev, such as by generating a gratuitous ARP. This may be used when
* a device wants to inform the rest of the network about some sort of
* reconfiguration such as a failover event or virtual machine
* migration.
*/
void netdev_notify_peers(struct net_device *dev)
{
rtnl_lock();
call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
rtnl_unlock();
}
EXPORT_SYMBOL(netdev_notify_peers);
static int __dev_open(struct net_device *dev)
{
const struct net_device_ops *ops = dev->netdev_ops;
int ret;
ASSERT_RTNL();
if (!netif_device_present(dev))
return -ENODEV;
/* Block netpoll from trying to do any rx path servicing.
* If we don't do this there is a chance ndo_poll_controller
* or ndo_poll may be running while we open the device
*/
netpoll_poll_disable(dev);
ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
ret = notifier_to_errno(ret);
if (ret)
return ret;
set_bit(__LINK_STATE_START, &dev->state);
if (ops->ndo_validate_addr)
ret = ops->ndo_validate_addr(dev);
if (!ret && ops->ndo_open)
ret = ops->ndo_open(dev);
netpoll_poll_enable(dev);
if (ret)
clear_bit(__LINK_STATE_START, &dev->state);
else {
dev->flags |= IFF_UP;
dev_set_rx_mode(dev);
dev_activate(dev);
add_device_randomness(dev->dev_addr, dev->addr_len);
}
return ret;
}
/**
* dev_open - prepare an interface for use.
* @dev: device to open
*
* Takes a device from down to up state. The device's private open
* function is invoked and then the multicast lists are loaded. Finally
* the device is moved into the up state and a %NETDEV_UP message is
* sent to the netdev notifier chain.
*
* Calling this function on an active interface is a nop. On a failure
* a negative errno code is returned.
*/
int dev_open(struct net_device *dev)
{
int ret;
if (dev->flags & IFF_UP)
return 0;
ret = __dev_open(dev);
if (ret < 0)
return ret;
rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
call_netdevice_notifiers(NETDEV_UP, dev);
return ret;
}
EXPORT_SYMBOL(dev_open);
static int __dev_close_many(struct list_head *head)
{
struct net_device *dev;
ASSERT_RTNL();
might_sleep();
list_for_each_entry(dev, head, close_list) {
/* Temporarily disable netpoll until the interface is down */
netpoll_poll_disable(dev);
call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
clear_bit(__LINK_STATE_START, &dev->state);
/* Synchronize to scheduled poll. We cannot touch poll list, it
* can be even on different cpu. So just clear netif_running().
*
* dev->stop() will invoke napi_disable() on all of it's
* napi_struct instances on this device.
*/
smp_mb__after_atomic(); /* Commit netif_running(). */
}
dev_deactivate_many(head);
list_for_each_entry(dev, head, close_list) {
const struct net_device_ops *ops = dev->netdev_ops;
/*
* Call the device specific close. This cannot fail.
* Only if device is UP
*
* We allow it to be called even after a DETACH hot-plug
* event.
*/
if (ops->ndo_stop)
ops->ndo_stop(dev);
dev->flags &= ~IFF_UP;
netpoll_poll_enable(dev);
}
return 0;
}
static int __dev_close(struct net_device *dev)
{
int retval;
LIST_HEAD(single);
list_add(&dev->close_list, &single);
retval = __dev_close_many(&single);
list_del(&single);
return retval;
}
int dev_close_many(struct list_head *head, bool unlink)
{
struct net_device *dev, *tmp;
/* Remove the devices that don't need to be closed */
list_for_each_entry_safe(dev, tmp, head, close_list)
if (!(dev->flags & IFF_UP))
list_del_init(&dev->close_list);
__dev_close_many(head);
list_for_each_entry_safe(dev, tmp, head, close_list) {
rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
call_netdevice_notifiers(NETDEV_DOWN, dev);
if (unlink)
list_del_init(&dev->close_list);
}
return 0;
}
EXPORT_SYMBOL(dev_close_many);
/**
* dev_close - shutdown an interface.
* @dev: device to shutdown
*
* This function moves an active device into down state. A
* %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
* is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
* chain.
*/
int dev_close(struct net_device *dev)
{
if (dev->flags & IFF_UP) {
LIST_HEAD(single);
list_add(&dev->close_list, &single);
dev_close_many(&single, true);
list_del(&single);
}
return 0;
}
EXPORT_SYMBOL(dev_close);
/**
* dev_disable_lro - disable Large Receive Offload on a device
* @dev: device
*
* Disable Large Receive Offload (LRO) on a net device. Must be
* called under RTNL. This is needed if received packets may be
* forwarded to another interface.
*/
void dev_disable_lro(struct net_device *dev)
{
struct net_device *lower_dev;
struct list_head *iter;
dev->wanted_features &= ~NETIF_F_LRO;
netdev_update_features(dev);
if (unlikely(dev->features & NETIF_F_LRO))
netdev_WARN(dev, "failed to disable LRO!\n");
netdev_for_each_lower_dev(dev, lower_dev, iter)
dev_disable_lro(lower_dev);
}
EXPORT_SYMBOL(dev_disable_lro);
static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
struct net_device *dev)
{
struct netdev_notifier_info info;
netdev_notifier_info_init(&info, dev);
return nb->notifier_call(nb, val, &info);
}
static int dev_boot_phase = 1;
/**
* register_netdevice_notifier - register a network notifier block
* @nb: notifier
*
* Register a notifier to be called when network device events occur.
* The notifier passed is linked into the kernel structures and must
* not be reused until it has been unregistered. A negative errno code
* is returned on a failure.
*
* When registered all registration and up events are replayed
* to the new notifier to allow device to have a race free
* view of the network device list.
*/
int register_netdevice_notifier(struct notifier_block *nb)
{
struct net_device *dev;
struct net_device *last;
struct net *net;
int err;
rtnl_lock();
err = raw_notifier_chain_register(&netdev_chain, nb);
if (err)
goto unlock;
if (dev_boot_phase)
goto unlock;
for_each_net(net) {
for_each_netdev(net, dev) {
err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
err = notifier_to_errno(err);
if (err)
goto rollback;
if (!(dev->flags & IFF_UP))
continue;
call_netdevice_notifier(nb, NETDEV_UP, dev);
}
}
unlock:
rtnl_unlock();
return err;
rollback:
last = dev;
for_each_net(net) {
for_each_netdev(net, dev) {
if (dev == last)
goto outroll;
if (dev->flags & IFF_UP) {
call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
dev);
call_netdevice_notifier(nb, NETDEV_DOWN, dev);
}
call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
}
}
outroll:
raw_notifier_chain_unregister(&netdev_chain, nb);
goto unlock;
}
EXPORT_SYMBOL(register_netdevice_notifier);
/**
* unregister_netdevice_notifier - unregister a network notifier block
* @nb: notifier
*
* Unregister a notifier previously registered by
* register_netdevice_notifier(). The notifier is unlinked into the
* kernel structures and may then be reused. A negative errno code
* is returned on a failure.
*
* After unregistering unregister and down device events are synthesized
* for all devices on the device list to the removed notifier to remove
* the need for special case cleanup code.
*/
int unregister_netdevice_notifier(struct notifier_block *nb)
{
struct net_device *dev;
struct net *net;
int err;
rtnl_lock();
err = raw_notifier_chain_unregister(&netdev_chain, nb);
if (err)
goto unlock;
for_each_net(net) {
for_each_netdev(net, dev) {
if (dev->flags & IFF_UP) {
call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
dev);
call_netdevice_notifier(nb, NETDEV_DOWN, dev);
}
call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
}
}
unlock:
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(unregister_netdevice_notifier);
/**
* call_netdevice_notifiers_info - call all network notifier blocks
* @val: value passed unmodified to notifier function
* @dev: net_device pointer passed unmodified to notifier function
* @info: notifier information data
*
* Call all network notifier blocks. Parameters and return value
* are as for raw_notifier_call_chain().
*/
static int call_netdevice_notifiers_info(unsigned long val,
struct net_device *dev,
struct netdev_notifier_info *info)
{
ASSERT_RTNL();
netdev_notifier_info_init(info, dev);
return raw_notifier_call_chain(&netdev_chain, val, info);
}
/**
* call_netdevice_notifiers - call all network notifier blocks
* @val: value passed unmodified to notifier function
* @dev: net_device pointer passed unmodified to notifier function
*
* Call all network notifier blocks. Parameters and return value
* are as for raw_notifier_call_chain().
*/
int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
{
struct netdev_notifier_info info;
return call_netdevice_notifiers_info(val, dev, &info);
}
EXPORT_SYMBOL(call_netdevice_notifiers);
#ifdef CONFIG_NET_INGRESS
static struct static_key ingress_needed __read_mostly;
void net_inc_ingress_queue(void)
{
static_key_slow_inc(&ingress_needed);
}
EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
void net_dec_ingress_queue(void)
{
static_key_slow_dec(&ingress_needed);
}
EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
#endif
#ifdef CONFIG_NET_EGRESS
static struct static_key egress_needed __read_mostly;
void net_inc_egress_queue(void)
{
static_key_slow_inc(&egress_needed);
}
EXPORT_SYMBOL_GPL(net_inc_egress_queue);
void net_dec_egress_queue(void)
{
static_key_slow_dec(&egress_needed);
}
EXPORT_SYMBOL_GPL(net_dec_egress_queue);
#endif
static struct static_key netstamp_needed __read_mostly;
#ifdef HAVE_JUMP_LABEL
static atomic_t netstamp_needed_deferred;
static atomic_t netstamp_wanted;
static void netstamp_clear(struct work_struct *work)
{
int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
int wanted;
wanted = atomic_add_return(deferred, &netstamp_wanted);
if (wanted > 0)
static_key_enable(&netstamp_needed);
else
static_key_disable(&netstamp_needed);
}
static DECLARE_WORK(netstamp_work, netstamp_clear);
#endif
void net_enable_timestamp(void)
{
#ifdef HAVE_JUMP_LABEL
int wanted;
while (1) {
wanted = atomic_read(&netstamp_wanted);
if (wanted <= 0)
break;
if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
return;
}
atomic_inc(&netstamp_needed_deferred);
schedule_work(&netstamp_work);
#else
static_key_slow_inc(&netstamp_needed);
#endif
}
EXPORT_SYMBOL(net_enable_timestamp);
void net_disable_timestamp(void)
{
#ifdef HAVE_JUMP_LABEL
int wanted;
while (1) {
wanted = atomic_read(&netstamp_wanted);
if (wanted <= 1)
break;
if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
return;
}
atomic_dec(&netstamp_needed_deferred);
schedule_work(&netstamp_work);
#else
static_key_slow_dec(&netstamp_needed);
#endif
}
EXPORT_SYMBOL(net_disable_timestamp);
static inline void net_timestamp_set(struct sk_buff *skb)
{
skb->tstamp = 0;
if (static_key_false(&netstamp_needed))
__net_timestamp(skb);
}
#define net_timestamp_check(COND, SKB) \
if (static_key_false(&netstamp_needed)) { \
if ((COND) && !(SKB)->tstamp) \
__net_timestamp(SKB); \
} \
bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
{
unsigned int len;
if (!(dev->flags & IFF_UP))
return false;
len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
if (skb->len <= len)
return true;
/* if TSO is enabled, we don't care about the length as the packet
* could be forwarded without being segmented before
*/
if (skb_is_gso(skb))
return true;
return false;
}
EXPORT_SYMBOL_GPL(is_skb_forwardable);
int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
int ret = ____dev_forward_skb(dev, skb);
if (likely(!ret)) {
skb->protocol = eth_type_trans(skb, dev);
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
}
return ret;
}
EXPORT_SYMBOL_GPL(__dev_forward_skb);
/**
* dev_forward_skb - loopback an skb to another netif
*
* @dev: destination network device
* @skb: buffer to forward
*
* return values:
* NET_RX_SUCCESS (no congestion)
* NET_RX_DROP (packet was dropped, but freed)
*
* dev_forward_skb can be used for injecting an skb from the
* start_xmit function of one device into the receive queue
* of another device.
*
* The receiving device may be in another namespace, so
* we have to clear all information in the skb that could
* impact namespace isolation.
*/
int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
{
return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
}
EXPORT_SYMBOL_GPL(dev_forward_skb);
static inline int deliver_skb(struct sk_buff *skb,
struct packet_type *pt_prev,
struct net_device *orig_dev)
{
if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
return -ENOMEM;
atomic_inc(&skb->users);
return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}
static inline void deliver_ptype_list_skb(struct sk_buff *skb,
struct packet_type **pt,
struct net_device *orig_dev,
__be16 type,
struct list_head *ptype_list)
{
struct packet_type *ptype, *pt_prev = *pt;
list_for_each_entry_rcu(ptype, ptype_list, list) {
if (ptype->type != type)
continue;
if (pt_prev)
deliver_skb(skb, pt_prev, orig_dev);
pt_prev = ptype;
}
*pt = pt_prev;
}
static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
{
if (!ptype->af_packet_priv || !skb->sk)
return false;
if (ptype->id_match)
return ptype->id_match(ptype, skb->sk);
else if ((struct sock *)ptype->af_packet_priv == skb->sk)
return true;
return false;
}
/*
* Support routine. Sends outgoing frames to any network
* taps currently in use.
*/
void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
{
struct packet_type *ptype;
struct sk_buff *skb2 = NULL;
struct packet_type *pt_prev = NULL;
struct list_head *ptype_list = &ptype_all;
rcu_read_lock();
again:
list_for_each_entry_rcu(ptype, ptype_list, list) {
/* Never send packets back to the socket
* they originated from - MvS (miquels@drinkel.ow.org)
*/
if (skb_loop_sk(ptype, skb))
continue;
if (pt_prev) {
deliver_skb(skb2, pt_prev, skb->dev);
pt_prev = ptype;
continue;
}
/* need to clone skb, done only once */
skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2)
goto out_unlock;
net_timestamp_set(skb2);
/* skb->nh should be correctly
* set by sender, so that the second statement is
* just protection against buggy protocols.
*/
skb_reset_mac_header(skb2);
if (skb_network_header(skb2) < skb2->data ||
skb_network_header(skb2) > skb_tail_pointer(skb2)) {
net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
ntohs(skb2->protocol),
dev->name);
skb_reset_network_header(skb2);
}
skb2->transport_header = skb2->network_header;
skb2->pkt_type = PACKET_OUTGOING;
pt_prev = ptype;
}
if (ptype_list == &ptype_all) {
ptype_list = &dev->ptype_all;
goto again;
}
out_unlock:
if (pt_prev)
pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
/**
* netif_setup_tc - Handle tc mappings on real_num_tx_queues change
* @dev: Network device
* @txq: number of queues available
*
* If real_num_tx_queues is changed the tc mappings may no longer be
* valid. To resolve this verify the tc mapping remains valid and if
* not NULL the mapping. With no priorities mapping to this
* offset/count pair it will no longer be used. In the worst case TC0
* is invalid nothing can be done so disable priority mappings. If is
* expected that drivers will fix this mapping if they can before
* calling netif_set_real_num_tx_queues.
*/
static void netif_setup_tc(struct net_device *dev, unsigned int txq)
{
int i;
struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
/* If TC0 is invalidated disable TC mapping */
if (tc->offset + tc->count > txq) {
pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
dev->num_tc = 0;
return;
}
/* Invalidated prio to tc mappings set to TC0 */
for (i = 1; i < TC_BITMASK + 1; i++) {
int q = netdev_get_prio_tc_map(dev, i);
tc = &dev->tc_to_txq[q];
if (tc->offset + tc->count > txq) {
pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
i, q);
netdev_set_prio_tc_map(dev, i, 0);
}
}
}
int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
{
if (dev->num_tc) {
struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
int i;
for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
if ((txq - tc->offset) < tc->count)
return i;
}
return -1;
}
return 0;
}
#ifdef CONFIG_XPS
static DEFINE_MUTEX(xps_map_mutex);
#define xmap_dereference(P) \
rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
int tci, u16 index)
{
struct xps_map *map = NULL;
int pos;
if (dev_maps)
map = xmap_dereference(dev_maps->cpu_map[tci]);
if (!map)
return false;
for (pos = map->len; pos--;) {
if (map->queues[pos] != index)
continue;
if (map->len > 1) {
map->queues[pos] = map->queues[--map->len];
break;
}
RCU_INIT_POINTER(dev_maps->cpu_map[tci], NULL);
kfree_rcu(map, rcu);
return false;
}
return true;
}
static bool remove_xps_queue_cpu(struct net_device *dev,
struct xps_dev_maps *dev_maps,
int cpu, u16 offset, u16 count)
{
int num_tc = dev->num_tc ? : 1;
bool active = false;
int tci;
for (tci = cpu * num_tc; num_tc--; tci++) {
int i, j;
for (i = count, j = offset; i--; j++) {
if (!remove_xps_queue(dev_maps, cpu, j))
break;
}
active |= i < 0;
}
return active;
}
static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
u16 count)
{
struct xps_dev_maps *dev_maps;
int cpu, i;
bool active = false;
mutex_lock(&xps_map_mutex);
dev_maps = xmap_dereference(dev->xps_maps);
if (!dev_maps)
goto out_no_maps;
for_each_possible_cpu(cpu)
active |= remove_xps_queue_cpu(dev, dev_maps, cpu,
offset, count);
if (!active) {
RCU_INIT_POINTER(dev->xps_maps, NULL);
kfree_rcu(dev_maps, rcu);
}
for (i = offset + (count - 1); count--; i--)
netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
NUMA_NO_NODE);
out_no_maps:
mutex_unlock(&xps_map_mutex);
}
static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
{
netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
}
static struct xps_map *expand_xps_map(struct xps_map *map,
int cpu, u16 index)
{
struct xps_map *new_map;
int alloc_len = XPS_MIN_MAP_ALLOC;
int i, pos;
for (pos = 0; map && pos < map->len; pos++) {
if (map->queues[pos] != index)
continue;
return map;
}
/* Need to add queue to this CPU's existing map */
if (map) {
if (pos < map->alloc_len)
return map;
alloc_len = map->alloc_len * 2;
}
/* Need to allocate new map to store queue on this CPU's map */
new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
cpu_to_node(cpu));
if (!new_map)
return NULL;
for (i = 0; i < pos; i++)
new_map->queues[i] = map->queues[i];
new_map->alloc_len = alloc_len;
new_map->len = pos;
return new_map;
}
int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
u16 index)
{
struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
int i, cpu, tci, numa_node_id = -2;
int maps_sz, num_tc = 1, tc = 0;
struct xps_map *map, *new_map;
bool active = false;
if (dev->num_tc) {
num_tc = dev->num_tc;
tc = netdev_txq_to_tc(dev, index);
if (tc < 0)
return -EINVAL;
}
maps_sz = XPS_DEV_MAPS_SIZE(num_tc);
if (maps_sz < L1_CACHE_BYTES)
maps_sz = L1_CACHE_BYTES;
mutex_lock(&xps_map_mutex);
dev_maps = xmap_dereference(dev->xps_maps);
/* allocate memory for queue storage */
for_each_cpu_and(cpu, cpu_online_mask, mask) {
if (!new_dev_maps)
new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
if (!new_dev_maps) {
mutex_unlock(&xps_map_mutex);
return -ENOMEM;
}
tci = cpu * num_tc + tc;
map = dev_maps ? xmap_dereference(dev_maps->cpu_map[tci]) :
NULL;
map = expand_xps_map(map, cpu, index);
if (!map)
goto error;
RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
}
if (!new_dev_maps)
goto out_no_new_maps;
for_each_possible_cpu(cpu) {
/* copy maps belonging to foreign traffic classes */
for (i = tc, tci = cpu * num_tc; dev_maps && i--; tci++) {
/* fill in the new device map from the old device map */
map = xmap_dereference(dev_maps->cpu_map[tci]);
RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
}
/* We need to explicitly update tci as prevous loop
* could break out early if dev_maps is NULL.
*/
tci = cpu * num_tc + tc;
if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
/* add queue to CPU maps */
int pos = 0;
map = xmap_dereference(new_dev_maps->cpu_map[tci]);
while ((pos < map->len) && (map->queues[pos] != index))
pos++;
if (pos == map->len)
map->queues[map->len++] = index;
#ifdef CONFIG_NUMA
if (numa_node_id == -2)
numa_node_id = cpu_to_node(cpu);
else if (numa_node_id != cpu_to_node(cpu))
numa_node_id = -1;
#endif
} else if (dev_maps) {
/* fill in the new device map from the old device map */
map = xmap_dereference(dev_maps->cpu_map[tci]);
RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
}
/* copy maps belonging to foreign traffic classes */
for (i = num_tc - tc, tci++; dev_maps && --i; tci++) {
/* fill in the new device map from the old device map */
map = xmap_dereference(dev_maps->cpu_map[tci]);
RCU_INIT_POINTER(new_dev_maps->cpu_map[tci], map);
}
}
rcu_assign_pointer(dev->xps_maps, new_dev_maps);
/* Cleanup old maps */
if (!dev_maps)
goto out_no_old_maps;
for_each_possible_cpu(cpu) {
for (i = num_tc, tci = cpu * num_tc; i--; tci++) {
new_map = xmap_dereference(new_dev_maps->cpu_map[tci]);
map = xmap_dereference(dev_maps->cpu_map[tci]);
if (map && map != new_map)
kfree_rcu(map, rcu);
}
}
kfree_rcu(dev_maps, rcu);
out_no_old_maps:
dev_maps = new_dev_maps;
active = true;
out_no_new_maps:
/* update Tx queue numa node */
netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
(numa_node_id >= 0) ? numa_node_id :
NUMA_NO_NODE);
if (!dev_maps)
goto out_no_maps;
/* removes queue from unused CPUs */
for_each_possible_cpu(cpu) {
for (i = tc, tci = cpu * num_tc; i--; tci++)
active |= remove_xps_queue(dev_maps, tci, index);
if (!cpumask_test_cpu(cpu, mask) || !cpu_online(cpu))
active |= remove_xps_queue(dev_maps, tci, index);
for (i = num_tc - tc, tci++; --i; tci++)
active |= remove_xps_queue(dev_maps, tci, index);
}
/* free map if not active */
if (!active) {
RCU_INIT_POINTER(dev->xps_maps, NULL);
kfree_rcu(dev_maps, rcu);
}
out_no_maps:
mutex_unlock(&xps_map_mutex);
return 0;
error:
/* remove any maps that we added */
for_each_possible_cpu(cpu) {
for (i = num_tc, tci = cpu * num_tc; i--; tci++) {
new_map = xmap_dereference(new_dev_maps->cpu_map[tci]);
map = dev_maps ?
xmap_dereference(dev_maps->cpu_map[tci]) :
NULL;
if (new_map && new_map != map)
kfree(new_map);
}
}
mutex_unlock(&xps_map_mutex);
kfree(new_dev_maps);
return -ENOMEM;
}
EXPORT_SYMBOL(netif_set_xps_queue);
#endif
void netdev_reset_tc(struct net_device *dev)
{
#ifdef CONFIG_XPS
netif_reset_xps_queues_gt(dev, 0);
#endif
dev->num_tc = 0;
memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
}
EXPORT_SYMBOL(netdev_reset_tc);
int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
{
if (tc >= dev->num_tc)
return -EINVAL;
#ifdef CONFIG_XPS
netif_reset_xps_queues(dev, offset, count);
#endif
dev->tc_to_txq[tc].count = count;
dev->tc_to_txq[tc].offset = offset;
return 0;
}
EXPORT_SYMBOL(netdev_set_tc_queue);
int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
{
if (num_tc > TC_MAX_QUEUE)
return -EINVAL;
#ifdef CONFIG_XPS
netif_reset_xps_queues_gt(dev, 0);
#endif
dev->num_tc = num_tc;
return 0;
}
EXPORT_SYMBOL(netdev_set_num_tc);
/*
* Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
* greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
*/
int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
{
int rc;
if (txq < 1 || txq > dev->num_tx_queues)
return -EINVAL;
if (dev->reg_state == NETREG_REGISTERED ||
dev->reg_state == NETREG_UNREGISTERING) {
ASSERT_RTNL();
rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
txq);
if (rc)
return rc;
if (dev->num_tc)
netif_setup_tc(dev, txq);
if (txq < dev->real_num_tx_queues) {
qdisc_reset_all_tx_gt(dev, txq);
#ifdef CONFIG_XPS
netif_reset_xps_queues_gt(dev, txq);
#endif
}
}
dev->real_num_tx_queues = txq;
return 0;
}
EXPORT_SYMBOL(netif_set_real_num_tx_queues);
#ifdef CONFIG_SYSFS
/**
* netif_set_real_num_rx_queues - set actual number of RX queues used
* @dev: Network device
* @rxq: Actual number of RX queues
*
* This must be called either with the rtnl_lock held or before
* registration of the net device. Returns 0 on success, or a
* negative error code. If called before registration, it always
* succeeds.
*/
int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
{
int rc;
if (rxq < 1 || rxq > dev->num_rx_queues)
return -EINVAL;
if (dev->reg_state == NETREG_REGISTERED) {
ASSERT_RTNL();
rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
rxq);
if (rc)
return rc;
}
dev->real_num_rx_queues = rxq;
return 0;
}
EXPORT_SYMBOL(netif_set_real_num_rx_queues);
#endif
/**
* netif_get_num_default_rss_queues - default number of RSS queues
*
* This routine should set an upper limit on the number of RSS queues
* used by default by multiqueue devices.
*/
int netif_get_num_default_rss_queues(void)
{
return is_kdump_kernel() ?
1 : min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
}
EXPORT_SYMBOL(netif_get_num_default_rss_queues);
static void __netif_reschedule(struct Qdisc *q)
{
struct softnet_data *sd;
unsigned long flags;
local_irq_save(flags);
sd = this_cpu_ptr(&softnet_data);
q->next_sched = NULL;
*sd->output_queue_tailp = q;
sd->output_queue_tailp = &q->next_sched;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
}
void __netif_schedule(struct Qdisc *q)
{
if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
__netif_reschedule(q);
}
EXPORT_SYMBOL(__netif_schedule);
struct dev_kfree_skb_cb {
enum skb_free_reason reason;
};
static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
{
return (struct dev_kfree_skb_cb *)skb->cb;
}
void netif_schedule_queue(struct netdev_queue *txq)
{
rcu_read_lock();
if (!(txq->state & QUEUE_STATE_ANY_XOFF)) {
struct Qdisc *q = rcu_dereference(txq->qdisc);
__netif_schedule(q);
}
rcu_read_unlock();
}
EXPORT_SYMBOL(netif_schedule_queue);
void netif_tx_wake_queue(struct netdev_queue *dev_queue)
{
if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
struct Qdisc *q;
rcu_read_lock();
q = rcu_dereference(dev_queue->qdisc);
__netif_schedule(q);
rcu_read_unlock();
}
}
EXPORT_SYMBOL(netif_tx_wake_queue);
void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
{
unsigned long flags;
if (likely(atomic_read(&skb->users) == 1)) {
smp_rmb();
atomic_set(&skb->users, 0);
} else if (likely(!atomic_dec_and_test(&skb->users))) {
return;
}
get_kfree_skb_cb(skb)->reason = reason;
local_irq_save(flags);
skb->next = __this_cpu_read(softnet_data.completion_queue);
__this_cpu_write(softnet_data.completion_queue, skb);
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
}
EXPORT_SYMBOL(__dev_kfree_skb_irq);
void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
{
if (in_irq() || irqs_disabled())
__dev_kfree_skb_irq(skb, reason);
else
dev_kfree_skb(skb);
}
EXPORT_SYMBOL(__dev_kfree_skb_any);
/**
* netif_device_detach - mark device as removed
* @dev: network device
*
* Mark device as removed from system and therefore no longer available.
*/
void netif_device_detach(struct net_device *dev)
{
if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
netif_running(dev)) {
netif_tx_stop_all_queues(dev);
}
}
EXPORT_SYMBOL(netif_device_detach);
/**
* netif_device_attach - mark device as attached
* @dev: network device
*
* Mark device as attached from system and restart if needed.
*/
void netif_device_attach(struct net_device *dev)
{
if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
netif_running(dev)) {
netif_tx_wake_all_queues(dev);
__netdev_watchdog_up(dev);
}
}
EXPORT_SYMBOL(netif_device_attach);
/*
* Returns a Tx hash based on the given packet descriptor a Tx queues' number
* to be used as a distribution range.
*/
u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
unsigned int num_tx_queues)
{
u32 hash;
u16 qoffset = 0;
u16 qcount = num_tx_queues;
if (skb_rx_queue_recorded(skb)) {
hash = skb_get_rx_queue(skb);
while (unlikely(hash >= num_tx_queues))
hash -= num_tx_queues;
return hash;
}
if (dev->num_tc) {
u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
qoffset = dev->tc_to_txq[tc].offset;
qcount = dev->tc_to_txq[tc].count;
}
return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
}
EXPORT_SYMBOL(__skb_tx_hash);
static void skb_warn_bad_offload(const struct sk_buff *skb)
{
static const netdev_features_t null_features;
struct net_device *dev = skb->dev;
const char *name = "";
if (!net_ratelimit())
return;
if (dev) {
if (dev->dev.parent)
name = dev_driver_string(dev->dev.parent);
else
name = netdev_name(dev);
}
WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
"gso_type=%d ip_summed=%d\n",
name, dev ? &dev->features : &null_features,
skb->sk ? &skb->sk->sk_route_caps : &null_features,
skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
skb_shinfo(skb)->gso_type, skb->ip_summed);
}
/*
* Invalidate hardware checksum when packet is to be mangled, and
* complete checksum manually on outgoing path.
*/
int skb_checksum_help(struct sk_buff *skb)
{
__wsum csum;
int ret = 0, offset;
if (skb->ip_summed == CHECKSUM_COMPLETE)
goto out_set_summed;
if (unlikely(skb_shinfo(skb)->gso_size)) {
skb_warn_bad_offload(skb);
return -EINVAL;
}
/* Before computing a checksum, we should make sure no frag could
* be modified by an external entity : checksum could be wrong.
*/
if (skb_has_shared_frag(skb)) {
ret = __skb_linearize(skb);
if (ret)
goto out;
}
offset = skb_checksum_start_offset(skb);
BUG_ON(offset >= skb_headlen(skb));
csum = skb_checksum(skb, offset, skb->len - offset, 0);
offset += skb->csum_offset;
BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
if (skb_cloned(skb) &&
!skb_clone_writable(skb, offset + sizeof(__sum16))) {
ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
if (ret)
goto out;
}
*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
out_set_summed:
skb->ip_summed = CHECKSUM_NONE;
out:
return ret;
}
EXPORT_SYMBOL(skb_checksum_help);
__be16 skb_network_protocol(struct sk_buff *skb, int *depth)
{
__be16 type = skb->protocol;
/* Tunnel gso handlers can set protocol to ethernet. */
if (type == htons(ETH_P_TEB)) {
struct ethhdr *eth;
if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
return 0;
eth = (struct ethhdr *)skb_mac_header(skb);
type = eth->h_proto;
}
return __vlan_get_protocol(skb, type, depth);
}
/**
* skb_mac_gso_segment - mac layer segmentation handler.
* @skb: buffer to segment
* @features: features for the output path (see dev->features)
*/
struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
struct packet_offload *ptype;
int vlan_depth = skb->mac_len;
__be16 type = skb_network_protocol(skb, &vlan_depth);
if (unlikely(!type))
return ERR_PTR(-EINVAL);
__skb_pull(skb, vlan_depth);
rcu_read_lock();
list_for_each_entry_rcu(ptype, &offload_base, list) {
if (ptype->type == type && ptype->callbacks.gso_segment) {
segs = ptype->callbacks.gso_segment(skb, features);
break;
}
}
rcu_read_unlock();
__skb_push(skb, skb->data - skb_mac_header(skb));
return segs;
}
EXPORT_SYMBOL(skb_mac_gso_segment);
/* openvswitch calls this on rx path, so we need a different check.
*/
static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
{
if (tx_path)
return skb->ip_summed != CHECKSUM_PARTIAL &&
skb->ip_summed != CHECKSUM_NONE;
return skb->ip_summed == CHECKSUM_NONE;
}
/**
* __skb_gso_segment - Perform segmentation on skb.
* @skb: buffer to segment
* @features: features for the output path (see dev->features)
* @tx_path: whether it is called in TX path
*
* This function segments the given skb and returns a list of segments.
*
* It may return NULL if the skb requires no segmentation. This is
* only possible when GSO is used for verifying header integrity.
*
* Segmentation preserves SKB_SGO_CB_OFFSET bytes of previous skb cb.
*/
struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
netdev_features_t features, bool tx_path)
{
struct sk_buff *segs;
if (unlikely(skb_needs_check(skb, tx_path))) {
int err;
/* We're going to init ->check field in TCP or UDP header */
err = skb_cow_head(skb, 0);
if (err < 0)
return ERR_PTR(err);
}
/* Only report GSO partial support if it will enable us to
* support segmentation on this frame without needing additional
* work.
*/
if (features & NETIF_F_GSO_PARTIAL) {
netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
struct net_device *dev = skb->dev;
partial_features |= dev->features & dev->gso_partial_features;
if (!skb_gso_ok(skb, features | partial_features))
features &= ~NETIF_F_GSO_PARTIAL;
}
BUILD_BUG_ON(SKB_SGO_CB_OFFSET +
sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
SKB_GSO_CB(skb)->encap_level = 0;
skb_reset_mac_header(skb);
skb_reset_mac_len(skb);
segs = skb_mac_gso_segment(skb, features);
if (unlikely(skb_needs_check(skb, tx_path)))
skb_warn_bad_offload(skb);
return segs;
}
EXPORT_SYMBOL(__skb_gso_segment);
/* Take action when hardware reception checksum errors are detected. */
#ifdef CONFIG_BUG
void netdev_rx_csum_fault(struct net_device *dev)
{
if (net_ratelimit()) {
pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
dump_stack();
}
}
EXPORT_SYMBOL(netdev_rx_csum_fault);
#endif
/* Actually, we should eliminate this check as soon as we know, that:
* 1. IOMMU is present and allows to map all the memory.
* 2. No high memory really exists on this machine.
*/
static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
{
#ifdef CONFIG_HIGHMEM
int i;
if (!(dev->features & NETIF_F_HIGHDMA)) {
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
if (PageHighMem(skb_frag_page(frag)))
return 1;
}
}
if (PCI_DMA_BUS_IS_PHYS) {
struct device *pdev = dev->dev.parent;
if (!pdev)
return 0;
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
dma_addr_t addr = page_to_phys(skb_frag_page(frag));
if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
return 1;
}
}
#endif
return 0;
}
/* If MPLS offload request, verify we are testing hardware MPLS features
* instead of standard features for the netdev.
*/
#if IS_ENABLED(CONFIG_NET_MPLS_GSO)
static netdev_features_t net_mpls_features(struct sk_buff *skb,
netdev_features_t features,
__be16 type)
{
if (eth_p_mpls(type))
features &= skb->dev->mpls_features;
return features;
}
#else
static netdev_features_t net_mpls_features(struct sk_buff *skb,
netdev_features_t features,
__be16 type)
{
return features;
}
#endif
static netdev_features_t harmonize_features(struct sk_buff *skb,
netdev_features_t features)
{
int tmp;
__be16 type;
type = skb_network_protocol(skb, &tmp);
features = net_mpls_features(skb, features, type);
if (skb->ip_summed != CHECKSUM_NONE &&
!can_checksum_protocol(features, type)) {
features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
}
if (illegal_highdma(skb->dev, skb))
features &= ~NETIF_F_SG;
return features;
}
netdev_features_t passthru_features_check(struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{
return features;
}
EXPORT_SYMBOL(passthru_features_check);
static netdev_features_t dflt_features_check(const struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{
return vlan_features_check(skb, features);
}
static netdev_features_t gso_features_check(const struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{
u16 gso_segs = skb_shinfo(skb)->gso_segs;
if (gso_segs > dev->gso_max_segs)
return features & ~NETIF_F_GSO_MASK;
/* Support for GSO partial features requires software
* intervention before we can actually process the packets
* so we need to strip support for any partial features now
* and we can pull them back in after we have partially
* segmented the frame.
*/
if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
features &= ~dev->gso_partial_features;
/* Make sure to clear the IPv4 ID mangling feature if the
* IPv4 header has the potential to be fragmented.
*/
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
struct iphdr *iph = skb->encapsulation ?
inner_ip_hdr(skb) : ip_hdr(skb);
if (!(iph->frag_off & htons(IP_DF)))
features &= ~NETIF_F_TSO_MANGLEID;
}
return features;
}
netdev_features_t netif_skb_features(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
netdev_features_t features = dev->features;
if (skb_is_gso(skb))
features = gso_features_check(skb, dev, features);
/* If encapsulation offload request, verify we are testing
* hardware encapsulation features instead of standard
* features for the netdev
*/
if (skb->encapsulation)
features &= dev->hw_enc_features;
if (skb_vlan_tagged(skb))
features = netdev_intersect_features(features,
dev->vlan_features |
NETIF_F_HW_VLAN_CTAG_TX |
NETIF_F_HW_VLAN_STAG_TX);
if (dev->netdev_ops->ndo_features_check)
features &= dev->netdev_ops->ndo_features_check(skb, dev,
features);
else
features &= dflt_features_check(skb, dev, features);
return harmonize_features(skb, features);
}
EXPORT_SYMBOL(netif_skb_features);
static int xmit_one(struct sk_buff *skb, struct net_device *dev,
struct netdev_queue *txq, bool more)
{
unsigned int len;
int rc;
if (!list_empty(&ptype_all) || !list_empty(&dev->ptype_all))
dev_queue_xmit_nit(skb, dev);
len = skb->len;
trace_net_dev_start_xmit(skb, dev);
rc = netdev_start_xmit(skb, dev, txq, more);
trace_net_dev_xmit(skb, rc, dev, len);
return rc;
}
struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
struct netdev_queue *txq, int *ret)
{
struct sk_buff *skb = first;
int rc = NETDEV_TX_OK;
while (skb) {
struct sk_buff *next = skb->next;
skb->next = NULL;
rc = xmit_one(skb, dev, txq, next != NULL);
if (unlikely(!dev_xmit_complete(rc))) {
skb->next = next;
goto out;
}
skb = next;
if (netif_xmit_stopped(txq) && skb) {
rc = NETDEV_TX_BUSY;
break;
}
}
out:
*ret = rc;
return skb;
}
static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
netdev_features_t features)
{
if (skb_vlan_tag_present(skb) &&
!vlan_hw_offload_capable(features, skb->vlan_proto))
skb = __vlan_hwaccel_push_inside(skb);
return skb;
}
static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev)
{
netdev_features_t features;
features = netif_skb_features(skb);
skb = validate_xmit_vlan(skb, features);
if (unlikely(!skb))
goto out_null;
if (netif_needs_gso(skb, features)) {
struct sk_buff *segs;
segs = skb_gso_segment(skb, features);
if (IS_ERR(segs)) {
goto out_kfree_skb;
} else if (segs) {
consume_skb(skb);
skb = segs;
}
} else {
if (skb_needs_linearize(skb, features) &&
__skb_linearize(skb))
goto out_kfree_skb;
/* If packet is not checksummed and device does not
* support checksumming for this protocol, complete
* checksumming here.
*/
if (skb->ip_summed == CHECKSUM_PARTIAL) {
if (skb->encapsulation)
skb_set_inner_transport_header(skb,
skb_checksum_start_offset(skb));
else
skb_set_transport_header(skb,
skb_checksum_start_offset(skb));
if (!(features & NETIF_F_CSUM_MASK) &&
skb_checksum_help(skb))
goto out_kfree_skb;
}
}
return skb;
out_kfree_skb:
kfree_skb(skb);
out_null:
atomic_long_inc(&dev->tx_dropped);
return NULL;
}
struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev)
{
struct sk_buff *next, *head = NULL, *tail;
for (; skb != NULL; skb = next) {
next = skb->next;
skb->next = NULL;
/* in case skb wont be segmented, point to itself */
skb->prev = skb;
skb = validate_xmit_skb(skb, dev);
if (!skb)
continue;
if (!head)
head = skb;
else
tail->next = skb;
/* If skb was segmented, skb->prev points to
* the last segment. If not, it still contains skb.
*/
tail = skb->prev;
}
return head;
}
EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
static void qdisc_pkt_len_init(struct sk_buff *skb)
{
const struct skb_shared_info *shinfo = skb_shinfo(skb);
qdisc_skb_cb(skb)->pkt_len = skb->len;
/* To get more precise estimation of bytes sent on wire,
* we add to pkt_len the headers size of all segments
*/
if (shinfo->gso_size) {
unsigned int hdr_len;
u16 gso_segs = shinfo->gso_segs;
/* mac layer + network layer */
hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
/* + transport layer */
if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
hdr_len += tcp_hdrlen(skb);
else
hdr_len += sizeof(struct udphdr);
if (shinfo->gso_type & SKB_GSO_DODGY)
gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
shinfo->gso_size);
qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
}
}
static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
struct net_device *dev,
struct netdev_queue *txq)
{
spinlock_t *root_lock = qdisc_lock(q);
struct sk_buff *to_free = NULL;
bool contended;
int rc;
qdisc_calculate_pkt_len(skb, q);
/*
* Heuristic to force contended enqueues to serialize on a
* separate lock before trying to get qdisc main lock.
* This permits qdisc->running owner to get the lock more
* often and dequeue packets faster.
*/
contended = qdisc_is_running(q);
if (unlikely(contended))
spin_lock(&q->busylock);
spin_lock(root_lock);
if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
__qdisc_drop(skb, &to_free);
rc = NET_XMIT_DROP;
} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
qdisc_run_begin(q)) {
/*
* This is a work-conserving queue; there are no old skbs
* waiting to be sent out; and the qdisc is not running -
* xmit the skb directly.
*/
qdisc_bstats_update(q, skb);
if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
if (unlikely(contended)) {
spin_unlock(&q->busylock);
contended = false;
}
__qdisc_run(q);
} else
qdisc_run_end(q);
rc = NET_XMIT_SUCCESS;
} else {
rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
if (qdisc_run_begin(q)) {
if (unlikely(contended)) {
spin_unlock(&q->busylock);
contended = false;
}
__qdisc_run(q);
}
}
spin_unlock(root_lock);
if (unlikely(to_free))
kfree_skb_list(to_free);
if (unlikely(contended))
spin_unlock(&q->busylock);
return rc;
}
#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
static void skb_update_prio(struct sk_buff *skb)
{
struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
if (!skb->priority && skb->sk && map) {
unsigned int prioidx =
sock_cgroup_prioidx(&skb->sk->sk_cgrp_data);
if (prioidx < map->priomap_len)
skb->priority = map->priomap[prioidx];
}
}
#else
#define skb_update_prio(skb)
#endif
DEFINE_PER_CPU(int, xmit_recursion);
EXPORT_SYMBOL(xmit_recursion);
/**
* dev_loopback_xmit - loop back @skb
* @net: network namespace this loopback is happening in
* @sk: sk needed to be a netfilter okfn
* @skb: buffer to transmit
*/
int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
{
skb_reset_mac_header(skb);
__skb_pull(skb, skb_network_offset(skb));
skb->pkt_type = PACKET_LOOPBACK;
skb->ip_summed = CHECKSUM_UNNECESSARY;
WARN_ON(!skb_dst(skb));
skb_dst_force(skb);
netif_rx_ni(skb);
return 0;
}
EXPORT_SYMBOL(dev_loopback_xmit);
#ifdef CONFIG_NET_EGRESS
static struct sk_buff *
sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
{
struct tcf_proto *cl = rcu_dereference_bh(dev->egress_cl_list);
struct tcf_result cl_res;
if (!cl)
return skb;
/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
qdisc_bstats_cpu_update(cl->q, skb);
switch (tc_classify(skb, cl, &cl_res, false)) {
case TC_ACT_OK:
case TC_ACT_RECLASSIFY:
skb->tc_index = TC_H_MIN(cl_res.classid);
break;
case TC_ACT_SHOT:
qdisc_qstats_cpu_drop(cl->q);
*ret = NET_XMIT_DROP;
kfree_skb(skb);
return NULL;
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
*ret = NET_XMIT_SUCCESS;
consume_skb(skb);
return NULL;
case TC_ACT_REDIRECT:
/* No need to push/pop skb's mac_header here on egress! */
skb_do_redirect(skb);
*ret = NET_XMIT_SUCCESS;
return NULL;
default:
break;
}
return skb;
}
#endif /* CONFIG_NET_EGRESS */
static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
{
#ifdef CONFIG_XPS
struct xps_dev_maps *dev_maps;
struct xps_map *map;
int queue_index = -1;
rcu_read_lock();
dev_maps = rcu_dereference(dev->xps_maps);
if (dev_maps) {
unsigned int tci = skb->sender_cpu - 1;
if (dev->num_tc) {
tci *= dev->num_tc;
tci += netdev_get_prio_tc_map(dev, skb->priority);
}
map = rcu_dereference(dev_maps->cpu_map[tci]);
if (map) {
if (map->len == 1)
queue_index = map->queues[0];
else
queue_index = map->queues[reciprocal_scale(skb_get_hash(skb),
map->len)];
if (unlikely(queue_index >= dev->real_num_tx_queues))
queue_index = -1;
}
}
rcu_read_unlock();
return queue_index;
#else
return -1;
#endif
}
static u16 __netdev_pick_tx(struct net_device *dev, struct sk_buff *skb)
{
struct sock *sk = skb->sk;
int queue_index = sk_tx_queue_get(sk);
if (queue_index < 0 || skb->ooo_okay ||
queue_index >= dev->real_num_tx_queues) {
int new_index = get_xps_queue(dev, skb);
if (new_index < 0)
new_index = skb_tx_hash(dev, skb);
if (queue_index != new_index && sk &&
sk_fullsock(sk) &&
rcu_access_pointer(sk->sk_dst_cache))
sk_tx_queue_set(sk, new_index);
queue_index = new_index;
}
return queue_index;
}
struct netdev_queue *netdev_pick_tx(struct net_device *dev,
struct sk_buff *skb,
void *accel_priv)
{
int queue_index = 0;
#ifdef CONFIG_XPS
u32 sender_cpu = skb->sender_cpu - 1;
if (sender_cpu >= (u32)NR_CPUS)
skb->sender_cpu = raw_smp_processor_id() + 1;
#endif
if (dev->real_num_tx_queues != 1) {
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_select_queue)
queue_index = ops->ndo_select_queue(dev, skb, accel_priv,
__netdev_pick_tx);
else
queue_index = __netdev_pick_tx(dev, skb);
if (!accel_priv)
queue_index = netdev_cap_txqueue(dev, queue_index);
}
skb_set_queue_mapping(skb, queue_index);
return netdev_get_tx_queue(dev, queue_index);
}
/**
* __dev_queue_xmit - transmit a buffer
* @skb: buffer to transmit
* @accel_priv: private data used for L2 forwarding offload
*
* Queue a buffer for transmission to a network device. The caller must
* have set the device and priority and built the buffer before calling
* this function. The function can be called from an interrupt.
*
* A negative errno code is returned on a failure. A success does not
* guarantee the frame will be transmitted as it may be dropped due
* to congestion or traffic shaping.
*
* -----------------------------------------------------------------------------------
* I notice this method can also return errors from the queue disciplines,
* including NET_XMIT_DROP, which is a positive value. So, errors can also
* be positive.
*
* Regardless of the return value, the skb is consumed, so it is currently
* difficult to retry a send to this method. (You can bump the ref count
* before sending to hold a reference for retry if you are careful.)
*
* When calling this method, interrupts MUST be enabled. This is because
* the BH enable code must have IRQs enabled so that it will not deadlock.
* --BLG
*/
static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
{
struct net_device *dev = skb->dev;
struct netdev_queue *txq;
struct Qdisc *q;
int rc = -ENOMEM;
skb_reset_mac_header(skb);
if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
__skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED);
/* Disable soft irqs for various locks below. Also
* stops preemption for RCU.
*/
rcu_read_lock_bh();
skb_update_prio(skb);
qdisc_pkt_len_init(skb);
#ifdef CONFIG_NET_CLS_ACT
skb->tc_at_ingress = 0;
# ifdef CONFIG_NET_EGRESS
if (static_key_false(&egress_needed)) {
skb = sch_handle_egress(skb, &rc, dev);
if (!skb)
goto out;
}
# endif
#endif
/* If device/qdisc don't need skb->dst, release it right now while
* its hot in this cpu cache.
*/
if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
skb_dst_drop(skb);
else
skb_dst_force(skb);
txq = netdev_pick_tx(dev, skb, accel_priv);
q = rcu_dereference_bh(txq->qdisc);
trace_net_dev_queue(skb);
if (q->enqueue) {
rc = __dev_xmit_skb(skb, q, dev, txq);
goto out;
}
/* The device has no queue. Common case for software devices:
* loopback, all the sorts of tunnels...
* Really, it is unlikely that netif_tx_lock protection is necessary
* here. (f.e. loopback and IP tunnels are clean ignoring statistics
* counters.)
* However, it is possible, that they rely on protection
* made by us here.
* Check this and shot the lock. It is not prone from deadlocks.
*Either shot noqueue qdisc, it is even simpler 8)
*/
if (dev->flags & IFF_UP) {
int cpu = smp_processor_id(); /* ok because BHs are off */
if (txq->xmit_lock_owner != cpu) {
if (unlikely(__this_cpu_read(xmit_recursion) >
XMIT_RECURSION_LIMIT))
goto recursion_alert;
skb = validate_xmit_skb(skb, dev);
if (!skb)
goto out;
HARD_TX_LOCK(dev, txq, cpu);
if (!netif_xmit_stopped(txq)) {
__this_cpu_inc(xmit_recursion);
skb = dev_hard_start_xmit(skb, dev, txq, &rc);
__this_cpu_dec(xmit_recursion);
if (dev_xmit_complete(rc)) {
HARD_TX_UNLOCK(dev, txq);
goto out;
}
}
HARD_TX_UNLOCK(dev, txq);
net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
dev->name);
} else {
/* Recursion is detected! It is possible,
* unfortunately
*/
recursion_alert:
net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
dev->name);
}
}
rc = -ENETDOWN;
rcu_read_unlock_bh();
atomic_long_inc(&dev->tx_dropped);
kfree_skb_list(skb);
return rc;
out:
rcu_read_unlock_bh();
return rc;
}
int dev_queue_xmit(struct sk_buff *skb)
{
return __dev_queue_xmit(skb, NULL);
}
EXPORT_SYMBOL(dev_queue_xmit);
int dev_queue_xmit_accel(struct sk_buff *skb, void *accel_priv)
{
return __dev_queue_xmit(skb, accel_priv);
}
EXPORT_SYMBOL(dev_queue_xmit_accel);
/*************************************************************************
* Receiver routines
*************************************************************************/
int netdev_max_backlog __read_mostly = 1000;
EXPORT_SYMBOL(netdev_max_backlog);
int netdev_tstamp_prequeue __read_mostly = 1;
int netdev_budget __read_mostly = 300;
int weight_p __read_mostly = 64; /* old backlog weight */
int dev_weight_rx_bias __read_mostly = 1; /* bias for backlog weight */
int dev_weight_tx_bias __read_mostly = 1; /* bias for output_queue quota */
int dev_rx_weight __read_mostly = 64;
int dev_tx_weight __read_mostly = 64;
/* Called with irq disabled */
static inline void ____napi_schedule(struct softnet_data *sd,
struct napi_struct *napi)
{
list_add_tail(&napi->poll_list, &sd->poll_list);
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
}
#ifdef CONFIG_RPS
/* One global table that all flow-based protocols share. */
struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
EXPORT_SYMBOL(rps_sock_flow_table);
u32 rps_cpu_mask __read_mostly;
EXPORT_SYMBOL(rps_cpu_mask);
struct static_key rps_needed __read_mostly;
EXPORT_SYMBOL(rps_needed);
struct static_key rfs_needed __read_mostly;
EXPORT_SYMBOL(rfs_needed);
static struct rps_dev_flow *
set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
struct rps_dev_flow *rflow, u16 next_cpu)
{
if (next_cpu < nr_cpu_ids) {
#ifdef CONFIG_RFS_ACCEL
struct netdev_rx_queue *rxqueue;
struct rps_dev_flow_table *flow_table;
struct rps_dev_flow *old_rflow;
u32 flow_id;
u16 rxq_index;
int rc;
/* Should we steer this flow to a different hardware queue? */
if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
!(dev->features & NETIF_F_NTUPLE))
goto out;
rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
if (rxq_index == skb_get_rx_queue(skb))
goto out;
rxqueue = dev->_rx + rxq_index;
flow_table = rcu_dereference(rxqueue->rps_flow_table);
if (!flow_table)
goto out;
flow_id = skb_get_hash(skb) & flow_table->mask;
rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
rxq_index, flow_id);
if (rc < 0)
goto out;
old_rflow = rflow;
rflow = &flow_table->flows[flow_id];
rflow->filter = rc;
if (old_rflow->filter == rflow->filter)
old_rflow->filter = RPS_NO_FILTER;
out:
#endif
rflow->last_qtail =
per_cpu(softnet_data, next_cpu).input_queue_head;
}
rflow->cpu = next_cpu;
return rflow;
}
/*
* get_rps_cpu is called from netif_receive_skb and returns the target
* CPU from the RPS map of the receiving queue for a given skb.
* rcu_read_lock must be held on entry.
*/
static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
struct rps_dev_flow **rflowp)
{
const struct rps_sock_flow_table *sock_flow_table;
struct netdev_rx_queue *rxqueue = dev->_rx;
struct rps_dev_flow_table *flow_table;
struct rps_map *map;
int cpu = -1;
u32 tcpu;
u32 hash;
if (skb_rx_queue_recorded(skb)) {
u16 index = skb_get_rx_queue(skb);
if (unlikely(index >= dev->real_num_rx_queues)) {
WARN_ONCE(dev->real_num_rx_queues > 1,
"%s received packet on queue %u, but number "
"of RX queues is %u\n",
dev->name, index, dev->real_num_rx_queues);
goto done;
}
rxqueue += index;
}
/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
flow_table = rcu_dereference(rxqueue->rps_flow_table);
map = rcu_dereference(rxqueue->rps_map);
if (!flow_table && !map)
goto done;
skb_reset_network_header(skb);
hash = skb_get_hash(skb);
if (!hash)
goto done;
sock_flow_table = rcu_dereference(rps_sock_flow_table);
if (flow_table && sock_flow_table) {
struct rps_dev_flow *rflow;
u32 next_cpu;
u32 ident;
/* First check into global flow table if there is a match */
ident = sock_flow_table->ents[hash & sock_flow_table->mask];
if ((ident ^ hash) & ~rps_cpu_mask)
goto try_rps;
next_cpu = ident & rps_cpu_mask;
/* OK, now we know there is a match,
* we can look at the local (per receive queue) flow table
*/
rflow = &flow_table->flows[hash & flow_table->mask];
tcpu = rflow->cpu;
/*
* If the desired CPU (where last recvmsg was done) is
* different from current CPU (one in the rx-queue flow
* table entry), switch if one of the following holds:
* - Current CPU is unset (>= nr_cpu_ids).
* - Current CPU is offline.
* - The current CPU's queue tail has advanced beyond the
* last packet that was enqueued using this table entry.
* This guarantees that all previous packets for the flow
* have been dequeued, thus preserving in order delivery.
*/
if (unlikely(tcpu != next_cpu) &&
(tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
((int)(per_cpu(softnet_data, tcpu).input_queue_head -
rflow->last_qtail)) >= 0)) {
tcpu = next_cpu;
rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
}
if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
*rflowp = rflow;
cpu = tcpu;
goto done;
}
}
try_rps:
if (map) {
tcpu = map->cpus[reciprocal_scale(hash, map->len)];
if (cpu_online(tcpu)) {
cpu = tcpu;
goto done;
}
}
done:
return cpu;
}
#ifdef CONFIG_RFS_ACCEL
/**
* rps_may_expire_flow - check whether an RFS hardware filter may be removed
* @dev: Device on which the filter was set
* @rxq_index: RX queue index
* @flow_id: Flow ID passed to ndo_rx_flow_steer()
* @filter_id: Filter ID returned by ndo_rx_flow_steer()
*
* Drivers that implement ndo_rx_flow_steer() should periodically call
* this function for each installed filter and remove the filters for
* which it returns %true.
*/
bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
u32 flow_id, u16 filter_id)
{
struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
struct rps_dev_flow_table *flow_table;
struct rps_dev_flow *rflow;
bool expire = true;
unsigned int cpu;
rcu_read_lock();
flow_table = rcu_dereference(rxqueue->rps_flow_table);
if (flow_table && flow_id <= flow_table->mask) {
rflow = &flow_table->flows[flow_id];
cpu = ACCESS_ONCE(rflow->cpu);
if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
((int)(per_cpu(softnet_data, cpu).input_queue_head -
rflow->last_qtail) <
(int)(10 * flow_table->mask)))
expire = false;
}
rcu_read_unlock();
return expire;
}
EXPORT_SYMBOL(rps_may_expire_flow);
#endif /* CONFIG_RFS_ACCEL */
/* Called from hardirq (IPI) context */
static void rps_trigger_softirq(void *data)
{
struct softnet_data *sd = data;
____napi_schedule(sd, &sd->backlog);
sd->received_rps++;
}
#endif /* CONFIG_RPS */
/*
* Check if this softnet_data structure is another cpu one
* If yes, queue it to our IPI list and return 1
* If no, return 0
*/
static int rps_ipi_queued(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
if (sd != mysd) {
sd->rps_ipi_next = mysd->rps_ipi_list;
mysd->rps_ipi_list = sd;
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
return 1;
}
#endif /* CONFIG_RPS */
return 0;
}
#ifdef CONFIG_NET_FLOW_LIMIT
int netdev_flow_limit_table_len __read_mostly = (1 << 12);
#endif
static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
{
#ifdef CONFIG_NET_FLOW_LIMIT
struct sd_flow_limit *fl;
struct softnet_data *sd;
unsigned int old_flow, new_flow;
if (qlen < (netdev_max_backlog >> 1))
return false;
sd = this_cpu_ptr(&softnet_data);
rcu_read_lock();
fl = rcu_dereference(sd->flow_limit);
if (fl) {
new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
old_flow = fl->history[fl->history_head];
fl->history[fl->history_head] = new_flow;
fl->history_head++;
fl->history_head &= FLOW_LIMIT_HISTORY - 1;
if (likely(fl->buckets[old_flow]))
fl->buckets[old_flow]--;
if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
fl->count++;
rcu_read_unlock();
return true;
}
}
rcu_read_unlock();
#endif
return false;
}
/*
* enqueue_to_backlog is called to queue an skb to a per CPU backlog
* queue (may be a remote CPU queue).
*/
static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
unsigned int *qtail)
{
struct softnet_data *sd;
unsigned long flags;
unsigned int qlen;
sd = &per_cpu(softnet_data, cpu);
local_irq_save(flags);
rps_lock(sd);
if (!netif_running(skb->dev))
goto drop;
qlen = skb_queue_len(&sd->input_pkt_queue);
if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
if (qlen) {
enqueue:
__skb_queue_tail(&sd->input_pkt_queue, skb);
input_queue_tail_incr_save(sd, qtail);
rps_unlock(sd);
local_irq_restore(flags);
return NET_RX_SUCCESS;
}
/* Schedule NAPI for backlog device
* We can use non atomic operation since we own the queue lock
*/
if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
if (!rps_ipi_queued(sd))
____napi_schedule(sd, &sd->backlog);
}
goto enqueue;
}
drop:
sd->dropped++;
rps_unlock(sd);
local_irq_restore(flags);
atomic_long_inc(&skb->dev->rx_dropped);
kfree_skb(skb);
return NET_RX_DROP;
}
static int netif_rx_internal(struct sk_buff *skb)
{
int ret;
net_timestamp_check(netdev_tstamp_prequeue, skb);
trace_netif_rx(skb);
#ifdef CONFIG_RPS
if (static_key_false(&rps_needed)) {
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu;
preempt_disable();
rcu_read_lock();
cpu = get_rps_cpu(skb->dev, skb, &rflow);
if (cpu < 0)
cpu = smp_processor_id();
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
preempt_enable();
} else
#endif
{
unsigned int qtail;
ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
put_cpu();
}
return ret;
}
/**
* netif_rx - post buffer to the network code
* @skb: buffer to post
*
* This function receives a packet from a device driver and queues it for
* the upper (protocol) levels to process. It always succeeds. The buffer
* may be dropped during processing for congestion control or by the
* protocol layers.
*
* return values:
* NET_RX_SUCCESS (no congestion)
* NET_RX_DROP (packet was dropped)
*
*/
int netif_rx(struct sk_buff *skb)
{
trace_netif_rx_entry(skb);
return netif_rx_internal(skb);
}
EXPORT_SYMBOL(netif_rx);
int netif_rx_ni(struct sk_buff *skb)
{
int err;
trace_netif_rx_ni_entry(skb);
preempt_disable();
err = netif_rx_internal(skb);
if (local_softirq_pending())
do_softirq();
preempt_enable();
return err;
}
EXPORT_SYMBOL(netif_rx_ni);
static __latent_entropy void net_tx_action(struct softirq_action *h)
{
struct softnet_data *sd = this_cpu_ptr(&softnet_data);
if (sd->completion_queue) {
struct sk_buff *clist;
local_irq_disable();
clist = sd->completion_queue;
sd->completion_queue = NULL;
local_irq_enable();
while (clist) {
struct sk_buff *skb = clist;
clist = clist->next;
WARN_ON(atomic_read(&skb->users));
if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
trace_consume_skb(skb);
else
trace_kfree_skb(skb, net_tx_action);
if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
__kfree_skb(skb);
else
__kfree_skb_defer(skb);
}
__kfree_skb_flush();
}
if (sd->output_queue) {
struct Qdisc *head;
local_irq_disable();
head = sd->output_queue;
sd->output_queue = NULL;
sd->output_queue_tailp = &sd->output_queue;
local_irq_enable();
while (head) {
struct Qdisc *q = head;
spinlock_t *root_lock;
head = head->next_sched;
root_lock = qdisc_lock(q);
spin_lock(root_lock);
/* We need to make sure head->next_sched is read
* before clearing __QDISC_STATE_SCHED
*/
smp_mb__before_atomic();
clear_bit(__QDISC_STATE_SCHED, &q->state);
qdisc_run(q);
spin_unlock(root_lock);
}
}
}
#if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
/* This hook is defined here for ATM LANE */
int (*br_fdb_test_addr_hook)(struct net_device *dev,
unsigned char *addr) __read_mostly;
EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
#endif
static inline struct sk_buff *
sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
struct net_device *orig_dev)
{
#ifdef CONFIG_NET_CLS_ACT
struct tcf_proto *cl = rcu_dereference_bh(skb->dev->ingress_cl_list);
struct tcf_result cl_res;
/* If there's at least one ingress present somewhere (so
* we get here via enabled static key), remaining devices
* that are not configured with an ingress qdisc will bail
* out here.
*/
if (!cl)
return skb;
if (*pt_prev) {
*ret = deliver_skb(skb, *pt_prev, orig_dev);
*pt_prev = NULL;
}
qdisc_skb_cb(skb)->pkt_len = skb->len;
skb->tc_at_ingress = 1;
qdisc_bstats_cpu_update(cl->q, skb);
switch (tc_classify(skb, cl, &cl_res, false)) {
case TC_ACT_OK:
case TC_ACT_RECLASSIFY:
skb->tc_index = TC_H_MIN(cl_res.classid);
break;
case TC_ACT_SHOT:
qdisc_qstats_cpu_drop(cl->q);
kfree_skb(skb);
return NULL;
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
consume_skb(skb);
return NULL;
case TC_ACT_REDIRECT:
/* skb_mac_header check was done by cls/act_bpf, so
* we can safely push the L2 header back before
* redirecting to another netdev
*/
__skb_push(skb, skb->mac_len);
skb_do_redirect(skb);
return NULL;
default:
break;
}
#endif /* CONFIG_NET_CLS_ACT */
return skb;
}
/**
* netdev_is_rx_handler_busy - check if receive handler is registered
* @dev: device to check
*
* Check if a receive handler is already registered for a given device.
* Return true if there one.
*
* The caller must hold the rtnl_mutex.
*/
bool netdev_is_rx_handler_busy(struct net_device *dev)
{
ASSERT_RTNL();
return dev && rtnl_dereference(dev->rx_handler);
}
EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
/**
* netdev_rx_handler_register - register receive handler
* @dev: device to register a handler for
* @rx_handler: receive handler to register
* @rx_handler_data: data pointer that is used by rx handler
*
* Register a receive handler for a device. This handler will then be
* called from __netif_receive_skb. A negative errno code is returned
* on a failure.
*
* The caller must hold the rtnl_mutex.
*
* For a general description of rx_handler, see enum rx_handler_result.
*/
int netdev_rx_handler_register(struct net_device *dev,
rx_handler_func_t *rx_handler,
void *rx_handler_data)
{
if (netdev_is_rx_handler_busy(dev))
return -EBUSY;
/* Note: rx_handler_data must be set before rx_handler */
rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
rcu_assign_pointer(dev->rx_handler, rx_handler);
return 0;
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
/**
* netdev_rx_handler_unregister - unregister receive handler
* @dev: device to unregister a handler from
*
* Unregister a receive handler from a device.
*
* The caller must hold the rtnl_mutex.
*/
void netdev_rx_handler_unregister(struct net_device *dev)
{
ASSERT_RTNL();
RCU_INIT_POINTER(dev->rx_handler, NULL);
/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
* section has a guarantee to see a non NULL rx_handler_data
* as well.
*/
synchronize_net();
RCU_INIT_POINTER(dev->rx_handler_data, NULL);
}
EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
/*
* Limit the use of PFMEMALLOC reserves to those protocols that implement
* the special handling of PFMEMALLOC skbs.
*/
static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
{
switch (skb->protocol) {
case htons(ETH_P_ARP):
case htons(ETH_P_IP):
case htons(ETH_P_IPV6):
case htons(ETH_P_8021Q):
case htons(ETH_P_8021AD):
return true;
default:
return false;
}
}
static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
int *ret, struct net_device *orig_dev)
{
#ifdef CONFIG_NETFILTER_INGRESS
if (nf_hook_ingress_active(skb)) {
int ingress_retval;
if (*pt_prev) {
*ret = deliver_skb(skb, *pt_prev, orig_dev);
*pt_prev = NULL;
}
rcu_read_lock();
ingress_retval = nf_hook_ingress(skb);
rcu_read_unlock();
return ingress_retval;
}
#endif /* CONFIG_NETFILTER_INGRESS */
return 0;
}
static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
{
struct packet_type *ptype, *pt_prev;
rx_handler_func_t *rx_handler;
struct net_device *orig_dev;
bool deliver_exact = false;
int ret = NET_RX_DROP;
__be16 type;
net_timestamp_check(!netdev_tstamp_prequeue, skb);
trace_netif_receive_skb(skb);
orig_dev = skb->dev;
skb_reset_network_header(skb);
if (!skb_transport_header_was_set(skb))
skb_reset_transport_header(skb);
skb_reset_mac_len(skb);
pt_prev = NULL;
another_round:
skb->skb_iif = skb->dev->ifindex;
__this_cpu_inc(softnet_data.processed);
if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
skb = skb_vlan_untag(skb);
if (unlikely(!skb))
goto out;
}
if (skb_skip_tc_classify(skb))
goto skip_classify;
if (pfmemalloc)
goto skip_taps;
list_for_each_entry_rcu(ptype, &ptype_all, list) {
if (pt_prev)
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = ptype;
}
list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
if (pt_prev)
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = ptype;
}
skip_taps:
#ifdef CONFIG_NET_INGRESS
if (static_key_false(&ingress_needed)) {
skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev);
if (!skb)
goto out;
if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
goto out;
}
#endif
skb_reset_tc(skb);
skip_classify:
if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
goto drop;
if (skb_vlan_tag_present(skb)) {
if (pt_prev) {
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = NULL;
}
if (vlan_do_receive(&skb))
goto another_round;
else if (unlikely(!skb))
goto out;
}
rx_handler = rcu_dereference(skb->dev->rx_handler);
if (rx_handler) {
if (pt_prev) {
ret = deliver_skb(skb, pt_prev, orig_dev);
pt_prev = NULL;
}
switch (rx_handler(&skb)) {
case RX_HANDLER_CONSUMED:
ret = NET_RX_SUCCESS;
goto out;
case RX_HANDLER_ANOTHER:
goto another_round;
case RX_HANDLER_EXACT:
deliver_exact = true;
case RX_HANDLER_PASS:
break;
default:
BUG();
}
}
if (unlikely(skb_vlan_tag_present(skb))) {
if (skb_vlan_tag_get_id(skb))
skb->pkt_type = PACKET_OTHERHOST;
/* Note: we might in the future use prio bits
* and set skb->priority like in vlan_do_receive()
* For the time being, just ignore Priority Code Point
*/
skb->vlan_tci = 0;
}
type = skb->protocol;
/* deliver only exact match when indicated */
if (likely(!deliver_exact)) {
deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
&ptype_base[ntohs(type) &
PTYPE_HASH_MASK]);
}
deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
&orig_dev->ptype_specific);
if (unlikely(skb->dev != orig_dev)) {
deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
&skb->dev->ptype_specific);
}
if (pt_prev) {
if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
goto drop;
else
ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
} else {
drop:
if (!deliver_exact)
atomic_long_inc(&skb->dev->rx_dropped);
else
atomic_long_inc(&skb->dev->rx_nohandler);
kfree_skb(skb);
/* Jamal, now you will not able to escape explaining
* me how you were going to use this. :-)
*/
ret = NET_RX_DROP;
}
out:
return ret;
}
static int __netif_receive_skb(struct sk_buff *skb)
{
int ret;
if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
unsigned long pflags = current->flags;
/*
* PFMEMALLOC skbs are special, they should
* - be delivered to SOCK_MEMALLOC sockets only
* - stay away from userspace
* - have bounded memory usage
*
* Use PF_MEMALLOC as this saves us from propagating the allocation
* context down to all allocation sites.
*/
current->flags |= PF_MEMALLOC;
ret = __netif_receive_skb_core(skb, true);
tsk_restore_flags(current, pflags, PF_MEMALLOC);
} else
ret = __netif_receive_skb_core(skb, false);
return ret;
}
static int netif_receive_skb_internal(struct sk_buff *skb)
{
int ret;
net_timestamp_check(netdev_tstamp_prequeue, skb);
if (skb_defer_rx_timestamp(skb))
return NET_RX_SUCCESS;
rcu_read_lock();
#ifdef CONFIG_RPS
if (static_key_false(&rps_needed)) {
struct rps_dev_flow voidflow, *rflow = &voidflow;
int cpu = get_rps_cpu(skb->dev, skb, &rflow);
if (cpu >= 0) {
ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
rcu_read_unlock();
return ret;
}
}
#endif
ret = __netif_receive_skb(skb);
rcu_read_unlock();
return ret;
}
/**
* netif_receive_skb - process receive buffer from network
* @skb: buffer to process
*
* netif_receive_skb() is the main receive data processing function.
* It always succeeds. The buffer may be dropped during processing
* for congestion control or by the protocol layers.
*
* This function may only be called from softirq context and interrupts
* should be enabled.
*
* Return values (usually ignored):
* NET_RX_SUCCESS: no congestion
* NET_RX_DROP: packet was dropped
*/
int netif_receive_skb(struct sk_buff *skb)
{
trace_netif_receive_skb_entry(skb);
return netif_receive_skb_internal(skb);
}
EXPORT_SYMBOL(netif_receive_skb);
DEFINE_PER_CPU(struct work_struct, flush_works);
/* Network device is going away, flush any packets still pending */
static void flush_backlog(struct work_struct *work)
{
struct sk_buff *skb, *tmp;
struct softnet_data *sd;
local_bh_disable();
sd = this_cpu_ptr(&softnet_data);
local_irq_disable();
rps_lock(sd);
skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
if (skb->dev->reg_state == NETREG_UNREGISTERING) {
__skb_unlink(skb, &sd->input_pkt_queue);
kfree_skb(skb);
input_queue_head_incr(sd);
}
}
rps_unlock(sd);
local_irq_enable();
skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
if (skb->dev->reg_state == NETREG_UNREGISTERING) {
__skb_unlink(skb, &sd->process_queue);
kfree_skb(skb);
input_queue_head_incr(sd);
}
}
local_bh_enable();
}
static void flush_all_backlogs(void)
{
unsigned int cpu;
get_online_cpus();
for_each_online_cpu(cpu)
queue_work_on(cpu, system_highpri_wq,
per_cpu_ptr(&flush_works, cpu));
for_each_online_cpu(cpu)
flush_work(per_cpu_ptr(&flush_works, cpu));
put_online_cpus();
}
static int napi_gro_complete(struct sk_buff *skb)
{
struct packet_offload *ptype;
__be16 type = skb->protocol;
struct list_head *head = &offload_base;
int err = -ENOENT;
BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
if (NAPI_GRO_CB(skb)->count == 1) {
skb_shinfo(skb)->gso_size = 0;
goto out;
}
rcu_read_lock();
list_for_each_entry_rcu(ptype, head, list) {
if (ptype->type != type || !ptype->callbacks.gro_complete)
continue;
err = ptype->callbacks.gro_complete(skb, 0);
break;
}
rcu_read_unlock();
if (err) {
WARN_ON(&ptype->list == head);
kfree_skb(skb);
return NET_RX_SUCCESS;
}
out:
return netif_receive_skb_internal(skb);
}
/* napi->gro_list contains packets ordered by age.
* youngest packets at the head of it.
* Complete skbs in reverse order to reduce latencies.
*/
void napi_gro_flush(struct napi_struct *napi, bool flush_old)
{
struct sk_buff *skb, *prev = NULL;
/* scan list and build reverse chain */
for (skb = napi->gro_list; skb != NULL; skb = skb->next) {
skb->prev = prev;
prev = skb;
}
for (skb = prev; skb; skb = prev) {
skb->next = NULL;
if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
return;
prev = skb->prev;
napi_gro_complete(skb);
napi->gro_count--;
}
napi->gro_list = NULL;
}
EXPORT_SYMBOL(napi_gro_flush);
static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb)
{
struct sk_buff *p;
unsigned int maclen = skb->dev->hard_header_len;
u32 hash = skb_get_hash_raw(skb);
for (p = napi->gro_list; p; p = p->next) {
unsigned long diffs;
NAPI_GRO_CB(p)->flush = 0;
if (hash != skb_get_hash_raw(p)) {
NAPI_GRO_CB(p)->same_flow = 0;
continue;
}
diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
diffs |= p->vlan_tci ^ skb->vlan_tci;
diffs |= skb_metadata_dst_cmp(p, skb);
if (maclen == ETH_HLEN)
diffs |= compare_ether_header(skb_mac_header(p),
skb_mac_header(skb));
else if (!diffs)
diffs = memcmp(skb_mac_header(p),
skb_mac_header(skb),
maclen);
NAPI_GRO_CB(p)->same_flow = !diffs;
}
}
static void skb_gro_reset_offset(struct sk_buff *skb)
{
const struct skb_shared_info *pinfo = skb_shinfo(skb);
const skb_frag_t *frag0 = &pinfo->frags[0];
NAPI_GRO_CB(skb)->data_offset = 0;
NAPI_GRO_CB(skb)->frag0 = NULL;
NAPI_GRO_CB(skb)->frag0_len = 0;
if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
pinfo->nr_frags &&
!PageHighMem(skb_frag_page(frag0))) {
NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
skb_frag_size(frag0),
skb->end - skb->tail);
}
}
static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
{
struct skb_shared_info *pinfo = skb_shinfo(skb);
BUG_ON(skb->end - skb->tail < grow);
memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
skb->data_len -= grow;
skb->tail += grow;
pinfo->frags[0].page_offset += grow;
skb_frag_size_sub(&pinfo->frags[0], grow);
if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
skb_frag_unref(skb, 0);
memmove(pinfo->frags, pinfo->frags + 1,
--pinfo->nr_frags * sizeof(pinfo->frags[0]));
}
}
static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
{
struct sk_buff **pp = NULL;
struct packet_offload *ptype;
__be16 type = skb->protocol;
struct list_head *head = &offload_base;
int same_flow;
enum gro_result ret;
int grow;
if (!(skb->dev->features & NETIF_F_GRO))
goto normal;
if (skb->csum_bad)
goto normal;
gro_list_prepare(napi, skb);
rcu_read_lock();
list_for_each_entry_rcu(ptype, head, list) {
if (ptype->type != type || !ptype->callbacks.gro_receive)
continue;
skb_set_network_header(skb, skb_gro_offset(skb));
skb_reset_mac_len(skb);
NAPI_GRO_CB(skb)->same_flow = 0;
NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
NAPI_GRO_CB(skb)->free = 0;
NAPI_GRO_CB(skb)->encap_mark = 0;
NAPI_GRO_CB(skb)->recursion_counter = 0;
NAPI_GRO_CB(skb)->is_fou = 0;
NAPI_GRO_CB(skb)->is_atomic = 1;
NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
/* Setup for GRO checksum validation */
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
NAPI_GRO_CB(skb)->csum = skb->csum;
NAPI_GRO_CB(skb)->csum_valid = 1;
NAPI_GRO_CB(skb)->csum_cnt = 0;
break;
case CHECKSUM_UNNECESSARY:
NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
NAPI_GRO_CB(skb)->csum_valid = 0;
break;
default:
NAPI_GRO_CB(skb)->csum_cnt = 0;
NAPI_GRO_CB(skb)->csum_valid = 0;
}
pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
break;
}
rcu_read_unlock();
if (&ptype->list == head)
goto normal;
if (IS_ERR(pp) && PTR_ERR(pp) == -EINPROGRESS) {
ret = GRO_CONSUMED;
goto ok;
}
same_flow = NAPI_GRO_CB(skb)->same_flow;
ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
if (pp) {
struct sk_buff *nskb = *pp;
*pp = nskb->next;
nskb->next = NULL;
napi_gro_complete(nskb);
napi->gro_count--;
}
if (same_flow)
goto ok;
if (NAPI_GRO_CB(skb)->flush)
goto normal;
if (unlikely(napi->gro_count >= MAX_GRO_SKBS)) {
struct sk_buff *nskb = napi->gro_list;
/* locate the end of the list to select the 'oldest' flow */
while (nskb->next) {
pp = &nskb->next;
nskb = *pp;
}
*pp = NULL;
nskb->next = NULL;
napi_gro_complete(nskb);
} else {
napi->gro_count++;
}
NAPI_GRO_CB(skb)->count = 1;
NAPI_GRO_CB(skb)->age = jiffies;
NAPI_GRO_CB(skb)->last = skb;
skb_shinfo(skb)->gso_size = skb_gro_len(skb);
skb->next = napi->gro_list;
napi->gro_list = skb;
ret = GRO_HELD;
pull:
grow = skb_gro_offset(skb) - skb_headlen(skb);
if (grow > 0)
gro_pull_from_frag0(skb, grow);
ok:
return ret;
normal:
ret = GRO_NORMAL;
goto pull;
}
struct packet_offload *gro_find_receive_by_type(__be16 type)
{
struct list_head *offload_head = &offload_base;
struct packet_offload *ptype;
list_for_each_entry_rcu(ptype, offload_head, list) {
if (ptype->type != type || !ptype->callbacks.gro_receive)
continue;
return ptype;
}
return NULL;
}
EXPORT_SYMBOL(gro_find_receive_by_type);
struct packet_offload *gro_find_complete_by_type(__be16 type)
{
struct list_head *offload_head = &offload_base;
struct packet_offload *ptype;
list_for_each_entry_rcu(ptype, offload_head, list) {
if (ptype->type != type || !ptype->callbacks.gro_complete)
continue;
return ptype;
}
return NULL;
}
EXPORT_SYMBOL(gro_find_complete_by_type);
static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
{
switch (ret) {
case GRO_NORMAL:
if (netif_receive_skb_internal(skb))
ret = GRO_DROP;
break;
case GRO_DROP:
kfree_skb(skb);
break;
case GRO_MERGED_FREE:
if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) {
skb_dst_drop(skb);
secpath_reset(skb);
kmem_cache_free(skbuff_head_cache, skb);
} else {
__kfree_skb(skb);
}
break;
case GRO_HELD:
case GRO_MERGED:
case GRO_CONSUMED:
break;
}
return ret;
}
gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
{
skb_mark_napi_id(skb, napi);
trace_napi_gro_receive_entry(skb);
skb_gro_reset_offset(skb);
return napi_skb_finish(dev_gro_receive(napi, skb), skb);
}
EXPORT_SYMBOL(napi_gro_receive);
static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
{
if (unlikely(skb->pfmemalloc)) {
consume_skb(skb);
return;
}
__skb_pull(skb, skb_headlen(skb));
/* restore the reserve we had after netdev_alloc_skb_ip_align() */
skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
skb->vlan_tci = 0;
skb->dev = napi->dev;
skb->skb_iif = 0;
skb->encapsulation = 0;
skb_shinfo(skb)->gso_type = 0;
skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
secpath_reset(skb);
napi->skb = skb;
}
struct sk_buff *napi_get_frags(struct napi_struct *napi)
{
struct sk_buff *skb = napi->skb;
if (!skb) {
skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
if (skb) {
napi->skb = skb;
skb_mark_napi_id(skb, napi);
}
}
return skb;
}
EXPORT_SYMBOL(napi_get_frags);
static gro_result_t napi_frags_finish(struct napi_struct *napi,
struct sk_buff *skb,
gro_result_t ret)
{
switch (ret) {
case GRO_NORMAL:
case GRO_HELD:
__skb_push(skb, ETH_HLEN);
skb->protocol = eth_type_trans(skb, skb->dev);
if (ret == GRO_NORMAL && netif_receive_skb_internal(skb))
ret = GRO_DROP;
break;
case GRO_DROP:
case GRO_MERGED_FREE:
napi_reuse_skb(napi, skb);
break;
case GRO_MERGED:
case GRO_CONSUMED:
break;
}
return ret;
}
/* Upper GRO stack assumes network header starts at gro_offset=0
* Drivers could call both napi_gro_frags() and napi_gro_receive()
* We copy ethernet header into skb->data to have a common layout.
*/
static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
{
struct sk_buff *skb = napi->skb;
const struct ethhdr *eth;
unsigned int hlen = sizeof(*eth);
napi->skb = NULL;
skb_reset_mac_header(skb);
skb_gro_reset_offset(skb);
eth = skb_gro_header_fast(skb, 0);
if (unlikely(skb_gro_header_hard(skb, hlen))) {
eth = skb_gro_header_slow(skb, hlen, 0);
if (unlikely(!eth)) {
net_warn_ratelimited("%s: dropping impossible skb from %s\n",
__func__, napi->dev->name);
napi_reuse_skb(napi, skb);
return NULL;
}
} else {
gro_pull_from_frag0(skb, hlen);
NAPI_GRO_CB(skb)->frag0 += hlen;
NAPI_GRO_CB(skb)->frag0_len -= hlen;
}
__skb_pull(skb, hlen);
/*
* This works because the only protocols we care about don't require
* special handling.
* We'll fix it up properly in napi_frags_finish()
*/
skb->protocol = eth->h_proto;
return skb;
}
gro_result_t napi_gro_frags(struct napi_struct *napi)
{
struct sk_buff *skb = napi_frags_skb(napi);
if (!skb)
return GRO_DROP;
trace_napi_gro_frags_entry(skb);
return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
}
EXPORT_SYMBOL(napi_gro_frags);
/* Compute the checksum from gro_offset and return the folded value
* after adding in any pseudo checksum.
*/
__sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
{
__wsum wsum;
__sum16 sum;
wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
/* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
if (likely(!sum)) {
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
!skb->csum_complete_sw)
netdev_rx_csum_fault(skb->dev);
}
NAPI_GRO_CB(skb)->csum = wsum;
NAPI_GRO_CB(skb)->csum_valid = 1;
return sum;
}
EXPORT_SYMBOL(__skb_gro_checksum_complete);
/*
* net_rps_action_and_irq_enable sends any pending IPI's for rps.
* Note: called with local irq disabled, but exits with local irq enabled.
*/
static void net_rps_action_and_irq_enable(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
struct softnet_data *remsd = sd->rps_ipi_list;
if (remsd) {
sd->rps_ipi_list = NULL;
local_irq_enable();
/* Send pending IPI's to kick RPS processing on remote cpus. */
while (remsd) {
struct softnet_data *next = remsd->rps_ipi_next;
if (cpu_online(remsd->cpu))
smp_call_function_single_async(remsd->cpu,
&remsd->csd);
remsd = next;
}
} else
#endif
local_irq_enable();
}
static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
return sd->rps_ipi_list != NULL;
#else
return false;
#endif
}
static int process_backlog(struct napi_struct *napi, int quota)
{
struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
bool again = true;
int work = 0;
/* Check if we have pending ipi, its better to send them now,
* not waiting net_rx_action() end.
*/
if (sd_has_rps_ipi_waiting(sd)) {
local_irq_disable();
net_rps_action_and_irq_enable(sd);
}
napi->weight = dev_rx_weight;
while (again) {
struct sk_buff *skb;
while ((skb = __skb_dequeue(&sd->process_queue))) {
rcu_read_lock();
__netif_receive_skb(skb);
rcu_read_unlock();
input_queue_head_incr(sd);
if (++work >= quota)
return work;
}
local_irq_disable();
rps_lock(sd);
if (skb_queue_empty(&sd->input_pkt_queue)) {
/*
* Inline a custom version of __napi_complete().
* only current cpu owns and manipulates this napi,
* and NAPI_STATE_SCHED is the only possible flag set
* on backlog.
* We can use a plain write instead of clear_bit(),
* and we dont need an smp_mb() memory barrier.
*/
napi->state = 0;
again = false;
} else {
skb_queue_splice_tail_init(&sd->input_pkt_queue,
&sd->process_queue);
}
rps_unlock(sd);
local_irq_enable();
}
return work;
}
/**
* __napi_schedule - schedule for receive
* @n: entry to schedule
*
* The entry's receive function will be scheduled to run.
* Consider using __napi_schedule_irqoff() if hard irqs are masked.
*/
void __napi_schedule(struct napi_struct *n)
{
unsigned long flags;
local_irq_save(flags);
____napi_schedule(this_cpu_ptr(&softnet_data), n);
local_irq_restore(flags);
}
EXPORT_SYMBOL(__napi_schedule);
/**
* napi_schedule_prep - check if napi can be scheduled
* @n: napi context
*
* Test if NAPI routine is already running, and if not mark
* it as running. This is used as a condition variable
* insure only one NAPI poll instance runs. We also make
* sure there is no pending NAPI disable.
*/
bool napi_schedule_prep(struct napi_struct *n)
{
unsigned long val, new;
do {
val = READ_ONCE(n->state);
if (unlikely(val & NAPIF_STATE_DISABLE))
return false;
new = val | NAPIF_STATE_SCHED;
/* Sets STATE_MISSED bit if STATE_SCHED was already set
* This was suggested by Alexander Duyck, as compiler
* emits better code than :
* if (val & NAPIF_STATE_SCHED)
* new |= NAPIF_STATE_MISSED;
*/
new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
NAPIF_STATE_MISSED;
} while (cmpxchg(&n->state, val, new) != val);
return !(val & NAPIF_STATE_SCHED);
}
EXPORT_SYMBOL(napi_schedule_prep);
/**
* __napi_schedule_irqoff - schedule for receive
* @n: entry to schedule
*
* Variant of __napi_schedule() assuming hard irqs are masked
*/
void __napi_schedule_irqoff(struct napi_struct *n)
{
____napi_schedule(this_cpu_ptr(&softnet_data), n);
}
EXPORT_SYMBOL(__napi_schedule_irqoff);
bool napi_complete_done(struct napi_struct *n, int work_done)
{
unsigned long flags, val, new;
/*
* 1) Don't let napi dequeue from the cpu poll list
* just in case its running on a different cpu.
* 2) If we are busy polling, do nothing here, we have
* the guarantee we will be called later.
*/
if (unlikely(n->state & (NAPIF_STATE_NPSVC |
NAPIF_STATE_IN_BUSY_POLL)))
return false;
if (n->gro_list) {
unsigned long timeout = 0;
if (work_done)
timeout = n->dev->gro_flush_timeout;
if (timeout)
hrtimer_start(&n->timer, ns_to_ktime(timeout),
HRTIMER_MODE_REL_PINNED);
else
napi_gro_flush(n, false);
}
if (unlikely(!list_empty(&n->poll_list))) {
/* If n->poll_list is not empty, we need to mask irqs */
local_irq_save(flags);
list_del_init(&n->poll_list);
local_irq_restore(flags);
}
do {
val = READ_ONCE(n->state);
WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED);
/* If STATE_MISSED was set, leave STATE_SCHED set,
* because we will call napi->poll() one more time.
* This C code was suggested by Alexander Duyck to help gcc.
*/
new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
NAPIF_STATE_SCHED;
} while (cmpxchg(&n->state, val, new) != val);
if (unlikely(val & NAPIF_STATE_MISSED)) {
__napi_schedule(n);
return false;
}
return true;
}
EXPORT_SYMBOL(napi_complete_done);
/* must be called under rcu_read_lock(), as we dont take a reference */
static struct napi_struct *napi_by_id(unsigned int napi_id)
{
unsigned int hash = napi_id % HASH_SIZE(napi_hash);
struct napi_struct *napi;
hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
if (napi->napi_id == napi_id)
return napi;
return NULL;
}
#if defined(CONFIG_NET_RX_BUSY_POLL)
#define BUSY_POLL_BUDGET 8
static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
{
int rc;
/* Busy polling means there is a high chance device driver hard irq
* could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
* set in napi_schedule_prep().
* Since we are about to call napi->poll() once more, we can safely
* clear NAPI_STATE_MISSED.
*
* Note: x86 could use a single "lock and ..." instruction
* to perform these two clear_bit()
*/
clear_bit(NAPI_STATE_MISSED, &napi->state);
clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
local_bh_disable();
/* All we really want here is to re-enable device interrupts.
* Ideally, a new ndo_busy_poll_stop() could avoid another round.
*/
rc = napi->poll(napi, BUSY_POLL_BUDGET);
netpoll_poll_unlock(have_poll_lock);
if (rc == BUSY_POLL_BUDGET)
__napi_schedule(napi);
local_bh_enable();
if (local_softirq_pending())
do_softirq();
}
void napi_busy_loop(unsigned int napi_id,
bool (*loop_end)(void *, unsigned long),
void *loop_end_arg)
{
unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
int (*napi_poll)(struct napi_struct *napi, int budget);
void *have_poll_lock = NULL;
struct napi_struct *napi;
restart:
napi_poll = NULL;
rcu_read_lock();
napi = napi_by_id(napi_id);
if (!napi)
goto out;
preempt_disable();
for (;;) {
int work = 0;
local_bh_disable();
if (!napi_poll) {
unsigned long val = READ_ONCE(napi->state);
/* If multiple threads are competing for this napi,
* we avoid dirtying napi->state as much as we can.
*/
if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
NAPIF_STATE_IN_BUSY_POLL))
goto count;
if (cmpxchg(&napi->state, val,
val | NAPIF_STATE_IN_BUSY_POLL |
NAPIF_STATE_SCHED) != val)
goto count;
have_poll_lock = netpoll_poll_lock(napi);
napi_poll = napi->poll;
}
work = napi_poll(napi, BUSY_POLL_BUDGET);
trace_napi_poll(napi, work, BUSY_POLL_BUDGET);
count:
if (work > 0)
__NET_ADD_STATS(dev_net(napi->dev),
LINUX_MIB_BUSYPOLLRXPACKETS, work);
local_bh_enable();
if (!loop_end || loop_end(loop_end_arg, start_time))
break;
if (unlikely(need_resched())) {
if (napi_poll)
busy_poll_stop(napi, have_poll_lock);
preempt_enable();
rcu_read_unlock();
cond_resched();
if (loop_end(loop_end_arg, start_time))
return;
goto restart;
}
cpu_relax();
}
if (napi_poll)
busy_poll_stop(napi, have_poll_lock);
preempt_enable();
out:
rcu_read_unlock();
}
EXPORT_SYMBOL(napi_busy_loop);
#endif /* CONFIG_NET_RX_BUSY_POLL */
static void napi_hash_add(struct napi_struct *napi)
{
if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state) ||
test_and_set_bit(NAPI_STATE_HASHED, &napi->state))
return;
spin_lock(&napi_hash_lock);
/* 0..NR_CPUS range is reserved for sender_cpu use */
do {
if (unlikely(++napi_gen_id < MIN_NAPI_ID))
napi_gen_id = MIN_NAPI_ID;
} while (napi_by_id(napi_gen_id));
napi->napi_id = napi_gen_id;
hlist_add_head_rcu(&napi->napi_hash_node,
&napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
spin_unlock(&napi_hash_lock);
}
/* Warning : caller is responsible to make sure rcu grace period
* is respected before freeing memory containing @napi
*/
bool napi_hash_del(struct napi_struct *napi)
{
bool rcu_sync_needed = false;
spin_lock(&napi_hash_lock);
if (test_and_clear_bit(NAPI_STATE_HASHED, &napi->state)) {
rcu_sync_needed = true;
hlist_del_rcu(&napi->napi_hash_node);
}
spin_unlock(&napi_hash_lock);
return rcu_sync_needed;
}
EXPORT_SYMBOL_GPL(napi_hash_del);
static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
{
struct napi_struct *napi;
napi = container_of(timer, struct napi_struct, timer);
/* Note : we use a relaxed variant of napi_schedule_prep() not setting
* NAPI_STATE_MISSED, since we do not react to a device IRQ.
*/
if (napi->gro_list && !napi_disable_pending(napi) &&
!test_and_set_bit(NAPI_STATE_SCHED, &napi->state))
__napi_schedule_irqoff(napi);
return HRTIMER_NORESTART;
}
void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
int (*poll)(struct napi_struct *, int), int weight)
{
INIT_LIST_HEAD(&napi->poll_list);
hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
napi->timer.function = napi_watchdog;
napi->gro_count = 0;
napi->gro_list = NULL;
napi->skb = NULL;
napi->poll = poll;
if (weight > NAPI_POLL_WEIGHT)
pr_err_once("netif_napi_add() called with weight %d on device %s\n",
weight, dev->name);
napi->weight = weight;
list_add(&napi->dev_list, &dev->napi_list);
napi->dev = dev;
#ifdef CONFIG_NETPOLL
napi->poll_owner = -1;
#endif
set_bit(NAPI_STATE_SCHED, &napi->state);
napi_hash_add(napi);
}
EXPORT_SYMBOL(netif_napi_add);
void napi_disable(struct napi_struct *n)
{
might_sleep();
set_bit(NAPI_STATE_DISABLE, &n->state);
while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
msleep(1);
while (test_and_set_bit(NAPI_STATE_NPSVC, &n->state))
msleep(1);
hrtimer_cancel(&n->timer);
clear_bit(NAPI_STATE_DISABLE, &n->state);
}
EXPORT_SYMBOL(napi_disable);
/* Must be called in process context */
void netif_napi_del(struct napi_struct *napi)
{
might_sleep();
if (napi_hash_del(napi))
synchronize_net();
list_del_init(&napi->dev_list);
napi_free_frags(napi);
kfree_skb_list(napi->gro_list);
napi->gro_list = NULL;
napi->gro_count = 0;
}
EXPORT_SYMBOL(netif_napi_del);
static int napi_poll(struct napi_struct *n, struct list_head *repoll)
{
void *have;
int work, weight;
list_del_init(&n->poll_list);
have = netpoll_poll_lock(n);
weight = n->weight;
/* This NAPI_STATE_SCHED test is for avoiding a race
* with netpoll's poll_napi(). Only the entity which
* obtains the lock and sees NAPI_STATE_SCHED set will
* actually make the ->poll() call. Therefore we avoid
* accidentally calling ->poll() when NAPI is not scheduled.
*/
work = 0;
if (test_bit(NAPI_STATE_SCHED, &n->state)) {
work = n->poll(n, weight);
trace_napi_poll(n, work, weight);
}
WARN_ON_ONCE(work > weight);
if (likely(work < weight))
goto out_unlock;
/* Drivers must not modify the NAPI state if they
* consume the entire weight. In such cases this code
* still "owns" the NAPI instance and therefore can
* move the instance around on the list at-will.
*/
if (unlikely(napi_disable_pending(n))) {
napi_complete(n);
goto out_unlock;
}
if (n->gro_list) {
/* flush too old packets
* If HZ < 1000, flush all packets.
*/
napi_gro_flush(n, HZ >= 1000);
}
/* Some drivers may have called napi_schedule
* prior to exhausting their budget.
*/
if (unlikely(!list_empty(&n->poll_list))) {
pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
n->dev ? n->dev->name : "backlog");
goto out_unlock;
}
list_add_tail(&n->poll_list, repoll);
out_unlock:
netpoll_poll_unlock(have);
return work;
}
static __latent_entropy void net_rx_action(struct softirq_action *h)
{
struct softnet_data *sd = this_cpu_ptr(&softnet_data);
unsigned long time_limit = jiffies + 2;
int budget = netdev_budget;
LIST_HEAD(list);
LIST_HEAD(repoll);
local_irq_disable();
list_splice_init(&sd->poll_list, &list);
local_irq_enable();
for (;;) {
struct napi_struct *n;
if (list_empty(&list)) {
if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
goto out;
break;
}
n = list_first_entry(&list, struct napi_struct, poll_list);
budget -= napi_poll(n, &repoll);
/* If softirq window is exhausted then punt.
* Allow this to run for 2 jiffies since which will allow
* an average latency of 1.5/HZ.
*/
if (unlikely(budget <= 0 ||
time_after_eq(jiffies, time_limit))) {
sd->time_squeeze++;
break;
}
}
local_irq_disable();
list_splice_tail_init(&sd->poll_list, &list);
list_splice_tail(&repoll, &list);
list_splice(&list, &sd->poll_list);
if (!list_empty(&sd->poll_list))
__raise_softirq_irqoff(NET_RX_SOFTIRQ);
net_rps_action_and_irq_enable(sd);
out:
__kfree_skb_flush();
}
struct netdev_adjacent {
struct net_device *dev;
/* upper master flag, there can only be one master device per list */
bool master;
/* counter for the number of times this device was added to us */
u16 ref_nr;
/* private field for the users */
void *private;
struct list_head list;
struct rcu_head rcu;
};
static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
struct list_head *adj_list)
{
struct netdev_adjacent *adj;
list_for_each_entry(adj, adj_list, list) {
if (adj->dev == adj_dev)
return adj;
}
return NULL;
}
static int __netdev_has_upper_dev(struct net_device *upper_dev, void *data)
{
struct net_device *dev = data;
return upper_dev == dev;
}
/**
* netdev_has_upper_dev - Check if device is linked to an upper device
* @dev: device
* @upper_dev: upper device to check
*
* Find out if a device is linked to specified upper device and return true
* in case it is. Note that this checks only immediate upper device,
* not through a complete stack of devices. The caller must hold the RTNL lock.
*/
bool netdev_has_upper_dev(struct net_device *dev,
struct net_device *upper_dev)
{
ASSERT_RTNL();
return netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev,
upper_dev);
}
EXPORT_SYMBOL(netdev_has_upper_dev);
/**
* netdev_has_upper_dev_all - Check if device is linked to an upper device
* @dev: device
* @upper_dev: upper device to check
*
* Find out if a device is linked to specified upper device and return true
* in case it is. Note that this checks the entire upper device chain.
* The caller must hold rcu lock.
*/
bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
struct net_device *upper_dev)
{
return !!netdev_walk_all_upper_dev_rcu(dev, __netdev_has_upper_dev,
upper_dev);
}
EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
/**
* netdev_has_any_upper_dev - Check if device is linked to some device
* @dev: device
*
* Find out if a device is linked to an upper device and return true in case
* it is. The caller must hold the RTNL lock.
*/
static bool netdev_has_any_upper_dev(struct net_device *dev)
{
ASSERT_RTNL();
return !list_empty(&dev->adj_list.upper);
}
/**
* netdev_master_upper_dev_get - Get master upper device
* @dev: device
*
* Find a master upper device and return pointer to it or NULL in case
* it's not there. The caller must hold the RTNL lock.
*/
struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
{
struct netdev_adjacent *upper;
ASSERT_RTNL();
if (list_empty(&dev->adj_list.upper))
return NULL;
upper = list_first_entry(&dev->adj_list.upper,
struct netdev_adjacent, list);
if (likely(upper->master))
return upper->dev;
return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);
/**
* netdev_has_any_lower_dev - Check if device is linked to some device
* @dev: device
*
* Find out if a device is linked to a lower device and return true in case
* it is. The caller must hold the RTNL lock.
*/
static bool netdev_has_any_lower_dev(struct net_device *dev)
{
ASSERT_RTNL();
return !list_empty(&dev->adj_list.lower);
}
void *netdev_adjacent_get_private(struct list_head *adj_list)
{
struct netdev_adjacent *adj;
adj = list_entry(adj_list, struct netdev_adjacent, list);
return adj->private;
}
EXPORT_SYMBOL(netdev_adjacent_get_private);
/**
* netdev_upper_get_next_dev_rcu - Get the next dev from upper list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next device from the dev's upper list, starting from iter
* position. The caller must hold RCU read lock.
*/
struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *upper;
WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&upper->list == &dev->adj_list.upper)
return NULL;
*iter = &upper->list;
return upper->dev;
}
EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *upper;
WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&upper->list == &dev->adj_list.upper)
return NULL;
*iter = &upper->list;
return upper->dev;
}
int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
int (*fn)(struct net_device *dev,
void *data),
void *data)
{
struct net_device *udev;
struct list_head *iter;
int ret;
for (iter = &dev->adj_list.upper,
udev = netdev_next_upper_dev_rcu(dev, &iter);
udev;
udev = netdev_next_upper_dev_rcu(dev, &iter)) {
/* first is the upper device itself */
ret = fn(udev, data);
if (ret)
return ret;
/* then look at all of its upper devices */
ret = netdev_walk_all_upper_dev_rcu(udev, fn, data);
if (ret)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
/**
* netdev_lower_get_next_private - Get the next ->private from the
* lower neighbour list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent->private from the dev's lower neighbour
* list, starting from iter position. The caller must hold either hold the
* RTNL lock or its own locking that guarantees that the neighbour lower
* list will remain unchanged.
*/
void *netdev_lower_get_next_private(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry(*iter, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = lower->list.next;
return lower->private;
}
EXPORT_SYMBOL(netdev_lower_get_next_private);
/**
* netdev_lower_get_next_private_rcu - Get the next ->private from the
* lower neighbour list, RCU
* variant
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent->private from the dev's lower neighbour
* list, starting from iter position. The caller must hold RCU read lock.
*/
void *netdev_lower_get_next_private_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
WARN_ON_ONCE(!rcu_read_lock_held());
lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = &lower->list;
return lower->private;
}
EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
/**
* netdev_lower_get_next - Get the next device from the lower neighbour
* list
* @dev: device
* @iter: list_head ** of the current position
*
* Gets the next netdev_adjacent from the dev's lower neighbour
* list, starting from iter position. The caller must hold RTNL lock or
* its own locking that guarantees that the neighbour lower
* list will remain unchanged.
*/
void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry(*iter, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = lower->list.next;
return lower->dev;
}
EXPORT_SYMBOL(netdev_lower_get_next);
static struct net_device *netdev_next_lower_dev(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry((*iter)->next, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = &lower->list;
return lower->dev;
}
int netdev_walk_all_lower_dev(struct net_device *dev,
int (*fn)(struct net_device *dev,
void *data),
void *data)
{
struct net_device *ldev;
struct list_head *iter;
int ret;
for (iter = &dev->adj_list.lower,
ldev = netdev_next_lower_dev(dev, &iter);
ldev;
ldev = netdev_next_lower_dev(dev, &iter)) {
/* first is the lower device itself */
ret = fn(ldev, data);
if (ret)
return ret;
/* then look at all of its lower devices */
ret = netdev_walk_all_lower_dev(ldev, fn, data);
if (ret)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
static struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
struct list_head **iter)
{
struct netdev_adjacent *lower;
lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
if (&lower->list == &dev->adj_list.lower)
return NULL;
*iter = &lower->list;
return lower->dev;
}
int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
int (*fn)(struct net_device *dev,
void *data),
void *data)
{
struct net_device *ldev;
struct list_head *iter;
int ret;
for (iter = &dev->adj_list.lower,
ldev = netdev_next_lower_dev_rcu(dev, &iter);
ldev;
ldev = netdev_next_lower_dev_rcu(dev, &iter)) {
/* first is the lower device itself */
ret = fn(ldev, data);
if (ret)
return ret;
/* then look at all of its lower devices */
ret = netdev_walk_all_lower_dev_rcu(ldev, fn, data);
if (ret)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
/**
* netdev_lower_get_first_private_rcu - Get the first ->private from the
* lower neighbour list, RCU
* variant
* @dev: device
*
* Gets the first netdev_adjacent->private from the dev's lower neighbour
* list. The caller must hold RCU read lock.
*/
void *netdev_lower_get_first_private_rcu(struct net_device *dev)
{
struct netdev_adjacent *lower;
lower = list_first_or_null_rcu(&dev->adj_list.lower,
struct netdev_adjacent, list);
if (lower)
return lower->private;
return NULL;
}
EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
/**
* netdev_master_upper_dev_get_rcu - Get master upper device
* @dev: device
*
* Find a master upper device and return pointer to it or NULL in case
* it's not there. The caller must hold the RCU read lock.
*/
struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
{
struct netdev_adjacent *upper;
upper = list_first_or_null_rcu(&dev->adj_list.upper,
struct netdev_adjacent, list);
if (upper && likely(upper->master))
return upper->dev;
return NULL;
}
EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
static int netdev_adjacent_sysfs_add(struct net_device *dev,
struct net_device *adj_dev,
struct list_head *dev_list)
{
char linkname[IFNAMSIZ+7];
sprintf(linkname, dev_list == &dev->adj_list.upper ?
"upper_%s" : "lower_%s", adj_dev->name);
return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
linkname);
}
static void netdev_adjacent_sysfs_del(struct net_device *dev,
char *name,
struct list_head *dev_list)
{
char linkname[IFNAMSIZ+7];
sprintf(linkname, dev_list == &dev->adj_list.upper ?
"upper_%s" : "lower_%s", name);
sysfs_remove_link(&(dev->dev.kobj), linkname);
}
static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
struct net_device *adj_dev,
struct list_head *dev_list)
{
return (dev_list == &dev->adj_list.upper ||
dev_list == &dev->adj_list.lower) &&
net_eq(dev_net(dev), dev_net(adj_dev));
}
static int __netdev_adjacent_dev_insert(struct net_device *dev,
struct net_device *adj_dev,
struct list_head *dev_list,
void *private, bool master)
{
struct netdev_adjacent *adj;
int ret;
adj = __netdev_find_adj(adj_dev, dev_list);
if (adj) {
adj->ref_nr += 1;
pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
dev->name, adj_dev->name, adj->ref_nr);
return 0;
}
adj = kmalloc(sizeof(*adj), GFP_KERNEL);
if (!adj)
return -ENOMEM;
adj->dev = adj_dev;
adj->master = master;
adj->ref_nr = 1;
adj->private = private;
dev_hold(adj_dev);
pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
if (ret)
goto free_adj;
}
/* Ensure that master link is always the first item in list. */
if (master) {
ret = sysfs_create_link(&(dev->dev.kobj),
&(adj_dev->dev.kobj), "master");
if (ret)
goto remove_symlinks;
list_add_rcu(&adj->list, dev_list);
} else {
list_add_tail_rcu(&adj->list, dev_list);
}
return 0;
remove_symlinks:
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
free_adj:
kfree(adj);
dev_put(adj_dev);
return ret;
}
static void __netdev_adjacent_dev_remove(struct net_device *dev,
struct net_device *adj_dev,
u16 ref_nr,
struct list_head *dev_list)
{
struct netdev_adjacent *adj;
pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
dev->name, adj_dev->name, ref_nr);
adj = __netdev_find_adj(adj_dev, dev_list);
if (!adj) {
pr_err("Adjacency does not exist for device %s from %s\n",
dev->name, adj_dev->name);
WARN_ON(1);
return;
}
if (adj->ref_nr > ref_nr) {
pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
dev->name, adj_dev->name, ref_nr,
adj->ref_nr - ref_nr);
adj->ref_nr -= ref_nr;
return;
}
if (adj->master)
sysfs_remove_link(&(dev->dev.kobj), "master");
if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
list_del_rcu(&adj->list);
pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
adj_dev->name, dev->name, adj_dev->name);
dev_put(adj_dev);
kfree_rcu(adj, rcu);
}
static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
struct net_device *upper_dev,
struct list_head *up_list,
struct list_head *down_list,
void *private, bool master)
{
int ret;
ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
private, master);
if (ret)
return ret;
ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
private, false);
if (ret) {
__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
return ret;
}
return 0;
}
static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
struct net_device *upper_dev,
u16 ref_nr,
struct list_head *up_list,
struct list_head *down_list)
{
__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
}
static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
struct net_device *upper_dev,
void *private, bool master)
{
return __netdev_adjacent_dev_link_lists(dev, upper_dev,
&dev->adj_list.upper,
&upper_dev->adj_list.lower,
private, master);
}
static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
struct net_device *upper_dev)
{
__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
&dev->adj_list.upper,
&upper_dev->adj_list.lower);
}
static int __netdev_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev, bool master,
void *upper_priv, void *upper_info)
{
struct netdev_notifier_changeupper_info changeupper_info;
int ret = 0;
ASSERT_RTNL();
if (dev == upper_dev)
return -EBUSY;
/* To prevent loops, check if dev is not upper device to upper_dev. */
if (netdev_has_upper_dev(upper_dev, dev))
return -EBUSY;
if (netdev_has_upper_dev(dev, upper_dev))
return -EEXIST;
if (master && netdev_master_upper_dev_get(dev))
return -EBUSY;
changeupper_info.upper_dev = upper_dev;
changeupper_info.master = master;
changeupper_info.linking = true;
changeupper_info.upper_info = upper_info;
ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER, dev,
&changeupper_info.info);
ret = notifier_to_errno(ret);
if (ret)
return ret;
ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
master);
if (ret)
return ret;
ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
&changeupper_info.info);
ret = notifier_to_errno(ret);
if (ret)
goto rollback;
return 0;
rollback:
__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
return ret;
}
/**
* netdev_upper_dev_link - Add a link to the upper device
* @dev: device
* @upper_dev: new upper device
*
* Adds a link to device which is upper to this one. The caller must hold
* the RTNL lock. On a failure a negative errno code is returned.
* On success the reference counts are adjusted and the function
* returns zero.
*/
int netdev_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev)
{
return __netdev_upper_dev_link(dev, upper_dev, false, NULL, NULL);
}
EXPORT_SYMBOL(netdev_upper_dev_link);
/**
* netdev_master_upper_dev_link - Add a master link to the upper device
* @dev: device
* @upper_dev: new upper device
* @upper_priv: upper device private
* @upper_info: upper info to be passed down via notifier
*
* Adds a link to device which is upper to this one. In this case, only
* one master upper device can be linked, although other non-master devices
* might be linked as well. The caller must hold the RTNL lock.
* On a failure a negative errno code is returned. On success the reference
* counts are adjusted and the function returns zero.
*/
int netdev_master_upper_dev_link(struct net_device *dev,
struct net_device *upper_dev,
void *upper_priv, void *upper_info)
{
return __netdev_upper_dev_link(dev, upper_dev, true,
upper_priv, upper_info);
}
EXPORT_SYMBOL(netdev_master_upper_dev_link);
/**
* netdev_upper_dev_unlink - Removes a link to upper device
* @dev: device
* @upper_dev: new upper device
*
* Removes a link to device which is upper to this one. The caller must hold
* the RTNL lock.
*/
void netdev_upper_dev_unlink(struct net_device *dev,
struct net_device *upper_dev)
{
struct netdev_notifier_changeupper_info changeupper_info;
ASSERT_RTNL();
changeupper_info.upper_dev = upper_dev;
changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
changeupper_info.linking = false;
call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER, dev,
&changeupper_info.info);
__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
call_netdevice_notifiers_info(NETDEV_CHANGEUPPER, dev,
&changeupper_info.info);
}
EXPORT_SYMBOL(netdev_upper_dev_unlink);
/**
* netdev_bonding_info_change - Dispatch event about slave change
* @dev: device
* @bonding_info: info to dispatch
*
* Send NETDEV_BONDING_INFO to netdev notifiers with info.
* The caller must hold the RTNL lock.
*/
void netdev_bonding_info_change(struct net_device *dev,
struct netdev_bonding_info *bonding_info)
{
struct netdev_notifier_bonding_info info;
memcpy(&info.bonding_info, bonding_info,
sizeof(struct netdev_bonding_info));
call_netdevice_notifiers_info(NETDEV_BONDING_INFO, dev,
&info.info);
}
EXPORT_SYMBOL(netdev_bonding_info_change);
static void netdev_adjacent_add_links(struct net_device *dev)
{
struct netdev_adjacent *iter;
struct net *net = dev_net(dev);
list_for_each_entry(iter, &dev->adj_list.upper, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.lower);
netdev_adjacent_sysfs_add(dev, iter->dev,
&dev->adj_list.upper);
}
list_for_each_entry(iter, &dev->adj_list.lower, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.upper);
netdev_adjacent_sysfs_add(dev, iter->dev,
&dev->adj_list.lower);
}
}
static void netdev_adjacent_del_links(struct net_device *dev)
{
struct netdev_adjacent *iter;
struct net *net = dev_net(dev);
list_for_each_entry(iter, &dev->adj_list.upper, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, dev->name,
&iter->dev->adj_list.lower);
netdev_adjacent_sysfs_del(dev, iter->dev->name,
&dev->adj_list.upper);
}
list_for_each_entry(iter, &dev->adj_list.lower, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, dev->name,
&iter->dev->adj_list.upper);
netdev_adjacent_sysfs_del(dev, iter->dev->name,
&dev->adj_list.lower);
}
}
void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
{
struct netdev_adjacent *iter;
struct net *net = dev_net(dev);
list_for_each_entry(iter, &dev->adj_list.upper, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, oldname,
&iter->dev->adj_list.lower);
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.lower);
}
list_for_each_entry(iter, &dev->adj_list.lower, list) {
if (!net_eq(net, dev_net(iter->dev)))
continue;
netdev_adjacent_sysfs_del(iter->dev, oldname,
&iter->dev->adj_list.upper);
netdev_adjacent_sysfs_add(iter->dev, dev,
&iter->dev->adj_list.upper);
}
}
void *netdev_lower_dev_get_private(struct net_device *dev,
struct net_device *lower_dev)
{
struct netdev_adjacent *lower;
if (!lower_dev)
return NULL;
lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
if (!lower)
return NULL;
return lower->private;
}
EXPORT_SYMBOL(netdev_lower_dev_get_private);
int dev_get_nest_level(struct net_device *dev)
{
struct net_device *lower = NULL;
struct list_head *iter;
int max_nest = -1;
int nest;
ASSERT_RTNL();
netdev_for_each_lower_dev(dev, lower, iter) {
nest = dev_get_nest_level(lower);
if (max_nest < nest)
max_nest = nest;
}
return max_nest + 1;
}
EXPORT_SYMBOL(dev_get_nest_level);
/**
* netdev_lower_change - Dispatch event about lower device state change
* @lower_dev: device
* @lower_state_info: state to dispatch
*
* Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
* The caller must hold the RTNL lock.
*/
void netdev_lower_state_changed(struct net_device *lower_dev,
void *lower_state_info)
{
struct netdev_notifier_changelowerstate_info changelowerstate_info;
ASSERT_RTNL();
changelowerstate_info.lower_state_info = lower_state_info;
call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE, lower_dev,
&changelowerstate_info.info);
}
EXPORT_SYMBOL(netdev_lower_state_changed);
static void dev_change_rx_flags(struct net_device *dev, int flags)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_change_rx_flags)
ops->ndo_change_rx_flags(dev, flags);
}
static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
{
unsigned int old_flags = dev->flags;
kuid_t uid;
kgid_t gid;
ASSERT_RTNL();
dev->flags |= IFF_PROMISC;
dev->promiscuity += inc;
if (dev->promiscuity == 0) {
/*
* Avoid overflow.
* If inc causes overflow, untouch promisc and return error.
*/
if (inc < 0)
dev->flags &= ~IFF_PROMISC;
else {
dev->promiscuity -= inc;
pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
dev->name);
return -EOVERFLOW;
}
}
if (dev->flags != old_flags) {
pr_info("device %s %s promiscuous mode\n",
dev->name,
dev->flags & IFF_PROMISC ? "entered" : "left");
if (audit_enabled) {
current_uid_gid(&uid, &gid);
audit_log(current->audit_context, GFP_ATOMIC,
AUDIT_ANOM_PROMISCUOUS,
"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
dev->name, (dev->flags & IFF_PROMISC),
(old_flags & IFF_PROMISC),
from_kuid(&init_user_ns, audit_get_loginuid(current)),
from_kuid(&init_user_ns, uid),
from_kgid(&init_user_ns, gid),
audit_get_sessionid(current));
}
dev_change_rx_flags(dev, IFF_PROMISC);
}
if (notify)
__dev_notify_flags(dev, old_flags, IFF_PROMISC);
return 0;
}
/**
* dev_set_promiscuity - update promiscuity count on a device
* @dev: device
* @inc: modifier
*
* Add or remove promiscuity from a device. While the count in the device
* remains above zero the interface remains promiscuous. Once it hits zero
* the device reverts back to normal filtering operation. A negative inc
* value is used to drop promiscuity on the device.
* Return 0 if successful or a negative errno code on error.
*/
int dev_set_promiscuity(struct net_device *dev, int inc)
{
unsigned int old_flags = dev->flags;
int err;
err = __dev_set_promiscuity(dev, inc, true);
if (err < 0)
return err;
if (dev->flags != old_flags)
dev_set_rx_mode(dev);
return err;
}
EXPORT_SYMBOL(dev_set_promiscuity);
static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
{
unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
ASSERT_RTNL();
dev->flags |= IFF_ALLMULTI;
dev->allmulti += inc;
if (dev->allmulti == 0) {
/*
* Avoid overflow.
* If inc causes overflow, untouch allmulti and return error.
*/
if (inc < 0)
dev->flags &= ~IFF_ALLMULTI;
else {
dev->allmulti -= inc;
pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
dev->name);
return -EOVERFLOW;
}
}
if (dev->flags ^ old_flags) {
dev_change_rx_flags(dev, IFF_ALLMULTI);
dev_set_rx_mode(dev);
if (notify)
__dev_notify_flags(dev, old_flags,
dev->gflags ^ old_gflags);
}
return 0;
}
/**
* dev_set_allmulti - update allmulti count on a device
* @dev: device
* @inc: modifier
*
* Add or remove reception of all multicast frames to a device. While the
* count in the device remains above zero the interface remains listening
* to all interfaces. Once it hits zero the device reverts back to normal
* filtering operation. A negative @inc value is used to drop the counter
* when releasing a resource needing all multicasts.
* Return 0 if successful or a negative errno code on error.
*/
int dev_set_allmulti(struct net_device *dev, int inc)
{
return __dev_set_allmulti(dev, inc, true);
}
EXPORT_SYMBOL(dev_set_allmulti);
/*
* Upload unicast and multicast address lists to device and
* configure RX filtering. When the device doesn't support unicast
* filtering it is put in promiscuous mode while unicast addresses
* are present.
*/
void __dev_set_rx_mode(struct net_device *dev)
{
const struct net_device_ops *ops = dev->netdev_ops;
/* dev_open will call this function so the list will stay sane. */
if (!(dev->flags&IFF_UP))
return;
if (!netif_device_present(dev))
return;
if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
/* Unicast addresses changes may only happen under the rtnl,
* therefore calling __dev_set_promiscuity here is safe.
*/
if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
__dev_set_promiscuity(dev, 1, false);
dev->uc_promisc = true;
} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
__dev_set_promiscuity(dev, -1, false);
dev->uc_promisc = false;
}
}
if (ops->ndo_set_rx_mode)
ops->ndo_set_rx_mode(dev);
}
void dev_set_rx_mode(struct net_device *dev)
{
netif_addr_lock_bh(dev);
__dev_set_rx_mode(dev);
netif_addr_unlock_bh(dev);
}
/**
* dev_get_flags - get flags reported to userspace
* @dev: device
*
* Get the combination of flag bits exported through APIs to userspace.
*/
unsigned int dev_get_flags(const struct net_device *dev)
{
unsigned int flags;
flags = (dev->flags & ~(IFF_PROMISC |
IFF_ALLMULTI |
IFF_RUNNING |
IFF_LOWER_UP |
IFF_DORMANT)) |
(dev->gflags & (IFF_PROMISC |
IFF_ALLMULTI));
if (netif_running(dev)) {
if (netif_oper_up(dev))
flags |= IFF_RUNNING;
if (netif_carrier_ok(dev))
flags |= IFF_LOWER_UP;
if (netif_dormant(dev))
flags |= IFF_DORMANT;
}
return flags;
}
EXPORT_SYMBOL(dev_get_flags);
int __dev_change_flags(struct net_device *dev, unsigned int flags)
{
unsigned int old_flags = dev->flags;
int ret;
ASSERT_RTNL();
/*
* Set the flags on our device.
*/
dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
IFF_AUTOMEDIA)) |
(dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
IFF_ALLMULTI));
/*
* Load in the correct multicast list now the flags have changed.
*/
if ((old_flags ^ flags) & IFF_MULTICAST)
dev_change_rx_flags(dev, IFF_MULTICAST);
dev_set_rx_mode(dev);
/*
* Have we downed the interface. We handle IFF_UP ourselves
* according to user attempts to set it, rather than blindly
* setting it.
*/
ret = 0;
if ((old_flags ^ flags) & IFF_UP)
ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
if ((flags ^ dev->gflags) & IFF_PROMISC) {
int inc = (flags & IFF_PROMISC) ? 1 : -1;
unsigned int old_flags = dev->flags;
dev->gflags ^= IFF_PROMISC;
if (__dev_set_promiscuity(dev, inc, false) >= 0)
if (dev->flags != old_flags)
dev_set_rx_mode(dev);
}
/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
* is important. Some (broken) drivers set IFF_PROMISC, when
* IFF_ALLMULTI is requested not asking us and not reporting.
*/
if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
dev->gflags ^= IFF_ALLMULTI;
__dev_set_allmulti(dev, inc, false);
}
return ret;
}
void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
unsigned int gchanges)
{
unsigned int changes = dev->flags ^ old_flags;
if (gchanges)
rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
if (changes & IFF_UP) {
if (dev->flags & IFF_UP)
call_netdevice_notifiers(NETDEV_UP, dev);
else
call_netdevice_notifiers(NETDEV_DOWN, dev);
}
if (dev->flags & IFF_UP &&
(changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
struct netdev_notifier_change_info change_info;
change_info.flags_changed = changes;
call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
&change_info.info);
}
}
/**
* dev_change_flags - change device settings
* @dev: device
* @flags: device state flags
*
* Change settings on device based state flags. The flags are
* in the userspace exported format.
*/
int dev_change_flags(struct net_device *dev, unsigned int flags)
{
int ret;
unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
ret = __dev_change_flags(dev, flags);
if (ret < 0)
return ret;
changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
__dev_notify_flags(dev, old_flags, changes);
return ret;
}
EXPORT_SYMBOL(dev_change_flags);
static int __dev_set_mtu(struct net_device *dev, int new_mtu)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_change_mtu)
return ops->ndo_change_mtu(dev, new_mtu);
dev->mtu = new_mtu;
return 0;
}
/**
* dev_set_mtu - Change maximum transfer unit
* @dev: device
* @new_mtu: new transfer unit
*
* Change the maximum transfer size of the network device.
*/
int dev_set_mtu(struct net_device *dev, int new_mtu)
{
int err, orig_mtu;
if (new_mtu == dev->mtu)
return 0;
/* MTU must be positive, and in range */
if (new_mtu < 0 || new_mtu < dev->min_mtu) {
net_err_ratelimited("%s: Invalid MTU %d requested, hw min %d\n",
dev->name, new_mtu, dev->min_mtu);
return -EINVAL;
}
if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
net_err_ratelimited("%s: Invalid MTU %d requested, hw max %d\n",
dev->name, new_mtu, dev->max_mtu);
return -EINVAL;
}
if (!netif_device_present(dev))
return -ENODEV;
err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
err = notifier_to_errno(err);
if (err)
return err;
orig_mtu = dev->mtu;
err = __dev_set_mtu(dev, new_mtu);
if (!err) {
err = call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
err = notifier_to_errno(err);
if (err) {
/* setting mtu back and notifying everyone again,
* so that they have a chance to revert changes.
*/
__dev_set_mtu(dev, orig_mtu);
call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
}
}
return err;
}
EXPORT_SYMBOL(dev_set_mtu);
/**
* dev_set_group - Change group this device belongs to
* @dev: device
* @new_group: group this device should belong to
*/
void dev_set_group(struct net_device *dev, int new_group)
{
dev->group = new_group;
}
EXPORT_SYMBOL(dev_set_group);
/**
* dev_set_mac_address - Change Media Access Control Address
* @dev: device
* @sa: new address
*
* Change the hardware (MAC) address of the device
*/
int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
{
const struct net_device_ops *ops = dev->netdev_ops;
int err;
if (!ops->ndo_set_mac_address)
return -EOPNOTSUPP;
if (sa->sa_family != dev->type)
return -EINVAL;
if (!netif_device_present(dev))
return -ENODEV;
err = ops->ndo_set_mac_address(dev, sa);
if (err)
return err;
dev->addr_assign_type = NET_ADDR_SET;
call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
add_device_randomness(dev->dev_addr, dev->addr_len);
return 0;
}
EXPORT_SYMBOL(dev_set_mac_address);
/**
* dev_change_carrier - Change device carrier
* @dev: device
* @new_carrier: new value
*
* Change device carrier
*/
int dev_change_carrier(struct net_device *dev, bool new_carrier)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_change_carrier)
return -EOPNOTSUPP;
if (!netif_device_present(dev))
return -ENODEV;
return ops->ndo_change_carrier(dev, new_carrier);
}
EXPORT_SYMBOL(dev_change_carrier);
/**
* dev_get_phys_port_id - Get device physical port ID
* @dev: device
* @ppid: port ID
*
* Get device physical port ID
*/
int dev_get_phys_port_id(struct net_device *dev,
struct netdev_phys_item_id *ppid)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_get_phys_port_id)
return -EOPNOTSUPP;
return ops->ndo_get_phys_port_id(dev, ppid);
}
EXPORT_SYMBOL(dev_get_phys_port_id);
/**
* dev_get_phys_port_name - Get device physical port name
* @dev: device
* @name: port name
* @len: limit of bytes to copy to name
*
* Get device physical port name
*/
int dev_get_phys_port_name(struct net_device *dev,
char *name, size_t len)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_get_phys_port_name)
return -EOPNOTSUPP;
return ops->ndo_get_phys_port_name(dev, name, len);
}
EXPORT_SYMBOL(dev_get_phys_port_name);
/**
* dev_change_proto_down - update protocol port state information
* @dev: device
* @proto_down: new value
*
* This info can be used by switch drivers to set the phys state of the
* port.
*/
int dev_change_proto_down(struct net_device *dev, bool proto_down)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (!ops->ndo_change_proto_down)
return -EOPNOTSUPP;
if (!netif_device_present(dev))
return -ENODEV;
return ops->ndo_change_proto_down(dev, proto_down);
}
EXPORT_SYMBOL(dev_change_proto_down);
/**
* dev_change_xdp_fd - set or clear a bpf program for a device rx path
* @dev: device
* @fd: new program fd or negative value to clear
* @flags: xdp-related flags
*
* Set or clear a bpf program for a device
*/
int dev_change_xdp_fd(struct net_device *dev, int fd, u32 flags)
{
const struct net_device_ops *ops = dev->netdev_ops;
struct bpf_prog *prog = NULL;
struct netdev_xdp xdp;
int err;
ASSERT_RTNL();
if (!ops->ndo_xdp)
return -EOPNOTSUPP;
if (fd >= 0) {
if (flags & XDP_FLAGS_UPDATE_IF_NOEXIST) {
memset(&xdp, 0, sizeof(xdp));
xdp.command = XDP_QUERY_PROG;
err = ops->ndo_xdp(dev, &xdp);
if (err < 0)
return err;
if (xdp.prog_attached)
return -EBUSY;
}
prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP);
if (IS_ERR(prog))
return PTR_ERR(prog);
}
memset(&xdp, 0, sizeof(xdp));
xdp.command = XDP_SETUP_PROG;
xdp.prog = prog;
err = ops->ndo_xdp(dev, &xdp);
if (err < 0 && prog)
bpf_prog_put(prog);
return err;
}
EXPORT_SYMBOL(dev_change_xdp_fd);
/**
* dev_new_index - allocate an ifindex
* @net: the applicable net namespace
*
* Returns a suitable unique value for a new device interface
* number. The caller must hold the rtnl semaphore or the
* dev_base_lock to be sure it remains unique.
*/
static int dev_new_index(struct net *net)
{
int ifindex = net->ifindex;
for (;;) {
if (++ifindex <= 0)
ifindex = 1;
if (!__dev_get_by_index(net, ifindex))
return net->ifindex = ifindex;
}
}
/* Delayed registration/unregisteration */
static LIST_HEAD(net_todo_list);
DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
static void net_set_todo(struct net_device *dev)
{
list_add_tail(&dev->todo_list, &net_todo_list);
dev_net(dev)->dev_unreg_count++;
}
static void rollback_registered_many(struct list_head *head)
{
struct net_device *dev, *tmp;
LIST_HEAD(close_head);
BUG_ON(dev_boot_phase);
ASSERT_RTNL();
list_for_each_entry_safe(dev, tmp, head, unreg_list) {
/* Some devices call without registering
* for initialization unwind. Remove those
* devices and proceed with the remaining.
*/
if (dev->reg_state == NETREG_UNINITIALIZED) {
pr_debug("unregister_netdevice: device %s/%p never was registered\n",
dev->name, dev);
WARN_ON(1);
list_del(&dev->unreg_list);
continue;
}
dev->dismantle = true;
BUG_ON(dev->reg_state != NETREG_REGISTERED);
}
/* If device is running, close it first. */
list_for_each_entry(dev, head, unreg_list)
list_add_tail(&dev->close_list, &close_head);
dev_close_many(&close_head, true);
list_for_each_entry(dev, head, unreg_list) {
/* And unlink it from device chain. */
unlist_netdevice(dev);
dev->reg_state = NETREG_UNREGISTERING;
}
flush_all_backlogs();
synchronize_net();
list_for_each_entry(dev, head, unreg_list) {
struct sk_buff *skb = NULL;
/* Shutdown queueing discipline. */
dev_shutdown(dev);
/* Notify protocols, that we are about to destroy
* this device. They should clean all the things.
*/
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
if (!dev->rtnl_link_ops ||
dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U,
GFP_KERNEL);
/*
* Flush the unicast and multicast chains
*/
dev_uc_flush(dev);
dev_mc_flush(dev);
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
if (skb)
rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
/* Notifier chain MUST detach us all upper devices. */
WARN_ON(netdev_has_any_upper_dev(dev));
WARN_ON(netdev_has_any_lower_dev(dev));
/* Remove entries from kobject tree */
netdev_unregister_kobject(dev);
#ifdef CONFIG_XPS
/* Remove XPS queueing entries */
netif_reset_xps_queues_gt(dev, 0);
#endif
}
synchronize_net();
list_for_each_entry(dev, head, unreg_list)
dev_put(dev);
}
static void rollback_registered(struct net_device *dev)
{
LIST_HEAD(single);
list_add(&dev->unreg_list, &single);
rollback_registered_many(&single);
list_del(&single);
}
static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
struct net_device *upper, netdev_features_t features)
{
netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
netdev_features_t feature;
int feature_bit;
for_each_netdev_feature(&upper_disables, feature_bit) {
feature = __NETIF_F_BIT(feature_bit);
if (!(upper->wanted_features & feature)
&& (features & feature)) {
netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
&feature, upper->name);
features &= ~feature;
}
}
return features;
}
static void netdev_sync_lower_features(struct net_device *upper,
struct net_device *lower, netdev_features_t features)
{
netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
netdev_features_t feature;
int feature_bit;
for_each_netdev_feature(&upper_disables, feature_bit) {
feature = __NETIF_F_BIT(feature_bit);
if (!(features & feature) && (lower->features & feature)) {
netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
&feature, lower->name);
lower->wanted_features &= ~feature;
netdev_update_features(lower);
if (unlikely(lower->features & feature))
netdev_WARN(upper, "failed to disable %pNF on %s!\n",
&feature, lower->name);
}
}
}
static netdev_features_t netdev_fix_features(struct net_device *dev,
netdev_features_t features)
{
/* Fix illegal checksum combinations */
if ((features & NETIF_F_HW_CSUM) &&
(features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
netdev_warn(dev, "mixed HW and IP checksum settings.\n");
features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
}
/* TSO requires that SG is present as well. */
if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
features &= ~NETIF_F_ALL_TSO;
}
if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
!(features & NETIF_F_IP_CSUM)) {
netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
features &= ~NETIF_F_TSO;
features &= ~NETIF_F_TSO_ECN;
}
if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
!(features & NETIF_F_IPV6_CSUM)) {
netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
features &= ~NETIF_F_TSO6;
}
/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
features &= ~NETIF_F_TSO_MANGLEID;
/* TSO ECN requires that TSO is present as well. */
if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
features &= ~NETIF_F_TSO_ECN;
/* Software GSO depends on SG. */
if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
features &= ~NETIF_F_GSO;
}
/* UFO needs SG and checksumming */
if (features & NETIF_F_UFO) {
/* maybe split UFO into V4 and V6? */
if (!(features & NETIF_F_HW_CSUM) &&
((features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) !=
(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM))) {
netdev_dbg(dev,
"Dropping NETIF_F_UFO since no checksum offload features.\n");
features &= ~NETIF_F_UFO;
}
if (!(features & NETIF_F_SG)) {
netdev_dbg(dev,
"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
features &= ~NETIF_F_UFO;
}
}
/* GSO partial features require GSO partial be set */
if ((features & dev->gso_partial_features) &&
!(features & NETIF_F_GSO_PARTIAL)) {
netdev_dbg(dev,
"Dropping partially supported GSO features since no GSO partial.\n");
features &= ~dev->gso_partial_features;
}
return features;
}
int __netdev_update_features(struct net_device *dev)
{
struct net_device *upper, *lower;
netdev_features_t features;
struct list_head *iter;
int err = -1;
ASSERT_RTNL();
features = netdev_get_wanted_features(dev);
if (dev->netdev_ops->ndo_fix_features)
features = dev->netdev_ops->ndo_fix_features(dev, features);
/* driver might be less strict about feature dependencies */
features = netdev_fix_features(dev, features);
/* some features can't be enabled if they're off an an upper device */
netdev_for_each_upper_dev_rcu(dev, upper, iter)
features = netdev_sync_upper_features(dev, upper, features);
if (dev->features == features)
goto sync_lower;
netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
&dev->features, &features);
if (dev->netdev_ops->ndo_set_features)
err = dev->netdev_ops->ndo_set_features(dev, features);
else
err = 0;
if (unlikely(err < 0)) {
netdev_err(dev,
"set_features() failed (%d); wanted %pNF, left %pNF\n",
err, &features, &dev->features);
/* return non-0 since some features might have changed and
* it's better to fire a spurious notification than miss it
*/
return -1;
}
sync_lower:
/* some features must be disabled on lower devices when disabled
* on an upper device (think: bonding master or bridge)
*/
netdev_for_each_lower_dev(dev, lower, iter)
netdev_sync_lower_features(dev, lower, features);
if (!err)
dev->features = features;
return err < 0 ? 0 : 1;
}
/**
* netdev_update_features - recalculate device features
* @dev: the device to check
*
* Recalculate dev->features set and send notifications if it
* has changed. Should be called after driver or hardware dependent
* conditions might have changed that influence the features.
*/
void netdev_update_features(struct net_device *dev)
{
if (__netdev_update_features(dev))
netdev_features_change(dev);
}
EXPORT_SYMBOL(netdev_update_features);
/**
* netdev_change_features - recalculate device features
* @dev: the device to check
*
* Recalculate dev->features set and send notifications even
* if they have not changed. Should be called instead of
* netdev_update_features() if also dev->vlan_features might
* have changed to allow the changes to be propagated to stacked
* VLAN devices.
*/
void netdev_change_features(struct net_device *dev)
{
__netdev_update_features(dev);
netdev_features_change(dev);
}
EXPORT_SYMBOL(netdev_change_features);
/**
* netif_stacked_transfer_operstate - transfer operstate
* @rootdev: the root or lower level device to transfer state from
* @dev: the device to transfer operstate to
*
* Transfer operational state from root to device. This is normally
* called when a stacking relationship exists between the root
* device and the device(a leaf device).
*/
void netif_stacked_transfer_operstate(const struct net_device *rootdev,
struct net_device *dev)
{
if (rootdev->operstate == IF_OPER_DORMANT)
netif_dormant_on(dev);
else
netif_dormant_off(dev);
if (netif_carrier_ok(rootdev)) {
if (!netif_carrier_ok(dev))
netif_carrier_on(dev);
} else {
if (netif_carrier_ok(dev))
netif_carrier_off(dev);
}
}
EXPORT_SYMBOL(netif_stacked_transfer_operstate);
#ifdef CONFIG_SYSFS
static int netif_alloc_rx_queues(struct net_device *dev)
{
unsigned int i, count = dev->num_rx_queues;
struct netdev_rx_queue *rx;
size_t sz = count * sizeof(*rx);
BUG_ON(count < 1);
rx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
if (!rx) {
rx = vzalloc(sz);
if (!rx)
return -ENOMEM;
}
dev->_rx = rx;
for (i = 0; i < count; i++)
rx[i].dev = dev;
return 0;
}
#endif
static void netdev_init_one_queue(struct net_device *dev,
struct netdev_queue *queue, void *_unused)
{
/* Initialize queue lock */
spin_lock_init(&queue->_xmit_lock);
netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
queue->xmit_lock_owner = -1;
netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
queue->dev = dev;
#ifdef CONFIG_BQL
dql_init(&queue->dql, HZ);
#endif
}
static void netif_free_tx_queues(struct net_device *dev)
{
kvfree(dev->_tx);
}
static int netif_alloc_netdev_queues(struct net_device *dev)
{
unsigned int count = dev->num_tx_queues;
struct netdev_queue *tx;
size_t sz = count * sizeof(*tx);
if (count < 1 || count > 0xffff)
return -EINVAL;
tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
if (!tx) {
tx = vzalloc(sz);
if (!tx)
return -ENOMEM;
}
dev->_tx = tx;
netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
spin_lock_init(&dev->tx_global_lock);
return 0;
}
void netif_tx_stop_all_queues(struct net_device *dev)
{
unsigned int i;
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
netif_tx_stop_queue(txq);
}
}
EXPORT_SYMBOL(netif_tx_stop_all_queues);
/**
* register_netdevice - register a network device
* @dev: device to register
*
* Take a completed network device structure and add it to the kernel
* interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
* chain. 0 is returned on success. A negative errno code is returned
* on a failure to set up the device, or if the name is a duplicate.
*
* Callers must hold the rtnl semaphore. You may want
* register_netdev() instead of this.
*
* BUGS:
* The locking appears insufficient to guarantee two parallel registers
* will not get the same name.
*/
int register_netdevice(struct net_device *dev)
{
int ret;
struct net *net = dev_net(dev);
BUG_ON(dev_boot_phase);
ASSERT_RTNL();
might_sleep();
/* When net_device's are persistent, this will be fatal. */
BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
BUG_ON(!net);
spin_lock_init(&dev->addr_list_lock);
netdev_set_addr_lockdep_class(dev);
ret = dev_get_valid_name(net, dev, dev->name);
if (ret < 0)
goto out;
/* Init, if this function is available */
if (dev->netdev_ops->ndo_init) {
ret = dev->netdev_ops->ndo_init(dev);
if (ret) {
if (ret > 0)
ret = -EIO;
goto out;
}
}
if (((dev->hw_features | dev->features) &
NETIF_F_HW_VLAN_CTAG_FILTER) &&
(!dev->netdev_ops->ndo_vlan_rx_add_vid ||
!dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
ret = -EINVAL;
goto err_uninit;
}
ret = -EBUSY;
if (!dev->ifindex)
dev->ifindex = dev_new_index(net);
else if (__dev_get_by_index(net, dev->ifindex))
goto err_uninit;
/* Transfer changeable features to wanted_features and enable
* software offloads (GSO and GRO).
*/
dev->hw_features |= NETIF_F_SOFT_FEATURES;
dev->features |= NETIF_F_SOFT_FEATURES;
dev->wanted_features = dev->features & dev->hw_features;
if (!(dev->flags & IFF_LOOPBACK))
dev->hw_features |= NETIF_F_NOCACHE_COPY;
/* If IPv4 TCP segmentation offload is supported we should also
* allow the device to enable segmenting the frame with the option
* of ignoring a static IP ID value. This doesn't enable the
* feature itself but allows the user to enable it later.
*/
if (dev->hw_features & NETIF_F_TSO)
dev->hw_features |= NETIF_F_TSO_MANGLEID;
if (dev->vlan_features & NETIF_F_TSO)
dev->vlan_features |= NETIF_F_TSO_MANGLEID;
if (dev->mpls_features & NETIF_F_TSO)
dev->mpls_features |= NETIF_F_TSO_MANGLEID;
if (dev->hw_enc_features & NETIF_F_TSO)
dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
*/
dev->vlan_features |= NETIF_F_HIGHDMA;
/* Make NETIF_F_SG inheritable to tunnel devices.
*/
dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
/* Make NETIF_F_SG inheritable to MPLS.
*/
dev->mpls_features |= NETIF_F_SG;
ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
ret = notifier_to_errno(ret);
if (ret)
goto err_uninit;
ret = netdev_register_kobject(dev);
if (ret)
goto err_uninit;
dev->reg_state = NETREG_REGISTERED;
__netdev_update_features(dev);
/*
* Default initial state at registry is that the
* device is present.
*/
set_bit(__LINK_STATE_PRESENT, &dev->state);
linkwatch_init_dev(dev);
dev_init_scheduler(dev);
dev_hold(dev);
list_netdevice(dev);
add_device_randomness(dev->dev_addr, dev->addr_len);
/* If the device has permanent device address, driver should
* set dev_addr and also addr_assign_type should be set to
* NET_ADDR_PERM (default value).
*/
if (dev->addr_assign_type == NET_ADDR_PERM)
memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
/* Notify protocols, that a new device appeared. */
ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
ret = notifier_to_errno(ret);
if (ret) {
rollback_registered(dev);
dev->reg_state = NETREG_UNREGISTERED;
}
/*
* Prevent userspace races by waiting until the network
* device is fully setup before sending notifications.
*/
if (!dev->rtnl_link_ops ||
dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
out:
return ret;
err_uninit:
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
goto out;
}
EXPORT_SYMBOL(register_netdevice);
/**
* init_dummy_netdev - init a dummy network device for NAPI
* @dev: device to init
*
* This takes a network device structure and initialize the minimum
* amount of fields so it can be used to schedule NAPI polls without
* registering a full blown interface. This is to be used by drivers
* that need to tie several hardware interfaces to a single NAPI
* poll scheduler due to HW limitations.
*/
int init_dummy_netdev(struct net_device *dev)
{
/* Clear everything. Note we don't initialize spinlocks
* are they aren't supposed to be taken by any of the
* NAPI code and this dummy netdev is supposed to be
* only ever used for NAPI polls
*/
memset(dev, 0, sizeof(struct net_device));
/* make sure we BUG if trying to hit standard
* register/unregister code path
*/
dev->reg_state = NETREG_DUMMY;
/* NAPI wants this */
INIT_LIST_HEAD(&dev->napi_list);
/* a dummy interface is started by default */
set_bit(__LINK_STATE_PRESENT, &dev->state);
set_bit(__LINK_STATE_START, &dev->state);
/* Note : We dont allocate pcpu_refcnt for dummy devices,
* because users of this 'device' dont need to change
* its refcount.
*/
return 0;
}
EXPORT_SYMBOL_GPL(init_dummy_netdev);
/**
* register_netdev - register a network device
* @dev: device to register
*
* Take a completed network device structure and add it to the kernel
* interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
* chain. 0 is returned on success. A negative errno code is returned
* on a failure to set up the device, or if the name is a duplicate.
*
* This is a wrapper around register_netdevice that takes the rtnl semaphore
* and expands the device name if you passed a format string to
* alloc_netdev.
*/
int register_netdev(struct net_device *dev)
{
int err;
rtnl_lock();
err = register_netdevice(dev);
rtnl_unlock();
return err;
}
EXPORT_SYMBOL(register_netdev);
int netdev_refcnt_read(const struct net_device *dev)
{
int i, refcnt = 0;
for_each_possible_cpu(i)
refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
return refcnt;
}
EXPORT_SYMBOL(netdev_refcnt_read);
/**
* netdev_wait_allrefs - wait until all references are gone.
* @dev: target net_device
*
* This is called when unregistering network devices.
*
* Any protocol or device that holds a reference should register
* for netdevice notification, and cleanup and put back the
* reference if they receive an UNREGISTER event.
* We can get stuck here if buggy protocols don't correctly
* call dev_put.
*/
static void netdev_wait_allrefs(struct net_device *dev)
{
unsigned long rebroadcast_time, warning_time;
int refcnt;
linkwatch_forget_dev(dev);
rebroadcast_time = warning_time = jiffies;
refcnt = netdev_refcnt_read(dev);
while (refcnt != 0) {
if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
rtnl_lock();
/* Rebroadcast unregister notification */
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
__rtnl_unlock();
rcu_barrier();
rtnl_lock();
call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
&dev->state)) {
/* We must not have linkwatch events
* pending on unregister. If this
* happens, we simply run the queue
* unscheduled, resulting in a noop
* for this device.
*/
linkwatch_run_queue();
}
__rtnl_unlock();
rebroadcast_time = jiffies;
}
msleep(250);
refcnt = netdev_refcnt_read(dev);
if (time_after(jiffies, warning_time + 10 * HZ)) {
pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
dev->name, refcnt);
warning_time = jiffies;
}
}
}
/* The sequence is:
*
* rtnl_lock();
* ...
* register_netdevice(x1);
* register_netdevice(x2);
* ...
* unregister_netdevice(y1);
* unregister_netdevice(y2);
* ...
* rtnl_unlock();
* free_netdev(y1);
* free_netdev(y2);
*
* We are invoked by rtnl_unlock().
* This allows us to deal with problems:
* 1) We can delete sysfs objects which invoke hotplug
* without deadlocking with linkwatch via keventd.
* 2) Since we run with the RTNL semaphore not held, we can sleep
* safely in order to wait for the netdev refcnt to drop to zero.
*
* We must not return until all unregister events added during
* the interval the lock was held have been completed.
*/
void netdev_run_todo(void)
{
struct list_head list;
/* Snapshot list, allow later requests */
list_replace_init(&net_todo_list, &list);
__rtnl_unlock();
/* Wait for rcu callbacks to finish before next phase */
if (!list_empty(&list))
rcu_barrier();
while (!list_empty(&list)) {
struct net_device *dev
= list_first_entry(&list, struct net_device, todo_list);
list_del(&dev->todo_list);
rtnl_lock();
call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
__rtnl_unlock();
if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
pr_err("network todo '%s' but state %d\n",
dev->name, dev->reg_state);
dump_stack();
continue;
}
dev->reg_state = NETREG_UNREGISTERED;
netdev_wait_allrefs(dev);
/* paranoia */
BUG_ON(netdev_refcnt_read(dev));
BUG_ON(!list_empty(&dev->ptype_all));
BUG_ON(!list_empty(&dev->ptype_specific));
WARN_ON(rcu_access_pointer(dev->ip_ptr));
WARN_ON(rcu_access_pointer(dev->ip6_ptr));
WARN_ON(dev->dn_ptr);
if (dev->destructor)
dev->destructor(dev);
/* Report a network device has been unregistered */
rtnl_lock();
dev_net(dev)->dev_unreg_count--;
__rtnl_unlock();
wake_up(&netdev_unregistering_wq);
/* Free network device */
kobject_put(&dev->dev.kobj);
}
}
/* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
* all the same fields in the same order as net_device_stats, with only
* the type differing, but rtnl_link_stats64 may have additional fields
* at the end for newer counters.
*/
void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
const struct net_device_stats *netdev_stats)
{
#if BITS_PER_LONG == 64
BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats));
memcpy(stats64, netdev_stats, sizeof(*stats64));
/* zero out counters that only exist in rtnl_link_stats64 */
memset((char *)stats64 + sizeof(*netdev_stats), 0,
sizeof(*stats64) - sizeof(*netdev_stats));
#else
size_t i, n = sizeof(*netdev_stats) / sizeof(unsigned long);
const unsigned long *src = (const unsigned long *)netdev_stats;
u64 *dst = (u64 *)stats64;
BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
for (i = 0; i < n; i++)
dst[i] = src[i];
/* zero out counters that only exist in rtnl_link_stats64 */
memset((char *)stats64 + n * sizeof(u64), 0,
sizeof(*stats64) - n * sizeof(u64));
#endif
}
EXPORT_SYMBOL(netdev_stats_to_stats64);
/**
* dev_get_stats - get network device statistics
* @dev: device to get statistics from
* @storage: place to store stats
*
* Get network statistics from device. Return @storage.
* The device driver may provide its own method by setting
* dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
* otherwise the internal statistics structure is used.
*/
struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
struct rtnl_link_stats64 *storage)
{
const struct net_device_ops *ops = dev->netdev_ops;
if (ops->ndo_get_stats64) {
memset(storage, 0, sizeof(*storage));
ops->ndo_get_stats64(dev, storage);
} else if (ops->ndo_get_stats) {
netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
} else {
netdev_stats_to_stats64(storage, &dev->stats);
}
storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
storage->tx_dropped += atomic_long_read(&dev->tx_dropped);
storage->rx_nohandler += atomic_long_read(&dev->rx_nohandler);
return storage;
}
EXPORT_SYMBOL(dev_get_stats);
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
{
struct netdev_queue *queue = dev_ingress_queue(dev);
#ifdef CONFIG_NET_CLS_ACT
if (queue)
return queue;
queue = kzalloc(sizeof(*queue), GFP_KERNEL);
if (!queue)
return NULL;
netdev_init_one_queue(dev, queue, NULL);
RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
queue->qdisc_sleeping = &noop_qdisc;
rcu_assign_pointer(dev->ingress_queue, queue);
#endif
return queue;
}
static const struct ethtool_ops default_ethtool_ops;
void netdev_set_default_ethtool_ops(struct net_device *dev,
const struct ethtool_ops *ops)
{
if (dev->ethtool_ops == &default_ethtool_ops)
dev->ethtool_ops = ops;
}
EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
void netdev_freemem(struct net_device *dev)
{
char *addr = (char *)dev - dev->padded;
kvfree(addr);
}
/**
* alloc_netdev_mqs - allocate network device
* @sizeof_priv: size of private data to allocate space for
* @name: device name format string
* @name_assign_type: origin of device name
* @setup: callback to initialize device
* @txqs: the number of TX subqueues to allocate
* @rxqs: the number of RX subqueues to allocate
*
* Allocates a struct net_device with private data area for driver use
* and performs basic initialization. Also allocates subqueue structs
* for each queue on the device.
*/
struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
unsigned char name_assign_type,
void (*setup)(struct net_device *),
unsigned int txqs, unsigned int rxqs)
{
struct net_device *dev;
size_t alloc_size;
struct net_device *p;
BUG_ON(strlen(name) >= sizeof(dev->name));
if (txqs < 1) {
pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
return NULL;
}
#ifdef CONFIG_SYSFS
if (rxqs < 1) {
pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
return NULL;
}
#endif
alloc_size = sizeof(struct net_device);
if (sizeof_priv) {
/* ensure 32-byte alignment of private area */
alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
alloc_size += sizeof_priv;
}
/* ensure 32-byte alignment of whole construct */
alloc_size += NETDEV_ALIGN - 1;
p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
if (!p)
p = vzalloc(alloc_size);
if (!p)
return NULL;
dev = PTR_ALIGN(p, NETDEV_ALIGN);
dev->padded = (char *)dev - (char *)p;
dev->pcpu_refcnt = alloc_percpu(int);
if (!dev->pcpu_refcnt)
goto free_dev;
if (dev_addr_init(dev))
goto free_pcpu;
dev_mc_init(dev);
dev_uc_init(dev);
dev_net_set(dev, &init_net);
dev->gso_max_size = GSO_MAX_SIZE;
dev->gso_max_segs = GSO_MAX_SEGS;
INIT_LIST_HEAD(&dev->napi_list);
INIT_LIST_HEAD(&dev->unreg_list);
INIT_LIST_HEAD(&dev->close_list);
INIT_LIST_HEAD(&dev->link_watch_list);
INIT_LIST_HEAD(&dev->adj_list.upper);
INIT_LIST_HEAD(&dev->adj_list.lower);
INIT_LIST_HEAD(&dev->ptype_all);
INIT_LIST_HEAD(&dev->ptype_specific);
#ifdef CONFIG_NET_SCHED
hash_init(dev->qdisc_hash);
#endif
dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
setup(dev);
if (!dev->tx_queue_len) {
dev->priv_flags |= IFF_NO_QUEUE;
dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
}
dev->num_tx_queues = txqs;
dev->real_num_tx_queues = txqs;
if (netif_alloc_netdev_queues(dev))
goto free_all;
#ifdef CONFIG_SYSFS
dev->num_rx_queues = rxqs;
dev->real_num_rx_queues = rxqs;
if (netif_alloc_rx_queues(dev))
goto free_all;
#endif
strcpy(dev->name, name);
dev->name_assign_type = name_assign_type;
dev->group = INIT_NETDEV_GROUP;
if (!dev->ethtool_ops)
dev->ethtool_ops = &default_ethtool_ops;
nf_hook_ingress_init(dev);
return dev;
free_all:
free_netdev(dev);
return NULL;
free_pcpu:
free_percpu(dev->pcpu_refcnt);
free_dev:
netdev_freemem(dev);
return NULL;
}
EXPORT_SYMBOL(alloc_netdev_mqs);
/**
* free_netdev - free network device
* @dev: device
*
* This function does the last stage of destroying an allocated device
* interface. The reference to the device object is released. If this
* is the last reference then it will be freed.Must be called in process
* context.
*/
void free_netdev(struct net_device *dev)
{
struct napi_struct *p, *n;
might_sleep();
netif_free_tx_queues(dev);
#ifdef CONFIG_SYSFS
kvfree(dev->_rx);
#endif
kfree(rcu_dereference_protected(dev->ingress_queue, 1));
/* Flush device addresses */
dev_addr_flush(dev);
list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
netif_napi_del(p);
free_percpu(dev->pcpu_refcnt);
dev->pcpu_refcnt = NULL;
/* Compatibility with error handling in drivers */
if (dev->reg_state == NETREG_UNINITIALIZED) {
netdev_freemem(dev);
return;
}
BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
dev->reg_state = NETREG_RELEASED;
/* will free via device release */
put_device(&dev->dev);
}
EXPORT_SYMBOL(free_netdev);
/**
* synchronize_net - Synchronize with packet receive processing
*
* Wait for packets currently being received to be done.
* Does not block later packets from starting.
*/
void synchronize_net(void)
{
might_sleep();
if (rtnl_is_locked())
synchronize_rcu_expedited();
else
synchronize_rcu();
}
EXPORT_SYMBOL(synchronize_net);
/**
* unregister_netdevice_queue - remove device from the kernel
* @dev: device
* @head: list
*
* This function shuts down a device interface and removes it
* from the kernel tables.
* If head not NULL, device is queued to be unregistered later.
*
* Callers must hold the rtnl semaphore. You may want
* unregister_netdev() instead of this.
*/
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
{
ASSERT_RTNL();
if (head) {
list_move_tail(&dev->unreg_list, head);
} else {
rollback_registered(dev);
/* Finish processing unregister after unlock */
net_set_todo(dev);
}
}
EXPORT_SYMBOL(unregister_netdevice_queue);
/**
* unregister_netdevice_many - unregister many devices
* @head: list of devices
*
* Note: As most callers use a stack allocated list_head,
* we force a list_del() to make sure stack wont be corrupted later.
*/
void unregister_netdevice_many(struct list_head *head)
{
struct net_device *dev;
if (!list_empty(head)) {
rollback_registered_many(head);
list_for_each_entry(dev, head, unreg_list)
net_set_todo(dev);
list_del(head);
}
}
EXPORT_SYMBOL(unregister_netdevice_many);
/**
* unregister_netdev - remove device from the kernel
* @dev: device
*
* This function shuts down a device interface and removes it
* from the kernel tables.
*
* This is just a wrapper for unregister_netdevice that takes
* the rtnl semaphore. In general you want to use this and not
* unregister_netdevice.
*/
void unregister_netdev(struct net_device *dev)
{
rtnl_lock();
unregister_netdevice(dev);
rtnl_unlock();
}
EXPORT_SYMBOL(unregister_netdev);
/**
* dev_change_net_namespace - move device to different nethost namespace
* @dev: device
* @net: network namespace
* @pat: If not NULL name pattern to try if the current device name
* is already taken in the destination network namespace.
*
* This function shuts down a device interface and moves it
* to a new network namespace. On success 0 is returned, on
* a failure a netagive errno code is returned.
*
* Callers must hold the rtnl semaphore.
*/
int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
{
int err;
ASSERT_RTNL();
/* Don't allow namespace local devices to be moved. */
err = -EINVAL;
if (dev->features & NETIF_F_NETNS_LOCAL)
goto out;
/* Ensure the device has been registrered */
if (dev->reg_state != NETREG_REGISTERED)
goto out;
/* Get out if there is nothing todo */
err = 0;
if (net_eq(dev_net(dev), net))
goto out;
/* Pick the destination device name, and ensure
* we can use it in the destination network namespace.
*/
err = -EEXIST;
if (__dev_get_by_name(net, dev->name)) {
/* We get here if we can't use the current device name */
if (!pat)
goto out;
if (dev_get_valid_name(net, dev, pat) < 0)
goto out;
}
/*
* And now a mini version of register_netdevice unregister_netdevice.
*/
/* If device is running close it first. */
dev_close(dev);
/* And unlink it from device chain */
err = -ENODEV;
unlist_netdevice(dev);
synchronize_net();
/* Shutdown queueing discipline. */
dev_shutdown(dev);
/* Notify protocols, that we are about to destroy
* this device. They should clean all the things.
*
* Note that dev->reg_state stays at NETREG_REGISTERED.
* This is wanted because this way 8021q and macvlan know
* the device is just moving and can keep their slaves up.
*/
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
rcu_barrier();
call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
/*
* Flush the unicast and multicast chains
*/
dev_uc_flush(dev);
dev_mc_flush(dev);
/* Send a netdev-removed uevent to the old namespace */
kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
netdev_adjacent_del_links(dev);
/* Actually switch the network namespace */
dev_net_set(dev, net);
/* If there is an ifindex conflict assign a new one */
if (__dev_get_by_index(net, dev->ifindex))
dev->ifindex = dev_new_index(net);
/* Send a netdev-add uevent to the new namespace */
kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
netdev_adjacent_add_links(dev);
/* Fixup kobjects */
err = device_rename(&dev->dev, dev->name);
WARN_ON(err);
/* Add the device back in the hashes */
list_netdevice(dev);
/* Notify protocols, that a new device appeared. */
call_netdevice_notifiers(NETDEV_REGISTER, dev);
/*
* Prevent userspace races by waiting until the network
* device is fully setup before sending notifications.
*/
rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
synchronize_net();
err = 0;
out:
return err;
}
EXPORT_SYMBOL_GPL(dev_change_net_namespace);
static int dev_cpu_dead(unsigned int oldcpu)
{
struct sk_buff **list_skb;
struct sk_buff *skb;
unsigned int cpu;
struct softnet_data *sd, *oldsd;
local_irq_disable();
cpu = smp_processor_id();
sd = &per_cpu(softnet_data, cpu);
oldsd = &per_cpu(softnet_data, oldcpu);
/* Find end of our completion_queue. */
list_skb = &sd->completion_queue;
while (*list_skb)
list_skb = &(*list_skb)->next;
/* Append completion queue from offline CPU. */
*list_skb = oldsd->completion_queue;
oldsd->completion_queue = NULL;
/* Append output queue from offline CPU. */
if (oldsd->output_queue) {
*sd->output_queue_tailp = oldsd->output_queue;
sd->output_queue_tailp = oldsd->output_queue_tailp;
oldsd->output_queue = NULL;
oldsd->output_queue_tailp = &oldsd->output_queue;
}
/* Append NAPI poll list from offline CPU, with one exception :
* process_backlog() must be called by cpu owning percpu backlog.
* We properly handle process_queue & input_pkt_queue later.
*/
while (!list_empty(&oldsd->poll_list)) {
struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
struct napi_struct,
poll_list);
list_del_init(&napi->poll_list);
if (napi->poll == process_backlog)
napi->state = 0;
else
____napi_schedule(sd, napi);
}
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_enable();
/* Process offline CPU's input_pkt_queue */
while ((skb = __skb_dequeue(&oldsd->process_queue))) {
netif_rx_ni(skb);
input_queue_head_incr(oldsd);
}
while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
netif_rx_ni(skb);
input_queue_head_incr(oldsd);
}
return 0;
}
/**
* netdev_increment_features - increment feature set by one
* @all: current feature set
* @one: new feature set
* @mask: mask feature set
*
* Computes a new feature set after adding a device with feature set
* @one to the master device with current feature set @all. Will not
* enable anything that is off in @mask. Returns the new feature set.
*/
netdev_features_t netdev_increment_features(netdev_features_t all,
netdev_features_t one, netdev_features_t mask)
{
if (mask & NETIF_F_HW_CSUM)
mask |= NETIF_F_CSUM_MASK;
mask |= NETIF_F_VLAN_CHALLENGED;
all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
all &= one | ~NETIF_F_ALL_FOR_ALL;
/* If one device supports hw checksumming, set for all. */
if (all & NETIF_F_HW_CSUM)
all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
return all;
}
EXPORT_SYMBOL(netdev_increment_features);
static struct hlist_head * __net_init netdev_create_hash(void)
{
int i;
struct hlist_head *hash;
hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
if (hash != NULL)
for (i = 0; i < NETDEV_HASHENTRIES; i++)
INIT_HLIST_HEAD(&hash[i]);
return hash;
}
/* Initialize per network namespace state */
static int __net_init netdev_init(struct net *net)
{
if (net != &init_net)
INIT_LIST_HEAD(&net->dev_base_head);
net->dev_name_head = netdev_create_hash();
if (net->dev_name_head == NULL)
goto err_name;
net->dev_index_head = netdev_create_hash();
if (net->dev_index_head == NULL)
goto err_idx;
return 0;
err_idx:
kfree(net->dev_name_head);
err_name:
return -ENOMEM;
}
/**
* netdev_drivername - network driver for the device
* @dev: network device
*
* Determine network driver for device.
*/
const char *netdev_drivername(const struct net_device *dev)
{
const struct device_driver *driver;
const struct device *parent;
const char *empty = "";
parent = dev->dev.parent;
if (!parent)
return empty;
driver = parent->driver;
if (driver && driver->name)
return driver->name;
return empty;
}
static void __netdev_printk(const char *level, const struct net_device *dev,
struct va_format *vaf)
{
if (dev && dev->dev.parent) {
dev_printk_emit(level[1] - '0',
dev->dev.parent,
"%s %s %s%s: %pV",
dev_driver_string(dev->dev.parent),
dev_name(dev->dev.parent),
netdev_name(dev), netdev_reg_state(dev),
vaf);
} else if (dev) {
printk("%s%s%s: %pV",
level, netdev_name(dev), netdev_reg_state(dev), vaf);
} else {
printk("%s(NULL net_device): %pV", level, vaf);
}
}
void netdev_printk(const char *level, const struct net_device *dev,
const char *format, ...)
{
struct va_format vaf;
va_list args;
va_start(args, format);
vaf.fmt = format;
vaf.va = &args;
__netdev_printk(level, dev, &vaf);
va_end(args);
}
EXPORT_SYMBOL(netdev_printk);
#define define_netdev_printk_level(func, level) \
void func(const struct net_device *dev, const char *fmt, ...) \
{ \
struct va_format vaf; \
va_list args; \
\
va_start(args, fmt); \
\
vaf.fmt = fmt; \
vaf.va = &args; \
\
__netdev_printk(level, dev, &vaf); \
\
va_end(args); \
} \
EXPORT_SYMBOL(func);
define_netdev_printk_level(netdev_emerg, KERN_EMERG);
define_netdev_printk_level(netdev_alert, KERN_ALERT);
define_netdev_printk_level(netdev_crit, KERN_CRIT);
define_netdev_printk_level(netdev_err, KERN_ERR);
define_netdev_printk_level(netdev_warn, KERN_WARNING);
define_netdev_printk_level(netdev_notice, KERN_NOTICE);
define_netdev_printk_level(netdev_info, KERN_INFO);
static void __net_exit netdev_exit(struct net *net)
{
kfree(net->dev_name_head);
kfree(net->dev_index_head);
}
static struct pernet_operations __net_initdata netdev_net_ops = {
.init = netdev_init,
.exit = netdev_exit,
};
static void __net_exit default_device_exit(struct net *net)
{
struct net_device *dev, *aux;
/*
* Push all migratable network devices back to the
* initial network namespace
*/
rtnl_lock();
for_each_netdev_safe(net, dev, aux) {
int err;
char fb_name[IFNAMSIZ];
/* Ignore unmoveable devices (i.e. loopback) */
if (dev->features & NETIF_F_NETNS_LOCAL)
continue;
/* Leave virtual devices for the generic cleanup */
if (dev->rtnl_link_ops)
continue;
/* Push remaining network devices to init_net */
snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
err = dev_change_net_namespace(dev, &init_net, fb_name);
if (err) {
pr_emerg("%s: failed to move %s to init_net: %d\n",
__func__, dev->name, err);
BUG();
}
}
rtnl_unlock();
}
static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
{
/* Return with the rtnl_lock held when there are no network
* devices unregistering in any network namespace in net_list.
*/
struct net *net;
bool unregistering;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
add_wait_queue(&netdev_unregistering_wq, &wait);
for (;;) {
unregistering = false;
rtnl_lock();
list_for_each_entry(net, net_list, exit_list) {
if (net->dev_unreg_count > 0) {
unregistering = true;
break;
}
}
if (!unregistering)
break;
__rtnl_unlock();
wait_woken(&wait, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
}
remove_wait_queue(&netdev_unregistering_wq, &wait);
}
static void __net_exit default_device_exit_batch(struct list_head *net_list)
{
/* At exit all network devices most be removed from a network
* namespace. Do this in the reverse order of registration.
* Do this across as many network namespaces as possible to
* improve batching efficiency.
*/
struct net_device *dev;
struct net *net;
LIST_HEAD(dev_kill_list);
/* To prevent network device cleanup code from dereferencing
* loopback devices or network devices that have been freed
* wait here for all pending unregistrations to complete,
* before unregistring the loopback device and allowing the
* network namespace be freed.
*
* The netdev todo list containing all network devices
* unregistrations that happen in default_device_exit_batch
* will run in the rtnl_unlock() at the end of
* default_device_exit_batch.
*/
rtnl_lock_unregistering(net_list);
list_for_each_entry(net, net_list, exit_list) {
for_each_netdev_reverse(net, dev) {
if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
else
unregister_netdevice_queue(dev, &dev_kill_list);
}
}
unregister_netdevice_many(&dev_kill_list);
rtnl_unlock();
}
static struct pernet_operations __net_initdata default_device_ops = {
.exit = default_device_exit,
.exit_batch = default_device_exit_batch,
};
/*
* Initialize the DEV module. At boot time this walks the device list and
* unhooks any devices that fail to initialise (normally hardware not
* present) and leaves us with a valid list of present and active devices.
*
*/
/*
* This is called single threaded during boot, so no need
* to take the rtnl semaphore.
*/
static int __init net_dev_init(void)
{
int i, rc = -ENOMEM;
BUG_ON(!dev_boot_phase);
if (dev_proc_init())
goto out;
if (netdev_kobject_init())
goto out;
INIT_LIST_HEAD(&ptype_all);
for (i = 0; i < PTYPE_HASH_SIZE; i++)
INIT_LIST_HEAD(&ptype_base[i]);
INIT_LIST_HEAD(&offload_base);
if (register_pernet_subsys(&netdev_net_ops))
goto out;
/*
* Initialise the packet receive queues.
*/
for_each_possible_cpu(i) {
struct work_struct *flush = per_cpu_ptr(&flush_works, i);
struct softnet_data *sd = &per_cpu(softnet_data, i);
INIT_WORK(flush, flush_backlog);
skb_queue_head_init(&sd->input_pkt_queue);
skb_queue_head_init(&sd->process_queue);
INIT_LIST_HEAD(&sd->poll_list);
sd->output_queue_tailp = &sd->output_queue;
#ifdef CONFIG_RPS
sd->csd.func = rps_trigger_softirq;
sd->csd.info = sd;
sd->cpu = i;
#endif
sd->backlog.poll = process_backlog;
sd->backlog.weight = weight_p;
}
dev_boot_phase = 0;
/* The loopback device is special if any other network devices
* is present in a network namespace the loopback device must
* be present. Since we now dynamically allocate and free the
* loopback device ensure this invariant is maintained by
* keeping the loopback device as the first device on the
* list of network devices. Ensuring the loopback devices
* is the first device that appears and the last network device
* that disappears.
*/
if (register_pernet_device(&loopback_net_ops))
goto out;
if (register_pernet_device(&default_device_ops))
goto out;
open_softirq(NET_TX_SOFTIRQ, net_tx_action);
open_softirq(NET_RX_SOFTIRQ, net_rx_action);
rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
NULL, dev_cpu_dead);
WARN_ON(rc < 0);
dst_subsys_init();
rc = 0;
out:
return rc;
}
subsys_initcall(net_dev_init);