[NET]: Supporting UDP-Lite (RFC 3828) in Linux
This is a revision of the previously submitted patch, which alters
the way files are organized and compiled in the following manner:
* UDP and UDP-Lite now use separate object files
* source file dependencies resolved via header files
net/ipv{4,6}/udp_impl.h
* order of inclusion files in udp.c/udplite.c adapted
accordingly
[NET/IPv4]: Support for the UDP-Lite protocol (RFC 3828)
This patch adds support for UDP-Lite to the IPv4 stack, provided as an
extension to the existing UDPv4 code:
* generic routines are all located in net/ipv4/udp.c
* UDP-Lite specific routines are in net/ipv4/udplite.c
* MIB/statistics support in /proc/net/snmp and /proc/net/udplite
* shared API with extensions for partial checksum coverage
[NET/IPv6]: Extension for UDP-Lite over IPv6
It extends the existing UDPv6 code base with support for UDP-Lite
in the same manner as per UDPv4. In particular,
* UDPv6 generic and shared code is in net/ipv6/udp.c
* UDP-Litev6 specific extensions are in net/ipv6/udplite.c
* MIB/statistics support in /proc/net/snmp6 and /proc/net/udplite6
* support for IPV6_ADDRFORM
* aligned the coding style of protocol initialisation with af_inet6.c
* made the error handling in udpv6_queue_rcv_skb consistent;
to return `-1' on error on all error cases
* consolidation of shared code
[NET]: UDP-Lite Documentation and basic XFRM/Netfilter support
The UDP-Lite patch further provides
* API documentation for UDP-Lite
* basic xfrm support
* basic netfilter support for IPv4 and IPv6 (LOG target)
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 9e1bd37..98ba750 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -92,22 +92,16 @@
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
-#include <linux/ipv6.h>
#include <linux/netdevice.h>
-#include <net/snmp.h>
-#include <net/ip.h>
#include <net/tcp_states.h>
-#include <net/protocol.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
-#include <net/sock.h>
-#include <net/udp.h>
#include <net/icmp.h>
#include <net/route.h>
-#include <net/inet_common.h>
#include <net/checksum.h>
#include <net/xfrm.h>
+#include "udp_impl.h"
/*
* Snmp MIB for the UDP layer
@@ -120,26 +114,30 @@
static int udp_port_rover;
-static inline int udp_lport_inuse(u16 num)
+static inline int __udp_lib_lport_inuse(__be16 num, struct hlist_head udptable[])
{
struct sock *sk;
struct hlist_node *node;
- sk_for_each(sk, node, &udp_hash[num & (UDP_HTABLE_SIZE - 1)])
+ sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)])
if (inet_sk(sk)->num == num)
return 1;
return 0;
}
/**
- * udp_get_port - common port lookup for IPv4 and IPv6
+ * __udp_lib_get_port - UDP/-Lite port lookup for IPv4 and IPv6
*
* @sk: socket struct in question
* @snum: port number to look up
+ * @udptable: hash list table, must be of UDP_HTABLE_SIZE
+ * @port_rover: pointer to record of last unallocated port
* @saddr_comp: AF-dependent comparison of bound local IP addresses
*/
-int udp_get_port(struct sock *sk, unsigned short snum,
- int (*saddr_cmp)(const struct sock *sk1, const struct sock *sk2))
+int __udp_lib_get_port(struct sock *sk, unsigned short snum,
+ struct hlist_head udptable[], int *port_rover,
+ int (*saddr_comp)(const struct sock *sk1,
+ const struct sock *sk2 ) )
{
struct hlist_node *node;
struct hlist_head *head;
@@ -150,15 +148,15 @@
if (snum == 0) {
int best_size_so_far, best, result, i;
- if (udp_port_rover > sysctl_local_port_range[1] ||
- udp_port_rover < sysctl_local_port_range[0])
- udp_port_rover = sysctl_local_port_range[0];
+ if (*port_rover > sysctl_local_port_range[1] ||
+ *port_rover < sysctl_local_port_range[0])
+ *port_rover = sysctl_local_port_range[0];
best_size_so_far = 32767;
- best = result = udp_port_rover;
+ best = result = *port_rover;
for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
int size;
- head = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
+ head = &udptable[result & (UDP_HTABLE_SIZE - 1)];
if (hlist_empty(head)) {
if (result > sysctl_local_port_range[1])
result = sysctl_local_port_range[0] +
@@ -179,15 +177,15 @@
result = sysctl_local_port_range[0]
+ ((result - sysctl_local_port_range[0]) &
(UDP_HTABLE_SIZE - 1));
- if (!udp_lport_inuse(result))
+ if (! __udp_lib_lport_inuse(result, udptable))
break;
}
if (i >= (1 << 16) / UDP_HTABLE_SIZE)
goto fail;
gotit:
- udp_port_rover = snum = result;
+ *port_rover = snum = result;
} else {
- head = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
+ head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
sk_for_each(sk2, node, head)
if (inet_sk(sk2)->num == snum &&
@@ -195,12 +193,12 @@
(!sk2->sk_reuse || !sk->sk_reuse) &&
(!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
|| sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
- (*saddr_cmp)(sk, sk2) )
+ (*saddr_comp)(sk, sk2) )
goto fail;
}
inet_sk(sk)->num = snum;
if (sk_unhashed(sk)) {
- head = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
+ head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
sk_add_node(sk, head);
sock_prot_inc_use(sk->sk_prot);
}
@@ -210,7 +208,13 @@
return error;
}
-static inline int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
+__inline__ int udp_get_port(struct sock *sk, unsigned short snum,
+ int (*scmp)(const struct sock *, const struct sock *))
+{
+ return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, scmp);
+}
+
+inline int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
{
struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
@@ -224,34 +228,20 @@
return udp_get_port(sk, snum, ipv4_rcv_saddr_equal);
}
-
-static void udp_v4_hash(struct sock *sk)
-{
- BUG();
-}
-
-static void udp_v4_unhash(struct sock *sk)
-{
- write_lock_bh(&udp_hash_lock);
- if (sk_del_node_init(sk)) {
- inet_sk(sk)->num = 0;
- sock_prot_dec_use(sk->sk_prot);
- }
- write_unlock_bh(&udp_hash_lock);
-}
-
/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
* harder than this. -DaveM
*/
-static struct sock *udp_v4_lookup_longway(__be32 saddr, __be16 sport,
- __be32 daddr, __be16 dport, int dif)
+static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
+ __be32 daddr, __be16 dport,
+ int dif, struct hlist_head udptable[])
{
struct sock *sk, *result = NULL;
struct hlist_node *node;
unsigned short hnum = ntohs(dport);
int badness = -1;
- sk_for_each(sk, node, &udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]) {
+ read_lock(&udp_hash_lock);
+ sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
struct inet_sock *inet = inet_sk(sk);
if (inet->num == hnum && !ipv6_only_sock(sk)) {
@@ -285,20 +275,10 @@
}
}
}
- return result;
-}
-
-static __inline__ struct sock *udp_v4_lookup(__be32 saddr, __be16 sport,
- __be32 daddr, __be16 dport, int dif)
-{
- struct sock *sk;
-
- read_lock(&udp_hash_lock);
- sk = udp_v4_lookup_longway(saddr, sport, daddr, dport, dif);
- if (sk)
- sock_hold(sk);
+ if (result)
+ sock_hold(result);
read_unlock(&udp_hash_lock);
- return sk;
+ return result;
}
static inline struct sock *udp_v4_mcast_next(struct sock *sk,
@@ -340,7 +320,7 @@
* to find the appropriate port.
*/
-void udp_err(struct sk_buff *skb, u32 info)
+void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
{
struct inet_sock *inet;
struct iphdr *iph = (struct iphdr*)skb->data;
@@ -351,7 +331,8 @@
int harderr;
int err;
- sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex);
+ sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
+ skb->dev->ifindex, udptable );
if (sk == NULL) {
ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
return; /* No socket for error */
@@ -405,6 +386,11 @@
sock_put(sk);
}
+__inline__ void udp_err(struct sk_buff *skb, u32 info)
+{
+ return __udp4_lib_err(skb, info, udp_hash);
+}
+
/*
* Throw away all pending data and cancel the corking. Socket is locked.
*/
@@ -419,16 +405,56 @@
}
}
+/**
+ * udp4_hwcsum_outgoing - handle outgoing HW checksumming
+ * @sk: socket we are sending on
+ * @skb: sk_buff containing the filled-in UDP header
+ * (checksum field must be zeroed out)
+ */
+static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
+ __be32 src, __be32 dst, int len )
+{
+ unsigned int csum = 0, offset;
+ struct udphdr *uh = skb->h.uh;
+
+ if (skb_queue_len(&sk->sk_write_queue) == 1) {
+ /*
+ * Only one fragment on the socket.
+ */
+ skb->csum = offsetof(struct udphdr, check);
+ uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
+ } else {
+ /*
+ * HW-checksum won't work as there are two or more
+ * fragments on the socket so that all csums of sk_buffs
+ * should be together
+ */
+ offset = skb->h.raw - skb->data;
+ skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
+
+ skb->ip_summed = CHECKSUM_NONE;
+
+ skb_queue_walk(&sk->sk_write_queue, skb) {
+ csum = csum_add(csum, skb->csum);
+ }
+
+ uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
+ if (uh->check == 0)
+ uh->check = -1;
+ }
+}
+
/*
* Push out all pending data as one UDP datagram. Socket is locked.
*/
-static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
+int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
{
struct inet_sock *inet = inet_sk(sk);
struct flowi *fl = &inet->cork.fl;
struct sk_buff *skb;
struct udphdr *uh;
int err = 0;
+ u32 csum = 0;
/* Grab the skbuff where UDP header space exists. */
if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
@@ -443,52 +469,28 @@
uh->len = htons(up->len);
uh->check = 0;
- if (sk->sk_no_check == UDP_CSUM_NOXMIT) {
+ if (up->pcflag) /* UDP-Lite */
+ csum = udplite_csum_outgoing(sk, skb);
+
+ else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */
+
skb->ip_summed = CHECKSUM_NONE;
goto send;
- }
- if (skb_queue_len(&sk->sk_write_queue) == 1) {
- /*
- * Only one fragment on the socket.
- */
- if (skb->ip_summed == CHECKSUM_PARTIAL) {
- skb->csum = offsetof(struct udphdr, check);
- uh->check = ~csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
- up->len, IPPROTO_UDP, 0);
- } else {
- skb->csum = csum_partial((char *)uh,
- sizeof(struct udphdr), skb->csum);
- uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
- up->len, IPPROTO_UDP, skb->csum);
- if (uh->check == 0)
- uh->check = -1;
- }
- } else {
- unsigned int csum = 0;
- /*
- * HW-checksum won't work as there are two or more
- * fragments on the socket so that all csums of sk_buffs
- * should be together.
- */
- if (skb->ip_summed == CHECKSUM_PARTIAL) {
- int offset = (unsigned char *)uh - skb->data;
- skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
+ } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
- skb->ip_summed = CHECKSUM_NONE;
- } else {
- skb->csum = csum_partial((char *)uh,
- sizeof(struct udphdr), skb->csum);
- }
+ udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
+ goto send;
- skb_queue_walk(&sk->sk_write_queue, skb) {
- csum = csum_add(csum, skb->csum);
- }
- uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
- up->len, IPPROTO_UDP, csum);
- if (uh->check == 0)
- uh->check = -1;
- }
+ } else /* `normal' UDP */
+ csum = udp_csum_outgoing(sk, skb);
+
+ /* add protocol-dependent pseudo-header */
+ uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
+ sk->sk_protocol, csum );
+ if (uh->check == 0)
+ uh->check = -1;
+
send:
err = ip_push_pending_frames(sk);
out:
@@ -497,12 +499,6 @@
return err;
}
-
-static unsigned short udp_check(struct udphdr *uh, int len, __be32 saddr, __be32 daddr, unsigned long base)
-{
- return(csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base));
-}
-
int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len)
{
@@ -516,8 +512,9 @@
__be32 daddr, faddr, saddr;
__be16 dport;
u8 tos;
- int err;
+ int err, is_udplite = up->pcflag;
int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
+ int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
if (len > 0xFFFF)
return -EMSGSIZE;
@@ -622,7 +619,7 @@
{ .daddr = faddr,
.saddr = saddr,
.tos = tos } },
- .proto = IPPROTO_UDP,
+ .proto = sk->sk_protocol,
.uli_u = { .ports =
{ .sport = inet->sport,
.dport = dport } } };
@@ -668,8 +665,9 @@
do_append_data:
up->len += ulen;
- err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen,
- sizeof(struct udphdr), &ipc, rt,
+ getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
+ err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
+ sizeof(struct udphdr), &ipc, rt,
corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
if (err)
udp_flush_pending_frames(sk);
@@ -684,7 +682,7 @@
if (free)
kfree(ipc.opt);
if (!err) {
- UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS);
+ UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite);
return len;
}
/*
@@ -695,7 +693,7 @@
* seems like overkill.
*/
if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
- UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS);
+ UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
}
return err;
@@ -707,8 +705,8 @@
goto out;
}
-static int udp_sendpage(struct sock *sk, struct page *page, int offset,
- size_t size, int flags)
+int udp_sendpage(struct sock *sk, struct page *page, int offset,
+ size_t size, int flags)
{
struct udp_sock *up = udp_sk(sk);
int ret;
@@ -795,29 +793,18 @@
return(0);
}
-static __inline__ int __udp_checksum_complete(struct sk_buff *skb)
-{
- return __skb_checksum_complete(skb);
-}
-
-static __inline__ int udp_checksum_complete(struct sk_buff *skb)
-{
- return skb->ip_summed != CHECKSUM_UNNECESSARY &&
- __udp_checksum_complete(skb);
-}
-
/*
* This should be easy, if there is something there we
* return it, otherwise we block.
*/
-static int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
- size_t len, int noblock, int flags, int *addr_len)
+int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+ size_t len, int noblock, int flags, int *addr_len)
{
struct inet_sock *inet = inet_sk(sk);
struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
struct sk_buff *skb;
- int copied, err;
+ int copied, err, copy_only, is_udplite = IS_UDPLITE(sk);
/*
* Check any passed addresses
@@ -839,15 +826,25 @@
msg->msg_flags |= MSG_TRUNC;
}
- if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
- err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
- copied);
- } else if (msg->msg_flags&MSG_TRUNC) {
- if (__udp_checksum_complete(skb))
+ /*
+ * Decide whether to checksum and/or copy data.
+ *
+ * UDP: checksum may have been computed in HW,
+ * (re-)compute it if message is truncated.
+ * UDP-Lite: always needs to checksum, no HW support.
+ */
+ copy_only = (skb->ip_summed==CHECKSUM_UNNECESSARY);
+
+ if (is_udplite || (!copy_only && msg->msg_flags&MSG_TRUNC)) {
+ if (__udp_lib_checksum_complete(skb))
goto csum_copy_err;
- err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
- copied);
- } else {
+ copy_only = 1;
+ }
+
+ if (copy_only)
+ err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
+ msg->msg_iov, copied );
+ else {
err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
if (err == -EINVAL)
@@ -880,7 +877,7 @@
return err;
csum_copy_err:
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
skb_kill_datagram(sk, skb, flags);
@@ -912,11 +909,6 @@
return 0;
}
-static void udp_close(struct sock *sk, long timeout)
-{
- sk_common_release(sk);
-}
-
/* return:
* 1 if the the UDP system should process it
* 0 if we should drop this packet
@@ -1022,7 +1014,7 @@
* Note that in the success and error cases, the skb is assumed to
* have either been requeued or freed.
*/
-static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
+int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
{
struct udp_sock *up = udp_sk(sk);
int rc;
@@ -1030,10 +1022,8 @@
/*
* Charge it to the socket, dropping if the queue is full.
*/
- if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
- kfree_skb(skb);
- return -1;
- }
+ if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+ goto drop;
nf_reset(skb);
if (up->encap_type) {
@@ -1057,31 +1047,68 @@
if (ret < 0) {
/* process the ESP packet */
ret = xfrm4_rcv_encap(skb, up->encap_type);
- UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
+ UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
return -ret;
}
/* FALLTHROUGH -- it's a UDP Packet */
}
- if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
- if (__udp_checksum_complete(skb)) {
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return -1;
+ /*
+ * UDP-Lite specific tests, ignored on UDP sockets
+ */
+ if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) {
+
+ /*
+ * MIB statistics other than incrementing the error count are
+ * disabled for the following two types of errors: these depend
+ * on the application settings, not on the functioning of the
+ * protocol stack as such.
+ *
+ * RFC 3828 here recommends (sec 3.3): "There should also be a
+ * way ... to ... at least let the receiving application block
+ * delivery of packets with coverage values less than a value
+ * provided by the application."
+ */
+ if (up->pcrlen == 0) { /* full coverage was set */
+ LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
+ "%d while full coverage %d requested\n",
+ UDP_SKB_CB(skb)->cscov, skb->len);
+ goto drop;
}
+ /* The next case involves violating the min. coverage requested
+ * by the receiver. This is subtle: if receiver wants x and x is
+ * greater than the buffersize/MTU then receiver will complain
+ * that it wants x while sender emits packets of smaller size y.
+ * Therefore the above ...()->partial_cov statement is essential.
+ */
+ if (UDP_SKB_CB(skb)->cscov < up->pcrlen) {
+ LIMIT_NETDEBUG(KERN_WARNING
+ "UDPLITE: coverage %d too small, need min %d\n",
+ UDP_SKB_CB(skb)->cscov, up->pcrlen);
+ goto drop;
+ }
+ }
+
+ if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
+ if (__udp_lib_checksum_complete(skb))
+ goto drop;
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
/* Note that an ENOMEM error is charged twice */
if (rc == -ENOMEM)
- UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS);
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return -1;
+ UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
+ goto drop;
}
- UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
+
+ UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
return 0;
+
+drop:
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
+ kfree_skb(skb);
+ return -1;
}
/*
@@ -1090,14 +1117,16 @@
* Note: called only from the BH handler context,
* so we don't need to lock the hashes.
*/
-static int udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh,
- __be32 saddr, __be32 daddr)
+static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
+ struct udphdr *uh,
+ __be32 saddr, __be32 daddr,
+ struct hlist_head udptable[])
{
struct sock *sk;
int dif;
read_lock(&udp_hash_lock);
- sk = sk_head(&udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
+ sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
dif = skb->dev->ifindex;
sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
if (sk) {
@@ -1131,65 +1160,75 @@
* Otherwise, csum completion requires chacksumming packet body,
* including udp header and folding it to skb->csum.
*/
-static void udp_checksum_init(struct sk_buff *skb, struct udphdr *uh,
- unsigned short ulen, __be32 saddr, __be32 daddr)
+static inline void udp4_csum_init(struct sk_buff *skb, struct udphdr *uh)
{
if (uh->check == 0) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
} else if (skb->ip_summed == CHECKSUM_COMPLETE) {
- if (!udp_check(uh, ulen, saddr, daddr, skb->csum))
+ if (!csum_tcpudp_magic(skb->nh.iph->saddr, skb->nh.iph->daddr,
+ skb->len, IPPROTO_UDP, skb->csum ))
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
if (skb->ip_summed != CHECKSUM_UNNECESSARY)
- skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
+ skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr,
+ skb->nh.iph->daddr,
+ skb->len, IPPROTO_UDP, 0);
/* Probably, we should checksum udp header (it should be in cache
* in any case) and data in tiny packets (< rx copybreak).
*/
+
+ /* UDP = UDP-Lite with a non-partial checksum coverage */
+ UDP_SKB_CB(skb)->partial_cov = 0;
}
/*
* All we need to do is get the socket, and then do a checksum.
*/
-int udp_rcv(struct sk_buff *skb)
+int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
+ int is_udplite)
{
struct sock *sk;
- struct udphdr *uh;
+ struct udphdr *uh = skb->h.uh;
unsigned short ulen;
struct rtable *rt = (struct rtable*)skb->dst;
__be32 saddr = skb->nh.iph->saddr;
__be32 daddr = skb->nh.iph->daddr;
- int len = skb->len;
/*
- * Validate the packet and the UDP length.
+ * Validate the packet.
*/
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
- goto no_header;
-
- uh = skb->h.uh;
+ goto drop; /* No space for header. */
ulen = ntohs(uh->len);
-
- if (ulen > len || ulen < sizeof(*uh))
+ if (ulen > skb->len)
goto short_packet;
- if (pskb_trim_rcsum(skb, ulen))
- goto short_packet;
+ if(! is_udplite ) { /* UDP validates ulen. */
- udp_checksum_init(skb, uh, ulen, saddr, daddr);
+ if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
+ goto short_packet;
+
+ udp4_csum_init(skb, uh);
+
+ } else { /* UDP-Lite validates cscov. */
+ if (udplite4_csum_init(skb, uh))
+ goto csum_error;
+ }
if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
- return udp_v4_mcast_deliver(skb, uh, saddr, daddr);
+ return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);
- sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex);
+ sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
+ skb->dev->ifindex, udptable );
if (sk != NULL) {
int ret = udp_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but
- * it it wants the return to be -protocol, or 0
+ * it wants the return to be -protocol, or 0
*/
if (ret > 0)
return -ret;
@@ -1201,10 +1240,10 @@
nf_reset(skb);
/* No socket. Drop packet silently, if checksum is wrong */
- if (udp_checksum_complete(skb))
+ if (udp_lib_checksum_complete(skb))
goto csum_error;
- UDP_INC_STATS_BH(UDP_MIB_NOPORTS);
+ UDP_INC_STATS_BH(UDP_MIB_NOPORTS, is_udplite);
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
/*
@@ -1215,36 +1254,40 @@
return(0);
short_packet:
- LIMIT_NETDEBUG(KERN_DEBUG "UDP: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
+ LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
+ is_udplite? "-Lite" : "",
NIPQUAD(saddr),
ntohs(uh->source),
ulen,
- len,
+ skb->len,
NIPQUAD(daddr),
ntohs(uh->dest));
-no_header:
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
- kfree_skb(skb);
- return(0);
+ goto drop;
csum_error:
/*
* RFC1122: OK. Discards the bad packet silently (as far as
* the network is concerned, anyway) as per 4.1.3.4 (MUST).
*/
- LIMIT_NETDEBUG(KERN_DEBUG "UDP: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
+ LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
+ is_udplite? "-Lite" : "",
NIPQUAD(saddr),
ntohs(uh->source),
NIPQUAD(daddr),
ntohs(uh->dest),
ulen);
drop:
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);
kfree_skb(skb);
return(0);
}
-static int udp_destroy_sock(struct sock *sk)
+__inline__ int udp_rcv(struct sk_buff *skb)
+{
+ return __udp4_lib_rcv(skb, udp_hash, 0);
+}
+
+int udp_destroy_sock(struct sock *sk)
{
lock_sock(sk);
udp_flush_pending_frames(sk);
@@ -1293,6 +1336,32 @@
}
break;
+ /*
+ * UDP-Lite's partial checksum coverage (RFC 3828).
+ */
+ /* The sender sets actual checksum coverage length via this option.
+ * The case coverage > packet length is handled by send module. */
+ case UDPLITE_SEND_CSCOV:
+ if (!up->pcflag) /* Disable the option on UDP sockets */
+ return -ENOPROTOOPT;
+ if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
+ val = 8;
+ up->pcslen = val;
+ up->pcflag |= UDPLITE_SEND_CC;
+ break;
+
+ /* The receiver specifies a minimum checksum coverage value. To make
+ * sense, this should be set to at least 8 (as done below). If zero is
+ * used, this again means full checksum coverage. */
+ case UDPLITE_RECV_CSCOV:
+ if (!up->pcflag) /* Disable the option on UDP sockets */
+ return -ENOPROTOOPT;
+ if (val != 0 && val < 8) /* Avoid silly minimal values. */
+ val = 8;
+ up->pcrlen = val;
+ up->pcflag |= UDPLITE_RECV_CC;
+ break;
+
default:
err = -ENOPROTOOPT;
break;
@@ -1301,21 +1370,21 @@
return err;
}
-static int udp_setsockopt(struct sock *sk, int level, int optname,
- char __user *optval, int optlen)
+int udp_setsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, int optlen)
{
- if (level != SOL_UDP)
- return ip_setsockopt(sk, level, optname, optval, optlen);
- return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ return ip_setsockopt(sk, level, optname, optval, optlen);
}
#ifdef CONFIG_COMPAT
-static int compat_udp_setsockopt(struct sock *sk, int level, int optname,
- char __user *optval, int optlen)
+int compat_udp_setsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, int optlen)
{
- if (level != SOL_UDP)
- return compat_ip_setsockopt(sk, level, optname, optval, optlen);
- return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_setsockopt(sk, level, optname, optval, optlen);
+ return compat_ip_setsockopt(sk, level, optname, optval, optlen);
}
#endif
@@ -1342,6 +1411,16 @@
val = up->encap_type;
break;
+ /* The following two cannot be changed on UDP sockets, the return is
+ * always 0 (which corresponds to the full checksum coverage of UDP). */
+ case UDPLITE_SEND_CSCOV:
+ val = up->pcslen;
+ break;
+
+ case UDPLITE_RECV_CSCOV:
+ val = up->pcrlen;
+ break;
+
default:
return -ENOPROTOOPT;
};
@@ -1353,21 +1432,21 @@
return 0;
}
-static int udp_getsockopt(struct sock *sk, int level, int optname,
- char __user *optval, int __user *optlen)
+int udp_getsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, int __user *optlen)
{
- if (level != SOL_UDP)
- return ip_getsockopt(sk, level, optname, optval, optlen);
- return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ return ip_getsockopt(sk, level, optname, optval, optlen);
}
#ifdef CONFIG_COMPAT
-static int compat_udp_getsockopt(struct sock *sk, int level, int optname,
+int compat_udp_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen)
{
- if (level != SOL_UDP)
- return compat_ip_getsockopt(sk, level, optname, optval, optlen);
- return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ if (level == SOL_UDP || level == SOL_UDPLITE)
+ return do_udp_getsockopt(sk, level, optname, optval, optlen);
+ return compat_ip_getsockopt(sk, level, optname, optval, optlen);
}
#endif
/**
@@ -1387,7 +1466,8 @@
{
unsigned int mask = datagram_poll(file, sock, wait);
struct sock *sk = sock->sk;
-
+ int is_lite = IS_UDPLITE(sk);
+
/* Check for false positives due to checksum errors */
if ( (mask & POLLRDNORM) &&
!(file->f_flags & O_NONBLOCK) &&
@@ -1397,8 +1477,8 @@
spin_lock_bh(&rcvq->lock);
while ((skb = skb_peek(rcvq)) != NULL) {
- if (udp_checksum_complete(skb)) {
- UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+ if (udp_lib_checksum_complete(skb)) {
+ UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
__skb_unlink(skb, rcvq);
kfree_skb(skb);
} else {
@@ -1420,7 +1500,7 @@
struct proto udp_prot = {
.name = "UDP",
.owner = THIS_MODULE,
- .close = udp_close,
+ .close = udp_lib_close,
.connect = ip4_datagram_connect,
.disconnect = udp_disconnect,
.ioctl = udp_ioctl,
@@ -1431,8 +1511,8 @@
.recvmsg = udp_recvmsg,
.sendpage = udp_sendpage,
.backlog_rcv = udp_queue_rcv_skb,
- .hash = udp_v4_hash,
- .unhash = udp_v4_unhash,
+ .hash = udp_lib_hash,
+ .unhash = udp_lib_unhash,
.get_port = udp_v4_get_port,
.obj_size = sizeof(struct udp_sock),
#ifdef CONFIG_COMPAT
@@ -1451,7 +1531,7 @@
for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
struct hlist_node *node;
- sk_for_each(sk, node, &udp_hash[state->bucket]) {
+ sk_for_each(sk, node, state->hashtable + state->bucket) {
if (sk->sk_family == state->family)
goto found;
}
@@ -1472,7 +1552,7 @@
} while (sk && sk->sk_family != state->family);
if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
- sk = sk_head(&udp_hash[state->bucket]);
+ sk = sk_head(state->hashtable + state->bucket);
goto try_again;
}
return sk;
@@ -1522,6 +1602,7 @@
if (!s)
goto out;
s->family = afinfo->family;
+ s->hashtable = afinfo->hashtable;
s->seq_ops.start = udp_seq_start;
s->seq_ops.next = udp_seq_next;
s->seq_ops.show = afinfo->seq_show;
@@ -1588,7 +1669,7 @@
atomic_read(&sp->sk_refcnt), sp);
}
-static int udp4_seq_show(struct seq_file *seq, void *v)
+int udp4_seq_show(struct seq_file *seq, void *v)
{
if (v == SEQ_START_TOKEN)
seq_printf(seq, "%-127s\n",
@@ -1611,6 +1692,7 @@
.owner = THIS_MODULE,
.name = "udp",
.family = AF_INET,
+ .hashtable = udp_hash,
.seq_show = udp4_seq_show,
.seq_fops = &udp4_seq_fops,
};