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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_NETLINK_H
2#define __LINUX_NETLINK_H
3
Linus Torvalds1da177e2005-04-16 15:20:36 -07004
5#include <linux/capability.h>
6#include <linux/skbuff.h>
Pablo Neira Ayusoabb17e62012-09-21 09:35:38 +00007#include <linux/export.h>
Eric W. Biedermandbe9a412012-09-06 18:20:01 +00008#include <net/scm.h>
David Howells607ca462012-10-13 10:46:48 +01009#include <uapi/linux/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010
Ollie Wild56b49f42010-09-22 05:54:54 +000011struct net;
12
Arnaldo Carvalho de Melob529ccf2007-04-25 19:08:35 -070013static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
14{
15 return (struct nlmsghdr *)skb->data;
16}
17
Patrick McHardy9652e932013-04-17 06:47:02 +000018enum netlink_skb_flags {
Eric W. Biederman2d7a85f2014-05-30 11:04:00 -070019 NETLINK_SKB_MMAPED = 0x1, /* Packet data is mmaped */
20 NETLINK_SKB_TX = 0x2, /* Packet was sent by userspace */
21 NETLINK_SKB_DELIVERED = 0x4, /* Packet was delivered */
22 NETLINK_SKB_DST = 0x8, /* Dst set in sendto or sendmsg */
Patrick McHardy9652e932013-04-17 06:47:02 +000023};
24
Eric Dumazetd94d9fe2009-11-04 09:50:58 -080025struct netlink_skb_parms {
Eric W. Biedermandbe9a412012-09-06 18:20:01 +000026 struct scm_creds creds; /* Skb credentials */
Eric W. Biederman15e47302012-09-07 20:12:54 +000027 __u32 portid;
Patrick McHardyd629b832005-08-14 19:27:50 -070028 __u32 dst_group;
Patrick McHardy9652e932013-04-17 06:47:02 +000029 __u32 flags;
Patrick McHardye32123e2013-04-17 06:46:57 +000030 struct sock *sk;
Nicolas Dichtel59324cf2015-05-07 11:02:53 +020031 bool nsid_is_set;
32 int nsid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033};
34
35#define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb))
36#define NETLINK_CREDS(skb) (&NETLINK_CB((skb)).creds)
37
38
Johannes Bergd136f1b2009-09-12 03:03:15 +000039extern void netlink_table_grab(void);
40extern void netlink_table_ungrab(void);
41
Pablo Neira Ayuso9785e102012-09-08 02:53:53 +000042#define NL_CFG_F_NONROOT_RECV (1 << 0)
43#define NL_CFG_F_NONROOT_SEND (1 << 1)
44
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +000045/* optional Netlink kernel configuration parameters */
46struct netlink_kernel_cfg {
47 unsigned int groups;
David S. Millerc9d2ea92012-09-23 02:09:23 -040048 unsigned int flags;
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +000049 void (*input)(struct sk_buff *skb);
50 struct mutex *cb_mutex;
Johannes Berg023e2cf2014-12-23 21:00:06 +010051 int (*bind)(struct net *net, int group);
52 void (*unbind)(struct net *net, int group);
Gao fengda12c902013-06-06 14:49:11 +080053 bool (*compare)(struct net *net, struct sock *sk);
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +000054};
55
Pablo Neira Ayuso9f00d972012-09-08 02:53:54 +000056extern struct sock *__netlink_kernel_create(struct net *net, int unit,
57 struct module *module,
58 struct netlink_kernel_cfg *cfg);
59static inline struct sock *
60netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg)
61{
62 return __netlink_kernel_create(net, unit, THIS_MODULE, cfg);
63}
64
Johannes Bergba0dc5f2017-04-12 14:34:06 +020065/* this can be increased when necessary - don't expose to userland */
66#define NETLINK_MAX_COOKIE_LEN 20
67
Johannes Berg2d4bc932017-04-12 14:34:04 +020068/**
69 * struct netlink_ext_ack - netlink extended ACK report struct
70 * @_msg: message string to report - don't access directly, use
71 * %NL_SET_ERR_MSG
72 * @bad_attr: attribute with error
Johannes Bergba0dc5f2017-04-12 14:34:06 +020073 * @cookie: cookie data to return to userspace (for success)
74 * @cookie_len: actual cookie data length
Johannes Berg2d4bc932017-04-12 14:34:04 +020075 */
76struct netlink_ext_ack {
77 const char *_msg;
78 const struct nlattr *bad_attr;
Johannes Bergba0dc5f2017-04-12 14:34:06 +020079 u8 cookie[NETLINK_MAX_COOKIE_LEN];
80 u8 cookie_len;
Johannes Berg2d4bc932017-04-12 14:34:04 +020081};
82
83/* Always use this macro, this allows later putting the
84 * message into a separate section or such for things
85 * like translation or listing all possible messages.
86 * Currently string formatting is not supported (due
87 * to the lack of an output buffer.)
88 */
Daniel Borkmann4d463c42017-05-03 00:39:17 +020089#define NL_SET_ERR_MSG(extack, msg) do { \
90 static const char __msg[] = (msg); \
91 struct netlink_ext_ack *__extack = (extack); \
92 \
93 if (__extack) \
94 __extack->_msg = __msg; \
Johannes Berg2d4bc932017-04-12 14:34:04 +020095} while (0)
96
Daniel Borkmann4d463c42017-05-03 00:39:17 +020097#define NL_SET_ERR_MSG_MOD(extack, msg) \
98 NL_SET_ERR_MSG((extack), KBUILD_MODNAME ": " msg)
Jakub Kicinski45d9b372017-04-30 21:46:45 -070099
David Ahernc3ab2b42017-05-21 10:12:03 -0600100#define NL_SET_BAD_ATTR(extack, attr) do { \
101 if ((extack)) \
102 (extack)->bad_attr = (attr); \
103} while (0)
104
David Ahern9ae28722017-05-27 16:19:28 -0600105#define NL_SET_ERR_MSG_ATTR(extack, attr, msg) do { \
106 static const char __msg[] = (msg); \
107 struct netlink_ext_ack *__extack = (extack); \
108 \
109 if (__extack) { \
110 __extack->_msg = __msg; \
111 __extack->bad_attr = (attr); \
112 } \
113} while (0)
114
Denis V. Lunevb7c6ba62008-01-28 14:41:19 -0800115extern void netlink_kernel_release(struct sock *sk);
Johannes Bergd136f1b2009-09-12 03:03:15 +0000116extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700117extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
Johannes Bergb8273572009-09-24 15:44:05 -0700118extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
Johannes Berg2d4bc932017-04-12 14:34:04 +0200119extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
120 const struct netlink_ext_ack *extack);
Patrick McHardy4277a082006-03-20 18:52:01 -0800121extern int netlink_has_listeners(struct sock *sk, unsigned int group);
Daniel Borkmann6bb0fef2015-09-10 02:10:57 +0200122
Eric W. Biederman15e47302012-09-07 20:12:54 +0000123extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
124extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
Al Virodd0fc662005-10-07 07:46:04 +0100125 __u32 group, gfp_t allocation);
Eric W. Biederman910a7e92010-05-04 17:36:46 -0700126extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
Eric W. Biederman15e47302012-09-07 20:12:54 +0000127 __u32 portid, __u32 group, gfp_t allocation,
Eric W. Biederman910a7e92010-05-04 17:36:46 -0700128 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
129 void *filter_data);
Eric W. Biederman15e47302012-09-07 20:12:54 +0000130extern int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131extern int netlink_register_notifier(struct notifier_block *nb);
132extern int netlink_unregister_notifier(struct notifier_block *nb);
133
134/* finegrained unicast helpers: */
135struct sock *netlink_getsockbyfilp(struct file *filp);
Denis V. Lunev9457afe2008-06-05 11:23:39 -0700136int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800137 long *timeo, struct sock *ssk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138void netlink_detachskb(struct sock *sk, struct sk_buff *skb);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700139int netlink_sendskb(struct sock *sk, struct sk_buff *skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
Pablo Neira3a365152013-06-28 03:04:23 +0200141static inline struct sk_buff *
142netlink_skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
143{
144 struct sk_buff *nskb;
145
146 nskb = skb_clone(skb, gfp_mask);
147 if (!nskb)
148 return NULL;
149
150 /* This is a large skb, set destructor callback to release head */
151 if (is_vmalloc_addr(skb->head))
152 nskb->destructor = skb->destructor;
153
154 return nskb;
155}
156
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157/*
158 * skb should fit one page. This choice is good for headerless malloc.
David S. Millerfc910a22007-03-25 20:27:59 -0700159 * But we should limit to 8K so that userspace does not have to
160 * use enormous buffer sizes on recvmsg() calls just to avoid
161 * MSG_TRUNC when PAGE_SIZE is very large.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 */
David S. Millerfc910a22007-03-25 20:27:59 -0700163#if PAGE_SIZE < 8192UL
164#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(PAGE_SIZE)
165#else
166#define NLMSG_GOODSIZE SKB_WITH_OVERHEAD(8192UL)
167#endif
168
Thomas Graf339bf982006-11-10 14:10:15 -0800169#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
171
Eric Dumazetd94d9fe2009-11-04 09:50:58 -0800172struct netlink_callback {
Patrick McHardy3a6c2b42009-08-25 16:07:40 +0200173 struct sk_buff *skb;
174 const struct nlmsghdr *nlh;
Tom Herbertfc9e50f2015-12-15 15:41:37 -0800175 int (*start)(struct netlink_callback *);
Patrick McHardy3a6c2b42009-08-25 16:07:40 +0200176 int (*dump)(struct sk_buff * skb,
177 struct netlink_callback *cb);
178 int (*done)(struct netlink_callback *cb);
Pablo Neira Ayuso7175c882012-02-24 14:30:16 +0000179 void *data;
Gao feng6dc878a2012-10-04 20:15:48 +0000180 /* the module that dump function belong to */
181 struct module *module;
Greg Rosec7ac8672011-06-10 01:27:09 +0000182 u16 family;
183 u16 min_dump_alloc;
Johannes Berg670dc282011-06-20 13:40:46 +0200184 unsigned int prev_seq, seq;
Patrick McHardy3a6c2b42009-08-25 16:07:40 +0200185 long args[6];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186};
187
Eric Dumazetd94d9fe2009-11-04 09:50:58 -0800188struct netlink_notify {
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200189 struct net *net;
Richard Weinberger0392d092015-04-13 00:52:35 +0200190 u32 portid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 int protocol;
192};
193
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500194struct nlmsghdr *
Eric W. Biederman15e47302012-09-07 20:12:54 +0000195__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
Pablo Neira Ayuso80d326f2012-02-24 14:30:15 +0000197struct netlink_dump_control {
Tom Herbertfc9e50f2015-12-15 15:41:37 -0800198 int (*start)(struct netlink_callback *);
Pablo Neira Ayuso80d326f2012-02-24 14:30:15 +0000199 int (*dump)(struct sk_buff *skb, struct netlink_callback *);
Gao feng6dc878a2012-10-04 20:15:48 +0000200 int (*done)(struct netlink_callback *);
Pablo Neira Ayuso7175c882012-02-24 14:30:16 +0000201 void *data;
Gao feng6dc878a2012-10-04 20:15:48 +0000202 struct module *module;
Pablo Neira Ayuso80d326f2012-02-24 14:30:15 +0000203 u16 min_dump_alloc;
204};
205
Gao feng6dc878a2012-10-04 20:15:48 +0000206extern int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
207 const struct nlmsghdr *nlh,
208 struct netlink_dump_control *control);
209static inline int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
210 const struct nlmsghdr *nlh,
211 struct netlink_dump_control *control)
212{
213 if (!control->module)
214 control->module = THIS_MODULE;
215
216 return __netlink_dump_start(ssk, skb, nlh, control);
217}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
Daniel Borkmannbcbde0d2013-06-21 19:38:07 +0200219struct netlink_tap {
220 struct net_device *dev;
221 struct module *module;
222 struct list_head list;
223};
224
225extern int netlink_add_tap(struct netlink_tap *nt);
Daniel Borkmannbcbde0d2013-06-21 19:38:07 +0200226extern int netlink_remove_tap(struct netlink_tap *nt);
227
Eric W. Biedermanaa4cf942014-04-23 14:28:03 -0700228bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
229 struct user_namespace *ns, int cap);
230bool netlink_ns_capable(const struct sk_buff *skb,
231 struct user_namespace *ns, int cap);
232bool netlink_capable(const struct sk_buff *skb, int cap);
233bool netlink_net_capable(const struct sk_buff *skb, int cap);
234
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235#endif /* __LINUX_NETLINK_H */