xref: /linux/include/linux/rtnetlink.h (revision 1a9239bb4253f9076b5b4b2a1a4e8d7defd77a95)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_RTNETLINK_H
3 #define __LINUX_RTNETLINK_H
4 
5 
6 #include <linux/mutex.h>
7 #include <linux/netdevice.h>
8 #include <linux/wait.h>
9 #include <linux/refcount.h>
10 #include <uapi/linux/rtnetlink.h>
11 
12 extern int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
13 
rtnetlink_maybe_send(struct sk_buff * skb,struct net * net,u32 pid,u32 group,int echo)14 static inline int rtnetlink_maybe_send(struct sk_buff *skb, struct net *net,
15 				       u32 pid, u32 group, int echo)
16 {
17 	return !skb ? 0 : rtnetlink_send(skb, net, pid, group, echo);
18 }
19 
20 extern int rtnl_unicast(struct sk_buff *skb, struct net *net, u32 pid);
21 extern void rtnl_notify(struct sk_buff *skb, struct net *net, u32 pid,
22 			u32 group, const struct nlmsghdr *nlh, gfp_t flags);
23 extern void rtnl_set_sk_err(struct net *net, u32 group, int error);
24 extern int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics);
25 extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst,
26 			      u32 id, long expires, u32 error);
27 
28 void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change, gfp_t flags,
29 		  u32 portid, const struct nlmsghdr *nlh);
30 void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
31 			 gfp_t flags, int *new_nsid, int new_ifindex);
32 struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
33 				       unsigned change, u32 event,
34 				       gfp_t flags, int *new_nsid,
35 				       int new_ifindex, u32 portid,
36 				       const struct nlmsghdr *nlh);
37 void rtmsg_ifinfo_send(struct sk_buff *skb, struct net_device *dev,
38 		       gfp_t flags, u32 portid, const struct nlmsghdr *nlh);
39 
40 
41 /* RTNL is used as a global lock for all changes to network configuration  */
42 extern void rtnl_lock(void);
43 extern void rtnl_unlock(void);
44 extern int rtnl_trylock(void);
45 extern int rtnl_is_locked(void);
46 extern int rtnl_lock_interruptible(void);
47 extern int rtnl_lock_killable(void);
48 extern bool refcount_dec_and_rtnl_lock(refcount_t *r);
49 
50 extern wait_queue_head_t netdev_unregistering_wq;
51 extern atomic_t dev_unreg_count;
52 extern struct rw_semaphore pernet_ops_rwsem;
53 extern struct rw_semaphore net_rwsem;
54 
55 #define ASSERT_RTNL() \
56 	WARN_ONCE(!rtnl_is_locked(), \
57 		  "RTNL: assertion failed at %s (%d)\n", __FILE__,  __LINE__)
58 
59 #ifdef CONFIG_PROVE_LOCKING
60 extern bool lockdep_rtnl_is_held(void);
61 #else
lockdep_rtnl_is_held(void)62 static inline bool lockdep_rtnl_is_held(void)
63 {
64 	return true;
65 }
66 #endif /* #ifdef CONFIG_PROVE_LOCKING */
67 
68 /**
69  * rcu_dereference_rtnl - rcu_dereference with debug checking
70  * @p: The pointer to read, prior to dereferencing
71  *
72  * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
73  * or RTNL. Note : Please prefer rtnl_dereference() or rcu_dereference()
74  */
75 #define rcu_dereference_rtnl(p)					\
76 	rcu_dereference_check(p, lockdep_rtnl_is_held())
77 
78 /**
79  * rtnl_dereference - fetch RCU pointer when updates are prevented by RTNL
80  * @p: The pointer to read, prior to dereferencing
81  *
82  * Return: the value of the specified RCU-protected pointer, but omit
83  * the READ_ONCE(), because caller holds RTNL.
84  */
85 #define rtnl_dereference(p)					\
86 	rcu_dereference_protected(p, lockdep_rtnl_is_held())
87 
88 /**
89  * rcu_replace_pointer_rtnl - replace an RCU pointer under rtnl_lock, returning
90  * its old value
91  * @rp: RCU pointer, whose value is returned
92  * @p: regular pointer
93  *
94  * Perform a replacement under rtnl_lock, where @rp is an RCU-annotated
95  * pointer. The old value of @rp is returned, and @rp is set to @p
96  */
97 #define rcu_replace_pointer_rtnl(rp, p)			\
98 	rcu_replace_pointer(rp, p, lockdep_rtnl_is_held())
99 
100 #ifdef CONFIG_DEBUG_NET_SMALL_RTNL
101 void __rtnl_net_lock(struct net *net);
102 void __rtnl_net_unlock(struct net *net);
103 void rtnl_net_lock(struct net *net);
104 void rtnl_net_unlock(struct net *net);
105 int rtnl_net_trylock(struct net *net);
106 int rtnl_net_lock_killable(struct net *net);
107 int rtnl_net_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map *b);
108 
109 bool rtnl_net_is_locked(struct net *net);
110 
111 #define ASSERT_RTNL_NET(net)						\
112 	WARN_ONCE(!rtnl_net_is_locked(net),				\
113 		  "RTNL_NET: assertion failed at %s (%d)\n",		\
114 		  __FILE__,  __LINE__)
115 
116 bool lockdep_rtnl_net_is_held(struct net *net);
117 
118 #define rcu_dereference_rtnl_net(net, p)				\
119 	rcu_dereference_check(p, lockdep_rtnl_net_is_held(net))
120 #define rtnl_net_dereference(net, p)					\
121 	rcu_dereference_protected(p, lockdep_rtnl_net_is_held(net))
122 #define rcu_replace_pointer_rtnl_net(net, rp, p)			\
123 	rcu_replace_pointer(rp, p, lockdep_rtnl_net_is_held(net))
124 #else
__rtnl_net_lock(struct net * net)125 static inline void __rtnl_net_lock(struct net *net) {}
__rtnl_net_unlock(struct net * net)126 static inline void __rtnl_net_unlock(struct net *net) {}
127 
rtnl_net_lock(struct net * net)128 static inline void rtnl_net_lock(struct net *net)
129 {
130 	rtnl_lock();
131 }
132 
rtnl_net_unlock(struct net * net)133 static inline void rtnl_net_unlock(struct net *net)
134 {
135 	rtnl_unlock();
136 }
137 
rtnl_net_trylock(struct net * net)138 static inline int rtnl_net_trylock(struct net *net)
139 {
140 	return rtnl_trylock();
141 }
142 
rtnl_net_lock_killable(struct net * net)143 static inline int rtnl_net_lock_killable(struct net *net)
144 {
145 	return rtnl_lock_killable();
146 }
147 
ASSERT_RTNL_NET(struct net * net)148 static inline void ASSERT_RTNL_NET(struct net *net)
149 {
150 	ASSERT_RTNL();
151 }
152 
153 #define rcu_dereference_rtnl_net(net, p)		\
154 	rcu_dereference_rtnl(p)
155 #define rtnl_net_dereference(net, p)			\
156 	rtnl_dereference(p)
157 #define rcu_replace_pointer_rtnl_net(net, rp, p)	\
158 	rcu_replace_pointer_rtnl(rp, p)
159 #endif
160 
dev_ingress_queue(struct net_device * dev)161 static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
162 {
163 	return rtnl_dereference(dev->ingress_queue);
164 }
165 
dev_ingress_queue_rcu(struct net_device * dev)166 static inline struct netdev_queue *dev_ingress_queue_rcu(struct net_device *dev)
167 {
168 	return rcu_dereference(dev->ingress_queue);
169 }
170 
171 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev);
172 
173 #ifdef CONFIG_NET_INGRESS
174 void net_inc_ingress_queue(void);
175 void net_dec_ingress_queue(void);
176 #endif
177 
178 #ifdef CONFIG_NET_EGRESS
179 void net_inc_egress_queue(void);
180 void net_dec_egress_queue(void);
181 void netdev_xmit_skip_txqueue(bool skip);
182 #endif
183 
184 void rtnetlink_init(void);
185 void __rtnl_unlock(void);
186 void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail);
187 
188 /* Shared by rtnl_fdb_dump() and various ndo_fdb_dump() helpers. */
189 struct ndo_fdb_dump_context {
190 	unsigned long ifindex;
191 	unsigned long fdb_idx;
192 };
193 
194 extern int ndo_dflt_fdb_dump(struct sk_buff *skb,
195 			     struct netlink_callback *cb,
196 			     struct net_device *dev,
197 			     struct net_device *filter_dev,
198 			     int *idx);
199 extern int ndo_dflt_fdb_add(struct ndmsg *ndm,
200 			    struct nlattr *tb[],
201 			    struct net_device *dev,
202 			    const unsigned char *addr,
203 			    u16 vid,
204 			    u16 flags);
205 extern int ndo_dflt_fdb_del(struct ndmsg *ndm,
206 			    struct nlattr *tb[],
207 			    struct net_device *dev,
208 			    const unsigned char *addr,
209 			    u16 vid);
210 
211 extern int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
212 				   struct net_device *dev, u16 mode,
213 				   u32 flags, u32 mask, int nlflags,
214 				   u32 filter_mask,
215 				   int (*vlan_fill)(struct sk_buff *skb,
216 						    struct net_device *dev,
217 						    u32 filter_mask));
218 
219 extern void rtnl_offload_xstats_notify(struct net_device *dev);
220 
rtnl_has_listeners(const struct net * net,u32 group)221 static inline int rtnl_has_listeners(const struct net *net, u32 group)
222 {
223 	struct sock *rtnl = net->rtnl;
224 
225 	return netlink_has_listeners(rtnl, group);
226 }
227 
228 /**
229  * rtnl_notify_needed - check if notification is needed
230  * @net: Pointer to the net namespace
231  * @nlflags: netlink ingress message flags
232  * @group: rtnl group
233  *
234  * Based on the ingress message flags and rtnl group, returns true
235  * if a notification is needed, false otherwise.
236  */
237 static inline bool
rtnl_notify_needed(const struct net * net,u16 nlflags,u32 group)238 rtnl_notify_needed(const struct net *net, u16 nlflags, u32 group)
239 {
240 	return (nlflags & NLM_F_ECHO) || rtnl_has_listeners(net, group);
241 }
242 
243 void netdev_set_operstate(struct net_device *dev, int newstate);
244 
245 #endif	/* __LINUX_RTNETLINK_H */
246