xref: /linux-6.15/include/linux/rtnetlink.h (revision da3ee3cd)
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 
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_killable(void);
47 extern bool refcount_dec_and_rtnl_lock(refcount_t *r);
48 
49 extern wait_queue_head_t netdev_unregistering_wq;
50 extern atomic_t dev_unreg_count;
51 extern struct rw_semaphore pernet_ops_rwsem;
52 extern struct rw_semaphore net_rwsem;
53 
54 #define ASSERT_RTNL() \
55 	WARN_ONCE(!rtnl_is_locked(), \
56 		  "RTNL: assertion failed at %s (%d)\n", __FILE__,  __LINE__)
57 
58 #ifdef CONFIG_PROVE_LOCKING
59 extern bool lockdep_rtnl_is_held(void);
60 #else
61 static inline bool lockdep_rtnl_is_held(void)
62 {
63 	return true;
64 }
65 #endif /* #ifdef CONFIG_PROVE_LOCKING */
66 
67 /**
68  * rcu_dereference_rtnl - rcu_dereference with debug checking
69  * @p: The pointer to read, prior to dereferencing
70  *
71  * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
72  * or RTNL. Note : Please prefer rtnl_dereference() or rcu_dereference()
73  */
74 #define rcu_dereference_rtnl(p)					\
75 	rcu_dereference_check(p, lockdep_rtnl_is_held())
76 
77 /**
78  * rtnl_dereference - fetch RCU pointer when updates are prevented by RTNL
79  * @p: The pointer to read, prior to dereferencing
80  *
81  * Return the value of the specified RCU-protected pointer, but omit
82  * the READ_ONCE(), because caller holds RTNL.
83  */
84 #define rtnl_dereference(p)					\
85 	rcu_dereference_protected(p, lockdep_rtnl_is_held())
86 
87 /**
88  * rcu_replace_pointer_rtnl - replace an RCU pointer under rtnl_lock, returning
89  * its old value
90  * @rp: RCU pointer, whose value is returned
91  * @p: regular pointer
92  *
93  * Perform a replacement under rtnl_lock, where @rp is an RCU-annotated
94  * pointer. The old value of @rp is returned, and @rp is set to @p
95  */
96 #define rcu_replace_pointer_rtnl(rp, p)			\
97 	rcu_replace_pointer(rp, p, lockdep_rtnl_is_held())
98 
99 #ifdef CONFIG_DEBUG_NET_SMALL_RTNL
100 void __rtnl_net_lock(struct net *net);
101 void __rtnl_net_unlock(struct net *net);
102 void rtnl_net_lock(struct net *net);
103 void rtnl_net_unlock(struct net *net);
104 int rtnl_net_trylock(struct net *net);
105 int rtnl_net_lock_cmp_fn(const struct lockdep_map *a, const struct lockdep_map *b);
106 
107 bool rtnl_net_is_locked(struct net *net);
108 
109 #define ASSERT_RTNL_NET(net)						\
110 	WARN_ONCE(!rtnl_net_is_locked(net),				\
111 		  "RTNL_NET: assertion failed at %s (%d)\n",		\
112 		  __FILE__,  __LINE__)
113 
114 bool lockdep_rtnl_net_is_held(struct net *net);
115 
116 #define rcu_dereference_rtnl_net(net, p)				\
117 	rcu_dereference_check(p, lockdep_rtnl_net_is_held(net))
118 #define rtnl_net_dereference(net, p)					\
119 	rcu_dereference_protected(p, lockdep_rtnl_net_is_held(net))
120 #define rcu_replace_pointer_rtnl_net(net, rp, p)			\
121 	rcu_replace_pointer(rp, p, lockdep_rtnl_net_is_held(net))
122 #else
123 static inline void __rtnl_net_lock(struct net *net) {}
124 static inline void __rtnl_net_unlock(struct net *net) {}
125 
126 static inline void rtnl_net_lock(struct net *net)
127 {
128 	rtnl_lock();
129 }
130 
131 static inline void rtnl_net_unlock(struct net *net)
132 {
133 	rtnl_unlock();
134 }
135 
136 static inline int rtnl_net_trylock(struct net *net)
137 {
138 	return rtnl_trylock();
139 }
140 
141 static inline void ASSERT_RTNL_NET(struct net *net)
142 {
143 	ASSERT_RTNL();
144 }
145 
146 #define rcu_dereference_rtnl_net(net, p)		\
147 	rcu_dereference_rtnl(p)
148 #define rtnl_net_dereference(net, p)			\
149 	rtnl_dereference(p)
150 #define rcu_replace_pointer_rtnl_net(net, rp, p)	\
151 	rcu_replace_pointer_rtnl(rp, p)
152 #endif
153 
154 static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
155 {
156 	return rtnl_dereference(dev->ingress_queue);
157 }
158 
159 static inline struct netdev_queue *dev_ingress_queue_rcu(struct net_device *dev)
160 {
161 	return rcu_dereference(dev->ingress_queue);
162 }
163 
164 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev);
165 
166 #ifdef CONFIG_NET_INGRESS
167 void net_inc_ingress_queue(void);
168 void net_dec_ingress_queue(void);
169 #endif
170 
171 #ifdef CONFIG_NET_EGRESS
172 void net_inc_egress_queue(void);
173 void net_dec_egress_queue(void);
174 void netdev_xmit_skip_txqueue(bool skip);
175 #endif
176 
177 void rtnetlink_init(void);
178 void __rtnl_unlock(void);
179 void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail);
180 
181 extern int ndo_dflt_fdb_dump(struct sk_buff *skb,
182 			     struct netlink_callback *cb,
183 			     struct net_device *dev,
184 			     struct net_device *filter_dev,
185 			     int *idx);
186 extern int ndo_dflt_fdb_add(struct ndmsg *ndm,
187 			    struct nlattr *tb[],
188 			    struct net_device *dev,
189 			    const unsigned char *addr,
190 			    u16 vid,
191 			    u16 flags);
192 extern int ndo_dflt_fdb_del(struct ndmsg *ndm,
193 			    struct nlattr *tb[],
194 			    struct net_device *dev,
195 			    const unsigned char *addr,
196 			    u16 vid);
197 
198 extern int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
199 				   struct net_device *dev, u16 mode,
200 				   u32 flags, u32 mask, int nlflags,
201 				   u32 filter_mask,
202 				   int (*vlan_fill)(struct sk_buff *skb,
203 						    struct net_device *dev,
204 						    u32 filter_mask));
205 
206 extern void rtnl_offload_xstats_notify(struct net_device *dev);
207 
208 static inline int rtnl_has_listeners(const struct net *net, u32 group)
209 {
210 	struct sock *rtnl = net->rtnl;
211 
212 	return netlink_has_listeners(rtnl, group);
213 }
214 
215 /**
216  * rtnl_notify_needed - check if notification is needed
217  * @net: Pointer to the net namespace
218  * @nlflags: netlink ingress message flags
219  * @group: rtnl group
220  *
221  * Based on the ingress message flags and rtnl group, returns true
222  * if a notification is needed, false otherwise.
223  */
224 static inline bool
225 rtnl_notify_needed(const struct net *net, u16 nlflags, u32 group)
226 {
227 	return (nlflags & NLM_F_ECHO) || rtnl_has_listeners(net, group);
228 }
229 
230 void netdev_set_operstate(struct net_device *dev, int newstate);
231 
232 #endif	/* __LINUX_RTNETLINK_H */
233