1 /*
2 * Operations on the network namespace
3 */
4 #ifndef __NET_NET_NAMESPACE_H
5 #define __NET_NET_NAMESPACE_H
6
7 #include <linux/atomic.h>
8 #include <linux/workqueue.h>
9 #include <linux/list.h>
10 #include <linux/sysctl.h>
11
12 #include <net/netns/core.h>
13 #include <net/netns/mib.h>
14 #include <net/netns/unix.h>
15 #include <net/netns/packet.h>
16 #include <net/netns/ipv4.h>
17 #include <net/netns/ipv6.h>
18 #include <net/netns/dccp.h>
19 #include <net/netns/x_tables.h>
20 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
21 #include <net/netns/conntrack.h>
22 #endif
23 #include <net/netns/xfrm.h>
24
25 struct proc_dir_entry;
26 struct net_device;
27 struct sock;
28 struct ctl_table_header;
29 struct net_generic;
30 struct sock;
31 struct netns_ipvs;
32
33
34 #define NETDEV_HASHBITS 8
35 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
36
37 struct net {
38 atomic_t passive; /* To decided when the network
39 * namespace should be freed.
40 */
41 atomic_t count; /* To decided when the network
42 * namespace should be shut down.
43 */
44 #ifdef NETNS_REFCNT_DEBUG
45 atomic_t use_count; /* To track references we
46 * destroy on demand
47 */
48 #endif
49 spinlock_t rules_mod_lock;
50
51 struct list_head list; /* list of network namespaces */
52 struct list_head cleanup_list; /* namespaces on death row */
53 struct list_head exit_list; /* Use only net_mutex */
54
55 unsigned int proc_inum;
56
57 struct proc_dir_entry *proc_net;
58 struct proc_dir_entry *proc_net_stat;
59
60 #ifdef CONFIG_SYSCTL
61 struct ctl_table_set sysctls;
62 #endif
63
64 struct sock *rtnl; /* rtnetlink socket */
65 struct sock *genl_sock;
66
67 struct list_head dev_base_head;
68 struct hlist_head *dev_name_head;
69 struct hlist_head *dev_index_head;
70 unsigned int dev_base_seq; /* protected by rtnl_mutex */
71
72 /* core fib_rules */
73 struct list_head rules_ops;
74
75
76 struct net_device *loopback_dev; /* The loopback */
77 struct netns_core core;
78 struct netns_mib mib;
79 struct netns_packet packet;
80 struct netns_unix unx;
81 struct netns_ipv4 ipv4;
82 #if IS_ENABLED(CONFIG_IPV6)
83 struct netns_ipv6 ipv6;
84 #endif
85 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
86 struct netns_dccp dccp;
87 #endif
88 #ifdef CONFIG_NETFILTER
89 struct netns_xt xt;
90 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
91 struct netns_ct ct;
92 #endif
93 struct sock *nfnl;
94 struct sock *nfnl_stash;
95 #endif
96 #ifdef CONFIG_WEXT_CORE
97 struct sk_buff_head wext_nlevents;
98 #endif
99 struct net_generic __rcu *gen;
100
101 /* Note : following structs are cache line aligned */
102 #ifdef CONFIG_XFRM
103 struct netns_xfrm xfrm;
104 #endif
105 struct netns_ipvs *ipvs;
106 };
107
108
109 #include <linux/seq_file_net.h>
110
111 /* Init's network namespace */
112 extern struct net init_net;
113
114 #ifdef CONFIG_NET
115 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
116
117 #else /* CONFIG_NET */
copy_net_ns(unsigned long flags,struct net * net_ns)118 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
119 {
120 /* There is nothing to copy so this is a noop */
121 return net_ns;
122 }
123 #endif /* CONFIG_NET */
124
125
126 extern struct list_head net_namespace_list;
127
128 extern struct net *get_net_ns_by_pid(pid_t pid);
129 extern struct net *get_net_ns_by_fd(int pid);
130
131 #ifdef CONFIG_NET_NS
132 extern void __put_net(struct net *net);
133
get_net(struct net * net)134 static inline struct net *get_net(struct net *net)
135 {
136 atomic_inc(&net->count);
137 return net;
138 }
139
maybe_get_net(struct net * net)140 static inline struct net *maybe_get_net(struct net *net)
141 {
142 /* Used when we know struct net exists but we
143 * aren't guaranteed a previous reference count
144 * exists. If the reference count is zero this
145 * function fails and returns NULL.
146 */
147 if (!atomic_inc_not_zero(&net->count))
148 net = NULL;
149 return net;
150 }
151
put_net(struct net * net)152 static inline void put_net(struct net *net)
153 {
154 if (atomic_dec_and_test(&net->count))
155 __put_net(net);
156 }
157
158 static inline
net_eq(const struct net * net1,const struct net * net2)159 int net_eq(const struct net *net1, const struct net *net2)
160 {
161 return net1 == net2;
162 }
163
164 extern void net_drop_ns(void *);
165
166 #else
167
get_net(struct net * net)168 static inline struct net *get_net(struct net *net)
169 {
170 return net;
171 }
172
put_net(struct net * net)173 static inline void put_net(struct net *net)
174 {
175 }
176
maybe_get_net(struct net * net)177 static inline struct net *maybe_get_net(struct net *net)
178 {
179 return net;
180 }
181
182 static inline
net_eq(const struct net * net1,const struct net * net2)183 int net_eq(const struct net *net1, const struct net *net2)
184 {
185 return 1;
186 }
187
188 #define net_drop_ns NULL
189 #endif
190
191
192 #ifdef NETNS_REFCNT_DEBUG
hold_net(struct net * net)193 static inline struct net *hold_net(struct net *net)
194 {
195 if (net)
196 atomic_inc(&net->use_count);
197 return net;
198 }
199
release_net(struct net * net)200 static inline void release_net(struct net *net)
201 {
202 if (net)
203 atomic_dec(&net->use_count);
204 }
205 #else
hold_net(struct net * net)206 static inline struct net *hold_net(struct net *net)
207 {
208 return net;
209 }
210
release_net(struct net * net)211 static inline void release_net(struct net *net)
212 {
213 }
214 #endif
215
216 #ifdef CONFIG_NET_NS
217
write_pnet(struct net ** pnet,struct net * net)218 static inline void write_pnet(struct net **pnet, struct net *net)
219 {
220 *pnet = net;
221 }
222
read_pnet(struct net * const * pnet)223 static inline struct net *read_pnet(struct net * const *pnet)
224 {
225 return *pnet;
226 }
227
228 #else
229
230 #define write_pnet(pnet, net) do { (void)(net);} while (0)
231 #define read_pnet(pnet) (&init_net)
232
233 #endif
234
235 #define for_each_net(VAR) \
236 list_for_each_entry(VAR, &net_namespace_list, list)
237
238 #define for_each_net_rcu(VAR) \
239 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
240
241 #ifdef CONFIG_NET_NS
242 #define __net_init
243 #define __net_exit
244 #define __net_initdata
245 #else
246 #define __net_init __init
247 #define __net_exit __exit_refok
248 #define __net_initdata __initdata
249 #endif
250
251 struct pernet_operations {
252 struct list_head list;
253 int (*init)(struct net *net);
254 void (*exit)(struct net *net);
255 void (*exit_batch)(struct list_head *net_exit_list);
256 int *id;
257 size_t size;
258 };
259
260 /*
261 * Use these carefully. If you implement a network device and it
262 * needs per network namespace operations use device pernet operations,
263 * otherwise use pernet subsys operations.
264 *
265 * Network interfaces need to be removed from a dying netns _before_
266 * subsys notifiers can be called, as most of the network code cleanup
267 * (which is done from subsys notifiers) runs with the assumption that
268 * dev_remove_pack has been called so no new packets will arrive during
269 * and after the cleanup functions have been called. dev_remove_pack
270 * is not per namespace so instead the guarantee of no more packets
271 * arriving in a network namespace is provided by ensuring that all
272 * network devices and all sockets have left the network namespace
273 * before the cleanup methods are called.
274 *
275 * For the longest time the ipv4 icmp code was registered as a pernet
276 * device which caused kernel oops, and panics during network
277 * namespace cleanup. So please don't get this wrong.
278 */
279 extern int register_pernet_subsys(struct pernet_operations *);
280 extern void unregister_pernet_subsys(struct pernet_operations *);
281 extern int register_pernet_device(struct pernet_operations *);
282 extern void unregister_pernet_device(struct pernet_operations *);
283
284 struct ctl_path;
285 struct ctl_table;
286 struct ctl_table_header;
287
288 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
289 const struct ctl_path *path, struct ctl_table *table);
290 extern struct ctl_table_header *register_net_sysctl_rotable(
291 const struct ctl_path *path, struct ctl_table *table);
292 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
293
294 #endif /* __NET_NET_NAMESPACE_H */
295