xref: /openbmc/linux/include/net/net_namespace.h (revision a09d2831)
1 /*
2  * Operations on the network namespace
3  */
4 #ifndef __NET_NET_NAMESPACE_H
5 #define __NET_NET_NAMESPACE_H
6 
7 #include <asm/atomic.h>
8 #include <linux/workqueue.h>
9 #include <linux/list.h>
10 
11 #include <net/netns/core.h>
12 #include <net/netns/mib.h>
13 #include <net/netns/unix.h>
14 #include <net/netns/packet.h>
15 #include <net/netns/ipv4.h>
16 #include <net/netns/ipv6.h>
17 #include <net/netns/dccp.h>
18 #include <net/netns/x_tables.h>
19 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
20 #include <net/netns/conntrack.h>
21 #endif
22 #include <net/netns/xfrm.h>
23 
24 struct proc_dir_entry;
25 struct net_device;
26 struct sock;
27 struct ctl_table_header;
28 struct net_generic;
29 struct sock;
30 
31 
32 #define NETDEV_HASHBITS    8
33 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
34 
35 struct net {
36 	atomic_t		count;		/* To decided when the network
37 						 *  namespace should be freed.
38 						 */
39 #ifdef NETNS_REFCNT_DEBUG
40 	atomic_t		use_count;	/* To track references we
41 						 * destroy on demand
42 						 */
43 #endif
44 	struct list_head	list;		/* list of network namespaces */
45 	struct list_head	cleanup_list;	/* namespaces on death row */
46 	struct list_head	exit_list;	/* Use only net_mutex */
47 
48 	struct proc_dir_entry 	*proc_net;
49 	struct proc_dir_entry 	*proc_net_stat;
50 
51 #ifdef CONFIG_SYSCTL
52 	struct ctl_table_set	sysctls;
53 #endif
54 
55 	struct net_device       *loopback_dev;          /* The loopback */
56 
57 	struct list_head 	dev_base_head;
58 	struct hlist_head 	*dev_name_head;
59 	struct hlist_head	*dev_index_head;
60 
61 	/* core fib_rules */
62 	struct list_head	rules_ops;
63 	spinlock_t		rules_mod_lock;
64 
65 	struct sock 		*rtnl;			/* rtnetlink socket */
66 	struct sock		*genl_sock;
67 
68 	struct netns_core	core;
69 	struct netns_mib	mib;
70 	struct netns_packet	packet;
71 	struct netns_unix	unx;
72 	struct netns_ipv4	ipv4;
73 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
74 	struct netns_ipv6	ipv6;
75 #endif
76 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
77 	struct netns_dccp	dccp;
78 #endif
79 #ifdef CONFIG_NETFILTER
80 	struct netns_xt		xt;
81 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
82 	struct netns_ct		ct;
83 #endif
84 #endif
85 #ifdef CONFIG_XFRM
86 	struct netns_xfrm	xfrm;
87 #endif
88 #ifdef CONFIG_WEXT_CORE
89 	struct sk_buff_head	wext_nlevents;
90 #endif
91 	struct net_generic	*gen;
92 };
93 
94 
95 #include <linux/seq_file_net.h>
96 
97 /* Init's network namespace */
98 extern struct net init_net;
99 
100 #ifdef CONFIG_NET
101 #define INIT_NET_NS(net_ns) .net_ns = &init_net,
102 
103 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
104 
105 #else /* CONFIG_NET */
106 
107 #define INIT_NET_NS(net_ns)
108 
109 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
110 {
111 	/* There is nothing to copy so this is a noop */
112 	return net_ns;
113 }
114 #endif /* CONFIG_NET */
115 
116 
117 extern struct list_head net_namespace_list;
118 
119 extern struct net *get_net_ns_by_pid(pid_t pid);
120 
121 #ifdef CONFIG_NET_NS
122 extern void __put_net(struct net *net);
123 
124 static inline struct net *get_net(struct net *net)
125 {
126 	atomic_inc(&net->count);
127 	return net;
128 }
129 
130 static inline struct net *maybe_get_net(struct net *net)
131 {
132 	/* Used when we know struct net exists but we
133 	 * aren't guaranteed a previous reference count
134 	 * exists.  If the reference count is zero this
135 	 * function fails and returns NULL.
136 	 */
137 	if (!atomic_inc_not_zero(&net->count))
138 		net = NULL;
139 	return net;
140 }
141 
142 static inline void put_net(struct net *net)
143 {
144 	if (atomic_dec_and_test(&net->count))
145 		__put_net(net);
146 }
147 
148 static inline
149 int net_eq(const struct net *net1, const struct net *net2)
150 {
151 	return net1 == net2;
152 }
153 #else
154 
155 static inline struct net *get_net(struct net *net)
156 {
157 	return net;
158 }
159 
160 static inline void put_net(struct net *net)
161 {
162 }
163 
164 static inline struct net *maybe_get_net(struct net *net)
165 {
166 	return net;
167 }
168 
169 static inline
170 int net_eq(const struct net *net1, const struct net *net2)
171 {
172 	return 1;
173 }
174 #endif
175 
176 
177 #ifdef NETNS_REFCNT_DEBUG
178 static inline struct net *hold_net(struct net *net)
179 {
180 	if (net)
181 		atomic_inc(&net->use_count);
182 	return net;
183 }
184 
185 static inline void release_net(struct net *net)
186 {
187 	if (net)
188 		atomic_dec(&net->use_count);
189 }
190 #else
191 static inline struct net *hold_net(struct net *net)
192 {
193 	return net;
194 }
195 
196 static inline void release_net(struct net *net)
197 {
198 }
199 #endif
200 
201 #ifdef CONFIG_NET_NS
202 
203 static inline void write_pnet(struct net **pnet, struct net *net)
204 {
205 	*pnet = net;
206 }
207 
208 static inline struct net *read_pnet(struct net * const *pnet)
209 {
210 	return *pnet;
211 }
212 
213 #else
214 
215 #define write_pnet(pnet, net)	do { (void)(net);} while (0)
216 #define read_pnet(pnet)		(&init_net)
217 
218 #endif
219 
220 #define for_each_net(VAR)				\
221 	list_for_each_entry(VAR, &net_namespace_list, list)
222 
223 #define for_each_net_rcu(VAR)				\
224 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
225 
226 #ifdef CONFIG_NET_NS
227 #define __net_init
228 #define __net_exit
229 #define __net_initdata
230 #else
231 #define __net_init	__init
232 #define __net_exit	__exit_refok
233 #define __net_initdata	__initdata
234 #endif
235 
236 struct pernet_operations {
237 	struct list_head list;
238 	int (*init)(struct net *net);
239 	void (*exit)(struct net *net);
240 	void (*exit_batch)(struct list_head *net_exit_list);
241 	int *id;
242 	size_t size;
243 };
244 
245 /*
246  * Use these carefully.  If you implement a network device and it
247  * needs per network namespace operations use device pernet operations,
248  * otherwise use pernet subsys operations.
249  *
250  * Network interfaces need to be removed from a dying netns _before_
251  * subsys notifiers can be called, as most of the network code cleanup
252  * (which is done from subsys notifiers) runs with the assumption that
253  * dev_remove_pack has been called so no new packets will arrive during
254  * and after the cleanup functions have been called.  dev_remove_pack
255  * is not per namespace so instead the guarantee of no more packets
256  * arriving in a network namespace is provided by ensuring that all
257  * network devices and all sockets have left the network namespace
258  * before the cleanup methods are called.
259  *
260  * For the longest time the ipv4 icmp code was registered as a pernet
261  * device which caused kernel oops, and panics during network
262  * namespace cleanup.   So please don't get this wrong.
263  */
264 extern int register_pernet_subsys(struct pernet_operations *);
265 extern void unregister_pernet_subsys(struct pernet_operations *);
266 extern int register_pernet_device(struct pernet_operations *);
267 extern void unregister_pernet_device(struct pernet_operations *);
268 
269 struct ctl_path;
270 struct ctl_table;
271 struct ctl_table_header;
272 
273 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
274 	const struct ctl_path *path, struct ctl_table *table);
275 extern struct ctl_table_header *register_net_sysctl_rotable(
276 	const struct ctl_path *path, struct ctl_table *table);
277 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
278 
279 #endif /* __NET_NET_NAMESPACE_H */
280