/include/net/net_namespace.h

  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
 24struct proc_dir_entry;
 25struct net_device;
 26struct sock;
 27struct ctl_table_header;
 28struct net_generic;
 29struct sock;
 30
 31
 32#define NETDEV_HASHBITS    8
 33#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
 34
 35struct 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	struct sock		*nfnl;
 85	struct sock		*nfnl_stash;
 86#endif
 87#ifdef CONFIG_XFRM
 88	struct netns_xfrm	xfrm;
 89#endif
 90#ifdef CONFIG_WEXT_CORE
 91	struct sk_buff_head	wext_nlevents;
 92#endif
 93	struct net_generic	*gen;
 94};
 95
 96
 97#include <linux/seq_file_net.h>
 98
 99/* Init's network namespace */
100extern struct net init_net;
101
102#ifdef CONFIG_NET
103extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
104
105#else /* CONFIG_NET */
106static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
107{
108	/* There is nothing to copy so this is a noop */
109	return net_ns;
110}
111#endif /* CONFIG_NET */
112
113
114extern struct list_head net_namespace_list;
115
116extern struct net *get_net_ns_by_pid(pid_t pid);
117
118#ifdef CONFIG_NET_NS
119extern void __put_net(struct net *net);
120
121static inline struct net *get_net(struct net *net)
122{
123	atomic_inc(&net->count);
124	return net;
125}
126
127static inline struct net *maybe_get_net(struct net *net)
128{
129	/* Used when we know struct net exists but we
130	 * aren't guaranteed a previous reference count
131	 * exists.  If the reference count is zero this
132	 * function fails and returns NULL.
133	 */
134	if (!atomic_inc_not_zero(&net->count))
135		net = NULL;
136	return net;
137}
138
139static inline void put_net(struct net *net)
140{
141	if (atomic_dec_and_test(&net->count))
142		__put_net(net);
143}
144
145static inline
146int net_eq(const struct net *net1, const struct net *net2)
147{
148	return net1 == net2;
149}
150#else
151
152static inline struct net *get_net(struct net *net)
153{
154	return net;
155}
156
157static inline void put_net(struct net *net)
158{
159}
160
161static inline struct net *maybe_get_net(struct net *net)
162{
163	return net;
164}
165
166static inline
167int net_eq(const struct net *net1, const struct net *net2)
168{
169	return 1;
170}
171#endif
172
173
174#ifdef NETNS_REFCNT_DEBUG
175static inline struct net *hold_net(struct net *net)
176{
177	if (net)
178		atomic_inc(&net->use_count);
179	return net;
180}
181
182static inline void release_net(struct net *net)
183{
184	if (net)
185		atomic_dec(&net->use_count);
186}
187#else
188static inline struct net *hold_net(struct net *net)
189{
190	return net;
191}
192
193static inline void release_net(struct net *net)
194{
195}
196#endif
197
198#ifdef CONFIG_NET_NS
199
200static inline void write_pnet(struct net **pnet, struct net *net)
201{
202	*pnet = net;
203}
204
205static inline struct net *read_pnet(struct net * const *pnet)
206{
207	return *pnet;
208}
209
210#else
211
212#define write_pnet(pnet, net)	do { (void)(net);} while (0)
213#define read_pnet(pnet)		(&init_net)
214
215#endif
216
217#define for_each_net(VAR)				\
218	list_for_each_entry(VAR, &net_namespace_list, list)
219
220#define for_each_net_rcu(VAR)				\
221	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
222
223#ifdef CONFIG_NET_NS
224#define __net_init
225#define __net_exit
226#define __net_initdata
227#else
228#define __net_init	__init
229#define __net_exit	__exit_refok
230#define __net_initdata	__initdata
231#endif
232
233struct pernet_operations {
234	struct list_head list;
235	int (*init)(struct net *net);
236	void (*exit)(struct net *net);
237	void (*exit_batch)(struct list_head *net_exit_list);
238	int *id;
239	size_t size;
240};
241
242/*
243 * Use these carefully.  If you implement a network device and it
244 * needs per network namespace operations use device pernet operations,
245 * otherwise use pernet subsys operations.
246 *
247 * Network interfaces need to be removed from a dying netns _before_
248 * subsys notifiers can be called, as most of the network code cleanup
249 * (which is done from subsys notifiers) runs with the assumption that
250 * dev_remove_pack has been called so no new packets will arrive during
251 * and after the cleanup functions have been called.  dev_remove_pack
252 * is not per namespace so instead the guarantee of no more packets
253 * arriving in a network namespace is provided by ensuring that all
254 * network devices and all sockets have left the network namespace
255 * before the cleanup methods are called.
256 *
257 * For the longest time the ipv4 icmp code was registered as a pernet
258 * device which caused kernel oops, and panics during network
259 * namespace cleanup.   So please don't get this wrong.
260 */
261extern int register_pernet_subsys(struct pernet_operations *);
262extern void unregister_pernet_subsys(struct pernet_operations *);
263extern int register_pernet_device(struct pernet_operations *);
264extern void unregister_pernet_device(struct pernet_operations *);
265
266struct ctl_path;
267struct ctl_table;
268struct ctl_table_header;
269
270extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
271	const struct ctl_path *path, struct ctl_table *table);
272extern struct ctl_table_header *register_net_sysctl_rotable(
273	const struct ctl_path *path, struct ctl_table *table);
274extern void unregister_net_sysctl_table(struct ctl_table_header *header);
275
276#endif /* __NET_NET_NAMESPACE_H */