struct net

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         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 */
100 extern struct net init_net;
101 
102 #ifdef CONFIG_NET
103 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
104 
105 #else /* CONFIG_NET */
106 static 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 
114 extern struct list_head net_namespace_list;
115 
116 extern struct net *get_net_ns_by_pid(pid_t pid);
117 
118 #ifdef CONFIG_NET_NS
119 extern void __put_net(struct net *net);
120 
121 static inline struct net *get_net(struct net *net)
122 {
123         atomic_inc(&net->count);
124         return net;
125 }
126 
127 static 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 
139 static inline void put_net(struct net *net)
140 {
141         if (atomic_dec_and_test(&net->count))
142                 __put_net(net);
143 }
144 
145 static inline
146 int net_eq(const struct net *net1, const struct net *net2)
147 {
148         return net1 == net2;
149 }
150 #else
151 
152 static inline struct net *get_net(struct net *net)
153 {
154         return net;
155 }
156 
157 static inline void put_net(struct net *net)
158 {
159 }
160 
161 static inline struct net *maybe_get_net(struct net *net)
162 {
163         return net;
164 }
165 
166 static inline
167 int net_eq(const struct net *net1, const struct net *net2)
168 {
169         return 1;
170 }
171 #endif
172 
173 
174 #ifdef NETNS_REFCNT_DEBUG
175 static inline struct net *hold_net(struct net *net)
176 {
177         if (net)
178                 atomic_inc(&net->use_count);
179         return net;
180 }
181 
182 static inline void release_net(struct net *net)
183 {
184         if (net)
185                 atomic_dec(&net->use_count);
186 }
187 #else
188 static inline struct net *hold_net(struct net *net)
189 {
190         return net;
191 }
192 
193 static inline void release_net(struct net *net)
194 {
195 }
196 #endif
197 
198 #ifdef CONFIG_NET_NS
199 
200 static inline void write_pnet(struct net **pnet, struct net *net)
201 {
202         *pnet = net;
203 }
204 
205 static 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 
233 struct 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  */
261 extern int register_pernet_subsys(struct pernet_operations *);
262 extern void unregister_pernet_subsys(struct pernet_operations *);
263 extern int register_pernet_device(struct pernet_operations *);
264 extern void unregister_pernet_device(struct pernet_operations *);
265 
266 struct ctl_path;
267 struct ctl_table;
268 struct ctl_table_header;
269 
270 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
271         const struct ctl_path *path, struct ctl_table *table);
272 extern struct ctl_table_header *register_net_sysctl_rotable(
273         const struct ctl_path *path, struct ctl_table *table);
274 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
275 
276 #endif /* __NET_NET_NAMESPACE_H */
277