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/sctp.h> 19 #include <net/netns/dccp.h> 20 #include <net/netns/netfilter.h> 21 #include <net/netns/x_tables.h> 22 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 23 #include <net/netns/conntrack.h> 24 #endif 25 #include <net/netns/xfrm.h> 26 27 struct user_namespace; 28 struct proc_dir_entry; 29 struct net_device; 30 struct sock; 31 struct ctl_table_header; 32 struct net_generic; 33 struct sock; 34 struct netns_ipvs; 35 36 37 #define NETDEV_HASHBITS 8 38 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 39 40 struct net { 41 atomic_t passive; /* To decided when the network 42 * namespace should be freed. 43 */ 44 atomic_t count; /* To decided when the network 45 * namespace should be shut down. 46 */ 47 #ifdef NETNS_REFCNT_DEBUG 48 atomic_t use_count; /* To track references we 49 * destroy on demand 50 */ 51 #endif 52 spinlock_t rules_mod_lock; 53 54 struct list_head list; /* list of network namespaces */ 55 struct list_head cleanup_list; /* namespaces on death row */ 56 struct list_head exit_list; /* Use only net_mutex */ 57 58 struct user_namespace *user_ns; /* Owning user namespace */ 59 60 unsigned int proc_inum; 61 62 struct proc_dir_entry *proc_net; 63 struct proc_dir_entry *proc_net_stat; 64 65 #ifdef CONFIG_SYSCTL 66 struct ctl_table_set sysctls; 67 #endif 68 69 struct sock *rtnl; /* rtnetlink socket */ 70 struct sock *genl_sock; 71 72 struct list_head dev_base_head; 73 struct hlist_head *dev_name_head; 74 struct hlist_head *dev_index_head; 75 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 76 int ifindex; 77 78 /* core fib_rules */ 79 struct list_head rules_ops; 80 81 82 struct net_device *loopback_dev; /* The loopback */ 83 struct netns_core core; 84 struct netns_mib mib; 85 struct netns_packet packet; 86 struct netns_unix unx; 87 struct netns_ipv4 ipv4; 88 #if IS_ENABLED(CONFIG_IPV6) 89 struct netns_ipv6 ipv6; 90 #endif 91 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 92 struct netns_sctp sctp; 93 #endif 94 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 95 struct netns_dccp dccp; 96 #endif 97 #ifdef CONFIG_NETFILTER 98 struct netns_nf nf; 99 struct netns_xt xt; 100 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 101 struct netns_ct ct; 102 #endif 103 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 104 struct netns_nf_frag nf_frag; 105 #endif 106 struct sock *nfnl; 107 struct sock *nfnl_stash; 108 #endif 109 #ifdef CONFIG_WEXT_CORE 110 struct sk_buff_head wext_nlevents; 111 #endif 112 struct net_generic __rcu *gen; 113 114 /* Note : following structs are cache line aligned */ 115 #ifdef CONFIG_XFRM 116 struct netns_xfrm xfrm; 117 #endif 118 struct netns_ipvs *ipvs; 119 struct sock *diag_nlsk; 120 atomic_t rt_genid; 121 }; 122 123 /* 124 * ifindex generation is per-net namespace, and loopback is 125 * always the 1st device in ns (see net_dev_init), thus any 126 * loopback device should get ifindex 1 127 */ 128 129 #define LOOPBACK_IFINDEX 1 130 131 #include <linux/seq_file_net.h> 132 133 /* Init's network namespace */ 134 extern struct net init_net; 135 136 #ifdef CONFIG_NET_NS 137 extern struct net *copy_net_ns(unsigned long flags, 138 struct user_namespace *user_ns, struct net *old_net); 139 140 #else /* CONFIG_NET_NS */ 141 #include <linux/sched.h> 142 #include <linux/nsproxy.h> 143 static inline struct net *copy_net_ns(unsigned long flags, 144 struct user_namespace *user_ns, struct net *old_net) 145 { 146 if (flags & CLONE_NEWNET) 147 return ERR_PTR(-EINVAL); 148 return old_net; 149 } 150 #endif /* CONFIG_NET_NS */ 151 152 153 extern struct list_head net_namespace_list; 154 155 extern struct net *get_net_ns_by_pid(pid_t pid); 156 extern struct net *get_net_ns_by_fd(int pid); 157 158 #ifdef CONFIG_NET_NS 159 extern void __put_net(struct net *net); 160 161 static inline struct net *get_net(struct net *net) 162 { 163 atomic_inc(&net->count); 164 return net; 165 } 166 167 static inline struct net *maybe_get_net(struct net *net) 168 { 169 /* Used when we know struct net exists but we 170 * aren't guaranteed a previous reference count 171 * exists. If the reference count is zero this 172 * function fails and returns NULL. 173 */ 174 if (!atomic_inc_not_zero(&net->count)) 175 net = NULL; 176 return net; 177 } 178 179 static inline void put_net(struct net *net) 180 { 181 if (atomic_dec_and_test(&net->count)) 182 __put_net(net); 183 } 184 185 static inline 186 int net_eq(const struct net *net1, const struct net *net2) 187 { 188 return net1 == net2; 189 } 190 191 extern void net_drop_ns(void *); 192 193 #else 194 195 static inline struct net *get_net(struct net *net) 196 { 197 return net; 198 } 199 200 static inline void put_net(struct net *net) 201 { 202 } 203 204 static inline struct net *maybe_get_net(struct net *net) 205 { 206 return net; 207 } 208 209 static inline 210 int net_eq(const struct net *net1, const struct net *net2) 211 { 212 return 1; 213 } 214 215 #define net_drop_ns NULL 216 #endif 217 218 219 #ifdef NETNS_REFCNT_DEBUG 220 static inline struct net *hold_net(struct net *net) 221 { 222 if (net) 223 atomic_inc(&net->use_count); 224 return net; 225 } 226 227 static inline void release_net(struct net *net) 228 { 229 if (net) 230 atomic_dec(&net->use_count); 231 } 232 #else 233 static inline struct net *hold_net(struct net *net) 234 { 235 return net; 236 } 237 238 static inline void release_net(struct net *net) 239 { 240 } 241 #endif 242 243 #ifdef CONFIG_NET_NS 244 245 static inline void write_pnet(struct net **pnet, struct net *net) 246 { 247 *pnet = net; 248 } 249 250 static inline struct net *read_pnet(struct net * const *pnet) 251 { 252 return *pnet; 253 } 254 255 #else 256 257 #define write_pnet(pnet, net) do { (void)(net);} while (0) 258 #define read_pnet(pnet) (&init_net) 259 260 #endif 261 262 #define for_each_net(VAR) \ 263 list_for_each_entry(VAR, &net_namespace_list, list) 264 265 #define for_each_net_rcu(VAR) \ 266 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 267 268 #ifdef CONFIG_NET_NS 269 #define __net_init 270 #define __net_exit 271 #define __net_initdata 272 #define __net_initconst 273 #else 274 #define __net_init __init 275 #define __net_exit __exit_refok 276 #define __net_initdata __initdata 277 #define __net_initconst __initconst 278 #endif 279 280 struct pernet_operations { 281 struct list_head list; 282 int (*init)(struct net *net); 283 void (*exit)(struct net *net); 284 void (*exit_batch)(struct list_head *net_exit_list); 285 int *id; 286 size_t size; 287 }; 288 289 /* 290 * Use these carefully. If you implement a network device and it 291 * needs per network namespace operations use device pernet operations, 292 * otherwise use pernet subsys operations. 293 * 294 * Network interfaces need to be removed from a dying netns _before_ 295 * subsys notifiers can be called, as most of the network code cleanup 296 * (which is done from subsys notifiers) runs with the assumption that 297 * dev_remove_pack has been called so no new packets will arrive during 298 * and after the cleanup functions have been called. dev_remove_pack 299 * is not per namespace so instead the guarantee of no more packets 300 * arriving in a network namespace is provided by ensuring that all 301 * network devices and all sockets have left the network namespace 302 * before the cleanup methods are called. 303 * 304 * For the longest time the ipv4 icmp code was registered as a pernet 305 * device which caused kernel oops, and panics during network 306 * namespace cleanup. So please don't get this wrong. 307 */ 308 extern int register_pernet_subsys(struct pernet_operations *); 309 extern void unregister_pernet_subsys(struct pernet_operations *); 310 extern int register_pernet_device(struct pernet_operations *); 311 extern void unregister_pernet_device(struct pernet_operations *); 312 313 struct ctl_table; 314 struct ctl_table_header; 315 316 #ifdef CONFIG_SYSCTL 317 extern int net_sysctl_init(void); 318 extern struct ctl_table_header *register_net_sysctl(struct net *net, 319 const char *path, struct ctl_table *table); 320 extern void unregister_net_sysctl_table(struct ctl_table_header *header); 321 #else 322 static inline int net_sysctl_init(void) { return 0; } 323 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 324 const char *path, struct ctl_table *table) 325 { 326 return NULL; 327 } 328 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 329 { 330 } 331 #endif 332 333 static inline int rt_genid(struct net *net) 334 { 335 return atomic_read(&net->rt_genid); 336 } 337 338 static inline void rt_genid_bump(struct net *net) 339 { 340 atomic_inc(&net->rt_genid); 341 } 342 343 #endif /* __NET_NET_NAMESPACE_H */ 344