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