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 proc_dir_entry; 27 struct net_device; 28 struct sock; 29 struct ctl_table_header; 30 struct net_generic; 31 struct sock; 32 struct netns_ipvs; 33 34 35 #define NETDEV_HASHBITS 8 36 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 37 38 struct net { 39 atomic_t passive; /* To decided when the network 40 * namespace should be freed. 41 */ 42 atomic_t count; /* To decided when the network 43 * namespace should be shut down. 44 */ 45 #ifdef NETNS_REFCNT_DEBUG 46 atomic_t use_count; /* To track references we 47 * destroy on demand 48 */ 49 #endif 50 spinlock_t rules_mod_lock; 51 52 struct list_head list; /* list of network namespaces */ 53 struct list_head cleanup_list; /* namespaces on death row */ 54 struct list_head exit_list; /* Use only net_mutex */ 55 56 struct proc_dir_entry *proc_net; 57 struct proc_dir_entry *proc_net_stat; 58 59 #ifdef CONFIG_SYSCTL 60 struct ctl_table_set sysctls; 61 #endif 62 63 struct sock *rtnl; /* rtnetlink socket */ 64 struct sock *genl_sock; 65 66 struct list_head dev_base_head; 67 struct hlist_head *dev_name_head; 68 struct hlist_head *dev_index_head; 69 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 70 int ifindex; 71 72 /* core fib_rules */ 73 struct list_head rules_ops; 74 75 76 struct net_device *loopback_dev; /* The loopback */ 77 struct netns_core core; 78 struct netns_mib mib; 79 struct netns_packet packet; 80 struct netns_unix unx; 81 struct netns_ipv4 ipv4; 82 #if IS_ENABLED(CONFIG_IPV6) 83 struct netns_ipv6 ipv6; 84 #endif 85 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 86 struct netns_sctp sctp; 87 #endif 88 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 89 struct netns_dccp dccp; 90 #endif 91 #ifdef CONFIG_NETFILTER 92 struct netns_xt xt; 93 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 94 struct netns_ct ct; 95 #endif 96 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 97 struct netns_nf_frag nf_frag; 98 #endif 99 struct sock *nfnl; 100 struct sock *nfnl_stash; 101 #endif 102 #ifdef CONFIG_WEXT_CORE 103 struct sk_buff_head wext_nlevents; 104 #endif 105 struct net_generic __rcu *gen; 106 107 /* Note : following structs are cache line aligned */ 108 #ifdef CONFIG_XFRM 109 struct netns_xfrm xfrm; 110 #endif 111 struct netns_ipvs *ipvs; 112 struct sock *diag_nlsk; 113 atomic_t rt_genid; 114 }; 115 116 /* 117 * ifindex generation is per-net namespace, and loopback is 118 * always the 1st device in ns (see net_dev_init), thus any 119 * loopback device should get ifindex 1 120 */ 121 122 #define LOOPBACK_IFINDEX 1 123 124 #include <linux/seq_file_net.h> 125 126 /* Init's network namespace */ 127 extern struct net init_net; 128 129 #ifdef CONFIG_NET 130 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns); 131 132 #else /* CONFIG_NET */ 133 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns) 134 { 135 /* There is nothing to copy so this is a noop */ 136 return net_ns; 137 } 138 #endif /* CONFIG_NET */ 139 140 141 extern struct list_head net_namespace_list; 142 143 extern struct net *get_net_ns_by_pid(pid_t pid); 144 extern struct net *get_net_ns_by_fd(int pid); 145 146 #ifdef CONFIG_NET_NS 147 extern void __put_net(struct net *net); 148 149 static inline struct net *get_net(struct net *net) 150 { 151 atomic_inc(&net->count); 152 return net; 153 } 154 155 static inline struct net *maybe_get_net(struct net *net) 156 { 157 /* Used when we know struct net exists but we 158 * aren't guaranteed a previous reference count 159 * exists. If the reference count is zero this 160 * function fails and returns NULL. 161 */ 162 if (!atomic_inc_not_zero(&net->count)) 163 net = NULL; 164 return net; 165 } 166 167 static inline void put_net(struct net *net) 168 { 169 if (atomic_dec_and_test(&net->count)) 170 __put_net(net); 171 } 172 173 static inline 174 int net_eq(const struct net *net1, const struct net *net2) 175 { 176 return net1 == net2; 177 } 178 179 extern void net_drop_ns(void *); 180 181 #else 182 183 static inline struct net *get_net(struct net *net) 184 { 185 return net; 186 } 187 188 static inline void put_net(struct net *net) 189 { 190 } 191 192 static inline struct net *maybe_get_net(struct net *net) 193 { 194 return net; 195 } 196 197 static inline 198 int net_eq(const struct net *net1, const struct net *net2) 199 { 200 return 1; 201 } 202 203 #define net_drop_ns NULL 204 #endif 205 206 207 #ifdef NETNS_REFCNT_DEBUG 208 static inline struct net *hold_net(struct net *net) 209 { 210 if (net) 211 atomic_inc(&net->use_count); 212 return net; 213 } 214 215 static inline void release_net(struct net *net) 216 { 217 if (net) 218 atomic_dec(&net->use_count); 219 } 220 #else 221 static inline struct net *hold_net(struct net *net) 222 { 223 return net; 224 } 225 226 static inline void release_net(struct net *net) 227 { 228 } 229 #endif 230 231 #ifdef CONFIG_NET_NS 232 233 static inline void write_pnet(struct net **pnet, struct net *net) 234 { 235 *pnet = net; 236 } 237 238 static inline struct net *read_pnet(struct net * const *pnet) 239 { 240 return *pnet; 241 } 242 243 #else 244 245 #define write_pnet(pnet, net) do { (void)(net);} while (0) 246 #define read_pnet(pnet) (&init_net) 247 248 #endif 249 250 #define for_each_net(VAR) \ 251 list_for_each_entry(VAR, &net_namespace_list, list) 252 253 #define for_each_net_rcu(VAR) \ 254 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 255 256 #ifdef CONFIG_NET_NS 257 #define __net_init 258 #define __net_exit 259 #define __net_initdata 260 #define __net_initconst 261 #else 262 #define __net_init __init 263 #define __net_exit __exit_refok 264 #define __net_initdata __initdata 265 #define __net_initconst __initconst 266 #endif 267 268 struct pernet_operations { 269 struct list_head list; 270 int (*init)(struct net *net); 271 void (*exit)(struct net *net); 272 void (*exit_batch)(struct list_head *net_exit_list); 273 int *id; 274 size_t size; 275 }; 276 277 /* 278 * Use these carefully. If you implement a network device and it 279 * needs per network namespace operations use device pernet operations, 280 * otherwise use pernet subsys operations. 281 * 282 * Network interfaces need to be removed from a dying netns _before_ 283 * subsys notifiers can be called, as most of the network code cleanup 284 * (which is done from subsys notifiers) runs with the assumption that 285 * dev_remove_pack has been called so no new packets will arrive during 286 * and after the cleanup functions have been called. dev_remove_pack 287 * is not per namespace so instead the guarantee of no more packets 288 * arriving in a network namespace is provided by ensuring that all 289 * network devices and all sockets have left the network namespace 290 * before the cleanup methods are called. 291 * 292 * For the longest time the ipv4 icmp code was registered as a pernet 293 * device which caused kernel oops, and panics during network 294 * namespace cleanup. So please don't get this wrong. 295 */ 296 extern int register_pernet_subsys(struct pernet_operations *); 297 extern void unregister_pernet_subsys(struct pernet_operations *); 298 extern int register_pernet_device(struct pernet_operations *); 299 extern void unregister_pernet_device(struct pernet_operations *); 300 301 struct ctl_table; 302 struct ctl_table_header; 303 304 #ifdef CONFIG_SYSCTL 305 extern int net_sysctl_init(void); 306 extern struct ctl_table_header *register_net_sysctl(struct net *net, 307 const char *path, struct ctl_table *table); 308 extern void unregister_net_sysctl_table(struct ctl_table_header *header); 309 #else 310 static inline int net_sysctl_init(void) { return 0; } 311 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 312 const char *path, struct ctl_table *table) 313 { 314 return NULL; 315 } 316 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 317 { 318 } 319 #endif 320 321 static inline int rt_genid(struct net *net) 322 { 323 return atomic_read(&net->rt_genid); 324 } 325 326 static inline void rt_genid_bump(struct net *net) 327 { 328 atomic_inc(&net->rt_genid); 329 } 330 331 #endif /* __NET_NET_NAMESPACE_H */ 332