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 }; 114 115 /* 116 * ifindex generation is per-net namespace, and loopback is 117 * always the 1st device in ns (see net_dev_init), thus any 118 * loopback device should get ifindex 1 119 */ 120 121 #define LOOPBACK_IFINDEX 1 122 123 #include <linux/seq_file_net.h> 124 125 /* Init's network namespace */ 126 extern struct net init_net; 127 128 #ifdef CONFIG_NET 129 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns); 130 131 #else /* CONFIG_NET */ 132 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns) 133 { 134 /* There is nothing to copy so this is a noop */ 135 return net_ns; 136 } 137 #endif /* CONFIG_NET */ 138 139 140 extern struct list_head net_namespace_list; 141 142 extern struct net *get_net_ns_by_pid(pid_t pid); 143 extern struct net *get_net_ns_by_fd(int pid); 144 145 #ifdef CONFIG_NET_NS 146 extern void __put_net(struct net *net); 147 148 static inline struct net *get_net(struct net *net) 149 { 150 atomic_inc(&net->count); 151 return net; 152 } 153 154 static inline struct net *maybe_get_net(struct net *net) 155 { 156 /* Used when we know struct net exists but we 157 * aren't guaranteed a previous reference count 158 * exists. If the reference count is zero this 159 * function fails and returns NULL. 160 */ 161 if (!atomic_inc_not_zero(&net->count)) 162 net = NULL; 163 return net; 164 } 165 166 static inline void put_net(struct net *net) 167 { 168 if (atomic_dec_and_test(&net->count)) 169 __put_net(net); 170 } 171 172 static inline 173 int net_eq(const struct net *net1, const struct net *net2) 174 { 175 return net1 == net2; 176 } 177 178 extern void net_drop_ns(void *); 179 180 #else 181 182 static inline struct net *get_net(struct net *net) 183 { 184 return net; 185 } 186 187 static inline void put_net(struct net *net) 188 { 189 } 190 191 static inline struct net *maybe_get_net(struct net *net) 192 { 193 return net; 194 } 195 196 static inline 197 int net_eq(const struct net *net1, const struct net *net2) 198 { 199 return 1; 200 } 201 202 #define net_drop_ns NULL 203 #endif 204 205 206 #ifdef NETNS_REFCNT_DEBUG 207 static inline struct net *hold_net(struct net *net) 208 { 209 if (net) 210 atomic_inc(&net->use_count); 211 return net; 212 } 213 214 static inline void release_net(struct net *net) 215 { 216 if (net) 217 atomic_dec(&net->use_count); 218 } 219 #else 220 static inline struct net *hold_net(struct net *net) 221 { 222 return net; 223 } 224 225 static inline void release_net(struct net *net) 226 { 227 } 228 #endif 229 230 #ifdef CONFIG_NET_NS 231 232 static inline void write_pnet(struct net **pnet, struct net *net) 233 { 234 *pnet = net; 235 } 236 237 static inline struct net *read_pnet(struct net * const *pnet) 238 { 239 return *pnet; 240 } 241 242 #else 243 244 #define write_pnet(pnet, net) do { (void)(net);} while (0) 245 #define read_pnet(pnet) (&init_net) 246 247 #endif 248 249 #define for_each_net(VAR) \ 250 list_for_each_entry(VAR, &net_namespace_list, list) 251 252 #define for_each_net_rcu(VAR) \ 253 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 254 255 #ifdef CONFIG_NET_NS 256 #define __net_init 257 #define __net_exit 258 #define __net_initdata 259 #else 260 #define __net_init __init 261 #define __net_exit __exit_refok 262 #define __net_initdata __initdata 263 #endif 264 265 struct pernet_operations { 266 struct list_head list; 267 int (*init)(struct net *net); 268 void (*exit)(struct net *net); 269 void (*exit_batch)(struct list_head *net_exit_list); 270 int *id; 271 size_t size; 272 }; 273 274 /* 275 * Use these carefully. If you implement a network device and it 276 * needs per network namespace operations use device pernet operations, 277 * otherwise use pernet subsys operations. 278 * 279 * Network interfaces need to be removed from a dying netns _before_ 280 * subsys notifiers can be called, as most of the network code cleanup 281 * (which is done from subsys notifiers) runs with the assumption that 282 * dev_remove_pack has been called so no new packets will arrive during 283 * and after the cleanup functions have been called. dev_remove_pack 284 * is not per namespace so instead the guarantee of no more packets 285 * arriving in a network namespace is provided by ensuring that all 286 * network devices and all sockets have left the network namespace 287 * before the cleanup methods are called. 288 * 289 * For the longest time the ipv4 icmp code was registered as a pernet 290 * device which caused kernel oops, and panics during network 291 * namespace cleanup. So please don't get this wrong. 292 */ 293 extern int register_pernet_subsys(struct pernet_operations *); 294 extern void unregister_pernet_subsys(struct pernet_operations *); 295 extern int register_pernet_device(struct pernet_operations *); 296 extern void unregister_pernet_device(struct pernet_operations *); 297 298 struct ctl_table; 299 struct ctl_table_header; 300 301 #ifdef CONFIG_SYSCTL 302 extern int net_sysctl_init(void); 303 extern struct ctl_table_header *register_net_sysctl(struct net *net, 304 const char *path, struct ctl_table *table); 305 extern void unregister_net_sysctl_table(struct ctl_table_header *header); 306 #else 307 static inline int net_sysctl_init(void) { return 0; } 308 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 309 const char *path, struct ctl_table *table) 310 { 311 return NULL; 312 } 313 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 314 { 315 } 316 #endif 317 318 319 #endif /* __NET_NET_NAMESPACE_H */ 320