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/dccp.h> 19 #include <net/netns/x_tables.h> 20 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 21 #include <net/netns/conntrack.h> 22 #endif 23 #include <net/netns/xfrm.h> 24 25 struct proc_dir_entry; 26 struct net_device; 27 struct sock; 28 struct ctl_table_header; 29 struct net_generic; 30 struct sock; 31 struct netns_ipvs; 32 33 34 #define NETDEV_HASHBITS 8 35 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 36 37 struct net { 38 atomic_t passive; /* To decided when the network 39 * namespace should be freed. 40 */ 41 atomic_t count; /* To decided when the network 42 * namespace should be shut down. 43 */ 44 #ifdef NETNS_REFCNT_DEBUG 45 atomic_t use_count; /* To track references we 46 * destroy on demand 47 */ 48 #endif 49 spinlock_t rules_mod_lock; 50 51 struct list_head list; /* list of network namespaces */ 52 struct list_head cleanup_list; /* namespaces on death row */ 53 struct list_head exit_list; /* Use only net_mutex */ 54 55 struct proc_dir_entry *proc_net; 56 struct proc_dir_entry *proc_net_stat; 57 58 #ifdef CONFIG_SYSCTL 59 struct ctl_table_set sysctls; 60 #endif 61 62 struct sock *rtnl; /* rtnetlink socket */ 63 struct sock *genl_sock; 64 65 struct list_head dev_base_head; 66 struct hlist_head *dev_name_head; 67 struct hlist_head *dev_index_head; 68 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 69 70 /* core fib_rules */ 71 struct list_head rules_ops; 72 73 74 struct net_device *loopback_dev; /* The loopback */ 75 struct netns_core core; 76 struct netns_mib mib; 77 struct netns_packet packet; 78 struct netns_unix unx; 79 struct netns_ipv4 ipv4; 80 #if IS_ENABLED(CONFIG_IPV6) 81 struct netns_ipv6 ipv6; 82 #endif 83 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 84 struct netns_dccp dccp; 85 #endif 86 #ifdef CONFIG_NETFILTER 87 struct netns_xt xt; 88 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 89 struct netns_ct ct; 90 #endif 91 struct sock *nfnl; 92 struct sock *nfnl_stash; 93 #endif 94 #ifdef CONFIG_WEXT_CORE 95 struct sk_buff_head wext_nlevents; 96 #endif 97 struct net_generic __rcu *gen; 98 99 /* Note : following structs are cache line aligned */ 100 #ifdef CONFIG_XFRM 101 struct netns_xfrm xfrm; 102 #endif 103 struct netns_ipvs *ipvs; 104 struct sock *diag_nlsk; 105 }; 106 107 108 #include <linux/seq_file_net.h> 109 110 /* Init's network namespace */ 111 extern struct net init_net; 112 113 #ifdef CONFIG_NET 114 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns); 115 116 #else /* CONFIG_NET */ 117 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns) 118 { 119 /* There is nothing to copy so this is a noop */ 120 return net_ns; 121 } 122 #endif /* CONFIG_NET */ 123 124 125 extern struct list_head net_namespace_list; 126 127 extern struct net *get_net_ns_by_pid(pid_t pid); 128 extern struct net *get_net_ns_by_fd(int pid); 129 130 #ifdef CONFIG_NET_NS 131 extern void __put_net(struct net *net); 132 133 static inline struct net *get_net(struct net *net) 134 { 135 atomic_inc(&net->count); 136 return net; 137 } 138 139 static inline struct net *maybe_get_net(struct net *net) 140 { 141 /* Used when we know struct net exists but we 142 * aren't guaranteed a previous reference count 143 * exists. If the reference count is zero this 144 * function fails and returns NULL. 145 */ 146 if (!atomic_inc_not_zero(&net->count)) 147 net = NULL; 148 return net; 149 } 150 151 static inline void put_net(struct net *net) 152 { 153 if (atomic_dec_and_test(&net->count)) 154 __put_net(net); 155 } 156 157 static inline 158 int net_eq(const struct net *net1, const struct net *net2) 159 { 160 return net1 == net2; 161 } 162 163 extern void net_drop_ns(void *); 164 165 #else 166 167 static inline struct net *get_net(struct net *net) 168 { 169 return net; 170 } 171 172 static inline void put_net(struct net *net) 173 { 174 } 175 176 static inline struct net *maybe_get_net(struct net *net) 177 { 178 return net; 179 } 180 181 static inline 182 int net_eq(const struct net *net1, const struct net *net2) 183 { 184 return 1; 185 } 186 187 #define net_drop_ns NULL 188 #endif 189 190 191 #ifdef NETNS_REFCNT_DEBUG 192 static inline struct net *hold_net(struct net *net) 193 { 194 if (net) 195 atomic_inc(&net->use_count); 196 return net; 197 } 198 199 static inline void release_net(struct net *net) 200 { 201 if (net) 202 atomic_dec(&net->use_count); 203 } 204 #else 205 static inline struct net *hold_net(struct net *net) 206 { 207 return net; 208 } 209 210 static inline void release_net(struct net *net) 211 { 212 } 213 #endif 214 215 #ifdef CONFIG_NET_NS 216 217 static inline void write_pnet(struct net **pnet, struct net *net) 218 { 219 *pnet = net; 220 } 221 222 static inline struct net *read_pnet(struct net * const *pnet) 223 { 224 return *pnet; 225 } 226 227 #else 228 229 #define write_pnet(pnet, net) do { (void)(net);} while (0) 230 #define read_pnet(pnet) (&init_net) 231 232 #endif 233 234 #define for_each_net(VAR) \ 235 list_for_each_entry(VAR, &net_namespace_list, list) 236 237 #define for_each_net_rcu(VAR) \ 238 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 239 240 #ifdef CONFIG_NET_NS 241 #define __net_init 242 #define __net_exit 243 #define __net_initdata 244 #else 245 #define __net_init __init 246 #define __net_exit __exit_refok 247 #define __net_initdata __initdata 248 #endif 249 250 struct pernet_operations { 251 struct list_head list; 252 int (*init)(struct net *net); 253 void (*exit)(struct net *net); 254 void (*exit_batch)(struct list_head *net_exit_list); 255 int *id; 256 size_t size; 257 }; 258 259 /* 260 * Use these carefully. If you implement a network device and it 261 * needs per network namespace operations use device pernet operations, 262 * otherwise use pernet subsys operations. 263 * 264 * Network interfaces need to be removed from a dying netns _before_ 265 * subsys notifiers can be called, as most of the network code cleanup 266 * (which is done from subsys notifiers) runs with the assumption that 267 * dev_remove_pack has been called so no new packets will arrive during 268 * and after the cleanup functions have been called. dev_remove_pack 269 * is not per namespace so instead the guarantee of no more packets 270 * arriving in a network namespace is provided by ensuring that all 271 * network devices and all sockets have left the network namespace 272 * before the cleanup methods are called. 273 * 274 * For the longest time the ipv4 icmp code was registered as a pernet 275 * device which caused kernel oops, and panics during network 276 * namespace cleanup. So please don't get this wrong. 277 */ 278 extern int register_pernet_subsys(struct pernet_operations *); 279 extern void unregister_pernet_subsys(struct pernet_operations *); 280 extern int register_pernet_device(struct pernet_operations *); 281 extern void unregister_pernet_device(struct pernet_operations *); 282 283 struct ctl_table; 284 struct ctl_table_header; 285 286 #ifdef CONFIG_SYSCTL 287 extern int net_sysctl_init(void); 288 extern struct ctl_table_header *register_net_sysctl(struct net *net, 289 const char *path, struct ctl_table *table); 290 extern void unregister_net_sysctl_table(struct ctl_table_header *header); 291 #else 292 static inline int net_sysctl_init(void) { return 0; } 293 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 294 const char *path, struct ctl_table *table) 295 { 296 return NULL; 297 } 298 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 299 { 300 } 301 #endif 302 303 304 #endif /* __NET_NET_NAMESPACE_H */ 305