include/linux/netfilter_ipv4/ip_conntrack.h

   1 #ifndef _IP_CONNTRACK_H
   2 #define _IP_CONNTRACK_H
   3
   4 #include <linux/netfilter/nf_conntrack_common.h>
   5
   6 #ifdef __KERNEL__
   7 #include <linux/config.h>
   8 #include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
   9 #include <linux/bitops.h>
  10 #include <linux/compiler.h>
  11 #include <asm/atomic.h>
  12
  13 #include <linux/netfilter_ipv4/ip_conntrack_tcp.h>
  14 #include <linux/netfilter_ipv4/ip_conntrack_icmp.h>
  15 #include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
  16 #include <linux/netfilter_ipv4/ip_conntrack_sctp.h>
  17
  18 /* per conntrack: protocol private data */
  19 union ip_conntrack_proto {
  20         /* insert conntrack proto private data here */
  21         struct ip_ct_gre gre;
  22         struct ip_ct_sctp sctp;
  23         struct ip_ct_tcp tcp;
  24         struct ip_ct_icmp icmp;
  25 };
  26
  27 union ip_conntrack_expect_proto {
  28         /* insert expect proto private data here */
  29 };
  30
  31 /* Add protocol helper include file here */
  32 #include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
  33 #include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
  34 #include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
  35 #include <linux/netfilter_ipv4/ip_conntrack_irc.h>
  36
  37 /* per conntrack: application helper private data */
  38 union ip_conntrack_help {
  39         /* insert conntrack helper private data (master) here */
  40         struct ip_ct_pptp_master ct_pptp_info;
  41         struct ip_ct_ftp_master ct_ftp_info;
  42         struct ip_ct_irc_master ct_irc_info;
  43 };
  44
  45 #ifdef CONFIG_IP_NF_NAT_NEEDED
  46 #include <linux/netfilter_ipv4/ip_nat.h>
  47 #include <linux/netfilter_ipv4/ip_nat_pptp.h>
  48
  49 /* per conntrack: nat application helper private data */
  50 union ip_conntrack_nat_help {
  51         /* insert nat helper private data here */
  52         struct ip_nat_pptp nat_pptp_info;
  53 };
  54 #endif
  55
  56 #include <linux/types.h>
  57 #include <linux/skbuff.h>
  58
  59 #ifdef CONFIG_NETFILTER_DEBUG
  60 #define IP_NF_ASSERT(x)                                                 \
  61 do {                                                                    \
  62         if (!(x))                                                       \
  63                 /* Wooah!  I'm tripping my conntrack in a frenzy of     \
  64                    netplay... */                                        \
  65                 printk("NF_IP_ASSERT: %s:%i(%s)\n",                     \
  66                        __FILE__, __LINE__, __FUNCTION__);               \
  67 } while(0)
  68 #else
  69 #define IP_NF_ASSERT(x)
  70 #endif
  71
  72 struct ip_conntrack_helper;
  73
  74 struct ip_conntrack
  75 {
  76         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  77            plus 1 for any connection(s) we are `master' for */
  78         struct nf_conntrack ct_general;
  79
  80         /* Have we seen traffic both ways yet? (bitset) */
  81         unsigned long status;
  82
  83         /* Timer function; drops refcnt when it goes off. */
  84         struct timer_list timeout;
  85
  86 #ifdef CONFIG_IP_NF_CT_ACCT
  87         /* Accounting Information (same cache line as other written members) */
  88         struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
  89 #endif
  90         /* If we were expected by an expectation, this will be it */
  91         struct ip_conntrack *master;
  92
  93         /* Current number of expected connections */
  94         unsigned int expecting;
  95
  96         /* Unique ID that identifies this conntrack*/
  97         unsigned int id;
  98
  99         /* Helper, if any. */
 100         struct ip_conntrack_helper *helper;
 101
 102         /* Storage reserved for other modules: */
 103         union ip_conntrack_proto proto;
 104
 105         union ip_conntrack_help help;
 106
 107 #ifdef CONFIG_IP_NF_NAT_NEEDED
 108         struct {
 109                 struct ip_nat_info info;
 110                 union ip_conntrack_nat_help help;
 111 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
 112         defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
 113                 int masq_index;
 114 #endif
 115         } nat;
 116 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 117
 118 #if defined(CONFIG_IP_NF_CONNTRACK_MARK)
 119         u_int32_t mark;
 120 #endif
 121
 122         /* Traversed often, so hopefully in different cacheline to top */
 123         /* These are my tuples; original and reply */
 124         struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 125 };
 126
 127 struct ip_conntrack_expect
 128 {
 129         /* Internal linked list (global expectation list) */
 130         struct list_head list;
 131
 132         /* We expect this tuple, with the following mask */
 133         struct ip_conntrack_tuple tuple, mask;
 134
 135         /* Function to call after setup and insertion */
 136         void (*expectfn)(struct ip_conntrack *new,
 137                          struct ip_conntrack_expect *this);
 138
 139         /* The conntrack of the master connection */
 140         struct ip_conntrack *master;
 141
 142         /* Timer function; deletes the expectation. */
 143         struct timer_list timeout;
 144
 145         /* Usage count. */
 146         atomic_t use;
 147
 148         /* Unique ID */
 149         unsigned int id;
 150
 151         /* Flags */
 152         unsigned int flags;
 153
 154 #ifdef CONFIG_IP_NF_NAT_NEEDED
 155         /* This is the original per-proto part, used to map the
 156          * expected connection the way the recipient expects. */
 157         union ip_conntrack_manip_proto saved_proto;
 158         /* Direction relative to the master connection. */
 159         enum ip_conntrack_dir dir;
 160 #endif
 161 };
 162
 163 #define IP_CT_EXPECT_PERMANENT  0x1
 164
 165 static inline struct ip_conntrack *
 166 tuplehash_to_ctrack(const struct ip_conntrack_tuple_hash *hash)
 167 {
 168         return container_of(hash, struct ip_conntrack,
 169                             tuplehash[hash->tuple.dst.dir]);
 170 }
 171
 172 /* get master conntrack via master expectation */
 173 #define master_ct(conntr) (conntr->master)
 174
 175 /* Alter reply tuple (maybe alter helper). */
 176 extern void
 177 ip_conntrack_alter_reply(struct ip_conntrack *conntrack,
 178                          const struct ip_conntrack_tuple *newreply);
 179
 180 /* Is this tuple taken? (ignoring any belonging to the given
 181    conntrack). */
 182 extern int
 183 ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple,
 184                          const struct ip_conntrack *ignored_conntrack);
 185
 186 /* Return conntrack_info and tuple hash for given skb. */
 187 static inline struct ip_conntrack *
 188 ip_conntrack_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 189 {
 190         *ctinfo = skb->nfctinfo;
 191         return (struct ip_conntrack *)skb->nfct;
 192 }
 193
 194 /* decrement reference count on a conntrack */
 195 static inline void
 196 ip_conntrack_put(struct ip_conntrack *ct)
 197 {
 198         IP_NF_ASSERT(ct);
 199         nf_conntrack_put(&ct->ct_general);
 200 }
 201
 202 /* call to create an explicit dependency on ip_conntrack. */
 203 extern void need_ip_conntrack(void);
 204
 205 extern int invert_tuplepr(struct ip_conntrack_tuple *inverse,
 206                           const struct ip_conntrack_tuple *orig);
 207
 208 extern void __ip_ct_refresh_acct(struct ip_conntrack *ct,
 209                                  enum ip_conntrack_info ctinfo,
 210                                  const struct sk_buff *skb,
 211                                  unsigned long extra_jiffies,
 212                                  int do_acct);
 213
 214 /* Refresh conntrack for this many jiffies and do accounting */
 215 static inline void ip_ct_refresh_acct(struct ip_conntrack *ct,
 216                                       enum ip_conntrack_info ctinfo,
 217                                       const struct sk_buff *skb,
 218                                       unsigned long extra_jiffies)
 219 {
 220         __ip_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 221 }
 222
 223 /* Refresh conntrack for this many jiffies */
 224 static inline void ip_ct_refresh(struct ip_conntrack *ct,
 225                                  const struct sk_buff *skb,
 226                                  unsigned long extra_jiffies)
 227 {
 228         __ip_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 229 }
 230
 231 /* These are for NAT.  Icky. */
 232 /* Update TCP window tracking data when NAT mangles the packet */
 233 extern void ip_conntrack_tcp_update(struct sk_buff *skb,
 234                                     struct ip_conntrack *conntrack,
 235                                     enum ip_conntrack_dir dir);
 236
 237 /* Call me when a conntrack is destroyed. */
 238 extern void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack);
 239
 240 /* Fake conntrack entry for untracked connections */
 241 extern struct ip_conntrack ip_conntrack_untracked;
 242
 243 /* Returns new sk_buff, or NULL */
 244 struct sk_buff *
 245 ip_ct_gather_frags(struct sk_buff *skb, u_int32_t user);
 246
 247 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 248 extern void
 249 ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *data),
 250                       void *data);
 251
 252 extern struct ip_conntrack_helper *
 253 __ip_conntrack_helper_find_byname(const char *);
 254 extern struct ip_conntrack_helper *
 255 ip_conntrack_helper_find_get(const struct ip_conntrack_tuple *tuple);
 256 extern void ip_conntrack_helper_put(struct ip_conntrack_helper *helper);
 257
 258 extern struct ip_conntrack_protocol *
 259 __ip_conntrack_proto_find(u_int8_t protocol);
 260 extern struct ip_conntrack_protocol *
 261 ip_conntrack_proto_find_get(u_int8_t protocol);
 262 extern void ip_conntrack_proto_put(struct ip_conntrack_protocol *proto);
 263
 264 extern void ip_ct_remove_expectations(struct ip_conntrack *ct);
 265
 266 extern struct ip_conntrack *ip_conntrack_alloc(struct ip_conntrack_tuple *,
 267                                                struct ip_conntrack_tuple *);
 268
 269 extern void ip_conntrack_free(struct ip_conntrack *ct);
 270
 271 extern void ip_conntrack_hash_insert(struct ip_conntrack *ct);
 272
 273 extern struct ip_conntrack_expect *
 274 __ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);
 275
 276 extern struct ip_conntrack_expect *
 277 ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);
 278
 279 extern struct ip_conntrack_tuple_hash *
 280 __ip_conntrack_find(const struct ip_conntrack_tuple *tuple,
 281                     const struct ip_conntrack *ignored_conntrack);
 282
 283 extern void ip_conntrack_flush(void);
 284
 285 /* It's confirmed if it is, or has been in the hash table. */
 286 static inline int is_confirmed(struct ip_conntrack *ct)
 287 {
 288         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 289 }
 290
 291 static inline int is_dying(struct ip_conntrack *ct)
 292 {
 293         return test_bit(IPS_DYING_BIT, &ct->status);
 294 }
 295
 296 extern unsigned int ip_conntrack_htable_size;
 297
 298 #define CONNTRACK_STAT_INC(count) (__get_cpu_var(ip_conntrack_stat).count++)
 299
 300 #ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
 301 #include <linux/notifier.h>
 302 #include <linux/interrupt.h>
 303
 304 struct ip_conntrack_ecache {
 305         struct ip_conntrack *ct;
 306         unsigned int events;
 307 };
 308 DECLARE_PER_CPU(struct ip_conntrack_ecache, ip_conntrack_ecache);
 309
 310 #define CONNTRACK_ECACHE(x)     (__get_cpu_var(ip_conntrack_ecache).x)
 311
 312 extern struct notifier_block *ip_conntrack_chain;
 313 extern struct notifier_block *ip_conntrack_expect_chain;
 314
 315 static inline int ip_conntrack_register_notifier(struct notifier_block *nb)
 316 {
 317         return notifier_chain_register(&ip_conntrack_chain, nb);
 318 }
 319
 320 static inline int ip_conntrack_unregister_notifier(struct notifier_block *nb)
 321 {
 322         return notifier_chain_unregister(&ip_conntrack_chain, nb);
 323 }
 324
 325 static inline int
 326 ip_conntrack_expect_register_notifier(struct notifier_block *nb)
 327 {
 328         return notifier_chain_register(&ip_conntrack_expect_chain, nb);
 329 }
 330
 331 static inline int
 332 ip_conntrack_expect_unregister_notifier(struct notifier_block *nb)
 333 {
 334         return notifier_chain_unregister(&ip_conntrack_expect_chain, nb);
 335 }
 336
 337 extern void ip_ct_deliver_cached_events(const struct ip_conntrack *ct);
 338 extern void __ip_ct_event_cache_init(struct ip_conntrack *ct);
 339
 340 static inline void
 341 ip_conntrack_event_cache(enum ip_conntrack_events event,
 342                          const struct sk_buff *skb)
 343 {
 344         struct ip_conntrack *ct = (struct ip_conntrack *)skb->nfct;
 345         struct ip_conntrack_ecache *ecache;
 346
 347         local_bh_disable();
 348         ecache = &__get_cpu_var(ip_conntrack_ecache);
 349         if (ct != ecache->ct)
 350                 __ip_ct_event_cache_init(ct);
 351         ecache->events |= event;
 352         local_bh_enable();
 353 }
 354
 355 static inline void ip_conntrack_event(enum ip_conntrack_events event,
 356                                       struct ip_conntrack *ct)
 357 {
 358         if (is_confirmed(ct) && !is_dying(ct))
 359                 notifier_call_chain(&ip_conntrack_chain, event, ct);
 360 }
 361
 362 static inline void
 363 ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
 364                           struct ip_conntrack_expect *exp)
 365 {
 366         notifier_call_chain(&ip_conntrack_expect_chain, event, exp);
 367 }
 368 #else /* CONFIG_IP_NF_CONNTRACK_EVENTS */
 369 static inline void ip_conntrack_event_cache(enum ip_conntrack_events event,
 370                                             const struct sk_buff *skb) {}
 371 static inline void ip_conntrack_event(enum ip_conntrack_events event,
 372                                       struct ip_conntrack *ct) {}
 373 static inline void ip_ct_deliver_cached_events(const struct ip_conntrack *ct) {}
 374 static inline void
 375 ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
 376                           struct ip_conntrack_expect *exp) {}
 377 #endif /* CONFIG_IP_NF_CONNTRACK_EVENTS */
 378
 379 #ifdef CONFIG_IP_NF_NAT_NEEDED
 380 static inline int ip_nat_initialized(struct ip_conntrack *conntrack,
 381                                      enum ip_nat_manip_type manip)
 382 {
 383         if (manip == IP_NAT_MANIP_SRC)
 384                 return test_bit(IPS_SRC_NAT_DONE_BIT, &conntrack->status);
 385         return test_bit(IPS_DST_NAT_DONE_BIT, &conntrack->status);
 386 }
 387 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 388
 389 #endif /* __KERNEL__ */
 390 #endif /* _IP_CONNTRACK_H */