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/netfilter_ipv4/ip_conntrack_tuple.h>
   8 #include <linux/bitops.h>
   9 #include <linux/compiler.h>
  10 #include <asm/atomic.h>
  11
  12 #include <linux/netfilter_ipv4/ip_conntrack_tcp.h>
  13 #include <linux/netfilter_ipv4/ip_conntrack_icmp.h>
  14 #include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h>
  15 #include <linux/netfilter_ipv4/ip_conntrack_sctp.h>
  16
  17 /* per conntrack: protocol private data */
  18 union ip_conntrack_proto {
  19         /* insert conntrack proto private data here */
  20         struct ip_ct_gre gre;
  21         struct ip_ct_sctp sctp;
  22         struct ip_ct_tcp tcp;
  23         struct ip_ct_icmp icmp;
  24 };
  25
  26 union ip_conntrack_expect_proto {
  27         /* insert expect proto private data here */
  28 };
  29
  30 /* Add protocol helper include file here */
  31 #include <linux/netfilter_ipv4/ip_conntrack_h323.h>
  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_h323_master ct_h323_info;
  41         struct ip_ct_pptp_master ct_pptp_info;
  42         struct ip_ct_ftp_master ct_ftp_info;
  43         struct ip_ct_irc_master ct_irc_info;
  44 };
  45
  46 #ifdef CONFIG_IP_NF_NAT_NEEDED
  47 #include <linux/netfilter_ipv4/ip_nat.h>
  48 #include <linux/netfilter_ipv4/ip_nat_pptp.h>
  49
  50 /* per conntrack: nat application helper private data */
  51 union ip_conntrack_nat_help {
  52         /* insert nat helper private data here */
  53         struct ip_nat_pptp nat_pptp_info;
  54 };
  55 #endif
  56
  57 #include <linux/types.h>
  58 #include <linux/skbuff.h>
  59
  60 #ifdef CONFIG_NETFILTER_DEBUG
  61 #define IP_NF_ASSERT(x)                                                 \
  62 do {                                                                    \
  63         if (!(x))                                                       \
  64                 /* Wooah!  I'm tripping my conntrack in a frenzy of     \
  65                    netplay... */                                        \
  66                 printk("NF_IP_ASSERT: %s:%i(%s)\n",                     \
  67                        __FILE__, __LINE__, __FUNCTION__);               \
  68 } while(0)
  69 #else
  70 #define IP_NF_ASSERT(x)
  71 #endif
  72
  73 struct ip_conntrack_helper;
  74
  75 struct ip_conntrack
  76 {
  77         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  78            plus 1 for any connection(s) we are `master' for */
  79         struct nf_conntrack ct_general;
  80
  81         /* Have we seen traffic both ways yet? (bitset) */
  82         unsigned long status;
  83
  84         /* Timer function; drops refcnt when it goes off. */
  85         struct timer_list timeout;
  86
  87 #ifdef CONFIG_IP_NF_CT_ACCT
  88         /* Accounting Information (same cache line as other written members) */
  89         struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
  90 #endif
  91         /* If we were expected by an expectation, this will be it */
  92         struct ip_conntrack *master;
  93
  94         /* Current number of expected connections */
  95         unsigned int expecting;
  96
  97         /* Unique ID that identifies this conntrack*/
  98         unsigned int id;
  99
 100         /* Helper, if any. */
 101         struct ip_conntrack_helper *helper;
 102
 103         /* Storage reserved for other modules: */
 104         union ip_conntrack_proto proto;
 105
 106         union ip_conntrack_help help;
 107
 108 #ifdef CONFIG_IP_NF_NAT_NEEDED
 109         struct {
 110                 struct ip_nat_info info;
 111                 union ip_conntrack_nat_help help;
 112 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
 113         defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
 114                 int masq_index;
 115 #endif
 116         } nat;
 117 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 118
 119 #if defined(CONFIG_IP_NF_CONNTRACK_MARK)
 120         u_int32_t mark;
 121 #endif
 122
 123 #ifdef CONFIG_IP_NF_CONNTRACK_SECMARK
 124         u_int32_t secmark;
 125 #endif
 126
 127         /* Traversed often, so hopefully in different cacheline to top */
 128         /* These are my tuples; original and reply */
 129         struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 130 };
 131
 132 struct ip_conntrack_expect
 133 {
 134         /* Internal linked list (global expectation list) */
 135         struct list_head list;
 136
 137         /* We expect this tuple, with the following mask */
 138         struct ip_conntrack_tuple tuple, mask;
 139
 140         /* Function to call after setup and insertion */
 141         void (*expectfn)(struct ip_conntrack *new,
 142                          struct ip_conntrack_expect *this);
 143
 144         /* The conntrack of the master connection */
 145         struct ip_conntrack *master;
 146
 147         /* Timer function; deletes the expectation. */
 148         struct timer_list timeout;
 149
 150         /* Usage count. */
 151         atomic_t use;
 152
 153         /* Unique ID */
 154         unsigned int id;
 155
 156         /* Flags */
 157         unsigned int flags;
 158
 159 #ifdef CONFIG_IP_NF_NAT_NEEDED
 160         u_int32_t saved_ip;
 161         /* This is the original per-proto part, used to map the
 162          * expected connection the way the recipient expects. */
 163         union ip_conntrack_manip_proto saved_proto;
 164         /* Direction relative to the master connection. */
 165         enum ip_conntrack_dir dir;
 166 #endif
 167 };
 168
 169 #define IP_CT_EXPECT_PERMANENT  0x1
 170
 171 static inline struct ip_conntrack *
 172 tuplehash_to_ctrack(const struct ip_conntrack_tuple_hash *hash)
 173 {
 174         return container_of(hash, struct ip_conntrack,
 175                             tuplehash[hash->tuple.dst.dir]);
 176 }
 177
 178 /* get master conntrack via master expectation */
 179 #define master_ct(conntr) (conntr->master)
 180
 181 /* Alter reply tuple (maybe alter helper). */
 182 extern void
 183 ip_conntrack_alter_reply(struct ip_conntrack *conntrack,
 184                          const struct ip_conntrack_tuple *newreply);
 185
 186 /* Is this tuple taken? (ignoring any belonging to the given
 187    conntrack). */
 188 extern int
 189 ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple,
 190                          const struct ip_conntrack *ignored_conntrack);
 191
 192 /* Return conntrack_info and tuple hash for given skb. */
 193 static inline struct ip_conntrack *
 194 ip_conntrack_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 195 {
 196         *ctinfo = skb->nfctinfo;
 197         return (struct ip_conntrack *)skb->nfct;
 198 }
 199
 200 /* decrement reference count on a conntrack */
 201 static inline void
 202 ip_conntrack_put(struct ip_conntrack *ct)
 203 {
 204         IP_NF_ASSERT(ct);
 205         nf_conntrack_put(&ct->ct_general);
 206 }
 207
 208 extern int invert_tuplepr(struct ip_conntrack_tuple *inverse,
 209                           const struct ip_conntrack_tuple *orig);
 210
 211 extern void __ip_ct_refresh_acct(struct ip_conntrack *ct,
 212                                  enum ip_conntrack_info ctinfo,
 213                                  const struct sk_buff *skb,
 214                                  unsigned long extra_jiffies,
 215                                  int do_acct);
 216
 217 /* Refresh conntrack for this many jiffies and do accounting */
 218 static inline void ip_ct_refresh_acct(struct ip_conntrack *ct,
 219                                       enum ip_conntrack_info ctinfo,
 220                                       const struct sk_buff *skb,
 221                                       unsigned long extra_jiffies)
 222 {
 223         __ip_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 224 }
 225
 226 /* Refresh conntrack for this many jiffies */
 227 static inline void ip_ct_refresh(struct ip_conntrack *ct,
 228                                  const struct sk_buff *skb,
 229                                  unsigned long extra_jiffies)
 230 {
 231         __ip_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 232 }
 233
 234 /* These are for NAT.  Icky. */
 235 /* Update TCP window tracking data when NAT mangles the packet */
 236 extern void ip_conntrack_tcp_update(struct sk_buff *skb,
 237                                     struct ip_conntrack *conntrack,
 238                                     enum ip_conntrack_dir dir);
 239
 240 /* Call me when a conntrack is destroyed. */
 241 extern void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack);
 242
 243 /* Fake conntrack entry for untracked connections */
 244 extern struct ip_conntrack ip_conntrack_untracked;
 245
 246 /* Returns new sk_buff, or NULL */
 247 struct sk_buff *
 248 ip_ct_gather_frags(struct sk_buff *skb, u_int32_t user);
 249
 250 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 251 extern void
 252 ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *data),
 253                       void *data);
 254
 255 extern struct ip_conntrack_helper *
 256 __ip_conntrack_helper_find_byname(const char *);
 257 extern struct ip_conntrack_helper *
 258 ip_conntrack_helper_find_get(const struct ip_conntrack_tuple *tuple);
 259 extern void ip_conntrack_helper_put(struct ip_conntrack_helper *helper);
 260
 261 extern struct ip_conntrack_protocol *
 262 __ip_conntrack_proto_find(u_int8_t protocol);
 263 extern struct ip_conntrack_protocol *
 264 ip_conntrack_proto_find_get(u_int8_t protocol);
 265 extern void ip_conntrack_proto_put(struct ip_conntrack_protocol *proto);
 266
 267 extern void ip_ct_remove_expectations(struct ip_conntrack *ct);
 268
 269 extern struct ip_conntrack *ip_conntrack_alloc(struct ip_conntrack_tuple *,
 270                                                struct ip_conntrack_tuple *);
 271
 272 extern void ip_conntrack_free(struct ip_conntrack *ct);
 273
 274 extern void ip_conntrack_hash_insert(struct ip_conntrack *ct);
 275
 276 extern struct ip_conntrack_expect *
 277 __ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);
 278
 279 extern struct ip_conntrack_expect *
 280 ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);
 281
 282 extern struct ip_conntrack_tuple_hash *
 283 __ip_conntrack_find(const struct ip_conntrack_tuple *tuple,
 284                     const struct ip_conntrack *ignored_conntrack);
 285
 286 extern void ip_conntrack_flush(void);
 287
 288 /* It's confirmed if it is, or has been in the hash table. */
 289 static inline int is_confirmed(struct ip_conntrack *ct)
 290 {
 291         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 292 }
 293
 294 static inline int is_dying(struct ip_conntrack *ct)
 295 {
 296         return test_bit(IPS_DYING_BIT, &ct->status);
 297 }
 298
 299 extern unsigned int ip_conntrack_htable_size;
 300 extern int ip_conntrack_checksum;
 301
 302 #define CONNTRACK_STAT_INC(count) (__get_cpu_var(ip_conntrack_stat).count++)
 303
 304 #ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
 305 #include <linux/notifier.h>
 306 #include <linux/interrupt.h>
 307
 308 struct ip_conntrack_ecache {
 309         struct ip_conntrack *ct;
 310         unsigned int events;
 311 };
 312 DECLARE_PER_CPU(struct ip_conntrack_ecache, ip_conntrack_ecache);
 313
 314 #define CONNTRACK_ECACHE(x)     (__get_cpu_var(ip_conntrack_ecache).x)
 315
 316 extern struct atomic_notifier_head ip_conntrack_chain;
 317 extern struct atomic_notifier_head ip_conntrack_expect_chain;
 318
 319 static inline int ip_conntrack_register_notifier(struct notifier_block *nb)
 320 {
 321         return atomic_notifier_chain_register(&ip_conntrack_chain, nb);
 322 }
 323
 324 static inline int ip_conntrack_unregister_notifier(struct notifier_block *nb)
 325 {
 326         return atomic_notifier_chain_unregister(&ip_conntrack_chain, nb);
 327 }
 328
 329 static inline int
 330 ip_conntrack_expect_register_notifier(struct notifier_block *nb)
 331 {
 332         return atomic_notifier_chain_register(&ip_conntrack_expect_chain, nb);
 333 }
 334
 335 static inline int
 336 ip_conntrack_expect_unregister_notifier(struct notifier_block *nb)
 337 {
 338         return atomic_notifier_chain_unregister(&ip_conntrack_expect_chain,
 339                         nb);
 340 }
 341
 342 extern void ip_ct_deliver_cached_events(const struct ip_conntrack *ct);
 343 extern void __ip_ct_event_cache_init(struct ip_conntrack *ct);
 344
 345 static inline void
 346 ip_conntrack_event_cache(enum ip_conntrack_events event,
 347                          const struct sk_buff *skb)
 348 {
 349         struct ip_conntrack *ct = (struct ip_conntrack *)skb->nfct;
 350         struct ip_conntrack_ecache *ecache;
 351
 352         local_bh_disable();
 353         ecache = &__get_cpu_var(ip_conntrack_ecache);
 354         if (ct != ecache->ct)
 355                 __ip_ct_event_cache_init(ct);
 356         ecache->events |= event;
 357         local_bh_enable();
 358 }
 359
 360 static inline void ip_conntrack_event(enum ip_conntrack_events event,
 361                                       struct ip_conntrack *ct)
 362 {
 363         if (is_confirmed(ct) && !is_dying(ct))
 364                 atomic_notifier_call_chain(&ip_conntrack_chain, event, ct);
 365 }
 366
 367 static inline void
 368 ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
 369                           struct ip_conntrack_expect *exp)
 370 {
 371         atomic_notifier_call_chain(&ip_conntrack_expect_chain, event, exp);
 372 }
 373 #else /* CONFIG_IP_NF_CONNTRACK_EVENTS */
 374 static inline void ip_conntrack_event_cache(enum ip_conntrack_events event,
 375                                             const struct sk_buff *skb) {}
 376 static inline void ip_conntrack_event(enum ip_conntrack_events event,
 377                                       struct ip_conntrack *ct) {}
 378 static inline void ip_ct_deliver_cached_events(const struct ip_conntrack *ct) {}
 379 static inline void
 380 ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
 381                           struct ip_conntrack_expect *exp) {}
 382 #endif /* CONFIG_IP_NF_CONNTRACK_EVENTS */
 383
 384 #ifdef CONFIG_IP_NF_NAT_NEEDED
 385 static inline int ip_nat_initialized(struct ip_conntrack *conntrack,
 386                                      enum ip_nat_manip_type manip)
 387 {
 388         if (manip == IP_NAT_MANIP_SRC)
 389                 return test_bit(IPS_SRC_NAT_DONE_BIT, &conntrack->status);
 390         return test_bit(IPS_DST_NAT_DONE_BIT, &conntrack->status);
 391 }
 392 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 393
 394 #endif /* __KERNEL__ */
 395 #endif /* _IP_CONNTRACK_H */