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/timer.h>
  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_h323.h>
  33 #include <linux/netfilter_ipv4/ip_conntrack_pptp.h>
  34 #include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
  35 #include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
  36 #include <linux/netfilter_ipv4/ip_conntrack_irc.h>
  37
  38 /* per conntrack: application helper private data */
  39 union ip_conntrack_help {
  40         /* insert conntrack helper private data (master) here */
  41         struct ip_ct_h323_master ct_h323_info;
  42         struct ip_ct_pptp_master ct_pptp_info;
  43         struct ip_ct_ftp_master ct_ftp_info;
  44         struct ip_ct_irc_master ct_irc_info;
  45 };
  46
  47 #ifdef CONFIG_IP_NF_NAT_NEEDED
  48 #include <linux/netfilter_ipv4/ip_nat.h>
  49 #include <linux/netfilter_ipv4/ip_nat_pptp.h>
  50
  51 /* per conntrack: nat application helper private data */
  52 union ip_conntrack_nat_help {
  53         /* insert nat helper private data here */
  54         struct ip_nat_pptp nat_pptp_info;
  55 };
  56 #endif
  57
  58 #include <linux/types.h>
  59 #include <linux/skbuff.h>
  60
  61 #ifdef CONFIG_NETFILTER_DEBUG
  62 #define IP_NF_ASSERT(x)                                                 \
  63 do {                                                                    \
  64         if (!(x))                                                       \
  65                 /* Wooah!  I'm tripping my conntrack in a frenzy of     \
  66                    netplay... */                                        \
  67                 printk("NF_IP_ASSERT: %s:%i(%s)\n",                     \
  68                        __FILE__, __LINE__, __FUNCTION__);               \
  69 } while(0)
  70 #else
  71 #define IP_NF_ASSERT(x)
  72 #endif
  73
  74 struct ip_conntrack_helper;
  75
  76 struct ip_conntrack
  77 {
  78         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  79            plus 1 for any connection(s) we are `master' for */
  80         struct nf_conntrack ct_general;
  81
  82         /* Have we seen traffic both ways yet? (bitset) */
  83         unsigned long status;
  84
  85         /* Timer function; drops refcnt when it goes off. */
  86         struct timer_list timeout;
  87
  88 #ifdef CONFIG_IP_NF_CT_ACCT
  89         /* Accounting Information (same cache line as other written members) */
  90         struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
  91 #endif
  92         /* If we were expected by an expectation, this will be it */
  93         struct ip_conntrack *master;
  94
  95         /* Current number of expected connections */
  96         unsigned int expecting;
  97
  98         /* Unique ID that identifies this conntrack*/
  99         unsigned int id;
 100
 101         /* Helper, if any. */
 102         struct ip_conntrack_helper *helper;
 103
 104         /* Storage reserved for other modules: */
 105         union ip_conntrack_proto proto;
 106
 107         union ip_conntrack_help help;
 108
 109 #ifdef CONFIG_IP_NF_NAT_NEEDED
 110         struct {
 111                 struct ip_nat_info info;
 112                 union ip_conntrack_nat_help help;
 113 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
 114         defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
 115                 int masq_index;
 116 #endif
 117         } nat;
 118 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 119
 120 #if defined(CONFIG_IP_NF_CONNTRACK_MARK)
 121         u_int32_t mark;
 122 #endif
 123
 124 #ifdef CONFIG_IP_NF_CONNTRACK_SECMARK
 125         u_int32_t secmark;
 126 #endif
 127
 128         /* Traversed often, so hopefully in different cacheline to top */
 129         /* These are my tuples; original and reply */
 130         struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 131 };
 132
 133 struct ip_conntrack_expect
 134 {
 135         /* Internal linked list (global expectation list) */
 136         struct list_head list;
 137
 138         /* We expect this tuple, with the following mask */
 139         struct ip_conntrack_tuple tuple, mask;
 140
 141         /* Function to call after setup and insertion */
 142         void (*expectfn)(struct ip_conntrack *new,
 143                          struct ip_conntrack_expect *this);
 144
 145         /* The conntrack of the master connection */
 146         struct ip_conntrack *master;
 147
 148         /* Timer function; deletes the expectation. */
 149         struct timer_list timeout;
 150
 151         /* Usage count. */
 152         atomic_t use;
 153
 154         /* Unique ID */
 155         unsigned int id;
 156
 157         /* Flags */
 158         unsigned int flags;
 159
 160 #ifdef CONFIG_IP_NF_NAT_NEEDED
 161         __be32 saved_ip;
 162         /* This is the original per-proto part, used to map the
 163          * expected connection the way the recipient expects. */
 164         union ip_conntrack_manip_proto saved_proto;
 165         /* Direction relative to the master connection. */
 166         enum ip_conntrack_dir dir;
 167 #endif
 168 };
 169
 170 #define IP_CT_EXPECT_PERMANENT  0x1
 171
 172 static inline struct ip_conntrack *
 173 tuplehash_to_ctrack(const struct ip_conntrack_tuple_hash *hash)
 174 {
 175         return container_of(hash, struct ip_conntrack,
 176                             tuplehash[hash->tuple.dst.dir]);
 177 }
 178
 179 /* get master conntrack via master expectation */
 180 #define master_ct(conntr) (conntr->master)
 181
 182 /* Alter reply tuple (maybe alter helper). */
 183 extern void
 184 ip_conntrack_alter_reply(struct ip_conntrack *conntrack,
 185                          const struct ip_conntrack_tuple *newreply);
 186
 187 /* Is this tuple taken? (ignoring any belonging to the given
 188    conntrack). */
 189 extern int
 190 ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple,
 191                          const struct ip_conntrack *ignored_conntrack);
 192
 193 /* Return conntrack_info and tuple hash for given skb. */
 194 static inline struct ip_conntrack *
 195 ip_conntrack_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 196 {
 197         *ctinfo = skb->nfctinfo;
 198         return (struct ip_conntrack *)skb->nfct;
 199 }
 200
 201 /* decrement reference count on a conntrack */
 202 static inline void
 203 ip_conntrack_put(struct ip_conntrack *ct)
 204 {
 205         IP_NF_ASSERT(ct);
 206         nf_conntrack_put(&ct->ct_general);
 207 }
 208
 209 extern int invert_tuplepr(struct ip_conntrack_tuple *inverse,
 210                           const struct ip_conntrack_tuple *orig);
 211
 212 extern void __ip_ct_refresh_acct(struct ip_conntrack *ct,
 213                                  enum ip_conntrack_info ctinfo,
 214                                  const struct sk_buff *skb,
 215                                  unsigned long extra_jiffies,
 216                                  int do_acct);
 217
 218 /* Refresh conntrack for this many jiffies and do accounting */
 219 static inline void ip_ct_refresh_acct(struct ip_conntrack *ct,
 220                                       enum ip_conntrack_info ctinfo,
 221                                       const struct sk_buff *skb,
 222                                       unsigned long extra_jiffies)
 223 {
 224         __ip_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 225 }
 226
 227 /* Refresh conntrack for this many jiffies */
 228 static inline void ip_ct_refresh(struct ip_conntrack *ct,
 229                                  const struct sk_buff *skb,
 230                                  unsigned long extra_jiffies)
 231 {
 232         __ip_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 233 }
 234
 235 /* These are for NAT.  Icky. */
 236 /* Update TCP window tracking data when NAT mangles the packet */
 237 extern void ip_conntrack_tcp_update(struct sk_buff *skb,
 238                                     struct ip_conntrack *conntrack,
 239                                     enum ip_conntrack_dir dir);
 240
 241 /* Call me when a conntrack is destroyed. */
 242 extern void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack);
 243
 244 /* Fake conntrack entry for untracked connections */
 245 extern struct ip_conntrack ip_conntrack_untracked;
 246
 247 /* Returns new sk_buff, or NULL */
 248 struct sk_buff *
 249 ip_ct_gather_frags(struct sk_buff *skb, u_int32_t user);
 250
 251 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 252 extern void
 253 ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *data),
 254                       void *data);
 255
 256 extern struct ip_conntrack_helper *
 257 __ip_conntrack_helper_find_byname(const char *);
 258 extern struct ip_conntrack_helper *
 259 ip_conntrack_helper_find_get(const struct ip_conntrack_tuple *tuple);
 260 extern void ip_conntrack_helper_put(struct ip_conntrack_helper *helper);
 261
 262 extern struct ip_conntrack_protocol *
 263 __ip_conntrack_proto_find(u_int8_t protocol);
 264 extern struct ip_conntrack_protocol *
 265 ip_conntrack_proto_find_get(u_int8_t protocol);
 266 extern void ip_conntrack_proto_put(struct ip_conntrack_protocol *proto);
 267
 268 extern void ip_ct_remove_expectations(struct ip_conntrack *ct);
 269
 270 extern struct ip_conntrack *ip_conntrack_alloc(struct ip_conntrack_tuple *,
 271                                                struct ip_conntrack_tuple *);
 272
 273 extern void ip_conntrack_free(struct ip_conntrack *ct);
 274
 275 extern void ip_conntrack_hash_insert(struct ip_conntrack *ct);
 276
 277 extern struct ip_conntrack_expect *
 278 __ip_conntrack_expect_find(const struct ip_conntrack_tuple *tuple);
 279
 280 extern struct ip_conntrack_expect *
 281 ip_conntrack_expect_find_get(const struct ip_conntrack_tuple *tuple);
 282
 283 extern struct ip_conntrack_tuple_hash *
 284 __ip_conntrack_find(const struct ip_conntrack_tuple *tuple,
 285                     const struct ip_conntrack *ignored_conntrack);
 286
 287 extern void ip_conntrack_flush(void);
 288
 289 /* It's confirmed if it is, or has been in the hash table. */
 290 static inline int is_confirmed(struct ip_conntrack *ct)
 291 {
 292         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 293 }
 294
 295 static inline int is_dying(struct ip_conntrack *ct)
 296 {
 297         return test_bit(IPS_DYING_BIT, &ct->status);
 298 }
 299
 300 extern unsigned int ip_conntrack_htable_size;
 301 extern int ip_conntrack_checksum;
 302
 303 #define CONNTRACK_STAT_INC(count) (__get_cpu_var(ip_conntrack_stat).count++)
 304 #define CONNTRACK_STAT_INC_ATOMIC(count)                \
 305 do {                                                    \
 306         local_bh_disable();                             \
 307         __get_cpu_var(ip_conntrack_stat).count++;       \
 308         local_bh_enable();                              \
 309 } while (0)
 310
 311 #ifdef CONFIG_IP_NF_CONNTRACK_EVENTS
 312 #include <linux/notifier.h>
 313 #include <linux/interrupt.h>
 314
 315 struct ip_conntrack_ecache {
 316         struct ip_conntrack *ct;
 317         unsigned int events;
 318 };
 319 DECLARE_PER_CPU(struct ip_conntrack_ecache, ip_conntrack_ecache);
 320
 321 #define CONNTRACK_ECACHE(x)     (__get_cpu_var(ip_conntrack_ecache).x)
 322
 323 extern struct atomic_notifier_head ip_conntrack_chain;
 324 extern struct atomic_notifier_head ip_conntrack_expect_chain;
 325
 326 static inline int ip_conntrack_register_notifier(struct notifier_block *nb)
 327 {
 328         return atomic_notifier_chain_register(&ip_conntrack_chain, nb);
 329 }
 330
 331 static inline int ip_conntrack_unregister_notifier(struct notifier_block *nb)
 332 {
 333         return atomic_notifier_chain_unregister(&ip_conntrack_chain, nb);
 334 }
 335
 336 static inline int
 337 ip_conntrack_expect_register_notifier(struct notifier_block *nb)
 338 {
 339         return atomic_notifier_chain_register(&ip_conntrack_expect_chain, nb);
 340 }
 341
 342 static inline int
 343 ip_conntrack_expect_unregister_notifier(struct notifier_block *nb)
 344 {
 345         return atomic_notifier_chain_unregister(&ip_conntrack_expect_chain,
 346                         nb);
 347 }
 348
 349 extern void ip_ct_deliver_cached_events(const struct ip_conntrack *ct);
 350 extern void __ip_ct_event_cache_init(struct ip_conntrack *ct);
 351
 352 static inline void
 353 ip_conntrack_event_cache(enum ip_conntrack_events event,
 354                          const struct sk_buff *skb)
 355 {
 356         struct ip_conntrack *ct = (struct ip_conntrack *)skb->nfct;
 357         struct ip_conntrack_ecache *ecache;
 358
 359         local_bh_disable();
 360         ecache = &__get_cpu_var(ip_conntrack_ecache);
 361         if (ct != ecache->ct)
 362                 __ip_ct_event_cache_init(ct);
 363         ecache->events |= event;
 364         local_bh_enable();
 365 }
 366
 367 static inline void ip_conntrack_event(enum ip_conntrack_events event,
 368                                       struct ip_conntrack *ct)
 369 {
 370         if (is_confirmed(ct) && !is_dying(ct))
 371                 atomic_notifier_call_chain(&ip_conntrack_chain, event, ct);
 372 }
 373
 374 static inline void
 375 ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
 376                           struct ip_conntrack_expect *exp)
 377 {
 378         atomic_notifier_call_chain(&ip_conntrack_expect_chain, event, exp);
 379 }
 380 #else /* CONFIG_IP_NF_CONNTRACK_EVENTS */
 381 static inline void ip_conntrack_event_cache(enum ip_conntrack_events event,
 382                                             const struct sk_buff *skb) {}
 383 static inline void ip_conntrack_event(enum ip_conntrack_events event,
 384                                       struct ip_conntrack *ct) {}
 385 static inline void ip_ct_deliver_cached_events(const struct ip_conntrack *ct) {}
 386 static inline void
 387 ip_conntrack_expect_event(enum ip_conntrack_expect_events event,
 388                           struct ip_conntrack_expect *exp) {}
 389 #endif /* CONFIG_IP_NF_CONNTRACK_EVENTS */
 390
 391 #ifdef CONFIG_IP_NF_NAT_NEEDED
 392 static inline int ip_nat_initialized(struct ip_conntrack *conntrack,
 393                                      enum ip_nat_manip_type manip)
 394 {
 395         if (manip == IP_NAT_MANIP_SRC)
 396                 return test_bit(IPS_SRC_NAT_DONE_BIT, &conntrack->status);
 397         return test_bit(IPS_DST_NAT_DONE_BIT, &conntrack->status);
 398 }
 399 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 400
 401 #endif /* __KERNEL__ */
 402 #endif /* _IP_CONNTRACK_H */