release/src-rt/linux/linux-2.6/include/net/netfilter/nf_conntrack.h

   1 /*
   2  * Connection state tracking for netfilter.  This is separated from,
   3  * but required by, the (future) NAT layer; it can also be used by an iptables
   4  * extension.
   5  *
   6  * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   7  *      - generalize L3 protocol dependent part.
   8  *
   9  * Derived from include/linux/netfiter_ipv4/ip_conntrack.h
  10  */
  11
  12 #ifndef _NF_CONNTRACK_H
  13 #define _NF_CONNTRACK_H
  14
  15 #include <linux/netfilter/nf_conntrack_common.h>
  16
  17 #ifdef __KERNEL__
  18 #include <linux/bitops.h>
  19 #include <linux/compiler.h>
  20 #include <asm/atomic.h>
  21
  22 #include <linux/netfilter/nf_conntrack_tcp.h>
  23 #include <linux/netfilter/nf_conntrack_sctp.h>
  24 #include <linux/netfilter/nf_conntrack_proto_gre.h>
  25 #include <net/netfilter/ipv4/nf_conntrack_icmp.h>
  26 #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
  27
  28 #include <net/netfilter/nf_conntrack_tuple.h>
  29
  30 /* per conntrack: protocol private data */
  31 union nf_conntrack_proto {
  32         /* insert conntrack proto private data here */
  33         struct ip_ct_sctp sctp;
  34         struct ip_ct_tcp tcp;
  35         struct ip_ct_icmp icmp;
  36         struct nf_ct_icmpv6 icmpv6;
  37         struct nf_ct_gre gre;
  38 };
  39
  40 union nf_conntrack_expect_proto {
  41         /* insert expect proto private data here */
  42 };
  43
  44 /* Add protocol helper include file here */
  45 #include <linux/netfilter/nf_conntrack_ftp.h>
  46 #include <linux/netfilter/nf_conntrack_pptp.h>
  47 #include <linux/netfilter/nf_conntrack_h323.h>
  48 #include <linux/netfilter/nf_conntrack_sane.h>
  49 #include <linux/netfilter/nf_conntrack_autofw.h>
  50
  51 /* per conntrack: application helper private data */
  52 union nf_conntrack_help {
  53         /* insert conntrack helper private data (master) here */
  54         struct nf_ct_ftp_master ct_ftp_info;
  55         struct nf_ct_pptp_master ct_pptp_info;
  56         struct nf_ct_h323_master ct_h323_info;
  57         struct nf_ct_sane_master ct_sane_info;
  58         struct nf_ct_autofw_master ct_autofw_info;
  59 };
  60
  61 #include <linux/types.h>
  62 #include <linux/skbuff.h>
  63 #include <linux/timer.h>
  64
  65 #ifdef CONFIG_NETFILTER_DEBUG
  66 #define NF_CT_ASSERT(x)                                                 \
  67 do {                                                                    \
  68         if (!(x))                                                       \
  69                 /* Wooah!  I'm tripping my conntrack in a frenzy of     \
  70                    netplay... */                                        \
  71                 printk("NF_CT_ASSERT: %s:%i(%s)\n",                     \
  72                        __FILE__, __LINE__, __FUNCTION__);               \
  73 } while(0)
  74 #else
  75 #define NF_CT_ASSERT(x)
  76 #endif
  77
  78 struct nf_conntrack_helper;
  79
  80 /* nf_conn feature for connections that have a helper */
  81 struct nf_conn_help {
  82         /* Helper. if any */
  83         struct nf_conntrack_helper *helper;
  84
  85         union nf_conntrack_help help;
  86
  87         /* Current number of expected connections */
  88         unsigned int expecting;
  89 };
  90
  91 #define CTF_FLAGS_CACHED        (1 << 0)        /* Indicates cached connection */
  92
  93 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  94 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  95
  96 struct nf_conn
  97 {
  98         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  99            plus 1 for any connection(s) we are `master' for */
 100         struct nf_conntrack ct_general;
 101
 102         /* XXX should I move this to the tail ? - Y.K */
 103         /* These are my tuples; original and reply */
 104         struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 105
 106         /* Have we seen traffic both ways yet? (bitset) */
 107         unsigned long status;
 108
 109         /* If we were expected by an expectation, this will be it */
 110         struct nf_conn *master;
 111
 112         /* Timer function; drops refcnt when it goes off. */
 113         struct timer_list timeout;
 114
 115 #ifdef CONFIG_NF_CT_ACCT
 116         /* Accounting Information (same cache line as other written members) */
 117         struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
 118 #endif
 119
 120         /* Unique ID that identifies this conntrack*/
 121         unsigned int id;
 122
 123         /* features - nat, helper, ... used by allocating system */
 124         u_int32_t features;
 125
 126 #if defined(CONFIG_NF_CONNTRACK_MARK)
 127         u_int32_t mark;
 128 #endif
 129
 130 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 131         u_int32_t secmark;
 132 #endif
 133
 134 #ifdef HNDCTF
 135         /* Timeout for the connection */
 136         u_int32_t expire_jiffies;
 137
 138         /* Flags for connection attributes */
 139         u_int32_t ctf_flags;
 140 #endif /* HNDCTF */
 141
 142         /* Storage reserved for other modules: */
 143         union nf_conntrack_proto proto;
 144
 145         /* features dynamically at the end: helper, nat (both optional) */
 146         char data[0];
 147
 148 #if defined(CONFIG_NETFILTER_XT_MATCH_LAYER7) || \
 149     defined(CONFIG_NETFILTER_XT_MATCH_LAYER7_MODULE)
 150         struct {
 151                 /*
 152                  * e.g. "http". NULL before decision. "unknown" after decision
 153                  * if no match.
 154                  */
 155                 char *app_proto;
 156                 /*
 157                  * application layer data so far. NULL after match decision.
 158                  */
 159                 char *app_data;
 160                 unsigned int app_data_len;
 161         } layer7;
 162 #endif
 163 };
 164
 165 static inline struct nf_conn *
 166 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 167 {
 168         return container_of(hash, struct nf_conn,
 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 nf_conntrack_alter_reply(struct nf_conn *conntrack,
 178                          const struct nf_conntrack_tuple *newreply);
 179
 180 /* Is this tuple taken? (ignoring any belonging to the given
 181    conntrack). */
 182 extern int
 183 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 184                          const struct nf_conn *ignored_conntrack);
 185
 186 /* Return conntrack_info and tuple hash for given skb. */
 187 static inline struct nf_conn *
 188 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 189 {
 190         *ctinfo = skb->nfctinfo;
 191         return (struct nf_conn *)skb->nfct;
 192 }
 193
 194 /* decrement reference count on a conntrack */
 195 static inline void nf_ct_put(struct nf_conn *ct)
 196 {
 197         NF_CT_ASSERT(ct);
 198         nf_conntrack_put(&ct->ct_general);
 199 }
 200
 201 /* Protocol module loading */
 202 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 203 extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 204
 205 extern struct nf_conntrack_tuple_hash *
 206 __nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
 207                     const struct nf_conn *ignored_conntrack);
 208
 209 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 210
 211 extern void nf_conntrack_flush(void);
 212
 213 extern int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 214                                 const struct nf_conntrack_tuple *orig);
 215
 216 extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 217                                  enum ip_conntrack_info ctinfo,
 218                                  const struct sk_buff *skb,
 219                                  unsigned long extra_jiffies,
 220                                  int do_acct);
 221
 222 /* Refresh conntrack for this many jiffies and do accounting */
 223 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 224                                       enum ip_conntrack_info ctinfo,
 225                                       const struct sk_buff *skb,
 226                                       unsigned long extra_jiffies)
 227 {
 228         __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 229 }
 230
 231 /* Refresh conntrack for this many jiffies */
 232 static inline void nf_ct_refresh(struct nf_conn *ct,
 233                                  const struct sk_buff *skb,
 234                                  unsigned long extra_jiffies)
 235 {
 236         __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 237 }
 238
 239 /* These are for NAT.  Icky. */
 240 /* Update TCP window tracking data when NAT mangles the packet */
 241 extern void nf_conntrack_tcp_update(struct sk_buff *skb,
 242                                     unsigned int dataoff,
 243                                     struct nf_conn *conntrack,
 244                                     int dir);
 245
 246 /* Call me when a conntrack is destroyed. */
 247 extern void (*nf_conntrack_destroyed)(struct nf_conn *conntrack);
 248
 249 /* Fake conntrack entry for untracked connections */
 250 extern struct nf_conn nf_conntrack_untracked;
 251
 252 extern int nf_ct_no_defrag;
 253
 254 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 255 extern void
 256 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data);
 257 extern void nf_conntrack_free(struct nf_conn *ct);
 258 extern struct nf_conn *
 259 nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 260                    const struct nf_conntrack_tuple *repl);
 261
 262 /* It's confirmed if it is, or has been in the hash table. */
 263 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 264 {
 265         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 266 }
 267
 268 static inline int nf_ct_is_dying(struct nf_conn *ct)
 269 {
 270         return test_bit(IPS_DYING_BIT, &ct->status);
 271 }
 272
 273 static inline int nf_ct_is_untracked(const struct sk_buff *skb)
 274 {
 275         return (skb->nfct == &nf_conntrack_untracked.ct_general);
 276 }
 277
 278 extern unsigned int nf_conntrack_htable_size;
 279 extern int nf_conntrack_checksum;
 280 extern atomic_t nf_conntrack_count;
 281 extern int nf_conntrack_max;
 282
 283 DECLARE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
 284 #define NF_CT_STAT_INC(count) (__get_cpu_var(nf_conntrack_stat).count++)
 285 #define NF_CT_STAT_INC_ATOMIC(count)                    \
 286 do {                                                    \
 287         local_bh_disable();                             \
 288         __get_cpu_var(nf_conntrack_stat).count++;       \
 289         local_bh_enable();                              \
 290 } while (0)
 291
 292 /* no helper, no nat */
 293 #define NF_CT_F_BASIC   0
 294 /* for helper */
 295 #define NF_CT_F_HELP    1
 296 /* for nat. */
 297 #define NF_CT_F_NAT     2
 298 #define NF_CT_F_NUM     4
 299
 300 extern int
 301 nf_conntrack_register_cache(u_int32_t features, const char *name, size_t size);
 302 extern void
 303 nf_conntrack_unregister_cache(u_int32_t features);
 304
 305 /* valid combinations:
 306  * basic: nf_conn, nf_conn .. nf_conn_help
 307  * nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat .. nf_conn help
 308  */
 309 #ifdef CONFIG_NF_NAT_NEEDED
 310 static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
 311 {
 312         unsigned int offset = sizeof(struct nf_conn);
 313
 314         if (!(ct->features & NF_CT_F_NAT))
 315                 return NULL;
 316
 317         offset = ALIGN(offset, __alignof__(struct nf_conn_nat));
 318         return (struct nf_conn_nat *) ((void *)ct + offset);
 319 }
 320
 321 static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
 322 {
 323         unsigned int offset = sizeof(struct nf_conn);
 324
 325         if (!(ct->features & NF_CT_F_HELP))
 326                 return NULL;
 327         if (ct->features & NF_CT_F_NAT) {
 328                 offset = ALIGN(offset, __alignof__(struct nf_conn_nat));
 329                 offset += sizeof(struct nf_conn_nat);
 330         }
 331
 332         offset = ALIGN(offset, __alignof__(struct nf_conn_help));
 333         return (struct nf_conn_help *) ((void *)ct + offset);
 334 }
 335 #else /* No NAT */
 336 static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
 337 {
 338         unsigned int offset = sizeof(struct nf_conn);
 339
 340         if (!(ct->features & NF_CT_F_HELP))
 341                 return NULL;
 342
 343         offset = ALIGN(offset, __alignof__(struct nf_conn_help));
 344         return (struct nf_conn_help *) ((void *)ct + offset);
 345 }
 346 #endif /* CONFIG_NF_NAT_NEEDED */
 347 #endif /* __KERNEL__ */
 348 #endif /* _NF_CONNTRACK_H */