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_dccp.h>
  24 #include <linux/netfilter/nf_conntrack_sctp.h>
  25 #include <linux/netfilter/nf_conntrack_proto_gre.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 nf_ct_dccp dccp;
  34         struct ip_ct_sctp sctp;
  35         struct ip_ct_tcp tcp;
  36         struct nf_ct_gre gre;
  37 };
  38
  39 union nf_conntrack_expect_proto {
  40         /* insert expect proto private data here */
  41 };
  42
  43 /* Add protocol helper include file here */
  44 #include <linux/netfilter/nf_conntrack_ftp.h>
  45 #include <linux/netfilter/nf_conntrack_pptp.h>
  46 #include <linux/netfilter/nf_conntrack_h323.h>
  47 #include <linux/netfilter/nf_conntrack_sane.h>
  48 #include <linux/netfilter/nf_conntrack_sip.h>
  49
  50 /* per conntrack: application helper private data */
  51 union nf_conntrack_help {
  52         /* insert conntrack helper private data (master) here */
  53         struct nf_ct_ftp_master ct_ftp_info;
  54         struct nf_ct_pptp_master ct_pptp_info;
  55         struct nf_ct_h323_master ct_h323_info;
  56         struct nf_ct_sane_master ct_sane_info;
  57         struct nf_ct_sip_master ct_sip_info;
  58 };
  59
  60 #include <linux/types.h>
  61 #include <linux/skbuff.h>
  62 #include <linux/timer.h>
  63
  64 #ifdef CONFIG_NETFILTER_DEBUG
  65 #define NF_CT_ASSERT(x)         WARN_ON(!(x))
  66 #else
  67 #define NF_CT_ASSERT(x)
  68 #endif
  69
  70 struct nf_conntrack_helper;
  71
  72 /* Must be kept in sync with the classes defined by helpers */
  73 #define NF_CT_MAX_EXPECT_CLASSES        3
  74
  75 /* nf_conn feature for connections that have a helper */
  76 struct nf_conn_help {
  77         /* Helper. if any */
  78         struct nf_conntrack_helper *helper;
  79
  80         union nf_conntrack_help help;
  81
  82         struct hlist_head expectations;
  83
  84         /* Current number of expected connections */
  85         u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
  86 };
  87
  88 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  89 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  90
  91 struct nf_conn {
  92         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  93            plus 1 for any connection(s) we are `master' for */
  94         struct nf_conntrack ct_general;
  95
  96         spinlock_t lock;
  97
  98         /* XXX should I move this to the tail ? - Y.K */
  99         /* These are my tuples; original and reply */
 100         struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 101
 102         /* Have we seen traffic both ways yet? (bitset) */
 103         unsigned long status;
 104
 105         /* If we were expected by an expectation, this will be it */
 106         struct nf_conn *master;
 107
 108         /* Timer function; drops refcnt when it goes off. */
 109         struct timer_list timeout;
 110
 111 #if defined(CONFIG_NF_CONNTRACK_MARK)
 112         u_int32_t mark;
 113 #endif
 114
 115 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 116         u_int32_t secmark;
 117 #endif
 118
 119         /* Storage reserved for other modules: */
 120         union nf_conntrack_proto proto;
 121
 122         /* Extensions */
 123         struct nf_ct_ext *ext;
 124 #ifdef CONFIG_NET_NS
 125         struct net *ct_net;
 126 #endif
 127 };
 128
 129 static inline struct nf_conn *
 130 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 131 {
 132         return container_of(hash, struct nf_conn,
 133                             tuplehash[hash->tuple.dst.dir]);
 134 }
 135
 136 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 137 {
 138         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 139 }
 140
 141 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 142 {
 143         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 144 }
 145
 146 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
 147
 148 /* get master conntrack via master expectation */
 149 #define master_ct(conntr) (conntr->master)
 150
 151 extern struct net init_net;
 152
 153 static inline struct net *nf_ct_net(const struct nf_conn *ct)
 154 {
 155 #ifdef CONFIG_NET_NS
 156         return ct->ct_net;
 157 #else
 158         return &init_net;
 159 #endif
 160 }
 161
 162 /* Alter reply tuple (maybe alter helper). */
 163 extern void
 164 nf_conntrack_alter_reply(struct nf_conn *ct,
 165                          const struct nf_conntrack_tuple *newreply);
 166
 167 /* Is this tuple taken? (ignoring any belonging to the given
 168    conntrack). */
 169 extern int
 170 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 171                          const struct nf_conn *ignored_conntrack);
 172
 173 /* Return conntrack_info and tuple hash for given skb. */
 174 static inline struct nf_conn *
 175 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 176 {
 177         *ctinfo = skb->nfctinfo;
 178         return (struct nf_conn *)skb->nfct;
 179 }
 180
 181 /* decrement reference count on a conntrack */
 182 static inline void nf_ct_put(struct nf_conn *ct)
 183 {
 184         NF_CT_ASSERT(ct);
 185         nf_conntrack_put(&ct->ct_general);
 186 }
 187
 188 /* Protocol module loading */
 189 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 190 extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 191
 192 /*
 193  * Allocate a hashtable of hlist_head (if nulls == 0),
 194  * or hlist_nulls_head (if nulls == 1)
 195  */
 196 extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int nulls);
 197
 198 extern void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size);
 199
 200 extern struct nf_conntrack_tuple_hash *
 201 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple);
 202
 203 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 204 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 205 extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 206
 207 extern void nf_conntrack_flush_report(struct net *net, u32 pid, int report);
 208
 209 extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 210                               unsigned int nhoff, u_int16_t l3num,
 211                               struct nf_conntrack_tuple *tuple);
 212 extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 213                                  const struct nf_conntrack_tuple *orig);
 214
 215 extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 216                                  enum ip_conntrack_info ctinfo,
 217                                  const struct sk_buff *skb,
 218                                  unsigned long extra_jiffies,
 219                                  int do_acct);
 220
 221 /* Refresh conntrack for this many jiffies and do accounting */
 222 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 223                                       enum ip_conntrack_info ctinfo,
 224                                       const struct sk_buff *skb,
 225                                       unsigned long extra_jiffies)
 226 {
 227         __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 228 }
 229
 230 /* Refresh conntrack for this many jiffies */
 231 static inline void nf_ct_refresh(struct nf_conn *ct,
 232                                  const struct sk_buff *skb,
 233                                  unsigned long extra_jiffies)
 234 {
 235         __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 236 }
 237
 238 extern bool __nf_ct_kill_acct(struct nf_conn *ct,
 239                               enum ip_conntrack_info ctinfo,
 240                               const struct sk_buff *skb,
 241                               int do_acct);
 242
 243 /* kill conntrack and do accounting */
 244 static inline bool nf_ct_kill_acct(struct nf_conn *ct,
 245                                    enum ip_conntrack_info ctinfo,
 246                                    const struct sk_buff *skb)
 247 {
 248         return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
 249 }
 250
 251 /* kill conntrack without accounting */
 252 static inline bool nf_ct_kill(struct nf_conn *ct)
 253 {
 254         return __nf_ct_kill_acct(ct, 0, NULL, 0);
 255 }
 256
 257 /* These are for NAT.  Icky. */
 258 /* Update TCP window tracking data when NAT mangles the packet */
 259 extern void nf_conntrack_tcp_update(const struct sk_buff *skb,
 260                                     unsigned int dataoff,
 261                                     struct nf_conn *ct, int dir,
 262                                     s16 offset);
 263
 264 /* Fake conntrack entry for untracked connections */
 265 extern struct nf_conn nf_conntrack_untracked;
 266
 267 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 268 extern void
 269 nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 270 extern void nf_conntrack_free(struct nf_conn *ct);
 271 extern struct nf_conn *
 272 nf_conntrack_alloc(struct net *net,
 273                    const struct nf_conntrack_tuple *orig,
 274                    const struct nf_conntrack_tuple *repl,
 275                    gfp_t gfp);
 276
 277 /* It's confirmed if it is, or has been in the hash table. */
 278 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 279 {
 280         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 281 }
 282
 283 static inline int nf_ct_is_dying(struct nf_conn *ct)
 284 {
 285         return test_bit(IPS_DYING_BIT, &ct->status);
 286 }
 287
 288 static inline int nf_ct_is_untracked(const struct sk_buff *skb)
 289 {
 290         return (skb->nfct == &nf_conntrack_untracked.ct_general);
 291 }
 292
 293 extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 294 extern unsigned int nf_conntrack_htable_size;
 295 extern unsigned int nf_conntrack_max;
 296
 297 #define NF_CT_STAT_INC(net, count)      \
 298         __this_cpu_inc((net)->ct.stat->count)
 299 #define NF_CT_STAT_INC_ATOMIC(net, count)               \
 300 do {                                                    \
 301         local_bh_disable();                             \
 302         __this_cpu_inc((net)->ct.stat->count);          \
 303         local_bh_enable();                              \
 304 } while (0)
 305
 306 #define MODULE_ALIAS_NFCT_HELPER(helper) \
 307         MODULE_ALIAS("nfct-helper-" helper)
 308
 309 #endif /* __KERNEL__ */
 310 #endif /* _NF_CONNTRACK_H */