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 #if defined(CONFIG_NF_CONNTRACK_FTP) || defined(CONFIG_NF_CONNTRACK_FTP_MODULE)
  54         struct nf_ct_ftp_master ct_ftp_info;
  55 #endif
  56 #if defined(CONFIG_NF_CONNTRACK_PPTP) || \
  57     defined(CONFIG_NF_CONNTRACK_PPTP_MODULE)
  58         struct nf_ct_pptp_master ct_pptp_info;
  59 #endif
  60 #if defined(CONFIG_NF_CONNTRACK_H323) || \
  61     defined(CONFIG_NF_CONNTRACK_H323_MODULE)
  62         struct nf_ct_h323_master ct_h323_info;
  63 #endif
  64 #if defined(CONFIG_NF_CONNTRACK_SANE) || \
  65     defined(CONFIG_NF_CONNTRACK_SANE_MODULE)
  66         struct nf_ct_sane_master ct_sane_info;
  67 #endif
  68 #if defined(CONFIG_NF_CONNTRACK_SIP) || defined(CONFIG_NF_CONNTRACK_SIP_MODULE)
  69         struct nf_ct_sip_master ct_sip_info;
  70 #endif
  71 };
  72
  73 #include <linux/types.h>
  74 #include <linux/skbuff.h>
  75 #include <linux/timer.h>
  76
  77 #ifdef CONFIG_NETFILTER_DEBUG
  78 #define NF_CT_ASSERT(x)         WARN_ON(!(x))
  79 #else
  80 #define NF_CT_ASSERT(x)
  81 #endif
  82
  83 struct nf_conntrack_helper;
  84
  85 /* Must be kept in sync with the classes defined by helpers */
  86 #define NF_CT_MAX_EXPECT_CLASSES        4
  87
  88 /* nf_conn feature for connections that have a helper */
  89 struct nf_conn_help {
  90         /* Helper. if any */
  91         struct nf_conntrack_helper __rcu *helper;
  92
  93         union nf_conntrack_help help;
  94
  95         struct hlist_head expectations;
  96
  97         /* Current number of expected connections */
  98         u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
  99 };
 100
 101 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
 102 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
 103
 104 struct nf_conn {
 105         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
 106            plus 1 for any connection(s) we are `master' for */
 107         struct nf_conntrack ct_general;
 108
 109         spinlock_t lock;
 110
 111         /* XXX should I move this to the tail ? - Y.K */
 112         /* These are my tuples; original and reply */
 113         struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 114
 115         /* Have we seen traffic both ways yet? (bitset) */
 116         unsigned long status;
 117
 118         /* If we were expected by an expectation, this will be it */
 119         struct nf_conn *master;
 120
 121         /* Timer function; drops refcnt when it goes off. */
 122         struct timer_list timeout;
 123
 124 #if defined(CONFIG_NF_CONNTRACK_MARK)
 125         u_int32_t mark;
 126 #endif
 127
 128 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 129         u_int32_t secmark;
 130 #endif
 131
 132         /* Extensions */
 133         struct nf_ct_ext *ext;
 134 #ifdef CONFIG_NET_NS
 135         struct net *ct_net;
 136 #endif
 137
 138         /* Storage reserved for other modules, must be the last member */
 139         union nf_conntrack_proto proto;
 140 };
 141
 142 static inline struct nf_conn *
 143 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 144 {
 145         return container_of(hash, struct nf_conn,
 146                             tuplehash[hash->tuple.dst.dir]);
 147 }
 148
 149 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 150 {
 151         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 152 }
 153
 154 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 155 {
 156         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 157 }
 158
 159 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
 160
 161 /* get master conntrack via master expectation */
 162 #define master_ct(conntr) (conntr->master)
 163
 164 extern struct net init_net;
 165
 166 static inline struct net *nf_ct_net(const struct nf_conn *ct)
 167 {
 168         return read_pnet(&ct->ct_net);
 169 }
 170
 171 /* Alter reply tuple (maybe alter helper). */
 172 extern void
 173 nf_conntrack_alter_reply(struct nf_conn *ct,
 174                          const struct nf_conntrack_tuple *newreply);
 175
 176 /* Is this tuple taken? (ignoring any belonging to the given
 177    conntrack). */
 178 extern int
 179 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 180                          const struct nf_conn *ignored_conntrack);
 181
 182 /* Return conntrack_info and tuple hash for given skb. */
 183 static inline struct nf_conn *
 184 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 185 {
 186         *ctinfo = skb->nfctinfo;
 187         return (struct nf_conn *)skb->nfct;
 188 }
 189
 190 /* decrement reference count on a conntrack */
 191 static inline void nf_ct_put(struct nf_conn *ct)
 192 {
 193         NF_CT_ASSERT(ct);
 194         nf_conntrack_put(&ct->ct_general);
 195 }
 196
 197 /* Protocol module loading */
 198 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 199 extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 200
 201 /*
 202  * Allocate a hashtable of hlist_head (if nulls == 0),
 203  * or hlist_nulls_head (if nulls == 1)
 204  */
 205 extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
 206
 207 extern void nf_ct_free_hashtable(void *hash, unsigned int size);
 208
 209 extern struct nf_conntrack_tuple_hash *
 210 __nf_conntrack_find(struct net *net, u16 zone,
 211                     const struct nf_conntrack_tuple *tuple);
 212
 213 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 214 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 215 extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 216
 217 extern void nf_conntrack_flush_report(struct net *net, u32 pid, int report);
 218
 219 extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 220                               unsigned int nhoff, u_int16_t l3num,
 221                               struct nf_conntrack_tuple *tuple);
 222 extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 223                                  const struct nf_conntrack_tuple *orig);
 224
 225 extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 226                                  enum ip_conntrack_info ctinfo,
 227                                  const struct sk_buff *skb,
 228                                  unsigned long extra_jiffies,
 229                                  int do_acct);
 230
 231 /* Refresh conntrack for this many jiffies and do accounting */
 232 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 233                                       enum ip_conntrack_info ctinfo,
 234                                       const struct sk_buff *skb,
 235                                       unsigned long extra_jiffies)
 236 {
 237         __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 238 }
 239
 240 /* Refresh conntrack for this many jiffies */
 241 static inline void nf_ct_refresh(struct nf_conn *ct,
 242                                  const struct sk_buff *skb,
 243                                  unsigned long extra_jiffies)
 244 {
 245         __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 246 }
 247
 248 extern bool __nf_ct_kill_acct(struct nf_conn *ct,
 249                               enum ip_conntrack_info ctinfo,
 250                               const struct sk_buff *skb,
 251                               int do_acct);
 252
 253 /* kill conntrack and do accounting */
 254 static inline bool nf_ct_kill_acct(struct nf_conn *ct,
 255                                    enum ip_conntrack_info ctinfo,
 256                                    const struct sk_buff *skb)
 257 {
 258         return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
 259 }
 260
 261 /* kill conntrack without accounting */
 262 static inline bool nf_ct_kill(struct nf_conn *ct)
 263 {
 264         return __nf_ct_kill_acct(ct, 0, NULL, 0);
 265 }
 266
 267 /* These are for NAT.  Icky. */
 268 extern s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
 269                                enum ip_conntrack_dir dir,
 270                                u32 seq);
 271
 272 /* Fake conntrack entry for untracked connections */
 273 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 274 static inline struct nf_conn *nf_ct_untracked_get(void)
 275 {
 276         return &__raw_get_cpu_var(nf_conntrack_untracked);
 277 }
 278 extern void nf_ct_untracked_status_or(unsigned long bits);
 279
 280 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 281 extern void
 282 nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 283 extern void nf_conntrack_free(struct nf_conn *ct);
 284 extern struct nf_conn *
 285 nf_conntrack_alloc(struct net *net, u16 zone,
 286                    const struct nf_conntrack_tuple *orig,
 287                    const struct nf_conntrack_tuple *repl,
 288                    gfp_t gfp);
 289
 290 static inline int nf_ct_is_template(const struct nf_conn *ct)
 291 {
 292         return test_bit(IPS_TEMPLATE_BIT, &ct->status);
 293 }
 294
 295 /* It's confirmed if it is, or has been in the hash table. */
 296 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 297 {
 298         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 299 }
 300
 301 static inline int nf_ct_is_dying(struct nf_conn *ct)
 302 {
 303         return test_bit(IPS_DYING_BIT, &ct->status);
 304 }
 305
 306 static inline int nf_ct_is_untracked(const struct nf_conn *ct)
 307 {
 308         return test_bit(IPS_UNTRACKED_BIT, &ct->status);
 309 }
 310
 311 extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 312 extern unsigned int nf_conntrack_htable_size;
 313 extern unsigned int nf_conntrack_max;
 314 extern unsigned int nf_conntrack_hash_rnd;
 315 void init_nf_conntrack_hash_rnd(void);
 316
 317 #define NF_CT_STAT_INC(net, count)      \
 318         __this_cpu_inc((net)->ct.stat->count)
 319 #define NF_CT_STAT_INC_ATOMIC(net, count)               \
 320 do {                                                    \
 321         local_bh_disable();                             \
 322         __this_cpu_inc((net)->ct.stat->count);          \
 323         local_bh_enable();                              \
 324 } while (0)
 325
 326 #define MODULE_ALIAS_NFCT_HELPER(helper) \
 327         MODULE_ALIAS("nfct-helper-" helper)
 328
 329 #endif /* __KERNEL__ */
 330 #endif /* _NF_CONNTRACK_H */