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/ipv4/nf_conntrack_icmp.h>
  27 #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
  28
  29 #include <net/netfilter/nf_conntrack_tuple.h>
  30
  31 /* per conntrack: protocol private data */
  32 union nf_conntrack_proto {
  33         /* insert conntrack proto private data here */
  34         struct nf_ct_dccp dccp;
  35         struct ip_ct_sctp sctp;
  36         struct ip_ct_tcp tcp;
  37         struct ip_ct_icmp icmp;
  38         struct nf_ct_icmpv6 icmpv6;
  39         struct nf_ct_gre gre;
  40 };
  41
  42 union nf_conntrack_expect_proto {
  43         /* insert expect proto private data here */
  44 };
  45
  46 /* Add protocol helper include file here */
  47 #include <linux/netfilter/nf_conntrack_ftp.h>
  48 #include <linux/netfilter/nf_conntrack_pptp.h>
  49 #include <linux/netfilter/nf_conntrack_h323.h>
  50 #include <linux/netfilter/nf_conntrack_sane.h>
  51 #include <linux/netfilter/nf_conntrack_sip.h>
  52
  53 /* per conntrack: application helper private data */
  54 union nf_conntrack_help {
  55         /* insert conntrack helper private data (master) here */
  56         struct nf_ct_ftp_master ct_ftp_info;
  57         struct nf_ct_pptp_master ct_pptp_info;
  58         struct nf_ct_h323_master ct_h323_info;
  59         struct nf_ct_sane_master ct_sane_info;
  60         struct nf_ct_sip_master ct_sip_info;
  61 };
  62
  63 #include <linux/types.h>
  64 #include <linux/skbuff.h>
  65 #include <linux/timer.h>
  66
  67 #ifdef CONFIG_NETFILTER_DEBUG
  68 #define NF_CT_ASSERT(x)         WARN_ON(!(x))
  69 #else
  70 #define NF_CT_ASSERT(x)
  71 #endif
  72
  73 struct nf_conntrack_helper;
  74
  75 /* Must be kept in sync with the classes defined by helpers */
  76 #define NF_CT_MAX_EXPECT_CLASSES        3
  77
  78 /* nf_conn feature for connections that have a helper */
  79 struct nf_conn_help {
  80         /* Helper. if any */
  81         struct nf_conntrack_helper *helper;
  82
  83         union nf_conntrack_help help;
  84
  85         struct hlist_head expectations;
  86
  87         /* Current number of expected connections */
  88         u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
  89 };
  90
  91 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  92 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  93
  94 struct nf_conn {
  95         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  96            plus 1 for any connection(s) we are `master' for */
  97         struct nf_conntrack ct_general;
  98
  99         /* XXX should I move this to the tail ? - Y.K */
 100         /* These are my tuples; original and reply */
 101         struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 102
 103         /* Have we seen traffic both ways yet? (bitset) */
 104         unsigned long status;
 105
 106         /* If we were expected by an expectation, this will be it */
 107         struct nf_conn *master;
 108
 109         /* Timer function; drops refcnt when it goes off. */
 110         struct timer_list timeout;
 111
 112 #if defined(CONFIG_NF_CONNTRACK_MARK)
 113         u_int32_t mark;
 114 #endif
 115
 116 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 117         u_int32_t secmark;
 118 #endif
 119
 120         /* Storage reserved for other modules: */
 121         union nf_conntrack_proto proto;
 122
 123         /* Extensions */
 124         struct nf_ct_ext *ext;
 125 #ifdef CONFIG_NET_NS
 126         struct net *ct_net;
 127 #endif
 128 };
 129
 130 static inline struct nf_conn *
 131 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 132 {
 133         return container_of(hash, struct nf_conn,
 134                             tuplehash[hash->tuple.dst.dir]);
 135 }
 136
 137 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 138 {
 139         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 140 }
 141
 142 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 143 {
 144         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 145 }
 146
 147 /* get master conntrack via master expectation */
 148 #define master_ct(conntr) (conntr->master)
 149
 150 extern struct net init_net;
 151
 152 static inline struct net *nf_ct_net(const struct nf_conn *ct)
 153 {
 154 #ifdef CONFIG_NET_NS
 155         return ct->ct_net;
 156 #else
 157         return &init_net;
 158 #endif
 159 }
 160
 161 /* Alter reply tuple (maybe alter helper). */
 162 extern void
 163 nf_conntrack_alter_reply(struct nf_conn *ct,
 164                          const struct nf_conntrack_tuple *newreply);
 165
 166 /* Is this tuple taken? (ignoring any belonging to the given
 167    conntrack). */
 168 extern int
 169 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 170                          const struct nf_conn *ignored_conntrack);
 171
 172 /* Return conntrack_info and tuple hash for given skb. */
 173 static inline struct nf_conn *
 174 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 175 {
 176         *ctinfo = skb->nfctinfo;
 177         return (struct nf_conn *)skb->nfct;
 178 }
 179
 180 /* decrement reference count on a conntrack */
 181 static inline void nf_ct_put(struct nf_conn *ct)
 182 {
 183         NF_CT_ASSERT(ct);
 184         nf_conntrack_put(&ct->ct_general);
 185 }
 186
 187 /* Protocol module loading */
 188 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 189 extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 190
 191 /*
 192  * Allocate a hashtable of hlist_head (if nulls == 0),
 193  * or hlist_nulls_head (if nulls == 1)
 194  */
 195 extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int nulls);
 196
 197 extern void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size);
 198
 199 extern struct nf_conntrack_tuple_hash *
 200 __nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple);
 201
 202 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 203
 204 extern void nf_conntrack_flush(struct net *net, u32 pid, int report);
 205
 206 extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 207                               unsigned int nhoff, u_int16_t l3num,
 208                               struct nf_conntrack_tuple *tuple);
 209 extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 210                                  const struct nf_conntrack_tuple *orig);
 211
 212 extern void __nf_ct_refresh_acct(struct nf_conn *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 nf_ct_refresh_acct(struct nf_conn *ct,
 220                                       enum ip_conntrack_info ctinfo,
 221                                       const struct sk_buff *skb,
 222                                       unsigned long extra_jiffies)
 223 {
 224         __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 225 }
 226
 227 /* Refresh conntrack for this many jiffies */
 228 static inline void nf_ct_refresh(struct nf_conn *ct,
 229                                  const struct sk_buff *skb,
 230                                  unsigned long extra_jiffies)
 231 {
 232         __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 233 }
 234
 235 extern bool __nf_ct_kill_acct(struct nf_conn *ct,
 236                               enum ip_conntrack_info ctinfo,
 237                               const struct sk_buff *skb,
 238                               int do_acct);
 239
 240 /* kill conntrack and do accounting */
 241 static inline bool nf_ct_kill_acct(struct nf_conn *ct,
 242                                    enum ip_conntrack_info ctinfo,
 243                                    const struct sk_buff *skb)
 244 {
 245         return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
 246 }
 247
 248 /* kill conntrack without accounting */
 249 static inline bool nf_ct_kill(struct nf_conn *ct)
 250 {
 251         return __nf_ct_kill_acct(ct, 0, NULL, 0);
 252 }
 253
 254 /* These are for NAT.  Icky. */
 255 /* Update TCP window tracking data when NAT mangles the packet */
 256 extern void nf_conntrack_tcp_update(const struct sk_buff *skb,
 257                                     unsigned int dataoff,
 258                                     struct nf_conn *ct, int dir,
 259                                     s16 offset);
 260
 261 /* Fake conntrack entry for untracked connections */
 262 extern struct nf_conn nf_conntrack_untracked;
 263
 264 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 265 extern void
 266 nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 267 extern void nf_conntrack_free(struct nf_conn *ct);
 268 extern struct nf_conn *
 269 nf_conntrack_alloc(struct net *net,
 270                    const struct nf_conntrack_tuple *orig,
 271                    const struct nf_conntrack_tuple *repl,
 272                    gfp_t gfp);
 273
 274 /* It's confirmed if it is, or has been in the hash table. */
 275 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 276 {
 277         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 278 }
 279
 280 static inline int nf_ct_is_dying(struct nf_conn *ct)
 281 {
 282         return test_bit(IPS_DYING_BIT, &ct->status);
 283 }
 284
 285 static inline int nf_ct_is_untracked(const struct sk_buff *skb)
 286 {
 287         return (skb->nfct == &nf_conntrack_untracked.ct_general);
 288 }
 289
 290 extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 291 extern unsigned int nf_conntrack_htable_size;
 292 extern unsigned int nf_conntrack_max;
 293
 294 #define NF_CT_STAT_INC(net, count)      \
 295         (per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++)
 296 #define NF_CT_STAT_INC_ATOMIC(net, count)               \
 297 do {                                                    \
 298         local_bh_disable();                             \
 299         per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++;   \
 300         local_bh_enable();                              \
 301 } while (0)
 302
 303 #define MODULE_ALIAS_NFCT_HELPER(helper) \
 304         MODULE_ALIAS("nfct-helper-" helper)
 305
 306 #endif /* __KERNEL__ */
 307 #endif /* _NF_CONNTRACK_H */