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
  92 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  93 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  94
  95 struct nf_conn
  96 {
  97         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  98            plus 1 for any connection(s) we are `master' for */
  99         struct nf_conntrack ct_general;
 100
 101         /* XXX should I move this to the tail ? - Y.K */
 102         /* These are my tuples; original and reply */
 103         struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 104
 105         /* Have we seen traffic both ways yet? (bitset) */
 106         unsigned long status;
 107
 108         /* If we were expected by an expectation, this will be it */
 109         struct nf_conn *master;
 110
 111         /* Timer function; drops refcnt when it goes off. */
 112         struct timer_list timeout;
 113
 114 #ifdef CONFIG_NF_CT_ACCT
 115         /* Accounting Information (same cache line as other written members) */
 116         struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
 117 #endif
 118
 119 #if defined(CONFIG_NF_CONNTRACK_MARK)
 120         u_int32_t mark;
 121 #endif
 122
 123 #ifdef CONFIG_NF_CONNTRACK_SECMARK
 124         u_int32_t secmark;
 125 #endif
 126
 127         /* Storage reserved for other modules: */
 128         union nf_conntrack_proto proto;
 129
 130         /* Extensions */
 131         struct nf_ct_ext *ext;
 132
 133         struct rcu_head rcu;
 134 };
 135
 136 static inline struct nf_conn *
 137 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 138 {
 139         return container_of(hash, struct nf_conn,
 140                             tuplehash[hash->tuple.dst.dir]);
 141 }
 142
 143 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 144 {
 145         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 146 }
 147
 148 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 149 {
 150         return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 151 }
 152
 153 /* get master conntrack via master expectation */
 154 #define master_ct(conntr) (conntr->master)
 155
 156 /* Alter reply tuple (maybe alter helper). */
 157 extern void
 158 nf_conntrack_alter_reply(struct nf_conn *ct,
 159                          const struct nf_conntrack_tuple *newreply);
 160
 161 /* Is this tuple taken? (ignoring any belonging to the given
 162    conntrack). */
 163 extern int
 164 nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 165                          const struct nf_conn *ignored_conntrack);
 166
 167 /* Return conntrack_info and tuple hash for given skb. */
 168 static inline struct nf_conn *
 169 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 170 {
 171         *ctinfo = skb->nfctinfo;
 172         return (struct nf_conn *)skb->nfct;
 173 }
 174
 175 /* decrement reference count on a conntrack */
 176 static inline void nf_ct_put(struct nf_conn *ct)
 177 {
 178         NF_CT_ASSERT(ct);
 179         nf_conntrack_put(&ct->ct_general);
 180 }
 181
 182 /* Protocol module loading */
 183 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 184 extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 185
 186 extern struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced);
 187 extern void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced,
 188                                  unsigned int size);
 189
 190 extern struct nf_conntrack_tuple_hash *
 191 __nf_conntrack_find(const struct nf_conntrack_tuple *tuple);
 192
 193 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 194
 195 extern void nf_conntrack_flush(void);
 196
 197 extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 198                               unsigned int nhoff, u_int16_t l3num,
 199                               struct nf_conntrack_tuple *tuple);
 200 extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 201                                  const struct nf_conntrack_tuple *orig);
 202
 203 extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 204                                  enum ip_conntrack_info ctinfo,
 205                                  const struct sk_buff *skb,
 206                                  unsigned long extra_jiffies,
 207                                  int do_acct);
 208
 209 /* Refresh conntrack for this many jiffies and do accounting */
 210 static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 211                                       enum ip_conntrack_info ctinfo,
 212                                       const struct sk_buff *skb,
 213                                       unsigned long extra_jiffies)
 214 {
 215         __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 216 }
 217
 218 /* Refresh conntrack for this many jiffies */
 219 static inline void nf_ct_refresh(struct nf_conn *ct,
 220                                  const struct sk_buff *skb,
 221                                  unsigned long extra_jiffies)
 222 {
 223         __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 224 }
 225
 226 /* These are for NAT.  Icky. */
 227 /* Update TCP window tracking data when NAT mangles the packet */
 228 extern void nf_conntrack_tcp_update(const struct sk_buff *skb,
 229                                     unsigned int dataoff,
 230                                     struct nf_conn *ct,
 231                                     int dir);
 232
 233 /* Fake conntrack entry for untracked connections */
 234 extern struct nf_conn nf_conntrack_untracked;
 235
 236 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 237 extern void
 238 nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data);
 239 extern void nf_conntrack_free(struct nf_conn *ct);
 240 extern struct nf_conn *
 241 nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 242                    const struct nf_conntrack_tuple *repl);
 243
 244 /* It's confirmed if it is, or has been in the hash table. */
 245 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 246 {
 247         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 248 }
 249
 250 static inline int nf_ct_is_dying(struct nf_conn *ct)
 251 {
 252         return test_bit(IPS_DYING_BIT, &ct->status);
 253 }
 254
 255 static inline int nf_ct_is_untracked(const struct sk_buff *skb)
 256 {
 257         return (skb->nfct == &nf_conntrack_untracked.ct_general);
 258 }
 259
 260 extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 261 extern unsigned int nf_conntrack_htable_size;
 262 extern int nf_conntrack_checksum;
 263 extern atomic_t nf_conntrack_count;
 264 extern int nf_conntrack_max;
 265
 266 DECLARE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
 267 #define NF_CT_STAT_INC(count) (__get_cpu_var(nf_conntrack_stat).count++)
 268 #define NF_CT_STAT_INC_ATOMIC(count)                    \
 269 do {                                                    \
 270         local_bh_disable();                             \
 271         __get_cpu_var(nf_conntrack_stat).count++;       \
 272         local_bh_enable();                              \
 273 } while (0)
 274
 275 #endif /* __KERNEL__ */
 276 #endif /* _NF_CONNTRACK_H */