LXR linux/include/net/netfilter/nf

   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 */
  32union 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
  42union 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 */
  54union 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
  73struct 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 */
  79struct 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
  94struct nf_conn
  95{
  96        /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  97           plus 1 for any connection(s) we are `master' for */
  98        struct nf_conntrack ct_general;
  99
 100        /* XXX should I move this to the tail ? - Y.K */
 101        /* These are my tuples; original and reply */
 102        struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 103
 104        /* Have we seen traffic both ways yet? (bitset) */
 105        unsigned long status;
 106
 107        /* If we were expected by an expectation, this will be it */
 108        struct nf_conn *master;
 109
 110        /* Timer function; drops refcnt when it goes off. */
 111        struct timer_list timeout;
 112
 113#if defined(CONFIG_NF_CONNTRACK_MARK)
 114        u_int32_t mark;
 115#endif
 116
 117#ifdef CONFIG_NF_CONNTRACK_SECMARK
 118        u_int32_t secmark;
 119#endif
 120
 121        /* Storage reserved for other modules: */
 122        union nf_conntrack_proto proto;
 123
 124        /* Extensions */
 125        struct nf_ct_ext *ext;
 126#ifdef CONFIG_NET_NS
 127        struct net *ct_net;
 128#endif
 129        struct rcu_head rcu;
 130};
 131
 132static inline struct nf_conn *
 133nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 134{
 135        return container_of(hash, struct nf_conn,
 136                            tuplehash[hash->tuple.dst.dir]);
 137}
 138
 139static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 140{
 141        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 142}
 143
 144static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 145{
 146        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 147}
 148
 149/* get master conntrack via master expectation */
 150#define master_ct(conntr) (conntr->master)
 151
 152extern struct net init_net;
 153
 154static inline struct net *nf_ct_net(const struct nf_conn *ct)
 155{
 156#ifdef CONFIG_NET_NS
 157        return ct->ct_net;
 158#else
 159        return &init_net;
 160#endif
 161}
 162
 163/* Alter reply tuple (maybe alter helper). */
 164extern void
 165nf_conntrack_alter_reply(struct nf_conn *ct,
 166                         const struct nf_conntrack_tuple *newreply);
 167
 168/* Is this tuple taken? (ignoring any belonging to the given
 169   conntrack). */
 170extern int
 171nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 172                         const struct nf_conn *ignored_conntrack);
 173
 174/* Return conntrack_info and tuple hash for given skb. */
 175static inline struct nf_conn *
 176nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 177{
 178        *ctinfo = skb->nfctinfo;
 179        return (struct nf_conn *)skb->nfct;
 180}
 181
 182/* decrement reference count on a conntrack */
 183static inline void nf_ct_put(struct nf_conn *ct)
 184{
 185        NF_CT_ASSERT(ct);
 186        nf_conntrack_put(&ct->ct_general);
 187}
 188
 189/* Protocol module loading */
 190extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 191extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 192
 193extern struct hlist_head *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced);
 194extern void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced,
 195                                 unsigned int size);
 196
 197extern struct nf_conntrack_tuple_hash *
 198__nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple);
 199
 200extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 201
 202extern void nf_conntrack_flush(struct net *net);
 203
 204extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 205                              unsigned int nhoff, u_int16_t l3num,
 206                              struct nf_conntrack_tuple *tuple);
 207extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 208                                 const struct nf_conntrack_tuple *orig);
 209
 210extern 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                                 int do_acct);
 215
 216/* Refresh conntrack for this many jiffies and do accounting */
 217static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 218                                      enum ip_conntrack_info ctinfo,
 219                                      const struct sk_buff *skb,
 220                                      unsigned long extra_jiffies)
 221{
 222        __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 223}
 224
 225/* Refresh conntrack for this many jiffies */
 226static inline void nf_ct_refresh(struct nf_conn *ct,
 227                                 const struct sk_buff *skb,
 228                                 unsigned long extra_jiffies)
 229{
 230        __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 231}
 232
 233extern bool __nf_ct_kill_acct(struct nf_conn *ct,
 234                              enum ip_conntrack_info ctinfo,
 235                              const struct sk_buff *skb,
 236                              int do_acct);
 237
 238/* kill conntrack and do accounting */
 239static inline bool nf_ct_kill_acct(struct nf_conn *ct,
 240                                   enum ip_conntrack_info ctinfo,
 241                                   const struct sk_buff *skb)
 242{
 243        return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
 244}
 245
 246/* kill conntrack without accounting */
 247static inline bool nf_ct_kill(struct nf_conn *ct)
 248{
 249        return __nf_ct_kill_acct(ct, 0, NULL, 0);
 250}
 251
 252/* These are for NAT.  Icky. */
 253/* Update TCP window tracking data when NAT mangles the packet */
 254extern void nf_conntrack_tcp_update(const struct sk_buff *skb,
 255                                    unsigned int dataoff,
 256                                    struct nf_conn *ct,
 257                                    int dir);
 258
 259/* Fake conntrack entry for untracked connections */
 260extern struct nf_conn nf_conntrack_untracked;
 261
 262/* Iterate over all conntracks: if iter returns true, it's deleted. */
 263extern void
 264nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 265extern void nf_conntrack_free(struct nf_conn *ct);
 266extern struct nf_conn *
 267nf_conntrack_alloc(struct net *net,
 268                   const struct nf_conntrack_tuple *orig,
 269                   const struct nf_conntrack_tuple *repl,
 270                   gfp_t gfp);
 271
 272/* It's confirmed if it is, or has been in the hash table. */
 273static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 274{
 275        return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 276}
 277
 278static inline int nf_ct_is_dying(struct nf_conn *ct)
 279{
 280        return test_bit(IPS_DYING_BIT, &ct->status);
 281}
 282
 283static inline int nf_ct_is_untracked(const struct sk_buff *skb)
 284{
 285        return (skb->nfct == &nf_conntrack_untracked.ct_general);
 286}
 287
 288extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 289extern unsigned int nf_conntrack_htable_size;
 290extern int nf_conntrack_max;
 291
 292#define NF_CT_STAT_INC(net, count)      \
 293        (per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++)
 294#define NF_CT_STAT_INC_ATOMIC(net, count)               \
 295do {                                                    \
 296        local_bh_disable();                             \
 297        per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++;   \
 298        local_bh_enable();                              \
 299} while (0)
 300
 301#endif /* __KERNEL__ */
 302#endif /* _NF_CONNTRACK_H */
 303