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#include <linux/bitops.h>
  18#include <linux/compiler.h>
  19#include <linux/atomic.h>
  20
  21#include <linux/netfilter/nf_conntrack_tcp.h>
  22#include <linux/netfilter/nf_conntrack_dccp.h>
  23#include <linux/netfilter/nf_conntrack_sctp.h>
  24#include <linux/netfilter/nf_conntrack_proto_gre.h>
  25#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
  26
  27#include <net/netfilter/nf_conntrack_tuple.h>
  28
  29/* per conntrack: protocol private data */
  30union nf_conntrack_proto {
  31        /* insert conntrack proto private data here */
  32        struct nf_ct_dccp dccp;
  33        struct ip_ct_sctp sctp;
  34        struct ip_ct_tcp tcp;
  35        struct nf_ct_gre gre;
  36};
  37
  38union nf_conntrack_expect_proto {
  39        /* insert expect proto private data here */
  40};
  41
  42#include <linux/types.h>
  43#include <linux/skbuff.h>
  44#include <linux/timer.h>
  45
  46#ifdef CONFIG_NETFILTER_DEBUG
  47#define NF_CT_ASSERT(x)         WARN_ON(!(x))
  48#else
  49#define NF_CT_ASSERT(x)
  50#endif
  51
  52struct nf_conntrack_helper;
  53
  54/* Must be kept in sync with the classes defined by helpers */
  55#define NF_CT_MAX_EXPECT_CLASSES        4
  56
  57/* nf_conn feature for connections that have a helper */
  58struct nf_conn_help {
  59        /* Helper. if any */
  60        struct nf_conntrack_helper __rcu *helper;
  61
  62        struct hlist_head expectations;
  63
  64        /* Current number of expected connections */
  65        u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
  66
  67        /* private helper information. */
  68        char data[];
  69};
  70
  71#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  72#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  73
  74struct nf_conn {
  75        /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  76           plus 1 for any connection(s) we are `master' for */
  77        struct nf_conntrack ct_general;
  78
  79        spinlock_t lock;
  80
  81        /* XXX should I move this to the tail ? - Y.K */
  82        /* These are my tuples; original and reply */
  83        struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
  84
  85        /* Have we seen traffic both ways yet? (bitset) */
  86        unsigned long status;
  87
  88        /* If we were expected by an expectation, this will be it */
  89        struct nf_conn *master;
  90
  91        /* Timer function; drops refcnt when it goes off. */
  92        struct timer_list timeout;
  93
  94#if defined(CONFIG_NF_CONNTRACK_MARK)
  95        u_int32_t mark;
  96#endif
  97
  98#ifdef CONFIG_NF_CONNTRACK_SECMARK
  99        u_int32_t secmark;
 100#endif
 101
 102        /* Extensions */
 103        struct nf_ct_ext *ext;
 104#ifdef CONFIG_NET_NS
 105        struct net *ct_net;
 106#endif
 107
 108        /* Storage reserved for other modules, must be the last member */
 109        union nf_conntrack_proto proto;
 110};
 111
 112static inline struct nf_conn *
 113nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 114{
 115        return container_of(hash, struct nf_conn,
 116                            tuplehash[hash->tuple.dst.dir]);
 117}
 118
 119static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 120{
 121        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 122}
 123
 124static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 125{
 126        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 127}
 128
 129#define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
 130
 131/* get master conntrack via master expectation */
 132#define master_ct(conntr) (conntr->master)
 133
 134extern struct net init_net;
 135
 136static inline struct net *nf_ct_net(const struct nf_conn *ct)
 137{
 138        return read_pnet(&ct->ct_net);
 139}
 140
 141/* Alter reply tuple (maybe alter helper). */
 142extern void
 143nf_conntrack_alter_reply(struct nf_conn *ct,
 144                         const struct nf_conntrack_tuple *newreply);
 145
 146/* Is this tuple taken? (ignoring any belonging to the given
 147   conntrack). */
 148extern int
 149nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 150                         const struct nf_conn *ignored_conntrack);
 151
 152/* Return conntrack_info and tuple hash for given skb. */
 153static inline struct nf_conn *
 154nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 155{
 156        *ctinfo = skb->nfctinfo;
 157        return (struct nf_conn *)skb->nfct;
 158}
 159
 160/* decrement reference count on a conntrack */
 161static inline void nf_ct_put(struct nf_conn *ct)
 162{
 163        NF_CT_ASSERT(ct);
 164        nf_conntrack_put(&ct->ct_general);
 165}
 166
 167/* Protocol module loading */
 168extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 169extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 170
 171/*
 172 * Allocate a hashtable of hlist_head (if nulls == 0),
 173 * or hlist_nulls_head (if nulls == 1)
 174 */
 175extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
 176
 177extern void nf_ct_free_hashtable(void *hash, unsigned int size);
 178
 179extern struct nf_conntrack_tuple_hash *
 180__nf_conntrack_find(struct net *net, u16 zone,
 181                    const struct nf_conntrack_tuple *tuple);
 182
 183extern int nf_conntrack_hash_check_insert(struct nf_conn *ct);
 184extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 185extern void nf_ct_dying_timeout(struct nf_conn *ct);
 186
 187extern void nf_conntrack_flush_report(struct net *net, u32 portid, int report);
 188
 189extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 190                              unsigned int nhoff, u_int16_t l3num,
 191                              struct nf_conntrack_tuple *tuple);
 192extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 193                                 const struct nf_conntrack_tuple *orig);
 194
 195extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 196                                 enum ip_conntrack_info ctinfo,
 197                                 const struct sk_buff *skb,
 198                                 unsigned long extra_jiffies,
 199                                 int do_acct);
 200
 201/* Refresh conntrack for this many jiffies and do accounting */
 202static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 203                                      enum ip_conntrack_info ctinfo,
 204                                      const struct sk_buff *skb,
 205                                      unsigned long extra_jiffies)
 206{
 207        __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 208}
 209
 210/* Refresh conntrack for this many jiffies */
 211static inline void nf_ct_refresh(struct nf_conn *ct,
 212                                 const struct sk_buff *skb,
 213                                 unsigned long extra_jiffies)
 214{
 215        __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 216}
 217
 218extern bool __nf_ct_kill_acct(struct nf_conn *ct,
 219                              enum ip_conntrack_info ctinfo,
 220                              const struct sk_buff *skb,
 221                              int do_acct);
 222
 223/* kill conntrack and do accounting */
 224static inline bool nf_ct_kill_acct(struct nf_conn *ct,
 225                                   enum ip_conntrack_info ctinfo,
 226                                   const struct sk_buff *skb)
 227{
 228        return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
 229}
 230
 231/* kill conntrack without accounting */
 232static inline bool nf_ct_kill(struct nf_conn *ct)
 233{
 234        return __nf_ct_kill_acct(ct, 0, NULL, 0);
 235}
 236
 237/* These are for NAT.  Icky. */
 238extern s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
 239                               enum ip_conntrack_dir dir,
 240                               u32 seq);
 241
 242/* Fake conntrack entry for untracked connections */
 243DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 244static inline struct nf_conn *nf_ct_untracked_get(void)
 245{
 246        return &__raw_get_cpu_var(nf_conntrack_untracked);
 247}
 248extern void nf_ct_untracked_status_or(unsigned long bits);
 249
 250/* Iterate over all conntracks: if iter returns true, it's deleted. */
 251extern void
 252nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 253extern void nf_conntrack_free(struct nf_conn *ct);
 254extern struct nf_conn *
 255nf_conntrack_alloc(struct net *net, u16 zone,
 256                   const struct nf_conntrack_tuple *orig,
 257                   const struct nf_conntrack_tuple *repl,
 258                   gfp_t gfp);
 259
 260static inline int nf_ct_is_template(const struct nf_conn *ct)
 261{
 262        return test_bit(IPS_TEMPLATE_BIT, &ct->status);
 263}
 264
 265/* It's confirmed if it is, or has been in the hash table. */
 266static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 267{
 268        return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 269}
 270
 271static inline int nf_ct_is_dying(struct nf_conn *ct)
 272{
 273        return test_bit(IPS_DYING_BIT, &ct->status);
 274}
 275
 276static inline int nf_ct_is_untracked(const struct nf_conn *ct)
 277{
 278        return test_bit(IPS_UNTRACKED_BIT, &ct->status);
 279}
 280
 281/* Packet is received from loopback */
 282static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
 283{
 284        return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
 285}
 286
 287struct kernel_param;
 288
 289extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 290extern unsigned int nf_conntrack_htable_size;
 291extern unsigned int nf_conntrack_max;
 292extern unsigned int nf_conntrack_hash_rnd;
 293void init_nf_conntrack_hash_rnd(void);
 294
 295#define NF_CT_STAT_INC(net, count)        __this_cpu_inc((net)->ct.stat->count)
 296#define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
 297
 298#define MODULE_ALIAS_NFCT_HELPER(helper) \
 299        MODULE_ALIAS("nfct-helper-" helper)
 300
 301#endif /* _NF_CONNTRACK_H */
 302