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/ipv6/nf_conntrack_icmpv6.h>
  27
  28#include <net/netfilter/nf_conntrack_tuple.h>
  29
  30/* per conntrack: protocol private data */
  31union 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
  39union 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 */
  51union nf_conntrack_help {
  52        /* insert conntrack helper private data (master) here */
  53        struct nf_ct_ftp_master ct_ftp_info;
  54        struct nf_ct_pptp_master ct_pptp_info;
  55        struct nf_ct_h323_master ct_h323_info;
  56        struct nf_ct_sane_master ct_sane_info;
  57        struct nf_ct_sip_master ct_sip_info;
  58};
  59
  60#include <linux/types.h>
  61#include <linux/skbuff.h>
  62#include <linux/timer.h>
  63
  64#ifdef CONFIG_NETFILTER_DEBUG
  65#define NF_CT_ASSERT(x)         WARN_ON(!(x))
  66#else
  67#define NF_CT_ASSERT(x)
  68#endif
  69
  70struct nf_conntrack_helper;
  71
  72/* Must be kept in sync with the classes defined by helpers */
  73#define NF_CT_MAX_EXPECT_CLASSES        3
  74
  75/* nf_conn feature for connections that have a helper */
  76struct nf_conn_help {
  77        /* Helper. if any */
  78        struct nf_conntrack_helper *helper;
  79
  80        union nf_conntrack_help help;
  81
  82        struct hlist_head expectations;
  83
  84        /* Current number of expected connections */
  85        u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
  86};
  87
  88#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  89#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  90
  91struct nf_conn {
  92        /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
  93           plus 1 for any connection(s) we are `master' for */
  94        struct nf_conntrack ct_general;
  95
  96        spinlock_t lock;
  97
  98        /* XXX should I move this to the tail ? - Y.K */
  99        /* These are my tuples; original and reply */
 100        struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 101
 102        /* Have we seen traffic both ways yet? (bitset) */
 103        unsigned long status;
 104
 105        /* If we were expected by an expectation, this will be it */
 106        struct nf_conn *master;
 107
 108        /* Timer function; drops refcnt when it goes off. */
 109        struct timer_list timeout;
 110
 111#if defined(CONFIG_NF_CONNTRACK_MARK)
 112        u_int32_t mark;
 113#endif
 114
 115#ifdef CONFIG_NF_CONNTRACK_SECMARK
 116        u_int32_t secmark;
 117#endif
 118
 119        /* Storage reserved for other modules: */
 120        union nf_conntrack_proto proto;
 121
 122        /* Extensions */
 123        struct nf_ct_ext *ext;
 124#ifdef CONFIG_NET_NS
 125        struct net *ct_net;
 126#endif
 127};
 128
 129static inline struct nf_conn *
 130nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 131{
 132        return container_of(hash, struct nf_conn,
 133                            tuplehash[hash->tuple.dst.dir]);
 134}
 135
 136static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 137{
 138        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 139}
 140
 141static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 142{
 143        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 144}
 145
 146#define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
 147
 148/* get master conntrack via master expectation */
 149#define master_ct(conntr) (conntr->master)
 150
 151extern struct net init_net;
 152
 153static inline struct net *nf_ct_net(const struct nf_conn *ct)
 154{
 155#ifdef CONFIG_NET_NS
 156        return ct->ct_net;
 157#else
 158        return &init_net;
 159#endif
 160}
 161
 162/* Alter reply tuple (maybe alter helper). */
 163extern void
 164nf_conntrack_alter_reply(struct nf_conn *ct,
 165                         const struct nf_conntrack_tuple *newreply);
 166
 167/* Is this tuple taken? (ignoring any belonging to the given
 168   conntrack). */
 169extern int
 170nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 171                         const struct nf_conn *ignored_conntrack);
 172
 173/* Return conntrack_info and tuple hash for given skb. */
 174static inline struct nf_conn *
 175nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 176{
 177        *ctinfo = skb->nfctinfo;
 178        return (struct nf_conn *)skb->nfct;
 179}
 180
 181/* decrement reference count on a conntrack */
 182static inline void nf_ct_put(struct nf_conn *ct)
 183{
 184        NF_CT_ASSERT(ct);
 185        nf_conntrack_put(&ct->ct_general);
 186}
 187
 188/* Protocol module loading */
 189extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 190extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 191
 192/*
 193 * Allocate a hashtable of hlist_head (if nulls == 0),
 194 * or hlist_nulls_head (if nulls == 1)
 195 */
 196extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int nulls);
 197
 198extern void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size);
 199
 200extern struct nf_conntrack_tuple_hash *
 201__nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple);
 202
 203extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 204extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 205extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 206
 207extern void nf_conntrack_flush_report(struct net *net, u32 pid, int report);
 208
 209extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 210                              unsigned int nhoff, u_int16_t l3num,
 211                              struct nf_conntrack_tuple *tuple);
 212extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 213                                 const struct nf_conntrack_tuple *orig);
 214
 215extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 216                                 enum ip_conntrack_info ctinfo,
 217                                 const struct sk_buff *skb,
 218                                 unsigned long extra_jiffies,
 219                                 int do_acct);
 220
 221/* Refresh conntrack for this many jiffies and do accounting */
 222static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 223                                      enum ip_conntrack_info ctinfo,
 224                                      const struct sk_buff *skb,
 225                                      unsigned long extra_jiffies)
 226{
 227        __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 228}
 229
 230/* Refresh conntrack for this many jiffies */
 231static inline void nf_ct_refresh(struct nf_conn *ct,
 232                                 const struct sk_buff *skb,
 233                                 unsigned long extra_jiffies)
 234{
 235        __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 236}
 237
 238extern bool __nf_ct_kill_acct(struct nf_conn *ct,
 239                              enum ip_conntrack_info ctinfo,
 240                              const struct sk_buff *skb,
 241                              int do_acct);
 242
 243/* kill conntrack and do accounting */
 244static inline bool nf_ct_kill_acct(struct nf_conn *ct,
 245                                   enum ip_conntrack_info ctinfo,
 246                                   const struct sk_buff *skb)
 247{
 248        return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
 249}
 250
 251/* kill conntrack without accounting */
 252static inline bool nf_ct_kill(struct nf_conn *ct)
 253{
 254        return __nf_ct_kill_acct(ct, 0, NULL, 0);
 255}
 256
 257/* These are for NAT.  Icky. */
 258extern s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
 259                               enum ip_conntrack_dir dir,
 260                               u32 seq);
 261
 262/* Fake conntrack entry for untracked connections */
 263extern struct nf_conn nf_conntrack_untracked;
 264
 265/* Iterate over all conntracks: if iter returns true, it's deleted. */
 266extern void
 267nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 268extern void nf_conntrack_free(struct nf_conn *ct);
 269extern struct nf_conn *
 270nf_conntrack_alloc(struct net *net,
 271                   const struct nf_conntrack_tuple *orig,
 272                   const struct nf_conntrack_tuple *repl,
 273                   gfp_t gfp);
 274
 275/* It's confirmed if it is, or has been in the hash table. */
 276static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 277{
 278        return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 279}
 280
 281static inline int nf_ct_is_dying(struct nf_conn *ct)
 282{
 283        return test_bit(IPS_DYING_BIT, &ct->status);
 284}
 285
 286static inline int nf_ct_is_untracked(const struct sk_buff *skb)
 287{
 288        return (skb->nfct == &nf_conntrack_untracked.ct_general);
 289}
 290
 291extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 292extern unsigned int nf_conntrack_htable_size;
 293extern unsigned int nf_conntrack_max;
 294
 295#define NF_CT_STAT_INC(net, count)      \
 296        (per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++)
 297#define NF_CT_STAT_INC_ATOMIC(net, count)               \
 298do {                                                    \
 299        local_bh_disable();                             \
 300        per_cpu_ptr((net)->ct.stat, raw_smp_processor_id())->count++;   \
 301        local_bh_enable();                              \
 302} while (0)
 303
 304#define MODULE_ALIAS_NFCT_HELPER(helper) \
 305        MODULE_ALIAS("nfct-helper-" helper)
 306
 307#endif /* __KERNEL__ */
 308#endif /* _NF_CONNTRACK_H */
 309