linux/include/net/netfilter/nf_conntrack.h
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   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/* Add protocol helper include file here */
  43#include <linux/netfilter/nf_conntrack_ftp.h>
  44#include <linux/netfilter/nf_conntrack_pptp.h>
  45#include <linux/netfilter/nf_conntrack_h323.h>
  46#include <linux/netfilter/nf_conntrack_sane.h>
  47#include <linux/netfilter/nf_conntrack_sip.h>
  48
  49/* per conntrack: application helper private data */
  50union nf_conntrack_help {
  51        /* insert conntrack helper private data (master) here */
  52#if defined(CONFIG_NF_CONNTRACK_FTP) || defined(CONFIG_NF_CONNTRACK_FTP_MODULE)
  53        struct nf_ct_ftp_master ct_ftp_info;
  54#endif
  55#if defined(CONFIG_NF_CONNTRACK_PPTP) || \
  56    defined(CONFIG_NF_CONNTRACK_PPTP_MODULE)
  57        struct nf_ct_pptp_master ct_pptp_info;
  58#endif
  59#if defined(CONFIG_NF_CONNTRACK_H323) || \
  60    defined(CONFIG_NF_CONNTRACK_H323_MODULE)
  61        struct nf_ct_h323_master ct_h323_info;
  62#endif
  63#if defined(CONFIG_NF_CONNTRACK_SANE) || \
  64    defined(CONFIG_NF_CONNTRACK_SANE_MODULE)
  65        struct nf_ct_sane_master ct_sane_info;
  66#endif
  67#if defined(CONFIG_NF_CONNTRACK_SIP) || defined(CONFIG_NF_CONNTRACK_SIP_MODULE)
  68        struct nf_ct_sip_master ct_sip_info;
  69#endif
  70};
  71
  72#include <linux/types.h>
  73#include <linux/skbuff.h>
  74#include <linux/timer.h>
  75
  76#ifdef CONFIG_NETFILTER_DEBUG
  77#define NF_CT_ASSERT(x)         WARN_ON(!(x))
  78#else
  79#define NF_CT_ASSERT(x)
  80#endif
  81
  82struct nf_conntrack_helper;
  83
  84/* Must be kept in sync with the classes defined by helpers */
  85#define NF_CT_MAX_EXPECT_CLASSES        4
  86
  87/* nf_conn feature for connections that have a helper */
  88struct nf_conn_help {
  89        /* Helper. if any */
  90        struct nf_conntrack_helper __rcu *helper;
  91
  92        union nf_conntrack_help help;
  93
  94        struct hlist_head expectations;
  95
  96        /* Current number of expected connections */
  97        u8 expecting[NF_CT_MAX_EXPECT_CLASSES];
  98};
  99
 100#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
 101#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
 102
 103struct nf_conn {
 104        /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
 105           plus 1 for any connection(s) we are `master' for */
 106        struct nf_conntrack ct_general;
 107
 108        spinlock_t lock;
 109
 110        /* XXX should I move this to the tail ? - Y.K */
 111        /* These are my tuples; original and reply */
 112        struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 113
 114        /* Have we seen traffic both ways yet? (bitset) */
 115        unsigned long status;
 116
 117        /* If we were expected by an expectation, this will be it */
 118        struct nf_conn *master;
 119
 120        /* Timer function; drops refcnt when it goes off. */
 121        struct timer_list timeout;
 122
 123#if defined(CONFIG_NF_CONNTRACK_MARK)
 124        u_int32_t mark;
 125#endif
 126
 127#ifdef CONFIG_NF_CONNTRACK_SECMARK
 128        u_int32_t secmark;
 129#endif
 130
 131        /* Extensions */
 132        struct nf_ct_ext *ext;
 133#ifdef CONFIG_NET_NS
 134        struct net *ct_net;
 135#endif
 136
 137        /* Storage reserved for other modules, must be the last member */
 138        union nf_conntrack_proto proto;
 139};
 140
 141static inline struct nf_conn *
 142nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 143{
 144        return container_of(hash, struct nf_conn,
 145                            tuplehash[hash->tuple.dst.dir]);
 146}
 147
 148static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
 149{
 150        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
 151}
 152
 153static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
 154{
 155        return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
 156}
 157
 158#define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
 159
 160/* get master conntrack via master expectation */
 161#define master_ct(conntr) (conntr->master)
 162
 163extern struct net init_net;
 164
 165static inline struct net *nf_ct_net(const struct nf_conn *ct)
 166{
 167        return read_pnet(&ct->ct_net);
 168}
 169
 170/* Alter reply tuple (maybe alter helper). */
 171extern void
 172nf_conntrack_alter_reply(struct nf_conn *ct,
 173                         const struct nf_conntrack_tuple *newreply);
 174
 175/* Is this tuple taken? (ignoring any belonging to the given
 176   conntrack). */
 177extern int
 178nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 179                         const struct nf_conn *ignored_conntrack);
 180
 181/* Return conntrack_info and tuple hash for given skb. */
 182static inline struct nf_conn *
 183nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 184{
 185        *ctinfo = skb->nfctinfo;
 186        return (struct nf_conn *)skb->nfct;
 187}
 188
 189/* decrement reference count on a conntrack */
 190static inline void nf_ct_put(struct nf_conn *ct)
 191{
 192        NF_CT_ASSERT(ct);
 193        nf_conntrack_put(&ct->ct_general);
 194}
 195
 196/* Protocol module loading */
 197extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 198extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 199
 200/*
 201 * Allocate a hashtable of hlist_head (if nulls == 0),
 202 * or hlist_nulls_head (if nulls == 1)
 203 */
 204extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
 205
 206extern void nf_ct_free_hashtable(void *hash, unsigned int size);
 207
 208extern struct nf_conntrack_tuple_hash *
 209__nf_conntrack_find(struct net *net, u16 zone,
 210                    const struct nf_conntrack_tuple *tuple);
 211
 212extern int nf_conntrack_hash_check_insert(struct nf_conn *ct);
 213extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 214extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 215
 216extern void nf_conntrack_flush_report(struct net *net, u32 pid, int report);
 217
 218extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 219                              unsigned int nhoff, u_int16_t l3num,
 220                              struct nf_conntrack_tuple *tuple);
 221extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 222                                 const struct nf_conntrack_tuple *orig);
 223
 224extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 225                                 enum ip_conntrack_info ctinfo,
 226                                 const struct sk_buff *skb,
 227                                 unsigned long extra_jiffies,
 228                                 int do_acct);
 229
 230/* Refresh conntrack for this many jiffies and do accounting */
 231static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 232                                      enum ip_conntrack_info ctinfo,
 233                                      const struct sk_buff *skb,
 234                                      unsigned long extra_jiffies)
 235{
 236        __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 237}
 238
 239/* Refresh conntrack for this many jiffies */
 240static inline void nf_ct_refresh(struct nf_conn *ct,
 241                                 const struct sk_buff *skb,
 242                                 unsigned long extra_jiffies)
 243{
 244        __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 245}
 246
 247extern bool __nf_ct_kill_acct(struct nf_conn *ct,
 248                              enum ip_conntrack_info ctinfo,
 249                              const struct sk_buff *skb,
 250                              int do_acct);
 251
 252/* kill conntrack and do accounting */
 253static inline bool nf_ct_kill_acct(struct nf_conn *ct,
 254                                   enum ip_conntrack_info ctinfo,
 255                                   const struct sk_buff *skb)
 256{
 257        return __nf_ct_kill_acct(ct, ctinfo, skb, 1);
 258}
 259
 260/* kill conntrack without accounting */
 261static inline bool nf_ct_kill(struct nf_conn *ct)
 262{
 263        return __nf_ct_kill_acct(ct, 0, NULL, 0);
 264}
 265
 266/* These are for NAT.  Icky. */
 267extern s16 (*nf_ct_nat_offset)(const struct nf_conn *ct,
 268                               enum ip_conntrack_dir dir,
 269                               u32 seq);
 270
 271/* Fake conntrack entry for untracked connections */
 272DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 273static inline struct nf_conn *nf_ct_untracked_get(void)
 274{
 275        return &__raw_get_cpu_var(nf_conntrack_untracked);
 276}
 277extern void nf_ct_untracked_status_or(unsigned long bits);
 278
 279/* Iterate over all conntracks: if iter returns true, it's deleted. */
 280extern void
 281nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 282extern void nf_conntrack_free(struct nf_conn *ct);
 283extern struct nf_conn *
 284nf_conntrack_alloc(struct net *net, u16 zone,
 285                   const struct nf_conntrack_tuple *orig,
 286                   const struct nf_conntrack_tuple *repl,
 287                   gfp_t gfp);
 288
 289static inline int nf_ct_is_template(const struct nf_conn *ct)
 290{
 291        return test_bit(IPS_TEMPLATE_BIT, &ct->status);
 292}
 293
 294/* It's confirmed if it is, or has been in the hash table. */
 295static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 296{
 297        return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 298}
 299
 300static inline int nf_ct_is_dying(struct nf_conn *ct)
 301{
 302        return test_bit(IPS_DYING_BIT, &ct->status);
 303}
 304
 305static inline int nf_ct_is_untracked(const struct nf_conn *ct)
 306{
 307        return test_bit(IPS_UNTRACKED_BIT, &ct->status);
 308}
 309
 310/* Packet is received from loopback */
 311static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
 312{
 313        return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
 314}
 315
 316struct kernel_param;
 317
 318extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 319extern unsigned int nf_conntrack_htable_size;
 320extern unsigned int nf_conntrack_max;
 321extern unsigned int nf_conntrack_hash_rnd;
 322void init_nf_conntrack_hash_rnd(void);
 323
 324#define NF_CT_STAT_INC(net, count)      \
 325        __this_cpu_inc((net)->ct.stat->count)
 326#define NF_CT_STAT_INC_ATOMIC(net, count)               \
 327do {                                                    \
 328        local_bh_disable();                             \
 329        __this_cpu_inc((net)->ct.stat->count);          \
 330        local_bh_enable();                              \
 331} while (0)
 332
 333#define MODULE_ALIAS_NFCT_HELPER(helper) \
 334        MODULE_ALIAS("nfct-helper-" helper)
 335
 336#endif /* _NF_CONNTRACK_H */
 337
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