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_sctp.h>
  24#include <linux/netfilter/nf_conntrack_proto_gre.h>
  25#include <net/netfilter/ipv4/nf_conntrack_icmp.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 ip_ct_sctp sctp;
  34        struct ip_ct_tcp tcp;
  35        struct ip_ct_icmp icmp;
  36        struct nf_ct_icmpv6 icmpv6;
  37        struct nf_ct_gre gre;
  38};
  39
  40union nf_conntrack_expect_proto {
  41        /* insert expect proto private data here */
  42};
  43
  44/* Add protocol helper include file here */
  45#include <linux/netfilter/nf_conntrack_ftp.h>
  46#include <linux/netfilter/nf_conntrack_pptp.h>
  47#include <linux/netfilter/nf_conntrack_h323.h>
  48#include <linux/netfilter/nf_conntrack_sane.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};
  58
  59#include <linux/types.h>
  60#include <linux/skbuff.h>
  61#include <linux/timer.h>
  62
  63#ifdef CONFIG_NETFILTER_DEBUG
  64#define NF_CT_ASSERT(x)                                                 \
  65do {                                                                    \
  66        if (!(x))                                                       \
  67                /* Wooah!  I'm tripping my conntrack in a frenzy of     \
  68                   netplay... */                                        \
  69                printk("NF_CT_ASSERT: %s:%i(%s)\n",                     \
  70                       __FILE__, __LINE__, __FUNCTION__);               \
  71} while(0)
  72#else
  73#define NF_CT_ASSERT(x)
  74#endif
  75
  76struct nf_conntrack_helper;
  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        unsigned int expecting;
  89};
  90
  91
  92#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
  93#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  94
  95struct 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
 134static inline struct nf_conn *
 135nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
 136{
 137        return container_of(hash, struct nf_conn,
 138                            tuplehash[hash->tuple.dst.dir]);
 139}
 140
 141/* get master conntrack via master expectation */
 142#define master_ct(conntr) (conntr->master)
 143
 144/* Alter reply tuple (maybe alter helper). */
 145extern void
 146nf_conntrack_alter_reply(struct nf_conn *conntrack,
 147                         const struct nf_conntrack_tuple *newreply);
 148
 149/* Is this tuple taken? (ignoring any belonging to the given
 150   conntrack). */
 151extern int
 152nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 153                         const struct nf_conn *ignored_conntrack);
 154
 155/* Return conntrack_info and tuple hash for given skb. */
 156static inline struct nf_conn *
 157nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 158{
 159        *ctinfo = skb->nfctinfo;
 160        return (struct nf_conn *)skb->nfct;
 161}
 162
 163/* decrement reference count on a conntrack */
 164static inline void nf_ct_put(struct nf_conn *ct)
 165{
 166        NF_CT_ASSERT(ct);
 167        nf_conntrack_put(&ct->ct_general);
 168}
 169
 170/* Protocol module loading */
 171extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 172extern void nf_ct_l3proto_module_put(unsigned short l3proto);
 173
 174extern struct hlist_head *nf_ct_alloc_hashtable(int *sizep, int *vmalloced);
 175extern void nf_ct_free_hashtable(struct hlist_head *hash, int vmalloced,
 176                                 int size);
 177
 178extern struct nf_conntrack_tuple_hash *
 179__nf_conntrack_find(const struct nf_conntrack_tuple *tuple,
 180                    const struct nf_conn *ignored_conntrack);
 181
 182extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 183
 184extern void nf_conntrack_flush(void);
 185
 186extern int nf_ct_get_tuplepr(const struct sk_buff *skb,
 187                             unsigned int nhoff,
 188                             u_int16_t l3num,
 189                             struct nf_conntrack_tuple *tuple);
 190extern int nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 191                                const struct nf_conntrack_tuple *orig);
 192
 193extern void __nf_ct_refresh_acct(struct nf_conn *ct,
 194                                 enum ip_conntrack_info ctinfo,
 195                                 const struct sk_buff *skb,
 196                                 unsigned long extra_jiffies,
 197                                 int do_acct);
 198
 199/* Refresh conntrack for this many jiffies and do accounting */
 200static inline void nf_ct_refresh_acct(struct nf_conn *ct,
 201                                      enum ip_conntrack_info ctinfo,
 202                                      const struct sk_buff *skb,
 203                                      unsigned long extra_jiffies)
 204{
 205        __nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, 1);
 206}
 207
 208/* Refresh conntrack for this many jiffies */
 209static inline void nf_ct_refresh(struct nf_conn *ct,
 210                                 const struct sk_buff *skb,
 211                                 unsigned long extra_jiffies)
 212{
 213        __nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, 0);
 214}
 215
 216/* These are for NAT.  Icky. */
 217/* Update TCP window tracking data when NAT mangles the packet */
 218extern void nf_conntrack_tcp_update(struct sk_buff *skb,
 219                                    unsigned int dataoff,
 220                                    struct nf_conn *conntrack,
 221                                    int dir);
 222
 223/* Fake conntrack entry for untracked connections */
 224extern struct nf_conn nf_conntrack_untracked;
 225
 226extern int nf_ct_no_defrag;
 227
 228/* Iterate over all conntracks: if iter returns true, it's deleted. */
 229extern void
 230nf_ct_iterate_cleanup(int (*iter)(struct nf_conn *i, void *data), void *data);
 231extern void nf_conntrack_free(struct nf_conn *ct);
 232extern struct nf_conn *
 233nf_conntrack_alloc(const struct nf_conntrack_tuple *orig,
 234                   const struct nf_conntrack_tuple *repl);
 235
 236/* It's confirmed if it is, or has been in the hash table. */
 237static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 238{
 239        return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 240}
 241
 242static inline int nf_ct_is_dying(struct nf_conn *ct)
 243{
 244        return test_bit(IPS_DYING_BIT, &ct->status);
 245}
 246
 247static inline int nf_ct_is_untracked(const struct sk_buff *skb)
 248{
 249        return (skb->nfct == &nf_conntrack_untracked.ct_general);
 250}
 251
 252extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 253extern unsigned int nf_conntrack_htable_size;
 254extern int nf_conntrack_checksum;
 255extern atomic_t nf_conntrack_count;
 256extern int nf_conntrack_max;
 257
 258DECLARE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat);
 259#define NF_CT_STAT_INC(count) (__get_cpu_var(nf_conntrack_stat).count++)
 260#define NF_CT_STAT_INC_ATOMIC(count)                    \
 261do {                                                    \
 262        local_bh_disable();                             \
 263        __get_cpu_var(nf_conntrack_stat).count++;       \
 264        local_bh_enable();                              \
 265} while (0)
 266
 267extern int
 268nf_conntrack_register_cache(u_int32_t features, const char *name, size_t size);
 269extern void
 270nf_conntrack_unregister_cache(u_int32_t features);
 271
 272#endif /* __KERNEL__ */
 273#endif /* _NF_CONNTRACK_H */
 274