include/net/netfilter/nf_conntrack.h

   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 */
  30 union 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
  38 union 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 */
  50 union 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
  82 struct 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 */
  88 struct 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
 103 struct 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
 141 static inline struct nf_conn *
 142 nf_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
 148 static 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
 153 static 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
 163 extern struct net init_net;
 164
 165 static 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). */
 171 extern void
 172 nf_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). */
 177 extern int
 178 nf_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. */
 182 static inline struct nf_conn *
 183 nf_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 */
 190 static 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 */
 197 extern int nf_ct_l3proto_try_module_get(unsigned short l3proto);
 198 extern 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  */
 204 extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
 205
 206 extern void nf_ct_free_hashtable(void *hash, unsigned int size);
 207
 208 extern struct nf_conntrack_tuple_hash *
 209 __nf_conntrack_find(struct net *net, u16 zone,
 210                     const struct nf_conntrack_tuple *tuple);
 211
 212 extern int nf_conntrack_hash_check_insert(struct nf_conn *ct);
 213 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 214 extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 215
 216 extern void nf_conntrack_flush_report(struct net *net, u32 pid, int report);
 217
 218 extern bool nf_ct_get_tuplepr(const struct sk_buff *skb,
 219                               unsigned int nhoff, u_int16_t l3num,
 220                               struct nf_conntrack_tuple *tuple);
 221 extern bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse,
 222                                  const struct nf_conntrack_tuple *orig);
 223
 224 extern 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 */
 231 static 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 */
 240 static 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
 247 extern 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 */
 253 static 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 */
 261 static 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. */
 267 extern 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 */
 272 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked);
 273 static inline struct nf_conn *nf_ct_untracked_get(void)
 274 {
 275         return &__raw_get_cpu_var(nf_conntrack_untracked);
 276 }
 277 extern void nf_ct_untracked_status_or(unsigned long bits);
 278
 279 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 280 extern void
 281 nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 282 extern void nf_conntrack_free(struct nf_conn *ct);
 283 extern struct nf_conn *
 284 nf_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
 289 static 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. */
 295 static inline int nf_ct_is_confirmed(struct nf_conn *ct)
 296 {
 297         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 298 }
 299
 300 static inline int nf_ct_is_dying(struct nf_conn *ct)
 301 {
 302         return test_bit(IPS_DYING_BIT, &ct->status);
 303 }
 304
 305 static 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 */
 311 static 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
 316 struct kernel_param;
 317
 318 extern int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);
 319 extern unsigned int nf_conntrack_htable_size;
 320 extern unsigned int nf_conntrack_max;
 321 extern unsigned int nf_conntrack_hash_rnd;
 322 void 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)               \
 327 do {                                                    \
 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 */