include/linux/netfilter_ipv4/ip_conntrack.h

   1 #ifndef _IP_CONNTRACK_H
   2 #define _IP_CONNTRACK_H
   3 /* Connection state tracking for netfilter.  This is separated from,
   4    but required by, the NAT layer; it can also be used by an iptables
   5    extension. */
   6 enum ip_conntrack_info
   7 {
   8         /* Part of an established connection (either direction). */
   9         IP_CT_ESTABLISHED,
  10
  11         /* Like NEW, but related to an existing connection, or ICMP error
  12            (in either direction). */
  13         IP_CT_RELATED,
  14
  15         /* Started a new connection to track (only
  16            IP_CT_DIR_ORIGINAL); may be a retransmission. */
  17         IP_CT_NEW,
  18
  19         /* >= this indicates reply direction */
  20         IP_CT_IS_REPLY,
  21
  22         /* Number of distinct IP_CT types (no NEW in reply dirn). */
  23         IP_CT_NUMBER = IP_CT_IS_REPLY * 2 - 1
  24 };
  25
  26 /* Bitset representing status of connection. */
  27 enum ip_conntrack_status {
  28         /* It's an expected connection: bit 0 set.  This bit never changed */
  29         IPS_EXPECTED_BIT = 0,
  30         IPS_EXPECTED = (1 << IPS_EXPECTED_BIT),
  31
  32         /* We've seen packets both ways: bit 1 set.  Can be set, not unset. */
  33         IPS_SEEN_REPLY_BIT = 1,
  34         IPS_SEEN_REPLY = (1 << IPS_SEEN_REPLY_BIT),
  35
  36         /* Conntrack should never be early-expired. */
  37         IPS_ASSURED_BIT = 2,
  38         IPS_ASSURED = (1 << IPS_ASSURED_BIT),
  39
  40         /* Connection is confirmed: originating packet has left box */
  41         IPS_CONFIRMED_BIT = 3,
  42         IPS_CONFIRMED = (1 << IPS_CONFIRMED_BIT),
  43
  44         /* Connection needs src nat in orig dir.  This bit never changed. */
  45         IPS_SRC_NAT_BIT = 4,
  46         IPS_SRC_NAT = (1 << IPS_SRC_NAT_BIT),
  47
  48         /* Connection needs dst nat in orig dir.  This bit never changed. */
  49         IPS_DST_NAT_BIT = 5,
  50         IPS_DST_NAT = (1 << IPS_DST_NAT_BIT),
  51
  52         /* Both together. */
  53         IPS_NAT_MASK = (IPS_DST_NAT | IPS_SRC_NAT),
  54
  55         /* Connection needs TCP sequence adjusted. */
  56         IPS_SEQ_ADJUST_BIT = 6,
  57         IPS_SEQ_ADJUST = (1 << IPS_SEQ_ADJUST_BIT),
  58
  59         /* NAT initialization bits. */
  60         IPS_SRC_NAT_DONE_BIT = 7,
  61         IPS_SRC_NAT_DONE = (1 << IPS_SRC_NAT_DONE_BIT),
  62
  63         IPS_DST_NAT_DONE_BIT = 8,
  64         IPS_DST_NAT_DONE = (1 << IPS_DST_NAT_DONE_BIT),
  65
  66         /* Both together */
  67         IPS_NAT_DONE_MASK = (IPS_DST_NAT_DONE | IPS_SRC_NAT_DONE),
  68 };
  69
  70 #ifdef __KERNEL__
  71 #include <linux/config.h>
  72 #include <linux/netfilter_ipv4/ip_conntrack_tuple.h>
  73 #include <linux/bitops.h>
  74 #include <linux/compiler.h>
  75 #include <asm/atomic.h>
  76
  77 #include <linux/netfilter_ipv4/ip_conntrack_tcp.h>
  78 #include <linux/netfilter_ipv4/ip_conntrack_icmp.h>
  79 #include <linux/netfilter_ipv4/ip_conntrack_sctp.h>
  80
  81 /* per conntrack: protocol private data */
  82 union ip_conntrack_proto {
  83         /* insert conntrack proto private data here */
  84         struct ip_ct_sctp sctp;
  85         struct ip_ct_tcp tcp;
  86         struct ip_ct_icmp icmp;
  87 };
  88
  89 union ip_conntrack_expect_proto {
  90         /* insert expect proto private data here */
  91 };
  92
  93 /* Add protocol helper include file here */
  94 #include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
  95 #include <linux/netfilter_ipv4/ip_conntrack_ftp.h>
  96 #include <linux/netfilter_ipv4/ip_conntrack_irc.h>
  97
  98 /* per conntrack: application helper private data */
  99 union ip_conntrack_help {
 100         /* insert conntrack helper private data (master) here */
 101         struct ip_ct_ftp_master ct_ftp_info;
 102         struct ip_ct_irc_master ct_irc_info;
 103 };
 104
 105 #ifdef CONFIG_IP_NF_NAT_NEEDED
 106 #include <linux/netfilter_ipv4/ip_nat.h>
 107 #endif
 108
 109 #include <linux/types.h>
 110 #include <linux/skbuff.h>
 111
 112 #ifdef CONFIG_NETFILTER_DEBUG
 113 #define IP_NF_ASSERT(x)                                                 \
 114 do {                                                                    \
 115         if (!(x))                                                       \
 116                 /* Wooah!  I'm tripping my conntrack in a frenzy of     \
 117                    netplay... */                                        \
 118                 printk("NF_IP_ASSERT: %s:%i(%s)\n",                     \
 119                        __FILE__, __LINE__, __FUNCTION__);               \
 120 } while(0)
 121 #else
 122 #define IP_NF_ASSERT(x)
 123 #endif
 124
 125 struct ip_conntrack_counter
 126 {
 127         u_int64_t packets;
 128         u_int64_t bytes;
 129 };
 130
 131 struct ip_conntrack_helper;
 132
 133 struct ip_conntrack
 134 {
 135         /* Usage count in here is 1 for hash table/destruct timer, 1 per skb,
 136            plus 1 for any connection(s) we are `master' for */
 137         struct nf_conntrack ct_general;
 138
 139         /* Have we seen traffic both ways yet? (bitset) */
 140         unsigned long status;
 141
 142         /* Timer function; drops refcnt when it goes off. */
 143         struct timer_list timeout;
 144
 145 #ifdef CONFIG_IP_NF_CT_ACCT
 146         /* Accounting Information (same cache line as other written members) */
 147         struct ip_conntrack_counter counters[IP_CT_DIR_MAX];
 148 #endif
 149         /* If we were expected by an expectation, this will be it */
 150         struct ip_conntrack *master;
 151
 152         /* Current number of expected connections */
 153         unsigned int expecting;
 154
 155         /* Helper, if any. */
 156         struct ip_conntrack_helper *helper;
 157
 158         /* Storage reserved for other modules: */
 159         union ip_conntrack_proto proto;
 160
 161         union ip_conntrack_help help;
 162
 163 #ifdef CONFIG_IP_NF_NAT_NEEDED
 164         struct {
 165                 struct ip_nat_info info;
 166 #if defined(CONFIG_IP_NF_TARGET_MASQUERADE) || \
 167         defined(CONFIG_IP_NF_TARGET_MASQUERADE_MODULE)
 168                 int masq_index;
 169 #endif
 170         } nat;
 171 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 172
 173 #if defined(CONFIG_IP_NF_CONNTRACK_MARK)
 174         u_int32_t mark;
 175 #endif
 176
 177         /* Traversed often, so hopefully in different cacheline to top */
 178         /* These are my tuples; original and reply */
 179         struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
 180 };
 181
 182 struct ip_conntrack_expect
 183 {
 184         /* Internal linked list (global expectation list) */
 185         struct list_head list;
 186
 187         /* We expect this tuple, with the following mask */
 188         struct ip_conntrack_tuple tuple, mask;
 189
 190         /* Function to call after setup and insertion */
 191         void (*expectfn)(struct ip_conntrack *new,
 192                          struct ip_conntrack_expect *this);
 193
 194         /* The conntrack of the master connection */
 195         struct ip_conntrack *master;
 196
 197         /* Timer function; deletes the expectation. */
 198         struct timer_list timeout;
 199
 200         /* Usage count. */
 201         atomic_t use;
 202
 203 #ifdef CONFIG_IP_NF_NAT_NEEDED
 204         /* This is the original per-proto part, used to map the
 205          * expected connection the way the recipient expects. */
 206         union ip_conntrack_manip_proto saved_proto;
 207         /* Direction relative to the master connection. */
 208         enum ip_conntrack_dir dir;
 209 #endif
 210 };
 211
 212 static inline struct ip_conntrack *
 213 tuplehash_to_ctrack(const struct ip_conntrack_tuple_hash *hash)
 214 {
 215         return container_of(hash, struct ip_conntrack,
 216                             tuplehash[hash->tuple.dst.dir]);
 217 }
 218
 219 /* get master conntrack via master expectation */
 220 #define master_ct(conntr) (conntr->master)
 221
 222 /* Alter reply tuple (maybe alter helper). */
 223 extern void
 224 ip_conntrack_alter_reply(struct ip_conntrack *conntrack,
 225                          const struct ip_conntrack_tuple *newreply);
 226
 227 /* Is this tuple taken? (ignoring any belonging to the given
 228    conntrack). */
 229 extern int
 230 ip_conntrack_tuple_taken(const struct ip_conntrack_tuple *tuple,
 231                          const struct ip_conntrack *ignored_conntrack);
 232
 233 /* Return conntrack_info and tuple hash for given skb. */
 234 static inline struct ip_conntrack *
 235 ip_conntrack_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
 236 {
 237         *ctinfo = skb->nfctinfo;
 238         return (struct ip_conntrack *)skb->nfct;
 239 }
 240
 241 /* decrement reference count on a conntrack */
 242 extern void ip_conntrack_put(struct ip_conntrack *ct);
 243
 244 /* call to create an explicit dependency on ip_conntrack. */
 245 extern void need_ip_conntrack(void);
 246
 247 extern int invert_tuplepr(struct ip_conntrack_tuple *inverse,
 248                           const struct ip_conntrack_tuple *orig);
 249
 250 /* Refresh conntrack for this many jiffies */
 251 extern void ip_ct_refresh_acct(struct ip_conntrack *ct,
 252                                enum ip_conntrack_info ctinfo,
 253                                const struct sk_buff *skb,
 254                                unsigned long extra_jiffies);
 255
 256 /* These are for NAT.  Icky. */
 257 /* Update TCP window tracking data when NAT mangles the packet */
 258 extern void ip_conntrack_tcp_update(struct sk_buff *skb,
 259                                     struct ip_conntrack *conntrack,
 260                                     enum ip_conntrack_dir dir);
 261
 262 /* Call me when a conntrack is destroyed. */
 263 extern void (*ip_conntrack_destroyed)(struct ip_conntrack *conntrack);
 264
 265 /* Fake conntrack entry for untracked connections */
 266 extern struct ip_conntrack ip_conntrack_untracked;
 267
 268 /* Returns new sk_buff, or NULL */
 269 struct sk_buff *
 270 ip_ct_gather_frags(struct sk_buff *skb, u_int32_t user);
 271
 272 /* Iterate over all conntracks: if iter returns true, it's deleted. */
 273 extern void
 274 ip_ct_iterate_cleanup(int (*iter)(struct ip_conntrack *i, void *data),
 275                       void *data);
 276
 277 /* It's confirmed if it is, or has been in the hash table. */
 278 static inline int is_confirmed(struct ip_conntrack *ct)
 279 {
 280         return test_bit(IPS_CONFIRMED_BIT, &ct->status);
 281 }
 282
 283 extern unsigned int ip_conntrack_htable_size;
 284
 285 struct ip_conntrack_stat
 286 {
 287         unsigned int searched;
 288         unsigned int found;
 289         unsigned int new;
 290         unsigned int invalid;
 291         unsigned int ignore;
 292         unsigned int delete;
 293         unsigned int delete_list;
 294         unsigned int insert;
 295         unsigned int insert_failed;
 296         unsigned int drop;
 297         unsigned int early_drop;
 298         unsigned int error;
 299         unsigned int expect_new;
 300         unsigned int expect_create;
 301         unsigned int expect_delete;
 302 };
 303
 304 #define CONNTRACK_STAT_INC(count) (__get_cpu_var(ip_conntrack_stat).count++)
 305
 306 #ifdef CONFIG_IP_NF_NAT_NEEDED
 307 static inline int ip_nat_initialized(struct ip_conntrack *conntrack,
 308                                      enum ip_nat_manip_type manip)
 309 {
 310         if (manip == IP_NAT_MANIP_SRC)
 311                 return test_bit(IPS_SRC_NAT_DONE_BIT, &conntrack->status);
 312         return test_bit(IPS_DST_NAT_DONE_BIT, &conntrack->status);
 313 }
 314 #endif /* CONFIG_IP_NF_NAT_NEEDED */
 315
 316 #endif /* __KERNEL__ */
 317 #endif /* _IP_CONNTRACK_H */