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 #include <linux/types.h> 43 #include <linux/skbuff.h> 44 #include <linux/timer.h> 45 46 #ifdef CONFIG_NETFILTER_DEBUG 47 #define NF_CT_ASSERT(x) WARN_ON(!(x)) 48 #else 49 #define NF_CT_ASSERT(x) 50 #endif 51 52 struct nf_conntrack_helper; 53 54 /* Must be kept in sync with the classes defined by helpers */ 55 #define NF_CT_MAX_EXPECT_CLASSES 4 56 57 /* nf_conn feature for connections that have a helper */ 58 struct nf_conn_help { 59 /* Helper. if any */ 60 struct nf_conntrack_helper __rcu *helper; 61 62 struct hlist_head expectations; 63 64 /* Current number of expected connections */ 65 u8 expecting[NF_CT_MAX_EXPECT_CLASSES]; 66 67 /* private helper information. */ 68 char data[]; 69 }; 70 71 #include <net/netfilter/ipv4/nf_conntrack_ipv4.h> 72 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> 73 74 struct nf_conn { 75 /* Usage count in here is 1 for hash table/destruct timer, 1 per skb, 76 * plus 1 for any connection(s) we are `master' for 77 * 78 * Hint, SKB address this struct and refcnt via skb->nfct and 79 * helpers nf_conntrack_get() and nf_conntrack_put(). 80 * Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt, 81 * beware nf_ct_get() is different and don't inc refcnt. 82 */ 83 struct nf_conntrack ct_general; 84 85 spinlock_t lock; 86 u16 cpu; 87 88 /* XXX should I move this to the tail ? - Y.K */ 89 /* These are my tuples; original and reply */ 90 struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX]; 91 92 /* Have we seen traffic both ways yet? (bitset) */ 93 unsigned long status; 94 95 /* Timer function; drops refcnt when it goes off. */ 96 struct timer_list timeout; 97 98 possible_net_t ct_net; 99 100 /* all members below initialized via memset */ 101 u8 __nfct_init_offset[0]; 102 103 /* If we were expected by an expectation, this will be it */ 104 struct nf_conn *master; 105 106 #if defined(CONFIG_NF_CONNTRACK_MARK) 107 u_int32_t mark; 108 #endif 109 110 #ifdef CONFIG_NF_CONNTRACK_SECMARK 111 u_int32_t secmark; 112 #endif 113 114 /* Extensions */ 115 struct nf_ct_ext *ext; 116 117 /* Storage reserved for other modules, must be the last member */ 118 union nf_conntrack_proto proto; 119 }; 120 121 static inline struct nf_conn * 122 nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash) 123 { 124 return container_of(hash, struct nf_conn, 125 tuplehash[hash->tuple.dst.dir]); 126 } 127 128 static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct) 129 { 130 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num; 131 } 132 133 static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct) 134 { 135 return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum; 136 } 137 138 #define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple) 139 140 /* get master conntrack via master expectation */ 141 #define master_ct(conntr) (conntr->master) 142 143 extern struct net init_net; 144 145 static inline struct net *nf_ct_net(const struct nf_conn *ct) 146 { 147 return read_pnet(&ct->ct_net); 148 } 149 150 /* Alter reply tuple (maybe alter helper). */ 151 void nf_conntrack_alter_reply(struct nf_conn *ct, 152 const struct nf_conntrack_tuple *newreply); 153 154 /* Is this tuple taken? (ignoring any belonging to the given 155 conntrack). */ 156 int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, 157 const struct nf_conn *ignored_conntrack); 158 159 /* Return conntrack_info and tuple hash for given skb. */ 160 static inline struct nf_conn * 161 nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo) 162 { 163 *ctinfo = skb->nfctinfo; 164 return (struct nf_conn *)skb->nfct; 165 } 166 167 /* decrement reference count on a conntrack */ 168 static inline void nf_ct_put(struct nf_conn *ct) 169 { 170 NF_CT_ASSERT(ct); 171 nf_conntrack_put(&ct->ct_general); 172 } 173 174 /* Protocol module loading */ 175 int nf_ct_l3proto_try_module_get(unsigned short l3proto); 176 void nf_ct_l3proto_module_put(unsigned short l3proto); 177 178 /* 179 * Allocate a hashtable of hlist_head (if nulls == 0), 180 * or hlist_nulls_head (if nulls == 1) 181 */ 182 void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls); 183 184 void nf_ct_free_hashtable(void *hash, unsigned int size); 185 186 int nf_conntrack_hash_check_insert(struct nf_conn *ct); 187 bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report); 188 189 bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff, 190 u_int16_t l3num, struct net *net, 191 struct nf_conntrack_tuple *tuple); 192 bool nf_ct_invert_tuplepr(struct nf_conntrack_tuple *inverse, 193 const struct nf_conntrack_tuple *orig); 194 195 void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo, 196 const struct sk_buff *skb, 197 unsigned long extra_jiffies, int do_acct); 198 199 /* Refresh conntrack for this many jiffies and do accounting */ 200 static 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 */ 209 static 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 bool __nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo, 217 const struct sk_buff *skb, int do_acct); 218 219 /* kill conntrack and do accounting */ 220 static inline bool nf_ct_kill_acct(struct nf_conn *ct, 221 enum ip_conntrack_info ctinfo, 222 const struct sk_buff *skb) 223 { 224 return __nf_ct_kill_acct(ct, ctinfo, skb, 1); 225 } 226 227 /* kill conntrack without accounting */ 228 static inline bool nf_ct_kill(struct nf_conn *ct) 229 { 230 return __nf_ct_kill_acct(ct, 0, NULL, 0); 231 } 232 233 /* These are for NAT. Icky. */ 234 extern s32 (*nf_ct_nat_offset)(const struct nf_conn *ct, 235 enum ip_conntrack_dir dir, 236 u32 seq); 237 238 /* Fake conntrack entry for untracked connections */ 239 DECLARE_PER_CPU(struct nf_conn, nf_conntrack_untracked); 240 static inline struct nf_conn *nf_ct_untracked_get(void) 241 { 242 return raw_cpu_ptr(&nf_conntrack_untracked); 243 } 244 void nf_ct_untracked_status_or(unsigned long bits); 245 246 /* Iterate over all conntracks: if iter returns true, it's deleted. */ 247 void nf_ct_iterate_cleanup(struct net *net, 248 int (*iter)(struct nf_conn *i, void *data), 249 void *data, u32 portid, int report); 250 251 struct nf_conntrack_zone; 252 253 void nf_conntrack_free(struct nf_conn *ct); 254 struct nf_conn *nf_conntrack_alloc(struct net *net, 255 const struct nf_conntrack_zone *zone, 256 const struct nf_conntrack_tuple *orig, 257 const struct nf_conntrack_tuple *repl, 258 gfp_t gfp); 259 260 static inline int nf_ct_is_template(const struct nf_conn *ct) 261 { 262 return test_bit(IPS_TEMPLATE_BIT, &ct->status); 263 } 264 265 /* It's confirmed if it is, or has been in the hash table. */ 266 static inline int nf_ct_is_confirmed(struct nf_conn *ct) 267 { 268 return test_bit(IPS_CONFIRMED_BIT, &ct->status); 269 } 270 271 static inline int nf_ct_is_dying(struct nf_conn *ct) 272 { 273 return test_bit(IPS_DYING_BIT, &ct->status); 274 } 275 276 static inline int nf_ct_is_untracked(const struct nf_conn *ct) 277 { 278 return test_bit(IPS_UNTRACKED_BIT, &ct->status); 279 } 280 281 /* Packet is received from loopback */ 282 static inline bool nf_is_loopback_packet(const struct sk_buff *skb) 283 { 284 return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK; 285 } 286 287 /* jiffies until ct expires, 0 if already expired */ 288 static inline unsigned long nf_ct_expires(const struct nf_conn *ct) 289 { 290 long timeout = (long)ct->timeout.expires - (long)jiffies; 291 292 return timeout > 0 ? timeout : 0; 293 } 294 295 struct kernel_param; 296 297 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp); 298 extern unsigned int nf_conntrack_htable_size; 299 extern unsigned int nf_conntrack_max; 300 301 struct nf_conn *nf_ct_tmpl_alloc(struct net *net, 302 const struct nf_conntrack_zone *zone, 303 gfp_t flags); 304 void nf_ct_tmpl_free(struct nf_conn *tmpl); 305 306 #define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count) 307 #define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count) 308 309 #define MODULE_ALIAS_NFCT_HELPER(helper) \ 310 MODULE_ALIAS("nfct-helper-" helper) 311 312 #endif /* _NF_CONNTRACK_H */ 313