Arnaldo Carvalho de Melo | 5324a04 | 2005-08-12 09:26:18 -0300 | [diff] [blame] | 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * Generic INET6 transport hashtables |
| 7 | * |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 8 | * Authors: Lotsa people, from code originally in tcp, generalised here |
| 9 | * by Arnaldo Carvalho de Melo <acme@mandriva.com> |
Arnaldo Carvalho de Melo | 5324a04 | 2005-08-12 09:26:18 -0300 | [diff] [blame] | 10 | * |
| 11 | * This program is free software; you can redistribute it and/or |
| 12 | * modify it under the terms of the GNU General Public License |
| 13 | * as published by the Free Software Foundation; either version |
| 14 | * 2 of the License, or (at your option) any later version. |
| 15 | */ |
| 16 | |
Arnaldo Carvalho de Melo | 5324a04 | 2005-08-12 09:26:18 -0300 | [diff] [blame] | 17 | #include <linux/module.h> |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 18 | #include <linux/random.h> |
Arnaldo Carvalho de Melo | 5324a04 | 2005-08-12 09:26:18 -0300 | [diff] [blame] | 19 | |
| 20 | #include <net/inet_connection_sock.h> |
| 21 | #include <net/inet_hashtables.h> |
| 22 | #include <net/inet6_hashtables.h> |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 23 | #include <net/ip.h> |
Arnaldo Carvalho de Melo | 5324a04 | 2005-08-12 09:26:18 -0300 | [diff] [blame] | 24 | |
Denis Vlasenko | b1a7ffc | 2006-04-09 22:48:59 -0700 | [diff] [blame] | 25 | void __inet6_hash(struct inet_hashinfo *hashinfo, |
| 26 | struct sock *sk) |
| 27 | { |
| 28 | struct hlist_head *list; |
| 29 | rwlock_t *lock; |
| 30 | |
| 31 | BUG_TRAP(sk_unhashed(sk)); |
| 32 | |
| 33 | if (sk->sk_state == TCP_LISTEN) { |
| 34 | list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)]; |
| 35 | lock = &hashinfo->lhash_lock; |
| 36 | inet_listen_wlock(hashinfo); |
| 37 | } else { |
| 38 | unsigned int hash; |
| 39 | sk->sk_hash = hash = inet6_sk_ehashfn(sk); |
| 40 | hash &= (hashinfo->ehash_size - 1); |
| 41 | list = &hashinfo->ehash[hash].chain; |
| 42 | lock = &hashinfo->ehash[hash].lock; |
| 43 | write_lock(lock); |
| 44 | } |
| 45 | |
| 46 | __sk_add_node(sk, list); |
| 47 | sock_prot_inc_use(sk->sk_prot); |
| 48 | write_unlock(lock); |
| 49 | } |
| 50 | EXPORT_SYMBOL(__inet6_hash); |
| 51 | |
| 52 | /* |
| 53 | * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so |
| 54 | * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM |
| 55 | * |
| 56 | * The sockhash lock must be held as a reader here. |
| 57 | */ |
| 58 | struct sock *__inet6_lookup_established(struct inet_hashinfo *hashinfo, |
| 59 | const struct in6_addr *saddr, |
Al Viro | d2ecd9c | 2006-11-08 00:20:00 -0800 | [diff] [blame] | 60 | const __be16 sport, |
Denis Vlasenko | b1a7ffc | 2006-04-09 22:48:59 -0700 | [diff] [blame] | 61 | const struct in6_addr *daddr, |
| 62 | const u16 hnum, |
| 63 | const int dif) |
| 64 | { |
| 65 | struct sock *sk; |
| 66 | const struct hlist_node *node; |
Al Viro | 4f765d8 | 2006-09-27 18:43:07 -0700 | [diff] [blame] | 67 | const __portpair ports = INET_COMBINED_PORTS(sport, hnum); |
Denis Vlasenko | b1a7ffc | 2006-04-09 22:48:59 -0700 | [diff] [blame] | 68 | /* Optimize here for direct hit, only listening connections can |
| 69 | * have wildcards anyways. |
| 70 | */ |
| 71 | unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport); |
| 72 | struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash); |
| 73 | |
| 74 | prefetch(head->chain.first); |
| 75 | read_lock(&head->lock); |
| 76 | sk_for_each(sk, node, &head->chain) { |
| 77 | /* For IPV6 do the cheaper port and family tests first. */ |
| 78 | if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif)) |
| 79 | goto hit; /* You sunk my battleship! */ |
| 80 | } |
| 81 | /* Must check for a TIME_WAIT'er before going to listener hash. */ |
| 82 | sk_for_each(sk, node, &(head + hashinfo->ehash_size)->chain) { |
| 83 | const struct inet_timewait_sock *tw = inet_twsk(sk); |
| 84 | |
Al Viro | 4f765d8 | 2006-09-27 18:43:07 -0700 | [diff] [blame] | 85 | if(*((__portpair *)&(tw->tw_dport)) == ports && |
Denis Vlasenko | b1a7ffc | 2006-04-09 22:48:59 -0700 | [diff] [blame] | 86 | sk->sk_family == PF_INET6) { |
| 87 | const struct inet6_timewait_sock *tw6 = inet6_twsk(sk); |
| 88 | |
| 89 | if (ipv6_addr_equal(&tw6->tw_v6_daddr, saddr) && |
| 90 | ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) && |
| 91 | (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)) |
| 92 | goto hit; |
| 93 | } |
| 94 | } |
| 95 | read_unlock(&head->lock); |
| 96 | return NULL; |
| 97 | |
| 98 | hit: |
| 99 | sock_hold(sk); |
| 100 | read_unlock(&head->lock); |
| 101 | return sk; |
| 102 | } |
| 103 | EXPORT_SYMBOL(__inet6_lookup_established); |
| 104 | |
Arnaldo Carvalho de Melo | 5324a04 | 2005-08-12 09:26:18 -0300 | [diff] [blame] | 105 | struct sock *inet6_lookup_listener(struct inet_hashinfo *hashinfo, |
| 106 | const struct in6_addr *daddr, |
| 107 | const unsigned short hnum, const int dif) |
| 108 | { |
| 109 | struct sock *sk; |
| 110 | const struct hlist_node *node; |
| 111 | struct sock *result = NULL; |
| 112 | int score, hiscore = 0; |
| 113 | |
| 114 | read_lock(&hashinfo->lhash_lock); |
| 115 | sk_for_each(sk, node, &hashinfo->listening_hash[inet_lhashfn(hnum)]) { |
| 116 | if (inet_sk(sk)->num == hnum && sk->sk_family == PF_INET6) { |
| 117 | const struct ipv6_pinfo *np = inet6_sk(sk); |
| 118 | |
| 119 | score = 1; |
| 120 | if (!ipv6_addr_any(&np->rcv_saddr)) { |
| 121 | if (!ipv6_addr_equal(&np->rcv_saddr, daddr)) |
| 122 | continue; |
| 123 | score++; |
| 124 | } |
| 125 | if (sk->sk_bound_dev_if) { |
| 126 | if (sk->sk_bound_dev_if != dif) |
| 127 | continue; |
| 128 | score++; |
| 129 | } |
| 130 | if (score == 3) { |
| 131 | result = sk; |
| 132 | break; |
| 133 | } |
| 134 | if (score > hiscore) { |
| 135 | hiscore = score; |
| 136 | result = sk; |
| 137 | } |
| 138 | } |
| 139 | } |
| 140 | if (result) |
| 141 | sock_hold(result); |
| 142 | read_unlock(&hashinfo->lhash_lock); |
| 143 | return result; |
| 144 | } |
| 145 | |
| 146 | EXPORT_SYMBOL_GPL(inet6_lookup_listener); |
| 147 | |
| 148 | struct sock *inet6_lookup(struct inet_hashinfo *hashinfo, |
Al Viro | d2ecd9c | 2006-11-08 00:20:00 -0800 | [diff] [blame] | 149 | const struct in6_addr *saddr, const __be16 sport, |
| 150 | const struct in6_addr *daddr, const __be16 dport, |
Arnaldo Carvalho de Melo | 5324a04 | 2005-08-12 09:26:18 -0300 | [diff] [blame] | 151 | const int dif) |
| 152 | { |
| 153 | struct sock *sk; |
| 154 | |
| 155 | local_bh_disable(); |
| 156 | sk = __inet6_lookup(hashinfo, saddr, sport, daddr, ntohs(dport), dif); |
| 157 | local_bh_enable(); |
| 158 | |
| 159 | return sk; |
| 160 | } |
| 161 | |
| 162 | EXPORT_SYMBOL_GPL(inet6_lookup); |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 163 | |
| 164 | static int __inet6_check_established(struct inet_timewait_death_row *death_row, |
| 165 | struct sock *sk, const __u16 lport, |
| 166 | struct inet_timewait_sock **twp) |
| 167 | { |
| 168 | struct inet_hashinfo *hinfo = death_row->hashinfo; |
Herbert Xu | 3759fa9 | 2006-03-13 14:26:12 -0800 | [diff] [blame] | 169 | struct inet_sock *inet = inet_sk(sk); |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 170 | const struct ipv6_pinfo *np = inet6_sk(sk); |
| 171 | const struct in6_addr *daddr = &np->rcv_saddr; |
| 172 | const struct in6_addr *saddr = &np->daddr; |
| 173 | const int dif = sk->sk_bound_dev_if; |
Al Viro | 4f765d8 | 2006-09-27 18:43:07 -0700 | [diff] [blame] | 174 | const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport); |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 175 | const unsigned int hash = inet6_ehashfn(daddr, inet->num, saddr, |
| 176 | inet->dport); |
| 177 | struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); |
| 178 | struct sock *sk2; |
| 179 | const struct hlist_node *node; |
| 180 | struct inet_timewait_sock *tw; |
| 181 | |
| 182 | prefetch(head->chain.first); |
| 183 | write_lock(&head->lock); |
| 184 | |
| 185 | /* Check TIME-WAIT sockets first. */ |
| 186 | sk_for_each(sk2, node, &(head + hinfo->ehash_size)->chain) { |
| 187 | const struct inet6_timewait_sock *tw6 = inet6_twsk(sk2); |
| 188 | |
| 189 | tw = inet_twsk(sk2); |
| 190 | |
Al Viro | 4f765d8 | 2006-09-27 18:43:07 -0700 | [diff] [blame] | 191 | if(*((__portpair *)&(tw->tw_dport)) == ports && |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 192 | sk2->sk_family == PF_INET6 && |
| 193 | ipv6_addr_equal(&tw6->tw_v6_daddr, saddr) && |
| 194 | ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr) && |
| 195 | sk2->sk_bound_dev_if == sk->sk_bound_dev_if) { |
| 196 | if (twsk_unique(sk, sk2, twp)) |
| 197 | goto unique; |
| 198 | else |
| 199 | goto not_unique; |
| 200 | } |
| 201 | } |
| 202 | tw = NULL; |
| 203 | |
| 204 | /* And established part... */ |
| 205 | sk_for_each(sk2, node, &head->chain) { |
| 206 | if (INET6_MATCH(sk2, hash, saddr, daddr, ports, dif)) |
| 207 | goto not_unique; |
| 208 | } |
| 209 | |
| 210 | unique: |
Herbert Xu | 3759fa9 | 2006-03-13 14:26:12 -0800 | [diff] [blame] | 211 | /* Must record num and sport now. Otherwise we will see |
| 212 | * in hash table socket with a funny identity. */ |
| 213 | inet->num = lport; |
| 214 | inet->sport = htons(lport); |
Arnaldo Carvalho de Melo | d8313f5 | 2005-12-13 23:25:44 -0800 | [diff] [blame] | 215 | BUG_TRAP(sk_unhashed(sk)); |
| 216 | __sk_add_node(sk, &head->chain); |
| 217 | sk->sk_hash = hash; |
| 218 | sock_prot_inc_use(sk->sk_prot); |
| 219 | write_unlock(&head->lock); |
| 220 | |
| 221 | if (twp != NULL) { |
| 222 | *twp = tw; |
| 223 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); |
| 224 | } else if (tw != NULL) { |
| 225 | /* Silly. Should hash-dance instead... */ |
| 226 | inet_twsk_deschedule(tw, death_row); |
| 227 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); |
| 228 | |
| 229 | inet_twsk_put(tw); |
| 230 | } |
| 231 | return 0; |
| 232 | |
| 233 | not_unique: |
| 234 | write_unlock(&head->lock); |
| 235 | return -EADDRNOTAVAIL; |
| 236 | } |
| 237 | |
| 238 | static inline u32 inet6_sk_port_offset(const struct sock *sk) |
| 239 | { |
| 240 | const struct inet_sock *inet = inet_sk(sk); |
| 241 | const struct ipv6_pinfo *np = inet6_sk(sk); |
| 242 | return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32, |
| 243 | np->daddr.s6_addr32, |
| 244 | inet->dport); |
| 245 | } |
| 246 | |
| 247 | int inet6_hash_connect(struct inet_timewait_death_row *death_row, |
| 248 | struct sock *sk) |
| 249 | { |
| 250 | struct inet_hashinfo *hinfo = death_row->hashinfo; |
| 251 | const unsigned short snum = inet_sk(sk)->num; |
| 252 | struct inet_bind_hashbucket *head; |
| 253 | struct inet_bind_bucket *tb; |
| 254 | int ret; |
| 255 | |
| 256 | if (snum == 0) { |
| 257 | const int low = sysctl_local_port_range[0]; |
| 258 | const int high = sysctl_local_port_range[1]; |
| 259 | const int range = high - low; |
| 260 | int i, port; |
| 261 | static u32 hint; |
| 262 | const u32 offset = hint + inet6_sk_port_offset(sk); |
| 263 | struct hlist_node *node; |
| 264 | struct inet_timewait_sock *tw = NULL; |
| 265 | |
| 266 | local_bh_disable(); |
| 267 | for (i = 1; i <= range; i++) { |
| 268 | port = low + (i + offset) % range; |
| 269 | head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)]; |
| 270 | spin_lock(&head->lock); |
| 271 | |
| 272 | /* Does not bother with rcv_saddr checks, |
| 273 | * because the established check is already |
| 274 | * unique enough. |
| 275 | */ |
| 276 | inet_bind_bucket_for_each(tb, node, &head->chain) { |
| 277 | if (tb->port == port) { |
| 278 | BUG_TRAP(!hlist_empty(&tb->owners)); |
| 279 | if (tb->fastreuse >= 0) |
| 280 | goto next_port; |
| 281 | if (!__inet6_check_established(death_row, |
| 282 | sk, port, |
| 283 | &tw)) |
| 284 | goto ok; |
| 285 | goto next_port; |
| 286 | } |
| 287 | } |
| 288 | |
| 289 | tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, |
| 290 | head, port); |
| 291 | if (!tb) { |
| 292 | spin_unlock(&head->lock); |
| 293 | break; |
| 294 | } |
| 295 | tb->fastreuse = -1; |
| 296 | goto ok; |
| 297 | |
| 298 | next_port: |
| 299 | spin_unlock(&head->lock); |
| 300 | } |
| 301 | local_bh_enable(); |
| 302 | |
| 303 | return -EADDRNOTAVAIL; |
| 304 | |
| 305 | ok: |
| 306 | hint += i; |
| 307 | |
| 308 | /* Head lock still held and bh's disabled */ |
| 309 | inet_bind_hash(sk, tb, port); |
| 310 | if (sk_unhashed(sk)) { |
| 311 | inet_sk(sk)->sport = htons(port); |
| 312 | __inet6_hash(hinfo, sk); |
| 313 | } |
| 314 | spin_unlock(&head->lock); |
| 315 | |
| 316 | if (tw) { |
| 317 | inet_twsk_deschedule(tw, death_row); |
| 318 | inet_twsk_put(tw); |
| 319 | } |
| 320 | |
| 321 | ret = 0; |
| 322 | goto out; |
| 323 | } |
| 324 | |
| 325 | head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)]; |
| 326 | tb = inet_csk(sk)->icsk_bind_hash; |
| 327 | spin_lock_bh(&head->lock); |
| 328 | |
| 329 | if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) { |
| 330 | __inet6_hash(hinfo, sk); |
| 331 | spin_unlock_bh(&head->lock); |
| 332 | return 0; |
| 333 | } else { |
| 334 | spin_unlock(&head->lock); |
| 335 | /* No definite answer... Walk to established hash table */ |
| 336 | ret = __inet6_check_established(death_row, sk, snum, NULL); |
| 337 | out: |
| 338 | local_bh_enable(); |
| 339 | return ret; |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | EXPORT_SYMBOL_GPL(inet6_hash_connect); |