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 * 8 * Authors: Lotsa people, from code originally in tcp, generalised here 9 * by Arnaldo Carvalho de Melo <acme@mandriva.com> 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 17 #include <linux/module.h> 18 #include <linux/random.h> 19 20 #include <net/inet_connection_sock.h> 21 #include <net/inet_hashtables.h> 22 #include <net/inet6_hashtables.h> 23 #include <net/ip.h> 24 25 void __inet6_hash(struct sock *sk) 26 { 27 struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo; 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 list = &inet_ehash_bucket(hashinfo, hash)->chain; 41 lock = inet_ehash_lockp(hashinfo, hash); 42 write_lock(lock); 43 } 44 45 __sk_add_node(sk, list); 46 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 47 write_unlock(lock); 48 } 49 EXPORT_SYMBOL(__inet6_hash); 50 51 /* 52 * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so 53 * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM 54 * 55 * The sockhash lock must be held as a reader here. 56 */ 57 struct sock *__inet6_lookup_established(struct net *net, 58 struct inet_hashinfo *hashinfo, 59 const struct in6_addr *saddr, 60 const __be16 sport, 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; 67 const __portpair ports = INET_COMBINED_PORTS(sport, hnum); 68 /* Optimize here for direct hit, only listening connections can 69 * have wildcards anyways. 70 */ 71 unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport); 72 struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash); 73 rwlock_t *lock = inet_ehash_lockp(hashinfo, hash); 74 75 prefetch(head->chain.first); 76 read_lock(lock); 77 sk_for_each(sk, node, &head->chain) { 78 /* For IPV6 do the cheaper port and family tests first. */ 79 if (INET6_MATCH(sk, net, hash, saddr, daddr, ports, dif)) 80 goto hit; /* You sunk my battleship! */ 81 } 82 /* Must check for a TIME_WAIT'er before going to listener hash. */ 83 sk_for_each(sk, node, &head->twchain) { 84 if (INET6_TW_MATCH(sk, net, hash, saddr, daddr, ports, dif)) 85 goto hit; 86 } 87 read_unlock(lock); 88 return NULL; 89 90 hit: 91 sock_hold(sk); 92 read_unlock(lock); 93 return sk; 94 } 95 EXPORT_SYMBOL(__inet6_lookup_established); 96 97 struct sock *inet6_lookup_listener(struct net *net, 98 struct inet_hashinfo *hashinfo, const struct in6_addr *daddr, 99 const unsigned short hnum, const int dif) 100 { 101 struct sock *sk; 102 const struct hlist_node *node; 103 struct sock *result = NULL; 104 int score, hiscore = 0; 105 106 read_lock(&hashinfo->lhash_lock); 107 sk_for_each(sk, node, 108 &hashinfo->listening_hash[inet_lhashfn(net, hnum)]) { 109 if (net_eq(sock_net(sk), net) && inet_sk(sk)->num == hnum && 110 sk->sk_family == PF_INET6) { 111 const struct ipv6_pinfo *np = inet6_sk(sk); 112 113 score = 1; 114 if (!ipv6_addr_any(&np->rcv_saddr)) { 115 if (!ipv6_addr_equal(&np->rcv_saddr, daddr)) 116 continue; 117 score++; 118 } 119 if (sk->sk_bound_dev_if) { 120 if (sk->sk_bound_dev_if != dif) 121 continue; 122 score++; 123 } 124 if (score == 3) { 125 result = sk; 126 break; 127 } 128 if (score > hiscore) { 129 hiscore = score; 130 result = sk; 131 } 132 } 133 } 134 if (result) 135 sock_hold(result); 136 read_unlock(&hashinfo->lhash_lock); 137 return result; 138 } 139 140 EXPORT_SYMBOL_GPL(inet6_lookup_listener); 141 142 struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo, 143 const struct in6_addr *saddr, const __be16 sport, 144 const struct in6_addr *daddr, const __be16 dport, 145 const int dif) 146 { 147 struct sock *sk; 148 149 local_bh_disable(); 150 sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif); 151 local_bh_enable(); 152 153 return sk; 154 } 155 156 EXPORT_SYMBOL_GPL(inet6_lookup); 157 158 static int __inet6_check_established(struct inet_timewait_death_row *death_row, 159 struct sock *sk, const __u16 lport, 160 struct inet_timewait_sock **twp) 161 { 162 struct inet_hashinfo *hinfo = death_row->hashinfo; 163 struct inet_sock *inet = inet_sk(sk); 164 const struct ipv6_pinfo *np = inet6_sk(sk); 165 const struct in6_addr *daddr = &np->rcv_saddr; 166 const struct in6_addr *saddr = &np->daddr; 167 const int dif = sk->sk_bound_dev_if; 168 const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport); 169 struct net *net = sock_net(sk); 170 const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr, 171 inet->dport); 172 struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash); 173 rwlock_t *lock = inet_ehash_lockp(hinfo, hash); 174 struct sock *sk2; 175 const struct hlist_node *node; 176 struct inet_timewait_sock *tw; 177 178 prefetch(head->chain.first); 179 write_lock(lock); 180 181 /* Check TIME-WAIT sockets first. */ 182 sk_for_each(sk2, node, &head->twchain) { 183 tw = inet_twsk(sk2); 184 185 if (INET6_TW_MATCH(sk2, net, hash, saddr, daddr, ports, dif)) { 186 if (twsk_unique(sk, sk2, twp)) 187 goto unique; 188 else 189 goto not_unique; 190 } 191 } 192 tw = NULL; 193 194 /* And established part... */ 195 sk_for_each(sk2, node, &head->chain) { 196 if (INET6_MATCH(sk2, net, hash, saddr, daddr, ports, dif)) 197 goto not_unique; 198 } 199 200 unique: 201 /* Must record num and sport now. Otherwise we will see 202 * in hash table socket with a funny identity. */ 203 inet->num = lport; 204 inet->sport = htons(lport); 205 BUG_TRAP(sk_unhashed(sk)); 206 __sk_add_node(sk, &head->chain); 207 sk->sk_hash = hash; 208 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 209 write_unlock(lock); 210 211 if (twp != NULL) { 212 *twp = tw; 213 NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITRECYCLED); 214 } else if (tw != NULL) { 215 /* Silly. Should hash-dance instead... */ 216 inet_twsk_deschedule(tw, death_row); 217 NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITRECYCLED); 218 219 inet_twsk_put(tw); 220 } 221 return 0; 222 223 not_unique: 224 write_unlock(lock); 225 return -EADDRNOTAVAIL; 226 } 227 228 static inline u32 inet6_sk_port_offset(const struct sock *sk) 229 { 230 const struct inet_sock *inet = inet_sk(sk); 231 const struct ipv6_pinfo *np = inet6_sk(sk); 232 return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32, 233 np->daddr.s6_addr32, 234 inet->dport); 235 } 236 237 int inet6_hash_connect(struct inet_timewait_death_row *death_row, 238 struct sock *sk) 239 { 240 return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk), 241 __inet6_check_established, __inet6_hash); 242 } 243 244 EXPORT_SYMBOL_GPL(inet6_hash_connect); 245