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 * Support for INET6 connection oriented protocols. 7 * 8 * Authors: See the TCPv6 sources 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or(at your option) any later version. 14 */ 15 16 #include <linux/module.h> 17 #include <linux/in6.h> 18 #include <linux/ipv6.h> 19 #include <linux/jhash.h> 20 #include <linux/slab.h> 21 22 #include <net/addrconf.h> 23 #include <net/inet_connection_sock.h> 24 #include <net/inet_ecn.h> 25 #include <net/inet_hashtables.h> 26 #include <net/ip6_route.h> 27 #include <net/sock.h> 28 #include <net/inet6_connection_sock.h> 29 30 int inet6_csk_bind_conflict(const struct sock *sk, 31 const struct inet_bind_bucket *tb, bool relax) 32 { 33 const struct sock *sk2; 34 int reuse = sk->sk_reuse; 35 int reuseport = sk->sk_reuseport; 36 kuid_t uid = sock_i_uid((struct sock *)sk); 37 38 /* We must walk the whole port owner list in this case. -DaveM */ 39 /* 40 * See comment in inet_csk_bind_conflict about sock lookup 41 * vs net namespaces issues. 42 */ 43 sk_for_each_bound(sk2, &tb->owners) { 44 if (sk != sk2 && 45 (!sk->sk_bound_dev_if || 46 !sk2->sk_bound_dev_if || 47 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { 48 if ((!reuse || !sk2->sk_reuse || 49 sk2->sk_state == TCP_LISTEN) && 50 (!reuseport || !sk2->sk_reuseport || 51 (sk2->sk_state != TCP_TIME_WAIT && 52 !uid_eq(uid, 53 sock_i_uid((struct sock *)sk2))))) { 54 if (ipv6_rcv_saddr_equal(sk, sk2)) 55 break; 56 } 57 } 58 } 59 60 return sk2 != NULL; 61 } 62 63 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict); 64 65 struct dst_entry *inet6_csk_route_req(struct sock *sk, 66 struct flowi6 *fl6, 67 const struct request_sock *req) 68 { 69 struct inet6_request_sock *treq = inet6_rsk(req); 70 struct ipv6_pinfo *np = inet6_sk(sk); 71 struct in6_addr *final_p, final; 72 struct dst_entry *dst; 73 74 memset(fl6, 0, sizeof(*fl6)); 75 fl6->flowi6_proto = IPPROTO_TCP; 76 fl6->daddr = treq->rmt_addr; 77 final_p = fl6_update_dst(fl6, np->opt, &final); 78 fl6->saddr = treq->loc_addr; 79 fl6->flowi6_oif = treq->iif; 80 fl6->flowi6_mark = sk->sk_mark; 81 fl6->fl6_dport = inet_rsk(req)->rmt_port; 82 fl6->fl6_sport = inet_rsk(req)->loc_port; 83 security_req_classify_flow(req, flowi6_to_flowi(fl6)); 84 85 dst = ip6_dst_lookup_flow(sk, fl6, final_p, false); 86 if (IS_ERR(dst)) 87 return NULL; 88 89 return dst; 90 } 91 92 /* 93 * request_sock (formerly open request) hash tables. 94 */ 95 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport, 96 const u32 rnd, const u32 synq_hsize) 97 { 98 u32 c; 99 100 c = jhash_3words((__force u32)raddr->s6_addr32[0], 101 (__force u32)raddr->s6_addr32[1], 102 (__force u32)raddr->s6_addr32[2], 103 rnd); 104 105 c = jhash_2words((__force u32)raddr->s6_addr32[3], 106 (__force u32)rport, 107 c); 108 109 return c & (synq_hsize - 1); 110 } 111 112 struct request_sock *inet6_csk_search_req(const struct sock *sk, 113 struct request_sock ***prevp, 114 const __be16 rport, 115 const struct in6_addr *raddr, 116 const struct in6_addr *laddr, 117 const int iif) 118 { 119 const struct inet_connection_sock *icsk = inet_csk(sk); 120 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; 121 struct request_sock *req, **prev; 122 123 for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport, 124 lopt->hash_rnd, 125 lopt->nr_table_entries)]; 126 (req = *prev) != NULL; 127 prev = &req->dl_next) { 128 const struct inet6_request_sock *treq = inet6_rsk(req); 129 130 if (inet_rsk(req)->rmt_port == rport && 131 req->rsk_ops->family == AF_INET6 && 132 ipv6_addr_equal(&treq->rmt_addr, raddr) && 133 ipv6_addr_equal(&treq->loc_addr, laddr) && 134 (!treq->iif || treq->iif == iif)) { 135 WARN_ON(req->sk != NULL); 136 *prevp = prev; 137 return req; 138 } 139 } 140 141 return NULL; 142 } 143 144 EXPORT_SYMBOL_GPL(inet6_csk_search_req); 145 146 void inet6_csk_reqsk_queue_hash_add(struct sock *sk, 147 struct request_sock *req, 148 const unsigned long timeout) 149 { 150 struct inet_connection_sock *icsk = inet_csk(sk); 151 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; 152 const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr, 153 inet_rsk(req)->rmt_port, 154 lopt->hash_rnd, lopt->nr_table_entries); 155 156 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout); 157 inet_csk_reqsk_queue_added(sk, timeout); 158 } 159 160 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add); 161 162 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr) 163 { 164 struct ipv6_pinfo *np = inet6_sk(sk); 165 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr; 166 167 sin6->sin6_family = AF_INET6; 168 sin6->sin6_addr = np->daddr; 169 sin6->sin6_port = inet_sk(sk)->inet_dport; 170 /* We do not store received flowlabel for TCP */ 171 sin6->sin6_flowinfo = 0; 172 sin6->sin6_scope_id = 0; 173 if (sk->sk_bound_dev_if && 174 ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) 175 sin6->sin6_scope_id = sk->sk_bound_dev_if; 176 } 177 178 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr); 179 180 static inline 181 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst, 182 const struct in6_addr *daddr, 183 const struct in6_addr *saddr) 184 { 185 __ip6_dst_store(sk, dst, daddr, saddr); 186 } 187 188 static inline 189 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie) 190 { 191 return __sk_dst_check(sk, cookie); 192 } 193 194 static struct dst_entry *inet6_csk_route_socket(struct sock *sk, 195 struct flowi6 *fl6) 196 { 197 struct inet_sock *inet = inet_sk(sk); 198 struct ipv6_pinfo *np = inet6_sk(sk); 199 struct in6_addr *final_p, final; 200 struct dst_entry *dst; 201 202 memset(fl6, 0, sizeof(*fl6)); 203 fl6->flowi6_proto = sk->sk_protocol; 204 fl6->daddr = np->daddr; 205 fl6->saddr = np->saddr; 206 fl6->flowlabel = np->flow_label; 207 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 208 fl6->flowi6_oif = sk->sk_bound_dev_if; 209 fl6->flowi6_mark = sk->sk_mark; 210 fl6->fl6_sport = inet->inet_sport; 211 fl6->fl6_dport = inet->inet_dport; 212 security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); 213 214 final_p = fl6_update_dst(fl6, np->opt, &final); 215 216 dst = __inet6_csk_dst_check(sk, np->dst_cookie); 217 if (!dst) { 218 dst = ip6_dst_lookup_flow(sk, fl6, final_p, false); 219 220 if (!IS_ERR(dst)) 221 __inet6_csk_dst_store(sk, dst, NULL, NULL); 222 } 223 return dst; 224 } 225 226 int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused) 227 { 228 struct sock *sk = skb->sk; 229 struct ipv6_pinfo *np = inet6_sk(sk); 230 struct flowi6 fl6; 231 struct dst_entry *dst; 232 int res; 233 234 dst = inet6_csk_route_socket(sk, &fl6); 235 if (IS_ERR(dst)) { 236 sk->sk_err_soft = -PTR_ERR(dst); 237 sk->sk_route_caps = 0; 238 kfree_skb(skb); 239 return PTR_ERR(dst); 240 } 241 242 rcu_read_lock(); 243 skb_dst_set_noref(skb, dst); 244 245 /* Restore final destination back after routing done */ 246 fl6.daddr = np->daddr; 247 248 res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass); 249 rcu_read_unlock(); 250 return res; 251 } 252 EXPORT_SYMBOL_GPL(inet6_csk_xmit); 253 254 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu) 255 { 256 struct flowi6 fl6; 257 struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6); 258 259 if (IS_ERR(dst)) 260 return NULL; 261 dst->ops->update_pmtu(dst, sk, NULL, mtu); 262 263 dst = inet6_csk_route_socket(sk, &fl6); 264 return IS_ERR(dst) ? NULL : dst; 265 } 266 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu); 267