| 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 | if (!relax && reuse && sk2->sk_reuse && |
| 58 | sk2->sk_state != TCP_LISTEN && |
| 59 | ipv6_rcv_saddr_equal(sk, sk2)) |
| 60 | break; |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | return sk2 != NULL; |
| 65 | } |
| 66 | |
| 67 | EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict); |
| 68 | |
| 69 | struct dst_entry *inet6_csk_route_req(struct sock *sk, |
| 70 | struct flowi6 *fl6, |
| 71 | const struct request_sock *req) |
| 72 | { |
| 73 | struct inet6_request_sock *treq = inet6_rsk(req); |
| 74 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 75 | struct in6_addr *final_p, final; |
| 76 | struct dst_entry *dst; |
| 77 | |
| 78 | memset(fl6, 0, sizeof(*fl6)); |
| 79 | fl6->flowi6_proto = IPPROTO_TCP; |
| 80 | fl6->daddr = treq->rmt_addr; |
| 81 | final_p = fl6_update_dst(fl6, np->opt, &final); |
| 82 | fl6->saddr = treq->loc_addr; |
| 83 | fl6->flowi6_oif = treq->iif; |
| 84 | fl6->flowi6_mark = inet_rsk(req)->ir_mark; |
| 85 | fl6->fl6_dport = inet_rsk(req)->rmt_port; |
| 86 | fl6->fl6_sport = inet_rsk(req)->loc_port; |
| 87 | fl6->flowi6_uid = sock_i_uid(sk); |
| 88 | security_req_classify_flow(req, flowi6_to_flowi(fl6)); |
| 89 | |
| 90 | dst = ip6_dst_lookup_flow(sk, fl6, final_p, false); |
| 91 | if (IS_ERR(dst)) |
| 92 | return NULL; |
| 93 | |
| 94 | return dst; |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | * request_sock (formerly open request) hash tables. |
| 99 | */ |
| 100 | static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport, |
| 101 | const u32 rnd, const u32 synq_hsize) |
| 102 | { |
| 103 | u32 c; |
| 104 | |
| 105 | c = jhash_3words((__force u32)raddr->s6_addr32[0], |
| 106 | (__force u32)raddr->s6_addr32[1], |
| 107 | (__force u32)raddr->s6_addr32[2], |
| 108 | rnd); |
| 109 | |
| 110 | c = jhash_2words((__force u32)raddr->s6_addr32[3], |
| 111 | (__force u32)rport, |
| 112 | c); |
| 113 | |
| 114 | return c & (synq_hsize - 1); |
| 115 | } |
| 116 | |
| 117 | struct request_sock *inet6_csk_search_req(const struct sock *sk, |
| 118 | struct request_sock ***prevp, |
| 119 | const __be16 rport, |
| 120 | const struct in6_addr *raddr, |
| 121 | const struct in6_addr *laddr, |
| 122 | const int iif) |
| 123 | { |
| 124 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 125 | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; |
| 126 | struct request_sock *req, **prev; |
| 127 | |
| 128 | for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport, |
| 129 | lopt->hash_rnd, |
| 130 | lopt->nr_table_entries)]; |
| 131 | (req = *prev) != NULL; |
| 132 | prev = &req->dl_next) { |
| 133 | const struct inet6_request_sock *treq = inet6_rsk(req); |
| 134 | |
| 135 | if (inet_rsk(req)->rmt_port == rport && |
| 136 | req->rsk_ops->family == AF_INET6 && |
| 137 | ipv6_addr_equal(&treq->rmt_addr, raddr) && |
| 138 | ipv6_addr_equal(&treq->loc_addr, laddr) && |
| 139 | (!treq->iif || treq->iif == iif)) { |
| 140 | WARN_ON(req->sk != NULL); |
| 141 | *prevp = prev; |
| 142 | return req; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | return NULL; |
| 147 | } |
| 148 | |
| 149 | EXPORT_SYMBOL_GPL(inet6_csk_search_req); |
| 150 | |
| 151 | void inet6_csk_reqsk_queue_hash_add(struct sock *sk, |
| 152 | struct request_sock *req, |
| 153 | const unsigned long timeout) |
| 154 | { |
| 155 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 156 | struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; |
| 157 | const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr, |
| 158 | inet_rsk(req)->rmt_port, |
| 159 | lopt->hash_rnd, lopt->nr_table_entries); |
| 160 | |
| 161 | reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout); |
| 162 | inet_csk_reqsk_queue_added(sk, timeout); |
| 163 | } |
| 164 | |
| 165 | EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add); |
| 166 | |
| 167 | void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr) |
| 168 | { |
| 169 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 170 | struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr; |
| 171 | |
| 172 | sin6->sin6_family = AF_INET6; |
| 173 | sin6->sin6_addr = np->daddr; |
| 174 | sin6->sin6_port = inet_sk(sk)->inet_dport; |
| 175 | /* We do not store received flowlabel for TCP */ |
| 176 | sin6->sin6_flowinfo = 0; |
| 177 | sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, |
| 178 | sk->sk_bound_dev_if); |
| 179 | } |
| 180 | |
| 181 | EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr); |
| 182 | |
| 183 | static inline |
| 184 | void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst, |
| 185 | const struct in6_addr *daddr, |
| 186 | const struct in6_addr *saddr) |
| 187 | { |
| 188 | __ip6_dst_store(sk, dst, daddr, saddr); |
| 189 | } |
| 190 | |
| 191 | static inline |
| 192 | struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie) |
| 193 | { |
| 194 | return __sk_dst_check(sk, cookie); |
| 195 | } |
| 196 | |
| 197 | static struct dst_entry *inet6_csk_route_socket(struct sock *sk, |
| 198 | struct flowi6 *fl6) |
| 199 | { |
| 200 | struct inet_sock *inet = inet_sk(sk); |
| 201 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 202 | struct in6_addr *final_p, final; |
| 203 | struct dst_entry *dst; |
| 204 | |
| 205 | memset(fl6, 0, sizeof(*fl6)); |
| 206 | fl6->flowi6_proto = sk->sk_protocol; |
| 207 | fl6->daddr = np->daddr; |
| 208 | fl6->saddr = np->saddr; |
| 209 | fl6->flowlabel = np->flow_label; |
| 210 | IP6_ECN_flow_xmit(sk, fl6->flowlabel); |
| 211 | fl6->flowi6_oif = sk->sk_bound_dev_if; |
| 212 | fl6->flowi6_mark = sk->sk_mark; |
| 213 | fl6->fl6_sport = inet->inet_sport; |
| 214 | fl6->fl6_dport = inet->inet_dport; |
| 215 | fl6->flowi6_uid = sock_i_uid(sk); |
| 216 | security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); |
| 217 | |
| 218 | final_p = fl6_update_dst(fl6, np->opt, &final); |
| 219 | |
| 220 | dst = __inet6_csk_dst_check(sk, np->dst_cookie); |
| 221 | if (!dst) { |
| 222 | dst = ip6_dst_lookup_flow(sk, fl6, final_p, false); |
| 223 | |
| 224 | if (!IS_ERR(dst)) |
| 225 | __inet6_csk_dst_store(sk, dst, NULL, NULL); |
| 226 | } |
| 227 | return dst; |
| 228 | } |
| 229 | |
| 230 | int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused) |
| 231 | { |
| 232 | struct sock *sk = skb->sk; |
| 233 | struct ipv6_pinfo *np = inet6_sk(sk); |
| 234 | struct flowi6 fl6; |
| 235 | struct dst_entry *dst; |
| 236 | int res; |
| 237 | |
| 238 | dst = inet6_csk_route_socket(sk, &fl6); |
| 239 | if (IS_ERR(dst)) { |
| 240 | sk->sk_err_soft = -PTR_ERR(dst); |
| 241 | sk->sk_route_caps = 0; |
| 242 | kfree_skb(skb); |
| 243 | return PTR_ERR(dst); |
| 244 | } |
| 245 | |
| 246 | rcu_read_lock(); |
| 247 | skb_dst_set_noref(skb, dst); |
| 248 | |
| 249 | /* Restore final destination back after routing done */ |
| 250 | fl6.daddr = np->daddr; |
| 251 | |
| 252 | res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass); |
| 253 | rcu_read_unlock(); |
| 254 | return res; |
| 255 | } |
| 256 | EXPORT_SYMBOL_GPL(inet6_csk_xmit); |
| 257 | |
| 258 | struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu) |
| 259 | { |
| 260 | struct flowi6 fl6; |
| 261 | struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6); |
| 262 | |
| 263 | if (IS_ERR(dst)) |
| 264 | return NULL; |
| 265 | dst->ops->update_pmtu(dst, sk, NULL, mtu); |
| 266 | |
| 267 | dst = inet6_csk_route_socket(sk, &fl6); |
| 268 | return IS_ERR(dst) ? NULL : dst; |
| 269 | } |
| 270 | EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu); |