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 30int 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} 66EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict); 67 68struct dst_entry *inet6_csk_route_req(struct sock *sk, 69 struct flowi6 *fl6, 70 const struct request_sock *req) 71{ 72 struct inet_request_sock *ireq = inet_rsk(req); 73 struct ipv6_pinfo *np = inet6_sk(sk); 74 struct in6_addr *final_p, final; 75 struct dst_entry *dst; 76 77 memset(fl6, 0, sizeof(*fl6)); 78 fl6->flowi6_proto = IPPROTO_TCP; 79 fl6->daddr = ireq->ir_v6_rmt_addr; 80 final_p = fl6_update_dst(fl6, np->opt, &final); 81 fl6->saddr = ireq->ir_v6_loc_addr; 82 fl6->flowi6_oif = ireq->ir_iif; 83 fl6->flowi6_mark = ireq->ir_mark; 84 fl6->fl6_dport = ireq->ir_rmt_port; 85 fl6->fl6_sport = htons(ireq->ir_num); 86 fl6->flowi6_uid = sock_i_uid(sk); 87 security_req_classify_flow(req, flowi6_to_flowi(fl6)); 88 89 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 90 if (IS_ERR(dst)) 91 return NULL; 92 93 return dst; 94} 95 96/* 97 * request_sock (formerly open request) hash tables. 98 */ 99static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport, 100 const u32 rnd, const u32 synq_hsize) 101{ 102 u32 c; 103 104 c = jhash_3words((__force u32)raddr->s6_addr32[0], 105 (__force u32)raddr->s6_addr32[1], 106 (__force u32)raddr->s6_addr32[2], 107 rnd); 108 109 c = jhash_2words((__force u32)raddr->s6_addr32[3], 110 (__force u32)rport, 111 c); 112 113 return c & (synq_hsize - 1); 114} 115 116struct request_sock *inet6_csk_search_req(const struct sock *sk, 117 struct request_sock ***prevp, 118 const __be16 rport, 119 const struct in6_addr *raddr, 120 const struct in6_addr *laddr, 121 const int iif) 122{ 123 const struct inet_connection_sock *icsk = inet_csk(sk); 124 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; 125 struct request_sock *req, **prev; 126 127 for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport, 128 lopt->hash_rnd, 129 lopt->nr_table_entries)]; 130 (req = *prev) != NULL; 131 prev = &req->dl_next) { 132 const struct inet_request_sock *ireq = inet_rsk(req); 133 134 if (ireq->ir_rmt_port == rport && 135 req->rsk_ops->family == AF_INET6 && 136 ipv6_addr_equal(&ireq->ir_v6_rmt_addr, raddr) && 137 ipv6_addr_equal(&ireq->ir_v6_loc_addr, laddr) && 138 (!ireq->ir_iif || ireq->ir_iif == iif)) { 139 WARN_ON(req->sk != NULL); 140 *prevp = prev; 141 return req; 142 } 143 } 144 145 return NULL; 146} 147EXPORT_SYMBOL_GPL(inet6_csk_search_req); 148 149void inet6_csk_reqsk_queue_hash_add(struct sock *sk, 150 struct request_sock *req, 151 const unsigned long timeout) 152{ 153 struct inet_connection_sock *icsk = inet_csk(sk); 154 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt; 155 const u32 h = inet6_synq_hash(&inet_rsk(req)->ir_v6_rmt_addr, 156 inet_rsk(req)->ir_rmt_port, 157 lopt->hash_rnd, lopt->nr_table_entries); 158 159 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout); 160 inet_csk_reqsk_queue_added(sk, timeout); 161} 162EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add); 163 164void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) 165{ 166 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr; 167 168 sin6->sin6_family = AF_INET6; 169 sin6->sin6_addr = sk->sk_v6_daddr; 170 sin6->sin6_port = inet_sk(sk)->inet_dport; 171 /* We do not store received flowlabel for TCP */ 172 sin6->sin6_flowinfo = 0; 173 sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, 174 sk->sk_bound_dev_if); 175} 176EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr); 177 178static inline 179void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst, 180 const struct in6_addr *daddr, 181 const struct in6_addr *saddr) 182{ 183 __ip6_dst_store(sk, dst, daddr, saddr); 184} 185 186static inline 187struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie) 188{ 189 return __sk_dst_check(sk, cookie); 190} 191 192static struct dst_entry *inet6_csk_route_socket(struct sock *sk, 193 struct flowi6 *fl6) 194{ 195 struct inet_sock *inet = inet_sk(sk); 196 struct ipv6_pinfo *np = inet6_sk(sk); 197 struct in6_addr *final_p, final; 198 struct dst_entry *dst; 199 200 memset(fl6, 0, sizeof(*fl6)); 201 fl6->flowi6_proto = sk->sk_protocol; 202 fl6->daddr = sk->sk_v6_daddr; 203 fl6->saddr = np->saddr; 204 fl6->flowlabel = np->flow_label; 205 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 206 fl6->flowi6_oif = sk->sk_bound_dev_if; 207 fl6->flowi6_mark = sk->sk_mark; 208 fl6->fl6_sport = inet->inet_sport; 209 fl6->fl6_dport = inet->inet_dport; 210 fl6->flowi6_uid = sock_i_uid(sk); 211 security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); 212 213 final_p = fl6_update_dst(fl6, np->opt, &final); 214 215 dst = __inet6_csk_dst_check(sk, np->dst_cookie); 216 if (!dst) { 217 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 218 219 if (!IS_ERR(dst)) 220 __inet6_csk_dst_store(sk, dst, NULL, NULL); 221 } 222 return dst; 223} 224 225int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused) 226{ 227 struct ipv6_pinfo *np = inet6_sk(sk); 228 struct flowi6 fl6; 229 struct dst_entry *dst; 230 int res; 231 232 dst = inet6_csk_route_socket(sk, &fl6); 233 if (IS_ERR(dst)) { 234 sk->sk_err_soft = -PTR_ERR(dst); 235 sk->sk_route_caps = 0; 236 kfree_skb(skb); 237 return PTR_ERR(dst); 238 } 239 240 rcu_read_lock(); 241 skb_dst_set_noref(skb, dst); 242 243 /* Restore final destination back after routing done */ 244 fl6.daddr = sk->sk_v6_daddr; 245 246 res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass); 247 rcu_read_unlock(); 248 return res; 249} 250EXPORT_SYMBOL_GPL(inet6_csk_xmit); 251 252struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu) 253{ 254 struct flowi6 fl6; 255 struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6); 256 257 if (IS_ERR(dst)) 258 return NULL; 259 dst->ops->update_pmtu(dst, sk, NULL, mtu); 260 261 dst = inet6_csk_route_socket(sk, &fl6); 262 return IS_ERR(dst) ? NULL : dst; 263} 264EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu); 265