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 #include <net/sock_reuseport.h> 30 31 int inet6_csk_bind_conflict(const struct sock *sk, 32 const struct inet_bind_bucket *tb, bool relax, 33 bool reuseport_ok) 34 { 35 const struct sock *sk2; 36 bool reuse = !!sk->sk_reuse; 37 bool reuseport = !!sk->sk_reuseport && reuseport_ok; 38 kuid_t uid = sock_i_uid((struct sock *)sk); 39 40 /* We must walk the whole port owner list in this case. -DaveM */ 41 /* 42 * See comment in inet_csk_bind_conflict about sock lookup 43 * vs net namespaces issues. 44 */ 45 sk_for_each_bound(sk2, &tb->owners) { 46 if (sk != sk2 && 47 (!sk->sk_bound_dev_if || 48 !sk2->sk_bound_dev_if || 49 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { 50 if ((!reuse || !sk2->sk_reuse || 51 sk2->sk_state == TCP_LISTEN) && 52 (!reuseport || !sk2->sk_reuseport || 53 rcu_access_pointer(sk->sk_reuseport_cb) || 54 (sk2->sk_state != TCP_TIME_WAIT && 55 !uid_eq(uid, 56 sock_i_uid((struct sock *)sk2))))) { 57 if (ipv6_rcv_saddr_equal(sk, sk2, true)) 58 break; 59 } 60 if (!relax && reuse && sk2->sk_reuse && 61 sk2->sk_state != TCP_LISTEN && 62 ipv6_rcv_saddr_equal(sk, sk2, true)) 63 break; 64 } 65 } 66 67 return sk2 != NULL; 68 } 69 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict); 70 71 struct dst_entry *inet6_csk_route_req(const struct sock *sk, 72 struct flowi6 *fl6, 73 const struct request_sock *req, 74 u8 proto) 75 { 76 struct inet_request_sock *ireq = inet_rsk(req); 77 const struct ipv6_pinfo *np = inet6_sk(sk); 78 struct in6_addr *final_p, final; 79 struct dst_entry *dst; 80 81 memset(fl6, 0, sizeof(*fl6)); 82 fl6->flowi6_proto = proto; 83 fl6->daddr = ireq->ir_v6_rmt_addr; 84 rcu_read_lock(); 85 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 86 rcu_read_unlock(); 87 fl6->saddr = ireq->ir_v6_loc_addr; 88 fl6->flowi6_oif = ireq->ir_iif; 89 fl6->flowi6_mark = ireq->ir_mark; 90 fl6->fl6_dport = ireq->ir_rmt_port; 91 fl6->fl6_sport = htons(ireq->ir_num); 92 fl6->flowi6_uid = sk->sk_uid; 93 security_req_classify_flow(req, flowi6_to_flowi(fl6)); 94 95 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 96 if (IS_ERR(dst)) 97 return NULL; 98 99 return dst; 100 } 101 EXPORT_SYMBOL(inet6_csk_route_req); 102 103 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) 104 { 105 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr; 106 107 sin6->sin6_family = AF_INET6; 108 sin6->sin6_addr = sk->sk_v6_daddr; 109 sin6->sin6_port = inet_sk(sk)->inet_dport; 110 /* We do not store received flowlabel for TCP */ 111 sin6->sin6_flowinfo = 0; 112 sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, 113 sk->sk_bound_dev_if); 114 } 115 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr); 116 117 static inline 118 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie) 119 { 120 return __sk_dst_check(sk, cookie); 121 } 122 123 static struct dst_entry *inet6_csk_route_socket(struct sock *sk, 124 struct flowi6 *fl6) 125 { 126 struct inet_sock *inet = inet_sk(sk); 127 struct ipv6_pinfo *np = inet6_sk(sk); 128 struct in6_addr *final_p, final; 129 struct dst_entry *dst; 130 131 memset(fl6, 0, sizeof(*fl6)); 132 fl6->flowi6_proto = sk->sk_protocol; 133 fl6->daddr = sk->sk_v6_daddr; 134 fl6->saddr = np->saddr; 135 fl6->flowlabel = np->flow_label; 136 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 137 fl6->flowi6_oif = sk->sk_bound_dev_if; 138 fl6->flowi6_mark = sk->sk_mark; 139 fl6->fl6_sport = inet->inet_sport; 140 fl6->fl6_dport = inet->inet_dport; 141 fl6->flowi6_uid = sk->sk_uid; 142 security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); 143 144 rcu_read_lock(); 145 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 146 rcu_read_unlock(); 147 148 dst = __inet6_csk_dst_check(sk, np->dst_cookie); 149 if (!dst) { 150 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 151 152 if (!IS_ERR(dst)) 153 ip6_dst_store(sk, dst, NULL, NULL); 154 } 155 return dst; 156 } 157 158 int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused) 159 { 160 struct ipv6_pinfo *np = inet6_sk(sk); 161 struct flowi6 fl6; 162 struct dst_entry *dst; 163 int res; 164 165 dst = inet6_csk_route_socket(sk, &fl6); 166 if (IS_ERR(dst)) { 167 sk->sk_err_soft = -PTR_ERR(dst); 168 sk->sk_route_caps = 0; 169 kfree_skb(skb); 170 return PTR_ERR(dst); 171 } 172 173 rcu_read_lock(); 174 skb_dst_set_noref(skb, dst); 175 176 /* Restore final destination back after routing done */ 177 fl6.daddr = sk->sk_v6_daddr; 178 179 res = ip6_xmit(sk, skb, &fl6, rcu_dereference(np->opt), 180 np->tclass); 181 rcu_read_unlock(); 182 return res; 183 } 184 EXPORT_SYMBOL_GPL(inet6_csk_xmit); 185 186 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu) 187 { 188 struct flowi6 fl6; 189 struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6); 190 191 if (IS_ERR(dst)) 192 return NULL; 193 dst->ops->update_pmtu(dst, sk, NULL, mtu); 194 195 dst = inet6_csk_route_socket(sk, &fl6); 196 return IS_ERR(dst) ? NULL : dst; 197 } 198 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu); 199