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