1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Support for INET6 connection oriented protocols. 8 * 9 * Authors: See the TCPv6 sources 10 */ 11 12 #include <linux/module.h> 13 #include <linux/in6.h> 14 #include <linux/ipv6.h> 15 #include <linux/jhash.h> 16 #include <linux/slab.h> 17 18 #include <net/addrconf.h> 19 #include <net/inet_connection_sock.h> 20 #include <net/inet_ecn.h> 21 #include <net/inet_hashtables.h> 22 #include <net/ip6_route.h> 23 #include <net/sock.h> 24 #include <net/inet6_connection_sock.h> 25 #include <net/sock_reuseport.h> 26 27 struct dst_entry *inet6_csk_route_req(const struct sock *sk, 28 struct flowi6 *fl6, 29 const struct request_sock *req, 30 u8 proto) 31 { 32 struct inet_request_sock *ireq = inet_rsk(req); 33 const struct ipv6_pinfo *np = inet6_sk(sk); 34 struct in6_addr *final_p, final; 35 struct dst_entry *dst; 36 37 memset(fl6, 0, sizeof(*fl6)); 38 fl6->flowi6_proto = proto; 39 fl6->daddr = ireq->ir_v6_rmt_addr; 40 rcu_read_lock(); 41 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 42 rcu_read_unlock(); 43 fl6->saddr = ireq->ir_v6_loc_addr; 44 fl6->flowi6_oif = ireq->ir_iif; 45 fl6->flowi6_mark = ireq->ir_mark; 46 fl6->fl6_dport = ireq->ir_rmt_port; 47 fl6->fl6_sport = htons(ireq->ir_num); 48 fl6->flowi6_uid = sk->sk_uid; 49 security_req_classify_flow(req, flowi6_to_flowi_common(fl6)); 50 51 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 52 if (IS_ERR(dst)) 53 return NULL; 54 55 return dst; 56 } 57 EXPORT_SYMBOL(inet6_csk_route_req); 58 59 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) 60 { 61 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr; 62 63 sin6->sin6_family = AF_INET6; 64 sin6->sin6_addr = sk->sk_v6_daddr; 65 sin6->sin6_port = inet_sk(sk)->inet_dport; 66 /* We do not store received flowlabel for TCP */ 67 sin6->sin6_flowinfo = 0; 68 sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr, 69 sk->sk_bound_dev_if); 70 } 71 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr); 72 73 static inline 74 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie) 75 { 76 return __sk_dst_check(sk, cookie); 77 } 78 79 static struct dst_entry *inet6_csk_route_socket(struct sock *sk, 80 struct flowi6 *fl6) 81 { 82 struct inet_sock *inet = inet_sk(sk); 83 struct ipv6_pinfo *np = inet6_sk(sk); 84 struct in6_addr *final_p, final; 85 struct dst_entry *dst; 86 87 memset(fl6, 0, sizeof(*fl6)); 88 fl6->flowi6_proto = sk->sk_protocol; 89 fl6->daddr = sk->sk_v6_daddr; 90 fl6->saddr = np->saddr; 91 fl6->flowlabel = np->flow_label; 92 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 93 fl6->flowi6_oif = sk->sk_bound_dev_if; 94 fl6->flowi6_mark = sk->sk_mark; 95 fl6->fl6_sport = inet->inet_sport; 96 fl6->fl6_dport = inet->inet_dport; 97 fl6->flowi6_uid = sk->sk_uid; 98 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6)); 99 100 rcu_read_lock(); 101 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 102 rcu_read_unlock(); 103 104 dst = __inet6_csk_dst_check(sk, np->dst_cookie); 105 if (!dst) { 106 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 107 108 if (!IS_ERR(dst)) 109 ip6_dst_store(sk, dst, NULL, NULL); 110 } 111 return dst; 112 } 113 114 int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused) 115 { 116 struct ipv6_pinfo *np = inet6_sk(sk); 117 struct flowi6 fl6; 118 struct dst_entry *dst; 119 int res; 120 121 dst = inet6_csk_route_socket(sk, &fl6); 122 if (IS_ERR(dst)) { 123 WRITE_ONCE(sk->sk_err_soft, -PTR_ERR(dst)); 124 sk->sk_route_caps = 0; 125 kfree_skb(skb); 126 return PTR_ERR(dst); 127 } 128 129 rcu_read_lock(); 130 skb_dst_set_noref(skb, dst); 131 132 /* Restore final destination back after routing done */ 133 fl6.daddr = sk->sk_v6_daddr; 134 135 res = ip6_xmit(sk, skb, &fl6, sk->sk_mark, rcu_dereference(np->opt), 136 np->tclass, sk->sk_priority); 137 rcu_read_unlock(); 138 return res; 139 } 140 EXPORT_SYMBOL_GPL(inet6_csk_xmit); 141 142 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu) 143 { 144 struct flowi6 fl6; 145 struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6); 146 147 if (IS_ERR(dst)) 148 return NULL; 149 dst->ops->update_pmtu(dst, sk, NULL, mtu, true); 150 151 dst = inet6_csk_route_socket(sk, &fl6); 152 return IS_ERR(dst) ? NULL : dst; 153 } 154 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu); 155