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
27struct 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(sk: req);
33 const struct ipv6_pinfo *np = inet6_sk(sk: sk);
34 struct in6_addr *final_p, final;
35 struct dst_entry *dst;
36
37 memset(s: fl6, c: 0, n: 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), orig: &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_uid(sk);
49 security_req_classify_flow(req, flic: flowi6_to_flowi_common(fl6));
50
51 dst = ip6_dst_lookup_flow(net: sock_net(sk), sk, fl6, final_dst: final_p);
52 if (IS_ERR(ptr: dst))
53 return NULL;
54
55 return dst;
56}
57
58static inline
59struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
60{
61 return __sk_dst_check(sk, cookie);
62}
63
64static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
65 struct flowi6 *fl6)
66{
67 struct inet_sock *inet = inet_sk(sk);
68 struct ipv6_pinfo *np = inet6_sk(sk: sk);
69 struct in6_addr *final_p, final;
70 struct dst_entry *dst;
71
72 memset(s: fl6, c: 0, n: sizeof(*fl6));
73 fl6->flowi6_proto = sk->sk_protocol;
74 fl6->daddr = sk->sk_v6_daddr;
75 fl6->saddr = np->saddr;
76 fl6->flowlabel = np->flow_label;
77 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
78 fl6->flowi6_oif = sk->sk_bound_dev_if;
79 fl6->flowi6_mark = sk->sk_mark;
80 fl6->fl6_sport = inet->inet_sport;
81 fl6->fl6_dport = inet->inet_dport;
82 fl6->flowi6_uid = sk_uid(sk);
83 security_sk_classify_flow(sk, flic: flowi6_to_flowi_common(fl6));
84
85 rcu_read_lock();
86 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), orig: &final);
87 rcu_read_unlock();
88
89 dst = __inet6_csk_dst_check(sk, cookie: np->dst_cookie);
90 if (!dst) {
91 dst = ip6_dst_lookup_flow(net: sock_net(sk), sk, fl6, final_dst: final_p);
92
93 if (!IS_ERR(ptr: dst))
94 ip6_dst_store(sk, dst, daddr_set: false, saddr_set: false);
95 }
96 return dst;
97}
98
99int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
100{
101 struct ipv6_pinfo *np = inet6_sk(sk: sk);
102 struct flowi6 fl6;
103 struct dst_entry *dst;
104 int res;
105
106 dst = inet6_csk_route_socket(sk, fl6: &fl6);
107 if (IS_ERR(ptr: dst)) {
108 WRITE_ONCE(sk->sk_err_soft, -PTR_ERR(dst));
109 sk->sk_route_caps = 0;
110 kfree_skb(skb);
111 return PTR_ERR(ptr: dst);
112 }
113
114 rcu_read_lock();
115 skb_dst_set_noref(skb, dst);
116
117 /* Restore final destination back after routing done */
118 fl6.daddr = sk->sk_v6_daddr;
119
120 res = ip6_xmit(sk, skb, fl6: &fl6, mark: sk->sk_mark, rcu_dereference(np->opt),
121 tclass: np->tclass, READ_ONCE(sk->sk_priority));
122 rcu_read_unlock();
123 return res;
124}
125EXPORT_SYMBOL_GPL(inet6_csk_xmit);
126
127struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
128{
129 struct flowi6 fl6;
130 struct dst_entry *dst = inet6_csk_route_socket(sk, fl6: &fl6);
131
132 if (IS_ERR(ptr: dst))
133 return NULL;
134 dst->ops->update_pmtu(dst, sk, NULL, mtu, true);
135
136 dst = inet6_csk_route_socket(sk, fl6: &fl6);
137 return IS_ERR(ptr: dst) ? NULL : dst;
138}
139