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
inet6_csk_route_req(const struct sock * sk,struct flowi6 * fl6,const struct request_sock * req,u8 proto)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 static inline
__inet6_csk_dst_check(struct sock * sk,u32 cookie)60 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
61 {
62 return __sk_dst_check(sk, cookie);
63 }
64
inet6_csk_route_socket(struct sock * sk,struct flowi6 * fl6)65 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
66 struct flowi6 *fl6)
67 {
68 struct inet_sock *inet = inet_sk(sk);
69 struct ipv6_pinfo *np = inet6_sk(sk);
70 struct in6_addr *final_p, final;
71 struct dst_entry *dst;
72
73 memset(fl6, 0, sizeof(*fl6));
74 fl6->flowi6_proto = sk->sk_protocol;
75 fl6->daddr = sk->sk_v6_daddr;
76 fl6->saddr = np->saddr;
77 fl6->flowlabel = np->flow_label;
78 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
79 fl6->flowi6_oif = sk->sk_bound_dev_if;
80 fl6->flowi6_mark = sk->sk_mark;
81 fl6->fl6_sport = inet->inet_sport;
82 fl6->fl6_dport = inet->inet_dport;
83 fl6->flowi6_uid = sk->sk_uid;
84 security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
85
86 rcu_read_lock();
87 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
88 rcu_read_unlock();
89
90 dst = __inet6_csk_dst_check(sk, np->dst_cookie);
91 if (!dst) {
92 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
93
94 if (!IS_ERR(dst))
95 ip6_dst_store(sk, dst, NULL, NULL);
96 }
97 return dst;
98 }
99
inet6_csk_xmit(struct sock * sk,struct sk_buff * skb,struct flowi * fl_unused)100 int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
101 {
102 struct ipv6_pinfo *np = inet6_sk(sk);
103 struct flowi6 fl6;
104 struct dst_entry *dst;
105 int res;
106
107 dst = inet6_csk_route_socket(sk, &fl6);
108 if (IS_ERR(dst)) {
109 WRITE_ONCE(sk->sk_err_soft, -PTR_ERR(dst));
110 sk->sk_route_caps = 0;
111 kfree_skb(skb);
112 return PTR_ERR(dst);
113 }
114
115 rcu_read_lock();
116 skb_dst_set_noref(skb, dst);
117
118 /* Restore final destination back after routing done */
119 fl6.daddr = sk->sk_v6_daddr;
120
121 res = ip6_xmit(sk, skb, &fl6, sk->sk_mark, rcu_dereference(np->opt),
122 np->tclass, READ_ONCE(sk->sk_priority));
123 rcu_read_unlock();
124 return res;
125 }
126 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
127
inet6_csk_update_pmtu(struct sock * sk,u32 mtu)128 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
129 {
130 struct flowi6 fl6;
131 struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
132
133 if (IS_ERR(dst))
134 return NULL;
135 dst->ops->update_pmtu(dst, sk, NULL, mtu, true);
136
137 dst = inet6_csk_route_socket(sk, &fl6);
138 return IS_ERR(dst) ? NULL : dst;
139 }
140 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);
141