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
inet6_csk_route_req(const struct sock * sk,struct flowi6 * fl6,const struct request_sock * req,u8 proto)31 struct dst_entry *inet6_csk_route_req(const struct sock *sk,
32 struct flowi6 *fl6,
33 const struct request_sock *req,
34 u8 proto)
35 {
36 struct inet_request_sock *ireq = inet_rsk(req);
37 const struct ipv6_pinfo *np = inet6_sk(sk);
38 struct in6_addr *final_p, final;
39 struct dst_entry *dst;
40
41 memset(fl6, 0, sizeof(*fl6));
42 fl6->flowi6_proto = proto;
43 fl6->daddr = ireq->ir_v6_rmt_addr;
44 rcu_read_lock();
45 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
46 rcu_read_unlock();
47 fl6->saddr = ireq->ir_v6_loc_addr;
48 fl6->flowi6_oif = ireq->ir_iif;
49 fl6->flowi6_mark = ireq->ir_mark;
50 fl6->fl6_dport = ireq->ir_rmt_port;
51 fl6->fl6_sport = htons(ireq->ir_num);
52 fl6->flowi6_uid = sk->sk_uid;
53 security_req_classify_flow(req, flowi6_to_flowi(fl6));
54
55 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
56 if (IS_ERR(dst))
57 return NULL;
58
59 return dst;
60 }
61 EXPORT_SYMBOL(inet6_csk_route_req);
62
inet6_csk_addr2sockaddr(struct sock * sk,struct sockaddr * uaddr)63 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
64 {
65 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
66
67 sin6->sin6_family = AF_INET6;
68 sin6->sin6_addr = sk->sk_v6_daddr;
69 sin6->sin6_port = inet_sk(sk)->inet_dport;
70 /* We do not store received flowlabel for TCP */
71 sin6->sin6_flowinfo = 0;
72 sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
73 sk->sk_bound_dev_if);
74 }
75 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
76
77 static inline
__inet6_csk_dst_check(struct sock * sk,u32 cookie)78 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
79 {
80 return __sk_dst_check(sk, cookie);
81 }
82
inet6_csk_route_socket(struct sock * sk,struct flowi6 * fl6)83 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
84 struct flowi6 *fl6)
85 {
86 struct inet_sock *inet = inet_sk(sk);
87 struct ipv6_pinfo *np = inet6_sk(sk);
88 struct in6_addr *final_p, final;
89 struct dst_entry *dst;
90
91 memset(fl6, 0, sizeof(*fl6));
92 fl6->flowi6_proto = sk->sk_protocol;
93 fl6->daddr = sk->sk_v6_daddr;
94 fl6->saddr = np->saddr;
95 fl6->flowlabel = np->flow_label;
96 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
97 fl6->flowi6_oif = sk->sk_bound_dev_if;
98 fl6->flowi6_mark = sk->sk_mark;
99 fl6->fl6_sport = inet->inet_sport;
100 fl6->fl6_dport = inet->inet_dport;
101 fl6->flowi6_uid = sk->sk_uid;
102 security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
103
104 rcu_read_lock();
105 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
106 rcu_read_unlock();
107
108 dst = __inet6_csk_dst_check(sk, np->dst_cookie);
109 if (!dst) {
110 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
111
112 if (!IS_ERR(dst))
113 ip6_dst_store(sk, dst, NULL, NULL);
114 }
115 return dst;
116 }
117
inet6_csk_xmit(struct sock * sk,struct sk_buff * skb,struct flowi * fl_unused)118 int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
119 {
120 struct ipv6_pinfo *np = inet6_sk(sk);
121 struct flowi6 fl6;
122 struct dst_entry *dst;
123 int res;
124
125 dst = inet6_csk_route_socket(sk, &fl6);
126 if (IS_ERR(dst)) {
127 sk->sk_err_soft = -PTR_ERR(dst);
128 sk->sk_route_caps = 0;
129 kfree_skb(skb);
130 return PTR_ERR(dst);
131 }
132
133 rcu_read_lock();
134 skb_dst_set_noref(skb, dst);
135
136 /* Restore final destination back after routing done */
137 fl6.daddr = sk->sk_v6_daddr;
138
139 res = ip6_xmit(sk, skb, &fl6, sk->sk_mark, rcu_dereference(np->opt),
140 np->tclass);
141 rcu_read_unlock();
142 return res;
143 }
144 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
145
inet6_csk_update_pmtu(struct sock * sk,u32 mtu)146 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
147 {
148 struct flowi6 fl6;
149 struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
150
151 if (IS_ERR(dst))
152 return NULL;
153 dst->ops->update_pmtu(dst, sk, NULL, mtu);
154
155 dst = inet6_csk_route_socket(sk, &fl6);
156 return IS_ERR(dst) ? NULL : dst;
157 }
158 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);
159
