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_bind_conflict(const struct sock * sk,const struct inet_bind_bucket * tb,bool relax)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
inet6_csk_route_req(const struct sock * sk,struct flowi6 * fl6,const struct request_sock * req,u8 proto)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
inet6_csk_addr2sockaddr(struct sock * sk,struct sockaddr * uaddr)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
__inet6_csk_dst_check(struct sock * sk,u32 cookie)117 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
118 {
119 return __sk_dst_check(sk, cookie);
120 }
121
inet6_csk_route_socket(struct sock * sk,struct flowi6 * fl6)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
inet6_csk_xmit(struct sock * sk,struct sk_buff * skb,struct flowi * fl_unused)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, sk->sk_mark, rcu_dereference(np->opt),
179 np->tclass);
180 rcu_read_unlock();
181 return res;
182 }
183 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
184
inet6_csk_update_pmtu(struct sock * sk,u32 mtu)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