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
inet6_csk_bind_conflict(const struct sock * sk,const struct inet_bind_bucket * tb)30 int inet6_csk_bind_conflict(const struct sock *sk,
31 const struct inet_bind_bucket *tb)
32 {
33 const struct sock *sk2;
34 const struct hlist_node *node;
35
36 /* We must walk the whole port owner list in this case. -DaveM */
37 /*
38 * See comment in inet_csk_bind_conflict about sock lookup
39 * vs net namespaces issues.
40 */
41 sk_for_each_bound(sk2, node, &tb->owners) {
42 if (sk != sk2 &&
43 (!sk->sk_bound_dev_if ||
44 !sk2->sk_bound_dev_if ||
45 sk->sk_bound_dev_if == sk2->sk_bound_dev_if) &&
46 (!sk->sk_reuse || !sk2->sk_reuse ||
47 sk2->sk_state == TCP_LISTEN) &&
48 ipv6_rcv_saddr_equal(sk, sk2))
49 break;
50 }
51
52 return node != NULL;
53 }
54
55 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
56
inet6_csk_route_req(struct sock * sk,const struct request_sock * req)57 struct dst_entry *inet6_csk_route_req(struct sock *sk,
58 const struct request_sock *req)
59 {
60 struct inet6_request_sock *treq = inet6_rsk(req);
61 struct ipv6_pinfo *np = inet6_sk(sk);
62 struct in6_addr *final_p, final;
63 struct dst_entry *dst;
64 struct flowi6 fl6;
65
66 memset(&fl6, 0, sizeof(fl6));
67 fl6.flowi6_proto = IPPROTO_TCP;
68 fl6.daddr = treq->rmt_addr;
69 final_p = fl6_update_dst(&fl6, np->opt, &final);
70 fl6.saddr = treq->loc_addr;
71 fl6.flowi6_oif = sk->sk_bound_dev_if;
72 fl6.flowi6_mark = sk->sk_mark;
73 fl6.fl6_dport = inet_rsk(req)->rmt_port;
74 fl6.fl6_sport = inet_rsk(req)->loc_port;
75 security_req_classify_flow(req, flowi6_to_flowi(&fl6));
76
77 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
78 if (IS_ERR(dst))
79 return NULL;
80
81 return dst;
82 }
83
84 /*
85 * request_sock (formerly open request) hash tables.
86 */
inet6_synq_hash(const struct in6_addr * raddr,const __be16 rport,const u32 rnd,const u32 synq_hsize)87 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
88 const u32 rnd, const u32 synq_hsize)
89 {
90 u32 c;
91
92 c = jhash_3words((__force u32)raddr->s6_addr32[0],
93 (__force u32)raddr->s6_addr32[1],
94 (__force u32)raddr->s6_addr32[2],
95 rnd);
96
97 c = jhash_2words((__force u32)raddr->s6_addr32[3],
98 (__force u32)rport,
99 c);
100
101 return c & (synq_hsize - 1);
102 }
103
inet6_csk_search_req(const struct sock * sk,struct request_sock *** prevp,const __be16 rport,const struct in6_addr * raddr,const struct in6_addr * laddr,const int iif)104 struct request_sock *inet6_csk_search_req(const struct sock *sk,
105 struct request_sock ***prevp,
106 const __be16 rport,
107 const struct in6_addr *raddr,
108 const struct in6_addr *laddr,
109 const int iif)
110 {
111 const struct inet_connection_sock *icsk = inet_csk(sk);
112 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
113 struct request_sock *req, **prev;
114
115 for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
116 lopt->hash_rnd,
117 lopt->nr_table_entries)];
118 (req = *prev) != NULL;
119 prev = &req->dl_next) {
120 const struct inet6_request_sock *treq = inet6_rsk(req);
121
122 if (inet_rsk(req)->rmt_port == rport &&
123 req->rsk_ops->family == AF_INET6 &&
124 ipv6_addr_equal(&treq->rmt_addr, raddr) &&
125 ipv6_addr_equal(&treq->loc_addr, laddr) &&
126 (!treq->iif || treq->iif == iif)) {
127 WARN_ON(req->sk != NULL);
128 *prevp = prev;
129 return req;
130 }
131 }
132
133 return NULL;
134 }
135
136 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
137
inet6_csk_reqsk_queue_hash_add(struct sock * sk,struct request_sock * req,const unsigned long timeout)138 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
139 struct request_sock *req,
140 const unsigned long timeout)
141 {
142 struct inet_connection_sock *icsk = inet_csk(sk);
143 struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
144 const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
145 inet_rsk(req)->rmt_port,
146 lopt->hash_rnd, lopt->nr_table_entries);
147
148 reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
149 inet_csk_reqsk_queue_added(sk, timeout);
150 }
151
152 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
153
inet6_csk_addr2sockaddr(struct sock * sk,struct sockaddr * uaddr)154 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
155 {
156 struct ipv6_pinfo *np = inet6_sk(sk);
157 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
158
159 sin6->sin6_family = AF_INET6;
160 sin6->sin6_addr = np->daddr;
161 sin6->sin6_port = inet_sk(sk)->inet_dport;
162 /* We do not store received flowlabel for TCP */
163 sin6->sin6_flowinfo = 0;
164 sin6->sin6_scope_id = 0;
165 if (sk->sk_bound_dev_if &&
166 ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
167 sin6->sin6_scope_id = sk->sk_bound_dev_if;
168 }
169
170 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
171
172 static inline
__inet6_csk_dst_store(struct sock * sk,struct dst_entry * dst,struct in6_addr * daddr,struct in6_addr * saddr)173 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
174 struct in6_addr *daddr, struct in6_addr *saddr)
175 {
176 __ip6_dst_store(sk, dst, daddr, saddr);
177
178 #ifdef CONFIG_XFRM
179 {
180 struct rt6_info *rt = (struct rt6_info *)dst;
181 rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
182 }
183 #endif
184 }
185
186 static inline
__inet6_csk_dst_check(struct sock * sk,u32 cookie)187 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
188 {
189 struct dst_entry *dst;
190
191 dst = __sk_dst_check(sk, cookie);
192
193 #ifdef CONFIG_XFRM
194 if (dst) {
195 struct rt6_info *rt = (struct rt6_info *)dst;
196 if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
197 __sk_dst_reset(sk);
198 dst = NULL;
199 }
200 }
201 #endif
202
203 return dst;
204 }
205
inet6_csk_xmit(struct sk_buff * skb,struct flowi * fl_unused)206 int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused)
207 {
208 struct sock *sk = skb->sk;
209 struct inet_sock *inet = inet_sk(sk);
210 struct ipv6_pinfo *np = inet6_sk(sk);
211 struct flowi6 fl6;
212 struct dst_entry *dst;
213 struct in6_addr *final_p, final;
214 int res;
215
216 memset(&fl6, 0, sizeof(fl6));
217 fl6.flowi6_proto = sk->sk_protocol;
218 fl6.daddr = np->daddr;
219 fl6.saddr = np->saddr;
220 fl6.flowlabel = np->flow_label;
221 IP6_ECN_flow_xmit(sk, fl6.flowlabel);
222 fl6.flowi6_oif = sk->sk_bound_dev_if;
223 fl6.flowi6_mark = sk->sk_mark;
224 fl6.fl6_sport = inet->inet_sport;
225 fl6.fl6_dport = inet->inet_dport;
226 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
227
228 final_p = fl6_update_dst(&fl6, np->opt, &final);
229
230 dst = __inet6_csk_dst_check(sk, np->dst_cookie);
231
232 if (dst == NULL) {
233 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
234
235 if (IS_ERR(dst)) {
236 sk->sk_err_soft = -PTR_ERR(dst);
237 sk->sk_route_caps = 0;
238 kfree_skb(skb);
239 return PTR_ERR(dst);
240 }
241
242 __inet6_csk_dst_store(sk, dst, NULL, NULL);
243 }
244
245 rcu_read_lock();
246 skb_dst_set_noref(skb, dst);
247
248 /* Restore final destination back after routing done */
249 fl6.daddr = np->daddr;
250
251 res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
252 rcu_read_unlock();
253 return res;
254 }
255 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
256