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
30int 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
55EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
56
57/*
58 * request_sock (formerly open request) hash tables.
59 */
60static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
61			   const u32 rnd, const u16 synq_hsize)
62{
63	u32 a = (__force u32)raddr->s6_addr32[0];
64	u32 b = (__force u32)raddr->s6_addr32[1];
65	u32 c = (__force u32)raddr->s6_addr32[2];
66
67	a += JHASH_GOLDEN_RATIO;
68	b += JHASH_GOLDEN_RATIO;
69	c += rnd;
70	__jhash_mix(a, b, c);
71
72	a += (__force u32)raddr->s6_addr32[3];
73	b += (__force u32)rport;
74	__jhash_mix(a, b, c);
75
76	return c & (synq_hsize - 1);
77}
78
79struct request_sock *inet6_csk_search_req(const struct sock *sk,
80					  struct request_sock ***prevp,
81					  const __be16 rport,
82					  const struct in6_addr *raddr,
83					  const struct in6_addr *laddr,
84					  const int iif)
85{
86	const struct inet_connection_sock *icsk = inet_csk(sk);
87	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
88	struct request_sock *req, **prev;
89
90	for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
91						     lopt->hash_rnd,
92						     lopt->nr_table_entries)];
93	     (req = *prev) != NULL;
94	     prev = &req->dl_next) {
95		const struct inet6_request_sock *treq = inet6_rsk(req);
96
97		if (inet_rsk(req)->rmt_port == rport &&
98		    req->rsk_ops->family == AF_INET6 &&
99		    ipv6_addr_equal(&treq->rmt_addr, raddr) &&
100		    ipv6_addr_equal(&treq->loc_addr, laddr) &&
101		    (!treq->iif || treq->iif == iif)) {
102			WARN_ON(req->sk != NULL);
103			*prevp = prev;
104			return req;
105		}
106	}
107
108	return NULL;
109}
110
111EXPORT_SYMBOL_GPL(inet6_csk_search_req);
112
113void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
114				    struct request_sock *req,
115				    const unsigned long timeout)
116{
117	struct inet_connection_sock *icsk = inet_csk(sk);
118	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
119	const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
120				      inet_rsk(req)->rmt_port,
121				      lopt->hash_rnd, lopt->nr_table_entries);
122
123	reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
124	inet_csk_reqsk_queue_added(sk, timeout);
125}
126
127EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
128
129void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
130{
131	struct ipv6_pinfo *np = inet6_sk(sk);
132	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
133
134	sin6->sin6_family = AF_INET6;
135	ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
136	sin6->sin6_port	= inet_sk(sk)->inet_dport;
137	/* We do not store received flowlabel for TCP */
138	sin6->sin6_flowinfo = 0;
139	sin6->sin6_scope_id = 0;
140	if (sk->sk_bound_dev_if &&
141	    ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
142		sin6->sin6_scope_id = sk->sk_bound_dev_if;
143}
144
145EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
146
147static inline
148void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
149			   struct in6_addr *daddr, struct in6_addr *saddr)
150{
151	__ip6_dst_store(sk, dst, daddr, saddr);
152
153#ifdef CONFIG_XFRM
154	{
155		struct rt6_info *rt = (struct rt6_info  *)dst;
156		rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
157	}
158#endif
159}
160
161static inline
162struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
163{
164	struct dst_entry *dst;
165
166	dst = __sk_dst_check(sk, cookie);
167
168#ifdef CONFIG_XFRM
169	if (dst) {
170		struct rt6_info *rt = (struct rt6_info *)dst;
171		if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
172			__sk_dst_reset(sk);
173			dst = NULL;
174		}
175	}
176#endif
177
178	return dst;
179}
180
181int inet6_csk_xmit(struct sk_buff *skb)
182{
183	struct sock *sk = skb->sk;
184	struct inet_sock *inet = inet_sk(sk);
185	struct ipv6_pinfo *np = inet6_sk(sk);
186	struct flowi fl;
187	struct dst_entry *dst;
188	struct in6_addr *final_p, final;
189
190	memset(&fl, 0, sizeof(fl));
191	fl.proto = sk->sk_protocol;
192	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
193	ipv6_addr_copy(&fl.fl6_src, &np->saddr);
194	fl.fl6_flowlabel = np->flow_label;
195	IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
196	fl.oif = sk->sk_bound_dev_if;
197	fl.mark = sk->sk_mark;
198	fl.fl_ip_sport = inet->inet_sport;
199	fl.fl_ip_dport = inet->inet_dport;
200	security_sk_classify_flow(sk, &fl);
201
202	final_p = fl6_update_dst(&fl, np->opt, &final);
203
204	dst = __inet6_csk_dst_check(sk, np->dst_cookie);
205
206	if (dst == NULL) {
207		int err = ip6_dst_lookup(sk, &dst, &fl);
208
209		if (err) {
210			sk->sk_err_soft = -err;
211			kfree_skb(skb);
212			return err;
213		}
214
215		if (final_p)
216			ipv6_addr_copy(&fl.fl6_dst, final_p);
217
218		if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {
219			sk->sk_route_caps = 0;
220			kfree_skb(skb);
221			return err;
222		}
223
224		__inet6_csk_dst_store(sk, dst, NULL, NULL);
225	}
226
227	skb_dst_set(skb, dst_clone(dst));
228
229	/* Restore final destination back after routing done */
230	ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
231
232	return ip6_xmit(sk, skb, &fl, np->opt);
233}
234
235EXPORT_SYMBOL_GPL(inet6_csk_xmit);
236