ipv4: add a sock pointer to ip_queue_xmit()
[sfrench/cifs-2.6.git] / net / ipv6 / inet6_connection_sock.c
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
30 int inet6_csk_bind_conflict(const struct sock *sk,
31                             const struct inet_bind_bucket *tb, bool relax)
32 {
33         const struct sock *sk2;
34         int reuse = sk->sk_reuse;
35         int reuseport = sk->sk_reuseport;
36         kuid_t uid = sock_i_uid((struct sock *)sk);
37
38         /* We must walk the whole port owner list in this case. -DaveM */
39         /*
40          * See comment in inet_csk_bind_conflict about sock lookup
41          * vs net namespaces issues.
42          */
43         sk_for_each_bound(sk2, &tb->owners) {
44                 if (sk != sk2 &&
45                     (!sk->sk_bound_dev_if ||
46                      !sk2->sk_bound_dev_if ||
47                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
48                         if ((!reuse || !sk2->sk_reuse ||
49                              sk2->sk_state == TCP_LISTEN) &&
50                             (!reuseport || !sk2->sk_reuseport ||
51                              (sk2->sk_state != TCP_TIME_WAIT &&
52                               !uid_eq(uid,
53                                       sock_i_uid((struct sock *)sk2))))) {
54                                 if (ipv6_rcv_saddr_equal(sk, sk2))
55                                         break;
56                         }
57                         if (!relax && reuse && sk2->sk_reuse &&
58                             sk2->sk_state != TCP_LISTEN &&
59                             ipv6_rcv_saddr_equal(sk, sk2))
60                                 break;
61                 }
62         }
63
64         return sk2 != NULL;
65 }
66
67 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
68
69 struct dst_entry *inet6_csk_route_req(struct sock *sk,
70                                       struct flowi6 *fl6,
71                                       const struct request_sock *req)
72 {
73         struct inet_request_sock *ireq = inet_rsk(req);
74         struct ipv6_pinfo *np = inet6_sk(sk);
75         struct in6_addr *final_p, final;
76         struct dst_entry *dst;
77
78         memset(fl6, 0, sizeof(*fl6));
79         fl6->flowi6_proto = IPPROTO_TCP;
80         fl6->daddr = ireq->ir_v6_rmt_addr;
81         final_p = fl6_update_dst(fl6, np->opt, &final);
82         fl6->saddr = ireq->ir_v6_loc_addr;
83         fl6->flowi6_oif = ireq->ir_iif;
84         fl6->flowi6_mark = sk->sk_mark;
85         fl6->fl6_dport = ireq->ir_rmt_port;
86         fl6->fl6_sport = htons(ireq->ir_num);
87         security_req_classify_flow(req, flowi6_to_flowi(fl6));
88
89         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
90         if (IS_ERR(dst))
91                 return NULL;
92
93         return dst;
94 }
95
96 /*
97  * request_sock (formerly open request) hash tables.
98  */
99 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
100                            const u32 rnd, const u32 synq_hsize)
101 {
102         u32 c;
103
104         c = jhash_3words((__force u32)raddr->s6_addr32[0],
105                          (__force u32)raddr->s6_addr32[1],
106                          (__force u32)raddr->s6_addr32[2],
107                          rnd);
108
109         c = jhash_2words((__force u32)raddr->s6_addr32[3],
110                          (__force u32)rport,
111                          c);
112
113         return c & (synq_hsize - 1);
114 }
115
116 struct request_sock *inet6_csk_search_req(const struct sock *sk,
117                                           struct request_sock ***prevp,
118                                           const __be16 rport,
119                                           const struct in6_addr *raddr,
120                                           const struct in6_addr *laddr,
121                                           const int iif)
122 {
123         const struct inet_connection_sock *icsk = inet_csk(sk);
124         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
125         struct request_sock *req, **prev;
126
127         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
128                                                      lopt->hash_rnd,
129                                                      lopt->nr_table_entries)];
130              (req = *prev) != NULL;
131              prev = &req->dl_next) {
132                 const struct inet_request_sock *ireq = inet_rsk(req);
133
134                 if (ireq->ir_rmt_port == rport &&
135                     req->rsk_ops->family == AF_INET6 &&
136                     ipv6_addr_equal(&ireq->ir_v6_rmt_addr, raddr) &&
137                     ipv6_addr_equal(&ireq->ir_v6_loc_addr, laddr) &&
138                     (!ireq->ir_iif || ireq->ir_iif == iif)) {
139                         WARN_ON(req->sk != NULL);
140                         *prevp = prev;
141                         return req;
142                 }
143         }
144
145         return NULL;
146 }
147
148 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
149
150 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
151                                     struct request_sock *req,
152                                     const unsigned long timeout)
153 {
154         struct inet_connection_sock *icsk = inet_csk(sk);
155         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
156         const u32 h = inet6_synq_hash(&inet_rsk(req)->ir_v6_rmt_addr,
157                                       inet_rsk(req)->ir_rmt_port,
158                                       lopt->hash_rnd, lopt->nr_table_entries);
159
160         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
161         inet_csk_reqsk_queue_added(sk, timeout);
162 }
163
164 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
165
166 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
167 {
168         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
169
170         sin6->sin6_family = AF_INET6;
171         sin6->sin6_addr = sk->sk_v6_daddr;
172         sin6->sin6_port = inet_sk(sk)->inet_dport;
173         /* We do not store received flowlabel for TCP */
174         sin6->sin6_flowinfo = 0;
175         sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
176                                                   sk->sk_bound_dev_if);
177 }
178
179 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
180
181 static inline
182 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
183                            const struct in6_addr *daddr,
184                            const struct in6_addr *saddr)
185 {
186         __ip6_dst_store(sk, dst, daddr, saddr);
187 }
188
189 static inline
190 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
191 {
192         return __sk_dst_check(sk, cookie);
193 }
194
195 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
196                                                 struct flowi6 *fl6)
197 {
198         struct inet_sock *inet = inet_sk(sk);
199         struct ipv6_pinfo *np = inet6_sk(sk);
200         struct in6_addr *final_p, final;
201         struct dst_entry *dst;
202
203         memset(fl6, 0, sizeof(*fl6));
204         fl6->flowi6_proto = sk->sk_protocol;
205         fl6->daddr = sk->sk_v6_daddr;
206         fl6->saddr = np->saddr;
207         fl6->flowlabel = np->flow_label;
208         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
209         fl6->flowi6_oif = sk->sk_bound_dev_if;
210         fl6->flowi6_mark = sk->sk_mark;
211         fl6->fl6_sport = inet->inet_sport;
212         fl6->fl6_dport = inet->inet_dport;
213         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
214
215         final_p = fl6_update_dst(fl6, np->opt, &final);
216
217         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
218         if (!dst) {
219                 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
220
221                 if (!IS_ERR(dst))
222                         __inet6_csk_dst_store(sk, dst, NULL, NULL);
223         }
224         return dst;
225 }
226
227 int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
228 {
229         struct ipv6_pinfo *np = inet6_sk(sk);
230         struct flowi6 fl6;
231         struct dst_entry *dst;
232         int res;
233
234         dst = inet6_csk_route_socket(sk, &fl6);
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         rcu_read_lock();
243         skb_dst_set_noref(skb, dst);
244
245         /* Restore final destination back after routing done */
246         fl6.daddr = sk->sk_v6_daddr;
247
248         res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
249         rcu_read_unlock();
250         return res;
251 }
252 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
253
254 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
255 {
256         struct flowi6 fl6;
257         struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
258
259         if (IS_ERR(dst))
260                 return NULL;
261         dst->ops->update_pmtu(dst, sk, NULL, mtu);
262
263         dst = inet6_csk_route_socket(sk, &fl6);
264         return IS_ERR(dst) ? NULL : dst;
265 }
266 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);