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Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001/*
2 * net/dccp/ipv4.c
3 *
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070013#include <linux/dccp.h>
14#include <linux/icmp.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090015#include <linux/slab.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070016#include <linux/module.h>
17#include <linux/skbuff.h>
18#include <linux/random.h>
19
20#include <net/icmp.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080021#include <net/inet_common.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070022#include <net/inet_hashtables.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020023#include <net/inet_sock.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080024#include <net/protocol.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070025#include <net/sock.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080026#include <net/timewait_sock.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070027#include <net/tcp_states.h>
28#include <net/xfrm.h>
29
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070030#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070031#include "ccid.h"
32#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080033#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070034
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080035/*
Pavel Emelyanov13f51d82008-04-14 02:38:45 -070036 * The per-net dccp.v4_ctl_sk socket is used for responding to
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080037 * the Out-of-the-blue (OOTB) packets. A control sock will be created
38 * for this socket at the initialization time.
39 */
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080040
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080041int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070042{
43 struct inet_sock *inet = inet_sk(sk);
44 struct dccp_sock *dp = dccp_sk(sk);
45 const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
46 struct rtable *rt;
Al Virobada8ad2006-09-26 21:27:15 -070047 __be32 daddr, nexthop;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070048 int tmp;
49 int err;
50
51 dp->dccps_role = DCCP_ROLE_CLIENT;
52
53 if (addr_len < sizeof(struct sockaddr_in))
54 return -EINVAL;
55
56 if (usin->sin_family != AF_INET)
57 return -EAFNOSUPPORT;
58
59 nexthop = daddr = usin->sin_addr.s_addr;
60 if (inet->opt != NULL && inet->opt->srr) {
61 if (daddr == 0)
62 return -EINVAL;
63 nexthop = inet->opt->faddr;
64 }
65
Eric Dumazetc720c7e2009-10-15 06:30:45 +000066 tmp = ip_route_connect(&rt, nexthop, inet->inet_saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070067 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
68 IPPROTO_DCCP,
Eric Dumazetc720c7e2009-10-15 06:30:45 +000069 inet->inet_sport, usin->sin_port, sk, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070070 if (tmp < 0)
71 return tmp;
72
73 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
74 ip_rt_put(rt);
75 return -ENETUNREACH;
76 }
77
78 if (inet->opt == NULL || !inet->opt->srr)
79 daddr = rt->rt_dst;
80
Eric Dumazetc720c7e2009-10-15 06:30:45 +000081 if (inet->inet_saddr == 0)
82 inet->inet_saddr = rt->rt_src;
83 inet->inet_rcv_saddr = inet->inet_saddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070084
Eric Dumazetc720c7e2009-10-15 06:30:45 +000085 inet->inet_dport = usin->sin_port;
86 inet->inet_daddr = daddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070087
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080088 inet_csk(sk)->icsk_ext_hdr_len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070089 if (inet->opt != NULL)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080090 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070091 /*
92 * Socket identity is still unknown (sport may be zero).
93 * However we set state to DCCP_REQUESTING and not releasing socket
94 * lock select source port, enter ourselves into the hash tables and
95 * complete initialization after this.
96 */
97 dccp_set_state(sk, DCCP_REQUESTING);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -080098 err = inet_hash_connect(&dccp_death_row, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070099 if (err != 0)
100 goto failure;
101
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000102 err = ip_route_newports(&rt, IPPROTO_DCCP, inet->inet_sport,
103 inet->inet_dport, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700104 if (err != 0)
105 goto failure;
106
107 /* OK, now commit destination to socket. */
108 sk_setup_caps(sk, &rt->u.dst);
109
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000110 dp->dccps_iss = secure_dccp_sequence_number(inet->inet_saddr,
111 inet->inet_daddr,
112 inet->inet_sport,
113 inet->inet_dport);
114 inet->inet_id = dp->dccps_iss ^ jiffies;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700115
116 err = dccp_connect(sk);
117 rt = NULL;
118 if (err != 0)
119 goto failure;
120out:
121 return err;
122failure:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300123 /*
124 * This unhashes the socket and releases the local port, if necessary.
125 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700126 dccp_set_state(sk, DCCP_CLOSED);
127 ip_rt_put(rt);
128 sk->sk_route_caps = 0;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000129 inet->inet_dport = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700130 goto out;
131}
132
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800133EXPORT_SYMBOL_GPL(dccp_v4_connect);
134
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700135/*
136 * This routine does path mtu discovery as defined in RFC1191.
137 */
138static inline void dccp_do_pmtu_discovery(struct sock *sk,
139 const struct iphdr *iph,
140 u32 mtu)
141{
142 struct dst_entry *dst;
143 const struct inet_sock *inet = inet_sk(sk);
144 const struct dccp_sock *dp = dccp_sk(sk);
145
146 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
147 * send out by Linux are always < 576bytes so they should go through
148 * unfragmented).
149 */
150 if (sk->sk_state == DCCP_LISTEN)
151 return;
152
153 /* We don't check in the destentry if pmtu discovery is forbidden
154 * on this route. We just assume that no packet_to_big packets
155 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900156 * There is a small race when the user changes this flag in the
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700157 * route, but I think that's acceptable.
158 */
159 if ((dst = __sk_dst_check(sk, 0)) == NULL)
160 return;
161
162 dst->ops->update_pmtu(dst, mtu);
163
164 /* Something is about to be wrong... Remember soft error
165 * for the case, if this connection will not able to recover.
166 */
167 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
168 sk->sk_err_soft = EMSGSIZE;
169
170 mtu = dst_mtu(dst);
171
172 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800173 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700174 dccp_sync_mss(sk, mtu);
175
176 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700177 * From RFC 4340, sec. 14.1:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700178 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300179 * DCCP-Sync packets are the best choice for upward
180 * probing, since DCCP-Sync probes do not risk application
181 * data loss.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700182 */
Arnaldo Carvalho de Meloe92ae932005-08-17 03:10:59 -0300183 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700184 } /* else let the usual retransmit timer handle it */
185}
186
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700187/*
188 * This routine is called by the ICMP module when it gets some sort of error
189 * condition. If err < 0 then the socket should be closed and the error
190 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
191 * After adjustment header points to the first 8 bytes of the tcp header. We
192 * need to find the appropriate port.
193 *
194 * The locking strategy used here is very "optimistic". When someone else
195 * accesses the socket the ICMP is just dropped and for some paths there is no
196 * check at all. A more general error queue to queue errors for later handling
197 * is probably better.
198 */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800199static void dccp_v4_err(struct sk_buff *skb, u32 info)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700200{
201 const struct iphdr *iph = (struct iphdr *)skb->data;
Wei Yongjun18e1d832008-07-26 11:59:10 +0100202 const u8 offset = iph->ihl << 2;
203 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700204 struct dccp_sock *dp;
205 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300206 const int type = icmp_hdr(skb)->type;
207 const int code = icmp_hdr(skb)->code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700208 struct sock *sk;
209 __u64 seq;
210 int err;
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700211 struct net *net = dev_net(skb->dev);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700212
Wei Yongjun18e1d832008-07-26 11:59:10 +0100213 if (skb->len < offset + sizeof(*dh) ||
214 skb->len < offset + __dccp_basic_hdr_len(dh)) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700215 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700216 return;
217 }
218
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700219 sk = inet_lookup(net, &dccp_hashinfo,
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700220 iph->daddr, dh->dccph_dport,
221 iph->saddr, dh->dccph_sport, inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700222 if (sk == NULL) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700223 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700224 return;
225 }
226
227 if (sk->sk_state == DCCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700228 inet_twsk_put(inet_twsk(sk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700229 return;
230 }
231
232 bh_lock_sock(sk);
233 /* If too many ICMPs get dropped on busy
234 * servers this needs to be solved differently.
235 */
236 if (sock_owned_by_user(sk))
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700237 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700238
239 if (sk->sk_state == DCCP_CLOSED)
240 goto out;
241
242 dp = dccp_sk(sk);
Gerrit Renkerfde20102007-10-24 10:12:09 -0200243 seq = dccp_hdr_seq(dh);
Gerrit Renker1238d082007-10-24 10:18:06 -0200244 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
Wei Yongjund68f0862008-07-26 11:59:10 +0100245 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700246 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700247 goto out;
248 }
249
250 switch (type) {
251 case ICMP_SOURCE_QUENCH:
252 /* Just silently ignore these. */
253 goto out;
254 case ICMP_PARAMETERPROB:
255 err = EPROTO;
256 break;
257 case ICMP_DEST_UNREACH:
258 if (code > NR_ICMP_UNREACH)
259 goto out;
260
261 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
262 if (!sock_owned_by_user(sk))
263 dccp_do_pmtu_discovery(sk, iph, info);
264 goto out;
265 }
266
267 err = icmp_err_convert[code].errno;
268 break;
269 case ICMP_TIME_EXCEEDED:
270 err = EHOSTUNREACH;
271 break;
272 default:
273 goto out;
274 }
275
276 switch (sk->sk_state) {
277 struct request_sock *req , **prev;
278 case DCCP_LISTEN:
279 if (sock_owned_by_user(sk))
280 goto out;
281 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
282 iph->daddr, iph->saddr);
283 if (!req)
284 goto out;
285
286 /*
287 * ICMPs are not backlogged, hence we cannot get an established
288 * socket here.
289 */
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700290 WARN_ON(req->sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700291
292 if (seq != dccp_rsk(req)->dreq_iss) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700293 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700294 goto out;
295 }
296 /*
297 * Still in RESPOND, just remove it silently.
298 * There is no good way to pass the error to the newly
299 * created socket, and POSIX does not want network
300 * errors returned from accept().
301 */
302 inet_csk_reqsk_queue_drop(sk, req, prev);
303 goto out;
304
305 case DCCP_REQUESTING:
306 case DCCP_RESPOND:
307 if (!sock_owned_by_user(sk)) {
308 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
309 sk->sk_err = err;
310
311 sk->sk_error_report(sk);
312
313 dccp_done(sk);
314 } else
315 sk->sk_err_soft = err;
316 goto out;
317 }
318
319 /* If we've already connected we will keep trying
320 * until we time out, or the user gives up.
321 *
322 * rfc1122 4.2.3.9 allows to consider as hard errors
323 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
324 * but it is obsoleted by pmtu discovery).
325 *
326 * Note, that in modern internet, where routing is unreliable
327 * and in each dark corner broken firewalls sit, sending random
328 * errors ordered by their masters even this two messages finally lose
329 * their original sense (even Linux sends invalid PORT_UNREACHs)
330 *
331 * Now we are in compliance with RFCs.
332 * --ANK (980905)
333 */
334
335 inet = inet_sk(sk);
336 if (!sock_owned_by_user(sk) && inet->recverr) {
337 sk->sk_err = err;
338 sk->sk_error_report(sk);
339 } else /* Only an error on timeout */
340 sk->sk_err_soft = err;
341out:
342 bh_unlock_sock(sk);
343 sock_put(sk);
344}
345
Al Viro2bda2852006-11-14 21:28:51 -0800346static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200347 __be32 src, __be32 dst)
348{
349 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
350}
351
352void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800353{
354 const struct inet_sock *inet = inet_sk(sk);
355 struct dccp_hdr *dh = dccp_hdr(skb);
356
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200357 dccp_csum_outgoing(skb);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000358 dh->dccph_checksum = dccp_v4_csum_finish(skb,
359 inet->inet_saddr,
360 inet->inet_daddr);
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800361}
362
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800363EXPORT_SYMBOL_GPL(dccp_v4_send_check);
364
Gerrit Renker865e9022006-11-13 13:31:50 -0200365static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700366{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700367 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
368 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700369 dccp_hdr(skb)->dccph_dport,
370 dccp_hdr(skb)->dccph_sport);
371}
372
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700373/*
374 * The three way handshake has completed - we got a valid ACK or DATAACK -
375 * now create the new socket.
376 *
377 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
378 */
379struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
380 struct request_sock *req,
381 struct dst_entry *dst)
382{
383 struct inet_request_sock *ireq;
384 struct inet_sock *newinet;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700385 struct sock *newsk;
386
387 if (sk_acceptq_is_full(sk))
388 goto exit_overflow;
389
390 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
391 goto exit;
392
393 newsk = dccp_create_openreq_child(sk, req, skb);
394 if (newsk == NULL)
395 goto exit;
396
397 sk_setup_caps(newsk, dst);
398
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700399 newinet = inet_sk(newsk);
400 ireq = inet_rsk(req);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000401 newinet->inet_daddr = ireq->rmt_addr;
402 newinet->inet_rcv_saddr = ireq->loc_addr;
403 newinet->inet_saddr = ireq->loc_addr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700404 newinet->opt = ireq->opt;
405 ireq->opt = NULL;
406 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700407 newinet->mc_ttl = ip_hdr(skb)->ttl;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000408 newinet->inet_id = jiffies;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700409
410 dccp_sync_mss(newsk, dst_mtu(dst));
411
Eric Dumazet9327f702009-12-04 03:46:54 +0000412 __inet_hash_nolisten(newsk, NULL);
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800413 __inet_inherit_port(sk, newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700414
415 return newsk;
416
417exit_overflow:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700418 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700419exit:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700420 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700421 dst_release(dst);
422 return NULL;
423}
424
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800425EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
426
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700427static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
428{
429 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700430 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700431 struct sock *nsk;
432 struct request_sock **prev;
433 /* Find possible connection requests. */
434 struct request_sock *req = inet_csk_search_req(sk, &prev,
435 dh->dccph_sport,
436 iph->saddr, iph->daddr);
437 if (req != NULL)
438 return dccp_check_req(sk, skb, req, prev);
439
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700440 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
Herbert Xu8f4910692006-08-09 15:47:12 -0700441 iph->saddr, dh->dccph_sport,
442 iph->daddr, dh->dccph_dport,
443 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700444 if (nsk != NULL) {
445 if (nsk->sk_state != DCCP_TIME_WAIT) {
446 bh_lock_sock(nsk);
447 return nsk;
448 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700449 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700450 return NULL;
451 }
452
453 return sk;
454}
455
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700456static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700457 struct sk_buff *skb)
458{
459 struct rtable *rt;
Eric Dumazet511c3f92009-06-02 05:14:27 +0000460 struct flowi fl = { .oif = skb_rtable(skb)->rt_iif,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700461 .nl_u = { .ip4_u =
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700462 { .daddr = ip_hdr(skb)->saddr,
463 .saddr = ip_hdr(skb)->daddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700464 .tos = RT_CONN_FLAGS(sk) } },
465 .proto = sk->sk_protocol,
466 .uli_u = { .ports =
467 { .sport = dccp_hdr(skb)->dccph_dport,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300468 .dport = dccp_hdr(skb)->dccph_sport }
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200469 }
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300470 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700471
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700472 security_skb_classify_flow(skb, &fl);
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700473 if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700474 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700475 return NULL;
476 }
477
478 return &rt->u.dst;
479}
480
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000481static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
482 struct request_values *rv_unused)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200483{
484 int err = -1;
485 struct sk_buff *skb;
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800486 struct dst_entry *dst;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200487
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800488 dst = inet_csk_route_req(sk, req);
489 if (dst == NULL)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200490 goto out;
491
492 skb = dccp_make_response(sk, dst, req);
493 if (skb != NULL) {
494 const struct inet_request_sock *ireq = inet_rsk(req);
495 struct dccp_hdr *dh = dccp_hdr(skb);
496
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200497 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
498 ireq->rmt_addr);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200499 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
500 ireq->rmt_addr,
501 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200502 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200503 }
504
505out:
506 dst_release(dst);
507 return err;
508}
509
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800510static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700511{
512 int err;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700513 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700514 struct sk_buff *skb;
515 struct dst_entry *dst;
Eric Dumazetadf30902009-06-02 05:19:30 +0000516 struct net *net = dev_net(skb_dst(rxskb)->dev);
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -0700517 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700518
519 /* Never send a reset in response to a reset. */
Gerrit Renkere356d372007-09-26 14:35:19 -0300520 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700521 return;
522
Eric Dumazet511c3f92009-06-02 05:14:27 +0000523 if (skb_rtable(rxskb)->rt_type != RTN_LOCAL)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700524 return;
525
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700526 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700527 if (dst == NULL)
528 return;
529
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700530 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700531 if (skb == NULL)
532 goto out;
533
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700534 rxiph = ip_hdr(rxskb);
Gerrit Renkere356d372007-09-26 14:35:19 -0300535 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
536 rxiph->daddr);
Eric Dumazetadf30902009-06-02 05:19:30 +0000537 skb_dst_set(skb, dst_clone(dst));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700538
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700539 bh_lock_sock(ctl_sk);
540 err = ip_build_and_send_pkt(skb, ctl_sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700541 rxiph->daddr, rxiph->saddr, NULL);
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700542 bh_unlock_sock(ctl_sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700543
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200544 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700545 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
546 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
547 }
548out:
549 dst_release(dst);
550}
551
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200552static void dccp_v4_reqsk_destructor(struct request_sock *req)
553{
Gerrit Renkerd99a7bd2008-11-04 23:56:30 -0800554 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200555 kfree(inet_rsk(req)->opt);
556}
557
558static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
559 .family = PF_INET,
560 .obj_size = sizeof(struct dccp_request_sock),
561 .rtx_syn_ack = dccp_v4_send_response,
562 .send_ack = dccp_reqsk_send_ack,
563 .destructor = dccp_v4_reqsk_destructor,
564 .send_reset = dccp_v4_ctl_send_reset,
565};
566
567int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
568{
569 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200570 struct request_sock *req;
571 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200572 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200573 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200574
575 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
Eric Dumazet511c3f92009-06-02 05:14:27 +0000576 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700577 return 0; /* discard, don't send a reset here */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200578
579 if (dccp_bad_service_code(sk, service)) {
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700580 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200581 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200582 }
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200583 /*
584 * TW buckets are converted to open requests without
585 * limitations, they conserve resources and peer is
586 * evidently real one.
587 */
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700588 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200589 if (inet_csk_reqsk_queue_is_full(sk))
590 goto drop;
591
592 /*
593 * Accept backlog is full. If we have already queued enough
594 * of warm entries in syn queue, drop request. It is better than
595 * clogging syn queue with openreqs with exponentially increasing
596 * timeout.
597 */
598 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
599 goto drop;
600
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -0700601 req = inet_reqsk_alloc(&dccp_request_sock_ops);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200602 if (req == NULL)
603 goto drop;
604
Gerrit Renkerac757732008-11-04 23:55:49 -0800605 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
606 goto drop_and_free;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200607
Gerrit Renker8b819412007-12-13 12:29:24 -0200608 dreq = dccp_rsk(req);
609 if (dccp_parse_options(sk, dreq, skb))
610 goto drop_and_free;
611
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200612 if (security_inet_conn_request(sk, skb, req))
613 goto drop_and_free;
614
615 ireq = inet_rsk(req);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700616 ireq->loc_addr = ip_hdr(skb)->daddr;
617 ireq->rmt_addr = ip_hdr(skb)->saddr;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200618
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200619 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200620 * Step 3: Process LISTEN state
621 *
622 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
623 *
624 * In fact we defer setting S.GSR, S.SWL, S.SWH to
625 * dccp_create_openreq_child.
626 */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200627 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200628 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200629 dreq->dreq_service = service;
630
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000631 if (dccp_v4_send_response(sk, req, NULL))
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200632 goto drop_and_free;
633
634 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
635 return 0;
636
637drop_and_free:
638 reqsk_free(req);
639drop:
640 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200641 return -1;
642}
643
644EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
645
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700646int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
647{
648 struct dccp_hdr *dh = dccp_hdr(skb);
649
650 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
651 if (dccp_rcv_established(sk, skb, dh, skb->len))
652 goto reset;
653 return 0;
654 }
655
656 /*
657 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200658 * If P.type == Request or P contains a valid Init Cookie option,
659 * (* Must scan the packet's options to check for Init
660 * Cookies. Only Init Cookies are processed here,
661 * however; other options are processed in Step 8. This
662 * scan need only be performed if the endpoint uses Init
663 * Cookies *)
664 * (* Generate a new socket and switch to that socket *)
665 * Set S := new socket for this port pair
666 * S.state = RESPOND
667 * Choose S.ISS (initial seqno) or set from Init Cookies
668 * Initialize S.GAR := S.ISS
669 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
670 * Continue with S.state == RESPOND
671 * (* A Response packet will be generated in Step 11 *)
672 * Otherwise,
673 * Generate Reset(No Connection) unless P.type == Reset
674 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700675 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300676 * NOTE: the check for the packet types is done in
677 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700678 */
679 if (sk->sk_state == DCCP_LISTEN) {
680 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
681
682 if (nsk == NULL)
683 goto discard;
684
685 if (nsk != sk) {
686 if (dccp_child_process(sk, nsk, skb))
687 goto reset;
688 return 0;
689 }
690 }
691
692 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
693 goto reset;
694 return 0;
695
696reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800697 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700698discard:
699 kfree_skb(skb);
700 return 0;
701}
702
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800703EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
704
Gerrit Renker09dbc382006-11-14 12:57:34 -0200705/**
706 * dccp_invalid_packet - check for malformed packets
707 * Implements RFC 4340, 8.5: Step 1: Check header basics
708 * Packets that fail these checks are ignored and do not receive Resets.
709 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800710int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700711{
712 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200713 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700714
715 if (skb->pkt_type != PACKET_HOST)
716 return 1;
717
Gerrit Renker09dbc382006-11-14 12:57:34 -0200718 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700719 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200720 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700721 return 1;
722 }
723
724 dh = dccp_hdr(skb);
725
Gerrit Renker09dbc382006-11-14 12:57:34 -0200726 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700727 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200728 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700729 return 1;
730 }
731
732 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200733 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700734 */
735 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200736 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700737 return 1;
738 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200739 /*
740 * If P.Data Offset is too too large for packet, drop packet and return
741 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700742 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200743 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700744 return 1;
745 }
746
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700747 /*
748 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
749 * has short sequence numbers), drop packet and return
750 */
Wei Yongjun6079a462008-05-27 06:22:38 -0700751 if ((dh->dccph_type < DCCP_PKT_DATA ||
752 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200753 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
754 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700755 return 1;
756 }
757
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200758 /*
759 * If P.CsCov is too large for the packet size, drop packet and return.
760 * This must come _before_ checksumming (not as RFC 4340 suggests).
761 */
762 cscov = dccp_csum_coverage(skb);
763 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200764 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
765 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200766 return 1;
767 }
768
769 /* If header checksum is incorrect, drop packet and return.
770 * (This step is completed in the AF-dependent functions.) */
771 skb->csum = skb_checksum(skb, 0, cscov, 0);
772
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700773 return 0;
774}
775
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800776EXPORT_SYMBOL_GPL(dccp_invalid_packet);
777
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700778/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800779static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700780{
781 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700782 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700783 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200784 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700785
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200786 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700787
788 if (dccp_invalid_packet(skb))
789 goto discard_it;
790
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700791 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200792 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700793 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200794 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800795 goto discard_it;
796 }
797
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700798 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700799
Gerrit Renkerfde20102007-10-24 10:12:09 -0200800 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700801 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
802
Harvey Harrison21454aa2008-10-31 00:54:56 -0700803 dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu",
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700804 dccp_packet_name(dh->dccph_type),
Harvey Harrison21454aa2008-10-31 00:54:56 -0700805 &iph->saddr, ntohs(dh->dccph_sport),
806 &iph->daddr, ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700807 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700808
809 if (dccp_packet_without_ack(skb)) {
810 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
811 dccp_pr_debug_cat("\n");
812 } else {
813 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200814 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700815 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700816 }
817
818 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200819 * Look up flow ID in table and get corresponding socket */
Arnaldo Carvalho de Melo9a1f27c2008-10-07 11:41:57 -0700820 sk = __inet_lookup_skb(&dccp_hashinfo, skb,
821 dh->dccph_sport, dh->dccph_dport);
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200822 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700823 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200824 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700825 */
826 if (sk == NULL) {
827 dccp_pr_debug("failed to look up flow ID in table and "
828 "get corresponding socket\n");
829 goto no_dccp_socket;
830 }
831
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200832 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700833 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200834 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700835 * Generate Reset(No Connection) unless P.type == Reset
836 * Drop packet and return
837 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700838 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200839 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
840 inet_twsk_put(inet_twsk(sk));
841 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700842 }
843
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200844 /*
845 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200846 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
847 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200848 */
849 min_cov = dccp_sk(sk)->dccps_pcrlen;
850 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
851 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
852 dh->dccph_cscov, min_cov);
853 /* FIXME: "Such packets SHOULD be reported using Data Dropped
854 * options (Section 11.7) with Drop Code 0, Protocol
855 * Constraints." */
856 goto discard_and_relse;
857 }
858
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200859 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700860 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800861 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700862
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200863 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700864
865no_dccp_socket:
866 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
867 goto discard_it;
868 /*
869 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200870 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700871 * Generate Reset(No Connection) unless P.type == Reset
872 * Drop packet and return
873 */
874 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300875 DCCP_SKB_CB(skb)->dccpd_reset_code =
876 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800877 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700878 }
879
880discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700881 kfree_skb(skb);
882 return 0;
883
884discard_and_relse:
885 sock_put(sk);
886 goto discard_it;
887}
888
Stephen Hemminger3b401a82009-09-01 19:25:04 +0000889static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800890 .queue_xmit = ip_queue_xmit,
891 .send_check = dccp_v4_send_check,
892 .rebuild_header = inet_sk_rebuild_header,
893 .conn_request = dccp_v4_conn_request,
894 .syn_recv_sock = dccp_v4_request_recv_sock,
895 .net_header_len = sizeof(struct iphdr),
896 .setsockopt = ip_setsockopt,
897 .getsockopt = ip_getsockopt,
898 .addr2sockaddr = inet_csk_addr2sockaddr,
899 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800900 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800901#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800902 .compat_setsockopt = compat_ip_setsockopt,
903 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800904#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800905};
906
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800907static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700908{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800909 static __u8 dccp_v4_ctl_sock_initialized;
910 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700911
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800912 if (err == 0) {
913 if (unlikely(!dccp_v4_ctl_sock_initialized))
914 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800915 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800916 }
917
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800918 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700919}
920
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800921static struct timewait_sock_ops dccp_timewait_sock_ops = {
922 .twsk_obj_size = sizeof(struct inet_timewait_sock),
923};
924
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800925static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700926 .name = "DCCP",
927 .owner = THIS_MODULE,
928 .close = dccp_close,
929 .connect = dccp_v4_connect,
930 .disconnect = dccp_disconnect,
931 .ioctl = dccp_ioctl,
932 .init = dccp_v4_init_sock,
933 .setsockopt = dccp_setsockopt,
934 .getsockopt = dccp_getsockopt,
935 .sendmsg = dccp_sendmsg,
936 .recvmsg = dccp_recvmsg,
937 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800938 .hash = inet_hash,
939 .unhash = inet_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700940 .accept = inet_csk_accept,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800941 .get_port = inet_csk_get_port,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700942 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800943 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700944 .orphan_count = &dccp_orphan_count,
945 .max_header = MAX_DCCP_HEADER,
946 .obj_size = sizeof(struct dccp_sock),
Eric Dumazet3ab5aee2008-11-16 19:40:17 -0800947 .slab_flags = SLAB_DESTROY_BY_RCU,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700948 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800949 .twsk_prot = &dccp_timewait_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -0700950 .h.hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800951#ifdef CONFIG_COMPAT
952 .compat_setsockopt = compat_dccp_setsockopt,
953 .compat_getsockopt = compat_dccp_getsockopt,
954#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700955};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800956
Alexey Dobriyan32613092009-09-14 12:21:47 +0000957static const struct net_protocol dccp_v4_protocol = {
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800958 .handler = dccp_v4_rcv,
959 .err_handler = dccp_v4_err,
960 .no_policy = 1,
Pavel Emelyanovfc5f8582008-04-13 22:31:05 -0700961 .netns_ok = 1,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800962};
963
964static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800965 .family = PF_INET,
966 .owner = THIS_MODULE,
967 .release = inet_release,
968 .bind = inet_bind,
969 .connect = inet_stream_connect,
970 .socketpair = sock_no_socketpair,
971 .accept = inet_accept,
972 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800973 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800974 .poll = dccp_poll,
975 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800976 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800977 .listen = inet_dccp_listen,
978 .shutdown = inet_shutdown,
979 .setsockopt = sock_common_setsockopt,
980 .getsockopt = sock_common_getsockopt,
981 .sendmsg = inet_sendmsg,
982 .recvmsg = sock_common_recvmsg,
983 .mmap = sock_no_mmap,
984 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800985#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800986 .compat_setsockopt = compat_sock_common_setsockopt,
987 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800988#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800989};
990
991static struct inet_protosw dccp_v4_protosw = {
992 .type = SOCK_DCCP,
993 .protocol = IPPROTO_DCCP,
994 .prot = &dccp_v4_prot,
995 .ops = &inet_dccp_ops,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800996 .no_check = 0,
997 .flags = INET_PROTOSW_ICSK,
998};
999
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001000static int __net_init dccp_v4_init_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001001{
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001002 if (dccp_hashinfo.bhash == NULL)
1003 return -ESOCKTNOSUPPORT;
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001004
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001005 return inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
1006 SOCK_DCCP, IPPROTO_DCCP, net);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001007}
1008
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001009static void __net_exit dccp_v4_exit_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001010{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001011 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001012}
1013
1014static struct pernet_operations dccp_v4_ops = {
1015 .init = dccp_v4_init_net,
1016 .exit = dccp_v4_exit_net,
1017};
1018
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001019static int __init dccp_v4_init(void)
1020{
1021 int err = proto_register(&dccp_v4_prot, 1);
1022
1023 if (err != 0)
1024 goto out;
1025
1026 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1027 if (err != 0)
1028 goto out_proto_unregister;
1029
1030 inet_register_protosw(&dccp_v4_protosw);
1031
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001032 err = register_pernet_subsys(&dccp_v4_ops);
1033 if (err)
1034 goto out_destroy_ctl_sock;
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001035out:
1036 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001037out_destroy_ctl_sock:
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001038 inet_unregister_protosw(&dccp_v4_protosw);
1039 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1040out_proto_unregister:
1041 proto_unregister(&dccp_v4_prot);
1042 goto out;
1043}
1044
1045static void __exit dccp_v4_exit(void)
1046{
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001047 unregister_pernet_subsys(&dccp_v4_ops);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001048 inet_unregister_protosw(&dccp_v4_protosw);
1049 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1050 proto_unregister(&dccp_v4_prot);
1051}
1052
1053module_init(dccp_v4_init);
1054module_exit(dccp_v4_exit);
1055
1056/*
1057 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1058 * values directly, Also cover the case where the protocol is not specified,
1059 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1060 */
Jean Delvare7131c6c2007-10-21 16:45:03 -07001061MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1062MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001063MODULE_LICENSE("GPL");
1064MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1065MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");