blob: 3f69ea1148291ce2e5ad4956f4c27931d8db7e8f [file] [log] [blame]
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. */
Changli Gaod8d1f302010-06-10 23:31:35 -0700108 sk_setup_caps(sk, &rt->dst);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700109
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
Herbert Xubb296242010-04-11 02:15:55 +0000352void dccp_v4_send_check(struct sock *sk, 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)
Balazs Scheidler093d2822010-10-21 13:06:43 +0200395 goto exit_nonewsk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700396
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
Balazs Scheidler093d2822010-10-21 13:06:43 +0200412 if (__inet_inherit_port(sk, newsk) < 0) {
413 sock_put(newsk);
414 goto exit;
415 }
Eric Dumazet9327f702009-12-04 03:46:54 +0000416 __inet_hash_nolisten(newsk, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700417
418 return newsk;
419
420exit_overflow:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700421 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
Balazs Scheidler093d2822010-10-21 13:06:43 +0200422exit_nonewsk:
423 dst_release(dst);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700424exit:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700425 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700426 return NULL;
427}
428
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800429EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
430
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700431static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
432{
433 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700434 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700435 struct sock *nsk;
436 struct request_sock **prev;
437 /* Find possible connection requests. */
438 struct request_sock *req = inet_csk_search_req(sk, &prev,
439 dh->dccph_sport,
440 iph->saddr, iph->daddr);
441 if (req != NULL)
442 return dccp_check_req(sk, skb, req, prev);
443
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700444 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
Herbert Xu8f4910692006-08-09 15:47:12 -0700445 iph->saddr, dh->dccph_sport,
446 iph->daddr, dh->dccph_dport,
447 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700448 if (nsk != NULL) {
449 if (nsk->sk_state != DCCP_TIME_WAIT) {
450 bh_lock_sock(nsk);
451 return nsk;
452 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700453 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700454 return NULL;
455 }
456
457 return sk;
458}
459
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700460static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700461 struct sk_buff *skb)
462{
463 struct rtable *rt;
Eric Dumazet511c3f92009-06-02 05:14:27 +0000464 struct flowi fl = { .oif = skb_rtable(skb)->rt_iif,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700465 .nl_u = { .ip4_u =
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700466 { .daddr = ip_hdr(skb)->saddr,
467 .saddr = ip_hdr(skb)->daddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700468 .tos = RT_CONN_FLAGS(sk) } },
469 .proto = sk->sk_protocol,
470 .uli_u = { .ports =
471 { .sport = dccp_hdr(skb)->dccph_dport,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300472 .dport = dccp_hdr(skb)->dccph_sport }
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200473 }
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300474 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700475
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700476 security_skb_classify_flow(skb, &fl);
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700477 if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700478 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700479 return NULL;
480 }
481
Changli Gaod8d1f302010-06-10 23:31:35 -0700482 return &rt->dst;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700483}
484
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000485static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
486 struct request_values *rv_unused)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200487{
488 int err = -1;
489 struct sk_buff *skb;
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800490 struct dst_entry *dst;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200491
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800492 dst = inet_csk_route_req(sk, req);
493 if (dst == NULL)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200494 goto out;
495
496 skb = dccp_make_response(sk, dst, req);
497 if (skb != NULL) {
498 const struct inet_request_sock *ireq = inet_rsk(req);
499 struct dccp_hdr *dh = dccp_hdr(skb);
500
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200501 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
502 ireq->rmt_addr);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200503 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
504 ireq->rmt_addr,
505 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200506 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200507 }
508
509out:
510 dst_release(dst);
511 return err;
512}
513
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800514static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700515{
516 int err;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700517 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700518 struct sk_buff *skb;
519 struct dst_entry *dst;
Eric Dumazetadf30902009-06-02 05:19:30 +0000520 struct net *net = dev_net(skb_dst(rxskb)->dev);
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -0700521 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700522
523 /* Never send a reset in response to a reset. */
Gerrit Renkere356d372007-09-26 14:35:19 -0300524 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700525 return;
526
Eric Dumazet511c3f92009-06-02 05:14:27 +0000527 if (skb_rtable(rxskb)->rt_type != RTN_LOCAL)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700528 return;
529
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700530 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700531 if (dst == NULL)
532 return;
533
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700534 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700535 if (skb == NULL)
536 goto out;
537
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700538 rxiph = ip_hdr(rxskb);
Gerrit Renkere356d372007-09-26 14:35:19 -0300539 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
540 rxiph->daddr);
Eric Dumazetadf30902009-06-02 05:19:30 +0000541 skb_dst_set(skb, dst_clone(dst));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700542
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700543 bh_lock_sock(ctl_sk);
544 err = ip_build_and_send_pkt(skb, ctl_sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700545 rxiph->daddr, rxiph->saddr, NULL);
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700546 bh_unlock_sock(ctl_sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700547
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200548 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700549 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
550 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
551 }
552out:
553 dst_release(dst);
554}
555
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200556static void dccp_v4_reqsk_destructor(struct request_sock *req)
557{
Gerrit Renkerd99a7bd2008-11-04 23:56:30 -0800558 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200559 kfree(inet_rsk(req)->opt);
560}
561
562static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
563 .family = PF_INET,
564 .obj_size = sizeof(struct dccp_request_sock),
565 .rtx_syn_ack = dccp_v4_send_response,
566 .send_ack = dccp_reqsk_send_ack,
567 .destructor = dccp_v4_reqsk_destructor,
568 .send_reset = dccp_v4_ctl_send_reset,
569};
570
571int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
572{
573 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200574 struct request_sock *req;
575 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200576 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200577 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200578
579 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
Eric Dumazet511c3f92009-06-02 05:14:27 +0000580 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700581 return 0; /* discard, don't send a reset here */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200582
583 if (dccp_bad_service_code(sk, service)) {
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700584 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200585 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200586 }
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200587 /*
588 * TW buckets are converted to open requests without
589 * limitations, they conserve resources and peer is
590 * evidently real one.
591 */
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700592 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200593 if (inet_csk_reqsk_queue_is_full(sk))
594 goto drop;
595
596 /*
597 * Accept backlog is full. If we have already queued enough
598 * of warm entries in syn queue, drop request. It is better than
599 * clogging syn queue with openreqs with exponentially increasing
600 * timeout.
601 */
602 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
603 goto drop;
604
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -0700605 req = inet_reqsk_alloc(&dccp_request_sock_ops);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200606 if (req == NULL)
607 goto drop;
608
Gerrit Renkerac757732008-11-04 23:55:49 -0800609 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
610 goto drop_and_free;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200611
Gerrit Renker8b819412007-12-13 12:29:24 -0200612 dreq = dccp_rsk(req);
613 if (dccp_parse_options(sk, dreq, skb))
614 goto drop_and_free;
615
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200616 if (security_inet_conn_request(sk, skb, req))
617 goto drop_and_free;
618
619 ireq = inet_rsk(req);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700620 ireq->loc_addr = ip_hdr(skb)->daddr;
621 ireq->rmt_addr = ip_hdr(skb)->saddr;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200622
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200623 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200624 * Step 3: Process LISTEN state
625 *
626 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
627 *
628 * In fact we defer setting S.GSR, S.SWL, S.SWH to
629 * dccp_create_openreq_child.
630 */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200631 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200632 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200633 dreq->dreq_service = service;
634
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000635 if (dccp_v4_send_response(sk, req, NULL))
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200636 goto drop_and_free;
637
638 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
639 return 0;
640
641drop_and_free:
642 reqsk_free(req);
643drop:
644 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200645 return -1;
646}
647
648EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
649
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700650int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
651{
652 struct dccp_hdr *dh = dccp_hdr(skb);
653
654 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
655 if (dccp_rcv_established(sk, skb, dh, skb->len))
656 goto reset;
657 return 0;
658 }
659
660 /*
661 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200662 * If P.type == Request or P contains a valid Init Cookie option,
663 * (* Must scan the packet's options to check for Init
664 * Cookies. Only Init Cookies are processed here,
665 * however; other options are processed in Step 8. This
666 * scan need only be performed if the endpoint uses Init
667 * Cookies *)
668 * (* Generate a new socket and switch to that socket *)
669 * Set S := new socket for this port pair
670 * S.state = RESPOND
671 * Choose S.ISS (initial seqno) or set from Init Cookies
672 * Initialize S.GAR := S.ISS
673 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
674 * Continue with S.state == RESPOND
675 * (* A Response packet will be generated in Step 11 *)
676 * Otherwise,
677 * Generate Reset(No Connection) unless P.type == Reset
678 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700679 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300680 * NOTE: the check for the packet types is done in
681 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700682 */
683 if (sk->sk_state == DCCP_LISTEN) {
684 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
685
686 if (nsk == NULL)
687 goto discard;
688
689 if (nsk != sk) {
690 if (dccp_child_process(sk, nsk, skb))
691 goto reset;
692 return 0;
693 }
694 }
695
696 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
697 goto reset;
698 return 0;
699
700reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800701 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700702discard:
703 kfree_skb(skb);
704 return 0;
705}
706
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800707EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
708
Gerrit Renker09dbc382006-11-14 12:57:34 -0200709/**
710 * dccp_invalid_packet - check for malformed packets
711 * Implements RFC 4340, 8.5: Step 1: Check header basics
712 * Packets that fail these checks are ignored and do not receive Resets.
713 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800714int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700715{
716 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200717 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700718
719 if (skb->pkt_type != PACKET_HOST)
720 return 1;
721
Gerrit Renker09dbc382006-11-14 12:57:34 -0200722 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700723 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200724 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700725 return 1;
726 }
727
728 dh = dccp_hdr(skb);
729
Gerrit Renker09dbc382006-11-14 12:57:34 -0200730 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700731 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200732 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700733 return 1;
734 }
735
736 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200737 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700738 */
739 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200740 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700741 return 1;
742 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200743 /*
744 * If P.Data Offset is too too large for packet, drop packet and return
745 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700746 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200747 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700748 return 1;
749 }
750
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700751 /*
752 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
753 * has short sequence numbers), drop packet and return
754 */
Wei Yongjun6079a462008-05-27 06:22:38 -0700755 if ((dh->dccph_type < DCCP_PKT_DATA ||
756 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200757 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
758 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700759 return 1;
760 }
761
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200762 /*
763 * If P.CsCov is too large for the packet size, drop packet and return.
764 * This must come _before_ checksumming (not as RFC 4340 suggests).
765 */
766 cscov = dccp_csum_coverage(skb);
767 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200768 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
769 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200770 return 1;
771 }
772
773 /* If header checksum is incorrect, drop packet and return.
774 * (This step is completed in the AF-dependent functions.) */
775 skb->csum = skb_checksum(skb, 0, cscov, 0);
776
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700777 return 0;
778}
779
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800780EXPORT_SYMBOL_GPL(dccp_invalid_packet);
781
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700782/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800783static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700784{
785 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700786 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700787 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200788 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700789
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200790 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700791
792 if (dccp_invalid_packet(skb))
793 goto discard_it;
794
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700795 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200796 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700797 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200798 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800799 goto discard_it;
800 }
801
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700802 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700803
Gerrit Renkerfde20102007-10-24 10:12:09 -0200804 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700805 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
806
Harvey Harrison21454aa2008-10-31 00:54:56 -0700807 dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu",
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700808 dccp_packet_name(dh->dccph_type),
Harvey Harrison21454aa2008-10-31 00:54:56 -0700809 &iph->saddr, ntohs(dh->dccph_sport),
810 &iph->daddr, ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700811 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700812
813 if (dccp_packet_without_ack(skb)) {
814 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
815 dccp_pr_debug_cat("\n");
816 } else {
817 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200818 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700819 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700820 }
821
822 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200823 * Look up flow ID in table and get corresponding socket */
Arnaldo Carvalho de Melo9a1f27c2008-10-07 11:41:57 -0700824 sk = __inet_lookup_skb(&dccp_hashinfo, skb,
825 dh->dccph_sport, dh->dccph_dport);
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200826 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700827 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200828 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700829 */
830 if (sk == NULL) {
831 dccp_pr_debug("failed to look up flow ID in table and "
832 "get corresponding socket\n");
833 goto no_dccp_socket;
834 }
835
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200836 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700837 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200838 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700839 * Generate Reset(No Connection) unless P.type == Reset
840 * Drop packet and return
841 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700842 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200843 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
844 inet_twsk_put(inet_twsk(sk));
845 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700846 }
847
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200848 /*
849 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200850 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
851 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200852 */
853 min_cov = dccp_sk(sk)->dccps_pcrlen;
854 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
855 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
856 dh->dccph_cscov, min_cov);
857 /* FIXME: "Such packets SHOULD be reported using Data Dropped
858 * options (Section 11.7) with Drop Code 0, Protocol
859 * Constraints." */
860 goto discard_and_relse;
861 }
862
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200863 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700864 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800865 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700866
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200867 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700868
869no_dccp_socket:
870 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
871 goto discard_it;
872 /*
873 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200874 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700875 * Generate Reset(No Connection) unless P.type == Reset
876 * Drop packet and return
877 */
878 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300879 DCCP_SKB_CB(skb)->dccpd_reset_code =
880 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800881 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700882 }
883
884discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700885 kfree_skb(skb);
886 return 0;
887
888discard_and_relse:
889 sock_put(sk);
890 goto discard_it;
891}
892
Stephen Hemminger3b401a82009-09-01 19:25:04 +0000893static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800894 .queue_xmit = ip_queue_xmit,
895 .send_check = dccp_v4_send_check,
896 .rebuild_header = inet_sk_rebuild_header,
897 .conn_request = dccp_v4_conn_request,
898 .syn_recv_sock = dccp_v4_request_recv_sock,
899 .net_header_len = sizeof(struct iphdr),
900 .setsockopt = ip_setsockopt,
901 .getsockopt = ip_getsockopt,
902 .addr2sockaddr = inet_csk_addr2sockaddr,
903 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800904 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800905#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800906 .compat_setsockopt = compat_ip_setsockopt,
907 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800908#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800909};
910
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800911static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700912{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800913 static __u8 dccp_v4_ctl_sock_initialized;
914 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700915
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800916 if (err == 0) {
917 if (unlikely(!dccp_v4_ctl_sock_initialized))
918 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800919 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800920 }
921
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800922 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700923}
924
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800925static struct timewait_sock_ops dccp_timewait_sock_ops = {
926 .twsk_obj_size = sizeof(struct inet_timewait_sock),
927};
928
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800929static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700930 .name = "DCCP",
931 .owner = THIS_MODULE,
932 .close = dccp_close,
933 .connect = dccp_v4_connect,
934 .disconnect = dccp_disconnect,
935 .ioctl = dccp_ioctl,
936 .init = dccp_v4_init_sock,
937 .setsockopt = dccp_setsockopt,
938 .getsockopt = dccp_getsockopt,
939 .sendmsg = dccp_sendmsg,
940 .recvmsg = dccp_recvmsg,
941 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800942 .hash = inet_hash,
943 .unhash = inet_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700944 .accept = inet_csk_accept,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800945 .get_port = inet_csk_get_port,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700946 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800947 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700948 .orphan_count = &dccp_orphan_count,
949 .max_header = MAX_DCCP_HEADER,
950 .obj_size = sizeof(struct dccp_sock),
Eric Dumazet3ab5aee2008-11-16 19:40:17 -0800951 .slab_flags = SLAB_DESTROY_BY_RCU,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700952 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800953 .twsk_prot = &dccp_timewait_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -0700954 .h.hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800955#ifdef CONFIG_COMPAT
956 .compat_setsockopt = compat_dccp_setsockopt,
957 .compat_getsockopt = compat_dccp_getsockopt,
958#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700959};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800960
Alexey Dobriyan32613092009-09-14 12:21:47 +0000961static const struct net_protocol dccp_v4_protocol = {
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800962 .handler = dccp_v4_rcv,
963 .err_handler = dccp_v4_err,
964 .no_policy = 1,
Pavel Emelyanovfc5f8582008-04-13 22:31:05 -0700965 .netns_ok = 1,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800966};
967
968static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800969 .family = PF_INET,
970 .owner = THIS_MODULE,
971 .release = inet_release,
972 .bind = inet_bind,
973 .connect = inet_stream_connect,
974 .socketpair = sock_no_socketpair,
975 .accept = inet_accept,
976 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800977 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800978 .poll = dccp_poll,
979 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800980 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800981 .listen = inet_dccp_listen,
982 .shutdown = inet_shutdown,
983 .setsockopt = sock_common_setsockopt,
984 .getsockopt = sock_common_getsockopt,
985 .sendmsg = inet_sendmsg,
986 .recvmsg = sock_common_recvmsg,
987 .mmap = sock_no_mmap,
988 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800989#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800990 .compat_setsockopt = compat_sock_common_setsockopt,
991 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800992#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800993};
994
995static struct inet_protosw dccp_v4_protosw = {
996 .type = SOCK_DCCP,
997 .protocol = IPPROTO_DCCP,
998 .prot = &dccp_v4_prot,
999 .ops = &inet_dccp_ops,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001000 .no_check = 0,
1001 .flags = INET_PROTOSW_ICSK,
1002};
1003
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001004static int __net_init dccp_v4_init_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001005{
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001006 if (dccp_hashinfo.bhash == NULL)
1007 return -ESOCKTNOSUPPORT;
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001008
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001009 return inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
1010 SOCK_DCCP, IPPROTO_DCCP, net);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001011}
1012
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001013static void __net_exit dccp_v4_exit_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001014{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001015 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001016}
1017
1018static struct pernet_operations dccp_v4_ops = {
1019 .init = dccp_v4_init_net,
1020 .exit = dccp_v4_exit_net,
1021};
1022
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001023static int __init dccp_v4_init(void)
1024{
1025 int err = proto_register(&dccp_v4_prot, 1);
1026
1027 if (err != 0)
1028 goto out;
1029
1030 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1031 if (err != 0)
1032 goto out_proto_unregister;
1033
1034 inet_register_protosw(&dccp_v4_protosw);
1035
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001036 err = register_pernet_subsys(&dccp_v4_ops);
1037 if (err)
1038 goto out_destroy_ctl_sock;
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001039out:
1040 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001041out_destroy_ctl_sock:
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001042 inet_unregister_protosw(&dccp_v4_protosw);
1043 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1044out_proto_unregister:
1045 proto_unregister(&dccp_v4_prot);
1046 goto out;
1047}
1048
1049static void __exit dccp_v4_exit(void)
1050{
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001051 unregister_pernet_subsys(&dccp_v4_ops);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001052 inet_unregister_protosw(&dccp_v4_protosw);
1053 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1054 proto_unregister(&dccp_v4_prot);
1055}
1056
1057module_init(dccp_v4_init);
1058module_exit(dccp_v4_exit);
1059
1060/*
1061 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1062 * values directly, Also cover the case where the protocol is not specified,
1063 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1064 */
Jean Delvare7131c6c2007-10-21 16:45:03 -07001065MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1066MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001067MODULE_LICENSE("GPL");
1068MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1069MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");