blob: 2b03c47cab1ba9ad0d00ff5d0c605d6aeca42639 [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>
15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/random.h>
18
19#include <net/icmp.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080020#include <net/inet_common.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070021#include <net/inet_hashtables.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020022#include <net/inet_sock.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080023#include <net/protocol.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070024#include <net/sock.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080025#include <net/timewait_sock.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070026#include <net/tcp_states.h>
27#include <net/xfrm.h>
28
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070029#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070030#include "ccid.h"
31#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080032#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070033
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080034/*
Pavel Emelyanov13f51d82008-04-14 02:38:45 -070035 * The per-net dccp.v4_ctl_sk socket is used for responding to
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080036 * the Out-of-the-blue (OOTB) packets. A control sock will be created
37 * for this socket at the initialization time.
38 */
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080039
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080040int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070041{
42 struct inet_sock *inet = inet_sk(sk);
43 struct dccp_sock *dp = dccp_sk(sk);
44 const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
45 struct rtable *rt;
Al Virobada8ad2006-09-26 21:27:15 -070046 __be32 daddr, nexthop;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070047 int tmp;
48 int err;
49
50 dp->dccps_role = DCCP_ROLE_CLIENT;
51
52 if (addr_len < sizeof(struct sockaddr_in))
53 return -EINVAL;
54
55 if (usin->sin_family != AF_INET)
56 return -EAFNOSUPPORT;
57
58 nexthop = daddr = usin->sin_addr.s_addr;
59 if (inet->opt != NULL && inet->opt->srr) {
60 if (daddr == 0)
61 return -EINVAL;
62 nexthop = inet->opt->faddr;
63 }
64
65 tmp = ip_route_connect(&rt, nexthop, inet->saddr,
66 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
67 IPPROTO_DCCP,
David S. Miller8eb90862007-02-08 02:09:21 -080068 inet->sport, usin->sin_port, sk, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070069 if (tmp < 0)
70 return tmp;
71
72 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
73 ip_rt_put(rt);
74 return -ENETUNREACH;
75 }
76
77 if (inet->opt == NULL || !inet->opt->srr)
78 daddr = rt->rt_dst;
79
80 if (inet->saddr == 0)
81 inet->saddr = rt->rt_src;
82 inet->rcv_saddr = inet->saddr;
83
84 inet->dport = usin->sin_port;
85 inet->daddr = daddr;
86
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080087 inet_csk(sk)->icsk_ext_hdr_len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070088 if (inet->opt != NULL)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080089 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070090 /*
91 * Socket identity is still unknown (sport may be zero).
92 * However we set state to DCCP_REQUESTING and not releasing socket
93 * lock select source port, enter ourselves into the hash tables and
94 * complete initialization after this.
95 */
96 dccp_set_state(sk, DCCP_REQUESTING);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -080097 err = inet_hash_connect(&dccp_death_row, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070098 if (err != 0)
99 goto failure;
100
Patrick McHardy5d39a792006-01-31 17:35:35 -0800101 err = ip_route_newports(&rt, IPPROTO_DCCP, inet->sport, inet->dport,
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900102 sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700103 if (err != 0)
104 goto failure;
105
106 /* OK, now commit destination to socket. */
107 sk_setup_caps(sk, &rt->u.dst);
108
Gerrit Renkerd7f73652006-11-13 13:34:38 -0200109 dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, inet->daddr,
110 inet->sport, inet->dport);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700111 inet->id = dp->dccps_iss ^ jiffies;
112
113 err = dccp_connect(sk);
114 rt = NULL;
115 if (err != 0)
116 goto failure;
117out:
118 return err;
119failure:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300120 /*
121 * This unhashes the socket and releases the local port, if necessary.
122 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700123 dccp_set_state(sk, DCCP_CLOSED);
124 ip_rt_put(rt);
125 sk->sk_route_caps = 0;
126 inet->dport = 0;
127 goto out;
128}
129
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800130EXPORT_SYMBOL_GPL(dccp_v4_connect);
131
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700132/*
133 * This routine does path mtu discovery as defined in RFC1191.
134 */
135static inline void dccp_do_pmtu_discovery(struct sock *sk,
136 const struct iphdr *iph,
137 u32 mtu)
138{
139 struct dst_entry *dst;
140 const struct inet_sock *inet = inet_sk(sk);
141 const struct dccp_sock *dp = dccp_sk(sk);
142
143 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
144 * send out by Linux are always < 576bytes so they should go through
145 * unfragmented).
146 */
147 if (sk->sk_state == DCCP_LISTEN)
148 return;
149
150 /* We don't check in the destentry if pmtu discovery is forbidden
151 * on this route. We just assume that no packet_to_big packets
152 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900153 * There is a small race when the user changes this flag in the
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700154 * route, but I think that's acceptable.
155 */
156 if ((dst = __sk_dst_check(sk, 0)) == NULL)
157 return;
158
159 dst->ops->update_pmtu(dst, mtu);
160
161 /* Something is about to be wrong... Remember soft error
162 * for the case, if this connection will not able to recover.
163 */
164 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
165 sk->sk_err_soft = EMSGSIZE;
166
167 mtu = dst_mtu(dst);
168
169 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800170 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700171 dccp_sync_mss(sk, mtu);
172
173 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700174 * From RFC 4340, sec. 14.1:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700175 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300176 * DCCP-Sync packets are the best choice for upward
177 * probing, since DCCP-Sync probes do not risk application
178 * data loss.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700179 */
Arnaldo Carvalho de Meloe92ae932005-08-17 03:10:59 -0300180 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700181 } /* else let the usual retransmit timer handle it */
182}
183
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700184/*
185 * This routine is called by the ICMP module when it gets some sort of error
186 * condition. If err < 0 then the socket should be closed and the error
187 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
188 * After adjustment header points to the first 8 bytes of the tcp header. We
189 * need to find the appropriate port.
190 *
191 * The locking strategy used here is very "optimistic". When someone else
192 * accesses the socket the ICMP is just dropped and for some paths there is no
193 * check at all. A more general error queue to queue errors for later handling
194 * is probably better.
195 */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800196static void dccp_v4_err(struct sk_buff *skb, u32 info)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700197{
198 const struct iphdr *iph = (struct iphdr *)skb->data;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300199 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
200 (iph->ihl << 2));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700201 struct dccp_sock *dp;
202 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300203 const int type = icmp_hdr(skb)->type;
204 const int code = icmp_hdr(skb)->code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700205 struct sock *sk;
206 __u64 seq;
207 int err;
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700208 struct net *net = dev_net(skb->dev);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700209
210 if (skb->len < (iph->ihl << 2) + 8) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700211 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700212 return;
213 }
214
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700215 sk = inet_lookup(net, &dccp_hashinfo,
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700216 iph->daddr, dh->dccph_dport,
217 iph->saddr, dh->dccph_sport, inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700218 if (sk == NULL) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700219 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700220 return;
221 }
222
223 if (sk->sk_state == DCCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700224 inet_twsk_put(inet_twsk(sk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700225 return;
226 }
227
228 bh_lock_sock(sk);
229 /* If too many ICMPs get dropped on busy
230 * servers this needs to be solved differently.
231 */
232 if (sock_owned_by_user(sk))
233 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
234
235 if (sk->sk_state == DCCP_CLOSED)
236 goto out;
237
238 dp = dccp_sk(sk);
Gerrit Renkerfde20102007-10-24 10:12:09 -0200239 seq = dccp_hdr_seq(dh);
Gerrit Renker1238d082007-10-24 10:18:06 -0200240 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700241 !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
Arnaldo Carvalho de Meloe523a152006-11-16 12:23:58 -0200242 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700243 goto out;
244 }
245
246 switch (type) {
247 case ICMP_SOURCE_QUENCH:
248 /* Just silently ignore these. */
249 goto out;
250 case ICMP_PARAMETERPROB:
251 err = EPROTO;
252 break;
253 case ICMP_DEST_UNREACH:
254 if (code > NR_ICMP_UNREACH)
255 goto out;
256
257 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
258 if (!sock_owned_by_user(sk))
259 dccp_do_pmtu_discovery(sk, iph, info);
260 goto out;
261 }
262
263 err = icmp_err_convert[code].errno;
264 break;
265 case ICMP_TIME_EXCEEDED:
266 err = EHOSTUNREACH;
267 break;
268 default:
269 goto out;
270 }
271
272 switch (sk->sk_state) {
273 struct request_sock *req , **prev;
274 case DCCP_LISTEN:
275 if (sock_owned_by_user(sk))
276 goto out;
277 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
278 iph->daddr, iph->saddr);
279 if (!req)
280 goto out;
281
282 /*
283 * ICMPs are not backlogged, hence we cannot get an established
284 * socket here.
285 */
286 BUG_TRAP(!req->sk);
287
288 if (seq != dccp_rsk(req)->dreq_iss) {
289 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
290 goto out;
291 }
292 /*
293 * Still in RESPOND, just remove it silently.
294 * There is no good way to pass the error to the newly
295 * created socket, and POSIX does not want network
296 * errors returned from accept().
297 */
298 inet_csk_reqsk_queue_drop(sk, req, prev);
299 goto out;
300
301 case DCCP_REQUESTING:
302 case DCCP_RESPOND:
303 if (!sock_owned_by_user(sk)) {
304 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
305 sk->sk_err = err;
306
307 sk->sk_error_report(sk);
308
309 dccp_done(sk);
310 } else
311 sk->sk_err_soft = err;
312 goto out;
313 }
314
315 /* If we've already connected we will keep trying
316 * until we time out, or the user gives up.
317 *
318 * rfc1122 4.2.3.9 allows to consider as hard errors
319 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
320 * but it is obsoleted by pmtu discovery).
321 *
322 * Note, that in modern internet, where routing is unreliable
323 * and in each dark corner broken firewalls sit, sending random
324 * errors ordered by their masters even this two messages finally lose
325 * their original sense (even Linux sends invalid PORT_UNREACHs)
326 *
327 * Now we are in compliance with RFCs.
328 * --ANK (980905)
329 */
330
331 inet = inet_sk(sk);
332 if (!sock_owned_by_user(sk) && inet->recverr) {
333 sk->sk_err = err;
334 sk->sk_error_report(sk);
335 } else /* Only an error on timeout */
336 sk->sk_err_soft = err;
337out:
338 bh_unlock_sock(sk);
339 sock_put(sk);
340}
341
Al Viro2bda2852006-11-14 21:28:51 -0800342static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200343 __be32 src, __be32 dst)
344{
345 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
346}
347
348void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800349{
350 const struct inet_sock *inet = inet_sk(sk);
351 struct dccp_hdr *dh = dccp_hdr(skb);
352
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200353 dccp_csum_outgoing(skb);
354 dh->dccph_checksum = dccp_v4_csum_finish(skb, inet->saddr, inet->daddr);
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800355}
356
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800357EXPORT_SYMBOL_GPL(dccp_v4_send_check);
358
Gerrit Renker865e9022006-11-13 13:31:50 -0200359static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700360{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700361 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
362 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700363 dccp_hdr(skb)->dccph_dport,
364 dccp_hdr(skb)->dccph_sport);
365}
366
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700367/*
368 * The three way handshake has completed - we got a valid ACK or DATAACK -
369 * now create the new socket.
370 *
371 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
372 */
373struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
374 struct request_sock *req,
375 struct dst_entry *dst)
376{
377 struct inet_request_sock *ireq;
378 struct inet_sock *newinet;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700379 struct sock *newsk;
380
381 if (sk_acceptq_is_full(sk))
382 goto exit_overflow;
383
384 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
385 goto exit;
386
387 newsk = dccp_create_openreq_child(sk, req, skb);
388 if (newsk == NULL)
389 goto exit;
390
391 sk_setup_caps(newsk, dst);
392
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700393 newinet = inet_sk(newsk);
394 ireq = inet_rsk(req);
395 newinet->daddr = ireq->rmt_addr;
396 newinet->rcv_saddr = ireq->loc_addr;
397 newinet->saddr = ireq->loc_addr;
398 newinet->opt = ireq->opt;
399 ireq->opt = NULL;
400 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700401 newinet->mc_ttl = ip_hdr(skb)->ttl;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700402 newinet->id = jiffies;
403
404 dccp_sync_mss(newsk, dst_mtu(dst));
405
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800406 __inet_hash_nolisten(newsk);
407 __inet_inherit_port(sk, newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700408
409 return newsk;
410
411exit_overflow:
412 NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
413exit:
414 NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
415 dst_release(dst);
416 return NULL;
417}
418
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800419EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
420
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700421static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
422{
423 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700424 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700425 struct sock *nsk;
426 struct request_sock **prev;
427 /* Find possible connection requests. */
428 struct request_sock *req = inet_csk_search_req(sk, &prev,
429 dh->dccph_sport,
430 iph->saddr, iph->daddr);
431 if (req != NULL)
432 return dccp_check_req(sk, skb, req, prev);
433
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700434 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
Herbert Xu8f4910692006-08-09 15:47:12 -0700435 iph->saddr, dh->dccph_sport,
436 iph->daddr, dh->dccph_dport,
437 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700438 if (nsk != NULL) {
439 if (nsk->sk_state != DCCP_TIME_WAIT) {
440 bh_lock_sock(nsk);
441 return nsk;
442 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700443 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700444 return NULL;
445 }
446
447 return sk;
448}
449
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700450static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700451 struct sk_buff *skb)
452{
453 struct rtable *rt;
Eric Dumazetee6b9672008-03-05 18:30:47 -0800454 struct flowi fl = { .oif = skb->rtable->rt_iif,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700455 .nl_u = { .ip4_u =
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700456 { .daddr = ip_hdr(skb)->saddr,
457 .saddr = ip_hdr(skb)->daddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700458 .tos = RT_CONN_FLAGS(sk) } },
459 .proto = sk->sk_protocol,
460 .uli_u = { .ports =
461 { .sport = dccp_hdr(skb)->dccph_dport,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300462 .dport = dccp_hdr(skb)->dccph_sport }
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200463 }
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300464 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700465
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700466 security_skb_classify_flow(skb, &fl);
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700467 if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700468 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
469 return NULL;
470 }
471
472 return &rt->u.dst;
473}
474
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800475static int dccp_v4_send_response(struct sock *sk, struct request_sock *req)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200476{
477 int err = -1;
478 struct sk_buff *skb;
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800479 struct dst_entry *dst;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200480
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800481 dst = inet_csk_route_req(sk, req);
482 if (dst == NULL)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200483 goto out;
484
485 skb = dccp_make_response(sk, dst, req);
486 if (skb != NULL) {
487 const struct inet_request_sock *ireq = inet_rsk(req);
488 struct dccp_hdr *dh = dccp_hdr(skb);
489
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200490 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
491 ireq->rmt_addr);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200492 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
493 ireq->rmt_addr,
494 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200495 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200496 }
497
498out:
499 dst_release(dst);
500 return err;
501}
502
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800503static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700504{
505 int err;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700506 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700507 struct sk_buff *skb;
508 struct dst_entry *dst;
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -0700509 struct net *net = dev_net(rxskb->dst->dev);
510 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700511
512 /* Never send a reset in response to a reset. */
Gerrit Renkere356d372007-09-26 14:35:19 -0300513 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700514 return;
515
Eric Dumazetee6b9672008-03-05 18:30:47 -0800516 if (rxskb->rtable->rt_type != RTN_LOCAL)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700517 return;
518
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700519 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700520 if (dst == NULL)
521 return;
522
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700523 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700524 if (skb == NULL)
525 goto out;
526
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700527 rxiph = ip_hdr(rxskb);
Gerrit Renkere356d372007-09-26 14:35:19 -0300528 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
529 rxiph->daddr);
530 skb->dst = dst_clone(dst);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700531
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700532 bh_lock_sock(ctl_sk);
533 err = ip_build_and_send_pkt(skb, ctl_sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700534 rxiph->daddr, rxiph->saddr, NULL);
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700535 bh_unlock_sock(ctl_sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700536
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200537 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700538 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
539 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
540 }
541out:
542 dst_release(dst);
543}
544
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200545static void dccp_v4_reqsk_destructor(struct request_sock *req)
546{
547 kfree(inet_rsk(req)->opt);
548}
549
550static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
551 .family = PF_INET,
552 .obj_size = sizeof(struct dccp_request_sock),
553 .rtx_syn_ack = dccp_v4_send_response,
554 .send_ack = dccp_reqsk_send_ack,
555 .destructor = dccp_v4_reqsk_destructor,
556 .send_reset = dccp_v4_ctl_send_reset,
557};
558
559int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
560{
561 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200562 struct request_sock *req;
563 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200564 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200565 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200566
567 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
Eric Dumazetee6b9672008-03-05 18:30:47 -0800568 if (skb->rtable->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700569 return 0; /* discard, don't send a reset here */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200570
571 if (dccp_bad_service_code(sk, service)) {
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700572 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200573 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200574 }
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200575 /*
576 * TW buckets are converted to open requests without
577 * limitations, they conserve resources and peer is
578 * evidently real one.
579 */
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700580 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200581 if (inet_csk_reqsk_queue_is_full(sk))
582 goto drop;
583
584 /*
585 * Accept backlog is full. If we have already queued enough
586 * of warm entries in syn queue, drop request. It is better than
587 * clogging syn queue with openreqs with exponentially increasing
588 * timeout.
589 */
590 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
591 goto drop;
592
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -0700593 req = inet_reqsk_alloc(&dccp_request_sock_ops);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200594 if (req == NULL)
595 goto drop;
596
Gerrit Renkercf557922006-11-10 16:08:37 -0200597 dccp_reqsk_init(req, skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200598
Gerrit Renker8b819412007-12-13 12:29:24 -0200599 dreq = dccp_rsk(req);
600 if (dccp_parse_options(sk, dreq, skb))
601 goto drop_and_free;
602
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200603 if (security_inet_conn_request(sk, skb, req))
604 goto drop_and_free;
605
606 ireq = inet_rsk(req);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700607 ireq->loc_addr = ip_hdr(skb)->daddr;
608 ireq->rmt_addr = ip_hdr(skb)->saddr;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200609
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200610 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200611 * Step 3: Process LISTEN state
612 *
613 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
614 *
615 * In fact we defer setting S.GSR, S.SWL, S.SWH to
616 * dccp_create_openreq_child.
617 */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200618 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200619 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200620 dreq->dreq_service = service;
621
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800622 if (dccp_v4_send_response(sk, req))
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200623 goto drop_and_free;
624
625 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
626 return 0;
627
628drop_and_free:
629 reqsk_free(req);
630drop:
631 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200632 return -1;
633}
634
635EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
636
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700637int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
638{
639 struct dccp_hdr *dh = dccp_hdr(skb);
640
641 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
642 if (dccp_rcv_established(sk, skb, dh, skb->len))
643 goto reset;
644 return 0;
645 }
646
647 /*
648 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200649 * If P.type == Request or P contains a valid Init Cookie option,
650 * (* Must scan the packet's options to check for Init
651 * Cookies. Only Init Cookies are processed here,
652 * however; other options are processed in Step 8. This
653 * scan need only be performed if the endpoint uses Init
654 * Cookies *)
655 * (* Generate a new socket and switch to that socket *)
656 * Set S := new socket for this port pair
657 * S.state = RESPOND
658 * Choose S.ISS (initial seqno) or set from Init Cookies
659 * Initialize S.GAR := S.ISS
660 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
661 * Continue with S.state == RESPOND
662 * (* A Response packet will be generated in Step 11 *)
663 * Otherwise,
664 * Generate Reset(No Connection) unless P.type == Reset
665 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700666 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300667 * NOTE: the check for the packet types is done in
668 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700669 */
670 if (sk->sk_state == DCCP_LISTEN) {
671 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
672
673 if (nsk == NULL)
674 goto discard;
675
676 if (nsk != sk) {
677 if (dccp_child_process(sk, nsk, skb))
678 goto reset;
679 return 0;
680 }
681 }
682
683 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
684 goto reset;
685 return 0;
686
687reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800688 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700689discard:
690 kfree_skb(skb);
691 return 0;
692}
693
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800694EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
695
Gerrit Renker09dbc382006-11-14 12:57:34 -0200696/**
697 * dccp_invalid_packet - check for malformed packets
698 * Implements RFC 4340, 8.5: Step 1: Check header basics
699 * Packets that fail these checks are ignored and do not receive Resets.
700 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800701int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700702{
703 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200704 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700705
706 if (skb->pkt_type != PACKET_HOST)
707 return 1;
708
Gerrit Renker09dbc382006-11-14 12:57:34 -0200709 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700710 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200711 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700712 return 1;
713 }
714
715 dh = dccp_hdr(skb);
716
Gerrit Renker09dbc382006-11-14 12:57:34 -0200717 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700718 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200719 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700720 return 1;
721 }
722
723 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200724 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700725 */
726 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200727 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700728 return 1;
729 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200730 /*
731 * If P.Data Offset is too too large for packet, drop packet and return
732 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700733 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200734 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700735 return 1;
736 }
737
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700738 /*
739 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
740 * has short sequence numbers), drop packet and return
741 */
Wei Yongjun6079a462008-05-27 06:22:38 -0700742 if ((dh->dccph_type < DCCP_PKT_DATA ||
743 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200744 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
745 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700746 return 1;
747 }
748
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200749 /*
750 * If P.CsCov is too large for the packet size, drop packet and return.
751 * This must come _before_ checksumming (not as RFC 4340 suggests).
752 */
753 cscov = dccp_csum_coverage(skb);
754 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200755 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
756 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200757 return 1;
758 }
759
760 /* If header checksum is incorrect, drop packet and return.
761 * (This step is completed in the AF-dependent functions.) */
762 skb->csum = skb_checksum(skb, 0, cscov, 0);
763
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700764 return 0;
765}
766
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800767EXPORT_SYMBOL_GPL(dccp_invalid_packet);
768
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700769/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800770static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700771{
772 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700773 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700774 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200775 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700776
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200777 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700778
779 if (dccp_invalid_packet(skb))
780 goto discard_it;
781
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700782 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200783 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700784 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200785 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800786 goto discard_it;
787 }
788
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700789 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700790
Gerrit Renkerfde20102007-10-24 10:12:09 -0200791 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700792 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
793
794 dccp_pr_debug("%8.8s "
795 "src=%u.%u.%u.%u@%-5d "
796 "dst=%u.%u.%u.%u@%-5d seq=%llu",
797 dccp_packet_name(dh->dccph_type),
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700798 NIPQUAD(iph->saddr), ntohs(dh->dccph_sport),
799 NIPQUAD(iph->daddr), ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700800 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700801
802 if (dccp_packet_without_ack(skb)) {
803 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
804 dccp_pr_debug_cat("\n");
805 } else {
806 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200807 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700808 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700809 }
810
811 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200812 * Look up flow ID in table and get corresponding socket */
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700813 sk = __inet_lookup(dev_net(skb->dst->dev), &dccp_hashinfo,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700814 iph->saddr, dh->dccph_sport,
815 iph->daddr, dh->dccph_dport, inet_iif(skb));
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200816 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700817 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200818 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700819 */
820 if (sk == NULL) {
821 dccp_pr_debug("failed to look up flow ID in table and "
822 "get corresponding socket\n");
823 goto no_dccp_socket;
824 }
825
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 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700829 * Generate Reset(No Connection) unless P.type == Reset
830 * Drop packet and return
831 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700832 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200833 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
834 inet_twsk_put(inet_twsk(sk));
835 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700836 }
837
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200838 /*
839 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200840 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
841 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200842 */
843 min_cov = dccp_sk(sk)->dccps_pcrlen;
844 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
845 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
846 dh->dccph_cscov, min_cov);
847 /* FIXME: "Such packets SHOULD be reported using Data Dropped
848 * options (Section 11.7) with Drop Code 0, Protocol
849 * Constraints." */
850 goto discard_and_relse;
851 }
852
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200853 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700854 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800855 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700856
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200857 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700858
859no_dccp_socket:
860 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
861 goto discard_it;
862 /*
863 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200864 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700865 * Generate Reset(No Connection) unless P.type == Reset
866 * Drop packet and return
867 */
868 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300869 DCCP_SKB_CB(skb)->dccpd_reset_code =
870 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800871 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700872 }
873
874discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700875 kfree_skb(skb);
876 return 0;
877
878discard_and_relse:
879 sock_put(sk);
880 goto discard_it;
881}
882
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800883static struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800884 .queue_xmit = ip_queue_xmit,
885 .send_check = dccp_v4_send_check,
886 .rebuild_header = inet_sk_rebuild_header,
887 .conn_request = dccp_v4_conn_request,
888 .syn_recv_sock = dccp_v4_request_recv_sock,
889 .net_header_len = sizeof(struct iphdr),
890 .setsockopt = ip_setsockopt,
891 .getsockopt = ip_getsockopt,
892 .addr2sockaddr = inet_csk_addr2sockaddr,
893 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800894 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800895#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800896 .compat_setsockopt = compat_ip_setsockopt,
897 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800898#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800899};
900
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800901static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700902{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800903 static __u8 dccp_v4_ctl_sock_initialized;
904 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700905
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800906 if (err == 0) {
907 if (unlikely(!dccp_v4_ctl_sock_initialized))
908 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800909 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800910 }
911
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800912 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700913}
914
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800915static struct timewait_sock_ops dccp_timewait_sock_ops = {
916 .twsk_obj_size = sizeof(struct inet_timewait_sock),
917};
918
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800919static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700920 .name = "DCCP",
921 .owner = THIS_MODULE,
922 .close = dccp_close,
923 .connect = dccp_v4_connect,
924 .disconnect = dccp_disconnect,
925 .ioctl = dccp_ioctl,
926 .init = dccp_v4_init_sock,
927 .setsockopt = dccp_setsockopt,
928 .getsockopt = dccp_getsockopt,
929 .sendmsg = dccp_sendmsg,
930 .recvmsg = dccp_recvmsg,
931 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800932 .hash = inet_hash,
933 .unhash = inet_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700934 .accept = inet_csk_accept,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800935 .get_port = inet_csk_get_port,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700936 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800937 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700938 .orphan_count = &dccp_orphan_count,
939 .max_header = MAX_DCCP_HEADER,
940 .obj_size = sizeof(struct dccp_sock),
941 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800942 .twsk_prot = &dccp_timewait_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -0700943 .h.hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800944#ifdef CONFIG_COMPAT
945 .compat_setsockopt = compat_dccp_setsockopt,
946 .compat_getsockopt = compat_dccp_getsockopt,
947#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700948};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800949
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800950static struct net_protocol dccp_v4_protocol = {
951 .handler = dccp_v4_rcv,
952 .err_handler = dccp_v4_err,
953 .no_policy = 1,
Pavel Emelyanovfc5f8582008-04-13 22:31:05 -0700954 .netns_ok = 1,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800955};
956
957static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800958 .family = PF_INET,
959 .owner = THIS_MODULE,
960 .release = inet_release,
961 .bind = inet_bind,
962 .connect = inet_stream_connect,
963 .socketpair = sock_no_socketpair,
964 .accept = inet_accept,
965 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800966 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800967 .poll = dccp_poll,
968 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800969 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800970 .listen = inet_dccp_listen,
971 .shutdown = inet_shutdown,
972 .setsockopt = sock_common_setsockopt,
973 .getsockopt = sock_common_getsockopt,
974 .sendmsg = inet_sendmsg,
975 .recvmsg = sock_common_recvmsg,
976 .mmap = sock_no_mmap,
977 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800978#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800979 .compat_setsockopt = compat_sock_common_setsockopt,
980 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800981#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800982};
983
984static struct inet_protosw dccp_v4_protosw = {
985 .type = SOCK_DCCP,
986 .protocol = IPPROTO_DCCP,
987 .prot = &dccp_v4_prot,
988 .ops = &inet_dccp_ops,
989 .capability = -1,
990 .no_check = 0,
991 .flags = INET_PROTOSW_ICSK,
992};
993
Pavel Emelyanov72a2d612008-04-13 22:29:13 -0700994static int dccp_v4_init_net(struct net *net)
995{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -0700996 int err;
997
998 err = inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
999 SOCK_DCCP, IPPROTO_DCCP, net);
1000 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001001}
1002
1003static void dccp_v4_exit_net(struct net *net)
1004{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001005 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001006}
1007
1008static struct pernet_operations dccp_v4_ops = {
1009 .init = dccp_v4_init_net,
1010 .exit = dccp_v4_exit_net,
1011};
1012
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001013static int __init dccp_v4_init(void)
1014{
1015 int err = proto_register(&dccp_v4_prot, 1);
1016
1017 if (err != 0)
1018 goto out;
1019
1020 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1021 if (err != 0)
1022 goto out_proto_unregister;
1023
1024 inet_register_protosw(&dccp_v4_protosw);
1025
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001026 err = register_pernet_subsys(&dccp_v4_ops);
1027 if (err)
1028 goto out_destroy_ctl_sock;
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001029out:
1030 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001031out_destroy_ctl_sock:
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001032 inet_unregister_protosw(&dccp_v4_protosw);
1033 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1034out_proto_unregister:
1035 proto_unregister(&dccp_v4_prot);
1036 goto out;
1037}
1038
1039static void __exit dccp_v4_exit(void)
1040{
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001041 unregister_pernet_subsys(&dccp_v4_ops);
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);
1044 proto_unregister(&dccp_v4_prot);
1045}
1046
1047module_init(dccp_v4_init);
1048module_exit(dccp_v4_exit);
1049
1050/*
1051 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1052 * values directly, Also cover the case where the protocol is not specified,
1053 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1054 */
Jean Delvare7131c6c2007-10-21 16:45:03 -07001055MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1056MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001057MODULE_LICENSE("GPL");
1058MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1059MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");