blob: 474075adbde4d7c426fc960ef4079686cd185e2e [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/*
35 * This is the global socket data structure used for responding to
36 * the Out-of-the-blue (OOTB) packets. A control sock will be created
37 * for this socket at the initialization time.
38 */
39static struct socket *dccp_v4_ctl_socket;
40
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
66 tmp = ip_route_connect(&rt, nexthop, inet->saddr,
67 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
68 IPPROTO_DCCP,
David S. Miller8eb90862007-02-08 02:09:21 -080069 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
81 if (inet->saddr == 0)
82 inet->saddr = rt->rt_src;
83 inet->rcv_saddr = inet->saddr;
84
85 inet->dport = usin->sin_port;
86 inet->daddr = daddr;
87
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
Patrick McHardy5d39a792006-01-31 17:35:35 -0800102 err = ip_route_newports(&rt, IPPROTO_DCCP, inet->sport, inet->dport,
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900103 sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700104 if (err != 0)
105 goto failure;
106
107 /* OK, now commit destination to socket. */
108 sk_setup_caps(sk, &rt->u.dst);
109
Gerrit Renkerd7f73652006-11-13 13:34:38 -0200110 dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, inet->daddr,
111 inet->sport, inet->dport);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700112 inet->id = dp->dccps_iss ^ jiffies;
113
114 err = dccp_connect(sk);
115 rt = NULL;
116 if (err != 0)
117 goto failure;
118out:
119 return err;
120failure:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300121 /*
122 * This unhashes the socket and releases the local port, if necessary.
123 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700124 dccp_set_state(sk, DCCP_CLOSED);
125 ip_rt_put(rt);
126 sk->sk_route_caps = 0;
127 inet->dport = 0;
128 goto out;
129}
130
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800131EXPORT_SYMBOL_GPL(dccp_v4_connect);
132
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700133/*
134 * This routine does path mtu discovery as defined in RFC1191.
135 */
136static inline void dccp_do_pmtu_discovery(struct sock *sk,
137 const struct iphdr *iph,
138 u32 mtu)
139{
140 struct dst_entry *dst;
141 const struct inet_sock *inet = inet_sk(sk);
142 const struct dccp_sock *dp = dccp_sk(sk);
143
144 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
145 * send out by Linux are always < 576bytes so they should go through
146 * unfragmented).
147 */
148 if (sk->sk_state == DCCP_LISTEN)
149 return;
150
151 /* We don't check in the destentry if pmtu discovery is forbidden
152 * on this route. We just assume that no packet_to_big packets
153 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900154 * There is a small race when the user changes this flag in the
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700155 * route, but I think that's acceptable.
156 */
157 if ((dst = __sk_dst_check(sk, 0)) == NULL)
158 return;
159
160 dst->ops->update_pmtu(dst, mtu);
161
162 /* Something is about to be wrong... Remember soft error
163 * for the case, if this connection will not able to recover.
164 */
165 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
166 sk->sk_err_soft = EMSGSIZE;
167
168 mtu = dst_mtu(dst);
169
170 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800171 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700172 dccp_sync_mss(sk, mtu);
173
174 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700175 * From RFC 4340, sec. 14.1:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700176 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300177 * DCCP-Sync packets are the best choice for upward
178 * probing, since DCCP-Sync probes do not risk application
179 * data loss.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700180 */
Arnaldo Carvalho de Meloe92ae932005-08-17 03:10:59 -0300181 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700182 } /* else let the usual retransmit timer handle it */
183}
184
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700185/*
186 * This routine is called by the ICMP module when it gets some sort of error
187 * condition. If err < 0 then the socket should be closed and the error
188 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
189 * After adjustment header points to the first 8 bytes of the tcp header. We
190 * need to find the appropriate port.
191 *
192 * The locking strategy used here is very "optimistic". When someone else
193 * accesses the socket the ICMP is just dropped and for some paths there is no
194 * check at all. A more general error queue to queue errors for later handling
195 * is probably better.
196 */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800197static void dccp_v4_err(struct sk_buff *skb, u32 info)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700198{
199 const struct iphdr *iph = (struct iphdr *)skb->data;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300200 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
201 (iph->ihl << 2));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700202 struct dccp_sock *dp;
203 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300204 const int type = icmp_hdr(skb)->type;
205 const int code = icmp_hdr(skb)->code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700206 struct sock *sk;
207 __u64 seq;
208 int err;
209
210 if (skb->len < (iph->ihl << 2) + 8) {
211 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
212 return;
213 }
214
Pavel Emelyanovc67499c2008-01-31 05:06:40 -0800215 sk = inet_lookup(&init_net, &dccp_hashinfo, iph->daddr, dh->dccph_dport,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700216 iph->saddr, dh->dccph_sport, inet_iif(skb));
217 if (sk == NULL) {
218 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
219 return;
220 }
221
222 if (sk->sk_state == DCCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700223 inet_twsk_put(inet_twsk(sk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700224 return;
225 }
226
227 bh_lock_sock(sk);
228 /* If too many ICMPs get dropped on busy
229 * servers this needs to be solved differently.
230 */
231 if (sock_owned_by_user(sk))
232 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
233
234 if (sk->sk_state == DCCP_CLOSED)
235 goto out;
236
237 dp = dccp_sk(sk);
Gerrit Renkerfde20102007-10-24 10:12:09 -0200238 seq = dccp_hdr_seq(dh);
Gerrit Renker1238d082007-10-24 10:18:06 -0200239 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700240 !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
Arnaldo Carvalho de Meloe523a152006-11-16 12:23:58 -0200241 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700242 goto out;
243 }
244
245 switch (type) {
246 case ICMP_SOURCE_QUENCH:
247 /* Just silently ignore these. */
248 goto out;
249 case ICMP_PARAMETERPROB:
250 err = EPROTO;
251 break;
252 case ICMP_DEST_UNREACH:
253 if (code > NR_ICMP_UNREACH)
254 goto out;
255
256 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
257 if (!sock_owned_by_user(sk))
258 dccp_do_pmtu_discovery(sk, iph, info);
259 goto out;
260 }
261
262 err = icmp_err_convert[code].errno;
263 break;
264 case ICMP_TIME_EXCEEDED:
265 err = EHOSTUNREACH;
266 break;
267 default:
268 goto out;
269 }
270
271 switch (sk->sk_state) {
272 struct request_sock *req , **prev;
273 case DCCP_LISTEN:
274 if (sock_owned_by_user(sk))
275 goto out;
276 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
277 iph->daddr, iph->saddr);
278 if (!req)
279 goto out;
280
281 /*
282 * ICMPs are not backlogged, hence we cannot get an established
283 * socket here.
284 */
285 BUG_TRAP(!req->sk);
286
287 if (seq != dccp_rsk(req)->dreq_iss) {
288 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
289 goto out;
290 }
291 /*
292 * Still in RESPOND, just remove it silently.
293 * There is no good way to pass the error to the newly
294 * created socket, and POSIX does not want network
295 * errors returned from accept().
296 */
297 inet_csk_reqsk_queue_drop(sk, req, prev);
298 goto out;
299
300 case DCCP_REQUESTING:
301 case DCCP_RESPOND:
302 if (!sock_owned_by_user(sk)) {
303 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
304 sk->sk_err = err;
305
306 sk->sk_error_report(sk);
307
308 dccp_done(sk);
309 } else
310 sk->sk_err_soft = err;
311 goto out;
312 }
313
314 /* If we've already connected we will keep trying
315 * until we time out, or the user gives up.
316 *
317 * rfc1122 4.2.3.9 allows to consider as hard errors
318 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
319 * but it is obsoleted by pmtu discovery).
320 *
321 * Note, that in modern internet, where routing is unreliable
322 * and in each dark corner broken firewalls sit, sending random
323 * errors ordered by their masters even this two messages finally lose
324 * their original sense (even Linux sends invalid PORT_UNREACHs)
325 *
326 * Now we are in compliance with RFCs.
327 * --ANK (980905)
328 */
329
330 inet = inet_sk(sk);
331 if (!sock_owned_by_user(sk) && inet->recverr) {
332 sk->sk_err = err;
333 sk->sk_error_report(sk);
334 } else /* Only an error on timeout */
335 sk->sk_err_soft = err;
336out:
337 bh_unlock_sock(sk);
338 sock_put(sk);
339}
340
Al Viro2bda2852006-11-14 21:28:51 -0800341static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200342 __be32 src, __be32 dst)
343{
344 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
345}
346
347void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800348{
349 const struct inet_sock *inet = inet_sk(sk);
350 struct dccp_hdr *dh = dccp_hdr(skb);
351
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200352 dccp_csum_outgoing(skb);
353 dh->dccph_checksum = dccp_v4_csum_finish(skb, inet->saddr, inet->daddr);
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800354}
355
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800356EXPORT_SYMBOL_GPL(dccp_v4_send_check);
357
Gerrit Renker865e9022006-11-13 13:31:50 -0200358static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700359{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700360 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
361 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700362 dccp_hdr(skb)->dccph_dport,
363 dccp_hdr(skb)->dccph_sport);
364}
365
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700366/*
367 * The three way handshake has completed - we got a valid ACK or DATAACK -
368 * now create the new socket.
369 *
370 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
371 */
372struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
373 struct request_sock *req,
374 struct dst_entry *dst)
375{
376 struct inet_request_sock *ireq;
377 struct inet_sock *newinet;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700378 struct sock *newsk;
379
380 if (sk_acceptq_is_full(sk))
381 goto exit_overflow;
382
383 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
384 goto exit;
385
386 newsk = dccp_create_openreq_child(sk, req, skb);
387 if (newsk == NULL)
388 goto exit;
389
390 sk_setup_caps(newsk, dst);
391
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700392 newinet = inet_sk(newsk);
393 ireq = inet_rsk(req);
394 newinet->daddr = ireq->rmt_addr;
395 newinet->rcv_saddr = ireq->loc_addr;
396 newinet->saddr = ireq->loc_addr;
397 newinet->opt = ireq->opt;
398 ireq->opt = NULL;
399 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700400 newinet->mc_ttl = ip_hdr(skb)->ttl;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700401 newinet->id = jiffies;
402
403 dccp_sync_mss(newsk, dst_mtu(dst));
404
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800405 __inet_hash_nolisten(newsk);
406 __inet_inherit_port(sk, newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700407
408 return newsk;
409
410exit_overflow:
411 NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
412exit:
413 NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
414 dst_release(dst);
415 return NULL;
416}
417
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800418EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
419
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700420static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
421{
422 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700423 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700424 struct sock *nsk;
425 struct request_sock **prev;
426 /* Find possible connection requests. */
427 struct request_sock *req = inet_csk_search_req(sk, &prev,
428 dh->dccph_sport,
429 iph->saddr, iph->daddr);
430 if (req != NULL)
431 return dccp_check_req(sk, skb, req, prev);
432
Pavel Emelyanovc67499c2008-01-31 05:06:40 -0800433 nsk = inet_lookup_established(&init_net, &dccp_hashinfo,
Herbert Xu8f4910692006-08-09 15:47:12 -0700434 iph->saddr, dh->dccph_sport,
435 iph->daddr, dh->dccph_dport,
436 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700437 if (nsk != NULL) {
438 if (nsk->sk_state != DCCP_TIME_WAIT) {
439 bh_lock_sock(nsk);
440 return nsk;
441 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700442 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700443 return NULL;
444 }
445
446 return sk;
447}
448
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700449static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
450 struct sk_buff *skb)
451{
452 struct rtable *rt;
453 struct flowi fl = { .oif = ((struct rtable *)skb->dst)->rt_iif,
454 .nl_u = { .ip4_u =
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700455 { .daddr = ip_hdr(skb)->saddr,
456 .saddr = ip_hdr(skb)->daddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700457 .tos = RT_CONN_FLAGS(sk) } },
458 .proto = sk->sk_protocol,
459 .uli_u = { .ports =
460 { .sport = dccp_hdr(skb)->dccph_dport,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300461 .dport = dccp_hdr(skb)->dccph_sport }
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200462 }
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300463 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700464
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700465 security_skb_classify_flow(skb, &fl);
Denis V. Lunevf1b050b2008-01-22 22:07:10 -0800466 if (ip_route_output_flow(&init_net, &rt, &fl, sk, 0)) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700467 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
468 return NULL;
469 }
470
471 return &rt->u.dst;
472}
473
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200474static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
475 struct dst_entry *dst)
476{
477 int err = -1;
478 struct sk_buff *skb;
479
480 /* First, grab a route. */
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900481
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200482 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
483 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 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
493 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
494 ireq->rmt_addr,
495 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200496 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200497 }
498
499out:
500 dst_release(dst);
501 return err;
502}
503
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800504static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700505{
506 int err;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700507 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700508 struct sk_buff *skb;
509 struct dst_entry *dst;
510
511 /* Never send a reset in response to a reset. */
Gerrit Renkere356d372007-09-26 14:35:19 -0300512 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700513 return;
514
515 if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
516 return;
517
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800518 dst = dccp_v4_route_skb(dccp_v4_ctl_socket->sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700519 if (dst == NULL)
520 return;
521
Gerrit Renkere356d372007-09-26 14:35:19 -0300522 skb = dccp_ctl_make_reset(dccp_v4_ctl_socket, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700523 if (skb == NULL)
524 goto out;
525
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700526 rxiph = ip_hdr(rxskb);
Gerrit Renkere356d372007-09-26 14:35:19 -0300527 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
528 rxiph->daddr);
529 skb->dst = dst_clone(dst);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700530
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800531 bh_lock_sock(dccp_v4_ctl_socket->sk);
532 err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700533 rxiph->daddr, rxiph->saddr, NULL);
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800534 bh_unlock_sock(dccp_v4_ctl_socket->sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700535
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200536 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700537 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
538 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
539 }
540out:
541 dst_release(dst);
542}
543
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200544static void dccp_v4_reqsk_destructor(struct request_sock *req)
545{
546 kfree(inet_rsk(req)->opt);
547}
548
549static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
550 .family = PF_INET,
551 .obj_size = sizeof(struct dccp_request_sock),
552 .rtx_syn_ack = dccp_v4_send_response,
553 .send_ack = dccp_reqsk_send_ack,
554 .destructor = dccp_v4_reqsk_destructor,
555 .send_reset = dccp_v4_ctl_send_reset,
556};
557
558int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
559{
560 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200561 struct request_sock *req;
562 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200563 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200564 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200565
566 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
567 if (((struct rtable *)skb->dst)->rt_flags &
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700568 (RTCF_BROADCAST | RTCF_MULTICAST))
569 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
593 req = reqsk_alloc(&dccp_request_sock_ops);
594 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 ireq->opt = NULL;
610
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200611 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200612 * Step 3: Process LISTEN state
613 *
614 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
615 *
616 * In fact we defer setting S.GSR, S.SWL, S.SWH to
617 * dccp_create_openreq_child.
618 */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200619 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200620 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200621 dreq->dreq_service = service;
622
623 if (dccp_v4_send_response(sk, req, NULL))
624 goto drop_and_free;
625
626 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
627 return 0;
628
629drop_and_free:
630 reqsk_free(req);
631drop:
632 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200633 return -1;
634}
635
636EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
637
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700638int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
639{
640 struct dccp_hdr *dh = dccp_hdr(skb);
641
642 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
643 if (dccp_rcv_established(sk, skb, dh, skb->len))
644 goto reset;
645 return 0;
646 }
647
648 /*
649 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200650 * If P.type == Request or P contains a valid Init Cookie option,
651 * (* Must scan the packet's options to check for Init
652 * Cookies. Only Init Cookies are processed here,
653 * however; other options are processed in Step 8. This
654 * scan need only be performed if the endpoint uses Init
655 * Cookies *)
656 * (* Generate a new socket and switch to that socket *)
657 * Set S := new socket for this port pair
658 * S.state = RESPOND
659 * Choose S.ISS (initial seqno) or set from Init Cookies
660 * Initialize S.GAR := S.ISS
661 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
662 * Continue with S.state == RESPOND
663 * (* A Response packet will be generated in Step 11 *)
664 * Otherwise,
665 * Generate Reset(No Connection) unless P.type == Reset
666 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700667 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300668 * NOTE: the check for the packet types is done in
669 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700670 */
671 if (sk->sk_state == DCCP_LISTEN) {
672 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
673
674 if (nsk == NULL)
675 goto discard;
676
677 if (nsk != sk) {
678 if (dccp_child_process(sk, nsk, skb))
679 goto reset;
680 return 0;
681 }
682 }
683
684 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
685 goto reset;
686 return 0;
687
688reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800689 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700690discard:
691 kfree_skb(skb);
692 return 0;
693}
694
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800695EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
696
Gerrit Renker09dbc382006-11-14 12:57:34 -0200697/**
698 * dccp_invalid_packet - check for malformed packets
699 * Implements RFC 4340, 8.5: Step 1: Check header basics
700 * Packets that fail these checks are ignored and do not receive Resets.
701 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800702int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700703{
704 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200705 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700706
707 if (skb->pkt_type != PACKET_HOST)
708 return 1;
709
Gerrit Renker09dbc382006-11-14 12:57:34 -0200710 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700711 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200712 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700713 return 1;
714 }
715
716 dh = dccp_hdr(skb);
717
Gerrit Renker09dbc382006-11-14 12:57:34 -0200718 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700719 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200720 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700721 return 1;
722 }
723
724 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200725 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700726 */
727 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200728 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700729 return 1;
730 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200731 /*
732 * If P.Data Offset is too too large for packet, drop packet and return
733 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700734 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200735 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700736 return 1;
737 }
738
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700739 /*
740 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
741 * has short sequence numbers), drop packet and return
742 */
Gerrit Renker09dbc382006-11-14 12:57:34 -0200743 if (dh->dccph_type >= DCCP_PKT_DATA &&
744 dh->dccph_type <= DCCP_PKT_DATAACK && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200745 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
746 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700747 return 1;
748 }
749
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200750 /*
751 * If P.CsCov is too large for the packet size, drop packet and return.
752 * This must come _before_ checksumming (not as RFC 4340 suggests).
753 */
754 cscov = dccp_csum_coverage(skb);
755 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200756 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
757 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200758 return 1;
759 }
760
761 /* If header checksum is incorrect, drop packet and return.
762 * (This step is completed in the AF-dependent functions.) */
763 skb->csum = skb_checksum(skb, 0, cscov, 0);
764
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700765 return 0;
766}
767
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800768EXPORT_SYMBOL_GPL(dccp_invalid_packet);
769
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700770/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800771static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700772{
773 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700774 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700775 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200776 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700777
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200778 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700779
780 if (dccp_invalid_packet(skb))
781 goto discard_it;
782
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700783 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200784 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700785 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200786 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800787 goto discard_it;
788 }
789
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700790 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700791
Gerrit Renkerfde20102007-10-24 10:12:09 -0200792 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700793 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
794
795 dccp_pr_debug("%8.8s "
796 "src=%u.%u.%u.%u@%-5d "
797 "dst=%u.%u.%u.%u@%-5d seq=%llu",
798 dccp_packet_name(dh->dccph_type),
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700799 NIPQUAD(iph->saddr), ntohs(dh->dccph_sport),
800 NIPQUAD(iph->daddr), ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700801 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700802
803 if (dccp_packet_without_ack(skb)) {
804 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
805 dccp_pr_debug_cat("\n");
806 } else {
807 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200808 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700809 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700810 }
811
812 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200813 * Look up flow ID in table and get corresponding socket */
Pavel Emelyanovc67499c2008-01-31 05:06:40 -0800814 sk = __inet_lookup(&init_net, &dccp_hashinfo,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700815 iph->saddr, dh->dccph_sport,
816 iph->daddr, dh->dccph_dport, inet_iif(skb));
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200817 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700818 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200819 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700820 */
821 if (sk == NULL) {
822 dccp_pr_debug("failed to look up flow ID in table and "
823 "get corresponding socket\n");
824 goto no_dccp_socket;
825 }
826
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200827 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700828 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200829 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700830 * Generate Reset(No Connection) unless P.type == Reset
831 * Drop packet and return
832 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700833 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200834 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
835 inet_twsk_put(inet_twsk(sk));
836 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700837 }
838
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200839 /*
840 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200841 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
842 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200843 */
844 min_cov = dccp_sk(sk)->dccps_pcrlen;
845 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
846 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
847 dh->dccph_cscov, min_cov);
848 /* FIXME: "Such packets SHOULD be reported using Data Dropped
849 * options (Section 11.7) with Drop Code 0, Protocol
850 * Constraints." */
851 goto discard_and_relse;
852 }
853
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200854 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700855 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800856 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700857
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200858 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700859
860no_dccp_socket:
861 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
862 goto discard_it;
863 /*
864 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200865 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700866 * Generate Reset(No Connection) unless P.type == Reset
867 * Drop packet and return
868 */
869 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300870 DCCP_SKB_CB(skb)->dccpd_reset_code =
871 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800872 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700873 }
874
875discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700876 kfree_skb(skb);
877 return 0;
878
879discard_and_relse:
880 sock_put(sk);
881 goto discard_it;
882}
883
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800884static struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800885 .queue_xmit = ip_queue_xmit,
886 .send_check = dccp_v4_send_check,
887 .rebuild_header = inet_sk_rebuild_header,
888 .conn_request = dccp_v4_conn_request,
889 .syn_recv_sock = dccp_v4_request_recv_sock,
890 .net_header_len = sizeof(struct iphdr),
891 .setsockopt = ip_setsockopt,
892 .getsockopt = ip_getsockopt,
893 .addr2sockaddr = inet_csk_addr2sockaddr,
894 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800895 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800896#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800897 .compat_setsockopt = compat_ip_setsockopt,
898 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800899#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800900};
901
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800902static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700903{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800904 static __u8 dccp_v4_ctl_sock_initialized;
905 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700906
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800907 if (err == 0) {
908 if (unlikely(!dccp_v4_ctl_sock_initialized))
909 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800910 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800911 }
912
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800913 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700914}
915
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800916static struct timewait_sock_ops dccp_timewait_sock_ops = {
917 .twsk_obj_size = sizeof(struct inet_timewait_sock),
918};
919
David S. Millerc62cf5c2007-11-05 23:42:25 -0800920DEFINE_PROTO_INUSE(dccp_v4)
921
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800922static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700923 .name = "DCCP",
924 .owner = THIS_MODULE,
925 .close = dccp_close,
926 .connect = dccp_v4_connect,
927 .disconnect = dccp_disconnect,
928 .ioctl = dccp_ioctl,
929 .init = dccp_v4_init_sock,
930 .setsockopt = dccp_setsockopt,
931 .getsockopt = dccp_getsockopt,
932 .sendmsg = dccp_sendmsg,
933 .recvmsg = dccp_recvmsg,
934 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800935 .hash = inet_hash,
936 .unhash = inet_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700937 .accept = inet_csk_accept,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800938 .get_port = inet_csk_get_port,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700939 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800940 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700941 .orphan_count = &dccp_orphan_count,
942 .max_header = MAX_DCCP_HEADER,
943 .obj_size = sizeof(struct dccp_sock),
944 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800945 .twsk_prot = &dccp_timewait_sock_ops,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800946 .hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800947#ifdef CONFIG_COMPAT
948 .compat_setsockopt = compat_dccp_setsockopt,
949 .compat_getsockopt = compat_dccp_getsockopt,
950#endif
David S. Millerc62cf5c2007-11-05 23:42:25 -0800951 REF_PROTO_INUSE(dccp_v4)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700952};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800953
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800954static struct net_protocol dccp_v4_protocol = {
955 .handler = dccp_v4_rcv,
956 .err_handler = dccp_v4_err,
957 .no_policy = 1,
958};
959
960static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800961 .family = PF_INET,
962 .owner = THIS_MODULE,
963 .release = inet_release,
964 .bind = inet_bind,
965 .connect = inet_stream_connect,
966 .socketpair = sock_no_socketpair,
967 .accept = inet_accept,
968 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800969 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800970 .poll = dccp_poll,
971 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800972 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800973 .listen = inet_dccp_listen,
974 .shutdown = inet_shutdown,
975 .setsockopt = sock_common_setsockopt,
976 .getsockopt = sock_common_getsockopt,
977 .sendmsg = inet_sendmsg,
978 .recvmsg = sock_common_recvmsg,
979 .mmap = sock_no_mmap,
980 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800981#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800982 .compat_setsockopt = compat_sock_common_setsockopt,
983 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800984#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800985};
986
987static struct inet_protosw dccp_v4_protosw = {
988 .type = SOCK_DCCP,
989 .protocol = IPPROTO_DCCP,
990 .prot = &dccp_v4_prot,
991 .ops = &inet_dccp_ops,
992 .capability = -1,
993 .no_check = 0,
994 .flags = INET_PROTOSW_ICSK,
995};
996
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800997static int __init dccp_v4_init(void)
998{
999 int err = proto_register(&dccp_v4_prot, 1);
1000
1001 if (err != 0)
1002 goto out;
1003
1004 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1005 if (err != 0)
1006 goto out_proto_unregister;
1007
1008 inet_register_protosw(&dccp_v4_protosw);
1009
Arnaldo Carvalho de Meloc4d93902006-03-20 22:01:03 -08001010 err = inet_csk_ctl_sock_create(&dccp_v4_ctl_socket, PF_INET,
1011 SOCK_DCCP, IPPROTO_DCCP);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001012 if (err)
1013 goto out_unregister_protosw;
1014out:
1015 return err;
1016out_unregister_protosw:
1017 inet_unregister_protosw(&dccp_v4_protosw);
1018 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1019out_proto_unregister:
1020 proto_unregister(&dccp_v4_prot);
1021 goto out;
1022}
1023
1024static void __exit dccp_v4_exit(void)
1025{
1026 inet_unregister_protosw(&dccp_v4_protosw);
1027 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1028 proto_unregister(&dccp_v4_prot);
1029}
1030
1031module_init(dccp_v4_init);
1032module_exit(dccp_v4_exit);
1033
1034/*
1035 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1036 * values directly, Also cover the case where the protocol is not specified,
1037 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1038 */
Jean Delvare7131c6c2007-10-21 16:45:03 -07001039MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1040MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001041MODULE_LICENSE("GPL");
1042MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1043MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");