blob: 718f2fa923a10621b5ab3f107653a27125e0db15 [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 Melo7c657872005-08-09 20:14:34 -070041static int dccp_v4_get_port(struct sock *sk, const unsigned short snum)
42{
Arnaldo Carvalho de Melo971af182005-12-13 23:14:47 -080043 return inet_csk_get_port(&dccp_hashinfo, sk, snum,
44 inet_csk_bind_conflict);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070045}
46
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080047int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070048{
49 struct inet_sock *inet = inet_sk(sk);
50 struct dccp_sock *dp = dccp_sk(sk);
51 const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
52 struct rtable *rt;
Al Virobada8ad2006-09-26 21:27:15 -070053 __be32 daddr, nexthop;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070054 int tmp;
55 int err;
56
57 dp->dccps_role = DCCP_ROLE_CLIENT;
58
59 if (addr_len < sizeof(struct sockaddr_in))
60 return -EINVAL;
61
62 if (usin->sin_family != AF_INET)
63 return -EAFNOSUPPORT;
64
65 nexthop = daddr = usin->sin_addr.s_addr;
66 if (inet->opt != NULL && inet->opt->srr) {
67 if (daddr == 0)
68 return -EINVAL;
69 nexthop = inet->opt->faddr;
70 }
71
72 tmp = ip_route_connect(&rt, nexthop, inet->saddr,
73 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
74 IPPROTO_DCCP,
David S. Miller8eb90862007-02-08 02:09:21 -080075 inet->sport, usin->sin_port, sk, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070076 if (tmp < 0)
77 return tmp;
78
79 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
80 ip_rt_put(rt);
81 return -ENETUNREACH;
82 }
83
84 if (inet->opt == NULL || !inet->opt->srr)
85 daddr = rt->rt_dst;
86
87 if (inet->saddr == 0)
88 inet->saddr = rt->rt_src;
89 inet->rcv_saddr = inet->saddr;
90
91 inet->dport = usin->sin_port;
92 inet->daddr = daddr;
93
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080094 inet_csk(sk)->icsk_ext_hdr_len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070095 if (inet->opt != NULL)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080096 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070097 /*
98 * Socket identity is still unknown (sport may be zero).
99 * However we set state to DCCP_REQUESTING and not releasing socket
100 * lock select source port, enter ourselves into the hash tables and
101 * complete initialization after this.
102 */
103 dccp_set_state(sk, DCCP_REQUESTING);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -0800104 err = inet_hash_connect(&dccp_death_row, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700105 if (err != 0)
106 goto failure;
107
Patrick McHardy5d39a792006-01-31 17:35:35 -0800108 err = ip_route_newports(&rt, IPPROTO_DCCP, inet->sport, inet->dport,
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900109 sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700110 if (err != 0)
111 goto failure;
112
113 /* OK, now commit destination to socket. */
114 sk_setup_caps(sk, &rt->u.dst);
115
Gerrit Renkerd7f73652006-11-13 13:34:38 -0200116 dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, inet->daddr,
117 inet->sport, inet->dport);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700118 inet->id = dp->dccps_iss ^ jiffies;
119
120 err = dccp_connect(sk);
121 rt = NULL;
122 if (err != 0)
123 goto failure;
124out:
125 return err;
126failure:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300127 /*
128 * This unhashes the socket and releases the local port, if necessary.
129 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700130 dccp_set_state(sk, DCCP_CLOSED);
131 ip_rt_put(rt);
132 sk->sk_route_caps = 0;
133 inet->dport = 0;
134 goto out;
135}
136
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800137EXPORT_SYMBOL_GPL(dccp_v4_connect);
138
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700139/*
140 * This routine does path mtu discovery as defined in RFC1191.
141 */
142static inline void dccp_do_pmtu_discovery(struct sock *sk,
143 const struct iphdr *iph,
144 u32 mtu)
145{
146 struct dst_entry *dst;
147 const struct inet_sock *inet = inet_sk(sk);
148 const struct dccp_sock *dp = dccp_sk(sk);
149
150 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
151 * send out by Linux are always < 576bytes so they should go through
152 * unfragmented).
153 */
154 if (sk->sk_state == DCCP_LISTEN)
155 return;
156
157 /* We don't check in the destentry if pmtu discovery is forbidden
158 * on this route. We just assume that no packet_to_big packets
159 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900160 * There is a small race when the user changes this flag in the
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700161 * route, but I think that's acceptable.
162 */
163 if ((dst = __sk_dst_check(sk, 0)) == NULL)
164 return;
165
166 dst->ops->update_pmtu(dst, mtu);
167
168 /* Something is about to be wrong... Remember soft error
169 * for the case, if this connection will not able to recover.
170 */
171 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
172 sk->sk_err_soft = EMSGSIZE;
173
174 mtu = dst_mtu(dst);
175
176 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800177 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700178 dccp_sync_mss(sk, mtu);
179
180 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700181 * From RFC 4340, sec. 14.1:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700182 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300183 * DCCP-Sync packets are the best choice for upward
184 * probing, since DCCP-Sync probes do not risk application
185 * data loss.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700186 */
Arnaldo Carvalho de Meloe92ae932005-08-17 03:10:59 -0300187 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700188 } /* else let the usual retransmit timer handle it */
189}
190
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700191/*
192 * This routine is called by the ICMP module when it gets some sort of error
193 * condition. If err < 0 then the socket should be closed and the error
194 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
195 * After adjustment header points to the first 8 bytes of the tcp header. We
196 * need to find the appropriate port.
197 *
198 * The locking strategy used here is very "optimistic". When someone else
199 * accesses the socket the ICMP is just dropped and for some paths there is no
200 * check at all. A more general error queue to queue errors for later handling
201 * is probably better.
202 */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800203static void dccp_v4_err(struct sk_buff *skb, u32 info)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700204{
205 const struct iphdr *iph = (struct iphdr *)skb->data;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300206 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
207 (iph->ihl << 2));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700208 struct dccp_sock *dp;
209 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300210 const int type = icmp_hdr(skb)->type;
211 const int code = icmp_hdr(skb)->code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700212 struct sock *sk;
213 __u64 seq;
214 int err;
215
216 if (skb->len < (iph->ihl << 2) + 8) {
217 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
218 return;
219 }
220
221 sk = inet_lookup(&dccp_hashinfo, iph->daddr, dh->dccph_dport,
222 iph->saddr, dh->dccph_sport, inet_iif(skb));
223 if (sk == NULL) {
224 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
225 return;
226 }
227
228 if (sk->sk_state == DCCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700229 inet_twsk_put(inet_twsk(sk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700230 return;
231 }
232
233 bh_lock_sock(sk);
234 /* If too many ICMPs get dropped on busy
235 * servers this needs to be solved differently.
236 */
237 if (sock_owned_by_user(sk))
238 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
239
240 if (sk->sk_state == DCCP_CLOSED)
241 goto out;
242
243 dp = dccp_sk(sk);
244 seq = dccp_hdr_seq(skb);
245 if (sk->sk_state != DCCP_LISTEN &&
246 !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
Arnaldo Carvalho de Meloe523a152006-11-16 12:23:58 -0200247 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700248 goto out;
249 }
250
251 switch (type) {
252 case ICMP_SOURCE_QUENCH:
253 /* Just silently ignore these. */
254 goto out;
255 case ICMP_PARAMETERPROB:
256 err = EPROTO;
257 break;
258 case ICMP_DEST_UNREACH:
259 if (code > NR_ICMP_UNREACH)
260 goto out;
261
262 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
263 if (!sock_owned_by_user(sk))
264 dccp_do_pmtu_discovery(sk, iph, info);
265 goto out;
266 }
267
268 err = icmp_err_convert[code].errno;
269 break;
270 case ICMP_TIME_EXCEEDED:
271 err = EHOSTUNREACH;
272 break;
273 default:
274 goto out;
275 }
276
277 switch (sk->sk_state) {
278 struct request_sock *req , **prev;
279 case DCCP_LISTEN:
280 if (sock_owned_by_user(sk))
281 goto out;
282 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
283 iph->daddr, iph->saddr);
284 if (!req)
285 goto out;
286
287 /*
288 * ICMPs are not backlogged, hence we cannot get an established
289 * socket here.
290 */
291 BUG_TRAP(!req->sk);
292
293 if (seq != dccp_rsk(req)->dreq_iss) {
294 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
295 goto out;
296 }
297 /*
298 * Still in RESPOND, just remove it silently.
299 * There is no good way to pass the error to the newly
300 * created socket, and POSIX does not want network
301 * errors returned from accept().
302 */
303 inet_csk_reqsk_queue_drop(sk, req, prev);
304 goto out;
305
306 case DCCP_REQUESTING:
307 case DCCP_RESPOND:
308 if (!sock_owned_by_user(sk)) {
309 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
310 sk->sk_err = err;
311
312 sk->sk_error_report(sk);
313
314 dccp_done(sk);
315 } else
316 sk->sk_err_soft = err;
317 goto out;
318 }
319
320 /* If we've already connected we will keep trying
321 * until we time out, or the user gives up.
322 *
323 * rfc1122 4.2.3.9 allows to consider as hard errors
324 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
325 * but it is obsoleted by pmtu discovery).
326 *
327 * Note, that in modern internet, where routing is unreliable
328 * and in each dark corner broken firewalls sit, sending random
329 * errors ordered by their masters even this two messages finally lose
330 * their original sense (even Linux sends invalid PORT_UNREACHs)
331 *
332 * Now we are in compliance with RFCs.
333 * --ANK (980905)
334 */
335
336 inet = inet_sk(sk);
337 if (!sock_owned_by_user(sk) && inet->recverr) {
338 sk->sk_err = err;
339 sk->sk_error_report(sk);
340 } else /* Only an error on timeout */
341 sk->sk_err_soft = err;
342out:
343 bh_unlock_sock(sk);
344 sock_put(sk);
345}
346
Al Viro2bda2852006-11-14 21:28:51 -0800347static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200348 __be32 src, __be32 dst)
349{
350 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
351}
352
353void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800354{
355 const struct inet_sock *inet = inet_sk(sk);
356 struct dccp_hdr *dh = dccp_hdr(skb);
357
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200358 dccp_csum_outgoing(skb);
359 dh->dccph_checksum = dccp_v4_csum_finish(skb, inet->saddr, inet->daddr);
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800360}
361
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800362EXPORT_SYMBOL_GPL(dccp_v4_send_check);
363
Gerrit Renker865e9022006-11-13 13:31:50 -0200364static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700365{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700366 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
367 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700368 dccp_hdr(skb)->dccph_dport,
369 dccp_hdr(skb)->dccph_sport);
370}
371
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700372/*
373 * The three way handshake has completed - we got a valid ACK or DATAACK -
374 * now create the new socket.
375 *
376 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
377 */
378struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
379 struct request_sock *req,
380 struct dst_entry *dst)
381{
382 struct inet_request_sock *ireq;
383 struct inet_sock *newinet;
384 struct dccp_sock *newdp;
385 struct sock *newsk;
386
387 if (sk_acceptq_is_full(sk))
388 goto exit_overflow;
389
390 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
391 goto exit;
392
393 newsk = dccp_create_openreq_child(sk, req, skb);
394 if (newsk == NULL)
395 goto exit;
396
397 sk_setup_caps(newsk, dst);
398
399 newdp = dccp_sk(newsk);
400 newinet = inet_sk(newsk);
401 ireq = inet_rsk(req);
402 newinet->daddr = ireq->rmt_addr;
403 newinet->rcv_saddr = ireq->loc_addr;
404 newinet->saddr = ireq->loc_addr;
405 newinet->opt = ireq->opt;
406 ireq->opt = NULL;
407 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700408 newinet->mc_ttl = ip_hdr(skb)->ttl;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700409 newinet->id = jiffies;
410
411 dccp_sync_mss(newsk, dst_mtu(dst));
412
413 __inet_hash(&dccp_hashinfo, newsk, 0);
414 __inet_inherit_port(&dccp_hashinfo, sk, newsk);
415
416 return newsk;
417
418exit_overflow:
419 NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
420exit:
421 NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
422 dst_release(dst);
423 return NULL;
424}
425
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800426EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
427
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700428static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
429{
430 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700431 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700432 struct sock *nsk;
433 struct request_sock **prev;
434 /* Find possible connection requests. */
435 struct request_sock *req = inet_csk_search_req(sk, &prev,
436 dh->dccph_sport,
437 iph->saddr, iph->daddr);
438 if (req != NULL)
439 return dccp_check_req(sk, skb, req, prev);
440
Herbert Xu8f4910692006-08-09 15:47:12 -0700441 nsk = inet_lookup_established(&dccp_hashinfo,
442 iph->saddr, dh->dccph_sport,
443 iph->daddr, dh->dccph_dport,
444 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700445 if (nsk != NULL) {
446 if (nsk->sk_state != DCCP_TIME_WAIT) {
447 bh_lock_sock(nsk);
448 return nsk;
449 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700450 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700451 return NULL;
452 }
453
454 return sk;
455}
456
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700457static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
458 struct sk_buff *skb)
459{
460 struct rtable *rt;
461 struct flowi fl = { .oif = ((struct rtable *)skb->dst)->rt_iif,
462 .nl_u = { .ip4_u =
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700463 { .daddr = ip_hdr(skb)->saddr,
464 .saddr = ip_hdr(skb)->daddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700465 .tos = RT_CONN_FLAGS(sk) } },
466 .proto = sk->sk_protocol,
467 .uli_u = { .ports =
468 { .sport = dccp_hdr(skb)->dccph_dport,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300469 .dport = dccp_hdr(skb)->dccph_sport }
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200470 }
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300471 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700472
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700473 security_skb_classify_flow(skb, &fl);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700474 if (ip_route_output_flow(&rt, &fl, sk, 0)) {
475 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
476 return NULL;
477 }
478
479 return &rt->u.dst;
480}
481
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200482static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
483 struct dst_entry *dst)
484{
485 int err = -1;
486 struct sk_buff *skb;
487
488 /* First, grab a route. */
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900489
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200490 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
491 goto out;
492
493 skb = dccp_make_response(sk, dst, req);
494 if (skb != NULL) {
495 const struct inet_request_sock *ireq = inet_rsk(req);
496 struct dccp_hdr *dh = dccp_hdr(skb);
497
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200498 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
499 ireq->rmt_addr);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200500 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
501 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
502 ireq->rmt_addr,
503 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200504 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200505 }
506
507out:
508 dst_release(dst);
509 return err;
510}
511
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800512static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700513{
514 int err;
515 struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700516 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700517 const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
518 sizeof(struct dccp_hdr_ext) +
519 sizeof(struct dccp_hdr_reset);
520 struct sk_buff *skb;
521 struct dst_entry *dst;
Gerrit Renker09dbc382006-11-14 12:57:34 -0200522 u64 seqno = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700523
524 /* Never send a reset in response to a reset. */
525 if (rxdh->dccph_type == DCCP_PKT_RESET)
526 return;
527
528 if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
529 return;
530
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800531 dst = dccp_v4_route_skb(dccp_v4_ctl_socket->sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700532 if (dst == NULL)
533 return;
534
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800535 skb = alloc_skb(dccp_v4_ctl_socket->sk->sk_prot->max_header,
536 GFP_ATOMIC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700537 if (skb == NULL)
538 goto out;
539
540 /* Reserve space for headers. */
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800541 skb_reserve(skb, dccp_v4_ctl_socket->sk->sk_prot->max_header);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700542 skb->dst = dst_clone(dst);
543
Gerrit Renker9b420782006-11-10 11:22:32 -0200544 dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700545
546 /* Build DCCP header and checksum it. */
547 dh->dccph_type = DCCP_PKT_RESET;
548 dh->dccph_sport = rxdh->dccph_dport;
549 dh->dccph_dport = rxdh->dccph_sport;
550 dh->dccph_doff = dccp_hdr_reset_len / 4;
551 dh->dccph_x = 1;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300552 dccp_hdr_reset(skb)->dccph_reset_code =
553 DCCP_SKB_CB(rxskb)->dccpd_reset_code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700554
Gerrit Renker0e64e942006-10-24 16:17:51 -0700555 /* See "8.3.1. Abnormal Termination" in RFC 4340 */
Arnaldo Carvalho de Melo2807d4f2005-08-21 05:33:48 -0300556 if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
557 dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
558
559 dccp_hdr_set_seq(dh, seqno);
Gerrit Renker09dbc382006-11-14 12:57:34 -0200560 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700561
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200562 dccp_csum_outgoing(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700563 rxiph = ip_hdr(rxskb);
564 dh->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
565 rxiph->daddr);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700566
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800567 bh_lock_sock(dccp_v4_ctl_socket->sk);
568 err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700569 rxiph->daddr, rxiph->saddr, NULL);
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800570 bh_unlock_sock(dccp_v4_ctl_socket->sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700571
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200572 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700573 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
574 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
575 }
576out:
577 dst_release(dst);
578}
579
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200580static void dccp_v4_reqsk_destructor(struct request_sock *req)
581{
582 kfree(inet_rsk(req)->opt);
583}
584
585static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
586 .family = PF_INET,
587 .obj_size = sizeof(struct dccp_request_sock),
588 .rtx_syn_ack = dccp_v4_send_response,
589 .send_ack = dccp_reqsk_send_ack,
590 .destructor = dccp_v4_reqsk_destructor,
591 .send_reset = dccp_v4_ctl_send_reset,
592};
593
594int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
595{
596 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200597 struct request_sock *req;
598 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200599 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200600 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
601 __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
602
603 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
604 if (((struct rtable *)skb->dst)->rt_flags &
605 (RTCF_BROADCAST | RTCF_MULTICAST)) {
606 reset_code = DCCP_RESET_CODE_NO_CONNECTION;
607 goto drop;
608 }
609
610 if (dccp_bad_service_code(sk, service)) {
611 reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
612 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200613 }
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200614 /*
615 * TW buckets are converted to open requests without
616 * limitations, they conserve resources and peer is
617 * evidently real one.
618 */
619 if (inet_csk_reqsk_queue_is_full(sk))
620 goto drop;
621
622 /*
623 * Accept backlog is full. If we have already queued enough
624 * of warm entries in syn queue, drop request. It is better than
625 * clogging syn queue with openreqs with exponentially increasing
626 * timeout.
627 */
628 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
629 goto drop;
630
631 req = reqsk_alloc(&dccp_request_sock_ops);
632 if (req == NULL)
633 goto drop;
634
635 if (dccp_parse_options(sk, skb))
636 goto drop_and_free;
637
Gerrit Renkercf557922006-11-10 16:08:37 -0200638 dccp_reqsk_init(req, skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200639
640 if (security_inet_conn_request(sk, skb, req))
641 goto drop_and_free;
642
643 ireq = inet_rsk(req);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700644 ireq->loc_addr = ip_hdr(skb)->daddr;
645 ireq->rmt_addr = ip_hdr(skb)->saddr;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200646 ireq->opt = NULL;
647
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200648 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200649 * Step 3: Process LISTEN state
650 *
651 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
652 *
653 * In fact we defer setting S.GSR, S.SWL, S.SWH to
654 * dccp_create_openreq_child.
655 */
656 dreq = dccp_rsk(req);
657 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200658 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200659 dreq->dreq_service = service;
660
661 if (dccp_v4_send_response(sk, req, NULL))
662 goto drop_and_free;
663
664 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
665 return 0;
666
667drop_and_free:
668 reqsk_free(req);
669drop:
670 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
671 dcb->dccpd_reset_code = reset_code;
672 return -1;
673}
674
675EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
676
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700677int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
678{
679 struct dccp_hdr *dh = dccp_hdr(skb);
680
681 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
682 if (dccp_rcv_established(sk, skb, dh, skb->len))
683 goto reset;
684 return 0;
685 }
686
687 /*
688 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200689 * If P.type == Request or P contains a valid Init Cookie option,
690 * (* Must scan the packet's options to check for Init
691 * Cookies. Only Init Cookies are processed here,
692 * however; other options are processed in Step 8. This
693 * scan need only be performed if the endpoint uses Init
694 * Cookies *)
695 * (* Generate a new socket and switch to that socket *)
696 * Set S := new socket for this port pair
697 * S.state = RESPOND
698 * Choose S.ISS (initial seqno) or set from Init Cookies
699 * Initialize S.GAR := S.ISS
700 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
701 * Continue with S.state == RESPOND
702 * (* A Response packet will be generated in Step 11 *)
703 * Otherwise,
704 * Generate Reset(No Connection) unless P.type == Reset
705 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700706 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300707 * NOTE: the check for the packet types is done in
708 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700709 */
710 if (sk->sk_state == DCCP_LISTEN) {
711 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
712
713 if (nsk == NULL)
714 goto discard;
715
716 if (nsk != sk) {
717 if (dccp_child_process(sk, nsk, skb))
718 goto reset;
719 return 0;
720 }
721 }
722
723 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
724 goto reset;
725 return 0;
726
727reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800728 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700729discard:
730 kfree_skb(skb);
731 return 0;
732}
733
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800734EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
735
Gerrit Renker09dbc382006-11-14 12:57:34 -0200736/**
737 * dccp_invalid_packet - check for malformed packets
738 * Implements RFC 4340, 8.5: Step 1: Check header basics
739 * Packets that fail these checks are ignored and do not receive Resets.
740 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800741int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700742{
743 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200744 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700745
746 if (skb->pkt_type != PACKET_HOST)
747 return 1;
748
Gerrit Renker09dbc382006-11-14 12:57:34 -0200749 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700750 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200751 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700752 return 1;
753 }
754
755 dh = dccp_hdr(skb);
756
Gerrit Renker09dbc382006-11-14 12:57:34 -0200757 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700758 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200759 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700760 return 1;
761 }
762
763 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200764 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700765 */
766 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200767 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700768 return 1;
769 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200770 /*
771 * If P.Data Offset is too too large for packet, drop packet and return
772 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700773 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200774 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700775 return 1;
776 }
777
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700778 /*
779 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
780 * has short sequence numbers), drop packet and return
781 */
Gerrit Renker09dbc382006-11-14 12:57:34 -0200782 if (dh->dccph_type >= DCCP_PKT_DATA &&
783 dh->dccph_type <= DCCP_PKT_DATAACK && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200784 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
785 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700786 return 1;
787 }
788
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200789 /*
790 * If P.CsCov is too large for the packet size, drop packet and return.
791 * This must come _before_ checksumming (not as RFC 4340 suggests).
792 */
793 cscov = dccp_csum_coverage(skb);
794 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200795 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
796 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200797 return 1;
798 }
799
800 /* If header checksum is incorrect, drop packet and return.
801 * (This step is completed in the AF-dependent functions.) */
802 skb->csum = skb_checksum(skb, 0, cscov, 0);
803
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700804 return 0;
805}
806
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800807EXPORT_SYMBOL_GPL(dccp_invalid_packet);
808
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700809/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800810static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700811{
812 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700813 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700814 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200815 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700816
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200817 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700818
819 if (dccp_invalid_packet(skb))
820 goto discard_it;
821
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700822 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200823 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700824 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200825 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800826 goto discard_it;
827 }
828
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700829 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700830
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700831 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(skb);
832 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
833
834 dccp_pr_debug("%8.8s "
835 "src=%u.%u.%u.%u@%-5d "
836 "dst=%u.%u.%u.%u@%-5d seq=%llu",
837 dccp_packet_name(dh->dccph_type),
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700838 NIPQUAD(iph->saddr), ntohs(dh->dccph_sport),
839 NIPQUAD(iph->daddr), ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700840 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700841
842 if (dccp_packet_without_ack(skb)) {
843 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
844 dccp_pr_debug_cat("\n");
845 } else {
846 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200847 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700848 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700849 }
850
851 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200852 * Look up flow ID in table and get corresponding socket */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700853 sk = __inet_lookup(&dccp_hashinfo,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700854 iph->saddr, dh->dccph_sport,
855 iph->daddr, dh->dccph_dport, inet_iif(skb));
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200856 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700857 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200858 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700859 */
860 if (sk == NULL) {
861 dccp_pr_debug("failed to look up flow ID in table and "
862 "get corresponding socket\n");
863 goto no_dccp_socket;
864 }
865
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200866 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700867 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200868 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700869 * Generate Reset(No Connection) unless P.type == Reset
870 * Drop packet and return
871 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700872 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200873 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
874 inet_twsk_put(inet_twsk(sk));
875 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700876 }
877
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200878 /*
879 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200880 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
881 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200882 */
883 min_cov = dccp_sk(sk)->dccps_pcrlen;
884 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
885 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
886 dh->dccph_cscov, min_cov);
887 /* FIXME: "Such packets SHOULD be reported using Data Dropped
888 * options (Section 11.7) with Drop Code 0, Protocol
889 * Constraints." */
890 goto discard_and_relse;
891 }
892
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200893 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700894 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800895 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700896
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200897 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700898
899no_dccp_socket:
900 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
901 goto discard_it;
902 /*
903 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200904 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700905 * Generate Reset(No Connection) unless P.type == Reset
906 * Drop packet and return
907 */
908 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300909 DCCP_SKB_CB(skb)->dccpd_reset_code =
910 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800911 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700912 }
913
914discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700915 kfree_skb(skb);
916 return 0;
917
918discard_and_relse:
919 sock_put(sk);
920 goto discard_it;
921}
922
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800923static struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800924 .queue_xmit = ip_queue_xmit,
925 .send_check = dccp_v4_send_check,
926 .rebuild_header = inet_sk_rebuild_header,
927 .conn_request = dccp_v4_conn_request,
928 .syn_recv_sock = dccp_v4_request_recv_sock,
929 .net_header_len = sizeof(struct iphdr),
930 .setsockopt = ip_setsockopt,
931 .getsockopt = ip_getsockopt,
932 .addr2sockaddr = inet_csk_addr2sockaddr,
933 .sockaddr_len = sizeof(struct sockaddr_in),
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800934#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800935 .compat_setsockopt = compat_ip_setsockopt,
936 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800937#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800938};
939
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800940static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700941{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800942 static __u8 dccp_v4_ctl_sock_initialized;
943 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700944
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800945 if (err == 0) {
946 if (unlikely(!dccp_v4_ctl_sock_initialized))
947 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800948 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800949 }
950
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800951 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700952}
953
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800954static struct timewait_sock_ops dccp_timewait_sock_ops = {
955 .twsk_obj_size = sizeof(struct inet_timewait_sock),
956};
957
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800958static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700959 .name = "DCCP",
960 .owner = THIS_MODULE,
961 .close = dccp_close,
962 .connect = dccp_v4_connect,
963 .disconnect = dccp_disconnect,
964 .ioctl = dccp_ioctl,
965 .init = dccp_v4_init_sock,
966 .setsockopt = dccp_setsockopt,
967 .getsockopt = dccp_getsockopt,
968 .sendmsg = dccp_sendmsg,
969 .recvmsg = dccp_recvmsg,
970 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloc985ed72006-03-20 21:23:39 -0800971 .hash = dccp_hash,
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800972 .unhash = dccp_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700973 .accept = inet_csk_accept,
974 .get_port = dccp_v4_get_port,
975 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800976 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700977 .orphan_count = &dccp_orphan_count,
978 .max_header = MAX_DCCP_HEADER,
979 .obj_size = sizeof(struct dccp_sock),
980 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800981 .twsk_prot = &dccp_timewait_sock_ops,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800982#ifdef CONFIG_COMPAT
983 .compat_setsockopt = compat_dccp_setsockopt,
984 .compat_getsockopt = compat_dccp_getsockopt,
985#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700986};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800987
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800988static struct net_protocol dccp_v4_protocol = {
989 .handler = dccp_v4_rcv,
990 .err_handler = dccp_v4_err,
991 .no_policy = 1,
992};
993
994static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800995 .family = PF_INET,
996 .owner = THIS_MODULE,
997 .release = inet_release,
998 .bind = inet_bind,
999 .connect = inet_stream_connect,
1000 .socketpair = sock_no_socketpair,
1001 .accept = inet_accept,
1002 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001003 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001004 .poll = dccp_poll,
1005 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001006 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001007 .listen = inet_dccp_listen,
1008 .shutdown = inet_shutdown,
1009 .setsockopt = sock_common_setsockopt,
1010 .getsockopt = sock_common_getsockopt,
1011 .sendmsg = inet_sendmsg,
1012 .recvmsg = sock_common_recvmsg,
1013 .mmap = sock_no_mmap,
1014 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001015#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001016 .compat_setsockopt = compat_sock_common_setsockopt,
1017 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001018#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001019};
1020
1021static struct inet_protosw dccp_v4_protosw = {
1022 .type = SOCK_DCCP,
1023 .protocol = IPPROTO_DCCP,
1024 .prot = &dccp_v4_prot,
1025 .ops = &inet_dccp_ops,
1026 .capability = -1,
1027 .no_check = 0,
1028 .flags = INET_PROTOSW_ICSK,
1029};
1030
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001031static int __init dccp_v4_init(void)
1032{
1033 int err = proto_register(&dccp_v4_prot, 1);
1034
1035 if (err != 0)
1036 goto out;
1037
1038 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1039 if (err != 0)
1040 goto out_proto_unregister;
1041
1042 inet_register_protosw(&dccp_v4_protosw);
1043
Arnaldo Carvalho de Meloc4d93902006-03-20 22:01:03 -08001044 err = inet_csk_ctl_sock_create(&dccp_v4_ctl_socket, PF_INET,
1045 SOCK_DCCP, IPPROTO_DCCP);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001046 if (err)
1047 goto out_unregister_protosw;
1048out:
1049 return err;
1050out_unregister_protosw:
1051 inet_unregister_protosw(&dccp_v4_protosw);
1052 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1053out_proto_unregister:
1054 proto_unregister(&dccp_v4_prot);
1055 goto out;
1056}
1057
1058static void __exit dccp_v4_exit(void)
1059{
1060 inet_unregister_protosw(&dccp_v4_protosw);
1061 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1062 proto_unregister(&dccp_v4_prot);
1063}
1064
1065module_init(dccp_v4_init);
1066module_exit(dccp_v4_exit);
1067
1068/*
1069 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1070 * values directly, Also cover the case where the protocol is not specified,
1071 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1072 */
1073MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-33-type-6");
1074MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-0-type-6");
1075MODULE_LICENSE("GPL");
1076MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1077MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");