blob: f2c011fd2ba128f92757aa816da604804d99394f [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
13#include <linux/config.h>
14#include <linux/dccp.h>
15#include <linux/icmp.h>
16#include <linux/module.h>
17#include <linux/skbuff.h>
18#include <linux/random.h>
19
20#include <net/icmp.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080021#include <net/inet_common.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070022#include <net/inet_hashtables.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020023#include <net/inet_sock.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080024#include <net/protocol.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070025#include <net/sock.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080026#include <net/timewait_sock.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070027#include <net/tcp_states.h>
28#include <net/xfrm.h>
29
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070030#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070031#include "ccid.h"
32#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080033#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070034
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080035/*
36 * This is the global socket data structure used for responding to
37 * the Out-of-the-blue (OOTB) packets. A control sock will be created
38 * for this socket at the initialization time.
39 */
40static struct socket *dccp_v4_ctl_socket;
41
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070042static int dccp_v4_get_port(struct sock *sk, const unsigned short snum)
43{
Arnaldo Carvalho de Melo971af182005-12-13 23:14:47 -080044 return inet_csk_get_port(&dccp_hashinfo, sk, snum,
45 inet_csk_bind_conflict);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070046}
47
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080048int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070049{
50 struct inet_sock *inet = inet_sk(sk);
51 struct dccp_sock *dp = dccp_sk(sk);
52 const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
53 struct rtable *rt;
54 u32 daddr, nexthop;
55 int tmp;
56 int err;
57
58 dp->dccps_role = DCCP_ROLE_CLIENT;
59
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -070060 if (dccp_service_not_initialized(sk))
61 return -EPROTO;
62
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070063 if (addr_len < sizeof(struct sockaddr_in))
64 return -EINVAL;
65
66 if (usin->sin_family != AF_INET)
67 return -EAFNOSUPPORT;
68
69 nexthop = daddr = usin->sin_addr.s_addr;
70 if (inet->opt != NULL && inet->opt->srr) {
71 if (daddr == 0)
72 return -EINVAL;
73 nexthop = inet->opt->faddr;
74 }
75
76 tmp = ip_route_connect(&rt, nexthop, inet->saddr,
77 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
78 IPPROTO_DCCP,
79 inet->sport, usin->sin_port, sk);
80 if (tmp < 0)
81 return tmp;
82
83 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
84 ip_rt_put(rt);
85 return -ENETUNREACH;
86 }
87
88 if (inet->opt == NULL || !inet->opt->srr)
89 daddr = rt->rt_dst;
90
91 if (inet->saddr == 0)
92 inet->saddr = rt->rt_src;
93 inet->rcv_saddr = inet->saddr;
94
95 inet->dport = usin->sin_port;
96 inet->daddr = daddr;
97
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080098 inet_csk(sk)->icsk_ext_hdr_len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070099 if (inet->opt != NULL)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800100 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700101 /*
102 * Socket identity is still unknown (sport may be zero).
103 * However we set state to DCCP_REQUESTING and not releasing socket
104 * lock select source port, enter ourselves into the hash tables and
105 * complete initialization after this.
106 */
107 dccp_set_state(sk, DCCP_REQUESTING);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -0800108 err = inet_hash_connect(&dccp_death_row, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700109 if (err != 0)
110 goto failure;
111
Patrick McHardy5d39a792006-01-31 17:35:35 -0800112 err = ip_route_newports(&rt, IPPROTO_DCCP, inet->sport, inet->dport,
113 sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700114 if (err != 0)
115 goto failure;
116
117 /* OK, now commit destination to socket. */
118 sk_setup_caps(sk, &rt->u.dst);
119
120 dp->dccps_gar =
121 dp->dccps_iss = secure_dccp_sequence_number(inet->saddr,
122 inet->daddr,
123 inet->sport,
124 usin->sin_port);
125 dccp_update_gss(sk, dp->dccps_iss);
126
127 inet->id = dp->dccps_iss ^ jiffies;
128
129 err = dccp_connect(sk);
130 rt = NULL;
131 if (err != 0)
132 goto failure;
133out:
134 return err;
135failure:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300136 /*
137 * This unhashes the socket and releases the local port, if necessary.
138 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700139 dccp_set_state(sk, DCCP_CLOSED);
140 ip_rt_put(rt);
141 sk->sk_route_caps = 0;
142 inet->dport = 0;
143 goto out;
144}
145
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800146EXPORT_SYMBOL_GPL(dccp_v4_connect);
147
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700148/*
149 * This routine does path mtu discovery as defined in RFC1191.
150 */
151static inline void dccp_do_pmtu_discovery(struct sock *sk,
152 const struct iphdr *iph,
153 u32 mtu)
154{
155 struct dst_entry *dst;
156 const struct inet_sock *inet = inet_sk(sk);
157 const struct dccp_sock *dp = dccp_sk(sk);
158
159 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
160 * send out by Linux are always < 576bytes so they should go through
161 * unfragmented).
162 */
163 if (sk->sk_state == DCCP_LISTEN)
164 return;
165
166 /* We don't check in the destentry if pmtu discovery is forbidden
167 * on this route. We just assume that no packet_to_big packets
168 * are send back when pmtu discovery is not active.
169 * There is a small race when the user changes this flag in the
170 * route, but I think that's acceptable.
171 */
172 if ((dst = __sk_dst_check(sk, 0)) == NULL)
173 return;
174
175 dst->ops->update_pmtu(dst, mtu);
176
177 /* Something is about to be wrong... Remember soft error
178 * for the case, if this connection will not able to recover.
179 */
180 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
181 sk->sk_err_soft = EMSGSIZE;
182
183 mtu = dst_mtu(dst);
184
185 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800186 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700187 dccp_sync_mss(sk, mtu);
188
189 /*
190 * From: draft-ietf-dccp-spec-11.txt
191 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300192 * DCCP-Sync packets are the best choice for upward
193 * probing, since DCCP-Sync probes do not risk application
194 * data loss.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700195 */
Arnaldo Carvalho de Meloe92ae932005-08-17 03:10:59 -0300196 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700197 } /* else let the usual retransmit timer handle it */
198}
199
Arnaldo Carvalho de Meloc5fed152006-03-20 22:31:26 -0800200static void dccp_v4_reqsk_send_ack(struct sk_buff *rxskb,
201 struct request_sock *req)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700202{
203 int err;
204 struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800205 const u32 dccp_hdr_ack_len = sizeof(struct dccp_hdr) +
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700206 sizeof(struct dccp_hdr_ext) +
207 sizeof(struct dccp_hdr_ack_bits);
208 struct sk_buff *skb;
209
210 if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
211 return;
212
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800213 skb = alloc_skb(dccp_v4_ctl_socket->sk->sk_prot->max_header, GFP_ATOMIC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700214 if (skb == NULL)
215 return;
216
217 /* Reserve space for headers. */
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800218 skb_reserve(skb, dccp_v4_ctl_socket->sk->sk_prot->max_header);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700219
220 skb->dst = dst_clone(rxskb->dst);
221
222 skb->h.raw = skb_push(skb, dccp_hdr_ack_len);
223 dh = dccp_hdr(skb);
224 memset(dh, 0, dccp_hdr_ack_len);
225
226 /* Build DCCP header and checksum it. */
227 dh->dccph_type = DCCP_PKT_ACK;
228 dh->dccph_sport = rxdh->dccph_dport;
229 dh->dccph_dport = rxdh->dccph_sport;
230 dh->dccph_doff = dccp_hdr_ack_len / 4;
231 dh->dccph_x = 1;
232
233 dccp_hdr_set_seq(dh, DCCP_SKB_CB(rxskb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300234 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
235 DCCP_SKB_CB(rxskb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700236
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800237 bh_lock_sock(dccp_v4_ctl_socket->sk);
238 err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300239 rxskb->nh.iph->daddr,
240 rxskb->nh.iph->saddr, NULL);
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800241 bh_unlock_sock(dccp_v4_ctl_socket->sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700242
243 if (err == NET_XMIT_CN || err == 0) {
244 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
245 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
246 }
247}
248
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700249static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
250 struct dst_entry *dst)
251{
252 int err = -1;
253 struct sk_buff *skb;
254
255 /* First, grab a route. */
256
257 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
258 goto out;
259
260 skb = dccp_make_response(sk, dst, req);
261 if (skb != NULL) {
262 const struct inet_request_sock *ireq = inet_rsk(req);
Arnaldo Carvalho de Melo0a1ec672006-03-20 21:23:59 -0800263 struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700264
Arnaldo Carvalho de Melo0a1ec672006-03-20 21:23:59 -0800265 dh->dccph_checksum = dccp_v4_checksum(skb, ireq->loc_addr,
266 ireq->rmt_addr);
Herbert Xu49c5bfa2005-10-18 12:03:28 +1000267 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700268 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
269 ireq->rmt_addr,
270 ireq->opt);
271 if (err == NET_XMIT_CN)
272 err = 0;
273 }
274
275out:
276 dst_release(dst);
277 return err;
278}
279
280/*
281 * This routine is called by the ICMP module when it gets some sort of error
282 * condition. If err < 0 then the socket should be closed and the error
283 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
284 * After adjustment header points to the first 8 bytes of the tcp header. We
285 * need to find the appropriate port.
286 *
287 * The locking strategy used here is very "optimistic". When someone else
288 * accesses the socket the ICMP is just dropped and for some paths there is no
289 * check at all. A more general error queue to queue errors for later handling
290 * is probably better.
291 */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800292static void dccp_v4_err(struct sk_buff *skb, u32 info)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700293{
294 const struct iphdr *iph = (struct iphdr *)skb->data;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300295 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
296 (iph->ihl << 2));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700297 struct dccp_sock *dp;
298 struct inet_sock *inet;
299 const int type = skb->h.icmph->type;
300 const int code = skb->h.icmph->code;
301 struct sock *sk;
302 __u64 seq;
303 int err;
304
305 if (skb->len < (iph->ihl << 2) + 8) {
306 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
307 return;
308 }
309
310 sk = inet_lookup(&dccp_hashinfo, iph->daddr, dh->dccph_dport,
311 iph->saddr, dh->dccph_sport, inet_iif(skb));
312 if (sk == NULL) {
313 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
314 return;
315 }
316
317 if (sk->sk_state == DCCP_TIME_WAIT) {
318 inet_twsk_put((struct inet_timewait_sock *)sk);
319 return;
320 }
321
322 bh_lock_sock(sk);
323 /* If too many ICMPs get dropped on busy
324 * servers this needs to be solved differently.
325 */
326 if (sock_owned_by_user(sk))
327 NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
328
329 if (sk->sk_state == DCCP_CLOSED)
330 goto out;
331
332 dp = dccp_sk(sk);
333 seq = dccp_hdr_seq(skb);
334 if (sk->sk_state != DCCP_LISTEN &&
335 !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
336 NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS);
337 goto out;
338 }
339
340 switch (type) {
341 case ICMP_SOURCE_QUENCH:
342 /* Just silently ignore these. */
343 goto out;
344 case ICMP_PARAMETERPROB:
345 err = EPROTO;
346 break;
347 case ICMP_DEST_UNREACH:
348 if (code > NR_ICMP_UNREACH)
349 goto out;
350
351 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
352 if (!sock_owned_by_user(sk))
353 dccp_do_pmtu_discovery(sk, iph, info);
354 goto out;
355 }
356
357 err = icmp_err_convert[code].errno;
358 break;
359 case ICMP_TIME_EXCEEDED:
360 err = EHOSTUNREACH;
361 break;
362 default:
363 goto out;
364 }
365
366 switch (sk->sk_state) {
367 struct request_sock *req , **prev;
368 case DCCP_LISTEN:
369 if (sock_owned_by_user(sk))
370 goto out;
371 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
372 iph->daddr, iph->saddr);
373 if (!req)
374 goto out;
375
376 /*
377 * ICMPs are not backlogged, hence we cannot get an established
378 * socket here.
379 */
380 BUG_TRAP(!req->sk);
381
382 if (seq != dccp_rsk(req)->dreq_iss) {
383 NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
384 goto out;
385 }
386 /*
387 * Still in RESPOND, just remove it silently.
388 * There is no good way to pass the error to the newly
389 * created socket, and POSIX does not want network
390 * errors returned from accept().
391 */
392 inet_csk_reqsk_queue_drop(sk, req, prev);
393 goto out;
394
395 case DCCP_REQUESTING:
396 case DCCP_RESPOND:
397 if (!sock_owned_by_user(sk)) {
398 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
399 sk->sk_err = err;
400
401 sk->sk_error_report(sk);
402
403 dccp_done(sk);
404 } else
405 sk->sk_err_soft = err;
406 goto out;
407 }
408
409 /* If we've already connected we will keep trying
410 * until we time out, or the user gives up.
411 *
412 * rfc1122 4.2.3.9 allows to consider as hard errors
413 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
414 * but it is obsoleted by pmtu discovery).
415 *
416 * Note, that in modern internet, where routing is unreliable
417 * and in each dark corner broken firewalls sit, sending random
418 * errors ordered by their masters even this two messages finally lose
419 * their original sense (even Linux sends invalid PORT_UNREACHs)
420 *
421 * Now we are in compliance with RFCs.
422 * --ANK (980905)
423 */
424
425 inet = inet_sk(sk);
426 if (!sock_owned_by_user(sk) && inet->recverr) {
427 sk->sk_err = err;
428 sk->sk_error_report(sk);
429 } else /* Only an error on timeout */
430 sk->sk_err_soft = err;
431out:
432 bh_unlock_sock(sk);
433 sock_put(sk);
434}
435
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800436/* This routine computes an IPv4 DCCP checksum. */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800437void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800438{
439 const struct inet_sock *inet = inet_sk(sk);
440 struct dccp_hdr *dh = dccp_hdr(skb);
441
442 dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr, inet->daddr);
443}
444
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800445EXPORT_SYMBOL_GPL(dccp_v4_send_check);
446
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700447static inline u64 dccp_v4_init_sequence(const struct sock *sk,
448 const struct sk_buff *skb)
449{
450 return secure_dccp_sequence_number(skb->nh.iph->daddr,
451 skb->nh.iph->saddr,
452 dccp_hdr(skb)->dccph_dport,
453 dccp_hdr(skb)->dccph_sport);
454}
455
456int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
457{
458 struct inet_request_sock *ireq;
459 struct dccp_sock dp;
460 struct request_sock *req;
461 struct dccp_request_sock *dreq;
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800462 const __be32 saddr = skb->nh.iph->saddr;
463 const __be32 daddr = skb->nh.iph->daddr;
464 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Arnaldo Carvalho de Melo0c10c5d2005-09-16 16:58:33 -0700465 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
466 __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700467
468 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
469 if (((struct rtable *)skb->dst)->rt_flags &
Arnaldo Carvalho de Melo0c10c5d2005-09-16 16:58:33 -0700470 (RTCF_BROADCAST | RTCF_MULTICAST)) {
471 reset_code = DCCP_RESET_CODE_NO_CONNECTION;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700472 goto drop;
Arnaldo Carvalho de Melo0c10c5d2005-09-16 16:58:33 -0700473 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700474
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700475 if (dccp_bad_service_code(sk, service)) {
476 reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
477 goto drop;
478 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700479 /*
480 * TW buckets are converted to open requests without
481 * limitations, they conserve resources and peer is
482 * evidently real one.
483 */
484 if (inet_csk_reqsk_queue_is_full(sk))
485 goto drop;
486
487 /*
488 * Accept backlog is full. If we have already queued enough
489 * of warm entries in syn queue, drop request. It is better than
490 * clogging syn queue with openreqs with exponentially increasing
491 * timeout.
492 */
493 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
494 goto drop;
495
496 req = reqsk_alloc(sk->sk_prot->rsk_prot);
497 if (req == NULL)
498 goto drop;
499
Andrea Bittauafe00252006-03-20 17:43:56 -0800500 if (dccp_parse_options(sk, skb))
Eric Sesterhennb8282dc2006-04-10 16:43:03 -0700501 goto drop_and_free;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700502
503 dccp_openreq_init(req, &dp, skb);
504
505 ireq = inet_rsk(req);
506 ireq->loc_addr = daddr;
507 ireq->rmt_addr = saddr;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300508 req->rcv_wnd = 100; /* Fake, option parsing will get the
509 right value */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700510 ireq->opt = NULL;
511
512 /*
513 * Step 3: Process LISTEN state
514 *
515 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
516 *
517 * In fact we defer setting S.GSR, S.SWL, S.SWH to
518 * dccp_create_openreq_child.
519 */
520 dreq = dccp_rsk(req);
Arnaldo Carvalho de Melo67e6b622005-09-16 16:58:40 -0700521 dreq->dreq_isr = dcb->dccpd_seq;
522 dreq->dreq_iss = dccp_v4_init_sequence(sk, skb);
523 dreq->dreq_service = service;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700524
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800525 if (dccp_v4_send_response(sk, req, NULL))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700526 goto drop_and_free;
527
528 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
529 return 0;
530
531drop_and_free:
Arnaldo Carvalho de Melofc44b982005-12-13 23:25:06 -0800532 reqsk_free(req);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700533drop:
534 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Arnaldo Carvalho de Melo0c10c5d2005-09-16 16:58:33 -0700535 dcb->dccpd_reset_code = reset_code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700536 return -1;
537}
538
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800539EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
540
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700541/*
542 * The three way handshake has completed - we got a valid ACK or DATAACK -
543 * now create the new socket.
544 *
545 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
546 */
547struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
548 struct request_sock *req,
549 struct dst_entry *dst)
550{
551 struct inet_request_sock *ireq;
552 struct inet_sock *newinet;
553 struct dccp_sock *newdp;
554 struct sock *newsk;
555
556 if (sk_acceptq_is_full(sk))
557 goto exit_overflow;
558
559 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
560 goto exit;
561
562 newsk = dccp_create_openreq_child(sk, req, skb);
563 if (newsk == NULL)
564 goto exit;
565
566 sk_setup_caps(newsk, dst);
567
568 newdp = dccp_sk(newsk);
569 newinet = inet_sk(newsk);
570 ireq = inet_rsk(req);
571 newinet->daddr = ireq->rmt_addr;
572 newinet->rcv_saddr = ireq->loc_addr;
573 newinet->saddr = ireq->loc_addr;
574 newinet->opt = ireq->opt;
575 ireq->opt = NULL;
576 newinet->mc_index = inet_iif(skb);
577 newinet->mc_ttl = skb->nh.iph->ttl;
578 newinet->id = jiffies;
579
580 dccp_sync_mss(newsk, dst_mtu(dst));
581
582 __inet_hash(&dccp_hashinfo, newsk, 0);
583 __inet_inherit_port(&dccp_hashinfo, sk, newsk);
584
585 return newsk;
586
587exit_overflow:
588 NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
589exit:
590 NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
591 dst_release(dst);
592 return NULL;
593}
594
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800595EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
596
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700597static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
598{
599 const struct dccp_hdr *dh = dccp_hdr(skb);
600 const struct iphdr *iph = skb->nh.iph;
601 struct sock *nsk;
602 struct request_sock **prev;
603 /* Find possible connection requests. */
604 struct request_sock *req = inet_csk_search_req(sk, &prev,
605 dh->dccph_sport,
606 iph->saddr, iph->daddr);
607 if (req != NULL)
608 return dccp_check_req(sk, skb, req, prev);
609
610 nsk = __inet_lookup_established(&dccp_hashinfo,
611 iph->saddr, dh->dccph_sport,
612 iph->daddr, ntohs(dh->dccph_dport),
613 inet_iif(skb));
614 if (nsk != NULL) {
615 if (nsk->sk_state != DCCP_TIME_WAIT) {
616 bh_lock_sock(nsk);
617 return nsk;
618 }
619 inet_twsk_put((struct inet_timewait_sock *)nsk);
620 return NULL;
621 }
622
623 return sk;
624}
625
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800626int dccp_v4_checksum(const struct sk_buff *skb, const __be32 saddr,
627 const __be32 daddr)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700628{
Yoshifumi Nishida95b81ef2005-08-09 20:15:35 -0700629 const struct dccp_hdr* dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700630 int checksum_len;
631 u32 tmp;
632
633 if (dh->dccph_cscov == 0)
634 checksum_len = skb->len;
635 else {
636 checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300637 checksum_len = checksum_len < skb->len ? checksum_len :
638 skb->len;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700639 }
640
641 tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300642 return csum_tcpudp_magic(saddr, daddr, checksum_len,
643 IPPROTO_DCCP, tmp);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700644}
645
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800646EXPORT_SYMBOL_GPL(dccp_v4_checksum);
647
Yoshifumi Nishida95b81ef2005-08-09 20:15:35 -0700648static int dccp_v4_verify_checksum(struct sk_buff *skb,
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800649 const __be32 saddr, const __be32 daddr)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700650{
Yoshifumi Nishida95b81ef2005-08-09 20:15:35 -0700651 struct dccp_hdr *dh = dccp_hdr(skb);
652 int checksum_len;
653 u32 tmp;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700654
Yoshifumi Nishida95b81ef2005-08-09 20:15:35 -0700655 if (dh->dccph_cscov == 0)
656 checksum_len = skb->len;
657 else {
658 checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300659 checksum_len = checksum_len < skb->len ? checksum_len :
660 skb->len;
Yoshifumi Nishida95b81ef2005-08-09 20:15:35 -0700661 }
662 tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300663 return csum_tcpudp_magic(saddr, daddr, checksum_len,
664 IPPROTO_DCCP, tmp) == 0 ? 0 : -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700665}
666
667static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
668 struct sk_buff *skb)
669{
670 struct rtable *rt;
671 struct flowi fl = { .oif = ((struct rtable *)skb->dst)->rt_iif,
672 .nl_u = { .ip4_u =
673 { .daddr = skb->nh.iph->saddr,
674 .saddr = skb->nh.iph->daddr,
675 .tos = RT_CONN_FLAGS(sk) } },
676 .proto = sk->sk_protocol,
677 .uli_u = { .ports =
678 { .sport = dccp_hdr(skb)->dccph_dport,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300679 .dport = dccp_hdr(skb)->dccph_sport }
680 }
681 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700682
683 if (ip_route_output_flow(&rt, &fl, sk, 0)) {
684 IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
685 return NULL;
686 }
687
688 return &rt->u.dst;
689}
690
Arnaldo Carvalho de Meloa1d3a352005-08-13 22:42:25 -0300691static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700692{
693 int err;
694 struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
695 const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
696 sizeof(struct dccp_hdr_ext) +
697 sizeof(struct dccp_hdr_reset);
698 struct sk_buff *skb;
699 struct dst_entry *dst;
Arnaldo Carvalho de Melo2807d4f2005-08-21 05:33:48 -0300700 u64 seqno;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700701
702 /* Never send a reset in response to a reset. */
703 if (rxdh->dccph_type == DCCP_PKT_RESET)
704 return;
705
706 if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
707 return;
708
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800709 dst = dccp_v4_route_skb(dccp_v4_ctl_socket->sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700710 if (dst == NULL)
711 return;
712
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800713 skb = alloc_skb(dccp_v4_ctl_socket->sk->sk_prot->max_header,
714 GFP_ATOMIC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700715 if (skb == NULL)
716 goto out;
717
718 /* Reserve space for headers. */
Arnaldo Carvalho de Melo118b2c92006-03-20 22:31:09 -0800719 skb_reserve(skb, dccp_v4_ctl_socket->sk->sk_prot->max_header);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700720 skb->dst = dst_clone(dst);
721
722 skb->h.raw = skb_push(skb, dccp_hdr_reset_len);
723 dh = dccp_hdr(skb);
724 memset(dh, 0, dccp_hdr_reset_len);
725
726 /* Build DCCP header and checksum it. */
727 dh->dccph_type = DCCP_PKT_RESET;
728 dh->dccph_sport = rxdh->dccph_dport;
729 dh->dccph_dport = rxdh->dccph_sport;
730 dh->dccph_doff = dccp_hdr_reset_len / 4;
731 dh->dccph_x = 1;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300732 dccp_hdr_reset(skb)->dccph_reset_code =
733 DCCP_SKB_CB(rxskb)->dccpd_reset_code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700734
Arnaldo Carvalho de Melo2807d4f2005-08-21 05:33:48 -0300735 /* See "8.3.1. Abnormal Termination" in draft-ietf-dccp-spec-11 */
736 seqno = 0;
737 if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
738 dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
739
740 dccp_hdr_set_seq(dh, seqno);
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300741 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
742 DCCP_SKB_CB(rxskb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700743
Yoshifumi Nishida95b81ef2005-08-09 20:15:35 -0700744 dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr,
745 rxskb->nh.iph->daddr);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700746
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800747 bh_lock_sock(dccp_v4_ctl_socket->sk);
748 err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300749 rxskb->nh.iph->daddr,
750 rxskb->nh.iph->saddr, NULL);
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800751 bh_unlock_sock(dccp_v4_ctl_socket->sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700752
753 if (err == NET_XMIT_CN || err == 0) {
754 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
755 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
756 }
757out:
758 dst_release(dst);
759}
760
761int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
762{
763 struct dccp_hdr *dh = dccp_hdr(skb);
764
765 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
766 if (dccp_rcv_established(sk, skb, dh, skb->len))
767 goto reset;
768 return 0;
769 }
770
771 /*
772 * Step 3: Process LISTEN state
773 * If S.state == LISTEN,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300774 * If P.type == Request or P contains a valid Init Cookie
775 * option,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700776 * * Must scan the packet's options to check for an Init
777 * Cookie. Only the Init Cookie is processed here,
778 * however; other options are processed in Step 8. This
779 * scan need only be performed if the endpoint uses Init
780 * Cookies *
781 * * Generate a new socket and switch to that socket *
782 * Set S := new socket for this port pair
783 * S.state = RESPOND
784 * Choose S.ISS (initial seqno) or set from Init Cookie
785 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
786 * Continue with S.state == RESPOND
787 * * A Response packet will be generated in Step 11 *
788 * Otherwise,
789 * Generate Reset(No Connection) unless P.type == Reset
790 * Drop packet and return
791 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300792 * NOTE: the check for the packet types is done in
793 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700794 */
795 if (sk->sk_state == DCCP_LISTEN) {
796 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
797
798 if (nsk == NULL)
799 goto discard;
800
801 if (nsk != sk) {
802 if (dccp_child_process(sk, nsk, skb))
803 goto reset;
804 return 0;
805 }
806 }
807
808 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
809 goto reset;
810 return 0;
811
812reset:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700813 dccp_v4_ctl_send_reset(skb);
814discard:
815 kfree_skb(skb);
816 return 0;
817}
818
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800819EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
820
821int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700822{
823 const struct dccp_hdr *dh;
824
825 if (skb->pkt_type != PACKET_HOST)
826 return 1;
827
828 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Arnaldo Carvalho de Meloc59eab42005-08-18 21:12:02 -0300829 LIMIT_NETDEBUG(KERN_WARNING "DCCP: pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700830 return 1;
831 }
832
833 dh = dccp_hdr(skb);
834
835 /* If the packet type is not understood, drop packet and return */
836 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Arnaldo Carvalho de Meloc59eab42005-08-18 21:12:02 -0300837 LIMIT_NETDEBUG(KERN_WARNING "DCCP: invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700838 return 1;
839 }
840
841 /*
842 * If P.Data Offset is too small for packet type, or too large for
843 * packet, drop packet and return
844 */
845 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Arnaldo Carvalho de Meloc59eab42005-08-18 21:12:02 -0300846 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
847 "too small 1\n",
848 dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700849 return 1;
850 }
851
852 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Arnaldo Carvalho de Meloc59eab42005-08-18 21:12:02 -0300853 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
854 "too small 2\n",
855 dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700856 return 1;
857 }
858
859 dh = dccp_hdr(skb);
860
861 /*
862 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
863 * has short sequence numbers), drop packet and return
864 */
865 if (dh->dccph_x == 0 &&
866 dh->dccph_type != DCCP_PKT_DATA &&
867 dh->dccph_type != DCCP_PKT_ACK &&
868 dh->dccph_type != DCCP_PKT_DATAACK) {
Arnaldo Carvalho de Meloc59eab42005-08-18 21:12:02 -0300869 LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data, Ack "
870 "nor DataAck and P.X == 0\n",
871 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700872 return 1;
873 }
874
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700875 return 0;
876}
877
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800878EXPORT_SYMBOL_GPL(dccp_invalid_packet);
879
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700880/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800881static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700882{
883 const struct dccp_hdr *dh;
884 struct sock *sk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700885
886 /* Step 1: Check header basics: */
887
888 if (dccp_invalid_packet(skb))
889 goto discard_it;
890
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800891 /* If the header checksum is incorrect, drop packet and return */
892 if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
893 skb->nh.iph->daddr) < 0) {
894 LIMIT_NETDEBUG(KERN_WARNING "%s: incorrect header checksum\n",
895 __FUNCTION__);
896 goto discard_it;
897 }
898
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700899 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700900
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700901 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(skb);
902 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
903
904 dccp_pr_debug("%8.8s "
905 "src=%u.%u.%u.%u@%-5d "
906 "dst=%u.%u.%u.%u@%-5d seq=%llu",
907 dccp_packet_name(dh->dccph_type),
908 NIPQUAD(skb->nh.iph->saddr), ntohs(dh->dccph_sport),
909 NIPQUAD(skb->nh.iph->daddr), ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700910 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700911
912 if (dccp_packet_without_ack(skb)) {
913 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
914 dccp_pr_debug_cat("\n");
915 } else {
916 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
David S. Millerf6ccf552005-08-09 20:27:14 -0700917 dccp_pr_debug_cat(", ack=%llu\n",
918 (unsigned long long)
919 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700920 }
921
922 /* Step 2:
923 * Look up flow ID in table and get corresponding socket */
924 sk = __inet_lookup(&dccp_hashinfo,
925 skb->nh.iph->saddr, dh->dccph_sport,
926 skb->nh.iph->daddr, ntohs(dh->dccph_dport),
927 inet_iif(skb));
928
929 /*
930 * Step 2:
931 * If no socket ...
932 * Generate Reset(No Connection) unless P.type == Reset
933 * Drop packet and return
934 */
935 if (sk == NULL) {
936 dccp_pr_debug("failed to look up flow ID in table and "
937 "get corresponding socket\n");
938 goto no_dccp_socket;
939 }
940
941 /*
942 * Step 2:
943 * ... or S.state == TIMEWAIT,
944 * Generate Reset(No Connection) unless P.type == Reset
945 * Drop packet and return
946 */
947
948 if (sk->sk_state == DCCP_TIME_WAIT) {
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -0700949 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: "
950 "do_time_wait\n");
951 goto do_time_wait;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700952 }
953
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200954 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700955 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800956 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700957
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200958 return sk_receive_skb(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700959
960no_dccp_socket:
961 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
962 goto discard_it;
963 /*
964 * Step 2:
965 * Generate Reset(No Connection) unless P.type == Reset
966 * Drop packet and return
967 */
968 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300969 DCCP_SKB_CB(skb)->dccpd_reset_code =
970 DCCP_RESET_CODE_NO_CONNECTION;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700971 dccp_v4_ctl_send_reset(skb);
972 }
973
974discard_it:
975 /* Discard frame. */
976 kfree_skb(skb);
977 return 0;
978
979discard_and_relse:
980 sock_put(sk);
981 goto discard_it;
Arnaldo Carvalho de Melo64cf1e52005-08-09 20:45:21 -0700982
983do_time_wait:
984 inet_twsk_put((struct inet_timewait_sock *)sk);
985 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700986}
987
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800988static struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800989 .queue_xmit = ip_queue_xmit,
990 .send_check = dccp_v4_send_check,
991 .rebuild_header = inet_sk_rebuild_header,
992 .conn_request = dccp_v4_conn_request,
993 .syn_recv_sock = dccp_v4_request_recv_sock,
994 .net_header_len = sizeof(struct iphdr),
995 .setsockopt = ip_setsockopt,
996 .getsockopt = ip_getsockopt,
997 .addr2sockaddr = inet_csk_addr2sockaddr,
998 .sockaddr_len = sizeof(struct sockaddr_in),
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800999#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001000 .compat_setsockopt = compat_ip_setsockopt,
1001 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001002#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -08001003};
1004
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -08001005static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001006{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001007 static __u8 dccp_v4_ctl_sock_initialized;
1008 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001009
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001010 if (err == 0) {
1011 if (unlikely(!dccp_v4_ctl_sock_initialized))
1012 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -08001013 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -08001014 }
1015
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -08001016 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001017}
1018
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001019static void dccp_v4_reqsk_destructor(struct request_sock *req)
1020{
1021 kfree(inet_rsk(req)->opt);
1022}
1023
1024static struct request_sock_ops dccp_request_sock_ops = {
1025 .family = PF_INET,
1026 .obj_size = sizeof(struct dccp_request_sock),
1027 .rtx_syn_ack = dccp_v4_send_response,
1028 .send_ack = dccp_v4_reqsk_send_ack,
1029 .destructor = dccp_v4_reqsk_destructor,
1030 .send_reset = dccp_v4_ctl_send_reset,
1031};
1032
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001033static struct timewait_sock_ops dccp_timewait_sock_ops = {
1034 .twsk_obj_size = sizeof(struct inet_timewait_sock),
1035};
1036
Adrian Bunk5e0817f2006-03-20 21:58:29 -08001037static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001038 .name = "DCCP",
1039 .owner = THIS_MODULE,
1040 .close = dccp_close,
1041 .connect = dccp_v4_connect,
1042 .disconnect = dccp_disconnect,
1043 .ioctl = dccp_ioctl,
1044 .init = dccp_v4_init_sock,
1045 .setsockopt = dccp_setsockopt,
1046 .getsockopt = dccp_getsockopt,
1047 .sendmsg = dccp_sendmsg,
1048 .recvmsg = dccp_recvmsg,
1049 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloc985ed72006-03-20 21:23:39 -08001050 .hash = dccp_hash,
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -08001051 .unhash = dccp_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001052 .accept = inet_csk_accept,
1053 .get_port = dccp_v4_get_port,
1054 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -08001055 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001056 .orphan_count = &dccp_orphan_count,
1057 .max_header = MAX_DCCP_HEADER,
1058 .obj_size = sizeof(struct dccp_sock),
1059 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001060 .twsk_prot = &dccp_timewait_sock_ops,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001061#ifdef CONFIG_COMPAT
1062 .compat_setsockopt = compat_dccp_setsockopt,
1063 .compat_getsockopt = compat_dccp_getsockopt,
1064#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001065};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -08001066
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001067static struct net_protocol dccp_v4_protocol = {
1068 .handler = dccp_v4_rcv,
1069 .err_handler = dccp_v4_err,
1070 .no_policy = 1,
1071};
1072
1073static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001074 .family = PF_INET,
1075 .owner = THIS_MODULE,
1076 .release = inet_release,
1077 .bind = inet_bind,
1078 .connect = inet_stream_connect,
1079 .socketpair = sock_no_socketpair,
1080 .accept = inet_accept,
1081 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001082 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001083 .poll = dccp_poll,
1084 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001085 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001086 .listen = inet_dccp_listen,
1087 .shutdown = inet_shutdown,
1088 .setsockopt = sock_common_setsockopt,
1089 .getsockopt = sock_common_getsockopt,
1090 .sendmsg = inet_sendmsg,
1091 .recvmsg = sock_common_recvmsg,
1092 .mmap = sock_no_mmap,
1093 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001094#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001095 .compat_setsockopt = compat_sock_common_setsockopt,
1096 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001097#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001098};
1099
1100static struct inet_protosw dccp_v4_protosw = {
1101 .type = SOCK_DCCP,
1102 .protocol = IPPROTO_DCCP,
1103 .prot = &dccp_v4_prot,
1104 .ops = &inet_dccp_ops,
1105 .capability = -1,
1106 .no_check = 0,
1107 .flags = INET_PROTOSW_ICSK,
1108};
1109
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001110static int __init dccp_v4_init(void)
1111{
1112 int err = proto_register(&dccp_v4_prot, 1);
1113
1114 if (err != 0)
1115 goto out;
1116
1117 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1118 if (err != 0)
1119 goto out_proto_unregister;
1120
1121 inet_register_protosw(&dccp_v4_protosw);
1122
Arnaldo Carvalho de Meloc4d93902006-03-20 22:01:03 -08001123 err = inet_csk_ctl_sock_create(&dccp_v4_ctl_socket, PF_INET,
1124 SOCK_DCCP, IPPROTO_DCCP);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001125 if (err)
1126 goto out_unregister_protosw;
1127out:
1128 return err;
1129out_unregister_protosw:
1130 inet_unregister_protosw(&dccp_v4_protosw);
1131 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1132out_proto_unregister:
1133 proto_unregister(&dccp_v4_prot);
1134 goto out;
1135}
1136
1137static void __exit dccp_v4_exit(void)
1138{
1139 inet_unregister_protosw(&dccp_v4_protosw);
1140 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1141 proto_unregister(&dccp_v4_prot);
1142}
1143
1144module_init(dccp_v4_init);
1145module_exit(dccp_v4_exit);
1146
1147/*
1148 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1149 * values directly, Also cover the case where the protocol is not specified,
1150 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1151 */
1152MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-33-type-6");
1153MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-0-type-6");
1154MODULE_LICENSE("GPL");
1155MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1156MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");