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Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001/*
2 * net/dccp/ipv4.c
3 *
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070013#include <linux/dccp.h>
14#include <linux/icmp.h>
15#include <linux/module.h>
16#include <linux/skbuff.h>
17#include <linux/random.h>
18
19#include <net/icmp.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080020#include <net/inet_common.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070021#include <net/inet_hashtables.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020022#include <net/inet_sock.h>
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -080023#include <net/protocol.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070024#include <net/sock.h>
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -080025#include <net/timewait_sock.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070026#include <net/tcp_states.h>
27#include <net/xfrm.h>
28
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070029#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070030#include "ccid.h"
31#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080032#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070033
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080034/*
Pavel Emelyanov13f51d82008-04-14 02:38:45 -070035 * The per-net dccp.v4_ctl_sk socket is used for responding to
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080036 * the Out-of-the-blue (OOTB) packets. A control sock will be created
37 * for this socket at the initialization time.
38 */
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080039
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080040int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070041{
42 struct inet_sock *inet = inet_sk(sk);
43 struct dccp_sock *dp = dccp_sk(sk);
44 const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
45 struct rtable *rt;
Al Virobada8ad2006-09-26 21:27:15 -070046 __be32 daddr, nexthop;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070047 int tmp;
48 int err;
49
50 dp->dccps_role = DCCP_ROLE_CLIENT;
51
52 if (addr_len < sizeof(struct sockaddr_in))
53 return -EINVAL;
54
55 if (usin->sin_family != AF_INET)
56 return -EAFNOSUPPORT;
57
58 nexthop = daddr = usin->sin_addr.s_addr;
59 if (inet->opt != NULL && inet->opt->srr) {
60 if (daddr == 0)
61 return -EINVAL;
62 nexthop = inet->opt->faddr;
63 }
64
Eric Dumazetc720c7e2009-10-15 06:30:45 +000065 tmp = ip_route_connect(&rt, nexthop, inet->inet_saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070066 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
67 IPPROTO_DCCP,
Eric Dumazetc720c7e2009-10-15 06:30:45 +000068 inet->inet_sport, usin->sin_port, sk, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070069 if (tmp < 0)
70 return tmp;
71
72 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
73 ip_rt_put(rt);
74 return -ENETUNREACH;
75 }
76
77 if (inet->opt == NULL || !inet->opt->srr)
78 daddr = rt->rt_dst;
79
Eric Dumazetc720c7e2009-10-15 06:30:45 +000080 if (inet->inet_saddr == 0)
81 inet->inet_saddr = rt->rt_src;
82 inet->inet_rcv_saddr = inet->inet_saddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070083
Eric Dumazetc720c7e2009-10-15 06:30:45 +000084 inet->inet_dport = usin->sin_port;
85 inet->inet_daddr = daddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070086
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080087 inet_csk(sk)->icsk_ext_hdr_len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070088 if (inet->opt != NULL)
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080089 inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070090 /*
91 * Socket identity is still unknown (sport may be zero).
92 * However we set state to DCCP_REQUESTING and not releasing socket
93 * lock select source port, enter ourselves into the hash tables and
94 * complete initialization after this.
95 */
96 dccp_set_state(sk, DCCP_REQUESTING);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -080097 err = inet_hash_connect(&dccp_death_row, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070098 if (err != 0)
99 goto failure;
100
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000101 err = ip_route_newports(&rt, IPPROTO_DCCP, inet->inet_sport,
102 inet->inet_dport, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700103 if (err != 0)
104 goto failure;
105
106 /* OK, now commit destination to socket. */
107 sk_setup_caps(sk, &rt->u.dst);
108
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000109 dp->dccps_iss = secure_dccp_sequence_number(inet->inet_saddr,
110 inet->inet_daddr,
111 inet->inet_sport,
112 inet->inet_dport);
113 inet->inet_id = dp->dccps_iss ^ jiffies;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700114
115 err = dccp_connect(sk);
116 rt = NULL;
117 if (err != 0)
118 goto failure;
119out:
120 return err;
121failure:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300122 /*
123 * This unhashes the socket and releases the local port, if necessary.
124 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700125 dccp_set_state(sk, DCCP_CLOSED);
126 ip_rt_put(rt);
127 sk->sk_route_caps = 0;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000128 inet->inet_dport = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700129 goto out;
130}
131
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800132EXPORT_SYMBOL_GPL(dccp_v4_connect);
133
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700134/*
135 * This routine does path mtu discovery as defined in RFC1191.
136 */
137static inline void dccp_do_pmtu_discovery(struct sock *sk,
138 const struct iphdr *iph,
139 u32 mtu)
140{
141 struct dst_entry *dst;
142 const struct inet_sock *inet = inet_sk(sk);
143 const struct dccp_sock *dp = dccp_sk(sk);
144
145 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
146 * send out by Linux are always < 576bytes so they should go through
147 * unfragmented).
148 */
149 if (sk->sk_state == DCCP_LISTEN)
150 return;
151
152 /* We don't check in the destentry if pmtu discovery is forbidden
153 * on this route. We just assume that no packet_to_big packets
154 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900155 * There is a small race when the user changes this flag in the
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700156 * route, but I think that's acceptable.
157 */
158 if ((dst = __sk_dst_check(sk, 0)) == NULL)
159 return;
160
161 dst->ops->update_pmtu(dst, mtu);
162
163 /* Something is about to be wrong... Remember soft error
164 * for the case, if this connection will not able to recover.
165 */
166 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
167 sk->sk_err_soft = EMSGSIZE;
168
169 mtu = dst_mtu(dst);
170
171 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800172 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700173 dccp_sync_mss(sk, mtu);
174
175 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700176 * From RFC 4340, sec. 14.1:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700177 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300178 * DCCP-Sync packets are the best choice for upward
179 * probing, since DCCP-Sync probes do not risk application
180 * data loss.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700181 */
Arnaldo Carvalho de Meloe92ae932005-08-17 03:10:59 -0300182 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700183 } /* else let the usual retransmit timer handle it */
184}
185
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700186/*
187 * This routine is called by the ICMP module when it gets some sort of error
188 * condition. If err < 0 then the socket should be closed and the error
189 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
190 * After adjustment header points to the first 8 bytes of the tcp header. We
191 * need to find the appropriate port.
192 *
193 * The locking strategy used here is very "optimistic". When someone else
194 * accesses the socket the ICMP is just dropped and for some paths there is no
195 * check at all. A more general error queue to queue errors for later handling
196 * is probably better.
197 */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800198static void dccp_v4_err(struct sk_buff *skb, u32 info)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700199{
200 const struct iphdr *iph = (struct iphdr *)skb->data;
Wei Yongjun18e1d832008-07-26 11:59:10 +0100201 const u8 offset = iph->ihl << 2;
202 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700203 struct dccp_sock *dp;
204 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300205 const int type = icmp_hdr(skb)->type;
206 const int code = icmp_hdr(skb)->code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700207 struct sock *sk;
208 __u64 seq;
209 int err;
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700210 struct net *net = dev_net(skb->dev);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700211
Wei Yongjun18e1d832008-07-26 11:59:10 +0100212 if (skb->len < offset + sizeof(*dh) ||
213 skb->len < offset + __dccp_basic_hdr_len(dh)) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700214 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700215 return;
216 }
217
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700218 sk = inet_lookup(net, &dccp_hashinfo,
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700219 iph->daddr, dh->dccph_dport,
220 iph->saddr, dh->dccph_sport, inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700221 if (sk == NULL) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700222 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700223 return;
224 }
225
226 if (sk->sk_state == DCCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700227 inet_twsk_put(inet_twsk(sk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700228 return;
229 }
230
231 bh_lock_sock(sk);
232 /* If too many ICMPs get dropped on busy
233 * servers this needs to be solved differently.
234 */
235 if (sock_owned_by_user(sk))
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700236 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700237
238 if (sk->sk_state == DCCP_CLOSED)
239 goto out;
240
241 dp = dccp_sk(sk);
Gerrit Renkerfde20102007-10-24 10:12:09 -0200242 seq = dccp_hdr_seq(dh);
Gerrit Renker1238d082007-10-24 10:18:06 -0200243 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
Wei Yongjund68f0862008-07-26 11:59:10 +0100244 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700245 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700246 goto out;
247 }
248
249 switch (type) {
250 case ICMP_SOURCE_QUENCH:
251 /* Just silently ignore these. */
252 goto out;
253 case ICMP_PARAMETERPROB:
254 err = EPROTO;
255 break;
256 case ICMP_DEST_UNREACH:
257 if (code > NR_ICMP_UNREACH)
258 goto out;
259
260 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
261 if (!sock_owned_by_user(sk))
262 dccp_do_pmtu_discovery(sk, iph, info);
263 goto out;
264 }
265
266 err = icmp_err_convert[code].errno;
267 break;
268 case ICMP_TIME_EXCEEDED:
269 err = EHOSTUNREACH;
270 break;
271 default:
272 goto out;
273 }
274
275 switch (sk->sk_state) {
276 struct request_sock *req , **prev;
277 case DCCP_LISTEN:
278 if (sock_owned_by_user(sk))
279 goto out;
280 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
281 iph->daddr, iph->saddr);
282 if (!req)
283 goto out;
284
285 /*
286 * ICMPs are not backlogged, hence we cannot get an established
287 * socket here.
288 */
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700289 WARN_ON(req->sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700290
291 if (seq != dccp_rsk(req)->dreq_iss) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700292 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700293 goto out;
294 }
295 /*
296 * Still in RESPOND, just remove it silently.
297 * There is no good way to pass the error to the newly
298 * created socket, and POSIX does not want network
299 * errors returned from accept().
300 */
301 inet_csk_reqsk_queue_drop(sk, req, prev);
302 goto out;
303
304 case DCCP_REQUESTING:
305 case DCCP_RESPOND:
306 if (!sock_owned_by_user(sk)) {
307 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
308 sk->sk_err = err;
309
310 sk->sk_error_report(sk);
311
312 dccp_done(sk);
313 } else
314 sk->sk_err_soft = err;
315 goto out;
316 }
317
318 /* If we've already connected we will keep trying
319 * until we time out, or the user gives up.
320 *
321 * rfc1122 4.2.3.9 allows to consider as hard errors
322 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
323 * but it is obsoleted by pmtu discovery).
324 *
325 * Note, that in modern internet, where routing is unreliable
326 * and in each dark corner broken firewalls sit, sending random
327 * errors ordered by their masters even this two messages finally lose
328 * their original sense (even Linux sends invalid PORT_UNREACHs)
329 *
330 * Now we are in compliance with RFCs.
331 * --ANK (980905)
332 */
333
334 inet = inet_sk(sk);
335 if (!sock_owned_by_user(sk) && inet->recverr) {
336 sk->sk_err = err;
337 sk->sk_error_report(sk);
338 } else /* Only an error on timeout */
339 sk->sk_err_soft = err;
340out:
341 bh_unlock_sock(sk);
342 sock_put(sk);
343}
344
Al Viro2bda2852006-11-14 21:28:51 -0800345static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200346 __be32 src, __be32 dst)
347{
348 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
349}
350
351void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800352{
353 const struct inet_sock *inet = inet_sk(sk);
354 struct dccp_hdr *dh = dccp_hdr(skb);
355
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200356 dccp_csum_outgoing(skb);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000357 dh->dccph_checksum = dccp_v4_csum_finish(skb,
358 inet->inet_saddr,
359 inet->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;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700384 struct sock *newsk;
385
386 if (sk_acceptq_is_full(sk))
387 goto exit_overflow;
388
389 if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
390 goto exit;
391
392 newsk = dccp_create_openreq_child(sk, req, skb);
393 if (newsk == NULL)
394 goto exit;
395
396 sk_setup_caps(newsk, dst);
397
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700398 newinet = inet_sk(newsk);
399 ireq = inet_rsk(req);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000400 newinet->inet_daddr = ireq->rmt_addr;
401 newinet->inet_rcv_saddr = ireq->loc_addr;
402 newinet->inet_saddr = ireq->loc_addr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700403 newinet->opt = ireq->opt;
404 ireq->opt = NULL;
405 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700406 newinet->mc_ttl = ip_hdr(skb)->ttl;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000407 newinet->inet_id = jiffies;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700408
409 dccp_sync_mss(newsk, dst_mtu(dst));
410
Eric Dumazet9327f702009-12-04 03:46:54 +0000411 __inet_hash_nolisten(newsk, NULL);
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800412 __inet_inherit_port(sk, newsk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700413
414 return newsk;
415
416exit_overflow:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700417 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700418exit:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700419 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700420 dst_release(dst);
421 return NULL;
422}
423
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800424EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
425
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700426static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
427{
428 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700429 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700430 struct sock *nsk;
431 struct request_sock **prev;
432 /* Find possible connection requests. */
433 struct request_sock *req = inet_csk_search_req(sk, &prev,
434 dh->dccph_sport,
435 iph->saddr, iph->daddr);
436 if (req != NULL)
437 return dccp_check_req(sk, skb, req, prev);
438
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700439 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
Herbert Xu8f491062006-08-09 15:47:12 -0700440 iph->saddr, dh->dccph_sport,
441 iph->daddr, dh->dccph_dport,
442 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700443 if (nsk != NULL) {
444 if (nsk->sk_state != DCCP_TIME_WAIT) {
445 bh_lock_sock(nsk);
446 return nsk;
447 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700448 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700449 return NULL;
450 }
451
452 return sk;
453}
454
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700455static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700456 struct sk_buff *skb)
457{
458 struct rtable *rt;
Eric Dumazet511c3f92009-06-02 05:14:27 +0000459 struct flowi fl = { .oif = skb_rtable(skb)->rt_iif,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700460 .nl_u = { .ip4_u =
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700461 { .daddr = ip_hdr(skb)->saddr,
462 .saddr = ip_hdr(skb)->daddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700463 .tos = RT_CONN_FLAGS(sk) } },
464 .proto = sk->sk_protocol,
465 .uli_u = { .ports =
466 { .sport = dccp_hdr(skb)->dccph_dport,
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300467 .dport = dccp_hdr(skb)->dccph_sport }
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200468 }
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300469 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700470
Venkat Yekkiralabeb8d132006-08-04 23:12:42 -0700471 security_skb_classify_flow(skb, &fl);
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700472 if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700473 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700474 return NULL;
475 }
476
477 return &rt->u.dst;
478}
479
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000480static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
481 struct request_values *rv_unused)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200482{
483 int err = -1;
484 struct sk_buff *skb;
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800485 struct dst_entry *dst;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200486
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800487 dst = inet_csk_route_req(sk, req);
488 if (dst == NULL)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200489 goto out;
490
491 skb = dccp_make_response(sk, dst, req);
492 if (skb != NULL) {
493 const struct inet_request_sock *ireq = inet_rsk(req);
494 struct dccp_hdr *dh = dccp_hdr(skb);
495
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200496 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
497 ireq->rmt_addr);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200498 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
499 ireq->rmt_addr,
500 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200501 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200502 }
503
504out:
505 dst_release(dst);
506 return err;
507}
508
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800509static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700510{
511 int err;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700512 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700513 struct sk_buff *skb;
514 struct dst_entry *dst;
Eric Dumazetadf30902009-06-02 05:19:30 +0000515 struct net *net = dev_net(skb_dst(rxskb)->dev);
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -0700516 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700517
518 /* Never send a reset in response to a reset. */
Gerrit Renkere356d372007-09-26 14:35:19 -0300519 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700520 return;
521
Eric Dumazet511c3f92009-06-02 05:14:27 +0000522 if (skb_rtable(rxskb)->rt_type != RTN_LOCAL)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700523 return;
524
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700525 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700526 if (dst == NULL)
527 return;
528
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700529 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700530 if (skb == NULL)
531 goto out;
532
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700533 rxiph = ip_hdr(rxskb);
Gerrit Renkere356d372007-09-26 14:35:19 -0300534 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
535 rxiph->daddr);
Eric Dumazetadf30902009-06-02 05:19:30 +0000536 skb_dst_set(skb, dst_clone(dst));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700537
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700538 bh_lock_sock(ctl_sk);
539 err = ip_build_and_send_pkt(skb, ctl_sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700540 rxiph->daddr, rxiph->saddr, NULL);
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700541 bh_unlock_sock(ctl_sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700542
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200543 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700544 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
545 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
546 }
547out:
548 dst_release(dst);
549}
550
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200551static void dccp_v4_reqsk_destructor(struct request_sock *req)
552{
Gerrit Renkerd99a7bd2008-11-04 23:56:30 -0800553 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200554 kfree(inet_rsk(req)->opt);
555}
556
557static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
558 .family = PF_INET,
559 .obj_size = sizeof(struct dccp_request_sock),
560 .rtx_syn_ack = dccp_v4_send_response,
561 .send_ack = dccp_reqsk_send_ack,
562 .destructor = dccp_v4_reqsk_destructor,
563 .send_reset = dccp_v4_ctl_send_reset,
564};
565
566int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
567{
568 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200569 struct request_sock *req;
570 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200571 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200572 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200573
574 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
Eric Dumazet511c3f92009-06-02 05:14:27 +0000575 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700576 return 0; /* discard, don't send a reset here */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200577
578 if (dccp_bad_service_code(sk, service)) {
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700579 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200580 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200581 }
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200582 /*
583 * TW buckets are converted to open requests without
584 * limitations, they conserve resources and peer is
585 * evidently real one.
586 */
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700587 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200588 if (inet_csk_reqsk_queue_is_full(sk))
589 goto drop;
590
591 /*
592 * Accept backlog is full. If we have already queued enough
593 * of warm entries in syn queue, drop request. It is better than
594 * clogging syn queue with openreqs with exponentially increasing
595 * timeout.
596 */
597 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
598 goto drop;
599
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -0700600 req = inet_reqsk_alloc(&dccp_request_sock_ops);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200601 if (req == NULL)
602 goto drop;
603
Gerrit Renkerac757732008-11-04 23:55:49 -0800604 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
605 goto drop_and_free;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200606
Gerrit Renker8b819412007-12-13 12:29:24 -0200607 dreq = dccp_rsk(req);
608 if (dccp_parse_options(sk, dreq, skb))
609 goto drop_and_free;
610
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200611 if (security_inet_conn_request(sk, skb, req))
612 goto drop_and_free;
613
614 ireq = inet_rsk(req);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700615 ireq->loc_addr = ip_hdr(skb)->daddr;
616 ireq->rmt_addr = ip_hdr(skb)->saddr;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200617
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200618 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200619 * Step 3: Process LISTEN state
620 *
621 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
622 *
623 * In fact we defer setting S.GSR, S.SWL, S.SWH to
624 * dccp_create_openreq_child.
625 */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200626 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200627 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200628 dreq->dreq_service = service;
629
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000630 if (dccp_v4_send_response(sk, req, NULL))
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200631 goto drop_and_free;
632
633 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
634 return 0;
635
636drop_and_free:
637 reqsk_free(req);
638drop:
639 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200640 return -1;
641}
642
643EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
644
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700645int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
646{
647 struct dccp_hdr *dh = dccp_hdr(skb);
648
649 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
650 if (dccp_rcv_established(sk, skb, dh, skb->len))
651 goto reset;
652 return 0;
653 }
654
655 /*
656 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200657 * If P.type == Request or P contains a valid Init Cookie option,
658 * (* Must scan the packet's options to check for Init
659 * Cookies. Only Init Cookies are processed here,
660 * however; other options are processed in Step 8. This
661 * scan need only be performed if the endpoint uses Init
662 * Cookies *)
663 * (* Generate a new socket and switch to that socket *)
664 * Set S := new socket for this port pair
665 * S.state = RESPOND
666 * Choose S.ISS (initial seqno) or set from Init Cookies
667 * Initialize S.GAR := S.ISS
668 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
669 * Continue with S.state == RESPOND
670 * (* A Response packet will be generated in Step 11 *)
671 * Otherwise,
672 * Generate Reset(No Connection) unless P.type == Reset
673 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700674 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300675 * NOTE: the check for the packet types is done in
676 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700677 */
678 if (sk->sk_state == DCCP_LISTEN) {
679 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
680
681 if (nsk == NULL)
682 goto discard;
683
684 if (nsk != sk) {
685 if (dccp_child_process(sk, nsk, skb))
686 goto reset;
687 return 0;
688 }
689 }
690
691 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
692 goto reset;
693 return 0;
694
695reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800696 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700697discard:
698 kfree_skb(skb);
699 return 0;
700}
701
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800702EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
703
Gerrit Renker09dbc382006-11-14 12:57:34 -0200704/**
705 * dccp_invalid_packet - check for malformed packets
706 * Implements RFC 4340, 8.5: Step 1: Check header basics
707 * Packets that fail these checks are ignored and do not receive Resets.
708 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800709int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700710{
711 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200712 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700713
714 if (skb->pkt_type != PACKET_HOST)
715 return 1;
716
Gerrit Renker09dbc382006-11-14 12:57:34 -0200717 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700718 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200719 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700720 return 1;
721 }
722
723 dh = dccp_hdr(skb);
724
Gerrit Renker09dbc382006-11-14 12:57:34 -0200725 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700726 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200727 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700728 return 1;
729 }
730
731 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200732 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700733 */
734 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200735 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700736 return 1;
737 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200738 /*
739 * If P.Data Offset is too too large for packet, drop packet and return
740 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700741 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200742 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700743 return 1;
744 }
745
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700746 /*
747 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
748 * has short sequence numbers), drop packet and return
749 */
Wei Yongjun6079a462008-05-27 06:22:38 -0700750 if ((dh->dccph_type < DCCP_PKT_DATA ||
751 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200752 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
753 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700754 return 1;
755 }
756
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200757 /*
758 * If P.CsCov is too large for the packet size, drop packet and return.
759 * This must come _before_ checksumming (not as RFC 4340 suggests).
760 */
761 cscov = dccp_csum_coverage(skb);
762 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200763 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
764 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200765 return 1;
766 }
767
768 /* If header checksum is incorrect, drop packet and return.
769 * (This step is completed in the AF-dependent functions.) */
770 skb->csum = skb_checksum(skb, 0, cscov, 0);
771
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700772 return 0;
773}
774
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800775EXPORT_SYMBOL_GPL(dccp_invalid_packet);
776
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700777/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800778static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700779{
780 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700781 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700782 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200783 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700784
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200785 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700786
787 if (dccp_invalid_packet(skb))
788 goto discard_it;
789
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700790 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200791 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700792 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200793 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800794 goto discard_it;
795 }
796
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700797 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700798
Gerrit Renkerfde20102007-10-24 10:12:09 -0200799 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700800 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
801
Harvey Harrison21454aa2008-10-31 00:54:56 -0700802 dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu",
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700803 dccp_packet_name(dh->dccph_type),
Harvey Harrison21454aa2008-10-31 00:54:56 -0700804 &iph->saddr, ntohs(dh->dccph_sport),
805 &iph->daddr, ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700806 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700807
808 if (dccp_packet_without_ack(skb)) {
809 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
810 dccp_pr_debug_cat("\n");
811 } else {
812 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200813 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700814 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700815 }
816
817 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200818 * Look up flow ID in table and get corresponding socket */
Arnaldo Carvalho de Melo9a1f27c2008-10-07 11:41:57 -0700819 sk = __inet_lookup_skb(&dccp_hashinfo, skb,
820 dh->dccph_sport, dh->dccph_dport);
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200821 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700822 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200823 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700824 */
825 if (sk == NULL) {
826 dccp_pr_debug("failed to look up flow ID in table and "
827 "get corresponding socket\n");
828 goto no_dccp_socket;
829 }
830
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200831 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700832 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200833 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700834 * Generate Reset(No Connection) unless P.type == Reset
835 * Drop packet and return
836 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700837 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200838 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
839 inet_twsk_put(inet_twsk(sk));
840 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700841 }
842
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200843 /*
844 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200845 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
846 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200847 */
848 min_cov = dccp_sk(sk)->dccps_pcrlen;
849 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
850 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
851 dh->dccph_cscov, min_cov);
852 /* FIXME: "Such packets SHOULD be reported using Data Dropped
853 * options (Section 11.7) with Drop Code 0, Protocol
854 * Constraints." */
855 goto discard_and_relse;
856 }
857
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200858 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700859 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800860 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700861
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200862 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700863
864no_dccp_socket:
865 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
866 goto discard_it;
867 /*
868 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200869 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700870 * Generate Reset(No Connection) unless P.type == Reset
871 * Drop packet and return
872 */
873 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300874 DCCP_SKB_CB(skb)->dccpd_reset_code =
875 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800876 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700877 }
878
879discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700880 kfree_skb(skb);
881 return 0;
882
883discard_and_relse:
884 sock_put(sk);
885 goto discard_it;
886}
887
Stephen Hemminger3b401a82009-09-01 19:25:04 +0000888static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800889 .queue_xmit = ip_queue_xmit,
890 .send_check = dccp_v4_send_check,
891 .rebuild_header = inet_sk_rebuild_header,
892 .conn_request = dccp_v4_conn_request,
893 .syn_recv_sock = dccp_v4_request_recv_sock,
894 .net_header_len = sizeof(struct iphdr),
895 .setsockopt = ip_setsockopt,
896 .getsockopt = ip_getsockopt,
897 .addr2sockaddr = inet_csk_addr2sockaddr,
898 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800899 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800900#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800901 .compat_setsockopt = compat_ip_setsockopt,
902 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800903#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800904};
905
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800906static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700907{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800908 static __u8 dccp_v4_ctl_sock_initialized;
909 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700910
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800911 if (err == 0) {
912 if (unlikely(!dccp_v4_ctl_sock_initialized))
913 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800914 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800915 }
916
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800917 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700918}
919
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800920static struct timewait_sock_ops dccp_timewait_sock_ops = {
921 .twsk_obj_size = sizeof(struct inet_timewait_sock),
922};
923
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800924static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700925 .name = "DCCP",
926 .owner = THIS_MODULE,
927 .close = dccp_close,
928 .connect = dccp_v4_connect,
929 .disconnect = dccp_disconnect,
930 .ioctl = dccp_ioctl,
931 .init = dccp_v4_init_sock,
932 .setsockopt = dccp_setsockopt,
933 .getsockopt = dccp_getsockopt,
934 .sendmsg = dccp_sendmsg,
935 .recvmsg = dccp_recvmsg,
936 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800937 .hash = inet_hash,
938 .unhash = inet_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700939 .accept = inet_csk_accept,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800940 .get_port = inet_csk_get_port,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700941 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800942 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700943 .orphan_count = &dccp_orphan_count,
944 .max_header = MAX_DCCP_HEADER,
945 .obj_size = sizeof(struct dccp_sock),
Eric Dumazet3ab5aee2008-11-16 19:40:17 -0800946 .slab_flags = SLAB_DESTROY_BY_RCU,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700947 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800948 .twsk_prot = &dccp_timewait_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -0700949 .h.hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800950#ifdef CONFIG_COMPAT
951 .compat_setsockopt = compat_dccp_setsockopt,
952 .compat_getsockopt = compat_dccp_getsockopt,
953#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700954};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800955
Alexey Dobriyan32613092009-09-14 12:21:47 +0000956static const struct net_protocol dccp_v4_protocol = {
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800957 .handler = dccp_v4_rcv,
958 .err_handler = dccp_v4_err,
959 .no_policy = 1,
Pavel Emelyanovfc5f8582008-04-13 22:31:05 -0700960 .netns_ok = 1,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800961};
962
963static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800964 .family = PF_INET,
965 .owner = THIS_MODULE,
966 .release = inet_release,
967 .bind = inet_bind,
968 .connect = inet_stream_connect,
969 .socketpair = sock_no_socketpair,
970 .accept = inet_accept,
971 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800972 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800973 .poll = dccp_poll,
974 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800975 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800976 .listen = inet_dccp_listen,
977 .shutdown = inet_shutdown,
978 .setsockopt = sock_common_setsockopt,
979 .getsockopt = sock_common_getsockopt,
980 .sendmsg = inet_sendmsg,
981 .recvmsg = sock_common_recvmsg,
982 .mmap = sock_no_mmap,
983 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800984#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800985 .compat_setsockopt = compat_sock_common_setsockopt,
986 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800987#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800988};
989
990static struct inet_protosw dccp_v4_protosw = {
991 .type = SOCK_DCCP,
992 .protocol = IPPROTO_DCCP,
993 .prot = &dccp_v4_prot,
994 .ops = &inet_dccp_ops,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800995 .no_check = 0,
996 .flags = INET_PROTOSW_ICSK,
997};
998
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +0000999static int __net_init dccp_v4_init_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001000{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001001 int err;
1002
1003 err = inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
1004 SOCK_DCCP, IPPROTO_DCCP, net);
1005 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001006}
1007
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001008static void __net_exit dccp_v4_exit_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001009{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001010 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001011}
1012
1013static struct pernet_operations dccp_v4_ops = {
1014 .init = dccp_v4_init_net,
1015 .exit = dccp_v4_exit_net,
1016};
1017
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001018static int __init dccp_v4_init(void)
1019{
1020 int err = proto_register(&dccp_v4_prot, 1);
1021
1022 if (err != 0)
1023 goto out;
1024
1025 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1026 if (err != 0)
1027 goto out_proto_unregister;
1028
1029 inet_register_protosw(&dccp_v4_protosw);
1030
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001031 err = register_pernet_subsys(&dccp_v4_ops);
1032 if (err)
1033 goto out_destroy_ctl_sock;
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001034out:
1035 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001036out_destroy_ctl_sock:
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001037 inet_unregister_protosw(&dccp_v4_protosw);
1038 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1039out_proto_unregister:
1040 proto_unregister(&dccp_v4_prot);
1041 goto out;
1042}
1043
1044static void __exit dccp_v4_exit(void)
1045{
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001046 unregister_pernet_subsys(&dccp_v4_ops);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001047 inet_unregister_protosw(&dccp_v4_protosw);
1048 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1049 proto_unregister(&dccp_v4_prot);
1050}
1051
1052module_init(dccp_v4_init);
1053module_exit(dccp_v4_exit);
1054
1055/*
1056 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1057 * values directly, Also cover the case where the protocol is not specified,
1058 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1059 */
Jean Delvare7131c6c2007-10-21 16:45:03 -07001060MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1061MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001062MODULE_LICENSE("GPL");
1063MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1064MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");