blob: caf6e1734b6296b92a8d4223632a264d9ee09075 [file] [log] [blame]
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001/*
2 * net/dccp/ipv4.c
3 *
4 * An implementation of the DCCP protocol
5 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070013#include <linux/dccp.h>
14#include <linux/icmp.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090015#include <linux/slab.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070016#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>
David S. Miller6e5714e2011-08-03 20:50:44 -070029#include <net/secure_seq.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070030
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070031#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070032#include "ccid.h"
33#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080034#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070035
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080036/*
Pavel Emelyanov13f51d82008-04-14 02:38:45 -070037 * The per-net dccp.v4_ctl_sk socket is used for responding to
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080038 * the Out-of-the-blue (OOTB) packets. A control sock will be created
39 * for this socket at the initialization time.
40 */
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -080041
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -080042int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070043{
David S. Miller2d7192d2011-04-26 13:28:44 -070044 const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070045 struct inet_sock *inet = inet_sk(sk);
46 struct dccp_sock *dp = dccp_sk(sk);
David S. Millerdca8b082011-02-24 13:38:12 -080047 __be16 orig_sport, orig_dport;
Al Virobada8ad2006-09-26 21:27:15 -070048 __be32 daddr, nexthop;
David S. Miller2c427582011-05-06 16:10:41 -070049 struct flowi4 *fl4;
David S. Miller2d7192d2011-04-26 13:28:44 -070050 struct rtable *rt;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070051 int err;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000052 struct ip_options_rcu *inet_opt;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070053
54 dp->dccps_role = DCCP_ROLE_CLIENT;
55
56 if (addr_len < sizeof(struct sockaddr_in))
57 return -EINVAL;
58
59 if (usin->sin_family != AF_INET)
60 return -EAFNOSUPPORT;
61
62 nexthop = daddr = usin->sin_addr.s_addr;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000063
64 inet_opt = rcu_dereference_protected(inet->inet_opt,
65 sock_owned_by_user(sk));
66 if (inet_opt != NULL && inet_opt->opt.srr) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070067 if (daddr == 0)
68 return -EINVAL;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000069 nexthop = inet_opt->opt.faddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070070 }
71
David S. Millerdca8b082011-02-24 13:38:12 -080072 orig_sport = inet->inet_sport;
73 orig_dport = usin->sin_port;
David S. Miller2c427582011-05-06 16:10:41 -070074 fl4 = &inet->cork.fl.u.ip4;
75 rt = ip_route_connect(fl4, nexthop, inet->inet_saddr,
David S. Millerb23dd4f2011-03-02 14:31:35 -080076 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
77 IPPROTO_DCCP,
78 orig_sport, orig_dport, sk, true);
79 if (IS_ERR(rt))
80 return PTR_ERR(rt);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070081
82 if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
83 ip_rt_put(rt);
84 return -ENETUNREACH;
85 }
86
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000087 if (inet_opt == NULL || !inet_opt->opt.srr)
David S. Miller2c427582011-05-06 16:10:41 -070088 daddr = fl4->daddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070089
Eric Dumazetc720c7e2009-10-15 06:30:45 +000090 if (inet->inet_saddr == 0)
David S. Miller2c427582011-05-06 16:10:41 -070091 inet->inet_saddr = fl4->saddr;
Eric Dumazetc720c7e2009-10-15 06:30:45 +000092 inet->inet_rcv_saddr = inet->inet_saddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070093
Eric Dumazetc720c7e2009-10-15 06:30:45 +000094 inet->inet_dport = usin->sin_port;
95 inet->inet_daddr = daddr;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070096
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -080097 inet_csk(sk)->icsk_ext_hdr_len = 0;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +000098 if (inet_opt)
99 inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700100 /*
101 * Socket identity is still unknown (sport may be zero).
102 * However we set state to DCCP_REQUESTING and not releasing socket
103 * lock select source port, enter ourselves into the hash tables and
104 * complete initialization after this.
105 */
106 dccp_set_state(sk, DCCP_REQUESTING);
Arnaldo Carvalho de Meloa7f5e7f2005-12-13 23:25:31 -0800107 err = inet_hash_connect(&dccp_death_row, sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700108 if (err != 0)
109 goto failure;
110
David S. Miller2c427582011-05-06 16:10:41 -0700111 rt = ip_route_newports(fl4, rt, orig_sport, orig_dport,
David S. Millerb23dd4f2011-03-02 14:31:35 -0800112 inet->inet_sport, inet->inet_dport, sk);
113 if (IS_ERR(rt)) {
RongQing.Li525c6462011-11-21 16:45:26 -0500114 err = PTR_ERR(rt);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800115 rt = NULL;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700116 goto failure;
David S. Millerb23dd4f2011-03-02 14:31:35 -0800117 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700118 /* OK, now commit destination to socket. */
Changli Gaod8d1f302010-06-10 23:31:35 -0700119 sk_setup_caps(sk, &rt->dst);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700120
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000121 dp->dccps_iss = secure_dccp_sequence_number(inet->inet_saddr,
122 inet->inet_daddr,
123 inet->inet_sport,
124 inet->inet_dport);
125 inet->inet_id = dp->dccps_iss ^ jiffies;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700126
127 err = dccp_connect(sk);
128 rt = NULL;
129 if (err != 0)
130 goto failure;
131out:
132 return err;
133failure:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300134 /*
135 * This unhashes the socket and releases the local port, if necessary.
136 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700137 dccp_set_state(sk, DCCP_CLOSED);
138 ip_rt_put(rt);
139 sk->sk_route_caps = 0;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000140 inet->inet_dport = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700141 goto out;
142}
143
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800144EXPORT_SYMBOL_GPL(dccp_v4_connect);
145
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700146/*
147 * This routine does path mtu discovery as defined in RFC1191.
148 */
149static inline void dccp_do_pmtu_discovery(struct sock *sk,
150 const struct iphdr *iph,
151 u32 mtu)
152{
153 struct dst_entry *dst;
154 const struct inet_sock *inet = inet_sk(sk);
155 const struct dccp_sock *dp = dccp_sk(sk);
156
157 /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs
158 * send out by Linux are always < 576bytes so they should go through
159 * unfragmented).
160 */
161 if (sk->sk_state == DCCP_LISTEN)
162 return;
163
164 /* We don't check in the destentry if pmtu discovery is forbidden
165 * on this route. We just assume that no packet_to_big packets
166 * are send back when pmtu discovery is not active.
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900167 * There is a small race when the user changes this flag in the
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700168 * route, but I think that's acceptable.
169 */
170 if ((dst = __sk_dst_check(sk, 0)) == NULL)
171 return;
172
173 dst->ops->update_pmtu(dst, mtu);
174
175 /* Something is about to be wrong... Remember soft error
176 * for the case, if this connection will not able to recover.
177 */
178 if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
179 sk->sk_err_soft = EMSGSIZE;
180
181 mtu = dst_mtu(dst);
182
183 if (inet->pmtudisc != IP_PMTUDISC_DONT &&
Arnaldo Carvalho de Melod83d8462005-12-13 23:26:10 -0800184 inet_csk(sk)->icsk_pmtu_cookie > mtu) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700185 dccp_sync_mss(sk, mtu);
186
187 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700188 * From RFC 4340, sec. 14.1:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700189 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300190 * DCCP-Sync packets are the best choice for upward
191 * probing, since DCCP-Sync probes do not risk application
192 * data loss.
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700193 */
Arnaldo Carvalho de Meloe92ae932005-08-17 03:10:59 -0300194 dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700195 } /* else let the usual retransmit timer handle it */
196}
197
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700198/*
199 * This routine is called by the ICMP module when it gets some sort of error
200 * condition. If err < 0 then the socket should be closed and the error
201 * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code.
202 * After adjustment header points to the first 8 bytes of the tcp header. We
203 * need to find the appropriate port.
204 *
205 * The locking strategy used here is very "optimistic". When someone else
206 * accesses the socket the ICMP is just dropped and for some paths there is no
207 * check at all. A more general error queue to queue errors for later handling
208 * is probably better.
209 */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800210static void dccp_v4_err(struct sk_buff *skb, u32 info)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700211{
212 const struct iphdr *iph = (struct iphdr *)skb->data;
Wei Yongjun18e1d832008-07-26 11:59:10 +0100213 const u8 offset = iph->ihl << 2;
214 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700215 struct dccp_sock *dp;
216 struct inet_sock *inet;
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300217 const int type = icmp_hdr(skb)->type;
218 const int code = icmp_hdr(skb)->code;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700219 struct sock *sk;
220 __u64 seq;
221 int err;
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700222 struct net *net = dev_net(skb->dev);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700223
Wei Yongjun18e1d832008-07-26 11:59:10 +0100224 if (skb->len < offset + sizeof(*dh) ||
225 skb->len < offset + __dccp_basic_hdr_len(dh)) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700226 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700227 return;
228 }
229
Pavel Emelyanovfd54d712008-07-14 23:01:40 -0700230 sk = inet_lookup(net, &dccp_hashinfo,
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700231 iph->daddr, dh->dccph_dport,
232 iph->saddr, dh->dccph_sport, inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700233 if (sk == NULL) {
Pavel Emelyanovdcfc23c2008-07-14 23:03:00 -0700234 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700235 return;
236 }
237
238 if (sk->sk_state == DCCP_TIME_WAIT) {
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700239 inet_twsk_put(inet_twsk(sk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700240 return;
241 }
242
243 bh_lock_sock(sk);
244 /* If too many ICMPs get dropped on busy
245 * servers this needs to be solved differently.
246 */
247 if (sock_owned_by_user(sk))
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700248 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700249
250 if (sk->sk_state == DCCP_CLOSED)
251 goto out;
252
253 dp = dccp_sk(sk);
Gerrit Renkerfde20102007-10-24 10:12:09 -0200254 seq = dccp_hdr_seq(dh);
Gerrit Renker1238d082007-10-24 10:18:06 -0200255 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
Wei Yongjund68f0862008-07-26 11:59:10 +0100256 !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700257 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700258 goto out;
259 }
260
261 switch (type) {
262 case ICMP_SOURCE_QUENCH:
263 /* Just silently ignore these. */
264 goto out;
265 case ICMP_PARAMETERPROB:
266 err = EPROTO;
267 break;
268 case ICMP_DEST_UNREACH:
269 if (code > NR_ICMP_UNREACH)
270 goto out;
271
272 if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
273 if (!sock_owned_by_user(sk))
274 dccp_do_pmtu_discovery(sk, iph, info);
275 goto out;
276 }
277
278 err = icmp_err_convert[code].errno;
279 break;
280 case ICMP_TIME_EXCEEDED:
281 err = EHOSTUNREACH;
282 break;
283 default:
284 goto out;
285 }
286
287 switch (sk->sk_state) {
288 struct request_sock *req , **prev;
289 case DCCP_LISTEN:
290 if (sock_owned_by_user(sk))
291 goto out;
292 req = inet_csk_search_req(sk, &prev, dh->dccph_dport,
293 iph->daddr, iph->saddr);
294 if (!req)
295 goto out;
296
297 /*
298 * ICMPs are not backlogged, hence we cannot get an established
299 * socket here.
300 */
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700301 WARN_ON(req->sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700302
Samuel Jerof541fb72012-02-26 18:22:02 -0700303 if (!between48(seq, dccp_rsk(req)->dreq_iss,
304 dccp_rsk(req)->dreq_gss)) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700305 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700306 goto out;
307 }
308 /*
309 * Still in RESPOND, just remove it silently.
310 * There is no good way to pass the error to the newly
311 * created socket, and POSIX does not want network
312 * errors returned from accept().
313 */
314 inet_csk_reqsk_queue_drop(sk, req, prev);
315 goto out;
316
317 case DCCP_REQUESTING:
318 case DCCP_RESPOND:
319 if (!sock_owned_by_user(sk)) {
320 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
321 sk->sk_err = err;
322
323 sk->sk_error_report(sk);
324
325 dccp_done(sk);
326 } else
327 sk->sk_err_soft = err;
328 goto out;
329 }
330
331 /* If we've already connected we will keep trying
332 * until we time out, or the user gives up.
333 *
334 * rfc1122 4.2.3.9 allows to consider as hard errors
335 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
336 * but it is obsoleted by pmtu discovery).
337 *
338 * Note, that in modern internet, where routing is unreliable
339 * and in each dark corner broken firewalls sit, sending random
340 * errors ordered by their masters even this two messages finally lose
341 * their original sense (even Linux sends invalid PORT_UNREACHs)
342 *
343 * Now we are in compliance with RFCs.
344 * --ANK (980905)
345 */
346
347 inet = inet_sk(sk);
348 if (!sock_owned_by_user(sk) && inet->recverr) {
349 sk->sk_err = err;
350 sk->sk_error_report(sk);
351 } else /* Only an error on timeout */
352 sk->sk_err_soft = err;
353out:
354 bh_unlock_sock(sk);
355 sock_put(sk);
356}
357
Al Viro2bda2852006-11-14 21:28:51 -0800358static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200359 __be32 src, __be32 dst)
360{
361 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
362}
363
Herbert Xubb296242010-04-11 02:15:55 +0000364void dccp_v4_send_check(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800365{
366 const struct inet_sock *inet = inet_sk(sk);
367 struct dccp_hdr *dh = dccp_hdr(skb);
368
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200369 dccp_csum_outgoing(skb);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000370 dh->dccph_checksum = dccp_v4_csum_finish(skb,
371 inet->inet_saddr,
372 inet->inet_daddr);
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800373}
374
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800375EXPORT_SYMBOL_GPL(dccp_v4_send_check);
376
Gerrit Renker865e9022006-11-13 13:31:50 -0200377static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700378{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700379 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
380 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700381 dccp_hdr(skb)->dccph_dport,
382 dccp_hdr(skb)->dccph_sport);
383}
384
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700385/*
386 * The three way handshake has completed - we got a valid ACK or DATAACK -
387 * now create the new socket.
388 *
389 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
390 */
391struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
392 struct request_sock *req,
393 struct dst_entry *dst)
394{
395 struct inet_request_sock *ireq;
396 struct inet_sock *newinet;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700397 struct sock *newsk;
398
399 if (sk_acceptq_is_full(sk))
400 goto exit_overflow;
401
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700402 newsk = dccp_create_openreq_child(sk, req, skb);
403 if (newsk == NULL)
Balazs Scheidler093d2822010-10-21 13:06:43 +0200404 goto exit_nonewsk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700405
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700406 newinet = inet_sk(newsk);
407 ireq = inet_rsk(req);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000408 newinet->inet_daddr = ireq->rmt_addr;
409 newinet->inet_rcv_saddr = ireq->loc_addr;
410 newinet->inet_saddr = ireq->loc_addr;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000411 newinet->inet_opt = ireq->opt;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700412 ireq->opt = NULL;
413 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700414 newinet->mc_ttl = ip_hdr(skb)->ttl;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000415 newinet->inet_id = jiffies;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700416
David S. Miller0e734412011-05-08 15:28:03 -0700417 if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
418 goto put_and_exit;
419
420 sk_setup_caps(newsk, dst);
421
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700422 dccp_sync_mss(newsk, dst_mtu(dst));
423
David S. Miller0e734412011-05-08 15:28:03 -0700424 if (__inet_inherit_port(sk, newsk) < 0)
425 goto put_and_exit;
Eric Dumazet9327f702009-12-04 03:46:54 +0000426 __inet_hash_nolisten(newsk, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700427
428 return newsk;
429
430exit_overflow:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700431 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
Balazs Scheidler093d2822010-10-21 13:06:43 +0200432exit_nonewsk:
433 dst_release(dst);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700434exit:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700435 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700436 return NULL;
David S. Miller0e734412011-05-08 15:28:03 -0700437put_and_exit:
Eric Dumazet918eb392011-11-02 12:42:56 +0000438 bh_unlock_sock(newsk);
David S. Miller0e734412011-05-08 15:28:03 -0700439 sock_put(newsk);
440 goto exit;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700441}
442
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800443EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
444
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700445static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
446{
447 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700448 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700449 struct sock *nsk;
450 struct request_sock **prev;
451 /* Find possible connection requests. */
452 struct request_sock *req = inet_csk_search_req(sk, &prev,
453 dh->dccph_sport,
454 iph->saddr, iph->daddr);
455 if (req != NULL)
456 return dccp_check_req(sk, skb, req, prev);
457
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700458 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
Herbert Xu8f4910692006-08-09 15:47:12 -0700459 iph->saddr, dh->dccph_sport,
460 iph->daddr, dh->dccph_dport,
461 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700462 if (nsk != NULL) {
463 if (nsk->sk_state != DCCP_TIME_WAIT) {
464 bh_lock_sock(nsk);
465 return nsk;
466 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700467 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700468 return NULL;
469 }
470
471 return sk;
472}
473
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700474static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700475 struct sk_buff *skb)
476{
477 struct rtable *rt;
David S. Miller898f7352011-12-01 13:28:34 -0500478 const struct iphdr *iph = ip_hdr(skb);
David S. Miller9d6ec932011-03-12 01:12:47 -0500479 struct flowi4 fl4 = {
480 .flowi4_oif = skb_rtable(skb)->rt_iif,
David S. Miller898f7352011-12-01 13:28:34 -0500481 .daddr = iph->saddr,
482 .saddr = iph->daddr,
David S. Miller9d6ec932011-03-12 01:12:47 -0500483 .flowi4_tos = RT_CONN_FLAGS(sk),
484 .flowi4_proto = sk->sk_protocol,
David S. Miller9cce96d2011-03-12 03:00:33 -0500485 .fl4_sport = dccp_hdr(skb)->dccph_dport,
486 .fl4_dport = dccp_hdr(skb)->dccph_sport,
David S. Miller1d28f422011-03-12 00:29:39 -0500487 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700488
David S. Miller9d6ec932011-03-12 01:12:47 -0500489 security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
490 rt = ip_route_output_flow(net, &fl4, sk);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800491 if (IS_ERR(rt)) {
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700492 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700493 return NULL;
494 }
495
Changli Gaod8d1f302010-06-10 23:31:35 -0700496 return &rt->dst;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700497}
498
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000499static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
500 struct request_values *rv_unused)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200501{
502 int err = -1;
503 struct sk_buff *skb;
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800504 struct dst_entry *dst;
David S. Miller6bd023f2011-05-18 18:32:03 -0400505 struct flowi4 fl4;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200506
David S. Miller6bd023f2011-05-18 18:32:03 -0400507 dst = inet_csk_route_req(sk, &fl4, req);
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800508 if (dst == NULL)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200509 goto out;
510
511 skb = dccp_make_response(sk, dst, req);
512 if (skb != NULL) {
513 const struct inet_request_sock *ireq = inet_rsk(req);
514 struct dccp_hdr *dh = dccp_hdr(skb);
515
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200516 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
517 ireq->rmt_addr);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200518 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
519 ireq->rmt_addr,
520 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200521 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200522 }
523
524out:
525 dst_release(dst);
526 return err;
527}
528
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800529static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700530{
531 int err;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700532 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700533 struct sk_buff *skb;
534 struct dst_entry *dst;
Eric Dumazetadf30902009-06-02 05:19:30 +0000535 struct net *net = dev_net(skb_dst(rxskb)->dev);
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -0700536 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700537
538 /* Never send a reset in response to a reset. */
Gerrit Renkere356d372007-09-26 14:35:19 -0300539 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700540 return;
541
Eric Dumazet511c3f92009-06-02 05:14:27 +0000542 if (skb_rtable(rxskb)->rt_type != RTN_LOCAL)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700543 return;
544
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700545 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700546 if (dst == NULL)
547 return;
548
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700549 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700550 if (skb == NULL)
551 goto out;
552
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700553 rxiph = ip_hdr(rxskb);
Gerrit Renkere356d372007-09-26 14:35:19 -0300554 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
555 rxiph->daddr);
Eric Dumazetadf30902009-06-02 05:19:30 +0000556 skb_dst_set(skb, dst_clone(dst));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700557
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700558 bh_lock_sock(ctl_sk);
559 err = ip_build_and_send_pkt(skb, ctl_sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700560 rxiph->daddr, rxiph->saddr, NULL);
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700561 bh_unlock_sock(ctl_sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700562
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200563 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700564 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
565 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
566 }
567out:
568 dst_release(dst);
569}
570
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200571static void dccp_v4_reqsk_destructor(struct request_sock *req)
572{
Gerrit Renkerd99a7bd2008-11-04 23:56:30 -0800573 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200574 kfree(inet_rsk(req)->opt);
575}
576
577static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
578 .family = PF_INET,
579 .obj_size = sizeof(struct dccp_request_sock),
580 .rtx_syn_ack = dccp_v4_send_response,
581 .send_ack = dccp_reqsk_send_ack,
582 .destructor = dccp_v4_reqsk_destructor,
583 .send_reset = dccp_v4_ctl_send_reset,
584};
585
586int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
587{
588 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200589 struct request_sock *req;
590 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200591 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200592 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200593
594 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
Eric Dumazet511c3f92009-06-02 05:14:27 +0000595 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700596 return 0; /* discard, don't send a reset here */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200597
598 if (dccp_bad_service_code(sk, service)) {
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700599 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200600 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200601 }
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200602 /*
603 * TW buckets are converted to open requests without
604 * limitations, they conserve resources and peer is
605 * evidently real one.
606 */
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700607 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200608 if (inet_csk_reqsk_queue_is_full(sk))
609 goto drop;
610
611 /*
612 * Accept backlog is full. If we have already queued enough
613 * of warm entries in syn queue, drop request. It is better than
614 * clogging syn queue with openreqs with exponentially increasing
615 * timeout.
616 */
617 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
618 goto drop;
619
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -0700620 req = inet_reqsk_alloc(&dccp_request_sock_ops);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200621 if (req == NULL)
622 goto drop;
623
Gerrit Renkerac757732008-11-04 23:55:49 -0800624 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
625 goto drop_and_free;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200626
Gerrit Renker8b819412007-12-13 12:29:24 -0200627 dreq = dccp_rsk(req);
628 if (dccp_parse_options(sk, dreq, skb))
629 goto drop_and_free;
630
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200631 if (security_inet_conn_request(sk, skb, req))
632 goto drop_and_free;
633
634 ireq = inet_rsk(req);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700635 ireq->loc_addr = ip_hdr(skb)->daddr;
636 ireq->rmt_addr = ip_hdr(skb)->saddr;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200637
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200638 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200639 * Step 3: Process LISTEN state
640 *
641 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
642 *
Samuel Jerof541fb72012-02-26 18:22:02 -0700643 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200644 */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200645 dreq->dreq_isr = dcb->dccpd_seq;
Samuel Jerof541fb72012-02-26 18:22:02 -0700646 dreq->dreq_gsr = dreq->dreq_isr;
Gerrit Renker865e9022006-11-13 13:31:50 -0200647 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Samuel Jerof541fb72012-02-26 18:22:02 -0700648 dreq->dreq_gss = dreq->dreq_iss;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200649 dreq->dreq_service = service;
650
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000651 if (dccp_v4_send_response(sk, req, NULL))
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200652 goto drop_and_free;
653
654 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
655 return 0;
656
657drop_and_free:
658 reqsk_free(req);
659drop:
660 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200661 return -1;
662}
663
664EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
665
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700666int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
667{
668 struct dccp_hdr *dh = dccp_hdr(skb);
669
670 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
671 if (dccp_rcv_established(sk, skb, dh, skb->len))
672 goto reset;
673 return 0;
674 }
675
676 /*
677 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200678 * If P.type == Request or P contains a valid Init Cookie option,
679 * (* Must scan the packet's options to check for Init
680 * Cookies. Only Init Cookies are processed here,
681 * however; other options are processed in Step 8. This
682 * scan need only be performed if the endpoint uses Init
683 * Cookies *)
684 * (* Generate a new socket and switch to that socket *)
685 * Set S := new socket for this port pair
686 * S.state = RESPOND
687 * Choose S.ISS (initial seqno) or set from Init Cookies
688 * Initialize S.GAR := S.ISS
689 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
690 * Continue with S.state == RESPOND
691 * (* A Response packet will be generated in Step 11 *)
692 * Otherwise,
693 * Generate Reset(No Connection) unless P.type == Reset
694 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700695 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300696 * NOTE: the check for the packet types is done in
697 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700698 */
699 if (sk->sk_state == DCCP_LISTEN) {
700 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
701
702 if (nsk == NULL)
703 goto discard;
704
705 if (nsk != sk) {
706 if (dccp_child_process(sk, nsk, skb))
707 goto reset;
708 return 0;
709 }
710 }
711
712 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
713 goto reset;
714 return 0;
715
716reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800717 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700718discard:
719 kfree_skb(skb);
720 return 0;
721}
722
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800723EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
724
Gerrit Renker09dbc382006-11-14 12:57:34 -0200725/**
726 * dccp_invalid_packet - check for malformed packets
727 * Implements RFC 4340, 8.5: Step 1: Check header basics
728 * Packets that fail these checks are ignored and do not receive Resets.
729 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800730int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700731{
732 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200733 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700734
735 if (skb->pkt_type != PACKET_HOST)
736 return 1;
737
Gerrit Renker09dbc382006-11-14 12:57:34 -0200738 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700739 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200740 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700741 return 1;
742 }
743
744 dh = dccp_hdr(skb);
745
Gerrit Renker09dbc382006-11-14 12:57:34 -0200746 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700747 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200748 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700749 return 1;
750 }
751
752 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200753 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700754 */
755 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200756 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700757 return 1;
758 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200759 /*
760 * If P.Data Offset is too too large for packet, drop packet and return
761 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700762 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200763 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700764 return 1;
765 }
766
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700767 /*
768 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
769 * has short sequence numbers), drop packet and return
770 */
Wei Yongjun6079a462008-05-27 06:22:38 -0700771 if ((dh->dccph_type < DCCP_PKT_DATA ||
772 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200773 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
774 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700775 return 1;
776 }
777
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200778 /*
779 * If P.CsCov is too large for the packet size, drop packet and return.
780 * This must come _before_ checksumming (not as RFC 4340 suggests).
781 */
782 cscov = dccp_csum_coverage(skb);
783 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200784 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
785 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200786 return 1;
787 }
788
789 /* If header checksum is incorrect, drop packet and return.
790 * (This step is completed in the AF-dependent functions.) */
791 skb->csum = skb_checksum(skb, 0, cscov, 0);
792
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700793 return 0;
794}
795
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800796EXPORT_SYMBOL_GPL(dccp_invalid_packet);
797
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700798/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800799static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700800{
801 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700802 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700803 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200804 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700805
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200806 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700807
808 if (dccp_invalid_packet(skb))
809 goto discard_it;
810
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700811 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200812 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700813 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200814 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800815 goto discard_it;
816 }
817
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700818 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700819
Gerrit Renkerfde20102007-10-24 10:12:09 -0200820 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700821 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
822
Harvey Harrison21454aa2008-10-31 00:54:56 -0700823 dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu",
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700824 dccp_packet_name(dh->dccph_type),
Harvey Harrison21454aa2008-10-31 00:54:56 -0700825 &iph->saddr, ntohs(dh->dccph_sport),
826 &iph->daddr, ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700827 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700828
829 if (dccp_packet_without_ack(skb)) {
830 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
831 dccp_pr_debug_cat("\n");
832 } else {
833 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200834 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700835 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700836 }
837
838 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200839 * Look up flow ID in table and get corresponding socket */
Arnaldo Carvalho de Melo9a1f27c2008-10-07 11:41:57 -0700840 sk = __inet_lookup_skb(&dccp_hashinfo, skb,
841 dh->dccph_sport, dh->dccph_dport);
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200842 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700843 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200844 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700845 */
846 if (sk == NULL) {
847 dccp_pr_debug("failed to look up flow ID in table and "
848 "get corresponding socket\n");
849 goto no_dccp_socket;
850 }
851
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200852 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700853 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200854 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700855 * Generate Reset(No Connection) unless P.type == Reset
856 * Drop packet and return
857 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700858 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200859 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
860 inet_twsk_put(inet_twsk(sk));
861 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700862 }
863
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200864 /*
865 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200866 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
867 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200868 */
869 min_cov = dccp_sk(sk)->dccps_pcrlen;
870 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
871 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
872 dh->dccph_cscov, min_cov);
873 /* FIXME: "Such packets SHOULD be reported using Data Dropped
874 * options (Section 11.7) with Drop Code 0, Protocol
875 * Constraints." */
876 goto discard_and_relse;
877 }
878
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200879 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700880 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800881 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700882
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200883 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700884
885no_dccp_socket:
886 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
887 goto discard_it;
888 /*
889 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200890 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700891 * Generate Reset(No Connection) unless P.type == Reset
892 * Drop packet and return
893 */
894 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300895 DCCP_SKB_CB(skb)->dccpd_reset_code =
896 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800897 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700898 }
899
900discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700901 kfree_skb(skb);
902 return 0;
903
904discard_and_relse:
905 sock_put(sk);
906 goto discard_it;
907}
908
Stephen Hemminger3b401a82009-09-01 19:25:04 +0000909static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800910 .queue_xmit = ip_queue_xmit,
911 .send_check = dccp_v4_send_check,
912 .rebuild_header = inet_sk_rebuild_header,
913 .conn_request = dccp_v4_conn_request,
914 .syn_recv_sock = dccp_v4_request_recv_sock,
915 .net_header_len = sizeof(struct iphdr),
916 .setsockopt = ip_setsockopt,
917 .getsockopt = ip_getsockopt,
918 .addr2sockaddr = inet_csk_addr2sockaddr,
919 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800920 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800921#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800922 .compat_setsockopt = compat_ip_setsockopt,
923 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800924#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800925};
926
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800927static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700928{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800929 static __u8 dccp_v4_ctl_sock_initialized;
930 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700931
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800932 if (err == 0) {
933 if (unlikely(!dccp_v4_ctl_sock_initialized))
934 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800935 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800936 }
937
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800938 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700939}
940
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800941static struct timewait_sock_ops dccp_timewait_sock_ops = {
942 .twsk_obj_size = sizeof(struct inet_timewait_sock),
943};
944
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800945static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700946 .name = "DCCP",
947 .owner = THIS_MODULE,
948 .close = dccp_close,
949 .connect = dccp_v4_connect,
950 .disconnect = dccp_disconnect,
951 .ioctl = dccp_ioctl,
952 .init = dccp_v4_init_sock,
953 .setsockopt = dccp_setsockopt,
954 .getsockopt = dccp_getsockopt,
955 .sendmsg = dccp_sendmsg,
956 .recvmsg = dccp_recvmsg,
957 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800958 .hash = inet_hash,
959 .unhash = inet_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700960 .accept = inet_csk_accept,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800961 .get_port = inet_csk_get_port,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700962 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800963 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700964 .orphan_count = &dccp_orphan_count,
965 .max_header = MAX_DCCP_HEADER,
966 .obj_size = sizeof(struct dccp_sock),
Eric Dumazet3ab5aee2008-11-16 19:40:17 -0800967 .slab_flags = SLAB_DESTROY_BY_RCU,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700968 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800969 .twsk_prot = &dccp_timewait_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -0700970 .h.hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800971#ifdef CONFIG_COMPAT
972 .compat_setsockopt = compat_dccp_setsockopt,
973 .compat_getsockopt = compat_dccp_getsockopt,
974#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700975};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800976
Alexey Dobriyan32613092009-09-14 12:21:47 +0000977static const struct net_protocol dccp_v4_protocol = {
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800978 .handler = dccp_v4_rcv,
979 .err_handler = dccp_v4_err,
980 .no_policy = 1,
Pavel Emelyanovfc5f8582008-04-13 22:31:05 -0700981 .netns_ok = 1,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800982};
983
984static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800985 .family = PF_INET,
986 .owner = THIS_MODULE,
987 .release = inet_release,
988 .bind = inet_bind,
989 .connect = inet_stream_connect,
990 .socketpair = sock_no_socketpair,
991 .accept = inet_accept,
992 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800993 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800994 .poll = dccp_poll,
995 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800996 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800997 .listen = inet_dccp_listen,
998 .shutdown = inet_shutdown,
999 .setsockopt = sock_common_setsockopt,
1000 .getsockopt = sock_common_getsockopt,
1001 .sendmsg = inet_sendmsg,
1002 .recvmsg = sock_common_recvmsg,
1003 .mmap = sock_no_mmap,
1004 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001005#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001006 .compat_setsockopt = compat_sock_common_setsockopt,
1007 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001008#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001009};
1010
1011static struct inet_protosw dccp_v4_protosw = {
1012 .type = SOCK_DCCP,
1013 .protocol = IPPROTO_DCCP,
1014 .prot = &dccp_v4_prot,
1015 .ops = &inet_dccp_ops,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001016 .no_check = 0,
1017 .flags = INET_PROTOSW_ICSK,
1018};
1019
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001020static int __net_init dccp_v4_init_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001021{
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001022 if (dccp_hashinfo.bhash == NULL)
1023 return -ESOCKTNOSUPPORT;
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001024
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001025 return inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
1026 SOCK_DCCP, IPPROTO_DCCP, net);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001027}
1028
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001029static void __net_exit dccp_v4_exit_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001030{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001031 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001032}
1033
1034static struct pernet_operations dccp_v4_ops = {
1035 .init = dccp_v4_init_net,
1036 .exit = dccp_v4_exit_net,
1037};
1038
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001039static int __init dccp_v4_init(void)
1040{
1041 int err = proto_register(&dccp_v4_prot, 1);
1042
1043 if (err != 0)
1044 goto out;
1045
1046 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1047 if (err != 0)
1048 goto out_proto_unregister;
1049
1050 inet_register_protosw(&dccp_v4_protosw);
1051
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001052 err = register_pernet_subsys(&dccp_v4_ops);
1053 if (err)
1054 goto out_destroy_ctl_sock;
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001055out:
1056 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001057out_destroy_ctl_sock:
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001058 inet_unregister_protosw(&dccp_v4_protosw);
1059 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1060out_proto_unregister:
1061 proto_unregister(&dccp_v4_prot);
1062 goto out;
1063}
1064
1065static void __exit dccp_v4_exit(void)
1066{
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001067 unregister_pernet_subsys(&dccp_v4_ops);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001068 inet_unregister_protosw(&dccp_v4_protosw);
1069 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1070 proto_unregister(&dccp_v4_prot);
1071}
1072
1073module_init(dccp_v4_init);
1074module_exit(dccp_v4_exit);
1075
1076/*
1077 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1078 * values directly, Also cover the case where the protocol is not specified,
1079 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1080 */
Jean Delvare7131c6c2007-10-21 16:45:03 -07001081MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1082MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001083MODULE_LICENSE("GPL");
1084MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1085MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");