blob: 1c67fe8ff90d27f32779d4fc674dbc25083393ed [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
303 if (seq != dccp_rsk(req)->dreq_iss) {
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700304 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700305 goto out;
306 }
307 /*
308 * Still in RESPOND, just remove it silently.
309 * There is no good way to pass the error to the newly
310 * created socket, and POSIX does not want network
311 * errors returned from accept().
312 */
313 inet_csk_reqsk_queue_drop(sk, req, prev);
314 goto out;
315
316 case DCCP_REQUESTING:
317 case DCCP_RESPOND:
318 if (!sock_owned_by_user(sk)) {
319 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
320 sk->sk_err = err;
321
322 sk->sk_error_report(sk);
323
324 dccp_done(sk);
325 } else
326 sk->sk_err_soft = err;
327 goto out;
328 }
329
330 /* If we've already connected we will keep trying
331 * until we time out, or the user gives up.
332 *
333 * rfc1122 4.2.3.9 allows to consider as hard errors
334 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
335 * but it is obsoleted by pmtu discovery).
336 *
337 * Note, that in modern internet, where routing is unreliable
338 * and in each dark corner broken firewalls sit, sending random
339 * errors ordered by their masters even this two messages finally lose
340 * their original sense (even Linux sends invalid PORT_UNREACHs)
341 *
342 * Now we are in compliance with RFCs.
343 * --ANK (980905)
344 */
345
346 inet = inet_sk(sk);
347 if (!sock_owned_by_user(sk) && inet->recverr) {
348 sk->sk_err = err;
349 sk->sk_error_report(sk);
350 } else /* Only an error on timeout */
351 sk->sk_err_soft = err;
352out:
353 bh_unlock_sock(sk);
354 sock_put(sk);
355}
356
Al Viro2bda2852006-11-14 21:28:51 -0800357static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200358 __be32 src, __be32 dst)
359{
360 return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
361}
362
Herbert Xubb296242010-04-11 02:15:55 +0000363void dccp_v4_send_check(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800364{
365 const struct inet_sock *inet = inet_sk(sk);
366 struct dccp_hdr *dh = dccp_hdr(skb);
367
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200368 dccp_csum_outgoing(skb);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000369 dh->dccph_checksum = dccp_v4_csum_finish(skb,
370 inet->inet_saddr,
371 inet->inet_daddr);
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800372}
373
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800374EXPORT_SYMBOL_GPL(dccp_v4_send_check);
375
Gerrit Renker865e9022006-11-13 13:31:50 -0200376static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700377{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700378 return secure_dccp_sequence_number(ip_hdr(skb)->daddr,
379 ip_hdr(skb)->saddr,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700380 dccp_hdr(skb)->dccph_dport,
381 dccp_hdr(skb)->dccph_sport);
382}
383
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700384/*
385 * The three way handshake has completed - we got a valid ACK or DATAACK -
386 * now create the new socket.
387 *
388 * This is the equivalent of TCP's tcp_v4_syn_recv_sock
389 */
390struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
391 struct request_sock *req,
392 struct dst_entry *dst)
393{
394 struct inet_request_sock *ireq;
395 struct inet_sock *newinet;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700396 struct sock *newsk;
397
398 if (sk_acceptq_is_full(sk))
399 goto exit_overflow;
400
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700401 newsk = dccp_create_openreq_child(sk, req, skb);
402 if (newsk == NULL)
Balazs Scheidler093d2822010-10-21 13:06:43 +0200403 goto exit_nonewsk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700404
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700405 newinet = inet_sk(newsk);
406 ireq = inet_rsk(req);
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000407 newinet->inet_daddr = ireq->rmt_addr;
408 newinet->inet_rcv_saddr = ireq->loc_addr;
409 newinet->inet_saddr = ireq->loc_addr;
Eric Dumazetf6d8bd02011-04-21 09:45:37 +0000410 newinet->inet_opt = ireq->opt;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700411 ireq->opt = NULL;
412 newinet->mc_index = inet_iif(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700413 newinet->mc_ttl = ip_hdr(skb)->ttl;
Eric Dumazetc720c7e2009-10-15 06:30:45 +0000414 newinet->inet_id = jiffies;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700415
David S. Miller0e734412011-05-08 15:28:03 -0700416 if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
417 goto put_and_exit;
418
419 sk_setup_caps(newsk, dst);
420
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700421 dccp_sync_mss(newsk, dst_mtu(dst));
422
David S. Miller0e734412011-05-08 15:28:03 -0700423 if (__inet_inherit_port(sk, newsk) < 0)
424 goto put_and_exit;
Eric Dumazet9327f702009-12-04 03:46:54 +0000425 __inet_hash_nolisten(newsk, NULL);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700426
427 return newsk;
428
429exit_overflow:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700430 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
Balazs Scheidler093d2822010-10-21 13:06:43 +0200431exit_nonewsk:
432 dst_release(dst);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700433exit:
Pavel Emelyanovde0744a2008-07-16 20:31:16 -0700434 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700435 return NULL;
David S. Miller0e734412011-05-08 15:28:03 -0700436put_and_exit:
Eric Dumazet918eb392011-11-02 12:42:56 +0000437 bh_unlock_sock(newsk);
David S. Miller0e734412011-05-08 15:28:03 -0700438 sock_put(newsk);
439 goto exit;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700440}
441
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800442EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock);
443
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700444static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
445{
446 const struct dccp_hdr *dh = dccp_hdr(skb);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700447 const struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700448 struct sock *nsk;
449 struct request_sock **prev;
450 /* Find possible connection requests. */
451 struct request_sock *req = inet_csk_search_req(sk, &prev,
452 dh->dccph_sport,
453 iph->saddr, iph->daddr);
454 if (req != NULL)
455 return dccp_check_req(sk, skb, req, prev);
456
Pavel Emelyanovb9901a82008-04-13 22:30:43 -0700457 nsk = inet_lookup_established(sock_net(sk), &dccp_hashinfo,
Herbert Xu8f4910692006-08-09 15:47:12 -0700458 iph->saddr, dh->dccph_sport,
459 iph->daddr, dh->dccph_dport,
460 inet_iif(skb));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700461 if (nsk != NULL) {
462 if (nsk->sk_state != DCCP_TIME_WAIT) {
463 bh_lock_sock(nsk);
464 return nsk;
465 }
YOSHIFUJI Hideaki9469c7b2006-10-10 19:41:46 -0700466 inet_twsk_put(inet_twsk(nsk));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700467 return NULL;
468 }
469
470 return sk;
471}
472
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700473static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700474 struct sk_buff *skb)
475{
476 struct rtable *rt;
David S. Miller898f7352011-12-01 13:28:34 -0500477 const struct iphdr *iph = ip_hdr(skb);
David S. Miller9d6ec932011-03-12 01:12:47 -0500478 struct flowi4 fl4 = {
479 .flowi4_oif = skb_rtable(skb)->rt_iif,
David S. Miller898f7352011-12-01 13:28:34 -0500480 .daddr = iph->saddr,
481 .saddr = iph->daddr,
David S. Miller9d6ec932011-03-12 01:12:47 -0500482 .flowi4_tos = RT_CONN_FLAGS(sk),
483 .flowi4_proto = sk->sk_protocol,
David S. Miller9cce96d2011-03-12 03:00:33 -0500484 .fl4_sport = dccp_hdr(skb)->dccph_dport,
485 .fl4_dport = dccp_hdr(skb)->dccph_sport,
David S. Miller1d28f422011-03-12 00:29:39 -0500486 };
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700487
David S. Miller9d6ec932011-03-12 01:12:47 -0500488 security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
489 rt = ip_route_output_flow(net, &fl4, sk);
David S. Millerb23dd4f2011-03-02 14:31:35 -0800490 if (IS_ERR(rt)) {
Pavel Emelyanov7c73a6f2008-07-16 20:20:11 -0700491 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700492 return NULL;
493 }
494
Changli Gaod8d1f302010-06-10 23:31:35 -0700495 return &rt->dst;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700496}
497
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000498static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
499 struct request_values *rv_unused)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200500{
501 int err = -1;
502 struct sk_buff *skb;
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800503 struct dst_entry *dst;
David S. Miller6bd023f2011-05-18 18:32:03 -0400504 struct flowi4 fl4;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200505
David S. Miller6bd023f2011-05-18 18:32:03 -0400506 dst = inet_csk_route_req(sk, &fl4, req);
Denis V. Lunevfd80eb92008-02-29 11:43:03 -0800507 if (dst == NULL)
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200508 goto out;
509
510 skb = dccp_make_response(sk, dst, req);
511 if (skb != NULL) {
512 const struct inet_request_sock *ireq = inet_rsk(req);
513 struct dccp_hdr *dh = dccp_hdr(skb);
514
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200515 dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
516 ireq->rmt_addr);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200517 err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
518 ireq->rmt_addr,
519 ireq->opt);
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200520 err = net_xmit_eval(err);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200521 }
522
523out:
524 dst_release(dst);
525 return err;
526}
527
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800528static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700529{
530 int err;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700531 const struct iphdr *rxiph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700532 struct sk_buff *skb;
533 struct dst_entry *dst;
Eric Dumazetadf30902009-06-02 05:19:30 +0000534 struct net *net = dev_net(skb_dst(rxskb)->dev);
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -0700535 struct sock *ctl_sk = net->dccp.v4_ctl_sk;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700536
537 /* Never send a reset in response to a reset. */
Gerrit Renkere356d372007-09-26 14:35:19 -0300538 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700539 return;
540
Eric Dumazet511c3f92009-06-02 05:14:27 +0000541 if (skb_rtable(rxskb)->rt_type != RTN_LOCAL)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700542 return;
543
Pavel Emelyanovf5487392008-04-13 22:30:19 -0700544 dst = dccp_v4_route_skb(net, ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700545 if (dst == NULL)
546 return;
547
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700548 skb = dccp_ctl_make_reset(ctl_sk, rxskb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700549 if (skb == NULL)
550 goto out;
551
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700552 rxiph = ip_hdr(rxskb);
Gerrit Renkere356d372007-09-26 14:35:19 -0300553 dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr,
554 rxiph->daddr);
Eric Dumazetadf30902009-06-02 05:19:30 +0000555 skb_dst_set(skb, dst_clone(dst));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700556
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700557 bh_lock_sock(ctl_sk);
558 err = ip_build_and_send_pkt(skb, ctl_sk,
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700559 rxiph->daddr, rxiph->saddr, NULL);
Pavel Emelyanov7b1cffa2008-04-13 22:29:37 -0700560 bh_unlock_sock(ctl_sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700561
Gerrit Renkerb9df3cb2006-11-14 11:21:36 -0200562 if (net_xmit_eval(err) == 0) {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700563 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
564 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
565 }
566out:
567 dst_release(dst);
568}
569
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200570static void dccp_v4_reqsk_destructor(struct request_sock *req)
571{
Gerrit Renkerd99a7bd2008-11-04 23:56:30 -0800572 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200573 kfree(inet_rsk(req)->opt);
574}
575
576static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
577 .family = PF_INET,
578 .obj_size = sizeof(struct dccp_request_sock),
579 .rtx_syn_ack = dccp_v4_send_response,
580 .send_ack = dccp_reqsk_send_ack,
581 .destructor = dccp_v4_reqsk_destructor,
582 .send_reset = dccp_v4_ctl_send_reset,
583};
584
585int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
586{
587 struct inet_request_sock *ireq;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200588 struct request_sock *req;
589 struct dccp_request_sock *dreq;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200590 const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200591 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200592
593 /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
Eric Dumazet511c3f92009-06-02 05:14:27 +0000594 if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700595 return 0; /* discard, don't send a reset here */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200596
597 if (dccp_bad_service_code(sk, service)) {
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700598 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200599 goto drop;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200600 }
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200601 /*
602 * TW buckets are converted to open requests without
603 * limitations, they conserve resources and peer is
604 * evidently real one.
605 */
Gerrit Renker4a5409a2007-10-04 14:52:28 -0700606 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200607 if (inet_csk_reqsk_queue_is_full(sk))
608 goto drop;
609
610 /*
611 * Accept backlog is full. If we have already queued enough
612 * of warm entries in syn queue, drop request. It is better than
613 * clogging syn queue with openreqs with exponentially increasing
614 * timeout.
615 */
616 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
617 goto drop;
618
Arnaldo Carvalho de Meloce4a7d02008-06-10 12:39:35 -0700619 req = inet_reqsk_alloc(&dccp_request_sock_ops);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200620 if (req == NULL)
621 goto drop;
622
Gerrit Renkerac757732008-11-04 23:55:49 -0800623 if (dccp_reqsk_init(req, dccp_sk(sk), skb))
624 goto drop_and_free;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200625
Gerrit Renker8b819412007-12-13 12:29:24 -0200626 dreq = dccp_rsk(req);
627 if (dccp_parse_options(sk, dreq, skb))
628 goto drop_and_free;
629
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200630 if (security_inet_conn_request(sk, skb, req))
631 goto drop_and_free;
632
633 ireq = inet_rsk(req);
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700634 ireq->loc_addr = ip_hdr(skb)->daddr;
635 ireq->rmt_addr = ip_hdr(skb)->saddr;
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200636
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200637 /*
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200638 * Step 3: Process LISTEN state
639 *
640 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
641 *
642 * In fact we defer setting S.GSR, S.SWL, S.SWH to
643 * dccp_create_openreq_child.
644 */
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200645 dreq->dreq_isr = dcb->dccpd_seq;
Gerrit Renker865e9022006-11-13 13:31:50 -0200646 dreq->dreq_iss = dccp_v4_init_sequence(skb);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200647 dreq->dreq_service = service;
648
William Allen Simpsone6b4d112009-12-02 18:07:39 +0000649 if (dccp_v4_send_response(sk, req, NULL))
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200650 goto drop_and_free;
651
652 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
653 return 0;
654
655drop_and_free:
656 reqsk_free(req);
657drop:
658 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
Gerrit Renker3d2fe622006-11-10 12:52:36 -0200659 return -1;
660}
661
662EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
663
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700664int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
665{
666 struct dccp_hdr *dh = dccp_hdr(skb);
667
668 if (sk->sk_state == DCCP_OPEN) { /* Fast path */
669 if (dccp_rcv_established(sk, skb, dh, skb->len))
670 goto reset;
671 return 0;
672 }
673
674 /*
675 * Step 3: Process LISTEN state
Gerrit Renkerd83ca5a2006-11-10 16:29:14 -0200676 * If P.type == Request or P contains a valid Init Cookie option,
677 * (* Must scan the packet's options to check for Init
678 * Cookies. Only Init Cookies are processed here,
679 * however; other options are processed in Step 8. This
680 * scan need only be performed if the endpoint uses Init
681 * Cookies *)
682 * (* Generate a new socket and switch to that socket *)
683 * Set S := new socket for this port pair
684 * S.state = RESPOND
685 * Choose S.ISS (initial seqno) or set from Init Cookies
686 * Initialize S.GAR := S.ISS
687 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
688 * Continue with S.state == RESPOND
689 * (* A Response packet will be generated in Step 11 *)
690 * Otherwise,
691 * Generate Reset(No Connection) unless P.type == Reset
692 * Drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700693 *
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300694 * NOTE: the check for the packet types is done in
695 * dccp_rcv_state_process
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700696 */
697 if (sk->sk_state == DCCP_LISTEN) {
698 struct sock *nsk = dccp_v4_hnd_req(sk, skb);
699
700 if (nsk == NULL)
701 goto discard;
702
703 if (nsk != sk) {
704 if (dccp_child_process(sk, nsk, skb))
705 goto reset;
706 return 0;
707 }
708 }
709
710 if (dccp_rcv_state_process(sk, skb, dh, skb->len))
711 goto reset;
712 return 0;
713
714reset:
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800715 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700716discard:
717 kfree_skb(skb);
718 return 0;
719}
720
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800721EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
722
Gerrit Renker09dbc382006-11-14 12:57:34 -0200723/**
724 * dccp_invalid_packet - check for malformed packets
725 * Implements RFC 4340, 8.5: Step 1: Check header basics
726 * Packets that fail these checks are ignored and do not receive Resets.
727 */
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800728int dccp_invalid_packet(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700729{
730 const struct dccp_hdr *dh;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200731 unsigned int cscov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700732
733 if (skb->pkt_type != PACKET_HOST)
734 return 1;
735
Gerrit Renker09dbc382006-11-14 12:57:34 -0200736 /* If the packet is shorter than 12 bytes, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700737 if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200738 DCCP_WARN("pskb_may_pull failed\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700739 return 1;
740 }
741
742 dh = dccp_hdr(skb);
743
Gerrit Renker09dbc382006-11-14 12:57:34 -0200744 /* If P.type is not understood, drop packet and return */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700745 if (dh->dccph_type >= DCCP_PKT_INVALID) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200746 DCCP_WARN("invalid packet type\n");
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700747 return 1;
748 }
749
750 /*
Gerrit Renker09dbc382006-11-14 12:57:34 -0200751 * If P.Data Offset is too small for packet type, drop packet and return
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700752 */
753 if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200754 DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700755 return 1;
756 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200757 /*
758 * If P.Data Offset is too too large for packet, drop packet and return
759 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700760 if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200761 DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700762 return 1;
763 }
764
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700765 /*
766 * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
767 * has short sequence numbers), drop packet and return
768 */
Wei Yongjun6079a462008-05-27 06:22:38 -0700769 if ((dh->dccph_type < DCCP_PKT_DATA ||
770 dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200771 DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
772 dccp_packet_name(dh->dccph_type));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700773 return 1;
774 }
775
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200776 /*
777 * If P.CsCov is too large for the packet size, drop packet and return.
778 * This must come _before_ checksumming (not as RFC 4340 suggests).
779 */
780 cscov = dccp_csum_coverage(skb);
781 if (cscov > skb->len) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200782 DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
783 dh->dccph_cscov, skb->len);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200784 return 1;
785 }
786
787 /* If header checksum is incorrect, drop packet and return.
788 * (This step is completed in the AF-dependent functions.) */
789 skb->csum = skb_checksum(skb, 0, cscov, 0);
790
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700791 return 0;
792}
793
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800794EXPORT_SYMBOL_GPL(dccp_invalid_packet);
795
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700796/* this is called when real data arrives */
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800797static int dccp_v4_rcv(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700798{
799 const struct dccp_hdr *dh;
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700800 const struct iphdr *iph;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700801 struct sock *sk;
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200802 int min_cov;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700803
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200804 /* Step 1: Check header basics */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700805
806 if (dccp_invalid_packet(skb))
807 goto discard_it;
808
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700809 iph = ip_hdr(skb);
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200810 /* Step 1: If header checksum is incorrect, drop packet and return */
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700811 if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) {
Gerrit Renker59348b12006-11-20 18:39:23 -0200812 DCCP_WARN("dropped packet with invalid checksum\n");
Arnaldo Carvalho de Melof21e68c2005-12-13 23:24:16 -0800813 goto discard_it;
814 }
815
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700816 dh = dccp_hdr(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700817
Gerrit Renkerfde20102007-10-24 10:12:09 -0200818 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700819 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
820
Harvey Harrison21454aa2008-10-31 00:54:56 -0700821 dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu",
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700822 dccp_packet_name(dh->dccph_type),
Harvey Harrison21454aa2008-10-31 00:54:56 -0700823 &iph->saddr, ntohs(dh->dccph_sport),
824 &iph->daddr, ntohs(dh->dccph_dport),
David S. Millerf6ccf552005-08-09 20:27:14 -0700825 (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700826
827 if (dccp_packet_without_ack(skb)) {
828 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
829 dccp_pr_debug_cat("\n");
830 } else {
831 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200832 dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
David S. Millerf6ccf552005-08-09 20:27:14 -0700833 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700834 }
835
836 /* Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200837 * Look up flow ID in table and get corresponding socket */
Arnaldo Carvalho de Melo9a1f27c2008-10-07 11:41:57 -0700838 sk = __inet_lookup_skb(&dccp_hashinfo, skb,
839 dh->dccph_sport, dh->dccph_dport);
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200840 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700841 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200842 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700843 */
844 if (sk == NULL) {
845 dccp_pr_debug("failed to look up flow ID in table and "
846 "get corresponding socket\n");
847 goto no_dccp_socket;
848 }
849
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200850 /*
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700851 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200852 * ... or S.state == TIMEWAIT,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700853 * Generate Reset(No Connection) unless P.type == Reset
854 * Drop packet and return
855 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700856 if (sk->sk_state == DCCP_TIME_WAIT) {
Gerrit Renkerd23c7102006-11-10 11:46:34 -0200857 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
858 inet_twsk_put(inet_twsk(sk));
859 goto no_dccp_socket;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700860 }
861
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200862 /*
863 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200864 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
865 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
Gerrit Renker6f4e5ff2006-11-10 17:43:06 -0200866 */
867 min_cov = dccp_sk(sk)->dccps_pcrlen;
868 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
869 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
870 dh->dccph_cscov, min_cov);
871 /* FIXME: "Such packets SHOULD be reported using Data Dropped
872 * options (Section 11.7) with Drop Code 0, Protocol
873 * Constraints." */
874 goto discard_and_relse;
875 }
876
Arnaldo Carvalho de Melo25995ff2005-12-27 02:42:22 -0200877 if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700878 goto discard_and_relse;
Patrick McHardyeb9c7eb2006-01-06 23:06:30 -0800879 nf_reset(skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700880
Arnaldo Carvalho de Melo58a5a7b2006-11-16 14:06:06 -0200881 return sk_receive_skb(sk, skb, 1);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700882
883no_dccp_socket:
884 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
885 goto discard_it;
886 /*
887 * Step 2:
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200888 * If no socket ...
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700889 * Generate Reset(No Connection) unless P.type == Reset
890 * Drop packet and return
891 */
892 if (dh->dccph_type != DCCP_PKT_RESET) {
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300893 DCCP_SKB_CB(skb)->dccpd_reset_code =
894 DCCP_RESET_CODE_NO_CONNECTION;
YOSHIFUJI Hideakicfb6eeb2006-11-14 19:07:45 -0800895 dccp_v4_ctl_send_reset(sk, skb);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700896 }
897
898discard_it:
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700899 kfree_skb(skb);
900 return 0;
901
902discard_and_relse:
903 sock_put(sk);
904 goto discard_it;
905}
906
Stephen Hemminger3b401a82009-09-01 19:25:04 +0000907static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800908 .queue_xmit = ip_queue_xmit,
909 .send_check = dccp_v4_send_check,
910 .rebuild_header = inet_sk_rebuild_header,
911 .conn_request = dccp_v4_conn_request,
912 .syn_recv_sock = dccp_v4_request_recv_sock,
913 .net_header_len = sizeof(struct iphdr),
914 .setsockopt = ip_setsockopt,
915 .getsockopt = ip_getsockopt,
916 .addr2sockaddr = inet_csk_addr2sockaddr,
917 .sockaddr_len = sizeof(struct sockaddr_in),
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800918 .bind_conflict = inet_csk_bind_conflict,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800919#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800920 .compat_setsockopt = compat_ip_setsockopt,
921 .compat_getsockopt = compat_ip_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -0800922#endif
Arnaldo Carvalho de Melo57cca052005-12-13 23:16:16 -0800923};
924
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800925static int dccp_v4_init_sock(struct sock *sk)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700926{
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800927 static __u8 dccp_v4_ctl_sock_initialized;
928 int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700929
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800930 if (err == 0) {
931 if (unlikely(!dccp_v4_ctl_sock_initialized))
932 dccp_v4_ctl_sock_initialized = 1;
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800933 inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops;
Arnaldo Carvalho de Melo72478872006-03-20 22:00:37 -0800934 }
935
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800936 return err;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700937}
938
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800939static struct timewait_sock_ops dccp_timewait_sock_ops = {
940 .twsk_obj_size = sizeof(struct inet_timewait_sock),
941};
942
Adrian Bunk5e0817f2006-03-20 21:58:29 -0800943static struct proto dccp_v4_prot = {
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700944 .name = "DCCP",
945 .owner = THIS_MODULE,
946 .close = dccp_close,
947 .connect = dccp_v4_connect,
948 .disconnect = dccp_disconnect,
949 .ioctl = dccp_ioctl,
950 .init = dccp_v4_init_sock,
951 .setsockopt = dccp_setsockopt,
952 .getsockopt = dccp_getsockopt,
953 .sendmsg = dccp_sendmsg,
954 .recvmsg = dccp_recvmsg,
955 .backlog_rcv = dccp_v4_do_rcv,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800956 .hash = inet_hash,
957 .unhash = inet_unhash,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700958 .accept = inet_csk_accept,
Arnaldo Carvalho de Meloab1e0a12008-02-03 04:06:04 -0800959 .get_port = inet_csk_get_port,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700960 .shutdown = dccp_shutdown,
Arnaldo Carvalho de Melo3e0fadc2006-03-20 21:23:15 -0800961 .destroy = dccp_destroy_sock,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700962 .orphan_count = &dccp_orphan_count,
963 .max_header = MAX_DCCP_HEADER,
964 .obj_size = sizeof(struct dccp_sock),
Eric Dumazet3ab5aee2008-11-16 19:40:17 -0800965 .slab_flags = SLAB_DESTROY_BY_RCU,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700966 .rsk_prot = &dccp_request_sock_ops,
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800967 .twsk_prot = &dccp_timewait_sock_ops,
Pavel Emelyanov39d8cda2008-03-22 16:50:58 -0700968 .h.hashinfo = &dccp_hashinfo,
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800969#ifdef CONFIG_COMPAT
970 .compat_setsockopt = compat_dccp_setsockopt,
971 .compat_getsockopt = compat_dccp_getsockopt,
972#endif
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700973};
Arnaldo Carvalho de Melo6d6ee432005-12-13 23:25:19 -0800974
Alexey Dobriyan32613092009-09-14 12:21:47 +0000975static const struct net_protocol dccp_v4_protocol = {
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800976 .handler = dccp_v4_rcv,
977 .err_handler = dccp_v4_err,
978 .no_policy = 1,
Pavel Emelyanovfc5f8582008-04-13 22:31:05 -0700979 .netns_ok = 1,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800980};
981
982static const struct proto_ops inet_dccp_ops = {
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800983 .family = PF_INET,
984 .owner = THIS_MODULE,
985 .release = inet_release,
986 .bind = inet_bind,
987 .connect = inet_stream_connect,
988 .socketpair = sock_no_socketpair,
989 .accept = inet_accept,
990 .getname = inet_getname,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800991 /* FIXME: work on tcp_poll to rename it to inet_csk_poll */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800992 .poll = dccp_poll,
993 .ioctl = inet_ioctl,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800994 /* FIXME: work on inet_listen to rename it to sock_common_listen */
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -0800995 .listen = inet_dccp_listen,
996 .shutdown = inet_shutdown,
997 .setsockopt = sock_common_setsockopt,
998 .getsockopt = sock_common_getsockopt,
999 .sendmsg = inet_sendmsg,
1000 .recvmsg = sock_common_recvmsg,
1001 .mmap = sock_no_mmap,
1002 .sendpage = sock_no_sendpage,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001003#ifdef CONFIG_COMPAT
Arnaldo Carvalho de Melo543d9cf2006-03-20 22:48:35 -08001004 .compat_setsockopt = compat_sock_common_setsockopt,
1005 .compat_getsockopt = compat_sock_common_getsockopt,
Dmitry Mishin3fdadf72006-03-20 22:45:21 -08001006#endif
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001007};
1008
1009static struct inet_protosw dccp_v4_protosw = {
1010 .type = SOCK_DCCP,
1011 .protocol = IPPROTO_DCCP,
1012 .prot = &dccp_v4_prot,
1013 .ops = &inet_dccp_ops,
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001014 .no_check = 0,
1015 .flags = INET_PROTOSW_ICSK,
1016};
1017
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001018static int __net_init dccp_v4_init_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001019{
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001020 if (dccp_hashinfo.bhash == NULL)
1021 return -ESOCKTNOSUPPORT;
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001022
Gerrit Renkerd14a0eb2010-03-14 20:13:19 +00001023 return inet_ctl_sock_create(&net->dccp.v4_ctl_sk, PF_INET,
1024 SOCK_DCCP, IPPROTO_DCCP, net);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001025}
1026
Alexey Dobriyan2c8c1e72010-01-17 03:35:32 +00001027static void __net_exit dccp_v4_exit_net(struct net *net)
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001028{
Pavel Emelyanovb76c4b22008-04-13 22:29:59 -07001029 inet_ctl_sock_destroy(net->dccp.v4_ctl_sk);
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001030}
1031
1032static struct pernet_operations dccp_v4_ops = {
1033 .init = dccp_v4_init_net,
1034 .exit = dccp_v4_exit_net,
1035};
1036
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001037static int __init dccp_v4_init(void)
1038{
1039 int err = proto_register(&dccp_v4_prot, 1);
1040
1041 if (err != 0)
1042 goto out;
1043
1044 err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1045 if (err != 0)
1046 goto out_proto_unregister;
1047
1048 inet_register_protosw(&dccp_v4_protosw);
1049
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001050 err = register_pernet_subsys(&dccp_v4_ops);
1051 if (err)
1052 goto out_destroy_ctl_sock;
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001053out:
1054 return err;
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001055out_destroy_ctl_sock:
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001056 inet_unregister_protosw(&dccp_v4_protosw);
1057 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1058out_proto_unregister:
1059 proto_unregister(&dccp_v4_prot);
1060 goto out;
1061}
1062
1063static void __exit dccp_v4_exit(void)
1064{
Pavel Emelyanov72a2d612008-04-13 22:29:13 -07001065 unregister_pernet_subsys(&dccp_v4_ops);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001066 inet_unregister_protosw(&dccp_v4_protosw);
1067 inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP);
1068 proto_unregister(&dccp_v4_prot);
1069}
1070
1071module_init(dccp_v4_init);
1072module_exit(dccp_v4_exit);
1073
1074/*
1075 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1076 * values directly, Also cover the case where the protocol is not specified,
1077 * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP
1078 */
Jean Delvare7131c6c2007-10-21 16:45:03 -07001079MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6);
1080MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6);
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -08001081MODULE_LICENSE("GPL");
1082MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1083MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");