Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/ipv4.c | |
3 | * | |
4 | * An implementation of the DCCP protocol | |
5 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/config.h> | |
14 | #include <linux/dccp.h> | |
15 | #include <linux/icmp.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/random.h> | |
19 | ||
20 | #include <net/icmp.h> | |
21 | #include <net/inet_hashtables.h> | |
22 | #include <net/sock.h> | |
23 | #include <net/tcp_states.h> | |
24 | #include <net/xfrm.h> | |
25 | ||
ae31c339 | 26 | #include "ackvec.h" |
7c657876 ACM |
27 | #include "ccid.h" |
28 | #include "dccp.h" | |
29 | ||
30 | struct inet_hashinfo __cacheline_aligned dccp_hashinfo = { | |
31 | .lhash_lock = RW_LOCK_UNLOCKED, | |
32 | .lhash_users = ATOMIC_INIT(0), | |
7690af3f | 33 | .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait), |
7c657876 ACM |
34 | .portalloc_lock = SPIN_LOCK_UNLOCKED, |
35 | .port_rover = 1024 - 1, | |
36 | }; | |
37 | ||
540722ff ACM |
38 | EXPORT_SYMBOL_GPL(dccp_hashinfo); |
39 | ||
7c657876 ACM |
40 | static int dccp_v4_get_port(struct sock *sk, const unsigned short snum) |
41 | { | |
42 | return inet_csk_get_port(&dccp_hashinfo, sk, snum); | |
43 | } | |
44 | ||
45 | static void dccp_v4_hash(struct sock *sk) | |
46 | { | |
47 | inet_hash(&dccp_hashinfo, sk); | |
48 | } | |
49 | ||
50 | static void dccp_v4_unhash(struct sock *sk) | |
51 | { | |
52 | inet_unhash(&dccp_hashinfo, sk); | |
53 | } | |
54 | ||
55 | /* called with local bh disabled */ | |
56 | static int __dccp_v4_check_established(struct sock *sk, const __u16 lport, | |
57 | struct inet_timewait_sock **twp) | |
58 | { | |
59 | struct inet_sock *inet = inet_sk(sk); | |
60 | const u32 daddr = inet->rcv_saddr; | |
61 | const u32 saddr = inet->daddr; | |
62 | const int dif = sk->sk_bound_dev_if; | |
63 | INET_ADDR_COOKIE(acookie, saddr, daddr) | |
64 | const __u32 ports = INET_COMBINED_PORTS(inet->dport, lport); | |
81c3d547 ED |
65 | unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport); |
66 | struct inet_ehash_bucket *head = inet_ehash_bucket(&dccp_hashinfo, hash); | |
7c657876 ACM |
67 | const struct sock *sk2; |
68 | const struct hlist_node *node; | |
69 | struct inet_timewait_sock *tw; | |
70 | ||
81c3d547 | 71 | prefetch(head->chain.first); |
7c657876 ACM |
72 | write_lock(&head->lock); |
73 | ||
74 | /* Check TIME-WAIT sockets first. */ | |
75 | sk_for_each(sk2, node, &(head + dccp_hashinfo.ehash_size)->chain) { | |
76 | tw = inet_twsk(sk2); | |
77 | ||
81c3d547 | 78 | if (INET_TW_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) |
7c657876 ACM |
79 | goto not_unique; |
80 | } | |
81 | tw = NULL; | |
82 | ||
83 | /* And established part... */ | |
84 | sk_for_each(sk2, node, &head->chain) { | |
81c3d547 | 85 | if (INET_MATCH(sk2, hash, acookie, saddr, daddr, ports, dif)) |
7c657876 ACM |
86 | goto not_unique; |
87 | } | |
88 | ||
89 | /* Must record num and sport now. Otherwise we will see | |
90 | * in hash table socket with a funny identity. */ | |
91 | inet->num = lport; | |
92 | inet->sport = htons(lport); | |
81c3d547 | 93 | sk->sk_hash = hash; |
7c657876 ACM |
94 | BUG_TRAP(sk_unhashed(sk)); |
95 | __sk_add_node(sk, &head->chain); | |
96 | sock_prot_inc_use(sk->sk_prot); | |
97 | write_unlock(&head->lock); | |
98 | ||
99 | if (twp != NULL) { | |
100 | *twp = tw; | |
101 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); | |
102 | } else if (tw != NULL) { | |
103 | /* Silly. Should hash-dance instead... */ | |
64cf1e5d | 104 | inet_twsk_deschedule(tw, &dccp_death_row); |
7c657876 ACM |
105 | NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED); |
106 | ||
107 | inet_twsk_put(tw); | |
108 | } | |
109 | ||
110 | return 0; | |
111 | ||
112 | not_unique: | |
113 | write_unlock(&head->lock); | |
114 | return -EADDRNOTAVAIL; | |
115 | } | |
116 | ||
117 | /* | |
118 | * Bind a port for a connect operation and hash it. | |
119 | */ | |
120 | static int dccp_v4_hash_connect(struct sock *sk) | |
121 | { | |
122 | const unsigned short snum = inet_sk(sk)->num; | |
123 | struct inet_bind_hashbucket *head; | |
124 | struct inet_bind_bucket *tb; | |
125 | int ret; | |
126 | ||
127 | if (snum == 0) { | |
128 | int rover; | |
129 | int low = sysctl_local_port_range[0]; | |
130 | int high = sysctl_local_port_range[1]; | |
131 | int remaining = (high - low) + 1; | |
132 | struct hlist_node *node; | |
133 | struct inet_timewait_sock *tw = NULL; | |
134 | ||
135 | local_bh_disable(); | |
136 | ||
137 | /* TODO. Actually it is not so bad idea to remove | |
7690af3f ACM |
138 | * dccp_hashinfo.portalloc_lock before next submission to |
139 | * Linus. | |
7c657876 ACM |
140 | * As soon as we touch this place at all it is time to think. |
141 | * | |
7690af3f ACM |
142 | * Now it protects single _advisory_ variable |
143 | * dccp_hashinfo.port_rover, hence it is mostly useless. | |
7c657876 ACM |
144 | * Code will work nicely if we just delete it, but |
145 | * I am afraid in contented case it will work not better or | |
146 | * even worse: another cpu just will hit the same bucket | |
147 | * and spin there. | |
148 | * So some cpu salt could remove both contention and | |
149 | * memory pingpong. Any ideas how to do this in a nice way? | |
150 | */ | |
151 | spin_lock(&dccp_hashinfo.portalloc_lock); | |
152 | rover = dccp_hashinfo.port_rover; | |
153 | ||
154 | do { | |
155 | rover++; | |
156 | if ((rover < low) || (rover > high)) | |
157 | rover = low; | |
7690af3f ACM |
158 | head = &dccp_hashinfo.bhash[inet_bhashfn(rover, |
159 | dccp_hashinfo.bhash_size)]; | |
7c657876 ACM |
160 | spin_lock(&head->lock); |
161 | ||
162 | /* Does not bother with rcv_saddr checks, | |
163 | * because the established check is already | |
164 | * unique enough. | |
165 | */ | |
166 | inet_bind_bucket_for_each(tb, node, &head->chain) { | |
167 | if (tb->port == rover) { | |
168 | BUG_TRAP(!hlist_empty(&tb->owners)); | |
169 | if (tb->fastreuse >= 0) | |
170 | goto next_port; | |
171 | if (!__dccp_v4_check_established(sk, | |
172 | rover, | |
173 | &tw)) | |
174 | goto ok; | |
175 | goto next_port; | |
176 | } | |
177 | } | |
178 | ||
7690af3f ACM |
179 | tb = inet_bind_bucket_create(dccp_hashinfo.bind_bucket_cachep, |
180 | head, rover); | |
7c657876 ACM |
181 | if (tb == NULL) { |
182 | spin_unlock(&head->lock); | |
183 | break; | |
184 | } | |
185 | tb->fastreuse = -1; | |
186 | goto ok; | |
187 | ||
188 | next_port: | |
189 | spin_unlock(&head->lock); | |
190 | } while (--remaining > 0); | |
191 | dccp_hashinfo.port_rover = rover; | |
192 | spin_unlock(&dccp_hashinfo.portalloc_lock); | |
193 | ||
194 | local_bh_enable(); | |
195 | ||
196 | return -EADDRNOTAVAIL; | |
197 | ||
198 | ok: | |
199 | /* All locks still held and bhs disabled */ | |
200 | dccp_hashinfo.port_rover = rover; | |
201 | spin_unlock(&dccp_hashinfo.portalloc_lock); | |
202 | ||
203 | inet_bind_hash(sk, tb, rover); | |
204 | if (sk_unhashed(sk)) { | |
205 | inet_sk(sk)->sport = htons(rover); | |
206 | __inet_hash(&dccp_hashinfo, sk, 0); | |
207 | } | |
208 | spin_unlock(&head->lock); | |
209 | ||
210 | if (tw != NULL) { | |
64cf1e5d | 211 | inet_twsk_deschedule(tw, &dccp_death_row); |
7c657876 ACM |
212 | inet_twsk_put(tw); |
213 | } | |
214 | ||
215 | ret = 0; | |
216 | goto out; | |
217 | } | |
218 | ||
7690af3f ACM |
219 | head = &dccp_hashinfo.bhash[inet_bhashfn(snum, |
220 | dccp_hashinfo.bhash_size)]; | |
7c657876 ACM |
221 | tb = inet_csk(sk)->icsk_bind_hash; |
222 | spin_lock_bh(&head->lock); | |
223 | if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) { | |
224 | __inet_hash(&dccp_hashinfo, sk, 0); | |
225 | spin_unlock_bh(&head->lock); | |
226 | return 0; | |
227 | } else { | |
228 | spin_unlock(&head->lock); | |
229 | /* No definite answer... Walk to established hash table */ | |
230 | ret = __dccp_v4_check_established(sk, snum, NULL); | |
231 | out: | |
232 | local_bh_enable(); | |
233 | return ret; | |
234 | } | |
235 | } | |
236 | ||
237 | static int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, | |
238 | int addr_len) | |
239 | { | |
240 | struct inet_sock *inet = inet_sk(sk); | |
241 | struct dccp_sock *dp = dccp_sk(sk); | |
242 | const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; | |
243 | struct rtable *rt; | |
244 | u32 daddr, nexthop; | |
245 | int tmp; | |
246 | int err; | |
247 | ||
248 | dp->dccps_role = DCCP_ROLE_CLIENT; | |
249 | ||
67e6b629 ACM |
250 | if (dccp_service_not_initialized(sk)) |
251 | return -EPROTO; | |
252 | ||
7c657876 ACM |
253 | if (addr_len < sizeof(struct sockaddr_in)) |
254 | return -EINVAL; | |
255 | ||
256 | if (usin->sin_family != AF_INET) | |
257 | return -EAFNOSUPPORT; | |
258 | ||
259 | nexthop = daddr = usin->sin_addr.s_addr; | |
260 | if (inet->opt != NULL && inet->opt->srr) { | |
261 | if (daddr == 0) | |
262 | return -EINVAL; | |
263 | nexthop = inet->opt->faddr; | |
264 | } | |
265 | ||
266 | tmp = ip_route_connect(&rt, nexthop, inet->saddr, | |
267 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if, | |
268 | IPPROTO_DCCP, | |
269 | inet->sport, usin->sin_port, sk); | |
270 | if (tmp < 0) | |
271 | return tmp; | |
272 | ||
273 | if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { | |
274 | ip_rt_put(rt); | |
275 | return -ENETUNREACH; | |
276 | } | |
277 | ||
278 | if (inet->opt == NULL || !inet->opt->srr) | |
279 | daddr = rt->rt_dst; | |
280 | ||
281 | if (inet->saddr == 0) | |
282 | inet->saddr = rt->rt_src; | |
283 | inet->rcv_saddr = inet->saddr; | |
284 | ||
285 | inet->dport = usin->sin_port; | |
286 | inet->daddr = daddr; | |
287 | ||
288 | dp->dccps_ext_header_len = 0; | |
289 | if (inet->opt != NULL) | |
290 | dp->dccps_ext_header_len = inet->opt->optlen; | |
291 | /* | |
292 | * Socket identity is still unknown (sport may be zero). | |
293 | * However we set state to DCCP_REQUESTING and not releasing socket | |
294 | * lock select source port, enter ourselves into the hash tables and | |
295 | * complete initialization after this. | |
296 | */ | |
297 | dccp_set_state(sk, DCCP_REQUESTING); | |
298 | err = dccp_v4_hash_connect(sk); | |
299 | if (err != 0) | |
300 | goto failure; | |
301 | ||
302 | err = ip_route_newports(&rt, inet->sport, inet->dport, sk); | |
303 | if (err != 0) | |
304 | goto failure; | |
305 | ||
306 | /* OK, now commit destination to socket. */ | |
307 | sk_setup_caps(sk, &rt->u.dst); | |
308 | ||
309 | dp->dccps_gar = | |
310 | dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, | |
311 | inet->daddr, | |
312 | inet->sport, | |
313 | usin->sin_port); | |
314 | dccp_update_gss(sk, dp->dccps_iss); | |
315 | ||
03ace394 ACM |
316 | /* |
317 | * SWL and AWL are initially adjusted so that they are not less than | |
318 | * the initial Sequence Numbers received and sent, respectively: | |
319 | * SWL := max(GSR + 1 - floor(W/4), ISR), | |
320 | * AWL := max(GSS - W' + 1, ISS). | |
321 | * These adjustments MUST be applied only at the beginning of the | |
322 | * connection. | |
323 | */ | |
324 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); | |
325 | ||
7c657876 ACM |
326 | inet->id = dp->dccps_iss ^ jiffies; |
327 | ||
328 | err = dccp_connect(sk); | |
329 | rt = NULL; | |
330 | if (err != 0) | |
331 | goto failure; | |
332 | out: | |
333 | return err; | |
334 | failure: | |
7690af3f ACM |
335 | /* |
336 | * This unhashes the socket and releases the local port, if necessary. | |
337 | */ | |
7c657876 ACM |
338 | dccp_set_state(sk, DCCP_CLOSED); |
339 | ip_rt_put(rt); | |
340 | sk->sk_route_caps = 0; | |
341 | inet->dport = 0; | |
342 | goto out; | |
343 | } | |
344 | ||
345 | /* | |
346 | * This routine does path mtu discovery as defined in RFC1191. | |
347 | */ | |
348 | static inline void dccp_do_pmtu_discovery(struct sock *sk, | |
349 | const struct iphdr *iph, | |
350 | u32 mtu) | |
351 | { | |
352 | struct dst_entry *dst; | |
353 | const struct inet_sock *inet = inet_sk(sk); | |
354 | const struct dccp_sock *dp = dccp_sk(sk); | |
355 | ||
356 | /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs | |
357 | * send out by Linux are always < 576bytes so they should go through | |
358 | * unfragmented). | |
359 | */ | |
360 | if (sk->sk_state == DCCP_LISTEN) | |
361 | return; | |
362 | ||
363 | /* We don't check in the destentry if pmtu discovery is forbidden | |
364 | * on this route. We just assume that no packet_to_big packets | |
365 | * are send back when pmtu discovery is not active. | |
366 | * There is a small race when the user changes this flag in the | |
367 | * route, but I think that's acceptable. | |
368 | */ | |
369 | if ((dst = __sk_dst_check(sk, 0)) == NULL) | |
370 | return; | |
371 | ||
372 | dst->ops->update_pmtu(dst, mtu); | |
373 | ||
374 | /* Something is about to be wrong... Remember soft error | |
375 | * for the case, if this connection will not able to recover. | |
376 | */ | |
377 | if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) | |
378 | sk->sk_err_soft = EMSGSIZE; | |
379 | ||
380 | mtu = dst_mtu(dst); | |
381 | ||
382 | if (inet->pmtudisc != IP_PMTUDISC_DONT && | |
383 | dp->dccps_pmtu_cookie > mtu) { | |
384 | dccp_sync_mss(sk, mtu); | |
385 | ||
386 | /* | |
387 | * From: draft-ietf-dccp-spec-11.txt | |
388 | * | |
7690af3f ACM |
389 | * DCCP-Sync packets are the best choice for upward |
390 | * probing, since DCCP-Sync probes do not risk application | |
391 | * data loss. | |
7c657876 | 392 | */ |
e92ae93a | 393 | dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); |
7c657876 ACM |
394 | } /* else let the usual retransmit timer handle it */ |
395 | } | |
396 | ||
397 | static void dccp_v4_ctl_send_ack(struct sk_buff *rxskb) | |
398 | { | |
399 | int err; | |
400 | struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh; | |
401 | const int dccp_hdr_ack_len = sizeof(struct dccp_hdr) + | |
402 | sizeof(struct dccp_hdr_ext) + | |
403 | sizeof(struct dccp_hdr_ack_bits); | |
404 | struct sk_buff *skb; | |
405 | ||
406 | if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL) | |
407 | return; | |
408 | ||
409 | skb = alloc_skb(MAX_DCCP_HEADER + 15, GFP_ATOMIC); | |
410 | if (skb == NULL) | |
411 | return; | |
412 | ||
413 | /* Reserve space for headers. */ | |
414 | skb_reserve(skb, MAX_DCCP_HEADER); | |
415 | ||
416 | skb->dst = dst_clone(rxskb->dst); | |
417 | ||
418 | skb->h.raw = skb_push(skb, dccp_hdr_ack_len); | |
419 | dh = dccp_hdr(skb); | |
420 | memset(dh, 0, dccp_hdr_ack_len); | |
421 | ||
422 | /* Build DCCP header and checksum it. */ | |
423 | dh->dccph_type = DCCP_PKT_ACK; | |
424 | dh->dccph_sport = rxdh->dccph_dport; | |
425 | dh->dccph_dport = rxdh->dccph_sport; | |
426 | dh->dccph_doff = dccp_hdr_ack_len / 4; | |
427 | dh->dccph_x = 1; | |
428 | ||
429 | dccp_hdr_set_seq(dh, DCCP_SKB_CB(rxskb)->dccpd_ack_seq); | |
7690af3f ACM |
430 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), |
431 | DCCP_SKB_CB(rxskb)->dccpd_seq); | |
7c657876 ACM |
432 | |
433 | bh_lock_sock(dccp_ctl_socket->sk); | |
434 | err = ip_build_and_send_pkt(skb, dccp_ctl_socket->sk, | |
7690af3f ACM |
435 | rxskb->nh.iph->daddr, |
436 | rxskb->nh.iph->saddr, NULL); | |
7c657876 ACM |
437 | bh_unlock_sock(dccp_ctl_socket->sk); |
438 | ||
439 | if (err == NET_XMIT_CN || err == 0) { | |
440 | DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS); | |
441 | DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS); | |
442 | } | |
443 | } | |
444 | ||
7690af3f ACM |
445 | static void dccp_v4_reqsk_send_ack(struct sk_buff *skb, |
446 | struct request_sock *req) | |
7c657876 ACM |
447 | { |
448 | dccp_v4_ctl_send_ack(skb); | |
449 | } | |
450 | ||
451 | static int dccp_v4_send_response(struct sock *sk, struct request_sock *req, | |
452 | struct dst_entry *dst) | |
453 | { | |
454 | int err = -1; | |
455 | struct sk_buff *skb; | |
456 | ||
457 | /* First, grab a route. */ | |
458 | ||
459 | if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL) | |
460 | goto out; | |
461 | ||
462 | skb = dccp_make_response(sk, dst, req); | |
463 | if (skb != NULL) { | |
464 | const struct inet_request_sock *ireq = inet_rsk(req); | |
465 | ||
49c5bfaf | 466 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
7c657876 ACM |
467 | err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr, |
468 | ireq->rmt_addr, | |
469 | ireq->opt); | |
470 | if (err == NET_XMIT_CN) | |
471 | err = 0; | |
472 | } | |
473 | ||
474 | out: | |
475 | dst_release(dst); | |
476 | return err; | |
477 | } | |
478 | ||
479 | /* | |
480 | * This routine is called by the ICMP module when it gets some sort of error | |
481 | * condition. If err < 0 then the socket should be closed and the error | |
482 | * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code. | |
483 | * After adjustment header points to the first 8 bytes of the tcp header. We | |
484 | * need to find the appropriate port. | |
485 | * | |
486 | * The locking strategy used here is very "optimistic". When someone else | |
487 | * accesses the socket the ICMP is just dropped and for some paths there is no | |
488 | * check at all. A more general error queue to queue errors for later handling | |
489 | * is probably better. | |
490 | */ | |
491 | void dccp_v4_err(struct sk_buff *skb, u32 info) | |
492 | { | |
493 | const struct iphdr *iph = (struct iphdr *)skb->data; | |
7690af3f ACM |
494 | const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + |
495 | (iph->ihl << 2)); | |
7c657876 ACM |
496 | struct dccp_sock *dp; |
497 | struct inet_sock *inet; | |
498 | const int type = skb->h.icmph->type; | |
499 | const int code = skb->h.icmph->code; | |
500 | struct sock *sk; | |
501 | __u64 seq; | |
502 | int err; | |
503 | ||
504 | if (skb->len < (iph->ihl << 2) + 8) { | |
505 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
506 | return; | |
507 | } | |
508 | ||
509 | sk = inet_lookup(&dccp_hashinfo, iph->daddr, dh->dccph_dport, | |
510 | iph->saddr, dh->dccph_sport, inet_iif(skb)); | |
511 | if (sk == NULL) { | |
512 | ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); | |
513 | return; | |
514 | } | |
515 | ||
516 | if (sk->sk_state == DCCP_TIME_WAIT) { | |
517 | inet_twsk_put((struct inet_timewait_sock *)sk); | |
518 | return; | |
519 | } | |
520 | ||
521 | bh_lock_sock(sk); | |
522 | /* If too many ICMPs get dropped on busy | |
523 | * servers this needs to be solved differently. | |
524 | */ | |
525 | if (sock_owned_by_user(sk)) | |
526 | NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS); | |
527 | ||
528 | if (sk->sk_state == DCCP_CLOSED) | |
529 | goto out; | |
530 | ||
531 | dp = dccp_sk(sk); | |
532 | seq = dccp_hdr_seq(skb); | |
533 | if (sk->sk_state != DCCP_LISTEN && | |
534 | !between48(seq, dp->dccps_swl, dp->dccps_swh)) { | |
535 | NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS); | |
536 | goto out; | |
537 | } | |
538 | ||
539 | switch (type) { | |
540 | case ICMP_SOURCE_QUENCH: | |
541 | /* Just silently ignore these. */ | |
542 | goto out; | |
543 | case ICMP_PARAMETERPROB: | |
544 | err = EPROTO; | |
545 | break; | |
546 | case ICMP_DEST_UNREACH: | |
547 | if (code > NR_ICMP_UNREACH) | |
548 | goto out; | |
549 | ||
550 | if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ | |
551 | if (!sock_owned_by_user(sk)) | |
552 | dccp_do_pmtu_discovery(sk, iph, info); | |
553 | goto out; | |
554 | } | |
555 | ||
556 | err = icmp_err_convert[code].errno; | |
557 | break; | |
558 | case ICMP_TIME_EXCEEDED: | |
559 | err = EHOSTUNREACH; | |
560 | break; | |
561 | default: | |
562 | goto out; | |
563 | } | |
564 | ||
565 | switch (sk->sk_state) { | |
566 | struct request_sock *req , **prev; | |
567 | case DCCP_LISTEN: | |
568 | if (sock_owned_by_user(sk)) | |
569 | goto out; | |
570 | req = inet_csk_search_req(sk, &prev, dh->dccph_dport, | |
571 | iph->daddr, iph->saddr); | |
572 | if (!req) | |
573 | goto out; | |
574 | ||
575 | /* | |
576 | * ICMPs are not backlogged, hence we cannot get an established | |
577 | * socket here. | |
578 | */ | |
579 | BUG_TRAP(!req->sk); | |
580 | ||
581 | if (seq != dccp_rsk(req)->dreq_iss) { | |
582 | NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS); | |
583 | goto out; | |
584 | } | |
585 | /* | |
586 | * Still in RESPOND, just remove it silently. | |
587 | * There is no good way to pass the error to the newly | |
588 | * created socket, and POSIX does not want network | |
589 | * errors returned from accept(). | |
590 | */ | |
591 | inet_csk_reqsk_queue_drop(sk, req, prev); | |
592 | goto out; | |
593 | ||
594 | case DCCP_REQUESTING: | |
595 | case DCCP_RESPOND: | |
596 | if (!sock_owned_by_user(sk)) { | |
597 | DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS); | |
598 | sk->sk_err = err; | |
599 | ||
600 | sk->sk_error_report(sk); | |
601 | ||
602 | dccp_done(sk); | |
603 | } else | |
604 | sk->sk_err_soft = err; | |
605 | goto out; | |
606 | } | |
607 | ||
608 | /* If we've already connected we will keep trying | |
609 | * until we time out, or the user gives up. | |
610 | * | |
611 | * rfc1122 4.2.3.9 allows to consider as hard errors | |
612 | * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, | |
613 | * but it is obsoleted by pmtu discovery). | |
614 | * | |
615 | * Note, that in modern internet, where routing is unreliable | |
616 | * and in each dark corner broken firewalls sit, sending random | |
617 | * errors ordered by their masters even this two messages finally lose | |
618 | * their original sense (even Linux sends invalid PORT_UNREACHs) | |
619 | * | |
620 | * Now we are in compliance with RFCs. | |
621 | * --ANK (980905) | |
622 | */ | |
623 | ||
624 | inet = inet_sk(sk); | |
625 | if (!sock_owned_by_user(sk) && inet->recverr) { | |
626 | sk->sk_err = err; | |
627 | sk->sk_error_report(sk); | |
628 | } else /* Only an error on timeout */ | |
629 | sk->sk_err_soft = err; | |
630 | out: | |
631 | bh_unlock_sock(sk); | |
632 | sock_put(sk); | |
633 | } | |
634 | ||
7c657876 ACM |
635 | int dccp_v4_send_reset(struct sock *sk, enum dccp_reset_codes code) |
636 | { | |
637 | struct sk_buff *skb; | |
638 | /* | |
639 | * FIXME: what if rebuild_header fails? | |
640 | * Should we be doing a rebuild_header here? | |
641 | */ | |
642 | int err = inet_sk_rebuild_header(sk); | |
643 | ||
644 | if (err != 0) | |
645 | return err; | |
646 | ||
647 | skb = dccp_make_reset(sk, sk->sk_dst_cache, code); | |
648 | if (skb != NULL) { | |
7c657876 ACM |
649 | const struct inet_sock *inet = inet_sk(sk); |
650 | ||
49c5bfaf | 651 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
7c657876 ACM |
652 | err = ip_build_and_send_pkt(skb, sk, |
653 | inet->saddr, inet->daddr, NULL); | |
654 | if (err == NET_XMIT_CN) | |
655 | err = 0; | |
7c657876 ACM |
656 | } |
657 | ||
658 | return err; | |
659 | } | |
660 | ||
661 | static inline u64 dccp_v4_init_sequence(const struct sock *sk, | |
662 | const struct sk_buff *skb) | |
663 | { | |
664 | return secure_dccp_sequence_number(skb->nh.iph->daddr, | |
665 | skb->nh.iph->saddr, | |
666 | dccp_hdr(skb)->dccph_dport, | |
667 | dccp_hdr(skb)->dccph_sport); | |
668 | } | |
669 | ||
67e6b629 ACM |
670 | static inline int dccp_bad_service_code(const struct sock *sk, |
671 | const __u32 service) | |
672 | { | |
673 | const struct dccp_sock *dp = dccp_sk(sk); | |
674 | ||
675 | if (dp->dccps_service == service) | |
676 | return 0; | |
677 | return !dccp_list_has_service(dp->dccps_service_list, service); | |
678 | } | |
679 | ||
7c657876 ACM |
680 | int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
681 | { | |
682 | struct inet_request_sock *ireq; | |
683 | struct dccp_sock dp; | |
684 | struct request_sock *req; | |
685 | struct dccp_request_sock *dreq; | |
686 | const __u32 saddr = skb->nh.iph->saddr; | |
687 | const __u32 daddr = skb->nh.iph->daddr; | |
67e6b629 | 688 | const __u32 service = dccp_hdr_request(skb)->dccph_req_service; |
0c10c5d9 ACM |
689 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
690 | __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY; | |
7c657876 ACM |
691 | struct dst_entry *dst = NULL; |
692 | ||
693 | /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */ | |
694 | if (((struct rtable *)skb->dst)->rt_flags & | |
0c10c5d9 ACM |
695 | (RTCF_BROADCAST | RTCF_MULTICAST)) { |
696 | reset_code = DCCP_RESET_CODE_NO_CONNECTION; | |
7c657876 | 697 | goto drop; |
0c10c5d9 | 698 | } |
7c657876 | 699 | |
67e6b629 ACM |
700 | if (dccp_bad_service_code(sk, service)) { |
701 | reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; | |
702 | goto drop; | |
703 | } | |
7c657876 ACM |
704 | /* |
705 | * TW buckets are converted to open requests without | |
706 | * limitations, they conserve resources and peer is | |
707 | * evidently real one. | |
708 | */ | |
709 | if (inet_csk_reqsk_queue_is_full(sk)) | |
710 | goto drop; | |
711 | ||
712 | /* | |
713 | * Accept backlog is full. If we have already queued enough | |
714 | * of warm entries in syn queue, drop request. It is better than | |
715 | * clogging syn queue with openreqs with exponentially increasing | |
716 | * timeout. | |
717 | */ | |
718 | if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) | |
719 | goto drop; | |
720 | ||
721 | req = reqsk_alloc(sk->sk_prot->rsk_prot); | |
722 | if (req == NULL) | |
723 | goto drop; | |
724 | ||
725 | /* FIXME: process options */ | |
726 | ||
727 | dccp_openreq_init(req, &dp, skb); | |
728 | ||
729 | ireq = inet_rsk(req); | |
730 | ireq->loc_addr = daddr; | |
731 | ireq->rmt_addr = saddr; | |
732 | /* FIXME: Merge Aristeu's option parsing code when ready */ | |
7690af3f ACM |
733 | req->rcv_wnd = 100; /* Fake, option parsing will get the |
734 | right value */ | |
7c657876 ACM |
735 | ireq->opt = NULL; |
736 | ||
737 | /* | |
738 | * Step 3: Process LISTEN state | |
739 | * | |
740 | * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie | |
741 | * | |
742 | * In fact we defer setting S.GSR, S.SWL, S.SWH to | |
743 | * dccp_create_openreq_child. | |
744 | */ | |
745 | dreq = dccp_rsk(req); | |
67e6b629 ACM |
746 | dreq->dreq_isr = dcb->dccpd_seq; |
747 | dreq->dreq_iss = dccp_v4_init_sequence(sk, skb); | |
748 | dreq->dreq_service = service; | |
7c657876 ACM |
749 | |
750 | if (dccp_v4_send_response(sk, req, dst)) | |
751 | goto drop_and_free; | |
752 | ||
753 | inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); | |
754 | return 0; | |
755 | ||
756 | drop_and_free: | |
757 | /* | |
758 | * FIXME: should be reqsk_free after implementing req->rsk_ops | |
759 | */ | |
760 | __reqsk_free(req); | |
761 | drop: | |
762 | DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS); | |
0c10c5d9 | 763 | dcb->dccpd_reset_code = reset_code; |
7c657876 ACM |
764 | return -1; |
765 | } | |
766 | ||
767 | /* | |
768 | * The three way handshake has completed - we got a valid ACK or DATAACK - | |
769 | * now create the new socket. | |
770 | * | |
771 | * This is the equivalent of TCP's tcp_v4_syn_recv_sock | |
772 | */ | |
773 | struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb, | |
774 | struct request_sock *req, | |
775 | struct dst_entry *dst) | |
776 | { | |
777 | struct inet_request_sock *ireq; | |
778 | struct inet_sock *newinet; | |
779 | struct dccp_sock *newdp; | |
780 | struct sock *newsk; | |
781 | ||
782 | if (sk_acceptq_is_full(sk)) | |
783 | goto exit_overflow; | |
784 | ||
785 | if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL) | |
786 | goto exit; | |
787 | ||
788 | newsk = dccp_create_openreq_child(sk, req, skb); | |
789 | if (newsk == NULL) | |
790 | goto exit; | |
791 | ||
792 | sk_setup_caps(newsk, dst); | |
793 | ||
794 | newdp = dccp_sk(newsk); | |
795 | newinet = inet_sk(newsk); | |
796 | ireq = inet_rsk(req); | |
797 | newinet->daddr = ireq->rmt_addr; | |
798 | newinet->rcv_saddr = ireq->loc_addr; | |
799 | newinet->saddr = ireq->loc_addr; | |
800 | newinet->opt = ireq->opt; | |
801 | ireq->opt = NULL; | |
802 | newinet->mc_index = inet_iif(skb); | |
803 | newinet->mc_ttl = skb->nh.iph->ttl; | |
804 | newinet->id = jiffies; | |
805 | ||
806 | dccp_sync_mss(newsk, dst_mtu(dst)); | |
807 | ||
808 | __inet_hash(&dccp_hashinfo, newsk, 0); | |
809 | __inet_inherit_port(&dccp_hashinfo, sk, newsk); | |
810 | ||
811 | return newsk; | |
812 | ||
813 | exit_overflow: | |
814 | NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS); | |
815 | exit: | |
816 | NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS); | |
817 | dst_release(dst); | |
818 | return NULL; | |
819 | } | |
820 | ||
821 | static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) | |
822 | { | |
823 | const struct dccp_hdr *dh = dccp_hdr(skb); | |
824 | const struct iphdr *iph = skb->nh.iph; | |
825 | struct sock *nsk; | |
826 | struct request_sock **prev; | |
827 | /* Find possible connection requests. */ | |
828 | struct request_sock *req = inet_csk_search_req(sk, &prev, | |
829 | dh->dccph_sport, | |
830 | iph->saddr, iph->daddr); | |
831 | if (req != NULL) | |
832 | return dccp_check_req(sk, skb, req, prev); | |
833 | ||
834 | nsk = __inet_lookup_established(&dccp_hashinfo, | |
835 | iph->saddr, dh->dccph_sport, | |
836 | iph->daddr, ntohs(dh->dccph_dport), | |
837 | inet_iif(skb)); | |
838 | if (nsk != NULL) { | |
839 | if (nsk->sk_state != DCCP_TIME_WAIT) { | |
840 | bh_lock_sock(nsk); | |
841 | return nsk; | |
842 | } | |
843 | inet_twsk_put((struct inet_timewait_sock *)nsk); | |
844 | return NULL; | |
845 | } | |
846 | ||
847 | return sk; | |
848 | } | |
849 | ||
7690af3f ACM |
850 | int dccp_v4_checksum(const struct sk_buff *skb, const u32 saddr, |
851 | const u32 daddr) | |
7c657876 | 852 | { |
95b81ef7 | 853 | const struct dccp_hdr* dh = dccp_hdr(skb); |
7c657876 ACM |
854 | int checksum_len; |
855 | u32 tmp; | |
856 | ||
857 | if (dh->dccph_cscov == 0) | |
858 | checksum_len = skb->len; | |
859 | else { | |
860 | checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32); | |
7690af3f ACM |
861 | checksum_len = checksum_len < skb->len ? checksum_len : |
862 | skb->len; | |
7c657876 ACM |
863 | } |
864 | ||
865 | tmp = csum_partial((unsigned char *)dh, checksum_len, 0); | |
7690af3f ACM |
866 | return csum_tcpudp_magic(saddr, daddr, checksum_len, |
867 | IPPROTO_DCCP, tmp); | |
7c657876 ACM |
868 | } |
869 | ||
95b81ef7 YN |
870 | static int dccp_v4_verify_checksum(struct sk_buff *skb, |
871 | const u32 saddr, const u32 daddr) | |
7c657876 | 872 | { |
95b81ef7 YN |
873 | struct dccp_hdr *dh = dccp_hdr(skb); |
874 | int checksum_len; | |
875 | u32 tmp; | |
7c657876 | 876 | |
95b81ef7 YN |
877 | if (dh->dccph_cscov == 0) |
878 | checksum_len = skb->len; | |
879 | else { | |
880 | checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32); | |
7690af3f ACM |
881 | checksum_len = checksum_len < skb->len ? checksum_len : |
882 | skb->len; | |
95b81ef7 YN |
883 | } |
884 | tmp = csum_partial((unsigned char *)dh, checksum_len, 0); | |
7690af3f ACM |
885 | return csum_tcpudp_magic(saddr, daddr, checksum_len, |
886 | IPPROTO_DCCP, tmp) == 0 ? 0 : -1; | |
7c657876 ACM |
887 | } |
888 | ||
889 | static struct dst_entry* dccp_v4_route_skb(struct sock *sk, | |
890 | struct sk_buff *skb) | |
891 | { | |
892 | struct rtable *rt; | |
893 | struct flowi fl = { .oif = ((struct rtable *)skb->dst)->rt_iif, | |
894 | .nl_u = { .ip4_u = | |
895 | { .daddr = skb->nh.iph->saddr, | |
896 | .saddr = skb->nh.iph->daddr, | |
897 | .tos = RT_CONN_FLAGS(sk) } }, | |
898 | .proto = sk->sk_protocol, | |
899 | .uli_u = { .ports = | |
900 | { .sport = dccp_hdr(skb)->dccph_dport, | |
7690af3f ACM |
901 | .dport = dccp_hdr(skb)->dccph_sport } |
902 | } | |
903 | }; | |
7c657876 ACM |
904 | |
905 | if (ip_route_output_flow(&rt, &fl, sk, 0)) { | |
906 | IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES); | |
907 | return NULL; | |
908 | } | |
909 | ||
910 | return &rt->u.dst; | |
911 | } | |
912 | ||
a1d3a355 | 913 | static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb) |
7c657876 ACM |
914 | { |
915 | int err; | |
916 | struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh; | |
917 | const int dccp_hdr_reset_len = sizeof(struct dccp_hdr) + | |
918 | sizeof(struct dccp_hdr_ext) + | |
919 | sizeof(struct dccp_hdr_reset); | |
920 | struct sk_buff *skb; | |
921 | struct dst_entry *dst; | |
2807d4ff | 922 | u64 seqno; |
7c657876 ACM |
923 | |
924 | /* Never send a reset in response to a reset. */ | |
925 | if (rxdh->dccph_type == DCCP_PKT_RESET) | |
926 | return; | |
927 | ||
928 | if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL) | |
929 | return; | |
930 | ||
931 | dst = dccp_v4_route_skb(dccp_ctl_socket->sk, rxskb); | |
932 | if (dst == NULL) | |
933 | return; | |
934 | ||
935 | skb = alloc_skb(MAX_DCCP_HEADER + 15, GFP_ATOMIC); | |
936 | if (skb == NULL) | |
937 | goto out; | |
938 | ||
939 | /* Reserve space for headers. */ | |
940 | skb_reserve(skb, MAX_DCCP_HEADER); | |
941 | skb->dst = dst_clone(dst); | |
942 | ||
943 | skb->h.raw = skb_push(skb, dccp_hdr_reset_len); | |
944 | dh = dccp_hdr(skb); | |
945 | memset(dh, 0, dccp_hdr_reset_len); | |
946 | ||
947 | /* Build DCCP header and checksum it. */ | |
948 | dh->dccph_type = DCCP_PKT_RESET; | |
949 | dh->dccph_sport = rxdh->dccph_dport; | |
950 | dh->dccph_dport = rxdh->dccph_sport; | |
951 | dh->dccph_doff = dccp_hdr_reset_len / 4; | |
952 | dh->dccph_x = 1; | |
7690af3f ACM |
953 | dccp_hdr_reset(skb)->dccph_reset_code = |
954 | DCCP_SKB_CB(rxskb)->dccpd_reset_code; | |
7c657876 | 955 | |
2807d4ff ACM |
956 | /* See "8.3.1. Abnormal Termination" in draft-ietf-dccp-spec-11 */ |
957 | seqno = 0; | |
958 | if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) | |
959 | dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1); | |
960 | ||
961 | dccp_hdr_set_seq(dh, seqno); | |
7690af3f ACM |
962 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), |
963 | DCCP_SKB_CB(rxskb)->dccpd_seq); | |
7c657876 | 964 | |
95b81ef7 YN |
965 | dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr, |
966 | rxskb->nh.iph->daddr); | |
7c657876 ACM |
967 | |
968 | bh_lock_sock(dccp_ctl_socket->sk); | |
969 | err = ip_build_and_send_pkt(skb, dccp_ctl_socket->sk, | |
7690af3f ACM |
970 | rxskb->nh.iph->daddr, |
971 | rxskb->nh.iph->saddr, NULL); | |
7c657876 ACM |
972 | bh_unlock_sock(dccp_ctl_socket->sk); |
973 | ||
974 | if (err == NET_XMIT_CN || err == 0) { | |
975 | DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS); | |
976 | DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS); | |
977 | } | |
978 | out: | |
979 | dst_release(dst); | |
980 | } | |
981 | ||
982 | int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) | |
983 | { | |
984 | struct dccp_hdr *dh = dccp_hdr(skb); | |
985 | ||
986 | if (sk->sk_state == DCCP_OPEN) { /* Fast path */ | |
987 | if (dccp_rcv_established(sk, skb, dh, skb->len)) | |
988 | goto reset; | |
989 | return 0; | |
990 | } | |
991 | ||
992 | /* | |
993 | * Step 3: Process LISTEN state | |
994 | * If S.state == LISTEN, | |
7690af3f ACM |
995 | * If P.type == Request or P contains a valid Init Cookie |
996 | * option, | |
7c657876 ACM |
997 | * * Must scan the packet's options to check for an Init |
998 | * Cookie. Only the Init Cookie is processed here, | |
999 | * however; other options are processed in Step 8. This | |
1000 | * scan need only be performed if the endpoint uses Init | |
1001 | * Cookies * | |
1002 | * * Generate a new socket and switch to that socket * | |
1003 | * Set S := new socket for this port pair | |
1004 | * S.state = RESPOND | |
1005 | * Choose S.ISS (initial seqno) or set from Init Cookie | |
1006 | * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie | |
1007 | * Continue with S.state == RESPOND | |
1008 | * * A Response packet will be generated in Step 11 * | |
1009 | * Otherwise, | |
1010 | * Generate Reset(No Connection) unless P.type == Reset | |
1011 | * Drop packet and return | |
1012 | * | |
7690af3f ACM |
1013 | * NOTE: the check for the packet types is done in |
1014 | * dccp_rcv_state_process | |
7c657876 ACM |
1015 | */ |
1016 | if (sk->sk_state == DCCP_LISTEN) { | |
1017 | struct sock *nsk = dccp_v4_hnd_req(sk, skb); | |
1018 | ||
1019 | if (nsk == NULL) | |
1020 | goto discard; | |
1021 | ||
1022 | if (nsk != sk) { | |
1023 | if (dccp_child_process(sk, nsk, skb)) | |
1024 | goto reset; | |
1025 | return 0; | |
1026 | } | |
1027 | } | |
1028 | ||
1029 | if (dccp_rcv_state_process(sk, skb, dh, skb->len)) | |
1030 | goto reset; | |
1031 | return 0; | |
1032 | ||
1033 | reset: | |
7c657876 ACM |
1034 | dccp_v4_ctl_send_reset(skb); |
1035 | discard: | |
1036 | kfree_skb(skb); | |
1037 | return 0; | |
1038 | } | |
1039 | ||
1040 | static inline int dccp_invalid_packet(struct sk_buff *skb) | |
1041 | { | |
1042 | const struct dccp_hdr *dh; | |
1043 | ||
1044 | if (skb->pkt_type != PACKET_HOST) | |
1045 | return 1; | |
1046 | ||
1047 | if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) { | |
c59eab46 | 1048 | LIMIT_NETDEBUG(KERN_WARNING "DCCP: pskb_may_pull failed\n"); |
7c657876 ACM |
1049 | return 1; |
1050 | } | |
1051 | ||
1052 | dh = dccp_hdr(skb); | |
1053 | ||
1054 | /* If the packet type is not understood, drop packet and return */ | |
1055 | if (dh->dccph_type >= DCCP_PKT_INVALID) { | |
c59eab46 | 1056 | LIMIT_NETDEBUG(KERN_WARNING "DCCP: invalid packet type\n"); |
7c657876 ACM |
1057 | return 1; |
1058 | } | |
1059 | ||
1060 | /* | |
1061 | * If P.Data Offset is too small for packet type, or too large for | |
1062 | * packet, drop packet and return | |
1063 | */ | |
1064 | if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) { | |
c59eab46 ACM |
1065 | LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) " |
1066 | "too small 1\n", | |
1067 | dh->dccph_doff); | |
7c657876 ACM |
1068 | return 1; |
1069 | } | |
1070 | ||
1071 | if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) { | |
c59eab46 ACM |
1072 | LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) " |
1073 | "too small 2\n", | |
1074 | dh->dccph_doff); | |
7c657876 ACM |
1075 | return 1; |
1076 | } | |
1077 | ||
1078 | dh = dccp_hdr(skb); | |
1079 | ||
1080 | /* | |
1081 | * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet | |
1082 | * has short sequence numbers), drop packet and return | |
1083 | */ | |
1084 | if (dh->dccph_x == 0 && | |
1085 | dh->dccph_type != DCCP_PKT_DATA && | |
1086 | dh->dccph_type != DCCP_PKT_ACK && | |
1087 | dh->dccph_type != DCCP_PKT_DATAACK) { | |
c59eab46 ACM |
1088 | LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data, Ack " |
1089 | "nor DataAck and P.X == 0\n", | |
1090 | dccp_packet_name(dh->dccph_type)); | |
7c657876 ACM |
1091 | return 1; |
1092 | } | |
1093 | ||
1094 | /* If the header checksum is incorrect, drop packet and return */ | |
95b81ef7 YN |
1095 | if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr, |
1096 | skb->nh.iph->daddr) < 0) { | |
c59eab46 ACM |
1097 | LIMIT_NETDEBUG(KERN_WARNING "DCCP: header checksum is " |
1098 | "incorrect\n"); | |
7c657876 ACM |
1099 | return 1; |
1100 | } | |
1101 | ||
1102 | return 0; | |
1103 | } | |
1104 | ||
1105 | /* this is called when real data arrives */ | |
1106 | int dccp_v4_rcv(struct sk_buff *skb) | |
1107 | { | |
1108 | const struct dccp_hdr *dh; | |
1109 | struct sock *sk; | |
1110 | int rc; | |
1111 | ||
1112 | /* Step 1: Check header basics: */ | |
1113 | ||
1114 | if (dccp_invalid_packet(skb)) | |
1115 | goto discard_it; | |
1116 | ||
1117 | dh = dccp_hdr(skb); | |
7c657876 | 1118 | |
7c657876 ACM |
1119 | DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(skb); |
1120 | DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; | |
1121 | ||
1122 | dccp_pr_debug("%8.8s " | |
1123 | "src=%u.%u.%u.%u@%-5d " | |
1124 | "dst=%u.%u.%u.%u@%-5d seq=%llu", | |
1125 | dccp_packet_name(dh->dccph_type), | |
1126 | NIPQUAD(skb->nh.iph->saddr), ntohs(dh->dccph_sport), | |
1127 | NIPQUAD(skb->nh.iph->daddr), ntohs(dh->dccph_dport), | |
f6ccf554 | 1128 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); |
7c657876 ACM |
1129 | |
1130 | if (dccp_packet_without_ack(skb)) { | |
1131 | DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; | |
1132 | dccp_pr_debug_cat("\n"); | |
1133 | } else { | |
1134 | DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); | |
f6ccf554 DM |
1135 | dccp_pr_debug_cat(", ack=%llu\n", |
1136 | (unsigned long long) | |
1137 | DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
7c657876 ACM |
1138 | } |
1139 | ||
1140 | /* Step 2: | |
1141 | * Look up flow ID in table and get corresponding socket */ | |
1142 | sk = __inet_lookup(&dccp_hashinfo, | |
1143 | skb->nh.iph->saddr, dh->dccph_sport, | |
1144 | skb->nh.iph->daddr, ntohs(dh->dccph_dport), | |
1145 | inet_iif(skb)); | |
1146 | ||
1147 | /* | |
1148 | * Step 2: | |
1149 | * If no socket ... | |
1150 | * Generate Reset(No Connection) unless P.type == Reset | |
1151 | * Drop packet and return | |
1152 | */ | |
1153 | if (sk == NULL) { | |
1154 | dccp_pr_debug("failed to look up flow ID in table and " | |
1155 | "get corresponding socket\n"); | |
1156 | goto no_dccp_socket; | |
1157 | } | |
1158 | ||
1159 | /* | |
1160 | * Step 2: | |
1161 | * ... or S.state == TIMEWAIT, | |
1162 | * Generate Reset(No Connection) unless P.type == Reset | |
1163 | * Drop packet and return | |
1164 | */ | |
1165 | ||
1166 | if (sk->sk_state == DCCP_TIME_WAIT) { | |
64cf1e5d ACM |
1167 | dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: " |
1168 | "do_time_wait\n"); | |
1169 | goto do_time_wait; | |
7c657876 ACM |
1170 | } |
1171 | ||
1172 | if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) { | |
1173 | dccp_pr_debug("xfrm4_policy_check failed\n"); | |
1174 | goto discard_and_relse; | |
1175 | } | |
1176 | ||
1177 | if (sk_filter(sk, skb, 0)) { | |
1178 | dccp_pr_debug("sk_filter failed\n"); | |
1179 | goto discard_and_relse; | |
1180 | } | |
1181 | ||
1182 | skb->dev = NULL; | |
1183 | ||
1184 | bh_lock_sock(sk); | |
1185 | rc = 0; | |
1186 | if (!sock_owned_by_user(sk)) | |
1187 | rc = dccp_v4_do_rcv(sk, skb); | |
1188 | else | |
1189 | sk_add_backlog(sk, skb); | |
1190 | bh_unlock_sock(sk); | |
1191 | ||
1192 | sock_put(sk); | |
1193 | return rc; | |
1194 | ||
1195 | no_dccp_socket: | |
1196 | if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) | |
1197 | goto discard_it; | |
1198 | /* | |
1199 | * Step 2: | |
1200 | * Generate Reset(No Connection) unless P.type == Reset | |
1201 | * Drop packet and return | |
1202 | */ | |
1203 | if (dh->dccph_type != DCCP_PKT_RESET) { | |
7690af3f ACM |
1204 | DCCP_SKB_CB(skb)->dccpd_reset_code = |
1205 | DCCP_RESET_CODE_NO_CONNECTION; | |
7c657876 ACM |
1206 | dccp_v4_ctl_send_reset(skb); |
1207 | } | |
1208 | ||
1209 | discard_it: | |
1210 | /* Discard frame. */ | |
1211 | kfree_skb(skb); | |
1212 | return 0; | |
1213 | ||
1214 | discard_and_relse: | |
1215 | sock_put(sk); | |
1216 | goto discard_it; | |
64cf1e5d ACM |
1217 | |
1218 | do_time_wait: | |
1219 | inet_twsk_put((struct inet_timewait_sock *)sk); | |
1220 | goto no_dccp_socket; | |
7c657876 ACM |
1221 | } |
1222 | ||
1223 | static int dccp_v4_init_sock(struct sock *sk) | |
1224 | { | |
1225 | struct dccp_sock *dp = dccp_sk(sk); | |
1226 | static int dccp_ctl_socket_init = 1; | |
1227 | ||
1228 | dccp_options_init(&dp->dccps_options); | |
b0e56780 | 1229 | do_gettimeofday(&dp->dccps_epoch); |
7c657876 ACM |
1230 | |
1231 | if (dp->dccps_options.dccpo_send_ack_vector) { | |
ae31c339 ACM |
1232 | dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(DCCP_MAX_ACKVEC_LEN, |
1233 | GFP_KERNEL); | |
1234 | if (dp->dccps_hc_rx_ackvec == NULL) | |
7c657876 ACM |
1235 | return -ENOMEM; |
1236 | } | |
1237 | ||
1238 | /* | |
1239 | * FIXME: We're hardcoding the CCID, and doing this at this point makes | |
1240 | * the listening (master) sock get CCID control blocks, which is not | |
1241 | * necessary, but for now, to not mess with the test userspace apps, | |
1242 | * lets leave it here, later the real solution is to do this in a | |
1243 | * setsockopt(CCIDs-I-want/accept). -acme | |
1244 | */ | |
1245 | if (likely(!dccp_ctl_socket_init)) { | |
561713cf | 1246 | dp->dccps_hc_rx_ccid = ccid_init(dp->dccps_options.dccpo_rx_ccid, |
7690af3f | 1247 | sk); |
561713cf | 1248 | dp->dccps_hc_tx_ccid = ccid_init(dp->dccps_options.dccpo_tx_ccid, |
7690af3f | 1249 | sk); |
7c657876 ACM |
1250 | if (dp->dccps_hc_rx_ccid == NULL || |
1251 | dp->dccps_hc_tx_ccid == NULL) { | |
1252 | ccid_exit(dp->dccps_hc_rx_ccid, sk); | |
1253 | ccid_exit(dp->dccps_hc_tx_ccid, sk); | |
ae31c339 ACM |
1254 | if (dp->dccps_options.dccpo_send_ack_vector) { |
1255 | dccp_ackvec_free(dp->dccps_hc_rx_ackvec); | |
1256 | dp->dccps_hc_rx_ackvec = NULL; | |
1257 | } | |
7c657876 ACM |
1258 | dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; |
1259 | return -ENOMEM; | |
1260 | } | |
1261 | } else | |
1262 | dccp_ctl_socket_init = 0; | |
1263 | ||
1264 | dccp_init_xmit_timers(sk); | |
0b4e03bf | 1265 | inet_csk(sk)->icsk_rto = DCCP_TIMEOUT_INIT; |
7c657876 | 1266 | sk->sk_state = DCCP_CLOSED; |
c530cfb1 | 1267 | sk->sk_write_space = dccp_write_space; |
7c657876 ACM |
1268 | dp->dccps_mss_cache = 536; |
1269 | dp->dccps_role = DCCP_ROLE_UNDEFINED; | |
67e6b629 | 1270 | dp->dccps_service = DCCP_SERVICE_INVALID_VALUE; |
7c657876 ACM |
1271 | |
1272 | return 0; | |
1273 | } | |
1274 | ||
a1d3a355 | 1275 | static int dccp_v4_destroy_sock(struct sock *sk) |
7c657876 ACM |
1276 | { |
1277 | struct dccp_sock *dp = dccp_sk(sk); | |
1278 | ||
1279 | /* | |
1280 | * DCCP doesn't use sk_qrite_queue, just sk_send_head | |
1281 | * for retransmissions | |
1282 | */ | |
1283 | if (sk->sk_send_head != NULL) { | |
1284 | kfree_skb(sk->sk_send_head); | |
1285 | sk->sk_send_head = NULL; | |
1286 | } | |
1287 | ||
1288 | /* Clean up a referenced DCCP bind bucket. */ | |
1289 | if (inet_csk(sk)->icsk_bind_hash != NULL) | |
1290 | inet_put_port(&dccp_hashinfo, sk); | |
1291 | ||
67e6b629 ACM |
1292 | if (dp->dccps_service_list != NULL) { |
1293 | kfree(dp->dccps_service_list); | |
1294 | dp->dccps_service_list = NULL; | |
1295 | } | |
1296 | ||
8efa544f ACM |
1297 | ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk); |
1298 | ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk); | |
ae31c339 ACM |
1299 | if (dp->dccps_options.dccpo_send_ack_vector) { |
1300 | dccp_ackvec_free(dp->dccps_hc_rx_ackvec); | |
1301 | dp->dccps_hc_rx_ackvec = NULL; | |
1302 | } | |
7c657876 ACM |
1303 | ccid_exit(dp->dccps_hc_rx_ccid, sk); |
1304 | ccid_exit(dp->dccps_hc_tx_ccid, sk); | |
1305 | dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; | |
1306 | ||
1307 | return 0; | |
1308 | } | |
1309 | ||
1310 | static void dccp_v4_reqsk_destructor(struct request_sock *req) | |
1311 | { | |
1312 | kfree(inet_rsk(req)->opt); | |
1313 | } | |
1314 | ||
1315 | static struct request_sock_ops dccp_request_sock_ops = { | |
1316 | .family = PF_INET, | |
1317 | .obj_size = sizeof(struct dccp_request_sock), | |
1318 | .rtx_syn_ack = dccp_v4_send_response, | |
1319 | .send_ack = dccp_v4_reqsk_send_ack, | |
1320 | .destructor = dccp_v4_reqsk_destructor, | |
1321 | .send_reset = dccp_v4_ctl_send_reset, | |
1322 | }; | |
1323 | ||
1324 | struct proto dccp_v4_prot = { | |
1325 | .name = "DCCP", | |
1326 | .owner = THIS_MODULE, | |
1327 | .close = dccp_close, | |
1328 | .connect = dccp_v4_connect, | |
1329 | .disconnect = dccp_disconnect, | |
1330 | .ioctl = dccp_ioctl, | |
1331 | .init = dccp_v4_init_sock, | |
1332 | .setsockopt = dccp_setsockopt, | |
1333 | .getsockopt = dccp_getsockopt, | |
1334 | .sendmsg = dccp_sendmsg, | |
1335 | .recvmsg = dccp_recvmsg, | |
1336 | .backlog_rcv = dccp_v4_do_rcv, | |
1337 | .hash = dccp_v4_hash, | |
1338 | .unhash = dccp_v4_unhash, | |
1339 | .accept = inet_csk_accept, | |
1340 | .get_port = dccp_v4_get_port, | |
1341 | .shutdown = dccp_shutdown, | |
1342 | .destroy = dccp_v4_destroy_sock, | |
1343 | .orphan_count = &dccp_orphan_count, | |
1344 | .max_header = MAX_DCCP_HEADER, | |
1345 | .obj_size = sizeof(struct dccp_sock), | |
1346 | .rsk_prot = &dccp_request_sock_ops, | |
64cf1e5d | 1347 | .twsk_obj_size = sizeof(struct inet_timewait_sock), |
7c657876 | 1348 | }; |