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13#include <linux/dccp.h>
14#include <linux/kernel.h>
15#include <linux/skbuff.h>
16
17#include <net/inet_sock.h>
18#include <net/sock.h>
19
20#include "ackvec.h"
21#include "ccid.h"
22#include "dccp.h"
23
24static inline void dccp_event_ack_sent(struct sock *sk)
25{
26 inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
27}
28
29static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
30{
31 skb_set_owner_w(skb, sk);
32 WARN_ON(sk->sk_send_head);
33 sk->sk_send_head = skb;
34}
35
36
37
38
39
40
41
42static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
43{
44 if (likely(skb != NULL)) {
45 const struct inet_sock *inet = inet_sk(sk);
46 const struct inet_connection_sock *icsk = inet_csk(sk);
47 struct dccp_sock *dp = dccp_sk(sk);
48 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
49 struct dccp_hdr *dh;
50
51 const u32 dccp_header_size = sizeof(*dh) +
52 sizeof(struct dccp_hdr_ext) +
53 dccp_packet_hdr_len(dcb->dccpd_type);
54 int err, set_ack = 1;
55 u64 ackno = dp->dccps_gsr;
56
57
58
59
60 dcb->dccpd_seq = ADD48(dp->dccps_gss, 1);
61
62 switch (dcb->dccpd_type) {
63 case DCCP_PKT_DATA:
64 set_ack = 0;
65
66 case DCCP_PKT_DATAACK:
67 case DCCP_PKT_RESET:
68 break;
69
70 case DCCP_PKT_REQUEST:
71 set_ack = 0;
72
73 if (icsk->icsk_retransmits == 0)
74 dcb->dccpd_seq = dp->dccps_iss;
75
76
77 case DCCP_PKT_SYNC:
78 case DCCP_PKT_SYNCACK:
79 ackno = dcb->dccpd_ack_seq;
80
81 default:
82
83
84
85
86
87
88 WARN_ON(skb->sk);
89 skb_set_owner_w(skb, sk);
90 break;
91 }
92
93 if (dccp_insert_options(sk, skb)) {
94 kfree_skb(skb);
95 return -EPROTO;
96 }
97
98
99
100 dh = dccp_zeroed_hdr(skb, dccp_header_size);
101 dh->dccph_type = dcb->dccpd_type;
102 dh->dccph_sport = inet->sport;
103 dh->dccph_dport = inet->dport;
104 dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4;
105 dh->dccph_ccval = dcb->dccpd_ccval;
106 dh->dccph_cscov = dp->dccps_pcslen;
107
108 dh->dccph_x = 1;
109
110 dccp_update_gss(sk, dcb->dccpd_seq);
111 dccp_hdr_set_seq(dh, dp->dccps_gss);
112 if (set_ack)
113 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);
114
115 switch (dcb->dccpd_type) {
116 case DCCP_PKT_REQUEST:
117 dccp_hdr_request(skb)->dccph_req_service =
118 dp->dccps_service;
119
120
121
122
123 dp->dccps_awl = dp->dccps_iss;
124 break;
125 case DCCP_PKT_RESET:
126 dccp_hdr_reset(skb)->dccph_reset_code =
127 dcb->dccpd_reset_code;
128 break;
129 }
130
131 icsk->icsk_af_ops->send_check(sk, 0, skb);
132
133 if (set_ack)
134 dccp_event_ack_sent(sk);
135
136 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
137
138 err = icsk->icsk_af_ops->queue_xmit(skb, 0);
139 return net_xmit_eval(err);
140 }
141 return -ENOBUFS;
142}
143
144
145
146
147
148
149
150static u32 dccp_determine_ccmps(const struct dccp_sock *dp)
151{
152 const struct ccid *tx_ccid = dp->dccps_hc_tx_ccid;
153
154 if (tx_ccid == NULL || tx_ccid->ccid_ops == NULL)
155 return 0;
156 return tx_ccid->ccid_ops->ccid_ccmps;
157}
158
159unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
160{
161 struct inet_connection_sock *icsk = inet_csk(sk);
162 struct dccp_sock *dp = dccp_sk(sk);
163 u32 ccmps = dccp_determine_ccmps(dp);
164 u32 cur_mps = ccmps ? min(pmtu, ccmps) : pmtu;
165
166
167 cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len +
168 sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext));
169
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180
181
182
183 cur_mps -= roundup(1 + 6 + 10 + dp->dccps_send_ndp_count * 8 + 6 +
184 (dp->dccps_hc_rx_ackvec ? DCCPAV_MIN_OPTLEN : 0), 4);
185
186
187 icsk->icsk_pmtu_cookie = pmtu;
188 dp->dccps_mss_cache = cur_mps;
189
190 return cur_mps;
191}
192
193EXPORT_SYMBOL_GPL(dccp_sync_mss);
194
195void dccp_write_space(struct sock *sk)
196{
197 read_lock(&sk->sk_callback_lock);
198
199 if (sk_has_sleeper(sk))
200 wake_up_interruptible(sk->sk_sleep);
201
202 if (sock_writeable(sk))
203 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
204
205 read_unlock(&sk->sk_callback_lock);
206}
207
208
209
210
211
212
213
214
215
216static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay)
217{
218 struct dccp_sock *dp = dccp_sk(sk);
219 DEFINE_WAIT(wait);
220 unsigned long jiffdelay;
221 int rc;
222
223 do {
224 dccp_pr_debug("delayed send by %d msec\n", delay);
225 jiffdelay = msecs_to_jiffies(delay);
226
227 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
228
229 sk->sk_write_pending++;
230 release_sock(sk);
231 schedule_timeout(jiffdelay);
232 lock_sock(sk);
233 sk->sk_write_pending--;
234
235 if (sk->sk_err)
236 goto do_error;
237 if (signal_pending(current))
238 goto do_interrupted;
239
240 rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
241 } while ((delay = rc) > 0);
242out:
243 finish_wait(sk->sk_sleep, &wait);
244 return rc;
245
246do_error:
247 rc = -EPIPE;
248 goto out;
249do_interrupted:
250 rc = -EINTR;
251 goto out;
252}
253
254void dccp_write_xmit(struct sock *sk, int block)
255{
256 struct dccp_sock *dp = dccp_sk(sk);
257 struct sk_buff *skb;
258
259 while ((skb = skb_peek(&sk->sk_write_queue))) {
260 int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
261
262 if (err > 0) {
263 if (!block) {
264 sk_reset_timer(sk, &dp->dccps_xmit_timer,
265 msecs_to_jiffies(err)+jiffies);
266 break;
267 } else
268 err = dccp_wait_for_ccid(sk, skb, err);
269 if (err && err != -EINTR)
270 DCCP_BUG("err=%d after dccp_wait_for_ccid", err);
271 }
272
273 skb_dequeue(&sk->sk_write_queue);
274 if (err == 0) {
275 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
276 const int len = skb->len;
277
278 if (sk->sk_state == DCCP_PARTOPEN) {
279 const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD;
280
281
282
283
284
285
286
287 if (!list_empty(&dp->dccps_featneg) && len > cur_mps) {
288 DCCP_WARN("Payload too large (%d) for featneg.\n", len);
289 dccp_send_ack(sk);
290 dccp_feat_list_purge(&dp->dccps_featneg);
291 }
292
293 inet_csk_schedule_ack(sk);
294 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
295 inet_csk(sk)->icsk_rto,
296 DCCP_RTO_MAX);
297 dcb->dccpd_type = DCCP_PKT_DATAACK;
298 } else if (dccp_ack_pending(sk))
299 dcb->dccpd_type = DCCP_PKT_DATAACK;
300 else
301 dcb->dccpd_type = DCCP_PKT_DATA;
302
303 err = dccp_transmit_skb(sk, skb);
304 ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len);
305 if (err)
306 DCCP_BUG("err=%d after ccid_hc_tx_packet_sent",
307 err);
308 } else {
309 dccp_pr_debug("packet discarded due to err=%d\n", err);
310 kfree_skb(skb);
311 }
312 }
313}
314
315
316
317
318
319
320
321
322
323
324int dccp_retransmit_skb(struct sock *sk)
325{
326 WARN_ON(sk->sk_send_head == NULL);
327
328 if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0)
329 return -EHOSTUNREACH;
330
331
332 inet_csk(sk)->icsk_retransmits++;
333
334 return dccp_transmit_skb(sk, skb_clone(sk->sk_send_head, GFP_ATOMIC));
335}
336
337struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
338 struct request_sock *req)
339{
340 struct dccp_hdr *dh;
341 struct dccp_request_sock *dreq;
342 const u32 dccp_header_size = sizeof(struct dccp_hdr) +
343 sizeof(struct dccp_hdr_ext) +
344 sizeof(struct dccp_hdr_response);
345 struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
346 GFP_ATOMIC);
347 if (skb == NULL)
348 return NULL;
349
350
351 skb_reserve(skb, sk->sk_prot->max_header);
352
353 skb_dst_set(skb, dst_clone(dst));
354
355 dreq = dccp_rsk(req);
356 if (inet_rsk(req)->acked)
357 dccp_inc_seqno(&dreq->dreq_iss);
358 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
359 DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss;
360
361
362 if (dccp_feat_server_ccid_dependencies(dreq))
363 goto response_failed;
364
365 if (dccp_insert_options_rsk(dreq, skb))
366 goto response_failed;
367
368
369 dh = dccp_zeroed_hdr(skb, dccp_header_size);
370
371 dh->dccph_sport = inet_rsk(req)->loc_port;
372 dh->dccph_dport = inet_rsk(req)->rmt_port;
373 dh->dccph_doff = (dccp_header_size +
374 DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
375 dh->dccph_type = DCCP_PKT_RESPONSE;
376 dh->dccph_x = 1;
377 dccp_hdr_set_seq(dh, dreq->dreq_iss);
378 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr);
379 dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;
380
381 dccp_csum_outgoing(skb);
382
383
384 inet_rsk(req)->acked = 1;
385 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
386 return skb;
387response_failed:
388 kfree_skb(skb);
389 return NULL;
390}
391
392EXPORT_SYMBOL_GPL(dccp_make_response);
393
394
395struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *rcv_skb)
396{
397 struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh;
398 struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb);
399 const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
400 sizeof(struct dccp_hdr_ext) +
401 sizeof(struct dccp_hdr_reset);
402 struct dccp_hdr_reset *dhr;
403 struct sk_buff *skb;
404
405 skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
406 if (skb == NULL)
407 return NULL;
408
409 skb_reserve(skb, sk->sk_prot->max_header);
410
411
412 dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
413 dh->dccph_type = DCCP_PKT_RESET;
414 dh->dccph_sport = rxdh->dccph_dport;
415 dh->dccph_dport = rxdh->dccph_sport;
416 dh->dccph_doff = dccp_hdr_reset_len / 4;
417 dh->dccph_x = 1;
418
419 dhr = dccp_hdr_reset(skb);
420 dhr->dccph_reset_code = dcb->dccpd_reset_code;
421
422 switch (dcb->dccpd_reset_code) {
423 case DCCP_RESET_CODE_PACKET_ERROR:
424 dhr->dccph_reset_data[0] = rxdh->dccph_type;
425 break;
426 case DCCP_RESET_CODE_OPTION_ERROR:
427 case DCCP_RESET_CODE_MANDATORY_ERROR:
428 memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3);
429 break;
430 }
431
432
433
434
435
436 if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
437 dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1));
438 dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq);
439
440 dccp_csum_outgoing(skb);
441 return skb;
442}
443
444EXPORT_SYMBOL_GPL(dccp_ctl_make_reset);
445
446
447int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
448{
449 struct sk_buff *skb;
450
451
452
453
454 int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk);
455
456 if (err != 0)
457 return err;
458
459 skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC);
460 if (skb == NULL)
461 return -ENOBUFS;
462
463
464 skb_reserve(skb, sk->sk_prot->max_header);
465 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET;
466 DCCP_SKB_CB(skb)->dccpd_reset_code = code;
467
468 return dccp_transmit_skb(sk, skb);
469}
470
471
472
473
474static inline void dccp_connect_init(struct sock *sk)
475{
476 struct dccp_sock *dp = dccp_sk(sk);
477 struct dst_entry *dst = __sk_dst_get(sk);
478 struct inet_connection_sock *icsk = inet_csk(sk);
479
480 sk->sk_err = 0;
481 sock_reset_flag(sk, SOCK_DONE);
482
483 dccp_sync_mss(sk, dst_mtu(dst));
484
485
486 dp->dccps_gar = dp->dccps_iss;
487
488 icsk->icsk_retransmits = 0;
489}
490
491int dccp_connect(struct sock *sk)
492{
493 struct sk_buff *skb;
494 struct inet_connection_sock *icsk = inet_csk(sk);
495
496
497 if (dccp_feat_finalise_settings(dccp_sk(sk)))
498 return -EPROTO;
499
500 dccp_connect_init(sk);
501
502 skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation);
503 if (unlikely(skb == NULL))
504 return -ENOBUFS;
505
506
507 skb_reserve(skb, sk->sk_prot->max_header);
508
509 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
510
511 dccp_skb_entail(sk, skb);
512 dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL));
513 DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS);
514
515
516 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
517 icsk->icsk_rto, DCCP_RTO_MAX);
518 return 0;
519}
520
521EXPORT_SYMBOL_GPL(dccp_connect);
522
523void dccp_send_ack(struct sock *sk)
524{
525
526 if (sk->sk_state != DCCP_CLOSED) {
527 struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header,
528 GFP_ATOMIC);
529
530 if (skb == NULL) {
531 inet_csk_schedule_ack(sk);
532 inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
533 inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
534 TCP_DELACK_MAX,
535 DCCP_RTO_MAX);
536 return;
537 }
538
539
540 skb_reserve(skb, sk->sk_prot->max_header);
541 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK;
542 dccp_transmit_skb(sk, skb);
543 }
544}
545
546EXPORT_SYMBOL_GPL(dccp_send_ack);
547
548#if 0
549
550void dccp_send_delayed_ack(struct sock *sk)
551{
552 struct inet_connection_sock *icsk = inet_csk(sk);
553
554
555
556
557
558 unsigned long timeout = jiffies + 2 * HZ;
559
560
561 if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) {
562
563
564
565
566
567 if (icsk->icsk_ack.blocked) {
568 dccp_send_ack(sk);
569 return;
570 }
571
572 if (!time_before(timeout, icsk->icsk_ack.timeout))
573 timeout = icsk->icsk_ack.timeout;
574 }
575 icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
576 icsk->icsk_ack.timeout = timeout;
577 sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
578}
579#endif
580
581void dccp_send_sync(struct sock *sk, const u64 ackno,
582 const enum dccp_pkt_type pkt_type)
583{
584
585
586
587
588
589 struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
590
591 if (skb == NULL) {
592
593 DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type));
594 return;
595 }
596
597
598 skb_reserve(skb, sk->sk_prot->max_header);
599 DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
600 DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno;
601
602 dccp_transmit_skb(sk, skb);
603}
604
605EXPORT_SYMBOL_GPL(dccp_send_sync);
606
607
608
609
610
611
612void dccp_send_close(struct sock *sk, const int active)
613{
614 struct dccp_sock *dp = dccp_sk(sk);
615 struct sk_buff *skb;
616 const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC;
617
618 skb = alloc_skb(sk->sk_prot->max_header, prio);
619 if (skb == NULL)
620 return;
621
622
623 skb_reserve(skb, sk->sk_prot->max_header);
624 if (dp->dccps_role == DCCP_ROLE_SERVER && !dp->dccps_server_timewait)
625 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSEREQ;
626 else
627 DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE;
628
629 if (active) {
630 dccp_write_xmit(sk, 1);
631 dccp_skb_entail(sk, skb);
632 dccp_transmit_skb(sk, skb_clone(skb, prio));
633
634
635
636
637
638
639
640
641
642
643 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
644 DCCP_TIMEOUT_INIT, DCCP_RTO_MAX);
645 } else
646 dccp_transmit_skb(sk, skb);
647}
648