aboutsummaryrefslogtreecommitdiffstats
path: root/net/dccp/proto.c
blob: 1747ccae8e8d098f50232253e7be60a40867848f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
/*
 *  net/dccp/proto.c
 *
 *  An implementation of the DCCP protocol
 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License version 2 as
 *	published by the Free Software Foundation.
 */

#include <linux/dccp.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/random.h>
#include <net/checksum.h>

#include <net/inet_sock.h>
#include <net/sock.h>
#include <net/xfrm.h>

#include <asm/ioctls.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <linux/poll.h>

#include "ccid.h"
#include "dccp.h"
#include "feat.h"

DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;

EXPORT_SYMBOL_GPL(dccp_statistics);

struct percpu_counter dccp_orphan_count;
EXPORT_SYMBOL_GPL(dccp_orphan_count);

struct inet_hashinfo dccp_hashinfo;
EXPORT_SYMBOL_GPL(dccp_hashinfo);

/* the maximum queue length for tx in packets. 0 is no limit */
int sysctl_dccp_tx_qlen __read_mostly = 5;

void dccp_set_state(struct sock *sk, const int state)
{
	const int oldstate = sk->sk_state;

	dccp_pr_debug("%s(%p)  %s  -->  %s\n", dccp_role(sk), sk,
		      dccp_state_name(oldstate), dccp_state_name(state));
	WARN_ON(state == oldstate);

	switch (state) {
	case DCCP_OPEN:
		if (oldstate != DCCP_OPEN)
			DCCP_INC_STATS(DCCP_MIB_CURRESTAB);
		/* Client retransmits all Confirm options until entering OPEN */
		if (oldstate == DCCP_PARTOPEN)
			dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg);
		break;

	case DCCP_CLOSED:
		if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ ||
		    oldstate == DCCP_CLOSING)
			DCCP_INC_STATS(DCCP_MIB_ESTABRESETS);

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash != NULL &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
			inet_put_port(sk);
		/* fall through */
	default:
		if (oldstate == DCCP_OPEN)
			DCCP_DEC_STATS(DCCP_MIB_CURRESTAB);
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
	sk->sk_state = state;
}

EXPORT_SYMBOL_GPL(dccp_set_state);

static void dccp_finish_passive_close(struct sock *sk)
{
	switch (sk->sk_state) {
	case DCCP_PASSIVE_CLOSE:
		/* Node (client or server) has received Close packet. */
		dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
		dccp_set_state(sk, DCCP_CLOSED);
		break;
	case DCCP_PASSIVE_CLOSEREQ:
		/*
		 * Client received CloseReq. We set the `active' flag so that
		 * dccp_send_close() retransmits the Close as per RFC 4340, 8.3.
		 */
		dccp_send_close(sk, 1);
		dccp_set_state(sk, DCCP_CLOSING);
	}
}

void dccp_done(struct sock *sk)
{
	dccp_set_state(sk, DCCP_CLOSED);
	dccp_clear_xmit_timers(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_state_change(sk);
	else
		inet_csk_destroy_sock(sk);
}

EXPORT_SYMBOL_GPL(dccp_done);

const char *dccp_packet_name(const int type)
{
	static const char *dccp_packet_names[] = {
		[DCCP_PKT_REQUEST]  = "REQUEST",
		[DCCP_PKT_RESPONSE] = "RESPONSE",
		[DCCP_PKT_DATA]	    = "DATA",
		[DCCP_PKT_ACK]	    = "ACK",
		[DCCP_PKT_DATAACK]  = "DATAACK",
		[DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
		[DCCP_PKT_CLOSE]    = "CLOSE",
		[DCCP_PKT_RESET]    = "RESET",
		[DCCP_PKT_SYNC]	    = "SYNC",
		[DCCP_PKT_SYNCACK]  = "SYNCACK",
	};

	if (type >= DCCP_NR_PKT_TYPES)
		return "INVALID";
	else
		return dccp_packet_names[type];
}

EXPORT_SYMBOL_GPL(dccp_packet_name);

const char *dccp_state_name(const int state)
{
	static char *dccp_state_names[] = {
	[DCCP_OPEN]		= "OPEN",
	[DCCP_REQUESTING]	= "REQUESTING",
	[DCCP_PARTOPEN]		= "PARTOPEN",
	[DCCP_LISTEN]		= "LISTEN",
	[DCCP_RESPOND]		= "RESPOND",
	[DCCP_CLOSING]		= "CLOSING",
	[DCCP_ACTIVE_CLOSEREQ]	= "CLOSEREQ",
	[DCCP_PASSIVE_CLOSE]	= "PASSIVE_CLOSE",
	[DCCP_PASSIVE_CLOSEREQ]	= "PASSIVE_CLOSEREQ",
	[DCCP_TIME_WAIT]	= "TIME_WAIT",
	[DCCP_CLOSED]		= "CLOSED",
	};

	if (state >= DCCP_MAX_STATES)
		return "INVALID STATE!";
	else
		return dccp_state_names[state];
}

EXPORT_SYMBOL_GPL(dccp_state_name);

int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct inet_connection_sock *icsk = inet_csk(sk);

	dccp_minisock_init(&dp->dccps_minisock);

	icsk->icsk_rto		= DCCP_TIMEOUT_INIT;
	icsk->icsk_syn_retries	= sysctl_dccp_request_retries;
	sk->sk_state		= DCCP_CLOSED;
	sk->sk_write_space	= dccp_write_space;
	icsk->icsk_sync_mss	= dccp_sync_mss;
	dp->dccps_mss_cache	= 536;
	dp->dccps_rate_last	= jiffies;
	dp->dccps_role		= DCCP_ROLE_UNDEFINED;
	dp->dccps_service	= DCCP_SERVICE_CODE_IS_ABSENT;
	dp->dccps_l_ack_ratio	= dp->dccps_r_ack_ratio = 1;

	dccp_init_xmit_timers(sk);

	INIT_LIST_HEAD(&dp->dccps_featneg);
	/* control socket doesn't need feat nego */
	if (likely(ctl_sock_initialized))
		return dccp_feat_init(sk);
	return 0;
}

EXPORT_SYMBOL_GPL(dccp_init_sock);

void dccp_destroy_sock(struct sock *sk)
{
	struct dccp_sock *dp = dccp_sk(sk);

	/*
	 * DCCP doesn't use sk_write_queue, just sk_send_head
	 * for retransmissions
	 */
	if (sk->sk_send_head != NULL) {
		kfree_skb(sk->sk_send_head);
		sk->sk_send_head = NULL;
	}

	/* Clean up a referenced DCCP bind bucket. */
	if (inet_csk(sk)->icsk_bind_hash != NULL)
		inet_put_port(sk);

	kfree(dp->dccps_service_list);
	dp->dccps_service_list = NULL;

	if (dp->dccps_hc_rx_ackvec != NULL) {
		dccp_ackvec_free(dp->dccps_hc_rx_ackvec);
		dp->dccps_hc_rx_ackvec = NULL;
	}
	ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
	ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
	dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;

	/* clean up feature negotiation state */
	dccp_feat_list_purge(&dp->dccps_featneg);
}

EXPORT_SYMBOL_GPL(dccp_destroy_sock);

static inline int dccp_listen_start(struct sock *sk, int backlog)
{
	struct dccp_sock *dp = dccp_sk(sk);

	dp->dccps_role = DCCP_ROLE_LISTEN;
	/* do not start to listen if feature negotiation setup fails */
	if (dccp_feat_finalise_settings(dp))
		return -EPROTO;
	return inet_csk_listen_start(sk, backlog);
}

static inline int dccp_need_reset(int state)
{
	return state != DCCP_CLOSED && state != DCCP_LISTEN &&
	       state != DCCP_REQUESTING;
}

int dccp_disconnect(struct sock *sk, int flags)
{
	struct inet_connection_sock *icsk = inet_csk(sk);
	struct inet_sock *inet = inet_sk(sk);
	int err = 0;
	const int old_state = sk->sk_state;

	if (old_state != DCCP_CLOSED)
		dccp_set_state(sk, DCCP_CLOSED);

	/*
	 * This corresponds to the ABORT function of RFC793, sec. 3.8
	 * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted".
	 */
	if (old_state == DCCP_LISTEN) {
		inet_csk_listen_stop(sk);
	} else if (dccp_need_reset(old_state)) {
		dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
		sk->sk_err = ECONNRESET;
	} else if (old_state == DCCP_REQUESTING)
		sk->sk_err = ECONNRESET;

	dccp_clear_xmit_timers(sk);

	__skb_queue_purge(&sk->sk_receive_queue);
	__skb_queue_purge(&sk->sk_write_queue);
	if (sk->sk_send_head != NULL) {
		__kfree_skb(sk->sk_send_head);
		sk->sk_send_head = NULL;
	}

	inet->dport = 0;

	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
		inet_reset_saddr(sk);

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);

	icsk->icsk_backoff = 0;
	inet_csk_delack_init(sk);
	__sk_dst_reset(sk);

	WARN_ON(inet->num && !icsk->icsk_bind_hash);

	sk->sk_error_report(sk);
	return err;
}

EXPORT_SYMBOL_GPL(dccp_disconnect);

/*
 *	Wait for a DCCP event.
 *
 *	Note that we don't need to lock the socket, as the upper poll layers
 *	take care of normal races (between the test and the event) and we don't
 *	go look at any of the socket buffers directly.
 */
unsigned int dccp_poll(struct file *file, struct socket *sock,
		       poll_table *wait)
{
	unsigned int mask;
	struct sock *sk = sock->sk;

	poll_wait(file, sk->sk_sleep, wait);
	if (sk->sk_state == DCCP_LISTEN)
		return inet_csk_listen_poll(sk);

	/* Socket is not locked. We are protected from async events
	   by poll logic and correct handling of state changes
	   made by another threads is impossible in any case.
	 */

	mask = 0;
	if (sk->sk_err)
		mask = POLLERR;

	if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == DCCP_CLOSED)
		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
		mask |= POLLIN | POLLRDNORM | POLLRDHUP;

	/* Connected? */
	if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) {
		if (atomic_read(&sk->sk_rmem_alloc) > 0)
			mask |= POLLIN | POLLRDNORM;

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
			if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
				mask |= POLLOUT | POLLWRNORM;
			} else {  /* send SIGIO later */
				set_bit(SOCK_ASYNC_NOSPACE,
					&sk->sk_socket->flags);
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
				 * IO signal will be lost.
				 */
				if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
					mask |= POLLOUT | POLLWRNORM;
			}
		}
	}
	return mask;
}

EXPORT_SYMBOL_GPL(dccp_poll);

int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
	int rc = -ENOTCONN;

	lock_sock(sk);

	if (sk->sk_state == DCCP_LISTEN)
		goto out;

	switch (cmd) {
	case SIOCINQ: {
		struct sk_buff *skb;
		unsigned long amount = 0;

		skb = skb_peek(&sk->sk_receive_queue);
		if (skb != NULL) {
			/*
			 * We will only return the amount of this packet since
			 * that is all that will be read.
			 */
			amount = skb->len;
		}
		rc = put_user(amount, (int __user *)arg);
	}
		break;
	default:
		rc = -ENOIOCTLCMD;
		break;
	}
out:
	release_sock(sk);
	return rc;
}

EXPORT_SYMBOL_GPL(dccp_ioctl);

static int dccp_setsockopt_service(struct sock *sk, const __be32 service,
				   char __user *optval, int optlen)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct dccp_service_list *sl = NULL;

	if (service == DCCP_SERVICE_INVALID_VALUE ||
	    optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32))
		return -EINVAL;

	if (optlen > sizeof(service)) {
		sl = kmalloc(optlen, GFP_KERNEL);
		if (sl == NULL)
			return -ENOMEM;

		sl->dccpsl_nr = optlen / sizeof(u32) - 1;
		if (copy_from_user(sl->dccpsl_list,
				   optval + sizeof(service),
				   optlen - sizeof(service)) ||
		    dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) {
			kfree(sl);
			return -EFAULT;
		}
	}

	lock_sock(sk);
	dp->dccps_service = service;

	kfree(dp->dccps_service_list);

	dp->dccps_service_list = sl;
	release_sock(sk);
	return 0;
}

static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx)
{
	u8 *list, len;
	int i, rc;

	if (cscov < 0 || cscov > 15)
		return -EINVAL;
	/*
	 * Populate a list of permissible values, in the range cscov...15. This
	 * is necessary since feature negotiation of single values only works if
	 * both sides incidentally choose the same value. Since the list starts
	 * lowest-value first, negotiation will pick the smallest shared value.
	 */
	if (cscov == 0)
		return 0;
	len = 16 - cscov;

	list = kmalloc(len, GFP_KERNEL);
	if (list == NULL)
		return -ENOBUFS;

	for (i = 0; i < len; i++)
		list[i] = cscov++;

	rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len);

	if (rc == 0) {
		if (rx)
			dccp_sk(sk)->dccps_pcrlen = cscov;
		else
			dccp_sk(sk)->dccps_pcslen = cscov;
	}
	kfree(list);
	return rc;
}

static int dccp_setsockopt_ccid(struct sock *sk, int type,
				char __user *optval, int optlen)
{
	u8 *val;
	int rc = 0;

	if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
		return -EINVAL;

	val = kmalloc(optlen, GFP_KERNEL);
	if (val == NULL)
		return -ENOMEM;

	if (copy_from_user(val, optval, optlen)) {
		kfree(val);
		return -EFAULT;
	}

	lock_sock(sk);
	if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
		rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);

	if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
		rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
	release_sock(sk);

	kfree(val);
	return rc;
}

static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
		char __user *optval, int optlen)
{
	struct dccp_sock *dp = dccp_sk(sk);
	int val, err = 0;

	switch (optname) {
	case DCCP_SOCKOPT_PACKET_SIZE:
		DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
		return 0;
	case DCCP_SOCKOPT_CHANGE_L:
	case DCCP_SOCKOPT_CHANGE_R:
		DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
		return 0;
	case DCCP_SOCKOPT_CCID:
	case DCCP_SOCKOPT_RX_CCID:
	case DCCP_SOCKOPT_TX_CCID:
		return dccp_setsockopt_ccid(sk, optname, optval, optlen);
	}

	if (optlen < (int)sizeof(int))
		return -EINVAL;

	if (get_user(val, (int __user *)optval))
		return -EFAULT;

	if (optname == DCCP_SOCKOPT_SERVICE)
		return dccp_setsockopt_service(sk, val, optval, optlen);

	lock_sock(sk);
	switch (optname) {
	case DCCP_SOCKOPT_SERVER_TIMEWAIT:
		if (dp->dccps_role != DCCP_ROLE_SERVER)
			err = -EOPNOTSUPP;
		else
			dp->dccps_server_timewait = (val != 0);
		break;
	case DCCP_SOCKOPT_SEND_CSCOV:
		err = dccp_setsockopt_cscov(sk, val, false);
		break;
	case DCCP_SOCKOPT_RECV_CSCOV:
		err = dccp_setsockopt_cscov(sk, val, true);
		break;
	default:
		err = -ENOPROTOOPT;
		break;
	}
	release_sock(sk);

	return err;
}

int dccp_setsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, int optlen)
{
	if (level != SOL_DCCP)
		return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level,
							     optname, optval,
							     optlen);
	return do_dccp_setsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL_GPL(dccp_setsockopt);

#ifdef CONFIG_COMPAT
int compat_dccp_setsockopt(struct sock *sk, int level, int optname,
			   char __user *optval, int optlen)
{
	if (level != SOL_DCCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
	return do_dccp_setsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL_GPL(compat_dccp_setsockopt);
#endif

static int dccp_getsockopt_service(struct sock *sk, int len,
				   __be32 __user *optval,
				   int __user *optlen)
{
	const struct dccp_sock *dp = dccp_sk(sk);
	const struct dccp_service_list *sl;
	int err = -ENOENT, slen = 0, total_len = sizeof(u32);

	lock_sock(sk);
	if ((sl = dp->dccps_service_list) != NULL) {
		slen = sl->dccpsl_nr * sizeof(u32);
		total_len += slen;
	}

	err = -EINVAL;
	if (total_len > len)
		goto out;

	err = 0;
	if (put_user(total_len, optlen) ||
	    put_user(dp->dccps_service, optval) ||
	    (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen)))
		err = -EFAULT;
out:
	release_sock(sk);
	return err;
}

static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, int __user *optlen)
{
	struct dccp_sock *dp;
	int val, len;

	if (get_user(len, optlen))
		return -EFAULT;

	if (len < (int)sizeof(int))
		return -EINVAL;

	dp = dccp_sk(sk);

	switch (optname) {
	case DCCP_SOCKOPT_PACKET_SIZE:
		DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n");
		return 0;
	case DCCP_SOCKOPT_SERVICE:
		return dccp_getsockopt_service(sk, len,
					       (__be32 __user *)optval, optlen);
	case DCCP_SOCKOPT_GET_CUR_MPS:
		val = dp->dccps_mss_cache;
		break;
	case DCCP_SOCKOPT_AVAILABLE_CCIDS:
		return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen);
	case DCCP_SOCKOPT_TX_CCID:
		val = ccid_get_current_tx_ccid(dp);
		if (val < 0)
			return -ENOPROTOOPT;
		break;
	case DCCP_SOCKOPT_RX_CCID:
		val = ccid_get_current_rx_ccid(dp);
		if (val < 0)
			return -ENOPROTOOPT;
		break;
	case DCCP_SOCKOPT_SERVER_TIMEWAIT:
		val = dp->dccps_server_timewait;
		break;
	case DCCP_SOCKOPT_SEND_CSCOV:
		val = dp->dccps_pcslen;
		break;
	case DCCP_SOCKOPT_RECV_CSCOV:
		val = dp->dccps_pcrlen;
		break;
	case 128 ... 191:
		return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
					     len, (u32 __user *)optval, optlen);
	case 192 ... 255:
		return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname,
					     len, (u32 __user *)optval, optlen);
	default:
		return -ENOPROTOOPT;
	}

	len = sizeof(val);
	if (put_user(len, optlen) || copy_to_user(optval, &val, len))
		return -EFAULT;

	return 0;
}

int dccp_getsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, int __user *optlen)
{
	if (level != SOL_DCCP)
		return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level,
							     optname, optval,
							     optlen);
	return do_dccp_getsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL_GPL(dccp_getsockopt);

#ifdef CONFIG_COMPAT
int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
			   char __user *optval, int __user *optlen)
{
	if (level != SOL_DCCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
	return do_dccp_getsockopt(sk, level, optname, optval, optlen);
}

EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
#endif

int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
		 size_t len)
{
	const struct dccp_sock *dp = dccp_sk(sk);
	const int flags = msg->msg_flags;
	const int noblock = flags & MSG_DONTWAIT;
	struct sk_buff *skb;
	int rc, size;
	long timeo;

	if (len > dp->dccps_mss_cache)
		return -EMSGSIZE;

	lock_sock(sk);

	if (sysctl_dccp_tx_qlen &&
	    (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
		rc = -EAGAIN;
		goto out_release;
	}

	timeo = sock_sndtimeo(sk, noblock);

	/*
	 * We have to use sk_stream_wait_connect here to set sk_write_pending,
	 * so that the trick in dccp_rcv_request_sent_state_process.
	 */
	/* Wait for a connection to finish. */
	if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN))
		if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0)
			goto out_release;

	size = sk->sk_prot->max_header + len;
	release_sock(sk);
	skb = sock_alloc_send_skb(sk, size, noblock, &rc);
	lock_sock(sk);
	if (skb == NULL)
		goto out_release;

	skb_reserve(skb, sk->sk_prot->max_header);
	rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
	if (rc != 0)
		goto out_discard;

	skb_queue_tail(&sk->sk_write_queue, skb);
	dccp_write_xmit(sk,0);
out_release:
	release_sock(sk);
	return rc ? : len;
out_discard:
	kfree_skb(skb);
	goto out_release;
}

EXPORT_SYMBOL_GPL(dccp_sendmsg);

int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
		 size_t len, int nonblock, int flags, int *addr_len)
{
	const struct dccp_hdr *dh;
	long timeo;

	lock_sock(sk);

	if (sk->sk_state == DCCP_LISTEN) {
		len = -ENOTCONN;
		goto out;
	}

	timeo = sock_rcvtimeo(sk, nonblock);

	do {
		struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);

		if (skb == NULL)
			goto verify_sock_status;

		dh = dccp_hdr(skb);

		switch (dh->dccph_type) {
		case DCCP_PKT_DATA:
		case DCCP_PKT_DATAACK:
			goto found_ok_skb;

		case DCCP_PKT_CLOSE:
		case DCCP_PKT_CLOSEREQ:
			if (!(flags & MSG_PEEK))
				dccp_finish_passive_close(sk);
			/* fall through */
		case DCCP_PKT_RESET:
			dccp_pr_debug("found fin (%s) ok!\n",
				      dccp_packet_name(dh->dccph_type));
			len = 0;
			goto found_fin_ok;
		default:
			dccp_pr_debug("packet_type=%s\n",
				      dccp_packet_name(dh->dccph_type));
			sk_eat_skb(sk, skb, 0);
		}
verify_sock_status:
		if (sock_flag(sk, SOCK_DONE)) {
			len = 0;
			break;
		}

		if (sk->sk_err) {
			len = sock_error(sk);
			break;
		}

		if (sk->sk_shutdown & RCV_SHUTDOWN) {
			len = 0;
			break;
		}

		if (sk->sk_state == DCCP_CLOSED) {
			if (!sock_flag(sk, SOCK_DONE)) {
				/* This occurs when user tries to read
				 * from never connected socket.
				 */
				len = -ENOTCONN;
				break;
			}
			len = 0;
			break;
		}

		if (!timeo) {
			len = -EAGAIN;
			break;
		}

		if (signal_pending(current)) {
			len = sock_intr_errno(timeo);
			break;
		}

		sk_wait_data(sk, &timeo);
		continue;
	found_ok_skb:
		if (len > skb->len)
			len = skb->len;
		else if (len < skb->len)
			msg->msg_flags |= MSG_TRUNC;

		if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
			/* Exception. Bailout! */
			len = -EFAULT;
			break;
		}
	found_fin_ok:
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb, 0);
		break;
	} while (1);
out:
	release_sock(sk);
	return len;
}

EXPORT_SYMBOL_GPL(dccp_recvmsg);

int inet_dccp_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;
	unsigned char old_state;
	int err;

	lock_sock(sk);

	err = -EINVAL;
	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP)
		goto out;

	old_state = sk->sk_state;
	if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN)))
		goto out;

	/* Really, if the socket is already in listen state
	 * we can only allow the backlog to be adjusted.
	 */
	if (old_state != DCCP_LISTEN) {
		/*
		 * FIXME: here it probably should be sk->sk_prot->listen_start
		 * see tcp_listen_start
		 */
		err = dccp_listen_start(sk, backlog);
		if (err)
			goto out;
	}
	sk->sk_max_ack_backlog = backlog;
	err = 0;

out:
	release_sock(sk);
	return err;
}

EXPORT_SYMBOL_GPL(inet_dccp_listen);

static void dccp_terminate_connection(struct sock *sk)
{
	u8 next_state = DCCP_CLOSED;

	switch (sk->sk_state) {
	case DCCP_PASSIVE_CLOSE:
	case DCCP_PASSIVE_CLOSEREQ:
		dccp_finish_passive_close(sk);
		break;
	case DCCP_PARTOPEN:
		dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk);
		inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
		/* fall through */
	case DCCP_OPEN:
		dccp_send_close(sk, 1);

		if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER &&
		    !dccp_sk(sk)->dccps_server_timewait)
			next_state = DCCP_ACTIVE_CLOSEREQ;
		else
			next_state = DCCP_CLOSING;
		/* fall through */
	default:
		dccp_set_state(sk, next_state);
	}
}

void dccp_close(struct sock *sk, long timeout)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct sk_buff *skb;
	u32 data_was_unread = 0;
	int state;

	lock_sock(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;

	if (sk->sk_state == DCCP_LISTEN) {
		dccp_set_state(sk, DCCP_CLOSED);

		/* Special case. */
		inet_csk_listen_stop(sk);

		goto adjudge_to_death;
	}

	sk_stop_timer(sk, &dp->dccps_xmit_timer);

	/*
	 * We need to flush the recv. buffs.  We do this only on the
	 * descriptor close, not protocol-sourced closes, because the
	  *reader process may not have drained the data yet!
	 */
	while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
		data_was_unread += skb->len;
		__kfree_skb(skb);
	}

	if (data_was_unread) {
		/* Unread data was tossed, send an appropriate Reset Code */
		DCCP_WARN("DCCP: ABORT -- %u bytes unread\n", data_was_unread);
		dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
		dccp_set_state(sk, DCCP_CLOSED);
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
	} else if (sk->sk_state != DCCP_CLOSED) {
		dccp_terminate_connection(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

	/*
	 * It is the last release_sock in its life. It will remove backlog.
	 */
	release_sock(sk);
	/*
	 * Now socket is owned by kernel and we acquire BH lock
	 * to finish close. No need to check for user refs.
	 */
	local_bh_disable();
	bh_lock_sock(sk);
	WARN_ON(sock_owned_by_user(sk));

	percpu_counter_inc(sk->sk_prot->orphan_count);

	/* Have we already been destroyed by a softirq or backlog? */
	if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
		goto out;

	if (sk->sk_state == DCCP_CLOSED)
		inet_csk_destroy_sock(sk);

	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}

EXPORT_SYMBOL_GPL(dccp_close);

void dccp_shutdown(struct sock *sk, int how)
{
	dccp_pr_debug("called shutdown(%x)\n", how);
}

EXPORT_SYMBOL_GPL(dccp_shutdown);

static inline int dccp_mib_init(void)
{
	return snmp_mib_init((void**)dccp_statistics, sizeof(struct dccp_mib));
}

static inline void dccp_mib_exit(void)
{
	snmp_mib_free((void**)dccp_statistics);
}

static int thash_entries;
module_param(thash_entries, int, 0444);
MODULE_PARM_DESC(thash_entries, "Number of ehash buckets");

#ifdef CONFIG_IP_DCCP_DEBUG
int dccp_debug;
module_param(dccp_debug, bool, 0644);
MODULE_PARM_DESC(dccp_debug, "Enable debug messages");

EXPORT_SYMBOL_GPL(dccp_debug);
#endif

static int __init dccp_init(void)
{
	unsigned long goal;
	int ehash_order, bhash_order, i;
	int rc;

	BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
	rc = percpu_counter_init(&dccp_orphan_count, 0);
	if (rc)
		goto out;
	rc = -ENOBUFS;
	inet_hashinfo_init(&dccp_hashinfo);
	dccp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("dccp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
				  SLAB_HWCACHE_ALIGN, NULL);
	if (!dccp_hashinfo.bind_bucket_cachep)
		goto out_free_percpu;

	/*
	 * Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
	if (num_physpages >= (128 * 1024))
		goal = num_physpages >> (21 - PAGE_SHIFT);
	else
		goal = num_physpages >> (23 - PAGE_SHIFT);

	if (thash_entries)
		goal = (thash_entries *
			sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT;
	for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++)
		;
	do {
		dccp_hashinfo.ehash_size = (1UL << ehash_order) * PAGE_SIZE /
					sizeof(struct inet_ehash_bucket);
		while (dccp_hashinfo.ehash_size &
		       (dccp_hashinfo.ehash_size - 1))
			dccp_hashinfo.ehash_size--;
		dccp_hashinfo.ehash = (struct inet_ehash_bucket *)
			__get_free_pages(GFP_ATOMIC, ehash_order);
	} while (!dccp_hashinfo.ehash && --ehash_order > 0);

	if (!dccp_hashinfo.ehash) {
		DCCP_CRIT("Failed to allocate DCCP established hash table");
		goto out_free_bind_bucket_cachep;
	}

	for (i = 0; i < dccp_hashinfo.ehash_size; i++) {
		INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i);
		INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].twchain, i);
	}

	if (inet_ehash_locks_alloc(&dccp_hashinfo))
			goto out_free_dccp_ehash;

	bhash_order = ehash_order;

	do {
		dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE /
					sizeof(struct inet_bind_hashbucket);
		if ((dccp_hashinfo.bhash_size > (64 * 1024)) &&
		    bhash_order > 0)
			continue;
		dccp_hashinfo.bhash = (struct inet_bind_hashbucket *)
			__get_free_pages(GFP_ATOMIC, bhash_order);
	} while (!dccp_hashinfo.bhash && --bhash_order >= 0);

	if (!dccp_hashinfo.bhash) {
		DCCP_CRIT("Failed to allocate DCCP bind hash table");
		goto out_free_dccp_locks;
	}

	for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
		spin_lock_init(&dccp_hashinfo.bhash[i].lock);
		INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
	}

	rc = dccp_mib_init();
	if (rc)
		goto out_free_dccp_bhash;

	rc = dccp_ackvec_init();
	if (rc)
		goto out_free_dccp_mib;

	rc = dccp_sysctl_init();
	if (rc)
		goto out_ackvec_exit;

	dccp_timestamping_init();
out:
	return rc;
out_ackvec_exit:
	dccp_ackvec_exit();
out_free_dccp_mib:
	dccp_mib_exit();
out_free_dccp_bhash:
	free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
	dccp_hashinfo.bhash = NULL;
out_free_dccp_locks:
	inet_ehash_locks_free(&dccp_hashinfo);
out_free_dccp_ehash:
	free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
	dccp_hashinfo.ehash = NULL;
out_free_bind_bucket_cachep:
	kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
	dccp_hashinfo.bind_bucket_cachep = NULL;
out_free_percpu:
	percpu_counter_destroy(&dccp_orphan_count);
	goto out;
}

static void __exit dccp_fini(void)
{
	dccp_mib_exit();
	free_pages((unsigned long)dccp_hashinfo.bhash,
		   get_order(dccp_hashinfo.bhash_size *
			     sizeof(struct inet_bind_hashbucket)));
	free_pages((unsigned long)dccp_hashinfo.ehash,
		   get_order(dccp_hashinfo.ehash_size *
			     sizeof(struct inet_ehash_bucket)));
	inet_ehash_locks_free(&dccp_hashinfo);
	kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
	dccp_ackvec_exit();
	dccp_sysctl_exit();
}

module_init(dccp_init);
module_exit(dccp_fini);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@conectiva.com.br>");
MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol");