aboutsummaryrefslogtreecommitdiffstats
path: root/net/dccp/options.c
blob: a58e0b6340506d1d2123bad650757acf36b7334d (plain)
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
/*
 *  net/dccp/options.c
 *
 *  An implementation of the DCCP protocol
 *  Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
 *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */
#include <linux/dccp.h>
#include <linux/module.h>
#include <linux/types.h>
#include <asm/unaligned.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>

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

u64 dccp_decode_value_var(const u8 *bf, const u8 len)
{
	u64 value = 0;

	if (len >= DCCP_OPTVAL_MAXLEN)
		value += ((u64)*bf++) << 40;
	if (len > 4)
		value += ((u64)*bf++) << 32;
	if (len > 3)
		value += ((u64)*bf++) << 24;
	if (len > 2)
		value += ((u64)*bf++) << 16;
	if (len > 1)
		value += ((u64)*bf++) << 8;
	if (len > 0)
		value += *bf;

	return value;
}

/**
 * dccp_parse_options  -  Parse DCCP options present in @skb
 * @sk: client|server|listening dccp socket (when @dreq != NULL)
 * @dreq: request socket to use during connection setup, or NULL
 */
int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
		       struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	const struct dccp_hdr *dh = dccp_hdr(skb);
	const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
	unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
	unsigned char *opt_ptr = options;
	const unsigned char *opt_end = (unsigned char *)dh +
					(dh->dccph_doff * 4);
	struct dccp_options_received *opt_recv = &dp->dccps_options_received;
	unsigned char opt, len;
	unsigned char *uninitialized_var(value);
	u32 elapsed_time;
	__be32 opt_val;
	int rc;
	int mandatory = 0;

	memset(opt_recv, 0, sizeof(*opt_recv));

	opt = len = 0;
	while (opt_ptr != opt_end) {
		opt   = *opt_ptr++;
		len   = 0;
		value = NULL;

		/* Check if this isn't a single byte option */
		if (opt > DCCPO_MAX_RESERVED) {
			if (opt_ptr == opt_end)
				goto out_nonsensical_length;

			len = *opt_ptr++;
			if (len < 2)
				goto out_nonsensical_length;
			/*
			 * Remove the type and len fields, leaving
			 * just the value size
			 */
			len	-= 2;
			value	= opt_ptr;
			opt_ptr += len;

			if (opt_ptr > opt_end)
				goto out_nonsensical_length;
		}

		/*
		 * CCID-specific options are ignored during connection setup, as
		 * negotiation may still be in progress (see RFC 4340, 10.3).
		 * The same applies to Ack Vectors, as these depend on the CCID.
		 */
		if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC ||
		    opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1))
			goto ignore_option;

		switch (opt) {
		case DCCPO_PADDING:
			break;
		case DCCPO_MANDATORY:
			if (mandatory)
				goto out_invalid_option;
			if (pkt_type != DCCP_PKT_DATA)
				mandatory = 1;
			break;
		case DCCPO_NDP_COUNT:
			if (len > 6)
				goto out_invalid_option;

			opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
			dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
				      (unsigned long long)opt_recv->dccpor_ndp);
			break;
		case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R:
			if (pkt_type == DCCP_PKT_DATA)      /* RFC 4340, 6 */
				break;
			if (len == 0)
				goto out_invalid_option;
			rc = dccp_feat_parse_options(sk, dreq, mandatory, opt,
						    *value, value + 1, len - 1);
			if (rc)
				goto out_featneg_failed;
			break;
		case DCCPO_TIMESTAMP:
			if (len != 4)
				goto out_invalid_option;
			/*
			 * RFC 4340 13.1: "The precise time corresponding to
			 * Timestamp Value zero is not specified". We use
			 * zero to indicate absence of a meaningful timestamp.
			 */
			opt_val = get_unaligned((__be32 *)value);
			if (unlikely(opt_val == 0)) {
				DCCP_WARN("Timestamp with zero value\n");
				break;
			}

			if (dreq != NULL) {
				dreq->dreq_timestamp_echo = ntohl(opt_val);
				dreq->dreq_timestamp_time = dccp_timestamp();
			} else {
				opt_recv->dccpor_timestamp =
					dp->dccps_timestamp_echo = ntohl(opt_val);
				dp->dccps_timestamp_time = dccp_timestamp();
			}
			dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
				      dccp_role(sk), ntohl(opt_val),
				      (unsigned long long)
				      DCCP_SKB_CB(skb)->dccpd_ack_seq);
			/* schedule an Ack in case this sender is quiescent */
			inet_csk_schedule_ack(sk);
			break;
		case DCCPO_TIMESTAMP_ECHO:
			if (len != 4 && len != 6 && len != 8)
				goto out_invalid_option;

			opt_val = get_unaligned((__be32 *)value);
			opt_recv->dccpor_timestamp_echo = ntohl(opt_val);

			dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
				      "ackno=%llu", dccp_role(sk),
				      opt_recv->dccpor_timestamp_echo,
				      len + 2,
				      (unsigned long long)
				      DCCP_SKB_CB(skb)->dccpd_ack_seq);

			value += 4;

			if (len == 4) {		/* no elapsed time included */
				dccp_pr_debug_cat("\n");
				break;
			}

			if (len == 6) {		/* 2-byte elapsed time */
				__be16 opt_val2 = get_unaligned((__be16 *)value);
				elapsed_time = ntohs(opt_val2);
			} else {		/* 4-byte elapsed time */
				opt_val = get_unaligned((__be32 *)value);
				elapsed_time = ntohl(opt_val);
			}

			dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);

			/* Give precedence to the biggest ELAPSED_TIME */
			if (elapsed_time > opt_recv->dccpor_elapsed_time)
				opt_recv->dccpor_elapsed_time = elapsed_time;
			break;
		case DCCPO_ELAPSED_TIME:
			if (dccp_packet_without_ack(skb))   /* RFC 4340, 13.2 */
				break;

			if (len == 2) {
				__be16 opt_val2 = get_unaligned((__be16 *)value);
				elapsed_time = ntohs(opt_val2);
			} else if (len == 4) {
				opt_val = get_unaligned((__be32 *)value);
				elapsed_time = ntohl(opt_val);
			} else {
				goto out_invalid_option;
			}

			if (elapsed_time > opt_recv->dccpor_elapsed_time)
				opt_recv->dccpor_elapsed_time = elapsed_time;

			dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
				      dccp_role(sk), elapsed_time);
			break;
		case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC:
			if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
						     pkt_type, opt, value, len))
				goto out_invalid_option;
			break;
		case DCCPO_ACK_VECTOR_0:
		case DCCPO_ACK_VECTOR_1:
			if (dccp_packet_without_ack(skb))   /* RFC 4340, 11.4 */
				break;
			/*
			 * Ack vectors are processed by the TX CCID if it is
			 * interested. The RX CCID need not parse Ack Vectors,
			 * since it is only interested in clearing old state.
			 * Fall through.
			 */
		case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
			if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
						     pkt_type, opt, value, len))
				goto out_invalid_option;
			break;
		default:
			DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
				  "implemented, ignoring", sk, opt, len);
			break;
		}
ignore_option:
		if (opt != DCCPO_MANDATORY)
			mandatory = 0;
	}

	/* mandatory was the last byte in option list -> reset connection */
	if (mandatory)
		goto out_invalid_option;

out_nonsensical_length:
	/* RFC 4340, 5.8: ignore option and all remaining option space */
	return 0;

out_invalid_option:
	DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
	rc = DCCP_RESET_CODE_OPTION_ERROR;
out_featneg_failed:
	DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc);
	DCCP_SKB_CB(skb)->dccpd_reset_code = rc;
	DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
	DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
	DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
	return -1;
}

EXPORT_SYMBOL_GPL(dccp_parse_options);

void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
{
	if (len >= DCCP_OPTVAL_MAXLEN)
		*to++ = (value & 0xFF0000000000ull) >> 40;
	if (len > 4)
		*to++ = (value & 0xFF00000000ull) >> 32;
	if (len > 3)
		*to++ = (value & 0xFF000000) >> 24;
	if (len > 2)
		*to++ = (value & 0xFF0000) >> 16;
	if (len > 1)
		*to++ = (value & 0xFF00) >> 8;
	if (len > 0)
		*to++ = (value & 0xFF);
}

static inline u8 dccp_ndp_len(const u64 ndp)
{
	if (likely(ndp <= 0xFF))
		return 1;
	return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
}

int dccp_insert_option(struct sk_buff *skb, const unsigned char option,
		       const void *value, const unsigned char len)
{
	unsigned char *to;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;

	to    = skb_push(skb, len + 2);
	*to++ = option;
	*to++ = len + 2;

	memcpy(to, value, len);
	return 0;
}

EXPORT_SYMBOL_GPL(dccp_insert_option);

static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	u64 ndp = dp->dccps_ndp_count;

	if (dccp_non_data_packet(skb))
		++dp->dccps_ndp_count;
	else
		dp->dccps_ndp_count = 0;

	if (ndp > 0) {
		unsigned char *ptr;
		const int ndp_len = dccp_ndp_len(ndp);
		const int len = ndp_len + 2;

		if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
			return -1;

		DCCP_SKB_CB(skb)->dccpd_opt_len += len;

		ptr = skb_push(skb, len);
		*ptr++ = DCCPO_NDP_COUNT;
		*ptr++ = len;
		dccp_encode_value_var(ndp, ptr, ndp_len);
	}

	return 0;
}

static inline int dccp_elapsed_time_len(const u32 elapsed_time)
{
	return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
}

/* FIXME: This function is currently not used anywhere */
int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed_time)
{
	const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	const int len = 2 + elapsed_time_len;
	unsigned char *to;

	if (elapsed_time_len == 0)
		return 0;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len += len;

	to    = skb_push(skb, len);
	*to++ = DCCPO_ELAPSED_TIME;
	*to++ = len;

	if (elapsed_time_len == 2) {
		const __be16 var16 = htons((u16)elapsed_time);
		memcpy(to, &var16, 2);
	} else {
		const __be32 var32 = htonl(elapsed_time);
		memcpy(to, &var32, 4);
	}

	return 0;
}

EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);

static int dccp_insert_option_timestamp(struct sk_buff *skb)
{
	__be32 now = htonl(dccp_timestamp());
	/* yes this will overflow but that is the point as we want a
	 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */

	return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now));
}

static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
					     struct dccp_request_sock *dreq,
					     struct sk_buff *skb)
{
	__be32 tstamp_echo;
	unsigned char *to;
	u32 elapsed_time, elapsed_time_len, len;

	if (dreq != NULL) {
		elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
		tstamp_echo  = htonl(dreq->dreq_timestamp_echo);
		dreq->dreq_timestamp_echo = 0;
	} else {
		elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
		tstamp_echo  = htonl(dp->dccps_timestamp_echo);
		dp->dccps_timestamp_echo = 0;
	}

	elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
	len = 6 + elapsed_time_len;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len += len;

	to    = skb_push(skb, len);
	*to++ = DCCPO_TIMESTAMP_ECHO;
	*to++ = len;

	memcpy(to, &tstamp_echo, 4);
	to += 4;

	if (elapsed_time_len == 2) {
		const __be16 var16 = htons((u16)elapsed_time);
		memcpy(to, &var16, 2);
	} else if (elapsed_time_len == 4) {
		const __be32 var32 = htonl(elapsed_time);
		memcpy(to, &var32, 4);
	}

	return 0;
}

static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
	struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
	const u16 buflen = dccp_ackvec_buflen(av);
	/* Figure out how many options do we need to represent the ackvec */
	const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN);
	u16 len = buflen + 2 * nr_opts;
	u8 i, nonce = 0;
	const unsigned char *tail, *from;
	unsigned char *to;

	if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
		DCCP_WARN("Lacking space for %u bytes on %s packet\n", len,
			  dccp_packet_name(dcb->dccpd_type));
		return -1;
	}
	/*
	 * Since Ack Vectors are variable-length, we can not always predict
	 * their size. To catch exception cases where the space is running out
	 * on the skb, a separate Sync is scheduled to carry the Ack Vector.
	 */
	if (len > DCCPAV_MIN_OPTLEN &&
	    len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) {
		DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), "
			  "MPS=%u ==> reduce payload size?\n", len, skb->len,
			  dcb->dccpd_opt_len, dp->dccps_mss_cache);
		dp->dccps_sync_scheduled = 1;
		return 0;
	}
	dcb->dccpd_opt_len += len;

	to   = skb_push(skb, len);
	len  = buflen;
	from = av->av_buf + av->av_buf_head;
	tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;

	for (i = 0; i < nr_opts; ++i) {
		int copylen = len;

		if (len > DCCP_SINGLE_OPT_MAXLEN)
			copylen = DCCP_SINGLE_OPT_MAXLEN;

		/*
		 * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
		 * its type; ack_nonce is the sum of all individual buf_nonce's.
		 */
		nonce ^= av->av_buf_nonce[i];

		*to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
		*to++ = copylen + 2;

		/* Check if buf_head wraps */
		if (from + copylen > tail) {
			const u16 tailsize = tail - from;

			memcpy(to, from, tailsize);
			to	+= tailsize;
			len	-= tailsize;
			copylen	-= tailsize;
			from	= av->av_buf;
		}

		memcpy(to, from, copylen);
		from += copylen;
		to   += copylen;
		len  -= copylen;
	}
	/*
	 * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
	 */
	if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce))
		return -ENOBUFS;
	return 0;
}

/**
 * dccp_insert_option_mandatory  -  Mandatory option (5.8.2)
 * Note that since we are using skb_push, this function needs to be called
 * _after_ inserting the option it is supposed to influence (stack order).
 */
int dccp_insert_option_mandatory(struct sk_buff *skb)
{
	if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
		return -1;

	DCCP_SKB_CB(skb)->dccpd_opt_len++;
	*skb_push(skb, 1) = DCCPO_MANDATORY;
	return 0;
}

/**
 * dccp_insert_fn_opt  -  Insert single Feature-Negotiation option into @skb
 * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
 * @feat: one out of %dccp_feature_numbers
 * @val: NN value or SP array (preferred element first) to copy
 * @len: true length of @val in bytes (excluding first element repetition)
 * @repeat_first: whether to copy the first element of @val twice
 *
 * The last argument is used to construct Confirm options, where the preferred
 * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
 * lists are kept such that the preferred entry is always first, so we only need
 * to copy twice, and avoid the overhead of cloning into a bigger array.
 */
int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
		       u8 *val, u8 len, bool repeat_first)
{
	u8 tot_len, *to;

	/* take the `Feature' field and possible repetition into account */
	if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
		DCCP_WARN("length %u for feature %u too large\n", len, feat);
		return -1;
	}

	if (unlikely(val == NULL || len == 0))
		len = repeat_first = false;
	tot_len = 3 + repeat_first + len;

	if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
		DCCP_WARN("packet too small for feature %d option!\n", feat);
		return -1;
	}
	DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;

	to    = skb_push(skb, tot_len);
	*to++ = type;
	*to++ = tot_len;
	*to++ = feat;

	if (repeat_first)
		*to++ = *val;
	if (len)
		memcpy(to, val, len);
	return 0;
}

/* The length of all options needs to be a multiple of 4 (5.8) */
static void dccp_insert_option_padding(struct sk_buff *skb)
{
	int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;

	if (padding != 0) {
		padding = 4 - padding;
		memset(skb_push(skb, padding), 0, padding);
		DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
	}
}

int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
{
	struct dccp_sock *dp = dccp_sk(sk);

	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;

	if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb))
		return -1;

	if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {

		/* Feature Negotiation */
		if (dccp_feat_insert_opts(dp, NULL, skb))
			return -1;

		if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
			/*
			 * Obtain RTT sample from Request/Response exchange.
			 * This is currently used for TFRC initialisation.
			 */
			if (dccp_insert_option_timestamp(skb))
				return -1;

		} else if (dccp_ackvec_pending(sk) &&
			   dccp_insert_option_ackvec(sk, skb)) {
				return -1;
		}
	}

	if (dp->dccps_hc_rx_insert_options) {
		if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
			return -1;
		dp->dccps_hc_rx_insert_options = 0;
	}

	if (dp->dccps_timestamp_echo != 0 &&
	    dccp_insert_option_timestamp_echo(dp, NULL, skb))
		return -1;

	dccp_insert_option_padding(skb);
	return 0;
}

int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
{
	DCCP_SKB_CB(skb)->dccpd_opt_len = 0;

	if (dccp_feat_insert_opts(NULL, dreq, skb))
		return -1;

	/* Obtain RTT sample from Response/Ack exchange (used by TFRC). */
	if (dccp_insert_option_timestamp(skb))
		return -1;

	if (dreq->dreq_timestamp_echo != 0 &&
	    dccp_insert_option_timestamp_echo(NULL, dreq, skb))
		return -1;

	dccp_insert_option_padding(skb);
	return 0;
}