net/dccp/options.c

   1 /*
   2  *  net/dccp/options.c
   3  *
   4  *  An implementation of the DCCP protocol
   5  *  Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
   6  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
   7  *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      as published by the Free Software Foundation; either version
  12  *      2 of the License, or (at your option) any later version.
  13  */
  14 #include <linux/dccp.h>
  15 #include <linux/module.h>
  16 #include <linux/types.h>
  17 #include <asm/unaligned.h>
  18 #include <linux/kernel.h>
  19 #include <linux/skbuff.h>
  20
  21 #include "ackvec.h"
  22 #include "ccid.h"
  23 #include "dccp.h"
  24 #include "feat.h"
  25
  26 int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
  27 int sysctl_dccp_feat_rx_ccid          = DCCPF_INITIAL_CCID;
  28 int sysctl_dccp_feat_tx_ccid          = DCCPF_INITIAL_CCID;
  29 int sysctl_dccp_feat_ack_ratio        = DCCPF_INITIAL_ACK_RATIO;
  30 int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
  31 int sysctl_dccp_feat_send_ndp_count  = DCCPF_INITIAL_SEND_NDP_COUNT;
  32
  33 static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
  34 {
  35         u32 value = 0;
  36
  37         if (len > 3)
  38                 value += *bf++ << 24;
  39         if (len > 2)
  40                 value += *bf++ << 16;
  41         if (len > 1)
  42                 value += *bf++ << 8;
  43         if (len > 0)
  44                 value += *bf;
  45
  46         return value;
  47 }
  48
  49 /**
  50  * dccp_parse_options  -  Parse DCCP options present in @skb
  51  * @sk: client|server|listening dccp socket (when @dreq != NULL)
  52  * @dreq: request socket to use during connection setup, or NULL
  53  */
  54 int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
  55                        struct sk_buff *skb)
  56 {
  57         struct dccp_sock *dp = dccp_sk(sk);
  58         const struct dccp_hdr *dh = dccp_hdr(skb);
  59         const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
  60         u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
  61         unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
  62         unsigned char *opt_ptr = options;
  63         const unsigned char *opt_end = (unsigned char *)dh +
  64                                         (dh->dccph_doff * 4);
  65         struct dccp_options_received *opt_recv = &dp->dccps_options_received;
  66         unsigned char opt, len;
  67         unsigned char *value;
  68         u32 elapsed_time;
  69         __be32 opt_val;
  70         int rc;
  71         int mandatory = 0;
  72
  73         memset(opt_recv, 0, sizeof(*opt_recv));
  74
  75         opt = len = 0;
  76         while (opt_ptr != opt_end) {
  77                 opt   = *opt_ptr++;
  78                 len   = 0;
  79                 value = NULL;
  80
  81                 /* Check if this isn't a single byte option */
  82                 if (opt > DCCPO_MAX_RESERVED) {
  83                         if (opt_ptr == opt_end)
  84                                 goto out_invalid_option;
  85
  86                         len = *opt_ptr++;
  87                         if (len < 3)
  88                                 goto out_invalid_option;
  89                         /*
  90                          * Remove the type and len fields, leaving
  91                          * just the value size
  92                          */
  93                         len     -= 2;
  94                         value   = opt_ptr;
  95                         opt_ptr += len;
  96
  97                         if (opt_ptr > opt_end)
  98                                 goto out_invalid_option;
  99                 }
 100
 101                 /*
 102                  * CCID-Specific Options (from RFC 4340, sec. 10.3):
 103                  *
 104                  * Option numbers 128 through 191 are for options sent from the
 105                  * HC-Sender to the HC-Receiver; option numbers 192 through 255
 106                  * are for options sent from the HC-Receiver to the HC-Sender.
 107                  *
 108                  * CCID-specific options are ignored during connection setup, as
 109                  * negotiation may still be in progress (see RFC 4340, 10.3).
 110                  *
 111                  */
 112                 if (dreq != NULL && opt >= 128)
 113                         goto ignore_option;
 114
 115                 switch (opt) {
 116                 case DCCPO_PADDING:
 117                         break;
 118                 case DCCPO_MANDATORY:
 119                         if (mandatory)
 120                                 goto out_invalid_option;
 121                         if (pkt_type != DCCP_PKT_DATA)
 122                                 mandatory = 1;
 123                         break;
 124                 case DCCPO_NDP_COUNT:
 125                         if (len > 3)
 126                                 goto out_invalid_option;
 127
 128                         opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
 129                         dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
 130                                       opt_recv->dccpor_ndp);
 131                         break;
 132                 case DCCPO_CHANGE_L:
 133                         /* fall through */
 134                 case DCCPO_CHANGE_R:
 135                         if (pkt_type == DCCP_PKT_DATA)
 136                                 break;
 137                         if (len < 2)
 138                                 goto out_invalid_option;
 139                         rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
 140                                                    len - 1);
 141                         /*
 142                          * When there is a change error, change_recv is
 143                          * responsible for dealing with it.  i.e. reply with an
 144                          * empty confirm.
 145                          * If the change was mandatory, then we need to die.
 146                          */
 147                         if (rc && mandatory)
 148                                 goto out_invalid_option;
 149                         break;
 150                 case DCCPO_CONFIRM_L:
 151                         /* fall through */
 152                 case DCCPO_CONFIRM_R:
 153                         if (pkt_type == DCCP_PKT_DATA)
 154                                 break;
 155                         if (len < 2)    /* FIXME this disallows empty confirm */
 156                                 goto out_invalid_option;
 157                         if (dccp_feat_confirm_recv(sk, opt, *value,
 158                                                    value + 1, len - 1))
 159                                 goto out_invalid_option;
 160                         break;
 161                 case DCCPO_ACK_VECTOR_0:
 162                 case DCCPO_ACK_VECTOR_1:
 163                         if (dccp_packet_without_ack(skb))   /* RFC 4340, 11.4 */
 164                                 break;
 165
 166                         if (dccp_msk(sk)->dccpms_send_ack_vector &&
 167                             dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
 168                                 goto out_invalid_option;
 169                         break;
 170                 case DCCPO_TIMESTAMP:
 171                         if (len != 4)
 172                                 goto out_invalid_option;
 173                         /*
 174                          * RFC 4340 13.1: "The precise time corresponding to
 175                          * Timestamp Value zero is not specified". We use
 176                          * zero to indicate absence of a meaningful timestamp.
 177                          */
 178                         opt_val = get_unaligned((__be32 *)value);
 179                         if (unlikely(opt_val == 0)) {
 180                                 DCCP_WARN("Timestamp with zero value\n");
 181                                 break;
 182                         }
 183
 184                         if (dreq != NULL) {
 185                                 dreq->dreq_timestamp_echo = ntohl(opt_val);
 186                                 dreq->dreq_timestamp_time = dccp_timestamp();
 187                         } else {
 188                                 opt_recv->dccpor_timestamp =
 189                                         dp->dccps_timestamp_echo = ntohl(opt_val);
 190                                 dp->dccps_timestamp_time = dccp_timestamp();
 191                         }
 192                         dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
 193                                       dccp_role(sk), ntohl(opt_val),
 194                                       (unsigned long long)
 195                                       DCCP_SKB_CB(skb)->dccpd_ack_seq);
 196                         break;
 197                 case DCCPO_TIMESTAMP_ECHO:
 198                         if (len != 4 && len != 6 && len != 8)
 199                                 goto out_invalid_option;
 200
 201                         opt_val = get_unaligned((__be32 *)value);
 202                         opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
 203
 204                         dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
 205                                       "ackno=%llu", dccp_role(sk),
 206                                       opt_recv->dccpor_timestamp_echo,
 207                                       len + 2,
 208                                       (unsigned long long)
 209                                       DCCP_SKB_CB(skb)->dccpd_ack_seq);
 210
 211                         value += 4;
 212
 213                         if (len == 4) {         /* no elapsed time included */
 214                                 dccp_pr_debug_cat("\n");
 215                                 break;
 216                         }
 217
 218                         if (len == 6) {         /* 2-byte elapsed time */
 219                                 __be16 opt_val2 = get_unaligned((__be16 *)value);
 220                                 elapsed_time = ntohs(opt_val2);
 221                         } else {                /* 4-byte elapsed time */
 222                                 opt_val = get_unaligned((__be32 *)value);
 223                                 elapsed_time = ntohl(opt_val);
 224                         }
 225
 226                         dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
 227
 228                         /* Give precedence to the biggest ELAPSED_TIME */
 229                         if (elapsed_time > opt_recv->dccpor_elapsed_time)
 230                                 opt_recv->dccpor_elapsed_time = elapsed_time;
 231                         break;
 232                 case DCCPO_ELAPSED_TIME:
 233                         if (dccp_packet_without_ack(skb))   /* RFC 4340, 13.2 */
 234                                 break;
 235
 236                         if (len == 2) {
 237                                 __be16 opt_val2 = get_unaligned((__be16 *)value);
 238                                 elapsed_time = ntohs(opt_val2);
 239                         } else if (len == 4) {
 240                                 opt_val = get_unaligned((__be32 *)value);
 241                                 elapsed_time = ntohl(opt_val);
 242                         } else {
 243                                 goto out_invalid_option;
 244                         }
 245
 246                         if (elapsed_time > opt_recv->dccpor_elapsed_time)
 247                                 opt_recv->dccpor_elapsed_time = elapsed_time;
 248
 249                         dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
 250                                       dccp_role(sk), elapsed_time);
 251                         break;
 252                 case 128 ... 191: {
 253                         const u16 idx = value - options;
 254
 255                         if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
 256                                                      opt, len, idx,
 257                                                      value) != 0)
 258                                 goto out_invalid_option;
 259                 }
 260                         break;
 261                 case 192 ... 255: {
 262                         const u16 idx = value - options;
 263
 264                         if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
 265                                                      opt, len, idx,
 266                                                      value) != 0)
 267                                 goto out_invalid_option;
 268                 }
 269                         break;
 270                 default:
 271                         DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
 272                                   "implemented, ignoring", sk, opt, len);
 273                         break;
 274                 }
 275 ignore_option:
 276                 if (opt != DCCPO_MANDATORY)
 277                         mandatory = 0;
 278         }
 279
 280         /* mandatory was the last byte in option list -> reset connection */
 281         if (mandatory)
 282                 goto out_invalid_option;
 283
 284         return 0;
 285
 286 out_invalid_option:
 287         DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
 288         DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
 289         DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
 290         return -1;
 291 }
 292
 293 EXPORT_SYMBOL_GPL(dccp_parse_options);
 294
 295 static void dccp_encode_value_var(const u32 value, unsigned char *to,
 296                                   const unsigned int len)
 297 {
 298         if (len > 3)
 299                 *to++ = (value & 0xFF000000) >> 24;
 300         if (len > 2)
 301                 *to++ = (value & 0xFF0000) >> 16;
 302         if (len > 1)
 303                 *to++ = (value & 0xFF00) >> 8;
 304         if (len > 0)
 305                 *to++ = (value & 0xFF);
 306 }
 307
 308 static inline int dccp_ndp_len(const int ndp)
 309 {
 310         return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
 311 }
 312
 313 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 314                         const unsigned char option,
 315                         const void *value, const unsigned char len)
 316 {
 317         unsigned char *to;
 318
 319         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
 320                 return -1;
 321
 322         DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
 323
 324         to    = skb_push(skb, len + 2);
 325         *to++ = option;
 326         *to++ = len + 2;
 327
 328         memcpy(to, value, len);
 329         return 0;
 330 }
 331
 332 EXPORT_SYMBOL_GPL(dccp_insert_option);
 333
 334 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
 335 {
 336         struct dccp_sock *dp = dccp_sk(sk);
 337         int ndp = dp->dccps_ndp_count;
 338
 339         if (dccp_non_data_packet(skb))
 340                 ++dp->dccps_ndp_count;
 341         else
 342                 dp->dccps_ndp_count = 0;
 343
 344         if (ndp > 0) {
 345                 unsigned char *ptr;
 346                 const int ndp_len = dccp_ndp_len(ndp);
 347                 const int len = ndp_len + 2;
 348
 349                 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
 350                         return -1;
 351
 352                 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
 353
 354                 ptr = skb_push(skb, len);
 355                 *ptr++ = DCCPO_NDP_COUNT;
 356                 *ptr++ = len;
 357                 dccp_encode_value_var(ndp, ptr, ndp_len);
 358         }
 359
 360         return 0;
 361 }
 362
 363 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
 364 {
 365         return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
 366 }
 367
 368 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
 369                                     u32 elapsed_time)
 370 {
 371         const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
 372         const int len = 2 + elapsed_time_len;
 373         unsigned char *to;
 374
 375         if (elapsed_time_len == 0)
 376                 return 0;
 377
 378         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
 379                 return -1;
 380
 381         DCCP_SKB_CB(skb)->dccpd_opt_len += len;
 382
 383         to    = skb_push(skb, len);
 384         *to++ = DCCPO_ELAPSED_TIME;
 385         *to++ = len;
 386
 387         if (elapsed_time_len == 2) {
 388                 const __be16 var16 = htons((u16)elapsed_time);
 389                 memcpy(to, &var16, 2);
 390         } else {
 391                 const __be32 var32 = htonl(elapsed_time);
 392                 memcpy(to, &var32, 4);
 393         }
 394
 395         return 0;
 396 }
 397
 398 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
 399
 400 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
 401 {
 402         __be32 now = htonl(dccp_timestamp());
 403         /* yes this will overflow but that is the point as we want a
 404          * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
 405
 406         return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
 407 }
 408
 409 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
 410
 411 static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
 412                                              struct dccp_request_sock *dreq,
 413                                              struct sk_buff *skb)
 414 {
 415         __be32 tstamp_echo;
 416         unsigned char *to;
 417         u32 elapsed_time, elapsed_time_len, len;
 418
 419         if (dreq != NULL) {
 420                 elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
 421                 tstamp_echo  = htonl(dreq->dreq_timestamp_echo);
 422                 dreq->dreq_timestamp_echo = 0;
 423         } else {
 424                 elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
 425                 tstamp_echo  = htonl(dp->dccps_timestamp_echo);
 426                 dp->dccps_timestamp_echo = 0;
 427         }
 428
 429         elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
 430         len = 6 + elapsed_time_len;
 431
 432         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
 433                 return -1;
 434
 435         DCCP_SKB_CB(skb)->dccpd_opt_len += len;
 436
 437         to    = skb_push(skb, len);
 438         *to++ = DCCPO_TIMESTAMP_ECHO;
 439         *to++ = len;
 440
 441         memcpy(to, &tstamp_echo, 4);
 442         to += 4;
 443
 444         if (elapsed_time_len == 2) {
 445                 const __be16 var16 = htons((u16)elapsed_time);
 446                 memcpy(to, &var16, 2);
 447         } else if (elapsed_time_len == 4) {
 448                 const __be32 var32 = htonl(elapsed_time);
 449                 memcpy(to, &var32, 4);
 450         }
 451
 452         return 0;
 453 }
 454
 455 static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
 456                                 u8 *val, u8 len)
 457 {
 458         u8 *to;
 459
 460         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
 461                 DCCP_WARN("packet too small for feature %d option!\n", feat);
 462                 return -1;
 463         }
 464
 465         DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
 466
 467         to    = skb_push(skb, len + 3);
 468         *to++ = type;
 469         *to++ = len + 3;
 470         *to++ = feat;
 471
 472         if (len)
 473                 memcpy(to, val, len);
 474
 475         dccp_pr_debug("%s(%s (%d), ...), length %d\n",
 476                       dccp_feat_typename(type),
 477                       dccp_feat_name(feat), feat, len);
 478         return 0;
 479 }
 480
 481 static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
 482 {
 483         struct dccp_sock *dp = dccp_sk(sk);
 484         struct dccp_minisock *dmsk = dccp_msk(sk);
 485         struct dccp_opt_pend *opt, *next;
 486         int change = 0;
 487
 488         /* confirm any options [NN opts] */
 489         list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
 490                 dccp_insert_feat_opt(skb, opt->dccpop_type,
 491                                      opt->dccpop_feat, opt->dccpop_val,
 492                                      opt->dccpop_len);
 493                 /* fear empty confirms */
 494                 if (opt->dccpop_val)
 495                         kfree(opt->dccpop_val);
 496                 kfree(opt);
 497         }
 498         INIT_LIST_HEAD(&dmsk->dccpms_conf);
 499
 500         /* see which features we need to send */
 501         list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
 502                 /* see if we need to send any confirm */
 503                 if (opt->dccpop_sc) {
 504                         dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
 505                                              opt->dccpop_feat,
 506                                              opt->dccpop_sc->dccpoc_val,
 507                                              opt->dccpop_sc->dccpoc_len);
 508
 509                         BUG_ON(!opt->dccpop_sc->dccpoc_val);
 510                         kfree(opt->dccpop_sc->dccpoc_val);
 511                         kfree(opt->dccpop_sc);
 512                         opt->dccpop_sc = NULL;
 513                 }
 514
 515                 /* any option not confirmed, re-send it */
 516                 if (!opt->dccpop_conf) {
 517                         dccp_insert_feat_opt(skb, opt->dccpop_type,
 518                                              opt->dccpop_feat, opt->dccpop_val,
 519                                              opt->dccpop_len);
 520                         change++;
 521                 }
 522         }
 523
 524         /* Retransmit timer.
 525          * If this is the master listening sock, we don't set a timer on it.  It
 526          * should be fine because if the dude doesn't receive our RESPONSE
 527          * [which will contain the CHANGE] he will send another REQUEST which
 528          * will "retrnasmit" the change.
 529          */
 530         if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
 531                 dccp_pr_debug("reset feat negotiation timer %p\n", sk);
 532
 533                 /* XXX don't reset the timer on re-transmissions.  I.e. reset it
 534                  * only when sending new stuff i guess.  Currently the timer
 535                  * never backs off because on re-transmission it just resets it!
 536                  */
 537                 inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
 538                                           inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
 539         }
 540
 541         return 0;
 542 }
 543
 544 /* The length of all options needs to be a multiple of 4 (5.8) */
 545 static void dccp_insert_option_padding(struct sk_buff *skb)
 546 {
 547         int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
 548
 549         if (padding != 0) {
 550                 padding = 4 - padding;
 551                 memset(skb_push(skb, padding), 0, padding);
 552                 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
 553         }
 554 }
 555
 556 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
 557 {
 558         struct dccp_sock *dp = dccp_sk(sk);
 559         struct dccp_minisock *dmsk = dccp_msk(sk);
 560
 561         DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
 562
 563         if (dmsk->dccpms_send_ndp_count &&
 564             dccp_insert_option_ndp(sk, skb))
 565                 return -1;
 566
 567         if (!dccp_packet_without_ack(skb)) {
 568                 if (dmsk->dccpms_send_ack_vector &&
 569                     dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
 570                     dccp_insert_option_ackvec(sk, skb))
 571                         return -1;
 572         }
 573
 574         if (dp->dccps_hc_rx_insert_options) {
 575                 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
 576                         return -1;
 577                 dp->dccps_hc_rx_insert_options = 0;
 578         }
 579
 580         /* Feature negotiation */
 581         /* Data packets can't do feat negotiation */
 582         if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
 583             DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
 584             dccp_insert_options_feat(sk, skb))
 585                 return -1;
 586
 587         /*
 588          * Obtain RTT sample from Request/Response exchange.
 589          * This is currently used in CCID 3 initialisation.
 590          */
 591         if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
 592             dccp_insert_option_timestamp(sk, skb))
 593                 return -1;
 594
 595         if (dp->dccps_timestamp_echo != 0 &&
 596             dccp_insert_option_timestamp_echo(dp, NULL, skb))
 597                 return -1;
 598
 599         dccp_insert_option_padding(skb);
 600         return 0;
 601 }
 602
 603 int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
 604 {
 605         DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
 606
 607         if (dreq->dreq_timestamp_echo != 0 &&
 608             dccp_insert_option_timestamp_echo(NULL, dreq, skb))
 609                 return -1;
 610
 611         dccp_insert_option_padding(skb);
 612         return 0;
 613 }