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_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
  30 int sysctl_dccp_feat_send_ndp_count  = DCCPF_INITIAL_SEND_NDP_COUNT;
  31
  32 u64 dccp_decode_value_var(const u8 *bf, const u8 len)
  33 {
  34         u64 value = 0;
  35
  36         if (len >= DCCP_OPTVAL_MAXLEN)
  37                 value += ((u64)*bf++) << 40;
  38         if (len > 4)
  39                 value += ((u64)*bf++) << 32;
  40         if (len > 3)
  41                 value += ((u64)*bf++) << 24;
  42         if (len > 2)
  43                 value += ((u64)*bf++) << 16;
  44         if (len > 1)
  45                 value += ((u64)*bf++) << 8;
  46         if (len > 0)
  47                 value += *bf;
  48
  49         return value;
  50 }
  51
  52 /**
  53  * dccp_parse_options  -  Parse DCCP options present in @skb
  54  * @sk: client|server|listening dccp socket (when @dreq != NULL)
  55  * @dreq: request socket to use during connection setup, or NULL
  56  */
  57 int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
  58                        struct sk_buff *skb)
  59 {
  60         struct dccp_sock *dp = dccp_sk(sk);
  61         const struct dccp_hdr *dh = dccp_hdr(skb);
  62         const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
  63         u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
  64         unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
  65         unsigned char *opt_ptr = options;
  66         const unsigned char *opt_end = (unsigned char *)dh +
  67                                         (dh->dccph_doff * 4);
  68         struct dccp_options_received *opt_recv = &dp->dccps_options_received;
  69         unsigned char opt, len;
  70         unsigned char *uninitialized_var(value);
  71         u32 elapsed_time;
  72         __be32 opt_val;
  73         int rc;
  74         int mandatory = 0;
  75
  76         memset(opt_recv, 0, sizeof(*opt_recv));
  77
  78         opt = len = 0;
  79         while (opt_ptr != opt_end) {
  80                 opt   = *opt_ptr++;
  81                 len   = 0;
  82                 value = NULL;
  83
  84                 /* Check if this isn't a single byte option */
  85                 if (opt > DCCPO_MAX_RESERVED) {
  86                         if (opt_ptr == opt_end)
  87                                 goto out_nonsensical_length;
  88
  89                         len = *opt_ptr++;
  90                         if (len < 2)
  91                                 goto out_nonsensical_length;
  92                         /*
  93                          * Remove the type and len fields, leaving
  94                          * just the value size
  95                          */
  96                         len     -= 2;
  97                         value   = opt_ptr;
  98                         opt_ptr += len;
  99
 100                         if (opt_ptr > opt_end)
 101                                 goto out_nonsensical_length;
 102                 }
 103
 104                 /*
 105                  * CCID-Specific Options (from RFC 4340, sec. 10.3):
 106                  *
 107                  * Option numbers 128 through 191 are for options sent from the
 108                  * HC-Sender to the HC-Receiver; option numbers 192 through 255
 109                  * are for options sent from the HC-Receiver to the HC-Sender.
 110                  *
 111                  * CCID-specific options are ignored during connection setup, as
 112                  * negotiation may still be in progress (see RFC 4340, 10.3).
 113                  * The same applies to Ack Vectors, as these depend on the CCID.
 114                  *
 115                  */
 116                 if (dreq != NULL && (opt >= 128 ||
 117                     opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1))
 118                         goto ignore_option;
 119
 120                 switch (opt) {
 121                 case DCCPO_PADDING:
 122                         break;
 123                 case DCCPO_MANDATORY:
 124                         if (mandatory)
 125                                 goto out_invalid_option;
 126                         if (pkt_type != DCCP_PKT_DATA)
 127                                 mandatory = 1;
 128                         break;
 129                 case DCCPO_NDP_COUNT:
 130                         if (len > 6)
 131                                 goto out_invalid_option;
 132
 133                         opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
 134                         dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
 135                                       (unsigned long long)opt_recv->dccpor_ndp);
 136                         break;
 137                 case DCCPO_CHANGE_L:
 138                         /* fall through */
 139                 case DCCPO_CHANGE_R:
 140                         if (pkt_type == DCCP_PKT_DATA)
 141                                 break;
 142                         if (len < 2)
 143                                 goto out_invalid_option;
 144                         rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
 145                                                    len - 1);
 146                         /*
 147                          * When there is a change error, change_recv is
 148                          * responsible for dealing with it.  i.e. reply with an
 149                          * empty confirm.
 150                          * If the change was mandatory, then we need to die.
 151                          */
 152                         if (rc && mandatory)
 153                                 goto out_invalid_option;
 154                         break;
 155                 case DCCPO_CONFIRM_L:
 156                         /* fall through */
 157                 case DCCPO_CONFIRM_R:
 158                         if (pkt_type == DCCP_PKT_DATA)
 159                                 break;
 160                         if (len < 2)    /* FIXME this disallows empty confirm */
 161                                 goto out_invalid_option;
 162                         if (dccp_feat_confirm_recv(sk, opt, *value,
 163                                                    value + 1, len - 1))
 164                                 goto out_invalid_option;
 165                         break;
 166                 case DCCPO_ACK_VECTOR_0:
 167                 case DCCPO_ACK_VECTOR_1:
 168                         if (dccp_packet_without_ack(skb))   /* RFC 4340, 11.4 */
 169                                 break;
 170
 171                         if (dccp_msk(sk)->dccpms_send_ack_vector &&
 172                             dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
 173                                 goto out_invalid_option;
 174                         break;
 175                 case DCCPO_TIMESTAMP:
 176                         if (len != 4)
 177                                 goto out_invalid_option;
 178                         /*
 179                          * RFC 4340 13.1: "The precise time corresponding to
 180                          * Timestamp Value zero is not specified". We use
 181                          * zero to indicate absence of a meaningful timestamp.
 182                          */
 183                         opt_val = get_unaligned((__be32 *)value);
 184                         if (unlikely(opt_val == 0)) {
 185                                 DCCP_WARN("Timestamp with zero value\n");
 186                                 break;
 187                         }
 188
 189                         if (dreq != NULL) {
 190                                 dreq->dreq_timestamp_echo = ntohl(opt_val);
 191                                 dreq->dreq_timestamp_time = dccp_timestamp();
 192                         } else {
 193                                 opt_recv->dccpor_timestamp =
 194                                         dp->dccps_timestamp_echo = ntohl(opt_val);
 195                                 dp->dccps_timestamp_time = dccp_timestamp();
 196                         }
 197                         dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
 198                                       dccp_role(sk), ntohl(opt_val),
 199                                       (unsigned long long)
 200                                       DCCP_SKB_CB(skb)->dccpd_ack_seq);
 201                         break;
 202                 case DCCPO_TIMESTAMP_ECHO:
 203                         if (len != 4 && len != 6 && len != 8)
 204                                 goto out_invalid_option;
 205
 206                         opt_val = get_unaligned((__be32 *)value);
 207                         opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
 208
 209                         dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
 210                                       "ackno=%llu", dccp_role(sk),
 211                                       opt_recv->dccpor_timestamp_echo,
 212                                       len + 2,
 213                                       (unsigned long long)
 214                                       DCCP_SKB_CB(skb)->dccpd_ack_seq);
 215
 216                         value += 4;
 217
 218                         if (len == 4) {         /* no elapsed time included */
 219                                 dccp_pr_debug_cat("\n");
 220                                 break;
 221                         }
 222
 223                         if (len == 6) {         /* 2-byte elapsed time */
 224                                 __be16 opt_val2 = get_unaligned((__be16 *)value);
 225                                 elapsed_time = ntohs(opt_val2);
 226                         } else {                /* 4-byte elapsed time */
 227                                 opt_val = get_unaligned((__be32 *)value);
 228                                 elapsed_time = ntohl(opt_val);
 229                         }
 230
 231                         dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
 232
 233                         /* Give precedence to the biggest ELAPSED_TIME */
 234                         if (elapsed_time > opt_recv->dccpor_elapsed_time)
 235                                 opt_recv->dccpor_elapsed_time = elapsed_time;
 236                         break;
 237                 case DCCPO_ELAPSED_TIME:
 238                         if (dccp_packet_without_ack(skb))   /* RFC 4340, 13.2 */
 239                                 break;
 240
 241                         if (len == 2) {
 242                                 __be16 opt_val2 = get_unaligned((__be16 *)value);
 243                                 elapsed_time = ntohs(opt_val2);
 244                         } else if (len == 4) {
 245                                 opt_val = get_unaligned((__be32 *)value);
 246                                 elapsed_time = ntohl(opt_val);
 247                         } else {
 248                                 goto out_invalid_option;
 249                         }
 250
 251                         if (elapsed_time > opt_recv->dccpor_elapsed_time)
 252                                 opt_recv->dccpor_elapsed_time = elapsed_time;
 253
 254                         dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
 255                                       dccp_role(sk), elapsed_time);
 256                         break;
 257                 case 128 ... 191: {
 258                         const u16 idx = value - options;
 259
 260                         if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
 261                                                      opt, len, idx,
 262                                                      value) != 0)
 263                                 goto out_invalid_option;
 264                 }
 265                         break;
 266                 case 192 ... 255: {
 267                         const u16 idx = value - options;
 268
 269                         if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
 270                                                      opt, len, idx,
 271                                                      value) != 0)
 272                                 goto out_invalid_option;
 273                 }
 274                         break;
 275                 default:
 276                         DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
 277                                   "implemented, ignoring", sk, opt, len);
 278                         break;
 279                 }
 280 ignore_option:
 281                 if (opt != DCCPO_MANDATORY)
 282                         mandatory = 0;
 283         }
 284
 285         /* mandatory was the last byte in option list -> reset connection */
 286         if (mandatory)
 287                 goto out_invalid_option;
 288
 289 out_nonsensical_length:
 290         /* RFC 4340, 5.8: ignore option and all remaining option space */
 291         return 0;
 292
 293 out_invalid_option:
 294         DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
 295         DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
 296         DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
 297         DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
 298         DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
 299         DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
 300         return -1;
 301 }
 302
 303 EXPORT_SYMBOL_GPL(dccp_parse_options);
 304
 305 void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
 306 {
 307         if (len >= DCCP_OPTVAL_MAXLEN)
 308                 *to++ = (value & 0xFF0000000000ull) >> 40;
 309         if (len > 4)
 310                 *to++ = (value & 0xFF00000000ull) >> 32;
 311         if (len > 3)
 312                 *to++ = (value & 0xFF000000) >> 24;
 313         if (len > 2)
 314                 *to++ = (value & 0xFF0000) >> 16;
 315         if (len > 1)
 316                 *to++ = (value & 0xFF00) >> 8;
 317         if (len > 0)
 318                 *to++ = (value & 0xFF);
 319 }
 320
 321 static inline u8 dccp_ndp_len(const u64 ndp)
 322 {
 323         if (likely(ndp <= 0xFF))
 324                 return 1;
 325         return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
 326 }
 327
 328 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
 329                         const unsigned char option,
 330                         const void *value, const unsigned char len)
 331 {
 332         unsigned char *to;
 333
 334         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
 335                 return -1;
 336
 337         DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
 338
 339         to    = skb_push(skb, len + 2);
 340         *to++ = option;
 341         *to++ = len + 2;
 342
 343         memcpy(to, value, len);
 344         return 0;
 345 }
 346
 347 EXPORT_SYMBOL_GPL(dccp_insert_option);
 348
 349 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
 350 {
 351         struct dccp_sock *dp = dccp_sk(sk);
 352         u64 ndp = dp->dccps_ndp_count;
 353
 354         if (dccp_non_data_packet(skb))
 355                 ++dp->dccps_ndp_count;
 356         else
 357                 dp->dccps_ndp_count = 0;
 358
 359         if (ndp > 0) {
 360                 unsigned char *ptr;
 361                 const int ndp_len = dccp_ndp_len(ndp);
 362                 const int len = ndp_len + 2;
 363
 364                 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
 365                         return -1;
 366
 367                 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
 368
 369                 ptr = skb_push(skb, len);
 370                 *ptr++ = DCCPO_NDP_COUNT;
 371                 *ptr++ = len;
 372                 dccp_encode_value_var(ndp, ptr, ndp_len);
 373         }
 374
 375         return 0;
 376 }
 377
 378 static inline int dccp_elapsed_time_len(const u32 elapsed_time)
 379 {
 380         return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
 381 }
 382
 383 int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
 384                                     u32 elapsed_time)
 385 {
 386         const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
 387         const int len = 2 + elapsed_time_len;
 388         unsigned char *to;
 389
 390         if (elapsed_time_len == 0)
 391                 return 0;
 392
 393         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
 394                 return -1;
 395
 396         DCCP_SKB_CB(skb)->dccpd_opt_len += len;
 397
 398         to    = skb_push(skb, len);
 399         *to++ = DCCPO_ELAPSED_TIME;
 400         *to++ = len;
 401
 402         if (elapsed_time_len == 2) {
 403                 const __be16 var16 = htons((u16)elapsed_time);
 404                 memcpy(to, &var16, 2);
 405         } else {
 406                 const __be32 var32 = htonl(elapsed_time);
 407                 memcpy(to, &var32, 4);
 408         }
 409
 410         return 0;
 411 }
 412
 413 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
 414
 415 int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
 416 {
 417         __be32 now = htonl(dccp_timestamp());
 418         /* yes this will overflow but that is the point as we want a
 419          * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
 420
 421         return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
 422 }
 423
 424 EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
 425
 426 static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
 427                                              struct dccp_request_sock *dreq,
 428                                              struct sk_buff *skb)
 429 {
 430         __be32 tstamp_echo;
 431         unsigned char *to;
 432         u32 elapsed_time, elapsed_time_len, len;
 433
 434         if (dreq != NULL) {
 435                 elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
 436                 tstamp_echo  = htonl(dreq->dreq_timestamp_echo);
 437                 dreq->dreq_timestamp_echo = 0;
 438         } else {
 439                 elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
 440                 tstamp_echo  = htonl(dp->dccps_timestamp_echo);
 441                 dp->dccps_timestamp_echo = 0;
 442         }
 443
 444         elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
 445         len = 6 + elapsed_time_len;
 446
 447         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
 448                 return -1;
 449
 450         DCCP_SKB_CB(skb)->dccpd_opt_len += len;
 451
 452         to    = skb_push(skb, len);
 453         *to++ = DCCPO_TIMESTAMP_ECHO;
 454         *to++ = len;
 455
 456         memcpy(to, &tstamp_echo, 4);
 457         to += 4;
 458
 459         if (elapsed_time_len == 2) {
 460                 const __be16 var16 = htons((u16)elapsed_time);
 461                 memcpy(to, &var16, 2);
 462         } else if (elapsed_time_len == 4) {
 463                 const __be32 var32 = htonl(elapsed_time);
 464                 memcpy(to, &var32, 4);
 465         }
 466
 467         return 0;
 468 }
 469
 470 /**
 471  * dccp_insert_option_mandatory  -  Mandatory option (5.8.2)
 472  * Note that since we are using skb_push, this function needs to be called
 473  * _after_ inserting the option it is supposed to influence (stack order).
 474  */
 475 int dccp_insert_option_mandatory(struct sk_buff *skb)
 476 {
 477         if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
 478                 return -1;
 479
 480         DCCP_SKB_CB(skb)->dccpd_opt_len++;
 481         *skb_push(skb, 1) = DCCPO_MANDATORY;
 482         return 0;
 483 }
 484
 485 /**
 486  * dccp_insert_fn_opt  -  Insert single Feature-Negotiation option into @skb
 487  * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
 488  * @feat: one out of %dccp_feature_numbers
 489  * @val: NN value or SP array (preferred element first) to copy
 490  * @len: true length of @val in bytes (excluding first element repetition)
 491  * @repeat_first: whether to copy the first element of @val twice
 492  * The last argument is used to construct Confirm options, where the preferred
 493  * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
 494  * lists are kept such that the preferred entry is always first, so we only need
 495  * to copy twice, and avoid the overhead of cloning into a bigger array.
 496  */
 497 int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
 498                        u8 *val, u8 len, bool repeat_first)
 499 {
 500         u8 tot_len, *to;
 501
 502         /* take the `Feature' field and possible repetition into account */
 503         if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
 504                 DCCP_WARN("length %u for feature %u too large\n", len, feat);
 505                 return -1;
 506         }
 507
 508         if (unlikely(val == NULL || len == 0))
 509                 len = repeat_first = 0;
 510         tot_len = 3 + repeat_first + len;
 511
 512         if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
 513                 DCCP_WARN("packet too small for feature %d option!\n", feat);
 514                 return -1;
 515         }
 516         DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
 517
 518         to    = skb_push(skb, tot_len);
 519         *to++ = type;
 520         *to++ = tot_len;
 521         *to++ = feat;
 522
 523         if (repeat_first)
 524                 *to++ = *val;
 525         if (len)
 526                 memcpy(to, val, len);
 527
 528         dccp_pr_debug("%s(%s (%d), ...), length %d\n",
 529                       dccp_feat_typename(type),
 530                       dccp_feat_name(feat), feat, len);
 531         return 0;
 532 }
 533
 534 /* The length of all options needs to be a multiple of 4 (5.8) */
 535 static void dccp_insert_option_padding(struct sk_buff *skb)
 536 {
 537         int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
 538
 539         if (padding != 0) {
 540                 padding = 4 - padding;
 541                 memset(skb_push(skb, padding), 0, padding);
 542                 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
 543         }
 544 }
 545
 546 int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
 547 {
 548         struct dccp_sock *dp = dccp_sk(sk);
 549         struct dccp_minisock *dmsk = dccp_msk(sk);
 550
 551         DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
 552
 553         if (dmsk->dccpms_send_ndp_count &&
 554             dccp_insert_option_ndp(sk, skb))
 555                 return -1;
 556
 557         if (!dccp_packet_without_ack(skb)) {
 558                 if (dmsk->dccpms_send_ack_vector &&
 559                     dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
 560                     dccp_insert_option_ackvec(sk, skb))
 561                         return -1;
 562         }
 563
 564         if (dp->dccps_hc_rx_insert_options) {
 565                 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
 566                         return -1;
 567                 dp->dccps_hc_rx_insert_options = 0;
 568         }
 569
 570         /*
 571          * Obtain RTT sample from Request/Response exchange.
 572          * This is currently used in CCID 3 initialisation.
 573          */
 574         if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST &&
 575             dccp_insert_option_timestamp(sk, skb))
 576                 return -1;
 577
 578         if (dp->dccps_timestamp_echo != 0 &&
 579             dccp_insert_option_timestamp_echo(dp, NULL, skb))
 580                 return -1;
 581
 582         dccp_insert_option_padding(skb);
 583         return 0;
 584 }
 585
 586 int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
 587 {
 588         DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
 589
 590         if (dreq->dreq_timestamp_echo != 0 &&
 591             dccp_insert_option_timestamp_echo(NULL, dreq, skb))
 592                 return -1;
 593
 594         dccp_insert_option_padding(skb);
 595         return 0;
 596 }