sm_make_chunk.c 102 KB
Newer Older
1
/* SCTP kernel implementation
Linus Torvalds's avatar
Linus Torvalds committed
2 3 4 5 6
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001-2002 Intel Corp.
 *
7
 * This file is part of the SCTP kernel implementation
Linus Torvalds's avatar
Linus Torvalds committed
8 9 10 11 12
 *
 * These functions work with the state functions in sctp_sm_statefuns.c
 * to implement the state operations.  These functions implement the
 * steps which require modifying existing data structures.
 *
13
 * This SCTP implementation is free software;
Linus Torvalds's avatar
Linus Torvalds committed
14 15 16 17 18
 * 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, or (at your option)
 * any later version.
 *
19
 * This SCTP implementation is distributed in the hope that it
Linus Torvalds's avatar
Linus Torvalds committed
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
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 *
 * Or submit a bug report through the following website:
 *    http://www.sf.net/projects/lksctp
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    C. Robin              <chris@hundredacre.ac.uk>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
 *    Sridhar Samudrala	    <sri@us.ibm.com>
 *    Daisy Chang	    <daisyc@us.ibm.com>
 *    Ardelle Fan	    <ardelle.fan@intel.com>
 *    Kevin Gao             <kevin.gao@intel.com>
 *
 * Any bugs reported given to us we will try to fix... any fixes shared will
 * be incorporated into the next SCTP release.
 */

53 54
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

Linus Torvalds's avatar
Linus Torvalds committed
55 56 57 58 59 60
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/net.h>
#include <linux/inet.h>
Christian Borntraeger's avatar
Christian Borntraeger committed
61
#include <linux/scatterlist.h>
Linus Torvalds's avatar
Linus Torvalds committed
62
#include <linux/crypto.h>
63
#include <linux/slab.h>
Linus Torvalds's avatar
Linus Torvalds committed
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81
#include <net/sock.h>

#include <linux/skbuff.h>
#include <linux/random.h>	/* for get_random_bytes */
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

SCTP_STATIC
struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
				   __u8 type, __u8 flags, int paylen);
static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const struct sctp_chunk *init_chunk,
					int *cookie_len,
					const __u8 *raw_addrs, int addrs_len);
static int sctp_process_param(struct sctp_association *asoc,
			      union sctp_params param,
			      const union sctp_addr *peer_addr,
82
			      gfp_t gfp);
83 84
static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
			      const void *data);
Linus Torvalds's avatar
Linus Torvalds committed
85 86 87 88 89 90 91

/* What was the inbound interface for this chunk? */
int sctp_chunk_iif(const struct sctp_chunk *chunk)
{
	struct sctp_af *af;
	int iif = 0;

92
	af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
Linus Torvalds's avatar
Linus Torvalds committed
93 94 95 96 97 98 99 100 101 102 103 104 105
	if (af)
		iif = af->skb_iif(chunk->skb);

	return iif;
}

/* RFC 2960 3.3.2 Initiation (INIT) (1)
 *
 * Note 2: The ECN capable field is reserved for future use of
 * Explicit Congestion Notification.
 */
static const struct sctp_paramhdr ecap_param = {
	SCTP_PARAM_ECN_CAPABLE,
106
	cpu_to_be16(sizeof(struct sctp_paramhdr)),
Linus Torvalds's avatar
Linus Torvalds committed
107 108 109
};
static const struct sctp_paramhdr prsctp_param = {
	SCTP_PARAM_FWD_TSN_SUPPORT,
110
	cpu_to_be16(sizeof(struct sctp_paramhdr)),
Linus Torvalds's avatar
Linus Torvalds committed
111 112
};

113
/* A helper to initialize an op error inside a
Linus Torvalds's avatar
Linus Torvalds committed
114 115 116
 * provided chunk, as most cause codes will be embedded inside an
 * abort chunk.
 */
117
void  sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
118
		      size_t paylen)
Linus Torvalds's avatar
Linus Torvalds committed
119 120 121 122
{
	sctp_errhdr_t err;
	__u16 len;

123
	/* Cause code constants are now defined in network order.  */
Linus Torvalds's avatar
Linus Torvalds committed
124 125 126
	err.cause = cause_code;
	len = sizeof(sctp_errhdr_t) + paylen;
	err.length  = htons(len);
127
	chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
Linus Torvalds's avatar
Linus Torvalds committed
128 129
}

130 131 132 133 134
/* A helper to initialize an op error inside a
 * provided chunk, as most cause codes will be embedded inside an
 * abort chunk.  Differs from sctp_init_cause in that it won't oops
 * if there isn't enough space in the op error chunk
 */
135
static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
136 137 138 139 140 141 142 143 144 145
		      size_t paylen)
{
	sctp_errhdr_t err;
	__u16 len;

	/* Cause code constants are now defined in network order.  */
	err.cause = cause_code;
	len = sizeof(sctp_errhdr_t) + paylen;
	err.length  = htons(len);

146
	if (skb_tailroom(chunk->skb) < len)
147 148 149 150 151 152
		return -ENOSPC;
	chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
						     sizeof(sctp_errhdr_t),
						     &err);
	return 0;
}
Linus Torvalds's avatar
Linus Torvalds committed
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
/* 3.3.2 Initiation (INIT) (1)
 *
 * This chunk is used to initiate a SCTP association between two
 * endpoints. The format of the INIT chunk is shown below:
 *
 *     0                   1                   2                   3
 *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |   Type = 1    |  Chunk Flags  |      Chunk Length             |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |                         Initiate Tag                          |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |           Advertised Receiver Window Credit (a_rwnd)          |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |  Number of Outbound Streams   |  Number of Inbound Streams    |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |                          Initial TSN                          |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    \                                                               \
 *    /              Optional/Variable-Length Parameters              /
 *    \                                                               \
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *
 * The INIT chunk contains the following parameters. Unless otherwise
 * noted, each parameter MUST only be included once in the INIT chunk.
 *
 * Fixed Parameters                     Status
 * ----------------------------------------------
 * Initiate Tag                        Mandatory
 * Advertised Receiver Window Credit   Mandatory
 * Number of Outbound Streams          Mandatory
 * Number of Inbound Streams           Mandatory
 * Initial TSN                         Mandatory
 *
 * Variable Parameters                  Status     Type Value
 * -------------------------------------------------------------
 * IPv4 Address (Note 1)               Optional    5
 * IPv6 Address (Note 1)               Optional    6
 * Cookie Preservative                 Optional    9
 * Reserved for ECN Capable (Note 2)   Optional    32768 (0x8000)
 * Host Name Address (Note 3)          Optional    11
 * Supported Address Types (Note 4)    Optional    12
 */
struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
			     const struct sctp_bind_addr *bp,
199
			     gfp_t gfp, int vparam_len)
Linus Torvalds's avatar
Linus Torvalds committed
200
{
201
	struct net *net = sock_net(asoc->base.sk);
Linus Torvalds's avatar
Linus Torvalds committed
202 203 204 205 206 207 208
	sctp_inithdr_t init;
	union sctp_params addrs;
	size_t chunksize;
	struct sctp_chunk *retval = NULL;
	int num_types, addrs_len = 0;
	struct sctp_sock *sp;
	sctp_supported_addrs_param_t sat;
209
	__be16 types[2];
210
	sctp_adaptation_ind_param_t aiparam;
211 212 213
	sctp_supported_ext_param_t ext_param;
	int num_ext = 0;
	__u8 extensions[3];
214 215
	sctp_paramhdr_t *auth_chunks = NULL,
			*auth_hmacs = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236

	/* RFC 2960 3.3.2 Initiation (INIT) (1)
	 *
	 * Note 1: The INIT chunks can contain multiple addresses that
	 * can be IPv4 and/or IPv6 in any combination.
	 */
	retval = NULL;

	/* Convert the provided bind address list to raw format. */
	addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);

	init.init_tag		   = htonl(asoc->c.my_vtag);
	init.a_rwnd		   = htonl(asoc->rwnd);
	init.num_outbound_streams  = htons(asoc->c.sinit_num_ostreams);
	init.num_inbound_streams   = htons(asoc->c.sinit_max_instreams);
	init.initial_tsn	   = htonl(asoc->c.initial_tsn);

	/* How many address types are needed? */
	sp = sctp_sk(asoc->base.sk);
	num_types = sp->pf->supported_addrs(sp, types);

237 238
	chunksize = sizeof(init) + addrs_len;
	chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
Linus Torvalds's avatar
Linus Torvalds committed
239
	chunksize += sizeof(ecap_param);
240

241
	if (net->sctp.prsctp_enable)
242 243
		chunksize += sizeof(prsctp_param);

244 245 246 247 248
	/* ADDIP: Section 4.2.7:
	 *  An implementation supporting this extension [ADDIP] MUST list
	 *  the ASCONF,the ASCONF-ACK, and the AUTH  chunks in its INIT and
	 *  INIT-ACK parameters.
	 */
249
	if (net->sctp.addip_enable) {
250 251 252 253 254
		extensions[num_ext] = SCTP_CID_ASCONF;
		extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
		num_ext += 2;
	}

255 256 257
	if (sp->adaptation_ind)
		chunksize += sizeof(aiparam);

Linus Torvalds's avatar
Linus Torvalds committed
258 259
	chunksize += vparam_len;

260
	/* Account for AUTH related parameters */
261
	if (net->sctp.auth_enable) {
262 263 264 265 266 267
		/* Add random parameter length*/
		chunksize += sizeof(asoc->c.auth_random);

		/* Add HMACS parameter length if any were defined */
		auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
		if (auth_hmacs->length)
268
			chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
269 270 271 272 273 274
		else
			auth_hmacs = NULL;

		/* Add CHUNKS parameter length */
		auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
		if (auth_chunks->length)
275
			chunksize += WORD_ROUND(ntohs(auth_chunks->length));
276
		else
277
			auth_chunks = NULL;
278 279 280 281 282

		extensions[num_ext] = SCTP_CID_AUTH;
		num_ext += 1;
	}

283 284
	/* If we have any extensions to report, account for that */
	if (num_ext)
285 286
		chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
					num_ext);
287

Linus Torvalds's avatar
Linus Torvalds committed
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
	/* RFC 2960 3.3.2 Initiation (INIT) (1)
	 *
	 * Note 3: An INIT chunk MUST NOT contain more than one Host
	 * Name address parameter. Moreover, the sender of the INIT
	 * MUST NOT combine any other address types with the Host Name
	 * address in the INIT. The receiver of INIT MUST ignore any
	 * other address types if the Host Name address parameter is
	 * present in the received INIT chunk.
	 *
	 * PLEASE DO NOT FIXME [This version does not support Host Name.]
	 */

	retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize);
	if (!retval)
		goto nodata;

	retval->subh.init_hdr =
		sctp_addto_chunk(retval, sizeof(init), &init);
	retval->param_hdr.v =
		sctp_addto_chunk(retval, addrs_len, addrs.v);

	/* RFC 2960 3.3.2 Initiation (INIT) (1)
	 *
	 * Note 4: This parameter, when present, specifies all the
	 * address types the sending endpoint can support. The absence
	 * of this parameter indicates that the sending endpoint can
	 * support any address type.
	 */
	sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
	sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
	sctp_addto_chunk(retval, sizeof(sat), &sat);
	sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);

	sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
322

Joe Perches's avatar
Joe Perches committed
323
	/* Add the supported extensions parameter.  Be nice and add this
324 325 326 327 328 329 330 331
	 * fist before addiding the parameters for the extensions themselves
	 */
	if (num_ext) {
		ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
		ext_param.param_hdr.length =
			    htons(sizeof(sctp_supported_ext_param_t) + num_ext);
		sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
				&ext_param);
332
		sctp_addto_param(retval, num_ext, extensions);
333 334
	}

335
	if (net->sctp.prsctp_enable)
Linus Torvalds's avatar
Linus Torvalds committed
336
		sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
337

338 339 340 341 342 343
	if (sp->adaptation_ind) {
		aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
		aiparam.param_hdr.length = htons(sizeof(aiparam));
		aiparam.adaptation_ind = htonl(sp->adaptation_ind);
		sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
	}
344

345
	/* Add SCTP-AUTH chunks to the parameter list */
346
	if (net->sctp.auth_enable) {
347 348 349 350 351 352 353 354 355
		sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
				 asoc->c.auth_random);
		if (auth_hmacs)
			sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
					auth_hmacs);
		if (auth_chunks)
			sctp_addto_chunk(retval, ntohs(auth_chunks->length),
					auth_chunks);
	}
Linus Torvalds's avatar
Linus Torvalds committed
356
nodata:
Jesper Juhl's avatar
Jesper Juhl committed
357
	kfree(addrs.v);
Linus Torvalds's avatar
Linus Torvalds committed
358 359 360 361 362
	return retval;
}

struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
				 const struct sctp_chunk *chunk,
363
				 gfp_t gfp, int unkparam_len)
Linus Torvalds's avatar
Linus Torvalds committed
364 365 366 367
{
	sctp_inithdr_t initack;
	struct sctp_chunk *retval;
	union sctp_params addrs;
368
	struct sctp_sock *sp;
Linus Torvalds's avatar
Linus Torvalds committed
369 370 371 372
	int addrs_len;
	sctp_cookie_param_t *cookie;
	int cookie_len;
	size_t chunksize;
373
	sctp_adaptation_ind_param_t aiparam;
374 375 376
	sctp_supported_ext_param_t ext_param;
	int num_ext = 0;
	__u8 extensions[3];
377 378 379
	sctp_paramhdr_t *auth_chunks = NULL,
			*auth_hmacs = NULL,
			*auth_random = NULL;
Linus Torvalds's avatar
Linus Torvalds committed
380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402

	retval = NULL;

	/* Note: there may be no addresses to embed. */
	addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);

	initack.init_tag	        = htonl(asoc->c.my_vtag);
	initack.a_rwnd			= htonl(asoc->rwnd);
	initack.num_outbound_streams	= htons(asoc->c.sinit_num_ostreams);
	initack.num_inbound_streams	= htons(asoc->c.sinit_max_instreams);
	initack.initial_tsn		= htonl(asoc->c.initial_tsn);

	/* FIXME:  We really ought to build the cookie right
	 * into the packet instead of allocating more fresh memory.
	 */
	cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
				  addrs.v, addrs_len);
	if (!cookie)
		goto nomem_cookie;

	/* Calculate the total size of allocation, include the reserved
	 * space for reporting unknown parameters if it is specified.
	 */
403
	sp = sctp_sk(asoc->base.sk);
Linus Torvalds's avatar
Linus Torvalds committed
404 405
	chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;

406
	/* Tell peer that we'll do ECN only if peer advertised such cap.  */
Linus Torvalds's avatar
Linus Torvalds committed
407 408 409
	if (asoc->peer.ecn_capable)
		chunksize += sizeof(ecap_param);

410
	if (asoc->peer.prsctp_capable)
411 412
		chunksize += sizeof(prsctp_param);

413
	if (asoc->peer.asconf_capable) {
414 415 416 417 418
		extensions[num_ext] = SCTP_CID_ASCONF;
		extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
		num_ext += 2;
	}

419 420
	if (sp->adaptation_ind)
		chunksize += sizeof(aiparam);
Linus Torvalds's avatar
Linus Torvalds committed
421

422 423 424 425 426 427
	if (asoc->peer.auth_capable) {
		auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
		chunksize += ntohs(auth_random->length);

		auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
		if (auth_hmacs->length)
428
			chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
429 430 431 432 433
		else
			auth_hmacs = NULL;

		auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
		if (auth_chunks->length)
434
			chunksize += WORD_ROUND(ntohs(auth_chunks->length));
435 436 437 438 439 440 441
		else
			auth_chunks = NULL;

		extensions[num_ext] = SCTP_CID_AUTH;
		num_ext += 1;
	}

442
	if (num_ext)
443 444
		chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
					num_ext);
445

Linus Torvalds's avatar
Linus Torvalds committed
446 447 448 449 450
	/* Now allocate and fill out the chunk.  */
	retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
	if (!retval)
		goto nomem_chunk;

451 452 453 454 455 456 457 458
	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [INIT ACK back to where the INIT came from.]
Linus Torvalds's avatar
Linus Torvalds committed
459 460
	 */
	retval->transport = chunk->transport;
461

Linus Torvalds's avatar
Linus Torvalds committed
462 463 464 465 466 467
	retval->subh.init_hdr =
		sctp_addto_chunk(retval, sizeof(initack), &initack);
	retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
	sctp_addto_chunk(retval, cookie_len, cookie);
	if (asoc->peer.ecn_capable)
		sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
468 469 470 471 472 473
	if (num_ext) {
		ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
		ext_param.param_hdr.length =
			    htons(sizeof(sctp_supported_ext_param_t) + num_ext);
		sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
				 &ext_param);
474
		sctp_addto_param(retval, num_ext, extensions);
475
	}
Linus Torvalds's avatar
Linus Torvalds committed
476 477 478
	if (asoc->peer.prsctp_capable)
		sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);

479 480 481 482 483 484
	if (sp->adaptation_ind) {
		aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
		aiparam.param_hdr.length = htons(sizeof(aiparam));
		aiparam.adaptation_ind = htonl(sp->adaptation_ind);
		sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
	}
Linus Torvalds's avatar
Linus Torvalds committed
485

486 487 488 489 490 491 492 493 494 495 496
	if (asoc->peer.auth_capable) {
		sctp_addto_chunk(retval, ntohs(auth_random->length),
				 auth_random);
		if (auth_hmacs)
			sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
					auth_hmacs);
		if (auth_chunks)
			sctp_addto_chunk(retval, ntohs(auth_chunks->length),
					auth_chunks);
	}

Linus Torvalds's avatar
Linus Torvalds committed
497 498 499 500 501 502
	/* We need to remove the const qualifier at this point.  */
	retval->asoc = (struct sctp_association *) asoc;

nomem_chunk:
	kfree(cookie);
nomem_cookie:
Jesper Juhl's avatar
Jesper Juhl committed
503
	kfree(addrs.v);
Linus Torvalds's avatar
Linus Torvalds committed
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
	return retval;
}

/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
 *
 * This chunk is used only during the initialization of an association.
 * It is sent by the initiator of an association to its peer to complete
 * the initialization process. This chunk MUST precede any DATA chunk
 * sent within the association, but MAY be bundled with one or more DATA
 * chunks in the same packet.
 *
 *      0                   1                   2                   3
 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |   Type = 10   |Chunk  Flags   |         Length                |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     /                     Cookie                                    /
 *     \                                                               \
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * Chunk Flags: 8 bit
 *
 *   Set to zero on transmit and ignored on receipt.
 *
 * Length: 16 bits (unsigned integer)
 *
 *   Set to the size of the chunk in bytes, including the 4 bytes of
 *   the chunk header and the size of the Cookie.
 *
 * Cookie: variable size
 *
 *   This field must contain the exact cookie received in the
 *   State Cookie parameter from the previous INIT ACK.
 *
 *   An implementation SHOULD make the cookie as small as possible
 *   to insure interoperability.
 */
struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
				    const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;
	void *cookie;
	int cookie_len;

	cookie = asoc->peer.cookie;
	cookie_len = asoc->peer.cookie_len;

	/* Build a cookie echo chunk.  */
	retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
	if (!retval)
		goto nodata;
	retval->subh.cookie_hdr =
		sctp_addto_chunk(retval, cookie_len, cookie);

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [COOKIE ECHO back to where the INIT ACK came from.]
	 */
	if (chunk)
		retval->transport = chunk->transport;

nodata:
	return retval;
}

/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
 *
 * This chunk is used only during the initialization of an
 * association.  It is used to acknowledge the receipt of a COOKIE
 * ECHO chunk.  This chunk MUST precede any DATA or SACK chunk sent
 * within the association, but MAY be bundled with one or more DATA
 * chunks or SACK chunk in the same SCTP packet.
 *
 *      0                   1                   2                   3
 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |   Type = 11   |Chunk  Flags   |     Length = 4                |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * Chunk Flags: 8 bits
 *
 *   Set to zero on transmit and ignored on receipt.
 */
struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
				   const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;

	retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0);

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [COOKIE ACK back to where the COOKIE ECHO came from.]
	 */
	if (retval && chunk)
		retval->transport = chunk->transport;

	return retval;
}

/*
 *  Appendix A: Explicit Congestion Notification:
 *  CWR:
 *
 *  RFC 2481 details a specific bit for a sender to send in the header of
 *  its next outbound TCP segment to indicate to its peer that it has
 *  reduced its congestion window.  This is termed the CWR bit.  For
 *  SCTP the same indication is made by including the CWR chunk.
 *  This chunk contains one data element, i.e. the TSN number that
 *  was sent in the ECNE chunk.  This element represents the lowest
 *  TSN number in the datagram that was originally marked with the
 *  CE bit.
 *
 *     0                   1                   2                   3
 *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    | Chunk Type=13 | Flags=00000000|    Chunk Length = 8           |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |                      Lowest TSN Number                        |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *     Note: The CWR is considered a Control chunk.
 */
struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
			    const __u32 lowest_tsn,
			    const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;
	sctp_cwrhdr_t cwr;

	cwr.lowest_tsn = htonl(lowest_tsn);
	retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0,
				 sizeof(sctp_cwrhdr_t));

	if (!retval)
		goto nodata;

	retval->subh.ecn_cwr_hdr =
		sctp_addto_chunk(retval, sizeof(cwr), &cwr);

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [Report a reduced congestion window back to where the ECNE
	 * came from.]
	 */
	if (chunk)
		retval->transport = chunk->transport;

nodata:
	return retval;
}

/* Make an ECNE chunk.  This is a congestion experienced report.  */
struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
			     const __u32 lowest_tsn)
{
	struct sctp_chunk *retval;
	sctp_ecnehdr_t ecne;

	ecne.lowest_tsn = htonl(lowest_tsn);
	retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0,
				 sizeof(sctp_ecnehdr_t));
	if (!retval)
		goto nodata;
	retval->subh.ecne_hdr =
		sctp_addto_chunk(retval, sizeof(ecne), &ecne);

nodata:
	return retval;
}

/* Make a DATA chunk for the given association from the provided
 * parameters.  However, do not populate the data payload.
 */
struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
				       const struct sctp_sndrcvinfo *sinfo,
				       int data_len, __u8 flags, __u16 ssn)
{
	struct sctp_chunk *retval;
	struct sctp_datahdr dp;
	int chunk_len;

	/* We assign the TSN as LATE as possible, not here when
	 * creating the chunk.
	 */
	dp.tsn = 0;
	dp.stream = htons(sinfo->sinfo_stream);
	dp.ppid   = sinfo->sinfo_ppid;

	/* Set the flags for an unordered send.  */
709
	if (sinfo->sinfo_flags & SCTP_UNORDERED) {
Linus Torvalds's avatar
Linus Torvalds committed
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
		flags |= SCTP_DATA_UNORDERED;
		dp.ssn = 0;
	} else
		dp.ssn = htons(ssn);

	chunk_len = sizeof(dp) + data_len;
	retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len);
	if (!retval)
		goto nodata;

	retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
	memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));

nodata:
	return retval;
}

/* Create a selective ackowledgement (SACK) for the given
 * association.  This reports on which TSN's we've seen to date,
 * including duplicates and gaps.
 */
struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
{
	struct sctp_chunk *retval;
	struct sctp_sackhdr sack;
	int len;
	__u32 ctsn;
	__u16 num_gabs, num_dup_tsns;
738
	struct sctp_association *aptr = (struct sctp_association *)asoc;
Linus Torvalds's avatar
Linus Torvalds committed
739
	struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
740
	struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
741
	struct sctp_transport *trans;
Linus Torvalds's avatar
Linus Torvalds committed
742

743
	memset(gabs, 0, sizeof(gabs));
Linus Torvalds's avatar
Linus Torvalds committed
744 745 746 747
	ctsn = sctp_tsnmap_get_ctsn(map);
	SCTP_DEBUG_PRINTK("sackCTSNAck sent:  0x%x.\n", ctsn);

	/* How much room is needed in the chunk? */
748
	num_gabs = sctp_tsnmap_num_gabs(map, gabs);
Linus Torvalds's avatar
Linus Torvalds committed
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
	num_dup_tsns = sctp_tsnmap_num_dups(map);

	/* Initialize the SACK header.  */
	sack.cum_tsn_ack	    = htonl(ctsn);
	sack.a_rwnd 		    = htonl(asoc->a_rwnd);
	sack.num_gap_ack_blocks     = htons(num_gabs);
	sack.num_dup_tsns           = htons(num_dup_tsns);

	len = sizeof(sack)
		+ sizeof(struct sctp_gap_ack_block) * num_gabs
		+ sizeof(__u32) * num_dup_tsns;

	/* Create the chunk.  */
	retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len);
	if (!retval)
		goto nodata;

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, etc.) to the same destination transport
	 * address from which it received the DATA or control chunk to
	 * which it is replying.  This rule should also be followed if
	 * the endpoint is bundling DATA chunks together with the
	 * reply chunk.
	 *
	 * However, when acknowledging multiple DATA chunks received
	 * in packets from different source addresses in a single
	 * SACK, the SACK chunk may be transmitted to one of the
	 * destination transport addresses from which the DATA or
	 * control chunks being acknowledged were received.
	 *
	 * [BUG:  We do not implement the following paragraph.
	 * Perhaps we should remember the last transport we used for a
	 * SACK and avoid that (if possible) if we have seen any
	 * duplicates. --piggy]
	 *
	 * When a receiver of a duplicate DATA chunk sends a SACK to a
	 * multi- homed endpoint it MAY be beneficial to vary the
	 * destination address and not use the source address of the
	 * DATA chunk.  The reason being that receiving a duplicate
	 * from a multi-homed endpoint might indicate that the return
	 * path (as specified in the source address of the DATA chunk)
	 * for the SACK is broken.
	 *
	 * [Send to the address from which we last received a DATA chunk.]
	 */
	retval->transport = asoc->peer.last_data_from;

	retval->subh.sack_hdr =
		sctp_addto_chunk(retval, sizeof(sack), &sack);

	/* Add the gap ack block information.   */
	if (num_gabs)
		sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
804
				 gabs);
Linus Torvalds's avatar
Linus Torvalds committed
805 806

	/* Add the duplicate TSN information.  */
807 808
	if (num_dup_tsns) {
		aptr->stats.idupchunks += num_dup_tsns;
Linus Torvalds's avatar
Linus Torvalds committed
809 810
		sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
				 sctp_tsnmap_get_dups(map));
811
	}
812 813 814 815 816 817 818 819 820 821 822 823 824 825
	/* Once we have a sack generated, check to see what our sack
	 * generation is, if its 0, reset the transports to 0, and reset
	 * the association generation to 1
	 *
	 * The idea is that zero is never used as a valid generation for the
	 * association so no transport will match after a wrap event like this,
	 * Until the next sack
	 */
	if (++aptr->peer.sack_generation == 0) {
		list_for_each_entry(trans, &asoc->peer.transport_addr_list,
				    transports)
			trans->sack_generation = 0;
		aptr->peer.sack_generation = 1;
	}
Linus Torvalds's avatar
Linus Torvalds committed
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
nodata:
	return retval;
}

/* Make a SHUTDOWN chunk. */
struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
				      const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;
	sctp_shutdownhdr_t shut;
	__u32 ctsn;

	ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
	shut.cum_tsn_ack = htonl(ctsn);

	retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0,
				 sizeof(sctp_shutdownhdr_t));
	if (!retval)
		goto nodata;

	retval->subh.shutdown_hdr =
		sctp_addto_chunk(retval, sizeof(shut), &shut);

	if (chunk)
		retval->transport = chunk->transport;
nodata:
	return retval;
}

struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
				     const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;

	retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [ACK back to where the SHUTDOWN came from.]
	 */
	if (retval && chunk)
		retval->transport = chunk->transport;

	return retval;
}

struct sctp_chunk *sctp_make_shutdown_complete(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;
	__u8 flags = 0;

884 885 886
	/* Set the T-bit if we have no association (vtag will be
	 * reflected)
	 */
Linus Torvalds's avatar
Linus Torvalds committed
887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903
	flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;

	retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
	 * came from.]
	 */
	if (retval && chunk)
		retval->transport = chunk->transport;

904
	return retval;
Linus Torvalds's avatar
Linus Torvalds committed
905 906 907
}

/* Create an ABORT.  Note that we set the T bit if we have no
908
 * association, except when responding to an INIT (sctpimpguide 2.41).
Linus Torvalds's avatar
Linus Torvalds committed
909 910 911 912 913 914 915 916
 */
struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
			      const struct sctp_chunk *chunk,
			      const size_t hint)
{
	struct sctp_chunk *retval;
	__u8 flags = 0;

917 918 919 920 921 922 923 924 925 926
	/* Set the T-bit if we have no association and 'chunk' is not
	 * an INIT (vtag will be reflected).
	 */
	if (!asoc) {
		if (chunk && chunk->chunk_hdr &&
		    chunk->chunk_hdr->type == SCTP_CID_INIT)
			flags = 0;
		else
			flags = SCTP_CHUNK_FLAG_T;
	}
Linus Torvalds's avatar
Linus Torvalds committed
927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950

	retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [ABORT back to where the offender came from.]
	 */
	if (retval && chunk)
		retval->transport = chunk->transport;

	return retval;
}

/* Helper to create ABORT with a NO_USER_DATA error.  */
struct sctp_chunk *sctp_make_abort_no_data(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk, __u32 tsn)
{
	struct sctp_chunk *retval;
951
	__be32 payload;
Linus Torvalds's avatar
Linus Torvalds committed
952 953 954 955 956 957 958 959 960

	retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
				 + sizeof(tsn));

	if (!retval)
		goto no_mem;

	/* Put the tsn back into network byte order.  */
	payload = htonl(tsn);
961 962
	sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
	sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
Linus Torvalds's avatar
Linus Torvalds committed
963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [ABORT back to where the offender came from.]
	 */
	if (chunk)
		retval->transport = chunk->transport;

no_mem:
	return retval;
}

/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error.  */
struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
982 983
					const struct msghdr *msg,
					size_t paylen)
Linus Torvalds's avatar
Linus Torvalds committed
984 985
{
	struct sctp_chunk *retval;
986 987
	void *payload = NULL;
	int err;
Linus Torvalds's avatar
Linus Torvalds committed
988

989
	retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
Linus Torvalds's avatar
Linus Torvalds committed
990 991 992 993 994
	if (!retval)
		goto err_chunk;

	if (paylen) {
		/* Put the msg_iov together into payload.  */
995
		payload = kmalloc(paylen, GFP_KERNEL);
Linus Torvalds's avatar
Linus Torvalds committed
996 997
		if (!payload)
			goto err_payload;
998 999 1000 1001

		err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
		if (err < 0)
			goto err_copy;
Linus Torvalds's avatar
Linus Torvalds committed
1002 1003
	}

1004 1005
	sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
	sctp_addto_chunk(retval, paylen, payload);
Linus Torvalds's avatar
Linus Torvalds committed
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020

	if (paylen)
		kfree(payload);

	return retval;

err_copy:
	kfree(payload);
err_payload:
	sctp_chunk_free(retval);
	retval = NULL;
err_chunk:
	return retval;
}

1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
/* Append bytes to the end of a parameter.  Will panic if chunk is not big
 * enough.
 */
static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
			      const void *data)
{
	void *target;
	int chunklen = ntohs(chunk->chunk_hdr->length);

	target = skb_put(chunk->skb, len);

1032 1033 1034 1035
	if (data)
		memcpy(target, data, len);
	else
		memset(target, 0, len);
1036 1037 1038 1039 1040 1041 1042 1043

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length = htons(chunklen + len);
	chunk->chunk_end = skb_tail_pointer(chunk->skb);

	return target;
}

1044
/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
Linus Torvalds's avatar
Linus Torvalds committed
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
struct sctp_chunk *sctp_make_abort_violation(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk,
	const __u8   *payload,
	const size_t paylen)
{
	struct sctp_chunk  *retval;
	struct sctp_paramhdr phdr;

	retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1055
					+ sizeof(sctp_paramhdr_t));
Linus Torvalds's avatar
Linus Torvalds committed
1056 1057 1058
	if (!retval)
		goto end;

1059 1060
	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
					+ sizeof(sctp_paramhdr_t));
Linus Torvalds's avatar
Linus Torvalds committed
1061 1062 1063

	phdr.type = htons(chunk->chunk_hdr->type);
	phdr.length = chunk->chunk_hdr->length;
1064 1065
	sctp_addto_chunk(retval, paylen, payload);
	sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
Linus Torvalds's avatar
Linus Torvalds committed
1066 1067 1068 1069 1070

end:
	return retval;
}

1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093
struct sctp_chunk *sctp_make_violation_paramlen(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk,
	struct sctp_paramhdr *param)
{
	struct sctp_chunk *retval;
	static const char error[] = "The following parameter had invalid length:";
	size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
				sizeof(sctp_paramhdr_t);

	retval = sctp_make_abort(asoc, chunk, payload_len);
	if (!retval)
		goto nodata;

	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
			sizeof(error) + sizeof(sctp_paramhdr_t));
	sctp_addto_chunk(retval, sizeof(error), error);
	sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);

nodata:
	return retval;
}

1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
struct sctp_chunk *sctp_make_violation_max_retrans(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;
	static const char error[] = "Association exceeded its max_retans count";
	size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);

	retval = sctp_make_abort(asoc, chunk, payload_len);
	if (!retval)
		goto nodata;

	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
	sctp_addto_chunk(retval, sizeof(error), error);

nodata:
	return retval;
}

Linus Torvalds's avatar
Linus Torvalds committed
1113 1114
/* Make a HEARTBEAT chunk.  */
struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1115
				  const struct sctp_transport *transport)
Linus Torvalds's avatar
Linus Torvalds committed
1116
{
1117 1118 1119 1120
	struct sctp_chunk *retval;
	sctp_sender_hb_info_t hbinfo;

	retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
Linus Torvalds's avatar
Linus Torvalds committed
1121 1122 1123 1124

	if (!retval)
		goto nodata;

1125 1126 1127 1128 1129 1130
	hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
	hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
	hbinfo.daddr = transport->ipaddr;
	hbinfo.sent_at = jiffies;
	hbinfo.hb_nonce = transport->hb_nonce;

Linus Torvalds's avatar
Linus Torvalds committed
1131 1132 1133 1134
	/* Cast away the 'const', as this is just telling the chunk
	 * what transport it belongs to.
	 */
	retval->transport = (struct sctp_transport *) transport;
1135 1136
	retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
						&hbinfo);
Linus Torvalds's avatar
Linus Torvalds committed
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 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199

nodata:
	return retval;
}

struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
				      const struct sctp_chunk *chunk,
				      const void *payload, const size_t paylen)
{
	struct sctp_chunk *retval;

	retval  = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
	if (!retval)
		goto nodata;

	retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [HBACK back to where the HEARTBEAT came from.]
	 */
	if (chunk)
		retval->transport = chunk->transport;

nodata:
	return retval;
}

/* Create an Operation Error chunk with the specified space reserved.
 * This routine can be used for containing multiple causes in the chunk.
 */
static struct sctp_chunk *sctp_make_op_error_space(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk,
	size_t size)
{
	struct sctp_chunk *retval;

	retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0,
				 sizeof(sctp_errhdr_t) + size);
	if (!retval)
		goto nodata;

	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, etc.) to the same destination transport
	 * address from which it received the DATA or control chunk
	 * to which it is replying.
	 *
	 */
	if (chunk)
		retval->transport = chunk->transport;

nodata:
	return retval;
}

1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217
/* Create an Operation Error chunk of a fixed size,
 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
 * This is a helper function to allocate an error chunk for
 * for those invalid parameter codes in which we may not want
 * to report all the errors, if the incomming chunk is large
 */
static inline struct sctp_chunk *sctp_make_op_error_fixed(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk)
{
	size_t size = asoc ? asoc->pathmtu : 0;

	if (!size)
		size = SCTP_DEFAULT_MAXSEGMENT;

	return sctp_make_op_error_space(asoc, chunk, size);
}

Linus Torvalds's avatar
Linus Torvalds committed
1218 1219 1220
/* Create an Operation Error chunk.  */
struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
				 const struct sctp_chunk *chunk,
1221
				 __be16 cause_code, const void *payload,
1222
				 size_t paylen, size_t reserve_tail)
Linus Torvalds's avatar
Linus Torvalds committed
1223 1224 1225
{
	struct sctp_chunk *retval;

1226
	retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
Linus Torvalds's avatar
Linus Torvalds committed
1227 1228 1229
	if (!retval)
		goto nodata;

1230
	sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1231
	sctp_addto_chunk(retval, paylen, payload);
1232 1233
	if (reserve_tail)
		sctp_addto_param(retval, reserve_tail, NULL);
Linus Torvalds's avatar
Linus Torvalds committed
1234 1235 1236 1237 1238

nodata:
	return retval;
}

1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273
struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
{
	struct sctp_chunk *retval;
	struct sctp_hmac *hmac_desc;
	struct sctp_authhdr auth_hdr;
	__u8 *hmac;

	/* Get the first hmac that the peer told us to use */
	hmac_desc = sctp_auth_asoc_get_hmac(asoc);
	if (unlikely(!hmac_desc))
		return NULL;

	retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0,
			hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
	if (!retval)
		return NULL;

	auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
	auth_hdr.shkey_id = htons(asoc->active_key_id);

	retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
						&auth_hdr);

	hmac = skb_put(retval->skb, hmac_desc->hmac_len);
	memset(hmac, 0, hmac_desc->hmac_len);

	/* Adjust the chunk header to include the empty MAC */
	retval->chunk_hdr->length =
		htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
	retval->chunk_end = skb_tail_pointer(retval->skb);

	return retval;
}


Linus Torvalds's avatar
Linus Torvalds committed
1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286
/********************************************************************
 * 2nd Level Abstractions
 ********************************************************************/

/* Turn an skb into a chunk.
 * FIXME: Eventually move the structure directly inside the skb->cb[].
 */
struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
			    const struct sctp_association *asoc,
			    struct sock *sk)
{
	struct sctp_chunk *retval;

1287
	retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
Linus Torvalds's avatar
Linus Torvalds committed
1288 1289 1290 1291 1292 1293 1294 1295

	if (!retval)
		goto nodata;

	if (!sk) {
		SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
	}

1296
	INIT_LIST_HEAD(&retval->list);
Linus Torvalds's avatar
Linus Torvalds committed
1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315
	retval->skb		= skb;
	retval->asoc		= (struct sctp_association *)asoc;
	retval->has_tsn		= 0;
	retval->has_ssn         = 0;
	retval->rtt_in_progress	= 0;
	retval->sent_at		= 0;
	retval->singleton	= 1;
	retval->end_of_packet	= 0;
	retval->ecn_ce_done	= 0;
	retval->pdiscard	= 0;

	/* sctpimpguide-05.txt Section 2.8.2
	 * M1) Each time a new DATA chunk is transmitted
	 * set the 'TSN.Missing.Report' count for that TSN to 0. The
	 * 'TSN.Missing.Report' count will be used to determine missing chunks
	 * and when to fast retransmit.
	 */
	retval->tsn_missing_report = 0;
	retval->tsn_gap_acked = 0;
1316
	retval->fast_retransmit = SCTP_CAN_FRTX;
Linus Torvalds's avatar
Linus Torvalds committed
1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336

	/* If this is a fragmented message, track all fragments
	 * of the message (for SEND_FAILED).
	 */
	retval->msg = NULL;

	/* Polish the bead hole.  */
	INIT_LIST_HEAD(&retval->transmitted_list);
	INIT_LIST_HEAD(&retval->frag_list);
	SCTP_DBG_OBJCNT_INC(chunk);
	atomic_set(&retval->refcnt, 1);

nodata:
	return retval;
}

/* Set chunk->source and dest based on the IP header in chunk->skb.  */
void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
		     union sctp_addr *dest)
{
1337
	memcpy(&chunk->source, src, sizeof(union sctp_addr));
1338
	memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
Linus Torvalds's avatar
Linus Torvalds committed
1339 1340 1341 1342 1343 1344 1345
}

/* Extract the source address from a chunk.  */
const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
{
	/* If we have a known transport, use that.  */
	if (chunk->transport) {
1346
		return &chunk->transport->ipaddr;
Linus Torvalds's avatar
Linus Torvalds committed
1347 1348
	} else {
		/* Otherwise, extract it from the IP header.  */
1349
		return &chunk->source;
Linus Torvalds's avatar
Linus Torvalds committed
1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386
	}
}

/* Create a new chunk, setting the type and flags headers from the
 * arguments, reserving enough space for a 'paylen' byte payload.
 */
SCTP_STATIC
struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
				   __u8 type, __u8 flags, int paylen)
{
	struct sctp_chunk *retval;
	sctp_chunkhdr_t *chunk_hdr;
	struct sk_buff *skb;
	struct sock *sk;

	/* No need to allocate LL here, as this is only a chunk. */
	skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
			GFP_ATOMIC);
	if (!skb)
		goto nodata;

	/* Make room for the chunk header.  */
	chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
	chunk_hdr->type	  = type;
	chunk_hdr->flags  = flags;
	chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));

	sk = asoc ? asoc->base.sk : NULL;
	retval = sctp_chunkify(skb, asoc, sk);
	if (!retval) {
		kfree_skb(skb);
		goto nodata;
	}

	retval->chunk_hdr = chunk_hdr;
	retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);

1387 1388 1389 1390
	/* Determine if the chunk needs to be authenticated */
	if (sctp_auth_send_cid(type, asoc))
		retval->auth = 1;

Linus Torvalds's avatar
Linus Torvalds committed
1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402
	/* Set the skb to the belonging sock for accounting.  */
	skb->sk = sk;

	return retval;
nodata:
	return NULL;
}


/* Release the memory occupied by a chunk.  */
static void sctp_chunk_destroy(struct sctp_chunk *chunk)
{
1403 1404 1405
	BUG_ON(!list_empty(&chunk->list));
	list_del_init(&chunk->transmitted_list);

Linus Torvalds's avatar
Linus Torvalds committed
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443
	/* Free the chunk skb data and the SCTP_chunk stub itself. */
	dev_kfree_skb(chunk->skb);

	SCTP_DBG_OBJCNT_DEC(chunk);
	kmem_cache_free(sctp_chunk_cachep, chunk);
}

/* Possibly, free the chunk.  */
void sctp_chunk_free(struct sctp_chunk *chunk)
{
	/* Release our reference on the message tracker. */
	if (chunk->msg)
		sctp_datamsg_put(chunk->msg);

	sctp_chunk_put(chunk);
}

/* Grab a reference to the chunk. */
void sctp_chunk_hold(struct sctp_chunk *ch)
{
	atomic_inc(&ch->refcnt);
}

/* Release a reference to the chunk. */
void sctp_chunk_put(struct sctp_chunk *ch)
{
	if (atomic_dec_and_test(&ch->refcnt))
		sctp_chunk_destroy(ch);
}

/* Append bytes to the end of a chunk.  Will panic if chunk is not big
 * enough.
 */
void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
{
	void *target;
	void *padding;
	int chunklen = ntohs(chunk->chunk_hdr->length);
1444
	int padlen = WORD_ROUND(chunklen) - chunklen;
Linus Torvalds's avatar
Linus Torvalds committed
1445 1446 1447 1448 1449 1450 1451 1452 1453

	padding = skb_put(chunk->skb, padlen);
	target = skb_put(chunk->skb, len);

	memset(padding, 0, padlen);
	memcpy(target, data, len);

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1454
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
Linus Torvalds's avatar
Linus Torvalds committed
1455 1456 1457 1458

	return target;
}

1459 1460 1461 1462 1463 1464
/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
 * space in the chunk
 */
void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
			     int len, const void *data)
{
1465
	if (skb_tailroom(chunk->skb) >= len)
1466 1467 1468 1469 1470
		return sctp_addto_chunk(chunk, len, data);
	else
		return NULL;
}

Linus Torvalds's avatar
Linus Torvalds committed
1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490
/* Append bytes from user space to the end of a chunk.  Will panic if
 * chunk is not big enough.
 * Returns a kernel err value.
 */
int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
			  struct iovec *data)
{
	__u8 *target;
	int err = 0;

	/* Make room in chunk for data.  */
	target = skb_put(chunk->skb, len);

	/* Copy data (whole iovec) into chunk */
	if ((err = memcpy_fromiovecend(target, data, off, len)))
		goto out;

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length =
		htons(ntohs(chunk->chunk_hdr->length) + len);
1491
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
Linus Torvalds's avatar
Linus Torvalds committed
1492 1493 1494 1495 1496 1497 1498 1499 1500 1501

out:
	return err;
}

/* Helper function to assign a TSN if needed.  This assumes that both
 * the data_hdr and association have already been assigned.
 */
void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
{
1502 1503 1504
	struct sctp_datamsg *msg;
	struct sctp_chunk *lchunk;
	struct sctp_stream *stream;
Linus Torvalds's avatar
Linus Torvalds committed
1505 1506 1507 1508 1509 1510
	__u16 ssn;
	__u16 sid;

	if (chunk->has_ssn)
		return;

1511 1512 1513
	/* All fragments will be on the same stream */
	sid = ntohs(chunk->subh.data_hdr->stream);
	stream = &chunk->asoc->ssnmap->out;
Linus Torvalds's avatar
Linus Torvalds committed
1514

1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531
	/* Now assign the sequence number to the entire message.
	 * All fragments must have the same stream sequence number.
	 */
	msg = chunk->msg;
	list_for_each_entry(lchunk, &msg->chunks, frag_list) {
		if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
			ssn = 0;
		} else {
			if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
				ssn = sctp_ssn_next(stream, sid);
			else
				ssn = sctp_ssn_peek(stream, sid);
		}

		lchunk->subh.data_hdr->ssn = htons(ssn);
		lchunk->has_ssn = 1;
	}
Linus Torvalds's avatar
Linus Torvalds committed
1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550
}

/* Helper function to assign a TSN if needed.  This assumes that both
 * the data_hdr and association have already been assigned.
 */
void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
{
	if (!chunk->has_tsn) {
		/* This is the last possible instant to
		 * assign a TSN.
		 */
		chunk->subh.data_hdr->tsn =
			htonl(sctp_association_get_next_tsn(chunk->asoc));
		chunk->has_tsn = 1;
	}
}

/* Create a CLOSED association to use with an incoming packet.  */
struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1551
					struct sctp_chunk *chunk,
1552
					gfp_t gfp)
Linus Torvalds's avatar
Linus Torvalds committed
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566
{
	struct sctp_association *asoc;
	struct sk_buff *skb;
	sctp_scope_t scope;
	struct sctp_af *af;

	/* Create the bare association.  */
	scope = sctp_scope(sctp_source(chunk));
	asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
	if (!asoc)
		goto nodata;
	asoc->temp = 1;
	skb = chunk->skb;
	/* Create an entry for the source address of the packet.  */
1567
	af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
Linus Torvalds's avatar
Linus Torvalds committed
1568 1569
	if (unlikely(!af))
		goto fail;
1570
	af->from_skb(&asoc->c.peer_addr, skb, 1);
Linus Torvalds's avatar
Linus Torvalds committed
1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594
nodata:
	return asoc;

fail:
	sctp_association_free(asoc);
	return NULL;
}

/* Build a cookie representing asoc.
 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
 */
static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
				      const struct sctp_association *asoc,
				      const struct sctp_chunk *init_chunk,
				      int *cookie_len,
				      const __u8 *raw_addrs, int addrs_len)
{
	sctp_cookie_param_t *retval;
	struct sctp_signed_cookie *cookie;
	struct scatterlist sg;
	int headersize, bodysize;
	unsigned int keylen;
	char *key;

1595 1596 1597
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
1598 1599
	headersize = sizeof(sctp_paramhdr_t) +
		     (sizeof(struct sctp_signed_cookie) -
1600
		      sizeof(struct sctp_cookie));
Linus Torvalds's avatar
Linus Torvalds committed
1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614
	bodysize = sizeof(struct sctp_cookie)
		+ ntohs(init_chunk->chunk_hdr->length) + addrs_len;

	/* Pad out the cookie to a multiple to make the signature
	 * functions simpler to write.
	 */
	if (bodysize % SCTP_COOKIE_MULTIPLE)
		bodysize += SCTP_COOKIE_MULTIPLE
			- (bodysize % SCTP_COOKIE_MULTIPLE);
	*cookie_len = headersize + bodysize;

	/* Clear this memory since we are sending this data structure
	 * out on the network.
	 */
1615 1616 1617 1618
	retval = kzalloc(*cookie_len, GFP_ATOMIC);
	if (!retval)
		goto nodata;

Linus Torvalds's avatar
Linus Torvalds committed
1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632
	cookie = (struct sctp_signed_cookie *) retval->body;

	/* Set up the parameter header.  */
	retval->p.type = SCTP_PARAM_STATE_COOKIE;
	retval->p.length = htons(*cookie_len);

	/* Copy the cookie part of the association itself.  */
	cookie->c = asoc->c;
	/* Save the raw address list length in the cookie. */
	cookie->c.raw_addr_list_len = addrs_len;

	/* Remember PR-SCTP capability. */
	cookie->c.prsctp_capable = asoc->peer.prsctp_capable;

1633 1634
	/* Save adaptation indication in the cookie. */
	cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
Linus Torvalds's avatar
Linus Torvalds committed
1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647

	/* Set an expiration time for the cookie.  */
	do_gettimeofday(&cookie->c.expiration);
	TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);

	/* Copy the peer's init packet.  */
	memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
	       ntohs(init_chunk->chunk_hdr->length));

	/* Copy the raw local address list of the association. */
	memcpy((__u8 *)&cookie->c.peer_init[0] +
	       ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);

1648
	if (sctp_sk(ep->base.sk)->hmac) {
1649 1650
		struct hash_desc desc;

Linus Torvalds's avatar
Linus Torvalds committed
1651
		/* Sign the message.  */
1652
		sg_init_one(&sg, &cookie->c, bodysize);
Linus Torvalds's avatar
Linus Torvalds committed
1653 1654
		keylen = SCTP_SECRET_SIZE;
		key = (char *)ep->secret_key[ep->current_key];
1655 1656
		desc.tfm = sctp_sk(ep->base.sk)->hmac;
		desc.flags = 0;
Linus Torvalds's avatar
Linus Torvalds committed
1657

1658 1659 1660
		if (crypto_hash_setkey(desc.tfm, key, keylen) ||
		    crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
			goto free_cookie;
Linus Torvalds's avatar
Linus Torvalds committed
1661 1662 1663
	}

	return retval;
1664 1665 1666 1667 1668 1669

free_cookie:
	kfree(retval);
nodata:
	*cookie_len = 0;
	return NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1670 1671 1672 1673 1674 1675
}

/* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
struct sctp_association *sctp_unpack_cookie(
	const struct sctp_endpoint *ep,
	const struct sctp_association *asoc,
1676
	struct sctp_chunk *chunk, gfp_t gfp,
Linus Torvalds's avatar
Linus Torvalds committed
1677 1678 1679 1680 1681 1682
	int *error, struct sctp_chunk **errp)
{
	struct sctp_association *retval = NULL;
	struct sctp_signed_cookie *cookie;
	struct sctp_cookie *bear_cookie;
	int headersize, bodysize, fixed_size;
1683
	__u8 *digest = ep->digest;
Linus Torvalds's avatar
Linus Torvalds committed
1684 1685 1686 1687 1688
	struct scatterlist sg;
	unsigned int keylen, len;
	char *key;
	sctp_scope_t scope;
	struct sk_buff *skb = chunk->skb;
1689
	struct timeval tv;
1690
	struct hash_desc desc;
Linus Torvalds's avatar
Linus Torvalds committed
1691

1692 1693 1694 1695
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
	headersize = sizeof(sctp_chunkhdr_t) +
1696
		     (sizeof(struct sctp_signed_cookie) -
1697
		      sizeof(struct sctp_cookie));
Linus Torvalds's avatar
Linus Torvalds committed
1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721
	bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
	fixed_size = headersize + sizeof(struct sctp_cookie);

	/* Verify that the chunk looks like it even has a cookie.
	 * There must be enough room for our cookie and our peer's
	 * INIT chunk.
	 */
	len = ntohs(chunk->chunk_hdr->length);
	if (len < fixed_size + sizeof(struct sctp_chunkhdr))
		goto malformed;

	/* Verify that the cookie has been padded out. */
	if (bodysize % SCTP_COOKIE_MULTIPLE)
		goto malformed;

	/* Process the cookie.  */
	cookie = chunk->subh.cookie_hdr;
	bear_cookie = &cookie->c;

	if (!sctp_sk(ep->base.sk)->hmac)
		goto no_hmac;

	/* Check the signature.  */
	keylen = SCTP_SECRET_SIZE;
1722
	sg_init_one(&sg, bear_cookie, bodysize);
Linus Torvalds's avatar
Linus Torvalds committed
1723
	key = (char *)ep->secret_key[ep->current_key];
1724 1725
	desc.tfm = sctp_sk(ep->base.sk)->hmac;
	desc.flags = 0;
Linus Torvalds's avatar
Linus Torvalds committed
1726

Al Viro's avatar
Al Viro committed
1727
	memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1728 1729 1730 1731 1732
	if (crypto_hash_setkey(desc.tfm, key, keylen) ||
	    crypto_hash_digest(&desc, &sg, bodysize, digest)) {
		*error = -SCTP_IERROR_NOMEM;
		goto fail;
	}
Linus Torvalds's avatar
Linus Torvalds committed
1733 1734 1735 1736

	if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
		/* Try the previous key. */
		key = (char *)ep->secret_key[ep->last_key];
Al Viro's avatar
Al Viro committed
1737
		memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1738 1739 1740 1741 1742
		if (crypto_hash_setkey(desc.tfm, key, keylen) ||
		    crypto_hash_digest(&desc, &sg, bodysize, digest)) {
			*error = -SCTP_IERROR_NOMEM;
			goto fail;
		}
Linus Torvalds's avatar
Linus Torvalds committed
1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763

		if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
			/* Yikes!  Still bad signature! */
			*error = -SCTP_IERROR_BAD_SIG;
			goto fail;
		}
	}

no_hmac:
	/* IG Section 2.35.2:
	 *  3) Compare the port numbers and the verification tag contained
	 *     within the COOKIE ECHO chunk to the actual port numbers and the
	 *     verification tag within the SCTP common header of the received
	 *     packet. If these values do not match the packet MUST be silently
	 *     discarded,
	 */
	if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
		*error = -SCTP_IERROR_BAD_TAG;
		goto fail;
	}

1764
	if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
Linus Torvalds's avatar
Linus Torvalds committed
1765 1766 1767 1768 1769 1770 1771 1772
	    ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
		*error = -SCTP_IERROR_BAD_PORTS;
		goto fail;
	}

	/* Check to see if the cookie is stale.  If there is already
	 * an association, there is no need to check cookie's expiration
	 * for init collision case of lost COOKIE ACK.
1773 1774 1775 1776
	 * If skb has been timestamped, then use the stamp, otherwise
	 * use current time.  This introduces a small possibility that
	 * that a cookie may be considered expired, but his would only slow
	 * down the new association establishment instead of every packet.
Linus Torvalds's avatar
Linus Torvalds committed
1777
	 */
1778 1779 1780 1781 1782
	if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
		skb_get_timestamp(skb, &tv);
	else
		do_gettimeofday(&tv);

1783
	if (!asoc && tv_lt(bear_cookie->expiration, tv)) {
Linus Torvalds's avatar
Linus Torvalds committed
1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
		/*
		 * Section 3.3.10.3 Stale Cookie Error (3)
		 *
		 * Cause of error
		 * ---------------
		 * Stale Cookie Error:  Indicates the receipt of a valid State
		 * Cookie that has expired.
		 */
		len = ntohs(chunk->chunk_hdr->length);
		*errp = sctp_make_op_error_space(asoc, chunk, len);
		if (*errp) {
1795
			suseconds_t usecs = (tv.tv_sec -
Linus Torvalds's avatar
Linus Torvalds committed
1796
				bear_cookie->expiration.tv_sec) * 1000000L +
1797
				tv.tv_usec - bear_cookie->expiration.tv_usec;
1798
			__be32 n = htonl(usecs);
Linus Torvalds's avatar
Linus Torvalds committed
1799 1800

			sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1801 1802
					sizeof(n));
			sctp_addto_chunk(*errp, sizeof(n), &n);
Linus Torvalds's avatar
Linus Torvalds committed
1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831
			*error = -SCTP_IERROR_STALE_COOKIE;
		} else
			*error = -SCTP_IERROR_NOMEM;

		goto fail;
	}

	/* Make a new base association.  */
	scope = sctp_scope(sctp_source(chunk));
	retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
	if (!retval) {
		*error = -SCTP_IERROR_NOMEM;
		goto fail;
	}

	/* Set up our peer's port number.  */
	retval->peer.port = ntohs(chunk->sctp_hdr->source);

	/* Populate the association from the cookie.  */
	memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));

	if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
						 GFP_ATOMIC) < 0) {
		*error = -SCTP_IERROR_NOMEM;
		goto fail;
	}

	/* Also, add the destination address. */
	if (list_empty(&retval->base.bind_addr.address_list)) {
1832 1833
		sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
				SCTP_ADDR_SRC, GFP_ATOMIC);
Linus Torvalds's avatar
Linus Torvalds committed
1834 1835 1836 1837 1838 1839 1840
	}

	retval->next_tsn = retval->c.initial_tsn;
	retval->ctsn_ack_point = retval->next_tsn - 1;
	retval->addip_serial = retval->c.initial_tsn;
	retval->adv_peer_ack_point = retval->ctsn_ack_point;
	retval->peer.prsctp_capable = retval->c.prsctp_capable;
1841
	retval->peer.adaptation_ind = retval->c.adaptation_ind;
Linus Torvalds's avatar
Linus Torvalds committed
1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864

	/* The INIT stuff will be done by the side effects.  */
	return retval;

fail:
	if (retval)
		sctp_association_free(retval);

	return NULL;

malformed:
	/* Yikes!  The packet is either corrupt or deliberately
	 * malformed.
	 */
	*error = -SCTP_IERROR_MALFORMED;
	goto fail;
}

/********************************************************************
 * 3rd Level Abstractions
 ********************************************************************/

struct __sctp_missing {
1865 1866
	__be32 num_missing;
	__be16 type;
Eric Dumazet's avatar
Eric Dumazet committed
1867
}  __packed;
Linus Torvalds's avatar
Linus Torvalds committed
1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890

/*
 * Report a missing mandatory parameter.
 */
static int sctp_process_missing_param(const struct sctp_association *asoc,
				      sctp_param_t paramtype,
				      struct sctp_chunk *chunk,
				      struct sctp_chunk **errp)
{
	struct __sctp_missing report;
	__u16 len;

	len = WORD_ROUND(sizeof(report));

	/* Make an ERROR chunk, preparing enough room for
	 * returning multiple unknown parameters.
	 */
	if (!*errp)
		*errp = sctp_make_op_error_space(asoc, chunk, len);

	if (*errp) {
		report.num_missing = htonl(1);
		report.type = paramtype;
1891
		sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1892 1893
				sizeof(report));
		sctp_addto_chunk(*errp, sizeof(report), &report);
Linus Torvalds's avatar
Linus Torvalds committed
1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910
	}

	/* Stop processing this chunk. */
	return 0;
}

/* Report an Invalid Mandatory Parameter.  */
static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
				      struct sctp_chunk *chunk,
				      struct sctp_chunk **errp)
{
	/* Invalid Mandatory Parameter Error has no payload. */

	if (!*errp)
		*errp = sctp_make_op_error_space(asoc, chunk, 0);

	if (*errp)
1911
		sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
Linus Torvalds's avatar
Linus Torvalds committed
1912 1913 1914 1915 1916 1917 1918 1919 1920 1921

	/* Stop processing this chunk. */
	return 0;
}

static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
					struct sctp_paramhdr *param,
					const struct sctp_chunk *chunk,
					struct sctp_chunk **errp)
{
1922 1923 1924 1925 1926 1927
	/* This is a fatal error.  Any accumulated non-fatal errors are
	 * not reported.
	 */
	if (*errp)
		sctp_chunk_free(*errp);

Linus Torvalds's avatar
Linus Torvalds committed
1928
	/* Create an error chunk and fill it in with our payload. */
1929
	*errp = sctp_make_violation_paramlen(asoc, chunk, param);
Linus Torvalds's avatar
Linus Torvalds committed
1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944

	return 0;
}


/* Do not attempt to handle the HOST_NAME parm.  However, do
 * send back an indicator to the peer.
 */
static int sctp_process_hn_param(const struct sctp_association *asoc,
				 union sctp_params param,
				 struct sctp_chunk *chunk,
				 struct sctp_chunk **errp)
{
	__u16 len = ntohs(param.p->length);

<