sm_make_chunk.c 114.8 KB
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/* SCTP kernel implementation
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 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001-2002 Intel Corp.
 *
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 * This file is part of the SCTP kernel implementation
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 *
 * 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.
 *
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 * This SCTP implementation is free software;
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 * 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.
 *
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 * This SCTP implementation is distributed in the hope that it
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 * 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
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 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
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 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
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 *    lksctp developers <linux-sctp@vger.kernel.org>
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 *
 * 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>
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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#include <crypto/hash.h>
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#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/net.h>
#include <linux/inet.h>
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#include <linux/scatterlist.h>
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#include <linux/slab.h>
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#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>

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static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
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					    __u8 type, __u8 flags, int paylen,
					    gfp_t gfp);
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static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
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					 __u8 flags, int paylen, gfp_t gfp);
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static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
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					   __u8 type, __u8 flags, int paylen,
					   gfp_t gfp);
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static struct sctp_cookie_param *sctp_pack_cookie(
					const struct sctp_endpoint *ep,
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					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,
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			      gfp_t gfp);
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static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
			      const void *data);
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static void  *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
				     const void *data);
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/* Control chunk destructor */
static void sctp_control_release_owner(struct sk_buff *skb)
{
	/*TODO: do memory release */
}

static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
{
	struct sctp_association *asoc = chunk->asoc;
	struct sk_buff *skb = chunk->skb;

	/* TODO: properly account for control chunks.
	 * To do it right we'll need:
	 *  1) endpoint if association isn't known.
	 *  2) proper memory accounting.
	 *
	 *  For now don't do anything for now.
	 */
	skb->sk = asoc ? asoc->base.sk : NULL;
	skb->destructor = sctp_control_release_owner;
}

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/* What was the inbound interface for this chunk? */
int sctp_chunk_iif(const struct sctp_chunk *chunk)
{
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	struct sk_buff *skb = chunk->skb;
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	return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
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}

/* 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,
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	cpu_to_be16(sizeof(struct sctp_paramhdr)),
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};
static const struct sctp_paramhdr prsctp_param = {
	SCTP_PARAM_FWD_TSN_SUPPORT,
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	cpu_to_be16(sizeof(struct sctp_paramhdr)),
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};

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/* A helper to initialize an op error inside a
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 * provided chunk, as most cause codes will be embedded inside an
 * abort chunk.
 */
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void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
		     size_t paylen)
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{
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	struct sctp_errhdr err;
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	__u16 len;

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	/* Cause code constants are now defined in network order.  */
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	err.cause = cause_code;
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	len = sizeof(err) + paylen;
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	err.length  = htons(len);
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	chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
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}

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/* 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
 */
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static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
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				 size_t paylen)
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{
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	struct sctp_errhdr err;
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	__u16 len;

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

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	if (skb_tailroom(chunk->skb) < len)
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		return -ENOSPC;
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	chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err);

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	return 0;
}
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/* 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,
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				  const struct sctp_bind_addr *bp,
				  gfp_t gfp, int vparam_len)
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{
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	struct net *net = sock_net(asoc->base.sk);
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	struct sctp_supported_ext_param ext_param;
	struct sctp_adaptation_ind_param aiparam;
	struct sctp_paramhdr *auth_chunks = NULL;
	struct sctp_paramhdr *auth_hmacs = NULL;
	struct sctp_supported_addrs_param sat;
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	struct sctp_endpoint *ep = asoc->ep;
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	struct sctp_chunk *retval = NULL;
	int num_types, addrs_len = 0;
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	struct sctp_inithdr init;
	union sctp_params addrs;
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	struct sctp_sock *sp;
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	__u8 extensions[5];
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	size_t chunksize;
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	__be16 types[2];
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	int num_ext = 0;
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	/* 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.
	 */

	/* 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);

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	chunksize = sizeof(init) + addrs_len;
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	chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
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	chunksize += sizeof(ecap_param);
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	if (asoc->prsctp_enable)
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		chunksize += sizeof(prsctp_param);

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	/* 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.
	 */
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	if (net->sctp.addip_enable) {
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		extensions[num_ext] = SCTP_CID_ASCONF;
		extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
		num_ext += 2;
	}

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	if (asoc->reconf_enable) {
		extensions[num_ext] = SCTP_CID_RECONF;
		num_ext += 1;
	}

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

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	if (sp->strm_interleave) {
		extensions[num_ext] = SCTP_CID_I_DATA;
		num_ext += 1;
	}

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	chunksize += vparam_len;

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	/* Account for AUTH related parameters */
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	if (ep->auth_enable) {
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		/* Add random parameter length*/
		chunksize += sizeof(asoc->c.auth_random);

		/* Add HMACS parameter length if any were defined */
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		auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
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		if (auth_hmacs->length)
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			chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
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		else
			auth_hmacs = NULL;

		/* Add CHUNKS parameter length */
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		auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
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		if (auth_chunks->length)
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			chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
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		else
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			auth_chunks = NULL;
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		extensions[num_ext] = SCTP_CID_AUTH;
		num_ext += 1;
	}

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	/* If we have any extensions to report, account for that */
	if (num_ext)
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		chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
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	/* 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.]
	 */

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	retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
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	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);
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	/* Add the supported extensions parameter.  Be nice and add this
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	 * fist before addiding the parameters for the extensions themselves
	 */
	if (num_ext) {
		ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
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		ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
		sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
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		sctp_addto_param(retval, num_ext, extensions);
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	}

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	if (asoc->prsctp_enable)
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		sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
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	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);
	}
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	/* Add SCTP-AUTH chunks to the parameter list */
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	if (ep->auth_enable) {
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		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);
	}
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nodata:
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	kfree(addrs.v);
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	return retval;
}

struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
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				      const struct sctp_chunk *chunk,
				      gfp_t gfp, int unkparam_len)
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{
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	struct sctp_supported_ext_param ext_param;
	struct sctp_adaptation_ind_param aiparam;
	struct sctp_paramhdr *auth_chunks = NULL;
	struct sctp_paramhdr *auth_random = NULL;
	struct sctp_paramhdr *auth_hmacs = NULL;
	struct sctp_chunk *retval = NULL;
	struct sctp_cookie_param *cookie;
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	struct sctp_inithdr initack;
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	union sctp_params addrs;
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	struct sctp_sock *sp;
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	__u8 extensions[5];
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	size_t chunksize;
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	int num_ext = 0;
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	int cookie_len;
	int addrs_len;
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	/* 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.
	 */
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	sp = sctp_sk(asoc->base.sk);
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	chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;

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	/* Tell peer that we'll do ECN only if peer advertised such cap.  */
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	if (asoc->peer.ecn_capable)
		chunksize += sizeof(ecap_param);

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

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	if (asoc->peer.asconf_capable) {
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		extensions[num_ext] = SCTP_CID_ASCONF;
		extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
		num_ext += 2;
	}

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	if (asoc->peer.reconf_capable) {
		extensions[num_ext] = SCTP_CID_RECONF;
		num_ext += 1;
	}

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	if (sp->adaptation_ind)
		chunksize += sizeof(aiparam);
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	if (asoc->intl_enable) {
		extensions[num_ext] = SCTP_CID_I_DATA;
		num_ext += 1;
	}

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	if (asoc->peer.auth_capable) {
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		auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
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		chunksize += ntohs(auth_random->length);

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		auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
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		if (auth_hmacs->length)
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			chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
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		else
			auth_hmacs = NULL;

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		auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
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		if (auth_chunks->length)
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			chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
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		else
			auth_chunks = NULL;

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

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	if (num_ext)
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		chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
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	/* Now allocate and fill out the chunk.  */
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	retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
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	if (!retval)
		goto nomem_chunk;

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	/* 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.]
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	 */
	retval->transport = chunk->transport;
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	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);
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	if (num_ext) {
		ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
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		ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
		sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
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		sctp_addto_param(retval, num_ext, extensions);
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	}
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	if (asoc->peer.prsctp_capable)
		sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);

509 510 511 512 513 514
	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);
	}
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516 517 518 519 520 521 522 523 524 525 526
	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);
	}

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	/* We need to remove the const qualifier at this point.  */
	retval->asoc = (struct sctp_association *) asoc;

nomem_chunk:
	kfree(cookie);
nomem_cookie:
J
Jesper Juhl 已提交
533
	kfree(addrs.v);
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	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,
572
					 const struct sctp_chunk *chunk)
L
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{
	struct sctp_chunk *retval;
	int cookie_len;
576
	void *cookie;
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	cookie = asoc->peer.cookie;
	cookie_len = asoc->peer.cookie_len;

	/* Build a cookie echo chunk.  */
582 583
	retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
				   cookie_len, GFP_ATOMIC);
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	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,
624
					const struct sctp_chunk *chunk)
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{
	struct sctp_chunk *retval;

628
	retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
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	/* 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,
669 670
				 const __u32 lowest_tsn,
				 const struct sctp_chunk *chunk)
L
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{
	struct sctp_chunk *retval;
673
	struct sctp_cwrhdr cwr;
L
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	cwr.lowest_tsn = htonl(lowest_tsn);
676
	retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
677
				   sizeof(cwr), GFP_ATOMIC);
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	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,
704
				  const __u32 lowest_tsn)
L
Linus Torvalds 已提交
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{
	struct sctp_chunk *retval;
707
	struct sctp_ecnehdr ecne;
L
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708 709

	ecne.lowest_tsn = htonl(lowest_tsn);
710
	retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
711
				   sizeof(ecne), GFP_ATOMIC);
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	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.
 */
724
struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
725
					    const struct sctp_sndrcvinfo *sinfo,
726
					    int len, __u8 flags, gfp_t gfp)
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{
	struct sctp_chunk *retval;
	struct sctp_datahdr dp;

	/* We assign the TSN as LATE as possible, not here when
	 * creating the chunk.
	 */
734 735
	memset(&dp, 0, sizeof(dp));
	dp.ppid = sinfo->sinfo_ppid;
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	dp.stream = htons(sinfo->sinfo_stream);

	/* Set the flags for an unordered send.  */
739
	if (sinfo->sinfo_flags & SCTP_UNORDERED)
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		flags |= SCTP_DATA_UNORDERED;

742
	retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
L
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743
	if (!retval)
744
		return NULL;
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	retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
	memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));

	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_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
759
	struct sctp_association *aptr = (struct sctp_association *)asoc;
760
	struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
761
	__u16 num_gabs, num_dup_tsns;
762
	struct sctp_transport *trans;
763 764 765 766
	struct sctp_chunk *retval;
	struct sctp_sackhdr sack;
	__u32 ctsn;
	int len;
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768
	memset(gabs, 0, sizeof(gabs));
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	ctsn = sctp_tsnmap_get_ctsn(map);
770 771

	pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
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	/* How much room is needed in the chunk? */
774
	num_gabs = sctp_tsnmap_num_gabs(map, gabs);
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	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.  */
788
	retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
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	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,
830
				 gabs);
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	/* Add the duplicate TSN information.  */
833 834
	if (num_dup_tsns) {
		aptr->stats.idupchunks += num_dup_tsns;
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835 836
		sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
				 sctp_tsnmap_get_dups(map));
837
	}
838 839 840 841 842 843 844 845 846 847 848 849 850 851
	/* 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;
	}
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nodata:
	return retval;
}

/* Make a SHUTDOWN chunk. */
struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
				      const struct sctp_chunk *chunk)
{
860
	struct sctp_shutdownhdr shut;
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	struct sctp_chunk *retval;
	__u32 ctsn;

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

867
	retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
868
				   sizeof(shut), GFP_ATOMIC);
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	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,
882
					  const struct sctp_chunk *chunk)
L
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883 884 885
{
	struct sctp_chunk *retval;

886 887
	retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
				   GFP_ATOMIC);
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	/* 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(
905 906
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk)
L
Linus Torvalds 已提交
907 908 909 910
{
	struct sctp_chunk *retval;
	__u8 flags = 0;

911 912 913
	/* Set the T-bit if we have no association (vtag will be
	 * reflected)
	 */
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914 915
	flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;

916 917
	retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
				   0, GFP_ATOMIC);
L
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918 919 920 921 922 923 924 925 926 927 928 929 930 931

	/* 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;

932
	return retval;
L
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933 934 935
}

/* Create an ABORT.  Note that we set the T bit if we have no
936
 * association, except when responding to an INIT (sctpimpguide 2.41).
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 */
struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
939 940
				   const struct sctp_chunk *chunk,
				   const size_t hint)
L
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941 942 943 944
{
	struct sctp_chunk *retval;
	__u8 flags = 0;

945 946 947 948 949 950 951 952 953 954
	/* 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;
	}
L
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956 957
	retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
				   GFP_ATOMIC);
L
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	/* 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(
976 977 978
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					__u32 tsn)
L
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979 980
{
	struct sctp_chunk *retval;
A
Al Viro 已提交
981
	__be32 payload;
L
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983 984
	retval = sctp_make_abort(asoc, chunk,
				 sizeof(struct sctp_errhdr) + sizeof(tsn));
L
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985 986 987 988 989 990

	if (!retval)
		goto no_mem;

	/* Put the tsn back into network byte order.  */
	payload = htonl(tsn);
991 992
	sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
	sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
L
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	/* 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,
A
Al Viro 已提交
1012
					struct msghdr *msg,
1013
					size_t paylen)
L
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1014 1015
{
	struct sctp_chunk *retval;
1016 1017
	void *payload = NULL;
	int err;
L
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1018

1019 1020
	retval = sctp_make_abort(asoc, NULL,
				 sizeof(struct sctp_errhdr) + paylen);
L
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1021 1022 1023 1024 1025
	if (!retval)
		goto err_chunk;

	if (paylen) {
		/* Put the msg_iov together into payload.  */
1026
		payload = kmalloc(paylen, GFP_KERNEL);
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1027 1028
		if (!payload)
			goto err_payload;
1029

A
Al Viro 已提交
1030
		err = memcpy_from_msg(payload, msg, paylen);
1031 1032
		if (err < 0)
			goto err_copy;
L
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1033 1034
	}

1035 1036
	sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
	sctp_addto_chunk(retval, paylen, payload);
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	if (paylen)
		kfree(payload);

	return retval;

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

1052 1053 1054 1055 1056 1057 1058
/* 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)
{
	int chunklen = ntohs(chunk->chunk_hdr->length);
1059
	void *target;
1060 1061 1062

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

1063 1064 1065 1066
	if (data)
		memcpy(target, data, len);
	else
		memset(target, 0, len);
1067 1068 1069 1070 1071 1072 1073 1074

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

	return target;
}

1075
/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
L
Linus Torvalds 已提交
1076
struct sctp_chunk *sctp_make_abort_violation(
1077 1078 1079 1080
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					const __u8 *payload,
					const size_t paylen)
L
Linus Torvalds 已提交
1081 1082 1083 1084
{
	struct sctp_chunk  *retval;
	struct sctp_paramhdr phdr;

1085 1086
	retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
					      paylen + sizeof(phdr));
L
Linus Torvalds 已提交
1087 1088 1089
	if (!retval)
		goto end;

1090 1091
	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
							    sizeof(phdr));
L
Linus Torvalds 已提交
1092 1093 1094

	phdr.type = htons(chunk->chunk_hdr->type);
	phdr.length = chunk->chunk_hdr->length;
1095
	sctp_addto_chunk(retval, paylen, payload);
1096
	sctp_addto_param(retval, sizeof(phdr), &phdr);
L
Linus Torvalds 已提交
1097 1098 1099 1100 1101

end:
	return retval;
}

1102
struct sctp_chunk *sctp_make_violation_paramlen(
1103 1104 1105
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					struct sctp_paramhdr *param)
1106 1107
{
	static const char error[] = "The following parameter had invalid length:";
1108
	size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1109
			     sizeof(*param);
1110
	struct sctp_chunk *retval;
1111 1112 1113 1114 1115 1116

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

	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1117
			sizeof(error) + sizeof(*param));
1118
	sctp_addto_chunk(retval, sizeof(error), error);
1119
	sctp_addto_param(retval, sizeof(*param), param);
1120 1121 1122 1123 1124

nodata:
	return retval;
}

1125
struct sctp_chunk *sctp_make_violation_max_retrans(
1126 1127
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk)
1128 1129
{
	static const char error[] = "Association exceeded its max_retans count";
1130
	size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1131
	struct sctp_chunk *retval;
1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143

	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;
}

L
Linus Torvalds 已提交
1144 1145
/* Make a HEARTBEAT chunk.  */
struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1146
				       const struct sctp_transport *transport)
L
Linus Torvalds 已提交
1147
{
1148
	struct sctp_sender_hb_info hbinfo;
1149 1150
	struct sctp_chunk *retval;

1151 1152
	retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
				   sizeof(hbinfo), GFP_ATOMIC);
L
Linus Torvalds 已提交
1153 1154 1155 1156

	if (!retval)
		goto nodata;

1157
	hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1158
	hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1159 1160 1161 1162
	hbinfo.daddr = transport->ipaddr;
	hbinfo.sent_at = jiffies;
	hbinfo.hb_nonce = transport->hb_nonce;

L
Linus Torvalds 已提交
1163 1164 1165 1166
	/* Cast away the 'const', as this is just telling the chunk
	 * what transport it belongs to.
	 */
	retval->transport = (struct sctp_transport *) transport;
1167 1168
	retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
						&hbinfo);
L
Linus Torvalds 已提交
1169 1170 1171 1172 1173 1174

nodata:
	return retval;
}

struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1175 1176 1177
					   const struct sctp_chunk *chunk,
					   const void *payload,
					   const size_t paylen)
L
Linus Torvalds 已提交
1178 1179 1180
{
	struct sctp_chunk *retval;

1181 1182
	retval  = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
				    GFP_ATOMIC);
L
Linus Torvalds 已提交
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207
	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(
1208 1209 1210
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					size_t size)
L
Linus Torvalds 已提交
1211 1212 1213
{
	struct sctp_chunk *retval;

1214
	retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1215 1216
				   sizeof(struct sctp_errhdr) + size,
				   GFP_ATOMIC);
L
Linus Torvalds 已提交
1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234
	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;
}

1235 1236 1237 1238
/* 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
1239
 * to report all the errors, if the incoming chunk is large
1240 1241
 */
static inline struct sctp_chunk *sctp_make_op_error_fixed(
1242 1243
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk)
1244 1245 1246 1247 1248 1249 1250 1251 1252
{
	size_t size = asoc ? asoc->pathmtu : 0;

	if (!size)
		size = SCTP_DEFAULT_MAXSEGMENT;

	return sctp_make_op_error_space(asoc, chunk, size);
}

L
Linus Torvalds 已提交
1253 1254
/* Create an Operation Error chunk.  */
struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1255 1256 1257
				      const struct sctp_chunk *chunk,
				      __be16 cause_code, const void *payload,
				      size_t paylen, size_t reserve_tail)
L
Linus Torvalds 已提交
1258 1259 1260
{
	struct sctp_chunk *retval;

1261
	retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
L
Linus Torvalds 已提交
1262 1263 1264
	if (!retval)
		goto nodata;

1265
	sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1266
	sctp_addto_chunk(retval, paylen, payload);
1267 1268
	if (reserve_tail)
		sctp_addto_param(retval, reserve_tail, NULL);
L
Linus Torvalds 已提交
1269 1270 1271 1272 1273

nodata:
	return retval;
}

1274 1275 1276
struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
{
	struct sctp_authhdr auth_hdr;
1277 1278
	struct sctp_hmac *hmac_desc;
	struct sctp_chunk *retval;
1279 1280 1281 1282 1283 1284 1285
	__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;

1286
	retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1287 1288
				   hmac_desc->hmac_len + sizeof(auth_hdr),
				   GFP_ATOMIC);
1289 1290 1291 1292 1293 1294
	if (!retval)
		return NULL;

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

1295 1296
	retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
						 &auth_hdr);
1297

J
Johannes Berg 已提交
1298
	hmac = skb_put_zero(retval->skb, hmac_desc->hmac_len);
1299 1300 1301 1302 1303 1304 1305 1306 1307 1308

	/* 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;
}


L
Linus Torvalds 已提交
1309 1310 1311 1312 1313 1314
/********************************************************************
 * 2nd Level Abstractions
 ********************************************************************/

/* Turn an skb into a chunk.
 * FIXME: Eventually move the structure directly inside the skb->cb[].
1315 1316 1317 1318 1319 1320 1321
 *
 * 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.
 *
L
Linus Torvalds 已提交
1322 1323
 */
struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1324 1325
				 const struct sctp_association *asoc,
				 struct sock *sk, gfp_t gfp)
L
Linus Torvalds 已提交
1326 1327 1328
{
	struct sctp_chunk *retval;

1329
	retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
L
Linus Torvalds 已提交
1330 1331 1332

	if (!retval)
		goto nodata;
1333 1334
	if (!sk)
		pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
L
Linus Torvalds 已提交
1335

1336
	INIT_LIST_HEAD(&retval->list);
L
Linus Torvalds 已提交
1337 1338 1339 1340
	retval->skb		= skb;
	retval->asoc		= (struct sctp_association *)asoc;
	retval->singleton	= 1;

1341
	retval->fast_retransmit = SCTP_CAN_FRTX;
L
Linus Torvalds 已提交
1342 1343 1344 1345 1346

	/* Polish the bead hole.  */
	INIT_LIST_HEAD(&retval->transmitted_list);
	INIT_LIST_HEAD(&retval->frag_list);
	SCTP_DBG_OBJCNT_INC(chunk);
1347
	refcount_set(&retval->refcnt, 1);
L
Linus Torvalds 已提交
1348 1349 1350 1351 1352 1353 1354 1355 1356

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)
{
1357
	memcpy(&chunk->source, src, sizeof(union sctp_addr));
1358
	memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
L
Linus Torvalds 已提交
1359 1360 1361 1362 1363 1364 1365
}

/* 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) {
1366
		return &chunk->transport->ipaddr;
L
Linus Torvalds 已提交
1367 1368
	} else {
		/* Otherwise, extract it from the IP header.  */
1369
		return &chunk->source;
L
Linus Torvalds 已提交
1370 1371 1372 1373 1374 1375
	}
}

/* Create a new chunk, setting the type and flags headers from the
 * arguments, reserving enough space for a 'paylen' byte payload.
 */
1376
static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1377 1378
					   __u8 type, __u8 flags, int paylen,
					   gfp_t gfp)
L
Linus Torvalds 已提交
1379
{
1380
	struct sctp_chunkhdr *chunk_hdr;
1381
	struct sctp_chunk *retval;
L
Linus Torvalds 已提交
1382 1383 1384 1385
	struct sk_buff *skb;
	struct sock *sk;

	/* No need to allocate LL here, as this is only a chunk. */
1386
	skb = alloc_skb(SCTP_PAD4(sizeof(*chunk_hdr) + paylen), gfp);
L
Linus Torvalds 已提交
1387 1388 1389 1390
	if (!skb)
		goto nodata;

	/* Make room for the chunk header.  */
1391
	chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
L
Linus Torvalds 已提交
1392 1393
	chunk_hdr->type	  = type;
	chunk_hdr->flags  = flags;
1394
	chunk_hdr->length = htons(sizeof(*chunk_hdr));
L
Linus Torvalds 已提交
1395 1396

	sk = asoc ? asoc->base.sk : NULL;
1397
	retval = sctp_chunkify(skb, asoc, sk, gfp);
L
Linus Torvalds 已提交
1398 1399 1400 1401 1402 1403
	if (!retval) {
		kfree_skb(skb);
		goto nodata;
	}

	retval->chunk_hdr = chunk_hdr;
1404
	retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
L
Linus Torvalds 已提交
1405

1406 1407 1408 1409
	/* Determine if the chunk needs to be authenticated */
	if (sctp_auth_send_cid(type, asoc))
		retval->auth = 1;

L
Linus Torvalds 已提交
1410 1411 1412 1413 1414
	return retval;
nodata:
	return NULL;
}

1415
static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1416
					 __u8 flags, int paylen, gfp_t gfp)
1417
{
1418
	return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1419 1420
}

1421 1422 1423 1424 1425 1426
struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
				   __u8 flags, int paylen, gfp_t gfp)
{
	return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
}

1427
static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1428 1429
					    __u8 type, __u8 flags, int paylen,
					    gfp_t gfp)
1430
{
1431
	struct sctp_chunk *chunk;
1432

1433
	chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1434 1435 1436 1437 1438
	if (chunk)
		sctp_control_set_owner_w(chunk);

	return chunk;
}
L
Linus Torvalds 已提交
1439 1440 1441 1442

/* Release the memory occupied by a chunk.  */
static void sctp_chunk_destroy(struct sctp_chunk *chunk)
{
1443 1444 1445
	BUG_ON(!list_empty(&chunk->list));
	list_del_init(&chunk->transmitted_list);

1446 1447
	consume_skb(chunk->skb);
	consume_skb(chunk->auth_chunk);
L
Linus Torvalds 已提交
1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465

	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)
{
1466
	refcount_inc(&ch->refcnt);
L
Linus Torvalds 已提交
1467 1468 1469 1470 1471
}

/* Release a reference to the chunk. */
void sctp_chunk_put(struct sctp_chunk *ch)
{
1472
	if (refcount_dec_and_test(&ch->refcnt))
L
Linus Torvalds 已提交
1473 1474 1475 1476 1477 1478 1479 1480 1481
		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)
{
	int chunklen = ntohs(chunk->chunk_hdr->length);
1482
	int padlen = SCTP_PAD4(chunklen) - chunklen;
1483
	void *target;
L
Linus Torvalds 已提交
1484

1485
	skb_put_zero(chunk->skb, padlen);
1486
	target = skb_put_data(chunk->skb, data, len);
L
Linus Torvalds 已提交
1487 1488 1489

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1490
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
L
Linus Torvalds 已提交
1491 1492 1493 1494

	return target;
}

1495 1496 1497
/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
 * space in the chunk
 */
1498 1499
static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
				    int len, const void *data)
1500
{
1501
	if (skb_tailroom(chunk->skb) >= len)
1502 1503 1504 1505 1506
		return sctp_addto_chunk(chunk, len, data);
	else
		return NULL;
}

L
Linus Torvalds 已提交
1507 1508 1509 1510
/* Append bytes from user space to the end of a chunk.  Will panic if
 * chunk is not big enough.
 * Returns a kernel err value.
 */
1511 1512
int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
			  struct iov_iter *from)
L
Linus Torvalds 已提交
1513
{
1514
	void *target;
L
Linus Torvalds 已提交
1515 1516 1517 1518 1519

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

	/* Copy data (whole iovec) into chunk */
A
Al Viro 已提交
1520
	if (!copy_from_iter_full(target, len, from))
1521
		return -EFAULT;
L
Linus Torvalds 已提交
1522 1523 1524 1525

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length =
		htons(ntohs(chunk->chunk_hdr->length) + len);
1526
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
L
Linus Torvalds 已提交
1527

1528
	return 0;
L
Linus Torvalds 已提交
1529 1530 1531 1532 1533 1534 1535
}

/* 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)
{
1536
	struct sctp_stream *stream;
1537 1538 1539
	struct sctp_chunk *lchunk;
	struct sctp_datamsg *msg;
	__u16 ssn, sid;
L
Linus Torvalds 已提交
1540 1541 1542 1543

	if (chunk->has_ssn)
		return;

1544 1545
	/* All fragments will be on the same stream */
	sid = ntohs(chunk->subh.data_hdr->stream);
1546
	stream = &chunk->asoc->stream;
L
Linus Torvalds 已提交
1547

1548 1549 1550 1551 1552 1553 1554 1555 1556
	/* 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)
1557
				ssn = sctp_ssn_next(stream, out, sid);
1558
			else
1559
				ssn = sctp_ssn_peek(stream, out, sid);
1560 1561 1562 1563 1564
		}

		lchunk->subh.data_hdr->ssn = htons(ssn);
		lchunk->has_ssn = 1;
	}
L
Linus Torvalds 已提交
1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583
}

/* 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,
1584 1585
					     struct sctp_chunk *chunk,
					     gfp_t gfp)
L
Linus Torvalds 已提交
1586 1587
{
	struct sctp_association *asoc;
X
Xin Long 已提交
1588
	enum sctp_scope scope;
L
Linus Torvalds 已提交
1589 1590 1591 1592 1593 1594 1595 1596 1597 1598
	struct sk_buff *skb;

	/* 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.  */
1599 1600
	SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);

L
Linus Torvalds 已提交
1601 1602 1603 1604 1605 1606 1607
nodata:
	return asoc;
}

/* Build a cookie representing asoc.
 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
 */
1608 1609 1610 1611
static struct sctp_cookie_param *sctp_pack_cookie(
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const struct sctp_chunk *init_chunk,
1612 1613
					int *cookie_len, const __u8 *raw_addrs,
					int addrs_len)
L
Linus Torvalds 已提交
1614 1615
{
	struct sctp_signed_cookie *cookie;
1616
	struct sctp_cookie_param *retval;
L
Linus Torvalds 已提交
1617 1618
	int headersize, bodysize;

1619 1620 1621
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
1622
	headersize = sizeof(struct sctp_paramhdr) +
1623
		     (sizeof(struct sctp_signed_cookie) -
1624
		      sizeof(struct sctp_cookie));
L
Linus Torvalds 已提交
1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638
	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.
	 */
1639 1640 1641 1642
	retval = kzalloc(*cookie_len, GFP_ATOMIC);
	if (!retval)
		goto nodata;

L
Linus Torvalds 已提交
1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656
	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;

1657 1658
	/* Save adaptation indication in the cookie. */
	cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
L
Linus Torvalds 已提交
1659 1660

	/* Set an expiration time for the cookie.  */
1661
	cookie->c.expiration = ktime_add(asoc->cookie_life,
1662
					 ktime_get_real());
L
Linus Torvalds 已提交
1663 1664 1665 1666 1667 1668 1669 1670 1671

	/* 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);

1672
	if (sctp_sk(ep->base.sk)->hmac) {
H
Herbert Xu 已提交
1673 1674
		SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
		int err;
1675

L
Linus Torvalds 已提交
1676
		/* Sign the message.  */
H
Herbert Xu 已提交
1677 1678 1679 1680 1681 1682 1683 1684 1685
		desc->tfm = sctp_sk(ep->base.sk)->hmac;
		desc->flags = 0;

		err = crypto_shash_setkey(desc->tfm, ep->secret_key,
					  sizeof(ep->secret_key)) ?:
		      crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
					  cookie->signature);
		shash_desc_zero(desc);
		if (err)
1686
			goto free_cookie;
L
Linus Torvalds 已提交
1687 1688 1689
	}

	return retval;
1690 1691 1692 1693 1694 1695

free_cookie:
	kfree(retval);
nodata:
	*cookie_len = 0;
	return NULL;
L
Linus Torvalds 已提交
1696 1697 1698 1699
}

/* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
struct sctp_association *sctp_unpack_cookie(
1700 1701 1702 1703
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk, gfp_t gfp,
					int *error, struct sctp_chunk **errp)
L
Linus Torvalds 已提交
1704 1705
{
	struct sctp_association *retval = NULL;
1706
	int headersize, bodysize, fixed_size;
L
Linus Torvalds 已提交
1707
	struct sctp_signed_cookie *cookie;
1708
	struct sk_buff *skb = chunk->skb;
L
Linus Torvalds 已提交
1709
	struct sctp_cookie *bear_cookie;
1710
	__u8 *digest = ep->digest;
X
Xin Long 已提交
1711
	enum sctp_scope scope;
1712
	unsigned int len;
1713
	ktime_t kt;
L
Linus Torvalds 已提交
1714

1715 1716 1717
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
1718
	headersize = sizeof(struct sctp_chunkhdr) +
1719
		     (sizeof(struct sctp_signed_cookie) -
1720
		      sizeof(struct sctp_cookie));
L
Linus Torvalds 已提交
1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743
	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.  */
H
Herbert Xu 已提交
1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760
	{
		SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
		int err;

		desc->tfm = sctp_sk(ep->base.sk)->hmac;
		desc->flags = 0;

		err = crypto_shash_setkey(desc->tfm, ep->secret_key,
					  sizeof(ep->secret_key)) ?:
		      crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
					  digest);
		shash_desc_zero(desc);

		if (err) {
			*error = -SCTP_IERROR_NOMEM;
			goto fail;
		}
1761
	}
L
Linus Torvalds 已提交
1762 1763

	if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1764 1765
		*error = -SCTP_IERROR_BAD_SIG;
		goto fail;
L
Linus Torvalds 已提交
1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780
	}

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;
	}

1781
	if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
L
Linus Torvalds 已提交
1782 1783 1784 1785 1786 1787 1788 1789
	    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.
1790 1791 1792 1793
	 * 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.
L
Linus Torvalds 已提交
1794
	 */
1795
	if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1796
		kt = skb_get_ktime(skb);
1797
	else
1798
		kt = ktime_get_real();
1799

1800
	if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
L
Linus Torvalds 已提交
1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811
		/*
		 * 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) {
1812
			suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1813
			__be32 n = htonl(usecs);
L
Linus Torvalds 已提交
1814 1815

			sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1816 1817
					sizeof(n));
			sctp_addto_chunk(*errp, sizeof(n), &n);
L
Linus Torvalds 已提交
1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846
			*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)) {
1847
		sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1848 1849
				   sizeof(chunk->dest), SCTP_ADDR_SRC,
				   GFP_ATOMIC);
L
Linus Torvalds 已提交
1850 1851 1852 1853 1854
	}

	retval->next_tsn = retval->c.initial_tsn;
	retval->ctsn_ack_point = retval->next_tsn - 1;
	retval->addip_serial = retval->c.initial_tsn;
1855
	retval->strreset_outseq = retval->c.initial_tsn;
L
Linus Torvalds 已提交
1856 1857
	retval->adv_peer_ack_point = retval->ctsn_ack_point;
	retval->peer.prsctp_capable = retval->c.prsctp_capable;
1858
	retval->peer.adaptation_ind = retval->c.adaptation_ind;
L
Linus Torvalds 已提交
1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881

	/* 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 {
A
Al Viro 已提交
1882 1883
	__be32 num_missing;
	__be16 type;
E
Eric Dumazet 已提交
1884
}  __packed;
L
Linus Torvalds 已提交
1885 1886 1887 1888 1889

/*
 * Report a missing mandatory parameter.
 */
static int sctp_process_missing_param(const struct sctp_association *asoc,
X
Xin Long 已提交
1890
				      enum sctp_param paramtype,
L
Linus Torvalds 已提交
1891 1892 1893 1894 1895 1896
				      struct sctp_chunk *chunk,
				      struct sctp_chunk **errp)
{
	struct __sctp_missing report;
	__u16 len;

1897
	len = SCTP_PAD4(sizeof(report));
L
Linus Torvalds 已提交
1898 1899 1900 1901 1902 1903 1904 1905 1906 1907

	/* 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;
1908
		sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1909 1910
				sizeof(report));
		sctp_addto_chunk(*errp, sizeof(report), &report);
L
Linus Torvalds 已提交
1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927
	}

	/* 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)
1928
		sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
L
Linus Torvalds 已提交
1929 1930 1931 1932 1933 1934 1935 1936 1937 1938

	/* 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)
{
1939 1940 1941 1942 1943 1944
	/* This is a fatal error.  Any accumulated non-fatal errors are
	 * not reported.
	 */
	if (*errp)
		sctp_chunk_free(*errp);

L
Linus Torvalds 已提交
1945
	/* Create an error chunk and fill it in with our payload. */
1946
	*errp = sctp_make_violation_paramlen(asoc, chunk, param);
L
Linus Torvalds 已提交
1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961

	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);

1962 1963 1964 1965 1966 1967 1968 1969 1970
	/* Processing of the HOST_NAME parameter will generate an
	 * ABORT.  If we've accumulated any non-fatal errors, they
	 * would be unrecognized parameters and we should not include
	 * them in the ABORT.
	 */
	if (*errp)
		sctp_chunk_free(*errp);

	*errp = sctp_make_op_error_space(asoc, chunk, len);
L
Linus Torvalds 已提交
1971

1972 1973 1974 1975
	if (*errp) {
		sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
		sctp_addto_chunk(*errp, len, param.v);
	}
L
Linus Torvalds 已提交
1976 1977 1978 1979 1980

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

1981
static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1982
{
1983
	__u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
1984
	int have_asconf = 0;
1985
	int have_auth = 0;
1986 1987 1988 1989
	int i;

	for (i = 0; i < num_ext; i++) {
		switch (param.ext->chunks[i]) {
1990 1991 1992 1993 1994 1995 1996
		case SCTP_CID_AUTH:
			have_auth = 1;
			break;
		case SCTP_CID_ASCONF:
		case SCTP_CID_ASCONF_ACK:
			have_asconf = 1;
			break;
1997 1998 1999 2000 2001 2002 2003 2004
		}
	}

	/* ADD-IP Security: The draft requires us to ABORT or ignore the
	 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not.  Do this
	 * only if ADD-IP is turned on and we are not backward-compatible
	 * mode.
	 */
2005
	if (net->sctp.addip_noauth)
2006 2007
		return 1;

2008
	if (net->sctp.addip_enable && !have_auth && have_asconf)
2009 2010 2011 2012 2013
		return 0;

	return 1;
}

2014
static void sctp_process_ext_param(struct sctp_association *asoc,
2015
				   union sctp_params param)
2016
{
2017
	__u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2018
	struct net *net = sock_net(asoc->base.sk);
2019 2020 2021 2022
	int i;

	for (i = 0; i < num_ext; i++) {
		switch (param.ext->chunks[i]) {
2023 2024 2025 2026 2027
		case SCTP_CID_RECONF:
			if (asoc->reconf_enable &&
			    !asoc->peer.reconf_capable)
				asoc->peer.reconf_capable = 1;
			break;
2028
		case SCTP_CID_FWD_TSN:
2029 2030
			if (asoc->prsctp_enable && !asoc->peer.prsctp_capable)
				asoc->peer.prsctp_capable = 1;
2031 2032 2033 2034 2035
			break;
		case SCTP_CID_AUTH:
			/* if the peer reports AUTH, assume that he
			 * supports AUTH.
			 */
2036
			if (asoc->ep->auth_enable)
2037 2038 2039 2040 2041 2042 2043
				asoc->peer.auth_capable = 1;
			break;
		case SCTP_CID_ASCONF:
		case SCTP_CID_ASCONF_ACK:
			if (net->sctp.addip_enable)
				asoc->peer.asconf_capable = 1;
			break;
2044 2045 2046 2047
		case SCTP_CID_I_DATA:
			if (sctp_sk(asoc->base.sk)->strm_interleave)
				asoc->intl_enable = 1;
			break;
2048 2049
		default:
			break;
2050 2051 2052 2053
		}
	}
}

L
Linus Torvalds 已提交
2054 2055 2056 2057 2058 2059 2060
/* RFC 3.2.1 & the Implementers Guide 2.2.
 *
 * The Parameter Types are encoded such that the
 * highest-order two bits specify the action that must be
 * taken if the processing endpoint does not recognize the
 * Parameter Type.
 *
2061 2062
 * 00 - Stop processing this parameter; do not process any further
 * 	parameters within this chunk
L
Linus Torvalds 已提交
2063
 *
2064 2065 2066
 * 01 - Stop processing this parameter, do not process any further
 *	parameters within this chunk, and report the unrecognized
 *	parameter in an 'Unrecognized Parameter' ERROR chunk.
L
Linus Torvalds 已提交
2067 2068 2069 2070 2071
 *
 * 10 - Skip this parameter and continue processing.
 *
 * 11 - Skip this parameter and continue processing but
 *	report the unrecognized parameter in an
2072
 *	'Unrecognized Parameter' ERROR chunk.
L
Linus Torvalds 已提交
2073 2074
 *
 * Return value:
2075 2076 2077
 * 	SCTP_IERROR_NO_ERROR - continue with the chunk
 * 	SCTP_IERROR_ERROR    - stop and report an error.
 * 	SCTP_IERROR_NOMEME   - out of memory.
L
Linus Torvalds 已提交
2078
 */
2079 2080 2081 2082 2083
static enum sctp_ierror sctp_process_unk_param(
					const struct sctp_association *asoc,
					union sctp_params param,
					struct sctp_chunk *chunk,
					struct sctp_chunk **errp)
L
Linus Torvalds 已提交
2084
{
2085
	int retval = SCTP_IERROR_NO_ERROR;
L
Linus Torvalds 已提交
2086 2087 2088

	switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
	case SCTP_PARAM_ACTION_DISCARD:
2089
		retval =  SCTP_IERROR_ERROR;
L
Linus Torvalds 已提交
2090 2091 2092
		break;
	case SCTP_PARAM_ACTION_SKIP:
		break;
2093 2094 2095
	case SCTP_PARAM_ACTION_DISCARD_ERR:
		retval =  SCTP_IERROR_ERROR;
		/* Fall through */
L
Linus Torvalds 已提交
2096 2097 2098 2099 2100
	case SCTP_PARAM_ACTION_SKIP_ERR:
		/* Make an ERROR chunk, preparing enough room for
		 * returning multiple unknown parameters.
		 */
		if (NULL == *errp)
2101
			*errp = sctp_make_op_error_fixed(asoc, chunk);
L
Linus Torvalds 已提交
2102 2103

		if (*errp) {
2104
			if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2105
					SCTP_PAD4(ntohs(param.p->length))))
2106
				sctp_addto_chunk_fixed(*errp,
2107
						SCTP_PAD4(ntohs(param.p->length)),
2108
						param.v);
L
Linus Torvalds 已提交
2109 2110 2111 2112 2113 2114
		} else {
			/* If there is no memory for generating the ERROR
			 * report as specified, an ABORT will be triggered
			 * to the peer and the association won't be
			 * established.
			 */
2115
			retval = SCTP_IERROR_NOMEM;
L
Linus Torvalds 已提交
2116 2117 2118 2119 2120 2121 2122 2123 2124
		}
		break;
	default:
		break;
	}

	return retval;
}

2125
/* Verify variable length parameters
L
Linus Torvalds 已提交
2126
 * Return values:
2127 2128 2129 2130
 * 	SCTP_IERROR_ABORT - trigger an ABORT
 * 	SCTP_IERROR_NOMEM - out of memory (abort)
 *	SCTP_IERROR_ERROR - stop processing, trigger an ERROR
 * 	SCTP_IERROR_NO_ERROR - continue with the chunk
L
Linus Torvalds 已提交
2131
 */
2132 2133 2134 2135 2136 2137 2138
static enum sctp_ierror sctp_verify_param(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  union sctp_params param,
					  enum sctp_cid cid,
					  struct sctp_chunk *chunk,
					  struct sctp_chunk **err_chunk)
L
Linus Torvalds 已提交
2139
{
2140
	struct sctp_hmac_algo_param *hmacs;
2141
	int retval = SCTP_IERROR_NO_ERROR;
2142 2143
	__u16 n_elt, id = 0;
	int i;
L
Linus Torvalds 已提交
2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158

	/* FIXME - This routine is not looking at each parameter per the
	 * chunk type, i.e., unrecognized parameters should be further
	 * identified based on the chunk id.
	 */

	switch (param.p->type) {
	case SCTP_PARAM_IPV4_ADDRESS:
	case SCTP_PARAM_IPV6_ADDRESS:
	case SCTP_PARAM_COOKIE_PRESERVATIVE:
	case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
	case SCTP_PARAM_STATE_COOKIE:
	case SCTP_PARAM_HEARTBEAT_INFO:
	case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
	case SCTP_PARAM_ECN_CAPABLE:
2159
	case SCTP_PARAM_ADAPTATION_LAYER_IND:
2160 2161
		break;

2162
	case SCTP_PARAM_SUPPORTED_EXT:
2163
		if (!sctp_verify_ext_param(net, param))
2164
			return SCTP_IERROR_ABORT;
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Linus Torvalds 已提交
2165 2166
		break;

2167
	case SCTP_PARAM_SET_PRIMARY:
2168
		if (net->sctp.addip_enable)
2169 2170 2171
			break;
		goto fallthrough;

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2172 2173
	case SCTP_PARAM_HOST_NAME_ADDRESS:
		/* Tell the peer, we won't support this param.  */
2174 2175 2176
		sctp_process_hn_param(asoc, param, chunk, err_chunk);
		retval = SCTP_IERROR_ABORT;
		break;
2177

L
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2178
	case SCTP_PARAM_FWD_TSN_SUPPORT:
2179
		if (ep->prsctp_enable)
L
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2180
			break;
2181 2182 2183
		goto fallthrough;

	case SCTP_PARAM_RANDOM:
2184
		if (!ep->auth_enable)
2185 2186 2187 2188 2189 2190 2191 2192
			goto fallthrough;

		/* SCTP-AUTH: Secion 6.1
		 * If the random number is not 32 byte long the association
		 * MUST be aborted.  The ABORT chunk SHOULD contain the error
		 * cause 'Protocol Violation'.
		 */
		if (SCTP_AUTH_RANDOM_LENGTH !=
2193
			ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) {
2194
			sctp_process_inv_paramlength(asoc, param.p,
2195
							chunk, err_chunk);
2196 2197
			retval = SCTP_IERROR_ABORT;
		}
2198 2199 2200
		break;

	case SCTP_PARAM_CHUNKS:
2201
		if (!ep->auth_enable)
2202 2203 2204 2205 2206 2207 2208
			goto fallthrough;

		/* SCTP-AUTH: Section 3.2
		 * The CHUNKS parameter MUST be included once in the INIT or
		 *  INIT-ACK chunk if the sender wants to receive authenticated
		 *  chunks.  Its maximum length is 260 bytes.
		 */
2209 2210 2211 2212 2213
		if (260 < ntohs(param.p->length)) {
			sctp_process_inv_paramlength(asoc, param.p,
						     chunk, err_chunk);
			retval = SCTP_IERROR_ABORT;
		}
2214 2215 2216
		break;

	case SCTP_PARAM_HMAC_ALGO:
2217
		if (!ep->auth_enable)
2218 2219 2220
			goto fallthrough;

		hmacs = (struct sctp_hmac_algo_param *)param.p;
2221 2222
		n_elt = (ntohs(param.p->length) -
			 sizeof(struct sctp_paramhdr)) >> 1;
2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240

		/* SCTP-AUTH: Section 6.1
		 * The HMAC algorithm based on SHA-1 MUST be supported and
		 * included in the HMAC-ALGO parameter.
		 */
		for (i = 0; i < n_elt; i++) {
			id = ntohs(hmacs->hmac_ids[i]);

			if (id == SCTP_AUTH_HMAC_ID_SHA1)
				break;
		}

		if (id != SCTP_AUTH_HMAC_ID_SHA1) {
			sctp_process_inv_paramlength(asoc, param.p, chunk,
						     err_chunk);
			retval = SCTP_IERROR_ABORT;
		}
		break;
2241
fallthrough:
L
Linus Torvalds 已提交
2242
	default:
2243 2244 2245
		pr_debug("%s: unrecognized param:%d for chunk:%d\n",
			 __func__, ntohs(param.p->type), cid);

2246
		retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
L
Linus Torvalds 已提交
2247 2248 2249 2250 2251 2252
		break;
	}
	return retval;
}

/* Verify the INIT packet before we process it.  */
2253
int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
X
Xin Long 已提交
2254
		     const struct sctp_association *asoc, enum sctp_cid cid,
2255 2256
		     struct sctp_init_chunk *peer_init,
		     struct sctp_chunk *chunk, struct sctp_chunk **errp)
L
Linus Torvalds 已提交
2257 2258
{
	union sctp_params param;
2259
	bool has_cookie = false;
2260
	int result;
L
Linus Torvalds 已提交
2261

2262 2263 2264 2265 2266 2267 2268 2269
	/* Check for missing mandatory parameters. Note: Initial TSN is
	 * also mandatory, but is not checked here since the valid range
	 * is 0..2**32-1. RFC4960, section 3.3.3.
	 */
	if (peer_init->init_hdr.num_outbound_streams == 0 ||
	    peer_init->init_hdr.num_inbound_streams == 0 ||
	    peer_init->init_hdr.init_tag == 0 ||
	    ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2270
		return sctp_process_inv_mandatory(asoc, chunk, errp);
L
Linus Torvalds 已提交
2271 2272

	sctp_walk_params(param, peer_init, init_hdr.params) {
2273 2274 2275
		if (param.p->type == SCTP_PARAM_STATE_COOKIE)
			has_cookie = true;
	}
L
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2276 2277 2278 2279 2280 2281 2282 2283

	/* There is a possibility that a parameter length was bad and
	 * in that case we would have stoped walking the parameters.
	 * The current param.p would point at the bad one.
	 * Current consensus on the mailing list is to generate a PROTOCOL
	 * VIOLATION error.  We build the ERROR chunk here and let the normal
	 * error handling code build and send the packet.
	 */
2284
	if (param.v != (void *)chunk->chunk_end)
2285
		return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
L
Linus Torvalds 已提交
2286 2287 2288 2289

	/* The only missing mandatory param possible today is
	 * the state cookie for an INIT-ACK chunk.
	 */
2290 2291 2292
	if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
		return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
						  chunk, errp);
L
Linus Torvalds 已提交
2293

2294
	/* Verify all the variable length parameters */
L
Linus Torvalds 已提交
2295
	sctp_walk_params(param, peer_init, init_hdr.params) {
2296 2297
		result = sctp_verify_param(net, ep, asoc, param, cid,
					   chunk, errp);
2298
		switch (result) {
2299 2300 2301 2302 2303 2304 2305 2306
		case SCTP_IERROR_ABORT:
		case SCTP_IERROR_NOMEM:
			return 0;
		case SCTP_IERROR_ERROR:
			return 1;
		case SCTP_IERROR_NO_ERROR:
		default:
			break;
L
Linus Torvalds 已提交
2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317
		}

	} /* for (loop through all parameters) */

	return 1;
}

/* Unpack the parameters in an INIT packet into an association.
 * Returns 0 on failure, else success.
 * FIXME:  This is an association method.
 */
2318
int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
L
Linus Torvalds 已提交
2319
		      const union sctp_addr *peer_addr,
2320
		      struct sctp_init_chunk *peer_init, gfp_t gfp)
L
Linus Torvalds 已提交
2321
{
2322
	struct net *net = sock_net(asoc->base.sk);
L
Linus Torvalds 已提交
2323 2324
	struct sctp_transport *transport;
	struct list_head *pos, *temp;
2325
	union sctp_params param;
2326
	union sctp_addr addr;
2327
	struct sctp_af *af;
2328
	int src_match = 0;
2329
	char *cookie;
L
Linus Torvalds 已提交
2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340

	/* We must include the address that the INIT packet came from.
	 * This is the only address that matters for an INIT packet.
	 * When processing a COOKIE ECHO, we retrieve the from address
	 * of the INIT from the cookie.
	 */

	/* This implementation defaults to making the first transport
	 * added as the primary transport.  The source address seems to
	 * be a a better choice than any of the embedded addresses.
	 */
2341
	if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2342 2343 2344 2345
		goto nomem;

	if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
		src_match = 1;
L
Linus Torvalds 已提交
2346 2347 2348

	/* Process the initialization parameters.  */
	sctp_walk_params(param, peer_init, init_hdr.params) {
2349 2350 2351 2352 2353 2354 2355 2356
		if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
		    param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
			af = sctp_get_af_specific(param_type2af(param.p->type));
			af->from_addr_param(&addr, param.addr,
					    chunk->sctp_hdr->source, 0);
			if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
				src_match = 1;
		}
L
Linus Torvalds 已提交
2357 2358

		if (!sctp_process_param(asoc, param, peer_addr, gfp))
2359
			goto clean_up;
L
Linus Torvalds 已提交
2360 2361
	}

2362 2363 2364 2365
	/* source address of chunk may not match any valid address */
	if (!src_match)
		goto clean_up;

2366 2367 2368 2369 2370 2371 2372
	/* AUTH: After processing the parameters, make sure that we
	 * have all the required info to potentially do authentications.
	 */
	if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
					!asoc->peer.peer_hmacs))
		asoc->peer.auth_capable = 0;

2373 2374 2375 2376 2377
	/* In a non-backward compatible mode, if the peer claims
	 * support for ADD-IP but not AUTH,  the ADD-IP spec states
	 * that we MUST ABORT the association. Section 6.  The section
	 * also give us an option to silently ignore the packet, which
	 * is what we'll do here.
2378
	 */
2379
	if (!net->sctp.addip_noauth &&
2380
	     (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2381 2382 2383
		asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
						  SCTP_PARAM_DEL_IP |
						  SCTP_PARAM_SET_PRIMARY);
2384
		asoc->peer.asconf_capable = 0;
2385
		goto clean_up;
2386 2387
	}

F
Frank Filz 已提交
2388 2389 2390 2391 2392 2393 2394 2395
	/* Walk list of transports, removing transports in the UNKNOWN state. */
	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
		transport = list_entry(pos, struct sctp_transport, transports);
		if (transport->state == SCTP_UNKNOWN) {
			sctp_assoc_rm_peer(asoc, transport);
		}
	}

L
Linus Torvalds 已提交
2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409
	/* The fixed INIT headers are always in network byte
	 * order.
	 */
	asoc->peer.i.init_tag =
		ntohl(peer_init->init_hdr.init_tag);
	asoc->peer.i.a_rwnd =
		ntohl(peer_init->init_hdr.a_rwnd);
	asoc->peer.i.num_outbound_streams =
		ntohs(peer_init->init_hdr.num_outbound_streams);
	asoc->peer.i.num_inbound_streams =
		ntohs(peer_init->init_hdr.num_inbound_streams);
	asoc->peer.i.initial_tsn =
		ntohl(peer_init->init_hdr.initial_tsn);

2410 2411
	asoc->strreset_inseq = asoc->peer.i.initial_tsn;

L
Linus Torvalds 已提交
2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435
	/* Apply the upper bounds for output streams based on peer's
	 * number of inbound streams.
	 */
	if (asoc->c.sinit_num_ostreams  >
	    ntohs(peer_init->init_hdr.num_inbound_streams)) {
		asoc->c.sinit_num_ostreams =
			ntohs(peer_init->init_hdr.num_inbound_streams);
	}

	if (asoc->c.sinit_max_instreams >
	    ntohs(peer_init->init_hdr.num_outbound_streams)) {
		asoc->c.sinit_max_instreams =
			ntohs(peer_init->init_hdr.num_outbound_streams);
	}

	/* Copy Initiation tag from INIT to VT_peer in cookie.   */
	asoc->c.peer_vtag = asoc->peer.i.init_tag;

	/* Peer Rwnd   : Current calculated value of the peer's rwnd.  */
	asoc->peer.rwnd = asoc->peer.i.a_rwnd;

	/* Copy cookie in case we need to resend COOKIE-ECHO. */
	cookie = asoc->peer.cookie;
	if (cookie) {
2436
		asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
L
Linus Torvalds 已提交
2437 2438 2439 2440 2441 2442 2443 2444
		if (!asoc->peer.cookie)
			goto clean_up;
	}

	/* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
	 * high (for example, implementations MAY use the size of the receiver
	 * advertised window).
	 */
2445 2446
	list_for_each_entry(transport, &asoc->peer.transport_addr_list,
			transports) {
L
Linus Torvalds 已提交
2447 2448 2449 2450
		transport->ssthresh = asoc->peer.i.a_rwnd;
	}

	/* Set up the TSN tracking pieces.  */
2451 2452 2453
	if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
				asoc->peer.i.initial_tsn, gfp))
		goto clean_up;
L
Linus Torvalds 已提交
2454 2455 2456 2457 2458 2459 2460 2461 2462

	/* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
	 *
	 * The stream sequence number in all the streams shall start
	 * from 0 when the association is established.  Also, when the
	 * stream sequence number reaches the value 65535 the next
	 * stream sequence number shall be set to 0.
	 */

2463 2464
	if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
			     asoc->c.sinit_max_instreams, gfp))
2465
		goto clean_up;
L
Linus Torvalds 已提交
2466

2467 2468
	if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
		goto clean_up;
L
Linus Torvalds 已提交
2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486

	/* ADDIP Section 4.1 ASCONF Chunk Procedures
	 *
	 * When an endpoint has an ASCONF signaled change to be sent to the
	 * remote endpoint it should do the following:
	 * ...
	 * A2) A serial number should be assigned to the Chunk. The serial
	 * number should be a monotonically increasing number. All serial
	 * numbers are defined to be initialized at the start of the
	 * association to the same value as the Initial TSN.
	 */
	asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
	return 1;

clean_up:
	/* Release the transport structures. */
	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
		transport = list_entry(pos, struct sctp_transport, transports);
2487 2488
		if (transport->state != SCTP_ACTIVE)
			sctp_assoc_rm_peer(asoc, transport);
L
Linus Torvalds 已提交
2489
	}
F
Frank Filz 已提交
2490

L
Linus Torvalds 已提交
2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509
nomem:
	return 0;
}


/* Update asoc with the option described in param.
 *
 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
 *
 * asoc is the association to update.
 * param is the variable length parameter to use for update.
 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
 * If the current packet is an INIT we want to minimize the amount of
 * work we do.  In particular, we should not build transport
 * structures for the addresses.
 */
static int sctp_process_param(struct sctp_association *asoc,
			      union sctp_params param,
			      const union sctp_addr *peer_addr,
A
Al Viro 已提交
2510
			      gfp_t gfp)
L
Linus Torvalds 已提交
2511
{
2512
	struct net *net = sock_net(asoc->base.sk);
2513
	struct sctp_endpoint *ep = asoc->ep;
2514 2515
	union sctp_addr_param *addr_param;
	struct sctp_transport *t;
2516 2517 2518 2519 2520 2521
	enum sctp_scope scope;
	union sctp_addr addr;
	struct sctp_af *af;
	int retval = 1, i;
	u32 stale;
	__u16 sat;
L
Linus Torvalds 已提交
2522 2523 2524 2525 2526 2527 2528 2529 2530

	/* We maintain all INIT parameters in network byte order all the
	 * time.  This allows us to not worry about whether the parameters
	 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
	 */
	switch (param.p->type) {
	case SCTP_PARAM_IPV6_ADDRESS:
		if (PF_INET6 != asoc->base.sk->sk_family)
			break;
2531 2532
		goto do_addr_param;

L
Linus Torvalds 已提交
2533
	case SCTP_PARAM_IPV4_ADDRESS:
2534 2535 2536 2537
		/* v4 addresses are not allowed on v6-only socket */
		if (ipv6_only_sock(asoc->base.sk))
			break;
do_addr_param:
L
Linus Torvalds 已提交
2538
		af = sctp_get_af_specific(param_type2af(param.p->type));
2539
		af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
L
Linus Torvalds 已提交
2540
		scope = sctp_scope(peer_addr);
2541
		if (sctp_in_scope(net, &addr, scope))
2542
			if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
L
Linus Torvalds 已提交
2543 2544 2545 2546
				return 0;
		break;

	case SCTP_PARAM_COOKIE_PRESERVATIVE:
2547
		if (!net->sctp.cookie_preserve_enable)
L
Linus Torvalds 已提交
2548 2549 2550 2551 2552 2553 2554
			break;

		stale = ntohl(param.life->lifespan_increment);

		/* Suggested Cookie Life span increment's unit is msec,
		 * (1/1000sec).
		 */
2555
		asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
L
Linus Torvalds 已提交
2556 2557 2558
		break;

	case SCTP_PARAM_HOST_NAME_ADDRESS:
2559
		pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
L
Linus Torvalds 已提交
2560 2561 2562 2563 2564 2565 2566 2567 2568
		break;

	case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
		/* Turn off the default values first so we'll know which
		 * ones are really set by the peer.
		 */
		asoc->peer.ipv4_address = 0;
		asoc->peer.ipv6_address = 0;

2569 2570 2571 2572 2573 2574 2575 2576
		/* Assume that peer supports the address family
		 * by which it sends a packet.
		 */
		if (peer_addr->sa.sa_family == AF_INET6)
			asoc->peer.ipv6_address = 1;
		else if (peer_addr->sa.sa_family == AF_INET)
			asoc->peer.ipv4_address = 1;

L
Linus Torvalds 已提交
2577
		/* Cycle through address types; avoid divide by 0. */
2578
		sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
L
Linus Torvalds 已提交
2579 2580 2581 2582 2583 2584 2585 2586 2587 2588
		if (sat)
			sat /= sizeof(__u16);

		for (i = 0; i < sat; ++i) {
			switch (param.sat->types[i]) {
			case SCTP_PARAM_IPV4_ADDRESS:
				asoc->peer.ipv4_address = 1;
				break;

			case SCTP_PARAM_IPV6_ADDRESS:
2589 2590
				if (PF_INET6 == asoc->base.sk->sk_family)
					asoc->peer.ipv6_address = 1;
L
Linus Torvalds 已提交
2591 2592 2593 2594 2595 2596 2597 2598
				break;

			case SCTP_PARAM_HOST_NAME_ADDRESS:
				asoc->peer.hostname_address = 1;
				break;

			default: /* Just ignore anything else.  */
				break;
2599
			}
L
Linus Torvalds 已提交
2600 2601 2602 2603 2604
		}
		break;

	case SCTP_PARAM_STATE_COOKIE:
		asoc->peer.cookie_len =
2605
			ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
L
Linus Torvalds 已提交
2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620
		asoc->peer.cookie = param.cookie->body;
		break;

	case SCTP_PARAM_HEARTBEAT_INFO:
		/* Would be odd to receive, but it causes no problems. */
		break;

	case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
		/* Rejected during verify stage. */
		break;

	case SCTP_PARAM_ECN_CAPABLE:
		asoc->peer.ecn_capable = 1;
		break;

2621
	case SCTP_PARAM_ADAPTATION_LAYER_IND:
2622
		asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
L
Linus Torvalds 已提交
2623 2624
		break;

2625
	case SCTP_PARAM_SET_PRIMARY:
2626
		if (!net->sctp.addip_enable)
2627 2628
			goto fall_through;

2629
		addr_param = param.v + sizeof(struct sctp_addip_param);
2630

2631
		af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2632 2633 2634
		if (af == NULL)
			break;

2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650
		af->from_addr_param(&addr, addr_param,
				    htons(asoc->peer.port), 0);

		/* if the address is invalid, we can't process it.
		 * XXX: see spec for what to do.
		 */
		if (!af->addr_valid(&addr, NULL, NULL))
			break;

		t = sctp_assoc_lookup_paddr(asoc, &addr);
		if (!t)
			break;

		sctp_assoc_set_primary(asoc, t);
		break;

2651 2652 2653 2654
	case SCTP_PARAM_SUPPORTED_EXT:
		sctp_process_ext_param(asoc, param);
		break;

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	case SCTP_PARAM_FWD_TSN_SUPPORT:
2656
		if (asoc->prsctp_enable) {
L
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2657 2658 2659
			asoc->peer.prsctp_capable = 1;
			break;
		}
2660
		/* Fall Through */
2661 2662 2663
		goto fall_through;

	case SCTP_PARAM_RANDOM:
2664
		if (!ep->auth_enable)
2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676
			goto fall_through;

		/* Save peer's random parameter */
		asoc->peer.peer_random = kmemdup(param.p,
					    ntohs(param.p->length), gfp);
		if (!asoc->peer.peer_random) {
			retval = 0;
			break;
		}
		break;

	case SCTP_PARAM_HMAC_ALGO:
2677
		if (!ep->auth_enable)
2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692
			goto fall_through;

		/* Save peer's HMAC list */
		asoc->peer.peer_hmacs = kmemdup(param.p,
					    ntohs(param.p->length), gfp);
		if (!asoc->peer.peer_hmacs) {
			retval = 0;
			break;
		}

		/* Set the default HMAC the peer requested*/
		sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
		break;

	case SCTP_PARAM_CHUNKS:
2693
		if (!ep->auth_enable)
2694 2695 2696 2697 2698 2699 2700 2701
			goto fall_through;

		asoc->peer.peer_chunks = kmemdup(param.p,
					    ntohs(param.p->length), gfp);
		if (!asoc->peer.peer_chunks)
			retval = 0;
		break;
fall_through:
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	default:
		/* Any unrecognized parameters should have been caught
		 * and handled by sctp_verify_param() which should be
		 * called prior to this routine.  Simply log the error
		 * here.
		 */
2708 2709
		pr_debug("%s: ignoring param:%d for association:%p.\n",
			 __func__, ntohs(param.p->type), asoc);
L
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2710
		break;
2711
	}
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2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759

	return retval;
}

/* Select a new verification tag.  */
__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
{
	/* I believe that this random number generator complies with RFC1750.
	 * A tag of 0 is reserved for special cases (e.g. INIT).
	 */
	__u32 x;

	do {
		get_random_bytes(&x, sizeof(__u32));
	} while (x == 0);

	return x;
}

/* Select an initial TSN to send during startup.  */
__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
{
	__u32 retval;

	get_random_bytes(&retval, sizeof(__u32));
	return retval;
}

/*
 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
 *      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 = 0xC1   |  Chunk Flags  |      Chunk Length             |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                       Serial Number                           |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                    Address Parameter                          |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                     ASCONF Parameter #1                       |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     \                                                               \
 *     /                             ....                              /
 *     \                                                               \
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                     ASCONF Parameter #N                       |
 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2760
 * Address Parameter and other parameter will not be wrapped in this function
L
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2761 2762 2763 2764 2765
 */
static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
					   union sctp_addr *addr,
					   int vparam_len)
{
2766
	struct sctp_addiphdr asconf;
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	struct sctp_chunk *retval;
	int length = sizeof(asconf) + vparam_len;
	union sctp_addr_param addrparam;
	int addrlen;
	struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);

	addrlen = af->to_addr_param(addr, &addrparam);
	if (!addrlen)
		return NULL;
	length += addrlen;

	/* Create the chunk.  */
2779 2780
	retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
				   GFP_ATOMIC);
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	if (!retval)
		return NULL;

	asconf.serial = htonl(asoc->addip_serial++);

	retval->subh.addip_hdr =
		sctp_addto_chunk(retval, sizeof(asconf), &asconf);
	retval->param_hdr.v =
		sctp_addto_chunk(retval, addrlen, &addrparam);

	return retval;
}

/* ADDIP
 * 3.2.1 Add IP Address
 * 	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 = 0xC001          |    Length = Variable          |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |               ASCONF-Request Correlation ID                   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                       Address Parameter                       |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * 3.2.2 Delete IP Address
 * 	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 = 0xC002          |    Length = Variable          |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |               ASCONF-Request Correlation ID                   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                       Address Parameter                       |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 */
struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2819 2820 2821
					      union sctp_addr *laddr,
					      struct sockaddr *addrs,
					      int addrcnt, __be16 flags)
L
Linus Torvalds 已提交
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{
2823
	union sctp_addr_param addr_param;
2824
	struct sctp_addip_param	param;
2825 2826 2827 2828 2829 2830 2831 2832
	int paramlen = sizeof(param);
	struct sctp_chunk *retval;
	int addr_param_len = 0;
	union sctp_addr *addr;
	int totallen = 0, i;
	int del_pickup = 0;
	struct sctp_af *af;
	void *addr_buf;
L
Linus Torvalds 已提交
2833 2834 2835 2836

	/* Get total length of all the address parameters. */
	addr_buf = addrs;
	for (i = 0; i < addrcnt; i++) {
J
Joe Perches 已提交
2837
		addr = addr_buf;
L
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2838 2839 2840 2841 2842 2843 2844
		af = sctp_get_af_specific(addr->v4.sin_family);
		addr_param_len = af->to_addr_param(addr, &addr_param);

		totallen += paramlen;
		totallen += addr_param_len;

		addr_buf += af->sockaddr_len;
2845 2846 2847 2848 2849
		if (asoc->asconf_addr_del_pending && !del_pickup) {
			/* reuse the parameter length from the same scope one */
			totallen += paramlen;
			totallen += addr_param_len;
			del_pickup = 1;
2850 2851 2852 2853

			pr_debug("%s: picked same-scope del_pending addr, "
				 "totallen for all addresses is %d\n",
				 __func__, totallen);
2854
		}
L
Linus Torvalds 已提交
2855 2856 2857 2858 2859 2860 2861 2862 2863 2864
	}

	/* Create an asconf chunk with the required length. */
	retval = sctp_make_asconf(asoc, laddr, totallen);
	if (!retval)
		return NULL;

	/* Add the address parameters to the asconf chunk. */
	addr_buf = addrs;
	for (i = 0; i < addrcnt; i++) {
J
Joe Perches 已提交
2865
		addr = addr_buf;
L
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2866 2867 2868 2869
		af = sctp_get_af_specific(addr->v4.sin_family);
		addr_param_len = af->to_addr_param(addr, &addr_param);
		param.param_hdr.type = flags;
		param.param_hdr.length = htons(paramlen + addr_param_len);
2870
		param.crr_id = htonl(i);
L
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2871 2872 2873 2874 2875 2876

		sctp_addto_chunk(retval, paramlen, &param);
		sctp_addto_chunk(retval, addr_param_len, &addr_param);

		addr_buf += af->sockaddr_len;
	}
2877 2878 2879 2880 2881 2882
	if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
		addr = asoc->asconf_addr_del_pending;
		af = sctp_get_af_specific(addr->v4.sin_family);
		addr_param_len = af->to_addr_param(addr, &addr_param);
		param.param_hdr.type = SCTP_PARAM_DEL_IP;
		param.param_hdr.length = htons(paramlen + addr_param_len);
2883
		param.crr_id = htonl(i);
2884 2885 2886 2887

		sctp_addto_chunk(retval, paramlen, &param);
		sctp_addto_chunk(retval, addr_param_len, &addr_param);
	}
L
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2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902
	return retval;
}

/* ADDIP
 * 3.2.4 Set Primary IP Address
 *	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 =0xC004           |    Length = Variable          |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |               ASCONF-Request Correlation ID                   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                       Address Parameter                       |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2903
 * Create an ASCONF chunk with Set Primary IP address parameter.
L
Linus Torvalds 已提交
2904 2905 2906 2907
 */
struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
					     union sctp_addr *addr)
{
2908 2909
	struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
	union sctp_addr_param addrparam;
2910
	struct sctp_addip_param	param;
2911 2912 2913
	struct sctp_chunk *retval;
	int len = sizeof(param);
	int addrlen;
L
Linus Torvalds 已提交
2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951

	addrlen = af->to_addr_param(addr, &addrparam);
	if (!addrlen)
		return NULL;
	len += addrlen;

	/* Create the chunk and make asconf header. */
	retval = sctp_make_asconf(asoc, addr, len);
	if (!retval)
		return NULL;

	param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
	param.param_hdr.length = htons(len);
	param.crr_id = 0;

	sctp_addto_chunk(retval, sizeof(param), &param);
	sctp_addto_chunk(retval, addrlen, &addrparam);

	return retval;
}

/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
 *      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 = 0x80   |  Chunk Flags  |      Chunk Length             |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                       Serial Number                           |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                 ASCONF Parameter Response#1                   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     \                                                               \
 *     /                             ....                              /
 *     \                                                               \
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |                 ASCONF Parameter Response#N                   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2952
 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
L
Linus Torvalds 已提交
2953 2954 2955 2956
 */
static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
					       __u32 serial, int vparam_len)
{
2957 2958 2959
	struct sctp_addiphdr asconf;
	struct sctp_chunk *retval;
	int length = sizeof(asconf) + vparam_len;
L
Linus Torvalds 已提交
2960 2961

	/* Create the chunk.  */
2962 2963
	retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
				   GFP_ATOMIC);
L
Linus Torvalds 已提交
2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975
	if (!retval)
		return NULL;

	asconf.serial = htonl(serial);

	retval->subh.addip_hdr =
		sctp_addto_chunk(retval, sizeof(asconf), &asconf);

	return retval;
}

/* Add response parameters to an ASCONF_ACK chunk. */
A
Al Viro 已提交
2976
static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2977 2978
				     __be16 err_code,
				     struct sctp_addip_param *asconf_param)
L
Linus Torvalds 已提交
2979
{
2980
	struct sctp_addip_param ack_param;
2981 2982 2983 2984
	struct sctp_errhdr err_param;
	int asconf_param_len = 0;
	int err_param_len = 0;
	__be16 response_type;
L
Linus Torvalds 已提交
2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995

	if (SCTP_ERROR_NO_ERROR == err_code) {
		response_type = SCTP_PARAM_SUCCESS_REPORT;
	} else {
		response_type = SCTP_PARAM_ERR_CAUSE;
		err_param_len = sizeof(err_param);
		if (asconf_param)
			asconf_param_len =
				 ntohs(asconf_param->param_hdr.length);
	}

2996
	/* Add Success Indication or Error Cause Indication parameter. */
L
Linus Torvalds 已提交
2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017
	ack_param.param_hdr.type = response_type;
	ack_param.param_hdr.length = htons(sizeof(ack_param) +
					   err_param_len +
					   asconf_param_len);
	ack_param.crr_id = crr_id;
	sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);

	if (SCTP_ERROR_NO_ERROR == err_code)
		return;

	/* Add Error Cause parameter. */
	err_param.cause = err_code;
	err_param.length = htons(err_param_len + asconf_param_len);
	sctp_addto_chunk(chunk, err_param_len, &err_param);

	/* Add the failed TLV copied from ASCONF chunk. */
	if (asconf_param)
		sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
}

/* Process a asconf parameter. */
3018
static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3019 3020
					struct sctp_chunk *asconf,
					struct sctp_addip_param *asconf_param)
L
Linus Torvalds 已提交
3021
{
3022
	union sctp_addr_param *addr_param;
L
Linus Torvalds 已提交
3023 3024
	struct sctp_transport *peer;
	union sctp_addr	addr;
3025
	struct sctp_af *af;
3026

3027
	addr_param = (void *)asconf_param + sizeof(*asconf_param);
3028

3029 3030 3031 3032 3033
	if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
	    asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
	    asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
		return SCTP_ERROR_UNKNOWN_PARAM;

3034
	switch (addr_param->p.type) {
3035 3036
	case SCTP_PARAM_IPV6_ADDRESS:
		if (!asoc->peer.ipv6_address)
3037
			return SCTP_ERROR_DNS_FAILED;
3038 3039 3040
		break;
	case SCTP_PARAM_IPV4_ADDRESS:
		if (!asoc->peer.ipv4_address)
3041
			return SCTP_ERROR_DNS_FAILED;
3042 3043
		break;
	default:
3044
		return SCTP_ERROR_DNS_FAILED;
3045 3046
	}

3047
	af = sctp_get_af_specific(param_type2af(addr_param->p.type));
L
Linus Torvalds 已提交
3048
	if (unlikely(!af))
3049
		return SCTP_ERROR_DNS_FAILED;
L
Linus Torvalds 已提交
3050

3051
	af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3052 3053 3054 3055 3056 3057 3058

	/* ADDIP 4.2.1  This parameter MUST NOT contain a broadcast
	 * or multicast address.
	 * (note: wildcard is permitted and requires special handling so
	 *  make sure we check for that)
	 */
	if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3059
		return SCTP_ERROR_DNS_FAILED;
3060

L
Linus Torvalds 已提交
3061 3062
	switch (asconf_param->param_hdr.type) {
	case SCTP_PARAM_ADD_IP:
3063 3064 3065 3066 3067 3068 3069
		/* Section 4.2.1:
		 * If the address 0.0.0.0 or ::0 is provided, the source
		 * address of the packet MUST be added.
		 */
		if (af->is_any(&addr))
			memcpy(&addr, &asconf->source, sizeof(addr));

L
Linus Torvalds 已提交
3070
		/* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3071 3072 3073 3074 3075
		 * request and does not have the local resources to add this
		 * new address to the association, it MUST return an Error
		 * Cause TLV set to the new error code 'Operation Refused
		 * Due to Resource Shortage'.
		 */
L
Linus Torvalds 已提交
3076

3077
		peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
L
Linus Torvalds 已提交
3078 3079 3080 3081
		if (!peer)
			return SCTP_ERROR_RSRC_LOW;

		/* Start the heartbeat timer. */
3082
		sctp_transport_reset_hb_timer(peer);
3083
		asoc->new_transport = peer;
L
Linus Torvalds 已提交
3084 3085 3086
		break;
	case SCTP_PARAM_DEL_IP:
		/* ADDIP 4.3 D7) If a request is received to delete the
3087 3088 3089 3090
		 * last remaining IP address of a peer endpoint, the receiver
		 * MUST send an Error Cause TLV with the error cause set to the
		 * new error code 'Request to Delete Last Remaining IP Address'.
		 */
3091
		if (asoc->peer.transport_count == 1)
L
Linus Torvalds 已提交
3092 3093 3094 3095 3096 3097 3098 3099 3100
			return SCTP_ERROR_DEL_LAST_IP;

		/* ADDIP 4.3 D8) If a request is received to delete an IP
		 * address which is also the source address of the IP packet
		 * which contained the ASCONF chunk, the receiver MUST reject
		 * this request. To reject the request the receiver MUST send
		 * an Error Cause TLV set to the new error code 'Request to
		 * Delete Source IP Address'
		 */
3101
		if (sctp_cmp_addr_exact(&asconf->source, &addr))
L
Linus Torvalds 已提交
3102 3103
			return SCTP_ERROR_DEL_SRC_IP;

3104 3105 3106 3107 3108 3109 3110 3111 3112
		/* Section 4.2.2
		 * If the address 0.0.0.0 or ::0 is provided, all
		 * addresses of the peer except	the source address of the
		 * packet MUST be deleted.
		 */
		if (af->is_any(&addr)) {
			sctp_assoc_set_primary(asoc, asconf->transport);
			sctp_assoc_del_nonprimary_peers(asoc,
							asconf->transport);
3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125
			return SCTP_ERROR_NO_ERROR;
		}

		/* If the address is not part of the association, the
		 * ASCONF-ACK with Error Cause Indication Parameter
		 * which including cause of Unresolvable Address should
		 * be sent.
		 */
		peer = sctp_assoc_lookup_paddr(asoc, &addr);
		if (!peer)
			return SCTP_ERROR_DNS_FAILED;

		sctp_assoc_rm_peer(asoc, peer);
L
Linus Torvalds 已提交
3126 3127
		break;
	case SCTP_PARAM_SET_PRIMARY:
3128 3129 3130 3131 3132 3133 3134 3135
		/* ADDIP Section 4.2.4
		 * If the address 0.0.0.0 or ::0 is provided, the receiver
		 * MAY mark the source address of the packet as its
		 * primary.
		 */
		if (af->is_any(&addr))
			memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));

3136
		peer = sctp_assoc_lookup_paddr(asoc, &addr);
L
Linus Torvalds 已提交
3137
		if (!peer)
3138
			return SCTP_ERROR_DNS_FAILED;
L
Linus Torvalds 已提交
3139 3140 3141 3142 3143 3144 3145 3146

		sctp_assoc_set_primary(asoc, peer);
		break;
	}

	return SCTP_ERROR_NO_ERROR;
}

3147 3148 3149 3150 3151
/* Verify the ASCONF packet before we process it. */
bool sctp_verify_asconf(const struct sctp_association *asoc,
			struct sctp_chunk *chunk, bool addr_param_needed,
			struct sctp_paramhdr **errp)
{
3152
	struct sctp_addip_chunk *addip;
3153
	bool addr_param_seen = false;
3154
	union sctp_params param;
3155

3156
	addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3157 3158
	sctp_walk_params(param, addip, addip_hdr.params) {
		size_t length = ntohs(param.p->length);
3159

3160
		*errp = param.p;
3161
		switch (param.p->type) {
3162 3163 3164
		case SCTP_PARAM_ERR_CAUSE:
			break;
		case SCTP_PARAM_IPV4_ADDRESS:
3165
			if (length != sizeof(struct sctp_ipv4addr_param))
3166
				return false;
3167 3168 3169 3170 3171
			/* ensure there is only one addr param and it's in the
			 * beginning of addip_hdr params, or we reject it.
			 */
			if (param.v != addip->addip_hdr.params)
				return false;
3172 3173 3174
			addr_param_seen = true;
			break;
		case SCTP_PARAM_IPV6_ADDRESS:
3175
			if (length != sizeof(struct sctp_ipv6addr_param))
3176
				return false;
3177 3178
			if (param.v != addip->addip_hdr.params)
				return false;
3179 3180
			addr_param_seen = true;
			break;
3181 3182 3183
		case SCTP_PARAM_ADD_IP:
		case SCTP_PARAM_DEL_IP:
		case SCTP_PARAM_SET_PRIMARY:
3184 3185 3186 3187
			/* In ASCONF chunks, these need to be first. */
			if (addr_param_needed && !addr_param_seen)
				return false;
			length = ntohs(param.addip->param_hdr.length);
3188
			if (length < sizeof(struct sctp_addip_param) +
3189
				     sizeof(**errp))
3190
				return false;
3191 3192 3193
			break;
		case SCTP_PARAM_SUCCESS_REPORT:
		case SCTP_PARAM_ADAPTATION_LAYER_IND:
3194
			if (length != sizeof(struct sctp_addip_param))
3195
				return false;
3196 3197
			break;
		default:
3198 3199
			/* This is unkown to us, reject! */
			return false;
3200 3201 3202
		}
	}

3203 3204 3205 3206 3207 3208 3209
	/* Remaining sanity checks. */
	if (addr_param_needed && !addr_param_seen)
		return false;
	if (!addr_param_needed && addr_param_seen)
		return false;
	if (param.v != chunk->chunk_end)
		return false;
3210

3211
	return true;
3212 3213
}

3214
/* Process an incoming ASCONF chunk with the next expected serial no. and
L
Linus Torvalds 已提交
3215 3216 3217 3218 3219
 * return an ASCONF_ACK chunk to be sent in response.
 */
struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
				       struct sctp_chunk *asconf)
{
3220
	union sctp_addr_param *addr_param;
3221
	struct sctp_addip_chunk *addip;
3222
	struct sctp_chunk *asconf_ack;
3223
	bool all_param_pass = true;
3224 3225
	struct sctp_addiphdr *hdr;
	int length = 0, chunk_len;
3226
	union sctp_params param;
3227 3228
	__be16 err_code;
	__u32 serial;
L
Linus Torvalds 已提交
3229

3230
	addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3231 3232
	chunk_len = ntohs(asconf->chunk_hdr->length) -
		    sizeof(struct sctp_chunkhdr);
3233
	hdr = (struct sctp_addiphdr *)asconf->skb->data;
L
Linus Torvalds 已提交
3234 3235
	serial = ntohl(hdr->serial);

3236
	/* Skip the addiphdr and store a pointer to address parameter.  */
3237
	length = sizeof(*hdr);
L
Linus Torvalds 已提交
3238 3239 3240 3241
	addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
	chunk_len -= length;

	/* Skip the address parameter and store a pointer to the first
J
Joe Perches 已提交
3242
	 * asconf parameter.
3243
	 */
3244
	length = ntohs(addr_param->p.length);
L
Linus Torvalds 已提交
3245 3246
	chunk_len -= length;

3247
	/* create an ASCONF_ACK chunk.
L
Linus Torvalds 已提交
3248
	 * Based on the definitions of parameters, we know that the size of
3249
	 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
J
Joe Perches 已提交
3250
	 * parameters.
L
Linus Torvalds 已提交
3251
	 */
3252
	asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
L
Linus Torvalds 已提交
3253 3254 3255 3256
	if (!asconf_ack)
		goto done;

	/* Process the TLVs contained within the ASCONF chunk. */
3257 3258 3259 3260 3261 3262
	sctp_walk_params(param, addip, addip_hdr.params) {
		/* Skip preceeding address parameters. */
		if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
		    param.p->type == SCTP_PARAM_IPV6_ADDRESS)
			continue;

L
Linus Torvalds 已提交
3263
		err_code = sctp_process_asconf_param(asoc, asconf,
3264
						     param.addip);
L
Linus Torvalds 已提交
3265 3266 3267 3268 3269 3270 3271
		/* ADDIP 4.1 A7)
		 * If an error response is received for a TLV parameter,
		 * all TLVs with no response before the failed TLV are
		 * considered successful if not reported.  All TLVs after
		 * the failed response are considered unsuccessful unless
		 * a specific success indication is present for the parameter.
		 */
3272 3273
		if (err_code != SCTP_ERROR_NO_ERROR)
			all_param_pass = false;
L
Linus Torvalds 已提交
3274
		if (!all_param_pass)
3275 3276
			sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
						 err_code, param.addip);
L
Linus Torvalds 已提交
3277 3278 3279 3280

		/* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
		 * an IP address sends an 'Out of Resource' in its response, it
		 * MUST also fail any subsequent add or delete requests bundled
3281
		 * in the ASCONF.
L
Linus Torvalds 已提交
3282
		 */
3283
		if (err_code == SCTP_ERROR_RSRC_LOW)
L
Linus Torvalds 已提交
3284 3285 3286 3287 3288 3289
			goto done;
	}
done:
	asoc->peer.addip_serial++;

	/* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3290
	 * after freeing the reference to old asconf ack if any.
L
Linus Torvalds 已提交
3291 3292 3293
	 */
	if (asconf_ack) {
		sctp_chunk_hold(asconf_ack);
3294 3295
		list_add_tail(&asconf_ack->transmitted_list,
			      &asoc->asconf_ack_list);
L
Linus Torvalds 已提交
3296 3297 3298 3299 3300 3301
	}

	return asconf_ack;
}

/* Process a asconf parameter that is successfully acked. */
3302
static void sctp_asconf_param_success(struct sctp_association *asoc,
3303
				      struct sctp_addip_param *asconf_param)
L
Linus Torvalds 已提交
3304 3305 3306
{
	struct sctp_bind_addr *bp = &asoc->base.bind_addr;
	union sctp_addr_param *addr_param;
3307
	struct sctp_sockaddr_entry *saddr;
3308 3309 3310
	struct sctp_transport *transport;
	union sctp_addr	addr;
	struct sctp_af *af;
L
Linus Torvalds 已提交
3311

3312
	addr_param = (void *)asconf_param + sizeof(*asconf_param);
L
Linus Torvalds 已提交
3313 3314

	/* We have checked the packet before, so we do not check again.	*/
3315
	af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3316
	af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
L
Linus Torvalds 已提交
3317 3318 3319

	switch (asconf_param->param_hdr.type) {
	case SCTP_PARAM_ADD_IP:
3320 3321 3322
		/* This is always done in BH context with a socket lock
		 * held, so the list can not change.
		 */
3323
		local_bh_disable();
3324
		list_for_each_entry(saddr, &bp->address_list, list) {
3325
			if (sctp_cmp_addr_exact(&saddr->a, &addr))
3326
				saddr->state = SCTP_ADDR_SRC;
3327
		}
3328
		local_bh_enable();
3329 3330
		list_for_each_entry(transport, &asoc->peer.transport_addr_list,
				transports) {
3331
			sctp_transport_dst_release(transport);
3332
		}
L
Linus Torvalds 已提交
3333 3334
		break;
	case SCTP_PARAM_DEL_IP:
3335
		local_bh_disable();
3336
		sctp_del_bind_addr(bp, &addr);
3337 3338 3339 3340 3341
		if (asoc->asconf_addr_del_pending != NULL &&
		    sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
			kfree(asoc->asconf_addr_del_pending);
			asoc->asconf_addr_del_pending = NULL;
		}
3342
		local_bh_enable();
3343 3344
		list_for_each_entry(transport, &asoc->peer.transport_addr_list,
				transports) {
3345
			sctp_transport_dst_release(transport);
L
Linus Torvalds 已提交
3346 3347 3348 3349 3350 3351 3352 3353 3354
		}
		break;
	default:
		break;
	}
}

/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
 * for the given asconf parameter.  If there is no response for this parameter,
3355
 * return the error code based on the third argument 'no_err'.
L
Linus Torvalds 已提交
3356 3357 3358 3359 3360 3361
 * ADDIP 4.1
 * A7) If an error response is received for a TLV parameter, all TLVs with no
 * response before the failed TLV are considered successful if not reported.
 * All TLVs after the failed response are considered unsuccessful unless a
 * specific success indication is present for the parameter.
 */
3362
static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3363 3364
				       struct sctp_addip_param *asconf_param,
				       int no_err)
L
Linus Torvalds 已提交
3365
{
3366
	struct sctp_addip_param	*asconf_ack_param;
3367 3368 3369 3370
	struct sctp_errhdr *err_param;
	int asconf_ack_len;
	__be16 err_code;
	int length;
L
Linus Torvalds 已提交
3371 3372 3373 3374 3375 3376

	if (no_err)
		err_code = SCTP_ERROR_NO_ERROR;
	else
		err_code = SCTP_ERROR_REQ_REFUSED;

3377
	asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3378
			 sizeof(struct sctp_chunkhdr);
3379

L
Linus Torvalds 已提交
3380 3381
	/* Skip the addiphdr from the asconf_ack chunk and store a pointer to
	 * the first asconf_ack parameter.
3382
	 */
3383
	length = sizeof(struct sctp_addiphdr);
3384 3385
	asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
						       length);
L
Linus Torvalds 已提交
3386 3387 3388 3389
	asconf_ack_len -= length;

	while (asconf_ack_len > 0) {
		if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3390
			switch (asconf_ack_param->param_hdr.type) {
L
Linus Torvalds 已提交
3391 3392 3393
			case SCTP_PARAM_SUCCESS_REPORT:
				return SCTP_ERROR_NO_ERROR;
			case SCTP_PARAM_ERR_CAUSE:
3394
				length = sizeof(*asconf_ack_param);
J
Joe Perches 已提交
3395
				err_param = (void *)asconf_ack_param + length;
L
Linus Torvalds 已提交
3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407
				asconf_ack_len -= length;
				if (asconf_ack_len > 0)
					return err_param->cause;
				else
					return SCTP_ERROR_INV_PARAM;
				break;
			default:
				return SCTP_ERROR_INV_PARAM;
			}
		}

		length = ntohs(asconf_ack_param->param_hdr.length);
J
Joe Perches 已提交
3408
		asconf_ack_param = (void *)asconf_ack_param + length;
L
Linus Torvalds 已提交
3409 3410 3411 3412 3413 3414 3415 3416 3417 3418
		asconf_ack_len -= length;
	}

	return err_code;
}

/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
int sctp_process_asconf_ack(struct sctp_association *asoc,
			    struct sctp_chunk *asconf_ack)
{
3419 3420 3421 3422 3423 3424 3425 3426 3427
	struct sctp_chunk *asconf = asoc->addip_last_asconf;
	struct sctp_addip_param *asconf_param;
	__be16 err_code = SCTP_ERROR_NO_ERROR;
	union sctp_addr_param *addr_param;
	int asconf_len = asconf->skb->len;
	int all_param_pass = 0;
	int length = 0;
	int no_err = 1;
	int retval = 0;
L
Linus Torvalds 已提交
3428 3429 3430

	/* Skip the chunkhdr and addiphdr from the last asconf sent and store
	 * a pointer to address parameter.
3431
	 */
3432
	length = sizeof(struct sctp_addip_chunk);
L
Linus Torvalds 已提交
3433 3434 3435 3436
	addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
	asconf_len -= length;

	/* Skip the address parameter in the last asconf sent and store a
J
Joe Perches 已提交
3437
	 * pointer to the first asconf parameter.
3438
	 */
3439
	length = ntohs(addr_param->p.length);
J
Joe Perches 已提交
3440
	asconf_param = (void *)addr_param + length;
L
Linus Torvalds 已提交
3441 3442 3443 3444 3445 3446 3447
	asconf_len -= length;

	/* ADDIP 4.1
	 * A8) If there is no response(s) to specific TLV parameter(s), and no
	 * failures are indicated, then all request(s) are considered
	 * successful.
	 */
3448
	if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
L
Linus Torvalds 已提交
3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464
		all_param_pass = 1;

	/* Process the TLVs contained in the last sent ASCONF chunk. */
	while (asconf_len > 0) {
		if (all_param_pass)
			err_code = SCTP_ERROR_NO_ERROR;
		else {
			err_code = sctp_get_asconf_response(asconf_ack,
							    asconf_param,
							    no_err);
			if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
				no_err = 0;
		}

		switch (err_code) {
		case SCTP_ERROR_NO_ERROR:
3465
			sctp_asconf_param_success(asoc, asconf_param);
L
Linus Torvalds 已提交
3466 3467 3468 3469 3470 3471
			break;

		case SCTP_ERROR_RSRC_LOW:
			retval = 1;
			break;

3472
		case SCTP_ERROR_UNKNOWN_PARAM:
L
Linus Torvalds 已提交
3473 3474
			/* Disable sending this type of asconf parameter in
			 * future.
3475
			 */
L
Linus Torvalds 已提交
3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488
			asoc->peer.addip_disabled_mask |=
				asconf_param->param_hdr.type;
			break;

		case SCTP_ERROR_REQ_REFUSED:
		case SCTP_ERROR_DEL_LAST_IP:
		case SCTP_ERROR_DEL_SRC_IP:
		default:
			 break;
		}

		/* Skip the processed asconf parameter and move to the next
		 * one.
3489
		 */
L
Linus Torvalds 已提交
3490
		length = ntohs(asconf_param->param_hdr.length);
J
Joe Perches 已提交
3491
		asconf_param = (void *)asconf_param + length;
L
Linus Torvalds 已提交
3492 3493 3494
		asconf_len -= length;
	}

3495
	if (no_err && asoc->src_out_of_asoc_ok) {
3496
		asoc->src_out_of_asoc_ok = 0;
3497 3498
		sctp_transport_immediate_rtx(asoc->peer.primary_path);
	}
3499

L
Linus Torvalds 已提交
3500
	/* Free the cached last sent asconf chunk. */
3501
	list_del_init(&asconf->transmitted_list);
L
Linus Torvalds 已提交
3502 3503 3504 3505 3506 3507
	sctp_chunk_free(asconf);
	asoc->addip_last_asconf = NULL;

	return retval;
}

3508
/* Make a FWD TSN chunk. */
L
Linus Torvalds 已提交
3509 3510 3511 3512 3513
struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
				    __u32 new_cum_tsn, size_t nstreams,
				    struct sctp_fwdtsn_skip *skiplist)
{
	struct sctp_chunk *retval = NULL;
3514
	struct sctp_fwdtsn_hdr ftsn_hdr;
L
Linus Torvalds 已提交
3515 3516 3517 3518 3519 3520
	struct sctp_fwdtsn_skip skip;
	size_t hint;
	int i;

	hint = (nstreams + 1) * sizeof(__u32);

3521
	retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
L
Linus Torvalds 已提交
3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537

	if (!retval)
		return NULL;

	ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
	retval->subh.fwdtsn_hdr =
		sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);

	for (i = 0; i < nstreams; i++) {
		skip.stream = skiplist[i].stream;
		skip.ssn = skiplist[i].ssn;
		sctp_addto_chunk(retval, sizeof(skip), &skip);
	}

	return retval;
}
3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553

/* RE-CONFIG 3.1 (RE-CONFIG chunk)
 *   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 = 130    |  Chunk Flags  |      Chunk Length             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  \                                                               \
 *  /                  Re-configuration Parameter                   /
 *  \                                                               \
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  \                                                               \
 *  /             Re-configuration Parameter (optional)             /
 *  \                                                               \
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
3554 3555
static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
					   int length)
3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605
{
	struct sctp_reconf_chunk *reconf;
	struct sctp_chunk *retval;

	retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
				   GFP_ATOMIC);
	if (!retval)
		return NULL;

	reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
	retval->param_hdr.v = reconf->params;

	return retval;
}

/* RE-CONFIG 4.1 (STREAM OUT RESET)
 *   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
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 13       | Parameter Length = 16 + 2 * N |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |           Re-configuration Request Sequence Number            |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |           Re-configuration Response Sequence Number           |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                Sender's Last Assigned TSN                     |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  /                            ......                             /
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * RE-CONFIG 4.2 (STREAM IN RESET)
 *   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
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 14       |  Parameter Length = 8 + 2 * N |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |          Re-configuration Request Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  /                            ......                             /
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct sctp_chunk *sctp_make_strreset_req(
3606
					const struct sctp_association *asoc,
3607
					__u16 stream_num, __be16 *stream_list,
3608
					bool out, bool in)
3609
{
3610
	__u16 stream_len = stream_num * sizeof(__u16);
3611 3612 3613
	struct sctp_strreset_outreq outreq;
	struct sctp_strreset_inreq inreq;
	struct sctp_chunk *retval;
3614
	__u16 outlen, inlen;
3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648

	outlen = (sizeof(outreq) + stream_len) * out;
	inlen = (sizeof(inreq) + stream_len) * in;

	retval = sctp_make_reconf(asoc, outlen + inlen);
	if (!retval)
		return NULL;

	if (outlen) {
		outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
		outreq.param_hdr.length = htons(outlen);
		outreq.request_seq = htonl(asoc->strreset_outseq);
		outreq.response_seq = htonl(asoc->strreset_inseq - 1);
		outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);

		sctp_addto_chunk(retval, sizeof(outreq), &outreq);

		if (stream_len)
			sctp_addto_chunk(retval, stream_len, stream_list);
	}

	if (inlen) {
		inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
		inreq.param_hdr.length = htons(inlen);
		inreq.request_seq = htonl(asoc->strreset_outseq + out);

		sctp_addto_chunk(retval, sizeof(inreq), &inreq);

		if (stream_len)
			sctp_addto_chunk(retval, stream_len, stream_list);
	}

	return retval;
}
3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659

/* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
 *   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
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 15       |      Parameter Length = 8     |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |         Re-configuration Request Sequence Number              |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct sctp_chunk *sctp_make_strreset_tsnreq(
3660
					const struct sctp_association *asoc)
3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677
{
	struct sctp_strreset_tsnreq tsnreq;
	__u16 length = sizeof(tsnreq);
	struct sctp_chunk *retval;

	retval = sctp_make_reconf(asoc, length);
	if (!retval)
		return NULL;

	tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
	tsnreq.param_hdr.length = htons(length);
	tsnreq.request_seq = htonl(asoc->strreset_outseq);

	sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);

	return retval;
}
3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690

/* RE-CONFIG 4.5/4.6 (ADD STREAM)
 *   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
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 17       |      Parameter Length = 12    |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |          Re-configuration Request Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |      Number of new streams    |         Reserved              |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct sctp_chunk *sctp_make_strreset_addstrm(
3691 3692
					const struct sctp_association *asoc,
					__u16 out, __u16 in)
3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723
{
	struct sctp_strreset_addstrm addstrm;
	__u16 size = sizeof(addstrm);
	struct sctp_chunk *retval;

	retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
	if (!retval)
		return NULL;

	if (out) {
		addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
		addstrm.param_hdr.length = htons(size);
		addstrm.number_of_streams = htons(out);
		addstrm.request_seq = htonl(asoc->strreset_outseq);
		addstrm.reserved = 0;

		sctp_addto_chunk(retval, size, &addstrm);
	}

	if (in) {
		addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
		addstrm.param_hdr.length = htons(size);
		addstrm.number_of_streams = htons(in);
		addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
		addstrm.reserved = 0;

		sctp_addto_chunk(retval, size, &addstrm);
	}

	return retval;
}
3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735

/* RE-CONFIG 4.4 (RESP)
 *   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
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 16       |      Parameter Length         |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |         Re-configuration Response Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                            Result                             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
3736 3737
struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
					   __u32 result, __u32 sn)
3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771
{
	struct sctp_strreset_resp resp;
	__u16 length = sizeof(resp);
	struct sctp_chunk *retval;

	retval = sctp_make_reconf(asoc, length);
	if (!retval)
		return NULL;

	resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
	resp.param_hdr.length = htons(length);
	resp.response_seq = htonl(sn);
	resp.result = htonl(result);

	sctp_addto_chunk(retval, sizeof(resp), &resp);

	return retval;
}

/* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
 *   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
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 16       |      Parameter Length         |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |         Re-configuration Response Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                            Result                             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                   Sender's Next TSN (optional)                |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                  Receiver's Next TSN (optional)               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
3772 3773 3774 3775
struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
					      __u32 result, __u32 sn,
					      __u32 sender_tsn,
					      __u32 receiver_tsn)
3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796
{
	struct sctp_strreset_resptsn tsnresp;
	__u16 length = sizeof(tsnresp);
	struct sctp_chunk *retval;

	retval = sctp_make_reconf(asoc, length);
	if (!retval)
		return NULL;

	tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
	tsnresp.param_hdr.length = htons(length);

	tsnresp.response_seq = htonl(sn);
	tsnresp.result = htonl(result);
	tsnresp.senders_next_tsn = htonl(sender_tsn);
	tsnresp.receivers_next_tsn = htonl(receiver_tsn);

	sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);

	return retval;
}
3797 3798 3799 3800 3801 3802 3803

bool sctp_verify_reconf(const struct sctp_association *asoc,
			struct sctp_chunk *chunk,
			struct sctp_paramhdr **errp)
{
	struct sctp_reconf_chunk *hdr;
	union sctp_params param;
3804 3805
	__be16 last = 0;
	__u16 cnt = 0;
3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856

	hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
	sctp_walk_params(param, hdr, params) {
		__u16 length = ntohs(param.p->length);

		*errp = param.p;
		if (cnt++ > 2)
			return false;
		switch (param.p->type) {
		case SCTP_PARAM_RESET_OUT_REQUEST:
			if (length < sizeof(struct sctp_strreset_outreq) ||
			    (last && last != SCTP_PARAM_RESET_RESPONSE &&
			     last != SCTP_PARAM_RESET_IN_REQUEST))
				return false;
			break;
		case SCTP_PARAM_RESET_IN_REQUEST:
			if (length < sizeof(struct sctp_strreset_inreq) ||
			    (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
				return false;
			break;
		case SCTP_PARAM_RESET_RESPONSE:
			if ((length != sizeof(struct sctp_strreset_resp) &&
			     length != sizeof(struct sctp_strreset_resptsn)) ||
			    (last && last != SCTP_PARAM_RESET_RESPONSE &&
			     last != SCTP_PARAM_RESET_OUT_REQUEST))
				return false;
			break;
		case SCTP_PARAM_RESET_TSN_REQUEST:
			if (length !=
			    sizeof(struct sctp_strreset_tsnreq) || last)
				return false;
			break;
		case SCTP_PARAM_RESET_ADD_IN_STREAMS:
			if (length != sizeof(struct sctp_strreset_addstrm) ||
			    (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
				return false;
			break;
		case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
			if (length != sizeof(struct sctp_strreset_addstrm) ||
			    (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
				return false;
			break;
		default:
			return false;
		}

		last = param.p->type;
	}

	return true;
}