sm_make_chunk.c 95.3 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
 * along with GNU CC; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 *
 * Or submit a bug report through the following website:
 *    http://www.sf.net/projects/lksctp
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    C. Robin              <chris@hundredacre.ac.uk>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
 *    Sridhar Samudrala	    <sri@us.ibm.com>
 *    Daisy Chang	    <daisyc@us.ibm.com>
 *    Ardelle Fan	    <ardelle.fan@intel.com>
 *    Kevin Gao             <kevin.gao@intel.com>
 *
 * Any bugs reported given to us we will try to fix... any fixes shared will
 * be incorporated into the next SCTP release.
 */

#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/crypto.h>
#include <net/sock.h>

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

SCTP_STATIC
struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
				   __u8 type, __u8 flags, int paylen);
static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const struct sctp_chunk *init_chunk,
					int *cookie_len,
					const __u8 *raw_addrs, int addrs_len);
static int sctp_process_param(struct sctp_association *asoc,
			      union sctp_params param,
			      const union sctp_addr *peer_addr,
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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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/* What was the inbound interface for this chunk? */
int sctp_chunk_iif(const struct sctp_chunk *chunk)
{
	struct sctp_af *af;
	int iif = 0;

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	af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
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	if (af)
		iif = af->skb_iif(chunk->skb);

	return iif;
}

/* RFC 2960 3.3.2 Initiation (INIT) (1)
 *
 * Note 2: The ECN capable field is reserved for future use of
 * Explicit Congestion Notification.
 */
static const struct sctp_paramhdr ecap_param = {
	SCTP_PARAM_ECN_CAPABLE,
	__constant_htons(sizeof(struct sctp_paramhdr)),
};
static const struct sctp_paramhdr prsctp_param = {
	SCTP_PARAM_FWD_TSN_SUPPORT,
	__constant_htons(sizeof(struct sctp_paramhdr)),
};

/* A helper to initialize to initialize an op error inside a
 * 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,
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		      size_t paylen)
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{
	sctp_errhdr_t err;
	__u16 len;

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	/* Cause code constants are now defined in network order.  */
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	err.cause = cause_code;
	len = sizeof(sctp_errhdr_t) + paylen;
	err.length  = htons(len);
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	chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
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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,
			     const struct sctp_bind_addr *bp,
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			     gfp_t gfp, int vparam_len)
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{
	sctp_inithdr_t init;
	union sctp_params addrs;
	size_t chunksize;
	struct sctp_chunk *retval = NULL;
	int num_types, addrs_len = 0;
	struct sctp_sock *sp;
	sctp_supported_addrs_param_t sat;
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	__be16 types[2];
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	sctp_adaptation_ind_param_t aiparam;
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	sctp_supported_ext_param_t ext_param;
	int num_ext = 0;
	__u8 extensions[3];
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	sctp_paramhdr_t *auth_chunks = NULL,
			*auth_hmacs = NULL;
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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.
	 */
	retval = NULL;

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

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

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

	chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types);
	chunksize += sizeof(ecap_param);
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	if (sctp_prsctp_enable)
		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.
	 */
	if (sctp_addip_enable) {
		extensions[num_ext] = SCTP_CID_ASCONF;
		extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
		num_ext += 2;
	}

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	chunksize += sizeof(aiparam);
	chunksize += vparam_len;

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

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

		/* Add CHUNKS parameter length */
		auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
		if (auth_chunks->length)
			chunksize += ntohs(auth_chunks->length);
		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)
		chunksize += sizeof(sctp_supported_ext_param_t) + 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.]
	 */

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

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

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

	sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
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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;
		ext_param.param_hdr.length =
			    htons(sizeof(sctp_supported_ext_param_t) + num_ext);
		sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
				&ext_param);
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		sctp_addto_param(retval, num_ext, extensions);
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	}

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	if (sctp_prsctp_enable)
		sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
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	aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
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	aiparam.param_hdr.length = htons(sizeof(aiparam));
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	aiparam.adaptation_ind = htonl(sp->adaptation_ind);
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	sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
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	/* Add SCTP-AUTH chunks to the parameter list */
	if (sctp_auth_enable) {
		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,
				 const struct sctp_chunk *chunk,
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				 gfp_t gfp, int unkparam_len)
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{
	sctp_inithdr_t initack;
	struct sctp_chunk *retval;
	union sctp_params addrs;
	int addrs_len;
	sctp_cookie_param_t *cookie;
	int cookie_len;
	size_t chunksize;
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	sctp_adaptation_ind_param_t aiparam;
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	sctp_supported_ext_param_t ext_param;
	int num_ext = 0;
	__u8 extensions[3];
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	sctp_paramhdr_t *auth_chunks = NULL,
			*auth_hmacs = NULL,
			*auth_random = NULL;
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	retval = NULL;

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

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

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

	/* Calculate the total size of allocation, include the reserved
	 * space for reporting unknown parameters if it is specified.
	 */
	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 (sctp_prsctp_enable)
		chunksize += sizeof(prsctp_param);

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	if (sctp_addip_enable) {
		extensions[num_ext] = SCTP_CID_ASCONF;
		extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
		num_ext += 2;
	}

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	chunksize += sizeof(aiparam);

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

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

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

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

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	if (num_ext)
		chunksize += sizeof(sctp_supported_ext_param_t) + num_ext;

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	/* Now allocate and fill out the chunk.  */
	retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
	if (!retval)
		goto nomem_chunk;

	/* Per the advice in RFC 2960 6.4, send this reply to
	 * the source of the INIT packet.
	 */
	retval->transport = chunk->transport;
	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;
		ext_param.param_hdr.length =
			    htons(sizeof(sctp_supported_ext_param_t) + num_ext);
		sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
				 &ext_param);
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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);

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	aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
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	aiparam.param_hdr.length = htons(sizeof(aiparam));
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	aiparam.adaptation_ind = htonl(sctp_sk(asoc->base.sk)->adaptation_ind);
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	sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);

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	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;

	/* 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.]
	 */
	if (chunk)
		retval->transport = chunk->transport;

nomem_chunk:
	kfree(cookie);
nomem_cookie:
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	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,
				    const struct sctp_chunk *chunk)
{
	struct sctp_chunk *retval;
	void *cookie;
	int cookie_len;

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

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

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

nodata:
	return retval;
}

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

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

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

	return retval;
}

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

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

	if (!retval)
		goto nodata;

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

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

nodata:
	return retval;
}

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

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

nodata:
	return retval;
}

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

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

	/* Set the flags for an unordered send.  */
675
	if (sinfo->sinfo_flags & SCTP_UNORDERED) {
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		flags |= SCTP_DATA_UNORDERED;
		dp.ssn = 0;
	} else
		dp.ssn = htons(ssn);

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

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

nodata:
	return retval;
}

/* Create a selective ackowledgement (SACK) for the given
 * association.  This reports on which TSN's we've seen to date,
 * including duplicates and gaps.
 */
struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
{
	struct sctp_chunk *retval;
	struct sctp_sackhdr sack;
	int len;
	__u32 ctsn;
	__u16 num_gabs, num_dup_tsns;
	struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;

	ctsn = sctp_tsnmap_get_ctsn(map);
	SCTP_DEBUG_PRINTK("sackCTSNAck sent:  0x%x.\n", ctsn);

	/* How much room is needed in the chunk? */
	num_gabs = sctp_tsnmap_num_gabs(map);
	num_dup_tsns = sctp_tsnmap_num_dups(map);

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

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

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

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

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

	/* Add the gap ack block information.   */
	if (num_gabs)
		sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
				 sctp_tsnmap_get_gabs(map));

	/* Add the duplicate TSN information.  */
	if (num_dup_tsns)
		sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
				 sctp_tsnmap_get_dups(map));

nodata:
	return retval;
}

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

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

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

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

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

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

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

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

	return retval;
}

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

831 832 833
	/* Set the T-bit if we have no association (vtag will be
	 * reflected)
	 */
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	flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;

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

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

851
	return retval;
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}

/* Create an ABORT.  Note that we set the T bit if we have no
855
 * 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,
			      const struct sctp_chunk *chunk,
			      const size_t hint)
{
	struct sctp_chunk *retval;
	__u8 flags = 0;

864 865 866 867 868 869 870 871 872 873
	/* 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;
	}
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	retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);

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

	return retval;
}

/* Helper to create ABORT with a NO_USER_DATA error.  */
struct sctp_chunk *sctp_make_abort_no_data(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk, __u32 tsn)
{
	struct sctp_chunk *retval;
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	__be32 payload;
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	retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
				 + sizeof(tsn));

	if (!retval)
		goto no_mem;

	/* Put the tsn back into network byte order.  */
	payload = htonl(tsn);
908 909
	sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
	sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
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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,
929 930
					const struct msghdr *msg,
					size_t paylen)
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{
	struct sctp_chunk *retval;
933 934
	void *payload = NULL;
	int err;
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936
	retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
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	if (!retval)
		goto err_chunk;

	if (paylen) {
		/* Put the msg_iov together into payload.  */
942
		payload = kmalloc(paylen, GFP_KERNEL);
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		if (!payload)
			goto err_payload;
945 946 947 948

		err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
		if (err < 0)
			goto err_copy;
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	}

951 952
	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;
}

968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987
/* Append bytes to the end of a parameter.  Will panic if chunk is not big
 * enough.
 */
static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
			      const void *data)
{
	void *target;
	int chunklen = ntohs(chunk->chunk_hdr->length);

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

	memcpy(target, data, len);

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

	return target;
}

988
/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
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struct sctp_chunk *sctp_make_abort_violation(
	const struct sctp_association *asoc,
	const struct sctp_chunk *chunk,
	const __u8   *payload,
	const size_t paylen)
{
	struct sctp_chunk  *retval;
	struct sctp_paramhdr phdr;

	retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
999
					+ sizeof(sctp_paramhdr_t));
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	if (!retval)
		goto end;

1003 1004
	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
					+ sizeof(sctp_paramhdr_t));
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	phdr.type = htons(chunk->chunk_hdr->type);
	phdr.length = chunk->chunk_hdr->length;
1008 1009
	sctp_addto_chunk(retval, paylen, payload);
	sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
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end:
	return retval;
}

/* Make a HEARTBEAT chunk.  */
struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
				  const struct sctp_transport *transport,
				  const void *payload, const size_t paylen)
{
	struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT,
						    0, paylen);

	if (!retval)
		goto nodata;

	/* Cast away the 'const', as this is just telling the chunk
	 * what transport it belongs to.
	 */
	retval->transport = (struct sctp_transport *) transport;
	retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);

nodata:
	return retval;
}

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

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

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

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

nodata:
	return retval;
}

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

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

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

nodata:
	return retval;
}

/* Create an Operation Error chunk.  */
struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
				 const struct sctp_chunk *chunk,
1097
				 __be16 cause_code, const void *payload,
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				 size_t paylen)
{
	struct sctp_chunk *retval;

	retval = sctp_make_op_error_space(asoc, chunk, paylen);
	if (!retval)
		goto nodata;

1106 1107
	sctp_init_cause(retval, cause_code, paylen);
	sctp_addto_chunk(retval, paylen, payload);
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nodata:
	return retval;
}

1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
{
	struct sctp_chunk *retval;
	struct sctp_hmac *hmac_desc;
	struct sctp_authhdr auth_hdr;
	__u8 *hmac;

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

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

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

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

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

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

	return retval;
}


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/********************************************************************
 * 2nd Level Abstractions
 ********************************************************************/

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

1161
	retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
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	if (!retval)
		goto nodata;

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

1170
	INIT_LIST_HEAD(&retval->list);
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	retval->skb		= skb;
	retval->asoc		= (struct sctp_association *)asoc;
	retval->resent  	= 0;
	retval->has_tsn		= 0;
	retval->has_ssn         = 0;
	retval->rtt_in_progress	= 0;
	retval->sent_at		= 0;
	retval->singleton	= 1;
	retval->end_of_packet	= 0;
	retval->ecn_ce_done	= 0;
	retval->pdiscard	= 0;

	/* sctpimpguide-05.txt Section 2.8.2
	 * M1) Each time a new DATA chunk is transmitted
	 * set the 'TSN.Missing.Report' count for that TSN to 0. The
	 * 'TSN.Missing.Report' count will be used to determine missing chunks
	 * and when to fast retransmit.
	 */
	retval->tsn_missing_report = 0;
	retval->tsn_gap_acked = 0;
	retval->fast_retransmit = 0;

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

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

nodata:
	return retval;
}

/* Set chunk->source and dest based on the IP header in chunk->skb.  */
void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
		     union sctp_addr *dest)
{
1212
	memcpy(&chunk->source, src, sizeof(union sctp_addr));
1213
	memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
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}

/* 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) {
1221
		return &chunk->transport->ipaddr;
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	} else {
		/* Otherwise, extract it from the IP header.  */
1224
		return &chunk->source;
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	}
}

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

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

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

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

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

1262 1263 1264 1265
	/* Determine if the chunk needs to be authenticated */
	if (sctp_auth_send_cid(type, asoc))
		retval->auth = 1;

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	/* Set the skb to the belonging sock for accounting.  */
	skb->sk = sk;

	return retval;
nodata:
	return NULL;
}


/* Release the memory occupied by a chunk.  */
static void sctp_chunk_destroy(struct sctp_chunk *chunk)
{
1278 1279 1280
	BUG_ON(!list_empty(&chunk->list));
	list_del_init(&chunk->transmitted_list);

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	/* Free the chunk skb data and the SCTP_chunk stub itself. */
	dev_kfree_skb(chunk->skb);

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

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

	sctp_chunk_put(chunk);
}

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

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

/* Append bytes to the end of a chunk.  Will panic if chunk is not big
 * enough.
 */
void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
{
	void *target;
	void *padding;
	int chunklen = ntohs(chunk->chunk_hdr->length);
1319
	int padlen = WORD_ROUND(chunklen) - chunklen;
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	padding = skb_put(chunk->skb, padlen);
	target = skb_put(chunk->skb, len);

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

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1329
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
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	return target;
}

/* Append bytes from user space to the end of a chunk.  Will panic if
 * chunk is not big enough.
 * Returns a kernel err value.
 */
int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
			  struct iovec *data)
{
	__u8 *target;
	int err = 0;

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

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

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length =
		htons(ntohs(chunk->chunk_hdr->length) + len);
1354
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
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out:
	return err;
}

/* Helper function to assign a TSN if needed.  This assumes that both
 * the data_hdr and association have already been assigned.
 */
void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
{
1365 1366 1367
	struct sctp_datamsg *msg;
	struct sctp_chunk *lchunk;
	struct sctp_stream *stream;
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	__u16 ssn;
	__u16 sid;

	if (chunk->has_ssn)
		return;

1374 1375 1376
	/* All fragments will be on the same stream */
	sid = ntohs(chunk->subh.data_hdr->stream);
	stream = &chunk->asoc->ssnmap->out;
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1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394
	/* Now assign the sequence number to the entire message.
	 * All fragments must have the same stream sequence number.
	 */
	msg = chunk->msg;
	list_for_each_entry(lchunk, &msg->chunks, frag_list) {
		if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
			ssn = 0;
		} else {
			if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
				ssn = sctp_ssn_next(stream, sid);
			else
				ssn = sctp_ssn_peek(stream, sid);
		}

		lchunk->subh.data_hdr->ssn = htons(ssn);
		lchunk->has_ssn = 1;
	}
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}

/* 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,
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					struct sctp_chunk *chunk,
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					gfp_t gfp)
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{
	struct sctp_association *asoc;
	struct sk_buff *skb;
	sctp_scope_t scope;
	struct sctp_af *af;

	/* Create the bare association.  */
	scope = sctp_scope(sctp_source(chunk));
	asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
	if (!asoc)
		goto nodata;
	asoc->temp = 1;
	skb = chunk->skb;
	/* Create an entry for the source address of the packet.  */
1430
	af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
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	if (unlikely(!af))
		goto fail;
1433
	af->from_skb(&asoc->c.peer_addr, skb, 1);
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nodata:
	return asoc;

fail:
	sctp_association_free(asoc);
	return NULL;
}

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

1458 1459 1460
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
1461 1462
	headersize = sizeof(sctp_paramhdr_t) +
		     (sizeof(struct sctp_signed_cookie) -
1463
		      sizeof(struct sctp_cookie));
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	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.
	 */
1478 1479 1480 1481
	retval = kzalloc(*cookie_len, GFP_ATOMIC);
	if (!retval)
		goto nodata;

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	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;

1496 1497
	/* Save adaptation indication in the cookie. */
	cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
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	/* Set an expiration time for the cookie.  */
	do_gettimeofday(&cookie->c.expiration);
	TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);

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

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

1511
	if (sctp_sk(ep->base.sk)->hmac) {
1512 1513
		struct hash_desc desc;

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		/* Sign the message.  */
1515
		sg_init_one(&sg, &cookie->c, bodysize);
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		keylen = SCTP_SECRET_SIZE;
		key = (char *)ep->secret_key[ep->current_key];
1518 1519
		desc.tfm = sctp_sk(ep->base.sk)->hmac;
		desc.flags = 0;
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1521 1522 1523
		if (crypto_hash_setkey(desc.tfm, key, keylen) ||
		    crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
			goto free_cookie;
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	}

	return retval;
1527 1528 1529 1530 1531 1532

free_cookie:
	kfree(retval);
nodata:
	*cookie_len = 0;
	return NULL;
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}

/* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
struct sctp_association *sctp_unpack_cookie(
	const struct sctp_endpoint *ep,
	const struct sctp_association *asoc,
A
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	struct sctp_chunk *chunk, gfp_t gfp,
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	int *error, struct sctp_chunk **errp)
{
	struct sctp_association *retval = NULL;
	struct sctp_signed_cookie *cookie;
	struct sctp_cookie *bear_cookie;
	int headersize, bodysize, fixed_size;
1546
	__u8 *digest = ep->digest;
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	struct scatterlist sg;
	unsigned int keylen, len;
	char *key;
	sctp_scope_t scope;
	struct sk_buff *skb = chunk->skb;
1552
	struct timeval tv;
1553
	struct hash_desc desc;
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1555 1556 1557 1558
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
	headersize = sizeof(sctp_chunkhdr_t) +
1559
		     (sizeof(struct sctp_signed_cookie) -
1560
		      sizeof(struct sctp_cookie));
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	bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
	fixed_size = headersize + sizeof(struct sctp_cookie);

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

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

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

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

	/* Check the signature.  */
	keylen = SCTP_SECRET_SIZE;
1585
	sg_init_one(&sg, bear_cookie, bodysize);
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	key = (char *)ep->secret_key[ep->current_key];
1587 1588
	desc.tfm = sctp_sk(ep->base.sk)->hmac;
	desc.flags = 0;
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	memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1591 1592 1593 1594 1595
	if (crypto_hash_setkey(desc.tfm, key, keylen) ||
	    crypto_hash_digest(&desc, &sg, bodysize, digest)) {
		*error = -SCTP_IERROR_NOMEM;
		goto fail;
	}
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	if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
		/* Try the previous key. */
		key = (char *)ep->secret_key[ep->last_key];
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		memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1601 1602 1603 1604 1605
		if (crypto_hash_setkey(desc.tfm, key, keylen) ||
		    crypto_hash_digest(&desc, &sg, bodysize, digest)) {
			*error = -SCTP_IERROR_NOMEM;
			goto fail;
		}
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		if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
			/* Yikes!  Still bad signature! */
			*error = -SCTP_IERROR_BAD_SIG;
			goto fail;
		}
	}

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

1627
	if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
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	    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.
1636 1637 1638 1639
	 * 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.
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	 */
1641 1642 1643 1644 1645
	if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
		skb_get_timestamp(skb, &tv);
	else
		do_gettimeofday(&tv);

1646
	if (!asoc && tv_lt(bear_cookie->expiration, tv)) {
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		/*
		 * 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) {
1658
			suseconds_t usecs = (tv.tv_sec -
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				bear_cookie->expiration.tv_sec) * 1000000L +
1660
				tv.tv_usec - bear_cookie->expiration.tv_usec;
1661
			__be32 n = htonl(usecs);
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			sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1664 1665
					sizeof(n));
			sctp_addto_chunk(*errp, sizeof(n), &n);
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			*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)) {
1695 1696
		sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
				SCTP_ADDR_SRC, GFP_ATOMIC);
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	}

	retval->next_tsn = retval->c.initial_tsn;
	retval->ctsn_ack_point = retval->next_tsn - 1;
	retval->addip_serial = retval->c.initial_tsn;
	retval->adv_peer_ack_point = retval->ctsn_ack_point;
	retval->peer.prsctp_capable = retval->c.prsctp_capable;
1704
	retval->peer.adaptation_ind = retval->c.adaptation_ind;
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	/* 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
1728 1729
	__be32 num_missing;
	__be16 type;
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}  __attribute__((packed));

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

	len = WORD_ROUND(sizeof(report));

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

	if (*errp) {
		report.num_missing = htonl(1);
		report.type = paramtype;
1754
		sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1755 1756
				sizeof(report));
		sctp_addto_chunk(*errp, sizeof(report), &report);
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	}

	/* 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)
1774
		sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
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	/* 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)
{
	char		error[] = "The following parameter had invalid length:";
1786
	size_t		payload_len = WORD_ROUND(sizeof(error)) +
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						sizeof(sctp_paramhdr_t);


1790 1791 1792 1793 1794 1795
	/* This is a fatal error.  Any accumulated non-fatal errors are
	 * not reported.
	 */
	if (*errp)
		sctp_chunk_free(*errp);

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	/* Create an error chunk and fill it in with our payload. */
1797
	*errp = sctp_make_op_error_space(asoc, chunk, payload_len);
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	if (*errp) {
1800 1801 1802 1803
		sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION,
				sizeof(error) + sizeof(sctp_paramhdr_t));
		sctp_addto_chunk(*errp, sizeof(error), error);
		sctp_addto_param(*errp, sizeof(sctp_paramhdr_t), param);
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	}

	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);

1820 1821 1822 1823 1824 1825 1826 1827 1828
	/* 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
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1830 1831 1832 1833
	if (*errp) {
		sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
		sctp_addto_chunk(*errp, len, param.v);
	}
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1834 1835 1836 1837 1838

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

1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871
static int sctp_verify_ext_param(union sctp_params param)
{
	__u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
	int have_auth = 0;
	int have_asconf = 0;
	int i;

	for (i = 0; i < num_ext; i++) {
		switch (param.ext->chunks[i]) {
		    case SCTP_CID_AUTH:
			    have_auth = 1;
			    break;
		    case SCTP_CID_ASCONF:
		    case SCTP_CID_ASCONF_ACK:
			    have_asconf = 1;
			    break;
		}
	}

	/* 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.
	 */
	if (sctp_addip_noauth)
		return 1;

	if (sctp_addip_enable && !have_auth && have_asconf)
		return 0;

	return 1;
}

1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884
static void sctp_process_ext_param(struct sctp_association *asoc,
				    union sctp_params param)
{
	__u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
	int i;

	for (i = 0; i < num_ext; i++) {
		switch (param.ext->chunks[i]) {
		    case SCTP_CID_FWD_TSN:
			    if (sctp_prsctp_enable &&
				!asoc->peer.prsctp_capable)
				    asoc->peer.prsctp_capable = 1;
			    break;
1885 1886 1887 1888 1889 1890
		    case SCTP_CID_AUTH:
			    /* if the peer reports AUTH, assume that he
			     * supports AUTH.
			     */
			    asoc->peer.auth_capable = 1;
			    break;
1891 1892
		    case SCTP_CID_ASCONF:
		    case SCTP_CID_ASCONF_ACK:
1893
			    asoc->peer.asconf_capable = 1;
1894
			    break;
1895 1896 1897 1898 1899 1900
		    default:
			    break;
		}
	}
}

L
Linus Torvalds 已提交
1901 1902 1903 1904 1905 1906 1907
/* 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.
 *
1908 1909
 * 00 - Stop processing this parameter; do not process any further
 * 	parameters within this chunk
L
Linus Torvalds 已提交
1910
 *
1911 1912 1913
 * 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
1914 1915 1916 1917 1918
 *
 * 10 - Skip this parameter and continue processing.
 *
 * 11 - Skip this parameter and continue processing but
 *	report the unrecognized parameter in an
1919
 *	'Unrecognized Parameter' ERROR chunk.
L
Linus Torvalds 已提交
1920 1921
 *
 * Return value:
1922 1923 1924
 * 	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
1925
 */
1926 1927 1928 1929
static sctp_ierror_t 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
1930
{
1931
	int retval = SCTP_IERROR_NO_ERROR;
L
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1932 1933 1934

	switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
	case SCTP_PARAM_ACTION_DISCARD:
1935
		retval =  SCTP_IERROR_ERROR;
L
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		break;
	case SCTP_PARAM_ACTION_SKIP:
		break;
1939 1940 1941
	case SCTP_PARAM_ACTION_DISCARD_ERR:
		retval =  SCTP_IERROR_ERROR;
		/* Fall through */
L
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	case SCTP_PARAM_ACTION_SKIP_ERR:
		/* Make an ERROR chunk, preparing enough room for
		 * returning multiple unknown parameters.
		 */
		if (NULL == *errp)
			*errp = sctp_make_op_error_space(asoc, chunk,
					ntohs(chunk->chunk_hdr->length));

		if (*errp) {
			sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
					WORD_ROUND(ntohs(param.p->length)));
1953 1954 1955
			sctp_addto_chunk(*errp,
					WORD_ROUND(ntohs(param.p->length)),
					param.v);
L
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1956 1957 1958 1959 1960 1961
		} 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.
			 */
1962
			retval = SCTP_IERROR_NOMEM;
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1963 1964 1965 1966 1967 1968 1969 1970 1971
		}
		break;
	default:
		break;
	}

	return retval;
}

1972
/* Verify variable length parameters
L
Linus Torvalds 已提交
1973
 * Return values:
1974 1975 1976 1977
 * 	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
1978
 */
1979 1980 1981 1982 1983
static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
					union sctp_params param,
					sctp_cid_t cid,
					struct sctp_chunk *chunk,
					struct sctp_chunk **err_chunk)
L
Linus Torvalds 已提交
1984
{
1985
	int retval = SCTP_IERROR_NO_ERROR;
L
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1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

	/* 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:
2001
	case SCTP_PARAM_ADAPTATION_LAYER_IND:
2002 2003
		break;

2004
	case SCTP_PARAM_SUPPORTED_EXT:
2005 2006
		if (!sctp_verify_ext_param(param))
			return SCTP_IERROR_ABORT;
L
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2007 2008
		break;

2009 2010 2011 2012 2013
	case SCTP_PARAM_SET_PRIMARY:
		if (sctp_addip_enable)
			break;
		goto fallthrough;

L
Linus Torvalds 已提交
2014 2015
	case SCTP_PARAM_HOST_NAME_ADDRESS:
		/* Tell the peer, we won't support this param.  */
2016 2017 2018
		sctp_process_hn_param(asoc, param, chunk, err_chunk);
		retval = SCTP_IERROR_ABORT;
		break;
2019

L
Linus Torvalds 已提交
2020 2021 2022
	case SCTP_PARAM_FWD_TSN_SUPPORT:
		if (sctp_prsctp_enable)
			break;
2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
		goto fallthrough;

	case SCTP_PARAM_RANDOM:
		if (!sctp_auth_enable)
			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 !=
2035 2036
			ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
			sctp_process_inv_paramlength(asoc, param.p,
2037
							chunk, err_chunk);
2038 2039
			retval = SCTP_IERROR_ABORT;
		}
2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050
		break;

	case SCTP_PARAM_CHUNKS:
		if (!sctp_auth_enable)
			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.
		 */
2051 2052 2053 2054 2055
		if (260 < ntohs(param.p->length)) {
			sctp_process_inv_paramlength(asoc, param.p,
						     chunk, err_chunk);
			retval = SCTP_IERROR_ABORT;
		}
2056 2057 2058
		break;

	case SCTP_PARAM_HMAC_ALGO:
2059
		if (sctp_auth_enable)
2060
			break;
2061
		/* Fall Through */
2062
fallthrough:
L
Linus Torvalds 已提交
2063 2064 2065
	default:
		SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
				ntohs(param.p->type), cid);
2066
		retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
L
Linus Torvalds 已提交
2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080
		break;
	}
	return retval;
}

/* Verify the INIT packet before we process it.  */
int sctp_verify_init(const struct sctp_association *asoc,
		     sctp_cid_t cid,
		     sctp_init_chunk_t *peer_init,
		     struct sctp_chunk *chunk,
		     struct sctp_chunk **errp)
{
	union sctp_params param;
	int has_cookie = 0;
2081
	int result;
L
Linus Torvalds 已提交
2082 2083 2084

	/* Verify stream values are non-zero. */
	if ((0 == peer_init->init_hdr.num_outbound_streams) ||
2085 2086 2087
	    (0 == peer_init->init_hdr.num_inbound_streams) ||
	    (0 == peer_init->init_hdr.init_tag) ||
	    (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {
L
Linus Torvalds 已提交
2088

2089
		return sctp_process_inv_mandatory(asoc, chunk, errp);
L
Linus Torvalds 已提交
2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106
	}

	/* Check for missing mandatory parameters.  */
	sctp_walk_params(param, peer_init, init_hdr.params) {

		if (SCTP_PARAM_STATE_COOKIE == param.p->type)
			has_cookie = 1;

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

	/* 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.
	 */
2107 2108
	if (param.v != (void*)chunk->chunk_end)
		return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
L
Linus Torvalds 已提交
2109 2110 2111 2112

	/* The only missing mandatory param possible today is
	 * the state cookie for an INIT-ACK chunk.
	 */
2113 2114 2115
	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
2116

2117
	/* Verify all the variable length parameters */
L
Linus Torvalds 已提交
2118 2119
	sctp_walk_params(param, peer_init, init_hdr.params) {

2120 2121 2122 2123
		result = sctp_verify_param(asoc, param, cid, chunk, errp);
		switch (result) {
		    case SCTP_IERROR_ABORT:
		    case SCTP_IERROR_NOMEM:
L
Linus Torvalds 已提交
2124
				return 0;
2125
		    case SCTP_IERROR_ERROR:
L
Linus Torvalds 已提交
2126
				return 1;
2127 2128 2129
		    case SCTP_IERROR_NO_ERROR:
		    default:
				break;
L
Linus Torvalds 已提交
2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142
		}

	} /* 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.
 */
int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid,
		      const union sctp_addr *peer_addr,
A
Al Viro 已提交
2143
		      sctp_init_chunk_t *peer_init, gfp_t gfp)
L
Linus Torvalds 已提交
2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159
{
	union sctp_params param;
	struct sctp_transport *transport;
	struct list_head *pos, *temp;
	char *cookie;

	/* 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.
	 */
2160
	if (peer_addr) {
2161
		if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
L
Linus Torvalds 已提交
2162
			goto nomem;
2163
	}
L
Linus Torvalds 已提交
2164 2165 2166 2167 2168

	/* Process the initialization parameters.  */
	sctp_walk_params(param, peer_init, init_hdr.params) {

		if (!sctp_process_param(asoc, param, peer_addr, gfp))
2169
			goto clean_up;
L
Linus Torvalds 已提交
2170 2171
	}

2172 2173 2174 2175 2176 2177 2178
	/* 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;

2179 2180 2181 2182 2183
	/* 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.
2184
	 */
2185 2186
	if (!sctp_addip_noauth &&
	     (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2187 2188 2189
		asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
						  SCTP_PARAM_DEL_IP |
						  SCTP_PARAM_SET_PRIMARY);
2190
		asoc->peer.asconf_capable = 0;
2191
		goto clean_up;
2192 2193
	}

F
Frank Filz 已提交
2194 2195 2196 2197 2198 2199 2200 2201
	/* 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
2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239
	/* 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);

	/* 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) {
2240
		asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
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		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).
	 */
	list_for_each(pos, &asoc->peer.transport_addr_list) {
		transport = list_entry(pos, struct sctp_transport, transports);
		transport->ssthresh = asoc->peer.i.a_rwnd;
	}

	/* Set up the TSN tracking pieces.  */
	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
			 asoc->peer.i.initial_tsn);

	/* 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.
	 */

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	/* Allocate storage for the negotiated streams if it is not a temporary
2267
	 * association.
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	 */
	if (!asoc->temp) {
		int error;

		asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
					       asoc->c.sinit_num_ostreams, gfp);
		if (!asoc->ssnmap)
			goto clean_up;

2277 2278
		error = sctp_assoc_set_id(asoc, gfp);
		if (error)
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			goto clean_up;
	}

	/* 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);
		list_del_init(pos);
		sctp_transport_free(transport);
	}
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	asoc->peer.transport_count = 0;

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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,
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			      gfp_t gfp)
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{
	union sctp_addr addr;
	int i;
	__u16 sat;
	int retval = 1;
	sctp_scope_t scope;
	time_t stale;
	struct sctp_af *af;
2333 2334
	union sctp_addr_param *addr_param;
	struct sctp_transport *t;
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	/* 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;
		/* Fall through. */
	case SCTP_PARAM_IPV4_ADDRESS:
		af = sctp_get_af_specific(param_type2af(param.p->type));
2347
		af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
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		scope = sctp_scope(peer_addr);
2349 2350
		if (sctp_in_scope(&addr, scope))
			if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
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				return 0;
		break;

	case SCTP_PARAM_COOKIE_PRESERVATIVE:
		if (!sctp_cookie_preserve_enable)
			break;

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

		/* Suggested Cookie Life span increment's unit is msec,
		 * (1/1000sec).
		 */
		asoc->cookie_life.tv_sec += stale / 1000;
		asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
		break;

	case SCTP_PARAM_HOST_NAME_ADDRESS:
		SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
		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;

		/* Cycle through address types; avoid divide by 0. */
		sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
		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:
				asoc->peer.ipv6_address = 1;
				break;

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

			default: /* Just ignore anything else.  */
				break;
2399
			}
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		}
		break;

	case SCTP_PARAM_STATE_COOKIE:
		asoc->peer.cookie_len =
			ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
		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;

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	case SCTP_PARAM_ADAPTATION_LAYER_IND:
		asoc->peer.adaptation_ind = param.aind->adaptation_ind;
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		break;

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	case SCTP_PARAM_SET_PRIMARY:
		addr_param = param.v + sizeof(sctp_addip_param_t);

		af = sctp_get_af_specific(param_type2af(param.p->type));
		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;

2445 2446 2447 2448
	case SCTP_PARAM_SUPPORTED_EXT:
		sctp_process_ext_param(asoc, param);
		break;

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	case SCTP_PARAM_FWD_TSN_SUPPORT:
		if (sctp_prsctp_enable) {
			asoc->peer.prsctp_capable = 1;
			break;
		}
2454
		/* Fall Through */
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		goto fall_through;

	case SCTP_PARAM_RANDOM:
		if (!sctp_auth_enable)
			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:
		if (!sctp_auth_enable)
			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:
		if (!sctp_auth_enable)
			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.
		 */
		SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n",
				  ntohs(param.p->type), asoc);
		break;
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	}
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	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                       |
 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2554
 * Address Parameter and other parameter will not be wrapped in this function
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 */
static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
					   union sctp_addr *addr,
					   int vparam_len)
{
	sctp_addiphdr_t asconf;
	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.  */
	retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length);
	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,
					      union sctp_addr	      *laddr,
					      struct sockaddr	      *addrs,
					      int		      addrcnt,
2615
					      __be16		      flags)
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{
	sctp_addip_param_t	param;
	struct sctp_chunk	*retval;
	union sctp_addr_param	addr_param;
	union sctp_addr		*addr;
	void			*addr_buf;
	struct sctp_af		*af;
	int			paramlen = sizeof(param);
	int			addr_param_len = 0;
	int 			totallen = 0;
	int 			i;

	/* Get total length of all the address parameters. */
	addr_buf = addrs;
	for (i = 0; i < addrcnt; i++) {
		addr = (union sctp_addr *)addr_buf;
		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;
	}

	/* 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++) {
		addr = (union sctp_addr *)addr_buf;
		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);
		param.crr_id = i;

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

		addr_buf += af->sockaddr_len;
	}
	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                       |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2676
 * Create an ASCONF chunk with Set Primary IP address parameter.
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 */
struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
					     union sctp_addr *addr)
{
	sctp_addip_param_t	param;
	struct sctp_chunk 	*retval;
	int 			len = sizeof(param);
	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;
	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                   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2725
 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
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 */
static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
					       __u32 serial, int vparam_len)
{
	sctp_addiphdr_t		asconf;
	struct sctp_chunk	*retval;
	int			length = sizeof(asconf) + vparam_len;

	/* Create the chunk.  */
	retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length);
	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. */
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static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2749
			      __be16 err_code, sctp_addip_param_t *asconf_param)
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{
	sctp_addip_param_t 	ack_param;
	sctp_errhdr_t		err_param;
	int			asconf_param_len = 0;
	int			err_param_len = 0;
2755
	__be16			response_type;
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	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);
	}

2767
	/* Add Success Indication or Error Cause Indication parameter. */
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	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. */
2789
static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
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2790 2791 2792 2793 2794 2795 2796
				       struct sctp_chunk *asconf,
				       sctp_addip_param_t *asconf_param)
{
	struct sctp_transport *peer;
	struct sctp_af *af;
	union sctp_addr	addr;
	union sctp_addr_param *addr_param;
2797

L
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	addr_param = (union sctp_addr_param *)
			((void *)asconf_param + sizeof(sctp_addip_param_t));

	af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type));
	if (unlikely(!af))
		return SCTP_ERROR_INV_PARAM;

2805
	af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
2806 2807 2808 2809 2810 2811 2812 2813 2814

	/* 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))
		return SCTP_ERROR_INV_PARAM;

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2815 2816
	switch (asconf_param->param_hdr.type) {
	case SCTP_PARAM_ADD_IP:
2817 2818 2819 2820 2821 2822 2823
		/* 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
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2824
		/* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
2825 2826 2827 2828 2829
		 * 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
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2830

2831
		peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
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2832 2833 2834 2835 2836 2837 2838 2839 2840
		if (!peer)
			return SCTP_ERROR_RSRC_LOW;

		/* Start the heartbeat timer. */
		if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
			sctp_transport_hold(peer);
		break;
	case SCTP_PARAM_DEL_IP:
		/* ADDIP 4.3 D7) If a request is received to delete the
2841 2842 2843 2844
		 * 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'.
		 */
2845
		if (asoc->peer.transport_count == 1)
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2846 2847 2848 2849 2850 2851 2852 2853 2854
			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'
		 */
2855
		if (sctp_cmp_addr_exact(sctp_source(asconf), &addr))
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2856 2857
			return SCTP_ERROR_DEL_SRC_IP;

2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868
		/* 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);
		} else
			sctp_assoc_del_peer(asoc, &addr);
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2869 2870
		break;
	case SCTP_PARAM_SET_PRIMARY:
2871 2872 2873 2874 2875 2876 2877 2878
		/* 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));

2879
		peer = sctp_assoc_lookup_paddr(asoc, &addr);
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2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892
		if (!peer)
			return SCTP_ERROR_INV_PARAM;

		sctp_assoc_set_primary(asoc, peer);
		break;
	default:
		return SCTP_ERROR_INV_PARAM;
		break;
	}

	return SCTP_ERROR_NO_ERROR;
}

2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 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
/* Verify the ASCONF packet before we process it.  */
int sctp_verify_asconf(const struct sctp_association *asoc,
		       struct sctp_paramhdr *param_hdr, void *chunk_end,
		       struct sctp_paramhdr **errp) {
	sctp_addip_param_t *asconf_param;
	union sctp_params param;
	int length, plen;

	param.v = (sctp_paramhdr_t *) param_hdr;
	while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
		length = ntohs(param.p->length);
		*errp = param.p;

		if (param.v > chunk_end - length ||
		    length < sizeof(sctp_paramhdr_t))
			return 0;

		switch (param.p->type) {
		case SCTP_PARAM_ADD_IP:
		case SCTP_PARAM_DEL_IP:
		case SCTP_PARAM_SET_PRIMARY:
			asconf_param = (sctp_addip_param_t *)param.v;
			plen = ntohs(asconf_param->param_hdr.length);
			if (plen < sizeof(sctp_addip_param_t) +
			    sizeof(sctp_paramhdr_t))
				return 0;
			break;
		case SCTP_PARAM_SUCCESS_REPORT:
		case SCTP_PARAM_ADAPTATION_LAYER_IND:
			if (length != sizeof(sctp_addip_param_t))
				return 0;

			break;
		default:
			break;
		}

		param.v += WORD_ROUND(length);
	}

	if (param.v != chunk_end)
		return 0;

	return 1;
}

2939
/* Process an incoming ASCONF chunk with the next expected serial no. and
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2940 2941 2942 2943 2944 2945 2946 2947 2948 2949
 * return an ASCONF_ACK chunk to be sent in response.
 */
struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
				       struct sctp_chunk *asconf)
{
	sctp_addiphdr_t		*hdr;
	union sctp_addr_param	*addr_param;
	sctp_addip_param_t	*asconf_param;
	struct sctp_chunk	*asconf_ack;

2950
	__be16	err_code;
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2951
	int	length = 0;
2952
	int	chunk_len;
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2953 2954 2955
	__u32	serial;
	int	all_param_pass = 1;

2956
	chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
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2957 2958 2959
	hdr = (sctp_addiphdr_t *)asconf->skb->data;
	serial = ntohl(hdr->serial);

2960
	/* Skip the addiphdr and store a pointer to address parameter.  */
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2961 2962 2963 2964 2965
	length = sizeof(sctp_addiphdr_t);
	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
2966
	 * asconf parameter.
2967
	 */
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2968 2969 2970 2971
	length = ntohs(addr_param->v4.param_hdr.length);
	asconf_param = (sctp_addip_param_t *)((void *)addr_param + length);
	chunk_len -= length;

2972
	/* create an ASCONF_ACK chunk.
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	 * Based on the definitions of parameters, we know that the size of
	 * ASCONF_ACK parameters are less than or equal to the twice of ASCONF
J
Joe Perches 已提交
2975
	 * parameters.
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2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002
	 */
	asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2);
	if (!asconf_ack)
		goto done;

	/* Process the TLVs contained within the ASCONF chunk. */
	while (chunk_len > 0) {
		err_code = sctp_process_asconf_param(asoc, asconf,
						     asconf_param);
		/* 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.
		 */
		if (SCTP_ERROR_NO_ERROR != err_code)
			all_param_pass = 0;

		if (!all_param_pass)
			sctp_add_asconf_response(asconf_ack,
						 asconf_param->crr_id, err_code,
						 asconf_param);

		/* 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
3003
		 * in the ASCONF.
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		 */
		if (SCTP_ERROR_RSRC_LOW == err_code)
			goto done;

		/* Move to the next ASCONF param. */
		length = ntohs(asconf_param->param_hdr.length);
		asconf_param = (sctp_addip_param_t *)((void *)asconf_param +
						      length);
		chunk_len -= length;
	}
3014

L
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3015 3016 3017 3018
done:
	asoc->peer.addip_serial++;

	/* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3019
	 * after freeing the reference to old asconf ack if any.
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3020 3021 3022
	 */
	if (asconf_ack) {
		sctp_chunk_hold(asconf_ack);
3023 3024
		list_add_tail(&asconf_ack->transmitted_list,
			      &asoc->asconf_ack_list);
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3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039
	}

	return asconf_ack;
}

/* Process a asconf parameter that is successfully acked. */
static int sctp_asconf_param_success(struct sctp_association *asoc,
				     sctp_addip_param_t *asconf_param)
{
	struct sctp_af *af;
	union sctp_addr	addr;
	struct sctp_bind_addr *bp = &asoc->base.bind_addr;
	union sctp_addr_param *addr_param;
	struct list_head *pos;
	struct sctp_transport *transport;
3040
	struct sctp_sockaddr_entry *saddr;
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3041 3042 3043 3044 3045 3046 3047
	int retval = 0;

	addr_param = (union sctp_addr_param *)
			((void *)asconf_param + sizeof(sctp_addip_param_t));

	/* We have checked the packet before, so we do not check again.	*/
	af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type));
3048
	af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
L
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	switch (asconf_param->param_hdr.type) {
	case SCTP_PARAM_ADD_IP:
3052 3053 3054
		/* This is always done in BH context with a socket lock
		 * held, so the list can not change.
		 */
3055
		local_bh_disable();
3056
		list_for_each_entry(saddr, &bp->address_list, list) {
3057
			if (sctp_cmp_addr_exact(&saddr->a, &addr))
3058
				saddr->state = SCTP_ADDR_SRC;
3059
		}
3060
		local_bh_enable();
L
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3061 3062
		break;
	case SCTP_PARAM_DEL_IP:
3063 3064 3065
		local_bh_disable();
		retval = sctp_del_bind_addr(bp, &addr);
		local_bh_enable();
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3066 3067 3068
		list_for_each(pos, &asoc->peer.transport_addr_list) {
			transport = list_entry(pos, struct sctp_transport,
						 transports);
3069
			dst_release(transport->dst);
L
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3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082
			sctp_transport_route(transport, NULL,
					     sctp_sk(asoc->base.sk));
		}
		break;
	default:
		break;
	}

	return retval;
}

/* 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,
3083
 * return the error code based on the third argument 'no_err'.
L
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3084 3085 3086 3087 3088 3089
 * 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.
 */
3090
static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
L
Linus Torvalds 已提交
3091 3092 3093 3094 3095 3096
				      sctp_addip_param_t *asconf_param,
				      int no_err)
{
	sctp_addip_param_t	*asconf_ack_param;
	sctp_errhdr_t		*err_param;
	int			length;
3097
	int			asconf_ack_len;
3098
	__be16			err_code;
L
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3099 3100 3101 3102 3103 3104

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

3105 3106 3107
	asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
			     sizeof(sctp_chunkhdr_t);

L
Linus Torvalds 已提交
3108 3109
	/* Skip the addiphdr from the asconf_ack chunk and store a pointer to
	 * the first asconf_ack parameter.
3110
	 */
L
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3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156
	length = sizeof(sctp_addiphdr_t);
	asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
						  length);
	asconf_ack_len -= length;

	while (asconf_ack_len > 0) {
		if (asconf_ack_param->crr_id == asconf_param->crr_id) {
			switch(asconf_ack_param->param_hdr.type) {
			case SCTP_PARAM_SUCCESS_REPORT:
				return SCTP_ERROR_NO_ERROR;
			case SCTP_PARAM_ERR_CAUSE:
				length = sizeof(sctp_addip_param_t);
				err_param = (sctp_errhdr_t *)
					   ((void *)asconf_ack_param + length);
				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);
		asconf_ack_param = (sctp_addip_param_t *)
					((void *)asconf_ack_param + length);
		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)
{
	struct sctp_chunk	*asconf = asoc->addip_last_asconf;
	union sctp_addr_param	*addr_param;
	sctp_addip_param_t	*asconf_param;
	int	length = 0;
	int	asconf_len = asconf->skb->len;
	int	all_param_pass = 0;
	int	no_err = 1;
	int	retval = 0;
3157
	__be16	err_code = SCTP_ERROR_NO_ERROR;
L
Linus Torvalds 已提交
3158 3159 3160

	/* Skip the chunkhdr and addiphdr from the last asconf sent and store
	 * a pointer to address parameter.
3161
	 */
L
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3162 3163 3164 3165 3166
	length = sizeof(sctp_addip_chunk_t);
	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
3167
	 * pointer to the first asconf parameter.
3168
	 */
L
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3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204
	length = ntohs(addr_param->v4.param_hdr.length);
	asconf_param = (sctp_addip_param_t *)((void *)addr_param + length);
	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.
	 */
	if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
		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:
			retval = sctp_asconf_param_success(asoc, asconf_param);
			break;

		case SCTP_ERROR_RSRC_LOW:
			retval = 1;
			break;

		case SCTP_ERROR_INV_PARAM:
			/* Disable sending this type of asconf parameter in
			 * future.
3205
			 */
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3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218
			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.
3219
		 */
L
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3220 3221 3222 3223 3224 3225 3226
		length = ntohs(asconf_param->param_hdr.length);
		asconf_param = (sctp_addip_param_t *)((void *)asconf_param +
						      length);
		asconf_len -= length;
	}

	/* Free the cached last sent asconf chunk. */
3227
	list_del_init(&asconf->transmitted_list);
L
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3228 3229 3230 3231
	sctp_chunk_free(asconf);
	asoc->addip_last_asconf = NULL;

	/* Send the next asconf chunk from the addip chunk queue. */
3232 3233 3234 3235 3236 3237
	if (!list_empty(&asoc->addip_chunk_list)) {
		struct list_head *entry = asoc->addip_chunk_list.next;
		asconf = list_entry(entry, struct sctp_chunk, list);

		list_del_init(entry);

L
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3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248
		/* Hold the chunk until an ASCONF_ACK is received. */
		sctp_chunk_hold(asconf);
		if (sctp_primitive_ASCONF(asoc, asconf))
			sctp_chunk_free(asconf);
		else
			asoc->addip_last_asconf = asconf;
	}

	return retval;
}

3249
/* Make a FWD TSN chunk. */
L
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3250 3251 3252 3253 3254 3255
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;
	struct sctp_fwdtsn_chunk *ftsn_chunk;
3256
	struct sctp_fwdtsn_hdr ftsn_hdr;
L
Linus Torvalds 已提交
3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281
	struct sctp_fwdtsn_skip skip;
	size_t hint;
	int i;

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

	retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint);

	if (!retval)
		return NULL;

	ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr;

	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;
}