sm_make_chunk.c 115.9 KB
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/* SCTP kernel implementation
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 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001-2002 Intel Corp.
 *
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 * This file is part of the SCTP kernel implementation
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 *
 * These functions work with the state functions in sctp_sm_statefuns.c
 * to implement the state operations.  These functions implement the
 * steps which require modifying existing data structures.
 *
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 * This SCTP implementation is free software;
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 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
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 * This SCTP implementation is distributed in the hope that it
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 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
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 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
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 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
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 *    lksctp developers <linux-sctp@vger.kernel.org>
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 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    C. Robin              <chris@hundredacre.ac.uk>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
 *    Sridhar Samudrala	    <sri@us.ibm.com>
 *    Daisy Chang	    <daisyc@us.ibm.com>
 *    Ardelle Fan	    <ardelle.fan@intel.com>
 *    Kevin Gao             <kevin.gao@intel.com>
 */

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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

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

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static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
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					    __u8 type, __u8 flags, int paylen,
					    gfp_t gfp);
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static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
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					 __u8 flags, int paylen, gfp_t gfp);
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static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
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					   __u8 type, __u8 flags, int paylen,
					   gfp_t gfp);
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static struct sctp_cookie_param *sctp_pack_cookie(
					const struct sctp_endpoint *ep,
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					const struct sctp_association *asoc,
					const struct sctp_chunk *init_chunk,
					int *cookie_len,
					const __u8 *raw_addrs, int addrs_len);
static int sctp_process_param(struct sctp_association *asoc,
			      union sctp_params param,
			      const union sctp_addr *peer_addr,
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			      gfp_t gfp);
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static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
			      const void *data);
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/* Control chunk destructor */
static void sctp_control_release_owner(struct sk_buff *skb)
{
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	struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;

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	if (chunk->shkey) {
		struct sctp_shared_key *shkey = chunk->shkey;
		struct sctp_association *asoc = chunk->asoc;

		/* refcnt == 2 and !list_empty mean after this release, it's
		 * not being used anywhere, and it's time to notify userland
		 * that this shkey can be freed if it's been deactivated.
		 */
		if (shkey->deactivated && !list_empty(&shkey->key_list) &&
		    refcount_read(&shkey->refcnt) == 2) {
			struct sctp_ulpevent *ev;

			ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
							SCTP_AUTH_FREE_KEY,
							GFP_KERNEL);
			if (ev)
				asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
		}
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		sctp_auth_shkey_release(chunk->shkey);
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	}
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}

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

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

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

/* RFC 2960 3.3.2 Initiation (INIT) (1)
 *
 * Note 2: The ECN capable field is reserved for future use of
 * Explicit Congestion Notification.
 */
static const struct sctp_paramhdr ecap_param = {
	SCTP_PARAM_ECN_CAPABLE,
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	cpu_to_be16(sizeof(struct sctp_paramhdr)),
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};
static const struct sctp_paramhdr prsctp_param = {
	SCTP_PARAM_FWD_TSN_SUPPORT,
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	cpu_to_be16(sizeof(struct sctp_paramhdr)),
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};

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

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

	if (skb_tailroom(chunk->skb) < len)
		return -ENOSPC;

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	chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
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	return 0;
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}

/* 3.3.2 Initiation (INIT) (1)
 *
 * This chunk is used to initiate a SCTP association between two
 * endpoints. The format of the INIT chunk is shown below:
 *
 *     0                   1                   2                   3
 *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |   Type = 1    |  Chunk Flags  |      Chunk Length             |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |                         Initiate Tag                          |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |           Advertised Receiver Window Credit (a_rwnd)          |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |  Number of Outbound Streams   |  Number of Inbound Streams    |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    |                          Initial TSN                          |
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *    \                                                               \
 *    /              Optional/Variable-Length Parameters              /
 *    \                                                               \
 *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *
 * The INIT chunk contains the following parameters. Unless otherwise
 * noted, each parameter MUST only be included once in the INIT chunk.
 *
 * Fixed Parameters                     Status
 * ----------------------------------------------
 * Initiate Tag                        Mandatory
 * Advertised Receiver Window Credit   Mandatory
 * Number of Outbound Streams          Mandatory
 * Number of Inbound Streams           Mandatory
 * Initial TSN                         Mandatory
 *
 * Variable Parameters                  Status     Type Value
 * -------------------------------------------------------------
 * IPv4 Address (Note 1)               Optional    5
 * IPv6 Address (Note 1)               Optional    6
 * Cookie Preservative                 Optional    9
 * Reserved for ECN Capable (Note 2)   Optional    32768 (0x8000)
 * Host Name Address (Note 3)          Optional    11
 * Supported Address Types (Note 4)    Optional    12
 */
struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
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				  const struct sctp_bind_addr *bp,
				  gfp_t gfp, int vparam_len)
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{
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	struct net *net = sock_net(asoc->base.sk);
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	struct sctp_supported_ext_param ext_param;
	struct sctp_adaptation_ind_param aiparam;
	struct sctp_paramhdr *auth_chunks = NULL;
	struct sctp_paramhdr *auth_hmacs = NULL;
	struct sctp_supported_addrs_param sat;
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	struct sctp_endpoint *ep = asoc->ep;
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	struct sctp_chunk *retval = NULL;
	int num_types, addrs_len = 0;
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	struct sctp_inithdr init;
	union sctp_params addrs;
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	struct sctp_sock *sp;
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	__u8 extensions[5];
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	size_t chunksize;
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	__be16 types[2];
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	int num_ext = 0;
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	/* RFC 2960 3.3.2 Initiation (INIT) (1)
	 *
	 * Note 1: The INIT chunks can contain multiple addresses that
	 * can be IPv4 and/or IPv6 in any combination.
	 */

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

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

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

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

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

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

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

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

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	chunksize += vparam_len;

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

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

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

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	/* If we have any extensions to report, account for that */
	if (num_ext)
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		chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
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	/* RFC 2960 3.3.2 Initiation (INIT) (1)
	 *
	 * Note 3: An INIT chunk MUST NOT contain more than one Host
	 * Name address parameter. Moreover, the sender of the INIT
	 * MUST NOT combine any other address types with the Host Name
	 * address in the INIT. The receiver of INIT MUST ignore any
	 * other address types if the Host Name address parameter is
	 * present in the received INIT chunk.
	 *
	 * PLEASE DO NOT FIXME [This version does not support Host Name.]
	 */

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

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

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

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

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	if (asoc->prsctp_enable)
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		sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
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	if (sp->adaptation_ind) {
		aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
		aiparam.param_hdr.length = htons(sizeof(aiparam));
		aiparam.adaptation_ind = htonl(sp->adaptation_ind);
		sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
	}
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	/* Add SCTP-AUTH chunks to the parameter list */
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	if (ep->auth_enable) {
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		sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
				 asoc->c.auth_random);
		if (auth_hmacs)
			sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
					auth_hmacs);
		if (auth_chunks)
			sctp_addto_chunk(retval, ntohs(auth_chunks->length),
					auth_chunks);
	}
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nodata:
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	kfree(addrs.v);
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	return retval;
}

struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
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				      const struct sctp_chunk *chunk,
				      gfp_t gfp, int unkparam_len)
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{
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	struct sctp_supported_ext_param ext_param;
	struct sctp_adaptation_ind_param aiparam;
	struct sctp_paramhdr *auth_chunks = NULL;
	struct sctp_paramhdr *auth_random = NULL;
	struct sctp_paramhdr *auth_hmacs = NULL;
	struct sctp_chunk *retval = NULL;
	struct sctp_cookie_param *cookie;
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	struct sctp_inithdr initack;
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	union sctp_params addrs;
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	struct sctp_sock *sp;
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	__u8 extensions[5];
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	size_t chunksize;
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	int num_ext = 0;
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	int cookie_len;
	int addrs_len;
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	/* Note: there may be no addresses to embed. */
	addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);

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

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

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

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

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

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

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

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

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

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

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

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

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

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	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [INIT ACK back to where the INIT came from.]
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	 */
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	if (chunk->transport)
		retval->transport =
			sctp_assoc_lookup_paddr(asoc,
						&chunk->transport->ipaddr);
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	retval->subh.init_hdr =
		sctp_addto_chunk(retval, sizeof(initack), &initack);
	retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
	sctp_addto_chunk(retval, cookie_len, cookie);
	if (asoc->peer.ecn_capable)
		sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
509 510
	if (num_ext) {
		ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
511 512
		ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
		sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
513
		sctp_addto_param(retval, num_ext, extensions);
514
	}
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	if (asoc->peer.prsctp_capable)
		sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);

518 519 520 521 522 523
	if (sp->adaptation_ind) {
		aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
		aiparam.param_hdr.length = htons(sizeof(aiparam));
		aiparam.adaptation_ind = htonl(sp->adaptation_ind);
		sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
	}
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525 526 527 528 529 530 531 532 533 534 535
	if (asoc->peer.auth_capable) {
		sctp_addto_chunk(retval, ntohs(auth_random->length),
				 auth_random);
		if (auth_hmacs)
			sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
					auth_hmacs);
		if (auth_chunks)
			sctp_addto_chunk(retval, ntohs(auth_chunks->length),
					auth_chunks);
	}

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

nomem_chunk:
	kfree(cookie);
nomem_cookie:
J
Jesper Juhl 已提交
542
	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,
581
					 const struct sctp_chunk *chunk)
L
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{
	struct sctp_chunk *retval;
	int cookie_len;
585
	void *cookie;
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	cookie = asoc->peer.cookie;
	cookie_len = asoc->peer.cookie_len;

	/* Build a cookie echo chunk.  */
591 592
	retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
				   cookie_len, GFP_ATOMIC);
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	if (!retval)
		goto nodata;
	retval->subh.cookie_hdr =
		sctp_addto_chunk(retval, cookie_len, cookie);

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

nodata:
	return retval;
}

/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
 *
 * This chunk is used only during the initialization of an
 * association.  It is used to acknowledge the receipt of a COOKIE
 * ECHO chunk.  This chunk MUST precede any DATA or SACK chunk sent
 * within the association, but MAY be bundled with one or more DATA
 * chunks or SACK chunk in the same SCTP packet.
 *
 *      0                   1                   2                   3
 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |   Type = 11   |Chunk  Flags   |     Length = 4                |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * Chunk Flags: 8 bits
 *
 *   Set to zero on transmit and ignored on receipt.
 */
struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
633
					const struct sctp_chunk *chunk)
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{
	struct sctp_chunk *retval;

637
	retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
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	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [COOKIE ACK back to where the COOKIE ECHO came from.]
	 */
648 649 650 651
	if (retval && chunk && chunk->transport)
		retval->transport =
			sctp_assoc_lookup_paddr(asoc,
						&chunk->transport->ipaddr);
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	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,
680 681
				 const __u32 lowest_tsn,
				 const struct sctp_chunk *chunk)
L
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{
	struct sctp_chunk *retval;
684
	struct sctp_cwrhdr cwr;
L
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685 686

	cwr.lowest_tsn = htonl(lowest_tsn);
687
	retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
688
				   sizeof(cwr), GFP_ATOMIC);
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	if (!retval)
		goto nodata;

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

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

nodata:
	return retval;
}

/* Make an ECNE chunk.  This is a congestion experienced report.  */
struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
715
				  const __u32 lowest_tsn)
L
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{
	struct sctp_chunk *retval;
718
	struct sctp_ecnehdr ecne;
L
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719 720

	ecne.lowest_tsn = htonl(lowest_tsn);
721
	retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
722
				   sizeof(ecne), GFP_ATOMIC);
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723 724 725 726 727 728 729 730 731 732 733 734
	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.
 */
735
struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
736
					    const struct sctp_sndrcvinfo *sinfo,
737
					    int len, __u8 flags, gfp_t gfp)
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{
	struct sctp_chunk *retval;
	struct sctp_datahdr dp;

	/* We assign the TSN as LATE as possible, not here when
	 * creating the chunk.
	 */
745 746
	memset(&dp, 0, sizeof(dp));
	dp.ppid = sinfo->sinfo_ppid;
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	dp.stream = htons(sinfo->sinfo_stream);

	/* Set the flags for an unordered send.  */
750
	if (sinfo->sinfo_flags & SCTP_UNORDERED)
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		flags |= SCTP_DATA_UNORDERED;

753
	retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
L
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	if (!retval)
755
		return NULL;
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	retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
	memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));

	return retval;
}

/* Create a selective ackowledgement (SACK) for the given
 * association.  This reports on which TSN's we've seen to date,
 * including duplicates and gaps.
 */
767
struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
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{
	struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
770
	struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
771
	__u16 num_gabs, num_dup_tsns;
772
	struct sctp_transport *trans;
773 774 775 776
	struct sctp_chunk *retval;
	struct sctp_sackhdr sack;
	__u32 ctsn;
	int len;
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778
	memset(gabs, 0, sizeof(gabs));
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	ctsn = sctp_tsnmap_get_ctsn(map);
780 781

	pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
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	/* How much room is needed in the chunk? */
784
	num_gabs = sctp_tsnmap_num_gabs(map, gabs);
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	num_dup_tsns = sctp_tsnmap_num_dups(map);

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

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

	/* Create the chunk.  */
798
	retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
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	if (!retval)
		goto nodata;

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

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

	/* Add the gap ack block information.   */
	if (num_gabs)
		sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
840
				 gabs);
L
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	/* Add the duplicate TSN information.  */
843
	if (num_dup_tsns) {
844
		asoc->stats.idupchunks += num_dup_tsns;
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845 846
		sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
				 sctp_tsnmap_get_dups(map));
847
	}
848 849 850 851 852 853 854 855
	/* Once we have a sack generated, check to see what our sack
	 * generation is, if its 0, reset the transports to 0, and reset
	 * the association generation to 1
	 *
	 * The idea is that zero is never used as a valid generation for the
	 * association so no transport will match after a wrap event like this,
	 * Until the next sack
	 */
856
	if (++asoc->peer.sack_generation == 0) {
857 858 859
		list_for_each_entry(trans, &asoc->peer.transport_addr_list,
				    transports)
			trans->sack_generation = 0;
860
		asoc->peer.sack_generation = 1;
861
	}
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nodata:
	return retval;
}

/* Make a SHUTDOWN chunk. */
struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
				      const struct sctp_chunk *chunk)
{
870
	struct sctp_shutdownhdr shut;
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871 872 873 874 875 876
	struct sctp_chunk *retval;
	__u32 ctsn;

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

877
	retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
878
				   sizeof(shut), GFP_ATOMIC);
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879 880 881 882 883 884 885 886 887 888 889 890 891
	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,
892
					  const struct sctp_chunk *chunk)
L
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893 894 895
{
	struct sctp_chunk *retval;

896 897
	retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
				   GFP_ATOMIC);
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	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [ACK back to where the SHUTDOWN came from.]
	 */
	if (retval && chunk)
		retval->transport = chunk->transport;

	return retval;
}

struct sctp_chunk *sctp_make_shutdown_complete(
915 916
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk)
L
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917 918 919 920
{
	struct sctp_chunk *retval;
	__u8 flags = 0;

921 922 923
	/* Set the T-bit if we have no association (vtag will be
	 * reflected)
	 */
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	flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;

926 927
	retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
				   0, GFP_ATOMIC);
L
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	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
	 * came from.]
	 */
	if (retval && chunk)
		retval->transport = chunk->transport;

942
	return retval;
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943 944 945
}

/* Create an ABORT.  Note that we set the T bit if we have no
946
 * association, except when responding to an INIT (sctpimpguide 2.41).
L
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947 948
 */
struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
949 950
				   const struct sctp_chunk *chunk,
				   const size_t hint)
L
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951 952 953 954
{
	struct sctp_chunk *retval;
	__u8 flags = 0;

955 956 957 958 959 960 961 962 963 964
	/* Set the T-bit if we have no association and 'chunk' is not
	 * an INIT (vtag will be reflected).
	 */
	if (!asoc) {
		if (chunk && chunk->chunk_hdr &&
		    chunk->chunk_hdr->type == SCTP_CID_INIT)
			flags = 0;
		else
			flags = SCTP_CHUNK_FLAG_T;
	}
L
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966 967
	retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
				   GFP_ATOMIC);
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	/* RFC 2960 6.4 Multi-homed SCTP Endpoints
	 *
	 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
	 * HEARTBEAT ACK, * etc.) to the same destination transport
	 * address from which it * received the DATA or control chunk
	 * to which it is replying.
	 *
	 * [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(
986 987 988
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					__u32 tsn)
L
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989 990
{
	struct sctp_chunk *retval;
A
Al Viro 已提交
991
	__be32 payload;
L
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993 994
	retval = sctp_make_abort(asoc, chunk,
				 sizeof(struct sctp_errhdr) + sizeof(tsn));
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	if (!retval)
		goto no_mem;

	/* Put the tsn back into network byte order.  */
	payload = htonl(tsn);
1001 1002
	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,
A
Al Viro 已提交
1022
					struct msghdr *msg,
1023
					size_t paylen)
L
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{
	struct sctp_chunk *retval;
1026 1027
	void *payload = NULL;
	int err;
L
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1029 1030
	retval = sctp_make_abort(asoc, NULL,
				 sizeof(struct sctp_errhdr) + paylen);
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1031 1032 1033 1034 1035
	if (!retval)
		goto err_chunk;

	if (paylen) {
		/* Put the msg_iov together into payload.  */
1036
		payload = kmalloc(paylen, GFP_KERNEL);
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		if (!payload)
			goto err_payload;
1039

A
Al Viro 已提交
1040
		err = memcpy_from_msg(payload, msg, paylen);
1041 1042
		if (err < 0)
			goto err_copy;
L
Linus Torvalds 已提交
1043 1044
	}

1045 1046
	sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
	sctp_addto_chunk(retval, paylen, payload);
L
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1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061

	if (paylen)
		kfree(payload);

	return retval;

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

1062 1063 1064 1065 1066 1067 1068
/* Append bytes to the end of a parameter.  Will panic if chunk is not big
 * enough.
 */
static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
			      const void *data)
{
	int chunklen = ntohs(chunk->chunk_hdr->length);
1069
	void *target;
1070 1071 1072

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

1073 1074 1075 1076
	if (data)
		memcpy(target, data, len);
	else
		memset(target, 0, len);
1077 1078 1079 1080 1081 1082 1083 1084

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

	return target;
}

1085
/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
L
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1086
struct sctp_chunk *sctp_make_abort_violation(
1087 1088 1089 1090
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					const __u8 *payload,
					const size_t paylen)
L
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1091 1092 1093 1094
{
	struct sctp_chunk  *retval;
	struct sctp_paramhdr phdr;

1095 1096
	retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
					      paylen + sizeof(phdr));
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1097 1098 1099
	if (!retval)
		goto end;

1100 1101
	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
							    sizeof(phdr));
L
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1102 1103 1104

	phdr.type = htons(chunk->chunk_hdr->type);
	phdr.length = chunk->chunk_hdr->length;
1105
	sctp_addto_chunk(retval, paylen, payload);
1106
	sctp_addto_param(retval, sizeof(phdr), &phdr);
L
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1107 1108 1109 1110 1111

end:
	return retval;
}

1112
struct sctp_chunk *sctp_make_violation_paramlen(
1113 1114 1115
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					struct sctp_paramhdr *param)
1116 1117
{
	static const char error[] = "The following parameter had invalid length:";
1118
	size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1119
			     sizeof(*param);
1120
	struct sctp_chunk *retval;
1121 1122 1123 1124 1125 1126

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

	sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1127
			sizeof(error) + sizeof(*param));
1128
	sctp_addto_chunk(retval, sizeof(error), error);
1129
	sctp_addto_param(retval, sizeof(*param), param);
1130 1131 1132 1133 1134

nodata:
	return retval;
}

1135
struct sctp_chunk *sctp_make_violation_max_retrans(
1136 1137
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk)
1138
{
1139
	static const char error[] = "Association exceeded its max_retrans count";
1140
	size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1141
	struct sctp_chunk *retval;
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153

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

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

nodata:
	return retval;
}

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/* Make a HEARTBEAT chunk.  */
struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1156
				       const struct sctp_transport *transport)
L
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1157
{
1158
	struct sctp_sender_hb_info hbinfo;
1159 1160
	struct sctp_chunk *retval;

1161 1162
	retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
				   sizeof(hbinfo), GFP_ATOMIC);
L
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1163 1164 1165 1166

	if (!retval)
		goto nodata;

1167
	hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1168
	hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1169 1170 1171 1172
	hbinfo.daddr = transport->ipaddr;
	hbinfo.sent_at = jiffies;
	hbinfo.hb_nonce = transport->hb_nonce;

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1173 1174 1175 1176
	/* Cast away the 'const', as this is just telling the chunk
	 * what transport it belongs to.
	 */
	retval->transport = (struct sctp_transport *) transport;
1177 1178
	retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
						&hbinfo);
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1179 1180 1181 1182 1183 1184

nodata:
	return retval;
}

struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1185 1186 1187
					   const struct sctp_chunk *chunk,
					   const void *payload,
					   const size_t paylen)
L
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{
	struct sctp_chunk *retval;

1191 1192
	retval  = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
				    GFP_ATOMIC);
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1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217
	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(
1218 1219 1220
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk,
					size_t size)
L
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1221 1222 1223
{
	struct sctp_chunk *retval;

1224
	retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1225 1226
				   sizeof(struct sctp_errhdr) + size,
				   GFP_ATOMIC);
L
Linus Torvalds 已提交
1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244
	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;
}

1245 1246 1247 1248 1249 1250
/* Create an Operation Error chunk of a fixed size, specifically,
 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
 * This is a helper function to allocate an error chunk for for those
 * invalid parameter codes in which we may not want to report all the
 * errors, if the incoming chunk is large. If it can't fit in a single
 * packet, we ignore it.
1251
 */
1252
static inline struct sctp_chunk *sctp_make_op_error_limited(
1253 1254
					const struct sctp_association *asoc,
					const struct sctp_chunk *chunk)
1255
{
1256 1257 1258 1259 1260 1261 1262
	size_t size = SCTP_DEFAULT_MAXSEGMENT;
	struct sctp_sock *sp = NULL;

	if (asoc) {
		size = min_t(size_t, size, asoc->pathmtu);
		sp = sctp_sk(asoc->base.sk);
	}
1263

1264
	size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1265 1266 1267 1268

	return sctp_make_op_error_space(asoc, chunk, size);
}

L
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1269 1270
/* Create an Operation Error chunk.  */
struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1271 1272 1273
				      const struct sctp_chunk *chunk,
				      __be16 cause_code, const void *payload,
				      size_t paylen, size_t reserve_tail)
L
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1274 1275 1276
{
	struct sctp_chunk *retval;

1277
	retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
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1278 1279 1280
	if (!retval)
		goto nodata;

1281
	sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1282
	sctp_addto_chunk(retval, paylen, payload);
1283 1284
	if (reserve_tail)
		sctp_addto_param(retval, reserve_tail, NULL);
L
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1285 1286 1287 1288 1289

nodata:
	return retval;
}

X
Xin Long 已提交
1290 1291
struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
				  __u16 key_id)
1292 1293
{
	struct sctp_authhdr auth_hdr;
1294 1295
	struct sctp_hmac *hmac_desc;
	struct sctp_chunk *retval;
1296 1297 1298 1299 1300 1301

	/* 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;

1302
	retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1303 1304
				   hmac_desc->hmac_len + sizeof(auth_hdr),
				   GFP_ATOMIC);
1305 1306 1307 1308
	if (!retval)
		return NULL;

	auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
X
Xin Long 已提交
1309
	auth_hdr.shkey_id = htons(key_id);
1310

1311 1312
	retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
						 &auth_hdr);
1313

1314
	skb_put_zero(retval->skb, hmac_desc->hmac_len);
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324

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

	return retval;
}


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

/* Turn an skb into a chunk.
 * FIXME: Eventually move the structure directly inside the skb->cb[].
1331 1332 1333 1334 1335 1336 1337
 *
 * sctpimpguide-05.txt Section 2.8.2
 * M1) Each time a new DATA chunk is transmitted
 * set the 'TSN.Missing.Report' count for that TSN to 0. The
 * 'TSN.Missing.Report' count will be used to determine missing chunks
 * and when to fast retransmit.
 *
L
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 */
struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1340 1341
				 const struct sctp_association *asoc,
				 struct sock *sk, gfp_t gfp)
L
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1342 1343 1344
{
	struct sctp_chunk *retval;

1345
	retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
L
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1346 1347 1348

	if (!retval)
		goto nodata;
1349 1350
	if (!sk)
		pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
L
Linus Torvalds 已提交
1351

1352
	INIT_LIST_HEAD(&retval->list);
L
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1353 1354 1355 1356
	retval->skb		= skb;
	retval->asoc		= (struct sctp_association *)asoc;
	retval->singleton	= 1;

1357
	retval->fast_retransmit = SCTP_CAN_FRTX;
L
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1358 1359 1360 1361 1362

	/* Polish the bead hole.  */
	INIT_LIST_HEAD(&retval->transmitted_list);
	INIT_LIST_HEAD(&retval->frag_list);
	SCTP_DBG_OBJCNT_INC(chunk);
1363
	refcount_set(&retval->refcnt, 1);
L
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1364 1365 1366 1367 1368 1369 1370 1371 1372

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)
{
1373
	memcpy(&chunk->source, src, sizeof(union sctp_addr));
1374
	memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
L
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1375 1376 1377 1378 1379 1380 1381
}

/* 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) {
1382
		return &chunk->transport->ipaddr;
L
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1383 1384
	} else {
		/* Otherwise, extract it from the IP header.  */
1385
		return &chunk->source;
L
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1386 1387 1388 1389 1390 1391
	}
}

/* Create a new chunk, setting the type and flags headers from the
 * arguments, reserving enough space for a 'paylen' byte payload.
 */
1392
static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1393 1394
					   __u8 type, __u8 flags, int paylen,
					   gfp_t gfp)
L
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1395
{
1396
	struct sctp_chunkhdr *chunk_hdr;
1397
	struct sctp_chunk *retval;
L
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1398 1399
	struct sk_buff *skb;
	struct sock *sk;
1400 1401 1402 1403 1404
	int chunklen;

	chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
	if (chunklen > SCTP_MAX_CHUNK_LEN)
		goto nodata;
L
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1405 1406

	/* No need to allocate LL here, as this is only a chunk. */
1407
	skb = alloc_skb(chunklen, gfp);
L
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1408 1409 1410 1411
	if (!skb)
		goto nodata;

	/* Make room for the chunk header.  */
1412
	chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
L
Linus Torvalds 已提交
1413 1414
	chunk_hdr->type	  = type;
	chunk_hdr->flags  = flags;
1415
	chunk_hdr->length = htons(sizeof(*chunk_hdr));
L
Linus Torvalds 已提交
1416 1417

	sk = asoc ? asoc->base.sk : NULL;
1418
	retval = sctp_chunkify(skb, asoc, sk, gfp);
L
Linus Torvalds 已提交
1419 1420 1421 1422 1423 1424
	if (!retval) {
		kfree_skb(skb);
		goto nodata;
	}

	retval->chunk_hdr = chunk_hdr;
1425
	retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
L
Linus Torvalds 已提交
1426

1427 1428 1429 1430
	/* Determine if the chunk needs to be authenticated */
	if (sctp_auth_send_cid(type, asoc))
		retval->auth = 1;

L
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1431 1432 1433 1434 1435
	return retval;
nodata:
	return NULL;
}

1436
static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1437
					 __u8 flags, int paylen, gfp_t gfp)
1438
{
1439
	return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1440 1441
}

1442 1443 1444 1445 1446 1447
struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
				   __u8 flags, int paylen, gfp_t gfp)
{
	return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
}

1448
static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1449 1450
					    __u8 type, __u8 flags, int paylen,
					    gfp_t gfp)
1451
{
1452
	struct sctp_chunk *chunk;
1453

1454
	chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1455 1456 1457 1458 1459
	if (chunk)
		sctp_control_set_owner_w(chunk);

	return chunk;
}
L
Linus Torvalds 已提交
1460 1461 1462 1463

/* Release the memory occupied by a chunk.  */
static void sctp_chunk_destroy(struct sctp_chunk *chunk)
{
1464 1465 1466
	BUG_ON(!list_empty(&chunk->list));
	list_del_init(&chunk->transmitted_list);

1467 1468
	consume_skb(chunk->skb);
	consume_skb(chunk->auth_chunk);
L
Linus Torvalds 已提交
1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486

	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)
{
1487
	refcount_inc(&ch->refcnt);
L
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1488 1489 1490 1491 1492
}

/* Release a reference to the chunk. */
void sctp_chunk_put(struct sctp_chunk *ch)
{
1493
	if (refcount_dec_and_test(&ch->refcnt))
L
Linus Torvalds 已提交
1494 1495 1496 1497 1498 1499 1500 1501 1502
		sctp_chunk_destroy(ch);
}

/* Append bytes to the end of a chunk.  Will panic if chunk is not big
 * enough.
 */
void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
{
	int chunklen = ntohs(chunk->chunk_hdr->length);
1503
	int padlen = SCTP_PAD4(chunklen) - chunklen;
1504
	void *target;
L
Linus Torvalds 已提交
1505

1506
	skb_put_zero(chunk->skb, padlen);
1507
	target = skb_put_data(chunk->skb, data, len);
L
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1508 1509 1510

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1511
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
L
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1512 1513 1514 1515 1516 1517 1518 1519

	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.
 */
1520 1521
int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
			  struct iov_iter *from)
L
Linus Torvalds 已提交
1522
{
1523
	void *target;
L
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1524 1525 1526 1527 1528

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

	/* Copy data (whole iovec) into chunk */
A
Al Viro 已提交
1529
	if (!copy_from_iter_full(target, len, from))
1530
		return -EFAULT;
L
Linus Torvalds 已提交
1531 1532 1533 1534

	/* Adjust the chunk length field.  */
	chunk->chunk_hdr->length =
		htons(ntohs(chunk->chunk_hdr->length) + len);
1535
	chunk->chunk_end = skb_tail_pointer(chunk->skb);
L
Linus Torvalds 已提交
1536

1537
	return 0;
L
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1538 1539 1540 1541 1542 1543 1544
}

/* 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)
{
1545
	struct sctp_stream *stream;
1546 1547 1548
	struct sctp_chunk *lchunk;
	struct sctp_datamsg *msg;
	__u16 ssn, sid;
L
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1549 1550 1551 1552

	if (chunk->has_ssn)
		return;

1553 1554
	/* All fragments will be on the same stream */
	sid = ntohs(chunk->subh.data_hdr->stream);
1555
	stream = &chunk->asoc->stream;
L
Linus Torvalds 已提交
1556

1557 1558 1559 1560 1561 1562 1563 1564 1565
	/* 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)
1566
				ssn = sctp_ssn_next(stream, out, sid);
1567
			else
1568
				ssn = sctp_ssn_peek(stream, out, sid);
1569 1570 1571 1572 1573
		}

		lchunk->subh.data_hdr->ssn = htons(ssn);
		lchunk->has_ssn = 1;
	}
L
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1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592
}

/* 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,
1593 1594
					     struct sctp_chunk *chunk,
					     gfp_t gfp)
L
Linus Torvalds 已提交
1595 1596
{
	struct sctp_association *asoc;
X
Xin Long 已提交
1597
	enum sctp_scope scope;
L
Linus Torvalds 已提交
1598 1599 1600 1601 1602 1603 1604 1605 1606 1607
	struct sk_buff *skb;

	/* Create the bare association.  */
	scope = sctp_scope(sctp_source(chunk));
	asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
	if (!asoc)
		goto nodata;
	asoc->temp = 1;
	skb = chunk->skb;
	/* Create an entry for the source address of the packet.  */
1608 1609
	SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);

L
Linus Torvalds 已提交
1610 1611 1612 1613 1614 1615 1616
nodata:
	return asoc;
}

/* Build a cookie representing asoc.
 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
 */
1617 1618 1619 1620
static struct sctp_cookie_param *sctp_pack_cookie(
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					const struct sctp_chunk *init_chunk,
1621 1622
					int *cookie_len, const __u8 *raw_addrs,
					int addrs_len)
L
Linus Torvalds 已提交
1623 1624
{
	struct sctp_signed_cookie *cookie;
1625
	struct sctp_cookie_param *retval;
L
Linus Torvalds 已提交
1626 1627
	int headersize, bodysize;

1628 1629 1630
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
1631
	headersize = sizeof(struct sctp_paramhdr) +
1632
		     (sizeof(struct sctp_signed_cookie) -
1633
		      sizeof(struct sctp_cookie));
L
Linus Torvalds 已提交
1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647
	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.
	 */
1648 1649 1650 1651
	retval = kzalloc(*cookie_len, GFP_ATOMIC);
	if (!retval)
		goto nodata;

L
Linus Torvalds 已提交
1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665
	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;

1666 1667
	/* Save adaptation indication in the cookie. */
	cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
L
Linus Torvalds 已提交
1668 1669

	/* Set an expiration time for the cookie.  */
1670
	cookie->c.expiration = ktime_add(asoc->cookie_life,
1671
					 ktime_get_real());
L
Linus Torvalds 已提交
1672 1673 1674 1675 1676 1677 1678 1679 1680

	/* 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);

1681
	if (sctp_sk(ep->base.sk)->hmac) {
H
Herbert Xu 已提交
1682 1683
		SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
		int err;
1684

L
Linus Torvalds 已提交
1685
		/* Sign the message.  */
H
Herbert Xu 已提交
1686 1687 1688 1689 1690 1691 1692 1693 1694
		desc->tfm = sctp_sk(ep->base.sk)->hmac;
		desc->flags = 0;

		err = crypto_shash_setkey(desc->tfm, ep->secret_key,
					  sizeof(ep->secret_key)) ?:
		      crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
					  cookie->signature);
		shash_desc_zero(desc);
		if (err)
1695
			goto free_cookie;
L
Linus Torvalds 已提交
1696 1697 1698
	}

	return retval;
1699 1700 1701 1702 1703 1704

free_cookie:
	kfree(retval);
nodata:
	*cookie_len = 0;
	return NULL;
L
Linus Torvalds 已提交
1705 1706 1707 1708
}

/* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
struct sctp_association *sctp_unpack_cookie(
1709 1710 1711 1712
					const struct sctp_endpoint *ep,
					const struct sctp_association *asoc,
					struct sctp_chunk *chunk, gfp_t gfp,
					int *error, struct sctp_chunk **errp)
L
Linus Torvalds 已提交
1713 1714
{
	struct sctp_association *retval = NULL;
1715
	int headersize, bodysize, fixed_size;
L
Linus Torvalds 已提交
1716
	struct sctp_signed_cookie *cookie;
1717
	struct sk_buff *skb = chunk->skb;
L
Linus Torvalds 已提交
1718
	struct sctp_cookie *bear_cookie;
1719
	__u8 *digest = ep->digest;
X
Xin Long 已提交
1720
	enum sctp_scope scope;
1721
	unsigned int len;
1722
	ktime_t kt;
L
Linus Torvalds 已提交
1723

1724 1725 1726
	/* Header size is static data prior to the actual cookie, including
	 * any padding.
	 */
1727
	headersize = sizeof(struct sctp_chunkhdr) +
1728
		     (sizeof(struct sctp_signed_cookie) -
1729
		      sizeof(struct sctp_cookie));
L
Linus Torvalds 已提交
1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752
	bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
	fixed_size = headersize + sizeof(struct sctp_cookie);

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

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

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

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

	/* Check the signature.  */
H
Herbert Xu 已提交
1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769
	{
		SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
		int err;

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

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

		if (err) {
			*error = -SCTP_IERROR_NOMEM;
			goto fail;
		}
1770
	}
L
Linus Torvalds 已提交
1771 1772

	if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1773 1774
		*error = -SCTP_IERROR_BAD_SIG;
		goto fail;
L
Linus Torvalds 已提交
1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789
	}

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;
	}

1790
	if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
L
Linus Torvalds 已提交
1791 1792 1793 1794 1795 1796 1797 1798
	    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.
1799 1800 1801 1802
	 * If skb has been timestamped, then use the stamp, otherwise
	 * use current time.  This introduces a small possibility that
	 * that a cookie may be considered expired, but his would only slow
	 * down the new association establishment instead of every packet.
L
Linus Torvalds 已提交
1803
	 */
1804
	if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1805
		kt = skb_get_ktime(skb);
1806
	else
1807
		kt = ktime_get_real();
1808

1809
	if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1810 1811 1812
		suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
		__be32 n = htonl(usecs);

L
Linus Torvalds 已提交
1813 1814 1815 1816 1817 1818 1819 1820
		/*
		 * 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.
		 */
1821 1822 1823 1824
		*errp = sctp_make_op_error(asoc, chunk,
					   SCTP_ERROR_STALE_COOKIE, &n,
					   sizeof(n), 0);
		if (*errp)
L
Linus Torvalds 已提交
1825
			*error = -SCTP_IERROR_STALE_COOKIE;
1826
		else
L
Linus Torvalds 已提交
1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853
			*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)) {
1854
		sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1855 1856
				   sizeof(chunk->dest), SCTP_ADDR_SRC,
				   GFP_ATOMIC);
L
Linus Torvalds 已提交
1857 1858 1859 1860 1861
	}

	retval->next_tsn = retval->c.initial_tsn;
	retval->ctsn_ack_point = retval->next_tsn - 1;
	retval->addip_serial = retval->c.initial_tsn;
1862
	retval->strreset_outseq = retval->c.initial_tsn;
L
Linus Torvalds 已提交
1863 1864
	retval->adv_peer_ack_point = retval->ctsn_ack_point;
	retval->peer.prsctp_capable = retval->c.prsctp_capable;
1865
	retval->peer.adaptation_ind = retval->c.adaptation_ind;
L
Linus Torvalds 已提交
1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888

	/* 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
1889 1890
	__be32 num_missing;
	__be16 type;
E
Eric Dumazet 已提交
1891
}  __packed;
L
Linus Torvalds 已提交
1892 1893 1894 1895 1896

/*
 * Report a missing mandatory parameter.
 */
static int sctp_process_missing_param(const struct sctp_association *asoc,
X
Xin Long 已提交
1897
				      enum sctp_param paramtype,
L
Linus Torvalds 已提交
1898 1899 1900 1901 1902 1903
				      struct sctp_chunk *chunk,
				      struct sctp_chunk **errp)
{
	struct __sctp_missing report;
	__u16 len;

1904
	len = SCTP_PAD4(sizeof(report));
L
Linus Torvalds 已提交
1905 1906 1907 1908 1909 1910 1911 1912 1913 1914

	/* 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;
1915
		sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1916 1917
				sizeof(report));
		sctp_addto_chunk(*errp, sizeof(report), &report);
L
Linus Torvalds 已提交
1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934
	}

	/* 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)
1935
		sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
L
Linus Torvalds 已提交
1936 1937 1938 1939 1940 1941 1942 1943 1944 1945

	/* 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)
{
1946 1947 1948 1949 1950 1951
	/* This is a fatal error.  Any accumulated non-fatal errors are
	 * not reported.
	 */
	if (*errp)
		sctp_chunk_free(*errp);

L
Linus Torvalds 已提交
1952
	/* Create an error chunk and fill it in with our payload. */
1953
	*errp = sctp_make_violation_paramlen(asoc, chunk, param);
L
Linus Torvalds 已提交
1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968

	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);

1969 1970 1971 1972 1973 1974 1975 1976
	/* 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);

1977 1978
	*errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
				   param.v, len, 0);
L
Linus Torvalds 已提交
1979 1980 1981 1982 1983

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

1984
static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1985
{
1986
	__u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
1987
	int have_asconf = 0;
1988
	int have_auth = 0;
1989 1990 1991 1992
	int i;

	for (i = 0; i < num_ext; i++) {
		switch (param.ext->chunks[i]) {
1993 1994 1995 1996 1997 1998 1999
		case SCTP_CID_AUTH:
			have_auth = 1;
			break;
		case SCTP_CID_ASCONF:
		case SCTP_CID_ASCONF_ACK:
			have_asconf = 1;
			break;
2000 2001 2002 2003 2004 2005 2006 2007
		}
	}

	/* 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.
	 */
2008
	if (net->sctp.addip_noauth)
2009 2010
		return 1;

2011
	if (net->sctp.addip_enable && !have_auth && have_asconf)
2012 2013 2014 2015 2016
		return 0;

	return 1;
}

2017
static void sctp_process_ext_param(struct sctp_association *asoc,
2018
				   union sctp_params param)
2019
{
2020
	__u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2021
	struct net *net = sock_net(asoc->base.sk);
2022 2023 2024 2025
	int i;

	for (i = 0; i < num_ext; i++) {
		switch (param.ext->chunks[i]) {
2026 2027 2028 2029 2030
		case SCTP_CID_RECONF:
			if (asoc->reconf_enable &&
			    !asoc->peer.reconf_capable)
				asoc->peer.reconf_capable = 1;
			break;
2031
		case SCTP_CID_FWD_TSN:
2032 2033
			if (asoc->prsctp_enable && !asoc->peer.prsctp_capable)
				asoc->peer.prsctp_capable = 1;
2034 2035 2036 2037 2038
			break;
		case SCTP_CID_AUTH:
			/* if the peer reports AUTH, assume that he
			 * supports AUTH.
			 */
2039
			if (asoc->ep->auth_enable)
2040 2041 2042 2043 2044 2045 2046
				asoc->peer.auth_capable = 1;
			break;
		case SCTP_CID_ASCONF:
		case SCTP_CID_ASCONF_ACK:
			if (net->sctp.addip_enable)
				asoc->peer.asconf_capable = 1;
			break;
2047 2048 2049 2050
		case SCTP_CID_I_DATA:
			if (sctp_sk(asoc->base.sk)->strm_interleave)
				asoc->intl_enable = 1;
			break;
2051 2052
		default:
			break;
2053 2054 2055 2056
		}
	}
}

L
Linus Torvalds 已提交
2057 2058 2059 2060 2061 2062 2063
/* 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.
 *
2064 2065
 * 00 - Stop processing this parameter; do not process any further
 * 	parameters within this chunk
L
Linus Torvalds 已提交
2066
 *
2067 2068 2069
 * 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
2070 2071 2072 2073 2074
 *
 * 10 - Skip this parameter and continue processing.
 *
 * 11 - Skip this parameter and continue processing but
 *	report the unrecognized parameter in an
2075
 *	'Unrecognized Parameter' ERROR chunk.
L
Linus Torvalds 已提交
2076 2077
 *
 * Return value:
2078 2079 2080
 * 	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
2081
 */
2082 2083 2084 2085 2086
static enum sctp_ierror sctp_process_unk_param(
					const struct sctp_association *asoc,
					union sctp_params param,
					struct sctp_chunk *chunk,
					struct sctp_chunk **errp)
L
Linus Torvalds 已提交
2087
{
2088
	int retval = SCTP_IERROR_NO_ERROR;
L
Linus Torvalds 已提交
2089 2090 2091

	switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
	case SCTP_PARAM_ACTION_DISCARD:
2092
		retval =  SCTP_IERROR_ERROR;
L
Linus Torvalds 已提交
2093 2094 2095
		break;
	case SCTP_PARAM_ACTION_SKIP:
		break;
2096 2097 2098
	case SCTP_PARAM_ACTION_DISCARD_ERR:
		retval =  SCTP_IERROR_ERROR;
		/* Fall through */
L
Linus Torvalds 已提交
2099 2100 2101 2102
	case SCTP_PARAM_ACTION_SKIP_ERR:
		/* Make an ERROR chunk, preparing enough room for
		 * returning multiple unknown parameters.
		 */
2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113
		if (!*errp) {
			*errp = sctp_make_op_error_limited(asoc, chunk);
			if (!*errp) {
				/* 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.
				 */
				retval = SCTP_IERROR_NOMEM;
				break;
			}
L
Linus Torvalds 已提交
2114
		}
2115 2116 2117 2118 2119

		if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
				     ntohs(param.p->length)))
			sctp_addto_chunk(*errp, ntohs(param.p->length),
					 param.v);
L
Linus Torvalds 已提交
2120 2121 2122 2123 2124 2125 2126 2127
		break;
	default:
		break;
	}

	return retval;
}

2128
/* Verify variable length parameters
L
Linus Torvalds 已提交
2129
 * Return values:
2130 2131 2132 2133
 * 	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
2134
 */
2135 2136 2137 2138 2139 2140 2141
static enum sctp_ierror sctp_verify_param(struct net *net,
					  const struct sctp_endpoint *ep,
					  const struct sctp_association *asoc,
					  union sctp_params param,
					  enum sctp_cid cid,
					  struct sctp_chunk *chunk,
					  struct sctp_chunk **err_chunk)
L
Linus Torvalds 已提交
2142
{
2143
	struct sctp_hmac_algo_param *hmacs;
2144
	int retval = SCTP_IERROR_NO_ERROR;
2145 2146
	__u16 n_elt, id = 0;
	int i;
L
Linus Torvalds 已提交
2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161

	/* 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:
2162
	case SCTP_PARAM_ADAPTATION_LAYER_IND:
2163 2164
		break;

2165
	case SCTP_PARAM_SUPPORTED_EXT:
2166
		if (!sctp_verify_ext_param(net, param))
2167
			return SCTP_IERROR_ABORT;
L
Linus Torvalds 已提交
2168 2169
		break;

2170
	case SCTP_PARAM_SET_PRIMARY:
2171
		if (net->sctp.addip_enable)
2172 2173 2174
			break;
		goto fallthrough;

L
Linus Torvalds 已提交
2175 2176
	case SCTP_PARAM_HOST_NAME_ADDRESS:
		/* Tell the peer, we won't support this param.  */
2177 2178 2179
		sctp_process_hn_param(asoc, param, chunk, err_chunk);
		retval = SCTP_IERROR_ABORT;
		break;
2180

L
Linus Torvalds 已提交
2181
	case SCTP_PARAM_FWD_TSN_SUPPORT:
2182
		if (ep->prsctp_enable)
L
Linus Torvalds 已提交
2183
			break;
2184 2185 2186
		goto fallthrough;

	case SCTP_PARAM_RANDOM:
2187
		if (!ep->auth_enable)
2188 2189 2190 2191 2192 2193 2194
			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'.
		 */
2195 2196
		if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
					       sizeof(struct sctp_paramhdr)) {
2197
			sctp_process_inv_paramlength(asoc, param.p,
2198
						     chunk, err_chunk);
2199 2200
			retval = SCTP_IERROR_ABORT;
		}
2201 2202 2203
		break;

	case SCTP_PARAM_CHUNKS:
2204
		if (!ep->auth_enable)
2205 2206 2207 2208 2209 2210 2211
			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.
		 */
2212 2213 2214 2215 2216
		if (260 < ntohs(param.p->length)) {
			sctp_process_inv_paramlength(asoc, param.p,
						     chunk, err_chunk);
			retval = SCTP_IERROR_ABORT;
		}
2217 2218 2219
		break;

	case SCTP_PARAM_HMAC_ALGO:
2220
		if (!ep->auth_enable)
2221 2222 2223
			goto fallthrough;

		hmacs = (struct sctp_hmac_algo_param *)param.p;
2224 2225
		n_elt = (ntohs(param.p->length) -
			 sizeof(struct sctp_paramhdr)) >> 1;
2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243

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

			if (id == SCTP_AUTH_HMAC_ID_SHA1)
				break;
		}

		if (id != SCTP_AUTH_HMAC_ID_SHA1) {
			sctp_process_inv_paramlength(asoc, param.p, chunk,
						     err_chunk);
			retval = SCTP_IERROR_ABORT;
		}
		break;
2244
fallthrough:
L
Linus Torvalds 已提交
2245
	default:
2246 2247 2248
		pr_debug("%s: unrecognized param:%d for chunk:%d\n",
			 __func__, ntohs(param.p->type), cid);

2249
		retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
L
Linus Torvalds 已提交
2250 2251 2252 2253 2254 2255
		break;
	}
	return retval;
}

/* Verify the INIT packet before we process it.  */
2256
int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
X
Xin Long 已提交
2257
		     const struct sctp_association *asoc, enum sctp_cid cid,
2258 2259
		     struct sctp_init_chunk *peer_init,
		     struct sctp_chunk *chunk, struct sctp_chunk **errp)
L
Linus Torvalds 已提交
2260 2261
{
	union sctp_params param;
2262
	bool has_cookie = false;
2263
	int result;
L
Linus Torvalds 已提交
2264

2265 2266 2267 2268 2269 2270 2271 2272
	/* Check for missing mandatory parameters. Note: Initial TSN is
	 * also mandatory, but is not checked here since the valid range
	 * is 0..2**32-1. RFC4960, section 3.3.3.
	 */
	if (peer_init->init_hdr.num_outbound_streams == 0 ||
	    peer_init->init_hdr.num_inbound_streams == 0 ||
	    peer_init->init_hdr.init_tag == 0 ||
	    ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2273
		return sctp_process_inv_mandatory(asoc, chunk, errp);
L
Linus Torvalds 已提交
2274 2275

	sctp_walk_params(param, peer_init, init_hdr.params) {
2276 2277 2278
		if (param.p->type == SCTP_PARAM_STATE_COOKIE)
			has_cookie = true;
	}
L
Linus Torvalds 已提交
2279 2280 2281 2282 2283 2284 2285 2286

	/* 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.
	 */
2287
	if (param.v != (void *)chunk->chunk_end)
2288
		return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
L
Linus Torvalds 已提交
2289 2290 2291 2292

	/* The only missing mandatory param possible today is
	 * the state cookie for an INIT-ACK chunk.
	 */
2293 2294 2295
	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
2296

2297
	/* Verify all the variable length parameters */
L
Linus Torvalds 已提交
2298
	sctp_walk_params(param, peer_init, init_hdr.params) {
2299 2300
		result = sctp_verify_param(net, ep, asoc, param, cid,
					   chunk, errp);
2301
		switch (result) {
2302 2303 2304 2305 2306 2307 2308 2309
		case SCTP_IERROR_ABORT:
		case SCTP_IERROR_NOMEM:
			return 0;
		case SCTP_IERROR_ERROR:
			return 1;
		case SCTP_IERROR_NO_ERROR:
		default:
			break;
L
Linus Torvalds 已提交
2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320
		}

	} /* 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.
 */
2321
int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
L
Linus Torvalds 已提交
2322
		      const union sctp_addr *peer_addr,
2323
		      struct sctp_init_chunk *peer_init, gfp_t gfp)
L
Linus Torvalds 已提交
2324
{
2325
	struct net *net = sock_net(asoc->base.sk);
L
Linus Torvalds 已提交
2326 2327
	struct sctp_transport *transport;
	struct list_head *pos, *temp;
2328
	union sctp_params param;
2329
	union sctp_addr addr;
2330
	struct sctp_af *af;
2331
	int src_match = 0;
L
Linus Torvalds 已提交
2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342

	/* 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.
	 */
2343
	if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2344 2345 2346 2347
		goto nomem;

	if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
		src_match = 1;
L
Linus Torvalds 已提交
2348 2349 2350

	/* Process the initialization parameters.  */
	sctp_walk_params(param, peer_init, init_hdr.params) {
2351 2352 2353 2354 2355 2356 2357 2358
		if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
		    param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
			af = sctp_get_af_specific(param_type2af(param.p->type));
			af->from_addr_param(&addr, param.addr,
					    chunk->sctp_hdr->source, 0);
			if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
				src_match = 1;
		}
L
Linus Torvalds 已提交
2359 2360

		if (!sctp_process_param(asoc, param, peer_addr, gfp))
2361
			goto clean_up;
L
Linus Torvalds 已提交
2362 2363
	}

2364 2365 2366 2367
	/* source address of chunk may not match any valid address */
	if (!src_match)
		goto clean_up;

2368 2369 2370 2371 2372 2373 2374
	/* 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;

2375 2376 2377 2378 2379
	/* 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.
2380
	 */
2381
	if (!net->sctp.addip_noauth &&
2382
	     (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2383 2384 2385
		asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
						  SCTP_PARAM_DEL_IP |
						  SCTP_PARAM_SET_PRIMARY);
2386
		asoc->peer.asconf_capable = 0;
2387
		goto clean_up;
2388 2389
	}

F
Frank Filz 已提交
2390 2391 2392 2393 2394 2395 2396 2397
	/* 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
2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411
	/* 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);

2412 2413
	asoc->strreset_inseq = asoc->peer.i.initial_tsn;

L
Linus Torvalds 已提交
2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438
	/* 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;

	/* 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).
	 */
2439 2440
	list_for_each_entry(transport, &asoc->peer.transport_addr_list,
			transports) {
L
Linus Torvalds 已提交
2441 2442 2443 2444
		transport->ssthresh = asoc->peer.i.a_rwnd;
	}

	/* Set up the TSN tracking pieces.  */
2445 2446 2447
	if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
				asoc->peer.i.initial_tsn, gfp))
		goto clean_up;
L
Linus Torvalds 已提交
2448 2449 2450 2451 2452 2453 2454 2455 2456

	/* 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.
	 */

2457 2458
	if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
			     asoc->c.sinit_max_instreams, gfp))
2459
		goto clean_up;
L
Linus Torvalds 已提交
2460

2461 2462 2463
	/* Update frag_point when stream_interleave may get changed. */
	sctp_assoc_update_frag_point(asoc);

2464 2465
	if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
		goto clean_up;
L
Linus Torvalds 已提交
2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483

	/* 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);
2484 2485
		if (transport->state != SCTP_ACTIVE)
			sctp_assoc_rm_peer(asoc, transport);
L
Linus Torvalds 已提交
2486
	}
F
Frank Filz 已提交
2487

L
Linus Torvalds 已提交
2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506
nomem:
	return 0;
}


/* Update asoc with the option described in param.
 *
 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
 *
 * asoc is the association to update.
 * param is the variable length parameter to use for update.
 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
 * If the current packet is an INIT we want to minimize the amount of
 * work we do.  In particular, we should not build transport
 * structures for the addresses.
 */
static int sctp_process_param(struct sctp_association *asoc,
			      union sctp_params param,
			      const union sctp_addr *peer_addr,
A
Al Viro 已提交
2507
			      gfp_t gfp)
L
Linus Torvalds 已提交
2508
{
2509
	struct net *net = sock_net(asoc->base.sk);
2510
	struct sctp_endpoint *ep = asoc->ep;
2511 2512
	union sctp_addr_param *addr_param;
	struct sctp_transport *t;
2513 2514 2515 2516 2517 2518
	enum sctp_scope scope;
	union sctp_addr addr;
	struct sctp_af *af;
	int retval = 1, i;
	u32 stale;
	__u16 sat;
L
Linus Torvalds 已提交
2519 2520 2521 2522 2523 2524 2525 2526 2527

	/* 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;
2528 2529
		goto do_addr_param;

L
Linus Torvalds 已提交
2530
	case SCTP_PARAM_IPV4_ADDRESS:
2531 2532 2533 2534
		/* v4 addresses are not allowed on v6-only socket */
		if (ipv6_only_sock(asoc->base.sk))
			break;
do_addr_param:
L
Linus Torvalds 已提交
2535
		af = sctp_get_af_specific(param_type2af(param.p->type));
2536
		af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
L
Linus Torvalds 已提交
2537
		scope = sctp_scope(peer_addr);
2538
		if (sctp_in_scope(net, &addr, scope))
2539
			if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
L
Linus Torvalds 已提交
2540 2541 2542 2543
				return 0;
		break;

	case SCTP_PARAM_COOKIE_PRESERVATIVE:
2544
		if (!net->sctp.cookie_preserve_enable)
L
Linus Torvalds 已提交
2545 2546 2547 2548 2549 2550 2551
			break;

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

		/* Suggested Cookie Life span increment's unit is msec,
		 * (1/1000sec).
		 */
2552
		asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
L
Linus Torvalds 已提交
2553 2554 2555
		break;

	case SCTP_PARAM_HOST_NAME_ADDRESS:
2556
		pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
L
Linus Torvalds 已提交
2557 2558 2559 2560 2561 2562 2563 2564 2565
		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;

2566 2567 2568 2569 2570 2571 2572 2573
		/* Assume that peer supports the address family
		 * by which it sends a packet.
		 */
		if (peer_addr->sa.sa_family == AF_INET6)
			asoc->peer.ipv6_address = 1;
		else if (peer_addr->sa.sa_family == AF_INET)
			asoc->peer.ipv4_address = 1;

L
Linus Torvalds 已提交
2574
		/* Cycle through address types; avoid divide by 0. */
2575
		sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
L
Linus Torvalds 已提交
2576 2577 2578 2579 2580 2581 2582 2583 2584 2585
		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:
2586 2587
				if (PF_INET6 == asoc->base.sk->sk_family)
					asoc->peer.ipv6_address = 1;
L
Linus Torvalds 已提交
2588 2589 2590 2591 2592 2593 2594 2595
				break;

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

			default: /* Just ignore anything else.  */
				break;
2596
			}
L
Linus Torvalds 已提交
2597 2598 2599 2600 2601
		}
		break;

	case SCTP_PARAM_STATE_COOKIE:
		asoc->peer.cookie_len =
2602
			ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2603 2604
		if (asoc->peer.cookie)
			kfree(asoc->peer.cookie);
2605 2606 2607
		asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
		if (!asoc->peer.cookie)
			retval = 0;
L
Linus Torvalds 已提交
2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621
		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;

2622
	case SCTP_PARAM_ADAPTATION_LAYER_IND:
2623
		asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
L
Linus Torvalds 已提交
2624 2625
		break;

2626
	case SCTP_PARAM_SET_PRIMARY:
2627
		if (!net->sctp.addip_enable)
2628 2629
			goto fall_through;

2630
		addr_param = param.v + sizeof(struct sctp_addip_param);
2631

2632
		af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2633 2634 2635
		if (af == NULL)
			break;

2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651
		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;

2652 2653 2654 2655
	case SCTP_PARAM_SUPPORTED_EXT:
		sctp_process_ext_param(asoc, param);
		break;

L
Linus Torvalds 已提交
2656
	case SCTP_PARAM_FWD_TSN_SUPPORT:
2657
		if (asoc->prsctp_enable) {
L
Linus Torvalds 已提交
2658 2659 2660
			asoc->peer.prsctp_capable = 1;
			break;
		}
2661
		/* Fall Through */
2662 2663 2664
		goto fall_through;

	case SCTP_PARAM_RANDOM:
2665
		if (!ep->auth_enable)
2666 2667 2668
			goto fall_through;

		/* Save peer's random parameter */
2669 2670
		if (asoc->peer.peer_random)
			kfree(asoc->peer.peer_random);
2671 2672 2673 2674 2675 2676 2677 2678 2679
		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:
2680
		if (!ep->auth_enable)
2681 2682 2683
			goto fall_through;

		/* Save peer's HMAC list */
2684 2685
		if (asoc->peer.peer_hmacs)
			kfree(asoc->peer.peer_hmacs);
2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697
		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:
2698
		if (!ep->auth_enable)
2699 2700
			goto fall_through;

2701 2702
		if (asoc->peer.peer_chunks)
			kfree(asoc->peer.peer_chunks);
2703 2704 2705 2706 2707 2708
		asoc->peer.peer_chunks = kmemdup(param.p,
					    ntohs(param.p->length), gfp);
		if (!asoc->peer.peer_chunks)
			retval = 0;
		break;
fall_through:
L
Linus Torvalds 已提交
2709 2710 2711 2712 2713 2714
	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.
		 */
2715 2716
		pr_debug("%s: ignoring param:%d for association:%p.\n",
			 __func__, ntohs(param.p->type), asoc);
L
Linus Torvalds 已提交
2717
		break;
2718
	}
L
Linus Torvalds 已提交
2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766

	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                       |
 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2767
 * Address Parameter and other parameter will not be wrapped in this function
L
Linus Torvalds 已提交
2768 2769 2770 2771 2772
 */
static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
					   union sctp_addr *addr,
					   int vparam_len)
{
2773
	struct sctp_addiphdr asconf;
L
Linus Torvalds 已提交
2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785
	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.  */
2786 2787
	retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
				   GFP_ATOMIC);
L
Linus Torvalds 已提交
2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825
	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,
2826 2827 2828
					      union sctp_addr *laddr,
					      struct sockaddr *addrs,
					      int addrcnt, __be16 flags)
L
Linus Torvalds 已提交
2829
{
2830
	union sctp_addr_param addr_param;
2831
	struct sctp_addip_param	param;
2832 2833 2834 2835 2836 2837 2838 2839
	int paramlen = sizeof(param);
	struct sctp_chunk *retval;
	int addr_param_len = 0;
	union sctp_addr *addr;
	int totallen = 0, i;
	int del_pickup = 0;
	struct sctp_af *af;
	void *addr_buf;
L
Linus Torvalds 已提交
2840 2841 2842 2843

	/* Get total length of all the address parameters. */
	addr_buf = addrs;
	for (i = 0; i < addrcnt; i++) {
J
Joe Perches 已提交
2844
		addr = addr_buf;
L
Linus Torvalds 已提交
2845 2846 2847 2848 2849 2850 2851
		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;
2852 2853 2854 2855 2856
		if (asoc->asconf_addr_del_pending && !del_pickup) {
			/* reuse the parameter length from the same scope one */
			totallen += paramlen;
			totallen += addr_param_len;
			del_pickup = 1;
2857 2858 2859 2860

			pr_debug("%s: picked same-scope del_pending addr, "
				 "totallen for all addresses is %d\n",
				 __func__, totallen);
2861
		}
L
Linus Torvalds 已提交
2862 2863 2864 2865 2866 2867 2868 2869 2870 2871
	}

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

	/* Add the address parameters to the asconf chunk. */
	addr_buf = addrs;
	for (i = 0; i < addrcnt; i++) {
J
Joe Perches 已提交
2872
		addr = addr_buf;
L
Linus Torvalds 已提交
2873 2874 2875 2876
		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);
2877
		param.crr_id = htonl(i);
L
Linus Torvalds 已提交
2878 2879 2880 2881 2882 2883

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

		addr_buf += af->sockaddr_len;
	}
2884 2885 2886 2887 2888 2889
	if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
		addr = asoc->asconf_addr_del_pending;
		af = sctp_get_af_specific(addr->v4.sin_family);
		addr_param_len = af->to_addr_param(addr, &addr_param);
		param.param_hdr.type = SCTP_PARAM_DEL_IP;
		param.param_hdr.length = htons(paramlen + addr_param_len);
2890
		param.crr_id = htonl(i);
2891 2892 2893 2894

		sctp_addto_chunk(retval, paramlen, &param);
		sctp_addto_chunk(retval, addr_param_len, &addr_param);
	}
L
Linus Torvalds 已提交
2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909
	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                       |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2910
 * Create an ASCONF chunk with Set Primary IP address parameter.
L
Linus Torvalds 已提交
2911 2912 2913 2914
 */
struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
					     union sctp_addr *addr)
{
2915 2916
	struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
	union sctp_addr_param addrparam;
2917
	struct sctp_addip_param	param;
2918 2919 2920
	struct sctp_chunk *retval;
	int len = sizeof(param);
	int addrlen;
L
Linus Torvalds 已提交
2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958

	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                   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
2959
 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
L
Linus Torvalds 已提交
2960 2961 2962 2963
 */
static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
					       __u32 serial, int vparam_len)
{
2964 2965 2966
	struct sctp_addiphdr asconf;
	struct sctp_chunk *retval;
	int length = sizeof(asconf) + vparam_len;
L
Linus Torvalds 已提交
2967 2968

	/* Create the chunk.  */
2969 2970
	retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
				   GFP_ATOMIC);
L
Linus Torvalds 已提交
2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982
	if (!retval)
		return NULL;

	asconf.serial = htonl(serial);

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

	return retval;
}

/* Add response parameters to an ASCONF_ACK chunk. */
A
Al Viro 已提交
2983
static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2984 2985
				     __be16 err_code,
				     struct sctp_addip_param *asconf_param)
L
Linus Torvalds 已提交
2986
{
2987
	struct sctp_addip_param ack_param;
2988 2989 2990 2991
	struct sctp_errhdr err_param;
	int asconf_param_len = 0;
	int err_param_len = 0;
	__be16 response_type;
L
Linus Torvalds 已提交
2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002

	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);
	}

3003
	/* Add Success Indication or Error Cause Indication parameter. */
L
Linus Torvalds 已提交
3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024
	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. */
3025
static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3026 3027
					struct sctp_chunk *asconf,
					struct sctp_addip_param *asconf_param)
L
Linus Torvalds 已提交
3028
{
3029
	union sctp_addr_param *addr_param;
L
Linus Torvalds 已提交
3030 3031
	struct sctp_transport *peer;
	union sctp_addr	addr;
3032
	struct sctp_af *af;
3033

3034
	addr_param = (void *)asconf_param + sizeof(*asconf_param);
3035

3036 3037 3038 3039 3040
	if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
	    asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
	    asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
		return SCTP_ERROR_UNKNOWN_PARAM;

3041
	switch (addr_param->p.type) {
3042 3043
	case SCTP_PARAM_IPV6_ADDRESS:
		if (!asoc->peer.ipv6_address)
3044
			return SCTP_ERROR_DNS_FAILED;
3045 3046 3047
		break;
	case SCTP_PARAM_IPV4_ADDRESS:
		if (!asoc->peer.ipv4_address)
3048
			return SCTP_ERROR_DNS_FAILED;
3049 3050
		break;
	default:
3051
		return SCTP_ERROR_DNS_FAILED;
3052 3053
	}

3054
	af = sctp_get_af_specific(param_type2af(addr_param->p.type));
L
Linus Torvalds 已提交
3055
	if (unlikely(!af))
3056
		return SCTP_ERROR_DNS_FAILED;
L
Linus Torvalds 已提交
3057

3058
	af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3059 3060 3061 3062 3063 3064 3065

	/* 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))
3066
		return SCTP_ERROR_DNS_FAILED;
3067

L
Linus Torvalds 已提交
3068 3069
	switch (asconf_param->param_hdr.type) {
	case SCTP_PARAM_ADD_IP:
3070 3071 3072 3073 3074 3075 3076
		/* 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));

R
Richard Haines 已提交
3077 3078 3079 3080 3081 3082
		if (security_sctp_bind_connect(asoc->ep->base.sk,
					       SCTP_PARAM_ADD_IP,
					       (struct sockaddr *)&addr,
					       af->sockaddr_len))
			return SCTP_ERROR_REQ_REFUSED;

L
Linus Torvalds 已提交
3083
		/* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3084 3085 3086 3087 3088
		 * request and does not have the local resources to add this
		 * new address to the association, it MUST return an Error
		 * Cause TLV set to the new error code 'Operation Refused
		 * Due to Resource Shortage'.
		 */
L
Linus Torvalds 已提交
3089

3090
		peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
L
Linus Torvalds 已提交
3091 3092 3093 3094
		if (!peer)
			return SCTP_ERROR_RSRC_LOW;

		/* Start the heartbeat timer. */
3095
		sctp_transport_reset_hb_timer(peer);
3096
		asoc->new_transport = peer;
L
Linus Torvalds 已提交
3097 3098 3099
		break;
	case SCTP_PARAM_DEL_IP:
		/* ADDIP 4.3 D7) If a request is received to delete the
3100 3101 3102 3103
		 * 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'.
		 */
3104
		if (asoc->peer.transport_count == 1)
L
Linus Torvalds 已提交
3105 3106 3107 3108 3109 3110 3111 3112 3113
			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'
		 */
3114
		if (sctp_cmp_addr_exact(&asconf->source, &addr))
L
Linus Torvalds 已提交
3115 3116
			return SCTP_ERROR_DEL_SRC_IP;

3117 3118 3119 3120 3121 3122 3123 3124 3125
		/* 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);
3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138
			return SCTP_ERROR_NO_ERROR;
		}

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

		sctp_assoc_rm_peer(asoc, peer);
L
Linus Torvalds 已提交
3139 3140
		break;
	case SCTP_PARAM_SET_PRIMARY:
3141 3142 3143 3144 3145 3146 3147 3148
		/* 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));

R
Richard Haines 已提交
3149 3150 3151 3152 3153 3154
		if (security_sctp_bind_connect(asoc->ep->base.sk,
					       SCTP_PARAM_SET_PRIMARY,
					       (struct sockaddr *)&addr,
					       af->sockaddr_len))
			return SCTP_ERROR_REQ_REFUSED;

3155
		peer = sctp_assoc_lookup_paddr(asoc, &addr);
L
Linus Torvalds 已提交
3156
		if (!peer)
3157
			return SCTP_ERROR_DNS_FAILED;
L
Linus Torvalds 已提交
3158 3159 3160 3161 3162 3163 3164 3165

		sctp_assoc_set_primary(asoc, peer);
		break;
	}

	return SCTP_ERROR_NO_ERROR;
}

3166 3167 3168 3169 3170
/* Verify the ASCONF packet before we process it. */
bool sctp_verify_asconf(const struct sctp_association *asoc,
			struct sctp_chunk *chunk, bool addr_param_needed,
			struct sctp_paramhdr **errp)
{
3171
	struct sctp_addip_chunk *addip;
3172
	bool addr_param_seen = false;
3173
	union sctp_params param;
3174

3175
	addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3176 3177
	sctp_walk_params(param, addip, addip_hdr.params) {
		size_t length = ntohs(param.p->length);
3178

3179
		*errp = param.p;
3180
		switch (param.p->type) {
3181 3182 3183
		case SCTP_PARAM_ERR_CAUSE:
			break;
		case SCTP_PARAM_IPV4_ADDRESS:
3184
			if (length != sizeof(struct sctp_ipv4addr_param))
3185
				return false;
3186 3187 3188 3189 3190
			/* ensure there is only one addr param and it's in the
			 * beginning of addip_hdr params, or we reject it.
			 */
			if (param.v != addip->addip_hdr.params)
				return false;
3191 3192 3193
			addr_param_seen = true;
			break;
		case SCTP_PARAM_IPV6_ADDRESS:
3194
			if (length != sizeof(struct sctp_ipv6addr_param))
3195
				return false;
3196 3197
			if (param.v != addip->addip_hdr.params)
				return false;
3198 3199
			addr_param_seen = true;
			break;
3200 3201 3202
		case SCTP_PARAM_ADD_IP:
		case SCTP_PARAM_DEL_IP:
		case SCTP_PARAM_SET_PRIMARY:
3203 3204 3205 3206
			/* In ASCONF chunks, these need to be first. */
			if (addr_param_needed && !addr_param_seen)
				return false;
			length = ntohs(param.addip->param_hdr.length);
3207
			if (length < sizeof(struct sctp_addip_param) +
3208
				     sizeof(**errp))
3209
				return false;
3210 3211 3212
			break;
		case SCTP_PARAM_SUCCESS_REPORT:
		case SCTP_PARAM_ADAPTATION_LAYER_IND:
3213
			if (length != sizeof(struct sctp_addip_param))
3214
				return false;
3215 3216
			break;
		default:
3217 3218
			/* This is unkown to us, reject! */
			return false;
3219 3220 3221
		}
	}

3222 3223 3224 3225 3226 3227 3228
	/* Remaining sanity checks. */
	if (addr_param_needed && !addr_param_seen)
		return false;
	if (!addr_param_needed && addr_param_seen)
		return false;
	if (param.v != chunk->chunk_end)
		return false;
3229

3230
	return true;
3231 3232
}

3233
/* Process an incoming ASCONF chunk with the next expected serial no. and
L
Linus Torvalds 已提交
3234 3235 3236 3237 3238
 * return an ASCONF_ACK chunk to be sent in response.
 */
struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
				       struct sctp_chunk *asconf)
{
3239
	union sctp_addr_param *addr_param;
3240
	struct sctp_addip_chunk *addip;
3241
	struct sctp_chunk *asconf_ack;
3242
	bool all_param_pass = true;
3243 3244
	struct sctp_addiphdr *hdr;
	int length = 0, chunk_len;
3245
	union sctp_params param;
3246 3247
	__be16 err_code;
	__u32 serial;
L
Linus Torvalds 已提交
3248

3249
	addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3250 3251
	chunk_len = ntohs(asconf->chunk_hdr->length) -
		    sizeof(struct sctp_chunkhdr);
3252
	hdr = (struct sctp_addiphdr *)asconf->skb->data;
L
Linus Torvalds 已提交
3253 3254
	serial = ntohl(hdr->serial);

3255
	/* Skip the addiphdr and store a pointer to address parameter.  */
3256
	length = sizeof(*hdr);
L
Linus Torvalds 已提交
3257 3258 3259 3260
	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
3261
	 * asconf parameter.
3262
	 */
3263
	length = ntohs(addr_param->p.length);
L
Linus Torvalds 已提交
3264 3265
	chunk_len -= length;

3266
	/* create an ASCONF_ACK chunk.
L
Linus Torvalds 已提交
3267
	 * Based on the definitions of parameters, we know that the size of
3268
	 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
J
Joe Perches 已提交
3269
	 * parameters.
L
Linus Torvalds 已提交
3270
	 */
3271
	asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
L
Linus Torvalds 已提交
3272 3273 3274 3275
	if (!asconf_ack)
		goto done;

	/* Process the TLVs contained within the ASCONF chunk. */
3276 3277 3278 3279 3280 3281
	sctp_walk_params(param, addip, addip_hdr.params) {
		/* Skip preceeding address parameters. */
		if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
		    param.p->type == SCTP_PARAM_IPV6_ADDRESS)
			continue;

L
Linus Torvalds 已提交
3282
		err_code = sctp_process_asconf_param(asoc, asconf,
3283
						     param.addip);
L
Linus Torvalds 已提交
3284 3285 3286 3287 3288 3289 3290
		/* 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.
		 */
3291 3292
		if (err_code != SCTP_ERROR_NO_ERROR)
			all_param_pass = false;
L
Linus Torvalds 已提交
3293
		if (!all_param_pass)
3294 3295
			sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
						 err_code, param.addip);
L
Linus Torvalds 已提交
3296 3297 3298 3299

		/* 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
3300
		 * in the ASCONF.
L
Linus Torvalds 已提交
3301
		 */
3302
		if (err_code == SCTP_ERROR_RSRC_LOW)
L
Linus Torvalds 已提交
3303 3304 3305 3306 3307 3308
			goto done;
	}
done:
	asoc->peer.addip_serial++;

	/* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3309
	 * after freeing the reference to old asconf ack if any.
L
Linus Torvalds 已提交
3310 3311 3312
	 */
	if (asconf_ack) {
		sctp_chunk_hold(asconf_ack);
3313 3314
		list_add_tail(&asconf_ack->transmitted_list,
			      &asoc->asconf_ack_list);
L
Linus Torvalds 已提交
3315 3316 3317 3318 3319 3320
	}

	return asconf_ack;
}

/* Process a asconf parameter that is successfully acked. */
3321
static void sctp_asconf_param_success(struct sctp_association *asoc,
3322
				      struct sctp_addip_param *asconf_param)
L
Linus Torvalds 已提交
3323 3324 3325
{
	struct sctp_bind_addr *bp = &asoc->base.bind_addr;
	union sctp_addr_param *addr_param;
3326
	struct sctp_sockaddr_entry *saddr;
3327 3328 3329
	struct sctp_transport *transport;
	union sctp_addr	addr;
	struct sctp_af *af;
L
Linus Torvalds 已提交
3330

3331
	addr_param = (void *)asconf_param + sizeof(*asconf_param);
L
Linus Torvalds 已提交
3332 3333

	/* We have checked the packet before, so we do not check again.	*/
3334
	af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3335
	af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
L
Linus Torvalds 已提交
3336 3337 3338

	switch (asconf_param->param_hdr.type) {
	case SCTP_PARAM_ADD_IP:
3339 3340 3341
		/* This is always done in BH context with a socket lock
		 * held, so the list can not change.
		 */
3342
		local_bh_disable();
3343
		list_for_each_entry(saddr, &bp->address_list, list) {
3344
			if (sctp_cmp_addr_exact(&saddr->a, &addr))
3345
				saddr->state = SCTP_ADDR_SRC;
3346
		}
3347
		local_bh_enable();
3348 3349
		list_for_each_entry(transport, &asoc->peer.transport_addr_list,
				transports) {
3350
			sctp_transport_dst_release(transport);
3351
		}
L
Linus Torvalds 已提交
3352 3353
		break;
	case SCTP_PARAM_DEL_IP:
3354
		local_bh_disable();
3355
		sctp_del_bind_addr(bp, &addr);
3356 3357 3358 3359 3360
		if (asoc->asconf_addr_del_pending != NULL &&
		    sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
			kfree(asoc->asconf_addr_del_pending);
			asoc->asconf_addr_del_pending = NULL;
		}
3361
		local_bh_enable();
3362 3363
		list_for_each_entry(transport, &asoc->peer.transport_addr_list,
				transports) {
3364
			sctp_transport_dst_release(transport);
L
Linus Torvalds 已提交
3365 3366 3367 3368 3369 3370 3371 3372 3373
		}
		break;
	default:
		break;
	}
}

/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
 * for the given asconf parameter.  If there is no response for this parameter,
3374
 * return the error code based on the third argument 'no_err'.
L
Linus Torvalds 已提交
3375 3376 3377 3378 3379 3380
 * 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.
 */
3381
static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3382 3383
				       struct sctp_addip_param *asconf_param,
				       int no_err)
L
Linus Torvalds 已提交
3384
{
3385
	struct sctp_addip_param	*asconf_ack_param;
3386 3387 3388 3389
	struct sctp_errhdr *err_param;
	int asconf_ack_len;
	__be16 err_code;
	int length;
L
Linus Torvalds 已提交
3390 3391 3392 3393 3394 3395

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

3396
	asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3397
			 sizeof(struct sctp_chunkhdr);
3398

L
Linus Torvalds 已提交
3399 3400
	/* Skip the addiphdr from the asconf_ack chunk and store a pointer to
	 * the first asconf_ack parameter.
3401
	 */
3402
	length = sizeof(struct sctp_addiphdr);
3403 3404
	asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
						       length);
L
Linus Torvalds 已提交
3405 3406 3407 3408
	asconf_ack_len -= length;

	while (asconf_ack_len > 0) {
		if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3409
			switch (asconf_ack_param->param_hdr.type) {
L
Linus Torvalds 已提交
3410 3411 3412
			case SCTP_PARAM_SUCCESS_REPORT:
				return SCTP_ERROR_NO_ERROR;
			case SCTP_PARAM_ERR_CAUSE:
3413
				length = sizeof(*asconf_ack_param);
J
Joe Perches 已提交
3414
				err_param = (void *)asconf_ack_param + length;
L
Linus Torvalds 已提交
3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426
				asconf_ack_len -= length;
				if (asconf_ack_len > 0)
					return err_param->cause;
				else
					return SCTP_ERROR_INV_PARAM;
				break;
			default:
				return SCTP_ERROR_INV_PARAM;
			}
		}

		length = ntohs(asconf_ack_param->param_hdr.length);
J
Joe Perches 已提交
3427
		asconf_ack_param = (void *)asconf_ack_param + length;
L
Linus Torvalds 已提交
3428 3429 3430 3431 3432 3433 3434 3435 3436 3437
		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)
{
3438 3439 3440 3441 3442 3443 3444 3445 3446
	struct sctp_chunk *asconf = asoc->addip_last_asconf;
	struct sctp_addip_param *asconf_param;
	__be16 err_code = SCTP_ERROR_NO_ERROR;
	union sctp_addr_param *addr_param;
	int asconf_len = asconf->skb->len;
	int all_param_pass = 0;
	int length = 0;
	int no_err = 1;
	int retval = 0;
L
Linus Torvalds 已提交
3447 3448 3449

	/* Skip the chunkhdr and addiphdr from the last asconf sent and store
	 * a pointer to address parameter.
3450
	 */
3451
	length = sizeof(struct sctp_addip_chunk);
L
Linus Torvalds 已提交
3452 3453 3454 3455
	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
3456
	 * pointer to the first asconf parameter.
3457
	 */
3458
	length = ntohs(addr_param->p.length);
J
Joe Perches 已提交
3459
	asconf_param = (void *)addr_param + length;
L
Linus Torvalds 已提交
3460 3461 3462 3463 3464 3465 3466
	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.
	 */
3467
	if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
L
Linus Torvalds 已提交
3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483
		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:
3484
			sctp_asconf_param_success(asoc, asconf_param);
L
Linus Torvalds 已提交
3485 3486 3487 3488 3489 3490
			break;

		case SCTP_ERROR_RSRC_LOW:
			retval = 1;
			break;

3491
		case SCTP_ERROR_UNKNOWN_PARAM:
L
Linus Torvalds 已提交
3492 3493
			/* Disable sending this type of asconf parameter in
			 * future.
3494
			 */
L
Linus Torvalds 已提交
3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507
			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.
3508
		 */
L
Linus Torvalds 已提交
3509
		length = ntohs(asconf_param->param_hdr.length);
J
Joe Perches 已提交
3510
		asconf_param = (void *)asconf_param + length;
L
Linus Torvalds 已提交
3511 3512 3513
		asconf_len -= length;
	}

3514
	if (no_err && asoc->src_out_of_asoc_ok) {
3515
		asoc->src_out_of_asoc_ok = 0;
3516 3517
		sctp_transport_immediate_rtx(asoc->peer.primary_path);
	}
3518

L
Linus Torvalds 已提交
3519
	/* Free the cached last sent asconf chunk. */
3520
	list_del_init(&asconf->transmitted_list);
L
Linus Torvalds 已提交
3521 3522 3523 3524 3525 3526
	sctp_chunk_free(asconf);
	asoc->addip_last_asconf = NULL;

	return retval;
}

3527
/* Make a FWD TSN chunk. */
L
Linus Torvalds 已提交
3528 3529 3530 3531 3532
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;
3533
	struct sctp_fwdtsn_hdr ftsn_hdr;
L
Linus Torvalds 已提交
3534 3535 3536 3537 3538 3539
	struct sctp_fwdtsn_skip skip;
	size_t hint;
	int i;

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

3540
	retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
L
Linus Torvalds 已提交
3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556

	if (!retval)
		return NULL;

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

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

	return retval;
}
3557

3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581
struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
				     __u32 new_cum_tsn, size_t nstreams,
				     struct sctp_ifwdtsn_skip *skiplist)
{
	struct sctp_chunk *retval = NULL;
	struct sctp_ifwdtsn_hdr ftsn_hdr;
	size_t hint;

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

	retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
				   GFP_ATOMIC);
	if (!retval)
		return NULL;

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

	sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);

	return retval;
}

3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596
/* RE-CONFIG 3.1 (RE-CONFIG chunk)
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  | Type = 130    |  Chunk Flags  |      Chunk Length             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  \                                                               \
 *  /                  Re-configuration Parameter                   /
 *  \                                                               \
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  \                                                               \
 *  /             Re-configuration Parameter (optional)             /
 *  \                                                               \
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
3597 3598
static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
					   int length)
3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648
{
	struct sctp_reconf_chunk *reconf;
	struct sctp_chunk *retval;

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

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

	return retval;
}

/* RE-CONFIG 4.1 (STREAM OUT RESET)
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 13       | Parameter Length = 16 + 2 * N |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |           Re-configuration Request Sequence Number            |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |           Re-configuration Response Sequence Number           |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                Sender's Last Assigned TSN                     |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  /                            ......                             /
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * RE-CONFIG 4.2 (STREAM IN RESET)
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 14       |  Parameter Length = 8 + 2 * N |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |          Re-configuration Request Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  /                            ......                             /
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct sctp_chunk *sctp_make_strreset_req(
3649
					const struct sctp_association *asoc,
3650
					__u16 stream_num, __be16 *stream_list,
3651
					bool out, bool in)
3652
{
3653
	__u16 stream_len = stream_num * sizeof(__u16);
3654 3655 3656
	struct sctp_strreset_outreq outreq;
	struct sctp_strreset_inreq inreq;
	struct sctp_chunk *retval;
3657
	__u16 outlen, inlen;
3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691

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

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

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

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

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

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

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

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

	return retval;
}
3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702

/* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 15       |      Parameter Length = 8     |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |         Re-configuration Request Sequence Number              |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct sctp_chunk *sctp_make_strreset_tsnreq(
3703
					const struct sctp_association *asoc)
3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720
{
	struct sctp_strreset_tsnreq tsnreq;
	__u16 length = sizeof(tsnreq);
	struct sctp_chunk *retval;

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

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

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

	return retval;
}
3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733

/* RE-CONFIG 4.5/4.6 (ADD STREAM)
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 17       |      Parameter Length = 12    |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |          Re-configuration Request Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |      Number of new streams    |         Reserved              |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct sctp_chunk *sctp_make_strreset_addstrm(
3734 3735
					const struct sctp_association *asoc,
					__u16 out, __u16 in)
3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766
{
	struct sctp_strreset_addstrm addstrm;
	__u16 size = sizeof(addstrm);
	struct sctp_chunk *retval;

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

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

		sctp_addto_chunk(retval, size, &addstrm);
	}

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

		sctp_addto_chunk(retval, size, &addstrm);
	}

	return retval;
}
3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778

/* RE-CONFIG 4.4 (RESP)
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 16       |      Parameter Length         |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |         Re-configuration Response Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                            Result                             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
3779 3780
struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
					   __u32 result, __u32 sn)
3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814
{
	struct sctp_strreset_resp resp;
	__u16 length = sizeof(resp);
	struct sctp_chunk *retval;

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

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

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

	return retval;
}

/* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |     Parameter Type = 16       |      Parameter Length         |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |         Re-configuration Response Sequence Number             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                            Result                             |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                   Sender's Next TSN (optional)                |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                  Receiver's Next TSN (optional)               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
3815 3816 3817 3818
struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
					      __u32 result, __u32 sn,
					      __u32 sender_tsn,
					      __u32 receiver_tsn)
3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839
{
	struct sctp_strreset_resptsn tsnresp;
	__u16 length = sizeof(tsnresp);
	struct sctp_chunk *retval;

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

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

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

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

	return retval;
}
3840 3841 3842 3843 3844 3845 3846

bool sctp_verify_reconf(const struct sctp_association *asoc,
			struct sctp_chunk *chunk,
			struct sctp_paramhdr **errp)
{
	struct sctp_reconf_chunk *hdr;
	union sctp_params param;
3847 3848
	__be16 last = 0;
	__u16 cnt = 0;
3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899

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

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

		last = param.p->type;
	}

	return true;
}