blob: a85eeeb55dd0022e009895c53a6d8593929b7691 [file] [log] [blame]
/* SCTP kernel implementation
* (C) Copyright IBM Corp. 2001, 2004
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001-2002 Intel Corp.
*
* This file is part of the SCTP kernel implementation
*
* 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.
*
* This SCTP implementation is free software;
* 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.
*
* This SCTP implementation is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; without even the implied
* ************************
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU CC; see the file COPYING. If not, write to
* the Free Software Foundation, 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <lksctp-developers@lists.sourceforge.net>
*
* Or submit a bug report through the following website:
* http://www.sf.net/projects/lksctp
*
* Written or modified by:
* La Monte H.P. Yarroll <piggy@acm.org>
* Karl Knutson <karl@athena.chicago.il.us>
* C. Robin <chris@hundredacre.ac.uk>
* Jon Grimm <jgrimm@us.ibm.com>
* Xingang Guo <xingang.guo@intel.com>
* Dajiang Zhang <dajiang.zhang@nokia.com>
* Sridhar Samudrala <sri@us.ibm.com>
* Daisy Chang <daisyc@us.ibm.com>
* Ardelle Fan <ardelle.fan@intel.com>
* Kevin Gao <kevin.gao@intel.com>
*
* Any bugs reported given to us we will try to fix... any fixes shared will
* be incorporated into the next SCTP release.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/scatterlist.h>
#include <linux/crypto.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/skbuff.h>
#include <linux/random.h> /* for get_random_bytes */
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
SCTP_STATIC
struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
__u8 type, __u8 flags, int paylen);
static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
const struct sctp_chunk *init_chunk,
int *cookie_len,
const __u8 *raw_addrs, int addrs_len);
static int sctp_process_param(struct sctp_association *asoc,
union sctp_params param,
const union sctp_addr *peer_addr,
gfp_t gfp);
static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
const void *data);
/* What was the inbound interface for this chunk? */
int sctp_chunk_iif(const struct sctp_chunk *chunk)
{
struct sctp_af *af;
int iif = 0;
af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
if (af)
iif = af->skb_iif(chunk->skb);
return iif;
}
/* RFC 2960 3.3.2 Initiation (INIT) (1)
*
* Note 2: The ECN capable field is reserved for future use of
* Explicit Congestion Notification.
*/
static const struct sctp_paramhdr ecap_param = {
SCTP_PARAM_ECN_CAPABLE,
cpu_to_be16(sizeof(struct sctp_paramhdr)),
};
static const struct sctp_paramhdr prsctp_param = {
SCTP_PARAM_FWD_TSN_SUPPORT,
cpu_to_be16(sizeof(struct sctp_paramhdr)),
};
/* A helper to initialize an op error inside a
* provided chunk, as most cause codes will be embedded inside an
* abort chunk.
*/
void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
size_t paylen)
{
sctp_errhdr_t err;
__u16 len;
/* Cause code constants are now defined in network order. */
err.cause = cause_code;
len = sizeof(sctp_errhdr_t) + paylen;
err.length = htons(len);
chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
}
/* A helper to initialize an op error inside a
* provided chunk, as most cause codes will be embedded inside an
* abort chunk. Differs from sctp_init_cause in that it won't oops
* if there isn't enough space in the op error chunk
*/
int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
size_t paylen)
{
sctp_errhdr_t err;
__u16 len;
/* Cause code constants are now defined in network order. */
err.cause = cause_code;
len = sizeof(sctp_errhdr_t) + paylen;
err.length = htons(len);
if (skb_tailroom(chunk->skb) < len)
return -ENOSPC;
chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
sizeof(sctp_errhdr_t),
&err);
return 0;
}
/* 3.3.2 Initiation (INIT) (1)
*
* This chunk is used to initiate a SCTP association between two
* endpoints. The format of the INIT chunk is shown below:
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type = 1 | Chunk Flags | Chunk Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Initiate Tag |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Advertised Receiver Window Credit (a_rwnd) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Number of Outbound Streams | Number of Inbound Streams |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Initial TSN |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* \ \
* / Optional/Variable-Length Parameters /
* \ \
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*
* The INIT chunk contains the following parameters. Unless otherwise
* noted, each parameter MUST only be included once in the INIT chunk.
*
* Fixed Parameters Status
* ----------------------------------------------
* Initiate Tag Mandatory
* Advertised Receiver Window Credit Mandatory
* Number of Outbound Streams Mandatory
* Number of Inbound Streams Mandatory
* Initial TSN Mandatory
*
* Variable Parameters Status Type Value
* -------------------------------------------------------------
* IPv4 Address (Note 1) Optional 5
* IPv6 Address (Note 1) Optional 6
* Cookie Preservative Optional 9
* Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
* Host Name Address (Note 3) Optional 11
* Supported Address Types (Note 4) Optional 12
*/
struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
const struct sctp_bind_addr *bp,
gfp_t gfp, int vparam_len)
{
sctp_inithdr_t init;
union sctp_params addrs;
size_t chunksize;
struct sctp_chunk *retval = NULL;
int num_types, addrs_len = 0;
struct sctp_sock *sp;
sctp_supported_addrs_param_t sat;
__be16 types[2];
sctp_adaptation_ind_param_t aiparam;
sctp_supported_ext_param_t ext_param;
int num_ext = 0;
__u8 extensions[3];
sctp_paramhdr_t *auth_chunks = NULL,
*auth_hmacs = NULL;
/* RFC 2960 3.3.2 Initiation (INIT) (1)
*
* Note 1: The INIT chunks can contain multiple addresses that
* can be IPv4 and/or IPv6 in any combination.
*/
retval = NULL;
/* Convert the provided bind address list to raw format. */
addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
init.init_tag = htonl(asoc->c.my_vtag);
init.a_rwnd = htonl(asoc->rwnd);
init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
init.initial_tsn = htonl(asoc->c.initial_tsn);
/* How many address types are needed? */
sp = sctp_sk(asoc->base.sk);
num_types = sp->pf->supported_addrs(sp, types);
chunksize = sizeof(init) + addrs_len;
chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
chunksize += sizeof(ecap_param);
if (sctp_prsctp_enable)
chunksize += sizeof(prsctp_param);
/* ADDIP: Section 4.2.7:
* An implementation supporting this extension [ADDIP] MUST list
* the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
* INIT-ACK parameters.
*/
if (sctp_addip_enable) {
extensions[num_ext] = SCTP_CID_ASCONF;
extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
num_ext += 2;
}
if (sp->adaptation_ind)
chunksize += sizeof(aiparam);
chunksize += vparam_len;
/* Account for AUTH related parameters */
if (sctp_auth_enable) {
/* Add random parameter length*/
chunksize += sizeof(asoc->c.auth_random);
/* Add HMACS parameter length if any were defined */
auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
if (auth_hmacs->length)
chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
else
auth_hmacs = NULL;
/* Add CHUNKS parameter length */
auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
if (auth_chunks->length)
chunksize += WORD_ROUND(ntohs(auth_chunks->length));
else
auth_chunks = NULL;
extensions[num_ext] = SCTP_CID_AUTH;
num_ext += 1;
}
/* If we have any extensions to report, account for that */
if (num_ext)
chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
num_ext);
/* RFC 2960 3.3.2 Initiation (INIT) (1)
*
* Note 3: An INIT chunk MUST NOT contain more than one Host
* Name address parameter. Moreover, the sender of the INIT
* MUST NOT combine any other address types with the Host Name
* address in the INIT. The receiver of INIT MUST ignore any
* other address types if the Host Name address parameter is
* present in the received INIT chunk.
*
* PLEASE DO NOT FIXME [This version does not support Host Name.]
*/
retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize);
if (!retval)
goto nodata;
retval->subh.init_hdr =
sctp_addto_chunk(retval, sizeof(init), &init);
retval->param_hdr.v =
sctp_addto_chunk(retval, addrs_len, addrs.v);
/* RFC 2960 3.3.2 Initiation (INIT) (1)
*
* Note 4: This parameter, when present, specifies all the
* address types the sending endpoint can support. The absence
* of this parameter indicates that the sending endpoint can
* support any address type.
*/
sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
sctp_addto_chunk(retval, sizeof(sat), &sat);
sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
/* Add the supported extensions parameter. Be nice and add this
* fist before addiding the parameters for the extensions themselves
*/
if (num_ext) {
ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
ext_param.param_hdr.length =
htons(sizeof(sctp_supported_ext_param_t) + num_ext);
sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
&ext_param);
sctp_addto_param(retval, num_ext, extensions);
}
if (sctp_prsctp_enable)
sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
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);
}
/* Add SCTP-AUTH chunks to the parameter list */
if (sctp_auth_enable) {
sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
asoc->c.auth_random);
if (auth_hmacs)
sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
auth_hmacs);
if (auth_chunks)
sctp_addto_chunk(retval, ntohs(auth_chunks->length),
auth_chunks);
}
nodata:
kfree(addrs.v);
return retval;
}
struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
gfp_t gfp, int unkparam_len)
{
sctp_inithdr_t initack;
struct sctp_chunk *retval;
union sctp_params addrs;
struct sctp_sock *sp;
int addrs_len;
sctp_cookie_param_t *cookie;
int cookie_len;
size_t chunksize;
sctp_adaptation_ind_param_t aiparam;
sctp_supported_ext_param_t ext_param;
int num_ext = 0;
__u8 extensions[3];
sctp_paramhdr_t *auth_chunks = NULL,
*auth_hmacs = NULL,
*auth_random = NULL;
retval = NULL;
/* Note: there may be no addresses to embed. */
addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
initack.init_tag = htonl(asoc->c.my_vtag);
initack.a_rwnd = htonl(asoc->rwnd);
initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
initack.initial_tsn = htonl(asoc->c.initial_tsn);
/* FIXME: We really ought to build the cookie right
* into the packet instead of allocating more fresh memory.
*/
cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
addrs.v, addrs_len);
if (!cookie)
goto nomem_cookie;
/* Calculate the total size of allocation, include the reserved
* space for reporting unknown parameters if it is specified.
*/
sp = sctp_sk(asoc->base.sk);
chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
/* Tell peer that we'll do ECN only if peer advertised such cap. */
if (asoc->peer.ecn_capable)
chunksize += sizeof(ecap_param);
if (asoc->peer.prsctp_capable)
chunksize += sizeof(prsctp_param);
if (asoc->peer.asconf_capable) {
extensions[num_ext] = SCTP_CID_ASCONF;
extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
num_ext += 2;
}
if (sp->adaptation_ind)
chunksize += sizeof(aiparam);
if (asoc->peer.auth_capable) {
auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
chunksize += ntohs(auth_random->length);
auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
if (auth_hmacs->length)
chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
else
auth_hmacs = NULL;
auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
if (auth_chunks->length)
chunksize += WORD_ROUND(ntohs(auth_chunks->length));
else
auth_chunks = NULL;
extensions[num_ext] = SCTP_CID_AUTH;
num_ext += 1;
}
if (num_ext)
chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
num_ext);
/* Now allocate and fill out the chunk. */
retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
if (!retval)
goto nomem_chunk;
/* 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.]
*/
retval->transport = chunk->transport;
retval->subh.init_hdr =
sctp_addto_chunk(retval, sizeof(initack), &initack);
retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
sctp_addto_chunk(retval, cookie_len, cookie);
if (asoc->peer.ecn_capable)
sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
if (num_ext) {
ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
ext_param.param_hdr.length =
htons(sizeof(sctp_supported_ext_param_t) + num_ext);
sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
&ext_param);
sctp_addto_param(retval, num_ext, extensions);
}
if (asoc->peer.prsctp_capable)
sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
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);
}
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);
}
/* We need to remove the const qualifier at this point. */
retval->asoc = (struct sctp_association *) asoc;
nomem_chunk:
kfree(cookie);
nomem_cookie:
kfree(addrs.v);
return retval;
}
/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
*
* This chunk is used only during the initialization of an association.
* It is sent by the initiator of an association to its peer to complete
* the initialization process. This chunk MUST precede any DATA chunk
* sent within the association, but MAY be bundled with one or more DATA
* chunks in the same packet.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type = 10 |Chunk Flags | Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* / Cookie /
* \ \
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Chunk Flags: 8 bit
*
* Set to zero on transmit and ignored on receipt.
*
* Length: 16 bits (unsigned integer)
*
* Set to the size of the chunk in bytes, including the 4 bytes of
* the chunk header and the size of the Cookie.
*
* Cookie: variable size
*
* This field must contain the exact cookie received in the
* State Cookie parameter from the previous INIT ACK.
*
* An implementation SHOULD make the cookie as small as possible
* to insure interoperability.
*/
struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
struct sctp_chunk *retval;
void *cookie;
int cookie_len;
cookie = asoc->peer.cookie;
cookie_len = asoc->peer.cookie_len;
/* Build a cookie echo chunk. */
retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
if (!retval)
goto nodata;
retval->subh.cookie_hdr =
sctp_addto_chunk(retval, cookie_len, cookie);
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, * etc.) to the same destination transport
* address from which it * received the DATA or control chunk
* to which it is replying.
*
* [COOKIE ECHO back to where the INIT ACK came from.]
*/
if (chunk)
retval->transport = chunk->transport;
nodata:
return retval;
}
/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
*
* This chunk is used only during the initialization of an
* association. It is used to acknowledge the receipt of a COOKIE
* ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
* within the association, but MAY be bundled with one or more DATA
* chunks or SACK chunk in the same SCTP packet.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type = 11 |Chunk Flags | Length = 4 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Chunk Flags: 8 bits
*
* Set to zero on transmit and ignored on receipt.
*/
struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
struct sctp_chunk *retval;
retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, * etc.) to the same destination transport
* address from which it * received the DATA or control chunk
* to which it is replying.
*
* [COOKIE ACK back to where the COOKIE ECHO came from.]
*/
if (retval && chunk)
retval->transport = chunk->transport;
return retval;
}
/*
* Appendix A: Explicit Congestion Notification:
* CWR:
*
* RFC 2481 details a specific bit for a sender to send in the header of
* its next outbound TCP segment to indicate to its peer that it has
* reduced its congestion window. This is termed the CWR bit. For
* SCTP the same indication is made by including the CWR chunk.
* This chunk contains one data element, i.e. the TSN number that
* was sent in the ECNE chunk. This element represents the lowest
* TSN number in the datagram that was originally marked with the
* CE bit.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Lowest TSN Number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Note: The CWR is considered a Control chunk.
*/
struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
const __u32 lowest_tsn,
const struct sctp_chunk *chunk)
{
struct sctp_chunk *retval;
sctp_cwrhdr_t cwr;
cwr.lowest_tsn = htonl(lowest_tsn);
retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0,
sizeof(sctp_cwrhdr_t));
if (!retval)
goto nodata;
retval->subh.ecn_cwr_hdr =
sctp_addto_chunk(retval, sizeof(cwr), &cwr);
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, * etc.) to the same destination transport
* address from which it * received the DATA or control chunk
* to which it is replying.
*
* [Report a reduced congestion window back to where the ECNE
* came from.]
*/
if (chunk)
retval->transport = chunk->transport;
nodata:
return retval;
}
/* Make an ECNE chunk. This is a congestion experienced report. */
struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
const __u32 lowest_tsn)
{
struct sctp_chunk *retval;
sctp_ecnehdr_t ecne;
ecne.lowest_tsn = htonl(lowest_tsn);
retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0,
sizeof(sctp_ecnehdr_t));
if (!retval)
goto nodata;
retval->subh.ecne_hdr =
sctp_addto_chunk(retval, sizeof(ecne), &ecne);
nodata:
return retval;
}
/* Make a DATA chunk for the given association from the provided
* parameters. However, do not populate the data payload.
*/
struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
const struct sctp_sndrcvinfo *sinfo,
int data_len, __u8 flags, __u16 ssn)
{
struct sctp_chunk *retval;
struct sctp_datahdr dp;
int chunk_len;
/* We assign the TSN as LATE as possible, not here when
* creating the chunk.
*/
dp.tsn = 0;
dp.stream = htons(sinfo->sinfo_stream);
dp.ppid = sinfo->sinfo_ppid;
/* Set the flags for an unordered send. */
if (sinfo->sinfo_flags & SCTP_UNORDERED) {
flags |= SCTP_DATA_UNORDERED;
dp.ssn = 0;
} else
dp.ssn = htons(ssn);
chunk_len = sizeof(dp) + data_len;
retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len);
if (!retval)
goto nodata;
retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
nodata:
return retval;
}
/* Create a selective ackowledgement (SACK) for the given
* association. This reports on which TSN's we've seen to date,
* including duplicates and gaps.
*/
struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
{
struct sctp_chunk *retval;
struct sctp_sackhdr sack;
int len;
__u32 ctsn;
__u16 num_gabs, num_dup_tsns;
struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
memset(gabs, 0, sizeof(gabs));
ctsn = sctp_tsnmap_get_ctsn(map);
SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn);
/* How much room is needed in the chunk? */
num_gabs = sctp_tsnmap_num_gabs(map, gabs);
num_dup_tsns = sctp_tsnmap_num_dups(map);
/* Initialize the SACK header. */
sack.cum_tsn_ack = htonl(ctsn);
sack.a_rwnd = htonl(asoc->a_rwnd);
sack.num_gap_ack_blocks = htons(num_gabs);
sack.num_dup_tsns = htons(num_dup_tsns);
len = sizeof(sack)
+ sizeof(struct sctp_gap_ack_block) * num_gabs
+ sizeof(__u32) * num_dup_tsns;
/* Create the chunk. */
retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len);
if (!retval)
goto nodata;
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, etc.) to the same destination transport
* address from which it received the DATA or control chunk to
* which it is replying. This rule should also be followed if
* the endpoint is bundling DATA chunks together with the
* reply chunk.
*
* However, when acknowledging multiple DATA chunks received
* in packets from different source addresses in a single
* SACK, the SACK chunk may be transmitted to one of the
* destination transport addresses from which the DATA or
* control chunks being acknowledged were received.
*
* [BUG: We do not implement the following paragraph.
* Perhaps we should remember the last transport we used for a
* SACK and avoid that (if possible) if we have seen any
* duplicates. --piggy]
*
* When a receiver of a duplicate DATA chunk sends a SACK to a
* multi- homed endpoint it MAY be beneficial to vary the
* destination address and not use the source address of the
* DATA chunk. The reason being that receiving a duplicate
* from a multi-homed endpoint might indicate that the return
* path (as specified in the source address of the DATA chunk)
* for the SACK is broken.
*
* [Send to the address from which we last received a DATA chunk.]
*/
retval->transport = asoc->peer.last_data_from;
retval->subh.sack_hdr =
sctp_addto_chunk(retval, sizeof(sack), &sack);
/* Add the gap ack block information. */
if (num_gabs)
sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
gabs);
/* Add the duplicate TSN information. */
if (num_dup_tsns)
sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
sctp_tsnmap_get_dups(map));
nodata:
return retval;
}
/* Make a SHUTDOWN chunk. */
struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
struct sctp_chunk *retval;
sctp_shutdownhdr_t shut;
__u32 ctsn;
ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
shut.cum_tsn_ack = htonl(ctsn);
retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0,
sizeof(sctp_shutdownhdr_t));
if (!retval)
goto nodata;
retval->subh.shutdown_hdr =
sctp_addto_chunk(retval, sizeof(shut), &shut);
if (chunk)
retval->transport = chunk->transport;
nodata:
return retval;
}
struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
struct sctp_chunk *retval;
retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, * etc.) to the same destination transport
* address from which it * received the DATA or control chunk
* to which it is replying.
*
* [ACK back to where the SHUTDOWN came from.]
*/
if (retval && chunk)
retval->transport = chunk->transport;
return retval;
}
struct sctp_chunk *sctp_make_shutdown_complete(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
struct sctp_chunk *retval;
__u8 flags = 0;
/* Set the T-bit if we have no association (vtag will be
* reflected)
*/
flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, * etc.) to the same destination transport
* address from which it * received the DATA or control chunk
* to which it is replying.
*
* [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
* came from.]
*/
if (retval && chunk)
retval->transport = chunk->transport;
return retval;
}
/* Create an ABORT. Note that we set the T bit if we have no
* association, except when responding to an INIT (sctpimpguide 2.41).
*/
struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
const size_t hint)
{
struct sctp_chunk *retval;
__u8 flags = 0;
/* 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;
}
retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, * etc.) to the same destination transport
* address from which it * received the DATA or control chunk
* to which it is replying.
*
* [ABORT back to where the offender came from.]
*/
if (retval && chunk)
retval->transport = chunk->transport;
return retval;
}
/* Helper to create ABORT with a NO_USER_DATA error. */
struct sctp_chunk *sctp_make_abort_no_data(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk, __u32 tsn)
{
struct sctp_chunk *retval;
__be32 payload;
retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
+ sizeof(tsn));
if (!retval)
goto no_mem;
/* Put the tsn back into network byte order. */
payload = htonl(tsn);
sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
sctp_addto_chunk(retval, sizeof(payload), (const void *)&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.
*
* [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,
const struct msghdr *msg,
size_t paylen)
{
struct sctp_chunk *retval;
void *payload = NULL;
int err;
retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
if (!retval)
goto err_chunk;
if (paylen) {
/* Put the msg_iov together into payload. */
payload = kmalloc(paylen, GFP_KERNEL);
if (!payload)
goto err_payload;
err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
if (err < 0)
goto err_copy;
}
sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
sctp_addto_chunk(retval, paylen, payload);
if (paylen)
kfree(payload);
return retval;
err_copy:
kfree(payload);
err_payload:
sctp_chunk_free(retval);
retval = NULL;
err_chunk:
return retval;
}
/* Append bytes to the end of a parameter. Will panic if chunk is not big
* enough.
*/
static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
const void *data)
{
void *target;
int chunklen = ntohs(chunk->chunk_hdr->length);
target = skb_put(chunk->skb, len);
if (data)
memcpy(target, data, len);
else
memset(target, 0, len);
/* Adjust the chunk length field. */
chunk->chunk_hdr->length = htons(chunklen + len);
chunk->chunk_end = skb_tail_pointer(chunk->skb);
return target;
}
/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
struct sctp_chunk *sctp_make_abort_violation(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
const __u8 *payload,
const size_t paylen)
{
struct sctp_chunk *retval;
struct sctp_paramhdr phdr;
retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
+ sizeof(sctp_paramhdr_t));
if (!retval)
goto end;
sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
+ sizeof(sctp_paramhdr_t));
phdr.type = htons(chunk->chunk_hdr->type);
phdr.length = chunk->chunk_hdr->length;
sctp_addto_chunk(retval, paylen, payload);
sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
end:
return retval;
}
struct sctp_chunk *sctp_make_violation_paramlen(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
struct sctp_paramhdr *param)
{
struct sctp_chunk *retval;
static const char error[] = "The following parameter had invalid length:";
size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
sizeof(sctp_paramhdr_t);
retval = sctp_make_abort(asoc, chunk, payload_len);
if (!retval)
goto nodata;
sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
sizeof(error) + sizeof(sctp_paramhdr_t));
sctp_addto_chunk(retval, sizeof(error), error);
sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
nodata:
return retval;
}
/* Make a HEARTBEAT chunk. */
struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
const struct sctp_transport *transport)
{
struct sctp_chunk *retval;
sctp_sender_hb_info_t hbinfo;
retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
if (!retval)
goto nodata;
hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
hbinfo.daddr = transport->ipaddr;
hbinfo.sent_at = jiffies;
hbinfo.hb_nonce = transport->hb_nonce;
/* Cast away the 'const', as this is just telling the chunk
* what transport it belongs to.
*/
retval->transport = (struct sctp_transport *) transport;
retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
&hbinfo);
nodata:
return retval;
}
struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
const void *payload, const size_t paylen)
{
struct sctp_chunk *retval;
retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
if (!retval)
goto nodata;
retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, * etc.) to the same destination transport
* address from which it * received the DATA or control chunk
* to which it is replying.
*
* [HBACK back to where the HEARTBEAT came from.]
*/
if (chunk)
retval->transport = chunk->transport;
nodata:
return retval;
}
/* Create an Operation Error chunk with the specified space reserved.
* This routine can be used for containing multiple causes in the chunk.
*/
static struct sctp_chunk *sctp_make_op_error_space(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
size_t size)
{
struct sctp_chunk *retval;
retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0,
sizeof(sctp_errhdr_t) + size);
if (!retval)
goto nodata;
/* RFC 2960 6.4 Multi-homed SCTP Endpoints
*
* An endpoint SHOULD transmit reply chunks (e.g., SACK,
* HEARTBEAT ACK, etc.) to the same destination transport
* address from which it received the DATA or control chunk
* to which it is replying.
*
*/
if (chunk)
retval->transport = chunk->transport;
nodata:
return retval;
}
/* Create an Operation Error chunk of a fixed size,
* specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
* This is a helper function to allocate an error chunk for
* for those invalid parameter codes in which we may not want
* to report all the errors, if the incomming chunk is large
*/
static inline struct sctp_chunk *sctp_make_op_error_fixed(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
size_t size = asoc ? asoc->pathmtu : 0;
if (!size)
size = SCTP_DEFAULT_MAXSEGMENT;
return sctp_make_op_error_space(asoc, chunk, size);
}
/* Create an Operation Error chunk. */
struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
const struct sctp_chunk *chunk,
__be16 cause_code, const void *payload,
size_t paylen, size_t reserve_tail)
{
struct sctp_chunk *retval;
retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
if (!retval)
goto nodata;
sctp_init_cause(retval, cause_code, paylen + reserve_tail);
sctp_addto_chunk(retval, paylen, payload);
if (reserve_tail)
sctp_addto_param(retval, reserve_tail, NULL);
nodata:
return retval;
}
struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
{
struct sctp_chunk *retval;
struct sctp_hmac *hmac_desc;
struct sctp_authhdr auth_hdr;
__u8 *hmac;
/* Get the first hmac that the peer told us to use */
hmac_desc = sctp_auth_asoc_get_hmac(asoc);
if (unlikely(!hmac_desc))
return NULL;
retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0,
hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
if (!retval)
return NULL;
auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
auth_hdr.shkey_id = htons(asoc->active_key_id);
retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
&auth_hdr);
hmac = skb_put(retval->skb, hmac_desc->hmac_len);
memset(hmac, 0, hmac_desc->hmac_len);
/* Adjust the chunk header to include the empty MAC */
retval->chunk_hdr->length =
htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
retval->chunk_end = skb_tail_pointer(retval->skb);
return retval;
}
/********************************************************************
* 2nd Level Abstractions
********************************************************************/
/* Turn an skb into a chunk.
* FIXME: Eventually move the structure directly inside the skb->cb[].
*/
struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
const struct sctp_association *asoc,
struct sock *sk)
{
struct sctp_chunk *retval;
retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
if (!retval)
goto nodata;
if (!sk) {
SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
}
INIT_LIST_HEAD(&retval->list);
retval->skb = skb;
retval->asoc = (struct sctp_association *)asoc;
retval->has_tsn = 0;
retval->has_ssn = 0;
retval->rtt_in_progress = 0;
retval->sent_at = 0;
retval->singleton = 1;
retval->end_of_packet = 0;
retval->ecn_ce_done = 0;
retval->pdiscard = 0;
/* sctpimpguide-05.txt Section 2.8.2
* M1) Each time a new DATA chunk is transmitted
* set the 'TSN.Missing.Report' count for that TSN to 0. The
* 'TSN.Missing.Report' count will be used to determine missing chunks
* and when to fast retransmit.
*/
retval->tsn_missing_report = 0;
retval->tsn_gap_acked = 0;
retval->fast_retransmit = SCTP_CAN_FRTX;
/* If this is a fragmented message, track all fragments
* of the message (for SEND_FAILED).
*/
retval->msg = NULL;
/* Polish the bead hole. */
INIT_LIST_HEAD(&retval->transmitted_list);
INIT_LIST_HEAD(&retval->frag_list);
SCTP_DBG_OBJCNT_INC(chunk);
atomic_set(&retval->refcnt, 1);
nodata:
return retval;
}
/* Set chunk->source and dest based on the IP header in chunk->skb. */
void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
union sctp_addr *dest)
{
memcpy(&chunk->source, src, sizeof(union sctp_addr));
memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
}
/* 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) {
return &chunk->transport->ipaddr;
} else {
/* Otherwise, extract it from the IP header. */
return &chunk->source;
}
}
/* Create a new chunk, setting the type and flags headers from the
* arguments, reserving enough space for a 'paylen' byte payload.
*/
SCTP_STATIC
struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
__u8 type, __u8 flags, int paylen)
{
struct sctp_chunk *retval;
sctp_chunkhdr_t *chunk_hdr;
struct sk_buff *skb;
struct sock *sk;
/* No need to allocate LL here, as this is only a chunk. */
skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
GFP_ATOMIC);
if (!skb)
goto nodata;
/* Make room for the chunk header. */
chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
chunk_hdr->type = type;
chunk_hdr->flags = flags;
chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
sk = asoc ? asoc->base.sk : NULL;
retval = sctp_chunkify(skb, asoc, sk);
if (!retval) {
kfree_skb(skb);
goto nodata;
}
retval->chunk_hdr = chunk_hdr;
retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
/* Determine if the chunk needs to be authenticated */
if (sctp_auth_send_cid(type, asoc))
retval->auth = 1;
/* Set the skb to the belonging sock for accounting. */
skb->sk = sk;
return retval;
nodata:
return NULL;
}
/* Release the memory occupied by a chunk. */
static void sctp_chunk_destroy(struct sctp_chunk *chunk)
{
BUG_ON(!list_empty(&chunk->list));
list_del_init(&chunk->transmitted_list);
/* Free the chunk skb data and the SCTP_chunk stub itself. */
dev_kfree_skb(chunk->skb);
SCTP_DBG_OBJCNT_DEC(chunk);
kmem_cache_free(sctp_chunk_cachep, chunk);
}
/* Possibly, free the chunk. */
void sctp_chunk_free(struct sctp_chunk *chunk)
{
/* Release our reference on the message tracker. */
if (chunk->msg)
sctp_datamsg_put(chunk->msg);
sctp_chunk_put(chunk);
}
/* Grab a reference to the chunk. */
void sctp_chunk_hold(struct sctp_chunk *ch)
{
atomic_inc(&ch->refcnt);
}
/* Release a reference to the chunk. */
void sctp_chunk_put(struct sctp_chunk *ch)
{
if (atomic_dec_and_test(&ch->refcnt))
sctp_chunk_destroy(ch);
}
/* Append bytes to the end of a chunk. Will panic if chunk is not big
* enough.
*/
void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
{
void *target;
void *padding;
int chunklen = ntohs(chunk->chunk_hdr->length);
int padlen = WORD_ROUND(chunklen) - chunklen;
padding = skb_put(chunk->skb, padlen);
target = skb_put(chunk->skb, len);
memset(padding, 0, padlen);
memcpy(target, data, len);
/* Adjust the chunk length field. */
chunk->chunk_hdr->length = htons(chunklen + padlen + len);
chunk->chunk_end = skb_tail_pointer(chunk->skb);
return target;
}
/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
* space in the chunk
*/
void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
int len, const void *data)
{
if (skb_tailroom(chunk->skb) >= len)
return sctp_addto_chunk(chunk, len, data);
else
return NULL;
}
/* Append bytes from user space to the end of a chunk. Will panic if
* chunk is not big enough.
* Returns a kernel err value.
*/
int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
struct iovec *data)
{
__u8 *target;
int err = 0;
/* Make room in chunk for data. */
target = skb_put(chunk->skb, len);
/* Copy data (whole iovec) into chunk */
if ((err = memcpy_fromiovecend(target, data, off, len)))
goto out;
/* Adjust the chunk length field. */
chunk->chunk_hdr->length =
htons(ntohs(chunk->chunk_hdr->length) + len);
chunk->chunk_end = skb_tail_pointer(chunk->skb);
out:
return err;
}
/* Helper function to assign a TSN if needed. This assumes that both
* the data_hdr and association have already been assigned.
*/
void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
{
struct sctp_datamsg *msg;
struct sctp_chunk *lchunk;
struct sctp_stream *stream;
__u16 ssn;
__u16 sid;
if (chunk->has_ssn)
return;
/* All fragments will be on the same stream */
sid = ntohs(chunk->subh.data_hdr->stream);
stream = &chunk->asoc->ssnmap->out;
/* Now assign the sequence number to the entire message.
* All fragments must have the same stream sequence number.
*/
msg = chunk->msg;
list_for_each_entry(lchunk, &msg->chunks, frag_list) {
if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
ssn = 0;
} else {
if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
ssn = sctp_ssn_next(stream, sid);
else
ssn = sctp_ssn_peek(stream, sid);
}
lchunk->subh.data_hdr->ssn = htons(ssn);
lchunk->has_ssn = 1;
}
}
/* 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,
struct sctp_chunk *chunk,
gfp_t gfp)
{
struct sctp_association *asoc;
struct sk_buff *skb;
sctp_scope_t scope;
struct sctp_af *af;
/* Create the bare association. */
scope = sctp_scope(sctp_source(chunk));
asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
if (!asoc)
goto nodata;
asoc->temp = 1;
skb = chunk->skb;
/* Create an entry for the source address of the packet. */
af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
if (unlikely(!af))
goto fail;
af->from_skb(&asoc->c.peer_addr, skb, 1);
nodata:
return asoc;
fail:
sctp_association_free(asoc);
return NULL;
}
/* Build a cookie representing asoc.
* This INCLUDES the param header needed to put the cookie in the INIT ACK.
*/
static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
const struct sctp_chunk *init_chunk,
int *cookie_len,
const __u8 *raw_addrs, int addrs_len)
{
sctp_cookie_param_t *retval;
struct sctp_signed_cookie *cookie;
struct scatterlist sg;
int headersize, bodysize;
unsigned int keylen;
char *key;
/* Header size is static data prior to the actual cookie, including
* any padding.
*/
headersize = sizeof(sctp_paramhdr_t) +
(sizeof(struct sctp_signed_cookie) -
sizeof(struct sctp_cookie));
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.
*/
retval = kzalloc(*cookie_len, GFP_ATOMIC);
if (!retval)
goto nodata;
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;
/* Save adaptation indication in the cookie. */
cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
/* Set an expiration time for the cookie. */
do_gettimeofday(&cookie->c.expiration);
TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);
/* Copy the peer's init packet. */
memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
ntohs(init_chunk->chunk_hdr->length));
/* Copy the raw local address list of the association. */
memcpy((__u8 *)&cookie->c.peer_init[0] +
ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
if (sctp_sk(ep->base.sk)->hmac) {
struct hash_desc desc;
/* Sign the message. */
sg_init_one(&sg, &cookie->c, bodysize);
keylen = SCTP_SECRET_SIZE;
key = (char *)ep->secret_key[ep->current_key];
desc.tfm = sctp_sk(ep->base.sk)->hmac;
desc.flags = 0;
if (crypto_hash_setkey(desc.tfm, key, keylen) ||
crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
goto free_cookie;
}
return retval;
free_cookie:
kfree(retval);
nodata:
*cookie_len = 0;
return NULL;
}
/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
struct sctp_association *sctp_unpack_cookie(
const struct sctp_endpoint *ep,
const struct sctp_association *asoc,
struct sctp_chunk *chunk, gfp_t gfp,
int *error, struct sctp_chunk **errp)
{
struct sctp_association *retval = NULL;
struct sctp_signed_cookie *cookie;
struct sctp_cookie *bear_cookie;
int headersize, bodysize, fixed_size;
__u8 *digest = ep->digest;
struct scatterlist sg;
unsigned int keylen, len;
char *key;
sctp_scope_t scope;
struct sk_buff *skb = chunk->skb;
struct timeval tv;
struct hash_desc desc;
/* Header size is static data prior to the actual cookie, including
* any padding.
*/
headersize = sizeof(sctp_chunkhdr_t) +
(sizeof(struct sctp_signed_cookie) -
sizeof(struct sctp_cookie));
bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
fixed_size = headersize + sizeof(struct sctp_cookie);
/* Verify that the chunk looks like it even has a cookie.
* There must be enough room for our cookie and our peer's
* INIT chunk.
*/
len = ntohs(chunk->chunk_hdr->length);
if (len < fixed_size + sizeof(struct sctp_chunkhdr))
goto malformed;
/* Verify that the cookie has been padded out. */
if (bodysize % SCTP_COOKIE_MULTIPLE)
goto malformed;
/* Process the cookie. */
cookie = chunk->subh.cookie_hdr;
bear_cookie = &cookie->c;
if (!sctp_sk(ep->base.sk)->hmac)
goto no_hmac;
/* Check the signature. */
keylen = SCTP_SECRET_SIZE;
sg_init_one(&sg, bear_cookie, bodysize);
key = (char *)ep->secret_key[ep->current_key];
desc.tfm = sctp_sk(ep->base.sk)->hmac;
desc.flags = 0;
memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
if (crypto_hash_setkey(desc.tfm, key, keylen) ||
crypto_hash_digest(&desc, &sg, bodysize, digest)) {
*error = -SCTP_IERROR_NOMEM;
goto fail;
}
if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
/* Try the previous key. */
key = (char *)ep->secret_key[ep->last_key];
memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
if (crypto_hash_setkey(desc.tfm, key, keylen) ||
crypto_hash_digest(&desc, &sg, bodysize, digest)) {
*error = -SCTP_IERROR_NOMEM;
goto fail;
}
if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
/* Yikes! Still bad signature! */
*error = -SCTP_IERROR_BAD_SIG;
goto fail;
}
}
no_hmac:
/* IG Section 2.35.2:
* 3) Compare the port numbers and the verification tag contained
* within the COOKIE ECHO chunk to the actual port numbers and the
* verification tag within the SCTP common header of the received
* packet. If these values do not match the packet MUST be silently
* discarded,
*/
if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
*error = -SCTP_IERROR_BAD_TAG;
goto fail;
}
if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
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.
* 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.
*/
if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
skb_get_timestamp(skb, &tv);
else
do_gettimeofday(&tv);
if (!asoc && tv_lt(bear_cookie->expiration, tv)) {
/*
* Section 3.3.10.3 Stale Cookie Error (3)
*
* Cause of error
* ---------------
* Stale Cookie Error: Indicates the receipt of a valid State
* Cookie that has expired.
*/
len = ntohs(chunk->chunk_hdr->length);
*errp = sctp_make_op_error_space(asoc, chunk, len);
if (*errp) {
suseconds_t usecs = (tv.tv_sec -
bear_cookie->expiration.tv_sec) * 1000000L +
tv.tv_usec - bear_cookie->expiration.tv_usec;
__be32 n = htonl(usecs);
sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
sizeof(n));
sctp_addto_chunk(*errp, sizeof(n), &n);
*error = -SCTP_IERROR_STALE_COOKIE;
} else
*error = -SCTP_IERROR_NOMEM;
goto fail;
}
/* Make a new base association. */
scope = sctp_scope(sctp_source(chunk));
retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
if (!retval) {
*error = -SCTP_IERROR_NOMEM;
goto fail;
}
/* Set up our peer's port number. */
retval->peer.port = ntohs(chunk->sctp_hdr->source);
/* Populate the association from the cookie. */
memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
GFP_ATOMIC) < 0) {
*error = -SCTP_IERROR_NOMEM;
goto fail;
}
/* Also, add the destination address. */
if (list_empty(&retval->base.bind_addr.address_list)) {
sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
SCTP_ADDR_SRC, GFP_ATOMIC);
}
retval->next_tsn = retval->c.initial_tsn;
retval->ctsn_ack_point = retval->next_tsn - 1;
retval->addip_serial = retval->c.initial_tsn;
retval->adv_peer_ack_point = retval->ctsn_ack_point;
retval->peer.prsctp_capable = retval->c.prsctp_capable;
retval->peer.adaptation_ind = retval->c.adaptation_ind;
/* 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 {
__be32 num_missing;
__be16 type;
} __packed;
/*
* Report a missing mandatory parameter.
*/
static int sctp_process_missing_param(const struct sctp_association *asoc,
sctp_param_t paramtype,
struct sctp_chunk *chunk,
struct sctp_chunk **errp)
{
struct __sctp_missing report;
__u16 len;
len = WORD_ROUND(sizeof(report));
/* Make an ERROR chunk, preparing enough room for
* returning multiple unknown parameters.
*/
if (!*errp)
*errp = sctp_make_op_error_space(asoc, chunk, len);
if (*errp) {
report.num_missing = htonl(1);
report.type = paramtype;
sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
sizeof(report));
sctp_addto_chunk(*errp, sizeof(report), &report);
}
/* 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)
sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
/* 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)
{
/* This is a fatal error. Any accumulated non-fatal errors are
* not reported.
*/
if (*errp)
sctp_chunk_free(*errp);
/* Create an error chunk and fill it in with our payload. */
*errp = sctp_make_violation_paramlen(asoc, chunk, param);
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);
/* Processing of the HOST_NAME parameter will generate an
* ABORT. If we've accumulated any non-fatal errors, they
* would be unrecognized parameters and we should not include
* them in the ABORT.
*/
if (*errp)
sctp_chunk_free(*errp);
*errp = sctp_make_op_error_space(asoc, chunk, len);
if (*errp) {
sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
sctp_addto_chunk(*errp, len, param.v);
}
/* Stop processing this chunk. */
return 0;
}
static int sctp_verify_ext_param(union sctp_params param)
{
__u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
int have_auth = 0;
int have_asconf = 0;
int i;
for (i = 0; i < num_ext; i++) {
switch (param.ext->chunks[i]) {
case SCTP_CID_AUTH:
have_auth = 1;
break;
case SCTP_CID_ASCONF:
case SCTP_CID_ASCONF_ACK:
have_asconf = 1;
break;
}
}
/* ADD-IP Security: The draft requires us to ABORT or ignore the
* INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
* only if ADD-IP is turned on and we are not backward-compatible
* mode.
*/
if (sctp_addip_noauth)
return 1;
if (sctp_addip_enable && !have_auth && have_asconf)
return 0;
return 1;
}
static void sctp_process_ext_param(struct sctp_association *asoc,
union sctp_params param)
{
__u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
int i;
for (i = 0; i < num_ext; i++) {
switch (param.ext->chunks[i]) {
case SCTP_CID_FWD_TSN:
if (sctp_prsctp_enable &&
!asoc->peer.prsctp_capable)
asoc->peer.prsctp_capable = 1;
break;
case SCTP_CID_AUTH:
/* if the peer reports AUTH, assume that he
* supports AUTH.
*/
if (sctp_auth_enable)
asoc->peer.auth_capable = 1;
break;
case SCTP_CID_ASCONF:
case SCTP_CID_ASCONF_ACK:
if (sctp_addip_enable)
asoc->peer.asconf_capable = 1;
break;
default:
break;
}
}
}
/* 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.
*
* 00 - Stop processing this parameter; do not process any further
* parameters within this chunk
*
* 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.
*
* 10 - Skip this parameter and continue processing.
*
* 11 - Skip this parameter and continue processing but
* report the unrecognized parameter in an
* 'Unrecognized Parameter' ERROR chunk.
*
* Return value:
* SCTP_IERROR_NO_ERROR - continue with the chunk
* SCTP_IERROR_ERROR - stop and report an error.
* SCTP_IERROR_NOMEME - out of memory.
*/
static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
union sctp_params param,
struct sctp_chunk *chunk,
struct sctp_chunk **errp)
{
int retval = SCTP_IERROR_NO_ERROR;
switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
case SCTP_PARAM_ACTION_DISCARD:
retval = SCTP_IERROR_ERROR;
break;
case SCTP_PARAM_ACTION_SKIP:
break;
case SCTP_PARAM_ACTION_DISCARD_ERR:
retval = SCTP_IERROR_ERROR;
/* Fall through */
case SCTP_PARAM_ACTION_SKIP_ERR:
/* Make an ERROR chunk, preparing enough room for
* returning multiple unknown parameters.
*/
if (NULL == *errp)
*errp = sctp_make_op_error_fixed(asoc, chunk);
if (*errp) {
if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
WORD_ROUND(ntohs(param.p->length))))
sctp_addto_chunk_fixed(*errp,
WORD_ROUND(ntohs(param.p->length)),
param.v);
} else {
/* If there is no memory for generating the ERROR
* report as specified, an ABORT will be triggered
* to the peer and the association won't be
* established.
*/
retval = SCTP_IERROR_NOMEM;
}
break;
default:
break;
}
return retval;
}
/* Verify variable length parameters
* Return values:
* 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
*/
static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
union sctp_params param,
sctp_cid_t cid,
struct sctp_chunk *chunk,
struct sctp_chunk **err_chunk)
{
struct sctp_hmac_algo_param *hmacs;
int retval = SCTP_IERROR_NO_ERROR;
__u16 n_elt, id = 0;
int i;
/* 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:
case SCTP_PARAM_ADAPTATION_LAYER_IND:
break;
case SCTP_PARAM_SUPPORTED_EXT:
if (!sctp_verify_ext_param(param))
return SCTP_IERROR_ABORT;
break;
case SCTP_PARAM_SET_PRIMARY:
if (sctp_addip_enable)
break;
goto fallthrough;
case SCTP_PARAM_HOST_NAME_ADDRESS:
/* Tell the peer, we won't support this param. */
sctp_process_hn_param(asoc, param, chunk, err_chunk);
retval = SCTP_IERROR_ABORT;
break;
case SCTP_PARAM_FWD_TSN_SUPPORT:
if (sctp_prsctp_enable)
break;
goto fallthrough;
case SCTP_PARAM_RANDOM:
if (!sctp_auth_enable)
goto fallthrough;
/* SCTP-AUTH: Secion 6.1
* If the random number is not 32 byte long the association
* MUST be aborted. The ABORT chunk SHOULD contain the error
* cause 'Protocol Violation'.
*/
if (SCTP_AUTH_RANDOM_LENGTH !=
ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
sctp_process_inv_paramlength(asoc, param.p,
chunk, err_chunk);
retval = SCTP_IERROR_ABORT;
}
break;
case SCTP_PARAM_CHUNKS:
if (!sctp_auth_enable)
goto fallthrough;
/* SCTP-AUTH: Section 3.2
* The CHUNKS parameter MUST be included once in the INIT or
* INIT-ACK chunk if the sender wants to receive authenticated
* chunks. Its maximum length is 260 bytes.
*/
if (260 < ntohs(param.p->length)) {
sctp_process_inv_paramlength(asoc, param.p,
chunk, err_chunk);
retval = SCTP_IERROR_ABORT;
}
break;
case SCTP_PARAM_HMAC_ALGO:
if (!sctp_auth_enable)
goto fallthrough;
hmacs = (struct sctp_hmac_algo_param *)param.p;
n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
/* 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;
fallthrough:
default:
SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
ntohs(param.p->type), cid);
retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
break;
}
return retval;
}
/* Verify the INIT packet before we process it. */
int sctp_verify_init(const struct sctp_association *asoc,
sctp_cid_t cid,
sctp_init_chunk_t *peer_init,
struct sctp_chunk *chunk,
struct sctp_chunk **errp)
{
union sctp_params param;
int has_cookie = 0;
int result;
/* Verify stream values are non-zero. */
if ((0 == peer_init->init_hdr.num_outbound_streams) ||
(0 == peer_init->init_hdr.num_inbound_streams) ||
(0 == peer_init->init_hdr.init_tag) ||
(SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {
return sctp_process_inv_mandatory(asoc, chunk, errp);
}
/* Check for missing mandatory parameters. */
sctp_walk_params(param, peer_init, init_hdr.params) {
if (SCTP_PARAM_STATE_COOKIE == param.p->type)
has_cookie = 1;
} /* for (loop through all parameters) */
/* There is a possibility that a parameter length was bad and
* in that case we would have stoped walking the parameters.
* The current param.p would point at the bad one.
* Current consensus on the mailing list is to generate a PROTOCOL
* VIOLATION error. We build the ERROR chunk here and let the normal
* error handling code build and send the packet.
*/
if (param.v != (void*)chunk->chunk_end)
return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
/* The only missing mandatory param possible today is
* the state cookie for an INIT-ACK chunk.
*/
if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
chunk, errp);
/* Verify all the variable length parameters */
sctp_walk_params(param, peer_init, init_hdr.params) {
result = sctp_verify_param(asoc, param, cid, chunk, errp);
switch (result) {
case SCTP_IERROR_ABORT:
case SCTP_IERROR_NOMEM:
return 0;
case SCTP_IERROR_ERROR:
return 1;
case SCTP_IERROR_NO_ERROR:
default:
break;
}
} /* for (loop through all parameters) */
return 1;
}
/* Unpack the parameters in an INIT packet into an association.
* Returns 0 on failure, else success.
* FIXME: This is an association method.
*/
int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
const union sctp_addr *peer_addr,
sctp_init_chunk_t *peer_init, gfp_t gfp)
{
union sctp_params param;
struct sctp_transport *transport;
struct list_head *pos, *temp;
struct sctp_af *af;
union sctp_addr addr;
char *cookie;
int src_match = 0;
/* 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.
*/
if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
goto nomem;
if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
src_match = 1;
/* Process the initialization parameters. */
sctp_walk_params(param, peer_init, init_hdr.params) {
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;
}
if (!sctp_process_param(asoc, param, peer_addr, gfp))
goto clean_up;
}
/* source address of chunk may not match any valid address */
if (!src_match)
goto clean_up;
/* 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;
/* 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.
*/
if (!sctp_addip_noauth &&
(asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
SCTP_PARAM_DEL_IP |
SCTP_PARAM_SET_PRIMARY);
asoc->peer.asconf_capable = 0;
goto clean_up;
}
/* 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);
}
}
/* The fixed INIT headers are always in network byte
* order.
*/
asoc->peer.i.init_tag =
ntohl(peer_init->init_hdr.init_tag);
asoc->peer.i.a_rwnd =
ntohl(peer_init->init_hdr.a_rwnd);
asoc->peer.i.num_outbound_streams =
ntohs(peer_init->init_hdr.num_outbound_streams);
asoc->peer.i.num_inbound_streams =
ntohs(peer_init->init_hdr.num_inbound_streams);
asoc->peer.i.initial_tsn =
ntohl(peer_init->init_hdr.initial_tsn);
/* Apply the upper bounds for output streams based on peer's
* number of inbound streams.
*/
if (asoc->c.sinit_num_ostreams >
ntohs(peer_init->init_hdr.num_inbound_streams)) {
asoc->c.sinit_num_ostreams =
ntohs(peer_init->init_hdr.num_inbound_streams);
}
if (asoc->c.sinit_max_instreams >
ntohs(peer_init->init_hdr.num_outbound_streams)) {
asoc->c.sinit_max_instreams =
ntohs(peer_init->init_hdr.num_outbound_streams);
}
/* Copy Initiation tag from INIT to VT_peer in cookie. */
asoc->c.peer_vtag = asoc->peer.i.init_tag;
/* Peer Rwnd : Current calculated value of the peer's rwnd. */
asoc->peer.rwnd = asoc->peer.i.a_rwnd;
/* Copy cookie in case we need to resend COOKIE-ECHO. */
cookie = asoc->peer.cookie;
if (cookie) {
asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
if (!asoc->peer.cookie)
goto clean_up;
}
/* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
* high (for example, implementations MAY use the size of the receiver
* advertised window).
*/
list_for_each_entry(transport, &asoc->peer.transport_addr_list,
transports) {
transport->ssthresh = asoc->peer.i.a_rwnd;
}
/* Set up the TSN tracking pieces. */
if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
asoc->peer.i.initial_tsn, gfp))
goto clean_up;
/* 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.
*/
/* Allocate storage for the negotiated streams if it is not a temporary
* association.
*/
if (!asoc->temp) {
int error;
asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
asoc->c.sinit_num_ostreams, gfp);
if (!asoc->ssnmap)
goto clean_up;
error = sctp_assoc_set_id(asoc, gfp);
if (error)
goto clean_up;
}
/* ADDIP Section 4.1 ASCONF Chunk Procedures
*
* When an endpoint has an ASCONF signaled change to be sent to the
* remote endpoint it should do the following:
* ...
* A2) A serial number should be assigned to the Chunk. The serial
* number should be a monotonically increasing number. All serial
* numbers are defined to be initialized at the start of the
* association to the same value as the Initial TSN.
*/
asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
return 1;
clean_up:
/* Release the transport structures. */
list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
transport = list_entry(pos, struct sctp_transport, transports);
if (transport->state != SCTP_ACTIVE)
sctp_assoc_rm_peer(asoc, transport);
}
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,
gfp_t gfp)
{
union sctp_addr addr;
int i;
__u16 sat;
int retval = 1;
sctp_scope_t scope;
time_t stale;
struct sctp_af *af;
union sctp_addr_param *addr_param;
struct sctp_transport *t;
/* 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;
goto do_addr_param;
case SCTP_PARAM_IPV4_ADDRESS:
/* v4 addresses are not allowed on v6-only socket */
if (ipv6_only_sock(asoc->base.sk))
break;
do_addr_param:
af = sctp_get_af_specific(param_type2af(param.p->type));
af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
scope = sctp_scope(peer_addr);
if (sctp_in_scope(&addr, scope))
if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
return 0;
break;
case SCTP_PARAM_COOKIE_PRESERVATIVE:
if (!sctp_cookie_preserve_enable)
break;
stale = ntohl(param.life->lifespan_increment);
/* Suggested Cookie Life span increment's unit is msec,
* (1/1000sec).
*/
asoc->cookie_life.tv_sec += stale / 1000;
asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
break;
case SCTP_PARAM_HOST_NAME_ADDRESS:
SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
break;
case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
/* Turn off the default values first so we'll know which
* ones are really set by the peer.
*/
asoc->peer.ipv4_address = 0;
asoc->peer.ipv6_address = 0;
/* 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;
/* Cycle through address types; avoid divide by 0. */
sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
if (sat)
sat /= sizeof(__u16);
for (i = 0; i < sat; ++i) {
switch (param.sat->types[i]) {
case SCTP_PARAM_IPV4_ADDRESS:
asoc->peer.ipv4_address = 1;
break;
case SCTP_PARAM_IPV6_ADDRESS:
if (PF_INET6 == asoc->base.sk->sk_family)
asoc->peer.ipv6_address = 1;
break;
case SCTP_PARAM_HOST_NAME_ADDRESS:
asoc->peer.hostname_address = 1;
break;
default: /* Just ignore anything else. */
break;
}
}
break;
case SCTP_PARAM_STATE_COOKIE:
asoc->peer.cookie_len =
ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
asoc->peer.cookie = param.cookie->body;
break;
case SCTP_PARAM_HEARTBEAT_INFO:
/* Would be odd to receive, but it causes no problems. */
break;
case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
/* Rejected during verify stage. */
break;
case SCTP_PARAM_ECN_CAPABLE:
asoc->peer.ecn_capable = 1;
break;
case SCTP_PARAM_ADAPTATION_LAYER_IND:
asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
break;
case SCTP_PARAM_SET_PRIMARY:
if (!sctp_addip_enable)
goto fall_through;
addr_param = param.v + sizeof(sctp_addip_param_t);
af = sctp_get_af_specific(param_type2af(param.p->type));
af->from_addr_param(&addr, addr_param,
htons(asoc->peer.port), 0);
/* if the address is invalid, we can't process it.
* XXX: see spec for what to do.
*/
if (!af->addr_valid(&addr, NULL, NULL))
break;
t = sctp_assoc_lookup_paddr(asoc, &addr);
if (!t)
break;
sctp_assoc_set_primary(asoc, t);
break;
case SCTP_PARAM_SUPPORTED_EXT:
sctp_process_ext_param(asoc, param);
break;
case SCTP_PARAM_FWD_TSN_SUPPORT:
if (sctp_prsctp_enable) {
asoc->peer.prsctp_capable = 1;
break;
}
/* Fall Through */
goto fall_through;
case SCTP_PARAM_RANDOM:
if (!sctp_auth_enable)
goto fall_through;
/* Save peer's random parameter */
asoc->peer.peer_random = kmemdup(param.p,
ntohs(param.p->length), gfp);
if (!asoc->peer.peer_random) {
retval = 0;
break;
}
break;
case SCTP_PARAM_HMAC_ALGO:
if (!sctp_auth_enable)
goto fall_through;
/* Save peer's HMAC list */
asoc->peer.peer_hmacs = kmemdup(param.p,
ntohs(param.p->length), gfp);
if (!asoc->peer.peer_hmacs) {
retval = 0;
break;
}
/* Set the default HMAC the peer requested*/
sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
break;
case SCTP_PARAM_CHUNKS:
if (!sctp_auth_enable)
goto fall_through;
asoc->peer.peer_chunks = kmemdup(param.p,
ntohs(param.p->length), gfp);
if (!asoc->peer.peer_chunks)
retval = 0;
break;
fall_through:
default:
/* Any unrecognized parameters should have been caught
* and handled by sctp_verify_param() which should be
* called prior to this routine. Simply log the error
* here.
*/
SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n",
ntohs(param.p->type), asoc);
break;
}
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 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Address Parameter and other parameter will not be wrapped in this function
*/
static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
union sctp_addr *addr,
int vparam_len)
{
sctp_addiphdr_t asconf;
struct sctp_chunk *retval;
int length = sizeof(asconf) + vparam_len;
union sctp_addr_param addrparam;
int addrlen;
struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
addrlen = af->to_addr_param(addr, &addrparam);
if (!addrlen)
return NULL;
length += addrlen;
/* Create the chunk. */
retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length);
if (!retval)
return NULL;
asconf.serial = htonl(asoc->addip_serial++);
retval->subh.addip_hdr =
sctp_addto_chunk(retval, sizeof(asconf), &asconf);
retval->param_hdr.v =
sctp_addto_chunk(retval, addrlen, &addrparam);
return retval;
}
/* ADDIP
* 3.2.1 Add IP Address
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type = 0xC001 | Length = Variable |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ASCONF-Request Correlation ID |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Address Parameter |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* 3.2.2 Delete IP Address
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type = 0xC002 | Length = Variable |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ASCONF-Request Correlation ID |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Address Parameter |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*/
struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
union sctp_addr *laddr,
struct sockaddr *addrs,
int addrcnt,
__be16 flags)
{
sctp_addip_param_t param;
struct sctp_chunk *retval;
union sctp_addr_param addr_param;
union sctp_addr *addr;
void *addr_buf;
struct sctp_af *af;
int paramlen = sizeof(param);
int addr_param_len = 0;
int totallen = 0;
int i;
int del_pickup = 0;
/* Get total length of all the address parameters. */
addr_buf = addrs;
for (i = 0; i < addrcnt; i++) {
addr = addr_buf;
af = sctp_get_af_specific(addr->v4.sin_family);
addr_param_len = af->to_addr_param(addr, &addr_param);
totallen += paramlen;
totallen += addr_param_len;
addr_buf += af->sockaddr_len;
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;
SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen);
}
}
/* Create an asconf chunk with the required length. */
retval = sctp_make_asconf(asoc, laddr, totallen);
if (!retval)
return NULL;
/* Add the address parameters to the asconf chunk. */
addr_buf = addrs;
for (i = 0; i < addrcnt; i++) {
addr = addr_buf;
af = sctp_get_af_specific(addr->v4.sin_family);
addr_param_len = af->to_addr_param(addr, &addr_param);
param.param_hdr.type = flags;
param.param_hdr.length = htons(paramlen + addr_param_len);
param.crr_id = i;
sctp_addto_chunk(retval, paramlen, &param);
sctp_addto_chunk(retval, addr_param_len, &addr_param);
addr_buf += af->sockaddr_len;
}
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);
param.crr_id = i;
sctp_addto_chunk(retval, paramlen, &param);
sctp_addto_chunk(retval, addr_param_len, &addr_param);
}
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 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Create an ASCONF chunk with Set Primary IP address parameter.
*/
struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
union sctp_addr *addr)
{
sctp_addip_param_t param;
struct sctp_chunk *retval;
int len = sizeof(param);
union sctp_addr_param addrparam;
int addrlen;
struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
addrlen = af->to_addr_param(addr, &addrparam);
if (!addrlen)
return NULL;
len += addrlen;
/* Create the chunk and make asconf header. */
retval = sctp_make_asconf(asoc, addr, len);
if (!retval)
return NULL;
param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
param.param_hdr.length = htons(len);
param.crr_id = 0;
sctp_addto_chunk(retval, sizeof(param), &param);
sctp_addto_chunk(retval, addrlen, &addrparam);
return retval;
}
/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Type = 0x80 | Chunk Flags | Chunk Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Serial Number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ASCONF Parameter Response#1 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* \ \
* / .... /
* \ \
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ASCONF Parameter Response#N |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Create an ASCONF_ACK chunk with enough space for the parameter responses.
*/
static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *