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linux/net/sctp/sm_make_chunk.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/* 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.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <linux-sctp@vger.kernel.org>
*
* 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>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <crypto/hash.h>
#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/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>
static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
__u8 type, __u8 flags, int paylen,
gfp_t gfp);
static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
__u8 flags, int paylen, gfp_t gfp);
static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
__u8 type, __u8 flags, int paylen,
gfp_t gfp);
static struct sctp_cookie_param *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);
/* Control chunk destructor */
static void sctp_control_release_owner(struct sk_buff *skb)
{
struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
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);
}
sctp_auth_shkey_release(chunk->shkey);
}
}
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.
*/
if (chunk->auth) {
chunk->shkey = asoc->shkey;
sctp_auth_shkey_hold(chunk->shkey);
}
skb->sk = asoc ? asoc->base.sk : NULL;
skb_shinfo(skb)->destructor_arg = chunk;
skb->destructor = sctp_control_release_owner;
}
/* What was the inbound interface for this chunk? */
int sctp_chunk_iif(const struct sctp_chunk *chunk)
{
struct sk_buff *skb = chunk->skb;
return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
}
/* 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.
*/
int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
size_t paylen)
{
struct sctp_errhdr err;
__u16 len;
/* Cause code constants are now defined in network order. */
err.cause = cause_code;
len = sizeof(err) + paylen;
err.length = htons(len);
if (skb_tailroom(chunk->skb) < len)
return -ENOSPC;
chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &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)
{
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;
struct sctp_endpoint *ep = asoc->ep;
struct sctp_chunk *retval = NULL;
int num_types, addrs_len = 0;
struct sctp_inithdr init;
union sctp_params addrs;
struct sctp_sock *sp;
__u8 extensions[5];
size_t chunksize;
__be16 types[2];
int num_ext = 0;
/* 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);
chunksize = sizeof(init) + addrs_len;
chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
if (asoc->ep->ecn_enable)
chunksize += sizeof(ecap_param);
if (asoc->ep->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 (asoc->ep->asconf_enable) {
extensions[num_ext] = SCTP_CID_ASCONF;
extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
num_ext += 2;
}
if (asoc->ep->reconf_enable) {
extensions[num_ext] = SCTP_CID_RECONF;
num_ext += 1;
}
if (sp->adaptation_ind)
chunksize += sizeof(aiparam);
if (asoc->ep->intl_enable) {
extensions[num_ext] = SCTP_CID_I_DATA;
num_ext += 1;
}
chunksize += vparam_len;
/* Account for AUTH related parameters */
if (ep->auth_enable) {
/* Add random parameter length*/
chunksize += sizeof(asoc->c.auth_random);
/* Add HMACS parameter length if any were defined */
auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
if (auth_hmacs->length)
chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
else
auth_hmacs = NULL;
/* Add CHUNKS parameter length */
auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
if (auth_chunks->length)
chunksize += SCTP_PAD4(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 += SCTP_PAD4(sizeof(ext_param) + 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_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
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);
if (asoc->ep->ecn_enable)
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(ext_param) + num_ext);
sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
sctp_addto_param(retval, num_ext, extensions);
}
if (asoc->ep->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 (ep->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)
{
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;
struct sctp_inithdr initack;
union sctp_params addrs;
struct sctp_sock *sp;
__u8 extensions[5];
size_t chunksize;
int num_ext = 0;
int cookie_len;
int addrs_len;
/* 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 (asoc->peer.reconf_capable) {
extensions[num_ext] = SCTP_CID_RECONF;
num_ext += 1;
}
if (sp->adaptation_ind)
chunksize += sizeof(aiparam);
if (asoc->peer.intl_capable) {
extensions[num_ext] = SCTP_CID_I_DATA;
num_ext += 1;
}
if (asoc->peer.auth_capable) {
auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
chunksize += ntohs(auth_random->length);
auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
if (auth_hmacs->length)
chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
else
auth_hmacs = NULL;
auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
if (auth_chunks->length)
chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
else
auth_chunks = NULL;
extensions[num_ext] = SCTP_CID_AUTH;
num_ext += 1;
}
if (num_ext)
chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
/* Now allocate and fill out the chunk. */
retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
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.]
*/
if (chunk->transport)
retval->transport =
sctp_assoc_lookup_paddr(asoc,
&chunk->transport->ipaddr);
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(ext_param) + num_ext);
sctp_addto_chunk(retval, sizeof(ext_param), &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;
int cookie_len;
void *cookie;
cookie = asoc->peer.cookie;
cookie_len = asoc->peer.cookie_len;
/* Build a cookie echo chunk. */
retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
cookie_len, GFP_ATOMIC);
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_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
/* 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 && chunk->transport)
retval->transport =
sctp_assoc_lookup_paddr(asoc,
&chunk->transport->ipaddr);
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;
struct sctp_cwrhdr cwr;
cwr.lowest_tsn = htonl(lowest_tsn);
retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
sizeof(cwr), GFP_ATOMIC);
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;
struct sctp_ecnehdr ecne;
ecne.lowest_tsn = htonl(lowest_tsn);
retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
sizeof(ecne), GFP_ATOMIC);
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(const struct sctp_association *asoc,
const struct sctp_sndrcvinfo *sinfo,
int len, __u8 flags, gfp_t gfp)
{
struct sctp_chunk *retval;
struct sctp_datahdr dp;
/* We assign the TSN as LATE as possible, not here when
* creating the chunk.
*/
memset(&dp, 0, sizeof(dp));
dp.ppid = sinfo->sinfo_ppid;
dp.stream = htons(sinfo->sinfo_stream);
/* Set the flags for an unordered send. */
if (sinfo->sinfo_flags & SCTP_UNORDERED)
flags |= SCTP_DATA_UNORDERED;
retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
if (!retval)
return NULL;
retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
return retval;
}
/* Create a selective ackowledgement (SACK) for the given
* association. This reports on which TSN's we've seen to date,
* including duplicates and gaps.
*/
struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
{
struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
__u16 num_gabs, num_dup_tsns;
struct sctp_transport *trans;
struct sctp_chunk *retval;
struct sctp_sackhdr sack;
__u32 ctsn;
int len;
memset(gabs, 0, sizeof(gabs));
ctsn = sctp_tsnmap_get_ctsn(map);
pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, 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_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
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) {
asoc->stats.idupchunks += num_dup_tsns;
sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
sctp_tsnmap_get_dups(map));
}
/* Once we have a sack generated, check to see what our sack
* generation is, if its 0, reset the transports to 0, and reset
* the association generation to 1
*
* The idea is that zero is never used as a valid generation for the
* association so no transport will match after a wrap event like this,
* Until the next sack
*/
if (++asoc->peer.sack_generation == 0) {
list_for_each_entry(trans, &asoc->peer.transport_addr_list,
transports)
trans->sack_generation = 0;
asoc->peer.sack_generation = 1;
}
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_shutdownhdr shut;
struct sctp_chunk *retval;
__u32 ctsn;
ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
shut.cum_tsn_ack = htonl(ctsn);
retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
sizeof(shut), GFP_ATOMIC);
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_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
GFP_ATOMIC);
/* 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_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
0, GFP_ATOMIC);
/* 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_control(asoc, SCTP_CID_ABORT, flags, hint,
GFP_ATOMIC);
/* 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(struct sctp_errhdr) + 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,
struct msghdr *msg,
size_t paylen)
{
struct sctp_chunk *retval;
void *payload = NULL;
int err;
retval = sctp_make_abort(asoc, NULL,
sizeof(struct sctp_errhdr) + 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_from_msg(payload, msg, 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)
{
int chunklen = ntohs(chunk->chunk_hdr->length);
void *target;
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(struct sctp_errhdr) +
paylen + sizeof(phdr));
if (!retval)
goto end;
sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
sizeof(phdr));
phdr.type = htons(chunk->chunk_hdr->type);
phdr.length = chunk->chunk_hdr->length;
sctp_addto_chunk(retval, paylen, payload);
sctp_addto_param(retval, sizeof(phdr), &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)
{
static const char error[] = "The following parameter had invalid length:";
size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
sizeof(*param);
struct sctp_chunk *retval;
retval = sctp_make_abort(asoc, chunk, payload_len);
if (!retval)
goto nodata;
sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
sizeof(error) + sizeof(*param));
sctp_addto_chunk(retval, sizeof(error), error);
sctp_addto_param(retval, sizeof(*param), param);
nodata:
return retval;
}
struct sctp_chunk *sctp_make_violation_max_retrans(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
static const char error[] = "Association exceeded its max_retrans count";
size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
struct sctp_chunk *retval;
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;
}
struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
struct sctp_new_encap_port_hdr nep;
struct sctp_chunk *retval;
retval = sctp_make_abort(asoc, chunk,
sizeof(struct sctp_errhdr) + sizeof(nep));
if (!retval)
goto nodata;
sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep));
nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
nep.new_port = chunk->transport->encap_port;
sctp_addto_chunk(retval, sizeof(nep), &nep);
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_sender_hb_info hbinfo;
struct sctp_chunk *retval;
retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
sizeof(hbinfo), GFP_ATOMIC);
if (!retval)
goto nodata;
hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
hbinfo.param_hdr.length = htons(sizeof(hbinfo));
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_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
GFP_ATOMIC);
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_control(asoc, SCTP_CID_ERROR, 0,
sizeof(struct sctp_errhdr) + size,
GFP_ATOMIC);
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,
* min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
* This is a helper function to allocate an error chunk 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.
*/
static inline struct sctp_chunk *sctp_make_op_error_limited(
const struct sctp_association *asoc,
const struct sctp_chunk *chunk)
{
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);
}
size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
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,
__u16 key_id)
{
struct sctp_authhdr auth_hdr;
struct sctp_hmac *hmac_desc;
struct sctp_chunk *retval;
/* 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_control(asoc, SCTP_CID_AUTH, 0,
hmac_desc->hmac_len + sizeof(auth_hdr),
GFP_ATOMIC);
if (!retval)
return NULL;
auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
auth_hdr.shkey_id = htons(key_id);
retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
&auth_hdr);
skb_put_zero(retval->skb, 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[].
*
* 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.
*
*/
struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
const struct sctp_association *asoc,
struct sock *sk, gfp_t gfp)
{
struct sctp_chunk *retval;
retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
if (!retval)
goto nodata;
if (!sk)
pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
INIT_LIST_HEAD(&retval->list);
retval->skb = skb;
retval->asoc = (struct sctp_association *)asoc;
retval->singleton = 1;
retval->fast_retransmit = SCTP_CAN_FRTX;
/* Polish the bead hole. */
INIT_LIST_HEAD(&retval->transmitted_list);
INIT_LIST_HEAD(&retval->frag_list);
SCTP_DBG_OBJCNT_INC(chunk);
refcount_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.
*/
static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
__u8 type, __u8 flags, int paylen,
gfp_t gfp)
{
struct sctp_chunkhdr *chunk_hdr;
struct sctp_chunk *retval;
struct sk_buff *skb;
struct sock *sk;
int chunklen;
chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
if (chunklen > SCTP_MAX_CHUNK_LEN)
goto nodata;
/* No need to allocate LL here, as this is only a chunk. */
skb = alloc_skb(chunklen, gfp);
if (!skb)
goto nodata;
/* Make room for the chunk header. */
chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
chunk_hdr->type = type;
chunk_hdr->flags = flags;
chunk_hdr->length = htons(sizeof(*chunk_hdr));
sk = asoc ? asoc->base.sk : NULL;
retval = sctp_chunkify(skb, asoc, sk, gfp);
if (!retval) {
kfree_skb(skb);
goto nodata;
}
retval->chunk_hdr = chunk_hdr;
retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
/* Determine if the chunk needs to be authenticated */
if (sctp_auth_send_cid(type, asoc))
retval->auth = 1;
return retval;
nodata:
return NULL;
}
static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
__u8 flags, int paylen, gfp_t gfp)
{
return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
}
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);
}
static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
__u8 type, __u8 flags, int paylen,
gfp_t gfp)
{
struct sctp_chunk *chunk;
chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
if (chunk)
sctp_control_set_owner_w(chunk);
return chunk;
}
/* 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);
consume_skb(chunk->skb);
consume_skb(chunk->auth_chunk);
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)
{
refcount_inc(&ch->refcnt);
}
/* Release a reference to the chunk. */
void sctp_chunk_put(struct sctp_chunk *ch)
{
if (refcount_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)
{
int chunklen = ntohs(chunk->chunk_hdr->length);
int padlen = SCTP_PAD4(chunklen) - chunklen;
void *target;
skb_put_zero(chunk->skb, padlen);
target = skb_put_data(chunk->skb, 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 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 len,
struct iov_iter *from)
{
void *target;
/* Make room in chunk for data. */
target = skb_put(chunk->skb, len);
/* Copy data (whole iovec) into chunk */
if (!copy_from_iter_full(target, len, from))
return -EFAULT;
/* Adjust the chunk length field. */
chunk->chunk_hdr->length =
htons(ntohs(chunk->chunk_hdr->length) + len);
chunk->chunk_end = skb_tail_pointer(chunk->skb);
return 0;
}
/* 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_stream *stream;
struct sctp_chunk *lchunk;
struct sctp_datamsg *msg;
__u16 ssn, sid;
if (chunk->has_ssn)
return;
/* All fragments will be on the same stream */
sid = ntohs(chunk->subh.data_hdr->stream);
stream = &chunk->asoc->stream;
/* 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, out, sid);
else
ssn = sctp_ssn_peek(stream, out, 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;
enum sctp_scope scope;
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. */
SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
nodata:
return asoc;
}
/* Build a cookie representing asoc.
* This INCLUDES the param header needed to put the cookie in the INIT ACK.
*/
static struct sctp_cookie_param *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)
{
struct sctp_signed_cookie *cookie;
struct sctp_cookie_param *retval;
int headersize, bodysize;
/* Header size is static data prior to the actual cookie, including
* any padding.
*/
headersize = sizeof(struct sctp_paramhdr) +
(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. */
cookie->c.expiration = ktime_add(asoc->cookie_life,
ktime_get_real());
/* 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 crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
int err;
/* Sign the message. */
err = crypto_shash_setkey(tfm, ep->secret_key,
sizeof(ep->secret_key)) ?:
crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize,
cookie->signature);
if (err)
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;
int headersize, bodysize, fixed_size;
struct sctp_signed_cookie *cookie;
struct sk_buff *skb = chunk->skb;
struct sctp_cookie *bear_cookie;
__u8 *digest = ep->digest;
enum sctp_scope scope;
unsigned int len;
ktime_t kt;
/* Header size is static data prior to the actual cookie, including
* any padding.
*/
headersize = sizeof(struct sctp_chunkhdr) +
(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. */
{
struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
int err;
err = crypto_shash_setkey(tfm, ep->secret_key,
sizeof(ep->secret_key)) ?:
crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize,
digest);
if (err) {
*error = -SCTP_IERROR_NOMEM;
goto fail;
}
}
if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
*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
* a cookie may be considered expired, but this would only slow
* down the new association establishment instead of every packet.
*/
if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
kt = skb_get_ktime(skb);
else
kt = ktime_get_real();
if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
__be32 n = htonl(usecs);
/*
* 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.
*/
*errp = sctp_make_op_error(asoc, chunk,
SCTP_ERROR_STALE_COOKIE, &n,
sizeof(n), 0);
if (*errp)
*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,
sizeof(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->strreset_outseq = 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,
enum sctp_param paramtype,
struct sctp_chunk *chunk,
struct sctp_chunk **errp)
{
struct __sctp_missing report;
__u16 len;
len = SCTP_PAD4(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(asoc, chunk, SCTP_ERROR_DNS_FAILED,
param.v, len, 0);
/* Stop processing this chunk. */
return 0;
}
static int sctp_verify_ext_param(struct net *net,
const struct sctp_endpoint *ep,
union sctp_params param)
{
__u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
int have_asconf = 0;
int have_auth = 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 (net->sctp.addip_noauth)
return 1;
if (ep->asconf_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(struct sctp_paramhdr);
int i;
for (i = 0; i < num_ext; i++) {
switch (param.ext->chunks[i]) {
case SCTP_CID_RECONF:
if (asoc->ep->reconf_enable)
asoc->peer.reconf_capable = 1;
break;
case SCTP_CID_FWD_TSN:
if (asoc->ep->prsctp_enable)
asoc->peer.prsctp_capable = 1;
break;
case SCTP_CID_AUTH:
/* if the peer reports AUTH, assume that he
* supports AUTH.
*/
if (asoc->ep->auth_enable)
asoc->peer.auth_capable = 1;
break;
case SCTP_CID_ASCONF:
case SCTP_CID_ASCONF_ACK:
if (asoc->ep->asconf_enable)
asoc->peer.asconf_capable = 1;
break;
case SCTP_CID_I_DATA:
if (asoc->ep->intl_enable)
asoc->peer.intl_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 enum sctp_ierror 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;
fallthrough;
case SCTP_PARAM_ACTION_SKIP_ERR:
/* Make an ERROR chunk, preparing enough room for
* returning multiple unknown parameters.
*/
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;
}
}
if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
ntohs(param.p->length)))
sctp_addto_chunk(*errp, ntohs(param.p->length),
param.v);
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 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)
{
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(net, ep, param))
return SCTP_IERROR_ABORT;
break;
case SCTP_PARAM_SET_PRIMARY:
if (ep->asconf_enable)
break;
goto unhandled;
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 (ep->prsctp_enable)
break;
goto unhandled;
case SCTP_PARAM_RANDOM:
if (!ep->auth_enable)
goto unhandled;
/* 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(struct sctp_paramhdr)) {
sctp_process_inv_paramlength(asoc, param.p,
chunk, err_chunk);
retval = SCTP_IERROR_ABORT;
}
break;
case SCTP_PARAM_CHUNKS:
if (!ep->auth_enable)
goto unhandled;
/* 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 (!ep->auth_enable)
goto unhandled;
hmacs = (struct sctp_hmac_algo_param *)param.p;
n_elt = (ntohs(param.p->length) -
sizeof(struct sctp_paramhdr)) >> 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;
unhandled:
default:
pr_debug("%s: unrecognized param:%d for chunk:%d\n",
__func__, 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(struct net *net, const struct sctp_endpoint *ep,
const struct sctp_association *asoc, enum sctp_cid cid,
struct sctp_init_chunk *peer_init,
struct sctp_chunk *chunk, struct sctp_chunk **errp)
{
union sctp_params param;
bool has_cookie = false;
int result;
/* 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)
return sctp_process_inv_mandatory(asoc, chunk, errp);
sctp_walk_params(param, peer_init, init_hdr.params) {
if (param.p->type == SCTP_PARAM_STATE_COOKIE)
has_cookie = true;
}
/* 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(net, ep, 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,
struct sctp_init_chunk *peer_init, gfp_t gfp)
{
struct sctp_transport *transport;
struct list_head *pos, *temp;
union sctp_params param;
union sctp_addr addr;
struct sctp_af *af;
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 better choice than any of the embedded addresses.
*/
asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
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 (!asoc->base.net->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);
asoc->strreset_inseq = asoc->peer.i.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;
/* 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.
*/
if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
asoc->c.sinit_max_instreams, gfp))
goto clean_up;
/* Update frag_point when stream_interleave may get changed. */
sctp_assoc_update_frag_point(asoc);
if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
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)
{
struct sctp_endpoint *ep = asoc->ep;
union sctp_addr_param *addr_param;
struct net *net = asoc->base.net;
struct sctp_transport *t;
enum sctp_scope scope;
union sctp_addr addr;
struct sctp_af *af;
int retval = 1, i;
u32 stale;
__u16 sat;
/* 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(net, &addr, scope))
if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
return 0;
break;
case SCTP_PARAM_COOKIE_PRESERVATIVE:
if (!net->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 = ktime_add_ms(asoc->cookie_life, stale);
break;
case SCTP_PARAM_HOST_NAME_ADDRESS:
pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
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(struct sctp_paramhdr);
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(struct sctp_paramhdr);
kfree(asoc->peer.cookie);
asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
if (!asoc->peer.cookie)
retval = 0;
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:
if (asoc->ep->ecn_enable) {
asoc->peer.ecn_capable = 1;
break;
}
/* Fall Through */
goto fall_through;
case SCTP_PARAM_ADAPTATION_LAYER_IND:
asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
break;
case SCTP_PARAM_SET_PRIMARY:
if (!ep->asconf_enable)
goto fall_through;
addr_param = param.v + sizeof(struct sctp_addip_param);
af = sctp_get_af_specific(param_type2af(addr_param->p.type));
if (af == NULL)
break;
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 (asoc->ep->prsctp_enable) {
asoc->peer.prsctp_capable = 1;
break;
}
/* Fall Through */
goto fall_through;
case SCTP_PARAM_RANDOM:
if (!ep->auth_enable)
goto fall_through;
/* Save peer's random parameter */
kfree(asoc->peer.peer_random);
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 (!ep->auth_enable)
goto fall_through;
/* Save peer's HMAC list */
kfree(asoc->peer.peer_hmacs);
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 (!ep->auth_enable)
goto fall_through;
kfree(asoc->peer.peer_chunks);
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.
*/
pr_debug("%s: ignoring param:%d for association:%p.\n",
__func__, 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)
{
struct sctp_addiphdr 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_control(asoc, SCTP_CID_ASCONF, 0, length,
GFP_ATOMIC);
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)
{
union sctp_addr_param addr_param;
struct sctp_addip_param param;
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;
/* 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;
pr_debug("%s: picked same-scope del_pending addr, "
"totallen for all addresses is %d\n",
__func__, 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 = htonl(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 = htonl(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)
{
struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
union sctp_addr_param addrparam;
struct sctp_addip_param param;
struct sctp_chunk *retval;
int len = sizeof(param);
int addrlen;
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 *asoc,
__u32 serial, int vparam_len)
{
struct sctp_addiphdr asconf;
struct sctp_chunk *retval;
int length = sizeof(asconf) + vparam_len;
/* Create the chunk. */
retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
GFP_ATOMIC);
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. */
static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
__be16 err_code,
struct sctp_addip_param *asconf_param)
{
struct sctp_addip_param ack_param;
struct sctp_errhdr err_param;
int asconf_param_len = 0;
int err_param_len = 0;
__be16 response_type;
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);
}
/* Add Success Indication or Error Cause Indication parameter. */
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. */
static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
struct sctp_chunk *asconf,
struct sctp_addip_param *asconf_param)
{
union sctp_addr_param *addr_param;
struct sctp_transport *peer;
union sctp_addr addr;
struct sctp_af *af;
addr_param = (void *)asconf_param + sizeof(*asconf_param);
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;
switch (addr_param->p.type) {
case SCTP_PARAM_IPV6_ADDRESS:
if (!asoc->peer.ipv6_address)
return SCTP_ERROR_DNS_FAILED;
break;
case SCTP_PARAM_IPV4_ADDRESS:
if (!asoc->peer.ipv4_address)
return SCTP_ERROR_DNS_FAILED;
break;
default:
return SCTP_ERROR_DNS_FAILED;
}
af = sctp_get_af_specific(param_type2af(addr_param->p.type));
if (unlikely(!af))
return SCTP_ERROR_DNS_FAILED;
af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
/* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
* or multicast address.
* (note: wildcard is permitted and requires special handling so
* make sure we check for that)
*/
if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
return SCTP_ERROR_DNS_FAILED;
switch (asconf_param->param_hdr.type) {
case SCTP_PARAM_ADD_IP:
/* 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));
if (security_sctp_bind_connect(asoc->ep->base.sk,
SCTP_PARAM_ADD_IP,
(struct sockaddr *)&addr,
af->sockaddr_len))
return SCTP_ERROR_REQ_REFUSED;
/* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
* 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'.
*/
peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
if (!peer)
return SCTP_ERROR_RSRC_LOW;
/* Start the heartbeat timer. */
sctp_transport_reset_hb_timer(peer);
asoc->new_transport = peer;
break;
case SCTP_PARAM_DEL_IP:
/* ADDIP 4.3 D7) If a request is received to delete the
* 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'.
*/
if (asoc->peer.transport_count == 1)
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'
*/
if (sctp_cmp_addr_exact(&asconf->source, &addr))
return SCTP_ERROR_DEL_SRC_IP;
/* 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);
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);
break;
case SCTP_PARAM_SET_PRIMARY:
/* 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, sctp_source(asconf), sizeof(addr));
if (security_sctp_bind_connect(asoc->ep->base.sk,
SCTP_PARAM_SET_PRIMARY,
(struct sockaddr *)&addr,
af->sockaddr_len))
return SCTP_ERROR_REQ_REFUSED;
peer = sctp_assoc_lookup_paddr(asoc, &addr);
if (!peer)
return SCTP_ERROR_DNS_FAILED;
sctp_assoc_set_primary(asoc, peer);
break;
}
return SCTP_ERROR_NO_ERROR;
}
/* 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)
{
struct sctp_addip_chunk *addip;
bool addr_param_seen = false;
union sctp_params param;
addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
sctp_walk_params(param, addip, addip_hdr.params) {
size_t length = ntohs(param.p->length);
*errp = param.p;
switch (param.p->type) {
case SCTP_PARAM_ERR_CAUSE:
break;
case SCTP_PARAM_IPV4_ADDRESS:
if (length != sizeof(struct sctp_ipv4addr_param))
return false;
/* 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;
addr_param_seen = true;
break;
case SCTP_PARAM_IPV6_ADDRESS:
if (length != sizeof(struct sctp_ipv6addr_param))
return false;
if (param.v != addip->addip_hdr.params)
return false;
addr_param_seen = true;
break;
case SCTP_PARAM_ADD_IP:
case SCTP_PARAM_DEL_IP:
case SCTP_PARAM_SET_PRIMARY:
/* In ASCONF chunks, these need to be first. */
if (addr_param_needed && !addr_param_seen)
return false;
length = ntohs(param.addip->param_hdr.length);
if (length < sizeof(struct sctp_addip_param) +
sizeof(**errp))
return false;
break;
case SCTP_PARAM_SUCCESS_REPORT:
case SCTP_PARAM_ADAPTATION_LAYER_IND:
if (length != sizeof(struct sctp_addip_param))
return false;
break;
default:
/* This is unknown to us, reject! */
return false;
}
}
/* 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;
return true;
}
/* Process an incoming ASCONF chunk with the next expected serial no. and
* return an ASCONF_ACK chunk to be sent in response.
*/
struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
struct sctp_chunk *asconf)
{
union sctp_addr_param *addr_param;
struct sctp_addip_chunk *addip;
struct sctp_chunk *asconf_ack;
bool all_param_pass = true;
struct sctp_addiphdr *hdr;
int length = 0, chunk_len;
union sctp_params param;
__be16 err_code;
__u32 serial;
addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
chunk_len = ntohs(asconf->chunk_hdr->length) -
sizeof(struct sctp_chunkhdr);
hdr = (struct sctp_addiphdr *)asconf->skb->data;
serial = ntohl(hdr->serial);
/* Skip the addiphdr and store a pointer to address parameter. */
length = sizeof(*hdr);
addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
chunk_len -= length;
/* Skip the address parameter and store a pointer to the first
* asconf parameter.
*/
length = ntohs(addr_param->p.length);
chunk_len -= length;
/* create an ASCONF_ACK chunk.
* Based on the definitions of parameters, we know that the size of
* ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
* parameters.
*/
asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
if (!asconf_ack)
goto done;
/* Process the TLVs contained within the ASCONF chunk. */
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;
err_code = sctp_process_asconf_param(asoc, asconf,
param.addip);
/* ADDIP 4.1 A7)
* If an error response is received for a TLV parameter,
* all TLVs with no response before the failed TLV are
* considered successful if not reported. All TLVs after
* the failed response are considered unsuccessful unless
* a specific success indication is present for the parameter.
*/
if (err_code != SCTP_ERROR_NO_ERROR)
all_param_pass = false;
if (!all_param_pass)
sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
err_code, param.addip);
/* 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
* in the ASCONF.
*/
if (err_code == SCTP_ERROR_RSRC_LOW)
goto done;
}
done:
asoc->peer.addip_serial++;
/* If we are sending a new ASCONF_ACK hold a reference to it in assoc
* after freeing the reference to old asconf ack if any.
*/
if (asconf_ack) {
sctp_chunk_hold(asconf_ack);
list_add_tail(&asconf_ack->transmitted_list,
&asoc->asconf_ack_list);
}
return asconf_ack;
}
/* Process a asconf parameter that is successfully acked. */
static void sctp_asconf_param_success(struct sctp_association *asoc,
struct sctp_addip_param *asconf_param)
{
struct sctp_bind_addr *bp = &asoc->base.bind_addr;
union sctp_addr_param *addr_param;
struct sctp_sockaddr_entry *saddr;
struct sctp_transport *transport;
union sctp_addr addr;
struct sctp_af *af;
addr_param = (void *)asconf_param + sizeof(*asconf_param);
/* We have checked the packet before, so we do not check again. */
af = sctp_get_af_specific(param_type2af(addr_param->p.type));
af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
switch (asconf_param->param_hdr.type) {
case SCTP_PARAM_ADD_IP:
/* This is always done in BH context with a socket lock
* held, so the list can not change.
*/
local_bh_disable();
list_for_each_entry(saddr, &bp->address_list, list) {
if (sctp_cmp_addr_exact(&saddr->a, &addr))
saddr->state = SCTP_ADDR_SRC;
}
local_bh_enable();
list_for_each_entry(transport, &asoc->peer.transport_addr_list,
transports) {
sctp_transport_dst_release(transport);
}
break;
case SCTP_PARAM_DEL_IP:
local_bh_disable();
sctp_del_bind_addr(bp, &addr);
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;
}
local_bh_enable();
list_for_each_entry(transport, &asoc->peer.transport_addr_list,
transports) {
sctp_transport_dst_release(transport);
}
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,
* return the error code based on the third argument 'no_err'.
* 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.
*/
static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
struct sctp_addip_param *asconf_param,
int no_err)
{
struct sctp_addip_param *asconf_ack_param;
struct sctp_errhdr *err_param;
int asconf_ack_len;
__be16 err_code;
int length;
if (no_err)
err_code = SCTP_ERROR_NO_ERROR;
else
err_code = SCTP_ERROR_REQ_REFUSED;
asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
sizeof(struct sctp_chunkhdr);
/* Skip the addiphdr from the asconf_ack chunk and store a pointer to
* the first asconf_ack parameter.
*/
length = sizeof(struct sctp_addiphdr);
asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
length);
asconf_ack_len -= length;
while (asconf_ack_len > 0) {
if (asconf_ack_param->crr_id == asconf_param->crr_id) {
switch (asconf_ack_param->param_hdr.type) {
case SCTP_PARAM_SUCCESS_REPORT:
return SCTP_ERROR_NO_ERROR;
case SCTP_PARAM_ERR_CAUSE:
length = sizeof(*asconf_ack_param);
err_param = (void *)asconf_ack_param + length;
asconf_ack_len -= length;
if (asconf_ack_len > 0)
return err_param->cause;
else
return SCTP_ERROR_INV_PARAM;
break;
default:
return SCTP_ERROR_INV_PARAM;
}
}
length = ntohs(asconf_ack_param->param_hdr.length);
asconf_ack_param = (void *)asconf_ack_param + length;
asconf_ack_len -= length;
}
return err_code;
}
/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
int sctp_process_asconf_ack(struct sctp_association *asoc,
struct sctp_chunk *asconf_ack)
{
struct sctp_chunk *asconf = asoc->addip_last_asconf;
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;
/* Skip the chunkhdr and addiphdr from the last asconf sent and store
* a pointer to address parameter.
*/
length = sizeof(struct sctp_addip_chunk);
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
* pointer to the first asconf parameter.
*/
length = ntohs(addr_param->p.length);
asconf_param = (void *)addr_param + length;
asconf_len -= length;
/* ADDIP 4.1
* A8) If there is no response(s) to specific TLV parameter(s), and no
* failures are indicated, then all request(s) are considered
* successful.
*/
if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
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:
sctp_asconf_param_success(asoc, asconf_param);
break;
case SCTP_ERROR_RSRC_LOW:
retval = 1;
break;
case SCTP_ERROR_UNKNOWN_PARAM:
/* Disable sending this type of asconf parameter in
* future.
*/
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.
*/
length = ntohs(asconf_param->param_hdr.length);
asconf_param = (void *)asconf_param + length;
asconf_len -= length;
}
if (no_err && asoc->src_out_of_asoc_ok) {
asoc->src_out_of_asoc_ok = 0;
sctp_transport_immediate_rtx(asoc->peer.primary_path);
}
/* Free the cached last sent asconf chunk. */
list_del_init(&asconf->transmitted_list);
sctp_chunk_free(asconf);
asoc->addip_last_asconf = NULL;
return retval;
}
/* Make a FWD TSN chunk. */
struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
__u32 new_cum_tsn, size_t nstreams,
struct sctp_fwdtsn_skip *skiplist)
{
struct sctp_chunk *retval = NULL;
struct sctp_fwdtsn_hdr ftsn_hdr;
struct sctp_fwdtsn_skip skip;
size_t hint;
int i;
hint = (nstreams + 1) * sizeof(__u32);
retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
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;
}
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;
}
/* 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) /
* \ \
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
int length)
{
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(
const struct sctp_association *asoc,
__u16 stream_num, __be16 *stream_list,
bool out, bool in)
{
__u16 stream_len = stream_num * sizeof(__u16);
struct sctp_strreset_outreq outreq;
struct sctp_strreset_inreq inreq;
struct sctp_chunk *retval;
__u16 outlen, inlen;
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;
}
/* 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(
const struct sctp_association *asoc)
{
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;
}
/* 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(
const struct sctp_association *asoc,
__u16 out, __u16 in)
{
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;
}
/* 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 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
__u32 result, __u32 sn)
{
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) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
__u32 result, __u32 sn,
__u32 sender_tsn,
__u32 receiver_tsn)
{
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;
}
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;
__be16 last = 0;
__u16 cnt = 0;
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;
}
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