2005-04-17 02:20:36 +04:00
/* SCTP kernel reference 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 .
* Copyright ( c ) 2002 Nokia Corp .
*
* This file is part of the SCTP kernel reference Implementation
*
* This is part of the SCTP Linux Kernel Reference Implementation .
*
* These are the state functions for the state machine .
*
* The SCTP reference implementation is free software ;
* you can redistribute it and / or modify it under the terms of
* the GNU General Public License as published by
* the Free Software Foundation ; either version 2 , or ( at your option )
* any later version .
*
* The SCTP reference implementation is distributed in the hope that it
* will be useful , but WITHOUT ANY WARRANTY ; without even the implied
* * * * * * * * * * * * * * * * * * * * * * * * *
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .
* See the GNU General Public License for more details .
*
* You should have received a copy of the GNU General Public License
* along with GNU CC ; see the file COPYING . If not , write to
* the Free Software Foundation , 59 Temple Place - Suite 330 ,
* Boston , MA 02111 - 1307 , USA .
*
* Please send any bug reports or fixes you make to the
* email address ( es ) :
* lksctp developers < lksctp - developers @ lists . sourceforge . net >
*
* Or submit a bug report through the following website :
* http : //www.sf.net/projects/lksctp
*
* Written or modified by :
* La Monte H . P . Yarroll < piggy @ acm . org >
* Karl Knutson < karl @ athena . chicago . il . us >
* Mathew Kotowsky < kotowsky @ sctp . org >
* Sridhar Samudrala < samudrala @ us . ibm . com >
* Jon Grimm < jgrimm @ us . ibm . com >
* Hui Huang < hui . huang @ nokia . com >
* Dajiang Zhang < dajiang . zhang @ nokia . com >
* Daisy Chang < daisyc @ us . ibm . com >
* Ardelle Fan < ardelle . fan @ intel . com >
* Ryan Layer < rmlayer @ us . ibm . com >
* Kevin Gao < kevin . gao @ intel . com >
*
* Any bugs reported given to us we will try to fix . . . any fixes shared will
* be incorporated into the next SCTP release .
*/
# include <linux/types.h>
# include <linux/kernel.h>
# include <linux/ip.h>
# include <linux/ipv6.h>
# include <linux/net.h>
# include <linux/inet.h>
# include <net/sock.h>
# include <net/inet_ecn.h>
# include <linux/skbuff.h>
# include <net/sctp/sctp.h>
# include <net/sctp/sm.h>
# include <net/sctp/structs.h>
static struct sctp_packet * sctp_abort_pkt_new ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
const void * payload ,
size_t paylen ) ;
static int sctp_eat_data ( const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands ) ;
static struct sctp_packet * sctp_ootb_pkt_new ( const struct sctp_association * asoc ,
const struct sctp_chunk * chunk ) ;
static void sctp_send_stale_cookie_err ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands ,
struct sctp_chunk * err_chunk ) ;
static sctp_disposition_t sctp_sf_do_5_2_6_stale ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands ) ;
static sctp_disposition_t sctp_sf_shut_8_4_5 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands ) ;
static struct sctp_sackhdr * sctp_sm_pull_sack ( struct sctp_chunk * chunk ) ;
2005-06-24 09:05:33 +04:00
static sctp_disposition_t sctp_stop_t1_and_abort ( sctp_cmd_seq_t * commands ,
__u16 error ,
const struct sctp_association * asoc ,
struct sctp_transport * transport ) ;
static sctp_disposition_t sctp_sf_violation_chunklen (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands ) ;
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/* Small helper function that checks if the chunk length
* is of the appropriate length . The ' required_length ' argument
* is set to be the size of a specific chunk we are testing .
* Return Values : 1 = Valid length
* 0 = Invalid length
*
*/
static inline int
sctp_chunk_length_valid ( struct sctp_chunk * chunk ,
__u16 required_length )
{
__u16 chunk_length = ntohs ( chunk - > chunk_hdr - > length ) ;
if ( unlikely ( chunk_length < required_length ) )
return 0 ;
return 1 ;
}
/**********************************************************
* These are the state functions for handling chunk events .
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* Process the final SHUTDOWN COMPLETE .
*
* Section : 4 ( C ) ( diagram ) , 9.2
* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
* that it is in SHUTDOWN - ACK - SENT state , if it is not the chunk should be
* discarded . If the endpoint is in the SHUTDOWN - ACK - SENT state the endpoint
* should stop the T2 - shutdown timer and remove all knowledge of the
* association ( and thus the association enters the CLOSED state ) .
*
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* Verification Tag : 8.5 .1 ( C ) , sctpimpguide 2.41 .
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* C ) Rules for packet carrying SHUTDOWN COMPLETE :
* . . .
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* - The receiver of a SHUTDOWN COMPLETE shall accept the packet
* if the Verification Tag field of the packet matches its own tag and
* the T bit is not set
* OR
* it is set to its peer ' s tag and the T bit is set in the Chunk
* Flags .
* Otherwise , the receiver MUST silently discard the packet
* and take no further action . An endpoint MUST ignore the
* SHUTDOWN COMPLETE if it is not in the SHUTDOWN - ACK - SENT state .
2005-04-17 02:20:36 +04:00
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_4_C ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_ulpevent * ev ;
/* RFC 2960 6.10 Bundling
*
* An endpoint MUST NOT bundle INIT , INIT ACK or
* SHUTDOWN COMPLETE with any other chunks .
*/
if ( ! chunk - > singleton )
return SCTP_DISPOSITION_VIOLATION ;
if ( ! sctp_vtag_verify_either ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* RFC 2960 10.2 SCTP-to-ULP
*
* H ) SHUTDOWN COMPLETE notification
*
* When SCTP completes the shutdown procedures ( section 9.2 ) this
* notification is passed to the upper layer .
*/
ev = sctp_ulpevent_make_assoc_change ( asoc , 0 , SCTP_SHUTDOWN_COMP ,
0 , 0 , 0 , GFP_ATOMIC ) ;
if ( ! ev )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP , SCTP_ULPEVENT ( ev ) ) ;
/* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
* will verify that it is in SHUTDOWN - ACK - SENT state , if it is
* not the chunk should be discarded . If the endpoint is in
* the SHUTDOWN - ACK - SENT state the endpoint should stop the
* T2 - shutdown timer and remove all knowledge of the
* association ( and thus the association enters the CLOSED
* state ) .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_SHUTDOWNS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB , SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Respond to a normal INIT chunk .
* We are the side that is being asked for an association .
*
* Section : 5.1 Normal Establishment of an Association , B
* B ) " Z " shall respond immediately with an INIT ACK chunk . The
* destination IP address of the INIT ACK MUST be set to the source
* IP address of the INIT to which this INIT ACK is responding . In
* the response , besides filling in other parameters , " Z " must set the
* Verification Tag field to Tag_A , and also provide its own
* Verification Tag ( Tag_Z ) in the Initiate Tag field .
*
* Verification Tag : Must be 0.
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_5_1B_init ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * repl ;
struct sctp_association * new_asoc ;
struct sctp_chunk * err_chunk ;
struct sctp_packet * packet ;
sctp_unrecognized_param_t * unk_param ;
struct sock * sk ;
int len ;
/* 6.10 Bundling
* An endpoint MUST NOT bundle INIT , INIT ACK or
* SHUTDOWN COMPLETE with any other chunks .
*
* IG Section 2.11 .2
* Furthermore , we require that the receiver of an INIT chunk MUST
* enforce these rules by silently discarding an arriving packet
* with an INIT chunk that is bundled with other chunks .
*/
if ( ! chunk - > singleton )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* If the packet is an OOTB packet which is temporarily on the
* control endpoint , respond with an ABORT .
*/
if ( ep = = sctp_sk ( ( sctp_get_ctl_sock ( ) ) ) - > ep )
return sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg , commands ) ;
sk = ep - > base . sk ;
/* If the endpoint is not listening or if the number of associations
* on the TCP - style socket exceed the max backlog , respond with an
* ABORT .
*/
if ( ! sctp_sstate ( sk , LISTENING ) | |
( sctp_style ( sk , TCP ) & &
sk_acceptq_is_full ( sk ) ) )
return sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg , commands ) ;
/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
* Tag .
*/
if ( chunk - > sctp_hdr - > vtag ! = 0 )
return sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg , commands ) ;
/* Make sure that the INIT chunk has a valid length.
* Normally , this would cause an ABORT with a Protocol Violation
* error , but since we don ' t have an association , we ' ll
* just discard the packet .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_init_chunk_t ) ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Verify the INIT chunk before processing it. */
err_chunk = NULL ;
if ( ! sctp_verify_init ( asoc , chunk - > chunk_hdr - > type ,
( sctp_init_chunk_t * ) chunk - > chunk_hdr , chunk ,
& err_chunk ) ) {
/* This chunk contains fatal error. It is to be discarded.
* Send an ABORT , with causes if there is any .
*/
if ( err_chunk ) {
packet = sctp_abort_pkt_new ( ep , asoc , arg ,
( __u8 * ) ( err_chunk - > chunk_hdr ) +
sizeof ( sctp_chunkhdr_t ) ,
ntohs ( err_chunk - > chunk_hdr - > length ) -
sizeof ( sctp_chunkhdr_t ) ) ;
sctp_chunk_free ( err_chunk ) ;
if ( packet ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_SEND_PKT ,
SCTP_PACKET ( packet ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
return SCTP_DISPOSITION_CONSUME ;
} else {
return SCTP_DISPOSITION_NOMEM ;
}
} else {
return sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg ,
commands ) ;
}
}
/* Grab the INIT header. */
chunk - > subh . init_hdr = ( sctp_inithdr_t * ) chunk - > skb - > data ;
/* Tag the variable length parameters. */
chunk - > param_hdr . v = skb_pull ( chunk - > skb , sizeof ( sctp_inithdr_t ) ) ;
new_asoc = sctp_make_temp_asoc ( ep , chunk , GFP_ATOMIC ) ;
if ( ! new_asoc )
goto nomem ;
/* The call, sctp_process_init(), can fail on memory allocation. */
if ( ! sctp_process_init ( new_asoc , chunk - > chunk_hdr - > type ,
sctp_source ( chunk ) ,
( sctp_init_chunk_t * ) chunk - > chunk_hdr ,
GFP_ATOMIC ) )
goto nomem_init ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_ASOC , SCTP_ASOC ( new_asoc ) ) ;
/* B) "Z" shall respond immediately with an INIT ACK chunk. */
/* If there are errors need to be reported for unknown parameters,
* make sure to reserve enough room in the INIT ACK for them .
*/
len = 0 ;
if ( err_chunk )
len = ntohs ( err_chunk - > chunk_hdr - > length ) -
sizeof ( sctp_chunkhdr_t ) ;
if ( sctp_assoc_set_bind_addr_from_ep ( new_asoc , GFP_ATOMIC ) < 0 )
goto nomem_ack ;
repl = sctp_make_init_ack ( new_asoc , chunk , GFP_ATOMIC , len ) ;
if ( ! repl )
goto nomem_ack ;
/* If there are errors need to be reported for unknown parameters,
* include them in the outgoing INIT ACK as " Unrecognized parameter "
* parameter .
*/
if ( err_chunk ) {
/* Get the "Unrecognized parameter" parameter(s) out of the
* ERROR chunk generated by sctp_verify_init ( ) . Since the
* error cause code for " unknown parameter " and the
* " Unrecognized parameter " type is the same , we can
* construct the parameters in INIT ACK by copying the
* ERROR causes over .
*/
unk_param = ( sctp_unrecognized_param_t * )
( ( __u8 * ) ( err_chunk - > chunk_hdr ) +
sizeof ( sctp_chunkhdr_t ) ) ;
/* Replace the cause code with the "Unrecognized parameter"
* parameter type .
*/
sctp_addto_chunk ( repl , len , unk_param ) ;
sctp_chunk_free ( err_chunk ) ;
}
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
/*
* Note : After sending out INIT ACK with the State Cookie parameter ,
* " Z " MUST NOT allocate any resources , nor keep any states for the
* new association . Otherwise , " Z " will be vulnerable to resource
* attacks .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB , SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
nomem_ack :
if ( err_chunk )
sctp_chunk_free ( err_chunk ) ;
nomem_init :
sctp_association_free ( new_asoc ) ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Respond to a normal INIT ACK chunk .
* We are the side that is initiating the association .
*
* Section : 5.1 Normal Establishment of an Association , C
* C ) Upon reception of the INIT ACK from " Z " , " A " shall stop the T1 - init
* timer and leave COOKIE - WAIT state . " A " shall then send the State
* Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk , start
* the T1 - cookie timer , and enter the COOKIE - ECHOED state .
*
* Note : The COOKIE ECHO chunk can be bundled with any pending outbound
* DATA chunks , but it MUST be the first chunk in the packet and
* until the COOKIE ACK is returned the sender MUST NOT send any
* other packets to the peer .
*
* Verification Tag : 3.3 .3
* If the value of the Initiate Tag in a received INIT ACK chunk is
* found to be 0 , the receiver MUST treat it as an error and close the
* association by transmitting an ABORT .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_5_1C_ack ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
sctp_init_chunk_t * initchunk ;
__u32 init_tag ;
struct sctp_chunk * err_chunk ;
struct sctp_packet * packet ;
sctp_disposition_t ret ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the INIT-ACK chunk has a valid length */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_initack_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* 6.10 Bundling
* An endpoint MUST NOT bundle INIT , INIT ACK or
* SHUTDOWN COMPLETE with any other chunks .
*/
if ( ! chunk - > singleton )
return SCTP_DISPOSITION_VIOLATION ;
/* Grab the INIT header. */
chunk - > subh . init_hdr = ( sctp_inithdr_t * ) chunk - > skb - > data ;
init_tag = ntohl ( chunk - > subh . init_hdr - > init_tag ) ;
/* Verification Tag: 3.3.3
* If the value of the Initiate Tag in a received INIT ACK
* chunk is found to be 0 , the receiver MUST treat it as an
* error and close the association by transmitting an ABORT .
*/
if ( ! init_tag ) {
struct sctp_chunk * reply = sctp_make_abort ( asoc , chunk , 0 ) ;
if ( ! reply )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB , SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
/* Verify the INIT chunk before processing it. */
err_chunk = NULL ;
if ( ! sctp_verify_init ( asoc , chunk - > chunk_hdr - > type ,
( sctp_init_chunk_t * ) chunk - > chunk_hdr , chunk ,
& err_chunk ) ) {
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
/* This chunk contains fatal error. It is to be discarded.
* Send an ABORT , with causes if there is any .
*/
if ( err_chunk ) {
packet = sctp_abort_pkt_new ( ep , asoc , arg ,
( __u8 * ) ( err_chunk - > chunk_hdr ) +
sizeof ( sctp_chunkhdr_t ) ,
ntohs ( err_chunk - > chunk_hdr - > length ) -
sizeof ( sctp_chunkhdr_t ) ) ;
sctp_chunk_free ( err_chunk ) ;
if ( packet ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_SEND_PKT ,
SCTP_PACKET ( packet ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB ,
SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_CONSUME ;
} else {
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB ,
SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_NOMEM ;
}
} else {
ret = sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg ,
commands ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB ,
SCTP_NULL ( ) ) ;
return ret ;
}
}
/* Tag the variable length parameters. Note that we never
* convert the parameters in an INIT chunk .
*/
chunk - > param_hdr . v = skb_pull ( chunk - > skb , sizeof ( sctp_inithdr_t ) ) ;
initchunk = ( sctp_init_chunk_t * ) chunk - > chunk_hdr ;
sctp_add_cmd_sf ( commands , SCTP_CMD_PEER_INIT ,
SCTP_PEER_INIT ( initchunk ) ) ;
2005-06-21 00:14:57 +04:00
/* Reset init error count upon receipt of INIT-ACK. */
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_COUNTER_RESET , SCTP_NULL ( ) ) ;
2005-04-17 02:20:36 +04:00
/* 5.1 C) "A" shall stop the T1-init timer and leave
* COOKIE - WAIT state . " A " shall then . . . start the T1 - cookie
* timer , and enter the COOKIE - ECHOED state .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_COOKIE ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_COOKIE_ECHOED ) ) ;
/* 5.1 C) "A" shall then send the State Cookie received in the
* INIT ACK chunk in a COOKIE ECHO chunk , . . .
*/
/* If there is any errors to report, send the ERROR chunk generated
* for unknown parameters as well .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_COOKIE_ECHO ,
SCTP_CHUNK ( err_chunk ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Respond to a normal COOKIE ECHO chunk .
* We are the side that is being asked for an association .
*
* Section : 5.1 Normal Establishment of an Association , D
* D ) Upon reception of the COOKIE ECHO chunk , Endpoint " Z " will reply
* with a COOKIE ACK chunk after building a TCB and moving to
* the ESTABLISHED state . A COOKIE ACK chunk may be bundled with
* any pending DATA chunks ( and / or SACK chunks ) , but the COOKIE ACK
* chunk MUST be the first chunk in the packet .
*
* IMPLEMENTATION NOTE : An implementation may choose to send the
* Communication Up notification to the SCTP user upon reception
* of a valid COOKIE ECHO chunk .
*
* Verification Tag : 8.5 .1 Exceptions in Verification Tag Rules
* D ) Rules for packet carrying a COOKIE ECHO
*
* - When sending a COOKIE ECHO , the endpoint MUST use the value of the
* Initial Tag received in the INIT ACK .
*
* - The receiver of a COOKIE ECHO follows the procedures in Section 5.
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_5_1D_ce ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type , void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_association * new_asoc ;
sctp_init_chunk_t * peer_init ;
struct sctp_chunk * repl ;
struct sctp_ulpevent * ev ;
int error = 0 ;
struct sctp_chunk * err_chk_p ;
/* If the packet is an OOTB packet which is temporarily on the
* control endpoint , respond with an ABORT .
*/
if ( ep = = sctp_sk ( ( sctp_get_ctl_sock ( ) ) ) - > ep )
return sctp_sf_ootb ( ep , asoc , type , arg , commands ) ;
/* Make sure that the COOKIE_ECHO chunk has a valid length.
* In this case , we check that we have enough for at least a
* chunk header . More detailed verification is done
* in sctp_unpack_cookie ( ) .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_chunkhdr_t ) ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* "Decode" the chunk. We have no optional parameters so we
* are in good shape .
*/
chunk - > subh . cookie_hdr =
( struct sctp_signed_cookie * ) chunk - > skb - > data ;
skb_pull ( chunk - > skb ,
ntohs ( chunk - > chunk_hdr - > length ) - sizeof ( sctp_chunkhdr_t ) ) ;
/* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
* " Z " will reply with a COOKIE ACK chunk after building a TCB
* and moving to the ESTABLISHED state .
*/
new_asoc = sctp_unpack_cookie ( ep , asoc , chunk , GFP_ATOMIC , & error ,
& err_chk_p ) ;
/* FIXME:
* If the re - build failed , what is the proper error path
* from here ?
*
* [ We should abort the association . - - piggy ]
*/
if ( ! new_asoc ) {
/* FIXME: Several errors are possible. A bad cookie should
* be silently discarded , but think about logging it too .
*/
switch ( error ) {
case - SCTP_IERROR_NOMEM :
goto nomem ;
case - SCTP_IERROR_STALE_COOKIE :
sctp_send_stale_cookie_err ( ep , asoc , chunk , commands ,
err_chk_p ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
case - SCTP_IERROR_BAD_SIG :
default :
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
} ;
}
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_ASOC , SCTP_ASOC ( new_asoc ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_ESTABLISHED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_CURRESTAB ) ;
SCTP_INC_STATS ( SCTP_MIB_PASSIVEESTABS ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMERS_START , SCTP_NULL ( ) ) ;
if ( new_asoc - > autoclose )
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_AUTOCLOSE ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TRANSMIT , SCTP_NULL ( ) ) ;
/* Re-build the bind address for the association is done in
* the sctp_unpack_cookie ( ) already .
*/
/* This is a brand-new association, so these are not yet side
* effects - - it is safe to run them here .
*/
peer_init = & chunk - > subh . cookie_hdr - > c . peer_init [ 0 ] ;
if ( ! sctp_process_init ( new_asoc , chunk - > chunk_hdr - > type ,
& chunk - > subh . cookie_hdr - > c . peer_addr ,
peer_init , GFP_ATOMIC ) )
goto nomem_init ;
repl = sctp_make_cookie_ack ( new_asoc , chunk ) ;
if ( ! repl )
goto nomem_repl ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
/* RFC 2960 5.1 Normal Establishment of an Association
*
* D ) IMPLEMENTATION NOTE : An implementation may choose to
* send the Communication Up notification to the SCTP user
* upon reception of a valid COOKIE ECHO chunk .
*/
ev = sctp_ulpevent_make_assoc_change ( new_asoc , 0 , SCTP_COMM_UP , 0 ,
new_asoc - > c . sinit_num_ostreams ,
new_asoc - > c . sinit_max_instreams ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem_ev ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP , SCTP_ULPEVENT ( ev ) ) ;
/* Sockets API Draft Section 5.3.1.6
* When a peer sends a Adaption Layer Indication parameter , SCTP
* delivers this notification to inform the application that of the
* peers requested adaption layer .
*/
if ( new_asoc - > peer . adaption_ind ) {
ev = sctp_ulpevent_make_adaption_indication ( new_asoc ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem_ev ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP ,
SCTP_ULPEVENT ( ev ) ) ;
}
return SCTP_DISPOSITION_CONSUME ;
nomem_ev :
sctp_chunk_free ( repl ) ;
nomem_repl :
nomem_init :
sctp_association_free ( new_asoc ) ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Respond to a normal COOKIE ACK chunk .
* We are the side that is being asked for an association .
*
* RFC 2960 5.1 Normal Establishment of an Association
*
* E ) Upon reception of the COOKIE ACK , endpoint " A " will move from the
* COOKIE - ECHOED state to the ESTABLISHED state , stopping the T1 - cookie
* timer . It may also notify its ULP about the successful
* establishment of the association with a Communication Up
* notification ( see Section 10 ) .
*
* Verification Tag :
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_5_1E_ca ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type , void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_ulpevent * ev ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Verify that the chunk length for the COOKIE-ACK is OK.
* If we don ' t do this , any bundled chunks may be junked .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_chunkhdr_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* Reset init error count upon receipt of COOKIE-ACK,
* to avoid problems with the managemement of this
* counter in stale cookie situations when a transition back
* from the COOKIE - ECHOED state to the COOKIE - WAIT
* state is performed .
*/
2005-06-21 00:14:57 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_COUNTER_RESET , SCTP_NULL ( ) ) ;
2005-04-17 02:20:36 +04:00
/* RFC 2960 5.1 Normal Establishment of an Association
*
* E ) Upon reception of the COOKIE ACK , endpoint " A " will move
* from the COOKIE - ECHOED state to the ESTABLISHED state ,
* stopping the T1 - cookie timer .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_COOKIE ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_ESTABLISHED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_CURRESTAB ) ;
SCTP_INC_STATS ( SCTP_MIB_ACTIVEESTABS ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMERS_START , SCTP_NULL ( ) ) ;
if ( asoc - > autoclose )
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_AUTOCLOSE ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TRANSMIT , SCTP_NULL ( ) ) ;
/* It may also notify its ULP about the successful
* establishment of the association with a Communication Up
* notification ( see Section 10 ) .
*/
ev = sctp_ulpevent_make_assoc_change ( asoc , 0 , SCTP_COMM_UP ,
0 , asoc - > c . sinit_num_ostreams ,
asoc - > c . sinit_max_instreams ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP , SCTP_ULPEVENT ( ev ) ) ;
/* Sockets API Draft Section 5.3.1.6
* When a peer sends a Adaption Layer Indication parameter , SCTP
* delivers this notification to inform the application that of the
* peers requested adaption layer .
*/
if ( asoc - > peer . adaption_ind ) {
ev = sctp_ulpevent_make_adaption_indication ( asoc , GFP_ATOMIC ) ;
if ( ! ev )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP ,
SCTP_ULPEVENT ( ev ) ) ;
}
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/* Generate and sendout a heartbeat packet. */
static sctp_disposition_t sctp_sf_heartbeat ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_transport * transport = ( struct sctp_transport * ) arg ;
struct sctp_chunk * reply ;
sctp_sender_hb_info_t hbinfo ;
size_t paylen = 0 ;
hbinfo . param_hdr . type = SCTP_PARAM_HEARTBEAT_INFO ;
hbinfo . param_hdr . length = htons ( sizeof ( sctp_sender_hb_info_t ) ) ;
hbinfo . daddr = transport - > ipaddr ;
hbinfo . sent_at = jiffies ;
/* Send a heartbeat to our peer. */
paylen = sizeof ( sctp_sender_hb_info_t ) ;
reply = sctp_make_heartbeat ( asoc , transport , & hbinfo , paylen ) ;
if ( ! reply )
return SCTP_DISPOSITION_NOMEM ;
/* Set rto_pending indicating that an RTT measurement
* is started with this heartbeat chunk .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_RTO_PENDING ,
SCTP_TRANSPORT ( transport ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/* Generate a HEARTBEAT packet on the given transport. */
sctp_disposition_t sctp_sf_sendbeat_8_3 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_transport * transport = ( struct sctp_transport * ) arg ;
if ( asoc - > overall_error_count > asoc - > max_retrans ) {
/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_ERROR ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
/* Section 3.3.5.
* The Sender - specific Heartbeat Info field should normally include
* information about the sender ' s current time when this HEARTBEAT
* chunk is sent and the destination transport address to which this
* HEARTBEAT is sent ( see Section 8.3 ) .
*/
2005-12-22 22:36:46 +03:00
if ( transport - > param_flags & SPP_HB_ENABLE ) {
2005-04-17 02:20:36 +04:00
if ( SCTP_DISPOSITION_NOMEM = =
sctp_sf_heartbeat ( ep , asoc , type , arg ,
commands ) )
return SCTP_DISPOSITION_NOMEM ;
/* Set transport error counter and association error counter
* when sending heartbeat .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TRANSPORT_RESET ,
SCTP_TRANSPORT ( transport ) ) ;
}
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMER_UPDATE ,
SCTP_TRANSPORT ( transport ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Process an heartbeat request .
*
* Section : 8.3 Path Heartbeat
* The receiver of the HEARTBEAT should immediately respond with a
* HEARTBEAT ACK that contains the Heartbeat Information field copied
* from the received HEARTBEAT chunk .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
* When receiving an SCTP packet , the endpoint MUST ensure that the
* value in the Verification Tag field of the received SCTP packet
* matches its own Tag . If the received Verification Tag value does not
* match the receiver ' s own tag value , the receiver shall silently
* discard the packet and shall not process it any further except for
* those cases listed in Section 8.5 .1 below .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_beat_8_3 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * reply ;
size_t paylen = 0 ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the HEARTBEAT chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_heartbeat_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* 8.3 The receiver of the HEARTBEAT should immediately
* respond with a HEARTBEAT ACK that contains the Heartbeat
* Information field copied from the received HEARTBEAT chunk .
*/
chunk - > subh . hb_hdr = ( sctp_heartbeathdr_t * ) chunk - > skb - > data ;
paylen = ntohs ( chunk - > chunk_hdr - > length ) - sizeof ( sctp_chunkhdr_t ) ;
skb_pull ( chunk - > skb , paylen ) ;
reply = sctp_make_heartbeat_ack ( asoc , chunk ,
chunk - > subh . hb_hdr , paylen ) ;
if ( ! reply )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Process the returning HEARTBEAT ACK .
*
* Section : 8.3 Path Heartbeat
* Upon the receipt of the HEARTBEAT ACK , the sender of the HEARTBEAT
* should clear the error counter of the destination transport
* address to which the HEARTBEAT was sent , and mark the destination
* transport address as active if it is not so marked . The endpoint may
* optionally report to the upper layer when an inactive destination
* address is marked as active due to the reception of the latest
* HEARTBEAT ACK . The receiver of the HEARTBEAT ACK must also
* clear the association overall error count as well ( as defined
* in section 8.1 ) .
*
* The receiver of the HEARTBEAT ACK should also perform an RTT
* measurement for that destination transport address using the time
* value carried in the HEARTBEAT ACK chunk .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_backbeat_8_3 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
union sctp_addr from_addr ;
struct sctp_transport * link ;
sctp_sender_hb_info_t * hbinfo ;
unsigned long max_interval ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_heartbeat_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
hbinfo = ( sctp_sender_hb_info_t * ) chunk - > skb - > data ;
from_addr = hbinfo - > daddr ;
link = sctp_assoc_lookup_paddr ( asoc , & from_addr ) ;
/* This should never happen, but lets log it if so. */
2005-06-21 00:14:57 +04:00
if ( unlikely ( ! link ) ) {
if ( from_addr . sa . sa_family = = AF_INET6 ) {
printk ( KERN_WARNING
" %s association %p could not find address "
" %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x \n " ,
__FUNCTION__ ,
asoc ,
NIP6 ( from_addr . v6 . sin6_addr ) ) ;
} else {
printk ( KERN_WARNING
" %s association %p could not find address "
" %u.%u.%u.%u \n " ,
__FUNCTION__ ,
asoc ,
NIPQUAD ( from_addr . v4 . sin_addr . s_addr ) ) ;
}
2005-04-17 02:20:36 +04:00
return SCTP_DISPOSITION_DISCARD ;
}
2005-12-22 22:36:46 +03:00
max_interval = link - > hbinterval + link - > rto ;
2005-04-17 02:20:36 +04:00
/* Check if the timestamp looks valid. */
if ( time_after ( hbinfo - > sent_at , jiffies ) | |
time_after ( jiffies , hbinfo - > sent_at + max_interval ) ) {
SCTP_DEBUG_PRINTK ( " %s: HEARTBEAT ACK with invalid timestamp "
" received for transport: %p \n " ,
__FUNCTION__ , link ) ;
return SCTP_DISPOSITION_DISCARD ;
}
/* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
* the HEARTBEAT should clear the error counter of the
* destination transport address to which the HEARTBEAT was
* sent and mark the destination transport address as active if
* it is not so marked .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TRANSPORT_ON , SCTP_TRANSPORT ( link ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/* Helper function to send out an abort for the restart
* condition .
*/
static int sctp_sf_send_restart_abort ( union sctp_addr * ssa ,
struct sctp_chunk * init ,
sctp_cmd_seq_t * commands )
{
int len ;
struct sctp_packet * pkt ;
union sctp_addr_param * addrparm ;
struct sctp_errhdr * errhdr ;
struct sctp_endpoint * ep ;
char buffer [ sizeof ( struct sctp_errhdr ) + sizeof ( union sctp_addr_param ) ] ;
struct sctp_af * af = sctp_get_af_specific ( ssa - > v4 . sin_family ) ;
/* Build the error on the stack. We are way to malloc crazy
* throughout the code today .
*/
errhdr = ( struct sctp_errhdr * ) buffer ;
addrparm = ( union sctp_addr_param * ) errhdr - > variable ;
/* Copy into a parm format. */
len = af - > to_addr_param ( ssa , addrparm ) ;
len + = sizeof ( sctp_errhdr_t ) ;
errhdr - > cause = SCTP_ERROR_RESTART ;
errhdr - > length = htons ( len ) ;
/* Assign to the control socket. */
ep = sctp_sk ( ( sctp_get_ctl_sock ( ) ) ) - > ep ;
/* Association is NULL since this may be a restart attack and we
* want to send back the attacker ' s vtag .
*/
pkt = sctp_abort_pkt_new ( ep , NULL , init , errhdr , len ) ;
if ( ! pkt )
goto out ;
sctp_add_cmd_sf ( commands , SCTP_CMD_SEND_PKT , SCTP_PACKET ( pkt ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
/* Discard the rest of the inbound packet. */
sctp_add_cmd_sf ( commands , SCTP_CMD_DISCARD_PACKET , SCTP_NULL ( ) ) ;
out :
/* Even if there is no memory, treat as a failure so
* the packet will get dropped .
*/
return 0 ;
}
/* A restart is occurring, check to make sure no new addresses
* are being added as we may be under a takeover attack .
*/
static int sctp_sf_check_restart_addrs ( const struct sctp_association * new_asoc ,
const struct sctp_association * asoc ,
struct sctp_chunk * init ,
sctp_cmd_seq_t * commands )
{
struct sctp_transport * new_addr , * addr ;
struct list_head * pos , * pos2 ;
int found ;
/* Implementor's Guide - Sectin 5.2.2
* . . .
* Before responding the endpoint MUST check to see if the
* unexpected INIT adds new addresses to the association . If new
* addresses are added to the association , the endpoint MUST respond
* with an ABORT . .
*/
/* Search through all current addresses and make sure
* we aren ' t adding any new ones .
*/
new_addr = NULL ;
found = 0 ;
list_for_each ( pos , & new_asoc - > peer . transport_addr_list ) {
new_addr = list_entry ( pos , struct sctp_transport , transports ) ;
found = 0 ;
list_for_each ( pos2 , & asoc - > peer . transport_addr_list ) {
addr = list_entry ( pos2 , struct sctp_transport ,
transports ) ;
if ( sctp_cmp_addr_exact ( & new_addr - > ipaddr ,
& addr - > ipaddr ) ) {
found = 1 ;
break ;
}
}
if ( ! found )
break ;
}
/* If a new address was added, ABORT the sender. */
if ( ! found & & new_addr ) {
sctp_sf_send_restart_abort ( & new_addr - > ipaddr , init , commands ) ;
}
/* Return success if all addresses were found. */
return found ;
}
/* Populate the verification/tie tags based on overlapping INIT
* scenario .
*
* Note : Do not use in CLOSED or SHUTDOWN - ACK - SENT state .
*/
static void sctp_tietags_populate ( struct sctp_association * new_asoc ,
const struct sctp_association * asoc )
{
switch ( asoc - > state ) {
/* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
case SCTP_STATE_COOKIE_WAIT :
new_asoc - > c . my_vtag = asoc - > c . my_vtag ;
new_asoc - > c . my_ttag = asoc - > c . my_vtag ;
new_asoc - > c . peer_ttag = 0 ;
break ;
case SCTP_STATE_COOKIE_ECHOED :
new_asoc - > c . my_vtag = asoc - > c . my_vtag ;
new_asoc - > c . my_ttag = asoc - > c . my_vtag ;
new_asoc - > c . peer_ttag = asoc - > c . peer_vtag ;
break ;
/* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
* COOKIE - WAIT and SHUTDOWN - ACK - SENT
*/
default :
new_asoc - > c . my_ttag = asoc - > c . my_vtag ;
new_asoc - > c . peer_ttag = asoc - > c . peer_vtag ;
break ;
} ;
/* Other parameters for the endpoint SHOULD be copied from the
* existing parameters of the association ( e . g . number of
* outbound streams ) into the INIT ACK and cookie .
*/
new_asoc - > rwnd = asoc - > rwnd ;
new_asoc - > c . sinit_num_ostreams = asoc - > c . sinit_num_ostreams ;
new_asoc - > c . sinit_max_instreams = asoc - > c . sinit_max_instreams ;
new_asoc - > c . initial_tsn = asoc - > c . initial_tsn ;
}
/*
* Compare vtag / tietag values to determine unexpected COOKIE - ECHO
* handling action .
*
* RFC 2960 5.2 .4 Handle a COOKIE ECHO when a TCB exists .
*
* Returns value representing action to be taken . These action values
* correspond to Action / Description values in RFC 2960 , Table 2.
*/
static char sctp_tietags_compare ( struct sctp_association * new_asoc ,
const struct sctp_association * asoc )
{
/* In this case, the peer may have restarted. */
if ( ( asoc - > c . my_vtag ! = new_asoc - > c . my_vtag ) & &
( asoc - > c . peer_vtag ! = new_asoc - > c . peer_vtag ) & &
( asoc - > c . my_vtag = = new_asoc - > c . my_ttag ) & &
( asoc - > c . peer_vtag = = new_asoc - > c . peer_ttag ) )
return ' A ' ;
/* Collision case B. */
if ( ( asoc - > c . my_vtag = = new_asoc - > c . my_vtag ) & &
( ( asoc - > c . peer_vtag ! = new_asoc - > c . peer_vtag ) | |
( 0 = = asoc - > c . peer_vtag ) ) ) {
return ' B ' ;
}
/* Collision case D. */
if ( ( asoc - > c . my_vtag = = new_asoc - > c . my_vtag ) & &
( asoc - > c . peer_vtag = = new_asoc - > c . peer_vtag ) )
return ' D ' ;
/* Collision case C. */
if ( ( asoc - > c . my_vtag ! = new_asoc - > c . my_vtag ) & &
( asoc - > c . peer_vtag = = new_asoc - > c . peer_vtag ) & &
( 0 = = new_asoc - > c . my_ttag ) & &
( 0 = = new_asoc - > c . peer_ttag ) )
return ' C ' ;
/* No match to any of the special cases; discard this packet. */
return ' E ' ;
}
/* Common helper routine for both duplicate and simulataneous INIT
* chunk handling .
*/
static sctp_disposition_t sctp_sf_do_unexpected_init (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg , sctp_cmd_seq_t * commands )
{
sctp_disposition_t retval ;
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * repl ;
struct sctp_association * new_asoc ;
struct sctp_chunk * err_chunk ;
struct sctp_packet * packet ;
sctp_unrecognized_param_t * unk_param ;
int len ;
/* 6.10 Bundling
* An endpoint MUST NOT bundle INIT , INIT ACK or
* SHUTDOWN COMPLETE with any other chunks .
*
* IG Section 2.11 .2
* Furthermore , we require that the receiver of an INIT chunk MUST
* enforce these rules by silently discarding an arriving packet
* with an INIT chunk that is bundled with other chunks .
*/
if ( ! chunk - > singleton )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* 3.1 A packet containing an INIT chunk MUST have a zero Verification
* Tag .
*/
if ( chunk - > sctp_hdr - > vtag ! = 0 )
return sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg , commands ) ;
/* Make sure that the INIT chunk has a valid length.
* In this case , we generate a protocol violation since we have
* an association established .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_init_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* Grab the INIT header. */
chunk - > subh . init_hdr = ( sctp_inithdr_t * ) chunk - > skb - > data ;
/* Tag the variable length parameters. */
chunk - > param_hdr . v = skb_pull ( chunk - > skb , sizeof ( sctp_inithdr_t ) ) ;
/* Verify the INIT chunk before processing it. */
err_chunk = NULL ;
if ( ! sctp_verify_init ( asoc , chunk - > chunk_hdr - > type ,
( sctp_init_chunk_t * ) chunk - > chunk_hdr , chunk ,
& err_chunk ) ) {
/* This chunk contains fatal error. It is to be discarded.
* Send an ABORT , with causes if there is any .
*/
if ( err_chunk ) {
packet = sctp_abort_pkt_new ( ep , asoc , arg ,
( __u8 * ) ( err_chunk - > chunk_hdr ) +
sizeof ( sctp_chunkhdr_t ) ,
ntohs ( err_chunk - > chunk_hdr - > length ) -
sizeof ( sctp_chunkhdr_t ) ) ;
if ( packet ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_SEND_PKT ,
SCTP_PACKET ( packet ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
retval = SCTP_DISPOSITION_CONSUME ;
} else {
retval = SCTP_DISPOSITION_NOMEM ;
}
goto cleanup ;
} else {
return sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg ,
commands ) ;
}
}
/*
* Other parameters for the endpoint SHOULD be copied from the
* existing parameters of the association ( e . g . number of
* outbound streams ) into the INIT ACK and cookie .
* FIXME : We are copying parameters from the endpoint not the
* association .
*/
new_asoc = sctp_make_temp_asoc ( ep , chunk , GFP_ATOMIC ) ;
if ( ! new_asoc )
goto nomem ;
/* In the outbound INIT ACK the endpoint MUST copy its current
* Verification Tag and Peers Verification tag into a reserved
* place ( local tie - tag and per tie - tag ) within the state cookie .
*/
if ( ! sctp_process_init ( new_asoc , chunk - > chunk_hdr - > type ,
sctp_source ( chunk ) ,
( sctp_init_chunk_t * ) chunk - > chunk_hdr ,
GFP_ATOMIC ) ) {
retval = SCTP_DISPOSITION_NOMEM ;
goto nomem_init ;
}
/* Make sure no new addresses are being added during the
* restart . Do not do this check for COOKIE - WAIT state ,
* since there are no peer addresses to check against .
* Upon return an ABORT will have been sent if needed .
*/
if ( ! sctp_state ( asoc , COOKIE_WAIT ) ) {
if ( ! sctp_sf_check_restart_addrs ( new_asoc , asoc , chunk ,
commands ) ) {
retval = SCTP_DISPOSITION_CONSUME ;
goto cleanup_asoc ;
}
}
sctp_tietags_populate ( new_asoc , asoc ) ;
/* B) "Z" shall respond immediately with an INIT ACK chunk. */
/* If there are errors need to be reported for unknown parameters,
* make sure to reserve enough room in the INIT ACK for them .
*/
len = 0 ;
if ( err_chunk ) {
len = ntohs ( err_chunk - > chunk_hdr - > length ) -
sizeof ( sctp_chunkhdr_t ) ;
}
if ( sctp_assoc_set_bind_addr_from_ep ( new_asoc , GFP_ATOMIC ) < 0 )
goto nomem ;
repl = sctp_make_init_ack ( new_asoc , chunk , GFP_ATOMIC , len ) ;
if ( ! repl )
goto nomem ;
/* If there are errors need to be reported for unknown parameters,
* include them in the outgoing INIT ACK as " Unrecognized parameter "
* parameter .
*/
if ( err_chunk ) {
/* Get the "Unrecognized parameter" parameter(s) out of the
* ERROR chunk generated by sctp_verify_init ( ) . Since the
* error cause code for " unknown parameter " and the
* " Unrecognized parameter " type is the same , we can
* construct the parameters in INIT ACK by copying the
* ERROR causes over .
*/
unk_param = ( sctp_unrecognized_param_t * )
( ( __u8 * ) ( err_chunk - > chunk_hdr ) +
sizeof ( sctp_chunkhdr_t ) ) ;
/* Replace the cause code with the "Unrecognized parameter"
* parameter type .
*/
sctp_addto_chunk ( repl , len , unk_param ) ;
}
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_ASOC , SCTP_ASOC ( new_asoc ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
/*
* Note : After sending out INIT ACK with the State Cookie parameter ,
* " Z " MUST NOT allocate any resources for this new association .
* Otherwise , " Z " will be vulnerable to resource attacks .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB , SCTP_NULL ( ) ) ;
retval = SCTP_DISPOSITION_CONSUME ;
cleanup :
if ( err_chunk )
sctp_chunk_free ( err_chunk ) ;
return retval ;
nomem :
retval = SCTP_DISPOSITION_NOMEM ;
goto cleanup ;
nomem_init :
cleanup_asoc :
sctp_association_free ( new_asoc ) ;
goto cleanup ;
}
/*
* Handle simultanous INIT .
* This means we started an INIT and then we got an INIT request from
* our peer .
*
* Section : 5.2 .1 INIT received in COOKIE - WAIT or COOKIE - ECHOED State ( Item B )
* This usually indicates an initialization collision , i . e . , each
* endpoint is attempting , at about the same time , to establish an
* association with the other endpoint .
*
* Upon receipt of an INIT in the COOKIE - WAIT or COOKIE - ECHOED state , an
* endpoint MUST respond with an INIT ACK using the same parameters it
* sent in its original INIT chunk ( including its Verification Tag ,
* unchanged ) . These original parameters are combined with those from the
* newly received INIT chunk . The endpoint shall also generate a State
* Cookie with the INIT ACK . The endpoint uses the parameters sent in its
* INIT to calculate the State Cookie .
*
* After that , the endpoint MUST NOT change its state , the T1 - init
* timer shall be left running and the corresponding TCB MUST NOT be
* destroyed . The normal procedures for handling State Cookies when
* a TCB exists will resolve the duplicate INITs to a single association .
*
* For an endpoint that is in the COOKIE - ECHOED state it MUST populate
* its Tie - Tags with the Tag information of itself and its peer ( see
* section 5.2 .2 for a description of the Tie - Tags ) .
*
* Verification Tag : Not explicit , but an INIT can not have a valid
* verification tag , so we skip the check .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_5_2_1_siminit ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* Call helper to do the real work for both simulataneous and
* duplicate INIT chunk handling .
*/
return sctp_sf_do_unexpected_init ( ep , asoc , type , arg , commands ) ;
}
/*
* Handle duplicated INIT messages . These are usually delayed
* restransmissions .
*
* Section : 5.2 .2 Unexpected INIT in States Other than CLOSED ,
* COOKIE - ECHOED and COOKIE - WAIT
*
* Unless otherwise stated , upon reception of an unexpected INIT for
* this association , the endpoint shall generate an INIT ACK with a
* State Cookie . In the outbound INIT ACK the endpoint MUST copy its
* current Verification Tag and peer ' s Verification Tag into a reserved
* place within the state cookie . We shall refer to these locations as
* the Peer ' s - Tie - Tag and the Local - Tie - Tag . The outbound SCTP packet
* containing this INIT ACK MUST carry a Verification Tag value equal to
* the Initiation Tag found in the unexpected INIT . And the INIT ACK
* MUST contain a new Initiation Tag ( randomly generated see Section
* 5.3 .1 ) . Other parameters for the endpoint SHOULD be copied from the
* existing parameters of the association ( e . g . number of outbound
* streams ) into the INIT ACK and cookie .
*
* After sending out the INIT ACK , the endpoint shall take no further
* actions , i . e . , the existing association , including its current state ,
* and the corresponding TCB MUST NOT be changed .
*
* Note : Only when a TCB exists and the association is not in a COOKIE -
* WAIT state are the Tie - Tags populated . For a normal association INIT
* ( i . e . the endpoint is in a COOKIE - WAIT state ) , the Tie - Tags MUST be
* set to 0 ( indicating that no previous TCB existed ) . The INIT ACK and
* State Cookie are populated as specified in section 5.2 .1 .
*
* Verification Tag : Not specified , but an INIT has no way of knowing
* what the verification tag could be , so we ignore it .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_5_2_2_dupinit ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* Call helper to do the real work for both simulataneous and
* duplicate INIT chunk handling .
*/
return sctp_sf_do_unexpected_init ( ep , asoc , type , arg , commands ) ;
}
/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
*
* Section 5.2 .4
* A ) In this case , the peer may have restarted .
*/
static sctp_disposition_t sctp_sf_do_dupcook_a ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands ,
struct sctp_association * new_asoc )
{
sctp_init_chunk_t * peer_init ;
struct sctp_ulpevent * ev ;
struct sctp_chunk * repl ;
struct sctp_chunk * err ;
sctp_disposition_t disposition ;
/* new_asoc is a brand-new association, so these are not yet
* side effects - - it is safe to run them here .
*/
peer_init = & chunk - > subh . cookie_hdr - > c . peer_init [ 0 ] ;
if ( ! sctp_process_init ( new_asoc , chunk - > chunk_hdr - > type ,
sctp_source ( chunk ) , peer_init ,
GFP_ATOMIC ) )
goto nomem ;
/* Make sure no new addresses are being added during the
* restart . Though this is a pretty complicated attack
* since you ' d have to get inside the cookie .
*/
if ( ! sctp_sf_check_restart_addrs ( new_asoc , asoc , chunk , commands ) ) {
return SCTP_DISPOSITION_CONSUME ;
}
/* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
* the peer has restarted ( Action A ) , it MUST NOT setup a new
* association but instead resend the SHUTDOWN ACK and send an ERROR
* chunk with a " Cookie Received while Shutting Down " error cause to
* its peer .
*/
if ( sctp_state ( asoc , SHUTDOWN_ACK_SENT ) ) {
disposition = sctp_sf_do_9_2_reshutack ( ep , asoc ,
SCTP_ST_CHUNK ( chunk - > chunk_hdr - > type ) ,
chunk , commands ) ;
if ( SCTP_DISPOSITION_NOMEM = = disposition )
goto nomem ;
err = sctp_make_op_error ( asoc , chunk ,
SCTP_ERROR_COOKIE_IN_SHUTDOWN ,
NULL , 0 ) ;
if ( err )
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( err ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/* For now, fail any unsent/unacked data. Consider the optional
* choice of resending of this data .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_PURGE_OUTQUEUE , SCTP_NULL ( ) ) ;
/* Update the content of current association. */
sctp_add_cmd_sf ( commands , SCTP_CMD_UPDATE_ASSOC , SCTP_ASOC ( new_asoc ) ) ;
repl = sctp_make_cookie_ack ( new_asoc , chunk ) ;
if ( ! repl )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
/* Report association restart to upper layer. */
ev = sctp_ulpevent_make_assoc_change ( asoc , 0 , SCTP_RESTART , 0 ,
new_asoc - > c . sinit_num_ostreams ,
new_asoc - > c . sinit_max_instreams ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem_ev ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP , SCTP_ULPEVENT ( ev ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem_ev :
sctp_chunk_free ( repl ) ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
*
* Section 5.2 .4
* B ) In this case , both sides may be attempting to start an association
* at about the same time but the peer endpoint started its INIT
* after responding to the local endpoint ' s INIT
*/
/* This case represents an initialization collision. */
static sctp_disposition_t sctp_sf_do_dupcook_b ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands ,
struct sctp_association * new_asoc )
{
sctp_init_chunk_t * peer_init ;
struct sctp_ulpevent * ev ;
struct sctp_chunk * repl ;
/* new_asoc is a brand-new association, so these are not yet
* side effects - - it is safe to run them here .
*/
peer_init = & chunk - > subh . cookie_hdr - > c . peer_init [ 0 ] ;
if ( ! sctp_process_init ( new_asoc , chunk - > chunk_hdr - > type ,
sctp_source ( chunk ) , peer_init ,
GFP_ATOMIC ) )
goto nomem ;
/* Update the content of current association. */
sctp_add_cmd_sf ( commands , SCTP_CMD_UPDATE_ASSOC , SCTP_ASOC ( new_asoc ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_ESTABLISHED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_CURRESTAB ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMERS_START , SCTP_NULL ( ) ) ;
repl = sctp_make_cookie_ack ( new_asoc , chunk ) ;
if ( ! repl )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TRANSMIT , SCTP_NULL ( ) ) ;
/* RFC 2960 5.1 Normal Establishment of an Association
*
* D ) IMPLEMENTATION NOTE : An implementation may choose to
* send the Communication Up notification to the SCTP user
* upon reception of a valid COOKIE ECHO chunk .
*/
ev = sctp_ulpevent_make_assoc_change ( asoc , 0 , SCTP_COMM_UP , 0 ,
new_asoc - > c . sinit_num_ostreams ,
new_asoc - > c . sinit_max_instreams ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem_ev ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP , SCTP_ULPEVENT ( ev ) ) ;
/* Sockets API Draft Section 5.3.1.6
* When a peer sends a Adaption Layer Indication parameter , SCTP
* delivers this notification to inform the application that of the
* peers requested adaption layer .
*/
if ( asoc - > peer . adaption_ind ) {
ev = sctp_ulpevent_make_adaption_indication ( asoc , GFP_ATOMIC ) ;
if ( ! ev )
goto nomem_ev ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP ,
SCTP_ULPEVENT ( ev ) ) ;
}
return SCTP_DISPOSITION_CONSUME ;
nomem_ev :
sctp_chunk_free ( repl ) ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
*
* Section 5.2 .4
* C ) In this case , the local endpoint ' s cookie has arrived late .
* Before it arrived , the local endpoint sent an INIT and received an
* INIT - ACK and finally sent a COOKIE ECHO with the peer ' s same tag
* but a new tag of its own .
*/
/* This case represents an initialization collision. */
static sctp_disposition_t sctp_sf_do_dupcook_c ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands ,
struct sctp_association * new_asoc )
{
/* The cookie should be silently discarded.
* The endpoint SHOULD NOT change states and should leave
* any timers running .
*/
return SCTP_DISPOSITION_DISCARD ;
}
/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
*
* Section 5.2 .4
*
* D ) When both local and remote tags match the endpoint should always
* enter the ESTABLISHED state , if it has not already done so .
*/
/* This case represents an initialization collision. */
static sctp_disposition_t sctp_sf_do_dupcook_d ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands ,
struct sctp_association * new_asoc )
{
struct sctp_ulpevent * ev = NULL ;
struct sctp_chunk * repl ;
/* Clarification from Implementor's Guide:
* D ) When both local and remote tags match the endpoint should
* enter the ESTABLISHED state , if it is in the COOKIE - ECHOED state .
* It should stop any cookie timer that may be running and send
* a COOKIE ACK .
*/
/* Don't accidentally move back into established state. */
if ( asoc - > state < SCTP_STATE_ESTABLISHED ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_COOKIE ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_ESTABLISHED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_CURRESTAB ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMERS_START ,
SCTP_NULL ( ) ) ;
/* RFC 2960 5.1 Normal Establishment of an Association
*
* D ) IMPLEMENTATION NOTE : An implementation may choose
* to send the Communication Up notification to the
* SCTP user upon reception of a valid COOKIE
* ECHO chunk .
*/
ev = sctp_ulpevent_make_assoc_change ( new_asoc , 0 ,
SCTP_COMM_UP , 0 ,
new_asoc - > c . sinit_num_ostreams ,
new_asoc - > c . sinit_max_instreams ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP ,
SCTP_ULPEVENT ( ev ) ) ;
/* Sockets API Draft Section 5.3.1.6
* When a peer sends a Adaption Layer Indication parameter ,
* SCTP delivers this notification to inform the application
* that of the peers requested adaption layer .
*/
if ( new_asoc - > peer . adaption_ind ) {
ev = sctp_ulpevent_make_adaption_indication ( new_asoc ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP ,
SCTP_ULPEVENT ( ev ) ) ;
}
}
sctp_add_cmd_sf ( commands , SCTP_CMD_TRANSMIT , SCTP_NULL ( ) ) ;
repl = sctp_make_cookie_ack ( new_asoc , chunk ) ;
if ( ! repl )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TRANSMIT , SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
if ( ev )
sctp_ulpevent_free ( ev ) ;
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Handle a duplicate COOKIE - ECHO . This usually means a cookie - carrying
* chunk was retransmitted and then delayed in the network .
*
* Section : 5.2 .4 Handle a COOKIE ECHO when a TCB exists
*
* Verification Tag : None . Do cookie validation .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_5_2_4_dupcook ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_disposition_t retval ;
struct sctp_chunk * chunk = arg ;
struct sctp_association * new_asoc ;
int error = 0 ;
char action ;
struct sctp_chunk * err_chk_p ;
/* Make sure that the chunk has a valid length from the protocol
* perspective . In this case check to make sure we have at least
* enough for the chunk header . Cookie length verification is
* done later .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_chunkhdr_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* "Decode" the chunk. We have no optional parameters so we
* are in good shape .
*/
chunk - > subh . cookie_hdr = ( struct sctp_signed_cookie * ) chunk - > skb - > data ;
skb_pull ( chunk - > skb , ntohs ( chunk - > chunk_hdr - > length ) -
sizeof ( sctp_chunkhdr_t ) ) ;
/* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
* of a duplicate COOKIE ECHO match the Verification Tags of the
* current association , consider the State Cookie valid even if
* the lifespan is exceeded .
*/
new_asoc = sctp_unpack_cookie ( ep , asoc , chunk , GFP_ATOMIC , & error ,
& err_chk_p ) ;
/* FIXME:
* If the re - build failed , what is the proper error path
* from here ?
*
* [ We should abort the association . - - piggy ]
*/
if ( ! new_asoc ) {
/* FIXME: Several errors are possible. A bad cookie should
* be silently discarded , but think about logging it too .
*/
switch ( error ) {
case - SCTP_IERROR_NOMEM :
goto nomem ;
case - SCTP_IERROR_STALE_COOKIE :
sctp_send_stale_cookie_err ( ep , asoc , chunk , commands ,
err_chk_p ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
case - SCTP_IERROR_BAD_SIG :
default :
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
} ;
}
/* Compare the tie_tag in cookie with the verification tag of
* current association .
*/
action = sctp_tietags_compare ( new_asoc , asoc ) ;
switch ( action ) {
case ' A ' : /* Association restart. */
retval = sctp_sf_do_dupcook_a ( ep , asoc , chunk , commands ,
new_asoc ) ;
break ;
case ' B ' : /* Collision case B. */
retval = sctp_sf_do_dupcook_b ( ep , asoc , chunk , commands ,
new_asoc ) ;
break ;
case ' C ' : /* Collision case C. */
retval = sctp_sf_do_dupcook_c ( ep , asoc , chunk , commands ,
new_asoc ) ;
break ;
case ' D ' : /* Collision case D. */
retval = sctp_sf_do_dupcook_d ( ep , asoc , chunk , commands ,
new_asoc ) ;
break ;
default : /* Discard packet for all others. */
retval = sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
break ;
} ;
/* Delete the tempory new association. */
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_ASOC , SCTP_ASOC ( new_asoc ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB , SCTP_NULL ( ) ) ;
return retval ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Process an ABORT . ( SHUTDOWN - PENDING state )
*
* See sctp_sf_do_9_1_abort ( ) .
*/
sctp_disposition_t sctp_sf_shutdown_pending_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
if ( ! sctp_vtag_verify_either ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the ABORT chunk has a valid length.
* Since this is an ABORT chunk , we have to discard it
* because of the following text :
* RFC 2960 , Section 3.3 .7
* If an endpoint receives an ABORT with a format error or for an
* association that doesn ' t exist , it MUST silently discard it .
* Becasue the length is " invalid " , we can ' t really discard just
* as we do not know its true length . So , to be safe , discard the
* packet .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_abort_chunk_t ) ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Stop the T5-shutdown guard timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
return sctp_sf_do_9_1_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* Process an ABORT . ( SHUTDOWN - SENT state )
*
* See sctp_sf_do_9_1_abort ( ) .
*/
sctp_disposition_t sctp_sf_shutdown_sent_abort ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
if ( ! sctp_vtag_verify_either ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the ABORT chunk has a valid length.
* Since this is an ABORT chunk , we have to discard it
* because of the following text :
* RFC 2960 , Section 3.3 .7
* If an endpoint receives an ABORT with a format error or for an
* association that doesn ' t exist , it MUST silently discard it .
* Becasue the length is " invalid " , we can ' t really discard just
* as we do not know its true length . So , to be safe , discard the
* packet .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_abort_chunk_t ) ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Stop the T2-shutdown timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
/* Stop the T5-shutdown guard timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
return sctp_sf_do_9_1_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* Process an ABORT . ( SHUTDOWN - ACK - SENT state )
*
* See sctp_sf_do_9_1_abort ( ) .
*/
sctp_disposition_t sctp_sf_shutdown_ack_sent_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* The same T2 timer, so we should be able to use
* common function with the SHUTDOWN - SENT state .
*/
return sctp_sf_shutdown_sent_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* Handle an Error received in COOKIE_ECHOED state .
*
* Only handle the error type of stale COOKIE Error , the other errors will
* be ignored .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_cookie_echoed_err ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
sctp_errhdr_t * err ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the ERROR chunk has a valid length.
* The parameter walking depends on this as well .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_operr_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* Process the error here */
/* FUTURE FIXME: When PR-SCTP related and other optional
* parms are emitted , this will have to change to handle multiple
* errors .
*/
sctp_walk_errors ( err , chunk - > chunk_hdr ) {
if ( SCTP_ERROR_STALE_COOKIE = = err - > cause )
return sctp_sf_do_5_2_6_stale ( ep , asoc , type ,
arg , commands ) ;
}
/* It is possible to have malformed error causes, and that
* will cause us to end the walk early . However , since
* we are discarding the packet , there should be no adverse
* affects .
*/
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
/*
* Handle a Stale COOKIE Error
*
* Section : 5.2 .6 Handle Stale COOKIE Error
* If the association is in the COOKIE - ECHOED state , the endpoint may elect
* one of the following three alternatives .
* . . .
* 3 ) Send a new INIT chunk to the endpoint , adding a Cookie
* Preservative parameter requesting an extension to the lifetime of
* the State Cookie . When calculating the time extension , an
* implementation SHOULD use the RTT information measured based on the
* previous COOKIE ECHO / ERROR exchange , and should add no more
* than 1 second beyond the measured RTT , due to long State Cookie
* lifetimes making the endpoint more subject to a replay attack .
*
* Verification Tag : Not explicit , but safe to ignore .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
static sctp_disposition_t sctp_sf_do_5_2_6_stale ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
time_t stale ;
sctp_cookie_preserve_param_t bht ;
sctp_errhdr_t * err ;
struct sctp_chunk * reply ;
struct sctp_bind_addr * bp ;
2005-06-21 00:14:57 +04:00
int attempts = asoc - > init_err_counter + 1 ;
2005-04-17 02:20:36 +04:00
if ( attempts > = asoc - > max_init_attempts ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_FAILED ,
SCTP_U32 ( SCTP_ERROR_STALE_COOKIE ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
err = ( sctp_errhdr_t * ) ( chunk - > skb - > data ) ;
/* When calculating the time extension, an implementation
* SHOULD use the RTT information measured based on the
* previous COOKIE ECHO / ERROR exchange , and should add no
* more than 1 second beyond the measured RTT , due to long
* State Cookie lifetimes making the endpoint more subject to
* a replay attack .
* Measure of Staleness ' s unit is usec . ( 1 / 1000000 sec )
* Suggested Cookie Life - span Increment ' s unit is msec .
* ( 1 / 1000 sec )
* In general , if you use the suggested cookie life , the value
* found in the field of measure of staleness should be doubled
* to give ample time to retransmit the new cookie and thus
* yield a higher probability of success on the reattempt .
*/
stale = ntohl ( * ( suseconds_t * ) ( ( u8 * ) err + sizeof ( sctp_errhdr_t ) ) ) ;
stale = ( stale * 2 ) / 1000 ;
bht . param_hdr . type = SCTP_PARAM_COOKIE_PRESERVATIVE ;
bht . param_hdr . length = htons ( sizeof ( bht ) ) ;
bht . lifespan_increment = htonl ( stale ) ;
/* Build that new INIT chunk. */
bp = ( struct sctp_bind_addr * ) & asoc - > base . bind_addr ;
reply = sctp_make_init ( asoc , bp , GFP_ATOMIC , sizeof ( bht ) ) ;
if ( ! reply )
goto nomem ;
sctp_addto_chunk ( reply , sizeof ( bht ) , & bht ) ;
/* Clear peer's init_tag cached in assoc as we are sending a new INIT */
sctp_add_cmd_sf ( commands , SCTP_CMD_CLEAR_INIT_TAG , SCTP_NULL ( ) ) ;
/* Stop pending T3-rtx and heartbeat timers */
sctp_add_cmd_sf ( commands , SCTP_CMD_T3_RTX_TIMERS_STOP , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMERS_STOP , SCTP_NULL ( ) ) ;
/* Delete non-primary peer ip addresses since we are transitioning
* back to the COOKIE - WAIT state
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_DEL_NON_PRIMARY , SCTP_NULL ( ) ) ;
/* If we've sent any data bundled with COOKIE-ECHO we will need to
* resend
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_RETRAN ,
SCTP_TRANSPORT ( asoc - > peer . primary_path ) ) ;
/* Cast away the const modifier, as we want to just
* rerun it through as a sideffect .
*/
2005-06-21 00:14:57 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_COUNTER_INC , SCTP_NULL ( ) ) ;
2005-04-17 02:20:36 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_COOKIE ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_COOKIE_WAIT ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Process an ABORT .
*
* Section : 9.1
* After checking the Verification Tag , the receiving endpoint shall
* remove the association from its record , and shall report the
* termination to its upper layer .
*
* Verification Tag : 8.5 .1 Exceptions in Verification Tag Rules
* B ) Rules for packet carrying ABORT :
*
* - The endpoint shall always fill in the Verification Tag field of the
* outbound packet with the destination endpoint ' s tag value if it
* is known .
*
* - If the ABORT is sent in response to an OOTB packet , the endpoint
* MUST follow the procedure described in Section 8.4 .
*
* - The receiver MUST accept the packet if the Verification Tag
* matches either its own tag , OR the tag of its peer . Otherwise , the
* receiver MUST silently discard the packet and take no further
* action .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_9_1_abort ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
unsigned len ;
__u16 error = SCTP_ERROR_NO_ERROR ;
if ( ! sctp_vtag_verify_either ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the ABORT chunk has a valid length.
* Since this is an ABORT chunk , we have to discard it
* because of the following text :
* RFC 2960 , Section 3.3 .7
* If an endpoint receives an ABORT with a format error or for an
* association that doesn ' t exist , it MUST silently discard it .
* Becasue the length is " invalid " , we can ' t really discard just
* as we do not know its true length . So , to be safe , discard the
* packet .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_abort_chunk_t ) ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* See if we have an error cause code in the chunk. */
len = ntohs ( chunk - > chunk_hdr - > length ) ;
if ( len > = sizeof ( struct sctp_chunkhdr ) + sizeof ( struct sctp_errhdr ) )
error = ( ( sctp_errhdr_t * ) chunk - > skb - > data ) - > cause ;
/* ASSOC_FAILED will DELETE_TCB. */
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED , SCTP_U32 ( error ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_DISPOSITION_ABORT ;
}
/*
* Process an ABORT . ( COOKIE - WAIT state )
*
* See sctp_sf_do_9_1_abort ( ) above .
*/
sctp_disposition_t sctp_sf_cookie_wait_abort ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
unsigned len ;
__u16 error = SCTP_ERROR_NO_ERROR ;
if ( ! sctp_vtag_verify_either ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the ABORT chunk has a valid length.
* Since this is an ABORT chunk , we have to discard it
* because of the following text :
* RFC 2960 , Section 3.3 .7
* If an endpoint receives an ABORT with a format error or for an
* association that doesn ' t exist , it MUST silently discard it .
* Becasue the length is " invalid " , we can ' t really discard just
* as we do not know its true length . So , to be safe , discard the
* packet .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_abort_chunk_t ) ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* See if we have an error cause code in the chunk. */
len = ntohs ( chunk - > chunk_hdr - > length ) ;
if ( len > = sizeof ( struct sctp_chunkhdr ) + sizeof ( struct sctp_errhdr ) )
error = ( ( sctp_errhdr_t * ) chunk - > skb - > data ) - > cause ;
2005-06-21 00:14:57 +04:00
return sctp_stop_t1_and_abort ( commands , error , asoc , chunk - > transport ) ;
2005-04-17 02:20:36 +04:00
}
/*
* Process an incoming ICMP as an ABORT . ( COOKIE - WAIT state )
*/
sctp_disposition_t sctp_sf_cookie_wait_icmp_abort ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
2005-06-21 00:14:57 +04:00
return sctp_stop_t1_and_abort ( commands , SCTP_ERROR_NO_ERROR , asoc ,
( struct sctp_transport * ) arg ) ;
2005-04-17 02:20:36 +04:00
}
/*
* Process an ABORT . ( COOKIE - ECHOED state )
*/
sctp_disposition_t sctp_sf_cookie_echoed_abort ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* There is a single T1 timer, so we should be able to use
* common function with the COOKIE - WAIT state .
*/
return sctp_sf_cookie_wait_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* Stop T1 timer and abort association with " INIT failed " .
*
* This is common code called by several sctp_sf_ * _abort ( ) functions above .
*/
2005-06-24 09:05:33 +04:00
static sctp_disposition_t sctp_stop_t1_and_abort ( sctp_cmd_seq_t * commands ,
2005-06-21 00:14:57 +04:00
__u16 error ,
const struct sctp_association * asoc ,
struct sctp_transport * transport )
2005-04-17 02:20:36 +04:00
{
2005-06-21 00:14:57 +04:00
SCTP_DEBUG_PRINTK ( " ABORT received (INIT). \n " ) ;
2005-04-17 02:20:36 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
/* CMD_INIT_FAILED will DELETE_TCB. */
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_FAILED ,
SCTP_U32 ( error ) ) ;
2005-06-21 00:14:57 +04:00
return SCTP_DISPOSITION_ABORT ;
2005-04-17 02:20:36 +04:00
}
/*
* sctp_sf_do_9_2_shut
*
* Section : 9.2
* Upon the reception of the SHUTDOWN , the peer endpoint shall
* - enter the SHUTDOWN - RECEIVED state ,
*
* - stop accepting new data from its SCTP user
*
* - verify , by checking the Cumulative TSN Ack field of the chunk ,
* that all its outstanding DATA chunks have been received by the
* SHUTDOWN sender .
*
* Once an endpoint as reached the SHUTDOWN - RECEIVED state it MUST NOT
* send a SHUTDOWN in response to a ULP request . And should discard
* subsequent SHUTDOWN chunks .
*
* If there are still outstanding DATA chunks left , the SHUTDOWN
* receiver shall continue to follow normal data transmission
* procedures defined in Section 6 until all outstanding DATA chunks
* are acknowledged ; however , the SHUTDOWN receiver MUST NOT accept
* new data from its SCTP user .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_9_2_shutdown ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
sctp_shutdownhdr_t * sdh ;
sctp_disposition_t disposition ;
struct sctp_ulpevent * ev ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the SHUTDOWN chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk ,
sizeof ( struct sctp_shutdown_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* Convert the elaborate header. */
sdh = ( sctp_shutdownhdr_t * ) chunk - > skb - > data ;
skb_pull ( chunk - > skb , sizeof ( sctp_shutdownhdr_t ) ) ;
chunk - > subh . shutdown_hdr = sdh ;
2005-09-23 10:48:38 +04:00
/* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
* When a peer sends a SHUTDOWN , SCTP delivers this notification to
* inform the application that it should cease sending data .
*/
ev = sctp_ulpevent_make_shutdown_event ( asoc , 0 , GFP_ATOMIC ) ;
if ( ! ev ) {
disposition = SCTP_DISPOSITION_NOMEM ;
goto out ;
}
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP , SCTP_ULPEVENT ( ev ) ) ;
2005-04-17 02:20:36 +04:00
/* Upon the reception of the SHUTDOWN, the peer endpoint shall
* - enter the SHUTDOWN - RECEIVED state ,
* - stop accepting new data from its SCTP user
*
* [ This is implicit in the new state . ]
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_SHUTDOWN_RECEIVED ) ) ;
disposition = SCTP_DISPOSITION_CONSUME ;
if ( sctp_outq_is_empty ( & asoc - > outqueue ) ) {
disposition = sctp_sf_do_9_2_shutdown_ack ( ep , asoc , type ,
arg , commands ) ;
}
if ( SCTP_DISPOSITION_NOMEM = = disposition )
goto out ;
/* - verify, by checking the Cumulative TSN Ack field of the
* chunk , that all its outstanding DATA chunks have been
* received by the SHUTDOWN sender .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_PROCESS_CTSN ,
SCTP_U32 ( chunk - > subh . shutdown_hdr - > cum_tsn_ack ) ) ;
out :
return disposition ;
}
/* RFC 2960 9.2
* If an endpoint is in SHUTDOWN - ACK - SENT state and receives an INIT chunk
* ( e . g . , if the SHUTDOWN COMPLETE was lost ) with source and destination
* transport addresses ( either in the IP addresses or in the INIT chunk )
* that belong to this association , it should discard the INIT chunk and
* retransmit the SHUTDOWN ACK chunk .
*/
sctp_disposition_t sctp_sf_do_9_2_reshutack ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = ( struct sctp_chunk * ) arg ;
struct sctp_chunk * reply ;
/* Since we are not going to really process this INIT, there
* is no point in verifying chunk boundries . Just generate
* the SHUTDOWN ACK .
*/
reply = sctp_make_shutdown_ack ( asoc , chunk ) ;
if ( NULL = = reply )
goto nomem ;
/* Set the transport for the SHUTDOWN ACK chunk and the timeout for
* the T2 - SHUTDOWN timer .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_SETUP_T2 , SCTP_CHUNK ( reply ) ) ;
/* and restart the T2-shutdown timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* sctp_sf_do_ecn_cwr
*
* Section : 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 .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_ecn_cwr ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_cwrhdr_t * cwr ;
struct sctp_chunk * chunk = arg ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_ecne_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
cwr = ( sctp_cwrhdr_t * ) chunk - > skb - > data ;
skb_pull ( chunk - > skb , sizeof ( sctp_cwrhdr_t ) ) ;
cwr - > lowest_tsn = ntohl ( cwr - > lowest_tsn ) ;
/* Does this CWR ack the last sent congestion notification? */
if ( TSN_lte ( asoc - > last_ecne_tsn , cwr - > lowest_tsn ) ) {
/* Stop sending ECNE. */
sctp_add_cmd_sf ( commands ,
SCTP_CMD_ECN_CWR ,
SCTP_U32 ( cwr - > lowest_tsn ) ) ;
}
return SCTP_DISPOSITION_CONSUME ;
}
/*
* sctp_sf_do_ecne
*
* Section : Appendix A : Explicit Congestion Notification
*
* ECN - Echo
*
* RFC 2481 details a specific bit for a receiver to send back in its
* TCP acknowledgements to notify the sender of the Congestion
* Experienced ( CE ) bit having arrived from the network . For SCTP this
* same indication is made by including the ECNE chunk . This chunk
* contains one data element , i . e . the lowest TSN associated with the IP
* datagram marked with the CE bit . . . . .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_ecne ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_ecnehdr_t * ecne ;
struct sctp_chunk * chunk = arg ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_ecne_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
ecne = ( sctp_ecnehdr_t * ) chunk - > skb - > data ;
skb_pull ( chunk - > skb , sizeof ( sctp_ecnehdr_t ) ) ;
/* If this is a newer ECNE than the last CWR packet we sent out */
sctp_add_cmd_sf ( commands , SCTP_CMD_ECN_ECNE ,
SCTP_U32 ( ntohl ( ecne - > lowest_tsn ) ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Section : 6.2 Acknowledgement on Reception of DATA Chunks
*
* The SCTP endpoint MUST always acknowledge the reception of each valid
* DATA chunk .
*
* The guidelines on delayed acknowledgement algorithm specified in
* Section 4.2 of [ RFC2581 ] SHOULD be followed . Specifically , an
* acknowledgement SHOULD be generated for at least every second packet
* ( not every second DATA chunk ) received , and SHOULD be generated within
* 200 ms of the arrival of any unacknowledged DATA chunk . In some
* situations it may be beneficial for an SCTP transmitter to be more
* conservative than the algorithms detailed in this document allow .
* However , an SCTP transmitter MUST NOT be more aggressive than the
* following algorithms allow .
*
* A SCTP receiver MUST NOT generate more than one SACK for every
* incoming packet , other than to update the offered window as the
* receiving application consumes new data .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_eat_data_6_2 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
int error ;
if ( ! sctp_vtag_verify ( chunk , asoc ) ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_BAD_TAG ,
SCTP_NULL ( ) ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_data_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
error = sctp_eat_data ( asoc , chunk , commands ) ;
switch ( error ) {
case SCTP_IERROR_NO_ERROR :
break ;
case SCTP_IERROR_HIGH_TSN :
case SCTP_IERROR_BAD_STREAM :
goto discard_noforce ;
case SCTP_IERROR_DUP_TSN :
case SCTP_IERROR_IGNORE_TSN :
goto discard_force ;
case SCTP_IERROR_NO_DATA :
goto consume ;
default :
BUG ( ) ;
}
if ( asoc - > autoclose ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_AUTOCLOSE ) ) ;
}
/* If this is the last chunk in a packet, we need to count it
* toward sack generation . Note that we need to SACK every
* OTHER packet containing data chunks , EVEN IF WE DISCARD
* THEM . We elect to NOT generate SACK ' s if the chunk fails
* the verification tag test .
*
* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
*
* The SCTP endpoint MUST always acknowledge the reception of
* each valid DATA chunk .
*
* The guidelines on delayed acknowledgement algorithm
* specified in Section 4.2 of [ RFC2581 ] SHOULD be followed .
* Specifically , an acknowledgement SHOULD be generated for at
* least every second packet ( not every second DATA chunk )
* received , and SHOULD be generated within 200 ms of the
* arrival of any unacknowledged DATA chunk . In some
* situations it may be beneficial for an SCTP transmitter to
* be more conservative than the algorithms detailed in this
* document allow . However , an SCTP transmitter MUST NOT be
* more aggressive than the following algorithms allow .
*/
2005-12-22 22:36:46 +03:00
if ( chunk - > end_of_packet )
2005-04-17 02:20:36 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SACK , SCTP_NOFORCE ( ) ) ;
return SCTP_DISPOSITION_CONSUME ;
discard_force :
/* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
*
* When a packet arrives with duplicate DATA chunk ( s ) and with
* no new DATA chunk ( s ) , the endpoint MUST immediately send a
* SACK with no delay . If a packet arrives with duplicate
* DATA chunk ( s ) bundled with new DATA chunks , the endpoint
* MAY immediately send a SACK . Normally receipt of duplicate
* DATA chunks will occur when the original SACK chunk was lost
* and the peer ' s RTO has expired . The duplicate TSN number ( s )
* SHOULD be reported in the SACK as duplicate .
*/
/* In our case, we split the MAY SACK advice up whether or not
* the last chunk is a duplicate . '
*/
if ( chunk - > end_of_packet )
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SACK , SCTP_FORCE ( ) ) ;
return SCTP_DISPOSITION_DISCARD ;
discard_noforce :
2005-12-22 22:36:46 +03:00
if ( chunk - > end_of_packet )
2005-04-17 02:20:36 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SACK , SCTP_NOFORCE ( ) ) ;
return SCTP_DISPOSITION_DISCARD ;
consume :
return SCTP_DISPOSITION_CONSUME ;
}
/*
* sctp_sf_eat_data_fast_4_4
*
* Section : 4 ( 4 )
* ( 4 ) In SHUTDOWN - SENT state the endpoint MUST acknowledge any received
* DATA chunks without delay .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_eat_data_fast_4_4 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
int error ;
if ( ! sctp_vtag_verify ( chunk , asoc ) ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_BAD_TAG ,
SCTP_NULL ( ) ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_data_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
error = sctp_eat_data ( asoc , chunk , commands ) ;
switch ( error ) {
case SCTP_IERROR_NO_ERROR :
case SCTP_IERROR_HIGH_TSN :
case SCTP_IERROR_DUP_TSN :
case SCTP_IERROR_IGNORE_TSN :
case SCTP_IERROR_BAD_STREAM :
break ;
case SCTP_IERROR_NO_DATA :
goto consume ;
default :
BUG ( ) ;
}
/* Go a head and force a SACK, since we are shutting down. */
/* Implementor's Guide.
*
* While in SHUTDOWN - SENT state , the SHUTDOWN sender MUST immediately
* respond to each received packet containing one or more DATA chunk ( s )
* with a SACK , a SHUTDOWN chunk , and restart the T2 - shutdown timer
*/
if ( chunk - > end_of_packet ) {
/* We must delay the chunk creation since the cumulative
* TSN has not been updated yet .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SHUTDOWN , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SACK , SCTP_FORCE ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
}
consume :
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Section : 6.2 Processing a Received SACK
* D ) Any time a SACK arrives , the endpoint performs the following :
*
* i ) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point ,
* then drop the SACK . Since Cumulative TSN Ack is monotonically
* increasing , a SACK whose Cumulative TSN Ack is less than the
* Cumulative TSN Ack Point indicates an out - of - order SACK .
*
* ii ) Set rwnd equal to the newly received a_rwnd minus the number
* of bytes still outstanding after processing the Cumulative TSN Ack
* and the Gap Ack Blocks .
*
* iii ) If the SACK is missing a TSN that was previously
* acknowledged via a Gap Ack Block ( e . g . , the data receiver
* reneged on the data ) , then mark the corresponding DATA chunk
* as available for retransmit : Mark it as missing for fast
* retransmit as described in Section 7.2 .4 and if no retransmit
* timer is running for the destination address to which the DATA
* chunk was originally transmitted , then T3 - rtx is started for
* that destination address .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_eat_sack_6_2 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
sctp_sackhdr_t * sackh ;
__u32 ctsn ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the SACK chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_sack_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* Pull the SACK chunk from the data buffer */
sackh = sctp_sm_pull_sack ( chunk ) ;
/* Was this a bogus SACK? */
if ( ! sackh )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
chunk - > subh . sack_hdr = sackh ;
ctsn = ntohl ( sackh - > cum_tsn_ack ) ;
/* i) If Cumulative TSN Ack is less than the Cumulative TSN
* Ack Point , then drop the SACK . Since Cumulative TSN
* Ack is monotonically increasing , a SACK whose
* Cumulative TSN Ack is less than the Cumulative TSN Ack
* Point indicates an out - of - order SACK .
*/
if ( TSN_lt ( ctsn , asoc - > ctsn_ack_point ) ) {
SCTP_DEBUG_PRINTK ( " ctsn %x \n " , ctsn ) ;
SCTP_DEBUG_PRINTK ( " ctsn_ack_point %x \n " , asoc - > ctsn_ack_point ) ;
return SCTP_DISPOSITION_DISCARD ;
}
/* Return this SACK for further processing. */
sctp_add_cmd_sf ( commands , SCTP_CMD_PROCESS_SACK , SCTP_SACKH ( sackh ) ) ;
/* Note: We do the rest of the work on the PROCESS_SACK
* sideeffect .
*/
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Generate an ABORT in response to a packet .
*
2005-04-28 22:58:43 +04:00
* Section : 8.4 Handle " Out of the blue " Packets , sctpimpguide 2.41
2005-04-17 02:20:36 +04:00
*
2005-04-28 22:58:43 +04:00
* 8 ) The receiver should respond to the sender of the OOTB packet with
* an ABORT . When sending the ABORT , the receiver of the OOTB packet
* MUST fill in the Verification Tag field of the outbound packet
* with the value found in the Verification Tag field of the OOTB
* packet and set the T - bit in the Chunk Flags to indicate that the
* Verification Tag is reflected . After sending this ABORT , the
* receiver of the OOTB packet shall discard the OOTB packet and take
* no further action .
2005-04-17 02:20:36 +04:00
*
* Verification Tag :
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_tabort_8_4_8 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_packet * packet = NULL ;
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * abort ;
packet = sctp_ootb_pkt_new ( asoc , chunk ) ;
if ( packet ) {
/* Make an ABORT. The T bit will be set if the asoc
* is NULL .
*/
abort = sctp_make_abort ( asoc , chunk , 0 ) ;
if ( ! abort ) {
sctp_ootb_pkt_free ( packet ) ;
return SCTP_DISPOSITION_NOMEM ;
}
2005-04-28 22:58:43 +04:00
/* Reflect vtag if T-Bit is set */
if ( sctp_test_T_bit ( abort ) )
packet - > vtag = ntohl ( chunk - > sctp_hdr - > vtag ) ;
2005-04-17 02:20:36 +04:00
/* Set the skb to the belonging sock for accounting. */
abort - > skb - > sk = ep - > base . sk ;
sctp_packet_append_chunk ( packet , abort ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_SEND_PKT ,
SCTP_PACKET ( packet ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
return SCTP_DISPOSITION_CONSUME ;
}
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Received an ERROR chunk from peer . Generate SCTP_REMOTE_ERROR
* event as ULP notification for each cause included in the chunk .
*
* API 5.3 .1 .3 - SCTP_REMOTE_ERROR
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_operr_notify ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_ulpevent * ev ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the ERROR chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_operr_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
while ( chunk - > chunk_end > chunk - > skb - > data ) {
ev = sctp_ulpevent_make_remote_error ( asoc , chunk , 0 ,
GFP_ATOMIC ) ;
if ( ! ev )
goto nomem ;
if ( ! sctp_add_cmd ( commands , SCTP_CMD_EVENT_ULP ,
SCTP_ULPEVENT ( ev ) ) ) {
sctp_ulpevent_free ( ev ) ;
goto nomem ;
}
sctp_add_cmd_sf ( commands , SCTP_CMD_PROCESS_OPERR ,
SCTP_CHUNK ( chunk ) ) ;
}
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Process an inbound SHUTDOWN ACK .
*
* From Section 9.2 :
* Upon the receipt of the SHUTDOWN ACK , the SHUTDOWN sender shall
* stop the T2 - shutdown timer , send a SHUTDOWN COMPLETE chunk to its
* peer , and remove all record of the association .
*
* The return value is the disposition .
*/
sctp_disposition_t sctp_sf_do_9_2_final ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * reply ;
struct sctp_ulpevent * ev ;
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_chunkhdr_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
/* 10.2 H) SHUTDOWN COMPLETE notification
*
* When SCTP completes the shutdown procedures ( section 9.2 ) this
* notification is passed to the upper layer .
*/
ev = sctp_ulpevent_make_assoc_change ( asoc , 0 , SCTP_SHUTDOWN_COMP ,
0 , 0 , 0 , GFP_ATOMIC ) ;
if ( ! ev )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_EVENT_ULP , SCTP_ULPEVENT ( ev ) ) ;
/* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
* stop the T2 - shutdown timer ,
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
/* ...send a SHUTDOWN COMPLETE chunk to its peer, */
reply = sctp_make_shutdown_complete ( asoc , chunk ) ;
if ( ! reply )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_SHUTDOWNS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
/* ...and remove all record of the association. */
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB , SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
2005-04-28 22:58:43 +04:00
* RFC 2960 , 8.4 - Handle " Out of the blue " Packets , sctpimpguide 2.41 .
*
2005-04-17 02:20:36 +04:00
* 5 ) If the packet contains a SHUTDOWN ACK chunk , the receiver should
* respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE .
* When sending the SHUTDOWN COMPLETE , the receiver of the OOTB
* packet must fill in the Verification Tag field of the outbound
* packet with the Verification Tag received in the SHUTDOWN ACK and
2005-04-28 22:58:43 +04:00
* set the T - bit in the Chunk Flags to indicate that the Verification
* Tag is reflected .
2005-04-17 02:20:36 +04:00
*
* 8 ) The receiver should respond to the sender of the OOTB packet with
* an ABORT . When sending the ABORT , the receiver of the OOTB packet
* MUST fill in the Verification Tag field of the outbound packet
* with the value found in the Verification Tag field of the OOTB
2005-04-28 22:58:43 +04:00
* packet and set the T - bit in the Chunk Flags to indicate that the
* Verification Tag is reflected . After sending this ABORT , the
* receiver of the OOTB packet shall discard the OOTB packet and take
* no further action .
2005-04-17 02:20:36 +04:00
*/
sctp_disposition_t sctp_sf_ootb ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sk_buff * skb = chunk - > skb ;
sctp_chunkhdr_t * ch ;
__u8 * ch_end ;
int ootb_shut_ack = 0 ;
SCTP_INC_STATS ( SCTP_MIB_OUTOFBLUES ) ;
ch = ( sctp_chunkhdr_t * ) chunk - > chunk_hdr ;
do {
/* Break out if chunk length is less then minimal. */
if ( ntohs ( ch - > length ) < sizeof ( sctp_chunkhdr_t ) )
break ;
ch_end = ( ( __u8 * ) ch ) + WORD_ROUND ( ntohs ( ch - > length ) ) ;
if ( SCTP_CID_SHUTDOWN_ACK = = ch - > type )
ootb_shut_ack = 1 ;
/* RFC 2960, Section 3.3.7
* Moreover , under any circumstances , an endpoint that
* receives an ABORT MUST NOT respond to that ABORT by
* sending an ABORT of its own .
*/
if ( SCTP_CID_ABORT = = ch - > type )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
ch = ( sctp_chunkhdr_t * ) ch_end ;
} while ( ch_end < skb - > tail ) ;
if ( ootb_shut_ack )
sctp_sf_shut_8_4_5 ( ep , asoc , type , arg , commands ) ;
else
sctp_sf_tabort_8_4_8 ( ep , asoc , type , arg , commands ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
/*
* Handle an " Out of the blue " SHUTDOWN ACK .
*
2005-04-28 22:58:43 +04:00
* Section : 8.4 5 , sctpimpguide 2.41 .
*
2005-04-17 02:20:36 +04:00
* 5 ) If the packet contains a SHUTDOWN ACK chunk , the receiver should
2005-04-28 22:58:43 +04:00
* respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE .
* When sending the SHUTDOWN COMPLETE , the receiver of the OOTB
* packet must fill in the Verification Tag field of the outbound
* packet with the Verification Tag received in the SHUTDOWN ACK and
* set the T - bit in the Chunk Flags to indicate that the Verification
* Tag is reflected .
2005-04-17 02:20:36 +04:00
*
* Inputs
* ( endpoint , asoc , type , arg , commands )
*
* Outputs
* ( sctp_disposition_t )
*
* The return value is the disposition of the chunk .
*/
static sctp_disposition_t sctp_sf_shut_8_4_5 ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_packet * packet = NULL ;
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * shut ;
packet = sctp_ootb_pkt_new ( asoc , chunk ) ;
if ( packet ) {
/* Make an SHUTDOWN_COMPLETE.
* The T bit will be set if the asoc is NULL .
*/
shut = sctp_make_shutdown_complete ( asoc , chunk ) ;
if ( ! shut ) {
sctp_ootb_pkt_free ( packet ) ;
return SCTP_DISPOSITION_NOMEM ;
}
2005-04-28 22:58:43 +04:00
/* Reflect vtag if T-Bit is set */
if ( sctp_test_T_bit ( shut ) )
packet - > vtag = ntohl ( chunk - > sctp_hdr - > vtag ) ;
2005-04-17 02:20:36 +04:00
/* Set the skb to the belonging sock for accounting. */
shut - > skb - > sk = ep - > base . sk ;
sctp_packet_append_chunk ( packet , shut ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_SEND_PKT ,
SCTP_PACKET ( packet ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
/* If the chunk length is invalid, we don't want to process
* the reset of the packet .
*/
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_chunkhdr_t ) ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
return SCTP_DISPOSITION_CONSUME ;
}
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state .
*
* Verification Tag : 8.5 .1 E ) Rules for packet carrying a SHUTDOWN ACK
* If the receiver is in COOKIE - ECHOED or COOKIE - WAIT state the
* procedures in section 8.4 SHOULD be followed , in other words it
* should be treated as an Out Of The Blue packet .
* [ This means that we do NOT check the Verification Tag on these
* chunks . - - piggy ]
*
*/
sctp_disposition_t sctp_sf_do_8_5_1_E_sa ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* Although we do have an association in this case, it corresponds
* to a restarted association . So the packet is treated as an OOTB
* packet and the state function that handles OOTB SHUTDOWN_ACK is
* called with a NULL association .
*/
return sctp_sf_shut_8_4_5 ( ep , NULL , type , arg , commands ) ;
}
/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
sctp_disposition_t sctp_sf_do_asconf ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type , void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * asconf_ack = NULL ;
sctp_addiphdr_t * hdr ;
__u32 serial ;
if ( ! sctp_vtag_verify ( chunk , asoc ) ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_BAD_TAG ,
SCTP_NULL ( ) ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
/* Make sure that the ASCONF ADDIP chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( sctp_addip_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
hdr = ( sctp_addiphdr_t * ) chunk - > skb - > data ;
serial = ntohl ( hdr - > serial ) ;
/* ADDIP 4.2 C1) Compare the value of the serial number to the value
* the endpoint stored in a new association variable
* ' Peer - Serial - Number ' .
*/
if ( serial = = asoc - > peer . addip_serial + 1 ) {
/* ADDIP 4.2 C2) If the value found in the serial number is
* equal to the ( ' Peer - Serial - Number ' + 1 ) , the endpoint MUST
* do V1 - V5 .
*/
asconf_ack = sctp_process_asconf ( ( struct sctp_association * )
asoc , chunk ) ;
if ( ! asconf_ack )
return SCTP_DISPOSITION_NOMEM ;
} else if ( serial = = asoc - > peer . addip_serial ) {
/* ADDIP 4.2 C3) If the value found in the serial number is
* equal to the value stored in the ' Peer - Serial - Number '
* IMPLEMENTATION NOTE : As an optimization a receiver may wish
* to save the last ASCONF - ACK for some predetermined period of
* time and instead of re - processing the ASCONF ( with the same
* serial number ) it may just re - transmit the ASCONF - ACK .
*/
if ( asoc - > addip_last_asconf_ack )
asconf_ack = asoc - > addip_last_asconf_ack ;
else
return SCTP_DISPOSITION_DISCARD ;
} else {
/* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
* it must be either a stale packet or from an attacker .
*/
return SCTP_DISPOSITION_DISCARD ;
}
/* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
* back to the source address contained in the IP header of the ASCONF
* being responded to .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( asconf_ack ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* ADDIP Section 4.3 General rules for address manipulation
* When building TLV parameters for the ASCONF Chunk that will add or
* delete IP addresses the D0 to D13 rules should be applied :
*/
sctp_disposition_t sctp_sf_do_asconf_ack ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type , void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * asconf_ack = arg ;
struct sctp_chunk * last_asconf = asoc - > addip_last_asconf ;
struct sctp_chunk * abort ;
sctp_addiphdr_t * addip_hdr ;
__u32 sent_serial , rcvd_serial ;
if ( ! sctp_vtag_verify ( asconf_ack , asoc ) ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_BAD_TAG ,
SCTP_NULL ( ) ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
/* Make sure that the ADDIP chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( asconf_ack , sizeof ( sctp_addip_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
addip_hdr = ( sctp_addiphdr_t * ) asconf_ack - > skb - > data ;
rcvd_serial = ntohl ( addip_hdr - > serial ) ;
if ( last_asconf ) {
addip_hdr = ( sctp_addiphdr_t * ) last_asconf - > subh . addip_hdr ;
sent_serial = ntohl ( addip_hdr - > serial ) ;
} else {
sent_serial = asoc - > addip_serial - 1 ;
}
/* D0) If an endpoint receives an ASCONF-ACK that is greater than or
* equal to the next serial number to be used but no ASCONF chunk is
* outstanding the endpoint MUST ABORT the association . Note that a
* sequence number is greater than if it is no more than 2 ^ ^ 31 - 1
* larger than the current sequence number ( using serial arithmetic ) .
*/
if ( ADDIP_SERIAL_gte ( rcvd_serial , sent_serial + 1 ) & &
! ( asoc - > addip_last_asconf ) ) {
abort = sctp_make_abort ( asoc , asconf_ack ,
sizeof ( sctp_errhdr_t ) ) ;
if ( abort ) {
sctp_init_cause ( abort , SCTP_ERROR_ASCONF_ACK , NULL , 0 ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( abort ) ) ;
}
/* We are going to ABORT, so we might as well stop
* processing the rest of the chunks in the packet .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T4_RTO ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DISCARD_PACKET , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_ASCONF_ACK ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_DISPOSITION_ABORT ;
}
if ( ( rcvd_serial = = sent_serial ) & & asoc - > addip_last_asconf ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T4_RTO ) ) ;
if ( ! sctp_process_asconf_ack ( ( struct sctp_association * ) asoc ,
asconf_ack ) )
return SCTP_DISPOSITION_CONSUME ;
abort = sctp_make_abort ( asoc , asconf_ack ,
sizeof ( sctp_errhdr_t ) ) ;
if ( abort ) {
sctp_init_cause ( abort , SCTP_ERROR_RSRC_LOW , NULL , 0 ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( abort ) ) ;
}
/* We are going to ABORT, so we might as well stop
* processing the rest of the chunks in the packet .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_DISCARD_PACKET , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_ASCONF_ACK ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_DISPOSITION_ABORT ;
}
return SCTP_DISPOSITION_DISCARD ;
}
/*
* PR - SCTP Section 3.6 Receiver Side Implementation of PR - SCTP
*
* When a FORWARD TSN chunk arrives , the data receiver MUST first update
* its cumulative TSN point to the value carried in the FORWARD TSN
* chunk , and then MUST further advance its cumulative TSN point locally
* if possible .
* After the above processing , the data receiver MUST stop reporting any
* missing TSNs earlier than or equal to the new cumulative TSN point .
*
* Verification Tag : 8.5 Verification Tag [ Normal verification ]
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_eat_fwd_tsn ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_fwdtsn_hdr * fwdtsn_hdr ;
__u16 len ;
__u32 tsn ;
if ( ! sctp_vtag_verify ( chunk , asoc ) ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_BAD_TAG ,
SCTP_NULL ( ) ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
/* Make sure that the FORWARD_TSN chunk has valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( struct sctp_fwdtsn_chunk ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
fwdtsn_hdr = ( struct sctp_fwdtsn_hdr * ) chunk - > skb - > data ;
chunk - > subh . fwdtsn_hdr = fwdtsn_hdr ;
len = ntohs ( chunk - > chunk_hdr - > length ) ;
len - = sizeof ( struct sctp_chunkhdr ) ;
skb_pull ( chunk - > skb , len ) ;
tsn = ntohl ( fwdtsn_hdr - > new_cum_tsn ) ;
SCTP_DEBUG_PRINTK ( " %s: TSN 0x%x. \n " , __FUNCTION__ , tsn ) ;
/* The TSN is too high--silently discard the chunk and count on it
* getting retransmitted later .
*/
if ( sctp_tsnmap_check ( & asoc - > peer . tsn_map , tsn ) < 0 )
goto discard_noforce ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_FWDTSN , SCTP_U32 ( tsn ) ) ;
if ( len > sizeof ( struct sctp_fwdtsn_hdr ) )
sctp_add_cmd_sf ( commands , SCTP_CMD_PROCESS_FWDTSN ,
SCTP_CHUNK ( chunk ) ) ;
/* Count this as receiving DATA. */
if ( asoc - > autoclose ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_AUTOCLOSE ) ) ;
}
/* FIXME: For now send a SACK, but DATA processing may
* send another .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SACK , SCTP_NOFORCE ( ) ) ;
return SCTP_DISPOSITION_CONSUME ;
discard_noforce :
return SCTP_DISPOSITION_DISCARD ;
}
sctp_disposition_t sctp_sf_eat_fwd_tsn_fast (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_fwdtsn_hdr * fwdtsn_hdr ;
__u16 len ;
__u32 tsn ;
if ( ! sctp_vtag_verify ( chunk , asoc ) ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_BAD_TAG ,
SCTP_NULL ( ) ) ;
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
}
/* Make sure that the FORWARD_TSN chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( struct sctp_fwdtsn_chunk ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
fwdtsn_hdr = ( struct sctp_fwdtsn_hdr * ) chunk - > skb - > data ;
chunk - > subh . fwdtsn_hdr = fwdtsn_hdr ;
len = ntohs ( chunk - > chunk_hdr - > length ) ;
len - = sizeof ( struct sctp_chunkhdr ) ;
skb_pull ( chunk - > skb , len ) ;
tsn = ntohl ( fwdtsn_hdr - > new_cum_tsn ) ;
SCTP_DEBUG_PRINTK ( " %s: TSN 0x%x. \n " , __FUNCTION__ , tsn ) ;
/* The TSN is too high--silently discard the chunk and count on it
* getting retransmitted later .
*/
if ( sctp_tsnmap_check ( & asoc - > peer . tsn_map , tsn ) < 0 )
goto gen_shutdown ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_FWDTSN , SCTP_U32 ( tsn ) ) ;
if ( len > sizeof ( struct sctp_fwdtsn_hdr ) )
sctp_add_cmd_sf ( commands , SCTP_CMD_PROCESS_FWDTSN ,
SCTP_CHUNK ( chunk ) ) ;
/* Go a head and force a SACK, since we are shutting down. */
gen_shutdown :
/* Implementor's Guide.
*
* While in SHUTDOWN - SENT state , the SHUTDOWN sender MUST immediately
* respond to each received packet containing one or more DATA chunk ( s )
* with a SACK , a SHUTDOWN chunk , and restart the T2 - shutdown timer
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SHUTDOWN , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SACK , SCTP_FORCE ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Process an unknown chunk .
*
* Section : 3.2 . Also , 2.1 in the implementor ' s guide .
*
* Chunk 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 Chunk Type .
*
* 00 - Stop processing this SCTP packet and discard it , do not process
* any further chunks within it .
*
* 01 - Stop processing this SCTP packet and discard it , do not process
* any further chunks within it , and report the unrecognized
* chunk in an ' Unrecognized Chunk Type ' .
*
* 10 - Skip this chunk and continue processing .
*
* 11 - Skip this chunk and continue processing , but report in an ERROR
* Chunk using the ' Unrecognized Chunk Type ' cause of error .
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_unk_chunk ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * unk_chunk = arg ;
struct sctp_chunk * err_chunk ;
sctp_chunkhdr_t * hdr ;
SCTP_DEBUG_PRINTK ( " Processing the unknown chunk id %d. \n " , type . chunk ) ;
if ( ! sctp_vtag_verify ( unk_chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the chunk has a valid length.
* Since we don ' t know the chunk type , we use a general
* chunkhdr structure to make a comparison .
*/
if ( ! sctp_chunk_length_valid ( unk_chunk , sizeof ( sctp_chunkhdr_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
switch ( type . chunk & SCTP_CID_ACTION_MASK ) {
case SCTP_CID_ACTION_DISCARD :
/* Discard the packet. */
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
break ;
case SCTP_CID_ACTION_DISCARD_ERR :
/* Discard the packet. */
sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Generate an ERROR chunk as response. */
hdr = unk_chunk - > chunk_hdr ;
err_chunk = sctp_make_op_error ( asoc , unk_chunk ,
SCTP_ERROR_UNKNOWN_CHUNK , hdr ,
WORD_ROUND ( ntohs ( hdr - > length ) ) ) ;
if ( err_chunk ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( err_chunk ) ) ;
}
return SCTP_DISPOSITION_CONSUME ;
break ;
case SCTP_CID_ACTION_SKIP :
/* Skip the chunk. */
return SCTP_DISPOSITION_DISCARD ;
break ;
case SCTP_CID_ACTION_SKIP_ERR :
/* Generate an ERROR chunk as response. */
hdr = unk_chunk - > chunk_hdr ;
err_chunk = sctp_make_op_error ( asoc , unk_chunk ,
SCTP_ERROR_UNKNOWN_CHUNK , hdr ,
WORD_ROUND ( ntohs ( hdr - > length ) ) ) ;
if ( err_chunk ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( err_chunk ) ) ;
}
/* Skip the chunk. */
return SCTP_DISPOSITION_CONSUME ;
break ;
default :
break ;
}
return SCTP_DISPOSITION_DISCARD ;
}
/*
* Discard the chunk .
*
* Section : 0.2 , 5.2 .3 , 5.2 .5 , 5.2 .6 , 6.0 , 8.4 .6 , 8.5 .1 c , 9.2
* [ Too numerous to mention . . . ]
* Verification Tag : No verification needed .
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_discard_chunk ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
SCTP_DEBUG_PRINTK ( " Chunk %d is discarded \n " , type . chunk ) ;
return SCTP_DISPOSITION_DISCARD ;
}
/*
* Discard the whole packet .
*
* Section : 8.4 2 )
*
* 2 ) If the OOTB packet contains an ABORT chunk , the receiver MUST
* silently discard the OOTB packet and take no further action .
*
* Verification Tag : No verification necessary
*
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_pdiscard ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_add_cmd_sf ( commands , SCTP_CMD_DISCARD_PACKET , SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* The other end is violating protocol .
*
* Section : Not specified
* Verification Tag : Not specified
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( asoc , reply_msg , msg_up , timers , counters )
*
* We simply tag the chunk as a violation . The state machine will log
* the violation and continue .
*/
sctp_disposition_t sctp_sf_violation ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
return SCTP_DISPOSITION_VIOLATION ;
}
/*
* Handle a protocol violation when the chunk length is invalid .
* " Invalid " length is identified as smaller then the minimal length a
* given chunk can be . For example , a SACK chunk has invalid length
* if it ' s length is set to be smaller then the size of sctp_sack_chunk_t .
*
* We inform the other end by sending an ABORT with a Protocol Violation
* error code .
*
* Section : Not specified
* Verification Tag : Nothing to do
* Inputs
* ( endpoint , asoc , chunk )
*
* Outputs
* ( reply_msg , msg_up , counters )
*
* Generate an ABORT chunk and terminate the association .
*/
2005-06-24 09:05:33 +04:00
static sctp_disposition_t sctp_sf_violation_chunklen (
const struct sctp_endpoint * ep ,
2005-04-17 02:20:36 +04:00
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
struct sctp_chunk * abort = NULL ;
char err_str [ ] = " The following chunk had invalid length: " ;
/* Make the abort chunk. */
abort = sctp_make_abort_violation ( asoc , chunk , err_str ,
sizeof ( err_str ) ) ;
if ( ! abort )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( abort ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
if ( asoc - > state < = SCTP_STATE_COOKIE_ECHOED ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_FAILED ,
SCTP_U32 ( SCTP_ERROR_PROTO_VIOLATION ) ) ;
} else {
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_PROTO_VIOLATION ) ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
}
sctp_add_cmd_sf ( commands , SCTP_CMD_DISCARD_PACKET , SCTP_NULL ( ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
return SCTP_DISPOSITION_ABORT ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/***************************************************************************
* These are the state functions for handling primitive ( Section 10 ) events .
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* sctp_sf_do_prm_asoc
*
* Section : 10.1 ULP - to - SCTP
* B ) Associate
*
* Format : ASSOCIATE ( local SCTP instance name , destination transport addr ,
* outbound stream count )
* - > association id [ , destination transport addr list ] [ , outbound stream
* count ]
*
* This primitive allows the upper layer to initiate an association to a
* specific peer endpoint .
*
* The peer endpoint shall be specified by one of the transport addresses
* which defines the endpoint ( see Section 1.4 ) . If the local SCTP
* instance has not been initialized , the ASSOCIATE is considered an
* error .
* [ This is not relevant for the kernel implementation since we do all
* initialization at boot time . It we hadn ' t initialized we wouldn ' t
* get anywhere near this code . ]
*
* An association id , which is a local handle to the SCTP association ,
* will be returned on successful establishment of the association . If
* SCTP is not able to open an SCTP association with the peer endpoint ,
* an error is returned .
* [ In the kernel implementation , the struct sctp_association needs to
* be created BEFORE causing this primitive to run . ]
*
* Other association parameters may be returned , including the
* complete destination transport addresses of the peer as well as the
* outbound stream count of the local endpoint . One of the transport
* address from the returned destination addresses will be selected by
* the local endpoint as default primary path for sending SCTP packets
* to this peer . The returned " destination transport addr list " can
* be used by the ULP to change the default primary path or to force
* sending a packet to a specific transport address . [ All of this
* stuff happens when the INIT ACK arrives . This is a NON - BLOCKING
* function . ]
*
* Mandatory attributes :
*
* o local SCTP instance name - obtained from the INITIALIZE operation .
* [ This is the argument asoc . ]
* o destination transport addr - specified as one of the transport
* addresses of the peer endpoint with which the association is to be
* established .
* [ This is asoc - > peer . active_path . ]
* o outbound stream count - the number of outbound streams the ULP
* would like to open towards this peer endpoint .
* [ BUG : This is not currently implemented . ]
* Optional attributes :
*
* None .
*
* The return value is a disposition .
*/
sctp_disposition_t sctp_sf_do_prm_asoc ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * repl ;
/* The comment below says that we enter COOKIE-WAIT AFTER
* sending the INIT , but that doesn ' t actually work in our
* implementation . . .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_COOKIE_WAIT ) ) ;
/* RFC 2960 5.1 Normal Establishment of an Association
*
* A ) " A " first sends an INIT chunk to " Z " . In the INIT , " A "
* must provide its Verification Tag ( Tag_A ) in the Initiate
* Tag field . Tag_A SHOULD be a random number in the range of
* 1 to 4294967295 ( see 5.3 .1 for Tag value selection ) . . . .
*/
repl = sctp_make_init ( asoc , & asoc - > base . bind_addr , GFP_ATOMIC , 0 ) ;
if ( ! repl )
goto nomem ;
/* Cast away the const modifier, as we want to just
* rerun it through as a sideffect .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_ASOC ,
SCTP_ASOC ( ( struct sctp_association * ) asoc ) ) ;
2005-06-21 00:14:57 +04:00
/* Choose transport for INIT. */
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_CHOOSE_TRANSPORT ,
SCTP_CHUNK ( repl ) ) ;
2005-04-17 02:20:36 +04:00
/* After sending the INIT, "A" starts the T1-init timer and
* enters the COOKIE - WAIT state .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Process the SEND primitive .
*
* Section : 10.1 ULP - to - SCTP
* E ) Send
*
* Format : SEND ( association id , buffer address , byte count [ , context ]
* [ , stream id ] [ , life time ] [ , destination transport address ]
* [ , unorder flag ] [ , no - bundle flag ] [ , payload protocol - id ] )
* - > result
*
* This is the main method to send user data via SCTP .
*
* Mandatory attributes :
*
* o association id - local handle to the SCTP association
*
* o buffer address - the location where the user message to be
* transmitted is stored ;
*
* o byte count - The size of the user data in number of bytes ;
*
* Optional attributes :
*
* o context - an optional 32 bit integer that will be carried in the
* sending failure notification to the ULP if the transportation of
* this User Message fails .
*
* o stream id - to indicate which stream to send the data on . If not
* specified , stream 0 will be used .
*
* o life time - specifies the life time of the user data . The user data
* will not be sent by SCTP after the life time expires . This
* parameter can be used to avoid efforts to transmit stale
* user messages . SCTP notifies the ULP if the data cannot be
* initiated to transport ( i . e . sent to the destination via SCTP ' s
* send primitive ) within the life time variable . However , the
* user data will be transmitted if SCTP has attempted to transmit a
* chunk before the life time expired .
*
* o destination transport address - specified as one of the destination
* transport addresses of the peer endpoint to which this packet
* should be sent . Whenever possible , SCTP should use this destination
* transport address for sending the packets , instead of the current
* primary path .
*
* o unorder flag - this flag , if present , indicates that the user
* would like the data delivered in an unordered fashion to the peer
* ( i . e . , the U flag is set to 1 on all DATA chunks carrying this
* message ) .
*
* o no - bundle flag - instructs SCTP not to bundle this user data with
* other outbound DATA chunks . SCTP MAY still bundle even when
* this flag is present , when faced with network congestion .
*
* o payload protocol - id - A 32 bit unsigned integer that is to be
* passed to the peer indicating the type of payload protocol data
* being transmitted . This value is passed as opaque data by SCTP .
*
* The return value is the disposition .
*/
sctp_disposition_t sctp_sf_do_prm_send ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( chunk ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Process the SHUTDOWN primitive .
*
* Section : 10.1 :
* C ) Shutdown
*
* Format : SHUTDOWN ( association id )
* - > result
*
* Gracefully closes an association . Any locally queued user data
* will be delivered to the peer . The association will be terminated only
* after the peer acknowledges all the SCTP packets sent . A success code
* will be returned on successful termination of the association . If
* attempting to terminate the association results in a failure , an error
* code shall be returned .
*
* Mandatory attributes :
*
* o association id - local handle to the SCTP association
*
* Optional attributes :
*
* None .
*
* The return value is the disposition .
*/
sctp_disposition_t sctp_sf_do_9_2_prm_shutdown (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
int disposition ;
/* From 9.2 Shutdown of an Association
* Upon receipt of the SHUTDOWN primitive from its upper
* layer , the endpoint enters SHUTDOWN - PENDING state and
* remains there until all outstanding data has been
* acknowledged by its peer . The endpoint accepts no new data
* from its upper layer , but retransmits data to the far end
* if necessary to fill gaps .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_SHUTDOWN_PENDING ) ) ;
/* sctpimpguide-05 Section 2.12.2
* The sender of the SHUTDOWN MAY also start an overall guard timer
* ' T5 - shutdown - guard ' to bound the overall time for shutdown sequence .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
disposition = SCTP_DISPOSITION_CONSUME ;
if ( sctp_outq_is_empty ( & asoc - > outqueue ) ) {
disposition = sctp_sf_do_9_2_start_shutdown ( ep , asoc , type ,
arg , commands ) ;
}
return disposition ;
}
/*
* Process the ABORT primitive .
*
* Section : 10.1 :
* C ) Abort
*
* Format : Abort ( association id [ , cause code ] )
* - > result
*
* Ungracefully closes an association . Any locally queued user data
* will be discarded and an ABORT chunk is sent to the peer . A success code
* will be returned on successful abortion of the association . If
* attempting to abort the association results in a failure , an error
* code shall be returned .
*
* Mandatory attributes :
*
* o association id - local handle to the SCTP association
*
* Optional attributes :
*
* o cause code - reason of the abort to be passed to the peer
*
* None .
*
* The return value is the disposition .
*/
sctp_disposition_t sctp_sf_do_9_1_prm_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* From 9.1 Abort of an Association
* Upon receipt of the ABORT primitive from its upper
* layer , the endpoint enters CLOSED state and
* discard all outstanding data has been
* acknowledged by its peer . The endpoint accepts no new data
* from its upper layer , but retransmits data to the far end
* if necessary to fill gaps .
*/
struct msghdr * msg = arg ;
struct sctp_chunk * abort ;
sctp_disposition_t retval ;
retval = SCTP_DISPOSITION_CONSUME ;
/* Generate ABORT chunk to send the peer. */
abort = sctp_make_abort_user ( asoc , NULL , msg ) ;
if ( ! abort )
retval = SCTP_DISPOSITION_NOMEM ;
else
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( abort ) ) ;
/* Even if we can't send the ABORT due to low memory delete the
* TCB . This is a departure from our typical NOMEM handling .
*/
/* Delete the established association. */
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_USER_ABORT ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return retval ;
}
/* We tried an illegal operation on an association which is closed. */
sctp_disposition_t sctp_sf_error_closed ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_ERROR , SCTP_ERROR ( - EINVAL ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/* We tried an illegal operation on an association which is shutting
* down .
*/
sctp_disposition_t sctp_sf_error_shutdown ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_ERROR ,
SCTP_ERROR ( - ESHUTDOWN ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* sctp_cookie_wait_prm_shutdown
*
* Section : 4 Note : 2
* Verification Tag :
* Inputs
* ( endpoint , asoc )
*
* The RFC does not explicitly address this issue , but is the route through the
* state table when someone issues a shutdown while in COOKIE_WAIT state .
*
* Outputs
* ( timers )
*/
sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_SHUTDOWNS ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_DELETE_TCB , SCTP_NULL ( ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
/*
* sctp_cookie_echoed_prm_shutdown
*
* Section : 4 Note : 2
* Verification Tag :
* Inputs
* ( endpoint , asoc )
*
* The RFC does not explcitly address this issue , but is the route through the
* state table when someone issues a shutdown while in COOKIE_ECHOED state .
*
* Outputs
* ( timers )
*/
sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg , sctp_cmd_seq_t * commands )
{
/* There is a single T1 timer, so we should be able to use
* common function with the COOKIE - WAIT state .
*/
return sctp_sf_cookie_wait_prm_shutdown ( ep , asoc , type , arg , commands ) ;
}
/*
* sctp_sf_cookie_wait_prm_abort
*
* Section : 4 Note : 2
* Verification Tag :
* Inputs
* ( endpoint , asoc )
*
* The RFC does not explicitly address this issue , but is the route through the
* state table when someone issues an abort while in COOKIE_WAIT state .
*
* Outputs
* ( timers )
*/
sctp_disposition_t sctp_sf_cookie_wait_prm_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct msghdr * msg = arg ;
struct sctp_chunk * abort ;
sctp_disposition_t retval ;
/* Stop T1-init timer */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
retval = SCTP_DISPOSITION_CONSUME ;
/* Generate ABORT chunk to send the peer */
abort = sctp_make_abort_user ( asoc , NULL , msg ) ;
if ( ! abort )
retval = SCTP_DISPOSITION_NOMEM ;
else
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( abort ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_CLOSED ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
/* Even if we can't send the ABORT due to low memory delete the
* TCB . This is a departure from our typical NOMEM handling .
*/
/* Delete the established association. */
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_FAILED ,
SCTP_U32 ( SCTP_ERROR_USER_ABORT ) ) ;
return retval ;
}
/*
* sctp_sf_cookie_echoed_prm_abort
*
* Section : 4 Note : 3
* Verification Tag :
* Inputs
* ( endpoint , asoc )
*
* The RFC does not explcitly address this issue , but is the route through the
* state table when someone issues an abort while in COOKIE_ECHOED state .
*
* Outputs
* ( timers )
*/
sctp_disposition_t sctp_sf_cookie_echoed_prm_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* There is a single T1 timer, so we should be able to use
* common function with the COOKIE - WAIT state .
*/
return sctp_sf_cookie_wait_prm_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* sctp_sf_shutdown_pending_prm_abort
*
* Inputs
* ( endpoint , asoc )
*
* The RFC does not explicitly address this issue , but is the route through the
* state table when someone issues an abort while in SHUTDOWN - PENDING state .
*
* Outputs
* ( timers )
*/
sctp_disposition_t sctp_sf_shutdown_pending_prm_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* Stop the T5-shutdown guard timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
return sctp_sf_do_9_1_prm_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* sctp_sf_shutdown_sent_prm_abort
*
* Inputs
* ( endpoint , asoc )
*
* The RFC does not explicitly address this issue , but is the route through the
* state table when someone issues an abort while in SHUTDOWN - SENT state .
*
* Outputs
* ( timers )
*/
sctp_disposition_t sctp_sf_shutdown_sent_prm_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* Stop the T2-shutdown timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
/* Stop the T5-shutdown guard timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
return sctp_sf_do_9_1_prm_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* sctp_sf_cookie_echoed_prm_abort
*
* Inputs
* ( endpoint , asoc )
*
* The RFC does not explcitly address this issue , but is the route through the
* state table when someone issues an abort while in COOKIE_ECHOED state .
*
* Outputs
* ( timers )
*/
sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
/* The same T2 timer, so we should be able to use
* common function with the SHUTDOWN - SENT state .
*/
return sctp_sf_shutdown_sent_prm_abort ( ep , asoc , type , arg , commands ) ;
}
/*
* Process the REQUESTHEARTBEAT primitive
*
* 10.1 ULP - to - SCTP
* J ) Request Heartbeat
*
* Format : REQUESTHEARTBEAT ( association id , destination transport address )
*
* - > result
*
* Instructs the local endpoint to perform a HeartBeat on the specified
* destination transport address of the given association . The returned
* result should indicate whether the transmission of the HEARTBEAT
* chunk to the destination address is successful .
*
* Mandatory attributes :
*
* o association id - local handle to the SCTP association
*
* o destination transport address - the transport address of the
* association on which a heartbeat should be issued .
*/
sctp_disposition_t sctp_sf_do_prm_requestheartbeat (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
return sctp_sf_heartbeat ( ep , asoc , type , ( struct sctp_transport * ) arg ,
commands ) ;
}
/*
* 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 A1 to A9
*/
sctp_disposition_t sctp_sf_do_prm_asconf ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = arg ;
sctp_add_cmd_sf ( commands , SCTP_CMD_SETUP_T4 , SCTP_CHUNK ( chunk ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T4_RTO ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( chunk ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Ignore the primitive event
*
* The return value is the disposition of the primitive .
*/
sctp_disposition_t sctp_sf_ignore_primitive (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
SCTP_DEBUG_PRINTK ( " Primitive type %d is ignored. \n " , type . primitive ) ;
return SCTP_DISPOSITION_DISCARD ;
}
/***************************************************************************
* These are the state functions for the OTHER events .
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* Start the shutdown negotiation .
*
* From Section 9.2 :
* Once all its outstanding data has been acknowledged , the endpoint
* shall send a SHUTDOWN chunk to its peer including in the Cumulative
* TSN Ack field the last sequential TSN it has received from the peer .
* It shall then start the T2 - shutdown timer and enter the SHUTDOWN - SENT
* state . If the timer expires , the endpoint must re - send the SHUTDOWN
* with the updated last sequential TSN received from its peer .
*
* The return value is the disposition .
*/
sctp_disposition_t sctp_sf_do_9_2_start_shutdown (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * reply ;
/* Once all its outstanding data has been acknowledged, the
* endpoint shall send a SHUTDOWN chunk to its peer including
* in the Cumulative TSN Ack field the last sequential TSN it
* has received from the peer .
*/
reply = sctp_make_shutdown ( asoc , NULL ) ;
if ( ! reply )
goto nomem ;
/* Set the transport for the SHUTDOWN chunk and the timeout for the
* T2 - shutdown timer .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_SETUP_T2 , SCTP_CHUNK ( reply ) ) ;
/* It shall then start the T2-shutdown timer */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
if ( asoc - > autoclose )
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_AUTOCLOSE ) ) ;
/* and enter the SHUTDOWN-SENT state. */
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_SHUTDOWN_SENT ) ) ;
/* sctp-implguide 2.10 Issues with Heartbeating and failover
*
* HEARTBEAT . . . is discontinued after sending either SHUTDOWN
* or SHUTDOWN - ACK .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMERS_STOP , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Generate a SHUTDOWN ACK now that everything is SACK ' d .
*
* From Section 9.2 :
*
* If it has no more outstanding DATA chunks , the SHUTDOWN receiver
* shall send a SHUTDOWN ACK and start a T2 - shutdown timer of its own ,
* entering the SHUTDOWN - ACK - SENT state . If the timer expires , the
* endpoint must re - send the SHUTDOWN ACK .
*
* The return value is the disposition .
*/
sctp_disposition_t sctp_sf_do_9_2_shutdown_ack (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = ( struct sctp_chunk * ) arg ;
struct sctp_chunk * reply ;
/* There are 2 ways of getting here:
* 1 ) called in response to a SHUTDOWN chunk
* 2 ) called when SCTP_EVENT_NO_PENDING_TSN event is issued .
*
* For the case ( 2 ) , the arg parameter is set to NULL . We need
* to check that we have a chunk before accessing it ' s fields .
*/
if ( chunk ) {
if ( ! sctp_vtag_verify ( chunk , asoc ) )
return sctp_sf_pdiscard ( ep , asoc , type , arg , commands ) ;
/* Make sure that the SHUTDOWN chunk has a valid length. */
if ( ! sctp_chunk_length_valid ( chunk , sizeof ( struct sctp_shutdown_chunk_t ) ) )
return sctp_sf_violation_chunklen ( ep , asoc , type , arg ,
commands ) ;
}
/* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
* shall send a SHUTDOWN ACK . . .
*/
reply = sctp_make_shutdown_ack ( asoc , chunk ) ;
if ( ! reply )
goto nomem ;
/* Set the transport for the SHUTDOWN ACK chunk and the timeout for
* the T2 - shutdown timer .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_SETUP_T2 , SCTP_CHUNK ( reply ) ) ;
/* and start/restart a T2-shutdown timer of its own, */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
if ( asoc - > autoclose )
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_AUTOCLOSE ) ) ;
/* Enter the SHUTDOWN-ACK-SENT state. */
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_SHUTDOWN_ACK_SENT ) ) ;
/* sctp-implguide 2.10 Issues with Heartbeating and failover
*
* HEARTBEAT . . . is discontinued after sending either SHUTDOWN
* or SHUTDOWN - ACK .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_HB_TIMERS_STOP , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* Ignore the event defined as other
*
* The return value is the disposition of the event .
*/
sctp_disposition_t sctp_sf_ignore_other ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
SCTP_DEBUG_PRINTK ( " The event other type %d is ignored \n " , type . other ) ;
return SCTP_DISPOSITION_DISCARD ;
}
/************************************************************
* These are the state functions for handling timeout events .
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* RTX Timeout
*
* Section : 6.3 .3 Handle T3 - rtx Expiration
*
* Whenever the retransmission timer T3 - rtx expires for a destination
* address , do the following :
* [ See below ]
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_do_6_3_3_rtx ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_transport * transport = arg ;
if ( asoc - > overall_error_count > = asoc - > max_retrans ) {
/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_ERROR ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
/* E1) For the destination address for which the timer
* expires , adjust its ssthresh with rules defined in Section
* 7.2 .3 and set the cwnd < - MTU .
*/
/* E2) For the destination address for which the timer
* expires , set RTO < - RTO * 2 ( " back off the timer " ) . The
* maximum value discussed in rule C7 above ( RTO . max ) may be
* used to provide an upper bound to this doubling operation .
*/
/* E3) Determine how many of the earliest (i.e., lowest TSN)
* outstanding DATA chunks for the address for which the
* T3 - rtx has expired will fit into a single packet , subject
* to the MTU constraint for the path corresponding to the
* destination transport address to which the retransmission
* is being sent ( this may be different from the address for
* which the timer expires [ see Section 6.4 ] ) . Call this
* value K . Bundle and retransmit those K DATA chunks in a
* single packet to the destination endpoint .
*
* Note : Any DATA chunks that were sent to the address for
* which the T3 - rtx timer expired but did not fit in one MTU
* ( rule E3 above ) , should be marked for retransmission and
* sent as soon as cwnd allows ( normally when a SACK arrives ) .
*/
/* NB: Rules E4 and F1 are implicit in R1. */
sctp_add_cmd_sf ( commands , SCTP_CMD_RETRAN , SCTP_TRANSPORT ( transport ) ) ;
/* Do some failure management (Section 8.2). */
sctp_add_cmd_sf ( commands , SCTP_CMD_STRIKE , SCTP_TRANSPORT ( transport ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
* Generate delayed SACK on timeout
*
* Section : 6.2 Acknowledgement on Reception of DATA Chunks
*
* The guidelines on delayed acknowledgement algorithm specified in
* Section 4.2 of [ RFC2581 ] SHOULD be followed . Specifically , an
* acknowledgement SHOULD be generated for at least every second packet
* ( not every second DATA chunk ) received , and SHOULD be generated
* within 200 ms of the arrival of any unacknowledged DATA chunk . In
* some situations it may be beneficial for an SCTP transmitter to be
* more conservative than the algorithms detailed in this document
* allow . However , an SCTP transmitter MUST NOT be more aggressive than
* the following algorithms allow .
*/
sctp_disposition_t sctp_sf_do_6_2_sack ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
sctp_add_cmd_sf ( commands , SCTP_CMD_GEN_SACK , SCTP_FORCE ( ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/*
2005-06-21 00:14:57 +04:00
* sctp_sf_t1_init_timer_expire
2005-04-17 02:20:36 +04:00
*
* Section : 4 Note : 2
* Verification Tag :
* Inputs
* ( endpoint , asoc )
*
* RFC 2960 Section 4 Notes
* 2 ) If the T1 - init timer expires , the endpoint MUST retransmit INIT
* and re - start the T1 - init timer without changing state . This MUST
* be repeated up to ' Max . Init . Retransmits ' times . After that , the
* endpoint MUST abort the initialization process and report the
* error to SCTP user .
*
2005-06-21 00:14:57 +04:00
* Outputs
* ( timers , events )
*
*/
sctp_disposition_t sctp_sf_t1_init_timer_expire ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * repl = NULL ;
struct sctp_bind_addr * bp ;
int attempts = asoc - > init_err_counter + 1 ;
SCTP_DEBUG_PRINTK ( " Timer T1 expired (INIT). \n " ) ;
if ( attempts < asoc - > max_init_attempts ) {
bp = ( struct sctp_bind_addr * ) & asoc - > base . bind_addr ;
repl = sctp_make_init ( asoc , bp , GFP_ATOMIC , 0 ) ;
if ( ! repl )
return SCTP_DISPOSITION_NOMEM ;
/* Choose transport for INIT. */
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_CHOOSE_TRANSPORT ,
SCTP_CHUNK ( repl ) ) ;
/* Issue a sideeffect to do the needed accounting. */
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_INIT ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
} else {
SCTP_DEBUG_PRINTK ( " Giving up on INIT, attempts: %d "
" max_init_attempts: %d \n " ,
attempts , asoc - > max_init_attempts ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_ERROR ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
return SCTP_DISPOSITION_CONSUME ;
}
/*
* sctp_sf_t1_cookie_timer_expire
*
* Section : 4 Note : 2
* Verification Tag :
* Inputs
* ( endpoint , asoc )
*
* RFC 2960 Section 4 Notes
* 3 ) If the T1 - cookie timer expires , the endpoint MUST retransmit
2005-04-17 02:20:36 +04:00
* COOKIE ECHO and re - start the T1 - cookie timer without changing
* state . This MUST be repeated up to ' Max . Init . Retransmits ' times .
* After that , the endpoint MUST abort the initialization process and
* report the error to SCTP user .
*
* Outputs
* ( timers , events )
*
*/
2005-06-21 00:14:57 +04:00
sctp_disposition_t sctp_sf_t1_cookie_timer_expire ( const struct sctp_endpoint * ep ,
2005-04-17 02:20:36 +04:00
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
2005-06-21 00:14:57 +04:00
struct sctp_chunk * repl = NULL ;
int attempts = asoc - > init_err_counter + 1 ;
2005-04-17 02:20:36 +04:00
2005-06-21 00:14:57 +04:00
SCTP_DEBUG_PRINTK ( " Timer T1 expired (COOKIE-ECHO). \n " ) ;
2005-04-17 02:20:36 +04:00
if ( attempts < asoc - > max_init_attempts ) {
2005-06-21 00:14:57 +04:00
repl = sctp_make_cookie_echo ( asoc , NULL ) ;
2005-04-17 02:20:36 +04:00
if ( ! repl )
2005-06-21 00:14:57 +04:00
return SCTP_DISPOSITION_NOMEM ;
2005-04-17 02:20:36 +04:00
/* Issue a sideeffect to do the needed accounting. */
2005-06-21 00:14:57 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_COOKIEECHO_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T1_COOKIE ) ) ;
2005-04-17 02:20:36 +04:00
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( repl ) ) ;
} else {
sctp_add_cmd_sf ( commands , SCTP_CMD_INIT_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_ERROR ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
return SCTP_DISPOSITION_CONSUME ;
}
/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
* with the updated last sequential TSN received from its peer .
*
* An endpoint should limit the number of retransmissions of the
* SHUTDOWN chunk to the protocol parameter ' Association . Max . Retrans ' .
* If this threshold is exceeded the endpoint should destroy the TCB and
* MUST report the peer endpoint unreachable to the upper layer ( and
* thus the association enters the CLOSED state ) . The reception of any
* packet from its peer ( i . e . as the peer sends all of its queued DATA
* chunks ) should clear the endpoint ' s retransmission count and restart
* the T2 - Shutdown timer , giving its peer ample opportunity to transmit
* all of its queued DATA chunks that have not yet been sent .
*/
sctp_disposition_t sctp_sf_t2_timer_expire ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * reply = NULL ;
SCTP_DEBUG_PRINTK ( " Timer T2 expired. \n " ) ;
if ( asoc - > overall_error_count > = asoc - > max_retrans ) {
/* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_ERROR ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
}
switch ( asoc - > state ) {
case SCTP_STATE_SHUTDOWN_SENT :
reply = sctp_make_shutdown ( asoc , NULL ) ;
break ;
case SCTP_STATE_SHUTDOWN_ACK_SENT :
reply = sctp_make_shutdown_ack ( asoc , NULL ) ;
break ;
default :
BUG ( ) ;
break ;
} ;
if ( ! reply )
goto nomem ;
/* Do some failure management (Section 8.2). */
sctp_add_cmd_sf ( commands , SCTP_CMD_STRIKE ,
SCTP_TRANSPORT ( asoc - > shutdown_last_sent_to ) ) ;
/* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
* the T2 - shutdown timer .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_SETUP_T2 , SCTP_CHUNK ( reply ) ) ;
/* Restart the T2-shutdown timer. */
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T2_SHUTDOWN ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
return SCTP_DISPOSITION_CONSUME ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/*
* ADDIP Section 4.1 ASCONF CHunk Procedures
* If the T4 RTO timer expires the endpoint should do B1 to B5
*/
sctp_disposition_t sctp_sf_t4_timer_expire (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * chunk = asoc - > addip_last_asconf ;
struct sctp_transport * transport = chunk - > transport ;
/* ADDIP 4.1 B1) Increment the error counters and perform path failure
* detection on the appropriate destination address as defined in
* RFC2960 [ 5 ] section 8.1 and 8.2 .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_STRIKE , SCTP_TRANSPORT ( transport ) ) ;
/* Reconfig T4 timer and transport. */
sctp_add_cmd_sf ( commands , SCTP_CMD_SETUP_T4 , SCTP_CHUNK ( chunk ) ) ;
/* ADDIP 4.1 B2) Increment the association error counters and perform
* endpoint failure detection on the association as defined in
* RFC2960 [ 5 ] section 8.1 and 8.2 .
* association error counter is incremented in SCTP_CMD_STRIKE .
*/
if ( asoc - > overall_error_count > = asoc - > max_retrans ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_STOP ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T4_RTO ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_ERROR ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_INC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_DISPOSITION_ABORT ;
}
/* ADDIP 4.1 B3) Back-off the destination address RTO value to which
* the ASCONF chunk was sent by doubling the RTO timer value .
* This is done in SCTP_CMD_STRIKE .
*/
/* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
* choose an alternate destination address ( please refer to RFC2960
* [ 5 ] section 6.4 .1 ) . An endpoint MUST NOT add new parameters to this
* chunk , it MUST be the same ( including its serial number ) as the last
* ASCONF sent .
*/
sctp_chunk_hold ( asoc - > addip_last_asconf ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( asoc - > addip_last_asconf ) ) ;
/* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
* destination is selected , then the RTO used will be that of the new
* destination address .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_RESTART ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T4_RTO ) ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/* sctpimpguide-05 Section 2.12.2
* The sender of the SHUTDOWN MAY also start an overall guard timer
* ' T5 - shutdown - guard ' to bound the overall time for shutdown sequence .
* At the expiration of this timer the sender SHOULD abort the association
* by sending an ABORT chunk .
*/
sctp_disposition_t sctp_sf_t5_timer_expire ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
struct sctp_chunk * reply = NULL ;
SCTP_DEBUG_PRINTK ( " Timer T5 expired. \n " ) ;
reply = sctp_make_abort ( asoc , NULL , 0 ) ;
if ( ! reply )
goto nomem ;
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY , SCTP_CHUNK ( reply ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_ERROR ) ) ;
return SCTP_DISPOSITION_DELETE_TCB ;
nomem :
return SCTP_DISPOSITION_NOMEM ;
}
/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
* the association is automatically closed by starting the shutdown process .
* The work that needs to be done is same as when SHUTDOWN is initiated by
* the user . So this routine looks same as sctp_sf_do_9_2_prm_shutdown ( ) .
*/
sctp_disposition_t sctp_sf_autoclose_timer_expire (
const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
int disposition ;
/* From 9.2 Shutdown of an Association
* Upon receipt of the SHUTDOWN primitive from its upper
* layer , the endpoint enters SHUTDOWN - PENDING state and
* remains there until all outstanding data has been
* acknowledged by its peer . The endpoint accepts no new data
* from its upper layer , but retransmits data to the far end
* if necessary to fill gaps .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_NEW_STATE ,
SCTP_STATE ( SCTP_STATE_SHUTDOWN_PENDING ) ) ;
/* sctpimpguide-05 Section 2.12.2
* The sender of the SHUTDOWN MAY also start an overall guard timer
* ' T5 - shutdown - guard ' to bound the overall time for shutdown sequence .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_TIMER_START ,
SCTP_TO ( SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD ) ) ;
disposition = SCTP_DISPOSITION_CONSUME ;
if ( sctp_outq_is_empty ( & asoc - > outqueue ) ) {
disposition = sctp_sf_do_9_2_start_shutdown ( ep , asoc , type ,
arg , commands ) ;
}
return disposition ;
}
/*****************************************************************************
* These are sa state functions which could apply to all types of events .
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* This table entry is not implemented .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_not_impl ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
return SCTP_DISPOSITION_NOT_IMPL ;
}
/*
* This table entry represents a bug .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_bug ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
return SCTP_DISPOSITION_BUG ;
}
/*
* This table entry represents the firing of a timer in the wrong state .
* Since timer deletion cannot be guaranteed a timer ' may ' end up firing
* when the association is in the wrong state . This event should
* be ignored , so as to prevent any rearming of the timer .
*
* Inputs
* ( endpoint , asoc , chunk )
*
* The return value is the disposition of the chunk .
*/
sctp_disposition_t sctp_sf_timer_ignore ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const sctp_subtype_t type ,
void * arg ,
sctp_cmd_seq_t * commands )
{
SCTP_DEBUG_PRINTK ( " Timer %d ignored. \n " , type . chunk ) ;
return SCTP_DISPOSITION_CONSUME ;
}
/********************************************************************
* 2 nd Level Abstractions
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Pull the SACK chunk based on the SACK header. */
static struct sctp_sackhdr * sctp_sm_pull_sack ( struct sctp_chunk * chunk )
{
struct sctp_sackhdr * sack ;
unsigned int len ;
__u16 num_blocks ;
__u16 num_dup_tsns ;
/* Protect ourselves from reading too far into
* the skb from a bogus sender .
*/
sack = ( struct sctp_sackhdr * ) chunk - > skb - > data ;
num_blocks = ntohs ( sack - > num_gap_ack_blocks ) ;
num_dup_tsns = ntohs ( sack - > num_dup_tsns ) ;
len = sizeof ( struct sctp_sackhdr ) ;
len + = ( num_blocks + num_dup_tsns ) * sizeof ( __u32 ) ;
if ( len > chunk - > skb - > len )
return NULL ;
skb_pull ( chunk - > skb , len ) ;
return sack ;
}
/* Create an ABORT packet to be sent as a response, with the specified
* error causes .
*/
static struct sctp_packet * sctp_abort_pkt_new ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
const void * payload ,
size_t paylen )
{
struct sctp_packet * packet ;
struct sctp_chunk * abort ;
packet = sctp_ootb_pkt_new ( asoc , chunk ) ;
if ( packet ) {
/* Make an ABORT.
* The T bit will be set if the asoc is NULL .
*/
abort = sctp_make_abort ( asoc , chunk , paylen ) ;
if ( ! abort ) {
sctp_ootb_pkt_free ( packet ) ;
return NULL ;
}
2005-04-28 22:58:43 +04:00
/* Reflect vtag if T-Bit is set */
if ( sctp_test_T_bit ( abort ) )
packet - > vtag = ntohl ( chunk - > sctp_hdr - > vtag ) ;
2005-04-17 02:20:36 +04:00
/* Add specified error causes, i.e., payload, to the
* end of the chunk .
*/
sctp_addto_chunk ( abort , paylen , payload ) ;
/* Set the skb to the belonging sock for accounting. */
abort - > skb - > sk = ep - > base . sk ;
sctp_packet_append_chunk ( packet , abort ) ;
}
return packet ;
}
/* Allocate a packet for responding in the OOTB conditions. */
static struct sctp_packet * sctp_ootb_pkt_new ( const struct sctp_association * asoc ,
const struct sctp_chunk * chunk )
{
struct sctp_packet * packet ;
struct sctp_transport * transport ;
__u16 sport ;
__u16 dport ;
__u32 vtag ;
/* Get the source and destination port from the inbound packet. */
sport = ntohs ( chunk - > sctp_hdr - > dest ) ;
dport = ntohs ( chunk - > sctp_hdr - > source ) ;
/* The V-tag is going to be the same as the inbound packet if no
* association exists , otherwise , use the peer ' s vtag .
*/
if ( asoc ) {
vtag = asoc - > peer . i . init_tag ;
} else {
/* Special case the INIT and stale COOKIE_ECHO as there is no
* vtag yet .
*/
switch ( chunk - > chunk_hdr - > type ) {
case SCTP_CID_INIT :
{
sctp_init_chunk_t * init ;
init = ( sctp_init_chunk_t * ) chunk - > chunk_hdr ;
vtag = ntohl ( init - > init_hdr . init_tag ) ;
break ;
}
default :
vtag = ntohl ( chunk - > sctp_hdr - > vtag ) ;
break ;
}
}
/* Make a transport for the bucket, Eliza... */
transport = sctp_transport_new ( sctp_source ( chunk ) , GFP_ATOMIC ) ;
if ( ! transport )
goto nomem ;
/* Cache a route for the transport with the chunk's destination as
* the source address .
*/
sctp_transport_route ( transport , ( union sctp_addr * ) & chunk - > dest ,
sctp_sk ( sctp_get_ctl_sock ( ) ) ) ;
packet = sctp_packet_init ( & transport - > packet , transport , sport , dport ) ;
packet = sctp_packet_config ( packet , vtag , 0 ) ;
return packet ;
nomem :
return NULL ;
}
/* Free the packet allocated earlier for responding in the OOTB condition. */
void sctp_ootb_pkt_free ( struct sctp_packet * packet )
{
sctp_transport_free ( packet - > transport ) ;
}
/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
static void sctp_send_stale_cookie_err ( const struct sctp_endpoint * ep ,
const struct sctp_association * asoc ,
const struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands ,
struct sctp_chunk * err_chunk )
{
struct sctp_packet * packet ;
if ( err_chunk ) {
packet = sctp_ootb_pkt_new ( asoc , chunk ) ;
if ( packet ) {
struct sctp_signed_cookie * cookie ;
/* Override the OOTB vtag from the cookie. */
cookie = chunk - > subh . cookie_hdr ;
packet - > vtag = cookie - > c . peer_vtag ;
/* Set the skb to the belonging sock for accounting. */
err_chunk - > skb - > sk = ep - > base . sk ;
sctp_packet_append_chunk ( packet , err_chunk ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_SEND_PKT ,
SCTP_PACKET ( packet ) ) ;
SCTP_INC_STATS ( SCTP_MIB_OUTCTRLCHUNKS ) ;
} else
sctp_chunk_free ( err_chunk ) ;
}
}
/* Process a data chunk */
static int sctp_eat_data ( const struct sctp_association * asoc ,
struct sctp_chunk * chunk ,
sctp_cmd_seq_t * commands )
{
sctp_datahdr_t * data_hdr ;
struct sctp_chunk * err ;
size_t datalen ;
sctp_verb_t deliver ;
int tmp ;
__u32 tsn ;
2005-11-12 03:08:24 +03:00
int account_value ;
struct sock * sk = asoc - > base . sk ;
2005-04-17 02:20:36 +04:00
data_hdr = chunk - > subh . data_hdr = ( sctp_datahdr_t * ) chunk - > skb - > data ;
skb_pull ( chunk - > skb , sizeof ( sctp_datahdr_t ) ) ;
tsn = ntohl ( data_hdr - > tsn ) ;
SCTP_DEBUG_PRINTK ( " eat_data: TSN 0x%x. \n " , tsn ) ;
/* ASSERT: Now skb->data is really the user data. */
2005-11-12 03:08:24 +03:00
/*
* if we are established , and we have used up our receive
* buffer memory , drop the frame
*/
if ( asoc - > state = = SCTP_STATE_ESTABLISHED ) {
/*
* If the receive buffer policy is 1 , then each
* association can allocate up to sk_rcvbuf bytes
* otherwise , all the associations in aggregate
* may allocate up to sk_rcvbuf bytes
*/
if ( asoc - > ep - > rcvbuf_policy )
account_value = atomic_read ( & asoc - > rmem_alloc ) ;
else
account_value = atomic_read ( & sk - > sk_rmem_alloc ) ;
if ( account_value > sk - > sk_rcvbuf )
return SCTP_IERROR_IGNORE_TSN ;
}
2005-04-17 02:20:36 +04:00
/* Process ECN based congestion.
*
* Since the chunk structure is reused for all chunks within
* a packet , we use ecn_ce_done to track if we ' ve already
* done CE processing for this packet .
*
* We need to do ECN processing even if we plan to discard the
* chunk later .
*/
if ( ! chunk - > ecn_ce_done ) {
struct sctp_af * af ;
chunk - > ecn_ce_done = 1 ;
af = sctp_get_af_specific (
ipver2af ( chunk - > skb - > nh . iph - > version ) ) ;
if ( af & & af - > is_ce ( chunk - > skb ) & & asoc - > peer . ecn_capable ) {
/* Do real work as sideffect. */
sctp_add_cmd_sf ( commands , SCTP_CMD_ECN_CE ,
SCTP_U32 ( tsn ) ) ;
}
}
tmp = sctp_tsnmap_check ( & asoc - > peer . tsn_map , tsn ) ;
if ( tmp < 0 ) {
/* The TSN is too high--silently discard the chunk and
* count on it getting retransmitted later .
*/
return SCTP_IERROR_HIGH_TSN ;
} else if ( tmp > 0 ) {
/* This is a duplicate. Record it. */
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_DUP , SCTP_U32 ( tsn ) ) ;
return SCTP_IERROR_DUP_TSN ;
}
/* This is a new TSN. */
/* Discard if there is no room in the receive window.
* Actually , allow a little bit of overflow ( up to a MTU ) .
*/
datalen = ntohs ( chunk - > chunk_hdr - > length ) ;
datalen - = sizeof ( sctp_data_chunk_t ) ;
deliver = SCTP_CMD_CHUNK_ULP ;
/* Think about partial delivery. */
if ( ( datalen > = asoc - > rwnd ) & & ( ! asoc - > ulpq . pd_mode ) ) {
/* Even if we don't accept this chunk there is
* memory pressure .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_PART_DELIVER , SCTP_NULL ( ) ) ;
}
/* Spill over rwnd a little bit. Note: While allowed, this spill over
* seems a bit troublesome in that frag_point varies based on
* PMTU . In cases , such as loopback , this might be a rather
* large spill over .
*/
if ( ! asoc - > rwnd | | asoc - > rwnd_over | |
( datalen > asoc - > rwnd + asoc - > frag_point ) ) {
/* If this is the next TSN, consider reneging to make
* room . Note : Playing nice with a confused sender . A
* malicious sender can still eat up all our buffer
* space and in the future we may want to detect and
* do more drastic reneging .
*/
if ( sctp_tsnmap_has_gap ( & asoc - > peer . tsn_map ) & &
( sctp_tsnmap_get_ctsn ( & asoc - > peer . tsn_map ) + 1 ) = = tsn ) {
SCTP_DEBUG_PRINTK ( " Reneging for tsn:%u \n " , tsn ) ;
deliver = SCTP_CMD_RENEGE ;
} else {
SCTP_DEBUG_PRINTK ( " Discard tsn: %u len: %Zd, "
" rwnd: %d \n " , tsn , datalen ,
asoc - > rwnd ) ;
return SCTP_IERROR_IGNORE_TSN ;
}
}
/*
* Section 3.3 .10 .9 No User Data ( 9 )
*
* Cause of error
* - - - - - - - - - - - - - - -
* No User Data : This error cause is returned to the originator of a
* DATA chunk if a received DATA chunk has no user data .
*/
if ( unlikely ( 0 = = datalen ) ) {
err = sctp_make_abort_no_data ( asoc , chunk , tsn ) ;
if ( err ) {
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( err ) ) ;
}
/* We are going to ABORT, so we might as well stop
* processing the rest of the chunks in the packet .
*/
sctp_add_cmd_sf ( commands , SCTP_CMD_DISCARD_PACKET , SCTP_NULL ( ) ) ;
sctp_add_cmd_sf ( commands , SCTP_CMD_ASSOC_FAILED ,
SCTP_U32 ( SCTP_ERROR_NO_DATA ) ) ;
SCTP_INC_STATS ( SCTP_MIB_ABORTEDS ) ;
SCTP_DEC_STATS ( SCTP_MIB_CURRESTAB ) ;
return SCTP_IERROR_NO_DATA ;
}
/* If definately accepting the DATA chunk, record its TSN, otherwise
* wait for renege processing .
*/
if ( SCTP_CMD_CHUNK_ULP = = deliver )
sctp_add_cmd_sf ( commands , SCTP_CMD_REPORT_TSN , SCTP_U32 ( tsn ) ) ;
/* Note: Some chunks may get overcounted (if we drop) or overcounted
* if we renege and the chunk arrives again .
*/
if ( chunk - > chunk_hdr - > flags & SCTP_DATA_UNORDERED )
SCTP_INC_STATS ( SCTP_MIB_INUNORDERCHUNKS ) ;
else
SCTP_INC_STATS ( SCTP_MIB_INORDERCHUNKS ) ;
/* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
*
* If an endpoint receive a DATA chunk with an invalid stream
* identifier , it shall acknowledge the reception of the DATA chunk
* following the normal procedure , immediately send an ERROR chunk
* with cause set to " Invalid Stream Identifier " ( See Section 3.3 .10 )
* and discard the DATA chunk .
*/
if ( ntohs ( data_hdr - > stream ) > = asoc - > c . sinit_max_instreams ) {
err = sctp_make_op_error ( asoc , chunk , SCTP_ERROR_INV_STRM ,
& data_hdr - > stream ,
sizeof ( data_hdr - > stream ) ) ;
if ( err )
sctp_add_cmd_sf ( commands , SCTP_CMD_REPLY ,
SCTP_CHUNK ( err ) ) ;
return SCTP_IERROR_BAD_STREAM ;
}
/* Send the data up to the user. Note: Schedule the
* SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK , as the SACK
* chunk needs the updated rwnd .
*/
sctp_add_cmd_sf ( commands , deliver , SCTP_CHUNK ( chunk ) ) ;
return SCTP_IERROR_NO_ERROR ;
}