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/*
* net / dccp / timer . c
*
* An implementation of the DCCP protocol
* Arnaldo Carvalho de Melo < acme @ conectiva . com . br >
*
* This program 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 of the License , or ( at your option ) any later version .
*/
# include <linux/config.h>
# include <linux/dccp.h>
# include <linux/skbuff.h>
# include "dccp.h"
static void dccp_write_timer ( unsigned long data ) ;
static void dccp_keepalive_timer ( unsigned long data ) ;
static void dccp_delack_timer ( unsigned long data ) ;
void dccp_init_xmit_timers ( struct sock * sk )
{
inet_csk_init_xmit_timers ( sk , & dccp_write_timer , & dccp_delack_timer ,
& dccp_keepalive_timer ) ;
}
static void dccp_write_err ( struct sock * sk )
{
sk - > sk_err = sk - > sk_err_soft ? : ETIMEDOUT ;
sk - > sk_error_report ( sk ) ;
dccp_v4_send_reset ( sk , DCCP_RESET_CODE_ABORTED ) ;
dccp_done ( sk ) ;
DCCP_INC_STATS_BH ( DCCP_MIB_ABORTONTIMEOUT ) ;
}
/* A write timeout has occurred. Process the after effects. */
static int dccp_write_timeout ( struct sock * sk )
{
const struct inet_connection_sock * icsk = inet_csk ( sk ) ;
int retry_until ;
if ( sk - > sk_state = = DCCP_REQUESTING | | sk - > sk_state = = DCCP_PARTOPEN ) {
if ( icsk - > icsk_retransmits ! = 0 )
dst_negative_advice ( & sk - > sk_dst_cache ) ;
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retry_until = icsk - > icsk_syn_retries ? :
/* FIXME! */ 3 /* FIXME! sysctl_tcp_syn_retries */ ;
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} else {
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if ( icsk - > icsk_retransmits > =
/* FIXME! sysctl_tcp_retries1 */ 5 /* FIXME! */ ) {
/* NOTE. draft-ietf-tcpimpl-pmtud-01.txt requires pmtu
black hole detection . : - (
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It is place to make it . It is not made . I do not want
to make it . It is disguisting . It does not work in any
case . Let me to cite the same draft , which requires for
us to implement this :
" The one security concern raised by this memo is that ICMP black holes
are often caused by over - zealous security administrators who block
all ICMP messages . It is vitally important that those who design and
deploy security systems understand the impact of strict filtering on
upper - layer protocols . The safest web site in the world is worthless
if most TCP implementations cannot transfer data from it . It would
be far nicer to have all of the black holes fixed rather than fixing
all of the TCP implementations . "
Golden words : - ) .
*/
dst_negative_advice ( & sk - > sk_dst_cache ) ;
}
retry_until = /* FIXME! */ 15 /* FIXME! sysctl_tcp_retries2 */ ;
/*
* FIXME : see tcp_write_timout and tcp_out_of_resources
*/
}
if ( icsk - > icsk_retransmits > = retry_until ) {
/* Has it gone just too far? */
dccp_write_err ( sk ) ;
return 1 ;
}
return 0 ;
}
/* This is the same as tcp_delack_timer, sans prequeue & mem_reclaim stuff */
static void dccp_delack_timer ( unsigned long data )
{
struct sock * sk = ( struct sock * ) data ;
struct inet_connection_sock * icsk = inet_csk ( sk ) ;
bh_lock_sock ( sk ) ;
if ( sock_owned_by_user ( sk ) ) {
/* Try again later. */
icsk - > icsk_ack . blocked = 1 ;
NET_INC_STATS_BH ( LINUX_MIB_DELAYEDACKLOCKED ) ;
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sk_reset_timer ( sk , & icsk - > icsk_delack_timer ,
jiffies + TCP_DELACK_MIN ) ;
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goto out ;
}
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if ( sk - > sk_state = = DCCP_CLOSED | |
! ( icsk - > icsk_ack . pending & ICSK_ACK_TIMER ) )
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goto out ;
if ( time_after ( icsk - > icsk_ack . timeout , jiffies ) ) {
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sk_reset_timer ( sk , & icsk - > icsk_delack_timer ,
icsk - > icsk_ack . timeout ) ;
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goto out ;
}
icsk - > icsk_ack . pending & = ~ ICSK_ACK_TIMER ;
if ( inet_csk_ack_scheduled ( sk ) ) {
if ( ! icsk - > icsk_ack . pingpong ) {
/* Delayed ACK missed: inflate ATO. */
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icsk - > icsk_ack . ato = min ( icsk - > icsk_ack . ato < < 1 ,
icsk - > icsk_rto ) ;
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} else {
/* Delayed ACK missed: leave pingpong mode and
* deflate ATO .
*/
icsk - > icsk_ack . pingpong = 0 ;
icsk - > icsk_ack . ato = TCP_ATO_MIN ;
}
dccp_send_ack ( sk ) ;
NET_INC_STATS_BH ( LINUX_MIB_DELAYEDACKS ) ;
}
out :
bh_unlock_sock ( sk ) ;
sock_put ( sk ) ;
}
/*
* The DCCP retransmit timer .
*/
static void dccp_retransmit_timer ( struct sock * sk )
{
struct inet_connection_sock * icsk = inet_csk ( sk ) ;
[DCCP]: Initial feature negotiation implementation
Still needs more work, but boots and doesn't crashes, even
does some negotiation!
18:38:52.174934 127.0.0.1.43458 > 127.0.0.1.5001: request <change_l ack_ratio 2, change_r ccid 2, change_l ccid 2>
18:38:52.218526 127.0.0.1.5001 > 127.0.0.1.43458: response <nop, nop, change_l ack_ratio 2, confirm_r ccid 2 2, confirm_l ccid 2 2, confirm_r ack_ratio 2>
18:38:52.185398 127.0.0.1.43458 > 127.0.0.1.5001: <nop, confirm_r ack_ratio 2, ack_vector0 0x00, elapsed_time 212>
:-)
Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-21 04:43:56 +03:00
/* retransmit timer is used for feature negotiation throughout
* connection . In this case , no packet is re - transmitted , but rather an
* ack is generated and pending changes are splaced into its options .
*/
if ( sk - > sk_send_head = = NULL ) {
dccp_pr_debug ( " feat negotiation retransmit timeout %p \n " , sk ) ;
if ( sk - > sk_state = = DCCP_OPEN )
dccp_send_ack ( sk ) ;
goto backoff ;
}
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/*
* sk - > sk_send_head has to have one skb with
* DCCP_SKB_CB ( skb ) - > dccpd_type set to one of the retransmittable DCCP
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* packet types ( REQUEST , RESPONSE , the ACK in the 3 way handshake
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* ( PARTOPEN timer ) , etc ) .
*/
BUG_TRAP ( sk - > sk_send_head ! = NULL ) ;
/*
* More than than 4 MSL ( 8 minutes ) has passed , a RESET ( aborted ) was
* sent , no need to retransmit , this sock is dead .
*/
if ( dccp_write_timeout ( sk ) )
goto out ;
/*
* We want to know the number of packets retransmitted , not the
* total number of retransmissions of clones of original packets .
*/
if ( icsk - > icsk_retransmits = = 0 )
DCCP_INC_STATS_BH ( DCCP_MIB_TIMEOUTS ) ;
if ( dccp_retransmit_skb ( sk , sk - > sk_send_head ) < 0 ) {
/*
* Retransmission failed because of local congestion ,
* do not backoff .
*/
if ( icsk - > icsk_retransmits = = 0 )
icsk - > icsk_retransmits = 1 ;
inet_csk_reset_xmit_timer ( sk , ICSK_TIME_RETRANS ,
min ( icsk - > icsk_rto ,
TCP_RESOURCE_PROBE_INTERVAL ) ,
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DCCP_RTO_MAX ) ;
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goto out ;
}
[DCCP]: Initial feature negotiation implementation
Still needs more work, but boots and doesn't crashes, even
does some negotiation!
18:38:52.174934 127.0.0.1.43458 > 127.0.0.1.5001: request <change_l ack_ratio 2, change_r ccid 2, change_l ccid 2>
18:38:52.218526 127.0.0.1.5001 > 127.0.0.1.43458: response <nop, nop, change_l ack_ratio 2, confirm_r ccid 2 2, confirm_l ccid 2 2, confirm_r ack_ratio 2>
18:38:52.185398 127.0.0.1.43458 > 127.0.0.1.5001: <nop, confirm_r ack_ratio 2, ack_vector0 0x00, elapsed_time 212>
:-)
Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-21 04:43:56 +03:00
backoff :
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icsk - > icsk_backoff + + ;
icsk - > icsk_retransmits + + ;
icsk - > icsk_rto = min ( icsk - > icsk_rto < < 1 , DCCP_RTO_MAX ) ;
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inet_csk_reset_xmit_timer ( sk , ICSK_TIME_RETRANS , icsk - > icsk_rto ,
DCCP_RTO_MAX ) ;
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if ( icsk - > icsk_retransmits > 3 /* FIXME: sysctl_dccp_retries1 */ )
__sk_dst_reset ( sk ) ;
out : ;
}
static void dccp_write_timer ( unsigned long data )
{
struct sock * sk = ( struct sock * ) data ;
struct inet_connection_sock * icsk = inet_csk ( sk ) ;
int event = 0 ;
bh_lock_sock ( sk ) ;
if ( sock_owned_by_user ( sk ) ) {
/* Try again later */
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sk_reset_timer ( sk , & icsk - > icsk_retransmit_timer ,
jiffies + ( HZ / 20 ) ) ;
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goto out ;
}
if ( sk - > sk_state = = DCCP_CLOSED | | ! icsk - > icsk_pending )
goto out ;
if ( time_after ( icsk - > icsk_timeout , jiffies ) ) {
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sk_reset_timer ( sk , & icsk - > icsk_retransmit_timer ,
icsk - > icsk_timeout ) ;
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goto out ;
}
event = icsk - > icsk_pending ;
icsk - > icsk_pending = 0 ;
switch ( event ) {
case ICSK_TIME_RETRANS :
dccp_retransmit_timer ( sk ) ;
break ;
}
out :
bh_unlock_sock ( sk ) ;
sock_put ( sk ) ;
}
/*
* Timer for listening sockets
*/
static void dccp_response_timer ( struct sock * sk )
{
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inet_csk_reqsk_queue_prune ( sk , TCP_SYNQ_INTERVAL , DCCP_TIMEOUT_INIT ,
DCCP_RTO_MAX ) ;
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}
static void dccp_keepalive_timer ( unsigned long data )
{
struct sock * sk = ( struct sock * ) data ;
/* Only process if socket is not in use. */
bh_lock_sock ( sk ) ;
if ( sock_owned_by_user ( sk ) ) {
/* Try again later. */
inet_csk_reset_keepalive_timer ( sk , HZ / 20 ) ;
goto out ;
}
if ( sk - > sk_state = = DCCP_LISTEN ) {
dccp_response_timer ( sk ) ;
goto out ;
}
out :
bh_unlock_sock ( sk ) ;
sock_put ( sk ) ;
}