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Make decisions pseudo-random in udp_proxy

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Manuel Pégourié-Gonnard 2014-09-20 18:06:23 +02:00 committed by Paul Bakker
parent cd32a50d67
commit 992e13665d
1 changed files with 36 additions and 37 deletions
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73
programs/test/udp_proxy.c
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@ -44,9 +44,7 @@ int main( void )
#include <stdio.h>
#include <stdlib.h>
#if defined(POLARSSL_HAVE_TIME)
#include <time.h>
#endif
/* For select() */
#if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
@ -87,15 +85,17 @@ int main( void )
" listen_port=%%d default: 4433\n" \
"\n" \
" duplicate=%%d default: 0 (no duplication)\n" \
" duplicate 1 packet every N packets\n" \
" duplicate about 1:N packets randomly\n" \
" delay=%%d default: 0 (no delayed packets)\n" \
" delay 1 packet every N packets\n" \
" delay about 1:N packets randomly\n" \
" delay_ccs=%%d default: 0 (don't delay ChangeCipherSuite)\n" \
" drop=%%d default: 0 (no dropped packets)\n" \
" drop 1 packet every N packets\n" \
" drop about 1:N packets randomly\n" \
" mtu=%%d default: 0 (unlimited)\n" \
" drop packets larger than N bytes\n" \
" bad_ad=%%d default: 0 (don't add bad ApplicationData)\n" \
"\n" \
" seed=%%d default: (use current time)\n" \
"\n"
/*
@ -114,30 +114,10 @@ static struct options
int drop; /* drop 1 packet in N (none if 0) */
int mtu; /* drop packets larger than this */
int bad_ad; /* inject corrupted ApplicationData record */
unsigned int seed; /* seed for "random" events */
} opt;
/*
* global counters
*/
static int dupl_cnt;
static int delay_cnt;
static int drop_cnt;
/* Do not always start with the same state */
static void randomize_counters( void )
{
#if defined(POLARSSL_HAVE_TIME)
srand( time( NULL ) );
#endif
if( opt.duplicate != 0 )
dupl_cnt = rand() % opt.duplicate;
if( opt.delay != 0 )
delay_cnt = rand() % opt.delay;
if( opt.drop != 0 )
drop_cnt = rand() % opt.drop;
}
static void exit_usage( const char *name, const char *value )
{
if( value == NULL )
@ -186,13 +166,13 @@ static void get_options( int argc, char *argv[] )
else if( strcmp( p, "duplicate" ) == 0 )
{
opt.duplicate = atoi( q );
if( opt.duplicate < 0 || opt.duplicate > 10 )
if( opt.duplicate < 0 || opt.duplicate > 20 )
exit_usage( p, q );
}
else if( strcmp( p, "delay" ) == 0 )
{
opt.delay = atoi( q );
if( opt.delay < 0 || opt.delay > 10 || opt.delay == 1 )
if( opt.delay < 0 || opt.delay > 20 || opt.delay == 1 )
exit_usage( p, q );
}
else if( strcmp( p, "delay_ccs" ) == 0 )
@ -204,7 +184,7 @@ static void get_options( int argc, char *argv[] )
else if( strcmp( p, "drop" ) == 0 )
{
opt.drop = atoi( q );
if( opt.drop < 0 || opt.drop > 10 || opt.drop == 1 )
if( opt.drop < 0 || opt.drop > 20 || opt.drop == 1 )
exit_usage( p, q );
}
else if( strcmp( p, "mtu" ) == 0 )
@ -219,6 +199,12 @@ static void get_options( int argc, char *argv[] )
if( opt.bad_ad < 0 || opt.bad_ad > 1 )
exit_usage( p, q );
}
else if( strcmp( p, "seed" ) == 0 )
{
opt.seed = atoi( q );
if( opt.seed == 0 )
exit_usage( p, q );
}
else
exit_usage( p, NULL );
}
@ -327,9 +313,8 @@ int send_packet( const packet *p, const char *why )
/* Don't duplicate Application Data, only handshake covered */
if( opt.duplicate != 0 &&
strcmp( p->type, "ApplicationData" ) != 0 &&
++dupl_cnt == opt.duplicate )
rand() % opt.duplicate == 0 )
{
dupl_cnt = 0;
print_packet( p, "duplicated" );
if( ( ret = net_send( p->dst, p->buf, p->len ) ) <= 0 )
@ -369,9 +354,9 @@ int handle_message( const char *way, int dst, int src )
strcmp( cur.type, "NewSessionTicket" ) != 0 && // temporary
strcmp( cur.type, "ChangeCipherSpec" ) != 0 && // temporary
strcmp( cur.type, "Unknown handshake" ) != 0 && // temporary
++drop_cnt == opt.drop ) )
rand() % opt.drop == 0 ) )
{
drop_cnt = 0;
; /* Nothing to do */
}
else if( ( opt.delay_ccs == 1 &&
strcmp( cur.type, "ChangeCipherSpec" ) == 0 ) ||
@ -380,9 +365,8 @@ int handle_message( const char *way, int dst, int src )
strcmp( cur.type, "NewSessionTicket" ) != 0 && // temporary
strcmp( cur.type, "ChangeCipherSpec" ) != 0 && // temporary
strcmp( cur.type, "Unknown handshake" ) != 0 && // temporary
++delay_cnt == opt.delay ) )
rand() % opt.delay == 0 ) )
{
delay_cnt = 0;
memcpy( &prev, &cur, sizeof( packet ) );
}
else
@ -416,7 +400,22 @@ int main( int argc, char *argv[] )
fd_set read_fds;
get_options( argc, argv );
randomize_counters();
/*
* Decisions to drop/delay/duplicate packets are pseudo-random: dropping
* exactly 1 in N packets would lead to problems when a flight has exactly
* N packets: the same packet would be dropped on every resend.
*
* In order to be able to reproduce problems reliably, the seed may be
* specified explicitly.
*/
if( opt.seed == 0 )
{
opt.seed = time( NULL );
printf( " . Pseudo-random seed: %u\n", opt.seed );
}
srand( opt.seed );
/*
* 0. "Connect" to the server