/* relay traffic from source to destination socket
*
*/
static int
relay_traffic( int ssockfd, int dsockfd, struct server_ctx* ctx,
int dfilefd, const struct in_addr* mifaddr )
{
volatile sig_atomic_t quit = 0;
int rc = 0;
ssize_t nmsgs = -1;
ssize_t nrcv = 0, nsent = 0, nwr = 0,
lrcv = 0, lsent = 0;
char* data = NULL;
size_t data_len = g_uopt.rbuf_len;
struct rdata_opt ropt;
time_t pause_time = 0, rfr_tm = time(NULL);
sigset_t ubset;
const int ALLOW_PAUSES = get_flagval( "UDPXY_ALLOW_PAUSES", 0 );
const ssize_t MAX_PAUSE_MSEC =
get_sizeval( "UDPXY_PAUSE_MSEC", 1000);
/* permissible variation in data-packet size */
static const ssize_t t_delta = 0x20;
struct dstream_ctx ds;
static const int SET_PID = 1;
struct tps_data tps;
assert( ctx && mifaddr && MAX_PAUSE_MSEC > 0 );
(void) sigemptyset (&ubset);
sigaddset (&ubset, SIGINT);
sigaddset (&ubset, SIGQUIT);
sigaddset (&ubset, SIGTERM);
/* restore the ability to receive *quit* signals */
rc = sigprocmask (SIG_UNBLOCK, &ubset, NULL);
if (0 != rc) {
mperror (g_flog, errno, "%s: sigprocmask", __func__);
return -1;
}
/* NOPs to eliminate warnings in lean version */
(void)&lrcv; (void)&lsent; (void)&t_delta;
check_fragments( NULL, 0, 0, 0, 0, g_flog );
/* INIT
*/
rc = calc_buf_settings( &nmsgs, NULL );
if (0 != rc) return -1;
TRACE( (void)tmfprintf( g_flog, "Data buffer will hold up to "
"[%d] messages\n", nmsgs ) );
rc = init_dstream_ctx( &ds, ctx->cmd, g_uopt.srcfile, nmsgs );
if( 0 != rc ) return -1;
(void) set_nice( g_uopt.nice_incr, g_flog );
do {
if( NULL == g_uopt.srcfile ) {
rc = set_timeouts( ssockfd, dsockfd,
ctx->rcv_tmout, 0,
ctx->snd_tmout, 0 );
if( 0 != rc ) break;
}
if( dsockfd > 0 ) {
rc = sync_dsockbuf_len( ssockfd, dsockfd );
if( 0 != rc ) break;
rc = send_http_response( dsockfd, 200, "OK" );
if( 0 != rc ) break;
/* timeshift: to detect PAUSE make destination
* socket non-blocking, otherwise make it blocking
* (since it might have been set unblocking earlier)
*/
rc = set_nblock( dsockfd, (ALLOW_PAUSES ? 1 : 0) );
if( 0 != rc ) break;
}
data = malloc(data_len);
if( NULL == data ) {
mperror( g_flog, errno, "%s: malloc", __func__ );
break;
}
if( g_uopt.cl_tpstat )
tpstat_init( &tps, SET_PID );
} while(0);
TRACE( (void)tmfprintf( g_flog, "Relaying traffic from socket[%d] "
"to socket[%d], buffer size=[%d], Rmsgs=[%d], pauses=[%d]\n",
ssockfd, dsockfd, data_len, g_uopt.rbuf_msgs, ALLOW_PAUSES) );
/* RELAY LOOP
*/
ropt.max_frgs = g_uopt.rbuf_msgs;
ropt.buf_tmout = g_uopt.dhold_tmout;
pause_time = 0;
while( (0 == rc) && !(quit = must_quit()) ) {
if( g_uopt.mcast_refresh > 0 ) {
check_mcast_refresh( ssockfd, &rfr_tm, mifaddr );
}
nrcv = read_data( &ds, ssockfd, data, data_len, &ropt );
if( -1 == nrcv ) break;
TRACE( check_fragments( "received new", data_len,
lrcv, nrcv, t_delta, g_flog ) );
lrcv = nrcv;
if( dsockfd && (nrcv > 0) ) {
nsent = write_data( &ds, data, nrcv, dsockfd );
if( -1 == nsent ) break;
if ( nsent < 0 ) {
if ( !ALLOW_PAUSES ) break;
if ( 0 != pause_detect( nsent, MAX_PAUSE_MSEC, &pause_time ) )
break;
}
TRACE( check_fragments("sent", nrcv,
lsent, nsent, t_delta, g_flog) );
lsent = nsent;
}
if( (dfilefd > 0) && (nrcv > 0) ) {
nwr = write_data( &ds, data, nrcv, dfilefd );
if( -1 == nwr )
break;
TRACE( check_fragments( "wrote to file",
nrcv, lsent, nwr, t_delta, g_flog ) );
lsent = nwr;
}
if( ds.flags & F_SCATTERED ) reset_pkt_registry( &ds );
if( uf_TRUE == g_uopt.cl_tpstat )
tpstat_update( ctx, &tps, nsent );
} /* end of RELAY LOOP */
/* CLEANUP
*/
TRACE( (void)tmfprintf( g_flog, "Exited relay loop: received=[%ld], "
"sent=[%ld], quit=[%ld]\n", (long)nrcv, (long)nsent, (long)quit ) );
free_dstream_ctx( &ds );
if( NULL != data ) free( data );
if( 0 != (quit = must_quit()) ) {
TRACE( (void)tmfprintf( g_flog, "Child process=[%d] must quit\n",
getpid()) );
}
return rc;
}
/* send statistics update to server (if it's time)
*/
void
tpstat_update( struct server_ctx* ctx,
struct tps_data* d, ssize_t nbytes )
{
static const double MAX_NOUPDATE_ITER = 1000.0;
static const double MAX_SEC = 10.0;
struct tput_stat ts;
int writefd = -1, rc = 0;
const int DO_NOT_SET_PID = 0;
ssize_t nwr = -1;
double nsec;
assert( ctx && d );
d->nbytes += nbytes;
nsec = difftime( time(NULL), d->tm_from );
d->niter++;
if( !((d->niter >= MAX_NOUPDATE_ITER) || (nsec >= MAX_SEC)) )
return;
/* attempt to send update to server */
d->niter = 0;
ts.sender_id = d->pid;
ts.nbytes = d->nbytes;
ts.nsec = nsec;
writefd = ctx->cpipe[1];
do {
nwr = write( writefd, &ts, sizeof(ts) );
if( nwr <= 0 ) {
if( (EINTR != errno) && (EAGAIN != errno) ) {
mperror( g_flog, errno, "%s: write", __func__ );
rc = -1;
break;
}
/* if it's an interrupt or pipe full - ignore */
TRACE( (void)tmfprintf( g_flog, "%s - write error [%s] - ignored\n",
__func__, strerror(errno)) );
break;
}
if( sizeof(ts) != (size_t)nwr ) {
(void)tmfprintf( g_flog, "%s - wrote [%d] bytes to pipe, "
"expected [%u]\n",
__func__, nwr, (int)sizeof(ts) );
rc = -1;
break;
}
/*
TRACE( (void)tmfprintf( g_flog,
"Sent TSTAT={ sender=[%ld], bytes=[%f], seconds=[%f] }\n",
(long)ts.sender_id, ts.nbytes, ts.nsec) );
*/
} while(0);
if( 0 == rc ) {
tpstat_init( d, DO_NOT_SET_PID );
}
return;
}
