#!/usr/bin/perl
#
# Copyright (c) 2003-2004 Linuxant inc.
#
# NOTE: The use and distribution of this software is governed by the terms in
# the file LICENSE, which is included in the package. You must read this and
# agree to these terms before using or distributing this software.
#
# This script is called as a usermodehelper to start and stop the
# DCP (Digital Call Progress) audio monitoring playback process for
# the @CNXTDRVDSC@ driver under Linux.
#
# It tries to be as system and distribution-neutral as possible.

$CNXTDCPDEVICE=$ENV{'CNXTDCPDEVICE'};
if ($CNXTDCPDEVICE eq "") {
	$CNXTDCPDEVICE=0;
}

$CNXTDCPACTION=$ENV{'CNXTDCPACTION'};
if ($CNXTDCPACTION) {
	open STDOUT, ">/var/run/@CNXTTARGET@dcpd$CNXTDCPDEVICE.out" or open STDOUT, ">/dev/null";
	open STDERR, ">/var/run/@CNXTTARGET@dcpd$CNXTDCPDEVICE.err" or open STDERR, ">/dev/console";
	open STDIN, "</dev/null";
}

if ($CNXTDCPACTION eq "start") {
	if($pid=fork) {
		# parent
		exit 0;
	} elsif (defined $pid) {
		# child continues
		$inchild=1;
	} else {
		die "$0: fork failed: $!\n";
	}

} elsif ($CNXTDCPACTION eq "stop") {
	system ("killall @CNXTTARGET@dcpd");
	exit 0;
} elsif ($CNXTDCPACTION eq "") {
} else {
	die "$0: invalid CNXTDCPACTION\n";
}

END {
#	if ($inchild) {
#		unlink $pidfile;
#	}
}

$SIG{TERM} = sub { exit; }; # execute END block
$SIG{INT} = sub { exit; }; # execute END block
$SIG{PIPE} = sub { };
$SIG{CHLD} = 'IGNORE'; # workaround for Turbolinux 2.4.18 kernel

use Errno;
use Fcntl;

$dcpdev="/dev/@CNXTTARGET@dcp$CNXTDCPDEVICE";

sleep(1); # give udev time to create DCP device

$retry=10;
while(!sysopen DCPDEV, "$dcpdev", (O_RDONLY | O_NDELAY | O_NONBLOCK)) {
	if(--$retry<=0){
		die "$0: can't open $dcpdev";
	}
	sleep(1); # give udev more time to create DCP device
}

$CNXTDCPRATE=$ENV{'CNXTDCPRATE'};
if ($CNXTDCPRATE eq "") {
	$CNXTDCPRATE=16000;
}

$blocksize=2048;


$rin = $win = $ein = "";
vec($rin, fileno(DCPDEV), 1) = 1;
$ein = $rin | $win;

# start with two-block buffer to prevent underruns
$buffersize=2*$blocksize;

$buf = pack("a$buffersize", "");

$timeout=undef;

$len=0;
$buflen=$buffersize;

$convertsamplestostereo = undef;

$unamer = `uname -r`;
$unamer =~ /^([0-9]+)\.([0-9]+)\./;
$kernmajver = $1;
$kernminver = $2;

if ($kernmajver >= 2 && $kernminver >= 6) {
	# Attempt to use ALSA before OSS on kernels >= 2.6
	@drivers = ( open_alsa, open_oss, open_sox );
} else {
	@drivers = ( open_oss, open_alsa, open_sox );
}

while(1) {

	($nfound, $timeleft) = select($rout=$rin, $wout=$win, $eout=$ein, $timeout);

	if ($nfound > 0) {
		if($rout eq $rin) {
			$r = sysread DCPDEV, $buf, $buflen - $len, $len;
			if ($r <= 0) {
				die "$0: read from $dcpdev: $!\n";
			} else {
				$len += $r;
			}
			if ($len == $buflen) {
				if((!defined(fileno(DSPDEV))) && (!defined(fileno(RECORD)))) {

					if (! -e "@CNXTETCDIR@/nodcpaudio") {
						foreach $driver (@drivers) {
							if (&$driver()) {
								last;
							}
						}
						
						if (!defined(fileno(DSPDEV))) {
							print STDERR "$0: Digital call progress playback disabled\n";
						}
					}

					if((!defined(fileno(RECORD))) && (-d "@CNXTETCDIR@/dcprecord")) {
						$cnt=0;
						while(1) {
							$recfn= sprintf "@CNXTETCDIR@/dcprecord/%03d", $cnt;
							if(sysopen (RECORD, $recfn, O_WRONLY | O_CREAT | O_EXCL, 0600)) {
								last;
							}
							if ($!{EEXIST}) {
								$cnt++;
								next;
							}
							print STDERR "$0: sysopen $recfn: $!\n";
							last;
						}
					}

					$timeout=0.5;
				}

				if(defined(fileno(RECORD))) {
					$w = syswrite RECORD, $buf, $len;
					if ($w != $len) {
						print STDERR "$0: syswrite record $len returned $w ($!)\n";
					}
				}

				if(defined(fileno(DSPDEV))) {
					if ($convertsamplestostereo) {
						@samples=unpack("S*", $buf);
						for ($c = 0; $c < @samples; $c++) {
					    	$samples[$c] = $samples[$c] | ($samples[$c] << 16);
						}
						$buf = pack("L*", @samples);
						$len *= 2;
					}
					$w = syswrite DSPDEV, $buf, $len;
					if ($w != $len) {
						print STDERR "$0: syswrite $len returned $w ($!)\n";
						if ($!{EPIPE}) {
							close DSPDEV;
						}
					}
				}

				if((!defined(fileno(DSPDEV))) && (!defined(fileno(RECORD)))) {
					sleep 5; # delay retry
					$len=0;
					$buflen=$buffersize;
					while(sysread(DCPDEV, $buf, $buflen) > 0) {};
					next;
				}

				$len = 0;
				$buflen = $blocksize;
			}
		}
		if($eout eq $ein) {
			print STDERR "$0: eout\n";
		}
	} else {
		# timeout
		if(defined(fileno(DSPDEV))) {
			close DSPDEV;
		}
		if(defined(fileno(RECORD))) {
			close RECORD;
		}
		$timeout=undef;
		$len=0;
		$buflen=$buffersize;
	}
}


sub open_oss()
{
	my $AFMT_S16_LE=0x10;
	my $AFMT_S16_BE=0x20;
	my $SNDCTL_DSP_RESET=0x5000;
	my $SNDCTL_DSP_STEREO=0xc0045003;
	my $SNDCTL_DSP_CHANNELS=0xc0045006;
	my $SNDCTL_DSP_SETFMT=0xc0045005;
	my $SNDCTL_DSP_SPEED=0xc0045002;
	my $SNDCTL_DSP_SETFRAGMENT=0xc004500a;

	my $snddev = "/dev/dsp";

	my $sndfrag = (0x7fff << 16) | (log($blocksize)/log(2));
	my $sndstereo = 0;
	my $sndchan = 1;
	my $sndfmt = $AFMT_S16_LE;
	my $sndspeed = $CNXTDCPRATE;

	my $sndfragarg = pack("L", $sndfrag);
	my $sndstereoarg = pack("L", $sndstereo);
	my $sndchanarg = pack("L", $sndchan);
	my $sndfmtarg = pack("L", $sndfmt);
	my $sndspeedarg = pack("L", $sndspeed);

	if (!((sysopen DSPDEV, "$snddev", (O_WRONLY | O_NDELAY | O_NONBLOCK)) &&
		ioctl(DSPDEV, $SNDCTL_DSP_RESET, 0) &&
		ioctl(DSPDEV, $SNDCTL_DSP_SETFRAGMENT, $sndfragarg) &&
		ioctl(DSPDEV, $SNDCTL_DSP_STEREO, $sndstereoarg) &&
		ioctl(DSPDEV, $SNDCTL_DSP_CHANNELS, $sndchanarg) &&
		ioctl(DSPDEV, $SNDCTL_DSP_SETFMT, $sndfmtarg) &&
		ioctl(DSPDEV, $SNDCTL_DSP_SPEED, $sndspeedarg)
		)) {
			print STDERR "$0: can't use $snddev (OSS): $!\n";
			return 0;
	}

	$convertsamplestostereo = unpack("L", $sndstereoarg);

	return 1;
}

sub open_alsa()
{
	if (!(open DSPDEV, "|aplay -q --file-type raw --format=S16_LE --rate=$CNXTDCPRATE 2>&1 | grep -v '^underrun'")) {
		print STDERR "$0: can't use aplay (ALSA): $!\n";
		return 0;
	}

	return 1;
}

sub open_sox()
{
	if (!(open DSPDEV, "|sox -t raw -r $CNXTDCPRATE -sw -c 1 - -t ossdsp $snddev")) {
		print STDERR "$0: can't open sox pipe: $!\n";
		return 0;
	}

	return 1;
}

