#
# syslog.pl
#
# $Log: syslog.pl,v $
#
# tom christiansen <[email protected]>
# modified to use sockets by Larry Wall <[email protected]>
# NOTE: openlog now takes three arguments, just like openlog(3)
#
# call syslog() with a string priority and a list of printf() args
# like syslog(3)
#
# usage: require 'syslog.pl';
#
# then (put these all in a script to test function)
#
#
# do openlog($program,'cons,pid','user');
# do syslog('info','this is another test');
# do syslog('mail|warning','this is a better test: %d', time);
# do closelog();
#
# do syslog('debug','this is the last test');
# do openlog("$program $$",'ndelay','user');
# do syslog('notice','fooprogram: this is really done');
#
# $! = 55;
# do syslog('info','problem was %m'); # %m == $! in syslog(3)

package syslog;

use warnings::register;

$host = 'localhost' unless $host; # set $syslog'host to change

if ($] >= 5 && warnings::enabled()) {
warnings::warn("You should 'use Sys::Syslog' instead; continuing");
}

require 'syslog.ph';

eval 'use Socket; 1' ||
eval { require "socket.ph" } ||
require "sys/socket.ph";

$maskpri = &LOG_UPTO(&LOG_DEBUG);

sub main'openlog {
($ident, $logopt, $facility) = @_; # package vars
$lo_pid = $logopt =~ /\bpid\b/;
$lo_ndelay = $logopt =~ /\bndelay\b/;
$lo_cons = $logopt =~ /\bcons\b/;
$lo_nowait = $logopt =~ /\bnowait\b/;
&connect if $lo_ndelay;
}

sub main'closelog {
$facility = $ident = '';
&disconnect;
}

sub main'setlogmask {
local($oldmask) = $maskpri;
$maskpri = shift;
$oldmask;
}

sub main'syslog {
local($priority) = shift;
local($mask) = shift;
local($message, $whoami);
local(@words, $num, $numpri, $numfac, $sum);
local($facility) = $facility; # may need to change temporarily.

die "syslog: expected both priority and mask" unless $mask && $priority;

@words = split(/\W+/, $priority, 2);# Allow "level" or "level|facility".
undef $numpri;
undef $numfac;
foreach (@words) {
$num = &xlate($_); # Translate word to number.
if (/^kern$/ || $num < 0) {
die "syslog: invalid level/facility: $_\n";
}
elsif ($num <= &LOG_PRIMASK) {
die "syslog: too many levels given: $_\n" if defined($numpri);
$numpri = $num;
return 0 unless &LOG_MASK($numpri) & $maskpri;
}
else {
die "syslog: too many facilities given: $_\n" if defined($numfac);
$facility = $_;
$numfac = $num;
}
}

die "syslog: level must be given\n" unless defined($numpri);

if (!defined($numfac)) { # Facility not specified in this call.
$facility = 'user' unless $facility;
$numfac = &xlate($facility);
}

&connect unless $connected;

$whoami = $ident;

if (!$ident && $mask =~ /^(\S.*):\s?(.*)/) {
$whoami = $1;
$mask = $2;
}

unless ($whoami) {
($whoami = getlogin) ||
($whoami = getpwuid($<)) ||
($whoami = 'syslog');
}

$whoami .= "[$$]" if $lo_pid;

$mask =~ s/%m/$!/g;
$mask .= "\n" unless $mask =~ /\n$/;
$message = sprintf ($mask, @_);

$sum = $numpri + $numfac;
unless (send(SYSLOG,"<$sum>$whoami: $message",0)) {
if ($lo_cons) {
if ($pid = fork) {
unless ($lo_nowait) {
do {$died = wait;} until $died == $pid || $died < 0;
}
}
else {
open(CONS,">/dev/console");
print CONS "<$facility.$priority>$whoami: $message\r";
exit if defined $pid; # if fork failed, we're parent
close CONS;
}
}
}
}

sub xlate {
local($name) = @_;
$name = uc $name;
$name = "LOG_$name" unless $name =~ /^LOG_/;
$name = "syslog'$name";
defined &$name ? &$name : -1;
}

sub connect {
$pat = 'S n C4 x8';

$af_unix = &AF_UNIX;
$af_inet = &AF_INET;

$stream = &SOCK_STREAM;
$datagram = &SOCK_DGRAM;

($name,$aliases,$proto) = getprotobyname('udp');
$udp = $proto;

($name,$aliases,$port,$proto) = getservbyname('syslog','udp');
$syslog = $port;

if (chop($myname = `hostname`)) {
($name,$aliases,$addrtype,$length,@addrs) = gethostbyname($myname);
die "Can't lookup $myname\n" unless $name;
@bytes = unpack("C4",$addrs[0]);
}
else {
@bytes = (0,0,0,0);
}
$this = pack($pat, $af_inet, 0, @bytes);

if ($host =~ /^\d+\./) {
@bytes = split(/\./,$host);
}
else {
($name,$aliases,$addrtype,$length,@addrs) = gethostbyname($host);
die "Can't lookup $host\n" unless $name;
@bytes = unpack("C4",$addrs[0]);
}
$that = pack($pat,$af_inet,$syslog,@bytes);

socket(SYSLOG,$af_inet,$datagram,$udp) || die "socket: $!\n";
bind(SYSLOG,$this) || die "bind: $!\n";
connect(SYSLOG,$that) || die "connect: $!\n";

local($old) = select(SYSLOG); $| = 1; select($old);
$connected = 1;
}

sub disconnect {
close SYSLOG;
$connected = 0;
}

1;