package Sys::Syslog;
-require 5.000;
-require Exporter;
-require DynaLoader;
+use strict;
use Carp;
+require 5.006;
+require Exporter;
-@ISA = qw(Exporter DynaLoader);
-@EXPORT = qw(openlog closelog setlogmask syslog);
-@EXPORT_OK = qw(setlogsock);
-$VERSION = '0.01';
+our $VERSION = '0.13';
+our @ISA = qw(Exporter);
+
+our %EXPORT_TAGS = (
+ standard => [qw(openlog syslog closelog setlogmask)],
+ extended => [qw(setlogsock)],
+ macros => [qw(
+ LOG_ALERT LOG_AUTH LOG_AUTHPRIV LOG_CONS LOG_CRIT LOG_CRON
+ LOG_DAEMON LOG_DEBUG LOG_EMERG LOG_ERR LOG_FACMASK LOG_FTP
+ LOG_INFO LOG_KERN LOG_LFMT LOG_LOCAL0 LOG_LOCAL1 LOG_LOCAL2
+ LOG_LOCAL3 LOG_LOCAL4 LOG_LOCAL5 LOG_LOCAL6 LOG_LOCAL7 LOG_LPR
+ LOG_MAIL LOG_NDELAY LOG_NEWS LOG_NFACILITIES LOG_NOTICE
+ LOG_NOWAIT LOG_ODELAY LOG_PERROR LOG_PID LOG_PRIMASK LOG_SYSLOG
+ LOG_USER LOG_UUCP LOG_WARNING
+ )],
+);
+
+our @EXPORT = (
+ @{$EXPORT_TAGS{standard}},
+);
+
+our @EXPORT_OK = (
+ @{$EXPORT_TAGS{extended}},
+ @{$EXPORT_TAGS{macros}},
+);
+
+# it would be nice to try stream/unix first, since that will be
+# most efficient. However streams are dodgy - see _syslog_send_stream
+my @connectMethods = ( 'tcp', 'udp', 'unix', 'stream', 'console' );
+if ($^O =~ /^(freebsd|linux)$/) {
+ @connectMethods = grep { $_ ne 'udp' } @connectMethods;
+}
+my @defaultMethods = @connectMethods;
+my $syslog_path = undef;
+my $transmit_ok = 0;
+my $current_proto = undef;
+my $failed = undef;
+my $fail_time = undef;
+our ($connected, @fallbackMethods, $syslog_send, $host);
-use Socket;
-use Sys::Hostname;
+use Socket ':all';
+use POSIX qw(strftime setlocale LC_TIME);
-# adapted from syslog.pl
-#
-# Tom Christiansen <tchrist@convex.com>
-# modified to use sockets by Larry Wall <lwall@jpl-devvax.jpl.nasa.gov>
-# NOTE: openlog now takes three arguments, just like openlog(3)
-# Modified to add UNIX domain sockets by Sean Robinson <robinson_s@sc.maricopa.edu>
-# with support from Tim Bunce <Tim.Bunce@ig.co.uk> and the perl5-porters mailing list
-# Modified to use an XS backend instead of syslog.ph by Tom Hughes <tom@compton.nu>
+=head1 NAME
-# Todo: enable connect to try all three types before failing (auto setlogsock)?
+Sys::Syslog - Perl interface to the UNIX syslog(3) calls
-=head1 NAME
+=head1 VERSION
-Sys::Syslog, openlog, closelog, setlogmask, syslog - Perl interface to the UNIX syslog(3) calls
+Version 0.13
=head1 SYNOPSIS
- use Sys::Syslog; # all except setlogsock, or:
- use Sys::Syslog qw(:DEFAULT setlogsock); # default set, plus setlogsock
+ use Sys::Syslog; # all except setlogsock(), or:
+ use Sys::Syslog qw(:DEFAULT setlogsock); # default set, plus setlogsock()
+ use Sys::Syslog qw(:standard :macros); # standard functions, plus macros
setlogsock $sock_type;
- openlog $ident, $logopt, $facility;
+ openlog $ident, $logopt, $facility; # don't forget this
syslog $priority, $format, @args;
$oldmask = setlogmask $mask_priority;
closelog;
+
=head1 DESCRIPTION
-Sys::Syslog is an interface to the UNIX C<syslog(3)> program.
+C<Sys::Syslog> is an interface to the UNIX C<syslog(3)> program.
Call C<syslog()> with a string priority and a list of C<printf()> args
just like C<syslog(3)>.
-Syslog provides the functions:
-=over
+=head1 EXPORTS
+
+C<Sys::Syslog> exports the following C<Exporter> tags:
+
+=over 4
+
+=item *
+
+C<:standard> exports the standard C<syslog(3)> functions:
+
+ openlog closelog setlogmask syslog
+
+=item *
+
+C<:extended> exports the Perl specific functions for C<syslog(3)>:
+
+ setlogsock
+
+=item *
+
+C<:macros> exports the symbols corresponding to most of your C<syslog(3)>
+macros. See L<"CONSTANTS"> for the supported constants and their meaning.
-=item openlog $ident, $logopt, $facility
+=back
+
+By default, C<Sys::Syslog> exports the symbols from the C<:standard> tag.
+
+
+=head1 FUNCTIONS
+
+=over 4
+
+=item B<openlog($ident, $logopt, $facility)>
+
+Opens the syslog.
+C<$ident> is prepended to every message. C<$logopt> contains zero or
+more of the words C<pid>, C<ndelay>, C<nowait>. The C<cons> option is
+ignored, since the failover mechanism will drop down to the console
+automatically if all other media fail. C<$facility> specifies the
+part of the system to report about, for example C<LOG_USER> or C<LOG_LOCAL0>:
+see your C<syslog(3)> documentation for the facilities available in
+your system. Facility can be given as a string or a numeric macro.
+
+This function will croak if it can't connect to the syslog daemon.
-I<$ident> is prepended to every message.
-I<$logopt> contains zero or more of the words I<pid>, I<ndelay>, I<cons>, I<nowait>.
-I<$facility> specifies the part of the system
+Note that C<openlog()> now takes three arguments, just like C<openlog(3)>.
-=item syslog $priority, $format, @args
+B<You should use openlog() before calling syslog().>
-If I<$priority> permits, logs I<($format, @args)>
-printed as by C<printf(3V)>, with the addition that I<%m>
-is replaced with C<"$!"> (the latest error message).
+B<Options>
-=item setlogmask $mask_priority
+=over 4
+
+=item *
+
+C<ndelay> - Open the connection immediately (normally, the connection is
+opened when the first message is logged).
+
+=item *
+
+C<nowait> - Don't wait for child processes that may have been created
+while logging the message. (The GNU C library does not create a child
+process, so this option has no effect on Linux.)
+
+=item *
+
+C<pid> - Include PID with each message.
+
+=back
-Sets log mask I<$mask_priority> and returns the old mask.
+B<Examples>
-=item setlogsock $sock_type (added in 5.004_02)
+Open the syslog with options C<ndelay> and C<pid>, and with facility C<LOCAL0>:
+
+ openlog($name, "ndelay,pid", "local0");
+
+Same thing, but this time using the macro corresponding to C<LOCAL0>:
+
+ openlog($name, "ndelay,pid", LOG_LOCAL0);
+
+
+=item B<syslog($priority, $message)>
+
+=item B<syslog($priority, $format, @args)>
+
+If C<$priority> permits, logs C<$message> or C<sprintf($format, @args)>
+with the addition that C<%m> in $message or C<$format> is replaced with
+C<"$!"> (the latest error message).
+
+C<$priority> can specify a level, or a level and a facility. Levels and
+facilities can be given as strings or as macros.
+
+If you didn't use C<openlog()> before using C<syslog()>, C<syslog()> will
+try to guess the C<$ident> by extracting the shortest prefix of
+C<$format> that ends in a C<":">.
+
+B<Examples>
+
+ syslog("info", $message); # informational level
+ syslog(LOG_INFO, $message); # informational level
+
+ syslog("info|local0", $message); # information level, Local0 facility
+ syslog(LOG_INFO|LOG_LOCAL0, $message); # information level, Local0 facility
+
+=over 4
+
+=item B<Note>
+
+C<Sys::Syslog> version v0.07 and older passed the C<$message> as the
+formatting string to C<sprintf()> even when no formatting arguments
+were provided. If the code calling C<syslog()> might execute with
+older versions of this module, make sure to call the function as
+C<syslog($priority, "%s", $message)> instead of C<syslog($priority,
+$message)>. This protects against hostile formatting sequences that
+might show up if $message contains tainted data.
+
+=back
+
+
+=item B<setlogmask($mask_priority)>
+
+Sets the log mask for the current process to C<$mask_priority> and
+returns the old mask. If the mask argument is 0, the current log mask
+is not modified. See L<"Levels"> for the list of available levels.
+
+B<Examples>
+
+Only log errors:
+
+ setlogmask(LOG_ERR);
+
+Log critical messages, errors and warnings:
+
+ setlogmask(LOG_CRIT|LOG_ERR|LOG_WARNING);
+
+
+=item B<setlogsock($sock_type)>
+
+=item B<setlogsock($sock_type, $stream_location)> (added in 5.004_02)
Sets the socket type to be used for the next call to
-C<openlog()> or C<syslog()> and returns TRUE on success,
-undef on failure.
+C<openlog()> or C<syslog()> and returns true on success,
+C<undef> on failure.
+
+A value of C<"unix"> will connect to the UNIX domain socket (in some
+systems a character special device) returned by the C<_PATH_LOG> macro
+(if your system defines it), or F</dev/log> or F</dev/conslog>,
+whatever is writable. A value of 'stream' will connect to the stream
+indicated by the pathname provided as the optional second parameter.
+(For example Solaris and IRIX require C<"stream"> instead of C<"unix">.)
+A value of C<"inet"> will connect to an INET socket (either C<tcp> or C<udp>,
+tried in that order) returned by C<getservbyname()>. C<"tcp"> and C<"udp"> can
+also be given as values. The value C<"console"> will send messages
+directly to the console, as for the C<"cons"> option in the logopts in
+C<openlog()>.
+
+A reference to an array can also be passed as the first parameter.
+When this calling method is used, the array should contain a list of
+sock_types which are attempted in order.
+
+The default is to try C<tcp>, C<udp>, C<unix>, C<stream>, C<console>.
-A value of 'unix' will connect to the UNIX domain socket returned by the
-C<_PATH_LOG> macro (if you system defines it) in F<syslog.h>. A value of
-'inet' will connect to an INET socket returned by getservbyname(). If
-C<_PATH_LOG> is unavailable or if getservbyname() fails, returns undef. Any
-other value croaks.
+Giving an invalid value for C<$sock_type> will croak.
-The default is for the INET socket to be used.
-=item closelog
+=item B<closelog()>
-Closes the log file.
+Closes the log file and return true on success.
=back
-Note that C<openlog> now takes three arguments, just like C<openlog(3)>.
=head1 EXAMPLES
openlog($program, 'cons,pid', 'user');
- syslog('info', 'this is another test');
+ syslog('info', '%s', 'this is another test');
syslog('mail|warning', 'this is a better test: %d', time);
closelog();
$! = 55;
syslog('info', 'problem was %m'); # %m == $! in syslog(3)
+ # Log to UDP port on $remotehost instead of logging locally
+ setlogsock('udp');
+ $Sys::Syslog::host = $remotehost;
+ openlog($program, 'ndelay', 'user');
+ syslog('info', 'something happened over here');
+
+
+=head1 CONSTANTS
+
+=head2 Facilities
+
+=over 4
+
+=item *
+
+C<LOG_AUTH> - security/authorization messages
+
+=item *
+
+C<LOG_AUTHPRIV> - security/authorization messages (private)
+
+=item *
+
+C<LOG_CRON> - clock daemon (B<cron> and B<at>)
+
+=item *
+
+C<LOG_DAEMON> - system daemons without separate facility value
+
+=item *
+
+C<LOG_FTP> - ftp daemon
+
+=item *
+
+C<LOG_KERN> - kernel messages
+
+=item *
+
+C<LOG_LOCAL0> through C<LOG_LOCAL7> - reserved for local use
+
+=item *
+
+C<LOG_LPR> - line printer subsystem
+
+=item *
+
+C<LOG_MAIL> - mail subsystem
+
+=item *
+
+C<LOG_NEWS> - USENET news subsystem
+
+=item *
+
+C<LOG_SYSLOG> - messages generated internally by B<syslogd>
+
+=item *
+
+C<LOG_USER> (default) - generic user-level messages
+
+=item *
+
+C<LOG_UUCP> - UUCP subsystem
+
+=back
+
+
+=head2 Levels
+
+=over 4
+
+=item *
+
+C<LOG_EMERG> - system is unusable
+
+=item *
+
+C<LOG_ALERT> - action must be taken immediately
+
+=item *
+
+C<LOG_CRIT> - critical conditions
+
+=item *
+
+C<LOG_ERR> - error conditions
+
+=item *
+
+C<LOG_WARNING> - warning conditions
+
+=item *
+
+C<LOG_NOTICE> - normal, but significant, condition
+
+=item *
+
+C<LOG_INFO> - informational message
+
+=item *
+
+C<LOG_DEBUG> - debug-level message
+
+=back
+
+
+=head1 DIAGNOSTICS
+
+=over 4
+
+=item Invalid argument passed to setlogsock
+
+B<(F)> You gave C<setlogsock()> an invalid value for C<$sock_type>.
+
+=item no connection to syslog available
+
+B<(F)> C<syslog()> failed to connect to the specified socket.
+
+=item stream passed to setlogsock, but %s is not writable
+
+B<(W)> You asked C<setlogsock()> to use a stream socket, but the given
+path is not writable.
+
+=item stream passed to setlogsock, but could not find any device
+
+B<(W)> You asked C<setlogsock()> to use a stream socket, but didn't
+provide a path, and C<Sys::Syslog> was unable to find an appropriate one.
+
+=item tcp passed to setlogsock, but tcp service unavailable
+
+B<(W)> You asked C<setlogsock()> to use a TCP socket, but the service
+is not available on the system.
+
+=item syslog: expecting argument %s
+
+B<(F)> You forgot to give C<syslog()> the indicated argument.
+
+=item syslog: invalid level/facility: %s
+
+B<(F)> You specified an invalid level or facility, like C<LOG_KERN>
+(which is reserved to the kernel).
+
+=item syslog: too many levels given: %s
+
+B<(F)> You specified too many levels.
+
+=item syslog: too many facilities given: %s
+
+B<(F)> You specified too many facilities.
+
+=item syslog: level must be given
+
+B<(F)> You forgot to specify a level.
+
+=item udp passed to setlogsock, but udp service unavailable
+
+B<(W)> You asked C<setlogsock()> to use a UDP socket, but the service
+is not available on the system.
+
+=item unix passed to setlogsock, but path not available
+
+B<(W)> You asked C<setlogsock()> to use a UNIX socket, but C<Sys::Syslog>
+was unable to find an appropriate an appropriate device.
+
+=back
+
+
=head1 SEE ALSO
L<syslog(3)>
+I<Syslogging with Perl>, L<http://lexington.pm.org/meetings/022001.html>
+
+
=head1 AUTHOR
Tom Christiansen E<lt>F<tchrist@perl.com>E<gt> and Larry Wall
E<lt>F<larry@wall.org>E<gt>.
UNIX domain sockets added by Sean Robinson
-E<lt>F<robinson_s@sc.maricopa.edu>E<gt> with support from Tim Bunce
-E<lt>F<Tim.Bunce@ig.co.uk>E<gt> and the perl5-porters mailing list.
+E<lt>F<robinson_s@sc.maricopa.edu>E<gt> with support from Tim Bunce
+E<lt>F<Tim.Bunce@ig.co.uk>E<gt> and the C<perl5-porters> mailing list.
Dependency on F<syslog.ph> replaced with XS code by Tom Hughes
E<lt>F<tom@compton.nu>E<gt>.
+Code for C<constant()>s regenerated by Nicholas Clark E<lt>F<nick@ccl4.org>E<gt>.
+
+Failover to different communication modes by Nick Williams
+E<lt>F<Nick.Williams@morganstanley.com>E<gt>.
+
+Extracted from core distribution for publishing on the CPAN by
+SE<eacute>bastien Aperghis-Tramoni E<lt>sebastien@aperghis.netE<gt>.
+
+
+=head1 BUGS
+
+Please report any bugs or feature requests to
+C<bug-sys-syslog at rt.cpan.org>, or through the web interface at
+L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Sys-Syslog>.
+I will be notified, and then you'll automatically be notified of progress on
+your bug as I make changes.
+
+
+=head1 SUPPORT
+
+You can find documentation for this module with the perldoc command.
+
+ perldoc Sys::Syslog
+
+You can also look for information at:
+
+=over 4
+
+=item * AnnoCPAN: Annotated CPAN documentation
+
+L<http://annocpan.org/dist/Sys-Syslog>
+
+=item * CPAN Ratings
+
+L<http://cpanratings.perl.org/d/Sys-Syslog>
+
+=item * RT: CPAN's request tracker
+
+L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Sys-Syslog>
+
+=item * Search CPAN
+
+L<http://search.cpan.org/dist/Sys-Syslog>
+
+=back
+
+
+=head1 LICENSE
+
+This program is free software; you can redistribute it and/or modify it
+under the same terms as Perl itself.
+
=cut
sub AUTOLOAD {
# This AUTOLOAD is used to 'autoload' constants from the constant()
# XS function.
-
my $constname;
our $AUTOLOAD;
($constname = $AUTOLOAD) =~ s/.*:://;
- croak "& not defined" if $constname eq 'constant';
- my $val = constant($constname);
- if ($! != 0) {
- croak "Your vendor has not defined Sys::Syslog macro $constname";
- }
+ croak "&Sys::Syslog::constant not defined" if $constname eq 'constant';
+ my ($error, $val) = constant($constname);
+ croak $error if $error;
+ no strict 'refs';
*$AUTOLOAD = sub { $val };
goto &$AUTOLOAD;
}
-bootstrap Sys::Syslog $VERSION;
+eval {
+ require XSLoader;
+ XSLoader::load('Sys::Syslog', $VERSION);
+ 1
+} or do {
+ require DynaLoader;
+ push @ISA, 'DynaLoader';
+ bootstrap Sys::Syslog $VERSION;
+};
-$maskpri = &LOG_UPTO(&LOG_DEBUG);
+our $maskpri = &LOG_UPTO(&LOG_DEBUG);
sub openlog {
- ($ident, $logopt, $facility) = @_; # package vars
- $lo_pid = $logopt =~ /\bpid\b/;
- $lo_ndelay = $logopt =~ /\bndelay\b/;
- $lo_cons = $logopt =~ /\bcons\b/;
- $lo_nowait = $logopt =~ /\bnowait\b/;
+ our ($ident, $logopt, $facility) = @_; # package vars
+ our $lo_pid = $logopt =~ /\bpid\b/;
+ our $lo_ndelay = $logopt =~ /\bndelay\b/;
+ our $lo_nowait = $logopt =~ /\bnowait\b/;
return 1 unless $lo_ndelay;
&connect;
}
sub closelog {
- $facility = $ident = '';
+ our $facility = our $ident = '';
&disconnect;
}
sub setlogmask {
- local($oldmask) = $maskpri;
- $maskpri = shift;
+ my $oldmask = $maskpri;
+ $maskpri = shift unless $_[0] == 0;
$oldmask;
}
sub setlogsock {
- local($setsock) = shift;
+ my $setsock = shift;
+ $syslog_path = shift;
&disconnect if $connected;
- if (lc($setsock) eq 'unix') {
- if (length _PATH_LOG()) {
- $sock_type = 1;
- } else {
- return undef;
+ $transmit_ok = 0;
+ @fallbackMethods = ();
+ @connectMethods = @defaultMethods;
+ if (ref $setsock eq 'ARRAY') {
+ @connectMethods = @$setsock;
+ } elsif (lc($setsock) eq 'stream') {
+ unless (defined $syslog_path) {
+ my @try = qw(/dev/log /dev/conslog);
+ if (length &_PATH_LOG) { # Undefined _PATH_LOG is "".
+ unshift @try, &_PATH_LOG;
+ }
+ for my $try (@try) {
+ if (-w $try) {
+ $syslog_path = $try;
+ last;
+ }
+ }
+ carp "stream passed to setlogsock, but could not find any device"
+ unless defined $syslog_path
}
- } elsif (lc($setsock) eq 'inet') {
- if (getservbyname('syslog','udp')) {
- undef($sock_type);
+ unless (-w $syslog_path) {
+ carp "stream passed to setlogsock, but $syslog_path is not writable";
+ return undef;
+ } else {
+ @connectMethods = ( 'stream' );
+ }
+ } elsif (lc($setsock) eq 'unix') {
+ if (length _PATH_LOG() && !defined $syslog_path) {
+ $syslog_path = _PATH_LOG();
+ @connectMethods = ( 'unix' );
} else {
- return undef;
+ carp 'unix passed to setlogsock, but path not available';
+ return undef;
}
+ } elsif (lc($setsock) eq 'tcp') {
+ if (getservbyname('syslog', 'tcp') || getservbyname('syslogng', 'tcp')) {
+ @connectMethods = ( 'tcp' );
+ } else {
+ carp "tcp passed to setlogsock, but tcp service unavailable";
+ return undef;
+ }
+ } elsif (lc($setsock) eq 'udp') {
+ if (getservbyname('syslog', 'udp')) {
+ @connectMethods = ( 'udp' );
+ } else {
+ carp "udp passed to setlogsock, but udp service unavailable";
+ return undef;
+ }
+ } elsif (lc($setsock) eq 'inet') {
+ @connectMethods = ( 'tcp', 'udp' );
+ } elsif (lc($setsock) eq 'console') {
+ @connectMethods = ( 'console' );
} else {
- croak "Invalid argument passed to setlogsock; must be 'unix' or 'inet'";
+ croak "Invalid argument passed to setlogsock; must be 'stream', 'unix', 'tcp', 'udp' or 'inet'"
}
return 1;
}
sub syslog {
- local($priority) = shift;
- local($mask) = shift;
- local($message, $whoami);
- local(@words, $num, $numpri, $numfac, $sum);
+ my $priority = shift;
+ my $mask = shift;
+ my ($message, $whoami);
+ my (@words, $num, $numpri, $numfac, $sum);
+ our $facility;
local($facility) = $facility; # may need to change temporarily.
- croak "syslog: expected both priority and mask" unless $mask && $priority;
+ croak "syslog: expecting argument \$priority" unless defined $priority;
+ croak "syslog: expecting argument \$format" unless defined $mask;
@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) {
- croak "syslog: invalid level/facility: $_";
+ if ($_ eq 'kern' || $num <= 0) {
+ croak "syslog: invalid level/facility: $_"
}
elsif ($num <= &LOG_PRIMASK) {
croak "syslog: too many levels given: $_" if defined($numpri);
&connect unless $connected;
- $whoami = $ident;
+ $whoami = our $ident;
if (!$whoami && $mask =~ /^(\S.*?):\s?(.*)/) {
$whoami = $1;
($whoami = 'syslog');
}
- $whoami .= "[$$]" if $lo_pid;
+ $whoami .= "[$$]" if our $lo_pid;
+
+ if ($mask =~ /%m/) {
+ my $err = $!;
+ # escape percent signs if sprintf will be called
+ $err =~ s/%/%%/g if @_;
+ # replace %m with $err, if preceded by an even number of percent signs
+ $mask =~ s/(?<!%)((?:%%)*)%m/$1$err/g;
+ }
- $mask =~ s/%m/$!/g;
$mask .= "\n" unless $mask =~ /\n$/;
- $message = sprintf ($mask, @_);
+ $message = @_ ? sprintf($mask, @_) : $mask;
$sum = $numpri + $numfac;
- unless (send(SYSLOG,"<$sum>$whoami: $message\0",0)) {
- if ($lo_cons) {
- if ($pid = fork) {
- unless ($lo_nowait) {
- $died = waitpid($pid, 0);
- }
+ my $oldlocale = setlocale(LC_TIME);
+ setlocale(LC_TIME, 'C');
+ my $timestamp = strftime "%b %e %T", localtime;
+ setlocale(LC_TIME, $oldlocale);
+ my $buf = "<$sum>$timestamp $whoami: $message\0";
+
+ # it's possible that we'll get an error from sending
+ # (e.g. if method is UDP and there is no UDP listener,
+ # then we'll get ECONNREFUSED on the send). So what we
+ # want to do at this point is to fallback onto a different
+ # connection method.
+ while (scalar @fallbackMethods || $syslog_send) {
+ if ($failed && (time - $fail_time) > 60) {
+ # it's been a while... maybe things have been fixed
+ @fallbackMethods = ();
+ disconnect();
+ $transmit_ok = 0; # make it look like a fresh attempt
+ &connect;
+ }
+ if ($connected && !connection_ok()) {
+ # Something was OK, but has now broken. Remember coz we'll
+ # want to go back to what used to be OK.
+ $failed = $current_proto unless $failed;
+ $fail_time = time;
+ disconnect();
+ }
+ &connect unless $connected;
+ $failed = undef if ($current_proto && $failed && $current_proto eq $failed);
+ if ($syslog_send) {
+ if (&{$syslog_send}($buf)) {
+ $transmit_ok++;
+ return 1;
}
- else {
- if (open(CONS,">/dev/console")) {
- print CONS "<$facility.$priority>$whoami: $message\r";
- close CONS;
- }
- exit if defined $pid; # if fork failed, we're parent
+ # typically doesn't happen, since errors are rare from write().
+ disconnect();
+ }
+ }
+ # could not send, could not fallback onto a working
+ # connection method. Lose.
+ return 0;
+}
+
+sub _syslog_send_console {
+ my ($buf) = @_;
+ chop($buf); # delete the NUL from the end
+ # The console print is a method which could block
+ # so we do it in a child process and always return success
+ # to the caller.
+ if (my $pid = fork) {
+ our $lo_nowait;
+ if ($lo_nowait) {
+ return 1;
+ } else {
+ if (waitpid($pid, 0) >= 0) {
+ return ($? >> 8);
+ } else {
+ # it's possible that the caller has other
+ # plans for SIGCHLD, so let's not interfere
+ return 1;
}
}
+ } else {
+ if (open(CONS, ">/dev/console")) {
+ my $ret = print CONS $buf . "\r";
+ exit ($ret) if defined $pid;
+ close CONS;
+ }
+ exit if defined $pid;
}
}
+sub _syslog_send_stream {
+ my ($buf) = @_;
+ # XXX: this only works if the OS stream implementation makes a write
+ # look like a putmsg() with simple header. For instance it works on
+ # Solaris 8 but not Solaris 7.
+ # To be correct, it should use a STREAMS API, but perl doesn't have one.
+ return syswrite(SYSLOG, $buf, length($buf));
+}
+
+sub _syslog_send_socket {
+ my ($buf) = @_;
+ return syswrite(SYSLOG, $buf, length($buf));
+ #return send(SYSLOG, $buf, 0);
+}
+
sub xlate {
- local($name) = @_;
+ my($name) = @_;
+ return $name+0 if $name =~ /^\s*\d+\s*$/;
$name = uc $name;
$name = "LOG_$name" unless $name =~ /^LOG_/;
$name = "Sys::Syslog::$name";
- eval { &$name } || -1;
+ # Can't have just eval { &$name } || -1 because some LOG_XXX may be zero.
+ my $value = eval { no strict 'refs'; &$name };
+ defined $value ? $value : -1;
}
sub connect {
- unless ($host) {
- require Sys::Hostname;
- my($host_uniq) = Sys::Hostname::hostname();
- ($host) = $host_uniq =~ /([A-Za-z0-9_.-]+)/; # allow FQDN (inc _)
+ @fallbackMethods = @connectMethods unless (scalar @fallbackMethods);
+ if ($transmit_ok && $current_proto) {
+ # Retry what we were on, because it's worked in the past.
+ unshift(@fallbackMethods, $current_proto);
}
- unless ( $sock_type ) {
- my $udp = getprotobyname('udp');
- my $syslog = getservbyname('syslog','udp');
- my $this = sockaddr_in($syslog, INADDR_ANY);
- my $that = sockaddr_in($syslog, inet_aton($host) || croak "Can't lookup $host");
- socket(SYSLOG,AF_INET,SOCK_DGRAM,$udp) || croak "socket: $!";
- connect(SYSLOG,$that) || croak "connect: $!";
+ $connected = 0;
+ my @errs = ();
+ my $proto = undef;
+ while ($proto = shift(@fallbackMethods)) {
+ no strict 'refs';
+ my $fn = "connect_$proto";
+ $connected = &$fn(\@errs) if defined &$fn;
+ last if ($connected);
+ }
+
+ $transmit_ok = 0;
+ if ($connected) {
+ $current_proto = $proto;
+ my($old) = select(SYSLOG); $| = 1; select($old);
} else {
- my $syslog = _PATH_LOG();
- length($syslog) || croak "_PATH_LOG unavailable in syslog.h";
- my $that = sockaddr_un($syslog) || croak "Can't locate $syslog";
- socket(SYSLOG,AF_UNIX,SOCK_STREAM,0) || croak "socket: $!";
- if (!connect(SYSLOG,$that)) {
- socket(SYSLOG,AF_UNIX,SOCK_DGRAM,0) || croak "socket: $!";
- connect(SYSLOG,$that) || croak "connect: $! (SOCK_DGRAM after trying SOCK_STREAM)";
- }
+ @fallbackMethods = ();
+ croak join "\n\t- ", "no connection to syslog available", @errs
+ }
+}
+
+sub connect_tcp {
+ my ($errs) = @_;
+ my $tcp = getprotobyname('tcp');
+ if (!defined $tcp) {
+ push(@{$errs}, "getprotobyname failed for tcp");
+ return 0;
+ }
+ my $syslog = getservbyname('syslog','tcp');
+ $syslog = getservbyname('syslogng','tcp') unless (defined $syslog);
+ if (!defined $syslog) {
+ push(@{$errs}, "getservbyname failed for syslog/tcp and syslogng/tcp");
+ return 0;
+ }
+
+ my $this = sockaddr_in($syslog, INADDR_ANY);
+ my $that;
+ if (defined $host) {
+ $that = inet_aton($host);
+ if (!$that) {
+ push(@{$errs}, "can't lookup $host");
+ return 0;
+ }
+ } else {
+ $that = INADDR_LOOPBACK;
+ }
+ $that = sockaddr_in($syslog, $that);
+
+ if (!socket(SYSLOG,AF_INET,SOCK_STREAM,$tcp)) {
+ push(@{$errs}, "tcp socket: $!");
+ return 0;
+ }
+ setsockopt(SYSLOG, SOL_SOCKET, SO_KEEPALIVE, 1);
+ setsockopt(SYSLOG, IPPROTO_TCP, TCP_NODELAY, 1);
+ if (!CORE::connect(SYSLOG,$that)) {
+ push(@{$errs}, "tcp connect: $!");
+ return 0;
+ }
+ $syslog_send = \&_syslog_send_socket;
+ return 1;
+}
+
+sub connect_udp {
+ my ($errs) = @_;
+ my $udp = getprotobyname('udp');
+ if (!defined $udp) {
+ push(@{$errs}, "getprotobyname failed for udp");
+ return 0;
}
- local($old) = select(SYSLOG); $| = 1; select($old);
- $connected = 1;
+ my $syslog = getservbyname('syslog','udp');
+ if (!defined $syslog) {
+ push(@{$errs}, "getservbyname failed for syslog/udp");
+ return 0;
+ }
+ my $this = sockaddr_in($syslog, INADDR_ANY);
+ my $that;
+ if (defined $host) {
+ $that = inet_aton($host);
+ if (!$that) {
+ push(@{$errs}, "can't lookup $host");
+ return 0;
+ }
+ } else {
+ $that = INADDR_LOOPBACK;
+ }
+ $that = sockaddr_in($syslog, $that);
+
+ if (!socket(SYSLOG,AF_INET,SOCK_DGRAM,$udp)) {
+ push(@{$errs}, "udp socket: $!");
+ return 0;
+ }
+ if (!CORE::connect(SYSLOG,$that)) {
+ push(@{$errs}, "udp connect: $!");
+ return 0;
+ }
+ # We want to check that the UDP connect worked. However the only
+ # way to do that is to send a message and see if an ICMP is returned
+ _syslog_send_socket("");
+ if (!connection_ok()) {
+ push(@{$errs}, "udp connect: nobody listening");
+ return 0;
+ }
+ $syslog_send = \&_syslog_send_socket;
+ return 1;
+}
+
+sub connect_stream {
+ my ($errs) = @_;
+ # might want syslog_path to be variable based on syslog.h (if only
+ # it were in there!)
+ $syslog_path = '/dev/conslog';
+ if (!-w $syslog_path) {
+ push(@{$errs}, "stream $syslog_path is not writable");
+ return 0;
+ }
+ if (!open(SYSLOG, ">" . $syslog_path)) {
+ push(@{$errs}, "stream can't open $syslog_path: $!");
+ return 0;
+ }
+ $syslog_send = \&_syslog_send_stream;
+ return 1;
+}
+
+sub connect_unix {
+ my ($errs) = @_;
+ if (length _PATH_LOG()) {
+ $syslog_path = _PATH_LOG();
+ } else {
+ push(@{$errs}, "_PATH_LOG not available in syslog.h");
+ return 0;
+ }
+ if (! -S $syslog_path) {
+ push(@{$errs}, "$syslog_path is not a socket");
+ return 0;
+ }
+ my $that = sockaddr_un($syslog_path);
+ if (!$that) {
+ push(@{$errs}, "can't locate $syslog_path");
+ return 0;
+ }
+ if (!socket(SYSLOG,AF_UNIX,SOCK_STREAM,0)) {
+ push(@{$errs}, "unix stream socket: $!");
+ return 0;
+ }
+ if (!CORE::connect(SYSLOG,$that)) {
+ if (!socket(SYSLOG,AF_UNIX,SOCK_DGRAM,0)) {
+ push(@{$errs}, "unix dgram socket: $!");
+ return 0;
+ }
+ if (!CORE::connect(SYSLOG,$that)) {
+ push(@{$errs}, "unix dgram connect: $!");
+ return 0;
+ }
+ }
+ $syslog_send = \&_syslog_send_socket;
+ return 1;
+}
+
+sub connect_console {
+ my ($errs) = @_;
+ if (!-w '/dev/console') {
+ push(@{$errs}, "console is not writable");
+ return 0;
+ }
+ $syslog_send = \&_syslog_send_console;
+ return 1;
+}
+
+# to test if the connection is still good, we need to check if any
+# errors are present on the connection. The errors will not be raised
+# by a write. Instead, sockets are made readable and the next read
+# would cause the error to be returned. Unfortunately the syslog
+# 'protocol' never provides anything for us to read. But with
+# judicious use of select(), we can see if it would be readable...
+sub connection_ok {
+ return 1 if (defined $current_proto && $current_proto eq 'console');
+ my $rin = '';
+ vec($rin, fileno(SYSLOG), 1) = 1;
+ my $ret = select $rin, undef, $rin, 0;
+ return ($ret ? 0 : 1);
}
sub disconnect {
- close SYSLOG;
$connected = 0;
+ $syslog_send = undef;
+ return close SYSLOG;
}
1;