| 1 |
package Sys::Syslog; |
| 2 |
require 5.006; |
| 3 |
require Exporter; |
| 4 |
require DynaLoader; |
| 5 |
use Carp; |
| 6 |
use strict; |
| 7 |
|
| 8 |
our @ISA = qw(Exporter DynaLoader); |
| 9 |
our @EXPORT = qw(openlog closelog setlogmask syslog); |
| 10 |
our @EXPORT_OK = qw(setlogsock); |
| 11 |
our $VERSION = '0.06'; |
| 12 |
|
| 13 |
# it would be nice to try stream/unix first, since that will be |
| 14 |
# most efficient. However streams are dodgy - see _syslog_send_stream |
| 15 |
my @connectMethods = ( 'tcp', 'udp', 'unix', 'stream', 'console' ); |
| 16 |
if ($^O =~ /^(freebsd|linux)$/) { |
| 17 |
@connectMethods = grep { $_ ne 'udp' } @connectMethods; |
| 18 |
} |
| 19 |
my @defaultMethods = @connectMethods; |
| 20 |
my $syslog_path = undef; |
| 21 |
my $transmit_ok = 0; |
| 22 |
my $current_proto = undef; |
| 23 |
my $failed = undef; |
| 24 |
my $fail_time = undef; |
| 25 |
our ($connected, @fallbackMethods, $syslog_send, $host); |
| 26 |
|
| 27 |
use Socket ':all'; |
| 28 |
use Sys::Hostname; |
| 29 |
|
| 30 |
=head1 NAME |
| 31 |
|
| 32 |
Sys::Syslog, openlog, closelog, setlogmask, syslog - Perl interface to the UNIX syslog(3) calls |
| 33 |
|
| 34 |
=head1 SYNOPSIS |
| 35 |
|
| 36 |
use Sys::Syslog; # all except setlogsock, or: |
| 37 |
use Sys::Syslog qw(:DEFAULT setlogsock); # default set, plus setlogsock |
| 38 |
|
| 39 |
setlogsock $sock_type; |
| 40 |
openlog $ident, $logopt, $facility; # don't forget this |
| 41 |
syslog $priority, $format, @args; |
| 42 |
$oldmask = setlogmask $mask_priority; |
| 43 |
closelog; |
| 44 |
|
| 45 |
=head1 DESCRIPTION |
| 46 |
|
| 47 |
Sys::Syslog is an interface to the UNIX C<syslog(3)> program. |
| 48 |
Call C<syslog()> with a string priority and a list of C<printf()> args |
| 49 |
just like C<syslog(3)>. |
| 50 |
|
| 51 |
Syslog provides the functions: |
| 52 |
|
| 53 |
=over 4 |
| 54 |
|
| 55 |
=item openlog $ident, $logopt, $facility |
| 56 |
|
| 57 |
I<$ident> is prepended to every message. I<$logopt> contains zero or |
| 58 |
more of the words I<pid>, I<ndelay>, I<nowait>. The cons option is |
| 59 |
ignored, since the failover mechanism will drop down to the console |
| 60 |
automatically if all other media fail. I<$facility> specifies the |
| 61 |
part of the system to report about, for example LOG_USER or LOG_LOCAL0: |
| 62 |
see your C<syslog(3)> documentation for the facilities available in |
| 63 |
your system. |
| 64 |
|
| 65 |
B<You should use openlog() before calling syslog().> |
| 66 |
|
| 67 |
=item syslog $priority, $format, @args |
| 68 |
|
| 69 |
If I<$priority> permits, logs I<($format, @args)> |
| 70 |
printed as by C<printf(3V)>, with the addition that I<%m> |
| 71 |
is replaced with C<"$!"> (the latest error message). |
| 72 |
|
| 73 |
If you didn't use openlog() before using syslog(), syslog will try to |
| 74 |
guess the I<$ident> by extracting the shortest prefix of I<$format> |
| 75 |
that ends in a ":". |
| 76 |
|
| 77 |
=item setlogmask $mask_priority |
| 78 |
|
| 79 |
Sets log mask I<$mask_priority> and returns the old mask. |
| 80 |
|
| 81 |
=item setlogsock $sock_type [$stream_location] (added in 5.004_02) |
| 82 |
|
| 83 |
Sets the socket type to be used for the next call to |
| 84 |
C<openlog()> or C<syslog()> and returns TRUE on success, |
| 85 |
undef on failure. |
| 86 |
|
| 87 |
A value of 'unix' will connect to the UNIX domain socket (in some |
| 88 |
systems a character special device) returned by the C<_PATH_LOG> macro |
| 89 |
(if your system defines it), or F</dev/log> or F</dev/conslog>, |
| 90 |
whatever is writable. A value of 'stream' will connect to the stream |
| 91 |
indicated by the pathname provided as the optional second parameter. |
| 92 |
(For example Solaris and IRIX require 'stream' instead of 'unix'.) |
| 93 |
A value of 'inet' will connect to an INET socket (either tcp or udp, |
| 94 |
tried in that order) returned by getservbyname(). 'tcp' and 'udp' can |
| 95 |
also be given as values. The value 'console' will send messages |
| 96 |
directly to the console, as for the 'cons' option in the logopts in |
| 97 |
openlog(). |
| 98 |
|
| 99 |
A reference to an array can also be passed as the first parameter. |
| 100 |
When this calling method is used, the array should contain a list of |
| 101 |
sock_types which are attempted in order. |
| 102 |
|
| 103 |
The default is to try tcp, udp, unix, stream, console. |
| 104 |
|
| 105 |
Giving an invalid value for sock_type will croak. |
| 106 |
|
| 107 |
=item closelog |
| 108 |
|
| 109 |
Closes the log file. |
| 110 |
|
| 111 |
=back |
| 112 |
|
| 113 |
Note that C<openlog> now takes three arguments, just like C<openlog(3)>. |
| 114 |
|
| 115 |
=head1 EXAMPLES |
| 116 |
|
| 117 |
openlog($program, 'cons,pid', 'user'); |
| 118 |
syslog('info', '%s', 'this is another test'); |
| 119 |
syslog('mail|warning', 'this is a better test: %d', time); |
| 120 |
closelog(); |
| 121 |
|
| 122 |
syslog('debug', 'this is the last test'); |
| 123 |
|
| 124 |
setlogsock('unix'); |
| 125 |
openlog("$program $$", 'ndelay', 'user'); |
| 126 |
syslog('notice', 'fooprogram: this is really done'); |
| 127 |
|
| 128 |
setlogsock('inet'); |
| 129 |
$! = 55; |
| 130 |
syslog('info', 'problem was %m'); # %m == $! in syslog(3) |
| 131 |
|
| 132 |
# Log to UDP port on $remotehost instead of logging locally |
| 133 |
setlogsock('udp'); |
| 134 |
$Sys::Syslog::host = $remotehost; |
| 135 |
openlog($program, 'ndelay', 'user'); |
| 136 |
syslog('info', 'something happened over here'); |
| 137 |
|
| 138 |
=head1 SEE ALSO |
| 139 |
|
| 140 |
L<syslog(3)> |
| 141 |
|
| 142 |
=head1 AUTHOR |
| 143 |
|
| 144 |
Tom Christiansen E<lt>F<tchrist@perl.com>E<gt> and Larry Wall |
| 145 |
E<lt>F<larry@wall.org>E<gt>. |
| 146 |
|
| 147 |
UNIX domain sockets added by Sean Robinson |
| 148 |
E<lt>F<robinson_s@sc.maricopa.edu>E<gt> with support from Tim Bunce |
| 149 |
E<lt>F<Tim.Bunce@ig.co.uk>E<gt> and the perl5-porters mailing list. |
| 150 |
|
| 151 |
Dependency on F<syslog.ph> replaced with XS code by Tom Hughes |
| 152 |
E<lt>F<tom@compton.nu>E<gt>. |
| 153 |
|
| 154 |
Code for constant()s regenerated by Nicholas Clark E<lt>F<nick@ccl4.org>E<gt>. |
| 155 |
|
| 156 |
Failover to different communication modes by Nick Williams |
| 157 |
E<lt>F<Nick.Williams@morganstanley.com>E<gt>. |
| 158 |
|
| 159 |
=cut |
| 160 |
|
| 161 |
sub AUTOLOAD { |
| 162 |
# This AUTOLOAD is used to 'autoload' constants from the constant() |
| 163 |
# XS function. |
| 164 |
|
| 165 |
my $constname; |
| 166 |
our $AUTOLOAD; |
| 167 |
($constname = $AUTOLOAD) =~ s/.*:://; |
| 168 |
croak "&Sys::Syslog::constant not defined" if $constname eq 'constant'; |
| 169 |
my ($error, $val) = constant($constname); |
| 170 |
if ($error) { |
| 171 |
croak $error; |
| 172 |
} |
| 173 |
no strict 'refs'; |
| 174 |
*$AUTOLOAD = sub { $val }; |
| 175 |
goto &$AUTOLOAD; |
| 176 |
} |
| 177 |
|
| 178 |
bootstrap Sys::Syslog $VERSION; |
| 179 |
|
| 180 |
our $maskpri = &LOG_UPTO(&LOG_DEBUG); |
| 181 |
|
| 182 |
sub openlog { |
| 183 |
our ($ident, $logopt, $facility) = @_; # package vars |
| 184 |
our $lo_pid = $logopt =~ /\bpid\b/; |
| 185 |
our $lo_ndelay = $logopt =~ /\bndelay\b/; |
| 186 |
our $lo_nowait = $logopt =~ /\bnowait\b/; |
| 187 |
return 1 unless $lo_ndelay; |
| 188 |
&connect; |
| 189 |
} |
| 190 |
|
| 191 |
sub closelog { |
| 192 |
our $facility = our $ident = ''; |
| 193 |
&disconnect; |
| 194 |
} |
| 195 |
|
| 196 |
sub setlogmask { |
| 197 |
my $oldmask = $maskpri; |
| 198 |
$maskpri = shift; |
| 199 |
$oldmask; |
| 200 |
} |
| 201 |
|
| 202 |
sub setlogsock { |
| 203 |
my $setsock = shift; |
| 204 |
$syslog_path = shift; |
| 205 |
&disconnect if $connected; |
| 206 |
$transmit_ok = 0; |
| 207 |
@fallbackMethods = (); |
| 208 |
@connectMethods = @defaultMethods; |
| 209 |
if (ref $setsock eq 'ARRAY') { |
| 210 |
@connectMethods = @$setsock; |
| 211 |
} elsif (lc($setsock) eq 'stream') { |
| 212 |
unless (defined $syslog_path) { |
| 213 |
my @try = qw(/dev/log /dev/conslog); |
| 214 |
if (length &_PATH_LOG) { # Undefined _PATH_LOG is "". |
| 215 |
unshift @try, &_PATH_LOG; |
| 216 |
} |
| 217 |
for my $try (@try) { |
| 218 |
if (-w $try) { |
| 219 |
$syslog_path = $try; |
| 220 |
last; |
| 221 |
} |
| 222 |
} |
| 223 |
carp "stream passed to setlogsock, but could not find any device" |
| 224 |
unless defined $syslog_path; |
| 225 |
} |
| 226 |
unless (-w $syslog_path) { |
| 227 |
carp "stream passed to setlogsock, but $syslog_path is not writable"; |
| 228 |
return undef; |
| 229 |
} else { |
| 230 |
@connectMethods = ( 'stream' ); |
| 231 |
} |
| 232 |
} elsif (lc($setsock) eq 'unix') { |
| 233 |
if (length _PATH_LOG() && !defined $syslog_path) { |
| 234 |
$syslog_path = _PATH_LOG(); |
| 235 |
@connectMethods = ( 'unix' ); |
| 236 |
} else { |
| 237 |
carp 'unix passed to setlogsock, but path not available'; |
| 238 |
return undef; |
| 239 |
} |
| 240 |
} elsif (lc($setsock) eq 'tcp') { |
| 241 |
if (getservbyname('syslog', 'tcp') || getservbyname('syslogng', 'tcp')) { |
| 242 |
@connectMethods = ( 'tcp' ); |
| 243 |
} else { |
| 244 |
carp "tcp passed to setlogsock, but tcp service unavailable"; |
| 245 |
return undef; |
| 246 |
} |
| 247 |
} elsif (lc($setsock) eq 'udp') { |
| 248 |
if (getservbyname('syslog', 'udp')) { |
| 249 |
@connectMethods = ( 'udp' ); |
| 250 |
} else { |
| 251 |
carp "udp passed to setlogsock, but udp service unavailable"; |
| 252 |
return undef; |
| 253 |
} |
| 254 |
} elsif (lc($setsock) eq 'inet') { |
| 255 |
@connectMethods = ( 'tcp', 'udp' ); |
| 256 |
} elsif (lc($setsock) eq 'console') { |
| 257 |
@connectMethods = ( 'console' ); |
| 258 |
} else { |
| 259 |
carp "Invalid argument passed to setlogsock; must be 'stream', 'unix', 'tcp', 'udp' or 'inet'"; |
| 260 |
} |
| 261 |
return 1; |
| 262 |
} |
| 263 |
|
| 264 |
sub syslog { |
| 265 |
my $priority = shift; |
| 266 |
my $mask = shift; |
| 267 |
my ($message, $whoami); |
| 268 |
my (@words, $num, $numpri, $numfac, $sum); |
| 269 |
our $facility; |
| 270 |
local($facility) = $facility; # may need to change temporarily. |
| 271 |
|
| 272 |
croak "syslog: expecting argument \$priority" unless $priority; |
| 273 |
croak "syslog: expecting argument \$format" unless $mask; |
| 274 |
|
| 275 |
@words = split(/\W+/, $priority, 2);# Allow "level" or "level|facility". |
| 276 |
undef $numpri; |
| 277 |
undef $numfac; |
| 278 |
foreach (@words) { |
| 279 |
$num = &xlate($_); # Translate word to number. |
| 280 |
if (/^kern$/ || $num < 0) { |
| 281 |
croak "syslog: invalid level/facility: $_"; |
| 282 |
} |
| 283 |
elsif ($num <= &LOG_PRIMASK) { |
| 284 |
croak "syslog: too many levels given: $_" if defined($numpri); |
| 285 |
$numpri = $num; |
| 286 |
return 0 unless &LOG_MASK($numpri) & $maskpri; |
| 287 |
} |
| 288 |
else { |
| 289 |
croak "syslog: too many facilities given: $_" if defined($numfac); |
| 290 |
$facility = $_; |
| 291 |
$numfac = $num; |
| 292 |
} |
| 293 |
} |
| 294 |
|
| 295 |
croak "syslog: level must be given" unless defined($numpri); |
| 296 |
|
| 297 |
if (!defined($numfac)) { # Facility not specified in this call. |
| 298 |
$facility = 'user' unless $facility; |
| 299 |
$numfac = &xlate($facility); |
| 300 |
} |
| 301 |
|
| 302 |
&connect unless $connected; |
| 303 |
|
| 304 |
$whoami = our $ident; |
| 305 |
|
| 306 |
if (!$whoami && $mask =~ /^(\S.*?):\s?(.*)/) { |
| 307 |
$whoami = $1; |
| 308 |
$mask = $2; |
| 309 |
} |
| 310 |
|
| 311 |
unless ($whoami) { |
| 312 |
($whoami = getlogin) || |
| 313 |
($whoami = getpwuid($<)) || |
| 314 |
($whoami = 'syslog'); |
| 315 |
} |
| 316 |
|
| 317 |
$whoami .= "[$$]" if our $lo_pid; |
| 318 |
|
| 319 |
$mask =~ s/(?<!%)%m/$!/g; |
| 320 |
$mask .= "\n" unless $mask =~ /\n$/; |
| 321 |
$message = sprintf ($mask, @_); |
| 322 |
|
| 323 |
$sum = $numpri + $numfac; |
| 324 |
my $buf = "<$sum>$whoami: $message\0"; |
| 325 |
|
| 326 |
# it's possible that we'll get an error from sending |
| 327 |
# (e.g. if method is UDP and there is no UDP listener, |
| 328 |
# then we'll get ECONNREFUSED on the send). So what we |
| 329 |
# want to do at this point is to fallback onto a different |
| 330 |
# connection method. |
| 331 |
while (scalar @fallbackMethods || $syslog_send) { |
| 332 |
if ($failed && (time - $fail_time) > 60) { |
| 333 |
# it's been a while... maybe things have been fixed |
| 334 |
@fallbackMethods = (); |
| 335 |
disconnect(); |
| 336 |
$transmit_ok = 0; # make it look like a fresh attempt |
| 337 |
&connect; |
| 338 |
} |
| 339 |
if ($connected && !connection_ok()) { |
| 340 |
# Something was OK, but has now broken. Remember coz we'll |
| 341 |
# want to go back to what used to be OK. |
| 342 |
$failed = $current_proto unless $failed; |
| 343 |
$fail_time = time; |
| 344 |
disconnect(); |
| 345 |
} |
| 346 |
&connect unless $connected; |
| 347 |
$failed = undef if ($current_proto && $failed && $current_proto eq $failed); |
| 348 |
if ($syslog_send) { |
| 349 |
if (&{$syslog_send}($buf)) { |
| 350 |
$transmit_ok++; |
| 351 |
return 1; |
| 352 |
} |
| 353 |
# typically doesn't happen, since errors are rare from write(). |
| 354 |
disconnect(); |
| 355 |
} |
| 356 |
} |
| 357 |
# could not send, could not fallback onto a working |
| 358 |
# connection method. Lose. |
| 359 |
return 0; |
| 360 |
} |
| 361 |
|
| 362 |
sub _syslog_send_console { |
| 363 |
my ($buf) = @_; |
| 364 |
chop($buf); # delete the NUL from the end |
| 365 |
# The console print is a method which could block |
| 366 |
# so we do it in a child process and always return success |
| 367 |
# to the caller. |
| 368 |
if (my $pid = fork) { |
| 369 |
our $lo_nowait; |
| 370 |
if ($lo_nowait) { |
| 371 |
return 1; |
| 372 |
} else { |
| 373 |
if (waitpid($pid, 0) >= 0) { |
| 374 |
return ($? >> 8); |
| 375 |
} else { |
| 376 |
# it's possible that the caller has other |
| 377 |
# plans for SIGCHLD, so let's not interfere |
| 378 |
return 1; |
| 379 |
} |
| 380 |
} |
| 381 |
} else { |
| 382 |
if (open(CONS, ">/dev/console")) { |
| 383 |
my $ret = print CONS $buf . "\r"; |
| 384 |
exit ($ret) if defined $pid; |
| 385 |
close CONS; |
| 386 |
} |
| 387 |
exit if defined $pid; |
| 388 |
} |
| 389 |
} |
| 390 |
|
| 391 |
sub _syslog_send_stream { |
| 392 |
my ($buf) = @_; |
| 393 |
# XXX: this only works if the OS stream implementation makes a write |
| 394 |
# look like a putmsg() with simple header. For instance it works on |
| 395 |
# Solaris 8 but not Solaris 7. |
| 396 |
# To be correct, it should use a STREAMS API, but perl doesn't have one. |
| 397 |
return syswrite(SYSLOG, $buf, length($buf)); |
| 398 |
} |
| 399 |
sub _syslog_send_socket { |
| 400 |
my ($buf) = @_; |
| 401 |
return syswrite(SYSLOG, $buf, length($buf)); |
| 402 |
#return send(SYSLOG, $buf, 0); |
| 403 |
} |
| 404 |
|
| 405 |
sub xlate { |
| 406 |
my($name) = @_; |
| 407 |
return $name+0 if $name =~ /^\s*\d+\s*$/; |
| 408 |
$name = uc $name; |
| 409 |
$name = "LOG_$name" unless $name =~ /^LOG_/; |
| 410 |
$name = "Sys::Syslog::$name"; |
| 411 |
# Can't have just eval { &$name } || -1 because some LOG_XXX may be zero. |
| 412 |
my $value = eval { no strict 'refs'; &$name }; |
| 413 |
defined $value ? $value : -1; |
| 414 |
} |
| 415 |
|
| 416 |
sub connect { |
| 417 |
@fallbackMethods = @connectMethods unless (scalar @fallbackMethods); |
| 418 |
if ($transmit_ok && $current_proto) { |
| 419 |
# Retry what we were on, because it's worked in the past. |
| 420 |
unshift(@fallbackMethods, $current_proto); |
| 421 |
} |
| 422 |
$connected = 0; |
| 423 |
my @errs = (); |
| 424 |
my $proto = undef; |
| 425 |
while ($proto = shift(@fallbackMethods)) { |
| 426 |
no strict 'refs'; |
| 427 |
my $fn = "connect_$proto"; |
| 428 |
$connected = &$fn(\@errs) if defined &$fn; |
| 429 |
last if ($connected); |
| 430 |
} |
| 431 |
|
| 432 |
$transmit_ok = 0; |
| 433 |
if ($connected) { |
| 434 |
$current_proto = $proto; |
| 435 |
my($old) = select(SYSLOG); $| = 1; select($old); |
| 436 |
} else { |
| 437 |
@fallbackMethods = (); |
| 438 |
foreach my $err (@errs) { |
| 439 |
carp $err; |
| 440 |
} |
| 441 |
croak "no connection to syslog available"; |
| 442 |
} |
| 443 |
} |
| 444 |
|
| 445 |
sub connect_tcp { |
| 446 |
my ($errs) = @_; |
| 447 |
unless ($host) { |
| 448 |
require Sys::Hostname; |
| 449 |
my($host_uniq) = Sys::Hostname::hostname(); |
| 450 |
($host) = $host_uniq =~ /([A-Za-z0-9_.-]+)/; # allow FQDN (inc _) |
| 451 |
} |
| 452 |
my $tcp = getprotobyname('tcp'); |
| 453 |
if (!defined $tcp) { |
| 454 |
push(@{$errs}, "getprotobyname failed for tcp"); |
| 455 |
return 0; |
| 456 |
} |
| 457 |
my $syslog = getservbyname('syslog','tcp'); |
| 458 |
$syslog = getservbyname('syslogng','tcp') unless (defined $syslog); |
| 459 |
if (!defined $syslog) { |
| 460 |
push(@{$errs}, "getservbyname failed for tcp"); |
| 461 |
return 0; |
| 462 |
} |
| 463 |
|
| 464 |
my $this = sockaddr_in($syslog, INADDR_ANY); |
| 465 |
my $that = sockaddr_in($syslog, inet_aton($host)); |
| 466 |
if (!$that) { |
| 467 |
push(@{$errs}, "can't lookup $host"); |
| 468 |
return 0; |
| 469 |
} |
| 470 |
if (!socket(SYSLOG,AF_INET,SOCK_STREAM,$tcp)) { |
| 471 |
push(@{$errs}, "tcp socket: $!"); |
| 472 |
return 0; |
| 473 |
} |
| 474 |
setsockopt(SYSLOG, SOL_SOCKET, SO_KEEPALIVE, 1); |
| 475 |
setsockopt(SYSLOG, IPPROTO_TCP, TCP_NODELAY, 1); |
| 476 |
if (!CORE::connect(SYSLOG,$that)) { |
| 477 |
push(@{$errs}, "tcp connect: $!"); |
| 478 |
return 0; |
| 479 |
} |
| 480 |
$syslog_send = \&_syslog_send_socket; |
| 481 |
return 1; |
| 482 |
} |
| 483 |
|
| 484 |
sub connect_udp { |
| 485 |
my ($errs) = @_; |
| 486 |
unless ($host) { |
| 487 |
require Sys::Hostname; |
| 488 |
my($host_uniq) = Sys::Hostname::hostname(); |
| 489 |
($host) = $host_uniq =~ /([A-Za-z0-9_.-]+)/; # allow FQDN (inc _) |
| 490 |
} |
| 491 |
my $udp = getprotobyname('udp'); |
| 492 |
if (!defined $udp) { |
| 493 |
push(@{$errs}, "getprotobyname failed for udp"); |
| 494 |
return 0; |
| 495 |
} |
| 496 |
my $syslog = getservbyname('syslog','udp'); |
| 497 |
if (!defined $syslog) { |
| 498 |
push(@{$errs}, "getservbyname failed for udp"); |
| 499 |
return 0; |
| 500 |
} |
| 501 |
my $this = sockaddr_in($syslog, INADDR_ANY); |
| 502 |
my $that = sockaddr_in($syslog, inet_aton($host)); |
| 503 |
if (!$that) { |
| 504 |
push(@{$errs}, "can't lookup $host"); |
| 505 |
return 0; |
| 506 |
} |
| 507 |
if (!socket(SYSLOG,AF_INET,SOCK_DGRAM,$udp)) { |
| 508 |
push(@{$errs}, "udp socket: $!"); |
| 509 |
return 0; |
| 510 |
} |
| 511 |
if (!CORE::connect(SYSLOG,$that)) { |
| 512 |
push(@{$errs}, "udp connect: $!"); |
| 513 |
return 0; |
| 514 |
} |
| 515 |
# We want to check that the UDP connect worked. However the only |
| 516 |
# way to do that is to send a message and see if an ICMP is returned |
| 517 |
_syslog_send_socket(""); |
| 518 |
if (!connection_ok()) { |
| 519 |
push(@{$errs}, "udp connect: nobody listening"); |
| 520 |
return 0; |
| 521 |
} |
| 522 |
$syslog_send = \&_syslog_send_socket; |
| 523 |
return 1; |
| 524 |
} |
| 525 |
|
| 526 |
sub connect_stream { |
| 527 |
my ($errs) = @_; |
| 528 |
# might want syslog_path to be variable based on syslog.h (if only |
| 529 |
# it were in there!) |
| 530 |
$syslog_path = '/dev/conslog'; |
| 531 |
if (!-w $syslog_path) { |
| 532 |
push(@{$errs}, "stream $syslog_path is not writable"); |
| 533 |
return 0; |
| 534 |
} |
| 535 |
if (!open(SYSLOG, ">" . $syslog_path)) { |
| 536 |
push(@{$errs}, "stream can't open $syslog_path: $!"); |
| 537 |
return 0; |
| 538 |
} |
| 539 |
$syslog_send = \&_syslog_send_stream; |
| 540 |
return 1; |
| 541 |
} |
| 542 |
|
| 543 |
sub connect_unix { |
| 544 |
my ($errs) = @_; |
| 545 |
if (length _PATH_LOG()) { |
| 546 |
$syslog_path = _PATH_LOG(); |
| 547 |
} else { |
| 548 |
push(@{$errs}, "_PATH_LOG not available in syslog.h"); |
| 549 |
return 0; |
| 550 |
} |
| 551 |
my $that = sockaddr_un($syslog_path); |
| 552 |
if (!$that) { |
| 553 |
push(@{$errs}, "can't locate $syslog_path"); |
| 554 |
return 0; |
| 555 |
} |
| 556 |
if (!socket(SYSLOG,AF_UNIX,SOCK_STREAM,0)) { |
| 557 |
push(@{$errs}, "unix stream socket: $!"); |
| 558 |
return 0; |
| 559 |
} |
| 560 |
if (!CORE::connect(SYSLOG,$that)) { |
| 561 |
if (!socket(SYSLOG,AF_UNIX,SOCK_DGRAM,0)) { |
| 562 |
push(@{$errs}, "unix dgram socket: $!"); |
| 563 |
return 0; |
| 564 |
} |
| 565 |
if (!CORE::connect(SYSLOG,$that)) { |
| 566 |
push(@{$errs}, "unix dgram connect: $!"); |
| 567 |
return 0; |
| 568 |
} |
| 569 |
} |
| 570 |
$syslog_send = \&_syslog_send_socket; |
| 571 |
return 1; |
| 572 |
} |
| 573 |
|
| 574 |
sub connect_console { |
| 575 |
my ($errs) = @_; |
| 576 |
if (!-w '/dev/console') { |
| 577 |
push(@{$errs}, "console is not writable"); |
| 578 |
return 0; |
| 579 |
} |
| 580 |
$syslog_send = \&_syslog_send_console; |
| 581 |
return 1; |
| 582 |
} |
| 583 |
|
| 584 |
# to test if the connection is still good, we need to check if any |
| 585 |
# errors are present on the connection. The errors will not be raised |
| 586 |
# by a write. Instead, sockets are made readable and the next read |
| 587 |
# would cause the error to be returned. Unfortunately the syslog |
| 588 |
# 'protocol' never provides anything for us to read. But with |
| 589 |
# judicious use of select(), we can see if it would be readable... |
| 590 |
sub connection_ok { |
| 591 |
return 1 if (defined $current_proto && $current_proto eq 'console'); |
| 592 |
my $rin = ''; |
| 593 |
vec($rin, fileno(SYSLOG), 1) = 1; |
| 594 |
my $ret = select $rin, undef, $rin, 0; |
| 595 |
return ($ret ? 0 : 1); |
| 596 |
} |
| 597 |
|
| 598 |
sub disconnect { |
| 599 |
close SYSLOG; |
| 600 |
$connected = 0; |
| 601 |
$syslog_send = undef; |
| 602 |
} |
| 603 |
|
| 604 |
1; |
