/usr/lib/amanda/perl/Amanda/ClientService.pm is in amanda-common 1:3.3.6-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 | # Copyright (c) 2010-2013 Zmanda, Inc. All Rights Reserved.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Contact information: Zmanda Inc., 465 S. Mathilda Ave., Suite 300
# Sunnyvale, CA 94085, USA, or: http://www.zmanda.com
package Amanda::ClientService;
=head1 NAME
Amanda::ClientService -- support for writing amandad and inetd services
=head1 SYNOPSIS
package main::Service;
use base qw( Amanda::ClientService );
sub start {
my $self = shift;
if ($self->from_inetd) {
$self->check_bsd_security('main');
}
# ...
}
#...
package main;
use Amanda::MainLoop;
my $svc = main::Service->new();
Amanda::MainLoop::run();
=head1 NOTE
Note that, despite the name, some client services are actually run on the
server - C<amidxtaped> and C<amindexd> in particular.
=head1 INTERFACE
This package is used as a parent class, and is usually subclassed as
C<main::Service>. Its constructor takes no arguments, and automatically
configures the MainLoop to call the C<start> method:
my $svc = main::Service->new();
Amanda::MainLoop::start();
The object is a blessed hashref. And all of the keys used by this class are
private, and begin with an underscore. Subclasses are free to use any key
names that do not begin with an underscore.
=head2 Invocation Type
Some client services can be invoked directly from inetd for backward
compatibility. This package will automatically detect this, and act
accordingly. Subclasses can determine if they were invoked from inetd with the
boolean C<from_inetd> and C<from_amandad> methods. If C<from_amandad> is true,
then the authentication specified is available from the C<amandad_auth> method
(and may be C<undef>).
print "hi, inetd"
if $self->from_inetd();
print "hi, amandadd w/ ", ($self->amandad_auth() || "none")
if $self->from_amandad();
=head2 Streams
This package manages the available data streams as pairs of file descriptors,
providing convenience methods to hide some of the complexity of dealing with
them. Note that the class does not handle asynchronous reading or writing to
these file descriptors, and in fact most of the operations are entirely
synchronous, as they are non-blocking. File descriptors for streams are
available from the C<rfd> and C<wfd> methods, which both take a stream name:
Amanda::Util::full_write($self->wfd('MESG'), $buf, length($buf));
Each bidirectional stream has a name. At startup, stdin and stdout constitute
the 'main' stream. For amandad invocations, this stream should be used to read
the REQ packet and write the PREP and REP packets (see below). For inetd
invocations, this is the primary means of communicating with the other end of
the connection.
For amandad invocations, the C<create_streams> method will create named streams
back to amandad. Each stream name is paired with direction indicators: C<'r'>
for read, C<'w'> for write, or C<'rw'> for both. Any unused file descriptors
will be closed. The method will return a C<CONNECT> line suitable for
inclusion in a REP packet, without a newline terminator, giving the streams in
the order they were specified.
push @replines, $self->connect_streams(
'DATA' => 'w', 'MESG' => 'rw', 'INDEX' => 'w');
For inetd invocations, the C<connection_listen> method will open a (privileged,
if C<$priv> is true) listening socket and return the port. You should then
write a C<CONNECT $port\n> to the main stream and call C<connection_acecpt> to
wait for a connection to the listening port. The latter method calls
C<finished_cb> with C<undef> on success or an error message on failure. The
C<$timeout> is specified in seconds. On success, the stream named C<$name> is
then available for use. Note that this method does not check security on the
connection. Also note that this process requires that the Amanda configuration
be initialized.
my $port = $self->connection_listen($name, $priv);
# send $port to the other side
$self->connection_accept($name, $timeout, $finished_cb);
To close a stream, use C<close>. This takes an optional second argument which
can be used to half-close connections which support it. Note that the
underlying file descriptor is closed immediately, without regard to any
outstanding asynchronous reads or writes.
$self->close('MESG'); # complete close ('rw' is OK too)
$self->close('INDEX', 'r'); # close for reading
$self->close('DATA', 'w'); # close for writing
=head2 Security
Invocations from inetd require a BSD-style security check. The
C<check_bsd_security> method takes the stream and the authentication string,
I<without> the C<"SECURITY "> prefix or trailing newline, and performs the
necesary checks. To be clear, this string usually has the form C<"USER root">.
The method returns C<undef> if the check succeeds, and an error message if it
fails.
if ($self->check_bsd_security($stream, $authstr)) { .. }
Not that the security check is skipped if the service is being run from an
installcheck, since BSD security can't be tested by installchecks.
=head2 REQ packets
When invoked from amandad, a REQ packet is available on stdin, and amanadad
expects a REP packet on stdout. The C<parse_req> method takes the entire REP
packet, splits it into lines without trailing whitespace, exracts any OPTIONS
line into a hash, and decodes any features in the OPTIONS line. If no OPTIONS
appear, or the OPTIONS do not include features, then the C<features> key of the
result will be undefined. If there are format errors in the REQ, then the
C<errors> key will contain a list of error messages.
my $req_info = parse_req($req_str);
if (@{$req_info->{'errors'}}) {
print join("\n", @{$req_info->{'errors'}}), "\n";
exit;
}
print $req_info->{'options'}{'auth'}; # access to options
print "yes!" if $req_info->{'features'}->has($fe_whatever);
for my $line (@{$req_info->{'lines'}) {
print "got REQ line '$line'\n";
}
Note that the general format of OPTION strings is unknown at this time, so this
method may change significantly as more client services are added.
=cut
use strict;
use warnings;
use Data::Dumper;
use IO::Handle;
use Amanda::Util qw( :constants stream_server stream_accept );
use Amanda::Debug qw( debug );
use Amanda::Constants;
use Amanda::MainLoop;
use Amanda::Feature;
sub new {
my $class = shift;
my $self = bless {
_streams => {},
_listen_sockets => {},
_argv => [ @ARGV ],
}, $class;
$self->_add_stream('main', 0, 1);
return $self;
}
sub from_inetd {
my $self = shift;
return 1 if (!defined $self->{'_argv'}[0] or $self->{'_argv'}[0] eq 'installcheck');
}
sub from_amandad {
my $self = shift;
return 1 if defined $self->{'_argv'}[0] and $self->{'_argv'}[0] eq 'amandad';
}
sub from_installcheck {
my $self = shift;
return 1 if defined $self->{'_argv'}[0] and $self->{'_argv'}[0] eq 'installcheck';
}
sub amandad_auth {
my $self = shift;
return undef unless $self->from_amandad();
return $self->{'_argv'}[1];
}
sub connect_streams {
my $self = shift;
my $connect_line = "CONNECT";
my $fd = $Amanda::Constants::DATA_FD_OFFSET;
my $handle = $Amanda::Constants::DATA_FD_OFFSET;
my @fds_to_close;
# NOTE: while $handle and $fd both start counting in the same place, they
# are not the same thing! $fd counts real file descriptors - two per
# stream. $handle only increases by one for each stream.
if (@_ > $Amanda::Constants::DATA_FD_COUNT * 2) {
die "too many streams!";
}
die "not using amandad" if $self->from_inetd();
while (@_) {
my $name = shift;
my $dirs = shift;
my ($wfd, $rfd) = (-1, -1);
# lower-numbered fd is for writing
if ($dirs =~ /w/) {
$wfd = $fd;
} else {
push @fds_to_close, $fd;
}
$fd++;
# higher-numbered fd is for reading
if ($dirs =~ /r/) {
$rfd = $fd;
} else {
push @fds_to_close, $fd;
}
$fd++;
$self->_add_stream($name, $rfd, $wfd);
$connect_line .= " $name $handle";
$handle++;
}
while ($fd < $Amanda::Constants::DATA_FD_OFFSET
+ 2 * $Amanda::Constants::DATA_FD_COUNT) {
push @fds_to_close, $fd++;
}
# _dont_use_real_fds indicats that we should mock the close operation
if (!$self->{'_dont_use_real_fds'}) {
for $fd (@fds_to_close) {
if (!POSIX::close($fd)) {
Amanda::Debug::warning("Error closing fd $fd: $!");
}
}
# let the stupid OpenBSD threads library know we're using these fd's
Amanda::Util::openbsd_fd_inform();
} else {
$self->{'_would_have_closed_fds'} = \@fds_to_close;
}
return $connect_line;
}
sub connection_listen {
my $self = shift;
my ($name, $priv) = @_;
die "not using inetd" unless $self->from_inetd();
die "stream $name already exists" if exists $self->{'_streams'}{$name};
die "stream $name is already listening" if exists $self->{'_listen_sockets'}{$name};
# first open a socket
my ($lsock, $port) = stream_server(
$AF_INET, $STREAM_BUFSIZE, $STREAM_BUFSIZE, $priv);
return 0 if ($lsock < 0);
$self->{'_listen_sockets'}{$name} = $lsock;
return $port;
}
sub connection_accept {
my $self = shift;
my ($name, $timeout, $finished_cb) = @_;
my $lsock = $self->{'_listen_sockets'}{$name};
die "stream $name is not listening" unless defined $lsock;
# set up a fd source *and* a timeout source
my ($fd_source, $timeout_source);
my $fired = 0;
# accept is a "read" operation on a listening socket
$fd_source = Amanda::MainLoop::fd_source($lsock, $Amanda::MainLoop::G_IO_IN);
$fd_source->set_callback(sub {
return if $fired;
$fired = 1;
$fd_source->remove();
$timeout_source->remove();
my $errmsg;
my $datasock = stream_accept($lsock, 1, $STREAM_BUFSIZE, $STREAM_BUFSIZE);
if ($datasock < 0) {
$errmsg = "error from stream_accept: $!";
}
# clean up
POSIX::close($lsock);
delete $self->{'_listen_sockets'}{$name};
if ($datasock >= 0) {
$self->_add_stream($name, $datasock, $datasock);
}
return $finished_cb->($errmsg);
});
$timeout_source = Amanda::MainLoop::timeout_source(1000*$timeout);
$timeout_source->set_callback(sub {
return if $fired;
$fired = 1;
$fd_source->remove();
$timeout_source->remove();
# clean up
POSIX::close($lsock);
delete $self->{'_listen_sockets'}{$name};
return $finished_cb->("timeout while waiting for incoming TCP connection");
});
}
sub rfd {
my $self = shift;
my ($name) = @_;
return -1 unless exists $self->{'_streams'}{$name};
my $fd = $self->{'_streams'}{$name}{'rfd'};
return defined($fd)? $fd : -1;
}
sub wfd {
my $self = shift;
my ($name) = @_;
return -1 unless exists $self->{'_streams'}{$name};
my $fd = $self->{'_streams'}{$name}{'wfd'};
return defined($fd)? $fd : -1;
}
sub close {
my $self = shift;
my ($name, $dir) = @_;
$dir = 'rw' unless defined $dir;
my $rfd = $self->rfd($name);
my $wfd = $self->wfd($name);
# sockets will have the read and write fd's, and are handled differently. If
# one end of a socket has been closed, then we can treat it like a regular fd
if ($rfd == $wfd) {
die "stream is already closed?" if ($rfd == -1);
if ($dir eq 'rw') {
POSIX::close($rfd);
$rfd = $wfd = -1;
} elsif ($dir eq 'r') {
# perl doesn't provide a fd-compatible shutdown, but luckily shudown
# affects dup'd file descriptors, too! So create a new handle and shut
# it down. When the handle is garbage collected, it will be closed,
# but that will not affect the original. This will look strange in an
# strace, but it works without SWIGging shutdown()
shutdown(IO::Handle->new_from_fd(POSIX::dup($rfd), "r"), 0);
$rfd = -1;
} elsif ($dir eq 'w') {
shutdown(IO::Handle->new_from_fd(POSIX::dup($wfd), "w"), 1);
$wfd = -1;
}
} else {
if ($dir =~ /r/ and $rfd != -1) {
POSIX::close($rfd);
$rfd = -1;
}
if ($dir =~ /w/ and $wfd != -1) {
POSIX::close($wfd);
$wfd = -1;
}
}
if ($rfd == -1 and $wfd == -1) {
delete $self->{'_streams'}{$name};
} else {
$self->{'_streams'}{$name}{'rfd'} = $rfd;
$self->{'_streams'}{$name}{'wfd'} = $wfd;
}
}
sub check_bsd_security {
my $self = shift;
my ($name, $authstr) = @_;
# find the open file descriptor
my $fd = $self->rfd($name);
$fd = $self->wfd($name) if $fd < 0;
die "stream '$name' not open" if $fd < 0;
# don't invoke check_security if we're run as an installcheck;
# installchecks are incompatible with BSD security
return undef if $self->from_installcheck();
return Amanda::Util::check_security($fd, $authstr);
}
sub parse_req {
my $self = shift;
my ($req_str) = @_;
my $rv = {
lines => [],
options => {},
features => undef,
errors => [],
};
# split into lines, split by '\n', filtering empty lines
my @req_lines = grep /.+/, (split(/\n/, $req_str));
$rv->{'lines'} = [ @req_lines ];
# find and parse the options line
my @opt_lines = grep /^OPTIONS /, @req_lines;
if (@opt_lines > 1) {
push @{$rv->{'errors'}}, "got multiple OPTIONS lines";
# (and use the first OPTIONS line anyway)
}
if (@opt_lines) {
my ($line) = $opt_lines[0] =~ /^OPTIONS (.*)$/;
my @opts = grep /.+/, (split(/;/, $line));
for my $opt (@opts) {
if ($opt =~ /^([^=]+)=(.*)$/) {
$rv->{'options'}{$1} = $2;
} else {
$rv->{'options'}{$opt} = 1;
}
}
}
# features
if ($rv->{'options'}{'features'}) {
$rv->{'features'} = Amanda::Feature::Set->from_string($rv->{'options'}{'features'});
}
return $rv;
}
# private methods
sub _add_stream {
my $self = shift;
my ($stream, $rfd, $wfd) = @_;
$self->{'_streams'}{$stream} = {
rfd => $rfd,
wfd => $wfd,
};
}
1;
|