util.swg

开源备份软件源码 AMANDA, the Advanced Maryland Automatic Network Disk Archiver, is a backup system that a

/*
 * Copyright (c) Zmanda, Inc.  All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 *
 * This library 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 Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA.
 *
 * Contact information: Zmanda Inc., 505 N Mathlida Ave, Suite 120
 * Sunnyvale, CA 94085, USA, or: http://www.zmanda.com
 */

%module "Amanda::Util"
%include "amglue/amglue.swg"
%include "exception.i"

%{
#include "debug.h"
/* use a relative path here to avoid conflicting with Perl's util.h. */
#include "../common-src/util.h"
#include "file.h"
%}

%perlcode %{
use Amanda::Debug qw(:init);
use Carp;
use POSIX qw(:fcntl_h);

=head1 NAME

Amanda::Util - Runtime support for Amanda applications

=head1 Application Initialization

Application initialization generally looks like this:

  use Amanda::Config qw( :init );
  use Amanda::Util qw( :check_running_as_flags );
  use Amanda::Debug;

  Amanda::Util::setup_application("myapp", "server", "cmdline");
  # .. command-line processing ..
  Amanda::Config::config_init(...);
  Amanda::Util::finish_setup($RUNNING_AS_DUMPUSER);

=over

=item C<setup_application($name, $type, $context)>

Set up the operating environment for an application, without requiring
any configuration.

=over

=item C<$name> is the name of the application, used in log messages, etc.

=item C<$type> is one of "server" or "client".

=item C<$context> is one of "cmdline" for a user-invoked command-line
utility (e.g., C<amadmin>) or "daemon" for a program started by
C<amandad>.  (TODO: daemon is not supported yet)

=back

Based on C<$type> and C<$context>, this function does the following:

=over

=item sets up debug logging;

=item configures internationalization

=item sets the umask;

=item sets the current working directory to the debug or temporary directory;

=item closes any unnecessary file descriptors as a security meaasure;

=item ignores C<SIGPIPE>; and

=item sets the appropriate target for error messages.

=back

=cut

# private package variables
my $_pname;
my $_ptype;
my $_pcontext;

sub setup_application {
    my ($name, $type, $context) = @_;

    # sanity check
    croak("no name given") unless ($name);
    croak("no type given") unless ($type);
    croak("no context given") unless ($context);

    # store these as perl values
    $_pname = $name;
    $_ptype = $type;
    $_pcontext = $context;

    # and let the C side know about the pname
    set_pname($name);

    safe_cd(); # (also sets umask)
    check_std_fds();

    # set up debugging for this application type
    dbopen($type);

    # ignore SIGPIPE
    $SIG{'PIPE'} = 'IGNORE';

    set_erroutput_type($type, $context);
}

=item C<finish_setup($running_as_flags)>

Perform final initialization tasks that require a loaded configuration.
Specifically, move the debug log into a configuration-specific
subdirectory, and check that the current userid is appropriate for
this applciation.

The user is specified by one of the following flags, which are
available in export tag C<:check_running_as_flags>:

  $RUNNING_AS_ROOT                # root
  $RUNNING_AS_DUMPUSER            # dumpuser, from configuration
  $RUNNING_AS_DUMPUSER_PREFERRED  # dumpuser, but client_login is OK too
  $RUNNING_AS_CLIENT_LOGIN        # client_login (--with-user at build time)

If the flag C<$RUNNING_AS_UID_ONLY> is bit-or'd into C<$running_as_flags>, then
the euid is ignored; this is used for programs that expect to be setuid-root.

=cut

sub finish_setup {
    my ($running_as) = @_;

    my $config_name = Amanda::Config::get_config_name();

    if ($config_name) {
	dbrename($config_name, $_ptype);
    }

    check_running_as($running_as);
}

=item safe_env

Return a "safe" environment hash.  For non-setuid programs, this means filtering out any
localization variables.

=cut

sub safe_env {
    my %rv = %ENV;

    delete @rv{qw(IFS CDPATH ENV BASH_ENV LANG)};

    # delete all LC_* variables
    for my $var (grep /^LC_/, keys %rv) {
        delete $rv{$var};
    }

    return %rv;
}

%}

amglue_add_flag_tag_fns(running_as_flags);
amglue_add_constant(RUNNING_AS_ROOT, running_as_flags);
amglue_add_constant(RUNNING_AS_DUMPUSER, running_as_flags);
amglue_add_constant(RUNNING_AS_DUMPUSER_PREFERRED, running_as_flags);
amglue_add_constant(RUNNING_AS_CLIENT_LOGIN, running_as_flags);
amglue_add_constant(RUNNING_AS_UID_ONLY, running_as_flags);

/* -------------------------------------------------------------------------
 * Functions below this line are only meant to be called within this module;
 * do not call them externally. */

void set_pname(char *name);
void safe_cd(void);

void check_running_as(running_as_flags who);

/* Set erroutput_type as appropriate for this process type and context.
 *
 * @param type: process type
 * @param context: process context
 */
%inline %{
void
set_erroutput_type(char *type, char *context)
{
    if (strcmp(context, "cmdline") == 0) {
	erroutput_type = ERR_INTERACTIVE;
    } else if (strcmp(context, "daemon") == 0) {
	if (strcmp(type, "server") == 0) {
	    erroutput_type = ERR_INTERACTIVE|ERR_AMANDALOG;
	} else if (strcmp(type, "client") == 0) {
	    erroutput_type = ERR_INTERACTIVE|ERR_SYSLOG;
	}
    }
}
%}

/* Check that fd's 0, 1, and 2 are open, calling critical() if not.
 */
%perlcode %{
sub check_std_fds {
    fcntl(STDIN, F_GETFD, 0) or critical("Standard input is not open");
    fcntl(STDOUT, F_GETFD, 0) or critical("Standard output is not open");
    fcntl(STDERR, F_GETFD, 0) or critical("Standard error is not open");
}
%}