#!/usr/bin/perl -wT
#
# ==========================================================================
#
# ZoneMinder Daemon Control Script, $Date$, $Revision$
# Copyright (C) 2001-2008 Philip Coombes
#
# 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# ==========================================================================

=head1 NAME

zmdc.pl - ZoneMinder Daemon Control script

=head1 SYNOPSIS

zmdc.pl {command} [daemon [options]]

=head1 DESCRIPTION

This script is the gateway for controlling the various ZoneMinder
daemons. All starting, stopping and restarting goes through here.
On the first invocation it starts up a server which subsequently
records what's running and what's not. Other invocations just
connect to the server and pass instructions to it.

=head1 OPTIONS

{command}           - One of 'startup|shutdown|status|check|logrot' or
'start|stop|restart|reload|version'.
[daemon [options]]  - Daemon name and options, required for second group of commands

=cut
use strict;
use warnings;
use bytes;

# ==========================================================================
#
# User config
#
# ==========================================================================

# in useconds, not seconds.
use constant MAX_CONNECT_DELAY => 10*1000*1000;

# ==========================================================================
#
# Don't change anything from here on down
#
# ==========================================================================

@EXTRA_PERL_LIB@
use ZoneMinder;
use POSIX;
use Socket;
use IO::Handle;
use Time::HiRes qw(usleep);
use autouse 'Pod::Usage'=>qw(pod2usage);
#use Data::Dumper;

use constant SOCK_FILE => $Config{ZM_PATH_SOCKS}.'/zmdc'.($Config{ZM_SERVER_ID}?$Config{ZM_SERVER_ID}:'').'.sock';

$| = 1;

$ENV{PATH}  = '/bin:/usr/bin:/usr/local/bin';
$ENV{SHELL} = '/bin/sh' if exists $ENV{SHELL};
if ( $Config{ZM_LD_PRELOAD} ) {
  Debug("Adding ENV{LD_PRELOAD} = $Config{ZM_LD_PRELOAD}");
  $ENV{LD_PRELOAD} = $Config{ZM_LD_PRELOAD};
  foreach my $lib ( split(/\s+/, $ENV{LD_PRELOAD} ) ) {
    if ( ! -e $lib ) {
      Warning("LD_PRELOAD lib $lib does not exist from LD_PRELOAD $ENV{LD_PRELOAD}.");
    }
  }
}
delete @ENV{qw(IFS CDPATH ENV BASH_ENV)};

my @daemons = (
    'zmc',
    'zma',
    'zmfilter.pl',
    'zmaudit.pl',
    'zmtrigger.pl',
    'zmx10.pl',
    'zmwatch.pl',
    'zmupdate.pl',
    'zmtrack.pl',
    'zmtelemetry.pl'
    );

my $command = shift @ARGV;
if( ! $command ) {
  print( STDERR "No command given\n" );
  pod2usage(-exitstatus => -1);
}
if ( $command eq 'version' ) {
  print ZoneMinder::Base::ZM_VERSION."\n";
  exit( 0 );
}
my $needs_daemon = $command !~ /(?:startup|shutdown|status|check|logrot|version)/;
my $daemon = shift( @ARGV );
if ( $needs_daemon && ! $daemon ) {
  print( STDERR "No daemon given\n" );
  pod2usage(-exitstatus => -1);
}
my @args;

my $daemon_patt = '('.join( '|', @daemons ).')';
if ( $needs_daemon ) {
  if ( $daemon =~ /^${daemon_patt}$/ ) {
    $daemon = $1;
  } else {
    print( STDERR "Invalid daemon '$daemon' specified" );
    pod2usage(-exitstatus => -1);
  }
}

foreach my $arg ( @ARGV ) {
# Detaint arguments, if they look ok
#if ( $arg =~ /^(-{0,2}[\w]+)/ )
  if ( $arg =~ /^(-{0,2}[\w\/?&=.-]+)$/ ) {
    push( @args, $1 );
  } else {
    print( STDERR "Bogus argument '$arg' found" );
    exit( -1 );
  }
}

socket( CLIENT, PF_UNIX, SOCK_STREAM, 0 ) or Fatal( "Can't open socket: $!" );

my $saddr = sockaddr_un( SOCK_FILE );
my $server_up = connect( CLIENT, $saddr );
if ( ! $server_up ) {
  # Server is not up.  Some commands can still be handled
  if ( $command eq 'logrot' ) {
    # If server is not running, then logrotate doesn't need to do anything.
    exit();
  }
  if ( $command eq 'check' ) {
    print( "stopped\n" );
    exit();
  } elsif ( $command ne 'startup' ) {
    print( "Unable to connect to server using socket at " . SOCK_FILE . "\n" );
    exit( -1 );
  }

  # The server isn't there
  print( "Starting server\n" );
  close( CLIENT );

  if ( my $cpid = fork() ) {
    # Parent process just sleep and fall through

    # I'm still not sure why we need to re-init the logs
    logInit();

    socket( CLIENT, PF_UNIX, SOCK_STREAM, 0 ) or Fatal( "Can't open socket: $!" );
    my $attempts = 0;
    while( !connect( CLIENT, $saddr ) ) {
      $attempts++;
      Error("Waiting for zmdc.pl server process, attempt $attempts" );
      Fatal( "Can't connect: $!" ) if ($attempts > MAX_CONNECT_DELAY);
      usleep(200000);
    } # end while
  } elsif ( defined($cpid) ) {
    ZMServer::run();
  } else {
    Fatal( "Can't fork: $!" );
  }
} # end if ! server is up

if ( $command eq 'check' && ! $daemon ) {
  print( "running\n" );
  exit();
} elsif ( $command eq 'startup' ) {
  # Our work here is done
  exit() if ( !$server_up );
}

# The server is there, connect to it
#print( "Writing commands\n" );
CLIENT->autoflush();
my $message = join(';', $command, ( $daemon ? $daemon : () ), @args );
print( CLIENT  $message );
shutdown( CLIENT, 1 );
while( my $line = <CLIENT> ) {
  chomp( $line );
  print( "$line\n" );
}
# And we're done!
close( CLIENT );
#print( "Finished writing, bye\n" );

exit;

package ZMServer;

use strict;
use warnings;
use bytes;

@EXTRA_PERL_LIB@
use ZoneMinder;
use POSIX;
use Socket;
use IO::Handle;
use Time::HiRes qw(usleep);
#use Data::Dumper;

use constant KILL_DELAY => 100*1000; # 1/10th of a second

our %cmd_hash;
our %pid_hash;

sub run {
  my $fd = 0;
  while( $fd < POSIX::sysconf( &POSIX::_SC_OPEN_MAX ) ) {
    POSIX::close( $fd++ );
  }

  setpgrp();

  logInit();

  dPrint( ZoneMinder::Logger::INFO, 'Server starting at '
      .strftime( '%y/%m/%d %H:%M:%S', localtime() )
      ."\n"
      );

  if ( open( my $PID, '>', ZM_PID ) ) {
    print( $PID $$ );
    close( $PID );
  } else {
    Error( "Can't open pid file at " . ZM_PID );
  }

  killAll( 1 );

  socket( SERVER, PF_UNIX, SOCK_STREAM, 0 ) or Fatal( "Can't open socket: $!" );
  unlink( main::SOCK_FILE ) or Error( 'Unable to unlink ' . main::SOCK_FILE .". Error message was: $!" ) if ( -e main::SOCK_FILE );
  bind( SERVER, $saddr ) or Fatal( "Can't bind to " . main::SOCK_FILE . ": $!" );
  listen( SERVER, SOMAXCONN ) or Fatal( "Can't listen: $!" );

  $SIG{CHLD} = \&reaper;
  $SIG{INT} = \&shutdownAll;
  $SIG{TERM} = \&shutdownAll;
  $SIG{ABRT} = \&shutdownAll;
  $SIG{HUP} = \&logrot;

  my $rin = '';
  vec( $rin, fileno(SERVER), 1 ) = 1;
  my $win = $rin;
  my $ein = $win;
  my $timeout = 0.1;
  while( 1 ) {
    my $nfound = select( my $rout = $rin, undef, undef, $timeout );
    if ( $nfound > 0 ) {
      if ( vec( $rout, fileno(SERVER), 1 ) ) {
        my $paddr = accept( CLIENT, SERVER );
        my $message = <CLIENT>;

        next if ( !$message );

        my ( $command, $daemon, @args ) = split( /;/, $message );

        if ( $command eq 'start' ) {
          start( $daemon, @args );
        } elsif ( $command eq 'stop' ) {
          stop( $daemon, @args );
        } elsif ( $command eq 'restart' ) {
          restart( $daemon, @args );
        } elsif ( $command eq 'reload' ) {
          reload( $daemon, @args );
        } elsif ( $command eq 'startup' ) {
# Do nothing, this is all we're here for
          dPrint( ZoneMinder::Logger::WARNING, "Already running, ignoring command '$command'\n" );
        } elsif ( $command eq 'shutdown' ) {
          shutdownAll();
        } elsif ( $command eq 'check' ) {
          check( $daemon, @args );
        } elsif ( $command eq 'status' ) {
          if ( $daemon ) {
            status( $daemon, @args );
          } else {
            status();
          }
        } elsif ( $command eq 'logrot' ) {
          logrot();
        } else {
          dPrint( ZoneMinder::Logger::ERROR, "Invalid command '$command'\n" );
        }
        close( CLIENT );
      } else {
        Fatal( 'Bogus descriptor' );
      }
    } elsif ( $nfound < 0 ) {
      if ( $! == EINTR ) {
# Dead child, will be reaped
#print( "Probable dead child\n" );
# See if it needs to start up again
        restartPending();
      } elsif ( $! == EPIPE ) {
        Error( "Can't select: $!" );
      } else {
        Fatal( "Can't select: $!" );
      }
    } else {
#print( "Select timed out\n" );
      restartPending();
    }
  }
  dPrint( ZoneMinder::Logger::INFO, 'Server exiting at '
      .strftime( '%y/%m/%d %H:%M:%S', localtime() )
      ."\n"
      );
  unlink( main::SOCK_FILE ) or Error( 'Unable to unlink ' . main::SOCK_FILE .". Error message was: $!" ) if ( -e main::SOCK_FILE );
  unlink( ZM_PID ) or Error( 'Unable to unlink ' . ZM_PID .". Error message was: $!" ) if ( -e ZM_PID );
  exit();
}

sub cPrint {
  if ( fileno(CLIENT) ) {
    print CLIENT @_
  }
}

sub dPrint {
  my $logLevel = shift;
  if ( fileno(CLIENT) ) {
    print CLIENT @_
  }
  if ( $logLevel == ZoneMinder::Logger::DEBUG ) {
    Debug( @_ );
  } elsif ( $logLevel == ZoneMinder::Logger::INFO ) {
    Info( @_ );
  } elsif ( $logLevel == ZoneMinder::Logger::WARNING ) {
    Warning( @_ );
  } elsif ( $logLevel == ZoneMinder::Logger::ERROR ) {
    Error( @_ );
  } elsif ( $logLevel == ZoneMinder::Logger::FATAL ) {
    Fatal( @_ );
  }
}

sub start {
  my $daemon = shift;
  my @args = @_;

  my $command = join(' ', $daemon, @args );
  my $process = $cmd_hash{$command};

  if ( !$process ) {
# It's not running, or at least it's not been started by us
    $process = { daemon=>$daemon, args=>\@args, command=>$command, keepalive=>!undef };
  } elsif ( $process->{pid} && $pid_hash{$process->{pid}} ) {
    dPrint( ZoneMinder::Logger::INFO, "'$process->{command}' already running at "
        .strftime( '%y/%m/%d %H:%M:%S', localtime( $process->{started}) )
        .", pid = $process->{pid}\n"
        );
    return();
  }

  my $sigset = POSIX::SigSet->new;
  my $blockset = POSIX::SigSet->new( SIGCHLD );
  sigprocmask( SIG_BLOCK, $blockset, $sigset ) or Fatal( "Can't block SIGCHLD: $!" );
  if ( my $cpid = fork() ) {
    logReinit();

    $process->{pid} = $cpid;
    $process->{started} = time();
    delete( $process->{pending} );

    dPrint( ZoneMinder::Logger::INFO, "'$command' starting at "
        .strftime( '%y/%m/%d %H:%M:%S', localtime( $process->{started}) )
        .", pid = $process->{pid}\n"
        );

    $cmd_hash{$process->{command}} = $pid_hash{$cpid} = $process;
    sigprocmask( SIG_SETMASK, $sigset ) or Fatal( "Can't restore SIGCHLD: $!" );
  } elsif ( defined($cpid ) ) {
# Force reconnection to the db.
    zmDbConnect(1);
    logReinit();

    dPrint( ZoneMinder::Logger::INFO, "'".join( ' ', ( $daemon, @args ) )
        ."' started at "
        .strftime( '%y/%m/%d %H:%M:%S', localtime() )
        ."\n"
        );

    if ( $daemon =~ /^${daemon_patt}$/ ) {
      $daemon = $Config{ZM_PATH_BIN}.'/'.$1;
    } else {
      Fatal( "Invalid daemon '$daemon' specified" );
    }

    my @good_args;
    foreach my $arg ( @args ) {
# Detaint arguments, if they look ok
      if ( $arg =~ /^(-{0,2}[\w\/?&=.-]+)$/ ) {
        push( @good_args, $1 );
      } else {
        Fatal( "Bogus argument '$arg' found" );
      }
    }

    logTerm();
    zmDbDisconnect();

    my $fd = 0;
    while( $fd < POSIX::sysconf( &POSIX::_SC_OPEN_MAX ) ) {
      POSIX::close( $fd++ );
    }

# Child process
    $SIG{CHLD} = 'DEFAULT';
    $SIG{INT} = 'DEFAULT';
    $SIG{TERM} = 'DEFAULT';
    $SIG{ABRT} = 'DEFAULT';

    exec( $daemon, @good_args ) or Fatal( "Can't exec: $!" );
  } else {
    Fatal( "Can't fork: $!" );
  }
}

# Sends the stop signal, without waiting around to see if the process died.
sub send_stop {
  my ( $final, $process ) = @_;

  my $command = $process->{command};
  if ( $process->{pending} ) {

    delete( $cmd_hash{$command} );
    dPrint( ZoneMinder::Logger::INFO, "Command '$command' removed from pending list at "
        .strftime( '%y/%m/%d %H:%M:%S', localtime() )
        ."\n"
        );
    return();
  }

  my $pid = $process->{pid};
  if ( !$pid_hash{$pid} ) {
    dPrint( ZoneMinder::Logger::ERROR, "No process with command of '$command' pid $pid is running\n" );
    return();
  }

  dPrint( ZoneMinder::Logger::INFO, "'$command' sending stop to pid $pid at "
      .strftime( '%y/%m/%d %H:%M:%S', localtime() )
      ."\n"
      );
  $process->{keepalive} = !$final;
  kill( 'TERM', $pid );
  return $pid;
} # end sub send_stop

sub kill_until_dead {
  my ( $process ) = @_;
# Now check it has actually gone away, if not kill -9 it
  my $count = 0;
  my $sigset = POSIX::SigSet->new;
  my $blockset = POSIX::SigSet->new(SIGCHLD);
  sigprocmask(SIG_BLOCK, $blockset, $sigset ) or die "dying at block...\n";
  while( $process and $$process{pid} and kill( 0, $$process{pid} ) ) {
    if ( $count++ > 50 ) {
      dPrint( ZoneMinder::Logger::WARNING, "'$$process{command}' has not stopped at "
          .strftime( '%y/%m/%d %H:%M:%S', localtime() )
          .". Sending KILL to pid $$process{pid}\n"
          );
      kill( 'KILL', $$process{pid} );
    }

    sigprocmask(SIG_UNBLOCK, $blockset) or die "dying at unblock...\n";
    usleep( KILL_DELAY );
    sigprocmask(SIG_BLOCK, $blockset, $sigset ) or die "dying at block...\n";
  }
  sigprocmask(SIG_UNBLOCK, $blockset) or die "dying at unblock...\n";
}

sub _stop {
  my ($final, $process ) = @_;

  my $pid = send_stop( $final, $process );
  return if ! $pid;
  delete( $cmd_hash{$$process{command}} );

  kill_until_dead( $process );
}

sub stop {
  my ( $daemon, @args ) = @_;
  my $command = join(' ', $daemon, @args );
  my $process = $cmd_hash{$command};
  if ( !$process ) {
    dPrint( ZoneMinder::Logger::WARNING, "Can't find process with command of '$command'\n" );
    return();
  }

  _stop( 1, $process );
}

sub restart {
  my $daemon = shift;
  my @args = @_;

  my $command = $daemon;
  $command .= ' '.join( ' ', ( @args ) ) if @args;
  my $process = $cmd_hash{$command};
  if ( $process ) {
    if ( $process->{pid} ) {
      my $cpid = $process->{pid};
      if ( defined($pid_hash{$cpid}) ) {
        _stop( 0, $process );
        return;
      }
    }
  }
  start( $daemon, @args );
}

sub reload {
  my $daemon = shift;
  my @args = @_;

  my $command = $daemon;
  $command .= ' '.join( ' ', ( @args ) ) if ( @args );
  my $process = $cmd_hash{$command};
  if ( $process ) {
    if ( $process->{pid} ) {
      kill( 'HUP', $process->{pid} );
    }
  }
}

sub logrot {
  logReinit();
  foreach my $process ( values( %pid_hash ) ) {
    if ( $process->{pid} && $process->{command} =~ /^zm.*\.pl/ ) {
      kill( 'HUP', $process->{pid} );
    }
  }
}

sub reaper {
  my $saved_status = $!;
  while ( (my $cpid = waitpid( -1, WNOHANG )) > 0 ) {
    my $status = $?;

    my $process = $pid_hash{$cpid};
    delete( $pid_hash{$cpid} );

    if ( !$process ) {
      dPrint( ZoneMinder::Logger::INFO, "Can't find child with pid of '$cpid'\n" );
      next;
    }

    $process->{stopped} = time();
    $process->{runtime} = ($process->{stopped}-$process->{started});
    delete( $process->{pid} );

    my $exit_status = $status>>8;
    my $exit_signal = $status&0xfe;
    my $core_dumped = $status&0x01;

    my $out_str = "'$process->{command}' ";
    if ( $exit_signal ) {
      if ( $exit_signal == 15 || $exit_signal == 14 ) {
# TERM or ALRM
        $out_str .= 'exited';
      } else {
        $out_str .= 'crashed';
      }
      $out_str .= ", signal $exit_signal";
    } else {
      $out_str .= 'exited ';
      if ( $exit_status ) {
        $out_str .= "abnormally, exit status $exit_status";
      } else {
        $out_str .= 'normally';
      }
    }
#print( ", core dumped" ) if ( $core_dumped );
    $out_str .= "\n";

    if ( $exit_status == 0 ) {
      Info( $out_str );
    } else {
      Error( $out_str );
    }

    if ( $process->{keepalive} ) {
# Schedule for immediate restart
      $cmd_hash{$process->{command}} = $process;
      if ( !$process->{delay} || ($process->{runtime} > $Config{ZM_MAX_RESTART_DELAY} ) ) {
#start( $process->{daemon}, @{$process->{args}} );
        $process->{pending} = $process->{stopped};
        $process->{delay} = 5;
      } else {
        $process->{pending} = $process->{stopped}+$process->{delay};
        $process->{delay} *= 2;
# Limit the start delay to 15 minutes max
        if ( $process->{delay} > $Config{ZM_MAX_RESTART_DELAY} ) {
          $process->{delay} = $Config{ZM_MAX_RESTART_DELAY};
        }
      }
    }
  }
  $SIG{CHLD} = \&reaper;
  $! = $saved_status;
}

sub restartPending {
# Restart any pending processes
  foreach my $process ( values( %cmd_hash ) ) {
    if ( $process->{pending} && $process->{pending} <= time() ) {
      dPrint( ZoneMinder::Logger::INFO, "Starting pending process, $process->{command}\n" );
      start( $process->{daemon}, @{$process->{args}} );
    }
  }
}

sub shutdownAll {
  foreach my $pid ( keys %pid_hash ) {
# This is a quick fix because a SIGCHLD can happen and alter pid_hash while we are in here.
    next if ! $pid_hash{$pid};
    send_stop( 1, $pid_hash{$pid} );
  }
  foreach my $pid ( keys %pid_hash ) {
# This is a quick fix because a SIGCHLD can happen and alter pid_hash while we are in here.
    next if ! $pid_hash{$pid};

    my $process = $pid_hash{$pid};

    kill_until_dead( $process );
    delete( $cmd_hash{$$process{command}} );
    delete( $pid_hash{$pid} );
  }
if ( 0 ) {
  killAll( 5 );
}
  dPrint( ZoneMinder::Logger::INFO, "Server shutdown at "
      .strftime( '%y/%m/%d %H:%M:%S', localtime() )
      ."\n"
      );
  unlink( main::SOCK_FILE ) or Error( "Unable to unlink " . main::SOCK_FILE .". Error message was: $!" ) if ( -e main::SOCK_FILE );
  unlink( ZM_PID ) or Error( "Unable to unlink " . ZM_PID .". Error message was: $!" ) if ( -e ZM_PID );
  close( CLIENT );
  close( SERVER );
  exit();
}

sub check {
  my $daemon = shift;
  my @args = @_;

  my $command = join( ' ', $daemon, @args );
  my $process = $cmd_hash{$command};
  if ( !$process ) {
    cPrint( "unknown\n" );
  } elsif ( $process->{pending} ) {
    cPrint( "pending\n" );
  } else {
    my $cpid = $process->{pid};
    if ( ! $pid_hash{$cpid} ) {
      cPrint( "stopped\n" );
    } else {
      cPrint( "running\n" );
    }
  }
}

sub status {
  my $daemon = shift;
  my @args = @_;

  if ( defined($daemon) ) {
    my $command = join( ' ', $daemon, @args );
    my $process = $cmd_hash{$command};
    if ( ! $process ) {
      dPrint( ZoneMinder::Logger::DEBUG, "'$command' not running\n" );
      return();
    }

    if ( $process->{pending} ) {
      dPrint( ZoneMinder::Logger::DEBUG, "'$process->{command}' pending at "
          .strftime( '%y/%m/%d %H:%M:%S', localtime( $process->{pending} ) )
          ."\n"
          );
    } else {
      my $cpid = $process->{pid};
      if ( ! $pid_hash{$cpid} ) {
        dPrint( ZoneMinder::Logger::DEBUG, "'$command' not running\n" );
        return();
      }
    }
    dPrint( ZoneMinder::Logger::DEBUG, "'$process->{command}' running since "
        .strftime( '%y/%m/%d %H:%M:%S', localtime( $process->{started} ) )
        .", pid = $process->{pid}"
        );
  } else {
    foreach my $process ( values(%pid_hash) ) {
      my $out_str = "'$process->{command}' running since "
        .strftime( '%y/%m/%d %H:%M:%S', localtime( $process->{started}) )
        .", pid = $process->{pid}"
        ;
      $out_str .= ", valid" if ( kill( 0, $process->{pid} ) );
      $out_str .= "\n";
      dPrint( ZoneMinder::Logger::DEBUG, $out_str );
    }
    foreach my $process ( values( %cmd_hash ) ) {
      if ( $process->{pending} ) {
        dPrint( ZoneMinder::Logger::DEBUG, "'$process->{command}' pending at "
            .strftime( '%y/%m/%d %H:%M:%S', localtime( $process->{pending} ) )
            ."\n"
            );
      }
    } # end foreach process
  }
}

sub killAll {
  my $delay = shift;
  sleep( $delay );
  my $killall;
  if ( '@HOST_OS@' eq 'BSD' ) {
    $killall = 'killall -q -';
  } elsif ( '@HOST_OS@' eq 'solaris' ) {
    $killall = 'pkill -';
  } else {
    $killall = 'killall -q -s ';
  }
  foreach my $daemon ( @daemons ) {
    my $cmd = $killall ."TERM $daemon";
    Debug( $cmd );
    qx( $cmd );
  }
  sleep( $delay );
  foreach my $daemon ( @daemons ) {
    my $cmd = $killall."KILL $daemon";
    Debug( $cmd );
    qx( $cmd );
  }
}

1;
__END__