#!/usr/bin/perl -T
# SPDX-License-Identifier: BSD-2-Clause

#------------------------------------------------------------------------------
# This is amavisd-submit, a simple demonstrational program, taking an email
# message on stdin and submiting it to amavisd daemon. It is functionally
# much like the old amavis.c helper program, except that it talks a new
# AM.PDP protocol with the amavisd daemon. See README.protocol for the
# description of AM.PDP protocol.
#
# Author: Mark Martinec <Mark.Martinec@ijs.si>
#
# Copyright (c) 2004,2010-2014, Mark Martinec
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright notice,
#    this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# The views and conclusions contained in the software and documentation are
# those of the authors and should not be interpreted as representing official
# policies, either expressed or implied, of the Jozef Stefan Institute.

# (the above license is the 2-clause BSD license, also known as
#  a "Simplified BSD License", and pertains to this program only)
#
# Patches and problem reports are welcome.
# The latest version of this program is available at:
#   http://www.ijs.si/software/amavisd/
#------------------------------------------------------------------------------

# Usage:
#   amavisd-submit sender recip1 recip2 recip3 ... <email.msg
# (should run under the same GID as amavisd, to make files accessible to it)
#
# To be placed in amavisd.conf:
#   $interface_policy{'SOCK'} = 'AM.PDP';
#   $policy_bank{'AM.PDP'} = { protocol=>'AM.PDP' };
#   $unix_socketname = '/var/amavis/amavisd.sock';

use warnings;
use warnings FATAL => 'utf8';
no  warnings 'uninitialized';
use strict;
use re 'taint';
use IO::Socket;
use IO::File;
use File::Temp ();
use Time::HiRes ();

BEGIN {
  use vars qw($VERSION);  $VERSION = 2.101;
  use vars qw($log_level $socketname $tempbase $io_socket_module_name);


### USER CONFIGURABLE:

  $log_level = 0;
  $tempbase = '/var/lib/amavis/tmp';  # where to create a temp directory with a msg

  $socketname = '/var/lib/amavis/amavisd.sock';
# $socketname = '127.0.0.1:9998';
# $socketname = '[::1]:9998';

### END OF USER CONFIGURABLE


  # load a suitable sockets module
  if ($socketname =~ m{^/}) {
    require IO::Socket::UNIX;
    $io_socket_module_name = 'IO::Socket::UNIX';
  } elsif (eval { require IO::Socket::IP }) {
    # prefer using module IO::Socket::IP if available,
    $io_socket_module_name = 'IO::Socket::IP';
  } elsif (eval { require IO::Socket::INET6 }) {
    # otherwise fall back to IO::Socket::INET6
    $io_socket_module_name = 'IO::Socket::INET6';
  } elsif (eval { require IO::Socket::INET }) {
    $io_socket_module_name = 'IO::Socket::INET';
  }
  $io_socket_module_name  or die "No suitable socket module available";
}

sub sanitize_str {
  my($str, $keep_eol) = @_;
  my(%map) = ("\r" => '\\r', "\n" => '\\n', "\f" => '\\f', "\t" => '\\t',
              "\b" => '\\b', "\e" => '\\e', "\\" => '\\\\');
  if ($keep_eol) {
    $str =~ s/([^\012\040-\133\135-\176])/  # and \240-\376 ?
              exists($map{$1}) ? $map{$1} :
                     sprintf(ord($1)>255 ? '\\x{%04x}' : '\\%03o', ord($1))/eg;
  } else {
    $str =~ s/([^\040-\133\135-\176])/      # and \240-\376 ?
              exists($map{$1}) ? $map{$1} :
                     sprintf(ord($1)>255 ? '\\x{%04x}' : '\\%03o', ord($1))/eg;
  }
  $str;
}

sub ll($) {
  my($level) = @_;
  $level <= $log_level;
}

sub do_log($$;@) {
  my($level, $errmsg, @args) = @_;
  $errmsg = sprintf($errmsg,@args)  if @args;
  print STDERR sanitize_str($errmsg),"\n"  if $level <= $log_level;
}

sub proto_decode($) {
  my($str) = @_;
  $str =~ s/%([0-9a-fA-F]{2})/pack("C",hex($1))/eg;
  $str;
}

sub proto_encode($@) {
  my($attribute_name,@strings) = @_; local($1);
  $attribute_name =~    # encode all but alfanumerics, '_' and '-'
    s/([^0-9a-zA-Z_-])/sprintf("%%%02x",ord($1))/eg;
  for (@strings) {      # encode % and nonprintables
    s/([^\041-\044\046-\176])/sprintf("%%%02x",ord($1))/eg;
  }
  $attribute_name . '=' . join(' ',@strings);
}

sub ask_amavisd($$) {
  my($sock,$query_ref) = @_;
  my(@encoded_query) =
    map { /^([^=]+)=(.*)\z/s; proto_encode($1,$2) } @$query_ref;
  do_log(2, "> %s", $_)  for @encoded_query;
  $sock->print( map($_."\015\012", (@encoded_query,'')) )
    or die "Can't write response to socket: $!";
  $sock->flush or die "Can't flush on socket: $!";
  my(%attr);
  local($/) = "\015\012";    # set line terminator to CRLF
  # must not use \r and \n, which may not be \015 and \012 on certain platforms
  do_log(2, "waiting for response");
  while(<$sock>) {
    last  if /^\015\012\z/;  # end of response
    if (/^ ([^=\000\012]*?) (=|:[ \t]*) ([^\012]*?) \015\012 \z/xsi) {
      my $attr_name = proto_decode($1);
      my $attr_val  = proto_decode($3);
      if (!exists $attr{$attr_name}) { $attr{$attr_name} = [] }
      push(@{$attr{$attr_name}}, $attr_val);
    }
  }
  if (!defined($_) && $! != 0) { die "read from socket failed: $!" }
  \%attr;
}

sub usage(;$) {
  my($msg) = @_;
  print STDERR $msg,"\n\n"  if $msg ne '';
  my $prog = $0;  $prog =~ s{^.*/(?=[^/]+\z)}{};
  print STDERR "$prog version $VERSION\n";
  die "Usage:  \$ $prog sender recip1 recip2 ... < email.msg\n";
}

# Main program starts here

  $SIG{INT}  = sub { die "\n" };  # do the END code block when interrupted
  $SIG{TERM} = sub { die "\n" };  # do the END code block when killed
  umask(0027);  # set our preferred umask

  @ARGV >= 1 or usage("Not enough arguments");

  my($sock, %sock_args);
  if ($io_socket_module_name eq 'IO::Socket::UNIX') {
    %sock_args = (Type => &SOCK_STREAM, Peer => $socketname);
  } else {
    %sock_args = (Type => &SOCK_STREAM, PeerAddr => $socketname);
  }
  do_log(2, "Connecting to %s using a module %s",
            $socketname, $io_socket_module_name);
  $sock = $io_socket_module_name->new(%sock_args)
    or die "Can't connect to a $io_socket_module_name socket $socketname: $!\n";

  my $tempdir = File::Temp::tempdir('amavis-XXXXXXXXXX', DIR => $tempbase);
  defined $tempdir && $tempdir ne ''
    or die "Can't create a temporary directory: $!";
  chmod(0750, $tempdir)
    or die "Can't change protection on directory $tempdir: $!";
  my $fname = "$tempdir/email.txt";

  # copy message from stdin to a file email.txt in the temporary directory

  my $fh = IO::File->new;
  $fh->open($fname, O_CREAT|O_EXCL|O_RDWR, 0640)
    or die "Can't create file $fname: $!";
  my($nbytes,$buff);
  while (($nbytes=read(STDIN,$buff,32768)) > 0) {
    $fh->print($buff) or die "Error writing to $fname: $!";
  }
  defined $nbytes or die "Error reading mail file: $!";
  $fh->close   or die "Error closing $fname: $!";
  close(STDIN) or die "Error closing STDIN: $!";

  my(@query) = (
    'request=AM.PDP',
    "mail_file=$fname",
    "tempdir=$tempdir",
    'tempdir_removed_by=server',
    map("sender=<$_>", shift(@ARGV)),
    map("recipient=<$_>", @ARGV),
#   'delivery_care_of=server',
#   'protocol_name=ESMTP',
#   'helo_name=b.example.com',
#   'client_address=::1',
  );
  my $attr_ref = ask_amavisd($sock,\@query);
  if (ll(2)) {
    for my $attr_name (keys %$attr_ref) {
      for my $attr_val (@{$attr_ref->{$attr_name}}) {
        do_log(2, "< %s=%s", $attr_name,$attr_val);
      }
    }
  }
  my($setreply,$exit_code);
  $setreply  = $attr_ref->{'setreply'}->[0]  if $attr_ref->{'setreply'};
  $exit_code = $attr_ref->{'exit_code'}->[0] if $attr_ref->{'exit_code'};
  if (defined $setreply && $setreply =~ /^2\d\d/) {  # all ok
    do_log(1, "%s", $setreply);
  } elsif (!defined($setreply)) {
    do_log(0, "Error, missing 'setreply' attribute");
  } else {
    do_log(0, "%s", $setreply);
  }
  # may do another request here if needed ...
  $sock->close or die "Error closing socket: $!";
  $exit_code = 0  if $exit_code==99;  # same thing in this case, both is ok
  exit 0+$exit_code;

END {
  # remove a temporary file and directory if necessary
  if (defined $fname && -f $fname) {
    unlink $fname or warn "Error deleting file $fname: $!";
  }
  if (defined $tempdir && -d $tempdir) {
    rmdir $tempdir or warn "Error deleting temporary directory $tempdir: $!";
  }
}