#! /bin/sh

# Copyright (c) The Exim Maintainers 2023 - 2025
# Copyright (c) University of Cambridge, 1995 - 2007
# See the file NOTICE for conditions of use and distribution.

# Except when they appear in comments, the following placeholders in this
# source are replaced when it is turned into a runnable script:
#
# CONFIGURE_FILE_USE_NODE
# CONFIGURE_FILE
# BIN_DIRECTORY
# MSGID_RE

# This file has been so processed.

# A shell+perl script to fish out the next retry time for a given domain;
# it first calls exim to find out which hosts are set up for that domain and
# then fishes out the retry data for each one.

# For testing the selection and formatting logic, and perhaps for use in
# special cases, the script can have an argument -C <filename> to specify
# the use of an alternate Exim configuration file. It may also have any number
# of -D options to set macros that are passed to exim.

config=
eximmacdef=
exim_path=

if [ "x$1" = x--version -o "x$1" = x-v ]
then
    echo "`basename $0`: $0"
    echo "build: 4.100.1"
    exit 0
fi

if expr -- $1 : '\-' >/dev/null ; then
  while expr -- $1 : '\-' >/dev/null ; do
    if [ "$1" = "-C" ]; then
      config=$2
      shift
      shift
    elif expr -- $1 : '\-D' >/dev/null ; then
      eximmacdef="$eximmacdef $1"
      if expr -- $1 : '\-DEXIM_PATH=' >/dev/null ; then
        exim_path=`expr -- $1 : '\-DEXIM_PATH=\(.*\)'`
      fi
      shift
    else
      break
    fi
  done
fi

# We need to save the script's argument because in the absence of -C we need to
# use shell arguments for sorting out the configuration file name.

argone=$1

# This is the normal case when no config file or macros are specified

if [ "$config" = "" ]; then
  # See if this installation is using the esoteric "USE_NODE" feature of Exim,
  # in which it uses the host's name as a suffix for the configuration file name.

  if [ "" = "yes" ]; then
    hostsuffix=.`uname -n`
  fi

  # Now find the configuration file name. This has got complicated because
  # /etc/exim.conf may now be a list of files. The one that is used is the first
  # one that exists. Mimic the code in readconf.c by testing first for the
  # suffixed file in each case.

  set `awk -F: '{ for (i = 1; i <= NF; i++) print $i }' <<End
/etc/exim.conf
End
`
  while [ "$config" = "" -a $# -gt 0 ] ; do
    if [ -f "$1$hostsuffix" ] ; then
      config="$1$hostsuffix"
    elif [ -f "$1" ] ; then
      config="$1"
    fi
    shift
  done
fi

# Determine where the spool directory is. Search for an exim_path setting
# in the configure file; otherwise use the bin directory. Call that version of
# Exim to find the spool directory and the qualify domain. BEWARE: a tab
# character is needed in the command below. It has had a nasty tendency to get
# lost in the past. Use a variable to hold a space and a tab to keep the tab in
# one place.

st='     '

if [ "$exim_path" = "" ]; then
  exim_path=`grep "^[$st]*exim_path" $config | sed "s/.*=[$st]*//"`
fi

if test "$exim_path" = ""; then exim_path=/usr/sbin/exim; fi
spool_directory=`$exim_path $eximmacdef -C $config -bP spool_directory | sed 's/.*=[  ]*//'`
qualify_domain=`$exim_path $eximmacdef -C $config -bP qualify_domain | sed 's/.*=[  ]*//'`

# Now do the job. Perl uses $ so frequently that we don't want to have to
# escape them all from the shell, so pass in shell variable values as
# arguments.

# 16-May-1996  Fixed it to do better if routing fails to complete.
#              Improved the format of the output.
# 10-Jun-1996  Complain if no argument given.
# 02-Aug-1996  Lower case the domain.
# 14-Jan-1999  Add subject to want list even if remote host found, so as to
#              pick up routing delays after temporary recipient errors.
#              Also add unqualified subject if it looks like a message id.
# 01-Apr-2004  Add the -C feature for testing
# 22-Dec-2005  Complete the -C feature (!)

if [ "$argone" = "" ]; then
  echo "Usage: exinext <address>|<domain>|<local-part>"
  exit 1
fi

perl - $exim_path "$eximmacdef" $argone $spool_directory $qualify_domain $config <<'End'

  # We don't import anything, but guard against future changes which do
  BEGIN { pop @INC if $INC[-1] eq '.' };

  # Name the arguments

  $exim = $ARGV[0];
  $eximmacdef = $ARGV[1];
  $subject = $ARGV[2];
  $spool = $ARGV[3];
  $qualify = $ARGV[4];
  $config = $ARGV[5];

# Insert MSGID_RE
# Start msgid.frag
# Copyright (c) The Exim Maintainers 2025
# SPDX-License-Identifier: GPL-2.0-or-later
#
# Regex patterns for exim message-id

# Simple matching

my $b62 = "[[:alnum:]]";

my $msgid_sec_re = "${b62}{6}";
my $msgid_pid_new_re = "${b62}{11}";
my $msgid_pid_old_re = "${b62}{6}";
my $msgid_frc_new_re = "${b62}{4}";
my $msgid_frc_old_re = "${b62}{2}";

my $msgid_new_re = "$msgid_sec_re-$msgid_pid_new_re-$msgid_frc_new_re";
my $msgid_old_re = "$msgid_sec_re-$msgid_pid_old_re-$msgid_frc_old_re";
my $msgid_re =     "(?:$msgid_new_re|$msgid_old_re)";


# Match with content submatches
# - requires variables seconds, pid, fractions

my $msgid_sec_cap_re = "(?<seconds>$msgid_sec_re)";
my $msgid_pid_cap_re = "(?<pid>(?:$msgid_pid_new_re|$msgid_pid_old_re))";
my $msgid_frc_cap_re = "(?<fractions>(?:$msgid_frc_new_re|$msgid_frc_old_re))";

my $msgid_cap_re = "(?:$msgid_sec_cap_re-$msgid_pid_cap_re-$msgid_frc_cap_re)";

# End msgid.frag

  # If the subject doesn't contain an @ then construct an address
  # for the domain, and ensure that in both cases the domain is
  # lower cased.

  $address = ($subject =~ /^([^\@]*)\@([^\@]*)$/)?
    "$1\@\L$2\E" : "User\@\L$subject\E";

  # Run Exim to get a list of hosts for the given domain; for
  # each one construct the appropriate retry key.

  open(LIST, "$exim -C $config -v -bt $address |") ||
    die "can't run exim to route $address";

  while (<LIST>)
    {
    chop;
    push(@list, $_) if s/\s*host (\S+)\s+\[(.+)\].*/$1:$2/;
    print "$_\n" if /cannot be resolved/;
    }
  close(LIST);

  # If there were no hosts, assume that what was given was a local
  # username, unless it contains an @, and construct a suitable retry
  # key for that. Also, if it looks like a message id, search for that
  # as well, so as to pick up message-specific retry data.

  if (scalar(@list) == 0)
    {
    push(@list, $subject) if $subject =~ /^$msgid_re$/;

    if ($subject !~ /\@/ && $subject !~ /\./)
      {
      push(@list, "$subject\@$qualify");
      }
    else
      {
      print "No remote hosts found for $subject\n";
      }
    }

  # Always search for the full address, even if hosts are found, in case
  # there is a routing delay caused by a temporary recipient error.

  push(@list, $subject);

  # Run exim_dumpdb to get out the retry data and pick off what we want

  open(DATA, "${exim}_dumpdb $spool retry |") ||
    die "can't run exim_dumpdb";

  while (<DATA>)
    {
    for ($i = 0; $i <= $#list; $i++)
      {
      if (/$list[$i]/)
        {
        $printed = 1;
        if (/^\s*T:[^:\s]*:/)
          {
	  # We rely on non-space-containing strings, for parsing

          ($key,$error,$error2,$text) = /^\s*T:(\S+)\s+(\S+)\s+(\S+)\s*(.*)$/;

	  ($host,$ip,$port,$msgid) = $key =~
	    /^([^:[]*|\[[^]]*\])	# host (could be an ip)
	      :([^:[]*|\[[^]]*\])	# ip
	      (?::(\d{1,5}))?		# maybe port
	      (?::(\S{23}))?		# maybe msgid
	      $/x;

          printf("Transport: %s %s", $host, $ip);
          print ":$port" if defined $port;
          print " $msgid" if defined $msgid;
          print " error $error: $text\n";
          }

        else
          {
          ($type,$domain,$error,$error2,$text) =
            /^\s*(\S):(\S+)\s+(\S+)\s+(\S+)\s*(.*)$/;
          $type = ($type eq 'R')? "Route: " :
                  ($type eq 'T')? "Transport: " : "";
          print "$type$domain error $error: $text\n";
          }
        $_ = <DATA>;
        ($first,$last,$next,$expired) =
          /^(\S+\s+\S+)\s+(\S+\s+\S+)\s+(\S+\s+\S+)\s*(\*?)/;
        print "  first failed: $first\n";
        print "  last tried:   $last\n";
        print "  next try at:  $next\n";
        print "  past final cutoff time\n" if $expired eq "*";
        }
      }
    }

  close(DATA);
  print "No retry data found for $subject\n" if !$printed;
End