Module: Sisimai::Lhost::Postfix

Defined in:

lib/sisimai/lhost/postfix.rb

Overview

Sisimai::Lhost::Postfix decodes a bounce email which created by Postfix www.postfix.org/. Methods in the module are called from only Sisimai::Message.

Constant Summary

Indicators =

Postfix manual - bounce(5) - www.postfix.org/bounce.5.html

Sisimai::Lhost.INDICATORS

Boundaries =

['Content-Type: message/rfc822', 'Content-Type: text/rfc822-headers'].freeze

StartingOf =

{
  # Postfix manual - bounce(5) - http://www.postfix.org/bounce.5.html
  message: [
    ['The ', 'Postfix '],           # The Postfix program, The Postfix on <os> program
    ['The ', 'mail system'],        # The mail system
    ['The ', 'program'],            # The <name> pogram
    ['This is the', 'Postfix'],     # This is the Postfix program
    ['This is the', 'mail system'], # This is the mail system at host <hostname>
  ],
}.freeze

Class Method Summary

• .description ⇒ Object
• .inquire(mhead, mbody) ⇒ Hash, Nil abstract

Class Method Details

.description ⇒ Object

# File 'lib/sisimai/lhost/postfix.rb', line 287

def description; return 'Postfix'; end

.inquire(mhead, mbody) ⇒ Hash, Nil

This method is abstract.

Decodes the bounce message from Postfix

Parameters:

• mhead (Hash) —

  Message headers of a bounce email

• mbody (String) —

  Message body of a bounce email

Returns:

• (Hash) —

  Bounce data list and message/rfc822 part

• (Nil) —

  it failed to decode or the arguments are missing

# File 'lib/sisimai/lhost/postfix.rb', line 31

def inquire(mhead, mbody)
  match = 0

  if mhead['subject'].include?('SMTP server: errors from ')
    # src/smtpd/smtpd_chat.c:|337: post_mail_fprintf(notice, "Subject: %s SMTP server: errors from %s",
    # src/smtpd/smtpd_chat.c:|338:   var_mail_name, state->namaddr);
    match = 2
  else
    # Subject: Undelivered Mail Returned to Sender
    match = 1 if mhead['subject'] == 'Undelivered Mail Returned to Sender'
  end
  return nil if match == 0 || mhead['x-aol-ip']

  permessage = {}     # (Hash) Store values of each Per-Message field
  dscontents = [Sisimai::Lhost.DELIVERYSTATUS]; v = nil
  emailparts = Sisimai::RFC5322.part(mbody, Boundaries)
  bodyslices = emailparts[0].split("\n")
  readslices = ['']
  recipients = 0      # (Integer) The number of 'Final-Recipient' header
  nomessages = false  # (Boolean) Delivery report unavailable
  commandset = []     # (Array) ``in reply to * command'' list
  anotherset = {}     # Another error information

  if match == 2
    # The message body starts with 'Transcript of session follows.'
    require 'sisimai/smtp/transcript'
    transcript = Sisimai::SMTP::Transcript.rise(emailparts[0], 'In:', 'Out:')

    return nil if transcript.nil? || transcript.size == 0

    transcript.each do |e|
      # Pick email addresses, error messages, and the last SMTP command.
      v ||= dscontents[-1]
      p   = e['response']

      case e["command"]
      # Use the argument of EHLO/HELO command as a value of "lhost"
      when "HELO", "EHLO" then v['lhost'] = e['argument']
      when "MAIL"
        # Set the argument of "MAIL" command to pseudo To: header of the original message
        emailparts[1] += sprintf("To: %s\n", e['argument']) if emailparts[1].size == 0

      when "RCPT"
        # RCPT TO: <...>
        if v["recipient"] != ""
          # There are multiple recipient addresses in the transcript of session
          dscontents << Sisimai::Lhost.DELIVERYSTATUS
          v = dscontents[-1]
        end
        v['recipient'] = e['argument']
        recipients += 1
      end

      next if p['reply'].to_i < 400
      commandset << e['command']
      v['diagnosis'] = p['text'].join(' ') if v["diagnosis"].empty?
      v['replycode'] = p['reply'] if v["replycode"].empty?
      v['status']    = p['status'] if v["status"].empty?
    end
  else
    fieldtable = Sisimai::RFC1894.FIELDTABLE
    readcursor = 0      # (Integer) Points the current cursor position

    while e = bodyslices.shift do
      # Read error messages and delivery status lines from the head of the email to the previous
      # line of the beginning of the original message.
      readslices << e # Save the current line for the next loop

      if readcursor == 0
        # Beginning of the bounce message or message/delivery-status part
        readcursor |= Indicators[:deliverystatus] if StartingOf[:message].any? { |a| Sisimai::String.aligned(e, a) }
        next
      end
      next if (readcursor & Indicators[:deliverystatus]) == 0 || e.empty?

      f = Sisimai::RFC1894.match(e)
      if f > 0
        # "e" matched with any field defined in RFC3464
        next unless o = Sisimai::RFC1894.field(e)
        v = dscontents[-1]

        case o[3]
        when "addr"
          # Final-Recipient: rfc822; kijitora@example.jp
          # X-Actual-Recipient: rfc822; kijitora@example.co.jp
          if Sisimai::Address.is_emailaddress(o[2])
            # The email address is a valid email address, avoid an email address
            # without a valid domain part such as "neko@mailhost".
            if o[0] == 'final-recipient'
              # Final-Recipient: rfc822; kijitora@example.jp
              if v["recipient"] != ""
                # There are multiple recipient addresses in the message body.
                dscontents << Sisimai::Lhost.DELIVERYSTATUS
                v = dscontents[-1]
              end
              v['recipient'] = o[2]
              recipients += 1
            else
              # X-Actual-Recipient: rfc822; kijitora@example.co.jp
              v['alias'] = o[2]
            end
          end
        when "code"
          # Diagnostic-Code: SMTP; 550 5.1.1 <userunknown@example.jp>... User Unknown
          v['spec'] = o[1]
          v['spec'] = 'SMTP' if v['spec'].upcase == 'X-POSTFIX'
          v['diagnosis'] = o[2]
        else
          # Other DSN fields defined in RFC3464
          next if fieldtable[o[0]].nil?
          next if o[3] == "host" && Sisimai::RFC1123.is_internethost(o[2]) == false
          v[fieldtable[o[0]]] = o[2]

          next if f != 1
          permessage[fieldtable[o[0]]] = o[2]
        end
      else
        # If you do so, please include this problem report. You can
        # delete your own text from the attached returned message.
        #
        #           The mail system
        #
        # <userunknown@example.co.jp>: host mx.example.co.jp[192.0.2.153] said: 550
        # 5.1.1 <userunknown@example.co.jp>... User Unknown (in reply to RCPT TO command)
        if readslices[-2].start_with?('Diagnostic-Code:') && e.include?(' ')
          # Continued line of the value of Diagnostic-Code header
          v['diagnosis'] += " " + e.split.join(" ")
          readslices[-1]  = "Diagnostic-Code: #{e}"

        elsif Sisimai::String.aligned(e, ['X-Postfix-Sender:', 'rfc822;', '@'])
          # X-Postfix-Sender: rfc822; shironeko@example.org
          emailparts[1] += "X-Postfix-Sender: #{Sisimai::Address.s3s4(e[e.index(';') + 1, e.size])}\n"

        else
          # Alternative error message and recipient
          if e.include?(' (in reply to ') || e.include?('command)')
            # 5.1.1 <userunknown@example.co.jp>... User Unknown (in reply to RCPT TO
            cv = Sisimai::SMTP::Command.find(e) || ""; commandset << cv if cv.empty? == false
            anotherset['diagnosis'] ||= ''
            anotherset['diagnosis']  += " #{e}"

          elsif Sisimai::String.aligned(e, ['<', '@', '>', '(expanded from ', '):'])
            # <r@example.ne.jp> (expanded from <kijitora@example.org>): user ...
            p1 = e.index('> ');                   next unless p1
            p2 = e.index('(expanded from ', p1);  next unless p2
            p3 = e.index('>): ', p2 + 14);        next unless p3
            anotherset['recipient'] = Sisimai::Address.s3s4(e[0, p1])
            anotherset['alias']     = Sisimai::Address.s3s4(e[p2 + 15, p3 - p2 - 15])
            anotherset['diagnosis'] = e[p3 + 3, e.size]

          elsif e.start_with?('<') && Sisimai::String.aligned(e, ['<', '@', '>:'])
            # <kijitora@exmaple.jp>: ...
            anotherset['recipient'] = Sisimai::Address.s3s4(e[0, e.index('>')])
            anotherset['diagnosis'] = e[e.index('>:') + 2, e.size]

          elsif e.include?('--- Delivery report unavailable ---')
            # postfix-3.1.4/src/bounce/bounce_notify_util.c
            # bounce_notify_util.c:602|if (bounce_info->log_handle == 0
            # bounce_notify_util.c:602||| bounce_log_rewind(bounce_info->log_handle)) {
            # bounce_notify_util.c:602|if (IS_FAILURE_TEMPLATE(bounce_info->template)) {
            # bounce_notify_util.c:602|    post_mail_fputs(bounce, "");
            # bounce_notify_util.c:602|    post_mail_fputs(bounce, "\t--- delivery report unavailable ---");
            # bounce_notify_util.c:602|    count = 1;              /* xxx don't abort */
            # bounce_notify_util.c:602|}
            # bounce_notify_util.c:602|} else {
            nomessages = true
          else
            # Get an error message continued from the previous line
            next if anotherset['diagnosis'].nil?
            if e.start_with?('    ')
              #    host mx.example.jp said:...
              anotherset['diagnosis'] += " #{e[4, e.size]}"
            end
          end
        end
      end
    end # end of while()
  end

  if recipients == 0
    # Fallback: get a recipient address from error messages
    %w[recipient alias].each do |e|
      # Set a valid recipient address picked from the anotherset
      next  if anotherset[e].nil? || Sisimai::Address.is_emailaddress(anotherset[e]) == false
      break if dscontents[-1]['recipient'].empty? == false
      dscontents[-1]['recipient'] = anotherset[e]
      recipients += 1
      break
    end

    if recipients == 0
      # Get a recipient address from message/rfc822 part if the delivery report was unavailable:
      # '--- Delivery report unavailable ---'
      p1 = emailparts[1].index("\nTo: ")     || -1
      p2 = emailparts[1].index("\n", p1 + 6) || -1
      if nomessages && p1 > 0
        # Try to get a recipient address from To: field in the original message at message/rfc822 part
        dscontents[-1]['recipient'] = Sisimai::Address.s3s4(emailparts[1][p1 + 5, p2 - p1 - 5])
        recipients += 1
      end
    end
  end
  return nil if recipients == 0

  dscontents.each do |e|
    # Set default values if each value is empty.
    permessage.each_key { |a| e[a] ||= permessage[a] || '' }

    if anotherset['diagnosis']
      # Copy alternative error message
      anotherset['diagnosis'] = anotherset['diagnosis'].split.join(" ")
      e['diagnosis'] = anotherset['diagnosis'] if e['diagnosis'].nil? || e['diagnosis'].empty?

      if e['diagnosis'] =~ /\A\d+\z/
        # Override the value of diagnostic code message
        e['diagnosis'] = anotherset['diagnosis']
      else
        # More detailed error message is in "anotherset"
        as = '' # status
        ar = '' # replycode
        if Sisimai::SMTP::Status.is_ambiguous(e['status'])
          # Check the value of D.S.N. in anotherset
          # The D.S.N. is neither an empty nor *.0.0
          as = Sisimai::SMTP::Status.find(anotherset['diagnosis'])
          e['status'] = as if Sisimai::SMTP::Status.is_ambiguous(as) == false
        end

        if e['replycode'].empty? || e['replycode'].end_with?('00')
          # Check the value of SMTP reply code in $anotherset
          ar = Sisimai::SMTP::Reply.find(anotherset['diagnosis'])
          if ar.size > 0 && ar.end_with?('00') == false
            # The SMTP reply code is neither an empty nor *00
            e['replycode'] = ar
          end
        end

        while true
          # Replace e['diagnosis'] with the value of anotherset['diagnosis'] when all the
          # following conditions have not matched.
          break if (as + ar).size == 0
          break if anotherset['diagnosis'].size < e['diagnosis'].size
          break if anotherset['diagnosis'].include?(e['diagnosis']) == false

          e['diagnosis'] = anotherset['diagnosis']
          break
        end
      end
    end

    e['command']   = commandset.shift || Sisimai::SMTP::Command.find(e['diagnosis'])
    e['command']   = 'HELO' if e["command"].empty? && e['diagnosis'].include?('refused to talk to me:')
    e['spec']      = 'SMTP' if e["spec"].empty?    && Sisimai::String.aligned(e['diagnosis'], ['host ', ' said:'])
  end

  return { 'ds' => dscontents, 'rfc822' => emailparts[1] }
end