move espect into Postal::MessageInspection

lib/postal/message_inspection.rb

@@ -0,0 +1,141 @@
+require 'timeout'
+require 'socket'
+require 'json'
+
+module Postal
+  class MessageInspection
+
+    SPAM_EXCLUSIONS = {
+      :outgoing => ['NO_RECEIVED', 'NO_RELAYS', 'ALL_TRUSTED', 'FREEMAIL_FORGED_REPLYTO', 'RDNS_DYNAMIC', /^SPF\_/, /^HELO\_/, /DKIM_/, /^RCVD_IN_/],
+      :incoming => []
+    }
+
+    def initialize(message, scope = :incoming)
+      @message = message
+      @scope = scope
+      @threat = false
+      @spam_score = 0.0
+      @spam_checks = []
+
+      if Postal.config.spamd.enabled?
+        scan_for_spam
+      end
+
+      if Postal.config.clamav.enabled?
+        scan_for_threats
+      end
+    end
+
+    def spam_score
+      @spam_score
+    end
+
+    def spam_checks
+      @spam_checks
+    end
+
+    def filtered_spam_checks
+      @filtered_spam_checks ||= @spam_checks.reject do |check|
+        SPAM_EXCLUSIONS[@scope].any? do |item|
+          item == check.code || (item.is_a?(Regexp) && item =~ check.code)
+        end
+      end
+    end
+
+    def filtered_spam_score
+      filtered_spam_checks.inject(0.0) do |total, check|
+        total += check.score || 0.0
+      end.round(2)
+    end
+
+    def threat?
+      @threat
+    end
+
+    def threat_message
+      @threat_message
+    end
+
+    private
+
+    def scan_for_spam
+      data = nil
+      Timeout.timeout(15) do
+        tcp_socket = TCPSocket.new(Postal.config.spamd.host, Postal.config.spamd.port)
+        tcp_socket.write("REPORT SPAMC/1.2\r\n")
+        tcp_socket.write("Content-length: #{@message.bytesize}\r\n")
+        tcp_socket.write("\r\n")
+        tcp_socket.write(@message)
+        tcp_socket.close_write
+        data = tcp_socket.read
+      end
+
+      spam_checks = []
+      total = 0.0
+      rules = data ? data.split(/^---(.*)\r?\n/).last.split(/\r?\n/) : []
+      while line = rules.shift
+        if line =~ /\A([\- ]?[\d\.]+)\s+(\w+)\s+(.*)/
+          total += $1.to_f
+          spam_checks << SPAMCheck.new($2, $1.to_f, $3)
+        else
+          spam_checks.last.description << " " + line.strip
+        end
+      end
+
+      @spam_score = total.round(1)
+      @spam_checks = spam_checks
+
+    rescue Timeout::Error
+      @spam_checks = [SPAMCheck.new("TIMEOUT", 0, "Timed out when scanning for spam")]
+    rescue => e
+      logger.error "Error talking to spamd: #{e.class} (#{e.message})"
+      logger.error e.backtrace[0,5]
+      @spam_checks = [SPAMCheck.new("ERROR", 0, "Error when scanning for spam")]
+    ensure
+      tcp_socket.close rescue nil
+    end
+
+    def scan_for_threats
+      @threat = false
+
+      data = nil
+      Timeout.timeout(10) do
+        tcp_socket = TCPSocket.new(Postal.config.clamav.host, Postal.config.clamav.port)
+        tcp_socket.write("zINSTREAM\0")
+        tcp_socket.write([@message.bytesize].pack("N"))
+        tcp_socket.write(@message)
+        tcp_socket.write([0].pack("N"))
+        tcp_socket.close_write
+        data = tcp_socket.read
+      end
+
+      if data && data =~ /\Astream\:\s+(.*?)[\s\0]+?/
+        if $1.upcase == 'OK'
+          @threat = false
+          @threat_message = "No threats found"
+        else
+          @threat = true
+          @threat_message = $1
+        end
+      else
+        @threat = false
+        @threat_message = "Could not scan message"
+      end
+    rescue Timeout::Error
+      @threat = false
+      @threat_message = "Timed out scanning for threats"
+    rescue => e
+      logger.error "Error talking to clamav: #{e.class} (#{e.message})"
+      logger.error e.backtrace[0,5]
+      @threat = false
+      @threat_message = "Error when scanning for threats"
+    ensure
+      tcp_socket.close rescue nil
+    end
+
+    def logger
+      Postal.logger_for(:message_inspection)
+    end
+
+  end
+end