src/mailvisa-check.ml

   1 (* mailvisa-check - Read a message, send it to mailvisad, and judge if it's ham or spam *)
   2
   3 open Sys
   4 open Unix
   5
   6 open Common
   7
   8 (* Defaults *)
   9
  10 let default_confdir = (getenv "HOME") ^ "/settings/mailvisa2"
  11 let default_sockpath = "mailvisad.sock"
  12 let default_blocksize = 16384
  13 let default_threshold = 0.5
  14 let default_passthrough = true  (** output message *)
  15 let default_header = true       (** output X-Spam headers *)
  16 let default_errorcodes = false  (** suppress error codes if true *)
  17 let default_input = Pervasives.stdin
  18 let default_output = Pervasives.stdout
  19
  20 (* Constants *)
  21
  22 let endl = "\x0d\x0a"
  23 let spam_status = 160
  24
  25 let usage = "USAGE: mailvisa [options]"
  26 let help = "Valid options are:
  27
  28 -c <path>       Look for files in <path> (default: $HOME/settings/mailvisa)
  29 -q              Do not output message or X-Spam headers
  30 -e              Do not use exit status to indicate spam
  31 -b <num>        Read <num> bytes at a time (default: 16384)
  32 -t <num>        Threshold for flagging messages as spam (default: 0.5)
  33 -m <command>    Pipe output to <command>
  34 -s <path>       Use <path> to connect to mailvisad (default: mailvisad.sock)"
  35
  36 (* Functions *)
  37
  38 (** Parse command options from args into hash table. *)
  39 let parse_options args =
  40   let options = Hashtbl.create 8 in
  41   let i = ref 1 in
  42   let add_flag name = Hashtbl.add options name "true" in
  43   let add_option name = increment i; Hashtbl.add options name args.(!i) in
  44     while !i < (Array.length args) do
  45       (match args.(!i) with
  46          | "-h" ->
  47              print_endline usage;
  48              print_endline help;
  49              exit 0
  50          | "-b" -> add_option "blocksize"
  51          | "-c" -> add_option "confdir"
  52          | "-e" -> add_flag "errorcodes"
  53          | "-m" -> add_option "mda"
  54          | "-q" -> add_flag "quiet"
  55          | "-t" -> add_option "threshold"
  56          | "-s" -> add_option "sockpath"
  57          | option ->
  58              output_string Pervasives.stderr ("Invalid option: " ^ option ^ "\n");
  59              exit 0x80);
  60       increment i
  61     done;
  62     options
  63
  64 (* Initialization *)
  65
  66 let options = parse_options argv
  67 let confdir = get_option_with_default options "confdir" default_confdir
  68
  69 (** Create an absolute path from a path, by prepending confdir if the path does not contain a slash. *)
  70 let absolute_path path =
  71   if String.contains path '/' then path
  72   else (confdir ^ "/" ^ path)
  73
  74 (* Set constants from command line options *)
  75 let sockpath = absolute_path (hash_get options "sockpath" ~default:default_sockpath)
  76 let blocksize = hash_get_int options "blocksize" ~default:default_blocksize
  77 let threshold = hash_get_float options "threshold" ~default:default_threshold
  78 let quiet = hash_get_bool options "quiet" ~default:false
  79 let passthrough = if quiet then false else default_passthrough
  80 let header = if quiet then false else default_header
  81 let errorcodes = hash_get_bool options "errorcodes" ~default:default_errorcodes
  82 let input_channel = default_input
  83
  84 let output_channel =
  85   (match hash_get_maybe options "mda" with
  86      | None -> default_output
  87      | Some command -> open_process_out command)
  88
  89 (* Main program *)
  90 let _ =
  91   let status = ref 0 in
  92   let msg = String.create blocksize in
  93   let bytes_read = input input_channel msg 0 blocksize in
  94     (* Analyze message *)
  95     begin
  96       try
  97           (* If we didn't get any bytes, raise End_of_file *)
  98           if bytes_read = 0 then raise End_of_file;
  99           (* We read n bytes; send them on to the daemon. *)
 100           let conn =
 101             try
 102               unix_connect sockpath
 103             with _ ->
 104               failwith ("Cannot connect to " ^ sockpath)
 105           in
 106           let bytes_written = write conn msg 0 bytes_read in
 107             ignore bytes_written;
 108             shutdown conn SHUTDOWN_SEND;
 109             (* Read response from daemon. *)
 110             let response = input_line (in_channel_of_descr conn) in
 111             let score = (float_of_string response) in
 112               if score > threshold then status := spam_status
 113       with error ->
 114         status := 1;
 115         match error with
 116           | Failure msg ->
 117               prerr_endline msg
 118           | Unix_error (errno, funname, _) ->
 119               prerr_endline (funname ^ ": " ^ (error_message errno))
 120           | _ ->
 121               prerr_endline (Printexc.to_string error)
 122     end;
 123
 124     (* Output X-Spam: header if requested *)
 125     if header && (!status = 0 || !status = spam_status) then
 126       output_string output_channel ("X-Spam: " ^
 127                                       (if !status = spam_status
 128                                        then "true"
 129                                        else "false") ^
 130                                       endl);
 131
 132     (* Pass through message if requested *)
 133     if passthrough then begin
 134       let rec aux n =
 135         if n > 0 then begin
 136           output output_channel msg 0 n;
 137           aux (input input_channel msg 0 blocksize)
 138         end
 139       in aux bytes_read
 140     end;
 141
 142     (* Return status *)
 143     exit (if errorcodes then 0 else !status)