Notify.hs

   1 -- This file is part of htalkat
   2 -- Copyright (C) 2021 Martin Bays <mbays@sdf.org>
   3 --
   4 -- This program is free software: you can redistribute it and/or modify
   5 -- it under the terms of version 3 of the GNU General Public License as
   6 -- published by the Free Software Foundation, or any later version.
   7 --
   8 -- You should have received a copy of the GNU General Public License
   9 -- along with this program.  If not, see http://www.gnu.org/licenses/.
  10
  11 module Notify where
  12
  13 import           Control.Monad      (void)
  14 import           System.Directory   (doesFileExist)
  15 import           System.FilePath    ((</>))
  16 import           System.Process
  17
  18 #ifndef WINDOWS
  19 import           System.Posix.Files (ownerModes, setFileMode)
  20 #endif
  21
  22 import           Certificate
  23 import           Fingerprint
  24 import           Petname
  25 import           Util
  26
  27 #if !(MIN_VERSION_base(4,11,0))
  28 import           Data.Semigroup
  29 #endif
  30
  31 notifyOfIncoming :: FilePath -> Certificate -> Petname -> IO ()
  32 notifyOfIncoming ddir cert petname = do
  33     case petname of
  34         Named name -> putStrLn $ "Talk request from '" <> name <> "'; accept with: htalkat a "<> shellQuotePetname (Named name) <>""
  35         p@(Unnamed _) -> do
  36             putStrLn $ "Talk request from unknown caller " <> showPetname p
  37             putStrLn $ "  Fingerprint: " <> showFingerprint (spkiFingerprint cert)
  38             putStrLn $ "  Public name: " <> certCN cert
  39             putStrLn $ "Accept with: htalkat a " <> shellQuotePetname p
  40     createNotifyScriptIfNecessary ddir
  41     void $ rawSystem (notifyScriptPath ddir)
  42         [ showPetname petname
  43         , showFingerprint $ spkiFingerprint cert
  44         , certCN cert
  45         ]
  46
  47 notifyScriptPath :: FilePath -> FilePath
  48 notifyScriptPath = (</> "notify.sh")
  49
  50 createNotifyScriptIfNecessary :: FilePath -> IO ()
  51 createNotifyScriptIfNecessary ddir =
  52     let spath = notifyScriptPath ddir
  53     in doesFileExist spath >>! do
  54         writeFile spath defaultNotifyScript
  55 #ifndef WINDOWS
  56         setFileMode spath ownerModes -- chmod 700
  57 #endif
  58
  59 defaultNotifyScript :: String
  60 defaultNotifyScript = unlines
  61     [ "#!/usr/bin/env bash"
  62     , "# This script is called when someone connects to the talkat server."
  63     , "# The following positional arguments are given to this script:"
  64     , "# $1: assigned name of caller, or +N for an unknown caller"
  65     , "# $2: fingerprint of caller's public key"
  66     , "# $3: \"public name\" set in CN field of caller's certificate"
  67     , ""
  68     , "# Example:"
  69     , "#announce=\"$(echo -n \"Talkat request from $1\"; \\"
  70     , "#    [[ \"$1\" =~ ^\\+ ]] && echo -n \" $2 (\\\"$3\\\")\")\""
  71     , "#write $USER <<<\"$announce\""
  72     , "#mail -s \"$announce\" $USER <<<\"Answer with htalkat a '$1'\""
  73     , "#notify-send \"$announce\""
  74     ]