plugins/mod_posix.lua

   1 -- Prosody IM
   2 -- Copyright (C) 2008-2010 Matthew Wild
   3 -- Copyright (C) 2008-2010 Waqas Hussain
   4 --
   5 -- This project is MIT/X11 licensed. Please see the
   6 -- COPYING file in the source package for more information.
   7 --
   8
   9
  10 local want_pposix_version = "0.3.6";
  11
  12 local pposix = assert(require "util.pposix");
  13 if pposix._VERSION ~= want_pposix_version then
  14         module:log("warn", "Unknown version (%s) of binary pposix module, expected %s. Perhaps you need to recompile?", tostring(pposix._VERSION), want_pposix_version);
  15 end
  16
  17 local have_signal, signal = pcall(require, "util.signal");
  18 if not have_signal then
  19         module:log("warn", "Couldn't load signal library, won't respond to SIGTERM");
  20 end
  21
  22 local lfs = require "lfs";
  23 local stat = lfs.attributes;
  24
  25 local prosody = _G.prosody;
  26
  27 module:set_global(); -- we're a global module
  28
  29 local umask = module:get_option("umask") or "027";
  30 pposix.umask(umask);
  31
  32 -- Allow switching away from root, some people like strange ports.
  33 module:hook("server-started", function ()
  34         local uid = module:get_option("setuid");
  35         local gid = module:get_option("setgid");
  36         if gid then
  37                 local success, msg = pposix.setgid(gid);
  38                 if success then
  39                         module:log("debug", "Changed group to %s successfully.", gid);
  40                 else
  41                         module:log("error", "Failed to change group to %s. Error: %s", gid, msg);
  42                         prosody.shutdown("Failed to change group to %s", gid);
  43                 end
  44         end
  45         if uid then
  46                 local success, msg = pposix.setuid(uid);
  47                 if success then
  48                         module:log("debug", "Changed user to %s successfully.", uid);
  49                 else
  50                         module:log("error", "Failed to change user to %s. Error: %s", uid, msg);
  51                         prosody.shutdown("Failed to change user to %s", uid);
  52                 end
  53         end
  54 end);
  55
  56 -- Don't even think about it!
  57 if not prosody.start_time then -- server-starting
  58         local suid = module:get_option("setuid");
  59         if not suid or suid == 0 or suid == "root" then
  60                 if pposix.getuid() == 0 and not module:get_option("run_as_root") then
  61                         module:log("error", "Danger, Will Robinson! Prosody doesn't need to be run as root, so don't do it!");
  62                         module:log("error", "For more information on running Prosody as root, see https://prosody.im/doc/root");
  63                         prosody.shutdown("Refusing to run as root");
  64                 end
  65         end
  66 end
  67
  68 local pidfile;
  69 local pidfile_handle;
  70
  71 local function remove_pidfile()
  72         if pidfile_handle then
  73                 pidfile_handle:close();
  74                 os.remove(pidfile);
  75                 pidfile, pidfile_handle = nil, nil;
  76         end
  77 end
  78
  79 local function write_pidfile()
  80         if pidfile_handle then
  81                 remove_pidfile();
  82         end
  83         pidfile = module:get_option_string("pidfile");
  84         if pidfile then
  85                 local err;
  86                 local mode = stat(pidfile) and "r+" or "w+";
  87                 pidfile_handle, err = io.open(pidfile, mode);
  88                 if not pidfile_handle then
  89                         module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
  90                         prosody.shutdown("Couldn't write pidfile");
  91                 else
  92                         if not lfs.lock(pidfile_handle, "w") then -- Exclusive lock
  93                                 local other_pid = pidfile_handle:read("*a");
  94                                 module:log("error", "Another Prosody instance seems to be running with PID %s, quitting", other_pid);
  95                                 pidfile_handle = nil;
  96                                 prosody.shutdown("Prosody already running");
  97                         else
  98                                 pidfile_handle:close();
  99                                 pidfile_handle, err = io.open(pidfile, "w+");
 100                                 if not pidfile_handle then
 101                                         module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
 102                                         prosody.shutdown("Couldn't write pidfile");
 103                                 else
 104                                         if lfs.lock(pidfile_handle, "w") then
 105                                                 pidfile_handle:write(tostring(pposix.getpid()));
 106                                                 pidfile_handle:flush();
 107                                         end
 108                                 end
 109                         end
 110                 end
 111         end
 112 end
 113
 114 local syslog_opened;
 115 function syslog_sink_maker(config)
 116         if not syslog_opened then
 117                 pposix.syslog_open("prosody", module:get_option_string("syslog_facility"));
 118                 syslog_opened = true;
 119         end
 120         local syslog, format = pposix.syslog_log, string.format;
 121         return function (name, level, message, ...)
 122                 if ... then
 123                         syslog(level, name, format(message, ...));
 124                 else
 125                         syslog(level, name, message);
 126                 end
 127         end;
 128 end
 129 require "core.loggingmanager".register_sink_type("syslog", syslog_sink_maker);
 130
 131 local daemonize = module:get_option("daemonize", prosody.installed);
 132
 133 local function remove_log_sinks()
 134         local lm = require "core.loggingmanager";
 135         lm.register_sink_type("console", nil);
 136         lm.register_sink_type("stdout", nil);
 137         lm.reload_logging();
 138 end
 139
 140 if daemonize then
 141         local function daemonize_server()
 142                 module:log("info", "Prosody is about to detach from the console, disabling further console output");
 143                 remove_log_sinks();
 144                 local ok, ret = pposix.daemonize();
 145                 if not ok then
 146                         module:log("error", "Failed to daemonize: %s", ret);
 147                 elseif ret and ret > 0 then
 148                         os.exit(0);
 149                 else
 150                         module:log("info", "Successfully daemonized to PID %d", pposix.getpid());
 151                         write_pidfile();
 152                 end
 153         end
 154         if not prosody.start_time then -- server-starting
 155                 daemonize_server();
 156         end
 157 else
 158         -- Not going to daemonize, so write the pid of this process
 159         write_pidfile();
 160 end
 161
 162 module:hook("server-stopped", remove_pidfile);
 163
 164 -- Set signal handlers
 165 if have_signal then
 166         signal.signal("SIGTERM", function ()
 167                 module:log("warn", "Received SIGTERM");
 168                 prosody.unlock_globals();
 169                 prosody.shutdown("Received SIGTERM");
 170                 prosody.lock_globals();
 171         end);
 172
 173         signal.signal("SIGHUP", function ()
 174                 module:log("info", "Received SIGHUP");
 175                 prosody.reload_config();
 176                 prosody.reopen_logfiles();
 177         end);
 178
 179         signal.signal("SIGINT", function ()
 180                 module:log("info", "Received SIGINT");
 181                 prosody.unlock_globals();
 182                 prosody.shutdown("Received SIGINT");
 183                 prosody.lock_globals();
 184         end);
 185 end