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 = "0.4.0";
  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."
  15                 .. "Perhaps you need to recompile?", tostring(pposix._VERSION), want_pposix_version);
  16 end
  17
  18 local have_signal, signal = pcall(require, "util.signal");
  19 if not have_signal then
  20         module:log("warn", "Couldn't load signal library, won't respond to SIGTERM");
  21 end
  22
  23 local format = require "util.format".format;
  24 local lfs = require "lfs";
  25 local stat = lfs.attributes;
  26
  27 local prosody = _G.prosody;
  28
  29 module:set_global(); -- we're a global module
  30
  31 local umask = module:get_option_string("umask", "027");
  32 pposix.umask(umask);
  33
  34 -- Allow switching away from root, some people like strange ports.
  35 module:hook("server-started", function ()
  36         local uid = module:get_option("setuid");
  37         local gid = module:get_option("setgid");
  38         if gid then
  39                 local success, msg = pposix.setgid(gid);
  40                 if success then
  41                         module:log("debug", "Changed group to %s successfully.", gid);
  42                 else
  43                         module:log("error", "Failed to change group to %s. Error: %s", gid, msg);
  44                         prosody.shutdown("Failed to change group to %s", gid);
  45                 end
  46         end
  47         if uid then
  48                 local success, msg = pposix.setuid(uid);
  49                 if success then
  50                         module:log("debug", "Changed user to %s successfully.", uid);
  51                 else
  52                         module:log("error", "Failed to change user to %s. Error: %s", uid, msg);
  53                         prosody.shutdown("Failed to change user to %s", uid);
  54                 end
  55         end
  56 end);
  57
  58 -- Don't even think about it!
  59 if not prosody.start_time then -- server-starting
  60         local suid = module:get_option("setuid");
  61         if not suid or suid == 0 or suid == "root" then
  62                 if pposix.getuid() == 0 and not module:get_option_boolean("run_as_root") then
  63                         module:log("error", "Danger, Will Robinson! Prosody doesn't need to be run as root, so don't do it!");
  64                         module:log("error", "For more information on running Prosody as root, see https://prosody.im/doc/root");
  65                         prosody.shutdown("Refusing to run as root");
  66                 end
  67         end
  68 end
  69
  70 local pidfile;
  71 local pidfile_handle;
  72
  73 local function remove_pidfile()
  74         if pidfile_handle then
  75                 pidfile_handle:close();
  76                 os.remove(pidfile);
  77                 pidfile, pidfile_handle = nil, nil;
  78         end
  79 end
  80
  81 local function write_pidfile()
  82         if pidfile_handle then
  83                 remove_pidfile();
  84         end
  85         pidfile = module:get_option_path("pidfile", nil, "data");
  86         if pidfile then
  87                 local err;
  88                 local mode = stat(pidfile) and "r+" or "w+";
  89                 pidfile_handle, err = io.open(pidfile, mode);
  90                 if not pidfile_handle then
  91                         module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
  92                         prosody.shutdown("Couldn't write pidfile");
  93                 else
  94                         if not lfs.lock(pidfile_handle, "w") then -- Exclusive lock
  95                                 local other_pid = pidfile_handle:read("*a");
  96                                 module:log("error", "Another Prosody instance seems to be running with PID %s, quitting", other_pid);
  97                                 pidfile_handle = nil;
  98                                 prosody.shutdown("Prosody already running");
  99                         else
 100                                 pidfile_handle:close();
 101                                 pidfile_handle, err = io.open(pidfile, "w+");
 102                                 if not pidfile_handle then
 103                                         module:log("error", "Couldn't write pidfile at %s; %s", pidfile, err);
 104                                         prosody.shutdown("Couldn't write pidfile");
 105                                 else
 106                                         if lfs.lock(pidfile_handle, "w") then
 107                                                 pidfile_handle:write(tostring(pposix.getpid()));
 108                                                 pidfile_handle:flush();
 109                                         end
 110                                 end
 111                         end
 112                 end
 113         end
 114 end
 115
 116 local syslog_opened;
 117 function syslog_sink_maker(config) -- luacheck: ignore 212/config
 118         if not syslog_opened then
 119                 pposix.syslog_open("prosody", module:get_option_string("syslog_facility"));
 120                 syslog_opened = true;
 121         end
 122         local syslog = pposix.syslog_log;
 123         return function (name, level, message, ...)
 124                 syslog(level, name, format(message, ...));
 125         end;
 126 end
 127 require "core.loggingmanager".register_sink_type("syslog", syslog_sink_maker);
 128
 129 local daemonize = module:get_option("daemonize", prosody.installed);
 130
 131 local function remove_log_sinks()
 132         local lm = require "core.loggingmanager";
 133         lm.register_sink_type("console", nil);
 134         lm.register_sink_type("stdout", nil);
 135         lm.reload_logging();
 136 end
 137
 138 if daemonize then
 139         local function daemonize_server()
 140                 module:log("info", "Prosody is about to detach from the console, disabling further console output");
 141                 remove_log_sinks();
 142                 local ok, ret = pposix.daemonize();
 143                 if not ok then
 144                         module:log("error", "Failed to daemonize: %s", ret);
 145                 elseif ret and ret > 0 then
 146                         os.exit(0);
 147                 else
 148                         module:log("info", "Successfully daemonized to PID %d", pposix.getpid());
 149                         write_pidfile();
 150                 end
 151         end
 152         if not prosody.start_time then -- server-starting
 153                 daemonize_server();
 154         end
 155 else
 156         -- Not going to daemonize, so write the pid of this process
 157         write_pidfile();
 158 end
 159
 160 module:hook("server-stopped", remove_pidfile);
 161
 162 -- Set signal handlers
 163 if have_signal then
 164         module:add_timer(0, function ()
 165                 signal.signal("SIGTERM", function ()
 166                         module:log("warn", "Received SIGTERM");
 167                         prosody.unlock_globals();
 168                         prosody.shutdown("Received SIGTERM");
 169                         prosody.lock_globals();
 170                 end);
 171
 172                 signal.signal("SIGHUP", function ()
 173                         module:log("info", "Received SIGHUP");
 174                         prosody.reload_config();
 175                         -- this also reloads logging
 176                 end);
 177
 178                 signal.signal("SIGINT", function ()
 179                         module:log("info", "Received SIGINT");
 180                         prosody.unlock_globals();
 181                         prosody.shutdown("Received SIGINT");
 182                         prosody.lock_globals();
 183                 end);
 184         end);
 185 end