lib/util/become_daemon.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 2001-2002
   6    Copyright (C) Simo Sorce 2001
   7    Copyright (C) Jim McDonough (jmcd@us.ibm.com)  2003.
   8    Copyright (C) James J Myers 2003
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "replace.h"
  25 #include "system/filesys.h"
  26 #include "system/locale.h"
  27 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
  28 #include <systemd/sd-daemon.h>
  29 #endif
  30
  31 #include "close_low_fd.h"
  32 #include "debug.h"
  33
  34 #include "become_daemon.h"
  35
  36 static bool sd_notifications = true;
  37
  38 /*******************************************************************
  39  Enable or disable daemon status systemd notifications
  40 ********************************************************************/
  41 void daemon_sd_notifications(bool enable)
  42 {
  43         sd_notifications = enable;
  44         DBG_DEBUG("Daemon status systemd notifications %s\n",
  45                   sd_notifications ? "enabled" : "disabled");
  46 }
  47
  48 /****************************************************************************
  49  Become a daemon, discarding the controlling terminal.
  50 ****************************************************************************/
  51
  52 void become_daemon(bool do_fork, bool no_session, bool log_stdout)
  53 {
  54         pid_t newpid;
  55         if (do_fork) {
  56                 newpid = fork();
  57                 if (newpid == -1) {
  58                         exit_daemon("Fork failed", errno);
  59                 }
  60                 if (newpid) {
  61                         _exit(0);
  62                 }
  63 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
  64         } else if (sd_notifications) {
  65                 sd_notify(0, "STATUS=Starting process...");
  66 #endif
  67         }
  68
  69         /* detach from the terminal */
  70 #ifdef HAVE_SETSID
  71         if (!no_session) {
  72                 int ret = setsid();
  73                 if (ret == -1) {
  74                         exit_daemon("Failed to create session", errno);
  75                 }
  76         }
  77 #elif defined(TIOCNOTTY)
  78         if (!no_session) {
  79                 int i = open("/dev/tty", O_RDWR, 0);
  80                 if (i != -1) {
  81                         ioctl(i, (int) TIOCNOTTY, (char *)0);
  82                         close(i);
  83                 }
  84         }
  85 #endif /* HAVE_SETSID */
  86
  87         /* Close fd's 0,1,2 as appropriate. Needed if started by rsh. */
  88         /* stdin must be open if we do not fork, for monitoring for
  89          * close.  stdout must be open if we are logging there, and we
  90          * never close stderr (but debug might dup it onto a log file) */
  91         if (do_fork) {
  92                 int ret = close_low_fd(0);
  93                 if (ret != 0) {
  94                         exit_daemon("close_low_fd(0) failed: %s\n", errno);
  95                 }
  96         }
  97         if (!log_stdout) {
  98                 int ret = close_low_fd(1);
  99                 if (ret != 0) {
 100                         exit_daemon("close_low_fd(1) failed: %s\n", errno);
 101                 }
 102         }
 103 }
 104
 105 void exit_daemon(const char *msg, int error)
 106 {
 107         if (msg == NULL) {
 108                 msg = strerror(error);
 109         }
 110
 111 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
 112         if (sd_notifications) {
 113                 sd_notifyf(0, "STATUS=daemon failed to start: %s\n"
 114                                   "ERRNO=%i",
 115                                   msg,
 116                                   error);
 117         }
 118 #endif
 119         DBG_ERR("daemon failed to start: %s, error code %d\n",
 120                 msg, error);
 121         exit(1);
 122 }
 123
 124 void daemon_ready(const char *daemon)
 125 {
 126         if (daemon == NULL) {
 127                 daemon = "Samba";
 128         }
 129 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
 130         if (sd_notifications) {
 131                 sd_notifyf(0,
 132                            "READY=1\nSTATUS=%s: ready to serve connections...",
 133                            daemon);
 134         }
 135 #endif
 136         DBG_INFO("daemon '%s' finished starting up and ready to serve "
 137                 "connections\n", daemon);
 138 }
 139
 140 void daemon_status(const char *daemon, const char *msg)
 141 {
 142         if (daemon == NULL) {
 143                 daemon = "Samba";
 144         }
 145 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
 146         if (sd_notifications) {
 147                 sd_notifyf(0, "STATUS=%s: %s", daemon, msg);
 148         }
 149 #endif
 150         DBG_ERR("daemon '%s' : %s\n", daemon, msg);
 151 }