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 /*******************************************************************
  37  Close the low 3 fd's and open dev/null in their place.
  38 ********************************************************************/
  39
  40 void close_low_fds(bool stdin_too, bool stdout_too, bool stderr_too)
  41 {
  42
  43         if (stdin_too) {
  44                 int ret = close_low_fd(0);
  45                 if (ret != 0) {
  46                         DBG_ERR("close_low_fd(0) failed: %s\n", strerror(ret));
  47                 }
  48         }
  49         if (stdout_too) {
  50                 int ret = close_low_fd(1);
  51                 if (ret != 0) {
  52                         DBG_ERR("close_low_fd(1) failed: %s\n", strerror(ret));
  53                 }
  54         }
  55         if (stderr_too) {
  56                 int ret = close_low_fd(2);
  57                 if (ret != 0) {
  58                         DBG_ERR("close_low_fd(2) failed: %s\n", strerror(ret));
  59                 }
  60         }
  61 }
  62
  63 /****************************************************************************
  64  Become a daemon, discarding the controlling terminal.
  65 ****************************************************************************/
  66
  67 void become_daemon(bool do_fork, bool no_session, bool log_stdout)
  68 {
  69         pid_t newpid;
  70         if (do_fork) {
  71                 newpid = fork();
  72                 if (newpid == -1) {
  73                         exit_daemon("Fork failed", errno);
  74                 }
  75                 if (newpid) {
  76 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
  77                         sd_notifyf(0,
  78                                    "READY=0\nSTATUS=Starting process...\n"
  79                                    "MAINPID=%lu",
  80                                    (unsigned long) newpid);
  81 #endif /* HAVE_LIBSYSTEMD_DAEMON */
  82                         _exit(0);
  83                 }
  84         }
  85
  86         /* detach from the terminal */
  87 #ifdef HAVE_SETSID
  88         if (!no_session) {
  89                 int ret = setsid();
  90                 if (ret == -1) {
  91                         exit_daemon("Failed to create session", errno);
  92                 }
  93         }
  94 #elif defined(TIOCNOTTY)
  95         if (!no_session) {
  96                 int i = open("/dev/tty", O_RDWR, 0);
  97                 if (i != -1) {
  98                         ioctl(i, (int) TIOCNOTTY, (char *)0);
  99                         close(i);
 100                 }
 101         }
 102 #endif /* HAVE_SETSID */
 103
 104         /* Close fd's 0,1,2 as appropriate. Needed if started by rsh. */
 105         /* stdin must be open if we do not fork, for monitoring for
 106          * close.  stdout must be open if we are logging there, and we
 107          * never close stderr (but debug might dup it onto a log file) */
 108         close_low_fds(do_fork, !log_stdout, false);
 109 }
 110
 111 void exit_daemon(const char *msg, int error)
 112 {
 113 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
 114         if (msg == NULL) {
 115                 msg = strerror(error);
 116         }
 117
 118         sd_notifyf(0, "STATUS=daemon failed to start: %s\n"
 119                                   "ERRNO=%i",
 120                                   msg,
 121                                   error);
 122 #endif
 123         DBG_ERR("STATUS=daemon failed to start: %s, error code %d\n",
 124                 msg, error);
 125         exit(1);
 126 }
 127
 128 void daemon_ready(const char *daemon)
 129 {
 130         if (daemon == NULL) {
 131                 daemon = "Samba";
 132         }
 133 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
 134         sd_notifyf(0, "READY=1\nSTATUS=%s: ready to serve connections...",
 135                    daemon);
 136 #endif
 137         DBG_ERR("STATUS=daemon '%s' finished starting up and ready to serve "
 138                 "connections\n", daemon);
 139 }
 140
 141 void daemon_status(const char *daemon, const char *msg)
 142 {
 143         if (daemon == NULL) {
 144                 daemon = "Samba";
 145         }
 146 #if defined(HAVE_LIBSYSTEMD_DAEMON) || defined(HAVE_LIBSYSTEMD)
 147         sd_notifyf(0, "\nSTATUS=%s: %s", daemon, msg);
 148 #endif
 149         DBG_ERR("STATUS=daemon '%s' : %s\n", daemon, msg);
 150 }