gen/FreeBSD/daemon.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)daemon.c    8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/daemon.c,v 1.8 2007/01/09 00:27:53 imp Exp $");
  35
  36 #ifndef VARIANT_PRE1050
  37 #include <mach/mach.h>
  38 #include <servers/bootstrap.h>
  39 #endif /* !VARIANT_PRE1050 */
  40 #include "namespace.h"
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <paths.h>
  44 #include <stdlib.h>
  45 #include <signal.h>
  46 #include <unistd.h>
  47 #include "un-namespace.h"
  48
  49 #ifndef VARIANT_PRE1050
  50 static void
  51 move_to_root_bootstrap(void)
  52 {
  53         mach_port_t parent_port = 0;
  54         mach_port_t previous_port = 0;
  55
  56         do {
  57                 if (previous_port) {
  58                         mach_port_deallocate(mach_task_self(), previous_port);
  59                         previous_port = parent_port;
  60                 } else {
  61                         previous_port = bootstrap_port;
  62                 }
  63
  64                 if (bootstrap_parent(previous_port, &parent_port) != 0) {
  65                         return;
  66                 }
  67         } while (parent_port != previous_port);
  68
  69         task_set_bootstrap_port(mach_task_self(), parent_port);
  70         bootstrap_port = parent_port;
  71 }
  72 #endif /* !VARIANT_PRE1050 */
  73
  74 int daemon(int, int) __DARWIN_1050(daemon);
  75
  76 int
  77 daemon(nochdir, noclose)
  78         int nochdir, noclose;
  79 {
  80         struct sigaction osa, sa;
  81         int fd;
  82         pid_t newgrp;
  83         int oerrno;
  84         int osa_ok;
  85
  86         /* A SIGHUP may be thrown when the parent exits below. */
  87         sigemptyset(&sa.sa_mask);
  88         sa.sa_handler = SIG_IGN;
  89         sa.sa_flags = 0;
  90         osa_ok = _sigaction(SIGHUP, &sa, &osa);
  91 #ifndef VARIANT_PRE1050
  92         move_to_root_bootstrap();
  93 #endif /* !VARIANT_PRE1050 */
  94         switch (fork()) {
  95         case -1:
  96                 return (-1);
  97         case 0:
  98                 break;
  99         default:
 100                 _exit(0);
 101         }
 102
 103         newgrp = setsid();
 104         oerrno = errno;
 105         if (osa_ok != -1)
 106                 _sigaction(SIGHUP, &osa, NULL);
 107
 108         if (newgrp == -1) {
 109                 errno = oerrno;
 110                 return (-1);
 111         }
 112
 113         if (!nochdir)
 114                 (void)chdir("/");
 115
 116         if (!noclose && (fd = _open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
 117                 (void)_dup2(fd, STDIN_FILENO);
 118                 (void)_dup2(fd, STDOUT_FILENO);
 119                 (void)_dup2(fd, STDERR_FILENO);
 120                 if (fd > 2)
 121                         (void)_close(fd);
 122         }
 123         return (0);
 124 }