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: 
   34: #include <errno.h>
   35: #include <fcntl.h>
   36: #include <paths.h>
   37: #include <unistd.h>
   38: #include <sys/stat.h>
   39: 
   40: #include <device-nrs.h>
   41: #include <not-cancel.h>
   42: 
   43: int
   44: daemon(nochdir, noclose)
   45:         int nochdir, noclose;
   46: {
   47:         int fd;
   48: 
   49:         switch (__fork()) {
   50:         case -1:
   51:                 return (-1);
   52:         case 0:
   53:                 break;
   54:         default:
   55:                 _exit(0);
   56:         }
   57: 
   58:         if (__setsid() == -1)
   59:                 return (-1);
   60: 
   61:         if (!nochdir)
   62:                 (void)__chdir("/");
   63: 
   64:         if (!noclose) {
   65:                 struct stat64 st;
   66: 
   67:                 if ((fd = open_not_cancel(_PATH_DEVNULL, O_RDWR, 0)) != -1
   68:                     && (__builtin_expect (__fxstat64 (_STAT_VER, fd, &st), 0)
   69:                         == 0)) {
   70:                         if (__builtin_expect (S_ISCHR (st.st_mode), 1) != 0
   71: #if defined DEV_NULL_MAJOR && defined DEV_NULL_MINOR
   72:                             && (st.st_rdev
   73:                                 == makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR))
   74: #endif
   75:                             ) {
   76:                                 (void)__dup2(fd, STDIN_FILENO);
   77:                                 (void)__dup2(fd, STDOUT_FILENO);
   78:                                 (void)__dup2(fd, STDERR_FILENO);
   79:                                 if (fd > 2)
   80:                                         (void)__close (fd);
   81:                         } else {
   82:                                 /* We must set an errno value since no
   83:                                    function call actually failed.  */
   84:                                 close_not_cancel_no_status (fd);
   85:                                 __set_errno (ENODEV);
   86:                                 return -1;
   87:                         }
   88:                 } else {
   89:                         close_not_cancel_no_status (fd);
   90:                         return -1;
   91:                 }
   92:         }
   93:         return (0);
   94: }