compat/lib/system.c

   1 /*
   2  *      Ported to Linux's Second Extended File System as part of the
   3  *      dump and restore backup suit
   4  *      Remy Card <card@Linux.EU.Org>, 1994-1997
   5  *      Stelian Pop <stelian@popies.net>, 1999-2000
   6  *      Stelian Pop <stelian@popies.net> - Alcôve <www.alcove.com>, 2000-2002
   7  */
   8
   9 /*-
  10  * Copyright (c) 1980, 1991, 1993
  11  *      The Regents of the University of California.  All rights reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  */
  37
  38 #ifndef lint
  39 static const char rcsid[] =
  40         "$Id: system.c,v 1.4 2003/03/30 15:40:35 stelian Exp $";
  41 #endif /* not lint */
  42
  43 #include <config.h>
  44 #include <errno.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.h>
  49 #include <sys/types.h>
  50 #include <sys/wait.h>
  51 #include "system.h"
  52
  53 /*
  54  * Executes the command in a shell.
  55  * Returns -1 if an error occured, the exit status of
  56  * the command on success.
  57  */
  58 int system_command(const char *command, const char *device, int volnum) {
  59         int pid, status;
  60         char commandstr[4096];
  61
  62         pid = fork();
  63         if (pid == -1) {
  64                 perror("  DUMP: unable to fork");
  65                 return -1;
  66         }
  67         if (pid == 0) {
  68                 setuid(getuid());
  69                 setgid(getgid());
  70 #if OLD_STYLE_FSCRIPT
  71                 snprintf(commandstr, sizeof(commandstr), "%s", command);
  72 #else
  73                 snprintf(commandstr, sizeof(commandstr), "%s %s %d", command, device, volnum);
  74 #endif
  75                 commandstr[sizeof(commandstr) - 1] = '\0';
  76                 execl("/bin/sh", "sh", "-c", commandstr, NULL);
  77                 perror("unable to execute shell");
  78                 exit(-1);
  79         }
  80         do {
  81                 if (waitpid(pid, &status, 0) == -1) {
  82                         if (errno != EINTR) {
  83                                 perror("waitpid error");
  84                                 return -1;
  85                         }
  86                 } else {
  87                         if (WIFEXITED(status))
  88                                 return WEXITSTATUS(status);
  89                         else
  90                                 return -1;
  91                 }
  92         } while(1);
  93 }
  94