release/src/router/busybox/libbb/run_shell.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include "libbb.h"
  32 #if ENABLE_SELINUX
  33 #include <selinux/selinux.h>  /* for setexeccon  */
  34 #endif
  35
  36 #if ENABLE_SELINUX
  37 static security_context_t current_sid;
  38
  39 void FAST_FUNC renew_current_security_context(void)
  40 {
  41         freecon(current_sid);  /* Release old context  */
  42         getcon(&current_sid);  /* update */
  43 }
  44 void FAST_FUNC set_current_security_context(security_context_t sid)
  45 {
  46         freecon(current_sid);  /* Release old context  */
  47         current_sid = sid;
  48 }
  49
  50 #endif
  51
  52 /* Run SHELL, or DEFAULT_SHELL if SHELL is empty.
  53    If COMMAND is nonzero, pass it to the shell with the -c option.
  54    If ADDITIONAL_ARGS is nonzero, pass it to the shell as more
  55    arguments.  */
  56
  57 void FAST_FUNC run_shell(const char *shell, int loginshell, const char *command, const char **additional_args)
  58 {
  59         const char **args;
  60         int argno = 1;
  61         int additional_args_cnt = 0;
  62
  63         for (args = additional_args; args && *args; args++)
  64                 additional_args_cnt++;
  65
  66         args = xmalloc(sizeof(char*) * (4 + additional_args_cnt));
  67
  68         args[0] = bb_get_last_path_component_nostrip(xstrdup(shell));
  69
  70         if (loginshell)
  71                 args[0] = xasprintf("-%s", args[0]);
  72
  73         if (command) {
  74                 args[argno++] = "-c";
  75                 args[argno++] = command;
  76         }
  77         if (additional_args) {
  78                 for (; *additional_args; ++additional_args)
  79                         args[argno++] = *additional_args;
  80         }
  81         args[argno] = NULL;
  82 #if ENABLE_SELINUX
  83         if (current_sid)
  84                 setexeccon(current_sid);
  85         if (ENABLE_FEATURE_CLEAN_UP)
  86                 freecon(current_sid);
  87 #endif
  88         execv(shell, (char **) args);
  89         bb_perror_msg_and_die("cannot run %s", shell);
  90 }