The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/kern/imgact_shell.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*
    2  * Copyright (c) 1993, David Greenman
    3  * 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  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  *
   26  * $FreeBSD: src/sys/kern/imgact_shell.c,v 1.12.2.2 1999/09/05 08:14:46 peter Exp $
   27  */
   28 
   29 #include <sys/param.h>
   30 #include <sys/systm.h>
   31 #include <sys/sysproto.h>
   32 #include <sys/resourcevar.h>
   33 #include <sys/exec.h>
   34 #include <sys/imgact.h>
   35 #include <sys/kernel.h>
   36 #include <machine/endian.h>
   37 
   38 #if BYTE_ORDER == LITTLE_ENDIAN
   39 #define SHELLMAGIC      0x2123 /* #! */
   40 #else
   41 #define SHELLMAGIC      0x2321
   42 #endif
   43 
   44 #define MAXSHELLCMDLEN  64
   45 
   46 static int      exec_shell_imgact __P((struct image_params *imgp));
   47 
   48 /*
   49  * Shell interpreter image activator. A interpreter name beginning
   50  *      at imgp->stringbase is the minimal successful exit requirement.
   51  */
   52 static int
   53 exec_shell_imgact(imgp)
   54         struct image_params *imgp;
   55 {
   56         const char *image_header = imgp->image_header;
   57         const char *ihp, *line_endp;
   58         char *interp;
   59 
   60         /* a shell script? */
   61         if (((const short *) image_header)[0] != SHELLMAGIC)
   62                 return(-1);
   63 
   64         /*
   65          * Don't allow a shell script to be the shell for a shell
   66          *      script. :-)
   67          */
   68         if (imgp->interpreted)
   69                 return(ENOEXEC);
   70 
   71         imgp->interpreted = 1;
   72 
   73         /*
   74          * Copy shell name and arguments from image_header into string
   75          *      buffer.
   76          */
   77 
   78         /*
   79          * Find end of line; return if the line > MAXSHELLCMDLEN long.
   80          */
   81         for (ihp = &image_header[2]; *ihp != '\n'; ++ihp) {
   82                 if (ihp >= &image_header[MAXSHELLCMDLEN])
   83                         return(ENOEXEC);
   84         }
   85         line_endp = ihp;
   86 
   87         /* reset for another pass */
   88         ihp = &image_header[2];
   89 
   90         /* Skip over leading spaces - until the interpreter name */
   91         while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
   92 
   93         /* copy the interpreter name */
   94         interp = imgp->interpreter_name;
   95         while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t'))
   96                 *interp++ = *ihp++;
   97         *interp = '\0';
   98 
   99         /* Disallow a null interpreter filename */
  100         if (*imgp->interpreter_name == '\0')
  101                 return(ENOEXEC);
  102 
  103         /* reset for another pass */
  104         ihp = &image_header[2];
  105 
  106         /* copy the interpreter name and arguments */
  107         while (ihp < line_endp) {
  108                 /* Skip over leading spaces */
  109                 while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
  110 
  111                 if (ihp < line_endp) {
  112                         /*
  113                          * Copy to end of token. No need to watch stringspace
  114                          *      because this is at the front of the string buffer
  115                          *      and the maximum shell command length is tiny.
  116                          */
  117                         while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) {
  118                                 *imgp->stringp++ = *ihp++;
  119                                 imgp->stringspace--;
  120                         }
  121 
  122                         *imgp->stringp++ = 0;
  123                         imgp->stringspace--;
  124 
  125                         imgp->argc++;
  126                 }
  127         }
  128 
  129         imgp->argv0 = imgp->uap->fname;
  130 
  131         return(0);
  132 }
  133 
  134 /*
  135  * Tell kern_execve.c about it, with a little help from the linker.
  136  * Since `const' objects end up in the text segment, TEXT_SET is the
  137  * correct directive to use.
  138  */
  139 static const struct execsw shell_execsw = { exec_shell_imgact, "#!" };
  140 TEXT_SET(execsw_set, shell_execsw);

Cache object: c5a624759d995cf1e8fe64cc9da83fc1


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.