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/*
* Copyright (c) 1993, David Greenman
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/exec.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#if BYTE_ORDER == LITTLE_ENDIAN
#define SHELLMAGIC 0x2123 /* #! */
#else
#define SHELLMAGIC 0x2321
#endif
#define MAXSHELLCMDLEN 64
static int exec_shell_imgact __P((struct image_params *imgp));
/*
* Shell interpreter image activator. A interpreter name beginning
* at imgp->stringbase is the minimal successful exit requirement.
*/
static int
exec_shell_imgact(imgp)
struct image_params *imgp;
{
const char *image_header = imgp->image_header;
const char *ihp, *line_endp;
char *interp;
/* a shell script? */
if (((const short *) image_header)[0] != SHELLMAGIC)
return(-1);
/*
* Don't allow a shell script to be the shell for a shell
* script. :-)
*/
if (imgp->interpreted)
return(ENOEXEC);
imgp->interpreted = 1;
/*
* Copy shell name and arguments from image_header into string
* buffer.
*/
/*
* Find end of line; return if the line > MAXSHELLCMDLEN long.
*/
for (ihp = &image_header[2]; *ihp != '\n'; ++ihp) {
if (ihp >= &image_header[MAXSHELLCMDLEN])
return(ENOEXEC);
}
line_endp = ihp;
/* reset for another pass */
ihp = &image_header[2];
/* Skip over leading spaces - until the interpreter name */
while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
/* copy the interpreter name */
interp = imgp->interpreter_name;
while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t'))
*interp++ = *ihp++;
*interp = '\0';
/* Disallow a null interpreter filename */
if (*imgp->interpreter_name == '\0')
return(ENOEXEC);
/* reset for another pass */
ihp = &image_header[2];
/* copy the interpreter name and arguments */
while (ihp < line_endp) {
/* Skip over leading spaces */
while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
if (ihp < line_endp) {
/*
* Copy to end of token. No need to watch stringspace
* because this is at the front of the string buffer
* and the maximum shell command length is tiny.
*/
while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) {
*imgp->stringp++ = *ihp++;
imgp->stringspace--;
}
*imgp->stringp++ = 0;
imgp->stringspace--;
imgp->argc++;
}
}
imgp->argv0 = imgp->uap->fname;
return(0);
}
/*
* Tell kern_execve.c about it, with a little help from the linker.
*/
static struct execsw shell_execsw = { exec_shell_imgact, "#!" };
EXEC_SET(shell, shell_execsw);
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