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a5f75648d8
exceeds MAXSHELLCMDLEN to avoid secondary /bin/sh execution. Update execve man page to reflect change. Increase MAXSHELLCMDLEN to a slightly more meaningful value. PR: kern/32106 Submitted by: b@etek.chalmers.se Reviewed by: bsd MFC after: 2 weeks
133 lines
3.7 KiB
C
133 lines
3.7 KiB
C
/*
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* Copyright (c) 1993, David Greenman
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/sysproto.h>
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#include <sys/exec.h>
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#include <sys/imgact.h>
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#include <sys/kernel.h>
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#if BYTE_ORDER == LITTLE_ENDIAN
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#define SHELLMAGIC 0x2123 /* #! */
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#else
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#define SHELLMAGIC 0x2321
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#endif
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/*
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* Shell interpreter image activator. A interpreter name beginning
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* at imgp->stringbase is the minimal successful exit requirement.
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*/
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int
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exec_shell_imgact(imgp)
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struct image_params *imgp;
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{
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const char *image_header = imgp->image_header;
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const char *ihp, *line_endp;
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char *interp;
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/* a shell script? */
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if (((const short *) image_header)[0] != SHELLMAGIC)
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return(-1);
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/*
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* Don't allow a shell script to be the shell for a shell
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* script. :-)
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*/
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if (imgp->interpreted)
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return(ENOEXEC);
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imgp->interpreted = 1;
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/*
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* Copy shell name and arguments from image_header into string
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* buffer.
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*/
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/*
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* Find end of line; return if the line > MAXSHELLCMDLEN long.
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*/
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for (ihp = &image_header[2]; *ihp != '\n' && *ihp != '#'; ++ihp) {
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if (ihp >= &image_header[MAXSHELLCMDLEN])
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return(ENAMETOOLONG);
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}
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line_endp = ihp;
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/* reset for another pass */
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ihp = &image_header[2];
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/* Skip over leading spaces - until the interpreter name */
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while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
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/* copy the interpreter name */
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interp = imgp->interpreter_name;
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while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t'))
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*interp++ = *ihp++;
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*interp = '\0';
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/* Disallow a null interpreter filename */
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if (*imgp->interpreter_name == '\0')
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return(ENOEXEC);
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/* reset for another pass */
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ihp = &image_header[2];
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/* copy the interpreter name and arguments */
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while (ihp < line_endp) {
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/* Skip over leading spaces */
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while ((*ihp == ' ') || (*ihp == '\t')) ihp++;
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if (ihp < line_endp) {
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/*
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* Copy to end of token. No need to watch stringspace
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* because this is at the front of the string buffer
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* and the maximum shell command length is tiny.
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*/
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while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t')) {
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*imgp->stringp++ = *ihp++;
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imgp->stringspace--;
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}
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*imgp->stringp++ = 0;
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imgp->stringspace--;
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imgp->argc++;
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}
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}
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imgp->argv0 = imgp->uap->fname;
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return(0);
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}
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/*
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* Tell kern_execve.c about it, with a little help from the linker.
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*/
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static struct execsw shell_execsw = { exec_shell_imgact, "#!" };
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EXEC_SET(shell, shell_execsw);
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