[unix-history] / sys / kern / imgact_shell.c

/*
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by David Greenman
 * 4. The name of the developer may be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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 REGENTS 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.
 *
 *	$Id: imgact_shell.c,v 1.1 1993/12/20 16:16:46 wollman Exp $
 */

#include "param.h"
#include "systm.h"
#include "resourcevar.h"
#include "imgact.h"
#include "kernel.h"
#include "machine/endian.h"

#if BYTE_ORDER == LITTLE_ENDIAN
#define SHELLMAGIC	0x2123 /* #! */
#else
#define SHELLMAGIC	0x2321
#endif

#define MAXSHELLCMDLEN	64

/*
 * Shell interpreter image activator. A interpreter name beginning
 *	at iparams->stringbase is the minimal successful exit requirement.
 */
int
exec_shell_imgact(iparams)
	struct image_params *iparams;
{
	const char *image_header = iparams->image_header;
	const char *ihp, *line_endp;
	int length;
	char *interp;
	char **argv;

	/* a shell script? */
	if (((short *) image_header)[0] != SHELLMAGIC)
		return(-1);

	/*
	 * Don't allow a shell script to be the shell for a shell
	 *	script. :-)
	 */
	if (iparams->interpreted)
		return(ENOEXEC);

	iparams->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 = iparams->interpreter_name;
	while ((ihp < line_endp) && (*ihp != ' ') && (*ihp != '\t'))
		*interp++ = *ihp++;
	*interp = '\0';

	/* Disallow a null interpreter filename */
	if (*iparams->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')) {
				*iparams->stringp++ = *ihp++;
				iparams->stringspace--;
			}

			*iparams->stringp++ = 0;
			iparams->stringspace--;

			iparams->argc++;
		}
	}

	/* set argv[0] to point to original file name */
	suword(iparams->uap->argv, (int)iparams->uap->fname);

	return(0);
}

/*
 * Tell kern_execve.c about it, with a little help from the linker.
 * Since `const' objects end up in the text segment, TEXT_SET is the
 * correct directive to use.
 */
static const struct execsw shell_execsw = { exec_shell_imgact };
TEXT_SET(execsw_set, shell_execsw);
Commit	Line	Data
965cadcc GW	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	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by David Greenman
	16	* 4. The name of the developer may be used to endorse or promote products
	17	* derived from this software without specific prior written permission.
	18	*
	19	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	20	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	21	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	22	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	23	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	24	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	25	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	26	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	27	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	28	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	29	* SUCH DAMAGE.
	30	*
3228baa0	31	* $Id: imgact_shell.c,v 1.1 1993/12/20 16:16:46 wollman Exp $
965cadcc GW	32	*/
	33
	34	#include "param.h"
	35	#include "systm.h"
	36	#include "resourcevar.h"
	37	#include "imgact.h"
3228baa0 GW	38	#include "kernel.h"
3228baa0 GW	39	#include "machine/endian.h"
965cadcc	40
3228baa0	41	#if BYTE_ORDER == LITTLE_ENDIAN
965cadcc	42	#define SHELLMAGIC 0x2123 /* #! */
3228baa0 GW	43	#else
	44	#define SHELLMAGIC 0x2321
	45	#endif
	46
965cadcc GW	47	#define MAXSHELLCMDLEN 64
	48
	49	/*
	50	* Shell interpreter image activator. A interpreter name beginning
	51	* at iparams->stringbase is the minimal successful exit requirement.
	52	*/
	53	int
	54	exec_shell_imgact(iparams)
	55	struct image_params *iparams;
	56	{
	57	const char *image_header = iparams->image_header;
	58	const char ihp, line_endp;
	59	int length;
	60	char *interp;
	61	char **argv;
	62
	63	/* a shell script? */
	64	if (((short *) image_header)[0] != SHELLMAGIC)
	65	return(-1);
	66
	67	/*
	68	* Don't allow a shell script to be the shell for a shell
	69	* script. :-)
	70	*/
	71	if (iparams->interpreted)
	72	return(ENOEXEC);
	73
	74	iparams->interpreted = 1;
	75
	76	/*
	77	* Copy shell name and arguments from image_header into string
	78	* buffer.
	79	*/
	80
	81	/*
	82	* Find end of line; return if the line > MAXSHELLCMDLEN long.
	83	*/
	84	for (ihp = &image_header[2]; *ihp != '\n'; ++ihp) {
	85	if (ihp >= &image_header[MAXSHELLCMDLEN])
	86	return(ENOEXEC);
	87	}
	88	line_endp = ihp;
	89
	90	/* reset for another pass */
	91	ihp = &image_header[2];
	92
	93	/* Skip over leading spaces - until the interpreter name */
	94	while ((ihp == ' ') \|\| (ihp == '\t')) ihp++;
	95
	96	/* copy the interpreter name */
	97	interp = iparams->interpreter_name;
	98	while ((ihp < line_endp) && (ihp != ' ') && (ihp != '\t'))
	99	interp++ = ihp++;
	100	*interp = '\0';
	101
	102	/* Disallow a null interpreter filename */
	103	if (*iparams->interpreter_name == '\0')
	104	return(ENOEXEC);
	105
	106	/* reset for another pass */
	107	ihp = &image_header[2];
	108
	109	/* copy the interpreter name and arguments */
	110	while (ihp < line_endp) {
111	/* Skip over leading spaces */
112	while ((ihp == ' ') \|\| (ihp == '\t')) ihp++;
113
114	if (ihp < line_endp) {
115	/*
116	* Copy to end of token. No need to watch stringspace
117	* because this is at the front of the string buffer
118	* and the maximum shell command length is tiny.
119	*/
120	while ((ihp < line_endp) && (ihp != ' ') && (ihp != '\t')) {
121	iparams->stringp++ = ihp++;
122	iparams->stringspace--;
123	}
124
125	*iparams->stringp++ = 0;
126	iparams->stringspace--;
127
128	iparams->argc++;
129	}
130	}
131
132	/* set argv[0] to point to original file name */
133	suword(iparams->uap->argv, (int)iparams->uap->fname);
134
135	return(0);
136	}
3228baa0 GW	137
	138	/*
	139	* Tell kern_execve.c about it, with a little help from the linker.
	140	* Since `const' objects end up in the text segment, TEXT_SET is the
	141	* correct directive to use.
	142	*/
	143	static const struct execsw shell_execsw = { exec_shell_imgact };
	144	TEXT_SET(execsw_set, shell_execsw);