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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI" /* from S5R4 1.6 */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/signal.h>
#include <sys/cred.h>
#include <sys/user.h>
#include <sys/errno.h>
#include <sys/vnode.h>
#include <sys/proc.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/pathname.h>
#include <sys/disp.h>
#include <sys/exec.h>
#include <sys/kmem.h>
#include <sys/note.h>
/*
* This is the loadable module wrapper.
*/
#include <sys/modctl.h>
extern int intpexec();
static struct execsw esw = {
intpmagicstr,
0,
2,
intpexec,
NULL
};
/*
* Module linkage information for the kernel.
*/
extern struct mod_ops mod_execops;
static struct modlexec modlexec = {
&mod_execops, "exec mod for interp", &esw
};
static struct modlinkage modlinkage = {
MODREV_1, (void *)&modlexec, NULL
};
int
_init()
{
return (mod_install(&modlinkage));
}
int
_fini()
{
return (mod_remove(&modlinkage));
}
int
_info(struct modinfo *modinfop)
{
return (mod_info(&modlinkage, modinfop));
}
/*
* Crack open a '#!' line.
*/
static int
getintphead(struct vnode *vp, struct intpdata *idatap)
{
int error;
char *cp, *linep = idatap->intp;
ssize_t resid;
/*
* Read the entire line and confirm that it starts with '#!'.
*/
if (error = vn_rdwr(UIO_READ, vp, linep, INTPSZ, (offset_t)0,
UIO_SYSSPACE, 0, (rlim64_t)0, CRED(), &resid))
return (error);
if (resid > INTPSZ-2 || linep[0] != '#' || linep[1] != '!')
return (ENOEXEC);
/*
* Blank all white space and find the newline.
*/
for (cp = &linep[2]; cp < &linep[INTPSZ] && *cp != '\n'; cp++)
if (*cp == '\t')
*cp = ' ';
if (cp >= &linep[INTPSZ])
return (ENOEXEC);
ASSERT(*cp == '\n');
*cp = '\0';
/*
* Locate the beginning and end of the interpreter name.
* In addition to the name, one additional argument may
* optionally be included here, to be prepended to the
* arguments provided on the command line. Thus, for
* example, you can say
*
* #! /usr/bin/awk -f
*/
for (cp = &linep[2]; *cp == ' '; cp++)
;
if (*cp == '\0')
return (ENOEXEC);
idatap->intp_name = cp;
while (*cp && *cp != ' ')
cp++;
if (*cp == '\0')
idatap->intp_arg = NULL;
else {
*cp++ = '\0';
while (*cp == ' ')
cp++;
if (*cp == '\0')
idatap->intp_arg = NULL;
else {
idatap->intp_arg = cp;
while (*cp && *cp != ' ')
cp++;
*cp = '\0';
}
}
return (0);
}
int
intpexec(
struct vnode *vp,
struct execa *uap,
struct uarg *args,
struct intpdata *idatap,
int level,
long *execsz,
int setid,
caddr_t exec_file,
struct cred *cred,
int brand_action)
{
_NOTE(ARGUNUSED(brand_action))
vnode_t *nvp;
int error = 0;
struct intpdata idata;
struct pathname intppn;
struct pathname resolvepn;
char *opath;
char devfd[14];
int fd = -1;
if (level) { /* Can't recurse */
error = ENOEXEC;
goto bad;
}
ASSERT(idatap == (struct intpdata *)NULL);
/*
* Allocate a buffer to read in the interpreter pathname.
*/
idata.intp = kmem_alloc(INTPSZ, KM_SLEEP);
if (error = getintphead(vp, &idata))
goto fail;
/*
* Look the new vnode up.
*/
if (error = pn_get(idata.intp_name, UIO_SYSSPACE, &intppn))
goto fail;
pn_alloc(&resolvepn);
if (error = lookuppn(&intppn, &resolvepn, FOLLOW, NULLVPP, &nvp)) {
pn_free(&resolvepn);
pn_free(&intppn);
goto fail;
}
opath = args->pathname;
args->pathname = resolvepn.pn_path;
/* don't free resolvepn until we are done with args */
pn_free(&intppn);
/*
* When we're executing a set-uid script resulting in uids
* mismatching or when we execute with additional privileges,
* we close the "replace script between exec and open by shell"
* hole by passing the script as /dev/fd parameter.
*/
if ((setid & EXECSETID_PRIVS) != 0 ||
(setid & (EXECSETID_UGIDS|EXECSETID_SETID)) ==
(EXECSETID_UGIDS|EXECSETID_SETID)) {
(void) strcpy(devfd, "/dev/fd/");
if (error = execopen(&vp, &fd))
goto done;
numtos(fd, &devfd[8]);
args->fname = devfd;
}
error = gexec(&nvp, uap, args, &idata, ++level, execsz, exec_file, cred,
EBA_NONE);
done:
VN_RELE(nvp);
args->pathname = opath;
pn_free(&resolvepn);
fail:
kmem_free(idata.intp, INTPSZ);
if (error && fd != -1)
(void) execclose(fd);
bad:
return (error);
}
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