1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26/*
27 * Launch Java executables via exec(2).
28 *
29 * Java executables are platform-independent executable files
30 * based on the JAR file format.  Executable JAR files contain a
31 * special 'extra field' header in the first file of the archive
32 * that marks the file as a true executable.   The data in that field
33 * is used to pass additional run-time information to the Java VM.
34 *
35 * This handler looks for the appropriate magic number on the
36 * front of the file, checks that the JAR file is executable, then
37 * invokes the Java runtime environment to do the rest of the work.
38 */
39
40#include <sys/types.h>
41#include <sys/proc.h>
42#include <sys/vnode.h>
43#include <sys/exec.h>
44#include <sys/modctl.h>
45#include <sys/cmn_err.h>
46#include <sys/pathname.h>
47
48/*
49 * These variables can be tweaked via /etc/system to allow prototyping
50 * and debugging.  See PSARC/1997/123.
51 *
52 * Modified by PSARC/1999/012 to be Contract Private between Solaris and
53 * the Java Technology Group.  It is expected that any future change to
54 * these variables be coordinated between the consolidations.
55 */
56#if defined(__sparc)
57char *jexec = "/usr/java/jre/lib/sparc/jexec";
58#elif defined(__i386) || defined(__i386_COMPAT)
59char *jexec = "/usr/java/jre/lib/i386/jexec";
60#else
61#error "Unknown ISA"
62#endif
63char *jexec_arg = "-jar";
64
65/*
66 * ZIP/JAR file header information
67 */
68#define	SIGSIZ		4
69#define	LOCSIG		"PK\003\004"
70#define	LOCHDRSIZ	30
71
72#define	CH(b, n)	(((unsigned char *)(b))[n])
73#define	SH(b, n)	(CH(b, n) | (CH(b, n+1) << 8))
74#define	LG(b, n)	(SH(b, n) | (SH(b, n+2) << 16))
75
76#define	LOCNAM(b)	(SH(b, 26))	/* filename size */
77#define	LOCEXT(b)	(SH(b, 28))	/* extra field size */
78
79#define	XFHSIZ		4		/* header id, data size */
80#define	XFHID(b)	(SH(b, 0))	/* extract field header id */
81#define	XFDATASIZ(b)	(SH(b, 2))	/* extract field data size */
82#define	XFJAVASIG	0xcafe		/* java executables */
83
84/*ARGSUSED3*/
85static int
86javaexec(vnode_t *vp, struct execa *uap, struct uarg *args,
87    struct intpdata *idatap, int level, long *execsz, int setid,
88    caddr_t execfile, cred_t *cred, int brand_action)
89{
90	struct intpdata idata;
91	int error;
92	ssize_t resid;
93	vnode_t *nvp;
94	off_t xoff, xoff_end;
95	char lochdr[LOCHDRSIZ];
96	struct pathname lookpn;
97	struct pathname resolvepn;
98	char *opath;
99
100	if (level)
101		return (ENOEXEC);	/* no recursion */
102
103	/*
104	 * Read in the full local file header, and validate
105	 * the initial signature.
106	 */
107	if ((error = vn_rdwr(UIO_READ, vp, lochdr, sizeof (lochdr),
108	    0, UIO_SYSSPACE, 0, (rlim64_t)0, cred, &resid)) != 0)
109		return (error);
110	if (resid != 0 || strncmp(lochdr, LOCSIG, SIGSIZ) != 0)
111		return (ENOEXEC);
112
113	/*
114	 * Ok, so this -is- a ZIP file, and might even be a JAR file.
115	 * Is it a Java executable?
116	 */
117	xoff = sizeof (lochdr) + LOCNAM(lochdr);
118	xoff_end = xoff + LOCEXT(lochdr);
119
120	while (xoff < xoff_end) {
121		char xfhdr[XFHSIZ];
122
123		if ((error = vn_rdwr(UIO_READ, vp, xfhdr, sizeof (xfhdr),
124		    xoff, UIO_SYSSPACE, 0, (rlim64_t)0, cred, &resid)) != 0)
125			return (error);
126		if (resid != 0)
127			return (ENOEXEC);
128		if (XFHID(xfhdr) == XFJAVASIG)
129			break;
130		xoff += sizeof (xfhdr) + XFDATASIZ(xfhdr);
131	}
132
133	if (xoff >= xoff_end)
134		return (ENOEXEC);
135
136	/*
137	 * Note: If we ever make setid execution work, we need to ensure
138	 * that we use /dev/fd to avoid the classic setuid shell script
139	 * security hole.
140	 */
141	if (setid)
142		return (EACCES);
143
144	/*
145	 * Find and invoke the Java runtime environment on the file
146	 */
147	idata.intp = NULL;
148	idata.intp_name = jexec;
149	idata.intp_arg = jexec_arg;
150	if (error = pn_get(idata.intp_name, UIO_SYSSPACE, &lookpn))
151		return (error);
152	pn_alloc(&resolvepn);
153	if (error = lookuppn(&lookpn, &resolvepn, FOLLOW, NULLVPP, &nvp)) {
154		pn_free(&resolvepn);
155		pn_free(&lookpn);
156		return (ENOEXEC);
157	}
158	opath = args->pathname;
159	args->pathname = resolvepn.pn_path;
160	/* don't free resolvepn until we are done with args */
161	pn_free(&lookpn);
162	error = gexec(&nvp, uap, args, &idata, level + 1, execsz, execfile,
163	    cred, EBA_NONE);
164
165	if (!error) {
166		/*
167		 * Close this Java executable as the interpreter
168		 * will open and close it later on.
169		 */
170		(void) VOP_CLOSE(vp, FREAD, 1, (offset_t)0, cred, NULL);
171	}
172
173	VN_RELE(nvp);
174	args->pathname = opath;
175	pn_free(&resolvepn);
176	return (error);
177}
178
179static struct execsw jexecsw = {
180	javamagicstr,
181	0,
182	4,
183	javaexec,
184	NULL
185};
186
187static struct modlexec jmodlexec = {
188	&mod_execops, "exec for Java", &jexecsw
189};
190
191static struct modlinkage jmodlinkage = {
192	MODREV_1, &jmodlexec, NULL
193};
194
195int
196_init(void)
197{
198	return (mod_install(&jmodlinkage));
199}
200
201int
202_fini(void)
203{
204	return (mod_remove(&jmodlinkage));
205}
206
207int
208_info(struct modinfo *modinfop)
209{
210	return (mod_info(&jmodlinkage, modinfop));
211}
212