xref: /titanic_44/usr/src/uts/common/exec/java/java.c (revision 9a70fc3be3b1e966bf78825cdb8d509963a6f0a1)
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 2006 Sun Microsystems, Inc.  All rights reserved.
23   * Use is subject to license terms.
24   */
25  
26  #pragma ident	"%Z%%M%	%I%	%E% SMI"
27  
28  /*
29   * Launch Java executables via exec(2).
30   *
31   * Java executables are platform-independent executable files
32   * based on the JAR file format.  Executable JAR files contain a
33   * special 'extra field' header in the first file of the archive
34   * that marks the file as a true executable.   The data in that field
35   * is used to pass additional run-time information to the Java VM.
36   *
37   * This handler looks for the appropriate magic number on the
38   * front of the file, checks that the JAR file is executable, then
39   * invokes the Java runtime environment to do the rest of the work.
40   */
41  
42  #include <sys/types.h>
43  #include <sys/proc.h>
44  #include <sys/vnode.h>
45  #include <sys/exec.h>
46  #include <sys/modctl.h>
47  #include <sys/cmn_err.h>
48  #include <sys/pathname.h>
49  
50  /*
51   * These variables can be tweaked via /etc/system to allow prototyping
52   * and debugging.  See PSARC/1997/123.
53   *
54   * Modified by PSARC/1999/012 to be Contract Private between Solaris and
55   * the Java Technology Group.  It is expected that any future change to
56   * these variables be coordinated between the consolidations.
57   */
58  #if defined(__sparc)
59  char *jexec = "/usr/java/jre/lib/sparc/jexec";
60  #elif defined(__i386) || defined(__i386_COMPAT)
61  char *jexec = "/usr/java/jre/lib/i386/jexec";
62  #else
63  #error "Unknown ISA"
64  #endif
65  char *jexec_arg = "-jar";
66  
67  /*
68   * ZIP/JAR file header information
69   */
70  #define	SIGSIZ		4
71  #define	LOCSIG		"PK\003\004"
72  #define	LOCHDRSIZ	30
73  
74  #define	CH(b, n)	(((unsigned char *)(b))[n])
75  #define	SH(b, n)	(CH(b, n) | (CH(b, n+1) << 8))
76  #define	LG(b, n)	(SH(b, n) | (SH(b, n+2) << 16))
77  
78  #define	LOCNAM(b)	(SH(b, 26))	/* filename size */
79  #define	LOCEXT(b)	(SH(b, 28))	/* extra field size */
80  
81  #define	XFHSIZ		4		/* header id, data size */
82  #define	XFHID(b)	(SH(b, 0))	/* extract field header id */
83  #define	XFDATASIZ(b)	(SH(b, 2))	/* extract field data size */
84  #define	XFJAVASIG	0xcafe		/* java executables */
85  
86  /*ARGSUSED3*/
87  static int
88  javaexec(vnode_t *vp, struct execa *uap, struct uarg *args,
89      struct intpdata *idatap, int level, long *execsz, int setid,
90      caddr_t execfile, cred_t *cred, int brand_action)
91  {
92  	struct intpdata idata;
93  	int error;
94  	ssize_t resid;
95  	vnode_t *nvp;
96  	off_t xoff, xoff_end;
97  	char lochdr[LOCHDRSIZ];
98  	struct pathname lookpn;
99  	struct pathname resolvepn;
100  	char *opath;
101  
102  	if (level)
103  		return (ENOEXEC);	/* no recursion */
104  
105  	/*
106  	 * Read in the full local file header, and validate
107  	 * the initial signature.
108  	 */
109  	if ((error = vn_rdwr(UIO_READ, vp, lochdr, sizeof (lochdr),
110  	    0, UIO_SYSSPACE, 0, (rlim64_t)0, cred, &resid)) != 0)
111  		return (error);
112  	if (resid != 0 || strncmp(lochdr, LOCSIG, SIGSIZ) != 0)
113  		return (ENOEXEC);
114  
115  	/*
116  	 * Ok, so this -is- a ZIP file, and might even be a JAR file.
117  	 * Is it a Java executable?
118  	 */
119  	xoff = sizeof (lochdr) + LOCNAM(lochdr);
120  	xoff_end = xoff + LOCEXT(lochdr);
121  
122  	while (xoff < xoff_end) {
123  		char xfhdr[XFHSIZ];
124  
125  		if ((error = vn_rdwr(UIO_READ, vp, xfhdr, sizeof (xfhdr),
126  		    xoff, UIO_SYSSPACE, 0, (rlim64_t)0, cred, &resid)) != 0)
127  			return (error);
128  		if (resid != 0)
129  			return (ENOEXEC);
130  		if (XFHID(xfhdr) == XFJAVASIG)
131  			break;
132  		xoff += sizeof (xfhdr) + XFDATASIZ(xfhdr);
133  	}
134  
135  	if (xoff >= xoff_end)
136  		return (ENOEXEC);
137  
138  	/*
139  	 * Note: If we ever make setid execution work, we need to ensure
140  	 * that we use /dev/fd to avoid the classic setuid shell script
141  	 * security hole.
142  	 */
143  	if (setid)
144  		return (EACCES);
145  
146  	/*
147  	 * Find and invoke the Java runtime environment on the file
148  	 */
149  	idata.intp = NULL;
150  	idata.intp_name = jexec;
151  	idata.intp_arg = jexec_arg;
152  	if (error = pn_get(idata.intp_name, UIO_SYSSPACE, &lookpn))
153  		return (error);
154  	pn_alloc(&resolvepn);
155  	if (error = lookuppn(&lookpn, &resolvepn, FOLLOW, NULLVPP, &nvp)) {
156  		pn_free(&resolvepn);
157  		pn_free(&lookpn);
158  		return (ENOEXEC);
159  	}
160  	opath = args->pathname;
161  	args->pathname = resolvepn.pn_path;
162  	/* don't free resolvepn until we are done with args */
163  	pn_free(&lookpn);
164  	error = gexec(&nvp, uap, args, &idata, level + 1, execsz, execfile,
165  	    cred, EBA_NONE);
166  	VN_RELE(nvp);
167  	args->pathname = opath;
168  	pn_free(&resolvepn);
169  	return (error);
170  }
171  
172  static struct execsw jexecsw = {
173  	javamagicstr,
174  	0,
175  	4,
176  	javaexec,
177  	NULL
178  };
179  
180  static struct modlexec jmodlexec = {
181  	&mod_execops, "exec for Java", &jexecsw
182  };
183  
184  static struct modlinkage jmodlinkage = {
185  	MODREV_1, &jmodlexec, NULL
186  };
187  
188  int
189  _init(void)
190  {
191  	return (mod_install(&jmodlinkage));
192  }
193  
194  int
195  _fini(void)
196  {
197  	return (mod_remove(&jmodlinkage));
198  }
199  
200  int
201  _info(struct modinfo *modinfop)
202  {
203  	return (mod_info(&jmodlinkage, modinfop));
204  }
205