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 * Copyright 2019 Joyent, Inc.
25 */
26
27 /*
28 * Launch Java executables via exec(2).
29 *
30 * Java executables are platform-independent executable files
31 * based on the JAR file format. Executable JAR files contain a
32 * special 'extra field' header in the first file of the archive
33 * that marks the file as a true executable. The data in that field
34 * is used to pass additional run-time information to the Java VM.
35 *
36 * This handler looks for the appropriate magic number on the
37 * front of the file, checks that the JAR file is executable, then
38 * invokes the Java runtime environment to do the rest of the work.
39 */
40
41 #include <sys/types.h>
42 #include <sys/proc.h>
43 #include <sys/vnode.h>
44 #include <sys/exec.h>
45 #include <sys/modctl.h>
46 #include <sys/cmn_err.h>
47 #include <sys/pathname.h>
48
49 /*
50 * These variables can be tweaked via /etc/system to allow prototyping
51 * and debugging. See PSARC/1997/123.
52 *
53 * Modified by PSARC/1999/012 to be Contract Private between Solaris and
54 * the Java Technology Group. It is expected that any future change to
55 * these variables be coordinated between the consolidations.
56 */
57 #if defined(__sparc)
58 char *jexec = "/usr/java/jre/lib/sparc/jexec";
59 #elif defined(__x86)
60 char *jexec = "/usr/java/jre/lib/i386/jexec";
61 #else
62 #error "Unknown ISA"
63 #endif
64 char *jexec_arg = "-jar";
65
66 /*
67 * ZIP/JAR file header information
68 */
69 #define SIGSIZ 4
70 #define LOCSIG "PK\003\004"
71 #define LOCHDRSIZ 30
72
73 #define CH(b, n) (((unsigned char *)(b))[n])
74 #define SH(b, n) (CH(b, n) | (CH(b, n+1) << 8))
75 #define LG(b, n) (SH(b, n) | (SH(b, n+2) << 16))
76
77 #define LOCNAM(b) (SH(b, 26)) /* filename size */
78 #define LOCEXT(b) (SH(b, 28)) /* extra field size */
79
80 #define XFHSIZ 4 /* header id, data size */
81 #define XFHID(b) (SH(b, 0)) /* extract field header id */
82 #define XFDATASIZ(b) (SH(b, 2)) /* extract field data size */
83 #define XFJAVASIG 0xcafe /* java executables */
84
85 /*ARGSUSED3*/
86 static int
javaexec(vnode_t * vp,struct execa * uap,struct uarg * args,struct intpdata * idatap,int level,size_t * execsz,int setid,caddr_t execfile,cred_t * cred,int brand_action)87 javaexec(vnode_t *vp, struct execa *uap, struct uarg *args,
88 struct intpdata *idatap, int level, size_t *execsz, int setid,
89 caddr_t execfile, cred_t *cred, int brand_action)
90 {
91 struct intpdata idata;
92 int error;
93 ssize_t resid;
94 vnode_t *nvp;
95 off_t xoff, xoff_end;
96 char lochdr[LOCHDRSIZ];
97 struct pathname lookpn;
98 struct pathname resolvepn;
99 char *opath;
100
101 if (level)
102 return (ENOEXEC); /* no recursion */
103
104 /*
105 * Read in the full local file header, and validate
106 * the initial signature.
107 */
108 if ((error = vn_rdwr(UIO_READ, vp, lochdr, sizeof (lochdr),
109 0, UIO_SYSSPACE, 0, (rlim64_t)0, cred, &resid)) != 0)
110 return (error);
111 if (resid != 0 || strncmp(lochdr, LOCSIG, SIGSIZ) != 0)
112 return (ENOEXEC);
113
114 /*
115 * Ok, so this -is- a ZIP file, and might even be a JAR file.
116 * Is it a Java executable?
117 */
118 xoff = sizeof (lochdr) + LOCNAM(lochdr);
119 xoff_end = xoff + LOCEXT(lochdr);
120
121 while (xoff < xoff_end) {
122 char xfhdr[XFHSIZ];
123
124 if ((error = vn_rdwr(UIO_READ, vp, xfhdr, sizeof (xfhdr),
125 xoff, UIO_SYSSPACE, 0, (rlim64_t)0, cred, &resid)) != 0)
126 return (error);
127 if (resid != 0)
128 return (ENOEXEC);
129 if (XFHID(xfhdr) == XFJAVASIG)
130 break;
131 xoff += sizeof (xfhdr) + XFDATASIZ(xfhdr);
132 }
133
134 if (xoff >= xoff_end)
135 return (ENOEXEC);
136
137 /*
138 * Note: If we ever make setid execution work, we need to ensure
139 * that we use /dev/fd to avoid the classic setuid shell script
140 * security hole.
141 */
142 if (setid)
143 return (EACCES);
144
145 /*
146 * Find and invoke the Java runtime environment on the file
147 */
148 bzero(&idata, sizeof (intpdata_t));
149 idata.intp = NULL;
150 idata.intp_name[0] = jexec;
151 idata.intp_arg[0] = jexec_arg;
152 if (error = pn_get(idata.intp_name[0], 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
167 if (!error) {
168 /*
169 * Close this Java executable as the interpreter
170 * will open and close it later on.
171 */
172 (void) VOP_CLOSE(vp, FREAD, 1, (offset_t)0, cred, NULL);
173 }
174
175 VN_RELE(nvp);
176 args->pathname = opath;
177 pn_free(&resolvepn);
178 return (error);
179 }
180
181 static struct execsw jexecsw = {
182 javamagicstr,
183 0,
184 4,
185 javaexec,
186 NULL
187 };
188
189 static struct modlexec jmodlexec = {
190 &mod_execops, "exec for Java", &jexecsw
191 };
192
193 static struct modlinkage jmodlinkage = {
194 MODREV_1, &jmodlexec, NULL
195 };
196
197 int
_init(void)198 _init(void)
199 {
200 return (mod_install(&jmodlinkage));
201 }
202
203 int
_fini(void)204 _fini(void)
205 {
206 return (mod_remove(&jmodlinkage));
207 }
208
209 int
_info(struct modinfo * modinfop)210 _info(struct modinfo *modinfop)
211 {
212 return (mod_info(&jmodlinkage, modinfop));
213 }
214