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 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 198 _init(void) 199 { 200 return (mod_install(&jmodlinkage)); 201 } 202 203 int 204 _fini(void) 205 { 206 return (mod_remove(&jmodlinkage)); 207 } 208 209 int 210 _info(struct modinfo *modinfop) 211 { 212 return (mod_info(&jmodlinkage, modinfop)); 213 } 214