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 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * Copyright 2019 OmniOS Community Edition (OmniOSce) Association. 29 */ 30 31 #pragma weak _isaexec = isaexec 32 33 #include "lint.h" 34 #include <sys/types.h> 35 #include <sys/systeminfo.h> 36 #include <unistd.h> 37 #include <string.h> 38 #include <errno.h> 39 #include <limits.h> 40 #include <stdarg.h> 41 #include <stdlib.h> 42 43 /* 44 * This is a utility routine to allow wrapper programs to simply 45 * implement the isalist exec algorithms. See PSARC/1997/220. 46 */ 47 int 48 isaexec(const char *execname, char *const *argv, char *const *envp) 49 { 50 const char *fname; 51 char *isalist; 52 char *pathname; 53 char *str; 54 char *lasts; 55 size_t isalen = 255; /* wild guess */ 56 size_t len; 57 int saved_errno; 58 59 /* 60 * Extract the isalist(7) for userland from the kernel. 61 */ 62 isalist = malloc(isalen); 63 do { 64 long ret = sysinfo(SI_ISALIST, isalist, isalen); 65 if (ret == -1l) { 66 free(isalist); 67 errno = ENOENT; 68 return (-1); 69 } 70 if (ret > isalen) { 71 isalen = ret; 72 isalist = reallocf(isalist, isalen); 73 } else { 74 break; 75 } 76 } while (isalist != NULL); 77 78 if (isalist == NULL) { 79 /* 80 * Then either a malloc or a realloc failed. 81 */ 82 errno = EAGAIN; 83 return (-1); 84 } 85 86 /* 87 * Allocate a full pathname buffer. The sum of the lengths of the 88 * 'path' and isalist strings is guaranteed to be big enough. 89 */ 90 len = strlen(execname) + isalen; 91 if ((pathname = malloc(len)) == NULL) { 92 free(isalist); 93 errno = EAGAIN; 94 return (-1); 95 } 96 97 /* 98 * Break the exec name into directory and file name components. 99 */ 100 (void) strcpy(pathname, execname); 101 if ((str = strrchr(pathname, '/')) != NULL) { 102 *++str = '\0'; 103 fname = execname + (str - pathname); 104 } else { 105 fname = execname; 106 *pathname = '\0'; 107 } 108 len = strlen(pathname); 109 110 /* 111 * For each name in the isa list, look for an executable file 112 * with the given file name in the corresponding subdirectory. 113 * If it's there, exec it. If it's not there, or the exec 114 * fails, then run the next version .. 115 */ 116 str = strtok_r(isalist, " ", &lasts); 117 saved_errno = ENOENT; 118 do { 119 (void) strcpy(pathname + len, str); 120 (void) strcat(pathname + len, "/"); 121 (void) strcat(pathname + len, fname); 122 if (access(pathname, X_OK) == 0) { 123 /* 124 * File exists and is marked executable. Attempt 125 * to execute the file from the subdirectory, 126 * using the user-supplied argv and envp. 127 */ 128 (void) execve(pathname, argv, envp); 129 130 /* 131 * If we failed to exec because of a temporary 132 * resource shortage, it's better to let our 133 * caller handle it (free memory, sleep for a while, 134 * or whatever before retrying) rather than drive 135 * on to run the "less capable" version. 136 */ 137 if (errno == EAGAIN) { 138 saved_errno = errno; 139 break; 140 } 141 } 142 } while ((str = strtok_r(NULL, " ", &lasts)) != NULL); 143 144 free(pathname); 145 free(isalist); 146 147 errno = saved_errno; 148 return (-1); 149 } 150