1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #if defined(LIBC_SCCS) && !defined(lint) 33 static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93"; 34 #endif /* LIBC_SCCS and not lint */ 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include "namespace.h" 39 #include <sys/param.h> 40 #include <sys/stat.h> 41 #include <errno.h> 42 #include <unistd.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <stdio.h> 46 #include <paths.h> 47 48 #include <stdarg.h> 49 #include "un-namespace.h" 50 #include "libc_private.h" 51 52 extern char **environ; 53 54 int 55 execl(const char *name, const char *arg, ...) 56 { 57 va_list ap; 58 const char **argv; 59 int n; 60 61 va_start(ap, arg); 62 n = 1; 63 while (va_arg(ap, char *) != NULL) 64 n++; 65 va_end(ap); 66 argv = alloca((n + 1) * sizeof(*argv)); 67 if (argv == NULL) { 68 errno = ENOMEM; 69 return (-1); 70 } 71 va_start(ap, arg); 72 n = 1; 73 argv[0] = arg; 74 while ((argv[n] = va_arg(ap, char *)) != NULL) 75 n++; 76 va_end(ap); 77 return (_execve(name, __DECONST(char **, argv), environ)); 78 } 79 80 int 81 execle(const char *name, const char *arg, ...) 82 { 83 va_list ap; 84 const char **argv; 85 char **envp; 86 int n; 87 88 va_start(ap, arg); 89 n = 1; 90 while (va_arg(ap, char *) != NULL) 91 n++; 92 va_end(ap); 93 argv = alloca((n + 1) * sizeof(*argv)); 94 if (argv == NULL) { 95 errno = ENOMEM; 96 return (-1); 97 } 98 va_start(ap, arg); 99 n = 1; 100 argv[0] = arg; 101 while ((argv[n] = va_arg(ap, char *)) != NULL) 102 n++; 103 envp = va_arg(ap, char **); 104 va_end(ap); 105 return (_execve(name, __DECONST(char **, argv), envp)); 106 } 107 108 int 109 execlp(const char *name, const char *arg, ...) 110 { 111 va_list ap; 112 const char **argv; 113 int n; 114 115 va_start(ap, arg); 116 n = 1; 117 while (va_arg(ap, char *) != NULL) 118 n++; 119 va_end(ap); 120 argv = alloca((n + 1) * sizeof(*argv)); 121 if (argv == NULL) { 122 errno = ENOMEM; 123 return (-1); 124 } 125 va_start(ap, arg); 126 n = 1; 127 argv[0] = arg; 128 while ((argv[n] = va_arg(ap, char *)) != NULL) 129 n++; 130 va_end(ap); 131 return (execvp(name, __DECONST(char **, argv))); 132 } 133 134 int 135 execv(const char *name, char * const *argv) 136 { 137 (void)_execve(name, argv, environ); 138 return (-1); 139 } 140 141 int 142 execvp(const char *name, char * const *argv) 143 { 144 return (_execvpe(name, argv, environ)); 145 } 146 147 static int 148 execvPe(const char *name, const char *path, char * const *argv, 149 char * const *envp) 150 { 151 const char **memp; 152 size_t cnt, lp, ln; 153 int eacces, save_errno; 154 char *cur, buf[MAXPATHLEN]; 155 const char *p, *bp; 156 struct stat sb; 157 158 eacces = 0; 159 160 /* If it's an absolute or relative path name, it's easy. */ 161 if (strchr(name, '/')) { 162 bp = name; 163 cur = NULL; 164 goto retry; 165 } 166 bp = buf; 167 168 /* If it's an empty path name, fail in the usual POSIX way. */ 169 if (*name == '\0') { 170 errno = ENOENT; 171 return (-1); 172 } 173 174 cur = alloca(strlen(path) + 1); 175 if (cur == NULL) { 176 errno = ENOMEM; 177 return (-1); 178 } 179 strcpy(cur, path); 180 while ((p = strsep(&cur, ":")) != NULL) { 181 /* 182 * It's a SHELL path -- double, leading and trailing colons 183 * mean the current directory. 184 */ 185 if (*p == '\0') { 186 p = "."; 187 lp = 1; 188 } else 189 lp = strlen(p); 190 ln = strlen(name); 191 192 /* 193 * If the path is too long complain. This is a possible 194 * security issue; given a way to make the path too long 195 * the user may execute the wrong program. 196 */ 197 if (lp + ln + 2 > sizeof(buf)) { 198 (void)_write(STDERR_FILENO, "execvP: ", 8); 199 (void)_write(STDERR_FILENO, p, lp); 200 (void)_write(STDERR_FILENO, ": path too long\n", 201 16); 202 continue; 203 } 204 bcopy(p, buf, lp); 205 buf[lp] = '/'; 206 bcopy(name, buf + lp + 1, ln); 207 buf[lp + ln + 1] = '\0'; 208 209 retry: (void)_execve(bp, argv, envp); 210 switch (errno) { 211 case E2BIG: 212 goto done; 213 case ELOOP: 214 case ENAMETOOLONG: 215 case ENOENT: 216 break; 217 case ENOEXEC: 218 for (cnt = 0; argv[cnt]; ++cnt) 219 ; 220 memp = alloca((cnt + 2) * sizeof(char *)); 221 if (memp == NULL) { 222 /* errno = ENOMEM; XXX override ENOEXEC? */ 223 goto done; 224 } 225 memp[0] = "sh"; 226 memp[1] = bp; 227 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 228 (void)_execve(_PATH_BSHELL, 229 __DECONST(char **, memp), envp); 230 goto done; 231 case ENOMEM: 232 goto done; 233 case ENOTDIR: 234 break; 235 case ETXTBSY: 236 /* 237 * We used to retry here, but sh(1) doesn't. 238 */ 239 goto done; 240 default: 241 /* 242 * EACCES may be for an inaccessible directory or 243 * a non-executable file. Call stat() to decide 244 * which. This also handles ambiguities for EFAULT 245 * and EIO, and undocumented errors like ESTALE. 246 * We hope that the race for a stat() is unimportant. 247 */ 248 save_errno = errno; 249 if (stat(bp, &sb) != 0) 250 break; 251 if (save_errno == EACCES) { 252 eacces = 1; 253 continue; 254 } 255 errno = save_errno; 256 goto done; 257 } 258 } 259 if (eacces) 260 errno = EACCES; 261 else 262 errno = ENOENT; 263 done: 264 return (-1); 265 } 266 267 int 268 execvP(const char *name, const char *path, char * const argv[]) 269 { 270 return execvPe(name, path, argv, environ); 271 } 272 273 int 274 _execvpe(const char *name, char * const argv[], char * const envp[]) 275 { 276 const char *path; 277 278 /* Get the path we're searching. */ 279 if ((path = getenv("PATH")) == NULL) 280 path = _PATH_DEFPATH; 281 282 return (execvPe(name, path, argv, envp)); 283 } 284