1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93"; 32 #endif /* LIBC_SCCS and not lint */ 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include "namespace.h" 37 #include <sys/param.h> 38 #include <sys/types.h> 39 #include <sys/stat.h> 40 #include <errno.h> 41 #include <unistd.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <stdio.h> 45 #include <paths.h> 46 47 #include <stdarg.h> 48 #include "un-namespace.h" 49 #include "libc_private.h" 50 51 extern char **environ; 52 53 int 54 execl(const char *name, const char *arg, ...) 55 { 56 va_list ap; 57 const char **argv; 58 int n; 59 60 va_start(ap, arg); 61 n = 1; 62 while (va_arg(ap, char *) != NULL) 63 n++; 64 va_end(ap); 65 argv = alloca((n + 1) * sizeof(*argv)); 66 if (argv == NULL) { 67 errno = ENOMEM; 68 return (-1); 69 } 70 va_start(ap, arg); 71 n = 1; 72 argv[0] = arg; 73 while ((argv[n] = va_arg(ap, char *)) != NULL) 74 n++; 75 va_end(ap); 76 return (_execve(name, __DECONST(char **, argv), environ)); 77 } 78 79 int 80 execle(const char *name, const char *arg, ...) 81 { 82 va_list ap; 83 const char **argv; 84 char **envp; 85 int n; 86 87 va_start(ap, arg); 88 n = 1; 89 while (va_arg(ap, char *) != NULL) 90 n++; 91 va_end(ap); 92 argv = alloca((n + 1) * sizeof(*argv)); 93 if (argv == NULL) { 94 errno = ENOMEM; 95 return (-1); 96 } 97 va_start(ap, arg); 98 n = 1; 99 argv[0] = arg; 100 while ((argv[n] = va_arg(ap, char *)) != NULL) 101 n++; 102 envp = va_arg(ap, char **); 103 va_end(ap); 104 return (_execve(name, __DECONST(char **, argv), envp)); 105 } 106 107 int 108 execlp(const char *name, const char *arg, ...) 109 { 110 va_list ap; 111 const char **argv; 112 int n; 113 114 va_start(ap, arg); 115 n = 1; 116 while (va_arg(ap, char *) != NULL) 117 n++; 118 va_end(ap); 119 argv = alloca((n + 1) * sizeof(*argv)); 120 if (argv == NULL) { 121 errno = ENOMEM; 122 return (-1); 123 } 124 va_start(ap, arg); 125 n = 1; 126 argv[0] = arg; 127 while ((argv[n] = va_arg(ap, char *)) != NULL) 128 n++; 129 va_end(ap); 130 return (execvp(name, __DECONST(char **, argv))); 131 } 132 133 int 134 execv(name, argv) 135 const char *name; 136 char * const *argv; 137 { 138 (void)_execve(name, argv, environ); 139 return (-1); 140 } 141 142 int 143 execvp(const char *name, char * const *argv) 144 { 145 return (_execvpe(name, argv, environ)); 146 } 147 148 static int 149 execvPe(const char *name, const char *path, char * const *argv, 150 char * const *envp) 151 { 152 const char **memp; 153 size_t cnt, lp, ln; 154 int eacces, save_errno; 155 char *cur, buf[MAXPATHLEN]; 156 const char *p, *bp; 157 struct stat sb; 158 159 eacces = 0; 160 161 /* If it's an absolute or relative path name, it's easy. */ 162 if (strchr(name, '/')) { 163 bp = name; 164 cur = NULL; 165 goto retry; 166 } 167 bp = buf; 168 169 /* If it's an empty path name, fail in the usual POSIX way. */ 170 if (*name == '\0') { 171 errno = ENOENT; 172 return (-1); 173 } 174 175 cur = alloca(strlen(path) + 1); 176 if (cur == NULL) { 177 errno = ENOMEM; 178 return (-1); 179 } 180 strcpy(cur, path); 181 while ((p = strsep(&cur, ":")) != NULL) { 182 /* 183 * It's a SHELL path -- double, leading and trailing colons 184 * mean the current directory. 185 */ 186 if (*p == '\0') { 187 p = "."; 188 lp = 1; 189 } else 190 lp = strlen(p); 191 ln = strlen(name); 192 193 /* 194 * If the path is too long complain. This is a possible 195 * security issue; given a way to make the path too long 196 * the user may execute the wrong program. 197 */ 198 if (lp + ln + 2 > sizeof(buf)) { 199 (void)_write(STDERR_FILENO, "execvP: ", 8); 200 (void)_write(STDERR_FILENO, p, lp); 201 (void)_write(STDERR_FILENO, ": path too long\n", 202 16); 203 continue; 204 } 205 bcopy(p, buf, lp); 206 buf[lp] = '/'; 207 bcopy(name, buf + lp + 1, ln); 208 buf[lp + ln + 1] = '\0'; 209 210 retry: (void)_execve(bp, argv, envp); 211 switch (errno) { 212 case E2BIG: 213 goto done; 214 case ELOOP: 215 case ENAMETOOLONG: 216 case ENOENT: 217 break; 218 case ENOEXEC: 219 for (cnt = 0; argv[cnt]; ++cnt) 220 ; 221 memp = alloca((cnt + 2) * sizeof(char *)); 222 if (memp == NULL) { 223 /* errno = ENOMEM; XXX override ENOEXEC? */ 224 goto done; 225 } 226 memp[0] = "sh"; 227 memp[1] = bp; 228 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 229 (void)_execve(_PATH_BSHELL, 230 __DECONST(char **, memp), envp); 231 goto done; 232 case ENOMEM: 233 goto done; 234 case ENOTDIR: 235 break; 236 case ETXTBSY: 237 /* 238 * We used to retry here, but sh(1) doesn't. 239 */ 240 goto done; 241 default: 242 /* 243 * EACCES may be for an inaccessible directory or 244 * a non-executable file. Call stat() to decide 245 * which. This also handles ambiguities for EFAULT 246 * and EIO, and undocumented errors like ESTALE. 247 * We hope that the race for a stat() is unimportant. 248 */ 249 save_errno = errno; 250 if (stat(bp, &sb) != 0) 251 break; 252 if (save_errno == EACCES) { 253 eacces = 1; 254 continue; 255 } 256 errno = save_errno; 257 goto done; 258 } 259 } 260 if (eacces) 261 errno = EACCES; 262 else 263 errno = ENOENT; 264 done: 265 return (-1); 266 } 267 268 int 269 execvP(const char *name, const char *path, char * const argv[]) 270 { 271 return execvPe(name, path, argv, environ); 272 } 273 274 int 275 _execvpe(const char *name, char * const argv[], char * const envp[]) 276 { 277 const char *path; 278 279 /* Get the path we're searching. */ 280 if ((path = getenv("PATH")) == NULL) 281 path = _PATH_DEFPATH; 282 283 return (execvPe(name, path, argv, envp)); 284 } 285