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 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] = (char *)arg; 73 while ((argv[n] = va_arg(ap, char *)) != NULL) 74 n++; 75 va_end(ap); 76 return (_execve(name, argv, environ)); 77 } 78 79 int 80 execle(const char *name, const char *arg, ...) 81 { 82 va_list ap; 83 char **argv, **envp; 84 int n; 85 86 va_start(ap, arg); 87 n = 1; 88 while (va_arg(ap, char *) != NULL) 89 n++; 90 va_end(ap); 91 argv = alloca((n + 1) * sizeof(*argv)); 92 if (argv == NULL) { 93 errno = ENOMEM; 94 return (-1); 95 } 96 va_start(ap, arg); 97 n = 1; 98 argv[0] = (char *)arg; 99 while ((argv[n] = va_arg(ap, char *)) != NULL) 100 n++; 101 envp = va_arg(ap, char **); 102 va_end(ap); 103 return (_execve(name, argv, envp)); 104 } 105 106 int 107 execlp(const char *name, const char *arg, ...) 108 { 109 va_list ap; 110 char **argv; 111 int n; 112 113 va_start(ap, arg); 114 n = 1; 115 while (va_arg(ap, char *) != NULL) 116 n++; 117 va_end(ap); 118 argv = alloca((n + 1) * sizeof(*argv)); 119 if (argv == NULL) { 120 errno = ENOMEM; 121 return (-1); 122 } 123 va_start(ap, arg); 124 n = 1; 125 argv[0] = (char *)arg; 126 while ((argv[n] = va_arg(ap, char *)) != NULL) 127 n++; 128 va_end(ap); 129 return (execvp(name, argv)); 130 } 131 132 int 133 execv(name, argv) 134 const char *name; 135 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(name, path, argv, envp) 149 const char *name; 150 const char *path; 151 char * const *argv; 152 char * const *envp; 153 { 154 char **memp; 155 int cnt, lp, ln; 156 char *p; 157 int eacces, save_errno; 158 char *bp, *cur, buf[MAXPATHLEN]; 159 struct stat sb; 160 161 eacces = 0; 162 163 /* If it's an absolute or relative path name, it's easy. */ 164 if (index(name, '/')) { 165 bp = (char *)name; 166 cur = NULL; 167 goto retry; 168 } 169 bp = buf; 170 171 /* If it's an empty path name, fail in the usual POSIX way. */ 172 if (*name == '\0') { 173 errno = ENOENT; 174 return (-1); 175 } 176 177 cur = alloca(strlen(path) + 1); 178 if (cur == NULL) { 179 errno = ENOMEM; 180 return (-1); 181 } 182 strcpy(cur, path); 183 while ((p = strsep(&cur, ":")) != NULL) { 184 /* 185 * It's a SHELL path -- double, leading and trailing colons 186 * mean the current directory. 187 */ 188 if (*p == '\0') { 189 p = "."; 190 lp = 1; 191 } else 192 lp = strlen(p); 193 ln = strlen(name); 194 195 /* 196 * If the path is too long complain. This is a possible 197 * security issue; given a way to make the path too long 198 * the user may execute the wrong program. 199 */ 200 if (lp + ln + 2 > sizeof(buf)) { 201 (void)_write(STDERR_FILENO, "execvP: ", 8); 202 (void)_write(STDERR_FILENO, p, lp); 203 (void)_write(STDERR_FILENO, ": path too long\n", 204 16); 205 continue; 206 } 207 bcopy(p, buf, lp); 208 buf[lp] = '/'; 209 bcopy(name, buf + lp + 1, ln); 210 buf[lp + ln + 1] = '\0'; 211 212 retry: (void)_execve(bp, argv, environ); 213 switch (errno) { 214 case E2BIG: 215 goto done; 216 case ELOOP: 217 case ENAMETOOLONG: 218 case ENOENT: 219 break; 220 case ENOEXEC: 221 for (cnt = 0; argv[cnt]; ++cnt) 222 ; 223 memp = alloca((cnt + 2) * sizeof(char *)); 224 if (memp == NULL) { 225 /* errno = ENOMEM; XXX override ENOEXEC? */ 226 goto done; 227 } 228 memp[0] = "sh"; 229 memp[1] = bp; 230 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 231 (void)_execve(_PATH_BSHELL, memp, environ); 232 goto done; 233 case ENOMEM: 234 goto done; 235 case ENOTDIR: 236 break; 237 case ETXTBSY: 238 /* 239 * We used to retry here, but sh(1) doesn't. 240 */ 241 goto done; 242 default: 243 /* 244 * EACCES may be for an inaccessible directory or 245 * a non-executable file. Call stat() to decide 246 * which. This also handles ambiguities for EFAULT 247 * and EIO, and undocumented errors like ESTALE. 248 * We hope that the race for a stat() is unimportant. 249 */ 250 save_errno = errno; 251 if (stat(bp, &sb) != 0) 252 break; 253 if (save_errno == EACCES) { 254 eacces = 1; 255 continue; 256 } 257 errno = save_errno; 258 goto done; 259 } 260 } 261 if (eacces) 262 errno = EACCES; 263 else 264 errno = ENOENT; 265 done: 266 return (-1); 267 } 268 269 int 270 execvP(const char *name, const char *path, char * const argv[]) 271 { 272 return execvPe(name, path, argv, environ); 273 } 274 275 int 276 _execvpe(const char *name, char * const argv[], char * const envp[]) 277 { 278 const char *path; 279 280 /* Get the path we're searching. */ 281 if ((path = getenv("PATH")) == NULL) 282 path = _PATH_DEFPATH; 283 284 return (execvPe(name, path, argv, envp)); 285 } 286