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(const char *name, char * const *argv) 135 { 136 (void)_execve(name, argv, environ); 137 return (-1); 138 } 139 140 int 141 execvp(const char *name, char * const *argv) 142 { 143 return (_execvpe(name, argv, environ)); 144 } 145 146 static int 147 execvPe(const char *name, const char *path, char * const *argv, 148 char * const *envp) 149 { 150 const char **memp; 151 size_t cnt, lp, ln; 152 int eacces, save_errno; 153 char *cur, buf[MAXPATHLEN]; 154 const char *p, *bp; 155 struct stat sb; 156 157 eacces = 0; 158 159 /* If it's an absolute or relative path name, it's easy. */ 160 if (strchr(name, '/')) { 161 bp = name; 162 cur = NULL; 163 goto retry; 164 } 165 bp = buf; 166 167 /* If it's an empty path name, fail in the usual POSIX way. */ 168 if (*name == '\0') { 169 errno = ENOENT; 170 return (-1); 171 } 172 173 cur = alloca(strlen(path) + 1); 174 if (cur == NULL) { 175 errno = ENOMEM; 176 return (-1); 177 } 178 strcpy(cur, path); 179 while ((p = strsep(&cur, ":")) != NULL) { 180 /* 181 * It's a SHELL path -- double, leading and trailing colons 182 * mean the current directory. 183 */ 184 if (*p == '\0') { 185 p = "."; 186 lp = 1; 187 } else 188 lp = strlen(p); 189 ln = strlen(name); 190 191 /* 192 * If the path is too long complain. This is a possible 193 * security issue; given a way to make the path too long 194 * the user may execute the wrong program. 195 */ 196 if (lp + ln + 2 > sizeof(buf)) { 197 (void)_write(STDERR_FILENO, "execvP: ", 8); 198 (void)_write(STDERR_FILENO, p, lp); 199 (void)_write(STDERR_FILENO, ": path too long\n", 200 16); 201 continue; 202 } 203 bcopy(p, buf, lp); 204 buf[lp] = '/'; 205 bcopy(name, buf + lp + 1, ln); 206 buf[lp + ln + 1] = '\0'; 207 208 retry: (void)_execve(bp, argv, envp); 209 switch (errno) { 210 case E2BIG: 211 goto done; 212 case ELOOP: 213 case ENAMETOOLONG: 214 case ENOENT: 215 break; 216 case ENOEXEC: 217 for (cnt = 0; argv[cnt]; ++cnt) 218 ; 219 memp = alloca((cnt + 2) * sizeof(char *)); 220 if (memp == NULL) { 221 /* errno = ENOMEM; XXX override ENOEXEC? */ 222 goto done; 223 } 224 memp[0] = "sh"; 225 memp[1] = bp; 226 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 227 (void)_execve(_PATH_BSHELL, 228 __DECONST(char **, memp), envp); 229 goto done; 230 case ENOMEM: 231 goto done; 232 case ENOTDIR: 233 break; 234 case ETXTBSY: 235 /* 236 * We used to retry here, but sh(1) doesn't. 237 */ 238 goto done; 239 default: 240 /* 241 * EACCES may be for an inaccessible directory or 242 * a non-executable file. Call stat() to decide 243 * which. This also handles ambiguities for EFAULT 244 * and EIO, and undocumented errors like ESTALE. 245 * We hope that the race for a stat() is unimportant. 246 */ 247 save_errno = errno; 248 if (stat(bp, &sb) != 0) 249 break; 250 if (save_errno == EACCES) { 251 eacces = 1; 252 continue; 253 } 254 errno = save_errno; 255 goto done; 256 } 257 } 258 if (eacces) 259 errno = EACCES; 260 else 261 errno = ENOENT; 262 done: 263 return (-1); 264 } 265 266 int 267 execvP(const char *name, const char *path, char * const argv[]) 268 { 269 return execvPe(name, path, argv, environ); 270 } 271 272 int 273 _execvpe(const char *name, char * const argv[], char * const envp[]) 274 { 275 const char *path; 276 277 /* Get the path we're searching. */ 278 if ((path = getenv("PATH")) == NULL) 279 path = _PATH_DEFPATH; 280 281 return (execvPe(name, path, argv, envp)); 282 } 283