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