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 rcsid[] = "$OpenBSD: exec.c,v 1.11 2000/08/22 18:46:04 deraadt Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/param.h> 39 #include <sys/types.h> 40 #include <sys/uio.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 #ifdef __STDC__ 49 #include <stdarg.h> 50 #else 51 #include <varargs.h> 52 #endif 53 54 extern char **environ; 55 56 int 57 #ifdef __STDC__ 58 execl(const char *name, const char *arg, ...) 59 #else 60 execl(name, arg, va_alist) 61 const char *name; 62 const char *arg; 63 va_dcl 64 #endif 65 { 66 va_list ap; 67 char **argv; 68 int n; 69 70 #ifdef __STDC__ 71 va_start(ap, arg); 72 #else 73 va_start(ap); 74 #endif 75 n = 1; 76 while (va_arg(ap, char *) != NULL) 77 n++; 78 va_end(ap); 79 argv = alloca((n + 1) * sizeof(*argv)); 80 if (argv == NULL) { 81 errno = ENOMEM; 82 return (-1); 83 } 84 #ifdef __STDC__ 85 va_start(ap, arg); 86 #else 87 va_start(ap); 88 #endif 89 n = 1; 90 argv[0] = (char *)arg; 91 while ((argv[n] = va_arg(ap, char *)) != NULL) 92 n++; 93 va_end(ap); 94 return (execve(name, argv, environ)); 95 } 96 97 int 98 #ifdef __STDC__ 99 execle(const char *name, const char *arg, ...) 100 #else 101 execle(name, arg, va_alist) 102 const char *name; 103 const char *arg; 104 va_dcl 105 #endif 106 { 107 va_list ap; 108 char **argv, **envp; 109 int n; 110 111 #ifdef __STDC__ 112 va_start(ap, arg); 113 #else 114 va_start(ap); 115 #endif 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 #ifdef __STDC__ 126 va_start(ap, arg); 127 #else 128 va_start(ap); 129 #endif 130 n = 1; 131 argv[0] = (char *)arg; 132 while ((argv[n] = va_arg(ap, char *)) != NULL) 133 n++; 134 envp = va_arg(ap, char **); 135 va_end(ap); 136 return (execve(name, argv, envp)); 137 } 138 139 int 140 #ifdef __STDC__ 141 execlp(const char *name, const char *arg, ...) 142 #else 143 execlp(name, arg, va_alist) 144 const char *name; 145 const char *arg; 146 va_dcl 147 #endif 148 { 149 va_list ap; 150 char **argv; 151 int n; 152 153 #ifdef __STDC__ 154 va_start(ap, arg); 155 #else 156 va_start(ap); 157 #endif 158 n = 1; 159 while (va_arg(ap, char *) != NULL) 160 n++; 161 va_end(ap); 162 argv = alloca((n + 1) * sizeof(*argv)); 163 if (argv == NULL) { 164 errno = ENOMEM; 165 return (-1); 166 } 167 #ifdef __STDC__ 168 va_start(ap, arg); 169 #else 170 va_start(ap); 171 #endif 172 n = 1; 173 argv[0] = (char *)arg; 174 while ((argv[n] = va_arg(ap, char *)) != NULL) 175 n++; 176 va_end(ap); 177 return (execvp(name, argv)); 178 } 179 180 int 181 execv(name, argv) 182 const char *name; 183 char * const *argv; 184 { 185 (void)execve(name, argv, environ); 186 return (-1); 187 } 188 189 int 190 execvp(name, argv) 191 const char *name; 192 char * const *argv; 193 { 194 char **memp; 195 register int cnt, lp, ln; 196 register char *p; 197 int eacces = 0; 198 char *bp, *cur, *path, buf[MAXPATHLEN]; 199 200 /* 201 * Do not allow null name 202 */ 203 if (name == NULL || *name == '\0') { 204 errno = ENOENT; 205 return (-1); 206 } 207 208 /* If it's an absolute or relative path name, it's easy. */ 209 if (strchr(name, '/')) { 210 bp = (char *)name; 211 cur = path = NULL; 212 goto retry; 213 } 214 bp = buf; 215 216 /* Get the path we're searching. */ 217 if (!(path = getenv("PATH"))) 218 path = _PATH_DEFPATH; 219 cur = alloca(strlen(path) + 1); 220 if (cur == NULL) { 221 errno = ENOMEM; 222 return (-1); 223 } 224 strcpy(cur, path); 225 path = cur; 226 while ((p = strsep(&cur, ":"))) { 227 /* 228 * It's a SHELL path -- double, leading and trailing colons 229 * mean the current directory. 230 */ 231 if (!*p) { 232 p = "."; 233 lp = 1; 234 } else 235 lp = strlen(p); 236 ln = strlen(name); 237 238 /* 239 * If the path is too long complain. This is a possible 240 * security issue; given a way to make the path too long 241 * the user may execute the wrong program. 242 */ 243 if (lp + ln + 2 > sizeof(buf)) { 244 struct iovec iov[3]; 245 246 iov[0].iov_base = "execvp: "; 247 iov[0].iov_len = 8; 248 iov[1].iov_base = p; 249 iov[1].iov_len = lp; 250 iov[2].iov_base = ": path too long\n"; 251 iov[2].iov_len = 16; 252 (void)writev(STDERR_FILENO, iov, 3); 253 continue; 254 } 255 bcopy(p, buf, lp); 256 buf[lp] = '/'; 257 bcopy(name, buf + lp + 1, ln); 258 buf[lp + ln + 1] = '\0'; 259 260 retry: (void)execve(bp, argv, environ); 261 switch(errno) { 262 case E2BIG: 263 goto done; 264 case ELOOP: 265 case ENAMETOOLONG: 266 case ENOENT: 267 break; 268 case ENOEXEC: 269 for (cnt = 0; argv[cnt]; ++cnt) 270 ; 271 memp = alloca((cnt + 2) * sizeof(char *)); 272 if (memp == NULL) 273 goto done; 274 memp[0] = "sh"; 275 memp[1] = bp; 276 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 277 (void)execve(_PATH_BSHELL, memp, environ); 278 goto done; 279 case ENOMEM: 280 goto done; 281 case ENOTDIR: 282 break; 283 case ETXTBSY: 284 /* 285 * We used to retry here, but sh(1) doesn't. 286 */ 287 goto done; 288 case EACCES: 289 eacces = 1; 290 break; 291 default: 292 goto done; 293 } 294 } 295 if (eacces) 296 errno = EACCES; 297 else if (!errno) 298 errno = ENOENT; 299 done: 300 return (-1); 301 } 302