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 1.8 1998/08/14 21:39:23 deraadt Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/param.h> 39 #include <sys/types.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 #ifdef __STDC__ 48 #include <stdarg.h> 49 #else 50 #include <varargs.h> 51 #endif 52 53 extern char **environ; 54 55 static char ** 56 buildargv(ap, arg, envpp) 57 va_list ap; 58 const char *arg; 59 char ***envpp; 60 { 61 register char **argv, **nargv; 62 register int memsize, off; 63 64 argv = NULL; 65 for (off = memsize = 0;; ++off) { 66 if (off >= memsize) { 67 memsize += 50; /* Starts out at 0. */ 68 memsize *= 2; /* Ramp up fast. */ 69 nargv = realloc(argv, memsize * sizeof(char *)); 70 if (nargv == NULL) { 71 if (argv) 72 free(argv); 73 return (NULL); 74 } 75 argv = nargv; 76 if (off == 0) { 77 argv[0] = (char *)arg; 78 off = 1; 79 } 80 } 81 if (!(argv[off] = va_arg(ap, char *))) 82 break; 83 } 84 /* Get environment pointer if user supposed to provide one. */ 85 if (envpp) 86 *envpp = va_arg(ap, char **); 87 return (argv); 88 } 89 90 int 91 #ifdef __STDC__ 92 execl(const char *name, const char *arg, ...) 93 #else 94 execl(name, arg, va_alist) 95 const char *name; 96 const char *arg; 97 va_dcl 98 #endif 99 { 100 va_list ap; 101 int sverrno; 102 char **argv; 103 104 #ifdef __STDC__ 105 va_start(ap, arg); 106 #else 107 va_start(ap); 108 #endif 109 if ((argv = buildargv(ap, arg, NULL))) 110 (void)execve(name, argv, environ); 111 va_end(ap); 112 sverrno = errno; 113 free(argv); 114 errno = sverrno; 115 return (-1); 116 } 117 118 int 119 #ifdef __STDC__ 120 execle(const char *name, const char *arg, ...) 121 #else 122 execle(name, arg, va_alist) 123 const char *name; 124 const char *arg; 125 va_dcl 126 #endif 127 { 128 va_list ap; 129 char **argv, **envp; 130 int i; 131 132 #ifdef __STDC__ 133 va_start(ap, arg); 134 #else 135 va_start(ap); 136 #endif 137 for (i = 1; va_arg(ap, char *) != NULL; i++) 138 ; 139 va_end(ap); 140 141 argv = alloca (i * sizeof (char *)); 142 143 #if __STDC__ 144 va_start(ap, arg); 145 #else 146 va_start(ap); 147 #endif 148 argv[0] = (char *) arg; 149 for (i = 1; (argv[i] = (char *) va_arg(ap, char *)) != NULL; i++) 150 ; 151 envp = (char **) va_arg(ap, char **); 152 va_end(ap); 153 154 return execve(name, argv, envp); 155 } 156 157 int 158 #ifdef __STDC__ 159 execlp(const char *name, const char *arg, ...) 160 #else 161 execlp(name, arg, va_alist) 162 const char *name; 163 const char *arg; 164 va_dcl 165 #endif 166 { 167 va_list ap; 168 int sverrno; 169 char **argv; 170 171 #ifdef __STDC__ 172 va_start(ap, arg); 173 #else 174 va_start(ap); 175 #endif 176 if ((argv = buildargv(ap, arg, NULL))) 177 (void)execvp(name, argv); 178 va_end(ap); 179 sverrno = errno; 180 free(argv); 181 errno = sverrno; 182 return (-1); 183 } 184 185 int 186 execv(name, argv) 187 const char *name; 188 char * const *argv; 189 { 190 (void)execve(name, argv, environ); 191 return (-1); 192 } 193 194 int 195 execvp(name, argv) 196 const char *name; 197 char * const *argv; 198 { 199 char **memp; 200 register int cnt, lp, ln; 201 register char *p; 202 int eacces = 0, etxtbsy = 0; 203 char *bp, *cur, *path, buf[MAXPATHLEN]; 204 205 /* 206 * Do not allow null name 207 */ 208 if (name == NULL || *name == '\0') { 209 errno = ENOENT; 210 return (-1); 211 } 212 213 /* If it's an absolute or relative path name, it's easy. */ 214 if (strchr(name, '/')) { 215 bp = (char *)name; 216 cur = path = NULL; 217 goto retry; 218 } 219 bp = buf; 220 221 /* Get the path we're searching. */ 222 if (!(path = getenv("PATH"))) 223 path = _PATH_DEFPATH; 224 cur = path = strdup(path); 225 226 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 (void)write(STDERR_FILENO, "execvp: ", 8); 245 (void)write(STDERR_FILENO, p, lp); 246 (void)write(STDERR_FILENO, ": path too long\n", 16); 247 continue; 248 } 249 bcopy(p, buf, lp); 250 buf[lp] = '/'; 251 bcopy(name, buf + lp + 1, ln); 252 buf[lp + ln + 1] = '\0'; 253 254 retry: (void)execve(bp, argv, environ); 255 switch(errno) { 256 case EACCES: 257 eacces = 1; 258 break; 259 case ENOENT: 260 break; 261 case ENOEXEC: 262 for (cnt = 0; argv[cnt]; ++cnt) 263 ; 264 memp = malloc((cnt + 2) * sizeof(char *)); 265 if (memp == NULL) 266 goto done; 267 memp[0] = "sh"; 268 memp[1] = bp; 269 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 270 (void)execve(_PATH_BSHELL, memp, environ); 271 free(memp); 272 goto done; 273 case ETXTBSY: 274 if (etxtbsy < 3) 275 (void)sleep(++etxtbsy); 276 goto retry; 277 default: 278 goto done; 279 } 280 } 281 if (eacces) 282 errno = EACCES; 283 else if (!errno) 284 errno = ENOENT; 285 done: if (path) 286 free(path); 287 return (-1); 288 } 289