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