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 50 extern char **environ; 51 52 int 53 execl(const char *name, const char *arg, ...) 54 { 55 va_list ap; 56 char **argv; 57 int n; 58 59 va_start(ap, arg); 60 n = 1; 61 while (va_arg(ap, char *) != NULL) 62 n++; 63 va_end(ap); 64 argv = alloca((n + 1) * sizeof(*argv)); 65 if (argv == NULL) { 66 errno = ENOMEM; 67 return (-1); 68 } 69 va_start(ap, arg); 70 n = 1; 71 argv[0] = (char *)arg; 72 while ((argv[n] = va_arg(ap, char *)) != NULL) 73 n++; 74 va_end(ap); 75 return (_execve(name, argv, environ)); 76 } 77 78 int 79 execle(const char *name, const char *arg, ...) 80 { 81 va_list ap; 82 char **argv, **envp; 83 int n; 84 85 va_start(ap, arg); 86 n = 1; 87 while (va_arg(ap, char *) != NULL) 88 n++; 89 va_end(ap); 90 argv = alloca((n + 1) * sizeof(*argv)); 91 if (argv == NULL) { 92 errno = ENOMEM; 93 return (-1); 94 } 95 va_start(ap, arg); 96 n = 1; 97 argv[0] = (char *)arg; 98 while ((argv[n] = va_arg(ap, char *)) != NULL) 99 n++; 100 envp = va_arg(ap, char **); 101 va_end(ap); 102 return (_execve(name, argv, envp)); 103 } 104 105 int 106 execlp(const char *name, const char *arg, ...) 107 { 108 va_list ap; 109 char **argv; 110 int n; 111 112 va_start(ap, arg); 113 n = 1; 114 while (va_arg(ap, char *) != NULL) 115 n++; 116 va_end(ap); 117 argv = alloca((n + 1) * sizeof(*argv)); 118 if (argv == NULL) { 119 errno = ENOMEM; 120 return (-1); 121 } 122 va_start(ap, arg); 123 n = 1; 124 argv[0] = (char *)arg; 125 while ((argv[n] = va_arg(ap, char *)) != NULL) 126 n++; 127 va_end(ap); 128 return (execvp(name, argv)); 129 } 130 131 int 132 execv(name, argv) 133 const char *name; 134 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 const char *path; 144 145 /* Get the path we're searching. */ 146 if ((path = getenv("PATH")) == NULL) 147 path = _PATH_DEFPATH; 148 149 return (execvP(name, path, argv)); 150 } 151 152 int 153 execvP(name, path, argv) 154 const char *name; 155 const char *path; 156 char * const *argv; 157 { 158 char **memp; 159 int cnt, lp, ln; 160 char *p; 161 int eacces, save_errno; 162 char *bp, *cur, buf[MAXPATHLEN]; 163 struct stat sb; 164 165 eacces = 0; 166 167 /* If it's an absolute or relative path name, it's easy. */ 168 if (index(name, '/')) { 169 bp = (char *)name; 170 cur = NULL; 171 goto retry; 172 } 173 bp = buf; 174 175 /* If it's an empty path name, fail in the usual POSIX way. */ 176 if (*name == '\0') { 177 errno = ENOENT; 178 return (-1); 179 } 180 181 cur = alloca(strlen(path) + 1); 182 if (cur == NULL) { 183 errno = ENOMEM; 184 return (-1); 185 } 186 strcpy(cur, path); 187 while ((p = strsep(&cur, ":")) != NULL) { 188 /* 189 * It's a SHELL path -- double, leading and trailing colons 190 * mean the current directory. 191 */ 192 if (*p == '\0') { 193 p = "."; 194 lp = 1; 195 } else 196 lp = strlen(p); 197 ln = strlen(name); 198 199 /* 200 * If the path is too long complain. This is a possible 201 * security issue; given a way to make the path too long 202 * the user may execute the wrong program. 203 */ 204 if (lp + ln + 2 > sizeof(buf)) { 205 (void)_write(STDERR_FILENO, "execvP: ", 8); 206 (void)_write(STDERR_FILENO, p, lp); 207 (void)_write(STDERR_FILENO, ": path too long\n", 208 16); 209 continue; 210 } 211 bcopy(p, buf, lp); 212 buf[lp] = '/'; 213 bcopy(name, buf + lp + 1, ln); 214 buf[lp + ln + 1] = '\0'; 215 216 retry: (void)_execve(bp, argv, environ); 217 switch (errno) { 218 case E2BIG: 219 goto done; 220 case ELOOP: 221 case ENAMETOOLONG: 222 case ENOENT: 223 break; 224 case ENOEXEC: 225 for (cnt = 0; argv[cnt]; ++cnt) 226 ; 227 memp = alloca((cnt + 2) * sizeof(char *)); 228 if (memp == NULL) { 229 /* errno = ENOMEM; XXX override ENOEXEC? */ 230 goto done; 231 } 232 memp[0] = "sh"; 233 memp[1] = bp; 234 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 235 (void)_execve(_PATH_BSHELL, memp, environ); 236 goto done; 237 case ENOMEM: 238 goto done; 239 case ENOTDIR: 240 break; 241 case ETXTBSY: 242 /* 243 * We used to retry here, but sh(1) doesn't. 244 */ 245 goto done; 246 default: 247 /* 248 * EACCES may be for an inaccessible directory or 249 * a non-executable file. Call stat() to decide 250 * which. This also handles ambiguities for EFAULT 251 * and EIO, and undocumented errors like ESTALE. 252 * We hope that the race for a stat() is unimportant. 253 */ 254 save_errno = errno; 255 if (stat(bp, &sb) != 0) 256 break; 257 if (save_errno == EACCES) { 258 eacces = 1; 259 continue; 260 } 261 errno = save_errno; 262 goto done; 263 } 264 } 265 if (eacces) 266 errno = EACCES; 267 else 268 errno = ENOENT; 269 done: 270 return (-1); 271 } 272