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. 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 * @(#)exec.c 8.1 (Berkeley) 6/4/93 30 * $FreeBSD: src/lib/libc/gen/exec.c,v 1.25 2008/06/23 05:22:06 ed Exp $ 31 */ 32 33 #include "namespace.h" 34 #include <sys/param.h> 35 #include <sys/types.h> 36 #include <sys/stat.h> 37 #include <errno.h> 38 #include <unistd.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <stdio.h> 42 #include <paths.h> 43 44 #include <stdarg.h> 45 #include "un-namespace.h" 46 #include "libc_private.h" 47 48 extern char **environ; 49 50 int 51 execl(const char *name, const char *arg, ...) 52 { 53 va_list ap; 54 const char **argv; 55 int n; 56 57 va_start(ap, arg); 58 n = 1; 59 while (va_arg(ap, char *) != NULL) 60 n++; 61 va_end(ap); 62 argv = alloca((n + 1) * sizeof(*argv)); 63 if (argv == NULL) { 64 errno = ENOMEM; 65 return (-1); 66 } 67 va_start(ap, arg); 68 n = 1; 69 argv[0] = arg; 70 while ((argv[n] = va_arg(ap, const char *)) != NULL) 71 n++; 72 va_end(ap); 73 return (_execve(name, __DECONST(char **, argv), 74 __DECONST(char **, environ))); 75 } 76 77 int 78 execle(const char *name, const char *arg, ...) 79 { 80 va_list ap; 81 const char **argv, **envp; 82 int n; 83 84 va_start(ap, arg); 85 n = 1; 86 while (va_arg(ap, char *) != NULL) 87 n++; 88 va_end(ap); 89 argv = alloca((n + 1) * sizeof(*argv)); 90 if (argv == NULL) { 91 errno = ENOMEM; 92 return (-1); 93 } 94 va_start(ap, arg); 95 n = 1; 96 argv[0] = arg; 97 while ((argv[n] = va_arg(ap, const char *)) != NULL) 98 n++; 99 envp = va_arg(ap, const char **); 100 va_end(ap); 101 return (_execve(name, __DECONST(char **, argv), 102 __DECONST(char **, envp))); 103 } 104 105 int 106 execlp(const char *name, const char *arg, ...) 107 { 108 va_list ap; 109 const 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] = arg; 125 while ((argv[n] = va_arg(ap, const char *)) != NULL) 126 n++; 127 va_end(ap); 128 return (execvp(name, __DECONST(char **, argv))); 129 } 130 131 int 132 execv(const char *name, char * const *argv) 133 { 134 _execve(name, argv, environ); 135 return (-1); 136 } 137 138 int 139 execvp(const char *name, char * const *argv) 140 { 141 return (_execvpe(name, argv, environ)); 142 } 143 144 static int 145 execvPe(const char *name, const char *path, char * const *argv, 146 char * const *envp) 147 { 148 const char **memp; 149 int cnt; 150 size_t lp, ln; 151 int eacces, save_errno; 152 const char *bp, *p; 153 char *cur, 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 (strchr(name, '/')) { 160 bp = name; 161 cur = 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 cur = alloca(strlen(path) + 1); 173 if (cur == NULL) { 174 errno = ENOMEM; 175 return (-1); 176 } 177 strcpy(cur, path); 178 while ((p = strsep(&cur, ":")) != NULL) { 179 /* 180 * It's a SHELL path -- double, leading and trailing colons 181 * mean the current directory. 182 */ 183 if (*p == '\0') { 184 p = "."; 185 lp = 1; 186 } else 187 lp = strlen(p); 188 ln = strlen(name); 189 190 /* 191 * If the path is too long complain. This is a possible 192 * security issue; given a way to make the path too long 193 * the user may execute the wrong program. 194 */ 195 if (lp + ln + 2 > sizeof(buf)) { 196 _write(STDERR_FILENO, "execvP: ", 8); 197 _write(STDERR_FILENO, p, lp); 198 _write(STDERR_FILENO, ": path too long\n", 16); 199 continue; 200 } 201 bcopy(p, buf, lp); 202 buf[lp] = '/'; 203 bcopy(name, buf + lp + 1, ln); 204 buf[lp + ln + 1] = '\0'; 205 retry: 206 _execve(bp, argv, envp); 207 switch (errno) { 208 case E2BIG: 209 goto done; 210 case ELOOP: 211 case ENAMETOOLONG: 212 case ENOENT: 213 break; 214 case ENOEXEC: 215 for (cnt = 0; argv[cnt]; ++cnt) 216 ; 217 memp = alloca((cnt + 2) * sizeof(char *)); 218 if (memp == NULL) { 219 /* errno = ENOMEM; XXX override ENOEXEC? */ 220 goto done; 221 } 222 memp[0] = "sh"; 223 memp[1] = bp; 224 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 225 _execve(_PATH_BSHELL, __DECONST(char **, memp), envp); 226 goto done; 227 case ENOMEM: 228 goto done; 229 case ENOTDIR: 230 break; 231 case ETXTBSY: 232 /* 233 * We used to retry here, but sh(1) doesn't. 234 */ 235 goto done; 236 default: 237 /* 238 * EACCES may be for an inaccessible directory or 239 * a non-executable file. Call stat() to decide 240 * which. This also handles ambiguities for EFAULT 241 * and EIO, and undocumented errors like ESTALE. 242 * We hope that the race for a stat() is unimportant. 243 */ 244 save_errno = errno; 245 if (stat(bp, &sb) != 0) 246 break; 247 if (save_errno == EACCES) { 248 eacces = 1; 249 continue; 250 } 251 errno = save_errno; 252 goto done; 253 } 254 } 255 if (eacces) 256 errno = EACCES; 257 else 258 errno = ENOENT; 259 done: 260 return (-1); 261 } 262 263 int 264 execvP(const char *name, const char *path, char * const argv[]) 265 { 266 return execvPe(name, path, argv, environ); 267 } 268 269 int 270 _execvpe(const char *name, char * const argv[], char * const envp[]) 271 { 272 const char *path; 273 274 /* Get the path we're searching. */ 275 if ((path = getenv("PATH")) == NULL) 276 path = _PATH_DEFPATH; 277 278 return (execvPe(name, path, argv, envp)); 279 } 280