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 * @(#)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 * $DragonFly: src/lib/libc/gen/exec.c,v 1.7 2005/11/13 00:07:42 swildner Exp $ 32 */ 33 34 #include "namespace.h" 35 #include <sys/param.h> 36 #include <sys/types.h> 37 #include <sys/stat.h> 38 #include <errno.h> 39 #include <unistd.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <stdio.h> 43 #include <paths.h> 44 45 #include <stdarg.h> 46 #include "un-namespace.h" 47 #include "libc_private.h" 48 49 extern char **environ; 50 51 int 52 execl(const char *name, const char *arg, ...) 53 { 54 va_list ap; 55 const char **argv; 56 int n; 57 58 va_start(ap, arg); 59 n = 1; 60 while (va_arg(ap, char *) != NULL) 61 n++; 62 va_end(ap); 63 argv = alloca((n + 1) * sizeof(*argv)); 64 if (argv == NULL) { 65 errno = ENOMEM; 66 return (-1); 67 } 68 va_start(ap, arg); 69 n = 1; 70 argv[0] = arg; 71 while ((argv[n] = va_arg(ap, const char *)) != NULL) 72 n++; 73 va_end(ap); 74 return (_execve(name, __DECONST(char **, argv), 75 __DECONST(char **, environ))); 76 } 77 78 int 79 execle(const char *name, const char *arg, ...) 80 { 81 va_list ap; 82 const 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] = arg; 98 while ((argv[n] = va_arg(ap, const char *)) != NULL) 99 n++; 100 envp = va_arg(ap, const char **); 101 va_end(ap); 102 return (_execve(name, __DECONST(char **, argv), 103 __DECONST(char **, envp))); 104 } 105 106 int 107 execlp(const char *name, const char *arg, ...) 108 { 109 va_list ap; 110 const char **argv; 111 int n; 112 113 va_start(ap, arg); 114 n = 1; 115 while (va_arg(ap, char *) != NULL) 116 n++; 117 va_end(ap); 118 argv = alloca((n + 1) * sizeof(*argv)); 119 if (argv == NULL) { 120 errno = ENOMEM; 121 return (-1); 122 } 123 va_start(ap, arg); 124 n = 1; 125 argv[0] = arg; 126 while ((argv[n] = va_arg(ap, const char *)) != NULL) 127 n++; 128 va_end(ap); 129 return (execvp(name, __DECONST(char **, argv))); 130 } 131 132 int 133 execv(const char *name, char * const *argv) 134 { 135 _execve(name, argv, environ); 136 return (-1); 137 } 138 139 int 140 execvp(const char *name, char * const *argv) 141 { 142 return (_execvpe(name, argv, environ)); 143 } 144 145 static int 146 execvPe(const char *name, const char *path, char * const *argv, 147 char * const *envp) 148 { 149 const char **memp; 150 int cnt; 151 size_t lp, ln; 152 int eacces, save_errno; 153 const char *bp, *p; 154 char *cur, buf[MAXPATHLEN]; 155 struct stat sb; 156 157 eacces = 0; 158 159 /* If it's an absolute or relative path name, it's easy. */ 160 if (index(name, '/')) { 161 bp = name; 162 cur = NULL; 163 goto retry; 164 } 165 bp = buf; 166 167 /* If it's an empty path name, fail in the usual POSIX way. */ 168 if (*name == '\0') { 169 errno = ENOENT; 170 return (-1); 171 } 172 173 cur = alloca(strlen(path) + 1); 174 if (cur == NULL) { 175 errno = ENOMEM; 176 return (-1); 177 } 178 strcpy(cur, path); 179 while ((p = strsep(&cur, ":")) != NULL) { 180 /* 181 * It's a SHELL path -- double, leading and trailing colons 182 * mean the current directory. 183 */ 184 if (*p == '\0') { 185 p = "."; 186 lp = 1; 187 } else 188 lp = strlen(p); 189 ln = strlen(name); 190 191 /* 192 * If the path is too long complain. This is a possible 193 * security issue; given a way to make the path too long 194 * the user may execute the wrong program. 195 */ 196 if (lp + ln + 2 > sizeof(buf)) { 197 _write(STDERR_FILENO, "execvP: ", 8); 198 _write(STDERR_FILENO, p, lp); 199 _write(STDERR_FILENO, ": path too long\n", 16); 200 continue; 201 } 202 bcopy(p, buf, lp); 203 buf[lp] = '/'; 204 bcopy(name, buf + lp + 1, ln); 205 buf[lp + ln + 1] = '\0'; 206 retry: 207 _execve(bp, argv, environ); 208 switch (errno) { 209 case E2BIG: 210 goto done; 211 case ELOOP: 212 case ENAMETOOLONG: 213 case ENOENT: 214 break; 215 case ENOEXEC: 216 for (cnt = 0; argv[cnt]; ++cnt) 217 ; 218 memp = alloca((cnt + 2) * sizeof(char *)); 219 if (memp == NULL) { 220 /* errno = ENOMEM; XXX override ENOEXEC? */ 221 goto done; 222 } 223 memp[0] = "sh"; 224 memp[1] = bp; 225 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 226 _execve(_PATH_BSHELL, __DECONST(char **, memp), environ); 227 goto done; 228 case ENOMEM: 229 goto done; 230 case ENOTDIR: 231 break; 232 case ETXTBSY: 233 /* 234 * We used to retry here, but sh(1) doesn't. 235 */ 236 goto done; 237 default: 238 /* 239 * EACCES may be for an inaccessible directory or 240 * a non-executable file. Call stat() to decide 241 * which. This also handles ambiguities for EFAULT 242 * and EIO, and undocumented errors like ESTALE. 243 * We hope that the race for a stat() is unimportant. 244 */ 245 save_errno = errno; 246 if (stat(bp, &sb) != 0) 247 break; 248 if (save_errno == EACCES) { 249 eacces = 1; 250 continue; 251 } 252 errno = save_errno; 253 goto done; 254 } 255 } 256 if (eacces) 257 errno = EACCES; 258 else 259 errno = ENOENT; 260 done: 261 return (-1); 262 } 263 264 int 265 execvP(const char *name, const char *path, char * const argv[]) 266 { 267 return execvPe(name, path, argv, environ); 268 } 269 270 int 271 _execvpe(const char *name, char * const argv[], char * const envp[]) 272 { 273 const char *path; 274 275 /* Get the path we're searching. */ 276 if ((path = getenv("PATH")) == NULL) 277 path = _PATH_DEFPATH; 278 279 return (execvPe(name, path, argv, envp)); 280 } 281