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 * $FreeBSD: src/lib/libc/gen/exec.c,v 1.15 2000/01/27 23:06:14 jasone Exp $ 34 * $DragonFly: src/lib/libc/gen/exec.c,v 1.7 2005/11/13 00:07:42 swildner Exp $ 35 * 36 * @(#)exec.c 8.1 (Berkeley) 6/4/93 37 * $FreeBSD: src/lib/libc/gen/exec.c,v 1.15 2000/01/27 23:06:14 jasone Exp $ 38 */ 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 #include "un-namespace.h" 51 52 #include <stdarg.h> 53 54 extern char **environ; 55 56 int 57 execl(const char *name, const char *arg, ...) 58 { 59 va_list ap; 60 const 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] = arg; 76 while ((argv[n] = va_arg(ap, const char *)) != NULL) 77 n++; 78 va_end(ap); 79 return (_execve(name, __DECONST(char **, argv), 80 __DECONST(char **, environ))); 81 } 82 83 int 84 execle(const char *name, const char *arg, ...) 85 { 86 va_list ap; 87 const char **argv, **envp; 88 int n; 89 90 va_start(ap, arg); 91 n = 1; 92 while (va_arg(ap, char *) != NULL) 93 n++; 94 va_end(ap); 95 argv = alloca((n + 1) * sizeof(*argv)); 96 if (argv == NULL) { 97 errno = ENOMEM; 98 return (-1); 99 } 100 va_start(ap, arg); 101 n = 1; 102 argv[0] = arg; 103 while ((argv[n] = va_arg(ap, const char *)) != NULL) 104 n++; 105 envp = va_arg(ap, const char **); 106 va_end(ap); 107 return (_execve(name, __DECONST(char **, argv), 108 __DECONST(char **, envp))); 109 } 110 111 int 112 execlp(const char *name, const char *arg, ...) 113 { 114 va_list ap; 115 const char **argv; 116 int n; 117 118 va_start(ap, arg); 119 n = 1; 120 while (va_arg(ap, char *) != NULL) 121 n++; 122 va_end(ap); 123 argv = alloca((n + 1) * sizeof(*argv)); 124 if (argv == NULL) { 125 errno = ENOMEM; 126 return (-1); 127 } 128 va_start(ap, arg); 129 n = 1; 130 argv[0] = arg; 131 while ((argv[n] = va_arg(ap, const char *)) != NULL) 132 n++; 133 va_end(ap); 134 return (execvp(name, __DECONST(char **, argv))); 135 } 136 137 int 138 execv(const char *name, char * const *argv) 139 { 140 _execve(name, argv, environ); 141 return (-1); 142 } 143 144 int 145 execvp(const char *name, char * const *argv) 146 { 147 const char **memp; 148 int cnt; 149 size_t lp, ln; 150 int eacces, save_errno; 151 const char *bp, *p, *path; 152 char *cur, buf[MAXPATHLEN]; 153 struct stat sb; 154 155 eacces = 0; 156 157 /* If it's an absolute or relative path name, it's easy. */ 158 if (index(name, '/')) { 159 bp = name; 160 cur = NULL; 161 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 _write(STDERR_FILENO, "execvp: ", 8); 201 _write(STDERR_FILENO, p, lp); 202 _write(STDERR_FILENO, ": path too long\n", 16); 203 continue; 204 } 205 bcopy(p, buf, lp); 206 buf[lp] = '/'; 207 bcopy(name, buf + lp + 1, ln); 208 buf[lp + ln + 1] = '\0'; 209 210 retry: _execve(bp, argv, environ); 211 switch(errno) { 212 case E2BIG: 213 goto done; 214 case ELOOP: 215 case ENAMETOOLONG: 216 case ENOENT: 217 break; 218 case ENOEXEC: 219 for (cnt = 0; argv[cnt]; ++cnt) 220 ; 221 memp = alloca((cnt + 2) * sizeof(char *)); 222 if (memp == NULL) { 223 /* errno = ENOMEM; XXX override ENOEXEC? */ 224 goto done; 225 } 226 memp[0] = "sh"; 227 memp[1] = bp; 228 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 229 _execve(_PATH_BSHELL, __DECONST(char **, memp), environ); 230 goto done; 231 case ENOMEM: 232 goto done; 233 case ENOTDIR: 234 break; 235 case ETXTBSY: 236 /* 237 * We used to retry here, but sh(1) doesn't. 238 */ 239 goto done; 240 default: 241 /* 242 * EACCES may be for an inaccessible directory or 243 * a non-executable file. Call stat() to decide 244 * which. This also handles ambiguities for EFAULT 245 * and EIO, and undocumented errors like ESTALE. 246 * We hope that the race for a stat() is unimportant. 247 */ 248 save_errno = errno; 249 if (stat(bp, &sb) != 0) 250 break; 251 if (save_errno == EACCES) { 252 eacces = 1; 253 continue; 254 } 255 errno = save_errno; 256 goto done; 257 } 258 } 259 if (eacces) 260 errno = EACCES; 261 else 262 errno = ENOENT; 263 done: 264 return (-1); 265 } 266