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 1.4 2004/07/27 07:59:10 asmodai 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 <sys/param.h> 41 #include <sys/types.h> 42 #include <sys/stat.h> 43 #include <errno.h> 44 #include <unistd.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <stdio.h> 48 #include <paths.h> 49 50 #include <stdarg.h> 51 52 extern char **environ; 53 54 int 55 execl(const char *name, const char *arg, ...) 56 { 57 va_list ap; 58 char **argv; 59 int n; 60 61 va_start(ap, arg); 62 n = 1; 63 while (va_arg(ap, char *) != NULL) 64 n++; 65 va_end(ap); 66 argv = alloca((n + 1) * sizeof(*argv)); 67 if (argv == NULL) { 68 errno = ENOMEM; 69 return (-1); 70 } 71 va_start(ap, arg); 72 n = 1; 73 argv[0] = (char *)arg; 74 while ((argv[n] = va_arg(ap, char *)) != NULL) 75 n++; 76 va_end(ap); 77 return (execve(name, argv, environ)); 78 } 79 80 int 81 execle(const char *name, const char *arg, ...) 82 { 83 va_list ap; 84 char **argv, **envp; 85 int n; 86 87 va_start(ap, arg); 88 n = 1; 89 while (va_arg(ap, char *) != NULL) 90 n++; 91 va_end(ap); 92 argv = alloca((n + 1) * sizeof(*argv)); 93 if (argv == NULL) { 94 errno = ENOMEM; 95 return (-1); 96 } 97 va_start(ap, arg); 98 n = 1; 99 argv[0] = (char *)arg; 100 while ((argv[n] = va_arg(ap, char *)) != NULL) 101 n++; 102 envp = va_arg(ap, char **); 103 va_end(ap); 104 return (execve(name, argv, envp)); 105 } 106 107 int 108 execlp(const char *name, const char *arg, ...) 109 { 110 va_list ap; 111 int sverrno; 112 char **argv; 113 int n; 114 115 va_start(ap, arg); 116 n = 1; 117 while (va_arg(ap, char *) != NULL) 118 n++; 119 va_end(ap); 120 argv = alloca((n + 1) * sizeof(*argv)); 121 if (argv == NULL) { 122 errno = ENOMEM; 123 return (-1); 124 } 125 va_start(ap, arg); 126 n = 1; 127 argv[0] = (char *)arg; 128 while ((argv[n] = va_arg(ap, char *)) != NULL) 129 n++; 130 va_end(ap); 131 return (execvp(name, argv)); 132 } 133 134 int 135 execv(name, argv) 136 const char *name; 137 char * const *argv; 138 { 139 (void)execve(name, argv, environ); 140 return (-1); 141 } 142 143 int 144 execvp(name, argv) 145 const char *name; 146 char * const *argv; 147 { 148 char **memp; 149 int cnt, lp, ln; 150 char *p; 151 int eacces, save_errno; 152 char *bp, *cur, *path, 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 = (char *)name; 160 cur = path = NULL; 161 goto retry; 162 } 163 bp = buf; 164 165 /* If it's an empty path name, fail in the usual POSIX way. */ 166 if (*name == '\0') { 167 errno = ENOENT; 168 return (-1); 169 } 170 171 /* Get the path we're searching. */ 172 if (!(path = getenv("PATH"))) 173 path = _PATH_DEFPATH; 174 cur = alloca(strlen(path) + 1); 175 if (cur == NULL) { 176 errno = ENOMEM; 177 return (-1); 178 } 179 strcpy(cur, path); 180 path = cur; 181 while ( (p = strsep(&cur, ":")) ) { 182 /* 183 * It's a SHELL path -- double, leading and trailing colons 184 * mean the current directory. 185 */ 186 if (!*p) { 187 p = "."; 188 lp = 1; 189 } else 190 lp = strlen(p); 191 ln = strlen(name); 192 193 /* 194 * If the path is too long complain. This is a possible 195 * security issue; given a way to make the path too long 196 * the user may execute the wrong program. 197 */ 198 if (lp + ln + 2 > sizeof(buf)) { 199 (void)_write(STDERR_FILENO, "execvp: ", 8); 200 (void)_write(STDERR_FILENO, p, lp); 201 (void)_write(STDERR_FILENO, ": path too long\n", 202 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: (void)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 (void)execve(_PATH_BSHELL, 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