1 /* $NetBSD: execvp.c,v 1.1 1996/07/03 21:41:54 jtc Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)exec.c 8.1 (Berkeley) 6/4/93"; 39 #else 40 static char rcsid[] = "$NetBSD: execvp.c,v 1.1 1996/07/03 21:41:54 jtc Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <errno.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <limits.h> 49 #include <unistd.h> 50 #include <paths.h> 51 52 extern char **environ; 53 54 int 55 execvp(name, argv) 56 const char *name; 57 char * const *argv; 58 { 59 static int memsize; 60 static char **memp; 61 register int cnt, lp, ln; 62 register char *p; 63 int eacces = 0, etxtbsy = 0; 64 char *bp, *cur, *path, buf[PATH_MAX]; 65 66 /* If it's an absolute or relative path name, it's easy. */ 67 if (strchr(name, '/')) { 68 bp = (char *)name; 69 cur = path = NULL; 70 goto retry; 71 } 72 bp = buf; 73 74 /* Get the path we're searching. */ 75 if (!(path = getenv("PATH"))) 76 path = _PATH_DEFPATH; 77 cur = path = strdup(path); 78 79 while (p = strsep(&cur, ":")) { 80 /* 81 * It's a SHELL path -- double, leading and trailing colons 82 * mean the current directory. 83 */ 84 if (!*p) { 85 p = "."; 86 lp = 1; 87 } else 88 lp = strlen(p); 89 ln = strlen(name); 90 91 /* 92 * If the path is too long complain. This is a possible 93 * security issue; given a way to make the path too long 94 * the user may execute the wrong program. 95 */ 96 if (lp + ln + 2 > sizeof(buf)) { 97 (void)write(STDERR_FILENO, "execvp: ", 8); 98 (void)write(STDERR_FILENO, p, lp); 99 (void)write(STDERR_FILENO, ": path too long\n", 16); 100 continue; 101 } 102 bcopy(p, buf, lp); 103 buf[lp] = '/'; 104 bcopy(name, buf + lp + 1, ln); 105 buf[lp + ln + 1] = '\0'; 106 107 retry: (void)execve(bp, argv, environ); 108 switch(errno) { 109 case EACCES: 110 eacces = 1; 111 break; 112 case ENOENT: 113 break; 114 case ENOEXEC: 115 for (cnt = 0; argv[cnt]; ++cnt); 116 if ((cnt + 2) * sizeof(char *) > memsize) { 117 memsize = (cnt + 2) * sizeof(char *); 118 if ((memp = realloc(memp, memsize)) == NULL) { 119 memsize = 0; 120 goto done; 121 } 122 } 123 memp[0] = "sh"; 124 memp[1] = bp; 125 bcopy(argv + 1, memp + 2, cnt * sizeof(char *)); 126 (void)execve(_PATH_BSHELL, memp, environ); 127 goto done; 128 case ETXTBSY: 129 if (etxtbsy < 3) 130 (void)sleep(++etxtbsy); 131 goto retry; 132 default: 133 goto done; 134 } 135 } 136 if (eacces) 137 errno = EACCES; 138 else if (!errno) 139 errno = ENOENT; 140 done: if (path) 141 free(path); 142 return (-1); 143 } 144