1 /* $OpenBSD: isexec.c,v 1.9 2014/07/05 05:31:35 guenther Exp $ */ 2 3 /* 4 * Copyright (c) 1983 Regents of the University of California. 5 * 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include "defs.h" 33 34 #include <elf_abi.h> 35 36 /* 37 * Determine whether 'file' is a binary executable or not. 38 */ 39 int 40 isexec(char *file, struct stat *statp) 41 { 42 Elf32_Ehdr hdr; 43 int fd, r; 44 45 /* 46 * Must be a regular file that has some executable mode bit on 47 */ 48 if (!S_ISREG(statp->st_mode) || 49 !(statp->st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))) 50 return(FALSE); 51 52 if ((fd = open(file, O_RDONLY, 0)) < 0) 53 return(FALSE); 54 55 r = read(fd, &hdr, sizeof(hdr)) == sizeof(hdr) && 56 IS_ELF(hdr) && hdr.e_type == ET_EXEC; 57 close(fd); 58 59 return (r); 60 } 61