1 /*- 2 * Copyright (c) 2011, Joseph Koshy 3 * 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 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/types.h> 28 #include <sys/stat.h> 29 30 #include <stdlib.h> 31 #include <unistd.h> 32 33 #include "libelftc.h" 34 #include "_libelftc.h" 35 36 #if ELFTC_HAVE_MMAP 37 #include <sys/mman.h> 38 #endif 39 40 ELFTC_VCSID("$Id: elftc_copyfile.c 2981 2014-02-01 02:41:13Z jkoshy $"); 41 42 /* 43 * Copy the contents referenced by 'ifd' to 'ofd'. Returns 0 on 44 * success and -1 on error. 45 */ 46 47 int 48 elftc_copyfile(int ifd, int ofd) 49 { 50 int buf_mmapped; 51 struct stat sb; 52 char *b, *buf; 53 ssize_t nw; 54 size_t n; 55 56 /* Determine the input file's size. */ 57 if (fstat(ifd, &sb) < 0) 58 return (-1); 59 60 /* Skip files without content. */ 61 if (sb.st_size == 0) 62 return (0); 63 64 buf = NULL; 65 buf_mmapped = 0; 66 67 #if ELFTC_HAVE_MMAP 68 /* 69 * Prefer mmap() if it is available. 70 */ 71 buf = mmap(NULL, sb.st_size, PROT_READ, MAP_SHARED, ifd, (off_t) 0); 72 if (buf != MAP_FAILED) 73 buf_mmapped = 1; 74 else 75 buf = NULL; 76 #endif 77 78 /* 79 * If mmap() is not available, or if the mmap() operation 80 * failed, allocate a buffer, and read in input data. 81 */ 82 if (buf_mmapped == false) { 83 if ((buf = malloc(sb.st_size)) == NULL) 84 return (-1); 85 if (read(ifd, buf, sb.st_size) != sb.st_size) { 86 free(buf); 87 return (-1); 88 } 89 } 90 91 /* 92 * Write data to the output file descriptor. 93 */ 94 for (n = sb.st_size, b = buf; n > 0; n -= nw, b += nw) 95 if ((nw = write(ofd, b, n)) <= 0) 96 break; 97 98 /* Release the input buffer. */ 99 #if ELFTC_HAVE_MMAP 100 if (buf_mmapped && munmap(buf, sb.st_size) < 0) 101 return (-1); 102 #endif 103 104 if (!buf_mmapped) 105 free(buf); 106 107 return (n > 0 ? -1 : 0); 108 } 109 110