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 3297 2016-01-09 15:26:34Z 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 size_t file_size, n; 51 int buf_mmapped; 52 struct stat sb; 53 char *b, *buf; 54 ssize_t nr, nw; 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 file_size = (size_t) sb.st_size; 67 68 #if ELFTC_HAVE_MMAP 69 /* 70 * Prefer mmap() if it is available. 71 */ 72 buf = mmap(NULL, file_size, PROT_READ, MAP_SHARED, ifd, (off_t) 0); 73 if (buf != MAP_FAILED) 74 buf_mmapped = 1; 75 else 76 buf = NULL; 77 #endif 78 79 /* 80 * If mmap() is not available, or if the mmap() operation 81 * failed, allocate a buffer, and read in input data. 82 */ 83 if (buf_mmapped == false) { 84 if ((buf = malloc(file_size)) == NULL) 85 return (-1); 86 b = buf; 87 for (n = file_size; n > 0; n -= (size_t) nr, b += nr) { 88 if ((nr = read(ifd, b, n)) < 0) { 89 free(buf); 90 return (-1); 91 } 92 } 93 } 94 95 /* 96 * Write data to the output file descriptor. 97 */ 98 for (n = file_size, b = buf; n > 0; n -= (size_t) nw, b += nw) 99 if ((nw = write(ofd, b, n)) <= 0) 100 break; 101 102 /* Release the input buffer. */ 103 #if ELFTC_HAVE_MMAP 104 if (buf_mmapped && munmap(buf, file_size) < 0) 105 return (-1); 106 #endif 107 108 if (!buf_mmapped) 109 free(buf); 110 111 return (n > 0 ? -1 : 0); 112 } 113 114