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
40ELFTC_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
47int
48elftc_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