1/*
2 * Copyright (C) 2008 The Android Open Source Project
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 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#undef _FORTIFY_SOURCE
30
31#include <errno.h>
32#include <fcntl.h>
33#include <stdarg.h>
34#include <sys/resource.h>
35#include <sys/types.h>
36#include <sys/vfs.h>
37#include <unistd.h>
38
39#if __LP64__
40#error This code is only needed on 32-bit systems!
41#endif
42
43// System calls we need.
44extern "C" int __fcntl64(int, int, void*);
45extern "C" int __llseek(int, unsigned long, unsigned long, off64_t*, int);
46
47// For fcntl we use the fcntl64 system call to signal that we're using struct flock64.
48int fcntl(int fd, int cmd, ...) {
49  va_list ap;
50
51  va_start(ap, cmd);
52  void* arg = va_arg(ap, void*);
53  va_end(ap);
54
55  return __fcntl64(fd, cmd, arg);
56}
57
58// For lseek64 we need to use the llseek system call which splits the off64_t in two and
59// returns the off64_t result via a pointer because 32-bit kernels can't return 64-bit results.
60off64_t lseek64(int fd, off64_t off, int whence) {
61  off64_t result;
62  unsigned long off_hi = static_cast<unsigned long>(off >> 32);
63  unsigned long off_lo = static_cast<unsigned long>(off);
64  if (__llseek(fd, off_hi, off_lo, &result, whence) < 0) {
65    return -1;
66  }
67  return result;
68}
69
70// There is no pread for 32-bit off_t, so we need to widen and call pread64.
71ssize_t pread(int fd, void* buf, size_t byte_count, off_t offset) {
72  return pread64(fd, buf, byte_count, static_cast<off64_t>(offset));
73}
74
75// There is no pwrite for 32-bit off_t, so we need to widen and call pwrite64.
76ssize_t pwrite(int fd, const void* buf, size_t byte_count, off_t offset) {
77  return pwrite64(fd, buf, byte_count, static_cast<off64_t>(offset));
78}
79
80// There is no fallocate for 32-bit off_t, so we need to widen and call fallocate64.
81int fallocate(int fd, int mode, off_t offset, off_t length) {
82  return fallocate64(fd, mode, static_cast<off64_t>(offset), static_cast<off64_t>(length));
83}
84
85// There is no getrlimit64 system call, so we need to use prlimit64.
86int getrlimit64(int resource, rlimit64* limits64) {
87  return prlimit64(0, resource, NULL, limits64);
88}
89
90// There is no setrlimit64 system call, so we need to use prlimit64.
91int setrlimit64(int resource, const rlimit64* limits64) {
92  return prlimit64(0, resource, limits64, NULL);
93}
94