1 /*
2  * Copyright (C) 2013 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 #include <fcntl.h>
30 #include <unistd.h>
31 
32 #include "private/bionic_fdtrack.h"
33 
34 extern "C" int __dup(int old_fd);
35 extern "C" int __dup3(int old_fd, int new_fd, int flags);
36 
dup(int old_fd)37 int dup(int old_fd) {
38   return FDTRACK_CREATE(__dup(old_fd));
39 }
40 
dup2(int old_fd,int new_fd)41 int dup2(int old_fd, int new_fd) {
42   // If old_fd is equal to new_fd and a valid file descriptor, dup2 returns
43   // old_fd without closing it. This is not true of dup3, so we have to
44   // handle this case ourselves.
45   if (old_fd == new_fd) {
46     if (fcntl(old_fd, F_GETFD) == -1) {
47       return -1;
48     }
49     return old_fd;
50   }
51 
52   return FDTRACK_CREATE(__dup3(old_fd, new_fd, 0));
53 }
54 
dup3(int old_fd,int new_fd,int flags)55 int dup3(int old_fd, int new_fd, int flags) {
56   return FDTRACK_CREATE(__dup3(old_fd, new_fd, flags));
57 }
58