1 /*
2  * Copyright (C) 2019 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 #pragma once
30 
31 #include <sys/cdefs.h>
32 #include <stdatomic.h>
33 
34 #include "platform/bionic/fdtrack.h"
35 
36 #include "bionic/pthread_internal.h"
37 #include "private/bionic_tls.h"
38 #include "private/ErrnoRestorer.h"
39 
40 extern "C" _Atomic(android_fdtrack_hook_t) __android_fdtrack_hook;
41 
42 // Macro to record file descriptor creation.
43 // e.g.:
44 //   int socket(int domain, int type, int protocol) {
45 //     return FDTRACK_CREATE_NAME("socket", __socket(domain, type, protocol));
46 //   }
47 #define FDTRACK_CREATE_NAME(name, fd_value)                       \
48   ({                                                              \
49     int __fd = (fd_value);                                        \
50     if (__fd != -1 && __predict_false(__android_fdtrack_hook) &&  \
51         !__predict_false(__get_thread()->is_vforked())) {         \
52       bionic_tls& tls = __get_bionic_tls();                       \
53       /* fdtrack_disabled is only true during reentrant calls. */ \
54       if (!__predict_false(tls.fdtrack_disabled)) {               \
55         ErrnoRestorer r;                                          \
56         tls.fdtrack_disabled = true;                              \
57         android_fdtrack_event event;                              \
58         event.fd = __fd;                                          \
59         event.type = ANDROID_FDTRACK_EVENT_TYPE_CREATE;           \
60         event.data.create.function_name = name;                   \
61         __android_fdtrack_hook(&event);                           \
62         tls.fdtrack_disabled = false;                             \
63       }                                                           \
64     }                                                             \
65     __fd;                                                         \
66   })
67 
68 // Macro to record file descriptor creation, with the current function's name.
69 // e.g.:
70 //   int socket(int domain, int type, int protocol) {
71 //     return FDTRACK_CREATE_NAME(__socket(domain, type, protocol));
72 //   }
73 #define FDTRACK_CREATE(fd_value) FDTRACK_CREATE_NAME(__func__, (fd_value))
74 
75 // Macro to record file descriptor closure.
76 // Note that this does not actually close the file descriptor.
77 #define FDTRACK_CLOSE(fd_value)                                  \
78   ({                                                             \
79     int __fd = (fd_value);                                       \
80     if (__fd != -1 && __predict_false(__android_fdtrack_hook) && \
81         !__predict_false(__get_thread()->is_vforked())) {        \
82       bionic_tls& tls = __get_bionic_tls();                      \
83       if (!__predict_false(tls.fdtrack_disabled)) {              \
84         int saved_errno = errno;                                 \
85         tls.fdtrack_disabled = true;                             \
86         android_fdtrack_event event;                             \
87         event.fd = __fd;                                         \
88         event.type = ANDROID_FDTRACK_EVENT_TYPE_CLOSE;           \
89         __android_fdtrack_hook(&event);                          \
90         tls.fdtrack_disabled = false;                            \
91         errno = saved_errno;                                     \
92       }                                                          \
93     }                                                            \
94     __fd;                                                        \
95   })
96