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 #include <string.h>
30 #include <sys/socket.h>
31
32 #include <async_safe/log.h>
33
34 #include "private/bionic_fdtrack.h"
35
36 extern "C" ssize_t __recvmsg(int __fd, struct msghdr* __msg, int __flags);
37 extern "C" int __recvmmsg(int __fd, struct mmsghdr* __msgs, unsigned int __msg_count, int __flags,
38 const struct timespec* __timeout);
39
track_fds(struct msghdr * msg,const char * function_name)40 static inline __attribute__((artificial)) __attribute__((always_inline)) void track_fds(
41 struct msghdr* msg, const char* function_name) {
42 if (!atomic_load(&__android_fdtrack_hook)) {
43 return;
44 }
45
46 for (struct cmsghdr* cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
47 if (cmsg->cmsg_type != SCM_RIGHTS) {
48 continue;
49 }
50
51 if (cmsg->cmsg_len <= sizeof(struct cmsghdr)) {
52 continue;
53 }
54
55 size_t data_length = cmsg->cmsg_len - sizeof(struct cmsghdr);
56 if (data_length % sizeof(int) != 0) {
57 async_safe_fatal("invalid cmsg length: %zu", data_length);
58 }
59
60 for (size_t offset = 0; offset < data_length; offset += sizeof(int)) {
61 int fd;
62 memcpy(&fd, CMSG_DATA(cmsg) + offset, sizeof(int));
63 FDTRACK_CREATE_NAME(function_name, fd);
64 }
65 }
66 }
67
recvmsg(int __fd,struct msghdr * __msg,int __flags)68 ssize_t recvmsg(int __fd, struct msghdr* __msg, int __flags) {
69 ssize_t rc = __recvmsg(__fd, __msg, __flags);
70 if (rc == -1) {
71 return -1;
72 }
73 track_fds(__msg, "recvmsg");
74 return rc;
75 }
76
recvmmsg(int __fd,struct mmsghdr * __msgs,unsigned int __msg_count,int __flags,const struct timespec * __timeout)77 int recvmmsg(int __fd, struct mmsghdr* __msgs, unsigned int __msg_count, int __flags,
78 const struct timespec* __timeout) {
79 int rc = __recvmmsg(__fd, __msgs, __msg_count, __flags, __timeout);
80 if (rc == -1) {
81 return -1;
82 }
83 for (int i = 0; i < rc; ++i) {
84 track_fds(&__msgs[i].msg_hdr, "recvmmsg");
85 }
86 return rc;
87 }
88