1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <private/gui/BitTube.h>
18
19 #include <stdint.h>
20 #include <sys/socket.h>
21 #include <sys/types.h>
22
23 #include <fcntl.h>
24 #include <unistd.h>
25
26 #include <utils/Errors.h>
27
28 #include <binder/Parcel.h>
29
30 namespace android {
31 namespace gui {
32
33 // Socket buffer size. The default is typically about 128KB, which is much larger than we really
34 // need. So we make it smaller.
35 static const size_t DEFAULT_SOCKET_BUFFER_SIZE = 4 * 1024;
36
BitTube(size_t bufsize)37 BitTube::BitTube(size_t bufsize) {
38 init(bufsize, bufsize);
39 }
40
BitTube(DefaultSizeType)41 BitTube::BitTube(DefaultSizeType) : BitTube(DEFAULT_SOCKET_BUFFER_SIZE) {}
42
BitTube(const Parcel & data)43 BitTube::BitTube(const Parcel& data) {
44 readFromParcel(&data);
45 }
46
init(size_t rcvbuf,size_t sndbuf)47 void BitTube::init(size_t rcvbuf, size_t sndbuf) {
48 int sockets[2];
49 if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) == 0) {
50 size_t size = DEFAULT_SOCKET_BUFFER_SIZE;
51 setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(rcvbuf));
52 setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &sndbuf, sizeof(sndbuf));
53 // since we don't use the "return channel", we keep it small...
54 setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
55 setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
56 fcntl(sockets[0], F_SETFL, O_NONBLOCK);
57 fcntl(sockets[1], F_SETFL, O_NONBLOCK);
58 mReceiveFd.reset(sockets[0]);
59 mSendFd.reset(sockets[1]);
60 } else {
61 mReceiveFd.reset();
62 ALOGE("BitTube: pipe creation failed (%s)", strerror(errno));
63 }
64 }
65
initCheck() const66 status_t BitTube::initCheck() const {
67 if (mReceiveFd < 0) {
68 return status_t(mReceiveFd);
69 }
70 return NO_ERROR;
71 }
72
getFd() const73 int BitTube::getFd() const {
74 return mReceiveFd;
75 }
76
getSendFd() const77 int BitTube::getSendFd() const {
78 return mSendFd;
79 }
80
moveReceiveFd()81 base::unique_fd BitTube::moveReceiveFd() {
82 return std::move(mReceiveFd);
83 }
84
setReceiveFd(base::unique_fd && receiveFd)85 void BitTube::setReceiveFd(base::unique_fd&& receiveFd) {
86 mReceiveFd = std::move(receiveFd);
87 }
88
setSendFd(base::unique_fd && sendFd)89 void BitTube::setSendFd(base::unique_fd&& sendFd) {
90 mSendFd = std::move(sendFd);
91 }
92
write(void const * vaddr,size_t size)93 ssize_t BitTube::write(void const* vaddr, size_t size) {
94 ssize_t err, len;
95 do {
96 len = ::send(mSendFd, vaddr, size, MSG_DONTWAIT | MSG_NOSIGNAL);
97 // cannot return less than size, since we're using SOCK_SEQPACKET
98 err = len < 0 ? errno : 0;
99 } while (err == EINTR);
100 return err == 0 ? len : -err;
101 }
102
read(void * vaddr,size_t size)103 ssize_t BitTube::read(void* vaddr, size_t size) {
104 ssize_t err, len;
105 do {
106 len = ::recv(mReceiveFd, vaddr, size, MSG_DONTWAIT);
107 err = len < 0 ? errno : 0;
108 } while (err == EINTR);
109 if (err == EAGAIN || err == EWOULDBLOCK) {
110 // EAGAIN means that we have non-blocking I/O but there was no data to be read. Nothing the
111 // client should care about.
112 return 0;
113 }
114 return err == 0 ? len : -err;
115 }
116
writeToParcel(Parcel * reply) const117 status_t BitTube::writeToParcel(Parcel* reply) const {
118 if (mReceiveFd < 0) return -EINVAL;
119
120 status_t result = reply->writeDupFileDescriptor(mReceiveFd);
121 mReceiveFd.reset();
122 if (result != NO_ERROR) {
123 return result;
124 }
125 result = reply->writeDupFileDescriptor(mSendFd);
126 mSendFd.reset();
127 return result;
128 }
129
readFromParcel(const Parcel * parcel)130 status_t BitTube::readFromParcel(const Parcel* parcel) {
131 mReceiveFd.reset(dup(parcel->readFileDescriptor()));
132 if (mReceiveFd < 0) {
133 mReceiveFd.reset();
134 int error = errno;
135 ALOGE("BitTube::readFromParcel: can't dup file descriptor (%s)", strerror(error));
136 return -error;
137 }
138 mSendFd.reset(dup(parcel->readFileDescriptor()));
139 if (mSendFd < 0) {
140 mSendFd.reset();
141 int error = errno;
142 ALOGE("BitTube::readFromParcel: can't dup file descriptor (%s)", strerror(error));
143 return -error;
144 }
145 return NO_ERROR;
146 }
147
sendObjects(BitTube * tube,void const * events,size_t count,size_t objSize)148 ssize_t BitTube::sendObjects(BitTube* tube, void const* events, size_t count, size_t objSize) {
149 const char* vaddr = reinterpret_cast<const char*>(events);
150 ssize_t size = tube->write(vaddr, count * objSize);
151
152 // should never happen because of SOCK_SEQPACKET
153 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % static_cast<ssize_t>(objSize)),
154 "BitTube::sendObjects(count=%zu, size=%zu), res=%zd (partial events were "
155 "sent!)",
156 count, objSize, size);
157
158 // ALOGE_IF(size<0, "error %d sending %d events", size, count);
159 return size < 0 ? size : size / static_cast<ssize_t>(objSize);
160 }
161
recvObjects(BitTube * tube,void * events,size_t count,size_t objSize)162 ssize_t BitTube::recvObjects(BitTube* tube, void* events, size_t count, size_t objSize) {
163 char* vaddr = reinterpret_cast<char*>(events);
164 ssize_t size = tube->read(vaddr, count * objSize);
165
166 // should never happen because of SOCK_SEQPACKET
167 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % static_cast<ssize_t>(objSize)),
168 "BitTube::recvObjects(count=%zu, size=%zu), res=%zd (partial events were "
169 "received!)",
170 count, objSize, size);
171
172 // ALOGE_IF(size<0, "error %d receiving %d events", size, count);
173 return size < 0 ? size : size / static_cast<ssize_t>(objSize);
174 }
175
176 } // namespace gui
177 } // namespace android
178