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 <stdint.h>
18 #include <sys/types.h>
19 #include <sys/socket.h>
20
21 #include <fcntl.h>
22 #include <unistd.h>
23
24 #include <utils/Errors.h>
25
26 #include <binder/Parcel.h>
27
28 #include <gui/BitTube.h>
29
30 namespace android {
31 // ----------------------------------------------------------------------------
32
33 // Socket buffer size. The default is typically about 128KB, which is much larger than
34 // we really need. So we make it smaller.
35 static const size_t DEFAULT_SOCKET_BUFFER_SIZE = 4 * 1024;
36
37
BitTube()38 BitTube::BitTube()
39 : mSendFd(-1), mReceiveFd(-1)
40 {
41 init(DEFAULT_SOCKET_BUFFER_SIZE, DEFAULT_SOCKET_BUFFER_SIZE);
42 }
43
BitTube(size_t bufsize)44 BitTube::BitTube(size_t bufsize)
45 : mSendFd(-1), mReceiveFd(-1)
46 {
47 init(bufsize, bufsize);
48 }
49
BitTube(const Parcel & data)50 BitTube::BitTube(const Parcel& data)
51 : mSendFd(-1), mReceiveFd(-1)
52 {
53 mReceiveFd = dup(data.readFileDescriptor());
54 if (mReceiveFd < 0) {
55 mReceiveFd = -errno;
56 ALOGE("BitTube(Parcel): can't dup filedescriptor (%s)",
57 strerror(-mReceiveFd));
58 }
59 }
60
~BitTube()61 BitTube::~BitTube()
62 {
63 if (mSendFd >= 0)
64 close(mSendFd);
65
66 if (mReceiveFd >= 0)
67 close(mReceiveFd);
68 }
69
init(size_t rcvbuf,size_t sndbuf)70 void BitTube::init(size_t rcvbuf, size_t sndbuf) {
71 int sockets[2];
72 if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) == 0) {
73 size_t size = DEFAULT_SOCKET_BUFFER_SIZE;
74 setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(rcvbuf));
75 setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &sndbuf, sizeof(sndbuf));
76 // sine we don't use the "return channel", we keep it small...
77 setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
78 setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
79 fcntl(sockets[0], F_SETFL, O_NONBLOCK);
80 fcntl(sockets[1], F_SETFL, O_NONBLOCK);
81 mReceiveFd = sockets[0];
82 mSendFd = sockets[1];
83 } else {
84 mReceiveFd = -errno;
85 ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd));
86 }
87 }
88
initCheck() const89 status_t BitTube::initCheck() const
90 {
91 if (mReceiveFd < 0) {
92 return status_t(mReceiveFd);
93 }
94 return NO_ERROR;
95 }
96
getFd() const97 int BitTube::getFd() const
98 {
99 return mReceiveFd;
100 }
101
getSendFd() const102 int BitTube::getSendFd() const
103 {
104 return mSendFd;
105 }
106
write(void const * vaddr,size_t size)107 ssize_t BitTube::write(void const* vaddr, size_t size)
108 {
109 ssize_t err, len;
110 do {
111 len = ::send(mSendFd, vaddr, size, MSG_DONTWAIT | MSG_NOSIGNAL);
112 // cannot return less than size, since we're using SOCK_SEQPACKET
113 err = len < 0 ? errno : 0;
114 } while (err == EINTR);
115 return err == 0 ? len : -err;
116 }
117
read(void * vaddr,size_t size)118 ssize_t BitTube::read(void* vaddr, size_t size)
119 {
120 ssize_t err, len;
121 do {
122 len = ::recv(mReceiveFd, vaddr, size, MSG_DONTWAIT);
123 err = len < 0 ? errno : 0;
124 } while (err == EINTR);
125 if (err == EAGAIN || err == EWOULDBLOCK) {
126 // EAGAIN means that we have non-blocking I/O but there was
127 // no data to be read. Nothing the client should care about.
128 return 0;
129 }
130 return err == 0 ? len : -err;
131 }
132
writeToParcel(Parcel * reply) const133 status_t BitTube::writeToParcel(Parcel* reply) const
134 {
135 if (mReceiveFd < 0)
136 return -EINVAL;
137
138 status_t result = reply->writeDupFileDescriptor(mReceiveFd);
139 close(mReceiveFd);
140 mReceiveFd = -1;
141 return result;
142 }
143
144
sendObjects(const sp<BitTube> & tube,void const * events,size_t count,size_t objSize)145 ssize_t BitTube::sendObjects(const sp<BitTube>& tube,
146 void const* events, size_t count, size_t objSize)
147 {
148 const char* vaddr = reinterpret_cast<const char*>(events);
149 ssize_t size = tube->write(vaddr, count*objSize);
150
151 // should never happen because of SOCK_SEQPACKET
152 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % static_cast<ssize_t>(objSize)),
153 "BitTube::sendObjects(count=%zu, size=%zu), res=%zd (partial events were sent!)",
154 count, objSize, size);
155
156 //ALOGE_IF(size<0, "error %d sending %d events", size, count);
157 return size < 0 ? size : size / static_cast<ssize_t>(objSize);
158 }
159
recvObjects(const sp<BitTube> & tube,void * events,size_t count,size_t objSize)160 ssize_t BitTube::recvObjects(const sp<BitTube>& tube,
161 void* events, size_t count, size_t objSize)
162 {
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 received!)",
169 count, objSize, size);
170
171 //ALOGE_IF(size<0, "error %d receiving %d events", size, count);
172 return size < 0 ? size : size / static_cast<ssize_t>(objSize);
173 }
174
175 // ----------------------------------------------------------------------------
176 }; // namespace android
177