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 37 BitTube::BitTube(size_t bufsize) { 38 init(bufsize, bufsize); 39 } 40 41 BitTube::BitTube(DefaultSizeType) : BitTube(DEFAULT_SOCKET_BUFFER_SIZE) {} 42 43 BitTube::BitTube(const Parcel& data) { 44 readFromParcel(&data); 45 } 46 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 66 status_t BitTube::initCheck() const { 67 if (mReceiveFd < 0) { 68 return status_t(mReceiveFd); 69 } 70 return NO_ERROR; 71 } 72 73 int BitTube::getFd() const { 74 return mReceiveFd; 75 } 76 77 int BitTube::getSendFd() const { 78 return mSendFd; 79 } 80 81 base::unique_fd BitTube::moveReceiveFd() { 82 return std::move(mReceiveFd); 83 } 84 85 void BitTube::setReceiveFd(base::unique_fd&& receiveFd) { 86 mReceiveFd = std::move(receiveFd); 87 } 88 89 ssize_t BitTube::write(void const* vaddr, size_t size) { 90 ssize_t err, len; 91 do { 92 len = ::send(mSendFd, vaddr, size, MSG_DONTWAIT | MSG_NOSIGNAL); 93 // cannot return less than size, since we're using SOCK_SEQPACKET 94 err = len < 0 ? errno : 0; 95 } while (err == EINTR); 96 return err == 0 ? len : -err; 97 } 98 99 ssize_t BitTube::read(void* vaddr, size_t size) { 100 ssize_t err, len; 101 do { 102 len = ::recv(mReceiveFd, vaddr, size, MSG_DONTWAIT); 103 err = len < 0 ? errno : 0; 104 } while (err == EINTR); 105 if (err == EAGAIN || err == EWOULDBLOCK) { 106 // EAGAIN means that we have non-blocking I/O but there was no data to be read. Nothing the 107 // client should care about. 108 return 0; 109 } 110 return err == 0 ? len : -err; 111 } 112 113 status_t BitTube::writeToParcel(Parcel* reply) const { 114 if (mReceiveFd < 0) return -EINVAL; 115 116 status_t result = reply->writeDupFileDescriptor(mReceiveFd); 117 mReceiveFd.reset(); 118 return result; 119 } 120 121 status_t BitTube::readFromParcel(const Parcel* parcel) { 122 mReceiveFd.reset(dup(parcel->readFileDescriptor())); 123 if (mReceiveFd < 0) { 124 mReceiveFd.reset(); 125 int error = errno; 126 ALOGE("BitTube::readFromParcel: can't dup file descriptor (%s)", strerror(error)); 127 return -error; 128 } 129 return NO_ERROR; 130 } 131 132 ssize_t BitTube::sendObjects(BitTube* tube, void const* events, size_t count, size_t objSize) { 133 const char* vaddr = reinterpret_cast<const char*>(events); 134 ssize_t size = tube->write(vaddr, count * objSize); 135 136 // should never happen because of SOCK_SEQPACKET 137 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % static_cast<ssize_t>(objSize)), 138 "BitTube::sendObjects(count=%zu, size=%zu), res=%zd (partial events were " 139 "sent!)", 140 count, objSize, size); 141 142 // ALOGE_IF(size<0, "error %d sending %d events", size, count); 143 return size < 0 ? size : size / static_cast<ssize_t>(objSize); 144 } 145 146 ssize_t BitTube::recvObjects(BitTube* tube, void* events, size_t count, size_t objSize) { 147 char* vaddr = reinterpret_cast<char*>(events); 148 ssize_t size = tube->read(vaddr, count * objSize); 149 150 // should never happen because of SOCK_SEQPACKET 151 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % static_cast<ssize_t>(objSize)), 152 "BitTube::recvObjects(count=%zu, size=%zu), res=%zd (partial events were " 153 "received!)", 154 count, objSize, size); 155 156 // ALOGE_IF(size<0, "error %d receiving %d events", size, count); 157 return size < 0 ? size : size / static_cast<ssize_t>(objSize); 158 } 159 160 } // namespace gui 161 } // namespace android 162
