1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "base/sync_socket.h"
13 #include <sys/ioctl.h>
14 #include <sys/socket.h>
15 #include <sys/types.h>
17 #if defined(OS_SOLARIS)
18 #include <sys/filio.h>
21 #include "base/check_op.h"
22 #include "base/files/file_util.h"
23 #include "base/threading/scoped_blocking_call.h"
24 #include "build/build_config.h"
29 // To avoid users sending negative message lengths to Send/Receive
30 // we clamp message lengths, which are size_t, to no more than INT_MAX.
31 const size_t kMaxMessageLength = static_cast<size_t>(INT_MAX);
33 // Writes |length| of |buffer| into |handle|. Returns the number of bytes
34 // written or zero on error. |length| must be greater than 0.
35 size_t SendHelper(SyncSocket::Handle handle,
38 DCHECK_GT(length, 0u);
39 DCHECK_LE(length, kMaxMessageLength);
40 DCHECK_NE(handle, SyncSocket::kInvalidHandle);
41 const char* charbuffer = static_cast<const char*>(buffer);
42 return WriteFileDescriptor(handle, charbuffer, length)
43 ? static_cast<size_t>(length)
50 bool SyncSocket::CreatePair(SyncSocket* socket_a, SyncSocket* socket_b) {
51 DCHECK_NE(socket_a, socket_b);
52 DCHECK(!socket_a->IsValid());
53 DCHECK(!socket_b->IsValid());
55 #if defined(OS_MACOSX)
57 #endif // defined(OS_MACOSX)
59 ScopedHandle handles[2];
62 Handle raw_handles[2] = {kInvalidHandle, kInvalidHandle};
63 if (socketpair(AF_UNIX, SOCK_STREAM, 0, raw_handles) != 0) {
66 handles[0].reset(raw_handles[0]);
67 handles[1].reset(raw_handles[1]);
70 #if defined(OS_MACOSX)
71 // On OSX an attempt to read or write to a closed socket may generate a
72 // SIGPIPE rather than returning -1. setsockopt will shut this off.
73 if (0 != setsockopt(handles[0].get(), SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe,
75 0 != setsockopt(handles[1].get(), SOL_SOCKET, SO_NOSIGPIPE, &nosigpipe,
81 // Copy the handles out for successful return.
82 socket_a->handle_ = std::move(handles[0]);
83 socket_b->handle_ = std::move(handles[1]);
88 void SyncSocket::Close() {
92 size_t SyncSocket::Send(const void* buffer, size_t length) {
93 ScopedBlockingCall scoped_blocking_call(FROM_HERE, BlockingType::MAY_BLOCK);
94 return SendHelper(handle(), buffer, length);
97 size_t SyncSocket::Receive(void* buffer, size_t length) {
98 ScopedBlockingCall scoped_blocking_call(FROM_HERE, BlockingType::MAY_BLOCK);
99 DCHECK_GT(length, 0u);
100 DCHECK_LE(length, kMaxMessageLength);
102 char* charbuffer = static_cast<char*>(buffer);
103 if (ReadFromFD(handle(), charbuffer, length))
108 size_t SyncSocket::ReceiveWithTimeout(void* buffer,
111 ScopedBlockingCall scoped_blocking_call(FROM_HERE, BlockingType::MAY_BLOCK);
112 DCHECK_GT(length, 0u);
113 DCHECK_LE(length, kMaxMessageLength);
116 // Only timeouts greater than zero and less than one second are allowed.
117 DCHECK_GT(timeout.InMicroseconds(), 0);
118 DCHECK_LT(timeout.InMicroseconds(),
119 TimeDelta::FromSeconds(1).InMicroseconds());
121 // Track the start time so we can reduce the timeout as data is read.
122 TimeTicks start_time = TimeTicks::Now();
123 const TimeTicks finish_time = start_time + timeout;
125 struct pollfd pollfd;
126 pollfd.fd = handle();
127 pollfd.events = POLLIN;
130 size_t bytes_read_total = 0;
131 while (bytes_read_total < length) {
132 const TimeDelta this_timeout = finish_time - TimeTicks::Now();
133 const int timeout_ms =
134 static_cast<int>(this_timeout.InMillisecondsRoundedUp());
137 const int poll_result = poll(&pollfd, 1, timeout_ms);
138 // Handle EINTR manually since we need to update the timeout value.
139 if (poll_result == -1 && errno == EINTR)
141 // Return if other type of error or a timeout.
142 if (poll_result <= 0)
143 return bytes_read_total;
145 // poll() only tells us that data is ready for reading, not how much. We
146 // must Peek() for the amount ready for reading to avoid blocking.
147 // At hang up (POLLHUP), the write end has been closed and there might still
148 // be data to be read.
149 // No special handling is needed for error (POLLERR); we can let any of the
150 // following operations fail and handle it there.
151 DCHECK(pollfd.revents & (POLLIN | POLLHUP | POLLERR)) << pollfd.revents;
152 const size_t bytes_to_read = std::min(Peek(), length - bytes_read_total);
154 // There may be zero bytes to read if the socket at the other end closed.
156 return bytes_read_total;
158 const size_t bytes_received =
159 Receive(static_cast<char*>(buffer) + bytes_read_total, bytes_to_read);
160 bytes_read_total += bytes_received;
161 if (bytes_received != bytes_to_read)
162 return bytes_read_total;
165 return bytes_read_total;
168 size_t SyncSocket::Peek() {
170 int number_chars = 0;
171 if (ioctl(handle_.get(), FIONREAD, &number_chars) == -1) {
172 // If there is an error in ioctl, signal that the channel would block.
175 DCHECK_GE(number_chars, 0);
179 bool SyncSocket::IsValid() const {
180 return handle_.is_valid();
183 SyncSocket::Handle SyncSocket::handle() const {
184 return handle_.get();
187 SyncSocket::Handle SyncSocket::Release() {
188 return handle_.release();
191 bool CancelableSyncSocket::Shutdown() {
193 return HANDLE_EINTR(shutdown(handle(), SHUT_RDWR)) >= 0;
196 size_t CancelableSyncSocket::Send(const void* buffer, size_t length) {
197 DCHECK_GT(length, 0u);
198 DCHECK_LE(length, kMaxMessageLength);
201 const int flags = fcntl(handle(), F_GETFL);
202 if (flags != -1 && (flags & O_NONBLOCK) == 0) {
203 // Set the socket to non-blocking mode for sending if its original mode
205 fcntl(handle(), F_SETFL, flags | O_NONBLOCK);
208 const size_t len = SendHelper(handle(), buffer, length);
210 if (flags != -1 && (flags & O_NONBLOCK) == 0) {
211 // Restore the original flags.
212 fcntl(handle(), F_SETFL, flags);
219 bool CancelableSyncSocket::CreatePair(CancelableSyncSocket* socket_a,
220 CancelableSyncSocket* socket_b) {
221 return SyncSocket::CreatePair(socket_a, socket_b);