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ipc_channel_posix.cc
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ipc_channel_posix.cc
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// Copyright (c) 2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/common/ipc_channel_posix.h"
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/uio.h>
#include <string>
#include <map>
#include "base/command_line.h"
#include "base/eintr_wrapper.h"
#include "base/lock.h"
#include "base/logging.h"
#include "base/process_util.h"
#include "base/scoped_ptr.h"
#include "base/string_util.h"
#include "base/singleton.h"
#include "base/stats_counters.h"
#include "chrome/common/chrome_counters.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/file_descriptor_set_posix.h"
#include "chrome/common/ipc_logging.h"
#include "chrome/common/ipc_message_utils.h"
#include "mozilla/ipc/ProtocolUtils.h"
namespace IPC {
// IPC channels on Windows use named pipes (CreateNamedPipe()) with
// channel ids as the pipe names. Channels on POSIX use anonymous
// Unix domain sockets created via socketpair() as pipes. These don't
// quite line up.
//
// When creating a child subprocess, the parent side of the fork
// arranges it such that the initial control channel ends up on the
// magic file descriptor kClientChannelFd in the child. Future
// connections (file descriptors) can then be passed via that
// connection via sendmsg().
//------------------------------------------------------------------------------
namespace {
// The PipeMap class works around this quirk related to unit tests:
//
// When running as a server, we install the client socket in a
// specific file descriptor number (@kClientChannelFd). However, we
// also have to support the case where we are running unittests in the
// same process. (We do not support forking without execing.)
//
// Case 1: normal running
// The IPC server object will install a mapping in PipeMap from the
// name which it was given to the client pipe. When forking the client, the
// GetClientFileDescriptorMapping will ensure that the socket is installed in
// the magic slot (@kClientChannelFd). The client will search for the
// mapping, but it won't find any since we are in a new process. Thus the
// magic fd number is returned. Once the client connects, the server will
// close its copy of the client socket and remove the mapping.
//
// Case 2: unittests - client and server in the same process
// The IPC server will install a mapping as before. The client will search
// for a mapping and find out. It duplicates the file descriptor and
// connects. Once the client connects, the server will close the original
// copy of the client socket and remove the mapping. Thus, when the client
// object closes, it will close the only remaining copy of the client socket
// in the fd table and the server will see EOF on its side.
//
// TODO(port): a client process cannot connect to multiple IPC channels with
// this scheme.
class PipeMap {
public:
// Lookup a given channel id. Return -1 if not found.
int Lookup(const std::string& channel_id) {
AutoLock locked(lock_);
ChannelToFDMap::const_iterator i = map_.find(channel_id);
if (i == map_.end())
return -1;
return i->second;
}
// Remove the mapping for the given channel id. No error is signaled if the
// channel_id doesn't exist
void Remove(const std::string& channel_id) {
AutoLock locked(lock_);
ChannelToFDMap::iterator i = map_.find(channel_id);
if (i != map_.end())
map_.erase(i);
}
// Insert a mapping from @channel_id to @fd. It's a fatal error to insert a
// mapping if one already exists for the given channel_id
void Insert(const std::string& channel_id, int fd) {
AutoLock locked(lock_);
DCHECK(fd != -1);
ChannelToFDMap::const_iterator i = map_.find(channel_id);
CHECK(i == map_.end()) << "Creating second IPC server for '"
<< channel_id
<< "' while first still exists";
map_[channel_id] = fd;
}
private:
Lock lock_;
typedef std::map<std::string, int> ChannelToFDMap;
ChannelToFDMap map_;
};
// This is the file descriptor number that a client process expects to find its
// IPC socket.
static const int kClientChannelFd = 3;
// Used to map a channel name to the equivalent FD # in the client process.
int ChannelNameToClientFD(const std::string& channel_id) {
// See the large block comment above PipeMap for the reasoning here.
const int fd = Singleton<PipeMap>()->Lookup(channel_id);
if (fd != -1)
return dup(fd);
// If we don't find an entry, we assume that the correct value has been
// inserted in the magic slot.
return kClientChannelFd;
}
//------------------------------------------------------------------------------
const size_t kMaxPipeNameLength = sizeof(((sockaddr_un*)0)->sun_path);
// Creates a Fifo with the specified name ready to listen on.
bool CreateServerFifo(const std::string& pipe_name, int* server_listen_fd) {
DCHECK(server_listen_fd);
DCHECK_GT(pipe_name.length(), 0u);
DCHECK_LT(pipe_name.length(), kMaxPipeNameLength);
if (pipe_name.length() == 0 || pipe_name.length() >= kMaxPipeNameLength) {
return false;
}
// Create socket.
int fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0) {
return false;
}
// Make socket non-blocking
if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
HANDLE_EINTR(close(fd));
return false;
}
// Delete any old FS instances.
unlink(pipe_name.c_str());
// Create unix_addr structure
struct sockaddr_un unix_addr;
memset(&unix_addr, 0, sizeof(unix_addr));
unix_addr.sun_family = AF_UNIX;
snprintf(unix_addr.sun_path, kMaxPipeNameLength, "%s", pipe_name.c_str());
size_t unix_addr_len = offsetof(struct sockaddr_un, sun_path) +
strlen(unix_addr.sun_path) + 1;
// Bind the socket.
if (bind(fd, reinterpret_cast<const sockaddr*>(&unix_addr),
unix_addr_len) != 0) {
HANDLE_EINTR(close(fd));
return false;
}
// Start listening on the socket.
const int listen_queue_length = 1;
if (listen(fd, listen_queue_length) != 0) {
HANDLE_EINTR(close(fd));
return false;
}
*server_listen_fd = fd;
return true;
}
// Accept a connection on a fifo.
bool ServerAcceptFifoConnection(int server_listen_fd, int* server_socket) {
DCHECK(server_socket);
int accept_fd = HANDLE_EINTR(accept(server_listen_fd, NULL, 0));
if (accept_fd < 0)
return false;
if (fcntl(accept_fd, F_SETFL, O_NONBLOCK) == -1) {
HANDLE_EINTR(close(accept_fd));
return false;
}
*server_socket = accept_fd;
return true;
}
bool ClientConnectToFifo(const std::string &pipe_name, int* client_socket) {
DCHECK(client_socket);
DCHECK_LT(pipe_name.length(), kMaxPipeNameLength);
// Create socket.
int fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0) {
LOG(ERROR) << "fd is invalid";
return false;
}
// Make socket non-blocking
if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
LOG(ERROR) << "fcntl failed";
HANDLE_EINTR(close(fd));
return false;
}
// Create server side of socket.
struct sockaddr_un server_unix_addr;
memset(&server_unix_addr, 0, sizeof(server_unix_addr));
server_unix_addr.sun_family = AF_UNIX;
snprintf(server_unix_addr.sun_path, kMaxPipeNameLength, "%s",
pipe_name.c_str());
size_t server_unix_addr_len = offsetof(struct sockaddr_un, sun_path) +
strlen(server_unix_addr.sun_path) + 1;
if (HANDLE_EINTR(connect(fd, reinterpret_cast<sockaddr*>(&server_unix_addr),
server_unix_addr_len)) != 0) {
HANDLE_EINTR(close(fd));
return false;
}
*client_socket = fd;
return true;
}
bool SetCloseOnExec(int fd) {
int flags = fcntl(fd, F_GETFD);
if (flags == -1)
return false;
flags |= FD_CLOEXEC;
if (fcntl(fd, F_SETFD, flags) == -1)
return false;
return true;
}
} // namespace
//------------------------------------------------------------------------------
Channel::ChannelImpl::ChannelImpl(const std::wstring& channel_id, Mode mode,
Listener* listener)
: factory_(this) {
Init(mode, listener);
uses_fifo_ = CommandLine::ForCurrentProcess()->HasSwitch(switches::kIPCUseFIFO);
if (!CreatePipe(channel_id, mode)) {
// The pipe may have been closed already.
LOG(WARNING) << "Unable to create pipe named \"" << channel_id <<
"\" in " << (mode == MODE_SERVER ? "server" : "client") <<
" mode error(" << strerror(errno) << ").";
}
}
Channel::ChannelImpl::ChannelImpl(int fd, Mode mode, Listener* listener)
: factory_(this) {
Init(mode, listener);
pipe_ = fd;
waiting_connect_ = (MODE_SERVER == mode);
EnqueueHelloMessage();
}
void Channel::ChannelImpl::Init(Mode mode, Listener* listener) {
mode_ = mode;
is_blocked_on_write_ = false;
message_send_bytes_written_ = 0;
uses_fifo_ = false;
server_listen_pipe_ = -1;
pipe_ = -1;
client_pipe_ = -1;
listener_ = listener;
waiting_connect_ = true;
processing_incoming_ = false;
closed_ = false;
#if defined(OS_MACOSX)
last_pending_fd_id_ = 0;
#endif
output_queue_length_ = 0;
}
bool Channel::ChannelImpl::CreatePipe(const std::wstring& channel_id,
Mode mode) {
DCHECK(server_listen_pipe_ == -1 && pipe_ == -1);
if (uses_fifo_) {
// This only happens in unit tests; see the comment above PipeMap.
// TODO(playmobil): We shouldn't need to create fifos on disk.
// TODO(playmobil): If we do, they should be in the user data directory.
// TODO(playmobil): Cleanup any stale fifos.
pipe_name_ = "/var/tmp/chrome_" + WideToASCII(channel_id);
if (mode == MODE_SERVER) {
if (!CreateServerFifo(pipe_name_, &server_listen_pipe_)) {
return false;
}
} else {
if (!ClientConnectToFifo(pipe_name_, &pipe_)) {
return false;
}
waiting_connect_ = false;
}
} else {
// socketpair()
pipe_name_ = WideToASCII(channel_id);
if (mode == MODE_SERVER) {
int pipe_fds[2];
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pipe_fds) != 0) {
return false;
}
// Set both ends to be non-blocking.
if (fcntl(pipe_fds[0], F_SETFL, O_NONBLOCK) == -1 ||
fcntl(pipe_fds[1], F_SETFL, O_NONBLOCK) == -1) {
HANDLE_EINTR(close(pipe_fds[0]));
HANDLE_EINTR(close(pipe_fds[1]));
return false;
}
if (!SetCloseOnExec(pipe_fds[0]) ||
!SetCloseOnExec(pipe_fds[1])) {
HANDLE_EINTR(close(pipe_fds[0]));
HANDLE_EINTR(close(pipe_fds[1]));
return false;
}
pipe_ = pipe_fds[0];
client_pipe_ = pipe_fds[1];
if (pipe_name_.length()) {
Singleton<PipeMap>()->Insert(pipe_name_, client_pipe_);
}
} else {
pipe_ = ChannelNameToClientFD(pipe_name_);
DCHECK(pipe_ > 0);
waiting_connect_ = false;
}
}
// Create the Hello message to be sent when Connect is called
return EnqueueHelloMessage();
}
bool Channel::ChannelImpl::EnqueueHelloMessage() {
scoped_ptr<Message> msg(new Message(MSG_ROUTING_NONE,
HELLO_MESSAGE_TYPE,
IPC::Message::PRIORITY_NORMAL));
if (!msg->WriteInt(base::GetCurrentProcId())) {
Close();
return false;
}
OutputQueuePush(msg.release());
return true;
}
static void
ClearAndShrink(std::string& s, size_t capacity)
{
// This swap trick is the closest thing C++ has to a guaranteed way to
// shrink the capacity of a string.
std::string tmp;
tmp.reserve(capacity);
s.swap(tmp);
}
bool Channel::ChannelImpl::Connect() {
if (mode_ == MODE_SERVER && uses_fifo_) {
if (server_listen_pipe_ == -1) {
return false;
}
MessageLoopForIO::current()->WatchFileDescriptor(
server_listen_pipe_,
true,
MessageLoopForIO::WATCH_READ,
&server_listen_connection_watcher_,
this);
} else {
if (pipe_ == -1) {
return false;
}
MessageLoopForIO::current()->WatchFileDescriptor(
pipe_,
true,
MessageLoopForIO::WATCH_READ,
&read_watcher_,
this);
waiting_connect_ = false;
}
if (!waiting_connect_)
return ProcessOutgoingMessages();
return true;
}
bool Channel::ChannelImpl::ProcessIncomingMessages() {
ssize_t bytes_read = 0;
struct msghdr msg = {0};
struct iovec iov = {input_buf_, Channel::kReadBufferSize};
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = input_cmsg_buf_;
for (;;) {
msg.msg_controllen = sizeof(input_cmsg_buf_);
if (bytes_read == 0) {
if (pipe_ == -1)
return false;
// Read from pipe.
// recvmsg() returns 0 if the connection has closed or EAGAIN if no data
// is waiting on the pipe.
bytes_read = HANDLE_EINTR(recvmsg(pipe_, &msg, MSG_DONTWAIT));
if (bytes_read < 0) {
if (errno == EAGAIN) {
return true;
} else {
LOG(ERROR) << "pipe error (" << pipe_ << "): " << strerror(errno);
return false;
}
} else if (bytes_read == 0) {
// The pipe has closed...
Close();
return false;
}
}
DCHECK(bytes_read);
if (client_pipe_ != -1) {
Singleton<PipeMap>()->Remove(pipe_name_);
HANDLE_EINTR(close(client_pipe_));
client_pipe_ = -1;
}
// a pointer to an array of |num_wire_fds| file descriptors from the read
const int* wire_fds = NULL;
unsigned num_wire_fds = 0;
// walk the list of control messages and, if we find an array of file
// descriptors, save a pointer to the array
// This next if statement is to work around an OSX issue where
// CMSG_FIRSTHDR will return non-NULL in the case that controllen == 0.
// Here's a test case:
//
// int main() {
// struct msghdr msg;
// msg.msg_control = &msg;
// msg.msg_controllen = 0;
// if (CMSG_FIRSTHDR(&msg))
// printf("Bug found!\n");
// }
if (msg.msg_controllen > 0) {
// On OSX, CMSG_FIRSTHDR doesn't handle the case where controllen is 0
// and will return a pointer into nowhere.
for (struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg); cmsg;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
const unsigned payload_len = cmsg->cmsg_len - CMSG_LEN(0);
DCHECK(payload_len % sizeof(int) == 0);
wire_fds = reinterpret_cast<int*>(CMSG_DATA(cmsg));
num_wire_fds = payload_len / 4;
if (msg.msg_flags & MSG_CTRUNC) {
LOG(ERROR) << "SCM_RIGHTS message was truncated"
<< " cmsg_len:" << cmsg->cmsg_len
<< " fd:" << pipe_;
for (unsigned i = 0; i < num_wire_fds; ++i)
HANDLE_EINTR(close(wire_fds[i]));
return false;
}
break;
}
}
}
// Process messages from input buffer.
const char *p;
const char *overflowp;
const char *end;
if (input_overflow_buf_.empty()) {
overflowp = NULL;
p = input_buf_;
end = p + bytes_read;
} else {
if (input_overflow_buf_.size() >
static_cast<size_t>(kMaximumMessageSize - bytes_read)) {
ClearAndShrink(input_overflow_buf_, Channel::kReadBufferSize);
LOG(ERROR) << "IPC message is too big";
return false;
}
input_overflow_buf_.append(input_buf_, bytes_read);
overflowp = p = input_overflow_buf_.data();
end = p + input_overflow_buf_.size();
}
// A pointer to an array of |num_fds| file descriptors which includes any
// fds that have spilled over from a previous read.
const int* fds;
unsigned num_fds;
unsigned fds_i = 0; // the index of the first unused descriptor
if (input_overflow_fds_.empty()) {
fds = wire_fds;
num_fds = num_wire_fds;
} else {
const size_t prev_size = input_overflow_fds_.size();
input_overflow_fds_.resize(prev_size + num_wire_fds);
memcpy(&input_overflow_fds_[prev_size], wire_fds,
num_wire_fds * sizeof(int));
fds = &input_overflow_fds_[0];
num_fds = input_overflow_fds_.size();
}
while (p < end) {
const char* message_tail = Message::FindNext(p, end);
if (message_tail) {
int len = static_cast<int>(message_tail - p);
Message m(p, len);
if (m.header()->num_fds) {
// the message has file descriptors
const char* error = NULL;
if (m.header()->num_fds > num_fds - fds_i) {
// the message has been completely received, but we didn't get
// enough file descriptors.
error = "Message needs unreceived descriptors";
}
if (m.header()->num_fds >
FileDescriptorSet::MAX_DESCRIPTORS_PER_MESSAGE) {
// There are too many descriptors in this message
error = "Message requires an excessive number of descriptors";
}
if (error) {
LOG(WARNING) << error
<< " channel:" << this
<< " message-type:" << m.type()
<< " header()->num_fds:" << m.header()->num_fds
<< " num_fds:" << num_fds
<< " fds_i:" << fds_i;
// close the existing file descriptors so that we don't leak them
for (unsigned i = fds_i; i < num_fds; ++i)
HANDLE_EINTR(close(fds[i]));
input_overflow_fds_.clear();
// abort the connection
return false;
}
#if defined(OS_MACOSX)
// Send a message to the other side, indicating that we are now
// responsible for closing the descriptor.
Message *fdAck = new Message(MSG_ROUTING_NONE,
RECEIVED_FDS_MESSAGE_TYPE,
IPC::Message::PRIORITY_NORMAL);
DCHECK(m.fd_cookie() != 0);
fdAck->set_fd_cookie(m.fd_cookie());
OutputQueuePush(fdAck);
#endif
m.file_descriptor_set()->SetDescriptors(
&fds[fds_i], m.header()->num_fds);
fds_i += m.header()->num_fds;
}
#ifdef IPC_MESSAGE_DEBUG_EXTRA
DLOG(INFO) << "received message on channel @" << this <<
" with type " << m.type();
#endif
if (m.routing_id() == MSG_ROUTING_NONE &&
m.type() == HELLO_MESSAGE_TYPE) {
// The Hello message contains only the process id.
listener_->OnChannelConnected(MessageIterator(m).NextInt());
#if defined(OS_MACOSX)
} else if (m.routing_id() == MSG_ROUTING_NONE &&
m.type() == RECEIVED_FDS_MESSAGE_TYPE) {
DCHECK(m.fd_cookie() != 0);
CloseDescriptors(m.fd_cookie());
#endif
} else {
listener_->OnMessageReceived(m);
}
p = message_tail;
} else {
// Last message is partial.
break;
}
}
if (end == p) {
ClearAndShrink(input_overflow_buf_, Channel::kReadBufferSize);
} else if (!overflowp) {
// p is from input_buf_
input_overflow_buf_.assign(p, end - p);
} else if (p > overflowp) {
// p is from input_overflow_buf_
input_overflow_buf_.erase(0, p - overflowp);
}
input_overflow_fds_ = std::vector<int>(&fds[fds_i], &fds[num_fds]);
// When the input data buffer is empty, the overflow fds should be too. If
// this is not the case, we probably have a rogue renderer which is trying
// to fill our descriptor table.
if (input_overflow_buf_.empty() && !input_overflow_fds_.empty()) {
// We close these descriptors in Close()
return false;
}
bytes_read = 0; // Get more data.
}
return true;
}
bool Channel::ChannelImpl::ProcessOutgoingMessages() {
DCHECK(!waiting_connect_); // Why are we trying to send messages if there's
// no connection?
is_blocked_on_write_ = false;
if (output_queue_.empty())
return true;
if (pipe_ == -1)
return false;
// Write out all the messages we can till the write blocks or there are no
// more outgoing messages.
while (!output_queue_.empty()) {
Message* msg = output_queue_.front();
struct msghdr msgh = {0};
static const int tmp = CMSG_SPACE(sizeof(
int[FileDescriptorSet::MAX_DESCRIPTORS_PER_MESSAGE]));
char buf[tmp];
if (message_send_bytes_written_ == 0 &&
!msg->file_descriptor_set()->empty()) {
// This is the first chunk of a message which has descriptors to send
struct cmsghdr *cmsg;
const unsigned num_fds = msg->file_descriptor_set()->size();
if (num_fds > FileDescriptorSet::MAX_DESCRIPTORS_PER_MESSAGE) {
LOG(FATAL) << "Too many file descriptors!";
// This should not be reached.
return false;
}
msgh.msg_control = buf;
msgh.msg_controllen = CMSG_SPACE(sizeof(int) * num_fds);
cmsg = CMSG_FIRSTHDR(&msgh);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(int) * num_fds);
msg->file_descriptor_set()->GetDescriptors(
reinterpret_cast<int*>(CMSG_DATA(cmsg)));
msgh.msg_controllen = cmsg->cmsg_len;
msg->header()->num_fds = num_fds;
#if defined(OS_MACOSX)
msg->set_fd_cookie(++last_pending_fd_id_);
#endif
}
size_t amt_to_write = msg->size() - message_send_bytes_written_;
DCHECK(amt_to_write != 0);
const char *out_bytes = reinterpret_cast<const char*>(msg->data()) +
message_send_bytes_written_;
struct iovec iov = {const_cast<char*>(out_bytes), amt_to_write};
msgh.msg_iov = &iov;
msgh.msg_iovlen = 1;
ssize_t bytes_written = HANDLE_EINTR(sendmsg(pipe_, &msgh, MSG_DONTWAIT));
#if !defined(OS_MACOSX)
// On OSX CommitAll gets called later, once we get the RECEIVED_FDS_MESSAGE_TYPE
// message.
if (bytes_written > 0)
msg->file_descriptor_set()->CommitAll();
#endif
if (bytes_written < 0 && errno != EAGAIN) {
LOG(ERROR) << "pipe error: " << strerror(errno);
return false;
}
if (static_cast<size_t>(bytes_written) != amt_to_write) {
if (bytes_written > 0) {
// If write() fails with EAGAIN then bytes_written will be -1.
message_send_bytes_written_ += bytes_written;
}
// Tell libevent to call us back once things are unblocked.
is_blocked_on_write_ = true;
MessageLoopForIO::current()->WatchFileDescriptor(
pipe_,
false, // One shot
MessageLoopForIO::WATCH_WRITE,
&write_watcher_,
this);
return true;
} else {
message_send_bytes_written_ = 0;
#if defined(OS_MACOSX)
if (!msg->file_descriptor_set()->empty())
pending_fds_.push_back(PendingDescriptors(msg->fd_cookie(),
msg->file_descriptor_set()));
#endif
// Message sent OK!
#ifdef IPC_MESSAGE_DEBUG_EXTRA
DLOG(INFO) << "sent message @" << msg << " on channel @" << this <<
" with type " << msg->type();
#endif
OutputQueuePop();
delete msg;
}
}
return true;
}
bool Channel::ChannelImpl::Send(Message* message) {
#ifdef IPC_MESSAGE_DEBUG_EXTRA
DLOG(INFO) << "sending message @" << message << " on channel @" << this
<< " with type " << message->type()
<< " (" << output_queue_.size() << " in queue)";
#endif
#ifdef IPC_MESSAGE_LOG_ENABLED
Logging::current()->OnSendMessage(message, L"");
#endif
// If the channel has been closed, ProcessOutgoingMessages() is never going
// to pop anything off output_queue; output_queue will only get emptied when
// the channel is destructed. We might as well delete message now, instead
// of waiting for the channel to be destructed.
if (closed_) {
if (mozilla::ipc::LoggingEnabled()) {
fprintf(stderr, "Can't send message %s, because this channel is closed.\n",
message->name());
}
delete message;
return false;
}
OutputQueuePush(message);
if (!waiting_connect_) {
if (!is_blocked_on_write_) {
if (!ProcessOutgoingMessages())
return false;
}
}
return true;
}
void Channel::ChannelImpl::GetClientFileDescriptorMapping(int *src_fd,
int *dest_fd) const {
DCHECK(mode_ == MODE_SERVER);
*src_fd = client_pipe_;
*dest_fd = kClientChannelFd;
}
void Channel::ChannelImpl::CloseClientFileDescriptor() {
if (client_pipe_ != -1) {
Singleton<PipeMap>()->Remove(pipe_name_);
HANDLE_EINTR(close(client_pipe_));
client_pipe_ = -1;
}
}
// Called by libevent when we can read from th pipe without blocking.
void Channel::ChannelImpl::OnFileCanReadWithoutBlocking(int fd) {
bool send_server_hello_msg = false;
if (waiting_connect_ && mode_ == MODE_SERVER) {
// In the case of a socketpair() the server starts listening on its end
// of the pipe in Connect().
DCHECK(uses_fifo_);
if (!ServerAcceptFifoConnection(server_listen_pipe_, &pipe_)) {
Close();
}
// No need to watch the listening socket any longer since only one client
// can connect. So unregister with libevent.
server_listen_connection_watcher_.StopWatchingFileDescriptor();
// Start watching our end of the socket.
MessageLoopForIO::current()->WatchFileDescriptor(
pipe_,
true,
MessageLoopForIO::WATCH_READ,
&read_watcher_,
this);
waiting_connect_ = false;
send_server_hello_msg = true;
}
if (!waiting_connect_ && fd == pipe_) {
if (!ProcessIncomingMessages()) {
Close();
listener_->OnChannelError();
}
}
// If we're a server and handshaking, then we want to make sure that we
// only send our handshake message after we've processed the client's.
// This gives us a chance to kill the client if the incoming handshake
// is invalid.
if (send_server_hello_msg) {
// This should be our first write so there's no chance we can block here...
DCHECK(is_blocked_on_write_ == false);
ProcessOutgoingMessages();
}
}
#if defined(OS_MACOSX)
void Channel::ChannelImpl::CloseDescriptors(uint32_t pending_fd_id)
{
DCHECK(pending_fd_id != 0);
for (std::list<PendingDescriptors>::iterator i = pending_fds_.begin();
i != pending_fds_.end();
i++) {
if ((*i).id == pending_fd_id) {
(*i).fds->CommitAll();
pending_fds_.erase(i);
return;
}
}
DCHECK(false) << "pending_fd_id not in our list!";
}
#endif
void Channel::ChannelImpl::OutputQueuePush(Message* msg)
{
output_queue_.push(msg);
output_queue_length_++;
}
void Channel::ChannelImpl::OutputQueuePop()
{
output_queue_.pop();
output_queue_length_--;
}
// Called by libevent when we can write to the pipe without blocking.
void Channel::ChannelImpl::OnFileCanWriteWithoutBlocking(int fd) {
if (!ProcessOutgoingMessages()) {
Close();
listener_->OnChannelError();
}
}
void Channel::ChannelImpl::Close() {
// Close can be called multiple times, so we need to make sure we're
// idempotent.
// Unregister libevent for the listening socket and close it.
server_listen_connection_watcher_.StopWatchingFileDescriptor();
if (server_listen_pipe_ != -1) {
HANDLE_EINTR(close(server_listen_pipe_));
server_listen_pipe_ = -1;
}
// Unregister libevent for the FIFO and close it.
read_watcher_.StopWatchingFileDescriptor();
write_watcher_.StopWatchingFileDescriptor();
if (pipe_ != -1) {
HANDLE_EINTR(close(pipe_));
pipe_ = -1;
}
if (client_pipe_ != -1) {
Singleton<PipeMap>()->Remove(pipe_name_);
HANDLE_EINTR(close(client_pipe_));
client_pipe_ = -1;
}
if (uses_fifo_) {
// Unlink the FIFO
unlink(pipe_name_.c_str());
}
while (!output_queue_.empty()) {
Message* m = output_queue_.front();
OutputQueuePop();
delete m;
}
// Close any outstanding, received file descriptors
for (std::vector<int>::iterator
i = input_overflow_fds_.begin(); i != input_overflow_fds_.end(); ++i) {
HANDLE_EINTR(close(*i));
}
input_overflow_fds_.clear();
#if defined(OS_MACOSX)
for (std::list<PendingDescriptors>::iterator i = pending_fds_.begin();
i != pending_fds_.end();
i++) {
(*i).fds->CommitAll();
}
pending_fds_.clear();
#endif
closed_ = true;
}
bool Channel::ChannelImpl::Unsound_IsClosed() const
{
return closed_;
}
uint32_t Channel::ChannelImpl::Unsound_NumQueuedMessages() const
{
return output_queue_length_;
}
//------------------------------------------------------------------------------
// Channel's methods simply call through to ChannelImpl.
Channel::Channel(const std::wstring& channel_id, Mode mode,
Listener* listener)
: channel_impl_(new ChannelImpl(channel_id, mode, listener)) {
}
Channel::Channel(int fd, Mode mode, Listener* listener)
: channel_impl_(new ChannelImpl(fd, mode, listener)) {
}
Channel::~Channel() {
delete channel_impl_;
}
bool Channel::Connect() {
return channel_impl_->Connect();
}
void Channel::Close() {
channel_impl_->Close();
}
Channel::Listener* Channel::set_listener(Listener* listener) {
return channel_impl_->set_listener(listener);
}
bool Channel::Send(Message* message) {
return channel_impl_->Send(message);
}
void Channel::GetClientFileDescriptorMapping(int *src_fd, int *dest_fd) const {
return channel_impl_->GetClientFileDescriptorMapping(src_fd, dest_fd);
}
int Channel::GetServerFileDescriptor() const {
return channel_impl_->GetServerFileDescriptor();
}
void Channel::CloseClientFileDescriptor() {
channel_impl_->CloseClientFileDescriptor();
}
bool Channel::Unsound_IsClosed() const {
return channel_impl_->Unsound_IsClosed();
}
uint32_t Channel::Unsound_NumQueuedMessages() const {
return channel_impl_->Unsound_NumQueuedMessages();
}
} // namespace IPC