The Tor Browser: ipc/chromium/src/chrome/common/ipc_channel

ipc/chromium/src/chrome/common/ipc_channel_posix.cc@6474c204b198 (annotated)

ipc/chromium/src/chrome/common/ipc_channel_posix.cc

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // 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_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"
 #ifdef MOZ_TASK_TRACER
 #include "GeckoTaskTracerImpl.h"
 using namespace mozilla::tasktracer;
 #endif
 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) {
     CHROMIUM_LOG(ERROR) << "fd is invalid";
     return false;
   }
   // Make socket non-blocking
   if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
     CHROMIUM_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.
     CHROMIUM_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();
 }
 /**
  * Reset the file descriptor for communication with the peer.
  */
 void Channel::ChannelImpl::ResetFileDescriptor(int fd) {
   NS_ASSERTION(fd > 0 && fd == pipe_, "Invalid file descriptor");
   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 {
           CHROMIUM_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) {
             CHROMIUM_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);
         CHROMIUM_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) {
             CHROMIUM_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
 #ifdef MOZ_TASK_TRACER
         AutoSaveCurTraceInfo saveCurTraceInfo;
         SetCurTraceInfo(m.header()->source_event_id,
                         m.header()->parent_task_id,
                         m.header()->source_event_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) {
         CHROMIUM_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
     }
 #ifdef MOZ_TASK_TRACER
     GetCurTraceInfo(&msg->header()->source_event_id,
                     &msg->header()->parent_task_id,
                     &msg->header()->source_event_type);
 #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) {
       CHROMIUM_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);
 }
 void Channel::ResetFileDescriptor(int fd) {
   channel_impl_->ResetFileDescriptor(fd);
 }
 int Channel::GetFileDescriptor() const {
     return channel_impl_->GetFileDescriptor();
 }
 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

The Tor Browser / annotate

ipc/chromium/src/chrome/common/ipc_channel_posix.cc@6474c204b198 (annotated)

ipc/chromium/src/chrome/common/ipc_channel_posix.cc