ipc/ipc_channel_factory.cc

   1 // Copyright 2013 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.
   4
   5 #include "ipc/ipc_channel_factory.h"
   6
   7 #include "base/file_util.h"
   8 #include "base/logging.h"
   9 #include "ipc/unix_domain_socket_util.h"
  10
  11 namespace IPC {
  12
  13 ChannelFactory::ChannelFactory(const base::FilePath& path, Delegate* delegate)
  14     : path_(path), delegate_(delegate), listen_fd_(-1) {
  15   DCHECK(delegate_);
  16   CreateSocket();
  17 }
  18
  19 ChannelFactory::~ChannelFactory() {
  20   Close();
  21 }
  22
  23 bool ChannelFactory::CreateSocket() {
  24   DCHECK(listen_fd_ < 0);
  25
  26   // Create the socket.
  27   return CreateServerUnixDomainSocket(path_, &listen_fd_);
  28 }
  29
  30 bool ChannelFactory::Listen() {
  31   if (listen_fd_ < 0)
  32     return false;
  33
  34   // Watch the fd for connections, and turn any connections into
  35   // active sockets.
  36   base::MessageLoopForIO::current()->WatchFileDescriptor(
  37       listen_fd_,
  38       true,
  39       base::MessageLoopForIO::WATCH_READ,
  40       &server_listen_connection_watcher_,
  41       this);
  42   return true;
  43 }
  44
  45 // Called by libevent when we can read from the fd without blocking.
  46 void ChannelFactory::OnFileCanReadWithoutBlocking(int fd) {
  47   DCHECK(fd == listen_fd_);
  48   int new_fd = -1;
  49   if (!ServerAcceptConnection(listen_fd_, &new_fd)) {
  50     Close();
  51     delegate_->OnListenError();
  52     return;
  53   }
  54
  55   if (new_fd < 0) {
  56     // The accept() failed, but not in such a way that the factory needs to be
  57     // shut down.
  58     return;
  59   }
  60
  61   file_util::ScopedFD scoped_fd(&new_fd);
  62
  63   // Verify that the IPC channel peer is running as the same user.
  64   if (!IsPeerAuthorized(new_fd))
  65     return;
  66
  67   ChannelHandle handle(std::string(),
  68                        base::FileDescriptor(*scoped_fd.release(), true));
  69   delegate_->OnClientConnected(handle);
  70 }
  71
  72 void ChannelFactory::OnFileCanWriteWithoutBlocking(int fd) {
  73   NOTREACHED() << "Listen fd should never be writable.";
  74 }
  75
  76 void ChannelFactory::Close() {
  77   if (listen_fd_ < 0)
  78     return;
  79   if (IGNORE_EINTR(close(listen_fd_)) < 0)
  80     PLOG(ERROR) << "close";
  81   listen_fd_ = -1;
  82   if (unlink(path_.value().c_str()) < 0)
  83     PLOG(ERROR) << "unlink";
  84
  85   // Unregister libevent for the listening socket and close it.
  86   server_listen_connection_watcher_.StopWatchingFileDescriptor();
  87 }
  88
  89 }  // namespace IPC