1// Copyright 2014 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 "chrome/browser/apps/app_shim/unix_domain_socket_acceptor.h"
6
7#include "base/files/file_util.h"
8#include "base/files/scoped_file.h"
9#include "base/logging.h"
10#include "ipc/unix_domain_socket_util.h"
11
12namespace apps {
13
14UnixDomainSocketAcceptor::UnixDomainSocketAcceptor(const base::FilePath& path,
15                                                   Delegate* delegate)
16    : path_(path), delegate_(delegate), listen_fd_(-1) {
17  DCHECK(delegate_);
18  CreateSocket();
19}
20
21UnixDomainSocketAcceptor::~UnixDomainSocketAcceptor() {
22  Close();
23}
24
25bool UnixDomainSocketAcceptor::CreateSocket() {
26  DCHECK(listen_fd_ < 0);
27
28  // Create the socket.
29  return IPC::CreateServerUnixDomainSocket(path_, &listen_fd_);
30}
31
32bool UnixDomainSocketAcceptor::Listen() {
33  if (listen_fd_ < 0)
34    return false;
35
36  // Watch the fd for connections, and turn any connections into
37  // active sockets.
38  base::MessageLoopForIO::current()->WatchFileDescriptor(
39      listen_fd_,
40      true,
41      base::MessageLoopForIO::WATCH_READ,
42      &server_listen_connection_watcher_,
43      this);
44  return true;
45}
46
47// Called by libevent when we can read from the fd without blocking.
48void UnixDomainSocketAcceptor::OnFileCanReadWithoutBlocking(int fd) {
49  DCHECK(fd == listen_fd_);
50  int new_fd = -1;
51  if (!IPC::ServerAcceptConnection(listen_fd_, &new_fd)) {
52    Close();
53    delegate_->OnListenError();
54    return;
55  }
56  base::ScopedFD scoped_fd(new_fd);
57
58  if (!scoped_fd.is_valid()) {
59    // The accept() failed, but not in such a way that the factory needs to be
60    // shut down.
61    return;
62  }
63
64  // Verify that the IPC channel peer is running as the same user.
65  if (!IPC::IsPeerAuthorized(scoped_fd.get()))
66    return;
67
68  IPC::ChannelHandle handle(std::string(),
69                            base::FileDescriptor(scoped_fd.release(), true));
70  delegate_->OnClientConnected(handle);
71}
72
73void UnixDomainSocketAcceptor::OnFileCanWriteWithoutBlocking(int fd) {
74  NOTREACHED() << "Listen fd should never be writable.";
75}
76
77void UnixDomainSocketAcceptor::Close() {
78  if (listen_fd_ < 0)
79    return;
80  if (IGNORE_EINTR(close(listen_fd_)) < 0)
81    PLOG(ERROR) << "close";
82  listen_fd_ = -1;
83  if (unlink(path_.value().c_str()) < 0)
84    PLOG(ERROR) << "unlink";
85
86  // Unregister libevent for the listening socket and close it.
87  server_listen_connection_watcher_.StopWatchingFileDescriptor();
88}
89
90}  // namespace apps
91