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.
4
5 #include "content/browser/renderer_host/render_sandbox_host_linux.h"
6
7 #include <sys/socket.h>
8
9 #include "base/memory/singleton.h"
10 #include "base/posix/eintr_wrapper.h"
11
12 namespace content {
13
14 // Runs on the main thread at startup.
RenderSandboxHostLinux()15 RenderSandboxHostLinux::RenderSandboxHostLinux()
16 : initialized_(false), renderer_socket_(0), childs_lifeline_fd_(0) {
17 }
18
19 // static
GetInstance()20 RenderSandboxHostLinux* RenderSandboxHostLinux::GetInstance() {
21 return Singleton<RenderSandboxHostLinux>::get();
22 }
23
Init()24 void RenderSandboxHostLinux::Init() {
25 DCHECK(!initialized_);
26 initialized_ = true;
27
28 int fds[2];
29 // We use SOCK_SEQPACKET rather than SOCK_DGRAM to prevent the renderer from
30 // sending datagrams to other sockets on the system. The sandbox may prevent
31 // the renderer from calling socket() to create new sockets, but it'll still
32 // inherit some sockets. With AF_UNIX+SOCK_DGRAM, it can call sendmsg to send
33 // a datagram to any (abstract) socket on the same system. With
34 // SOCK_SEQPACKET, this is prevented.
35 CHECK(socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds) == 0);
36
37 renderer_socket_ = fds[0];
38 // The SandboxIPC client is not expected to read from |renderer_socket_|.
39 // Instead, it reads from a temporary socket sent with the request.
40 PCHECK(0 == shutdown(renderer_socket_, SHUT_RD)) << "shutdown";
41
42 const int browser_socket = fds[1];
43 // The SandboxIPC handler is not expected to write to |browser_socket|.
44 // Instead, it replies on a temporary socket provided by the caller.
45 PCHECK(0 == shutdown(browser_socket, SHUT_WR)) << "shutdown";
46
47 int pipefds[2];
48 CHECK(0 == pipe(pipefds));
49 const int child_lifeline_fd = pipefds[0];
50 childs_lifeline_fd_ = pipefds[1];
51
52 ipc_handler_.reset(
53 new SandboxIPCHandler(child_lifeline_fd, browser_socket));
54 ipc_thread_.reset(
55 new base::DelegateSimpleThread(ipc_handler_.get(), "sandbox_ipc_thread"));
56 ipc_thread_->Start();
57 }
58
ShutdownIPCChannel()59 bool RenderSandboxHostLinux::ShutdownIPCChannel() {
60 return IGNORE_EINTR(close(childs_lifeline_fd_)) == 0;
61 }
62
~RenderSandboxHostLinux()63 RenderSandboxHostLinux::~RenderSandboxHostLinux() {
64 if (initialized_) {
65 if (!ShutdownIPCChannel())
66 LOG(ERROR) << "ShutdownIPCChannel failed";
67 if (IGNORE_EINTR(close(renderer_socket_)) < 0)
68 PLOG(ERROR) << "close";
69
70 ipc_thread_->Join();
71 }
72 }
73
74 } // namespace content
75