content/browser/renderer_host/render_sandbox_host_linux.cc

   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.
  15 RenderSandboxHostLinux::RenderSandboxHostLinux()
  16     : initialized_(false), renderer_socket_(0), childs_lifeline_fd_(0) {
  17 }
  18
  19 // static
  20 RenderSandboxHostLinux* RenderSandboxHostLinux::GetInstance() {
  21   return base::Singleton<RenderSandboxHostLinux>::get();
  22 }
  23
  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
  59 bool RenderSandboxHostLinux::ShutdownIPCChannel() {
  60   return IGNORE_EINTR(close(childs_lifeline_fd_)) == 0;
  61 }
  62
  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