DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>

#include <arpa/inet.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include <netinet/in.h>
#include <sys/socket.h>

#include "base/message_loop.h"
#include "mozilla/FileUtils.h"
#include "nsAutoPtr.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"

#include "UeventPoller.h"

namespace mozilla {
namespace hal_impl {

static void ShutdownUevent();

class NetlinkPoller : public MessageLoopForIO::Watcher
{
public:
  NetlinkPoller() : mSocket(-1),
                    mIOLoop(MessageLoopForIO::current())
  {
  }

  virtual ~NetlinkPoller() {}

  bool OpenSocket();

  virtual void OnFileCanReadWithoutBlocking(int fd);

  // no writing to the netlink socket
  virtual void OnFileCanWriteWithoutBlocking(int fd)
  {
    MOZ_NOT_REACHED("Must not write to netlink socket");
  }

  MessageLoopForIO *GetIOLoop () const { return mIOLoop; }
  void RegisterObserver(IUeventObserver *aObserver)
  {
    mUeventObserverList.AddObserver(aObserver);
  }

  void UnregisterObserver(IUeventObserver *aObserver)
  {
    mUeventObserverList.RemoveObserver(aObserver);
    if (mUeventObserverList.Length() == 0)
      ShutdownUevent();  // this will destroy self
  }

private:
  ScopedClose mSocket;
  MessageLoopForIO* mIOLoop;
  MessageLoopForIO::FileDescriptorWatcher mReadWatcher;

  NetlinkEvent mNetlinkEvent;
  const static int kBuffsize = 64 * 1024;
  uint8_t mBuffer [kBuffsize];

  typedef ObserverList<NetlinkEvent> UeventObserverList;
  UeventObserverList mUeventObserverList;
};

bool
NetlinkPoller::OpenSocket()
{
  mSocket.rwget() = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
  if (mSocket.get() < 0)
    return false;

  int sz = kBuffsize;

  if (setsockopt(mSocket.get(), SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)) < 0)
    return false;

  // add FD_CLOEXEC flag
  int flags = fcntl(mSocket.get(), F_GETFD);
  if (flags == -1) {
      return false;
  }
  flags |= FD_CLOEXEC;
  if (fcntl(mSocket.get(), F_SETFD, flags) == -1)
    return false;

  // set non-blocking
  if (fcntl(mSocket.get(), F_SETFL, O_NONBLOCK) == -1)
    return false;

  struct sockaddr_nl saddr;
  bzero(&saddr, sizeof(saddr));
  saddr.nl_family = AF_NETLINK;
  saddr.nl_groups = 1;
  saddr.nl_pid = getpid();

  if (bind(mSocket.get(), (struct sockaddr *)&saddr, sizeof(saddr)) == -1)
    return false;

  if (!mIOLoop->WatchFileDescriptor(mSocket.get(),
                                    true,
                                    MessageLoopForIO::WATCH_READ,
                                    &mReadWatcher,
                                    this)) {
      return false;
  }

  return true;
}

static nsAutoPtr<NetlinkPoller> sPoller;

class UeventInitTask : public Task
{
  virtual void Run()
  {
    if (!sPoller) {
      return;
    }
    if (sPoller->OpenSocket()) {
      return;
    }
    sPoller->GetIOLoop()->PostDelayedTask(FROM_HERE, new UeventInitTask(), 1000);
  }
};

void
NetlinkPoller::OnFileCanReadWithoutBlocking(int fd)
{
  MOZ_ASSERT(fd == mSocket.get());
  while (true) {
    int ret = read(fd, mBuffer, kBuffsize);
    if (ret == -1) {
      if (errno == EAGAIN || errno == EWOULDBLOCK) {
        return;
      }
      if (errno == EINTR) {
        continue;
      }
    }
    if (ret <= 0) {
      // fatal error on netlink socket which should not happen
      _exit(1);
    }
    mNetlinkEvent.decode(reinterpret_cast<char*>(mBuffer), ret);
    mUeventObserverList.Broadcast(mNetlinkEvent);
  }
}

static void
InitializeUevent()
{
  MOZ_ASSERT(!sPoller);
  sPoller = new NetlinkPoller();
  sPoller->GetIOLoop()->PostTask(FROM_HERE, new UeventInitTask());

}

static void
ShutdownUevent()
{
  sPoller = NULL;
}

void
RegisterUeventListener(IUeventObserver *aObserver)
{
  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());

  if (!sPoller)
    InitializeUevent();
  sPoller->RegisterObserver(aObserver);
}

void
UnregisterUeventListener(IUeventObserver *aObserver)
{
  MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());

  sPoller->UnregisterObserver(aObserver);
}

} // hal_impl
} // mozilla