michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* Copyright 2012 Mozilla Foundation and Mozilla contributors
michael@0:  *
michael@0:  * Licensed under the Apache License, Version 2.0 (the "License");
michael@0:  * you may not use this file except in compliance with the License.
michael@0:  * You may obtain a copy of the License at
michael@0:  *
michael@0:  *     http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing, software
michael@0:  * distributed under the License is distributed on an "AS IS" BASIS,
michael@0:  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
michael@0:  * See the License for the specific language governing permissions and
michael@0:  * limitations under the License.
michael@0:  */
michael@0: 
michael@0: #include <errno.h>
michael@0: #include <fcntl.h>
michael@0: #include <pthread.h>
michael@0: #include <signal.h>
michael@0: #include <string.h>
michael@0: #include <strings.h>
michael@0: #include <unistd.h>
michael@0: 
michael@0: #include <arpa/inet.h>
michael@0: #include <linux/types.h>
michael@0: #include <linux/netlink.h>
michael@0: #include <netinet/in.h>
michael@0: #include <sys/socket.h>
michael@0: 
michael@0: #include "nsDebug.h"
michael@0: #include "base/message_loop.h"
michael@0: #include "mozilla/FileUtils.h"
michael@0: #include "nsAutoPtr.h"
michael@0: #include "nsThreadUtils.h"
michael@0: #include "nsXULAppAPI.h"
michael@0: 
michael@0: #include "UeventPoller.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace hal_impl {
michael@0: 
michael@0: static void ShutdownUevent();
michael@0: 
michael@0: class NetlinkPoller : public MessageLoopForIO::Watcher
michael@0: {
michael@0: public:
michael@0:   NetlinkPoller() : mSocket(-1),
michael@0:                     mIOLoop(MessageLoopForIO::current())
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   virtual ~NetlinkPoller() {}
michael@0: 
michael@0:   bool OpenSocket();
michael@0: 
michael@0:   virtual void OnFileCanReadWithoutBlocking(int fd);
michael@0: 
michael@0:   // no writing to the netlink socket
michael@0:   virtual void OnFileCanWriteWithoutBlocking(int fd)
michael@0:   {
michael@0:     MOZ_CRASH("Must not write to netlink socket");
michael@0:   }
michael@0: 
michael@0:   MessageLoopForIO *GetIOLoop () const { return mIOLoop; }
michael@0:   void RegisterObserver(IUeventObserver *aObserver)
michael@0:   {
michael@0:     mUeventObserverList.AddObserver(aObserver);
michael@0:   }
michael@0: 
michael@0:   void UnregisterObserver(IUeventObserver *aObserver)
michael@0:   {
michael@0:     mUeventObserverList.RemoveObserver(aObserver);
michael@0:     if (mUeventObserverList.Length() == 0)
michael@0:       ShutdownUevent();  // this will destroy self
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   ScopedClose mSocket;
michael@0:   MessageLoopForIO* mIOLoop;
michael@0:   MessageLoopForIO::FileDescriptorWatcher mReadWatcher;
michael@0: 
michael@0:   const static int kBuffsize = 64 * 1024;
michael@0:   uint8_t mBuffer [kBuffsize];
michael@0: 
michael@0:   typedef ObserverList<NetlinkEvent> UeventObserverList;
michael@0:   UeventObserverList mUeventObserverList;
michael@0: };
michael@0: 
michael@0: bool
michael@0: NetlinkPoller::OpenSocket()
michael@0: {
michael@0:   mSocket.rwget() = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
michael@0:   if (mSocket.get() < 0)
michael@0:     return false;
michael@0: 
michael@0:   int sz = kBuffsize;
michael@0: 
michael@0:   if (setsockopt(mSocket.get(), SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)) < 0)
michael@0:     return false;
michael@0: 
michael@0:   // add FD_CLOEXEC flag
michael@0:   int flags = fcntl(mSocket.get(), F_GETFD);
michael@0:   if (flags == -1) {
michael@0:       return false;
michael@0:   }
michael@0:   flags |= FD_CLOEXEC;
michael@0:   if (fcntl(mSocket.get(), F_SETFD, flags) == -1)
michael@0:     return false;
michael@0: 
michael@0:   // set non-blocking
michael@0:   if (fcntl(mSocket.get(), F_SETFL, O_NONBLOCK) == -1)
michael@0:     return false;
michael@0: 
michael@0:   struct sockaddr_nl saddr;
michael@0:   bzero(&saddr, sizeof(saddr));
michael@0:   saddr.nl_family = AF_NETLINK;
michael@0:   saddr.nl_groups = 1;
michael@0:   saddr.nl_pid = gettid();
michael@0: 
michael@0:   do {
michael@0:     if (bind(mSocket.get(), (struct sockaddr *)&saddr, sizeof(saddr)) == 0) {
michael@0:       break;
michael@0:     }
michael@0: 
michael@0:     if (errno != EADDRINUSE) {
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     if (saddr.nl_pid == 0) {
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     // Once there was any other place in the same process assigning saddr.nl_pid by
michael@0:     // gettid(), we can detect it and print warning message.
michael@0:     printf_stderr("The netlink socket address saddr.nl_pid=%u is in use. Let the kernel re-assign.\n", saddr.nl_pid);
michael@0:     saddr.nl_pid = 0;
michael@0:   } while (true);
michael@0: 
michael@0:   if (!mIOLoop->WatchFileDescriptor(mSocket.get(),
michael@0:                                     true,
michael@0:                                     MessageLoopForIO::WATCH_READ,
michael@0:                                     &mReadWatcher,
michael@0:                                     this)) {
michael@0:       return false;
michael@0:   }
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: static nsAutoPtr<NetlinkPoller> sPoller;
michael@0: 
michael@0: class UeventInitTask : public Task
michael@0: {
michael@0:   virtual void Run()
michael@0:   {
michael@0:     if (!sPoller) {
michael@0:       return;
michael@0:     }
michael@0:     if (sPoller->OpenSocket()) {
michael@0:       return;
michael@0:     }
michael@0:     sPoller->GetIOLoop()->PostDelayedTask(FROM_HERE, new UeventInitTask(), 1000);
michael@0:   }
michael@0: };
michael@0: 
michael@0: void
michael@0: NetlinkPoller::OnFileCanReadWithoutBlocking(int fd)
michael@0: {
michael@0:   MOZ_ASSERT(fd == mSocket.get());
michael@0:   while (true) {
michael@0:     int ret = read(fd, mBuffer, kBuffsize);
michael@0:     if (ret == -1) {
michael@0:       if (errno == EAGAIN || errno == EWOULDBLOCK) {
michael@0:         return;
michael@0:       }
michael@0:       if (errno == EINTR) {
michael@0:         continue;
michael@0:       }
michael@0:     }
michael@0:     if (ret <= 0) {
michael@0:       // fatal error on netlink socket which should not happen
michael@0:       _exit(1);
michael@0:     }
michael@0:     NetlinkEvent netlinkEvent;
michael@0:     netlinkEvent.decode(reinterpret_cast<char*>(mBuffer), ret);
michael@0:     mUeventObserverList.Broadcast(netlinkEvent);
michael@0:   }
michael@0: }
michael@0: 
michael@0: static void
michael@0: InitializeUevent()
michael@0: {
michael@0:   MOZ_ASSERT(!sPoller);
michael@0:   sPoller = new NetlinkPoller();
michael@0:   sPoller->GetIOLoop()->PostTask(FROM_HERE, new UeventInitTask());
michael@0: 
michael@0: }
michael@0: 
michael@0: static void
michael@0: ShutdownUevent()
michael@0: {
michael@0:   sPoller = nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: RegisterUeventListener(IUeventObserver *aObserver)
michael@0: {
michael@0:   MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
michael@0: 
michael@0:   if (!sPoller)
michael@0:     InitializeUevent();
michael@0:   sPoller->RegisterObserver(aObserver);
michael@0: }
michael@0: 
michael@0: void
michael@0: UnregisterUeventListener(IUeventObserver *aObserver)
michael@0: {
michael@0:   MOZ_ASSERT(MessageLoop::current() == XRE_GetIOMessageLoop());
michael@0: 
michael@0:   sPoller->UnregisterObserver(aObserver);
michael@0: }
michael@0: 
michael@0: } // hal_impl
michael@0: } // mozilla
michael@0: