Filter.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
#ifndef NETWORK_STACK_FILTER_H
#define NETWORK_STACK_FILTER_H
#include "pedigree/kernel/Spinlock.h"
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/process/WaitQueue.h"
#include "pedigree/kernel/processor/types.h"
#include "pedigree/kernel/utilities/List.h"
 
#include <config.h>
 
class Thread;
 
class EXPORTED_PUBLIC NetworkFilter {
 public:
  NetworkFilter();
 
  virtual ~NetworkFilter();
 
  static NetworkFilter& instance() {
    return m_Instance;
  }
 
  bool filter(size_t level, uintptr_t packet, size_t sz);
 
  size_t installCallback(size_t level, bool (*callback)(uintptr_t, size_t));
 
  bool removeCallback(size_t level, size_t id);
 
#if (HOSTED && PEDIGREE_HOSTED_SMOKE_TESTS) || PEDIGREE_CONCURRENCY_SMOKE_TESTS
  using CallbackPinHook = void (*)(bool (*)(uintptr_t, size_t), size_t);
  static void setCallbackPinHook(CallbackPinHook hook);
#endif
 
 private:
  struct CallbackItem {
    size_t id;
    bool (*callback)(uintptr_t, size_t);
    size_t inFlight;
    size_t removers;
    bool enabled;
    bool draining;
    WaitQueue drainWaiters;
  };
 
  struct ActiveInvocation {
    CallbackItem* item;
    Thread* thread;
    ActiveInvocation* next;
  };
 
  void drainCallback(size_t level, CallbackItem* item);
  bool isCallbackInvocation(Thread* thread) const;
 
  static NetworkFilter m_Instance;
 
  List<CallbackItem*> m_Callbacks[4];
  Spinlock m_Lock;
  size_t m_NextCallbackId;
  ActiveInvocation* m_pActiveInvocations;
 
#if (HOSTED && PEDIGREE_HOSTED_SMOKE_TESTS) || PEDIGREE_CONCURRENCY_SMOKE_TESTS
  static CallbackPinHook m_CallbackPinHook;
#endif
};
 
#endif  // NETWORK_STACK_FILTER_H