// SoftEther VPN Source Code - Stable Edition Repository
// Cedar Communication Module
// 
// SoftEther VPN Server, Client and Bridge are free software under the Apache License, Version 2.0.
// 
// Copyright (c) Daiyuu Nobori.
// Copyright (c) SoftEther VPN Project, University of Tsukuba, Japan.
// Copyright (c) SoftEther Corporation.
// Copyright (c) all contributors on SoftEther VPN project in GitHub.
// 
// All Rights Reserved.
// 
// http://www.softether.org/
// 
// This stable branch is officially managed by Daiyuu Nobori, the owner of SoftEther VPN Project.
// Pull requests should be sent to the Developer Edition Master Repository on https://github.com/SoftEtherVPN/SoftEtherVPN
// 
// License: The Apache License, Version 2.0
// https://www.apache.org/licenses/LICENSE-2.0
// 
// DISCLAIMER
// ==========
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
// 
// THIS SOFTWARE IS DEVELOPED IN JAPAN, AND DISTRIBUTED FROM JAPAN, UNDER
// JAPANESE LAWS. YOU MUST AGREE IN ADVANCE TO USE, COPY, MODIFY, MERGE, PUBLISH,
// DISTRIBUTE, SUBLICENSE, AND/OR SELL COPIES OF THIS SOFTWARE, THAT ANY
// JURIDICAL DISPUTES WHICH ARE CONCERNED TO THIS SOFTWARE OR ITS CONTENTS,
// AGAINST US (SOFTETHER PROJECT, SOFTETHER CORPORATION, DAIYUU NOBORI OR OTHER
// SUPPLIERS), OR ANY JURIDICAL DISPUTES AGAINST US WHICH ARE CAUSED BY ANY KIND
// OF USING, COPYING, MODIFYING, MERGING, PUBLISHING, DISTRIBUTING, SUBLICENSING,
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// JURISDICTION AND VENUE IN THE COURTS SITTING IN TOKYO, JAPAN. YOU MUST WAIVE
// ALL DEFENSES OF LACK OF PERSONAL JURISDICTION AND FORUM NON CONVENIENS.
// PROCESS MAY BE SERVED ON EITHER PARTY IN THE MANNER AUTHORIZED BY APPLICABLE
// LAW OR COURT RULE.
// 
// USE ONLY IN JAPAN. DO NOT USE THIS SOFTWARE IN ANOTHER COUNTRY UNLESS YOU HAVE
// A CONFIRMATION THAT THIS SOFTWARE DOES NOT VIOLATE ANY CRIMINAL LAWS OR CIVIL
// RIGHTS IN THAT PARTICULAR COUNTRY. USING THIS SOFTWARE IN OTHER COUNTRIES IS
// COMPLETELY AT YOUR OWN RISK. THE SOFTETHER VPN PROJECT HAS DEVELOPED AND
// DISTRIBUTED THIS SOFTWARE TO COMPLY ONLY WITH THE JAPANESE LAWS AND EXISTING
// CIVIL RIGHTS INCLUDING PATENTS WHICH ARE SUBJECTS APPLY IN JAPAN. OTHER
// COUNTRIES' LAWS OR CIVIL RIGHTS ARE NONE OF OUR CONCERNS NOR RESPONSIBILITIES.
// WE HAVE NEVER INVESTIGATED ANY CRIMINAL REGULATIONS, CIVIL LAWS OR
// INTELLECTUAL PROPERTY RIGHTS INCLUDING PATENTS IN ANY OF OTHER 200+ COUNTRIES
// AND TERRITORIES. BY NATURE, THERE ARE 200+ REGIONS IN THE WORLD, WITH
// DIFFERENT LAWS. IT IS IMPOSSIBLE TO VERIFY EVERY COUNTRIES' LAWS, REGULATIONS
// AND CIVIL RIGHTS TO MAKE THE SOFTWARE COMPLY WITH ALL COUNTRIES' LAWS BY THE
// PROJECT. EVEN IF YOU WILL BE SUED BY A PRIVATE ENTITY OR BE DAMAGED BY A
// PUBLIC SERVANT IN YOUR COUNTRY, THE DEVELOPERS OF THIS SOFTWARE WILL NEVER BE
// LIABLE TO RECOVER OR COMPENSATE SUCH DAMAGES, CRIMINAL OR CIVIL
// RESPONSIBILITIES. NOTE THAT THIS LINE IS NOT LICENSE RESTRICTION BUT JUST A
// STATEMENT FOR WARNING AND DISCLAIMER.
// 
// READ AND UNDERSTAND THE 'WARNING.TXT' FILE BEFORE USING THIS SOFTWARE.
// SOME SOFTWARE PROGRAMS FROM THIRD PARTIES ARE INCLUDED ON THIS SOFTWARE WITH
// LICENSE CONDITIONS WHICH ARE DESCRIBED ON THE 'THIRD_PARTY.TXT' FILE.
// 
// 
// SOURCE CODE CONTRIBUTION
// ------------------------
// 
// Your contribution to SoftEther VPN Project is much appreciated.
// Please send patches to us through GitHub.
// Read the SoftEther VPN Patch Acceptance Policy in advance:
// http://www.softether.org/5-download/src/9.patch
// 
// 
// DEAR SECURITY EXPERTS
// ---------------------
// 
// If you find a bug or a security vulnerability please kindly inform us
// about the problem immediately so that we can fix the security problem
// to protect a lot of users around the world as soon as possible.
// 
// Our e-mail address for security reports is:
// softether-vpn-security [at] softether.org
// 
// Please note that the above e-mail address is not a technical support
// inquiry address. If you need technical assistance, please visit
// http://www.softether.org/ and ask your question on the users forum.
// 
// Thank you for your cooperation.
// 
// 
// NO MEMORY OR RESOURCE LEAKS
// ---------------------------
// 
// The memory-leaks and resource-leaks verification under the stress
// test has been passed before release this source code.


// Listener.h
// Header of Listener.c

#ifndef	LISTENER_H
#define	LISTENER_H


// Function to call when receiving a new connection
typedef void (NEW_CONNECTION_PROC)(CONNECTION *c);

// DOS attack list
struct DOS
{
	IP IpAddress;					// IP address
	UINT64 FirstConnectedTick;		// Time which a client connects at the first time
	UINT64 LastConnectedTick;		// Time which a client connected at the last time
	UINT64 CurrentExpireSpan;		// Current time-out period of this record
	UINT64 DeleteEntryTick;			// Time planned to delete this entry
	UINT AccessCount;				// The number of accesses
};


// Listener structure
struct LISTENER
{
	LOCK *lock;						// Lock
	REF *ref;						// Reference counter
	CEDAR *Cedar;					// Cedar
	UINT Protocol;					// Protocol
	UINT Port;						// Port number
	THREAD *Thread;					// Operating thread
	SOCK *Sock;						// Socket
	EVENT *Event;					// Event
	volatile bool Halt;				// Halting flag
	UINT Status;					// State

	LIST *DosList;					// DOS attack list
	UINT64 DosListLastRefreshTime;	// Time that the DOS list is refreshed at the last

	THREAD_PROC *ThreadProc;		// Thread procedure
	void *ThreadParam;				// Thread parameters
	bool LocalOnly;					// Can be connected only from localhost
	bool ShadowIPv6;				// Flag indicating that the shadow IPv6 listener
	LISTENER *ShadowListener;		// Reference to managing shadow IPv6 listener
	bool DisableDos;				// Disable the DoS attack detection
	volatile UINT *NatTGlobalUdpPort;	// NAT-T global UDP port number
	UCHAR RandPortId;				// NAT-T UDP random port ID
	bool EnableConditionalAccept;	// The flag of whether to enable the Conditional Accept
};

// Parameters of TCPAcceptedThread
struct TCP_ACCEPTED_PARAM
{
	LISTENER *r;
	SOCK *s;
};

// UDP entry
struct UDP_ENTRY
{
	UINT SessionKey32;				// 32bit session key
	SESSION *Session;				// Reference to the session
};

// Dynamic listener
struct DYNAMIC_LISTENER
{
	UINT Protocol;					// Protocol
	UINT Port;						// Port
	LOCK *Lock;						// Lock
	CEDAR *Cedar;					// Cedar
	bool *EnablePtr;				// A pointer to the flag of the valid / invalid state
	LISTENER *Listener;				// Listener
};


// Function prototype
LISTENER *NewListener(CEDAR *cedar, UINT proto, UINT port);
LISTENER *NewListenerEx(CEDAR *cedar, UINT proto, UINT port, THREAD_PROC *proc, void *thread_param);
LISTENER *NewListenerEx2(CEDAR *cedar, UINT proto, UINT port, THREAD_PROC *proc, void *thread_param, bool local_only);
LISTENER *NewListenerEx3(CEDAR *cedar, UINT proto, UINT port, THREAD_PROC *proc, void *thread_param, bool local_only, bool shadow_ipv6);
LISTENER *NewListenerEx4(CEDAR *cedar, UINT proto, UINT port, THREAD_PROC *proc, void *thread_param, bool local_only, bool shadow_ipv6,
						 volatile UINT *natt_global_udp_port, UCHAR rand_port_id);
LISTENER *NewListenerEx5(CEDAR *cedar, UINT proto, UINT port, THREAD_PROC *proc, void *thread_param, bool local_only, bool shadow_ipv6,
						 volatile UINT *natt_global_udp_port, UCHAR rand_port_id, bool enable_ca);
void ReleaseListener(LISTENER *r);
void CleanupListener(LISTENER *r);
void ListenerThread(THREAD *thread, void *param);
void ListenerTCPMainLoop(LISTENER *r);
void StopListener(LISTENER *r);
int CompareListener(void *p1, void *p2);
void TCPAccepted(LISTENER *r, SOCK *s);
void EnableDosProtect();
void DisableDosProtect();
void TCPAcceptedThread(THREAD *t, void *param);
void ListenerUDPMainLoop(LISTENER *r);
void UDPReceivedPacket(CEDAR *cedar, SOCK *s, IP *ip, UINT port, void *data, UINT size);
int CompareUDPEntry(void *p1, void *p2);
void CleanupUDPEntry(CEDAR *cedar);
void AddUDPEntry(CEDAR *cedar, SESSION *session);
void DelUDPEntry(CEDAR *cedar, SESSION *session);
SESSION *GetSessionFromUDPEntry(CEDAR *cedar, UINT key32);
UINT GetMaxConnectionsPerIp();
void SetMaxConnectionsPerIp(UINT num);
UINT GetMaxUnestablishedConnections();
void SetMaxUnestablishedConnections(UINT num);
DYNAMIC_LISTENER *NewDynamicListener(CEDAR *c, bool *enable_ptr, UINT protocol, UINT port);
void ApplyDynamicListener(DYNAMIC_LISTENER *d);
void FreeDynamicListener(DYNAMIC_LISTENER *d);
bool ListenerRUDPRpcRecvProc(RUDP_STACK *r, UDPPACKET *p);
void ListenerSetProcRecvRpcEnable(bool b);

int CompareDos(void *p1, void *p2);
DOS *SearchDosList(LISTENER *r, IP *ip);
void RefreshDosList(LISTENER *r);
bool CheckDosAttack(LISTENER *r, SOCK *s);
bool RemoveDosEntry(LISTENER *r, SOCK *s);

#endif	// LISTENER_H