// SoftEther VPN Source Code
// Cedar Communication Module
// 
// SoftEther VPN Server, Client and Bridge are free software under GPLv2.
// 
// Copyright (c) 2012-2014 Daiyuu Nobori.
// Copyright (c) 2012-2014 SoftEther VPN Project, University of Tsukuba, Japan.
// Copyright (c) 2012-2014 SoftEther Corporation.
// 
// All Rights Reserved.
// 
// http://www.softether.org/
// 
// Author: Daiyuu Nobori
// Comments: Tetsuo Sugiyama, Ph.D.
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// version 2 as published by the Free Software Foundation.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License version 2
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
// 
// 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.
// 
// THE LICENSE AGREEMENT IS ATTACHED ON THE SOURCE-CODE PACKAGE
// AS "LICENSE.TXT" FILE. READ THE TEXT FILE IN ADVANCE TO USE 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
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// SOFTETHER VPN PROJECT HAS DEVELOPED AND DISTRIBUTED THIS SOFTWARE TO
// COMPLY ONLY WITH THE JAPANESE LAWS AND EXISTING CIVIL RIGHTS INCLUDING
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// SUED BY A PRIVATE ENTITY OR BE DAMAGED BY A PUBLIC SERVANT IN YOUR
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// 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.
// 
// 
// 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.


// SecureNAT.c
// SecureNAT code

#include "CedarPch.h"

// SecureNAT server-side thread
void SnSecureNATThread(THREAD *t, void *param)
{
	SNAT *s;
	CONNECTION *c;
	SESSION *se;
	POLICY *policy;
	HUB *h;
	// Validate arguments
	if (t == NULL || param == NULL)
	{
		return;
	}

	s = (SNAT *)param;
	// Create a server connection
	c = NewServerConnection(s->Cedar, NULL, t);
	c->Protocol = CONNECTION_HUB_SECURE_NAT;

	// Apply the default policy
	policy = ClonePolicy(GetDefaultPolicy());

	// Not to limit the number of broadcast
	policy->NoBroadcastLimiter = true;

	h = s->Hub;
	AddRef(h->ref);

	// create a server session
	se = NewServerSession(s->Cedar, c, s->Hub, SNAT_USER_NAME, policy);
	se->SecureNATMode = true;
	se->SecureNAT = s;
	c->Session = se;
	ReleaseConnection(c);

	HLog(se->Hub, "LH_NAT_START", se->Name);

	// User name
	se->Username = CopyStr(SNAT_USER_NAME_PRINT);

	s->Session = se;
	AddRef(se->ref);

	// Notification initialization completion
	NoticeThreadInit(t);

	ReleaseCancel(s->Nat->Virtual->Cancel);
	s->Nat->Virtual->Cancel = se->Cancel1;
	AddRef(se->Cancel1->ref);

	if (s->Nat->Virtual->NativeNat != NULL)
	{
		CANCEL *old_cancel = NULL;

		Lock(s->Nat->Virtual->NativeNat->CancelLock);
		{
			if (s->Nat->Virtual->NativeNat->Cancel != NULL)
			{
				old_cancel = s->Nat->Virtual->NativeNat->Cancel;

				s->Nat->Virtual->NativeNat->Cancel = se->Cancel1;

				AddRef(se->Cancel1->ref);
			}
		}
		Unlock(s->Nat->Virtual->NativeNat->CancelLock);

		if (old_cancel != NULL)
		{
			ReleaseCancel(old_cancel);
		}
	}

	// Main function of the session
	Debug("SecureNAT Start.\n");
	SessionMain(se);
	Debug("SecureNAT Stop.\n");

	HLog(se->Hub, "LH_NAT_STOP");

	ReleaseHub(h);

	ReleaseSession(se);
}

// Release the SecureNAT
void SnFreeSecureNAT(SNAT *s)
{
	// Validate arguments
	if (s == NULL)
	{
		return;
	}

	// Stop the session 
	StopSession(s->Session);
	ReleaseSession(s->Session);

	// Virtual machine release
	Virtual_Free(s->Nat->Virtual);

	// NAT release
	NiFreeNat(s->Nat);

	DeleteLock(s->lock);

	Free(s);
}

// Create a new SecureNAT
SNAT *SnNewSecureNAT(HUB *h, VH_OPTION *o)
{
	SNAT *s;
	THREAD *t;
	// Validate arguments
	if (h == NULL || o == NULL)
	{
		return NULL;
	}

	s = ZeroMalloc(sizeof(SNAT));
	s->Cedar = h->Cedar;
	s->Hub = h;
	s->lock = NewLock();

	// Create a NAT
	s->Nat = NiNewNatEx(s, o);

	// Initialize the virtual machine
	VirtualInit(s->Nat->Virtual);

	// Create a thread
	t = NewThread(SnSecureNATThread, s);
	WaitThreadInit(t);
	ReleaseThread(t);

	return s;
}


// Developed by SoftEther VPN Project at University of Tsukuba in Japan.
// Department of Computer Science has dozens of overly-enthusiastic geeks.
// Join us: http://www.tsukuba.ac.jp/english/admission/