/*

* SRT - Secure, Reliable, Transport

* Copyright (c) 2018 Haivision Systems Inc.

*

* 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/.

*

*/

/*****************************************************************************

Copyright (c) 2001 - 2011, The Board of Trustees of the University of Illinois.

All rights reserved.

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are

met:

* Redistributions of source code must retain the above

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following disclaimer.

* Redistributions in binary form must reproduce the

above copyright notice, this list of conditions

and the following disclaimer in the documentation

and/or other materials provided with the distribution.

* Neither the name of the University of Illinois

nor the names of its contributors may be used to

endorse or promote products derived from this

software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR

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*****************************************************************************/

#include "platform_sys.h"

#include <cstring>

#include <string>

#include <sstream>

#include <iterator>

#include <algorithm>

#include "api.h"

#include "core.h"

#include "handshake.h"

#include "utilities.h"

using namespace std;

namespace srt

{

CHandShake::CHandShake()

: m_iVersion(0)

, m_iType(0) // Universal: UDT_UNDEFINED or no flags

, m_iISN(0)

, m_iMSS(0)

, m_iFlightFlagSize(0)

, m_iReqType(URQ_WAVEAHAND)

, m_iID(0)

, m_iCookie(0)

, m_extensionType(0)

{

for (int i = 0; i < 4; ++ i)

m_piPeerIP[i] = 0;

}

int CHandShake::store_to(char* buf, size_t& w_size)

{

if (w_size < m_iContentSize)

return -1;

int32_t* p = reinterpret_cast<int32_t*>(buf);

*p++ = m_iVersion;

*p++ = m_iType;

*p++ = m_iISN;

*p++ = m_iMSS;

*p++ = m_iFlightFlagSize;

*p++ = int32_t(m_iReqType);

*p++ = int32_t(m_iID);

*p++ = m_iCookie;

for (int i = 0; i < 4; ++ i)

*p++ = m_piPeerIP[i];

w_size = m_iContentSize;

return 0;

}

int CHandShake::load_from(const char* buf, size_t size)

{

if (size < m_iContentSize)

return -1;

const int32_t* p = reinterpret_cast<const int32_t*>(buf);

m_iVersion = *p++;

m_iType = *p++;

m_iISN = *p++;

m_iMSS = *p++;

m_iFlightFlagSize = *p++;

m_iReqType = UDTRequestType(*p++);

m_iID = SRTSOCKET(*p++);

m_iCookie = *p++;

for (int i = 0; i < 4; ++ i)

m_piPeerIP[i] = *p++;

m_extensionType = 0;

if (size > m_iContentSize + sizeof(int32_t) && m_iReqType == URQ_CONCLUSION)

{

// Extensions provided - check the first word for HSREQ/HSRSP

int cmd = HS_CMDSPEC_CMD::unwrap(*p);

if (cmd == SRT_CMD_HSREQ || cmd == SRT_CMD_HSRSP)

m_extensionType = cmd;

}

return 0;

}

#if HVU_ENABLE_LOGGING

const char* srt_rejectreason_name [] = {

"UNKNOWN",

"SYSTEM",

"PEER",

"RESOURCE",

"ROGUE",

"BACKLOG",

"IPE",

"CLOSE",

"VERSION",

"RDVCOOKIE",

"BADSECRET",

"UNSECURE",

"MESSAGEAPI",

"CONGESTION",

"FILTER",

"GROUP",

"TIMEOUT",

"CRYPTO"

};

std::string RequestTypeStr(UDTRequestType rq)

{

if (rq >= URQ_FAILURE_TYPES)

{

std::ostringstream rt;

rt << "ERROR:";

int id = RejectReasonForURQ(rq);

if (id < (int) Size(srt_rejectreason_name))

rt << srt_rejectreason_name[id];

else if (id < SRT_REJC_USERDEFINED)

{

if (id < SRT_REJC_PREDEFINED)

rt << "UNKNOWN:" << id;

else

rt << "PREDEFINED:" << (id - SRT_REJC_PREDEFINED);

}

else

rt << "USERDEFINED:" << (id - SRT_REJC_USERDEFINED);

return rt.str();

}

switch ( rq )

{

case URQ_INDUCTION: return "induction";

case URQ_WAVEAHAND: return "waveahand";

case URQ_CONCLUSION: return "conclusion";

case URQ_AGREEMENT: return "agreement";

default: return "INVALID";

}

}

string CHandShake::RdvStateStr(CHandShake::RendezvousState s)

{

switch (s)

{

case RDV_WAVING: return "waving";

case RDV_ATTENTION: return "attention";

case RDV_FINE: return "fine";

case RDV_INITIATED: return "initiated";

case RDV_CONNECTED: return "connected";

default: ;

}

return "invalid";

}

#endif

bool CHandShake::valid()

{

if (m_iVersion < CUDT::HS_VERSION_UDT4

|| m_iISN < 0 || m_iISN >= CSeqNo::m_iMaxSeqNo

|| m_iMSS < 32

|| m_iFlightFlagSize < 2)

return false;

return true;

}

string CHandShake::show()

{

using namespace hvu;

ofmtbufstream so;

so << "version=" << m_iVersion

<< " type=0x" << fmt(m_iType, hex)

<< " ISN=" << m_iISN << " MSS=" << m_iMSS << " FLW=" << m_iFlightFlagSize

<< " reqtype=" << RequestTypeStr(m_iReqType) << " srcID=" << m_iID

<< " cookie=" << fmt(m_iCookie, hex)

<< " srcIP=" << CIPAddress::show(m_piPeerIP);

// XXX HS version symbols should be probably declared inside

// CHandShake, not CUDT.

if ( m_iVersion > CUDT::HS_VERSION_UDT4 )

{

so << " FLAGS: ";

so << ExtensionFlagStr(m_iType);

}

return so.str();

}

string CHandShake::ExtensionFlagStr(int32_t fl)

{

std::ostringstream out;

const int flags = SrtHSRequest::SRT_HSTYPE_HSFLAGS::unwrap(fl);

const int kl = SrtHSRequest::SRT_HSTYPE_ENCFLAGS::unwrap(fl) << 6;

if (flags == SrtHSRequest::SRT_MAGIC_CODE)

out << "MAGIC ";

else if (fl == 0)

out << "NONE"; // no flags and no advertised pbkeylen

else

{

if ( fl & HS_EXT_HSREQ )

out << "hsx ";

if ( fl & HS_EXT_KMREQ )

out << "kmx ";

if ( fl & HS_EXT_CONFIG )

out << "cfg ";

}

if (kl != 0)

{

out << "[AES-" << kl << "]";

}

else

{

out << "[nokeyad]";

}

return out.str();

}

// XXX This code isn't currently used. Left here because it can

// be used in future, should any refactoring for the "manual word placement"

// code be done.

bool SrtHSRequest::serialize(char* buf, size_t size) const

{

if (size < SRT_HS_SIZE)

return false;

int32_t* p = reinterpret_cast<int32_t*>(buf);

*p++ = m_iSrtVersion;

*p++ = m_iSrtFlags;

*p++ = m_iSrtTsbpd;

*p++ = 0; // SURPRISE! Seriously, use (something) if this "reserved" is going to be used for something.

return true;

}

bool SrtHSRequest::deserialize(const char* buf, size_t size)

{

m_iSrtVersion = 0; // just to let users recognize if it succeeded or not.

if (size < SRT_HS_SIZE)

return false;

const int32_t* p = reinterpret_cast<const int32_t*>(buf);

m_iSrtVersion = (*p++);

m_iSrtFlags = (*p++);

m_iSrtTsbpd = (*p++);

m_iSrtReserved = (*p++);

return true;

}

string SrtFlagString(int32_t flags)

{

#define LEN(arr) (sizeof (arr)/(sizeof ((arr)[0])))

std::string output;

static std::string namera[] = { "TSBPD-snd", "TSBPD-rcv", "haicrypt", "TLPktDrop", "NAKReport", "ReXmitFlag", "StreamAPI", "FilterCapable" };

size_t i = 0;

for (; i < LEN(namera); ++i)

{

if ((flags & 1) == 1)

{

output += "+" + namera[i] + " ";

}

else

{

output += "-" + namera[i] + " ";

}

flags >>= 1;

}

#undef LEN

if (flags != 0)

{

output += "+unknown";

}

return output;

}

}