/*
 * Dibbler - a portable DHCPv6
 *
 * authors: Tomasz Mrugalski <thomson@klub.com.pl>
 *          Marek Senderski <msend@o2.pl>
 * chamges: Krzysztof Wnuk <keczi@poczta.onet.pl>
 * released under GNU GPL v2 only licence
 *
 * $Id: ClntMsgSolicit.cpp,v 1.27 2009-03-24 23:17:17 thomson Exp $
 */
#include "SmartPtr.h"
#include "Msg.h"

#include "ClntIfaceMgr.h"
#include "ClntCfgIface.h"
#include "ClntCfgIA.h"

#include "ClntMsg.h"
#include "ClntMsgSolicit.h"
#include "ClntMsgAdvertise.h"

#include "ClntOptIA_NA.h"
#include "ClntOptTA.h"
#include "ClntOptIA_PD.h"
#include "OptDUID.h"
#include "ClntOptOptionRequest.h"
#include "ClntOptElapsed.h"
#include "ClntOptPreference.h"
#include "OptEmpty.h"
#include "ClntOptStatusCode.h"
#include <cmath>
#include "Logger.h"

TClntMsgSolicit::TClntMsgSolicit(int iface, SPtr<TIPv6Addr> addr,
				 List(TClntCfgIA) iaLst, 
				 SPtr<TClntCfgTA> ta,
				 List(TClntCfgPD) pdLst, 
				 bool rapid, bool remoteAutoconf)
    :TClntMsg(iface, addr, SOLICIT_MSG)
{
    IRT=SOL_TIMEOUT;
    MRT=SOL_MAX_RT;
    MRC=0; //these both below mean there is no ending condition and transactions
    MRD=0; //lasts till receiving answer
    RT=0;
	
    // ClientIdentifier option
    appendClientID();

    SPtr<TAddrIA> addrIA;
    
    // all IAs are provided by ::checkSolicit()
    SPtr<TClntCfgIA> ia;
    iaLst.first();
    while (ia = iaLst.get()) {
        SPtr<TClntOptIA_NA> iaOpt;
        iaOpt = new TClntOptIA_NA(ia, this);
        Options.push_back( (Ptr*)iaOpt );
        if (!remoteAutoconf)
            ia->setState(STATE_INPROCESS);
        addrIA = ClntAddrMgr().getIA(ia->getIAID());
        if (addrIA)
            addrIA->setState(STATE_INPROCESS);
        else
            Log(Error) << "AddrMgr does not have IA with IAID=" << ia->getIAID() << LogEnd;
    }

    // TA is provided by ::checkSolicit()
    if (ta) {
	SPtr<TClntOptTA> taOpt = new TClntOptTA(ta->getIAID(), this);
	Options.push_back( (Ptr*) taOpt);
	if (!remoteAutoconf)
	    ta->setState(STATE_INPROCESS);
        addrIA = ClntAddrMgr().getTA(ta->getIAID());
        if (addrIA)
            addrIA->setState(STATE_INPROCESS);
        else
            Log(Error) << "AddrMgr does not have TA with IAID=" << ia->getIAID() << LogEnd;
    }

    // all PDs are provided by ::checkSolicit()
    SPtr<TClntCfgPD> pd;
    pdLst.first();
    while ( pd = pdLst.get() ) {
        SPtr<TClntOptIA_PD> pdOpt = new TClntOptIA_PD(pd, this);
        Options.push_back( (Ptr*)pdOpt );
        if (!remoteAutoconf)
            pd->setState(STATE_INPROCESS);
        addrIA = ClntAddrMgr().getPD(pd->getIAID());
        if (addrIA)
            addrIA->setState(STATE_INPROCESS);
        else
            Log(Error) << "AddrMgr does not have PD with IAID=" << pd->getIAID() << LogEnd;
    }
    
    if (rapid)
        Options.push_back(new TOptEmpty(OPTION_RAPID_COMMIT, this));

    // RECONF-ACCEPT is added in TClntMsg::appendRequestedOptions()

    // append and switch to INPROCESS state
    if (!remoteAutoconf)
	appendTAOptions(true); 

    // append options specified in the config file
    if (!remoteAutoconf)
	appendRequestedOptions();

    appendAuthenticationOption();
    
    IsDone = false;
    send();
}

void TClntMsgSolicit::answer(SPtr<TClntMsg> msg)
{
    if (shallRejectAnswer(msg)) {
        Log(Info) << "Server message was rejected." << LogEnd;
	return;
    }

    switch (msg->getType()) {
    case ADVERTISE_MSG:
    {
	if (this->getOption(OPTION_RAPID_COMMIT)) {
	    Log(Info) << "Server responded with ADVERTISE instead of REPLY, probably does not support"
		" RAPID-COMMIT." << LogEnd;
	}
	ClntTransMgr().addAdvertise((Ptr*)msg);
	SPtr<TOptInteger> prefOpt = (Ptr*) msg->getOption(OPTION_PREFERENCE);

	if (prefOpt && (prefOpt->getValue() == 255) )
	{
	    Log(Info) << "ADVERTISE message with preference set to 255 received, so wait time for"
		" other possible ADVERTISE messages is skipped." << LogEnd;
	    ClntTransMgr().sendRequest(Options, Iface);
	    IsDone = true;
	    return;
	}

	if (this->RC > 1)
	{
	    ClntTransMgr().sendRequest(Options, Iface);
	    IsDone = true;
	    return;
	}
	break;
    }
    case REPLY_MSG:
    {
	if (!this->getOption(OPTION_RAPID_COMMIT)) {
	    Log(Warning) << "REPLY received, but SOLICIT was sent without RAPID_COMMIT. Ignoring." 
			 << LogEnd;
	    return;
	}
	if (!msg->getOption(OPTION_RAPID_COMMIT)) {
	    Log(Warning) << "REPLY as answer for SOLICIT received without RAPID_COMMIT. Ignoring."
			 << LogEnd;
	    return;
	}

	TClntMsg::answer(msg);
	break;
    }
    default:
	Log(Warning) << "Invalid message type (" << msg->getType() 
		     << ") received as answer for SOLICIT message." << LogEnd;
	return;
    }
 }


/// @brief check if received message should be accepted.
///
/// The following conditions are checked:
/// - is server on the black-list?
/// - are all requested options present?
/// - is there requested IA option?
/// - is there requested TA option?
/// - is there requested PD option?
/// - is requested PD option valid?
///
/// @param msg server's REPLY
///
/// @return true if REPLY is rejected
bool TClntMsgSolicit::shallRejectAnswer(SPtr<TClntMsg> msg)
{
    bool somethingAssigned = false;

    // this == solicit or request
    // msg  == reply
    SPtr<TOptDUID> srvDUID = (Ptr*) msg->getOption(OPTION_SERVERID);
    if (!srvDUID) {
        Log(Notice) << "No server identifier provided. Message ignored." << LogEnd;
        return true;
    }
    
    //is this server rejected?
    SPtr<TClntCfgIface> iface = ClntCfgMgr().getIface(this->Iface);
    if (!iface) {
        Log(Error) << "Unable to find iface=" << this->Iface << "." << LogEnd;
        return true;
    }
    if (iface->isServerRejected(msg->getRemoteAddr(), srvDUID->getDUID())) {
	Log(Notice) << "Server was rejected (duid=" << srvDUID->getDUID() << ")." << LogEnd;
        return true;
    }

    // have we asked for IA?
    bool iaOk = true;
    if (this->getOption(OPTION_IA_NA))
    {
        /// @todo Check if proper IAIDs are returned, also if all IA were answered (if requested
        ///       several IAs were requested)
        /// @todo Check all IA_NAs, not just first one
        SPtr<TClntOptIA_NA> ia = (Ptr*)msg->getOption(OPTION_IA_NA);
        if (!ia)  {
            Log(Notice) << "IA_NA option requested, but not present in this message. Ignored." << LogEnd;
            iaOk = false;
        } else {
            if (!ia->getOption(OPTION_IAADDR)) {
                Log(Notice) << "IA_NA option returned, but without any addresses. Ignored." << LogEnd;
                iaOk = false;
            }
            SPtr<TClntOptStatusCode> st = (Ptr*)ia->getOption(OPTION_STATUS_CODE);
            if (st && st->getCode()!= STATUSCODE_SUCCESS) {
                Log(Notice) << "IA_NA has status code!=SUCCESS: " << st->getCode()
                            << "(" << st->getText() << "). Ignored." << LogEnd;
                iaOk = false;
            }
        }
        if (iaOk)
            somethingAssigned = true;
    }

    // have we asked for TA?
    bool taOk = true;
    if (this->getOption(OPTION_IA_TA)) {
        SPtr<TClntOptTA> ta = (Ptr*)msg->getOption(OPTION_IA_TA);
        if (!ta) {
            Log(Notice) << "TA option requested, but not present in this message. Ignored." << LogEnd;
            taOk = false;
        } else {
            if (!ta->getOption(OPTION_IAADDR)) {
                Log(Notice) << "TA option received, but without IAADDR" << LogEnd;
                taOk = false;
            }

            SPtr<TClntOptStatusCode> st = (Ptr*)ta->getOption(OPTION_STATUS_CODE);
            if (st && st->getCode()!= STATUSCODE_SUCCESS) {
                Log(Notice) << "IA_TA has status code!=SUCCESS: " << st->getCode()
                            << "(" << st->getText() << "). Ignored." << LogEnd;
                taOk = false;
            }
        }
        if (taOk)
            somethingAssigned = true;
    }

    // have we asked for PD?
    int msgPd = 0; // number of the IA_PDs requested
    msg->firstOption();
    SPtr<TOpt> optTemp;
    while (optTemp = msg->getOption()) {
        if (optTemp->getOptType() == OPTION_IA_PD) {
            msgPd++;
        }
    }

    bool pdOk = true;
    bool pdFound = false;
    int pdcnt = 0; // number of usable IA_PD options in the response

    SPtr<TOpt> opt_sent; // iterates over options in solicit
    SPtr<TOpt> opt_rcvd; // iterates over options in received response

    // Let's get over all options in sent message (solicit)
    firstOption();
    while (opt_sent = getOption()) {
        if (opt_sent->getOptType() != OPTION_IA_PD)
           continue; // ignore all options except IA_PD

        SPtr<TClntOptIA_PD> pdSol = (Ptr*) opt_sent;

        // Now for each sent IA_PD, try to find matching response
        msg->firstOption();
        while (opt_rcvd = msg->getOption()) {

            // Let's ignore options other than IA_PD
            if (opt_rcvd->getOptType() != OPTION_IA_PD)
                continue;

            // Let's ignore IA_PDs with different IAID
            SPtr<TClntOptIA_PD> pdResp = (Ptr*) opt_rcvd;
            if (pdSol->getIAID() != pdResp->getIAID())
                continue;

            // Found in response ia_pd that matches ia_pd from solicit
            pdFound = true;

            pdcnt++;
            if (!pdResp->getOption(OPTION_IAPREFIX)) {
                Log(Notice) << "Received PD with IAID = " << pdResp->getIAID() << " without "
                               "any prefixes." << LogEnd;
                pdcnt--;
                if (ClntCfgMgr().insistMode()) {
                    Log(Notice) << "Received response with IA_PD without any prefixes, "
                                << "insist mode enabled, so rejecting this answer." << LogEnd;
                    pdOk = false;
                    break;
                } else {
                    //insist-mode off
                    if (msgPd == 1) {
                        //if there was only one PD and it has no prefixes, reject.
                        pdOk = false;
                        break;
                    }
                    else if (msgPd > 1) {
                        // if there were more than 1 PDs, delete the one without prefixes.
                        deletePD(opt_rcvd);
                    }
                    continue;
                }
            }

            // ia_pd has some ia_prefix options, let's take a look at them
            int prefixCount = pdResp->countPrefixes();
            pdResp->firstPrefix();
            SPtr<TClntOptIAPrefix> ppref;
            while (ppref = pdResp->getPrefix()) {
                if (!ppref->isValid()) {
                    Log(Warning) << "Option IA_PREFIX from IA_PD " <<
                                 pdResp->getIAID() << " is not valid." << LogEnd;
                    // RFC 3633, section 10:
                    // A requesting router discards any prefixes for which the
                    // preferred lifetime is greater than the valid lifetime.
                    pdResp->deletePrefix(ppref);
                    prefixCount--;
                    if (!prefixCount) {
                        // ia_pd hasn't got any valid prefixes.
                        pdcnt--;
                        if (ClntCfgMgr().insistMode()) {
                            // if insist-mode is enabled and one of received
                            // pd's has no valid prefixes, answer is rejected.
                            pdOk = false;
                            Log(Notice) << "Received IA_PD with a prefix that has lifetime 0."
                                        << "Insist mode enabled, so rejecting this answer." << LogEnd;
                        }
                        // no valid prefixes and insist-mode is off? delete PD;
                        // if not deleted, it will be copied to REQUEST message;
                        // this leads to situation where IA_PD in REQUEST has no prefixes;
                        deletePD(opt_rcvd);
                        break;
                    }
                }
            }
            SPtr<TClntOptStatusCode> st = (Ptr*)pdResp->getOption(OPTION_STATUS_CODE);
            if (st && st->getCode()!= STATUSCODE_SUCCESS) {
                Log(Notice) << "IA_NA has status code!=SUCCESS: " << st->getCode()
                << "(" << st->getText() << "). Ignored." << LogEnd;
                pdOk = false;
            }
        }
        if (!pdFound) {
            Log(Notice) << "PD option(s) requested, but not returned in this message."
                           " Ignored." << LogEnd;
            pdOk = false;
            break;
        }
    }

    if (!pdcnt) {
        // if all of ia_pd's in received answer were malformed, reject answer.
        pdOk = false;
    }
    if (pdOk)
        somethingAssigned = true;

    if (!somethingAssigned)
        return true; // this advertise does not offers us anything

    if (!ClntCfgMgr().insistMode())
        return false; // accept this advertise

    // insist-mode enabled. We MUST get everything we wanted or we reject this answer

    if (iaOk && taOk && pdOk)
        return false;
    else
        return true;
}

void TClntMsgSolicit::doDuties()
{
    if ( ClntTransMgr().getAdvertiseLstCount() ) { 
        // there is a timeout, but we have already answers and all is ok
        ClntTransMgr().sendRequest(Options, Iface);
        IsDone = true;
        return;
    }
    send();
}


bool TClntMsgSolicit::check()
{
    return false;
}

std::string TClntMsgSolicit::getName() const {
    return "SOLICIT";
}

TClntMsgSolicit::~TClntMsgSolicit() {
}