/* $Id: DhcpOptions.cpp $ */
/** @file
 * DHCP server - DHCP options
 */

/*
 * Copyright (C) 2017-2023 Oracle and/or its affiliates.
 *
 * This file is part of VirtualBox base platform packages, as
 * available from https://www.virtualbox.org.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation, in version 3 of the
 * License.
 *
 * 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
 * along with this program; if not, see <https://www.gnu.org/licenses>.
 *
 * SPDX-License-Identifier: GPL-3.0-only
 */


/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#include "DhcpdInternal.h"
#include "DhcpOptions.h"
#ifndef IN_VBOXSVC
# include "DhcpMessage.h"
#endif

#include <iprt/cidr.h>


#ifndef IN_VBOXSVC

optmap_t &operator<<(optmap_t &optmap, DhcpOption *option)
{
    if (option == NULL)
        return optmap;

    if (option->present())
        optmap[option->optcode()] = std::shared_ptr<DhcpOption>(option);
    else
        optmap.erase(option->optcode());

    return optmap;
}


optmap_t &operator<<(optmap_t &optmap, const std::shared_ptr<DhcpOption> &option)
{
    if (!option)
        return optmap;

    if (option->present())
        optmap[option->optcode()] = option;
    else
        optmap.erase(option->optcode());

    return optmap;
}

#endif /* !IN_VBOXSVC */


int DhcpOption::encode(octets_t &dst) const
{
    if (!m_fPresent)
        return VERR_INVALID_STATE;

    size_t cbOrig = dst.size();

    append(dst, m_OptCode);
    appendLength(dst, 0);  /* placeholder */

    ssize_t cbValue = encodeValue(dst);
    if (cbValue < 0 || UINT8_MAX <= cbValue)
    {
        dst.resize(cbOrig); /* undo */
        return VERR_INVALID_PARAMETER;
    }

    dst[cbOrig+1] = (uint8_t)cbValue;
    return VINF_SUCCESS;
}


/* static */
const octets_t *DhcpOption::findOption(const rawopts_t &aOptMap, uint8_t aOptCode)
{
    rawopts_t::const_iterator it(aOptMap.find(aOptCode));
    if (it == aOptMap.end())
        return NULL;

    return &it->second;
}


int DhcpOption::decode(const rawopts_t &map)
{
    const octets_t *rawopt = DhcpOption::findOption(map, m_OptCode);
    if (rawopt == NULL)
        return VERR_NOT_FOUND;

    int rc = decodeValue(*rawopt, rawopt->size());
    if (RT_FAILURE(rc))
        return VERR_INVALID_PARAMETER;

    return VINF_SUCCESS;
}


#ifndef IN_VBOXSVC
int DhcpOption::decode(const DhcpClientMessage &req)
{
    return decode(req.rawopts());
}
#endif


int DhcpOption::parse1(bool &aValue, const char *pcszValue)
{
    pcszValue = RTStrStripL(pcszValue);
    if (   strcmp(pcszValue, "true") == 0
        || strcmp(pcszValue, "1")    == 0
        || strcmp(pcszValue, "yes")  == 0
        || strcmp(pcszValue, "on")   == 0 )
    {
        aValue = true;
        return VINF_SUCCESS;
    }

    if (   strcmp(pcszValue, "false") == 0
        || strcmp(pcszValue, "0")     == 0
        || strcmp(pcszValue, "no")    == 0
        || strcmp(pcszValue, "off")   == 0 )
    {
        aValue = false;
        return VINF_SUCCESS;
    }

    uint8_t bTmp;
    int rc = RTStrToUInt8Full(RTStrStripL(pcszValue), 10, &bTmp);
    if (rc == VERR_TRAILING_SPACES)
        rc = VINF_SUCCESS;
    if (RT_SUCCESS(rc))
        aValue = bTmp != 0;

    return rc;
}


int DhcpOption::parse1(uint8_t &aValue, const char *pcszValue)
{
    int rc = RTStrToUInt8Full(RTStrStripL(pcszValue), 10, &aValue);
    if (rc == VERR_TRAILING_SPACES)
        rc = VINF_SUCCESS;
    return rc;
}


int DhcpOption::parse1(uint16_t &aValue, const char *pcszValue)
{
    int rc = RTStrToUInt16Full(RTStrStripL(pcszValue), 10, &aValue);

    if (rc == VERR_TRAILING_SPACES)
        rc = VINF_SUCCESS;
    return rc;
}


int DhcpOption::parse1(uint32_t &aValue, const char *pcszValue)
{
    int rc = RTStrToUInt32Full(RTStrStripL(pcszValue), 10, &aValue);

    if (rc == VERR_TRAILING_SPACES)
        rc = VINF_SUCCESS;
    return rc;
}


int DhcpOption::parse1(RTNETADDRIPV4 &aValue, const char *pcszValue)
{
    return RTNetStrToIPv4Addr(pcszValue, &aValue);
}


int DhcpOption::parse1(DhcpIpv4AddrAndMask &aValue, const char *pcszValue)
{
    return RTCidrStrToIPv4(pcszValue, &aValue.Ipv4, &aValue.Mask);
}


template <typename a_Type>
/*static*/ int DhcpOption::parseList(std::vector<a_Type> &aList, const char *pcszValue)
{
    std::vector<a_Type> vecTmp;

    pcszValue = RTStrStripL(pcszValue);
    for (;;)
    {
        /* Assume space, tab, comma or semicolon is used as separator (superset of RTStrStrip): */
        const char *pszNext = strpbrk(pcszValue, " ,;:\t\n\r");
        char szTmp[256];
        if (pszNext)
        {
            size_t cchToCopy = (size_t)(pszNext - pcszValue);
            if (cchToCopy >= sizeof(szTmp))
                return VERR_INVALID_PARAMETER;
            memcpy(szTmp, pcszValue, cchToCopy);
            szTmp[cchToCopy] = '\0';
            pcszValue = szTmp;

            /* Advance pszNext past the separator character and fluff: */
            char ch;
            do
                pszNext++;
            while ((ch = *pszNext) == ' ' || ch == ':' || ch == ';' || ch == '\t' || ch == '\n' || ch == '\r');
            if (ch == '\0')
                pszNext = NULL;
        }

        /* Try convert it: */
        a_Type Value;
        int rc = DhcpOption::parse1(Value, pcszValue);
        if (RT_SUCCESS(rc))
            vecTmp.push_back(Value);
        else
            return VERR_INVALID_PARAMETER;

        if (pszNext)
            pcszValue = pszNext;
        else
            break;
    }

    aList.swap(vecTmp);
    return VINF_SUCCESS;

}

/** ASSUME that uint8_t means hex byte strings. */
template <>
/*static*/ int DhcpOption::parseList(std::vector<uint8_t> &aList, const char *pcszValue)
{
    uint8_t abBuf[255];
    size_t  cbReturned = 0;
    int rc = RTStrConvertHexBytesEx(RTStrStripL(pcszValue), abBuf, sizeof(abBuf), RTSTRCONVERTHEXBYTES_F_SEP_COLON,
                                    NULL, &cbReturned);
    if (RT_SUCCESS(rc))
    {
        if (rc != VWRN_TRAILING_CHARS)
        {
            for (size_t i = 0; i < cbReturned; i++)
                aList.push_back(abBuf[i]);
            rc = VINF_SUCCESS;
        }
        else
            rc = VERR_TRAILING_CHARS;
    }
    return rc;
}



/*
 * XXX: See DHCPServer::encodeOption()
 */
int DhcpOption::parseHex(octets_t &aRawValue, const char *pcszValue)
{
    uint8_t abBuf[255];
    size_t  cbReturned = 0;
    int rc = RTStrConvertHexBytesEx(RTStrStripL(pcszValue), abBuf, sizeof(abBuf), RTSTRCONVERTHEXBYTES_F_SEP_COLON,
                                    NULL, &cbReturned);
    if (RT_SUCCESS(rc))
    {
        if (rc != VWRN_TRAILING_CHARS)
        {
            for (size_t i = 0; i < cbReturned; i++)
                aRawValue.push_back(abBuf[i]);
            rc = VINF_SUCCESS;
        }
        else
            rc = VERR_TRAILING_CHARS;
    }
    return rc;
}


/*static*/ DhcpOption *DhcpOption::parse(uint8_t aOptCode, int aEnc, const char *pcszValue, int *prc /*= NULL*/)
{
    int rcIgn;
    if (!prc)
        prc = &rcIgn;

    switch (aEnc)
    {
        case 0: /* DHCPOptionEncoding_Normal */
            switch (aOptCode)
            {
#define HANDLE(a_OptClass)  \
                case a_OptClass::optcode: \
                    return a_OptClass::parse(pcszValue, prc)

                HANDLE(OptSubnetMask);                  // 1
                HANDLE(OptTimeOffset);                  // 2
                HANDLE(OptRouters);                     // 3
                HANDLE(OptTimeServers);                 // 4
                HANDLE(OptNameServers);                 // 5
                HANDLE(OptDNSes);                       // 6
                HANDLE(OptLogServers);                  // 7
                HANDLE(OptCookieServers);               // 8
                HANDLE(OptLPRServers);                  // 9
                HANDLE(OptImpressServers);              // 10
                HANDLE(OptResourceLocationServers);     // 11
                HANDLE(OptHostName);                    // 12
                HANDLE(OptBootFileSize);                // 13
                HANDLE(OptMeritDumpFile);               // 14
                HANDLE(OptDomainName);                  // 15
                HANDLE(OptSwapServer);                  // 16
                HANDLE(OptRootPath);                    // 17
                HANDLE(OptExtensionPath);               // 18
                HANDLE(OptIPForwarding);                // 19
                HANDLE(OptNonLocalSourceRouting);       // 20
                HANDLE(OptPolicyFilter);                // 21
                HANDLE(OptMaxDgramReassemblySize);      // 22
                HANDLE(OptDefaultIPTTL);                // 23
                HANDLE(OptPathMTUAgingTimeout);         // 24
                HANDLE(OptPathMTUPlateauTable);         // 25
                HANDLE(OptInterfaceMTU);                // 26
                HANDLE(OptAllSubnetsAreLocal);          // 27
                HANDLE(OptBroadcastAddress);            // 28
                HANDLE(OptPerformMaskDiscovery);        // 29
                HANDLE(OptMaskSupplier);                // 30
                HANDLE(OptPerformRouterDiscovery);      // 31
                HANDLE(OptRouterSolicitationAddress);   // 32
                HANDLE(OptStaticRoute);                 // 33
                HANDLE(OptTrailerEncapsulation);        // 34
                HANDLE(OptARPCacheTimeout);             // 35
                HANDLE(OptEthernetEncapsulation);       // 36
                HANDLE(OptTCPDefaultTTL);               // 37
                HANDLE(OptTCPKeepaliveInterval);        // 38
                HANDLE(OptTCPKeepaliveGarbage);         // 39
                HANDLE(OptNISDomain);                   // 40
                HANDLE(OptNISServers);                  // 41
                HANDLE(OptNTPServers);                  // 42
                //HANDLE(OptVendorSpecificInfo);          // 43 - Only DHCPOptionEncoding_hex
                HANDLE(OptNetBIOSNameServers);          // 44
                HANDLE(OptNetBIOSDatagramServers);      // 45
                HANDLE(OptNetBIOSNodeType);             // 46
                //HANDLE(OptNetBIOSScope);                // 47 - Only DHCPOptionEncoding_hex
                HANDLE(OptXWindowsFontServers);         // 48
                HANDLE(OptXWindowsDisplayManager);      // 49
#ifndef IN_VBOXSVC /* Don't allow these in new configs */
                // OptRequestedAddress (50) is client only and not configurable.
                HANDLE(OptLeaseTime);                   // 51 - for historical reasons?  Configuable elsewhere now.
                // OptOptionOverload (52) is part of the protocol and not configurable.
                // OptMessageType (53) is part of the protocol and not configurable.
                // OptServerId (54) is the IP address of the server and configurable elsewhere.
                // OptParameterRequest (55) is client only and not configurable.
                // OptMessage (56) is server failure message and not configurable.
                // OptMaxDHCPMessageSize (57) is client only (?) and not configurable.
                HANDLE(OptRenewalTime);                 // 58 - for historical reasons?
                HANDLE(OptRebindingTime);               // 59 - for historical reasons?
                // OptVendorClassId (60) is client only and not configurable.
                // OptClientId (61) is client only and not configurable.
#endif
                HANDLE(OptNetWareIPDomainName);         // 62
                //HANDLE(OptNetWareIPInformation);        // 63 - Only DHCPOptionEncoding_hex
                HANDLE(OptNISPlusDomain);               // 64
                HANDLE(OptNISPlusServers);              // 65
                HANDLE(OptTFTPServerName);              // 66 - perhaps we should use an alternative way to configure these.
                HANDLE(OptBootfileName);                // 67 - perhaps we should use an alternative way to configure these.
                HANDLE(OptMobileIPHomeAgents);          // 68
                HANDLE(OptSMTPServers);                 // 69
                HANDLE(OptPOP3Servers);                 // 70
                HANDLE(OptNNTPServers);                 // 71
                HANDLE(OptWWWServers);                  // 72
                HANDLE(OptFingerServers);               // 73
                HANDLE(OptIRCServers);                  // 74
                HANDLE(OptStreetTalkServers);           // 75
                HANDLE(OptSTDAServers);                 // 76
                // OptUserClassId (77) is client only and not configurable.
                //HANDLE(OptSLPDirectoryAgent);           // 78 - Only DHCPOptionEncoding_hex
                //HANDLE(OptSLPServiceScope);             // 79 - Only DHCPOptionEncoding_hex
                // OptRapidCommit (80) is not configurable.

                //HANDLE(OptDomainSearch);                // 119 - Only DHCPOptionEncoding_hex

#undef HANDLE
                default:
                    if (prc)
                        *prc = VERR_NOT_IMPLEMENTED;
                    return NULL;
            }
            break;

        case 1:
            return RawOption::parse(aOptCode, pcszValue, prc);

        default:
            if (prc)
                *prc = VERR_WRONG_TYPE;
            return NULL;
    }
}


/**
 * Gets the option name (simply "unknown" if not known) for logging purposes.
 */
/*static*/ const char *DhcpOption::name(uint8_t aOptCode)
{
    switch (aOptCode)
    {
#define HANDLE(a_OptClass) \
        case a_OptClass::optcode: \
            return &#a_OptClass[3]

        HANDLE(OptSubnetMask);                  // 1
        HANDLE(OptTimeOffset);                  // 2
        HANDLE(OptRouters);                     // 3
        HANDLE(OptTimeServers);                 // 4
        HANDLE(OptNameServers);                 // 5
        HANDLE(OptDNSes);                       // 6
        HANDLE(OptLogServers);                  // 7
        HANDLE(OptCookieServers);               // 8
        HANDLE(OptLPRServers);                  // 9
        HANDLE(OptImpressServers);              // 10
        HANDLE(OptResourceLocationServers);     // 11
        HANDLE(OptHostName);                    // 12
        HANDLE(OptBootFileSize);                // 13
        HANDLE(OptMeritDumpFile);               // 14
        HANDLE(OptDomainName);                  // 15
        HANDLE(OptSwapServer);                  // 16
        HANDLE(OptRootPath);                    // 17
        HANDLE(OptExtensionPath);               // 18
        HANDLE(OptIPForwarding);                // 19
        HANDLE(OptNonLocalSourceRouting);       // 20
        HANDLE(OptPolicyFilter);                // 21
        HANDLE(OptMaxDgramReassemblySize);      // 22
        HANDLE(OptDefaultIPTTL);                // 23
        HANDLE(OptPathMTUAgingTimeout);         // 24
        HANDLE(OptPathMTUPlateauTable);         // 25
        HANDLE(OptInterfaceMTU);                // 26
        HANDLE(OptAllSubnetsAreLocal);          // 27
        HANDLE(OptBroadcastAddress);            // 28
        HANDLE(OptPerformMaskDiscovery);        // 29
        HANDLE(OptMaskSupplier);                // 30
        HANDLE(OptPerformRouterDiscovery);      // 31
        HANDLE(OptRouterSolicitationAddress);   // 32
        HANDLE(OptStaticRoute);                 // 33
        HANDLE(OptTrailerEncapsulation);        // 34
        HANDLE(OptARPCacheTimeout);             // 35
        HANDLE(OptEthernetEncapsulation);       // 36
        HANDLE(OptTCPDefaultTTL);               // 37
        HANDLE(OptTCPKeepaliveInterval);        // 38
        HANDLE(OptTCPKeepaliveGarbage);         // 39
        HANDLE(OptNISDomain);                   // 40
        HANDLE(OptNISServers);                  // 41
        HANDLE(OptNTPServers);                  // 42
        HANDLE(OptVendorSpecificInfo);          // 43
        HANDLE(OptNetBIOSNameServers);          // 44
        HANDLE(OptNetBIOSDatagramServers);      // 45
        HANDLE(OptNetBIOSNodeType);             // 46
        HANDLE(OptNetBIOSScope);                // 47
        HANDLE(OptXWindowsFontServers);         // 48
        HANDLE(OptXWindowsDisplayManager);      // 49
        HANDLE(OptRequestedAddress);            // 50
        HANDLE(OptLeaseTime);                   // 51
        //HANDLE(OptOptionOverload);              // 52
        HANDLE(OptMessageType);                 // 53
        HANDLE(OptServerId);                    // 54
        HANDLE(OptParameterRequest);            // 55
        HANDLE(OptMessage);                     // 56
        HANDLE(OptMaxDHCPMessageSize);          // 57
        HANDLE(OptRenewalTime);                 // 58
        HANDLE(OptRebindingTime);               // 59
        HANDLE(OptVendorClassId);               // 60
        HANDLE(OptClientId);                    // 61
        HANDLE(OptNetWareIPDomainName);         // 62
        HANDLE(OptNetWareIPInformation);        // 63
        HANDLE(OptNISPlusDomain);               // 64
        HANDLE(OptNISPlusServers);              // 65
        HANDLE(OptTFTPServerName);              // 66
        HANDLE(OptBootfileName);                // 67
        HANDLE(OptMobileIPHomeAgents);          // 68
        HANDLE(OptSMTPServers);                 // 69
        HANDLE(OptPOP3Servers);                 // 70
        HANDLE(OptNNTPServers);                 // 71
        HANDLE(OptWWWServers);                  // 72
        HANDLE(OptFingerServers);               // 73
        HANDLE(OptIRCServers);                  // 74
        HANDLE(OptStreetTalkServers);           // 75
        HANDLE(OptSTDAServers);                 // 76
        HANDLE(OptUserClassId);                 // 77
        HANDLE(OptSLPDirectoryAgent);           // 78 - Only DHCPOptionEncoding_hex
        HANDLE(OptSLPServiceScope);             // 79 - Only DHCPOptionEncoding_hex
        HANDLE(OptRapidCommit);                 // 80

        HANDLE(OptDomainSearch);                // 119 - Only DHCPOptionEncoding_hex

#undef HANDLE
        default:
            return "unknown";
    }
}