/*
 *
 *    Copyright (c) 2020 Project CHIP Authors
 *    Copyright (c) 2018 Google LLC.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

/**
 *    @file
 *      This header file implements the <tt>Inet::IPEndPointBasis</tt>
 *      class, an intermediate, non-instantiable basis class
 *      supporting other IP-based end points.
 *
 */

// define to ensure we have the IPV6_PKTINFO
#define __APPLE_USE_RFC_3542

#include "IPEndPointBasis.h"

#include <string.h>

#include <EndPointBasis.h>
#include <InetInterface.h>
#include <InetLayer.h>

#include <support/CodeUtils.h>

#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if INET_CONFIG_ENABLE_IPV4
#include <lwip/igmp.h>
#endif // INET_CONFIG_ENABLE_IPV4
#include <lwip/init.h>
#include <lwip/ip.h>
#include <lwip/mld6.h>
#include <lwip/netif.h>
#include <lwip/raw.h>
#include <lwip/udp.h>
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
#include <errno.h>
#include <net/if.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <unistd.h>
#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif // HAVE_SYS_SOCKET_H

/*
 * Some systems define both IPV6_{ADD,DROP}_MEMBERSHIP and
 * IPV6_{JOIN,LEAVE}_GROUP while others only define
 * IPV6_{JOIN,LEAVE}_GROUP. Prefer the "_MEMBERSHIP" flavor for
 * parallelism with IPv4 and create the alias to the availabile
 * definitions.
 */
#if !defined(IPV6_ADD_MEMBERSHIP) && defined(IPV6_JOIN_GROUP)
#define INET_IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
#elif defined(IPV6_ADD_MEMBERSHIP)
#define INET_IPV6_ADD_MEMBERSHIP IPV6_ADD_MEMBERSHIP
#else
#error                                                                                                                             \
    "Neither IPV6_ADD_MEMBERSHIP nor IPV6_JOIN_GROUP are defined which are required for generalized IPv6 multicast group support."
#endif // !defined(IPV6_ADD_MEMBERSHIP) && defined(IPV6_JOIN_GROUP)

#if !defined(IPV6_DROP_MEMBERSHIP) && defined(IPV6_LEAVE_GROUP)
#define INET_IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
#elif defined(IPV6_DROP_MEMBERSHIP)
#define INET_IPV6_DROP_MEMBERSHIP IPV6_DROP_MEMBERSHIP
#else
#error                                                                                                                             \
    "Neither IPV6_DROP_MEMBERSHIP nor IPV6_LEAVE_GROUP are defined which are required for generalized IPv6 multicast group support."
#endif // !defined(IPV6_DROP_MEMBERSHIP) && defined(IPV6_LEAVE_GROUP)
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS

#if CHIP_SYSTEM_CONFIG_USE_NETWORK_FRAMEWORK
#define INET_PORTSTRLEN 6
#endif // CHIP_SYSTEM_CONFIG_USE_NETWORK_FRAMEWORK

namespace chip {
namespace Inet {

using chip::System::PacketBuffer;

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
union PeerSockAddr
{
    sockaddr any;
    sockaddr_in in;
    sockaddr_in6 in6;
};
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS

#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if INET_CONFIG_ENABLE_IPV4
#define LWIP_IPV4_ADDR_T ip4_addr_t
#define IPV4_TO_LWIPADDR(aAddress) (aAddress).ToIPv4()
#endif // INET_CONFIG_ENABLE_IPV4
#define LWIP_IPV6_ADDR_T ip6_addr_t
#define IPV6_TO_LWIPADDR(aAddress) (aAddress).ToIPv6()

#if !defined(RAW_FLAGS_MULTICAST_LOOP) || !defined(UDP_FLAGS_MULTICAST_LOOP) || !defined(raw_clear_flags) ||                       \
    !defined(raw_set_flags) || !defined(udp_clear_flags) || !defined(udp_set_flags)
#define HAVE_LWIP_MULTICAST_LOOP 0
#else
#define HAVE_LWIP_MULTICAST_LOOP 1
#endif // !defined(RAW_FLAGS_MULTICAST_LOOP) || !defined(UDP_FLAGS_MULTICAST_LOOP) || !defined(raw_clear_flags) ||
       // !defined(raw_set_flags) || !defined(udp_clear_flags) || !defined(udp_set_flags)
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

static INET_ERROR CheckMulticastGroupArgs(InterfaceId aInterfaceId, const IPAddress & aAddress)
{
    INET_ERROR lRetval = INET_NO_ERROR;
    bool lIsPresent, lIsMulticast;

    lIsPresent = IsInterfaceIdPresent(aInterfaceId);
    VerifyOrExit(lIsPresent, lRetval = INET_ERROR_UNKNOWN_INTERFACE);

    lIsMulticast = aAddress.IsMulticast();
    VerifyOrExit(lIsMulticast, lRetval = INET_ERROR_WRONG_ADDRESS_TYPE);

exit:
    return (lRetval);
}

#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if INET_CONFIG_ENABLE_IPV4
#if LWIP_IPV4 && LWIP_IGMP
static INET_ERROR LwIPIPv4JoinLeaveMulticastGroup(InterfaceId aInterfaceId, const IPAddress & aAddress,
                                                  err_t (*aMethod)(struct netif *, const LWIP_IPV4_ADDR_T *))
{
    INET_ERROR lRetval = INET_NO_ERROR;
    err_t lStatus;
    struct netif * lNetif;
    LWIP_IPV4_ADDR_T lIPv4Address;

    lNetif = IPEndPointBasis::FindNetifFromInterfaceId(aInterfaceId);
    VerifyOrExit(lNetif != NULL, lRetval = INET_ERROR_UNKNOWN_INTERFACE);

    lIPv4Address = IPV4_TO_LWIPADDR(aAddress);

    lStatus = aMethod(lNetif, &lIPv4Address);

    switch (lStatus)
    {

    case ERR_MEM:
        lRetval = INET_ERROR_NO_MEMORY;
        break;

    default:
        lRetval = chip::System::MapErrorLwIP(lStatus);
        break;
    }

exit:
    return (lRetval);
}
#endif // LWIP_IPV4 && LWIP_IGMP
#endif // INET_CONFIG_ENABLE_IPV4

#if LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
static INET_ERROR LwIPIPv6JoinLeaveMulticastGroup(InterfaceId aInterfaceId, const IPAddress & aAddress,
                                                  err_t (*aMethod)(struct netif *, const LWIP_IPV6_ADDR_T *))
{
    INET_ERROR lRetval = INET_NO_ERROR;
    err_t lStatus;
    struct netif * lNetif;
    LWIP_IPV6_ADDR_T lIPv6Address;

    lNetif = IPEndPointBasis::FindNetifFromInterfaceId(aInterfaceId);
    VerifyOrExit(lNetif != NULL, lRetval = INET_ERROR_UNKNOWN_INTERFACE);

    lIPv6Address = IPV6_TO_LWIPADDR(aAddress);

    lStatus = aMethod(lNetif, &lIPv6Address);

    switch (lStatus)
    {

    case ERR_MEM:
        lRetval = INET_ERROR_NO_MEMORY;
        break;

    default:
        lRetval = chip::System::MapErrorLwIP(lStatus);
        break;
    }

exit:
    return (lRetval);
}
#endif // LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
static INET_ERROR SocketsSetMulticastLoopback(int aSocket, bool aLoopback, int aProtocol, int aOption)
{
    INET_ERROR lRetval = INET_NO_ERROR;
    int lStatus;
    unsigned int lValue = aLoopback;

    lStatus = setsockopt(aSocket, aProtocol, aOption, &lValue, sizeof(lValue));
    VerifyOrExit(lStatus == 0, lRetval = chip::System::MapErrorPOSIX(errno));

exit:
    return (lRetval);
}

static INET_ERROR SocketsSetMulticastLoopback(int aSocket, IPVersion aIPVersion, bool aLoopback)
{
    INET_ERROR lRetval;

    switch (aIPVersion)
    {

    case kIPVersion_6:
        lRetval = SocketsSetMulticastLoopback(aSocket, aLoopback, IPPROTO_IPV6, IPV6_MULTICAST_LOOP);
        break;

#if INET_CONFIG_ENABLE_IPV4
    case kIPVersion_4:
        lRetval = SocketsSetMulticastLoopback(aSocket, aLoopback, IPPROTO_IP, IP_MULTICAST_LOOP);
        break;
#endif // INET_CONFIG_ENABLE_IPV4

    default:
        lRetval = INET_ERROR_WRONG_ADDRESS_TYPE;
        break;
    }

    return (lRetval);
}

#if INET_CONFIG_ENABLE_IPV4
static INET_ERROR SocketsIPv4JoinLeaveMulticastGroup(int aSocket, InterfaceId aInterfaceId, const IPAddress & aAddress,
                                                     int aCommand)
{
    INET_ERROR lRetval = INET_NO_ERROR;
    IPAddress lInterfaceAddress;
    bool lInterfaceAddressFound = false;
    struct ip_mreq lMulticastRequest;

    for (InterfaceAddressIterator lAddressIterator; lAddressIterator.HasCurrent(); lAddressIterator.Next())
    {
        const IPAddress lCurrentAddress = lAddressIterator.GetAddress();

        if (lAddressIterator.GetInterface() == aInterfaceId)
        {
            if (lCurrentAddress.IsIPv4())
            {
                lInterfaceAddressFound = true;
                lInterfaceAddress      = lCurrentAddress;
                break;
            }
        }
    }

    VerifyOrExit(lInterfaceAddressFound, lRetval = INET_ERROR_ADDRESS_NOT_FOUND);

    memset(&lMulticastRequest, 0, sizeof(lMulticastRequest));
    lMulticastRequest.imr_interface = lInterfaceAddress.ToIPv4();
    lMulticastRequest.imr_multiaddr = aAddress.ToIPv4();

    lRetval = setsockopt(aSocket, IPPROTO_IP, aCommand, &lMulticastRequest, sizeof(lMulticastRequest));
    VerifyOrExit(lRetval == 0, lRetval = chip::System::MapErrorPOSIX(errno));

exit:
    return (lRetval);
}
#endif // INET_CONFIG_ENABLE_IPV4

static INET_ERROR SocketsIPv6JoinLeaveMulticastGroup(int aSocket, InterfaceId aInterfaceId, const IPAddress & aAddress,
                                                     int aCommand)
{
    INET_ERROR lRetval = INET_NO_ERROR;
    const int lIfIndex = static_cast<int>(aInterfaceId);
    struct ipv6_mreq lMulticastRequest;

    memset(&lMulticastRequest, 0, sizeof(lMulticastRequest));
    lMulticastRequest.ipv6mr_interface = lIfIndex;
    lMulticastRequest.ipv6mr_multiaddr = aAddress.ToIPv6();

    lRetval = setsockopt(aSocket, IPPROTO_IPV6, aCommand, &lMulticastRequest, sizeof(lMulticastRequest));
    VerifyOrExit(lRetval == 0, lRetval = chip::System::MapErrorPOSIX(errno));

exit:
    return (lRetval);
}
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS

/**
 *  @brief Set whether IP multicast traffic should be looped back.
 *
 *  @param[in]   aIPVersion
 *
 *  @param[in]   aLoop
 *
 *  @retval  INET_NO_ERROR
 *       success: multicast loopback behavior set
 *  @retval  other
 *       another system or platform error
 *
 *  @details
 *     Set whether or not IP multicast traffic should be looped back
 *     to this endpoint.
 *
 */
INET_ERROR IPEndPointBasis::SetMulticastLoopback(IPVersion aIPVersion, bool aLoopback)
{
    INET_ERROR lRetval = INET_ERROR_NOT_IMPLEMENTED;

#if CHIP_SYSTEM_CONFIG_USE_LWIP || CHIP_SYSTEM_CONFIG_USE_SOCKETS
#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if !HAVE_LWIP_MULTICAST_LOOP
#pragma message "\n \
The version of LwIP appears older than that required for multicast loopback support.\n \
Please upgrade your version of LwIP for SetMulticastLoopback support."
    lRetval = INET_ERROR_NOT_SUPPORTED;
#else
    if (aLoopback)
    {
        switch (mLwIPEndPointType)
        {

#if INET_CONFIG_ENABLE_RAW_ENDPOINT
        case kLwIPEndPointType_Raw:
            raw_set_flags(mRaw, RAW_FLAGS_MULTICAST_LOOP);
            break;
#endif // INET_CONFIG_ENABLE_RAW_ENDPOINT

#if INET_CONFIG_ENABLE_UDP_ENDPOINT
        case kLwIPEndPointType_UDP:
            udp_set_flags(mUDP, UDP_FLAGS_MULTICAST_LOOP);
            break;
#endif // INET_CONFIG_ENABLE_UDP_ENDPOINT

        default:
            lRetval = INET_ERROR_NOT_SUPPORTED;
            break;
        }
    }
    else
    {
        switch (mLwIPEndPointType)
        {

#if INET_CONFIG_ENABLE_RAW_ENDPOINT
        case kLwIPEndPointType_Raw:
            raw_clear_flags(mRaw, RAW_FLAGS_MULTICAST_LOOP);
            break;
#endif // INET_CONFIG_ENABLE_RAW_ENDPOINT

#if INET_CONFIG_ENABLE_UDP_ENDPOINT
        case kLwIPEndPointType_UDP:
            udp_clear_flags(mUDP, UDP_FLAGS_MULTICAST_LOOP);
            break;
#endif // INET_CONFIG_ENABLE_UDP_ENDPOINT

        default:
            lRetval = INET_ERROR_NOT_SUPPORTED;
            break;
        }
    }

    lRetval = INET_NO_ERROR;
#endif // !HAVE_LWIP_MULTICAST_LOOP
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
    lRetval = SocketsSetMulticastLoopback(mSocket, aIPVersion, aLoopback);
    SuccessOrExit(lRetval);

exit:
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP || CHIP_SYSTEM_CONFIG_USE_SOCKETS
    return (lRetval);
}

/**
 *  @brief Join an IP multicast group.
 *
 *  @param[in]   aInterfaceId  the indicator of the network interface to
 *                             add to the multicast group
 *
 *  @param[in]   aAddress      the multicast group to add the
 *                             interface to
 *
 *  @retval  INET_NO_ERROR
 *       success: multicast group removed
 *
 *  @retval  INET_ERROR_UNKNOWN_INTERFACE
 *       unknown network interface, \c aInterfaceId
 *
 *  @retval  INET_ERROR_WRONG_ADDRESS_TYPE
 *       \c aAddress is not \c kIPAddressType_IPv4 or
 *       \c kIPAddressType_IPv6 or is not multicast
 *
 *  @retval  other
 *       another system or platform error
 *
 *  @details
 *     Join the endpoint to the supplied multicast group on the
 *     specified interface.
 *
 */
INET_ERROR IPEndPointBasis::JoinMulticastGroup(InterfaceId aInterfaceId, const IPAddress & aAddress)
{
    const IPAddressType lAddrType = aAddress.Type();
    INET_ERROR lRetval            = INET_ERROR_NOT_IMPLEMENTED;

#if CHIP_SYSTEM_CONFIG_USE_LWIP || CHIP_SYSTEM_CONFIG_USE_SOCKETS
    lRetval = CheckMulticastGroupArgs(aInterfaceId, aAddress);
    SuccessOrExit(lRetval);

    switch (lAddrType)
    {

#if INET_CONFIG_ENABLE_IPV4
    case kIPAddressType_IPv4: {
#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if LWIP_IPV4 && LWIP_IGMP
        lRetval = LwIPIPv4JoinLeaveMulticastGroup(aInterfaceId, aAddress, igmp_joingroup_netif);
#else // LWIP_IPV4 && LWIP_IGMP
#pragma message "\n \
Please enable LWIP_IPV4 and LWIP_IGMP for IPv4 JoinMulticastGroup and LeaveMulticastGroup support."
        lRetval = INET_ERROR_NOT_SUPPORTED;
#endif // LWIP_IPV4 && LWIP_IGMP
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
        lRetval = SocketsIPv4JoinLeaveMulticastGroup(mSocket, aInterfaceId, aAddress, IP_ADD_MEMBERSHIP);
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS
    }
    break;
#endif // INET_CONFIG_ENABLE_IPV4

    case kIPAddressType_IPv6: {
#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
        lRetval = LwIPIPv6JoinLeaveMulticastGroup(aInterfaceId, aAddress, mld6_joingroup_netif);
#else // LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
#pragma message "\n \
Please enable LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6 for IPv6 JoinMulticastGroup and LeaveMulticastGroup support."
        lRetval = INET_ERROR_NOT_SUPPORTED;
#endif // LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
        lRetval = SocketsIPv6JoinLeaveMulticastGroup(mSocket, aInterfaceId, aAddress, INET_IPV6_ADD_MEMBERSHIP);
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS
    }
    break;

    default:
        lRetval = INET_ERROR_WRONG_ADDRESS_TYPE;
        break;
    }

exit:
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP || CHIP_SYSTEM_CONFIG_USE_SOCKETS
    return (lRetval);
}

/**
 *  @brief Leave an IP multicast group.
 *
 *  @param[in]   aInterfaceId  the indicator of the network interface to
 *                             remove from the multicast group
 *
 *  @param[in]   aAddress      the multicast group to remove the
 *                             interface from
 *
 *  @retval  INET_NO_ERROR
 *       success: multicast group removed
 *
 *  @retval  INET_ERROR_UNKNOWN_INTERFACE
 *       unknown network interface, \c aInterfaceId
 *
 *  @retval  INET_ERROR_WRONG_ADDRESS_TYPE
 *       \c aAddress is not \c kIPAddressType_IPv4 or
 *       \c kIPAddressType_IPv6 or is not multicast
 *
 *  @retval  other
 *       another system or platform error
 *
 *  @details
 *     Remove the endpoint from the supplied multicast group on the
 *     specified interface.
 *
 */
INET_ERROR IPEndPointBasis::LeaveMulticastGroup(InterfaceId aInterfaceId, const IPAddress & aAddress)
{
    const IPAddressType lAddrType = aAddress.Type();
    INET_ERROR lRetval            = INET_ERROR_NOT_IMPLEMENTED;

#if CHIP_SYSTEM_CONFIG_USE_LWIP || CHIP_SYSTEM_CONFIG_USE_SOCKETS
    lRetval = CheckMulticastGroupArgs(aInterfaceId, aAddress);
    SuccessOrExit(lRetval);

    switch (lAddrType)
    {

#if INET_CONFIG_ENABLE_IPV4
    case kIPAddressType_IPv4: {
#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if LWIP_IPV4 && LWIP_IGMP
        lRetval = LwIPIPv4JoinLeaveMulticastGroup(aInterfaceId, aAddress, igmp_leavegroup_netif);
#else // LWIP_IPV4 && LWIP_IGMP
#pragma message "\n \
Please enable LWIP_IPV4 and LWIP_IGMP for IPv4 JoinMulticastGroup and LeaveMulticastGroup support."
        lRetval = INET_ERROR_NOT_SUPPORTED;
#endif // LWIP_IPV4 && LWIP_IGMP
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
        lRetval = SocketsIPv4JoinLeaveMulticastGroup(mSocket, aInterfaceId, aAddress, IP_DROP_MEMBERSHIP);
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS
    }
    break;
#endif // INET_CONFIG_ENABLE_IPV4

    case kIPAddressType_IPv6: {
#if CHIP_SYSTEM_CONFIG_USE_LWIP
#if LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
        lRetval = LwIPIPv6JoinLeaveMulticastGroup(aInterfaceId, aAddress, mld6_leavegroup_netif);
#else // LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
#pragma message "\n \
Please enable LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6 for IPv6 JoinMulticastGroup and LeaveMulticastGroup support."
        lRetval = INET_ERROR_NOT_SUPPORTED;
#endif // LWIP_IPV6_MLD && LWIP_IPV6_ND && LWIP_IPV6
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
        lRetval = SocketsIPv6JoinLeaveMulticastGroup(mSocket, aInterfaceId, aAddress, INET_IPV6_DROP_MEMBERSHIP);
        SuccessOrExit(lRetval);
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS
    }
    break;

    default:
        lRetval = INET_ERROR_WRONG_ADDRESS_TYPE;
        break;
    }

exit:
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP || CHIP_SYSTEM_CONFIG_USE_SOCKETS
    return (lRetval);
}

void IPEndPointBasis::Init(InetLayer * aInetLayer)
{
    InitEndPointBasis(*aInetLayer);

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
    mBoundIntfId = INET_NULL_INTERFACEID;
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS
}

#if CHIP_SYSTEM_CONFIG_USE_LWIP
void IPEndPointBasis::HandleDataReceived(PacketBuffer * aBuffer)
{
    if ((mState == kState_Listening) && (OnMessageReceived != NULL))
    {
        const IPPacketInfo * pktInfo = GetPacketInfo(aBuffer);

        if (pktInfo != NULL)
        {
            const IPPacketInfo pktInfoCopy = *pktInfo; // copy the address info so that the app can free the
                                                       // PacketBuffer without affecting access to address info.
            OnMessageReceived(this, aBuffer, &pktInfoCopy);
        }
        else
        {
            if (OnReceiveError != NULL)
                OnReceiveError(this, INET_ERROR_INBOUND_MESSAGE_TOO_BIG, NULL);
            PacketBuffer::Free(aBuffer);
        }
    }
    else
    {
        PacketBuffer::Free(aBuffer);
    }
}

/**
 *  @brief Get LwIP IP layer source and destination addressing information.
 *
 *  @param[in]   aBuffer       the packet buffer containing the IP message
 *
 *  @returns  a pointer to the address information on success; otherwise,
 *            NULL if there is insufficient space in the packet for
 *            the address information.
 *
 *  @details
 *     When using LwIP information about the packet is 'hidden' in the
 *     reserved space before the start of the data in the packet
 *     buffer. This is necessary because the system layer events only
 *     have two arguments, which in this case are used to convey the
 *     pointer to the end point and the pointer to the buffer.
 *
 *     In most cases this trick of storing information before the data
 *     works because the first buffer in an LwIP IP message contains
 *     the space that was used for the Ethernet/IP/UDP headers. However,
 *     given the current size of the IPPacketInfo structure (40 bytes),
 *     it is possible for there to not be enough room to store the
 *     structure along with the payload in a single packet buffer. In
 *     practice, this should only happen for extremely large IPv4
 *     packets that arrive without an Ethernet header.
 *
 */
IPPacketInfo * IPEndPointBasis::GetPacketInfo(PacketBuffer * aBuffer)
{
    uintptr_t lStart;
    uintptr_t lPacketInfoStart;
    IPPacketInfo * lPacketInfo = NULL;

    if (!aBuffer->EnsureReservedSize(sizeof(IPPacketInfo) + 3))
        goto done;

    lStart           = (uintptr_t) aBuffer->Start();
    lPacketInfoStart = lStart - sizeof(IPPacketInfo);

    // Align to a 4-byte boundary

    lPacketInfo = reinterpret_cast<IPPacketInfo *>(lPacketInfoStart & ~(sizeof(uint32_t) - 1));

done:
    return (lPacketInfo);
}
#endif // CHIP_SYSTEM_CONFIG_USE_LWIP

#if CHIP_SYSTEM_CONFIG_USE_SOCKETS
INET_ERROR IPEndPointBasis::Bind(IPAddressType aAddressType, IPAddress aAddress, uint16_t aPort, InterfaceId aInterfaceId)
{
    INET_ERROR lRetval = INET_NO_ERROR;

    if (aAddressType == kIPAddressType_IPv6)
    {
        struct sockaddr_in6 sa;

        memset(&sa, 0, sizeof(sa));

        sa.sin6_family   = AF_INET6;
        sa.sin6_port     = htons(aPort);
        sa.sin6_flowinfo = 0;
        sa.sin6_addr     = aAddress.ToIPv6();
        sa.sin6_scope_id = aInterfaceId;

        if (bind(mSocket, (const sockaddr *) &sa, (unsigned) sizeof(sa)) != 0)
            lRetval = chip::System::MapErrorPOSIX(errno);

            // Instruct the kernel that any messages to multicast destinations should be
            // sent down the interface specified by the caller.
#ifdef IPV6_MULTICAST_IF
        if (lRetval == INET_NO_ERROR)
            setsockopt(mSocket, IPPROTO_IPV6, IPV6_MULTICAST_IF, &aInterfaceId, sizeof(aInterfaceId));
#endif // defined(IPV6_MULTICAST_IF)

            // Instruct the kernel that any messages to multicast destinations should be
            // set with the configured hop limit value.
#ifdef IPV6_MULTICAST_HOPS
        int hops = INET_CONFIG_IP_MULTICAST_HOP_LIMIT;
        setsockopt(mSocket, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &hops, sizeof(hops));
#endif // defined(IPV6_MULTICAST_HOPS)
    }
#if INET_CONFIG_ENABLE_IPV4
    else if (aAddressType == kIPAddressType_IPv4)
    {
        struct sockaddr_in sa;
        int enable = 1;

        memset(&sa, 0, sizeof(sa));

        sa.sin_family = AF_INET;
        sa.sin_port   = htons(aPort);
        sa.sin_addr   = aAddress.ToIPv4();

        if (bind(mSocket, (const sockaddr *) &sa, (unsigned) sizeof(sa)) != 0)
            lRetval = chip::System::MapErrorPOSIX(errno);

            // Instruct the kernel that any messages to multicast destinations should be
            // sent down the interface to which the specified IPv4 address is bound.
#ifdef IP_MULTICAST_IF
        if (lRetval == INET_NO_ERROR)
            setsockopt(mSocket, IPPROTO_IP, IP_MULTICAST_IF, &sa, sizeof(sa));
#endif // defined(IP_MULTICAST_IF)

            // Instruct the kernel that any messages to multicast destinations should be
            // set with the configured hop limit value.
#ifdef IP_MULTICAST_TTL
        int ttl = INET_CONFIG_IP_MULTICAST_HOP_LIMIT;
        setsockopt(mSocket, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
#endif // defined(IP_MULTICAST_TTL)

        // Allow socket transmitting broadcast packets.
        if (lRetval == INET_NO_ERROR)
            setsockopt(mSocket, SOL_SOCKET, SO_BROADCAST, &enable, sizeof(enable));
    }
#endif // INET_CONFIG_ENABLE_IPV4
    else
        lRetval = INET_ERROR_WRONG_ADDRESS_TYPE;

    return (lRetval);
}

INET_ERROR IPEndPointBasis::BindInterface(IPAddressType aAddressType, InterfaceId aInterfaceId)
{
    INET_ERROR lRetval = INET_NO_ERROR;

#if HAVE_SO_BINDTODEVICE
    if (aInterfaceId == INET_NULL_INTERFACEID)
    {
        // Stop interface-based filtering.
        if (setsockopt(mSocket, SOL_SOCKET, SO_BINDTODEVICE, "", 0) == -1)
        {
            lRetval = chip::System::MapErrorPOSIX(errno);
        }
    }
    else
    {
        // Start filtering on the passed interface.
        char lInterfaceName[IF_NAMESIZE];

        if (if_indextoname(aInterfaceId, lInterfaceName) == NULL)
        {
            lRetval = chip::System::MapErrorPOSIX(errno);
        }

        if (lRetval == INET_NO_ERROR &&
            setsockopt(mSocket, SOL_SOCKET, SO_BINDTODEVICE, lInterfaceName, strlen(lInterfaceName)) == -1)
        {
            lRetval = chip::System::MapErrorPOSIX(errno);
        }
    }

    if (lRetval == INET_NO_ERROR)
        mBoundIntfId = aInterfaceId;

#else  // !HAVE_SO_BINDTODEVICE
    lRetval = INET_ERROR_NOT_IMPLEMENTED;
#endif // HAVE_SO_BINDTODEVICE

    return (lRetval);
}

INET_ERROR IPEndPointBasis::SendMsg(const IPPacketInfo * aPktInfo, chip::System::PacketBuffer * aBuffer, uint16_t aSendFlags)
{
    INET_ERROR res = INET_NO_ERROR;
    PeerSockAddr peerSockAddr;
    struct iovec msgIOV;
    uint8_t controlData[256];
    struct msghdr msgHeader;
    InterfaceId intfId = aPktInfo->Interface;

    // Ensure the destination address type is compatible with the endpoint address type.
    VerifyOrExit(mAddrType == aPktInfo->DestAddress.Type(), res = INET_ERROR_BAD_ARGS);

    // For now the entire message must fit within a single buffer.
    VerifyOrExit(aBuffer->Next() == NULL, res = INET_ERROR_MESSAGE_TOO_LONG);

    memset(&msgHeader, 0, sizeof(msgHeader));

    msgIOV.iov_base      = aBuffer->Start();
    msgIOV.iov_len       = aBuffer->DataLength();
    msgHeader.msg_iov    = &msgIOV;
    msgHeader.msg_iovlen = 1;

    // Construct a sockaddr_in/sockaddr_in6 structure containing the destination information.
    memset(&peerSockAddr, 0, sizeof(peerSockAddr));
    msgHeader.msg_name = &peerSockAddr;
    if (mAddrType == kIPAddressType_IPv6)
    {
        peerSockAddr.in6.sin6_family   = AF_INET6;
        peerSockAddr.in6.sin6_port     = htons(aPktInfo->DestPort);
        peerSockAddr.in6.sin6_flowinfo = 0;
        peerSockAddr.in6.sin6_addr     = aPktInfo->DestAddress.ToIPv6();
        peerSockAddr.in6.sin6_scope_id = aPktInfo->Interface;
        msgHeader.msg_namelen          = sizeof(sockaddr_in6);
    }
#if INET_CONFIG_ENABLE_IPV4
    else
    {
        peerSockAddr.in.sin_family = AF_INET;
        peerSockAddr.in.sin_port   = htons(aPktInfo->DestPort);
        peerSockAddr.in.sin_addr   = aPktInfo->DestAddress.ToIPv4();
        msgHeader.msg_namelen      = sizeof(sockaddr_in);
    }
#endif // INET_CONFIG_ENABLE_IPV4

    // If the endpoint has been bound to a particular interface,
    // and the caller didn't supply a specific interface to send
    // on, use the bound interface. This appears to be necessary
    // for messages to multicast addresses, which under Linux
    // don't seem to get sent out the correct interface, despite
    // the socket being bound.
    if (intfId == INET_NULL_INTERFACEID)
        intfId = mBoundIntfId;

    // If the packet should be sent over a specific interface, or with a specific source
    // address, construct an IP_PKTINFO/IPV6_PKTINFO "control message" to that effect
    // add add it to the message header.  If the local OS doesn't support IP_PKTINFO/IPV6_PKTINFO
    // fail with an error.
    if (intfId != INET_NULL_INTERFACEID || aPktInfo->SrcAddress.Type() != kIPAddressType_Any)
    {
#if defined(IP_PKTINFO) || defined(IPV6_PKTINFO)
        memset(controlData, 0, sizeof(controlData));
        msgHeader.msg_control    = controlData;
        msgHeader.msg_controllen = sizeof(controlData);

        struct cmsghdr * controlHdr = CMSG_FIRSTHDR(&msgHeader);

#if INET_CONFIG_ENABLE_IPV4

        if (mAddrType == kIPAddressType_IPv4)
        {
#if defined(IP_PKTINFO)
            controlHdr->cmsg_level = IPPROTO_IP;
            controlHdr->cmsg_type  = IP_PKTINFO;
            controlHdr->cmsg_len   = CMSG_LEN(sizeof(in_pktinfo));

            struct in_pktinfo * pktInfo = (struct in_pktinfo *) CMSG_DATA(controlHdr);
            pktInfo->ipi_ifindex        = intfId;
            pktInfo->ipi_spec_dst       = aPktInfo->SrcAddress.ToIPv4();

            msgHeader.msg_controllen = CMSG_SPACE(sizeof(in_pktinfo));
#else  // !defined(IP_PKTINFO)
            ExitNow(res = INET_ERROR_NOT_SUPPORTED);
#endif // !defined(IP_PKTINFO)
        }

#endif // INET_CONFIG_ENABLE_IPV4

        if (mAddrType == kIPAddressType_IPv6)
        {
#if defined(IPV6_PKTINFO)
            controlHdr->cmsg_level = IPPROTO_IPV6;
            controlHdr->cmsg_type  = IPV6_PKTINFO;
            controlHdr->cmsg_len   = CMSG_LEN(sizeof(in6_pktinfo));

            struct in6_pktinfo * pktInfo = (struct in6_pktinfo *) CMSG_DATA(controlHdr);
            pktInfo->ipi6_ifindex        = intfId;
            pktInfo->ipi6_addr           = aPktInfo->SrcAddress.ToIPv6();

            msgHeader.msg_controllen = CMSG_SPACE(sizeof(in6_pktinfo));
#else  // !defined(IPV6_PKTINFO)
            ExitNow(res = INET_ERROR_NOT_SUPPORTED);
#endif // !defined(IPV6_PKTINFO)
        }

#else // !(defined(IP_PKTINFO) && defined(IPV6_PKTINFO))

        ExitNow(res = INET_ERROR_NOT_SUPPORTED);

#endif // !(defined(IP_PKTINFO) && defined(IPV6_PKTINFO))
    }

    // Send IP packet.
    {
        const ssize_t lenSent = sendmsg(mSocket, &msgHeader, 0);
        if (lenSent == -1)
            res = chip::System::MapErrorPOSIX(errno);
        else if (lenSent != aBuffer->DataLength())
            res = INET_ERROR_OUTBOUND_MESSAGE_TRUNCATED;
    }

exit:
    return (res);
}

INET_ERROR IPEndPointBasis::GetSocket(IPAddressType aAddressType, int aType, int aProtocol)
{
    INET_ERROR res = INET_NO_ERROR;

    if (mSocket == INET_INVALID_SOCKET_FD)
    {
        const int one = 1;
        int family;

        switch (aAddressType)
        {
        case kIPAddressType_IPv6:
            family = PF_INET6;
            break;

#if INET_CONFIG_ENABLE_IPV4
        case kIPAddressType_IPv4:
            family = PF_INET;
            break;
#endif // INET_CONFIG_ENABLE_IPV4

        default:
            return INET_ERROR_WRONG_ADDRESS_TYPE;
        }

        mSocket = ::socket(family, aType, aProtocol);
        if (mSocket == -1)
            return chip::System::MapErrorPOSIX(errno);

        mAddrType = aAddressType;

        // NOTE WELL: the errors returned by setsockopt() here are not
        // returned as Inet layer chip::System::MapErrorPOSIX(errno)
        // codes because they are normally expected to fail on some
        // platforms where the socket option code is defined in the
        // header files but not [yet] implemented. Certainly, there is
        // room to improve this by connecting the build configuration
        // logic up to check for implementations of these options and
        // to provide appropriate HAVE_xxxxx definitions accordingly.

        res = setsockopt(mSocket, SOL_SOCKET, SO_REUSEADDR, (void *) &one, sizeof(one));
        static_cast<void>(res);

#ifdef SO_REUSEPORT
        res = setsockopt(mSocket, SOL_SOCKET, SO_REUSEPORT, (void *) &one, sizeof(one));
        if (res != 0)
        {
            ChipLogError(Inet, "SO_REUSEPORT failed: %d", errno);
        }
#endif // defined(SO_REUSEPORT)

        // If creating an IPv6 socket, tell the kernel that it will be
        // IPv6 only.  This makes it posible to bind two sockets to
        // the same port, one for IPv4 and one for IPv6.

#ifdef IPV6_V6ONLY
        if (aAddressType == kIPAddressType_IPv6)
        {
            res = setsockopt(mSocket, IPPROTO_IPV6, IPV6_V6ONLY, (void *) &one, sizeof(one));
            if (res != 0)
            {
                ChipLogError(Inet, "IPV6_V6ONLY failed: %d", errno);
            }
        }
#endif // defined(IPV6_V6ONLY)

#if INET_CONFIG_ENABLE_IPV4
#ifdef IP_PKTINFO
        if (aAddressType == kIPAddressType_IPv4)
        {
            res = setsockopt(mSocket, IPPROTO_IP, IP_PKTINFO, (void *) &one, sizeof(one));
            if (res != 0)
            {
                ChipLogError(Inet, "IP_PKTINFO failed: %d", errno);
            }
        }
#endif // defined(IP_PKTINFO)
#endif // INET_CONFIG_ENABLE_IPV4

#ifdef IPV6_RECVPKTINFO
        if (aAddressType == kIPAddressType_IPv6)
        {
            res = setsockopt(mSocket, IPPROTO_IPV6, IPV6_RECVPKTINFO, (void *) &one, sizeof(one));
            if (res != 0)
            {
                ChipLogError(Inet, "IPV6_PKTINFO failed: %d", errno);
            }
        }
#endif // defined(IPV6_RECVPKTINFO)

        // On systems that support it, disable the delivery of SIGPIPE
        // signals when writing to a closed socket.  This is mostly
        // needed on iOS which has the peculiar habit of sending
        // SIGPIPEs on unconnected UDP sockets.
#ifdef SO_NOSIGPIPE
        {
            res = setsockopt(mSocket, SOL_SOCKET, SO_NOSIGPIPE, &one, sizeof(one));
            if (res != 0)
            {
                ChipLogError(Inet, "SO_NOSIGPIPE failed: %d", errno);
            }
        }
#endif // defined(SO_NOSIGPIPE)
    }
    else if (mAddrType != aAddressType)
    {
        return INET_ERROR_INCORRECT_STATE;
    }

    return INET_NO_ERROR;
}

SocketEvents IPEndPointBasis::PrepareIO(void)
{
    SocketEvents res;

    if (mState == kState_Listening && OnMessageReceived != NULL)
        res.SetRead();

    return res;
}

void IPEndPointBasis::HandlePendingIO(uint16_t aPort)
{
    INET_ERROR lStatus = INET_NO_ERROR;
    IPPacketInfo lPacketInfo;
    PacketBuffer * lBuffer;

    lPacketInfo.Clear();
    lPacketInfo.DestPort = aPort;

    lBuffer = PacketBuffer::New(0);

    if (lBuffer != NULL)
    {
        struct iovec msgIOV;
        PeerSockAddr lPeerSockAddr;
        uint8_t controlData[256];
        struct msghdr msgHeader;

        msgIOV.iov_base = lBuffer->Start();
        msgIOV.iov_len  = lBuffer->AvailableDataLength();

        memset(&lPeerSockAddr, 0, sizeof(lPeerSockAddr));

        memset(&msgHeader, 0, sizeof(msgHeader));

        msgHeader.msg_name       = &lPeerSockAddr;
        msgHeader.msg_namelen    = sizeof(lPeerSockAddr);
        msgHeader.msg_iov        = &msgIOV;
        msgHeader.msg_iovlen     = 1;
        msgHeader.msg_control    = controlData;
        msgHeader.msg_controllen = sizeof(controlData);

        ssize_t rcvLen = recvmsg(mSocket, &msgHeader, MSG_DONTWAIT);

        if (rcvLen < 0)
        {
            lStatus = chip::System::MapErrorPOSIX(errno);
        }
        else if (rcvLen > lBuffer->AvailableDataLength())
        {
            lStatus = INET_ERROR_INBOUND_MESSAGE_TOO_BIG;
        }
        else
        {
            lBuffer->SetDataLength((uint16_t) rcvLen);

            if (lPeerSockAddr.any.sa_family == AF_INET6)
            {
                lPacketInfo.SrcAddress = IPAddress::FromIPv6(lPeerSockAddr.in6.sin6_addr);
                lPacketInfo.SrcPort    = ntohs(lPeerSockAddr.in6.sin6_port);
            }
#if INET_CONFIG_ENABLE_IPV4
            else if (lPeerSockAddr.any.sa_family == AF_INET)
            {
                lPacketInfo.SrcAddress = IPAddress::FromIPv4(lPeerSockAddr.in.sin_addr);
                lPacketInfo.SrcPort    = ntohs(lPeerSockAddr.in.sin_port);
            }
#endif // INET_CONFIG_ENABLE_IPV4
            else
            {
                lStatus = INET_ERROR_INCORRECT_STATE;
            }
        }

        if (lStatus == INET_NO_ERROR)
        {
            for (struct cmsghdr * controlHdr = CMSG_FIRSTHDR(&msgHeader); controlHdr != NULL;
                 controlHdr                  = CMSG_NXTHDR(&msgHeader, controlHdr))
            {
#if INET_CONFIG_ENABLE_IPV4
#ifdef IP_PKTINFO
                if (controlHdr->cmsg_level == IPPROTO_IP && controlHdr->cmsg_type == IP_PKTINFO)
                {
                    struct in_pktinfo * inPktInfo = (struct in_pktinfo *) CMSG_DATA(controlHdr);
                    lPacketInfo.Interface         = inPktInfo->ipi_ifindex;
                    lPacketInfo.DestAddress       = IPAddress::FromIPv4(inPktInfo->ipi_addr);
                    continue;
                }
#endif // defined(IP_PKTINFO)
#endif // INET_CONFIG_ENABLE_IPV4

#ifdef IPV6_PKTINFO
                if (controlHdr->cmsg_level == IPPROTO_IPV6 && controlHdr->cmsg_type == IPV6_PKTINFO)
                {
                    struct in6_pktinfo * in6PktInfo = (struct in6_pktinfo *) CMSG_DATA(controlHdr);
                    lPacketInfo.Interface           = in6PktInfo->ipi6_ifindex;
                    lPacketInfo.DestAddress         = IPAddress::FromIPv6(in6PktInfo->ipi6_addr);
                    continue;
                }
#endif // defined(IPV6_PKTINFO)
            }
        }
    }
    else
    {
        lStatus = INET_ERROR_NO_MEMORY;
    }

    if (lStatus == INET_NO_ERROR)
        OnMessageReceived(this, lBuffer, &lPacketInfo);
    else
    {
        PacketBuffer::Free(lBuffer);
        if (OnReceiveError != NULL && lStatus != chip::System::MapErrorPOSIX(EAGAIN))
            OnReceiveError(this, lStatus, NULL);
    }

    return;
}
#endif // CHIP_SYSTEM_CONFIG_USE_SOCKETS

#if CHIP_SYSTEM_CONFIG_USE_NETWORK_FRAMEWORK
INET_ERROR IPEndPointBasis::ConfigureProtocol(IPAddressType aAddressType, nw_parameters_t aParameters)
{
    INET_ERROR res = INET_NO_ERROR;

    nw_protocol_stack_t protocolStack = nw_parameters_copy_default_protocol_stack(aParameters);
    nw_protocol_options_t ipOptions   = nw_protocol_stack_copy_internet_protocol(protocolStack);

    switch (aAddressType)
    {

    case kIPAddressType_IPv6:
        nw_ip_options_set_version(ipOptions, nw_ip_version_6);
        break;

#if INET_CONFIG_ENABLE_IPV4
    case kIPAddressType_IPv4:
        nw_ip_options_set_version(ipOptions, nw_ip_version_4);
        break;
#endif // INET_CONFIG_ENABLE_IPV4

    default:
        res = INET_ERROR_WRONG_ADDRESS_TYPE;
        break;
    }
    nw_release(ipOptions);
    nw_release(protocolStack);

    return res;
}

INET_ERROR IPEndPointBasis::Bind(IPAddressType aAddressType, IPAddress aAddress, uint16_t aPort, nw_parameters_t aParameters)
{
    INET_ERROR res         = INET_NO_ERROR;
    nw_endpoint_t endpoint = nullptr;

    VerifyOrExit(aParameters != NULL, res = INET_ERROR_BAD_ARGS);

    res = ConfigureProtocol(aAddressType, aParameters);
    SuccessOrExit(res);

    res = GetEndPoint(endpoint, aAddress, aPort);
    SuccessOrExit(res);

    nw_parameters_set_local_endpoint(aParameters, endpoint);
    nw_release(endpoint);

    mDispatchQueue = dispatch_queue_create("inet_dispatch_global", DISPATCH_QUEUE_CONCURRENT);
    VerifyOrExit(mDispatchQueue != NULL, res = INET_ERROR_NO_MEMORY);
    dispatch_retain(mDispatchQueue);

    mConnectionSemaphore = dispatch_semaphore_create(0);
    VerifyOrExit(mConnectionSemaphore != NULL, res = INET_ERROR_NO_MEMORY);
    dispatch_retain(mConnectionSemaphore);

    mAddrType   = aAddressType;
    mConnection = NULL;

exit:
    return res;
}

INET_ERROR IPEndPointBasis::SendMsg(const IPPacketInfo * aPktInfo, chip::System::PacketBuffer * aBuffer, uint16_t aSendFlags)
{
    __block INET_ERROR res = INET_NO_ERROR;
    dispatch_data_t content;
    dispatch_semaphore_t send_semaphore;

    // Ensure the destination address type is compatible with the endpoint address type.
    VerifyOrExit(mAddrType == aPktInfo->DestAddress.Type(), res = INET_ERROR_BAD_ARGS);

    // For now the entire message must fit within a single buffer.
    VerifyOrExit(aBuffer->Next() == NULL, res = INET_ERROR_MESSAGE_TOO_LONG);

    res = GetConnection(aPktInfo);
    SuccessOrExit(res);

    // Send a message, and wait for it to be dispatched.
    send_semaphore = dispatch_semaphore_create(0);
    content = dispatch_data_create(aBuffer->Start(), aBuffer->DataLength(), mDispatchQueue, DISPATCH_DATA_DESTRUCTOR_DEFAULT);
    nw_connection_send(mConnection, content, NW_CONNECTION_DEFAULT_MESSAGE_CONTEXT, true, ^(nw_error_t error) {
        res = chip::System::MapErrorPOSIX(nw_error_get_error_code(error));
        dispatch_semaphore_signal(send_semaphore);
    });
    dispatch_release(content);

    dispatch_semaphore_wait(send_semaphore, DISPATCH_TIME_FOREVER);
    dispatch_release(send_semaphore);

exit:
    return res;
}

void IPEndPointBasis::HandleDataReceived(nw_connection_t aConnection)
{

    nw_connection_receive_completion_t handler =
        ^(dispatch_data_t content, nw_content_context_t context, bool is_complete, nw_error_t receive_error) {
            dispatch_block_t schedule_next_receive = ^{
                if (receive_error == NULL)
                {
                    HandleDataReceived(aConnection);
                }
                else if (OnReceiveError != NULL)
                {
                    nw_error_domain_t error_domain = nw_error_get_error_domain(receive_error);
                    errno                          = nw_error_get_error_code(receive_error);
                    if (!(error_domain == nw_error_domain_posix && errno == ECANCELED))
                    {
                        INET_ERROR error = chip::System::MapErrorPOSIX(errno);
                        IPPacketInfo packetInfo;
                        GetPacketInfo(aConnection, packetInfo);
                        dispatch_async(mDispatchQueue, ^{
                            OnReceiveError((IPEndPointBasis *) this, error, &packetInfo);
                        });
                    }
                }
            };

            if (content != NULL && OnMessageReceived != NULL)
            {
                size_t count                        = dispatch_data_get_size(content);
                System::PacketBuffer * packetBuffer = PacketBuffer::NewWithAvailableSize(count);
                dispatch_data_apply(content, ^(dispatch_data_t data, size_t offset, const void * buffer, size_t size) {
                    memmove(packetBuffer->Start() + offset, buffer, size);
                    return true;
                });
                packetBuffer->SetDataLength(count);

                IPPacketInfo packetInfo;
                GetPacketInfo(aConnection, packetInfo);
                dispatch_async(mDispatchQueue, ^{
                    OnMessageReceived((IPEndPointBasis *) this, packetBuffer, &packetInfo);
                });
            }

            schedule_next_receive();
        };

    nw_connection_receive_message(aConnection, handler);
}

void IPEndPointBasis::GetPacketInfo(nw_connection_t aConnection, IPPacketInfo & aPacketInfo)
{
    nw_parameters_t parameters    = nw_connection_copy_parameters(aConnection);
    nw_endpoint_t local_endpoint  = nw_parameters_copy_local_endpoint(parameters);
    nw_endpoint_t remote_endpoint = nw_connection_copy_endpoint(aConnection);

    aPacketInfo.Clear();
    aPacketInfo.SrcAddress  = IPAddress::FromSockAddr(*nw_endpoint_get_address(remote_endpoint));
    aPacketInfo.DestAddress = IPAddress::FromSockAddr(*nw_endpoint_get_address(local_endpoint));
    aPacketInfo.SrcPort     = nw_endpoint_get_port(remote_endpoint);
    aPacketInfo.DestPort    = nw_endpoint_get_port(local_endpoint);
}

INET_ERROR IPEndPointBasis::GetEndPoint(nw_endpoint_t & aEndPoint, const IPAddress aAddress, uint16_t aPort)
{
    INET_ERROR res = INET_NO_ERROR;

    char addrStr[INET6_ADDRSTRLEN];
    aAddress.ToString(addrStr, sizeof(addrStr));

    char portStr[INET_PORTSTRLEN];
    snprintf(portStr, sizeof(portStr), "%u", aPort);

    nw_endpoint_t endpoint = nw_endpoint_create_host(addrStr, portStr);
    VerifyOrExit(endpoint != NULL, res = INET_ERROR_BAD_ARGS);

    aEndPoint = endpoint;

exit:
    return res;
}

INET_ERROR IPEndPointBasis::GetConnection(const IPPacketInfo * aPktInfo)
{
    INET_ERROR res             = INET_NO_ERROR;
    nw_endpoint_t endpoint     = NULL;
    nw_connection_t connection = NULL;

    VerifyOrExit(mParameters != NULL, res = INET_ERROR_INCORRECT_STATE);

    if (mConnection)
    {
        nw_endpoint_t remote_endpoint  = nw_connection_copy_endpoint(mConnection);
        const IPAddress remote_address = IPAddress::FromSockAddr(*nw_endpoint_get_address(remote_endpoint));
        const uint16_t remote_port     = nw_endpoint_get_port(remote_endpoint);
        const bool isDifferentEndPoint = aPktInfo->DestPort != remote_port || aPktInfo->DestAddress != remote_address;
        VerifyOrExit(isDifferentEndPoint, res = INET_NO_ERROR);

        res = ReleaseConnection();
    }
    SuccessOrExit(res);

    res = GetEndPoint(endpoint, aPktInfo->DestAddress, aPktInfo->DestPort);
    SuccessOrExit(res);

    connection = nw_connection_create(endpoint, mParameters);
    nw_release(endpoint);

    VerifyOrExit(connection != NULL, res = INET_ERROR_INCORRECT_STATE);

    res = StartConnection(connection);

exit:
    return res;
}

INET_ERROR IPEndPointBasis::StartListener()
{
    __block INET_ERROR res = INET_NO_ERROR;
    nw_listener_t listener;

    VerifyOrExit(mListener == NULL, res = INET_ERROR_INCORRECT_STATE);
    VerifyOrExit(mListenerSemaphore == NULL, res = INET_ERROR_INCORRECT_STATE);
    VerifyOrExit(mListenerQueue == NULL, res = INET_ERROR_INCORRECT_STATE);

    listener = nw_listener_create(mParameters);
    VerifyOrExit(listener != NULL, res = INET_ERROR_INCORRECT_STATE);

    mListenerSemaphore = dispatch_semaphore_create(0);
    VerifyOrExit(mListenerSemaphore != NULL, res = INET_ERROR_NO_MEMORY);
    dispatch_retain(mListenerSemaphore);

    mListenerQueue = dispatch_queue_create("inet_dispatch_listener", DISPATCH_QUEUE_CONCURRENT);
    VerifyOrExit(mListenerQueue != NULL, res = INET_ERROR_NO_MEMORY);
    dispatch_retain(mListenerQueue);

    nw_listener_set_queue(listener, mListenerQueue);

    nw_listener_set_new_connection_handler(listener, ^(nw_connection_t connection) {
        ReleaseConnection();
        StartConnection(connection);
    });

    nw_listener_set_state_changed_handler(listener, ^(nw_listener_state_t state, nw_error_t error) {
        switch (state)
        {

        case nw_listener_state_invalid:
            ChipLogDetail(Inet, "Listener: Invalid");
            res = INET_ERROR_INCORRECT_STATE;
            nw_listener_cancel(listener);
            break;

        case nw_listener_state_waiting:
            ChipLogDetail(Inet, "Listener: Waiting");
            break;

        case nw_listener_state_failed:
            ChipLogDetail(Inet, "Listener: Failed");
            res = chip::System::MapErrorPOSIX(nw_error_get_error_code(error));
            nw_listener_cancel(listener);
            break;

        case nw_listener_state_ready:
            ChipLogDetail(Inet, "Listener: Ready");
            res = INET_NO_ERROR;
            dispatch_semaphore_signal(mListenerSemaphore);
            break;

        case nw_listener_state_cancelled:
            ChipLogDetail(Inet, "Listener: Cancelled");
            if (res == INET_NO_ERROR)
                res = INET_ERROR_CONNECTION_ABORTED;

            dispatch_semaphore_signal(mListenerSemaphore);
            break;
        }
    });

    nw_listener_start(listener);
    dispatch_semaphore_wait(mListenerSemaphore, DISPATCH_TIME_FOREVER);
    SuccessOrExit(res);

    mListener = listener;
    nw_retain(mListener);
exit:
    return res;
}

INET_ERROR IPEndPointBasis::StartConnection(nw_connection_t & aConnection)
{
    __block INET_ERROR res = INET_NO_ERROR;

    nw_connection_set_queue(aConnection, mDispatchQueue);

    nw_connection_set_state_changed_handler(aConnection, ^(nw_connection_state_t state, nw_error_t error) {
        switch (state)
        {

        case nw_connection_state_invalid:
            ChipLogDetail(Inet, "Connection: Invalid");
            res = INET_ERROR_INCORRECT_STATE;
            nw_connection_cancel(aConnection);
            break;

        case nw_connection_state_preparing:
            ChipLogDetail(Inet, "Connection: Preparing");
            res = INET_ERROR_INCORRECT_STATE;
            break;

        case nw_connection_state_waiting:
            ChipLogDetail(Inet, "Connection: Waiting");
            nw_connection_cancel(aConnection);
            break;

        case nw_connection_state_failed:
            ChipLogDetail(Inet, "Connection: Failed");
            res = chip::System::MapErrorPOSIX(nw_error_get_error_code(error));
            nw_connection_cancel(aConnection);
            break;

        case nw_connection_state_ready:
            ChipLogDetail(Inet, "Connection: Ready");
            res = INET_NO_ERROR;
            dispatch_semaphore_signal(mConnectionSemaphore);
            break;

        case nw_connection_state_cancelled:
            ChipLogDetail(Inet, "Connection: Cancelled");
            if (res == INET_NO_ERROR)
                res = INET_ERROR_CONNECTION_ABORTED;

            dispatch_semaphore_signal(mConnectionSemaphore);
            break;
        }
    });

    nw_connection_start(aConnection);
    dispatch_semaphore_wait(mConnectionSemaphore, DISPATCH_TIME_FOREVER);
    SuccessOrExit(res);

    mConnection = aConnection;
    nw_retain(mConnection);
    HandleDataReceived(mConnection);

exit:
    return res;
}

void IPEndPointBasis::ReleaseAll()
{

    OnMessageReceived = NULL;
    OnReceiveError    = NULL;

    ReleaseConnection();
    ReleaseListener();

    if (mParameters)
    {
        nw_release(mParameters);
        mParameters = NULL;
    }

    if (mDispatchQueue)
    {
        dispatch_suspend(mDispatchQueue);
        dispatch_release(mDispatchQueue);
        mDispatchQueue = NULL;
    }

    if (mConnectionSemaphore)
    {
        dispatch_release(mConnectionSemaphore);
        mConnectionSemaphore = NULL;
    }

    if (mListenerQueue)
    {
        dispatch_suspend(mListenerQueue);
        dispatch_release(mListenerQueue);
        mListenerQueue = NULL;
    }

    if (mListenerSemaphore)
    {
        dispatch_release(mListenerSemaphore);
        mListenerSemaphore = NULL;
    }
}

INET_ERROR IPEndPointBasis::ReleaseListener()
{
    INET_ERROR res = INET_NO_ERROR;

    VerifyOrExit(mListener, res = INET_ERROR_INCORRECT_STATE);
    VerifyOrExit(mDispatchQueue, res = INET_ERROR_INCORRECT_STATE);
    VerifyOrExit(mConnectionSemaphore, res = INET_ERROR_INCORRECT_STATE);

    nw_listener_cancel(mListener);
    dispatch_semaphore_wait(mListenerSemaphore, DISPATCH_TIME_FOREVER);
    nw_release(mListener);
    mListener = NULL;

exit:
    return res;
}

INET_ERROR IPEndPointBasis::ReleaseConnection()
{
    INET_ERROR res = INET_NO_ERROR;
    VerifyOrExit(mConnection, res = INET_ERROR_INCORRECT_STATE);
    VerifyOrExit(mDispatchQueue, res = INET_ERROR_INCORRECT_STATE);
    VerifyOrExit(mConnectionSemaphore, res = INET_ERROR_INCORRECT_STATE);

    nw_connection_cancel(mConnection);
    dispatch_semaphore_wait(mConnectionSemaphore, DISPATCH_TIME_FOREVER);
    nw_release(mConnection);
    mConnection = NULL;

exit:
    return res;
}

#endif // CHIP_SYSTEM_CONFIG_USE_NETWORK_FRAMEWORK

} // namespace Inet
} // namespace chip