Merge branch 'windows-port'
[platform/upstream/iotivity.git] / resource / csdk / connectivity / src / ip_adapter / caipserver.c
index b6a3e50..7e9d2cc 100644 (file)
@@ -1,4 +1,4 @@
-/******************************************************************
+/* ****************************************************************
  *
  * Copyright 2014 Samsung Electronics All Rights Reserved.
  *
  *
  ******************************************************************/
 
-#include "caipinterface.h"
+#ifndef __APPLE_USE_RFC_3542
+#define __APPLE_USE_RFC_3542 // for PKTINFO
+#endif
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE // for in6_pktinfo
+#endif
 
 #include <sys/types.h>
+#if !defined(_WIN32)
 #include <sys/socket.h>
+#endif
+
+#if defined(_WIN32)
+#include <assert.h>
+#include <winsock2.h>
+#include <ws2def.h>
+#include <mswsock.h>
+#include <ws2tcpip.h>
+#endif
+
+#include <stdio.h>
+#if !defined(_MSC_VER)
 #include <unistd.h>
+#endif //!defined(_MSC_VER)
+#include <sys/types.h>
 #include <fcntl.h>
+#if !defined(_WIN32)
 #include <sys/select.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
+#include <net/if.h>
+#endif
 #include <errno.h>
+#ifdef __linux__
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#endif
 
 #include "pdu.h"
+#include "caipinterface.h"
 #include "caadapterutils.h"
 #ifdef __WITH_DTLS__
 #include "caadapternetdtls.h"
 #include "camutex.h"
 #include "oic_malloc.h"
 #include "oic_string.h"
+#include "platform_features.h"
 
-/**
- * @def IP_SERVER_TAG
- * @brief Logging tag for module name
- */
-#define IP_SERVER_TAG "IP_SERVER"
+#define USE_IP_MREQN
+#if defined(_WIN32)
+#undef USE_IP_MREQN
+#endif
 
-/**
- * @def CA_UDP_BIND_RETRY_COUNT
- * @brief Retry count in case of socket bind failure.
+/*
+ * Logging tag for module name
  */
-#define CA_UDP_BIND_RETRY_COUNT 10
+#define TAG "OIC_CA_IP_SERVER"
+
+#define SELECT_TIMEOUT 1     // select() seconds (and termination latency)
+
+#define IPv4_MULTICAST     "224.0.1.187"
+static struct in_addr IPv4MulticastAddress = { 0 };
+
+#define IPv6_DOMAINS       16
+#define IPv6_MULTICAST_INT "ff01::fd"
+static struct in6_addr IPv6MulticastAddressInt;
+#define IPv6_MULTICAST_LNK "ff02::fd"
+static struct in6_addr IPv6MulticastAddressLnk;
+#define IPv6_MULTICAST_RLM "ff03::fd"
+static struct in6_addr IPv6MulticastAddressRlm;
+#define IPv6_MULTICAST_ADM "ff04::fd"
+static struct in6_addr IPv6MulticastAddressAdm;
+#define IPv6_MULTICAST_SIT "ff05::fd"
+static struct in6_addr IPv6MulticastAddressSit;
+#define IPv6_MULTICAST_ORG "ff08::fd"
+static struct in6_addr IPv6MulticastAddressOrg;
+#define IPv6_MULTICAST_GLB "ff0e::fd"
+static struct in6_addr IPv6MulticastAddressGlb;
+
+static char *ipv6mcnames[IPv6_DOMAINS] = {
+    NULL,
+    IPv6_MULTICAST_INT,
+    IPv6_MULTICAST_LNK,
+    IPv6_MULTICAST_RLM,
+    IPv6_MULTICAST_ADM,
+    IPv6_MULTICAST_SIT,
+    NULL,
+    NULL,
+    IPv6_MULTICAST_ORG,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    IPv6_MULTICAST_GLB,
+    NULL
+};
+
+#if defined (_WIN32)
+#define IFF_UP_RUNNING_FLAGS  (IFF_UP)
+
+    char* caips_get_error(){
+        static char buffer[32];
+        snprintf(buffer, 32, "%i", WSAGetLastError());
+        return buffer;
+    }
+#define CAIPS_GET_ERROR \
+    caips_get_error()
+#else
+#define IFF_UP_RUNNING_FLAGS  (IFF_UP|IFF_RUNNING)
 
-/**
- * @def IPNAMESIZE
- * @brief Max length for ip address.
- */
-#define IPNAMESIZE 16
+#define CAIPS_GET_ERROR \
+    strerror(errno)
+#endif
+static CAIPErrorHandleCallback g_ipErrorHandler = NULL;
 
-/**
- * @def SOCKETOPTION
- * @brief Socket option.
- */
-#define SOCKETOPTION 1
+static CAIPPacketReceivedCallback g_packetReceivedCallback = NULL;
 
-/**
- * @var g_packetHandlerStopFlag
- * @brief Flag for stopping packet handler thread.
- */
-static bool g_packetHandlerStopFlag = false;
+static void CAFindReadyMessage();
+#if !defined(WSA_WAIT_EVENT_0)
+static void CASelectReturned(fd_set *readFds, int ret);
+#else
+static void CAEventReturned(CASocketFd_t socket);
+#endif
+static void CAProcessNewInterface(CAInterface_t *ifchanged);
+static CAResult_t CAReceiveMessage(CASocketFd_t fd, CATransportFlags_t flags);
 
-/**
- * @var CAAdapterIPServerContext_t
- * @brief Thread context information for callbacks and threadpool.
- */
-typedef struct
+static void CAReceiveHandler(void *data)
 {
-    ca_thread_pool_t threadPool;
-    CAIPPacketReceivedCallback packetReceivedCallback;
-    CAIPExceptionCallback exceptionCallback;
-    CAIPErrorHandleCallback IPErrorCallback;
-} CAAdapterIPServerContext_t;
-
-/**
- * @var g_serverInfoList
- * @brief Mutex to synchronize ethenet adapter context.
- */
-static u_arraylist_t *g_serverInfoList = NULL;
+    (void)data;
 
-/**
- * @var g_mutexServerInfoList
- * @brief Mutex to synchronize Server Information.
- */
-static ca_mutex g_mutexServerInfoList = NULL;
+    while (!caglobals.ip.terminate)
+    {
+        CAFindReadyMessage();
+    }
+}
 
-/**
- * @var g_adapterIPServerContext
- * @brief Mutex to synchronize ethenet adapter context.
- */
-static CAAdapterIPServerContext_t *g_adapterIPServerContext = NULL;
+#if !defined(WSA_WAIT_EVENT_0)
 
-/**
- * @var g_mutexAdapterServerContext
- * @brief Mutex to synchronize unicast server
- */
-static ca_mutex g_mutexAdapterServerContext = NULL;
+#define CLOSE_SOCKET(TYPE) \
+    if (caglobals.ip.TYPE.fd != OC_INVALID_SOCKET) \
+    { \
+        close(caglobals.ip.TYPE.fd); \
+        caglobals.ip.TYPE.fd = OC_INVALID_SOCKET; \
+    }
+
+#define SET(TYPE, FDS) \
+    if (caglobals.ip.TYPE.fd != OC_INVALID_SOCKET) \
+    { \
+        FD_SET(caglobals.ip.TYPE.fd, FDS); \
+    }
+
+#define ISSET(TYPE, FDS, FLAGS) \
+    if (caglobals.ip.TYPE.fd != OC_INVALID_SOCKET && FD_ISSET(caglobals.ip.TYPE.fd, FDS)) \
+    { \
+        fd = caglobals.ip.TYPE.fd; \
+        flags = FLAGS; \
+    }
 
-static void CAReceiveHandler(void *data)
-{
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
 
+static void CAFindReadyMessage()
+{
     fd_set readFds;
-    int maxSd = 0;
     struct timeval timeout;
-    char recvBuffer[COAP_MAX_PDU_SIZE] = { 0 };
 
-    while (true != g_packetHandlerStopFlag)
+    timeout.tv_sec = caglobals.ip.selectTimeout;
+    timeout.tv_usec = 0;
+    struct timeval *tv = caglobals.ip.selectTimeout == -1 ? NULL : &timeout;
+
+    FD_ZERO(&readFds);
+    SET(u6,  &readFds)
+    SET(u6s, &readFds)
+    SET(u4,  &readFds)
+    SET(u4s, &readFds)
+    SET(m6,  &readFds)
+    SET(m6s, &readFds)
+    SET(m4,  &readFds)
+    SET(m4s, &readFds)
+
+    if (caglobals.ip.shutdownFds[0] != -1)
+    {
+        FD_SET(caglobals.ip.shutdownFds[0], &readFds);
+    }
+    if (caglobals.ip.netlinkFd != OC_INVALID_SOCKET)
     {
-        timeout.tv_sec = 1;
-        timeout.tv_usec = 0;
-        FD_ZERO(&readFds);
+        FD_SET(caglobals.ip.netlinkFd, &readFds);
+    }
 
-        ca_mutex_lock(g_mutexServerInfoList);
-        uint32_t listIndex = 0;
-        uint32_t listLength = u_arraylist_length(g_serverInfoList);
+    int ret = select(caglobals.ip.maxfd + 1, &readFds, NULL, NULL, tv);
 
-        u_arraylist_t *tempServerInfoList = u_arraylist_create();
-        if (!tempServerInfoList)
-        {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "u_arraylist_create failed");
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return;
-        }
+    if (caglobals.ip.terminate)
+    {
+        OIC_LOG_V(DEBUG, TAG, "Packet receiver Stop request received.");
+        return;
+    }
 
-        for (listIndex = 0; listIndex < listLength; listIndex++)
+    if (ret <= 0)
+    {
+        if (ret < 0)
         {
-            CAServerInfo_t *info = (CAServerInfo_t *) u_arraylist_get(g_serverInfoList, listIndex);
-            if (!info)
-            {
-                listIndex++;
-                continue;
-            }
-
-            int sd = info->socketFd;
-            //if valid socket descriptor then add to read list
-            if (sd > 0)
-            {
-                FD_SET(sd, &readFds);
-            }
-
-            //highest file descriptor number, need it for the select function
-            if (sd > maxSd)
-            {
-                maxSd = sd;
-            }
+            OIC_LOG_V(FATAL, TAG, "select error %s", CAIPS_GET_ERROR);
+        }
+        return;
+    }
 
-            CAServerInfo_t *newInfo = (CAServerInfo_t *) OICMalloc(sizeof(CAServerInfo_t));
-            if (!newInfo)
-            {
-                OIC_LOG(ERROR, IP_SERVER_TAG, "Malloc failed");
-                CAClearServerInfoList(tempServerInfoList);
-                ca_mutex_unlock(g_mutexServerInfoList);
-                return;
-            }
+    CASelectReturned(&readFds, ret);
+}
 
-            *newInfo = *info;
+static void CASelectReturned(fd_set *readFds, int ret)
+{
+    (void)ret;
+    CASocketFd_t fd = OC_INVALID_SOCKET;
+    CATransportFlags_t flags = CA_DEFAULT_FLAGS;
 
-            CAResult_t result = u_arraylist_add(tempServerInfoList, (void *) newInfo);
-            if (CA_STATUS_OK != result)
+    while (!caglobals.ip.terminate)
+    {
+        ISSET(u6,  readFds, CA_IPV6)
+        else ISSET(u6s, readFds, CA_IPV6 | CA_SECURE)
+        else ISSET(u4,  readFds, CA_IPV4)
+        else ISSET(u4s, readFds, CA_IPV4 | CA_SECURE)
+        else ISSET(m6,  readFds, CA_MULTICAST | CA_IPV6)
+        else ISSET(m6s, readFds, CA_MULTICAST | CA_IPV6 | CA_SECURE)
+        else ISSET(m4,  readFds, CA_MULTICAST | CA_IPV4)
+        else ISSET(m4s, readFds, CA_MULTICAST | CA_IPV4 | CA_SECURE)
+        else if ((caglobals.ip.netlinkFd != OC_INVALID_SOCKET) && FD_ISSET(caglobals.ip.netlinkFd, readFds))
+        {
+            CAInterface_t *ifchanged = CAFindInterfaceChange();
+            if (ifchanged)
             {
-                OIC_LOG(ERROR, IP_SERVER_TAG, "u_arraylist_add failed!Thread exit");
-                CAClearServerInfoList(tempServerInfoList);
-                ca_mutex_unlock(g_mutexServerInfoList);
-                return;
+                CAProcessNewInterface(ifchanged);
+                OICFree(ifchanged);
             }
+            break;
         }
-
-        ca_mutex_unlock(g_mutexServerInfoList);
-
-        int ret = select(maxSd + 1, &readFds, NULL, NULL, &timeout);
-        if (g_packetHandlerStopFlag)
+        else if (FD_ISSET(caglobals.ip.shutdownFds[0], readFds))
         {
-            OIC_LOG_V(DEBUG, IP_SERVER_TAG,
-                      "Packet receiver handler Stop request received. Thread exited");
-            CAClearServerInfoList(tempServerInfoList);
+            char buf[10] = {0};
+            ssize_t len = read(caglobals.ip.shutdownFds[0], buf, sizeof (buf));
+            if (-1 == len)
+            {
+                continue;
+            }
             break;
         }
-        if (ret < 0)
+        else
         {
-            OIC_LOG_V(FATAL, IP_SERVER_TAG, "select returned error %s", strerror(errno));
-            CAClearServerInfoList(tempServerInfoList);
-            continue;
+            break;
         }
+        (void)CAReceiveMessage(fd, flags);
+        FD_CLR(fd, readFds);
+    }
+}
 
-        listLength = u_arraylist_length(tempServerInfoList);
-        for (listIndex = 0; listIndex < listLength; listIndex++)
-        {
-            CAServerInfo_t *info = (CAServerInfo_t *) u_arraylist_get(tempServerInfoList,
-                                                                      listIndex);
-            if (!info)
-            {
-                continue;
-            }
+#else // if defined(WSA_WAIT_EVENT_0)
 
-            int sd = info->socketFd;
-            if (FD_ISSET(sd , &readFds))
-            {
-                OIC_LOG_V(ERROR, IP_SERVER_TAG,
-                          "data Received server information ip %s, port %d socket %d",
-                          info->endpoint.addr, info->endpoint.port, sd);
-                memset(recvBuffer, 0, sizeof(recvBuffer));
-
-                struct sockaddr_in srcSockAddress = { 0 };
-                socklen_t srcAddressLen = sizeof(srcSockAddress);
-
-                //Reading from socket
-                ssize_t recvLen = recvfrom(sd, recvBuffer, sizeof(recvBuffer), 0,
-                                           (struct sockaddr *) &srcSockAddress, &srcAddressLen);
-                if (-1 == recvLen)
-                {
-                    OIC_LOG_V(ERROR, IP_SERVER_TAG, "Recvfrom failed %s", strerror(errno));
-                    continue;
-                }
-                else if (0 == recvLen)
-                {
-                    OIC_LOG_V(ERROR, IP_SERVER_TAG, "Server socket shutdown sock fd[%d]", sd);
-                    ca_mutex_lock(g_mutexAdapterServerContext);
-                    // Notify upper layer this exception
-                    if (g_adapterIPServerContext->exceptionCallback)
-                    {
-                        // need to make proper exception callback.
-                        //g_adapterIPServerContext->exceptionCallback(ctx->type);
-                    }
-                    ca_mutex_unlock(g_mutexAdapterServerContext);
-                }
+#define CLOSE_SOCKET(TYPE) \
+    if (caglobals.ip.TYPE.fd != OC_INVALID_SOCKET) \
+    { \
+        closesocket(caglobals.ip.TYPE.fd); \
+        caglobals.ip.TYPE.fd = OC_INVALID_SOCKET; \
+    }
 
-                char srcIPAddress[CA_IPADDR_SIZE] = { 0 };
-                if (!inet_ntop(AF_INET, &srcSockAddress.sin_addr.s_addr, srcIPAddress,
-                               sizeof(srcIPAddress)))
-                {
+#define PUSH_HANDLE(HANDLE, ARRAY, INDEX) \
+{ \
+    ARRAY[INDEX] = HANDLE; \
+    INDEX++; \
+}
 
-                    OIC_LOG(ERROR, IP_SERVER_TAG, "inet_ntop is failed!");
-                    continue;
-                }
+// Turn handle into WSAEvent and push to ARRAY
+#define PUSH_SOCKET(SOCKET, ARRAY, INDEX) \
+    if (SOCKET != OC_INVALID_SOCKET) \
+    { \
+        WSAEVENT NewEvent; \
+        NewEvent = WSACreateEvent(); \
+        if (WSA_INVALID_EVENT != NewEvent) \
+        { \
+            if (0 != WSAEventSelect(SOCKET, NewEvent, FD_READ)) \
+            { \
+                OIC_LOG_V(ERROR, TAG, "WSAEventSelect failed 0x%08x ", WSAGetLastError()); \
+                if (!WSACloseEvent(NewEvent)) \
+                { \
+                    OIC_LOG_V(ERROR, TAG, "WSACloseEvent(NewEvent) failed 0x%08x", WSAGetLastError()); \
+                } \
+            } \
+            else \
+            { \
+                PUSH_HANDLE(NewEvent, ARRAY, INDEX); \
+            } \
+        } \
+        else \
+        { \
+            OIC_LOG_V(ERROR, TAG, "WSACreateEvent(NewEvent) failed 0x%08x", WSAGetLastError()); \
+        }\
+    }
 
-                uint16_t srcPort = ntohs(srcSockAddress.sin_port);
+#define INSERT_SOCKET(FD, ARRAY, INDEX) \
+    { \
+        if (OC_INVALID_SOCKET != FD) \
+        { \
+            ARRAY[INDEX] = FD; \
+        } \
+    }
 
-                OIC_LOG_V(DEBUG, IP_SERVER_TAG, "Received packet from %s:%d len %d",
-                          srcIPAddress, srcPort, recvLen);
 
-                char *netMask = NULL;
-                if (CA_STATUS_OK != CAIPGetInterfaceSubnetMask(info->ifAddr, &netMask))
-                {
-                    OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to get IP subnet");
-                    continue;
-                }
+// Inserts the socket into the SOCKET_ARRAY and pushes the socket event into EVENT_ARRAY
+#define PUSH_IP_SOCKET(TYPE, EVENT_ARRAY, SOCKET_ARRAY, INDEX) \
+    { \
+        if (OC_INVALID_SOCKET != caglobals.ip.TYPE.fd) \
+        { \
+            INSERT_SOCKET(caglobals.ip.TYPE.fd, SOCKET_ARRAY, INDEX); \
+            PUSH_SOCKET(caglobals.ip.TYPE.fd, EVENT_ARRAY, INDEX); \
+        } \
+    }
 
-                if (!CAAdapterIsSameSubnet(info->ifAddr, srcIPAddress, netMask))
-                {
-                    OIC_LOG(DEBUG, IP_SERVER_TAG,
-                            "Packet received from different subnet, Ignore!");
-                    OICFree(netMask);
-                    continue;
-                }
-                OICFree(netMask);
+#define IS_MATCHING_IP_SOCKET(TYPE, SOCKET, FLAGS) \
+    if ((caglobals.ip.TYPE.fd != OC_INVALID_SOCKET) && (caglobals.ip.TYPE.fd == SOCKET)) \
+    { \
+        fd = caglobals.ip.TYPE.fd; \
+        flags = FLAGS; \
+    }
 
-                CAEndpoint_t ep;
-                strncpy(ep.addr, srcIPAddress, MAX_ADDR_STR_SIZE_CA);
-                ep.port = srcPort;
-                ep.flags = (CATransportFlags_t)CA_IPV4 | CA_IPV6;
-                ep.adapter = CA_ADAPTER_IP;
+#define EVENT_ARRAY_SIZE  10
 
-                if (info->endpoint.flags & CA_SECURE)
-                {
-#ifdef __WITH_DTLS__
-                    ep.flags |= CA_SECURE;
-                    (void)CAAdapterNetDtlsDecrypt(&ep, (uint8_t *)recvBuffer, recvLen);
-                    OIC_LOG_V(DEBUG, IP_SERVER_TAG,
-                              "CAAdapterNetDtlsDecrypt returns [%d]", ret);
-#endif
-                }
-                else //both multicast and unicast
-                {
-                    ca_mutex_lock(g_mutexAdapterServerContext);
+static void CAFindReadyMessage()
+{
+    CASocketFd_t socketArray[EVENT_ARRAY_SIZE];
+    HANDLE eventArray[EVENT_ARRAY_SIZE];
+    int arraySize = 0;
+    int eventIndex;
+
+    // socketArray and eventArray should have same number of elements
+    OC_STATIC_ASSERT(_countof(socketArray) == _countof(eventArray), "Arrays should have same number of elements");
+
+    PUSH_IP_SOCKET(u6,  eventArray, socketArray, arraySize);
+    PUSH_IP_SOCKET(u6s, eventArray, socketArray, arraySize);
+    PUSH_IP_SOCKET(u4,  eventArray, socketArray, arraySize);
+    PUSH_IP_SOCKET(u4s, eventArray, socketArray, arraySize);
+    PUSH_IP_SOCKET(m6,  eventArray, socketArray, arraySize);
+    PUSH_IP_SOCKET(m6s, eventArray, socketArray, arraySize);
+    PUSH_IP_SOCKET(m4,  eventArray, socketArray, arraySize);
+    PUSH_IP_SOCKET(m4s, eventArray, socketArray, arraySize);
+
+    if (-1 != caglobals.ip.shutdownEvent)
+    {
+        INSERT_SOCKET(OC_INVALID_SOCKET, socketArray, arraySize);
+        PUSH_HANDLE(caglobals.ip.shutdownEvent, eventArray, arraySize);
+    }
+
+    /** @todo Support netlink events */
 
-                    if (g_adapterIPServerContext->packetReceivedCallback)
+    // Should not have overflowed buffer
+    assert(arraySize <= (_countof(socketArray)));
+
+    // Timeout is unnecessary on Windows
+    assert(-1 == caglobals.ip.selectTimeout);
+
+    while (!caglobals.ip.terminate)
+    {
+        int ret = WSAWaitForMultipleEvents(arraySize, eventArray, FALSE, WSA_INFINITE, FALSE);
+
+        switch (ret)
+        {
+            case WSA_WAIT_FAILED:
+                OIC_LOG_V(ERROR, TAG, "WSAWaitForMultipleEvents returned WSA_WAIT_FAILED 0x%08x", WSAGetLastError());
+                break;
+            case WSA_WAIT_IO_COMPLETION:
+                OIC_LOG_V(ERROR, TAG, "WSAWaitForMultipleEvents returned WSA_WAIT_IO_COMPLETION 0x%08x", WSAGetLastError());
+                break;
+            case WSA_WAIT_TIMEOUT:
+                OIC_LOG_V(ERROR, TAG, "WSAWaitForMultipleEvents returned WSA_WAIT_TIMEOUT 0x%08x", WSAGetLastError());
+                break;
+            default:
+                eventIndex = ret - WSA_WAIT_EVENT_0;
+                if ((eventIndex >= 0) && (eventIndex < arraySize))
+                {
+                    if (false == WSAResetEvent(eventArray[eventIndex]))
                     {
-                        g_adapterIPServerContext->packetReceivedCallback(&ep,
-                                                          recvBuffer, recvLen);
+                        OIC_LOG_V(ERROR, TAG, "WSAResetEvent failed 0x%08x", WSAGetLastError());
                     }
 
-                    ca_mutex_unlock(g_mutexAdapterServerContext);
+                    // Break out if shutdownEvent is triggered
+                    if ((caglobals.ip.shutdownEvent != -1) &&
+                        (caglobals.ip.shutdownEvent == eventArray[eventIndex]))
+                    {
+                        break;
+                    }
+                    CAEventReturned(socketArray[eventIndex]);
                 }
-            }
+                else
+                {
+                    OIC_LOG_V(ERROR, TAG, "WSAWaitForMultipleEvents failed 0x%08x", WSAGetLastError());
+                }
+                break;
         }
-        CAClearServerInfoList(tempServerInfoList);
+
+    }
+
+    while (arraySize > 0)
+    {
+        arraySize--;
+        if (!WSACloseEvent(eventArray[arraySize]))
+        {
+            OIC_LOG_V(ERROR, TAG, "WSACloseEvent (Index %i) failed 0x%08x", arraySize, WSAGetLastError());
+        }
+    }
+
+    if (caglobals.ip.terminate)
+    {
+        caglobals.ip.shutdownEvent = -1;
+        WSACleanup();
     }
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
 }
 
-static CAResult_t CACreateSocket(int *socketFD, const char *localIp, uint16_t *port, bool isSecured)
+static void CAEventReturned(CASocketFd_t socket)
 {
-    VERIFY_NON_NULL(socketFD, IP_SERVER_TAG, "socketFD is NULL");
-    VERIFY_NON_NULL(localIp, IP_SERVER_TAG, "localIp is NULL");
-    VERIFY_NON_NULL(port, IP_SERVER_TAG, "port is NULL");
-    // Create a UDP socket
-    int sock = -1;
+    CASocketFd_t fd = OC_INVALID_SOCKET;
+    CATransportFlags_t flags = CA_DEFAULT_FLAGS;
+
+    while (!caglobals.ip.terminate)
+    {
+        IS_MATCHING_IP_SOCKET(u6,  socket, CA_IPV6)
+        else IS_MATCHING_IP_SOCKET(u6s, socket, CA_IPV6 | CA_SECURE)
+        else IS_MATCHING_IP_SOCKET(u4,  socket, CA_IPV4)
+        else IS_MATCHING_IP_SOCKET(u4s, socket, CA_IPV4 | CA_SECURE)
+        else IS_MATCHING_IP_SOCKET(m6,  socket, CA_MULTICAST | CA_IPV6)
+        else IS_MATCHING_IP_SOCKET(m6s, socket, CA_MULTICAST | CA_IPV6 | CA_SECURE)
+        else IS_MATCHING_IP_SOCKET(m4,  socket, CA_MULTICAST | CA_IPV4)
+        else IS_MATCHING_IP_SOCKET(m4s, socket, CA_MULTICAST | CA_IPV4 | CA_SECURE)
+        else
+        {
+            break;
+        }
+        (void)CAReceiveMessage(socket, flags);
+        // We will never get more than one match per socket, so always break.
+        break;
+    }
+}
 
-#ifdef SOCK_CLOEXEC
-    sock = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
 #endif
 
-    if (-1 == sock)
+void CADeInitializeIPGlobals()
+{
+    CLOSE_SOCKET(u6);
+    CLOSE_SOCKET(u6s);
+    CLOSE_SOCKET(u4);
+    CLOSE_SOCKET(u4s);
+    CLOSE_SOCKET(m6);
+    CLOSE_SOCKET(m6s);
+    CLOSE_SOCKET(m4);
+    CLOSE_SOCKET(m4s);
+
+    if (caglobals.ip.netlinkFd != OC_INVALID_SOCKET)
     {
-        sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+#ifdef _WIN32
+        closesocket(caglobals.ip.netlinkFd);
+#else
+        close(caglobals.ip.netlinkFd);
+#endif
+        caglobals.ip.netlinkFd = OC_INVALID_SOCKET;
     }
+}
 
-    if (-1 == sock)
+static CAResult_t CAReceiveMessage(CASocketFd_t fd, CATransportFlags_t flags)
+{
+    char recvBuffer[COAP_MAX_PDU_SIZE] = {0};
+
+    size_t len;
+    int level, type, namelen;
+    struct sockaddr_storage srcAddr;
+    unsigned char *pktinfo = NULL;
+#if !defined(WSA_CMSG_DATA)
+    struct cmsghdr *cmp = NULL;
+    struct iovec iov = { .iov_base = recvBuffer, .iov_len = sizeof (recvBuffer) };
+    union control
     {
-        OIC_LOG_V(ERROR, IP_SERVER_TAG, "Failed to create Socket, Error code: %s",
-                  strerror(errno));
-        return CA_STATUS_FAILED;
-    }
+        struct cmsghdr cmsg;
+        unsigned char data[CMSG_SPACE(sizeof (struct in6_pktinfo))];
+    } cmsg;
 
-    // Make the socket non-blocking
-    if (-1 == fcntl(sock, F_SETFL, O_NONBLOCK))
+    if (flags & CA_IPV6)
     {
-        OIC_LOG_V(ERROR, IP_SERVER_TAG, "Failed to set non-block mode, Error code: %s",
-                  strerror(errno));
+        namelen = sizeof (struct sockaddr_in6);
+        level = IPPROTO_IPV6;
+        type = IPV6_PKTINFO;
+        len = sizeof (struct in6_pktinfo);
+    }
+    else
+    {
+        namelen = sizeof (struct sockaddr_in);
+        level = IPPROTO_IP;
+        type = IP_PKTINFO;
+        len = sizeof (struct in6_pktinfo);
+    }
 
-        close(sock);
+    struct msghdr msg = { .msg_name = &srcAddr,
+                          .msg_namelen = namelen,
+                          .msg_iov = &iov,
+                          .msg_iovlen = 1,
+                          .msg_control = &cmsg,
+                          .msg_controllen = CMSG_SPACE(len) };
+
+    ssize_t recvLen = recvmsg(fd, &msg, flags);
+    if (OC_SOCKET_ERROR == recvLen)
+    {
+        OIC_LOG_V(ERROR, TAG, "Recvfrom failed %s", strerror(errno));
         return CA_STATUS_FAILED;
     }
 
-    if (0 != *port && !isSecured)
+    if (flags & CA_MULTICAST)
     {
-        int setOptionOn = SOCKETOPTION;
-        if (-1 == setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *) &setOptionOn,
-                             sizeof(setOptionOn)))
+        for (cmp = CMSG_FIRSTHDR(&msg); cmp != NULL; cmp = CMSG_NXTHDR(&msg, cmp))
         {
-            OIC_LOG_V(ERROR, IP_SERVER_TAG, "Failed to set SO_REUSEADDR! Error code: %s",
-                      strerror(errno));
-            close(sock);
-            return CA_STATUS_FAILED;
+            if (cmp->cmsg_level == level && cmp->cmsg_type == type)
+            {
+                pktinfo = CMSG_DATA(cmp);
+            }
         }
     }
+#else // if defined(WSA_CMSG_DATA)
+    union control
+    {
+        WSACMSGHDR cmsg;
+        uint8_t data[WSA_CMSG_SPACE(sizeof (IN6_PKTINFO))];
+    } cmsg;
+    memset(&cmsg, 0, sizeof(cmsg));
 
-    struct sockaddr_in sockAddr = { 0 };
-    uint16_t serverPort = *port;
-    sockAddr.sin_family = AF_INET;
-    sockAddr.sin_port = htons(serverPort);
-    if (localIp)
+    if (flags & CA_IPV6)
+    {
+        namelen  = sizeof (struct sockaddr_in6);
+        level = IPPROTO_IPV6;
+        type = IPV6_PKTINFO;
+    }
+    else
     {
-        sockAddr.sin_addr.s_addr = inet_addr(localIp);
+        namelen = sizeof (struct sockaddr_in);
+        level = IPPROTO_IP;
+        type = IP_PKTINFO;
     }
 
-    bool isBound = false;
-    if (-1 != bind(sock, (struct sockaddr *) &sockAddr, sizeof(sockAddr)))
+    WSABUF iov = {.len = sizeof (recvBuffer), .buf = recvBuffer};
+    WSAMSG msg = {.name = &srcAddr,
+                  .namelen = namelen,
+                  .lpBuffers = &iov,
+                  .dwBufferCount = 1,
+                  .Control = {.buf = cmsg.data, .len = sizeof (cmsg)}
+                 };
+
+    uint32_t recvLen = 0;
+    uint32_t ret = caglobals.ip.wsaRecvMsg(fd, &msg, &recvLen, 0,0);
+    OIC_LOG_V(DEBUG, TAG, "WSARecvMsg recvd %u bytes", recvLen);
+    if (OC_SOCKET_ERROR == ret)
     {
-        isBound = true;
+        OIC_LOG_V(ERROR, TAG, "WSARecvMsg failed %i", WSAGetLastError());
     }
-    else if (isSecured)
+
+    if (flags & CA_MULTICAST)
     {
-        //if secure port 5684 is occupied, trying for another port
-        serverPort = 0;
-        sockAddr.sin_port = htons(serverPort);
-        if (-1 != bind(sock, (struct sockaddr *) &sockAddr, sizeof(sockAddr)))
+        for (WSACMSGHDR *cmp = WSA_CMSG_FIRSTHDR(&msg); cmp != NULL;
+             cmp = WSA_CMSG_NXTHDR(&msg, cmp))
         {
-            isBound = true;
+            if (cmp->cmsg_level == level && cmp->cmsg_type == type)
+            {
+                pktinfo = WSA_CMSG_DATA(cmp);
+            }
         }
     }
+#endif // !defined(WSA_CMSG_DATA)
+    CASecureEndpoint_t sep = {.endpoint = {.adapter = CA_ADAPTER_IP, .flags = flags}};
 
-    if (true == isBound)
+    if (flags & CA_IPV6)
     {
-        struct sockaddr_in sin;
-        socklen_t len = sizeof(sin);
-
-        if (-1 == getsockname(sock, (struct sockaddr *)&sin, &len))
-        {
-            OIC_LOG_V(ERROR, IP_SERVER_TAG, "Failed to get socket[%s]!",
-                      strerror(errno));
-            close(sock);
-            return CA_STATUS_FAILED;
-        }
-        else
+        /** @todo figure out correct usage for ifindex, and sin6_scope_id.*/
+        if ((flags & CA_MULTICAST) && pktinfo)
         {
-            serverPort = (uint16_t) ntohs(sin.sin_port);
+            struct in6_addr *addr = &(((struct in6_pktinfo *)pktinfo)->ipi6_addr);
+            unsigned char topbits = ((unsigned char *)addr)[0];
+            if (topbits != 0xff)
+            {
+                sep.endpoint.flags &= ~CA_MULTICAST;
+            }
         }
     }
     else
     {
-        OIC_LOG_V(ERROR, IP_SERVER_TAG, "Failed to bind socket[%s]!", strerror(errno));
-        close(sock);
-        return CA_STATUS_FAILED;
+        if ((flags & CA_MULTICAST) && pktinfo)
+        {
+            struct in_addr *addr = &((struct in_pktinfo *)pktinfo)->ipi_addr;
+            uint32_t host = ntohl(addr->s_addr);
+            unsigned char topbits = ((unsigned char *)&host)[3];
+            if (topbits < 224 || topbits > 239)
+            {
+                sep.endpoint.flags &= ~CA_MULTICAST;
+            }
+        }
     }
 
-    *port = serverPort;
-    *socketFD = sock;
-    return CA_STATUS_OK;
-}
+    CAConvertAddrToName(&srcAddr, namelen, sep.endpoint.addr, &sep.endpoint.port);
 
-static void CACloseSocket(int socketFD)
-{
-    if (-1 == socketFD)
+    if (flags & CA_SECURE)
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "Invalid Socket Fd");
-        return;
+#ifdef __WITH_DTLS__
+        int ret = CAAdapterNetDtlsDecrypt(&sep, (uint8_t *)recvBuffer, recvLen);
+        OIC_LOG_V(DEBUG, TAG, "CAAdapterNetDtlsDecrypt returns [%d]", ret);
+#else
+        OIC_LOG(ERROR, TAG, "Encrypted message but no DTLS");
+#endif
     }
-
-    // close the socket
-    if (-1 == close(socketFD))
+    else
     {
-        OIC_LOG_V(ERROR, IP_SERVER_TAG, "Failed to close the socket, Error code: %s\n",
-                  strerror(errno));
+        if (g_packetReceivedCallback)
+        {
+            g_packetReceivedCallback(&sep, recvBuffer, recvLen);
+        }
     }
-}
-
-static CAResult_t CAStartUnicastServer(const char *localAddress, uint16_t *port,
-                                       bool isSecured, int *serverFD)
-{
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
 
-    VERIFY_NON_NULL(serverFD, IP_SERVER_TAG, "serverFD");
-    VERIFY_NON_NULL(localAddress, IP_SERVER_TAG, "localAddress");
-    VERIFY_NON_NULL(port, IP_SERVER_TAG, "port");
+    return CA_STATUS_OK;
 
-    CAResult_t ret = CACreateSocket(serverFD, localAddress, port, isSecured);
-    if (CA_STATUS_OK != ret)
-    {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to create unicast socket");
-    }
+}
 
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-    return ret;
+void CAIPPullData()
+{
+    OIC_LOG(DEBUG, TAG, "IN");
+    OIC_LOG(DEBUG, TAG, "OUT");
 }
 
-static CAResult_t CAIPStartPacketReceiverHandler()
+static CASocketFd_t CACreateSocket(int family, uint16_t *port, bool isMulticast)
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
+    int socktype = SOCK_DGRAM;
+#ifdef SOCK_CLOEXEC
+    socktype |= SOCK_CLOEXEC;
+#endif
+    CASocketFd_t fd = socket(family, socktype, IPPROTO_UDP);
+    if (OC_INVALID_SOCKET == fd)
+    {
+        OIC_LOG_V(ERROR, TAG, "create socket failed: %s", CAIPS_GET_ERROR);
+        return OC_INVALID_SOCKET;
+    }
 
-    ca_mutex_lock(g_mutexServerInfoList);
+#if !defined(SOCK_CLOEXEC) && defined(FD_CLOEXEC)
+    int fl = fcntl(fd, F_GETFD);
+    if (-1 == fl || -1 == fcntl(fd, F_SETFD, fl|FD_CLOEXEC))
+    {
+        OIC_LOG_V(ERROR, TAG, "set FD_CLOEXEC failed: %s", strerror(errno));
+        close(fd);
+        return OC_INVALID_SOCKET;
+    }
+#endif
+    struct sockaddr_storage sa = { .ss_family = family };
+    socklen_t socklen;
 
-    uint32_t listLength = u_arraylist_length(g_serverInfoList);
+    if (family == AF_INET6)
+    {
+        int on = 1;
 
-    ca_mutex_unlock(g_mutexServerInfoList);
+        if (OC_SOCKET_ERROR == setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, OPTVAL_T(&on), sizeof (on)))
+        {
+            OIC_LOG_V(ERROR, TAG, "IPV6_V6ONLY failed: %s", CAIPS_GET_ERROR);
+        }
 
-    ca_mutex_lock(g_mutexAdapterServerContext);
+        if (isMulticast && *port) // only do this for multicast ports
+        {
+#if defined(IPV6_RECVPKTINFO)
+            if (OC_SOCKET_ERROR == setsockopt(fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on, sizeof (on)))
+#else
+            if (OC_SOCKET_ERROR == setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, OPTVAL_T(&on), sizeof (on)))
+#endif
+            {
+                OIC_LOG_V(ERROR, TAG, "IPV6_RECVPKTINFO failed: %s",CAIPS_GET_ERROR);
+            }
+        }
 
-    if (!g_adapterIPServerContext)
+        ((struct sockaddr_in6 *)&sa)->sin6_port = htons(*port);
+        socklen = sizeof (struct sockaddr_in6);
+    }
+    else
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "g_adapterIPServerContext NULL");
-        ca_mutex_unlock(g_mutexAdapterServerContext);
-        return CA_STATUS_FAILED;
+        if (isMulticast && *port) // only do this for multicast ports
+        {
+            int on = 1;
+            if (OC_SOCKET_ERROR == setsockopt(fd, IPPROTO_IP, IP_PKTINFO, OPTVAL_T(&on), sizeof (on)))
+            {
+                OIC_LOG_V(ERROR, TAG, "IP_PKTINFO failed: %s", CAIPS_GET_ERROR);
+            }
+        }
+
+        ((struct sockaddr_in *)&sa)->sin_port = htons(*port);
+        socklen = sizeof (struct sockaddr_in);
     }
 
-    if (1 == listLength) //Its first time.
+    if (isMulticast && *port) // use the given port
     {
-        g_packetHandlerStopFlag = false;
-        if (CA_STATUS_OK != ca_thread_pool_add_task(g_adapterIPServerContext->threadPool,
-                                                   CAReceiveHandler, NULL ))
+        int on = 1;
+        if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, OPTVAL_T(&on), sizeof (on)))
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "thread_pool_add_task failed!");
-            ca_mutex_unlock(g_mutexAdapterServerContext);
-            return CA_STATUS_FAILED;
+            OIC_LOG_V(ERROR, TAG, "SO_REUSEADDR failed: %s", CAIPS_GET_ERROR);
+#ifdef _WIN32
+            closesocket(fd);
+#else
+            close(fd);
+#endif
+            return OC_INVALID_SOCKET;
         }
-        OIC_LOG(DEBUG, IP_SERVER_TAG, "CAReceiveHandler thread started successfully.");
     }
-    else
+
+    if (OC_SOCKET_ERROR == bind(fd, (struct sockaddr *)&sa, socklen))
     {
-        OIC_LOG(DEBUG, IP_SERVER_TAG, "CAReceiveHandler thread already is running");
+        OIC_LOG_V(ERROR, TAG, "bind socket failed: %s", CAIPS_GET_ERROR);
+#ifdef _WIN32
+        closesocket(fd);
+#else
+        close(fd);
+#endif
+        return OC_INVALID_SOCKET;
     }
-    ca_mutex_unlock(g_mutexAdapterServerContext);
 
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
+    if (!*port) // return the assigned port
+    {
+        if (OC_SOCKET_ERROR == getsockname(fd, (struct sockaddr *)&sa, &socklen))
+        {
+            OIC_LOG_V(ERROR, TAG, "getsockname failed: %s", CAIPS_GET_ERROR);
+#ifdef _WIN32
+            closesocket(fd);
+#else
+            close(fd);
+#endif
+            return OC_INVALID_SOCKET;
+        }
+        *port = ntohs(family == AF_INET6 ?
+                      ((struct sockaddr_in6 *)&sa)->sin6_port :
+                      ((struct sockaddr_in *)&sa)->sin_port);
+    }
 
-    return CA_STATUS_OK;
+    return fd;
 }
 
-static void CAIPServerDestroyMutex(void)
+#define CHECKFD(FD) \
+    if (FD > caglobals.ip.maxfd) \
+        caglobals.ip.maxfd = FD;
+#define NEWSOCKET(FAMILY, NAME, MULTICAST) \
+    caglobals.ip.NAME.fd = CACreateSocket(FAMILY, &caglobals.ip.NAME.port, MULTICAST); \
+    if (caglobals.ip.NAME.fd == OC_INVALID_SOCKET) \
+    {   \
+        caglobals.ip.NAME.port = 0; \
+        caglobals.ip.NAME.fd = CACreateSocket(FAMILY, &caglobals.ip.NAME.port, MULTICAST); \
+    }   \
+    CHECKFD(caglobals.ip.NAME.fd)
+
+static void CAInitializeNetlink()
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
+    caglobals.ip.netlinkFd = OC_INVALID_SOCKET;
+#ifdef __linux__
+    // create NETLINK fd for interface change notifications
+    struct sockaddr_nl sa = { AF_NETLINK, 0, 0, RTMGRP_LINK };
 
-    if (g_mutexServerInfoList)
+    caglobals.ip.netlinkFd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, NETLINK_ROUTE);
+    if (caglobals.ip.netlinkFd == OC_INVALID_SOCKET)
     {
-        ca_mutex_free(g_mutexServerInfoList);
-        g_mutexServerInfoList = NULL;
+        OIC_LOG_V(ERROR, TAG, "netlink socket failed: %s", strerror(errno));
     }
-
-    if (g_mutexAdapterServerContext)
+    else
     {
-        ca_mutex_free(g_mutexAdapterServerContext);
-        g_mutexAdapterServerContext = NULL;
+        int r = bind(caglobals.ip.netlinkFd, (struct sockaddr *)&sa, sizeof (sa));
+        if (r)
+        {
+            OIC_LOG_V(ERROR, TAG, "netlink bind failed: %s", strerror(errno));
+            close(caglobals.ip.netlinkFd);
+            caglobals.ip.netlinkFd = OC_INVALID_SOCKET;
+        }
+        else
+        {
+            CHECKFD(caglobals.ip.netlinkFd);
+        }
     }
-
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
+#endif
 }
 
-static CAResult_t CAIPServerCreateMutex(void)
+static void CAInitializeFastShutdownMechanism()
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
+    caglobals.ip.selectTimeout = -1; // don't poll for shutdown
+    int ret = -1;
+#if defined(WSA_WAIT_EVENT_0)
+    caglobals.ip.shutdownEvent = -1;
+    caglobals.ip.shutdownEvent = WSACreateEvent();
 
-    g_mutexServerInfoList = ca_mutex_new();
-    if (!g_mutexServerInfoList)
+    if (caglobals.ip.shutdownEvent == WSA_INVALID_EVENT)
     {
-        OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-        return CA_MEMORY_ALLOC_FAILED;
+        caglobals.ip.shutdownEvent = -1;
     }
-
-    g_mutexAdapterServerContext = ca_mutex_new();
-    if (!g_mutexAdapterServerContext)
+    else
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to created mutex!");
-        ca_mutex_free(g_mutexServerInfoList);
-        g_mutexServerInfoList = NULL;
-        return CA_MEMORY_ALLOC_FAILED;
+        ret = 0;
+    }
+#elif defined(HAVE_PIPE2)
+    ret = pipe2(caglobals.ip.shutdownFds, O_CLOEXEC);
+    CHECKFD(caglobals.ip.shutdownFds[0]);
+    CHECKFD(caglobals.ip.shutdownFds[1]);
+#else
+    ret = pipe(caglobals.ip.shutdownFds);
+    if (-1 != ret)
+    {
+        ret = fcntl(caglobals.ip.shutdownFds[0], F_GETFD);
+        if (-1 != ret)
+        {
+            ret = fcntl(caglobals.ip.shutdownFds[0], F_SETFD, ret|FD_CLOEXEC);
+        }
+        if (-1 != ret)
+        {
+            ret = fcntl(caglobals.ip.shutdownFds[1], F_GETFD);
+        }
+        if (-1 != ret)
+        {
+            ret = fcntl(caglobals.ip.shutdownFds[1], F_SETFD, ret|FD_CLOEXEC);
+        }
+        if (-1 == ret)
+        {
+            close(caglobals.ip.shutdownFds[1]);
+            close(caglobals.ip.shutdownFds[0]);
+            caglobals.ip.shutdownFds[0] = -1;
+            caglobals.ip.shutdownFds[1] = -1;
+        }
+    }
+    CHECKFD(caglobals.ip.shutdownFds[0]);
+    CHECKFD(caglobals.ip.shutdownFds[1]);
+#endif
+    if (-1 == ret)
+    {
+        OIC_LOG_V(ERROR, TAG, "fast shutdown mechanism init failed: %s", CAIPS_GET_ERROR);
+        caglobals.ip.selectTimeout = SELECT_TIMEOUT; //poll needed for shutdown
     }
-
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-    return CA_STATUS_OK;
 }
 
-CAResult_t CAIPInitializeServer(const ca_thread_pool_t threadPool)
+CAResult_t CAIPStartServer(const ca_thread_pool_t threadPool)
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-
-    // Input validation
-    VERIFY_NON_NULL(threadPool, IP_SERVER_TAG, "Thread pool handle is NULL");
+    CAResult_t res = CA_STATUS_OK;
 
-    // Initialize mutex
-    if (CA_STATUS_OK != CAIPServerCreateMutex())
+    if (caglobals.ip.started)
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to create mutex!");
+        return res;
+    }
+#if defined (_WIN32)
+    WORD wVersionRequested = MAKEWORD(2, 2);
+    WSADATA wsaData ={.wVersion = 0};
+    int err = WSAStartup(wVersionRequested, &wsaData);
+    if (err != 0)
+    {
+        OIC_LOG_V(ERROR, TAG, "WSAStartup failed: %i", err);
         return CA_STATUS_FAILED;
     }
-
-    ca_mutex_lock(g_mutexAdapterServerContext);
-    g_adapterIPServerContext = (CAAdapterIPServerContext_t *) OICCalloc(1,
-                                 sizeof(CAAdapterIPServerContext_t));
-
-    if (!g_adapterIPServerContext)
+    OIC_LOG(DEBUG, TAG, "WSAStartup Succeeded");
+#endif
+    if (!IPv4MulticastAddress.s_addr)
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "Malloc failed");
-        ca_mutex_unlock(g_mutexAdapterServerContext);
-        return CA_MEMORY_ALLOC_FAILED;
+        (void)inet_pton(AF_INET, IPv4_MULTICAST, &IPv4MulticastAddress);
+        (void)inet_pton(AF_INET6, IPv6_MULTICAST_INT, &IPv6MulticastAddressInt);
+        (void)inet_pton(AF_INET6, IPv6_MULTICAST_LNK, &IPv6MulticastAddressLnk);
+        (void)inet_pton(AF_INET6, IPv6_MULTICAST_RLM, &IPv6MulticastAddressRlm);
+        (void)inet_pton(AF_INET6, IPv6_MULTICAST_ADM, &IPv6MulticastAddressAdm);
+        (void)inet_pton(AF_INET6, IPv6_MULTICAST_SIT, &IPv6MulticastAddressSit);
+        (void)inet_pton(AF_INET6, IPv6_MULTICAST_ORG, &IPv6MulticastAddressOrg);
+        (void)inet_pton(AF_INET6, IPv6_MULTICAST_GLB, &IPv6MulticastAddressGlb);
     }
 
-    g_adapterIPServerContext->threadPool = threadPool;
-
-    ca_mutex_unlock(g_mutexAdapterServerContext);
-
-    ca_mutex_lock(g_mutexServerInfoList);
-
-    g_serverInfoList = u_arraylist_create();
-    if (!g_serverInfoList)
+    if (!caglobals.ip.ipv6enabled && !caglobals.ip.ipv4enabled)
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "u_arraylist_create failed");
-        ca_mutex_unlock(g_mutexServerInfoList);
-        return CA_MEMORY_ALLOC_FAILED;
+        caglobals.ip.ipv4enabled = true;  // only needed to run CA tests
     }
-    ca_mutex_unlock(g_mutexServerInfoList);
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-    return CA_STATUS_OK;
-}
 
-void CAIPTerminateServer()
-{
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-    ca_mutex_lock(g_mutexAdapterServerContext);
-    if (!g_adapterIPServerContext)
+    if (caglobals.ip.ipv6enabled)
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "g_adapterIPServerContext NULL");
-        ca_mutex_unlock(g_mutexAdapterServerContext);
-        return;
+        NEWSOCKET(AF_INET6, u6, false)
+        NEWSOCKET(AF_INET6, u6s, false)
+        NEWSOCKET(AF_INET6, m6, true)
+        NEWSOCKET(AF_INET6, m6s, true)
+        OIC_LOG_V(INFO, TAG, "IPv6 unicast port: %u", caglobals.ip.u6.port);
+    }
+    if (caglobals.ip.ipv4enabled)
+    {
+        NEWSOCKET(AF_INET, u4, false)
+        NEWSOCKET(AF_INET, u4s, false)
+        NEWSOCKET(AF_INET, m4, true)
+        NEWSOCKET(AF_INET, m4s, true)
+        OIC_LOG_V(INFO, TAG, "IPv4 unicast port: %u", caglobals.ip.u4.port);
     }
 
-    OICFree(g_adapterIPServerContext);
-    g_adapterIPServerContext = NULL;
-
-    ca_mutex_unlock(g_mutexAdapterServerContext);
+    OIC_LOG_V(DEBUG, TAG,
+              "socket summary: u6=%d, u6s=%d, u4=%d, u4s=%d, m6=%d, m6s=%d, m4=%d, m4s=%d",
+              caglobals.ip.u6.fd, caglobals.ip.u6s.fd, caglobals.ip.u4.fd, caglobals.ip.u4s.fd,
+              caglobals.ip.m6.fd, caglobals.ip.m6s.fd, caglobals.ip.m4.fd, caglobals.ip.m4s.fd);
+
+    OIC_LOG_V(DEBUG, TAG,
+              "port summary: u6 port=%d, u6s port=%d, u4 port=%d, u4s port=%d, m6 port=%d,"
+              "m6s port=%d, m4 port=%d, m4s port=%d",
+              caglobals.ip.u6.port, caglobals.ip.u6s.port, caglobals.ip.u4.port,
+              caglobals.ip.u4s.port, caglobals.ip.m6.port, caglobals.ip.m6s.port,
+              caglobals.ip.m4.port, caglobals.ip.m4s.port);
+#if defined (SIO_GET_EXTENSION_FUNCTION_POINTER)
+    caglobals.ip.wsaRecvMsg = NULL;
+    GUID GuidWSARecvMsg = WSAID_WSARECVMSG;
+    DWORD copied = 0;
+    err = WSAIoctl(caglobals.ip.u4.fd, SIO_GET_EXTENSION_FUNCTION_POINTER, &GuidWSARecvMsg, sizeof(GuidWSARecvMsg), &(caglobals.ip.wsaRecvMsg), sizeof(caglobals.ip.wsaRecvMsg), &copied, 0, 0);
+    if (0 != err)
+    {
+        OIC_LOG_V(ERROR, TAG, "WSAIoctl failed %i", WSAGetLastError());
+        return CA_STATUS_FAILED;
+    }
+#endif
+    // set up appropriate FD mechanism for fast shutdown
+    CAInitializeFastShutdownMechanism();
 
-    ca_mutex_lock(g_mutexServerInfoList);
+    // create source of network interface change notifications
+    CAInitializeNetlink();
 
-    CAClearServerInfoList(g_serverInfoList);
-    g_serverInfoList = NULL;
+    caglobals.ip.selectTimeout = CAGetPollingInterval(caglobals.ip.selectTimeout);
 
-    ca_mutex_unlock(g_mutexServerInfoList);
-    // Destroy mutex
-    CAIPServerDestroyMutex();
+    res = CAIPStartListenServer();
+    if (CA_STATUS_OK != res)
+    {
+        OIC_LOG_V(ERROR, TAG, "Failed to start listening server![%d]", res);
+        return res;
+    }
 
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
+    caglobals.ip.terminate = false;
+    res = ca_thread_pool_add_task(threadPool, CAReceiveHandler, NULL);
+    if (CA_STATUS_OK != res)
+    {
+        OIC_LOG(ERROR, TAG, "thread_pool_add_task failed");
+        return res;
+    }
+    OIC_LOG(DEBUG, TAG, "CAReceiveHandler thread started successfully.");
 
+    caglobals.ip.started = true;
+    return CA_STATUS_OK;
 }
 
-CAResult_t CAIPStartUnicastServer(const char *localAddress, uint16_t *port, bool isSecured)
+void CAIPStopServer()
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
+    caglobals.ip.started = false;
+    caglobals.ip.terminate = true;
 
-    // Input validation
-    VERIFY_NON_NULL(localAddress, IP_SERVER_TAG, "localAddress");
-    VERIFY_NON_NULL(port, IP_SERVER_TAG, "port");
+#if !defined(WSA_WAIT_EVENT_0)
+    if (caglobals.ip.shutdownFds[1] != -1)
+    {
+        close(caglobals.ip.shutdownFds[1]);
+        // receive thread will stop immediately
+    }
+    else
+    {
+        // receive thread will stop in SELECT_TIMEOUT seconds.
+    }
+#else
+    // receive thread will stop immediately.
+    if (!WSASetEvent(caglobals.ip.shutdownEvent))
+    {
+        OIC_LOG_V(DEBUG, TAG, "set shutdown event failed: %#08X", GetLastError());
+    }
+#endif
+}
 
-    ca_mutex_lock(g_mutexServerInfoList);
-    bool isUnicastServerStarted = CAIsUnicastServerStarted(g_serverInfoList, localAddress, *port);
-    if (!isUnicastServerStarted)
+void CAWakeUpForChange()
+{
+#if !defined(WSA_WAIT_EVENT_0)
+    if (caglobals.ip.shutdownFds[1] != -1)
     {
-        int unicastServerFd = -1;
-        if (CA_STATUS_OK != CAStartUnicastServer(localAddress, port, isSecured,
-                                                 &unicastServerFd))
+        ssize_t len = 0;
+        do
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to start unicast server!");
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return CA_STATUS_FAILED;
-        }
-
-        CAServerInfo_t *info = (CAServerInfo_t *) OICCalloc(1, sizeof(CAServerInfo_t));
-        if (!info)
+            len = write(caglobals.ip.shutdownFds[1], "w", 1);
+        } while ((len == -1) && (errno == EINTR));
+        if ((len == -1) && (errno != EINTR) && (errno != EPIPE))
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "Malloc failed");
-            close(unicastServerFd);
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return CA_MEMORY_ALLOC_FAILED;
+            OIC_LOG_V(DEBUG, TAG, "write failed: %s", strerror(errno));
         }
+    }
+#else
+    if (!WSASetEvent(caglobals.ip.shutdownEvent))
+    {
+        OIC_LOG_V(DEBUG, TAG, "set shutdown event failed: %#08X", GetLastError());
+    }
+#endif
+}
 
-        char *netMask = NULL;
-        if (CA_STATUS_OK != CAIPGetInterfaceSubnetMask(localAddress, &netMask))
-        {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to get IP subnet");
-        }
-        if (netMask)
+static void applyMulticastToInterface4(uint32_t ifindex)
+{
+    if (!caglobals.ip.ipv4enabled)
+    {
+        return;
+    }
+
+#if defined(USE_IP_MREQN)
+    struct ip_mreqn mreq = { .imr_multiaddr = IPv4MulticastAddress,
+                             .imr_address.s_addr = htonl(INADDR_ANY),
+                             .imr_ifindex = ifindex };
+#else
+    struct ip_mreq mreq  = { .imr_multiaddr = IPv4MulticastAddress,
+                             .imr_interface.s_addr = htonl(ifindex) };
+#endif
+
+    int ret = setsockopt(caglobals.ip.m4.fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, OPTVAL_T(&mreq), sizeof (mreq));
+    if (OC_SOCKET_ERROR == ret)
+    {
+#if !defined(WSAEINVAL)
+        if (EADDRINUSE != errno)
+#else
+        if (WSAEINVAL != WSAGetLastError()) // Joining multicast group more than once (IPv4 Flavor)
+#endif
         {
-            OICStrcpy(info->subNetMask, sizeof(info->subNetMask), netMask);
-            OICFree(netMask);
+            OIC_LOG_V(ERROR, TAG, "       IPv4 IP_ADD_MEMBERSHIP failed: %s", CAIPS_GET_ERROR);
         }
-        OICStrcpy(info->endpoint.addr, sizeof(info->endpoint.addr), localAddress);
-        info->endpoint.port = *port;
-        info->endpoint.flags = isSecured ? CA_SECURE : 0;
-        info->endpoint.adapter = CA_ADAPTER_IP;
-        info->socketFd = unicastServerFd;
-        info->isServerStarted = true;
-        info->isMulticastServer = false;
-        OICStrcpy(info->ifAddr, sizeof(info->ifAddr), localAddress);
-
-        CAResult_t res = CAAddServerInfo(g_serverInfoList, info);
-        if (CA_STATUS_OK != res)
+    }
+    ret = setsockopt(caglobals.ip.m4s.fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, OPTVAL_T(&mreq), sizeof (mreq));
+    if (OC_SOCKET_ERROR == ret)
+    {
+#if !defined(WSAEINVAL)
+        if (EADDRINUSE != errno)
+#else
+        if (WSAEINVAL != WSAGetLastError()) // Joining multicast group more than once (IPv4 Flavor)
+#endif
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "CAAddServerInfo failed!");
-            close(unicastServerFd);
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return res;
+            OIC_LOG_V(ERROR, TAG, "SECURE IPv4 IP_ADD_MEMBERSHIP failed: %s", CAIPS_GET_ERROR);
         }
-        ca_mutex_unlock(g_mutexServerInfoList);
+    }
+}
 
-        res = CAIPStartPacketReceiverHandler();
-        if (CA_STATUS_OK != res)
+static void applyMulticast6(int fd, struct in6_addr *addr, uint32_t ifindex)
+{
+    struct ipv6_mreq mreq = {.ipv6mr_multiaddr = *addr,
+                             .ipv6mr_interface = ifindex };
+    int ret = setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, OPTVAL_T(&mreq), sizeof (mreq));
+    if (OC_SOCKET_ERROR == ret)
+    {
+#if !defined(_WIN32)
+                if (EADDRINUSE != errno)
+#else
+                if (WSAEINVAL != WSAGetLastError()) // Joining multicast group more than once (IPv6 Flavor)
+#endif
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "CAIPStartPacketReceiverHandler failed!");
-            close(unicastServerFd);
-            return res;
+            OIC_LOG_V(ERROR, TAG, "IPv6 IPV6_JOIN_GROUP failed: %s", CAIPS_GET_ERROR);
         }
     }
-    else
+}
+
+static void applyMulticastToInterface6(uint32_t ifindex)
+{
+    if (!caglobals.ip.ipv6enabled)
     {
-        OIC_LOG_V(DEBUG, IP_SERVER_TAG, "Already Unicast Server Started ip [%s] port [%d]",
-                  localAddress, *port);
-        ca_mutex_unlock(g_mutexServerInfoList);
+        return;
     }
-
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-    return CA_STATUS_OK;
+    //applyMulticast6(caglobals.ip.m6.fd, &IPv6MulticastAddressInt, ifindex);
+    applyMulticast6(caglobals.ip.m6.fd, &IPv6MulticastAddressLnk, ifindex);
+    //applyMulticast6(caglobals.ip.m6.fd, &IPv6MulticastAddressRlm, ifindex);
+    //applyMulticast6(caglobals.ip.m6.fd, &IPv6MulticastAddressAdm, ifindex);
+    //applyMulticast6(caglobals.ip.m6.fd, &IPv6MulticastAddressSit, ifindex);
+    //applyMulticast6(caglobals.ip.m6.fd, &IPv6MulticastAddressOrg, ifindex);
+    //applyMulticast6(caglobals.ip.m6.fd, &IPv6MulticastAddressGlb, ifindex);
+
+    //applyMulticast6(caglobals.ip.m6s.fd, &IPv6MulticastAddressInt, ifindex);
+    applyMulticast6(caglobals.ip.m6s.fd, &IPv6MulticastAddressLnk, ifindex);
+    //applyMulticast6(caglobals.ip.m6s.fd, &IPv6MulticastAddressRlm, ifindex);
+    //applyMulticast6(caglobals.ip.m6s.fd, &IPv6MulticastAddressAdm, ifindex);
+    //applyMulticast6(caglobals.ip.m6s.fd, &IPv6MulticastAddressSit, ifindex);
+    //applyMulticast6(caglobals.ip.m6s.fd, &IPv6MulticastAddressOrg, ifindex);
+    //applyMulticast6(caglobals.ip.m6s.fd, &IPv6MulticastAddressGlb, ifindex);
 }
 
-CAResult_t CAIPStartMulticastServer(const char *localAddress, const char *multicastAddress,
-                                          uint16_t multicastPort)
+CAResult_t CAIPStartListenServer()
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-
-    // Input validation
-    VERIFY_NON_NULL(localAddress, IP_SERVER_TAG, "localAddress");
-    VERIFY_NON_NULL(multicastAddress, IP_SERVER_TAG, "port");
-
-    uint16_t port = multicastPort;
-    if (0 >= port)
+    u_arraylist_t *iflist = CAIPGetInterfaceInformation(0);
+    if (!iflist)
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "Invalid input: Multicast port is invalid!");
-        return CA_STATUS_INVALID_PARAM;
+        OIC_LOG_V(ERROR, TAG, "CAIPGetInterfaceInformation() failed: %s", strerror(errno));
+        return CA_STATUS_FAILED;
     }
 
-    ca_mutex_lock(g_mutexServerInfoList);
-    bool isMulticastServerStarted = CAIsMulticastServerStarted(g_serverInfoList, localAddress,
-                                                               multicastAddress, port);
-    if (!isMulticastServerStarted)
-    {
-        int mulicastServerFd = -1;
-        CAResult_t ret = CACreateSocket(&mulicastServerFd, multicastAddress, &port, false);
-        if (ret != CA_STATUS_OK)
-        {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to create multicast socket");
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return ret;
-        }
+    uint32_t len = u_arraylist_length(iflist);
+    OIC_LOG_V(DEBUG, TAG, "IP network interfaces found: %d", len);
 
-        struct ip_mreq multicastMemberReq = {.imr_interface.s_addr = inet_addr(localAddress)};
-        inet_aton(multicastAddress, &multicastMemberReq.imr_multiaddr);
+    for (uint32_t i = 0; i < len; i++)
+    {
+        CAInterface_t *ifitem = (CAInterface_t *)u_arraylist_get(iflist, i);
 
-        if (-1 == setsockopt(mulicastServerFd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
-                             (char *) &multicastMemberReq, sizeof(struct ip_mreq)))
+        if (!ifitem)
         {
-            OIC_LOG_V(ERROR, IP_SERVER_TAG,
-                      "Failed to add to multicast group, Error code: %s\n", strerror(errno));
-            close(mulicastServerFd);
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return CA_STATUS_FAILED;
+            continue;
         }
-
-        CAServerInfo_t *info = (CAServerInfo_t *) OICCalloc(1, sizeof(CAServerInfo_t));
-        if (!info)
+        if ((ifitem->flags & IFF_UP_RUNNING_FLAGS) != IFF_UP_RUNNING_FLAGS)
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "Malloc failed");
-            close(mulicastServerFd);
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return CA_MEMORY_ALLOC_FAILED;
+            continue;
         }
-
-        char *netMask = NULL;
-        if (CA_STATUS_OK != CAIPGetInterfaceSubnetMask(localAddress, &netMask))
+        if (ifitem->family == AF_INET)
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "Failed to get IP subnet");
+            OIC_LOG_V(DEBUG, TAG, "Adding IPv4 interface %i to multicast group", ifitem->index);
+            applyMulticastToInterface4(ifitem->index);
         }
-        if (netMask)
+        if (ifitem->family == AF_INET6)
         {
-            OICStrcpy(info->subNetMask, sizeof(info->subNetMask), netMask);
-            OICFree(netMask);
+            OIC_LOG_V(DEBUG, TAG, "Adding IPv6 interface %i to multicast group", ifitem->index);
+            applyMulticastToInterface6(ifitem->index);
         }
+    }
 
-        OICStrcpy(info->endpoint.addr, sizeof(info->endpoint.addr), multicastAddress);
-        info->endpoint.port = multicastPort;
-        info->endpoint.flags = 0;
-        info->socketFd = mulicastServerFd;
-        info->isServerStarted = true;
-        info->isMulticastServer = true;
-        OICStrcpy(info->ifAddr, sizeof(info->ifAddr), localAddress);
+    u_arraylist_destroy(iflist);
+    return CA_STATUS_OK;
+}
+
+CAResult_t CAIPStopListenServer()
+{
+    u_arraylist_t *iflist = CAIPGetInterfaceInformation(0);
+    if (!iflist)
+    {
+        OIC_LOG_V(ERROR, TAG, "Get interface info failed: %s", strerror(errno));
+        return CA_STATUS_FAILED;
+    }
 
-        ret = CAAddServerInfo(g_serverInfoList, info);
+    uint32_t len = u_arraylist_length(iflist);
+    OIC_LOG_V(DEBUG, TAG, "IP network interfaces found: %d", len);
 
-        if (CA_STATUS_OK != ret)
+    for (uint32_t i = 0; i < len; i++)
+    {
+        CAInterface_t *ifitem = (CAInterface_t *)u_arraylist_get(iflist, i);
+
+        if (!ifitem)
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "CAAddServerInfo failed!");
-            close(mulicastServerFd);
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return ret;
+            continue;
         }
-        ca_mutex_unlock(g_mutexServerInfoList);
-
-        ret = CAIPStartPacketReceiverHandler();
-        if (CA_STATUS_OK != ret)
+        if ((ifitem->flags & IFF_UP_RUNNING_FLAGS) != IFF_UP_RUNNING_FLAGS)
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "CAIPStartPacketReceiverHandler failed!");
-            close(mulicastServerFd);
-            return ret;
+            continue;
+        }
+        if (ifitem->family == AF_INET)
+        {
+            CLOSE_SOCKET(m4);
+            CLOSE_SOCKET(m4s);
+            OIC_LOG_V(DEBUG, TAG, "IPv4 network interface: %s cloed", ifitem->name);
+        }
+        if (ifitem->family == AF_INET6)
+        {
+            CLOSE_SOCKET(m6);
+            CLOSE_SOCKET(m6s);
+            OIC_LOG_V(DEBUG, TAG, "IPv6 network interface: %s", ifitem->name);
         }
     }
-    else
+    u_arraylist_destroy(iflist);
+    return CA_STATUS_OK;
+}
+
+static void CAProcessNewInterface(CAInterface_t *ifitem)
+{
+    if (!ifitem)
     {
-        OIC_LOG_V(DEBUG, IP_SERVER_TAG,
-                  "Multicast Server is already started on interface addr[%s]", localAddress);
-        ca_mutex_unlock(g_mutexServerInfoList);
+        OIC_LOG(DEBUG, TAG, "ifitem is null");
+        return;
     }
 
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-    return CA_STATUS_OK;
+    if (ifitem->family == AF_INET6)
+    {
+        applyMulticastToInterface6(ifitem->index);
+    }
+    if (ifitem->family == AF_INET)
+    {
+        applyMulticastToInterface4(ifitem->index);
+    }
 }
 
-CAResult_t CAIPStopServer(const char *interfaceAddress)
+void CAIPSetPacketReceiveCallback(CAIPPacketReceivedCallback callback)
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
+    g_packetReceivedCallback = callback;
+}
 
-    VERIFY_NON_NULL(interfaceAddress, IP_SERVER_TAG, "interfaceAddress is NULL");
+void CAIPSetConnectionStateChangeCallback(CAIPConnectionStateChangeCallback callback)
+{
+    CAIPSetNetworkMonitorCallback(callback);
+}
 
-    ca_mutex_lock(g_mutexServerInfoList);
-    uint32_t listIndex = 0;
-    uint32_t listLength = u_arraylist_length(g_serverInfoList);
+static void sendData(int fd, const CAEndpoint_t *endpoint,
+                     const void *data, uint32_t dlen,
+                     const char *cast, const char *fam)
+{
+    OIC_LOG(DEBUG, TAG, "IN");
 
-    for (listIndex = 0; listIndex < listLength;)
+    if (!endpoint)
     {
-        CAServerInfo_t *info = (CAServerInfo_t *) u_arraylist_get(g_serverInfoList, listIndex);
-        if (!info)
+        OIC_LOG(DEBUG, TAG, "endpoint is null");
+        if (g_ipErrorHandler)
         {
-            listIndex++;
-            continue;
+            g_ipErrorHandler(endpoint, data, dlen, CA_STATUS_INVALID_PARAM);
         }
+        return;
+    }
+
+    char *secure = (endpoint->flags & CA_SECURE) ? "secure " : "";
+
+    (void)cast;  // eliminates release warning
+    (void)fam;
 
-        if (info->isMulticastServer && strncmp(interfaceAddress, info->ifAddr, strlen(info->ifAddr))
-                == 0)
+    struct sockaddr_storage sock;
+    CAConvertNameToAddr(endpoint->addr, endpoint->port, &sock);
+
+    socklen_t socklen;
+    if (sock.ss_family == AF_INET6)
+    {
+        /** @todo figure out correct usage for ifindex, and sin6_scope_id */
+        socklen = sizeof(struct sockaddr_in6);
+    }
+    else
+    {
+        socklen = sizeof(struct sockaddr_in);
+    }
+#if !defined(_WIN32)
+    ssize_t len = sendto(fd, data, dlen, 0, (struct sockaddr *)&sock, socklen);
+    if (OC_SOCKET_ERROR == len)
+    {
+         // If logging is not defined/enabled.
+        if (g_ipErrorHandler)
+        {
+            g_ipErrorHandler(endpoint, data, dlen, CA_SEND_FAILED);
+        }
+        OIC_LOG_V(ERROR, TAG, "%s%s %s sendTo failed: %s", secure, cast, fam, strerror(errno));
+    }
+    else
+    {
+        OIC_LOG_V(INFO, TAG, "%s%s %s sendTo is successful: %zd bytes", secure, cast, fam, len);
+    }
+#else
+    int err = 0;
+    int len = 0;
+    int sent = 0;
+    do {
+        len = sendto(fd, ((char*)data) + sent, dlen - sent, 0, (struct sockaddr *)&sock, socklen);
+        if (OC_SOCKET_ERROR == len)
         {
-            if (u_arraylist_remove(g_serverInfoList, listIndex))
+            err = WSAGetLastError();
+            if ((WSAEWOULDBLOCK != err) && (WSAENOBUFS != err))
             {
-                struct ip_mreq multicastMemberReq = { { 0 }, { 0 } };
-
-                multicastMemberReq.imr_interface.s_addr = inet_addr(info->ifAddr);
-                inet_aton(info->endpoint.addr, &multicastMemberReq.imr_multiaddr);
-                if (-1 == setsockopt(info->socketFd, IPPROTO_IP, IP_DROP_MEMBERSHIP,
-                                     (char *) &multicastMemberReq, sizeof(struct ip_mreq)))
+                 // If logging is not defined/enabled.
+                if (g_ipErrorHandler)
                 {
-                    OIC_LOG_V(ERROR, IP_SERVER_TAG,
-                              "Failed to leave multicast group, Error code: %s", strerror(errno));
+                    g_ipErrorHandler(endpoint, data, dlen, CA_SEND_FAILED);
                 }
-                CACloseSocket(info->socketFd);
-                OICFree(info);
-                OIC_LOG(DEBUG, IP_SERVER_TAG, "Multicast server is stopped successfully.");
-                // Reduce list length by 1 as we removed one element.
-                listLength--;
-            }
-            else
-            {
-                OIC_LOG(ERROR, IP_SERVER_TAG, "u_arraylist_remove failed.");
-                ca_mutex_unlock(g_mutexServerInfoList);
-                return CA_STATUS_FAILED;
+
+                OIC_LOG_V(ERROR, TAG, "%s%s %s sendTo failed: %i", secure, cast, fam, err);
             }
         }
-        else if (strncmp(interfaceAddress, info->endpoint.addr, strlen(info->endpoint.addr)) == 0)
+        else
         {
-            if (u_arraylist_remove(g_serverInfoList, listIndex))
+            sent += len;
+            if (sent != len)
             {
-                CACloseSocket(info->socketFd);
-                OICFree(info);
-                OIC_LOG(DEBUG, IP_SERVER_TAG, "Unicast server is stopped successfully.");
-                // Reduce list length by 1 as we removed one element.
-                listLength--;
+                OIC_LOG_V(DEBUG, TAG, "%s%s %s sendTo (Partial Send) is successful: "
+                                      "currently sent: %ld bytes, "
+                                      "total sent: %ld bytes, "
+                                      "remaining: %ld bytes",
+                                      secure, cast, fam, len, sent, dlen-sent);
             }
             else
             {
-                OIC_LOG(ERROR, IP_SERVER_TAG, "u_arraylist_remove failed.");
-                ca_mutex_unlock(g_mutexServerInfoList);
-                return CA_STATUS_FAILED;
+                OIC_LOG_V(INFO, TAG, "%s%s %s sendTo is successful: %ld bytes",
+                                     secure, cast, fam, len);
             }
         }
-        else
-        {
-            listIndex++;
-        }
-    }
-
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-    ca_mutex_unlock(g_mutexServerInfoList);
-    return CA_STATUS_OK;
+    } while ((OC_SOCKET_ERROR == len) && ((WSAEWOULDBLOCK == err) || (WSAENOBUFS == err)) || (sent < dlen));
+#endif
 }
 
-CAResult_t CAIPStopAllServers()
+static void sendMulticastData6(const u_arraylist_t *iflist,
+                               CAEndpoint_t *endpoint,
+                               const void *data, uint32_t datalen)
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-
-    g_packetHandlerStopFlag = true;
+    if (!endpoint)
+    {
+        OIC_LOG(DEBUG, TAG, "endpoint is null");
+        return;
+    }
 
-    ca_mutex_lock(g_mutexServerInfoList);
+    int scope = endpoint->flags & CA_SCOPE_MASK;
+    char *ipv6mcname = ipv6mcnames[scope];
+    if (!ipv6mcname)
+    {
+        OIC_LOG_V(INFO, TAG, "IPv6 multicast scope invalid: %d", scope);
+        return;
+    }
+    OICStrcpy(endpoint->addr, sizeof(endpoint->addr), ipv6mcname);
+    int fd = caglobals.ip.u6.fd;
 
-    uint32_t listIndex = 0;
-    uint32_t listLength = u_arraylist_length(g_serverInfoList);
-    for (listIndex = 0; listIndex < listLength;)
+    uint32_t len = u_arraylist_length(iflist);
+    for (uint32_t i = 0; i < len; i++)
     {
-        CAServerInfo_t *info = (CAServerInfo_t *) u_arraylist_get(g_serverInfoList, listIndex);
-        if (!info)
+        CAInterface_t *ifitem = (CAInterface_t *)u_arraylist_get(iflist, i);
+        if (!ifitem)
         {
-            listIndex++;
             continue;
         }
-        if (u_arraylist_remove(g_serverInfoList, listIndex))
+        if ((ifitem->flags & IFF_UP_RUNNING_FLAGS) != IFF_UP_RUNNING_FLAGS)
         {
-            if (info->isMulticastServer)
-            {
-                struct ip_mreq multicastMemberReq = { { 0 }, { 0 } };
-
-                multicastMemberReq.imr_interface.s_addr = inet_addr(info->ifAddr);
-                inet_aton(info->endpoint.addr, &multicastMemberReq.imr_multiaddr);
-                if (-1 == setsockopt(info->socketFd, IPPROTO_IP, IP_DROP_MEMBERSHIP,
-                                     (char *) &multicastMemberReq, sizeof(struct ip_mreq)))
-                {
-                    OIC_LOG_V(ERROR, IP_SERVER_TAG,
-                              "Failed to leave multicast group, Error code: %s", strerror(errno));
-                }
-            }
-            CACloseSocket(info->socketFd);
-            //Freeing server info.
-            OICFree(info);
-            // Reduce list length by 1 as we removed one element.
-            listLength--;
+            continue;
         }
-        else
+        if (ifitem->family != AF_INET6)
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "u_arraylist_remove failed.");
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return CA_STATUS_FAILED;
+            continue;
         }
-    }
-
-    ca_mutex_unlock(g_mutexServerInfoList);
 
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "All Server stopped successfully. OUT");
-    return CA_STATUS_OK;
-}
-
-void CAIPPullData()
-{
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
+        int index = ifitem->index;
+        if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, OPTVAL_T(&index), sizeof (index)))
+        {
+            OIC_LOG_V(ERROR, TAG, "setsockopt6 failed: %s", CAIPS_GET_ERROR);
+            return;
+        }
+        sendData(fd, endpoint, data, datalen, "multicast", "ipv6");
+    }
 }
 
-uint16_t CAGetServerPortNum(const char *ipAddress, bool isSecured)
+static void sendMulticastData4(const u_arraylist_t *iflist,
+                               CAEndpoint_t *endpoint,
+                               const void *data, uint32_t datalen)
 {
-    ca_mutex_lock(g_mutexServerInfoList);
-
-    uint16_t port = CAGetServerPort(g_serverInfoList, ipAddress, isSecured);
-
-    ca_mutex_unlock(g_mutexServerInfoList);
-
-    return port;
-}
+    VERIFY_NON_NULL_VOID(endpoint, TAG, "endpoint is NULL");
+
+#if defined(USE_IP_MREQN)
+    struct ip_mreqn mreq = { .imr_multiaddr = IPv4MulticastAddress,
+                             .imr_address.s_addr = htonl(INADDR_ANY),
+                             .imr_ifindex = 0};
+#else
+    struct ip_mreq mreq  = { .imr_multiaddr = IPv4MulticastAddress,
+                             .imr_interface = {0}};
+#endif
 
-CAResult_t CAGetIPServerInfoList(u_arraylist_t **serverInfoList)
-{
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-    ca_mutex_lock(g_mutexServerInfoList);
+    OICStrcpy(endpoint->addr, sizeof(endpoint->addr), IPv4_MULTICAST);
+    int fd = caglobals.ip.u4.fd;
 
-    uint32_t list_index = 0;
-    uint32_t list_length = u_arraylist_length(g_serverInfoList);
-    for (list_index = 0; list_index < list_length; list_index++)
+    uint32_t len = u_arraylist_length(iflist);
+    for (uint32_t i = 0; i < len; i++)
     {
-        CAServerInfo_t *info = (CAServerInfo_t *) u_arraylist_get(g_serverInfoList, list_index);
-        if (!info)
+        CAInterface_t *ifitem = (CAInterface_t *)u_arraylist_get(iflist, i);
+        if (!ifitem)
         {
             continue;
         }
-
-        CAServerInfo_t *newNetinfo = (CAServerInfo_t *) OICMalloc(sizeof(CAServerInfo_t));
-        if (!newNetinfo)
+        if ((ifitem->flags & IFF_UP_RUNNING_FLAGS) != IFF_UP_RUNNING_FLAGS)
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "Malloc failed!");
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return CA_MEMORY_ALLOC_FAILED;
+            continue;
         }
-
-        *newNetinfo = *info;
-
-        CAResult_t result = u_arraylist_add(*serverInfoList, (void *) newNetinfo);
-        if (CA_STATUS_OK != result)
+        if (ifitem->family != AF_INET)
         {
-            OIC_LOG(ERROR, IP_SERVER_TAG, "u_arraylist_add failed!");
-            ca_mutex_unlock(g_mutexServerInfoList);
-            return CA_STATUS_FAILED;
+            continue;
+        }
+#if defined(USE_IP_MREQN)
+        mreq.imr_ifindex = ifitem->index;
+#else
+        mreq.imr_interface.s_addr = htonl(ifitem->index);
+#endif
+        if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, OPTVAL_T(&mreq), sizeof (mreq)))
+        {
+            OIC_LOG_V(ERROR, TAG, "send IP_MULTICAST_IF failed: %s (using defualt)",
+                    CAIPS_GET_ERROR);
         }
+        sendData(fd, endpoint, data, datalen, "multicast", "ipv4");
     }
-    ca_mutex_unlock(g_mutexServerInfoList);
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-    return CA_STATUS_OK;
 }
 
-void CAIPSetPacketReceiveCallback(CAIPPacketReceivedCallback callback)
+void CAIPSendData(CAEndpoint_t *endpoint, const void *data, uint32_t datalen,
+                  bool isMulticast)
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
+    VERIFY_NON_NULL_VOID(endpoint, TAG, "endpoint is NULL");
+    VERIFY_NON_NULL_VOID(data, TAG, "data is NULL");
 
-    ca_mutex_lock(g_mutexAdapterServerContext);
+    bool isSecure = (endpoint->flags & CA_SECURE) != 0;
 
-    if (g_adapterIPServerContext)
+    if (isMulticast)
     {
-        g_adapterIPServerContext->packetReceivedCallback = callback;
+        endpoint->port = isSecure ? CA_SECURE_COAP : CA_COAP;
+
+        u_arraylist_t *iflist = CAIPGetInterfaceInformation(0);
+        if (!iflist)
+        {
+            OIC_LOG_V(ERROR, TAG, "get interface info failed: %s", strerror(errno));
+            return;
+        }
+
+        if ((endpoint->flags & CA_IPV6) && caglobals.ip.ipv6enabled)
+        {
+            sendMulticastData6(iflist, endpoint, data, datalen);
+        }
+        if ((endpoint->flags & CA_IPV4) && caglobals.ip.ipv4enabled)
+        {
+            sendMulticastData4(iflist, endpoint, data, datalen);
+        }
+
+        u_arraylist_destroy(iflist);
     }
     else
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "g_adapterIPServerContext NULL");
-    }
-
-    ca_mutex_unlock(g_mutexAdapterServerContext);
+        if (!endpoint->port)    // unicast discovery
+        {
+            endpoint->port = isSecure ? CA_SECURE_COAP : CA_COAP;
+        }
 
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
+        CASocketFd_t fd;
+        if (caglobals.ip.ipv6enabled && (endpoint->flags & CA_IPV6))
+        {
+            fd = isSecure ? caglobals.ip.u6s.fd : caglobals.ip.u6.fd;
+#ifndef __WITH_DTLS__
+            fd = caglobals.ip.u6.fd;
+#endif
+            sendData(fd, endpoint, data, datalen, "unicast", "ipv6");
+        }
+        if (caglobals.ip.ipv4enabled && (endpoint->flags & CA_IPV4))
+        {
+            fd = isSecure ? caglobals.ip.u4s.fd : caglobals.ip.u4.fd;
+#ifndef __WITH_DTLS__
+            fd = caglobals.ip.u4.fd;
+#endif
+            sendData(fd, endpoint, data, datalen, "unicast", "ipv4");
+        }
+    }
 }
 
-void CAIPSetErrorHandleCallback(CAIPErrorHandleCallback ipErrorCallback)
+CAResult_t CAGetIPInterfaceInformation(CAEndpoint_t **info, uint32_t *size)
 {
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-
-    ca_mutex_lock(g_mutexAdapterServerContext);
+    VERIFY_NON_NULL(info, TAG, "info is NULL");
+    VERIFY_NON_NULL(size, TAG, "size is NULL");
 
-    if (g_adapterIPServerContext)
+    u_arraylist_t *iflist = CAIPGetInterfaceInformation(0);
+    if (!iflist)
     {
-        g_adapterIPServerContext->IPErrorCallback = ipErrorCallback;
+        OIC_LOG_V(ERROR, TAG, "get interface info failed: %s", strerror(errno));
+        return CA_STATUS_FAILED;
     }
 
-    ca_mutex_unlock(g_mutexAdapterServerContext);
-
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
-}
+    uint32_t len = u_arraylist_length(iflist);
+    uint32_t length = len;
 
-void CAIPSetExceptionCallback(CAIPExceptionCallback callback)
-{
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "IN");
-    ca_mutex_lock(g_mutexAdapterServerContext);
+#ifdef __WITH_DTLS__
+    //If DTLS is supported, each interface can support secure port as well
+    length = len * 2;
+#endif
 
-    if (g_adapterIPServerContext)
+    CAEndpoint_t *eps = (CAEndpoint_t *)OICCalloc(length, sizeof (CAEndpoint_t));
+    if (!eps)
     {
-        g_adapterIPServerContext->exceptionCallback = callback;
+        OIC_LOG(ERROR, TAG, "Malloc Failed");
+        u_arraylist_destroy(iflist);
+        return CA_MEMORY_ALLOC_FAILED;
     }
-    else
+
+    for (uint32_t i = 0, j = 0; i < len; i++)
     {
-        OIC_LOG(ERROR, IP_SERVER_TAG, "g_adapterIPServerContext NULL");
+        CAInterface_t *ifitem = (CAInterface_t *)u_arraylist_get(iflist, i);
+        if(!ifitem)
+        {
+            continue;
+        }
+
+        eps[j].adapter = CA_ADAPTER_IP;
+        eps[j].ifindex = 0;
+
+        if (ifitem->family == AF_INET6)
+        {
+            eps[j].flags = CA_IPV6;
+            eps[j].port = caglobals.ip.u6.port;
+        }
+        else
+        {
+            eps[j].flags = CA_IPV4;
+            eps[j].port = caglobals.ip.u4.port;
+            /** @todo eps[j].addr not populated with IPv4 address string.
+             * it was using ifitem->ipv4addr to accomplish this.
+             * Need to understand what ipv4addr means to whom*/
+        }
+
+#ifdef __WITH_DTLS__
+        j++;
+
+        eps[j].adapter = CA_ADAPTER_IP;
+        eps[j].ifindex = 0;
+
+        if (ifitem->family == AF_INET6)
+        {
+            eps[j].flags = CA_IPV6 | CA_SECURE;
+            eps[j].port = caglobals.ip.u6s.port;
+        }
+        else
+        {
+            eps[j].flags = CA_IPV4 | CA_SECURE;
+            eps[j].port = caglobals.ip.u4s.port;
+            inet_ntop(AF_INET, &(ifitem->ipv4addr), eps[j].addr, MAX_ADDR_STR_SIZE_CA);
+        }
+#endif
+        j++;
     }
 
-    ca_mutex_unlock(g_mutexAdapterServerContext);
+    *info = eps;
+    *size = len;
+
+    u_arraylist_destroy(iflist);
 
-    OIC_LOG(DEBUG, IP_SERVER_TAG, "OUT");
+    return CA_STATUS_OK;
 }
 
+void CAIPSetErrorHandler(CAIPErrorHandleCallback errorHandleCallback)
+{
+    g_ipErrorHandler = errorHandleCallback;
+}