path: root/datapath-windows/ovsext/Vxlan.c

/*
 * Copyright (c) 2014 VMware, Inc.
 *
 * 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.
 */

#include "precomp.h"
#include "NetProto.h"
#include "Switch.h"
#include "Vport.h"
#include "Flow.h"
#include "Vxlan.h"
#include "IpHelper.h"
#include "Checksum.h"
#include "User.h"
#include "PacketIO.h"
#include "Flow.h"
#include "PacketParser.h"
#include "Checksum.h"

#pragma warning( push )
#pragma warning( disable:4127 )


#ifdef OVS_DBG_MOD
#undef OVS_DBG_MOD
#endif
#define OVS_DBG_MOD OVS_DBG_VXLAN
#include "Debug.h"

/* Helper macro to check if a VXLAN ID is valid. */
#define VXLAN_ID_IS_VALID(vxlanID) (0 < (vxlanID) && (vxlanID) <= 0xffffff)
#define VXLAN_TUNNELID_TO_VNI(_tID)   (UINT32)(((UINT64)(_tID)) >> 40)
#define VXLAN_VNI_TO_TUNNELID(_vni) (((UINT64)(_vni)) << 40)
#define IP_DF_NBO 0x0040
#define VXLAN_DEFAULT_TTL 64
#define VXLAN_MULTICAST_TTL 64
#define VXLAN_DEFAULT_INSTANCE_ID 1

/* Move to a header file */
extern POVS_SWITCH_CONTEXT gOvsSwitchContext;

NTSTATUS
OvsInitVxlanTunnel(POVS_VPORT_ENTRY vport,
                   POVS_VPORT_ADD_REQUEST addReq)
{
    POVS_VXLAN_VPORT vxlanPort;
    NTSTATUS status = STATUS_SUCCESS;

    ASSERT(addReq->type == OVSWIN_VPORT_TYPE_VXLAN);

    vxlanPort = OvsAllocateMemory(sizeof (*vxlanPort));
    if (vxlanPort == NULL) {
        status =  STATUS_INSUFFICIENT_RESOURCES;
    } else {
        RtlZeroMemory(vxlanPort, sizeof (*vxlanPort));
        vxlanPort->dstPort = addReq->dstPort;
        /*
         * since we are installing the WFP filter before the port is created
         * We need to check if it is the same number
         * XXX should be removed later
         */
        ASSERT(vxlanPort->dstPort == VXLAN_UDP_PORT);
        vport->priv = (PVOID)vxlanPort;
    }
    return status;
}


VOID
OvsCleanupVxlanTunnel(POVS_VPORT_ENTRY vport)
{
    if (vport->ovsType != OVSWIN_VPORT_TYPE_VXLAN ||
        vport->priv == NULL) {
        return;
    }

    OvsFreeMemory(vport->priv);
    vport->priv = NULL;
}


/*
 *----------------------------------------------------------------------------
 * OvsDoEncapVxlan
 *     Encapsulates the packet.
 *----------------------------------------------------------------------------
 */
static __inline NDIS_STATUS
OvsDoEncapVxlan(PNET_BUFFER_LIST curNbl,
                OvsIPv4TunnelKey *tunKey,
                POVS_FWD_INFO fwdInfo,
                POVS_PACKET_HDR_INFO layers,
                POVS_SWITCH_CONTEXT switchContext,
                PNET_BUFFER_LIST *newNbl)
{
    NDIS_STATUS status;
    PNET_BUFFER curNb;
    PMDL curMdl;
    PUINT8 bufferStart;
    EthHdr *ethHdr;
    IPHdr *ipHdr;
    UDPHdr *udpHdr;
    VXLANHdr *vxlanHdr;
    UINT32 headRoom = OvsGetVxlanTunHdrSize();
    UINT32 packetLength;

    /*
     * XXX: the assumption currently is that the NBL is owned by OVS, and
     * headroom has already been allocated as part of allocating the NBL and
     * MDL.
     */
    curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
    packetLength = NET_BUFFER_DATA_LENGTH(curNb);
    if (layers->isTcp) {
        NDIS_TCP_LARGE_SEND_OFFLOAD_NET_BUFFER_LIST_INFO tsoInfo;

        tsoInfo.Value = NET_BUFFER_LIST_INFO(curNbl,
                TcpLargeSendNetBufferListInfo);
        OVS_LOG_TRACE("MSS %u packet len %u", tsoInfo.LsoV1Transmit.MSS, packetLength);
        if (tsoInfo.LsoV1Transmit.MSS) {
            OVS_LOG_TRACE("l4Offset %d", layers->l4Offset);
            *newNbl = OvsTcpSegmentNBL(switchContext, curNbl, layers,
                        tsoInfo.LsoV1Transmit.MSS, headRoom);
            if (*newNbl == NULL) {
                OVS_LOG_ERROR("Unable to segment NBL");
                return NDIS_STATUS_FAILURE;
            }
        }
    }
    /* If we didn't split the packet above, make a copy now */
    if (*newNbl == NULL) {
        *newNbl = OvsPartialCopyNBL(switchContext, curNbl, 0, headRoom,
                                    FALSE /*NBL info*/);
        if (*newNbl == NULL) {
            OVS_LOG_ERROR("Unable to copy NBL");
            return NDIS_STATUS_FAILURE;
        }
    }

    curNbl = *newNbl;
    for (curNb = NET_BUFFER_LIST_FIRST_NB(curNbl); curNb != NULL;
            curNb = curNb->Next) {
        status = NdisRetreatNetBufferDataStart(curNb, headRoom, 0, NULL);
        if (status != NDIS_STATUS_SUCCESS) {
            goto ret_error;
        }

        curMdl = NET_BUFFER_CURRENT_MDL(curNb);
        bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl, LowPagePriority);
        if (!bufferStart) {
            status = NDIS_STATUS_RESOURCES;
            goto ret_error;
        }

        bufferStart += NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
        if (NET_BUFFER_NEXT_NB(curNb)) {
            OVS_LOG_TRACE("nb length %u next %u", NET_BUFFER_DATA_LENGTH(curNb),
                          NET_BUFFER_DATA_LENGTH(curNb->Next));
        }

        /* L2 header */
        ethHdr = (EthHdr *)bufferStart;
        NdisMoveMemory(ethHdr->Destination, fwdInfo->dstMacAddr,
                       sizeof ethHdr->Destination + sizeof ethHdr->Source);
        ASSERT(((PCHAR)&fwdInfo->dstMacAddr + sizeof fwdInfo->dstMacAddr) ==
               (PCHAR)&fwdInfo->srcMacAddr);
        ethHdr->Type = htons(ETH_TYPE_IPV4);

        // XXX: question: there are fields in the OvsIPv4TunnelKey for ttl and such,
        // should we use those values instead? or will they end up being
        // uninitialized;
        /* IP header */
        ipHdr = (IPHdr *)((PCHAR)ethHdr + sizeof *ethHdr);

        ipHdr->ihl = sizeof *ipHdr / 4;
        ipHdr->version = IPV4;
        ipHdr->tos = 0;
        ipHdr->tot_len = htons(NET_BUFFER_DATA_LENGTH(curNb) - sizeof *ethHdr);
        ipHdr->id = 0;
        ipHdr->frag_off = IP_DF_NBO;
        ipHdr->ttl = tunKey->ttl ? tunKey->ttl : VXLAN_DEFAULT_TTL;
        ipHdr->protocol = IPPROTO_UDP;
        ASSERT(tunKey->dst == fwdInfo->dstIpAddr);
        ASSERT(tunKey->src == fwdInfo->srcIpAddr || tunKey->src == 0);
        ipHdr->saddr = fwdInfo->srcIpAddr;
        ipHdr->daddr = fwdInfo->dstIpAddr;
        ipHdr->check = 0;
        ipHdr->check = IPChecksum((UINT8 *)ipHdr, sizeof *ipHdr, 0);

        /* UDP header */
        udpHdr = (UDPHdr *)((PCHAR)ipHdr + sizeof *ipHdr);
        udpHdr->source = htons(tunKey->flow_hash | 32768);
        udpHdr->dest = VXLAN_UDP_PORT_NBO;
        udpHdr->len = htons(NET_BUFFER_DATA_LENGTH(curNb) - headRoom +
                            sizeof *udpHdr + sizeof *vxlanHdr);
        udpHdr->check = 0;

        /* VXLAN header */
        vxlanHdr = (VXLANHdr *)((PCHAR)udpHdr + sizeof *udpHdr);
        vxlanHdr->flags1 = 0;
        vxlanHdr->locallyReplicate = 0;
        vxlanHdr->flags2 = 0;
        vxlanHdr->reserved1 = 0;
        if (tunKey->flags | OVS_TNL_F_KEY) {
            vxlanHdr->vxlanID = VXLAN_TUNNELID_TO_VNI(tunKey->tunnelId);
            vxlanHdr->instanceID = 1;
        }
        vxlanHdr->reserved2 = 0;
    }
    return STATUS_SUCCESS;

ret_error:
    OvsCompleteNBL(switchContext, *newNbl, TRUE);
    *newNbl = NULL;
    return status;
}


/*
 *----------------------------------------------------------------------------
 * OvsEncapVxlan --
 *     Encapsulates the packet if L2/L3 for destination resolves. Otherwise,
 *     enqueues a callback that does encapsulatation after resolution.
 *----------------------------------------------------------------------------
 */
NDIS_STATUS
OvsEncapVxlan(PNET_BUFFER_LIST curNbl,
              OvsIPv4TunnelKey *tunKey,
              POVS_SWITCH_CONTEXT switchContext,
              VOID *completionList,
              POVS_PACKET_HDR_INFO layers,
              PNET_BUFFER_LIST *newNbl)
{
    NTSTATUS status;
    OVS_FWD_INFO fwdInfo;
    UNREFERENCED_PARAMETER(completionList);

    status = OvsLookupIPFwdInfo(tunKey->dst, &fwdInfo);
    if (status != STATUS_SUCCESS) {
        OvsFwdIPHelperRequest(NULL, 0, tunKey, NULL, NULL, NULL);
        // return NDIS_STATUS_PENDING;
        /*
         * XXX: Don't know if the completionList will make any sense when
         * accessed in the callback. Make sure the caveats are known.
         *
         * XXX: This code will work once we are able to grab locks in the
         * callback.
         */
        return NDIS_STATUS_FAILURE;
    }

    return OvsDoEncapVxlan(curNbl, tunKey, &fwdInfo, layers,
                           switchContext, newNbl);
}


/*
 *----------------------------------------------------------------------------
 * OvsIpHlprCbVxlan --
 *     Callback function for IP helper.
 *     XXX: not used currently
 *----------------------------------------------------------------------------
 */
static VOID
OvsIpHlprCbVxlan(PNET_BUFFER_LIST curNbl,
                 UINT32 inPort,
                 OvsIPv4TunnelKey *tunKey,
                 PVOID cbData1,
                 PVOID cbData2,
                 NTSTATUS result,
                 POVS_FWD_INFO fwdInfo)
{
    OVS_PACKET_HDR_INFO layers;
    OvsFlowKey key;
    NDIS_STATUS status;
    UNREFERENCED_PARAMETER(inPort);

    status = OvsExtractFlow(curNbl, inPort, &key, &layers, NULL);
    if (result == STATUS_SUCCESS) {
        status = OvsDoEncapVxlan(curNbl, tunKey, fwdInfo, &layers,
                (POVS_SWITCH_CONTEXT)cbData1, NULL);
    } else {
        status = NDIS_STATUS_FAILURE;
    }

    if (status != NDIS_STATUS_SUCCESS) {
        // XXX: Free up the NBL;
        return;
    }

    OvsLookupFlowOutput((POVS_SWITCH_CONTEXT)cbData1, cbData2, curNbl);
}

/*
 *----------------------------------------------------------------------------
 * OvsCalculateUDPChecksum
 *     Calculate UDP checksum
 *----------------------------------------------------------------------------
 */
static __inline NDIS_STATUS
OvsCalculateUDPChecksum(PNET_BUFFER_LIST curNbl,
                        PNET_BUFFER curNb,
                        IPHdr *ipHdr,
                        UDPHdr *udpHdr,
                        UINT32 packetLength)
{
    NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO csumInfo;
    UINT16 checkSum;

    csumInfo.Value = NET_BUFFER_LIST_INFO(curNbl, TcpIpChecksumNetBufferListInfo);

    /* Next check if UDP checksum has been calculated. */
    if (!csumInfo.Receive.UdpChecksumSucceeded) {
        UINT32 l4Payload;

        checkSum = udpHdr->check;

        l4Payload = packetLength - sizeof(EthHdr) - ipHdr->ihl * 4;
        udpHdr->check = 0;
        udpHdr->check =
            IPPseudoChecksum((UINT32 *)&ipHdr->saddr,
                             (UINT32 *)&ipHdr->daddr,
                             IPPROTO_UDP, (UINT16)l4Payload);
        udpHdr->check = CalculateChecksumNB(curNb, (UINT16)l4Payload,
            sizeof(EthHdr) + ipHdr->ihl * 4);
        if (checkSum != udpHdr->check) {
            OVS_LOG_TRACE("UDP checksum incorrect.");
            return NDIS_STATUS_INVALID_PACKET;
        }
    }

    csumInfo.Receive.UdpChecksumSucceeded = 1;
    NET_BUFFER_LIST_INFO(curNbl, TcpIpChecksumNetBufferListInfo) = csumInfo.Value;
    return NDIS_STATUS_SUCCESS;
}

/*
 *----------------------------------------------------------------------------
 * OvsDoDecapVxlan
 *     Decapsulates to tunnel header in 'curNbl' and puts into 'tunKey'.
 *----------------------------------------------------------------------------
 */
NDIS_STATUS
OvsDoDecapVxlan(POVS_SWITCH_CONTEXT switchContext,
                PNET_BUFFER_LIST curNbl,
                OvsIPv4TunnelKey *tunKey,
                PNET_BUFFER_LIST *newNbl)
{
    PNET_BUFFER curNb;
    PMDL curMdl;
    EthHdr *ethHdr;
    IPHdr *ipHdr;
    UDPHdr *udpHdr;
    VXLANHdr *vxlanHdr;
    UINT32 tunnelSize = 0, packetLength = 0;
    PUINT8 bufferStart;
    NDIS_STATUS status;

    /* Check the the length of the UDP payload */
    curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
    packetLength = NET_BUFFER_DATA_LENGTH(curNb);
    tunnelSize = OvsGetVxlanTunHdrSize();
    if (packetLength <= tunnelSize) {
        return NDIS_STATUS_INVALID_LENGTH;
    }

    /*
     * Create a copy of the NBL so that we have all the headers in one MDL.
     */
    *newNbl = OvsPartialCopyNBL(switchContext, curNbl,
                                tunnelSize + OVS_DEFAULT_COPY_SIZE, 0,
                                TRUE /*copy NBL info */);

    if (*newNbl == NULL) {
        return NDIS_STATUS_RESOURCES;
    }

    /* XXX: Handle VLAN header. */
    curNbl = *newNbl;
    curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
    curMdl = NET_BUFFER_CURRENT_MDL(curNb);
    bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl, LowPagePriority) +
                  NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
    if (!bufferStart) {
        status = NDIS_STATUS_RESOURCES;
        goto dropNbl;
    }

    ethHdr = (EthHdr *)bufferStart;
    /* XXX: Handle IP options. */
    ipHdr = (IPHdr *)((PCHAR)ethHdr + sizeof *ethHdr);
    tunKey->src = ipHdr->saddr;
    tunKey->dst = ipHdr->daddr;
    tunKey->tos = ipHdr->tos;
    tunKey->ttl = ipHdr->ttl;
    tunKey->pad = 0;
    udpHdr = (UDPHdr *)((PCHAR)ipHdr + sizeof *ipHdr);

    /* Validate if NIC has indicated checksum failure. */
    status = OvsValidateUDPChecksum(curNbl, udpHdr->check == 0);
    if (status != NDIS_STATUS_SUCCESS) {
        goto dropNbl;
    }

    /* Calculate and verify UDP checksum if NIC didn't do it. */
    if (udpHdr->check != 0) {
        status = OvsCalculateUDPChecksum(curNbl, curNb, ipHdr, udpHdr, packetLength);
        if (status != NDIS_STATUS_SUCCESS) {
            goto dropNbl;
        }
    }

    vxlanHdr = (VXLANHdr *)((PCHAR)udpHdr + sizeof *udpHdr);
    if (vxlanHdr->instanceID) {
        tunKey->flags = OVS_TNL_F_KEY;
        tunKey->tunnelId = VXLAN_VNI_TO_TUNNELID(vxlanHdr->vxlanID);
    } else {
        tunKey->flags = 0;
        tunKey->tunnelId = 0;
    }

    /* Clear out the receive flag for the inner packet. */
    NET_BUFFER_LIST_INFO(curNbl, TcpIpChecksumNetBufferListInfo) = 0;
    NdisAdvanceNetBufferDataStart(curNb, tunnelSize, FALSE, NULL);
    return NDIS_STATUS_SUCCESS;

dropNbl:
    OvsCompleteNBL(switchContext, *newNbl, TRUE);
    *newNbl = NULL;
    return status;
}


NDIS_STATUS
OvsSlowPathDecapVxlan(const PNET_BUFFER_LIST packet,
                   OvsIPv4TunnelKey *tunnelKey)
{
    NDIS_STATUS status = NDIS_STATUS_FAILURE;
    UDPHdr udpStorage;
    const UDPHdr *udp;
    VXLANHdr *VxlanHeader;
    VXLANHdr  VxlanHeaderBuffer;
    struct IPHdr ip_storage;
    const struct IPHdr *nh;
    OVS_PACKET_HDR_INFO layers;

    layers.value = 0;

    do {
        nh = OvsGetIp(packet, layers.l3Offset, &ip_storage);
        if (nh) {
            layers.l4Offset = layers.l3Offset + nh->ihl * 4;
        } else {
            break;
        }

        /* make sure it's a VXLAN packet */
        udp = OvsGetUdp(packet, layers.l4Offset, &udpStorage);
        if (udp) {
            layers.l7Offset = layers.l4Offset + sizeof *udp;
        } else {
            break;
        }

        /* XXX Should be tested against the dynamic port # in the VXLAN vport */
        ASSERT(udp->dest == RtlUshortByteSwap(VXLAN_UDP_PORT));

        VxlanHeader = (VXLANHdr *)OvsGetPacketBytes(packet,
                                                    sizeof(*VxlanHeader),
                                                    layers.l7Offset,
                                                    &VxlanHeaderBuffer);

        if (VxlanHeader) {
            tunnelKey->src = nh->saddr;
            tunnelKey->dst = nh->daddr;
            tunnelKey->ttl = nh->ttl;
            tunnelKey->tos = nh->tos;
            if (VxlanHeader->instanceID) {
                tunnelKey->flags = OVS_TNL_F_KEY;
                tunnelKey->tunnelId = VXLAN_VNI_TO_TUNNELID(VxlanHeader->vxlanID);
            } else {
                tunnelKey->flags = 0;
                tunnelKey->tunnelId = 0;
            }
        } else {
            break;
        }
        status = NDIS_STATUS_SUCCESS;

    } while(FALSE);

    return status;
}

#pragma warning( pop )