datapath-windows/ovsext/Vxlan.c

   1 /*
   2  * Copyright (c) 2014 VMware, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include "precomp.h"
  18 #include "Atomic.h"
  19 #include "NetProto.h"
  20 #include "Switch.h"
  21 #include "Vport.h"
  22 #include "Flow.h"
  23 #include "Vxlan.h"
  24 #include "IpHelper.h"
  25 #include "Checksum.h"
  26 #include "User.h"
  27 #include "PacketIO.h"
  28 #include "Flow.h"
  29 #include "PacketParser.h"
  30
  31 #pragma warning( push )
  32 #pragma warning( disable:4127 )
  33
  34
  35 #ifdef OVS_DBG_MOD
  36 #undef OVS_DBG_MOD
  37 #endif
  38 #define OVS_DBG_MOD OVS_DBG_VXLAN
  39 #include "Debug.h"
  40
  41 /* Helper macro to check if a VXLAN ID is valid. */
  42 #define VXLAN_ID_IS_VALID(vxlanID) (0 < (vxlanID) && (vxlanID) <= 0xffffff)
  43 #define VXLAN_TUNNELID_TO_VNI(_tID)   (UINT32)(((UINT64)(_tID)) >> 40)
  44 #define VXLAN_VNI_TO_TUNNELID(_vni) (((UINT64)(_vni)) << 40)
  45 #define IP_DF_NBO 0x0040
  46 #define VXLAN_DEFAULT_TTL 64
  47 #define VXLAN_MULTICAST_TTL 64
  48 #define VXLAN_DEFAULT_INSTANCE_ID 1
  49
  50 /* Move to a header file */
  51 extern POVS_SWITCH_CONTEXT gOvsSwitchContext;
  52
  53 /*
  54  *----------------------------------------------------------------------------
  55  * This function verifies if the VXLAN tunnel already exists, in order to
  56  * avoid sending a duplicate request to the WFP base filtering engine.
  57  *----------------------------------------------------------------------------
  58  */
  59 static BOOLEAN
  60 OvsIsTunnelFilterCreated(POVS_SWITCH_CONTEXT switchContext,
  61                          UINT16 udpPortDest)
  62 {
  63     for (UINT hash = 0; hash < OVS_MAX_VPORT_ARRAY_SIZE; hash++) {
  64         PLIST_ENTRY head, link, next;
  65
  66         head = &(switchContext->portNoHashArray[hash & OVS_VPORT_MASK]);
  67         LIST_FORALL_SAFE(head, link, next) {
  68             POVS_VPORT_ENTRY vport = NULL;
  69             POVS_VXLAN_VPORT vxlanPort = NULL;
  70             vport = CONTAINING_RECORD(link, OVS_VPORT_ENTRY, portNoLink);
  71             vxlanPort = (POVS_VXLAN_VPORT)vport->priv;
  72             if (vxlanPort) {
  73                 if ((udpPortDest == vxlanPort->dstPort)) {
  74                     /* The VXLAN tunnel was already created. */
  75                     return TRUE;
  76                 }
  77             }
  78         }
  79     }
  80
  81     return FALSE;
  82 }
  83
  84 /*
  85  *----------------------------------------------------------------------------
  86  * This function allocates and initializes the OVS_VXLAN_VPORT. The function
  87  * also creates a WFP tunnel filter for the necessary destination port. The
  88  * tunnel filter create request is passed to the tunnel filter threads that
  89  * will complete the request at a later time when IRQL is lowered to
  90  * PASSIVE_LEVEL.
  91  *
  92  * udpDestPort: the vxlan is set as payload to a udp frame. If the destination
  93  * port of an udp frame is udpDestPort, we understand it to be vxlan.
  94  *----------------------------------------------------------------------------
  95  */
  96 NTSTATUS
  97 OvsInitVxlanTunnel(PIRP irp,
  98                    POVS_VPORT_ENTRY vport,
  99                    UINT16 udpDestPort,
 100                    PFNTunnelVportPendingOp callback,
 101                    PVOID tunnelContext)
 102 {
 103     NTSTATUS status = STATUS_SUCCESS;
 104     POVS_VXLAN_VPORT vxlanPort = NULL;
 105
 106     vxlanPort = OvsAllocateMemoryWithTag(sizeof (*vxlanPort),
 107                                          OVS_VXLAN_POOL_TAG);
 108     if (vxlanPort == NULL) {
 109         return STATUS_INSUFFICIENT_RESOURCES;
 110     }
 111
 112     RtlZeroMemory(vxlanPort, sizeof(*vxlanPort));
 113     vxlanPort->dstPort = udpDestPort;
 114     vport->priv = (PVOID)vxlanPort;
 115
 116     if (!OvsIsTunnelFilterCreated(gOvsSwitchContext, udpDestPort)) {
 117         status = OvsTunnelFilterCreate(irp,
 118                                        udpDestPort,
 119                                        &vxlanPort->filterID,
 120                                        callback,
 121                                        tunnelContext);
 122     } else {
 123         status = STATUS_OBJECT_NAME_EXISTS;
 124     }
 125
 126     return status;
 127 }
 128
 129 /*
 130  *----------------------------------------------------------------------------
 131  * This function releases the OVS_VXLAN_VPORT. The function also deletes the
 132  * WFP tunnel filter previously created. The tunnel filter delete request is
 133  * passed to the tunnel filter threads that will complete the request at a
 134  * later time when IRQL is lowered to PASSIVE_LEVEL.
 135  *----------------------------------------------------------------------------
 136  */
 137 NTSTATUS
 138 OvsCleanupVxlanTunnel(PIRP irp,
 139                       POVS_VPORT_ENTRY vport,
 140                       PFNTunnelVportPendingOp callback,
 141                       PVOID tunnelContext)
 142 {
 143     NTSTATUS status = STATUS_SUCCESS;
 144     POVS_VXLAN_VPORT vxlanPort = NULL;
 145
 146     if (vport->ovsType != OVS_VPORT_TYPE_VXLAN ||
 147         vport->priv == NULL) {
 148         return STATUS_SUCCESS;
 149     }
 150
 151     vxlanPort = (POVS_VXLAN_VPORT)vport->priv;
 152
 153     if (vxlanPort->filterID != 0) {
 154         status = OvsTunnelFilterDelete(irp,
 155                                        vxlanPort->filterID,
 156                                        callback,
 157                                        tunnelContext);
 158     } else {
 159         OvsFreeMemoryWithTag(vport->priv, OVS_VXLAN_POOL_TAG);
 160         vport->priv = NULL;
 161     }
 162
 163     return status;
 164 }
 165
 166
 167 /*
 168  *----------------------------------------------------------------------------
 169  * OvsDoEncapVxlan
 170  *     Encapsulates the packet.
 171  *----------------------------------------------------------------------------
 172  */
 173 static __inline NDIS_STATUS
 174 OvsDoEncapVxlan(POVS_VPORT_ENTRY vport,
 175                 PNET_BUFFER_LIST curNbl,
 176                 OvsIPv4TunnelKey *tunKey,
 177                 POVS_FWD_INFO fwdInfo,
 178                 POVS_PACKET_HDR_INFO layers,
 179                 POVS_SWITCH_CONTEXT switchContext,
 180                 PNET_BUFFER_LIST *newNbl)
 181 {
 182     NDIS_STATUS status;
 183     PNET_BUFFER curNb;
 184     PMDL curMdl;
 185     PUINT8 bufferStart;
 186     EthHdr *ethHdr;
 187     IPHdr *ipHdr;
 188     UDPHdr *udpHdr;
 189     VXLANHdr *vxlanHdr;
 190     POVS_VXLAN_VPORT vportVxlan;
 191     UINT32 headRoom = OvsGetVxlanTunHdrSize();
 192     UINT32 packetLength;
 193
 194     /*
 195      * XXX: the assumption currently is that the NBL is owned by OVS, and
 196      * headroom has already been allocated as part of allocating the NBL and
 197      * MDL.
 198      */
 199     curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
 200     packetLength = NET_BUFFER_DATA_LENGTH(curNb);
 201
 202     if (layers->isTcp) {
 203         NDIS_TCP_LARGE_SEND_OFFLOAD_NET_BUFFER_LIST_INFO tsoInfo;
 204
 205         tsoInfo.Value = NET_BUFFER_LIST_INFO(curNbl,
 206                                              TcpLargeSendNetBufferListInfo);
 207         OVS_LOG_TRACE("MSS %u packet len %u", tsoInfo.LsoV1Transmit.MSS,
 208                       packetLength);
 209         if (tsoInfo.LsoV1Transmit.MSS) {
 210             OVS_LOG_TRACE("l4Offset %d", layers->l4Offset);
 211             *newNbl = OvsTcpSegmentNBL(switchContext, curNbl, layers,
 212                                        tsoInfo.LsoV1Transmit.MSS, headRoom);
 213             if (*newNbl == NULL) {
 214                 OVS_LOG_ERROR("Unable to segment NBL");
 215                 return NDIS_STATUS_FAILURE;
 216             }
 217             /* Clear out LSO flags after this point */
 218             NET_BUFFER_LIST_INFO(*newNbl, TcpLargeSendNetBufferListInfo) = 0;
 219         }
 220     }
 221
 222     vportVxlan = (POVS_VXLAN_VPORT) GetOvsVportPriv(vport);
 223     ASSERT(vportVxlan);
 224
 225     /* If we didn't split the packet above, make a copy now */
 226     if (*newNbl == NULL) {
 227         *newNbl = OvsPartialCopyNBL(switchContext, curNbl, 0, headRoom,
 228                                     FALSE /*NBL info*/);
 229         if (*newNbl == NULL) {
 230             OVS_LOG_ERROR("Unable to copy NBL");
 231             return NDIS_STATUS_FAILURE;
 232         }
 233         /*
 234          * To this point we do not have VXLAN offloading.
 235          * Apply defined checksums
 236          */
 237         curNb = NET_BUFFER_LIST_FIRST_NB(*newNbl);
 238         curMdl = NET_BUFFER_CURRENT_MDL(curNb);
 239         bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl, LowPagePriority);
 240         if (!bufferStart) {
 241             status = NDIS_STATUS_RESOURCES;
 242             goto ret_error;
 243         }
 244
 245         NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO csumInfo;
 246         csumInfo.Value = NET_BUFFER_LIST_INFO(curNbl,
 247                                               TcpIpChecksumNetBufferListInfo);
 248
 249         bufferStart += NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
 250
 251         if (layers->isIPv4) {
 252             IPHdr *ip = (IPHdr *)(bufferStart + layers->l3Offset);
 253
 254             if (csumInfo.Transmit.IpHeaderChecksum) {
 255                 ip->check = 0;
 256                 ip->check = IPChecksum((UINT8 *)ip, 4 * ip->ihl, 0);
 257             }
 258
 259             if (layers->isTcp && csumInfo.Transmit.TcpChecksum) {
 260                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 261                 TCPHdr *tcp = (TCPHdr *)(bufferStart + layers->l4Offset);
 262                 tcp->check = IPPseudoChecksum(&ip->saddr, &ip->daddr,
 263                                               IPPROTO_TCP, csumLength);
 264                 tcp->check = CalculateChecksumNB(curNb, csumLength,
 265                                                  (UINT32)(layers->l4Offset));
 266             } else if (layers->isUdp && csumInfo.Transmit.UdpChecksum) {
 267                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 268                 UDPHdr *udp = (UDPHdr *)((PCHAR)ip + sizeof *ip);
 269                 udp->check = IPPseudoChecksum(&ip->saddr, &ip->daddr,
 270                                               IPPROTO_UDP, csumLength);
 271                 udp->check = CalculateChecksumNB(curNb, csumLength,
 272                                                  (UINT32)(layers->l4Offset));
 273             }
 274         } else if (layers->isIPv6) {
 275             IPv6Hdr *ip = (IPv6Hdr *)(bufferStart + layers->l3Offset);
 276
 277             if (layers->isTcp && csumInfo.Transmit.TcpChecksum) {
 278                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 279                 TCPHdr *tcp = (TCPHdr *)(bufferStart + layers->l4Offset);
 280                 tcp->check = IPv6PseudoChecksum((UINT32 *) &ip->saddr,
 281                                                 (UINT32 *) &ip->daddr,
 282                                                 IPPROTO_TCP, csumLength);
 283                 tcp->check = CalculateChecksumNB(curNb, csumLength,
 284                                                  (UINT32)(layers->l4Offset));
 285             } else if (layers->isUdp && csumInfo.Transmit.UdpChecksum) {
 286                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 287                 UDPHdr *udp = (UDPHdr *)((PCHAR)ip + sizeof *ip);
 288                 udp->check = IPv6PseudoChecksum((UINT32 *) &ip->saddr,
 289                                                 (UINT32 *) &ip->daddr,
 290                                                 IPPROTO_UDP, csumLength);
 291                 udp->check = CalculateChecksumNB(curNb, csumLength,
 292                                                  (UINT32)(layers->l4Offset));
 293             }
 294         }
 295         /* Clear out TcpIpChecksumNetBufferListInfo flag */
 296         NET_BUFFER_LIST_INFO(*newNbl, TcpIpChecksumNetBufferListInfo) = 0;
 297     }
 298
 299     curNbl = *newNbl;
 300     for (curNb = NET_BUFFER_LIST_FIRST_NB(curNbl); curNb != NULL;
 301             curNb = curNb->Next) {
 302         status = NdisRetreatNetBufferDataStart(curNb, headRoom, 0, NULL);
 303         if (status != NDIS_STATUS_SUCCESS) {
 304             goto ret_error;
 305         }
 306
 307         curMdl = NET_BUFFER_CURRENT_MDL(curNb);
 308         bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl, LowPagePriority);
 309         if (!bufferStart) {
 310             status = NDIS_STATUS_RESOURCES;
 311             goto ret_error;
 312         }
 313
 314         bufferStart += NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
 315         if (NET_BUFFER_NEXT_NB(curNb)) {
 316             OVS_LOG_TRACE("nb length %u next %u", NET_BUFFER_DATA_LENGTH(curNb),
 317                           NET_BUFFER_DATA_LENGTH(curNb->Next));
 318         }
 319
 320         /* L2 header */
 321         ethHdr = (EthHdr *)bufferStart;
 322         ASSERT(((PCHAR)&fwdInfo->dstMacAddr + sizeof fwdInfo->dstMacAddr) ==
 323                (PCHAR)&fwdInfo->srcMacAddr);
 324         NdisMoveMemory(ethHdr->Destination, fwdInfo->dstMacAddr,
 325                        sizeof ethHdr->Destination + sizeof ethHdr->Source);
 326         ethHdr->Type = htons(ETH_TYPE_IPV4);
 327
 328         /* IP header */
 329         ipHdr = (IPHdr *)((PCHAR)ethHdr + sizeof *ethHdr);
 330
 331         ipHdr->ihl = sizeof *ipHdr / 4;
 332         ipHdr->version = IPPROTO_IPV4;
 333         ipHdr->tos = tunKey->tos;
 334         ipHdr->tot_len = htons(NET_BUFFER_DATA_LENGTH(curNb) - sizeof *ethHdr);
 335         ipHdr->id = (uint16)atomic_add64(&vportVxlan->ipId,
 336                                          NET_BUFFER_DATA_LENGTH(curNb));
 337         ipHdr->frag_off = (tunKey->flags & OVS_TNL_F_DONT_FRAGMENT) ?
 338                           IP_DF_NBO : 0;
 339         ipHdr->ttl = tunKey->ttl ? tunKey->ttl : VXLAN_DEFAULT_TTL;
 340         ipHdr->protocol = IPPROTO_UDP;
 341         ASSERT(tunKey->dst == fwdInfo->dstIpAddr);
 342         ASSERT(tunKey->src == fwdInfo->srcIpAddr || tunKey->src == 0);
 343         ipHdr->saddr = fwdInfo->srcIpAddr;
 344         ipHdr->daddr = fwdInfo->dstIpAddr;
 345
 346         ipHdr->check = 0;
 347         ipHdr->check = IPChecksum((UINT8 *)ipHdr, sizeof *ipHdr, 0);
 348
 349         /* UDP header */
 350         udpHdr = (UDPHdr *)((PCHAR)ipHdr + sizeof *ipHdr);
 351         udpHdr->source = htons(tunKey->flow_hash | MAXINT16);
 352         udpHdr->dest = htons(vportVxlan->dstPort);
 353         udpHdr->len = htons(NET_BUFFER_DATA_LENGTH(curNb) - headRoom +
 354                             sizeof *udpHdr + sizeof *vxlanHdr);
 355         udpHdr->check = 0;
 356
 357         /* VXLAN header */
 358         vxlanHdr = (VXLANHdr *)((PCHAR)udpHdr + sizeof *udpHdr);
 359         vxlanHdr->flags1 = 0;
 360         vxlanHdr->locallyReplicate = 0;
 361         vxlanHdr->flags2 = 0;
 362         vxlanHdr->reserved1 = 0;
 363         if (tunKey->flags | OVS_TNL_F_KEY) {
 364             vxlanHdr->vxlanID = VXLAN_TUNNELID_TO_VNI(tunKey->tunnelId);
 365             vxlanHdr->instanceID = 1;
 366         }
 367         vxlanHdr->reserved2 = 0;
 368     }
 369     return STATUS_SUCCESS;
 370
 371 ret_error:
 372     OvsCompleteNBL(switchContext, *newNbl, TRUE);
 373     *newNbl = NULL;
 374     return status;
 375 }
 376
 377
 378 /*
 379  *----------------------------------------------------------------------------
 380  * OvsEncapVxlan --
 381  *     Encapsulates the packet if L2/L3 for destination resolves. Otherwise,
 382  *     enqueues a callback that does encapsulatation after resolution.
 383  *----------------------------------------------------------------------------
 384  */
 385 NDIS_STATUS
 386 OvsEncapVxlan(POVS_VPORT_ENTRY vport,
 387               PNET_BUFFER_LIST curNbl,
 388               OvsIPv4TunnelKey *tunKey,
 389               POVS_SWITCH_CONTEXT switchContext,
 390               POVS_PACKET_HDR_INFO layers,
 391               PNET_BUFFER_LIST *newNbl)
 392 {
 393     NTSTATUS status;
 394     OVS_FWD_INFO fwdInfo;
 395
 396     status = OvsLookupIPFwdInfo(tunKey->dst, &fwdInfo);
 397     if (status != STATUS_SUCCESS) {
 398         OvsFwdIPHelperRequest(NULL, 0, tunKey, NULL, NULL, NULL);
 399         // return NDIS_STATUS_PENDING;
 400         /*
 401          * XXX: Don't know if the completionList will make any sense when
 402          * accessed in the callback. Make sure the caveats are known.
 403          *
 404          * XXX: This code will work once we are able to grab locks in the
 405          * callback.
 406          */
 407         return NDIS_STATUS_FAILURE;
 408     }
 409
 410     return OvsDoEncapVxlan(vport, curNbl, tunKey, &fwdInfo, layers,
 411                            switchContext, newNbl);
 412 }
 413
 414 /*
 415  *----------------------------------------------------------------------------
 416  * OvsCalculateUDPChecksum
 417  *     Calculate UDP checksum
 418  *----------------------------------------------------------------------------
 419  */
 420 static __inline NDIS_STATUS
 421 OvsCalculateUDPChecksum(PNET_BUFFER_LIST curNbl,
 422                         PNET_BUFFER curNb,
 423                         IPHdr *ipHdr,
 424                         UDPHdr *udpHdr,
 425                         UINT32 packetLength)
 426 {
 427     NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO csumInfo;
 428     UINT16 checkSum;
 429
 430     csumInfo.Value = NET_BUFFER_LIST_INFO(curNbl, TcpIpChecksumNetBufferListInfo);
 431
 432     /* Next check if UDP checksum has been calculated. */
 433     if (!csumInfo.Receive.UdpChecksumSucceeded) {
 434         UINT32 l4Payload;
 435
 436         checkSum = udpHdr->check;
 437
 438         l4Payload = packetLength - sizeof(EthHdr) - ipHdr->ihl * 4;
 439         udpHdr->check = 0;
 440         udpHdr->check =
 441             IPPseudoChecksum((UINT32 *)&ipHdr->saddr,
 442                              (UINT32 *)&ipHdr->daddr,
 443                              IPPROTO_UDP, (UINT16)l4Payload);
 444         udpHdr->check = CalculateChecksumNB(curNb, (UINT16)l4Payload,
 445             sizeof(EthHdr) + ipHdr->ihl * 4);
 446         if (checkSum != udpHdr->check) {
 447             OVS_LOG_TRACE("UDP checksum incorrect.");
 448             return NDIS_STATUS_INVALID_PACKET;
 449         }
 450     }
 451
 452     csumInfo.Receive.UdpChecksumSucceeded = 1;
 453     NET_BUFFER_LIST_INFO(curNbl, TcpIpChecksumNetBufferListInfo) = csumInfo.Value;
 454     return NDIS_STATUS_SUCCESS;
 455 }
 456
 457 /*
 458  *----------------------------------------------------------------------------
 459  * OvsDecapVxlan
 460  *     Decapsulates to tunnel header in 'curNbl' and puts into 'tunKey'.
 461  *----------------------------------------------------------------------------
 462  */
 463 NDIS_STATUS
 464 OvsDecapVxlan(POVS_SWITCH_CONTEXT switchContext,
 465               PNET_BUFFER_LIST curNbl,
 466               OvsIPv4TunnelKey *tunKey,
 467               PNET_BUFFER_LIST *newNbl)
 468 {
 469     PNET_BUFFER curNb;
 470     PMDL curMdl;
 471     EthHdr *ethHdr;
 472     IPHdr *ipHdr;
 473     UDPHdr *udpHdr;
 474     VXLANHdr *vxlanHdr;
 475     UINT32 tunnelSize = 0, packetLength = 0;
 476     PUINT8 bufferStart;
 477     NDIS_STATUS status;
 478
 479     /* Check the length of the UDP payload */
 480     curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
 481     packetLength = NET_BUFFER_DATA_LENGTH(curNb);
 482     tunnelSize = OvsGetVxlanTunHdrSize();
 483     if (packetLength <= tunnelSize) {
 484         return NDIS_STATUS_INVALID_LENGTH;
 485     }
 486
 487     /*
 488      * Create a copy of the NBL so that we have all the headers in one MDL.
 489      */
 490     *newNbl = OvsPartialCopyNBL(switchContext, curNbl,
 491                                 tunnelSize + OVS_DEFAULT_COPY_SIZE, 0,
 492                                 TRUE /*copy NBL info */);
 493
 494     if (*newNbl == NULL) {
 495         return NDIS_STATUS_RESOURCES;
 496     }
 497
 498     /* XXX: Handle VLAN header. */
 499     curNbl = *newNbl;
 500     curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
 501     curMdl = NET_BUFFER_CURRENT_MDL(curNb);
 502     bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl, LowPagePriority) +
 503                   NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
 504     if (!bufferStart) {
 505         status = NDIS_STATUS_RESOURCES;
 506         goto dropNbl;
 507     }
 508
 509     ethHdr = (EthHdr *)bufferStart;
 510     /* XXX: Handle IP options. */
 511     ipHdr = (IPHdr *)((PCHAR)ethHdr + sizeof *ethHdr);
 512     tunKey->src = ipHdr->saddr;
 513     tunKey->dst = ipHdr->daddr;
 514     tunKey->tos = ipHdr->tos;
 515     tunKey->ttl = ipHdr->ttl;
 516     tunKey->pad = 0;
 517     udpHdr = (UDPHdr *)((PCHAR)ipHdr + sizeof *ipHdr);
 518
 519     /* Validate if NIC has indicated checksum failure. */
 520     status = OvsValidateUDPChecksum(curNbl, udpHdr->check == 0);
 521     if (status != NDIS_STATUS_SUCCESS) {
 522         goto dropNbl;
 523     }
 524
 525     /* Calculate and verify UDP checksum if NIC didn't do it. */
 526     if (udpHdr->check != 0) {
 527         status = OvsCalculateUDPChecksum(curNbl, curNb, ipHdr, udpHdr, packetLength);
 528         if (status != NDIS_STATUS_SUCCESS) {
 529             goto dropNbl;
 530         }
 531     }
 532
 533     vxlanHdr = (VXLANHdr *)((PCHAR)udpHdr + sizeof *udpHdr);
 534     if (vxlanHdr->instanceID) {
 535         tunKey->flags = OVS_TNL_F_KEY;
 536         tunKey->tunnelId = VXLAN_VNI_TO_TUNNELID(vxlanHdr->vxlanID);
 537     } else {
 538         tunKey->flags = 0;
 539         tunKey->tunnelId = 0;
 540     }
 541
 542     /* Clear out the receive flag for the inner packet. */
 543     NET_BUFFER_LIST_INFO(curNbl, TcpIpChecksumNetBufferListInfo) = 0;
 544     NdisAdvanceNetBufferDataStart(curNb, tunnelSize, FALSE, NULL);
 545     return NDIS_STATUS_SUCCESS;
 546
 547 dropNbl:
 548     OvsCompleteNBL(switchContext, *newNbl, TRUE);
 549     *newNbl = NULL;
 550     return status;
 551 }
 552
 553
 554 NDIS_STATUS
 555 OvsSlowPathDecapVxlan(const PNET_BUFFER_LIST packet,
 556                    OvsIPv4TunnelKey *tunnelKey)
 557 {
 558     NDIS_STATUS status = NDIS_STATUS_FAILURE;
 559     UDPHdr udpStorage;
 560     const UDPHdr *udp;
 561     VXLANHdr *VxlanHeader;
 562     VXLANHdr  VxlanHeaderBuffer;
 563     struct IPHdr ip_storage;
 564     const struct IPHdr *nh;
 565     OVS_PACKET_HDR_INFO layers;
 566
 567     layers.value = 0;
 568
 569     do {
 570         nh = OvsGetIp(packet, layers.l3Offset, &ip_storage);
 571         if (nh) {
 572             layers.l4Offset = layers.l3Offset + nh->ihl * 4;
 573         } else {
 574             break;
 575         }
 576
 577         /* make sure it's a VXLAN packet */
 578         udp = OvsGetUdp(packet, layers.l4Offset, &udpStorage);
 579         if (udp) {
 580             layers.l7Offset = layers.l4Offset + sizeof *udp;
 581         } else {
 582             break;
 583         }
 584
 585         VxlanHeader = (VXLANHdr *)OvsGetPacketBytes(packet,
 586                                                     sizeof(*VxlanHeader),
 587                                                     layers.l7Offset,
 588                                                     &VxlanHeaderBuffer);
 589
 590         if (VxlanHeader) {
 591             tunnelKey->src = nh->saddr;
 592             tunnelKey->dst = nh->daddr;
 593             tunnelKey->ttl = nh->ttl;
 594             tunnelKey->tos = nh->tos;
 595             if (VxlanHeader->instanceID) {
 596                 tunnelKey->flags = OVS_TNL_F_KEY;
 597                 tunnelKey->tunnelId = VXLAN_VNI_TO_TUNNELID(VxlanHeader->vxlanID);
 598             } else {
 599                 tunnelKey->flags = 0;
 600                 tunnelKey->tunnelId = 0;
 601             }
 602         } else {
 603             break;
 604         }
 605         status = NDIS_STATUS_SUCCESS;
 606
 607     } while(FALSE);
 608
 609     return status;
 610 }
 611
 612 #pragma warning( pop )