datapath-windows/ovsext/Gre.c

   1 /*
   2  * Copyright (c) 2015 Cloudbase Solutions Srl
   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
  19 #include "Atomic.h"
  20 #include "Checksum.h"
  21 #include "Flow.h"
  22 #include "Gre.h"
  23 #include "IpHelper.h"
  24 #include "NetProto.h"
  25 #include "PacketIO.h"
  26 #include "PacketParser.h"
  27 #include "Switch.h"
  28 #include "User.h"
  29 #include "Util.h"
  30 #include "Vport.h"
  31
  32 #ifdef OVS_DBG_MOD
  33 #undef OVS_DBG_MOD
  34 #endif
  35 #define OVS_DBG_MOD OVS_DBG_GRE
  36 #include "Debug.h"
  37
  38 static NDIS_STATUS
  39 OvsDoEncapGre(POVS_VPORT_ENTRY vport, PNET_BUFFER_LIST curNbl,
  40               const OvsIPv4TunnelKey *tunKey,
  41               const POVS_FWD_INFO fwdInfo,
  42               POVS_PACKET_HDR_INFO layers,
  43               POVS_SWITCH_CONTEXT switchContext,
  44               PNET_BUFFER_LIST *newNbl);
  45
  46 /*
  47  * --------------------------------------------------------------------------
  48  * OvsInitGreTunnel --
  49  *    Initialize GRE tunnel module.
  50  * --------------------------------------------------------------------------
  51  */
  52 NTSTATUS
  53 OvsInitGreTunnel(POVS_VPORT_ENTRY vport)
  54 {
  55     POVS_GRE_VPORT grePort;
  56
  57     grePort = (POVS_GRE_VPORT)OvsAllocateMemoryWithTag(sizeof(*grePort),
  58                                                        OVS_GRE_POOL_TAG);
  59     if (!grePort) {
  60         OVS_LOG_ERROR("Insufficient memory, can't allocate OVS_GRE_VPORT");
  61         return STATUS_INSUFFICIENT_RESOURCES;
  62     }
  63
  64     RtlZeroMemory(grePort, sizeof(*grePort));
  65     vport->priv = (PVOID)grePort;
  66     return STATUS_SUCCESS;
  67 }
  68
  69 /*
  70  * --------------------------------------------------------------------------
  71  * OvsCleanupGreTunnel --
  72  *    Cleanup GRE Tunnel module.
  73  * --------------------------------------------------------------------------
  74  */
  75 void
  76 OvsCleanupGreTunnel(POVS_VPORT_ENTRY vport)
  77 {
  78     if (vport->ovsType != OVS_VPORT_TYPE_GRE ||
  79         vport->priv == NULL) {
  80         return;
  81     }
  82
  83     OvsFreeMemoryWithTag(vport->priv, OVS_GRE_POOL_TAG);
  84     vport->priv = NULL;
  85 }
  86
  87 /*
  88  * --------------------------------------------------------------------------
  89  * OvsEncapGre --
  90  *     Encapsulates a packet with an GRE header.
  91  * --------------------------------------------------------------------------
  92  */
  93 NDIS_STATUS
  94 OvsEncapGre(POVS_VPORT_ENTRY vport,
  95             PNET_BUFFER_LIST curNbl,
  96             OvsIPv4TunnelKey *tunKey,
  97             POVS_SWITCH_CONTEXT switchContext,
  98             POVS_PACKET_HDR_INFO layers,
  99             PNET_BUFFER_LIST *newNbl)
 100 {
 101     OVS_FWD_INFO fwdInfo;
 102     NDIS_STATUS status;
 103
 104     status = OvsLookupIPFwdInfo(tunKey->dst, &fwdInfo);
 105     if (status != STATUS_SUCCESS) {
 106         OvsFwdIPHelperRequest(NULL, 0, tunKey, NULL, NULL, NULL);
 107         return NDIS_STATUS_FAILURE;
 108     }
 109
 110     status = OvsDoEncapGre(vport, curNbl, tunKey, &fwdInfo, layers,
 111                            switchContext, newNbl);
 112     return status;
 113 }
 114
 115 /*
 116  * --------------------------------------------------------------------------
 117  * OvsDoEncapGre --
 118  *    Internal utility function which actually does the GRE encap.
 119  * --------------------------------------------------------------------------
 120  */
 121 NDIS_STATUS
 122 OvsDoEncapGre(POVS_VPORT_ENTRY vport,
 123               PNET_BUFFER_LIST curNbl,
 124               const OvsIPv4TunnelKey *tunKey,
 125               const POVS_FWD_INFO fwdInfo,
 126               POVS_PACKET_HDR_INFO layers,
 127               POVS_SWITCH_CONTEXT switchContext,
 128               PNET_BUFFER_LIST *newNbl)
 129 {
 130     NDIS_STATUS status;
 131     PNET_BUFFER curNb;
 132     PMDL curMdl;
 133     PUINT8 bufferStart;
 134     EthHdr *ethHdr;
 135     IPHdr *ipHdr;
 136     PGREHdr greHdr;
 137     POVS_GRE_VPORT vportGre;
 138     UINT32 headRoom = GreTunHdrSize(tunKey->flags);
 139 #if DBG
 140     UINT32 counterHeadRoom;
 141 #endif
 142     UINT32 packetLength;
 143     ULONG mss = 0;
 144     ASSERT(*newNbl == NULL);
 145
 146     curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
 147     packetLength = NET_BUFFER_DATA_LENGTH(curNb);
 148
 149     if (layers->isTcp) {
 150         NDIS_TCP_LARGE_SEND_OFFLOAD_NET_BUFFER_LIST_INFO tsoInfo;
 151
 152         tsoInfo.Value = NET_BUFFER_LIST_INFO(curNbl,
 153                                              TcpLargeSendNetBufferListInfo);
 154         switch (tsoInfo.Transmit.Type) {
 155             case NDIS_TCP_LARGE_SEND_OFFLOAD_V1_TYPE:
 156                 mss = tsoInfo.LsoV1Transmit.MSS;
 157                 break;
 158             case NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE:
 159                 mss = tsoInfo.LsoV2Transmit.MSS;
 160                 break;
 161             default:
 162                 OVS_LOG_ERROR("Unknown LSO transmit type:%d",
 163                               tsoInfo.Transmit.Type);
 164         }
 165         OVS_LOG_TRACE("MSS %u packet len %u", mss,
 166                       packetLength);
 167         if (mss) {
 168             OVS_LOG_TRACE("l4Offset %d", layers->l4Offset);
 169             *newNbl = OvsTcpSegmentNBL(switchContext, curNbl, layers,
 170                                        mss, headRoom);
 171             if (*newNbl == NULL) {
 172                 OVS_LOG_ERROR("Unable to segment NBL");
 173                 return NDIS_STATUS_FAILURE;
 174             }
 175             /* Clear out LSO flags after this point */
 176             NET_BUFFER_LIST_INFO(*newNbl, TcpLargeSendNetBufferListInfo) = 0;
 177         }
 178     }
 179
 180     vportGre = (POVS_GRE_VPORT)GetOvsVportPriv(vport);
 181     ASSERT(vportGre);
 182
 183     /* If we didn't split the packet above, make a copy now */
 184     if (*newNbl == NULL) {
 185         *newNbl = OvsPartialCopyNBL(switchContext, curNbl, 0, headRoom,
 186                                     FALSE /*NBL info*/);
 187         if (*newNbl == NULL) {
 188             OVS_LOG_ERROR("Unable to copy NBL");
 189             return NDIS_STATUS_FAILURE;
 190         }
 191         /*
 192          * To this point we do not have GRE hardware offloading.
 193          * Apply defined checksums
 194          */
 195         curNb = NET_BUFFER_LIST_FIRST_NB(*newNbl);
 196         curMdl = NET_BUFFER_CURRENT_MDL(curNb);
 197         bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl,
 198                                                            LowPagePriority);
 199         if (!bufferStart) {
 200             status = NDIS_STATUS_RESOURCES;
 201             goto ret_error;
 202         }
 203
 204         NDIS_TCP_IP_CHECKSUM_NET_BUFFER_LIST_INFO csumInfo;
 205         csumInfo.Value = NET_BUFFER_LIST_INFO(curNbl,
 206                                               TcpIpChecksumNetBufferListInfo);
 207
 208         bufferStart += NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
 209
 210         if (layers->isIPv4) {
 211             IPHdr *ip = (IPHdr *)(bufferStart + layers->l3Offset);
 212
 213             if (csumInfo.Transmit.IpHeaderChecksum) {
 214                 ip->check = 0;
 215                 ip->check = IPChecksum((UINT8 *)ip, 4 * ip->ihl, 0);
 216             }
 217
 218             if (layers->isTcp && csumInfo.Transmit.TcpChecksum) {
 219                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 220                 TCPHdr *tcp = (TCPHdr *)(bufferStart + layers->l4Offset);
 221                 tcp->check = IPPseudoChecksum(&ip->saddr, &ip->daddr,
 222                                               IPPROTO_TCP, csumLength);
 223                 tcp->check = CalculateChecksumNB(curNb, csumLength,
 224                                                  (UINT32)(layers->l4Offset));
 225             } else if (layers->isUdp && csumInfo.Transmit.UdpChecksum) {
 226                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 227                 UDPHdr *udp = (UDPHdr *)((PCHAR)ip + sizeof *ip);
 228                 udp->check = IPPseudoChecksum(&ip->saddr, &ip->daddr,
 229                                               IPPROTO_UDP, csumLength);
 230                 udp->check = CalculateChecksumNB(curNb, csumLength,
 231                                                  (UINT32)(layers->l4Offset));
 232             }
 233         } else if (layers->isIPv6) {
 234             IPv6Hdr *ip = (IPv6Hdr *)(bufferStart + layers->l3Offset);
 235
 236             if (layers->isTcp && csumInfo.Transmit.TcpChecksum) {
 237                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 238                 TCPHdr *tcp = (TCPHdr *)(bufferStart + layers->l4Offset);
 239                 tcp->check = IPv6PseudoChecksum((UINT32 *) &ip->saddr,
 240                                                 (UINT32 *) &ip->daddr,
 241                                                 IPPROTO_TCP, csumLength);
 242                 tcp->check = CalculateChecksumNB(curNb, csumLength,
 243                                                  (UINT32)(layers->l4Offset));
 244             } else if (layers->isUdp && csumInfo.Transmit.UdpChecksum) {
 245                 UINT16 csumLength = (UINT16)(packetLength - layers->l4Offset);
 246                 UDPHdr *udp = (UDPHdr *)((PCHAR)ip + sizeof *ip);
 247                 udp->check = IPv6PseudoChecksum((UINT32 *) &ip->saddr,
 248                                                 (UINT32 *) &ip->daddr,
 249                                                 IPPROTO_UDP, csumLength);
 250                 udp->check = CalculateChecksumNB(curNb, csumLength,
 251                                                  (UINT32)(layers->l4Offset));
 252             }
 253         }
 254         /* Clear out TcpIpChecksumNetBufferListInfo flag */
 255         NET_BUFFER_LIST_INFO(*newNbl, TcpIpChecksumNetBufferListInfo) = 0;
 256     }
 257
 258     curNbl = *newNbl;
 259     for (curNb = NET_BUFFER_LIST_FIRST_NB(curNbl); curNb != NULL;
 260          curNb = curNb->Next) {
 261 #if DBG
 262         counterHeadRoom = headRoom;
 263 #endif
 264         status = NdisRetreatNetBufferDataStart(curNb, headRoom, 0, NULL);
 265         if (status != NDIS_STATUS_SUCCESS) {
 266             goto ret_error;
 267         }
 268
 269         curMdl = NET_BUFFER_CURRENT_MDL(curNb);
 270         bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl,
 271                                                            LowPagePriority);
 272         if (!bufferStart) {
 273             status = NDIS_STATUS_RESOURCES;
 274             goto ret_error;
 275         }
 276
 277         bufferStart += NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
 278         if (NET_BUFFER_NEXT_NB(curNb)) {
 279             OVS_LOG_TRACE("nb length %u next %u",
 280                           NET_BUFFER_DATA_LENGTH(curNb),
 281                           NET_BUFFER_DATA_LENGTH(curNb->Next));
 282         }
 283
 284         /* L2 header */
 285         ethHdr = (EthHdr *)bufferStart;
 286         ASSERT(((PCHAR)&fwdInfo->dstMacAddr + sizeof fwdInfo->dstMacAddr) ==
 287                (PCHAR)&fwdInfo->srcMacAddr);
 288         NdisMoveMemory(ethHdr->Destination, fwdInfo->dstMacAddr,
 289                        sizeof ethHdr->Destination + sizeof ethHdr->Source);
 290         ethHdr->Type = htons(ETH_TYPE_IPV4);
 291 #if DBG
 292         counterHeadRoom -= sizeof *ethHdr;
 293 #endif
 294
 295         /* IP header */
 296         ipHdr = (IPHdr *)((PCHAR)ethHdr + sizeof *ethHdr);
 297
 298         ipHdr->ihl = sizeof *ipHdr / 4;
 299         ipHdr->version = IPPROTO_IPV4;
 300         ipHdr->tos = tunKey->tos;
 301         ipHdr->tot_len = htons(NET_BUFFER_DATA_LENGTH(curNb) - sizeof *ethHdr);
 302         ipHdr->id = (uint16)atomic_add64(&vportGre->ipId,
 303                                          NET_BUFFER_DATA_LENGTH(curNb));
 304         ipHdr->frag_off = (tunKey->flags & OVS_TNL_F_DONT_FRAGMENT) ?
 305                           IP_DF_NBO : 0;
 306         ipHdr->ttl = tunKey->ttl ? tunKey->ttl : 64;
 307         ipHdr->protocol = IPPROTO_GRE;
 308         ASSERT(tunKey->dst == fwdInfo->dstIpAddr);
 309         ASSERT(tunKey->src == fwdInfo->srcIpAddr || tunKey->src == 0);
 310         ipHdr->saddr = fwdInfo->srcIpAddr;
 311         ipHdr->daddr = fwdInfo->dstIpAddr;
 312
 313         ipHdr->check = 0;
 314         ipHdr->check = IPChecksum((UINT8 *)ipHdr, sizeof *ipHdr, 0);
 315 #if DBG
 316         counterHeadRoom -= sizeof *ipHdr;
 317 #endif
 318
 319         /* GRE header */
 320         greHdr = (GREHdr *)((PCHAR)ipHdr + sizeof *ipHdr);
 321         greHdr->flags = OvsTunnelFlagsToGreFlags(tunKey->flags);
 322         greHdr->protocolType = GRE_NET_TEB;
 323 #if DBG
 324         counterHeadRoom -= sizeof *greHdr;
 325 #endif
 326
 327         PCHAR currentOffset = (PCHAR)greHdr + sizeof *greHdr;
 328
 329         if (tunKey->flags & OVS_TNL_F_CSUM) {
 330             RtlZeroMemory(currentOffset, 4);
 331             currentOffset += 4;
 332 #if DBG
 333             counterHeadRoom -= 4;
 334 #endif
 335         }
 336
 337         if (tunKey->flags & OVS_TNL_F_KEY) {
 338             RtlZeroMemory(currentOffset, 4);
 339             UINT32 key = (tunKey->tunnelId >> 32);
 340             RtlCopyMemory(currentOffset, &key, sizeof key);
 341             currentOffset += 4;
 342 #if DBG
 343             counterHeadRoom -= 4;
 344 #endif
 345         }
 346
 347 #if DBG
 348         ASSERT(counterHeadRoom == 0);
 349 #endif
 350
 351     }
 352     return STATUS_SUCCESS;
 353
 354 ret_error:
 355     OvsCompleteNBL(switchContext, *newNbl, TRUE);
 356     *newNbl = NULL;
 357     return status;
 358 }
 359
 360 NDIS_STATUS
 361 OvsDecapGre(POVS_SWITCH_CONTEXT switchContext,
 362             PNET_BUFFER_LIST curNbl,
 363             OvsIPv4TunnelKey *tunKey,
 364             PNET_BUFFER_LIST *newNbl)
 365 {
 366     PNET_BUFFER curNb;
 367     PMDL curMdl;
 368     EthHdr *ethHdr;
 369     IPHdr *ipHdr;
 370     GREHdr *greHdr;
 371     UINT32 tunnelSize = 0, packetLength = 0;
 372     UINT32 headRoom = 0;
 373     PUINT8 bufferStart;
 374     NDIS_STATUS status;
 375
 376     curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
 377     packetLength = NET_BUFFER_DATA_LENGTH(curNb);
 378     tunnelSize = GreTunHdrSize(tunKey->flags);
 379     if (packetLength <= tunnelSize) {
 380         return NDIS_STATUS_INVALID_LENGTH;
 381     }
 382
 383     /*
 384      * Create a copy of the NBL so that we have all the headers in one MDL.
 385      */
 386     *newNbl = OvsPartialCopyNBL(switchContext, curNbl,
 387                                 tunnelSize + OVS_DEFAULT_COPY_SIZE, 0,
 388                                 TRUE /*copy NBL info */);
 389
 390     if (*newNbl == NULL) {
 391         return NDIS_STATUS_RESOURCES;
 392     }
 393
 394     curNbl = *newNbl;
 395     curNb = NET_BUFFER_LIST_FIRST_NB(curNbl);
 396     curMdl = NET_BUFFER_CURRENT_MDL(curNb);
 397     bufferStart = (PUINT8)MmGetSystemAddressForMdlSafe(curMdl, LowPagePriority) +
 398                   NET_BUFFER_CURRENT_MDL_OFFSET(curNb);
 399     if (!bufferStart) {
 400         status = NDIS_STATUS_RESOURCES;
 401         goto dropNbl;
 402     }
 403
 404     ethHdr = (EthHdr *)bufferStart;
 405     headRoom += sizeof *ethHdr;
 406
 407     ipHdr = (IPHdr *)((PCHAR)ethHdr + sizeof *ethHdr);
 408     tunKey->src = ipHdr->saddr;
 409     tunKey->dst = ipHdr->daddr;
 410     tunKey->tos = ipHdr->tos;
 411     tunKey->ttl = ipHdr->ttl;
 412     tunKey->pad = 0;
 413     headRoom += sizeof *ipHdr;
 414
 415     greHdr = (GREHdr *)((PCHAR)ipHdr + sizeof *ipHdr);
 416     headRoom += sizeof *greHdr;
 417
 418     /* Validate if GRE header protocol type. */
 419     if (greHdr->protocolType != GRE_NET_TEB) {
 420         status = STATUS_NDIS_INVALID_PACKET;
 421         goto dropNbl;
 422     }
 423
 424     PCHAR currentOffset = (PCHAR)greHdr + sizeof *greHdr;
 425
 426     if (greHdr->flags & GRE_CSUM) {
 427         tunKey->flags |= OVS_TNL_F_CSUM;
 428         currentOffset += 4;
 429         headRoom += 4;
 430     }
 431
 432     if (greHdr->flags & GRE_KEY) {
 433         tunKey->flags |= OVS_TNL_F_KEY;
 434         UINT32 key = 0;
 435         RtlCopyMemory(&key, currentOffset, 4);
 436         tunKey->tunnelId = (UINT64)key << 32;
 437         currentOffset += 4;
 438         headRoom += 4;
 439     }
 440
 441     /* Clear out the receive flag for the inner packet. */
 442     NET_BUFFER_LIST_INFO(curNbl, TcpIpChecksumNetBufferListInfo) = 0;
 443     NdisAdvanceNetBufferDataStart(curNb, GreTunHdrSize(tunKey->flags), FALSE,
 444                                   NULL);
 445     ASSERT(headRoom == GreTunHdrSize(tunKey->flags));
 446     return NDIS_STATUS_SUCCESS;
 447
 448 dropNbl:
 449     OvsCompleteNBL(switchContext, *newNbl, TRUE);
 450     *newNbl = NULL;
 451     return status;
 452 }