X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=NetworkPkg%2FLibrary%2FDxeNetLib%2FNetBuffer.c;fp=NetworkPkg%2FLibrary%2FDxeNetLib%2FNetBuffer.c;h=2408e9a10456e97d1427bcad71f938769e017c49;hp=0000000000000000000000000000000000000000;hb=4542f8b8135f1f1ee5654e25139be9769e139ddd;hpb=c0fd7f734e2d33e22215899b40a47b843129541d diff --git a/NetworkPkg/Library/DxeNetLib/NetBuffer.c b/NetworkPkg/Library/DxeNetLib/NetBuffer.c new file mode 100644 index 0000000000..2408e9a104 --- /dev/null +++ b/NetworkPkg/Library/DxeNetLib/NetBuffer.c @@ -0,0 +1,1890 @@ +/** @file + Network library functions providing net buffer operation support. + +Copyright (c) 2005 - 2018, Intel Corporation. All rights reserved.
+SPDX-License-Identifier: BSD-2-Clause-Patent +**/ + +#include + +#include +#include +#include +#include +#include +#include + + +/** + Allocate and build up the sketch for a NET_BUF. + + The net buffer allocated has the BlockOpNum's NET_BLOCK_OP, and its associated + NET_VECTOR has the BlockNum's NET_BLOCK. But all the NET_BLOCK_OP and + NET_BLOCK remain un-initialized. + + @param[in] BlockNum The number of NET_BLOCK in the vector of net buffer + @param[in] BlockOpNum The number of NET_BLOCK_OP in the net buffer + + @return Pointer to the allocated NET_BUF, or NULL if the + allocation failed due to resource limit. + +**/ +NET_BUF * +NetbufAllocStruct ( + IN UINT32 BlockNum, + IN UINT32 BlockOpNum + ) +{ + NET_BUF *Nbuf; + NET_VECTOR *Vector; + + ASSERT (BlockOpNum >= 1); + + // + // Allocate three memory blocks. + // + Nbuf = AllocateZeroPool (NET_BUF_SIZE (BlockOpNum)); + + if (Nbuf == NULL) { + return NULL; + } + + Nbuf->Signature = NET_BUF_SIGNATURE; + Nbuf->RefCnt = 1; + Nbuf->BlockOpNum = BlockOpNum; + InitializeListHead (&Nbuf->List); + + if (BlockNum != 0) { + Vector = AllocateZeroPool (NET_VECTOR_SIZE (BlockNum)); + + if (Vector == NULL) { + goto FreeNbuf; + } + + Vector->Signature = NET_VECTOR_SIGNATURE; + Vector->RefCnt = 1; + Vector->BlockNum = BlockNum; + Nbuf->Vector = Vector; + } + + return Nbuf; + +FreeNbuf: + + FreePool (Nbuf); + return NULL; +} + + +/** + Allocate a single block NET_BUF. Upon allocation, all the + free space is in the tail room. + + @param[in] Len The length of the block. + + @return Pointer to the allocated NET_BUF, or NULL if the + allocation failed due to resource limit. + +**/ +NET_BUF * +EFIAPI +NetbufAlloc ( + IN UINT32 Len + ) +{ + NET_BUF *Nbuf; + NET_VECTOR *Vector; + UINT8 *Bulk; + + ASSERT (Len > 0); + + Nbuf = NetbufAllocStruct (1, 1); + + if (Nbuf == NULL) { + return NULL; + } + + Bulk = AllocatePool (Len); + + if (Bulk == NULL) { + goto FreeNBuf; + } + + Vector = Nbuf->Vector; + Vector->Len = Len; + + Vector->Block[0].Bulk = Bulk; + Vector->Block[0].Len = Len; + + Nbuf->BlockOp[0].BlockHead = Bulk; + Nbuf->BlockOp[0].BlockTail = Bulk + Len; + + Nbuf->BlockOp[0].Head = Bulk; + Nbuf->BlockOp[0].Tail = Bulk; + Nbuf->BlockOp[0].Size = 0; + + return Nbuf; + +FreeNBuf: + FreePool (Nbuf); + return NULL; +} + +/** + Free the net vector. + + Decrease the reference count of the net vector by one. The real resource free + operation isn't performed until the reference count of the net vector is + decreased to 0. + + @param[in] Vector Pointer to the NET_VECTOR to be freed. + +**/ +VOID +NetbufFreeVector ( + IN NET_VECTOR *Vector + ) +{ + UINT32 Index; + + ASSERT (Vector != NULL); + NET_CHECK_SIGNATURE (Vector, NET_VECTOR_SIGNATURE); + ASSERT (Vector->RefCnt > 0); + + Vector->RefCnt--; + + if (Vector->RefCnt > 0) { + return; + } + + if (Vector->Free != NULL) { + // + // Call external free function to free the vector if it + // isn't NULL. If NET_VECTOR_OWN_FIRST is set, release the + // first block since it is allocated by us + // + if ((Vector->Flag & NET_VECTOR_OWN_FIRST) != 0) { + gBS->FreePool (Vector->Block[0].Bulk); + } + + Vector->Free (Vector->Arg); + + } else { + // + // Free each memory block associated with the Vector + // + for (Index = 0; Index < Vector->BlockNum; Index++) { + gBS->FreePool (Vector->Block[Index].Bulk); + } + } + + FreePool (Vector); +} + + +/** + Free the net buffer and its associated NET_VECTOR. + + Decrease the reference count of the net buffer by one. Free the associated net + vector and itself if the reference count of the net buffer is decreased to 0. + The net vector free operation just decrease the reference count of the net + vector by one and do the real resource free operation when the reference count + of the net vector is 0. + + @param[in] Nbuf Pointer to the NET_BUF to be freed. + +**/ +VOID +EFIAPI +NetbufFree ( + IN NET_BUF *Nbuf + ) +{ + ASSERT (Nbuf != NULL); + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + ASSERT (Nbuf->RefCnt > 0); + + Nbuf->RefCnt--; + + if (Nbuf->RefCnt == 0) { + // + // Update Vector only when NBuf is to be released. That is, + // all the sharing of Nbuf increse Vector's RefCnt by one + // + NetbufFreeVector (Nbuf->Vector); + FreePool (Nbuf); + } +} + + +/** + Create a copy of the net buffer that shares the associated net vector. + + The reference count of the newly created net buffer is set to 1. The reference + count of the associated net vector is increased by one. + + @param[in] Nbuf Pointer to the net buffer to be cloned. + + @return Pointer to the cloned net buffer, or NULL if the + allocation failed due to resource limit. + +**/ +NET_BUF * +EFIAPI +NetbufClone ( + IN NET_BUF *Nbuf + ) +{ + NET_BUF *Clone; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + Clone = AllocatePool (NET_BUF_SIZE (Nbuf->BlockOpNum)); + + if (Clone == NULL) { + return NULL; + } + + Clone->Signature = NET_BUF_SIGNATURE; + Clone->RefCnt = 1; + InitializeListHead (&Clone->List); + + Clone->Ip = Nbuf->Ip; + Clone->Tcp = Nbuf->Tcp; + + CopyMem (Clone->ProtoData, Nbuf->ProtoData, NET_PROTO_DATA); + + NET_GET_REF (Nbuf->Vector); + + Clone->Vector = Nbuf->Vector; + Clone->BlockOpNum = Nbuf->BlockOpNum; + Clone->TotalSize = Nbuf->TotalSize; + CopyMem (Clone->BlockOp, Nbuf->BlockOp, sizeof (NET_BLOCK_OP) * Nbuf->BlockOpNum); + + return Clone; +} + + +/** + Create a duplicated copy of the net buffer with data copied and HeadSpace + bytes of head space reserved. + + The duplicated net buffer will allocate its own memory to hold the data of the + source net buffer. + + @param[in] Nbuf Pointer to the net buffer to be duplicated from. + @param[in, out] Duplicate Pointer to the net buffer to duplicate to, if + NULL a new net buffer is allocated. + @param[in] HeadSpace Length of the head space to reserve. + + @return Pointer to the duplicated net buffer, or NULL if + the allocation failed due to resource limit. + +**/ +NET_BUF * +EFIAPI +NetbufDuplicate ( + IN NET_BUF *Nbuf, + IN OUT NET_BUF *Duplicate OPTIONAL, + IN UINT32 HeadSpace + ) +{ + UINT8 *Dst; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + if (Duplicate == NULL) { + Duplicate = NetbufAlloc (Nbuf->TotalSize + HeadSpace); + } + + if (Duplicate == NULL) { + return NULL; + } + + // + // Don't set the IP and TCP head point, since it is most + // like that they are pointing to the memory of Nbuf. + // + CopyMem (Duplicate->ProtoData, Nbuf->ProtoData, NET_PROTO_DATA); + NetbufReserve (Duplicate, HeadSpace); + + Dst = NetbufAllocSpace (Duplicate, Nbuf->TotalSize, NET_BUF_TAIL); + NetbufCopy (Nbuf, 0, Nbuf->TotalSize, Dst); + + return Duplicate; +} + + +/** + Free a list of net buffers. + + @param[in, out] Head Pointer to the head of linked net buffers. + +**/ +VOID +EFIAPI +NetbufFreeList ( + IN OUT LIST_ENTRY *Head + ) +{ + LIST_ENTRY *Entry; + LIST_ENTRY *Next; + NET_BUF *Nbuf; + + Entry = Head->ForwardLink; + + NET_LIST_FOR_EACH_SAFE (Entry, Next, Head) { + Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List); + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + RemoveEntryList (Entry); + NetbufFree (Nbuf); + } + + ASSERT (IsListEmpty (Head)); +} + + +/** + Get the index of NET_BLOCK_OP that contains the byte at Offset in the net + buffer. + + This can be used to, for example, retrieve the IP header in the packet. It + also can be used to get the fragment that contains the byte which is used + mainly by the library implementation itself. + + @param[in] Nbuf Pointer to the net buffer. + @param[in] Offset The offset of the byte. + @param[out] Index Index of the NET_BLOCK_OP that contains the byte at + Offset. + + @return Pointer to the Offset'th byte of data in the net buffer, or NULL + if there is no such data in the net buffer. + +**/ +UINT8 * +EFIAPI +NetbufGetByte ( + IN NET_BUF *Nbuf, + IN UINT32 Offset, + OUT UINT32 *Index OPTIONAL + ) +{ + NET_BLOCK_OP *BlockOp; + UINT32 Loop; + UINT32 Len; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + if (Offset >= Nbuf->TotalSize) { + return NULL; + } + + BlockOp = Nbuf->BlockOp; + Len = 0; + + for (Loop = 0; Loop < Nbuf->BlockOpNum; Loop++) { + + if (Len + BlockOp[Loop].Size <= Offset) { + Len += BlockOp[Loop].Size; + continue; + } + + if (Index != NULL) { + *Index = Loop; + } + + return BlockOp[Loop].Head + (Offset - Len); + } + + return NULL; +} + + + +/** + Set the NET_BLOCK and corresponding NET_BLOCK_OP in the net buffer and + corresponding net vector according to the bulk pointer and bulk length. + + All the pointers in the Index'th NET_BLOCK and NET_BLOCK_OP are set to the + bulk's head and tail respectively. So, this function alone can't be used by + NetbufAlloc. + + @param[in, out] Nbuf Pointer to the net buffer. + @param[in] Bulk Pointer to the data. + @param[in] Len Length of the bulk data. + @param[in] Index The data block index in the net buffer the bulk + data should belong to. + +**/ +VOID +NetbufSetBlock ( + IN OUT NET_BUF *Nbuf, + IN UINT8 *Bulk, + IN UINT32 Len, + IN UINT32 Index + ) +{ + NET_BLOCK_OP *BlockOp; + NET_BLOCK *Block; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + NET_CHECK_SIGNATURE (Nbuf->Vector, NET_VECTOR_SIGNATURE); + ASSERT (Index < Nbuf->BlockOpNum); + + Block = &(Nbuf->Vector->Block[Index]); + BlockOp = &(Nbuf->BlockOp[Index]); + Block->Len = Len; + Block->Bulk = Bulk; + BlockOp->BlockHead = Bulk; + BlockOp->BlockTail = Bulk + Len; + BlockOp->Head = Bulk; + BlockOp->Tail = Bulk + Len; + BlockOp->Size = Len; +} + + + +/** + Set the NET_BLOCK_OP in the net buffer. The corresponding NET_BLOCK + structure is left untouched. + + Some times, there is no 1:1 relationship between NET_BLOCK and NET_BLOCK_OP. + For example, that in NetbufGetFragment. + + @param[in, out] Nbuf Pointer to the net buffer. + @param[in] Bulk Pointer to the data. + @param[in] Len Length of the bulk data. + @param[in] Index The data block index in the net buffer the bulk + data should belong to. + +**/ +VOID +NetbufSetBlockOp ( + IN OUT NET_BUF *Nbuf, + IN UINT8 *Bulk, + IN UINT32 Len, + IN UINT32 Index + ) +{ + NET_BLOCK_OP *BlockOp; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + ASSERT (Index < Nbuf->BlockOpNum); + + BlockOp = &(Nbuf->BlockOp[Index]); + BlockOp->BlockHead = Bulk; + BlockOp->BlockTail = Bulk + Len; + BlockOp->Head = Bulk; + BlockOp->Tail = Bulk + Len; + BlockOp->Size = Len; +} + + +/** + Helper function for NetbufGetFragment. NetbufGetFragment may allocate the + first block to reserve HeadSpace bytes header space. So it needs to create a + new net vector for the first block and can avoid copy for the remaining data + by sharing the old net vector. + + @param[in] Arg Point to the old NET_VECTOR. + +**/ +VOID +EFIAPI +NetbufGetFragmentFree ( + IN VOID *Arg + ) +{ + NET_VECTOR *Vector; + + Vector = (NET_VECTOR *)Arg; + NetbufFreeVector (Vector); +} + + +/** + Create a NET_BUF structure which contains Len byte data of Nbuf starting from + Offset. + + A new NET_BUF structure will be created but the associated data in NET_VECTOR + is shared. This function exists to do IP packet fragmentation. + + @param[in] Nbuf Pointer to the net buffer to be extracted. + @param[in] Offset Starting point of the data to be included in the new + net buffer. + @param[in] Len Bytes of data to be included in the new net buffer. + @param[in] HeadSpace Bytes of head space to reserve for protocol header. + + @return Pointer to the cloned net buffer, or NULL if the + allocation failed due to resource limit. + +**/ +NET_BUF * +EFIAPI +NetbufGetFragment ( + IN NET_BUF *Nbuf, + IN UINT32 Offset, + IN UINT32 Len, + IN UINT32 HeadSpace + ) +{ + NET_BUF *Child; + NET_VECTOR *Vector; + NET_BLOCK_OP *BlockOp; + UINT32 CurBlockOp; + UINT32 BlockOpNum; + UINT8 *FirstBulk; + UINT32 Index; + UINT32 First; + UINT32 Last; + UINT32 FirstSkip; + UINT32 FirstLen; + UINT32 LastLen; + UINT32 Cur; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + if ((Len == 0) || (Offset + Len > Nbuf->TotalSize)) { + return NULL; + } + + // + // First find the first and last BlockOp that contains + // the valid data, and compute the offset of the first + // BlockOp and length of the last BlockOp + // + BlockOp = Nbuf->BlockOp; + Cur = 0; + + for (Index = 0; Index < Nbuf->BlockOpNum; Index++) { + if (Offset < Cur + BlockOp[Index].Size) { + break; + } + + Cur += BlockOp[Index].Size; + } + + // + // First is the index of the first BlockOp, FirstSkip is + // the offset of the first byte in the first BlockOp. + // + First = Index; + FirstSkip = Offset - Cur; + FirstLen = BlockOp[Index].Size - FirstSkip; + + Last = 0; + LastLen = 0; + + if (Len > FirstLen) { + Cur += BlockOp[Index].Size; + Index++; + + for (; Index < Nbuf->BlockOpNum; Index++) { + if (Offset + Len <= Cur + BlockOp[Index].Size) { + Last = Index; + LastLen = Offset + Len - Cur; + break; + } + + Cur += BlockOp[Index].Size; + } + + } else { + Last = First; + LastLen = Len; + FirstLen = Len; + } + + ASSERT (Last >= First); + BlockOpNum = Last - First + 1; + CurBlockOp = 0; + + if (HeadSpace != 0) { + // + // Allocate an extra block to accomdate the head space. + // + BlockOpNum++; + + Child = NetbufAllocStruct (1, BlockOpNum); + + if (Child == NULL) { + return NULL; + } + + FirstBulk = AllocatePool (HeadSpace); + + if (FirstBulk == NULL) { + goto FreeChild; + } + + Vector = Child->Vector; + Vector->Free = NetbufGetFragmentFree; + Vector->Arg = Nbuf->Vector; + Vector->Flag = NET_VECTOR_OWN_FIRST; + Vector->Len = HeadSpace; + + // + // Reserve the head space in the first block + // + NetbufSetBlock (Child, FirstBulk, HeadSpace, 0); + Child->BlockOp[0].Head += HeadSpace; + Child->BlockOp[0].Size = 0; + CurBlockOp++; + + } else { + Child = NetbufAllocStruct (0, BlockOpNum); + + if (Child == NULL) { + return NULL; + } + + Child->Vector = Nbuf->Vector; + } + + NET_GET_REF (Nbuf->Vector); + Child->TotalSize = Len; + + // + // Set all the BlockOp up, the first and last one are special + // and need special process. + // + NetbufSetBlockOp ( + Child, + Nbuf->BlockOp[First].Head + FirstSkip, + FirstLen, + CurBlockOp++ + ); + + for (Index = First + 1; Index < Last; Index++) { + NetbufSetBlockOp ( + Child, + BlockOp[Index].Head, + BlockOp[Index].Size, + CurBlockOp++ + ); + } + + if (First != Last) { + NetbufSetBlockOp ( + Child, + BlockOp[Last].Head, + LastLen, + CurBlockOp + ); + } + + CopyMem (Child->ProtoData, Nbuf->ProtoData, NET_PROTO_DATA); + return Child; + +FreeChild: + + FreePool (Child); + return NULL; +} + + + +/** + Build a NET_BUF from external blocks. + + A new NET_BUF structure will be created from external blocks. Additional block + of memory will be allocated to hold reserved HeadSpace bytes of header room + and existing HeadLen bytes of header but the external blocks are shared by the + net buffer to avoid data copying. + + @param[in] ExtFragment Pointer to the data block. + @param[in] ExtNum The number of the data blocks. + @param[in] HeadSpace The head space to be reserved. + @param[in] HeadLen The length of the protocol header, This function + will pull that number of data into a linear block. + @param[in] ExtFree Pointer to the caller provided free function. + @param[in] Arg The argument passed to ExtFree when ExtFree is + called. + + @return Pointer to the net buffer built from the data blocks, + or NULL if the allocation failed due to resource + limit. + +**/ +NET_BUF * +EFIAPI +NetbufFromExt ( + IN NET_FRAGMENT *ExtFragment, + IN UINT32 ExtNum, + IN UINT32 HeadSpace, + IN UINT32 HeadLen, + IN NET_VECTOR_EXT_FREE ExtFree, + IN VOID *Arg OPTIONAL + ) +{ + NET_BUF *Nbuf; + NET_VECTOR *Vector; + NET_FRAGMENT SavedFragment; + UINT32 SavedIndex; + UINT32 TotalLen; + UINT32 BlockNum; + UINT8 *FirstBlock; + UINT32 FirstBlockLen; + UINT8 *Header; + UINT32 CurBlock; + UINT32 Index; + UINT32 Len; + UINT32 Copied; + + ASSERT ((ExtFragment != NULL) && (ExtNum > 0) && (ExtFree != NULL)); + + SavedFragment.Bulk = NULL; + SavedFragment.Len = 0; + + FirstBlockLen = 0; + FirstBlock = NULL; + BlockNum = ExtNum; + Index = 0; + TotalLen = 0; + SavedIndex = 0; + Len = 0; + Copied = 0; + + // + // No need to consolidate the header if the first block is + // longer than the header length or there is only one block. + // + if ((ExtFragment[0].Len >= HeadLen) || (ExtNum == 1)) { + HeadLen = 0; + } + + // + // Allocate an extra block if we need to: + // 1. Allocate some header space + // 2. aggreate the packet header + // + if ((HeadSpace != 0) || (HeadLen != 0)) { + FirstBlockLen = HeadLen + HeadSpace; + FirstBlock = AllocatePool (FirstBlockLen); + + if (FirstBlock == NULL) { + return NULL; + } + + BlockNum++; + } + + // + // Copy the header to the first block, reduce the NET_BLOCK + // to allocate by one for each block that is completely covered + // by the first bulk. + // + if (HeadLen != 0) { + Len = HeadLen; + Header = FirstBlock + HeadSpace; + + for (Index = 0; Index < ExtNum; Index++) { + if (Len >= ExtFragment[Index].Len) { + CopyMem (Header, ExtFragment[Index].Bulk, ExtFragment[Index].Len); + + Copied += ExtFragment[Index].Len; + Len -= ExtFragment[Index].Len; + Header += ExtFragment[Index].Len; + TotalLen += ExtFragment[Index].Len; + BlockNum--; + + if (Len == 0) { + // + // Increament the index number to point to the next + // non-empty fragment. + // + Index++; + break; + } + + } else { + CopyMem (Header, ExtFragment[Index].Bulk, Len); + + Copied += Len; + TotalLen += Len; + + // + // Adjust the block structure to exclude the data copied, + // So, the left-over block can be processed as other blocks. + // But it must be recovered later. (SavedIndex > 0) always + // holds since we don't aggreate the header if the first block + // is bigger enough that the header is continuous + // + SavedIndex = Index; + SavedFragment = ExtFragment[Index]; + ExtFragment[Index].Bulk += Len; + ExtFragment[Index].Len -= Len; + break; + } + } + } + + Nbuf = NetbufAllocStruct (BlockNum, BlockNum); + + if (Nbuf == NULL) { + goto FreeFirstBlock; + } + + Vector = Nbuf->Vector; + Vector->Free = ExtFree; + Vector->Arg = Arg; + Vector->Flag = ((FirstBlockLen != 0) ? NET_VECTOR_OWN_FIRST : 0); + + // + // Set the first block up which may contain + // some head space and aggregated header + // + CurBlock = 0; + + if (FirstBlockLen != 0) { + NetbufSetBlock (Nbuf, FirstBlock, HeadSpace + Copied, 0); + Nbuf->BlockOp[0].Head += HeadSpace; + Nbuf->BlockOp[0].Size = Copied; + + CurBlock++; + } + + for (; Index < ExtNum; Index++) { + NetbufSetBlock (Nbuf, ExtFragment[Index].Bulk, ExtFragment[Index].Len, CurBlock); + TotalLen += ExtFragment[Index].Len; + CurBlock++; + } + + Vector->Len = TotalLen + HeadSpace; + Nbuf->TotalSize = TotalLen; + + if (SavedIndex != 0) { + ExtFragment[SavedIndex] = SavedFragment; + } + + return Nbuf; + +FreeFirstBlock: + if (FirstBlock != NULL) { + FreePool (FirstBlock); + } + return NULL; +} + + +/** + Build a fragment table to contain the fragments in the net buffer. This is the + opposite operation of the NetbufFromExt. + + @param[in] Nbuf Point to the net buffer. + @param[in, out] ExtFragment Pointer to the data block. + @param[in, out] ExtNum The number of the data blocks. + + @retval EFI_BUFFER_TOO_SMALL The number of non-empty block is bigger than + ExtNum. + @retval EFI_SUCCESS Fragment table is built successfully. + +**/ +EFI_STATUS +EFIAPI +NetbufBuildExt ( + IN NET_BUF *Nbuf, + IN OUT NET_FRAGMENT *ExtFragment, + IN OUT UINT32 *ExtNum + ) +{ + UINT32 Index; + UINT32 Current; + + Current = 0; + + for (Index = 0; (Index < Nbuf->BlockOpNum); Index++) { + if (Nbuf->BlockOp[Index].Size == 0) { + continue; + } + + if (Current < *ExtNum) { + ExtFragment[Current].Bulk = Nbuf->BlockOp[Index].Head; + ExtFragment[Current].Len = Nbuf->BlockOp[Index].Size; + Current++; + } else { + return EFI_BUFFER_TOO_SMALL; + } + } + + *ExtNum = Current; + return EFI_SUCCESS; +} + + +/** + Build a net buffer from a list of net buffers. + + All the fragments will be collected from the list of NEW_BUF and then a new + net buffer will be created through NetbufFromExt. + + @param[in] BufList A List of the net buffer. + @param[in] HeadSpace The head space to be reserved. + @param[in] HeaderLen The length of the protocol header, This function + will pull that number of data into a linear block. + @param[in] ExtFree Pointer to the caller provided free function. + @param[in] Arg The argument passed to ExtFree when ExtFree is called. + + @return Pointer to the net buffer built from the list of net + buffers. + +**/ +NET_BUF * +EFIAPI +NetbufFromBufList ( + IN LIST_ENTRY *BufList, + IN UINT32 HeadSpace, + IN UINT32 HeaderLen, + IN NET_VECTOR_EXT_FREE ExtFree, + IN VOID *Arg OPTIONAL + ) +{ + NET_FRAGMENT *Fragment; + UINT32 FragmentNum; + LIST_ENTRY *Entry; + NET_BUF *Nbuf; + UINT32 Index; + UINT32 Current; + + // + //Compute how many blocks are there + // + FragmentNum = 0; + + NET_LIST_FOR_EACH (Entry, BufList) { + Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List); + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + FragmentNum += Nbuf->BlockOpNum; + } + + // + //Allocate and copy block points + // + Fragment = AllocatePool (sizeof (NET_FRAGMENT) * FragmentNum); + + if (Fragment == NULL) { + return NULL; + } + + Current = 0; + + NET_LIST_FOR_EACH (Entry, BufList) { + Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List); + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + for (Index = 0; Index < Nbuf->BlockOpNum; Index++) { + if (Nbuf->BlockOp[Index].Size != 0) { + Fragment[Current].Bulk = Nbuf->BlockOp[Index].Head; + Fragment[Current].Len = Nbuf->BlockOp[Index].Size; + Current++; + } + } + } + + Nbuf = NetbufFromExt (Fragment, Current, HeadSpace, HeaderLen, ExtFree, Arg); + FreePool (Fragment); + + return Nbuf; +} + + +/** + Reserve some space in the header room of the net buffer. + + Upon allocation, all the space are in the tail room of the buffer. Call this + function to move some space to the header room. This function is quite limited + in that it can only reserve space from the first block of an empty NET_BUF not + built from the external. But it should be enough for the network stack. + + @param[in, out] Nbuf Pointer to the net buffer. + @param[in] Len The length of buffer to be reserved from the header. + +**/ +VOID +EFIAPI +NetbufReserve ( + IN OUT NET_BUF *Nbuf, + IN UINT32 Len + ) +{ + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + NET_CHECK_SIGNATURE (Nbuf->Vector, NET_VECTOR_SIGNATURE); + + ASSERT ((Nbuf->BlockOpNum == 1) && (Nbuf->TotalSize == 0)); + ASSERT ((Nbuf->Vector->Free == NULL) && (Nbuf->Vector->Len >= Len)); + + Nbuf->BlockOp[0].Head += Len; + Nbuf->BlockOp[0].Tail += Len; + + ASSERT (Nbuf->BlockOp[0].Tail <= Nbuf->BlockOp[0].BlockTail); +} + + +/** + Allocate Len bytes of space from the header or tail of the buffer. + + @param[in, out] Nbuf Pointer to the net buffer. + @param[in] Len The length of the buffer to be allocated. + @param[in] FromHead The flag to indicate whether reserve the data + from head (TRUE) or tail (FALSE). + + @return Pointer to the first byte of the allocated buffer, + or NULL if there is no sufficient space. + +**/ +UINT8* +EFIAPI +NetbufAllocSpace ( + IN OUT NET_BUF *Nbuf, + IN UINT32 Len, + IN BOOLEAN FromHead + ) +{ + NET_BLOCK_OP *BlockOp; + UINT32 Index; + UINT8 *SavedTail; + + Index = 0; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + NET_CHECK_SIGNATURE (Nbuf->Vector, NET_VECTOR_SIGNATURE); + + ASSERT (Len > 0); + + if (FromHead) { + // + // Allocate some space from head. If the buffer is empty, + // allocate from the first block. If it isn't, allocate + // from the first non-empty block, or the block before that. + // + if (Nbuf->TotalSize == 0) { + Index = 0; + } else { + NetbufGetByte (Nbuf, 0, &Index); + + if ((NET_HEADSPACE(&(Nbuf->BlockOp[Index])) < Len) && (Index > 0)) { + Index--; + } + } + + BlockOp = &(Nbuf->BlockOp[Index]); + + if (NET_HEADSPACE (BlockOp) < Len) { + return NULL; + } + + BlockOp->Head -= Len; + BlockOp->Size += Len; + Nbuf->TotalSize += Len; + + return BlockOp->Head; + + } else { + // + // Allocate some space from the tail. If the buffer is empty, + // allocate from the first block. If it isn't, allocate + // from the last non-empty block, or the block after that. + // + if (Nbuf->TotalSize == 0) { + Index = 0; + } else { + NetbufGetByte (Nbuf, Nbuf->TotalSize - 1, &Index); + + if ((NET_TAILSPACE(&(Nbuf->BlockOp[Index])) < Len) && + (Index < Nbuf->BlockOpNum - 1)) { + + Index++; + } + } + + BlockOp = &(Nbuf->BlockOp[Index]); + + if (NET_TAILSPACE (BlockOp) < Len) { + return NULL; + } + + SavedTail = BlockOp->Tail; + + BlockOp->Tail += Len; + BlockOp->Size += Len; + Nbuf->TotalSize += Len; + + return SavedTail; + } +} + + +/** + Trim a single NET_BLOCK by Len bytes from the header or tail. + + @param[in, out] BlockOp Pointer to the NET_BLOCK. + @param[in] Len The length of the data to be trimmed. + @param[in] FromHead The flag to indicate whether trim data from head + (TRUE) or tail (FALSE). + +**/ +VOID +NetblockTrim ( + IN OUT NET_BLOCK_OP *BlockOp, + IN UINT32 Len, + IN BOOLEAN FromHead + ) +{ + ASSERT ((BlockOp != NULL) && (BlockOp->Size >= Len)); + + BlockOp->Size -= Len; + + if (FromHead) { + BlockOp->Head += Len; + } else { + BlockOp->Tail -= Len; + } +} + + +/** + Trim Len bytes from the header or tail of the net buffer. + + @param[in, out] Nbuf Pointer to the net buffer. + @param[in] Len The length of the data to be trimmed. + @param[in] FromHead The flag to indicate whether trim data from head + (TRUE) or tail (FALSE). + + @return Length of the actually trimmed data, which is possible to be less + than Len because the TotalSize of Nbuf is less than Len. + +**/ +UINT32 +EFIAPI +NetbufTrim ( + IN OUT NET_BUF *Nbuf, + IN UINT32 Len, + IN BOOLEAN FromHead + ) +{ + NET_BLOCK_OP *BlockOp; + UINT32 Index; + UINT32 Trimmed; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + if (Len == 0 || Nbuf->TotalSize == 0) { + return 0; + } + + if (Len > Nbuf->TotalSize) { + Len = Nbuf->TotalSize; + } + + // + // If FromTail is true, iterate backward. That + // is, init Index to NBuf->BlockNum - 1, and + // decrease it by 1 during each loop. Otherwise, + // iterate forward. That is, init Index to 0, and + // increase it by 1 during each loop. + // + Trimmed = 0; + Nbuf->TotalSize -= Len; + + Index = (FromHead ? 0 : Nbuf->BlockOpNum - 1); + BlockOp = Nbuf->BlockOp; + + for (;;) { + if (BlockOp[Index].Size == 0) { + Index += (FromHead ? 1 : -1); + continue; + } + + if (Len > BlockOp[Index].Size) { + Len -= BlockOp[Index].Size; + Trimmed += BlockOp[Index].Size; + NetblockTrim (&BlockOp[Index], BlockOp[Index].Size, FromHead); + } else { + Trimmed += Len; + NetblockTrim (&BlockOp[Index], Len, FromHead); + break; + } + + Index += (FromHead ? 1 : -1); + } + + return Trimmed; +} + + +/** + Copy Len bytes of data from the specific offset of the net buffer to the + destination memory. + + The Len bytes of data may cross the several fragments of the net buffer. + + @param[in] Nbuf Pointer to the net buffer. + @param[in] Offset The sequence number of the first byte to copy. + @param[in] Len Length of the data to copy. + @param[in] Dest The destination of the data to copy to. + + @return The length of the actual copied data, or 0 if the offset + specified exceeds the total size of net buffer. + +**/ +UINT32 +EFIAPI +NetbufCopy ( + IN NET_BUF *Nbuf, + IN UINT32 Offset, + IN UINT32 Len, + IN UINT8 *Dest + ) +{ + NET_BLOCK_OP *BlockOp; + UINT32 Skip; + UINT32 Left; + UINT32 Copied; + UINT32 Index; + UINT32 Cur; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + ASSERT (Dest); + + if ((Len == 0) || (Nbuf->TotalSize <= Offset)) { + return 0; + } + + if (Nbuf->TotalSize - Offset < Len) { + Len = Nbuf->TotalSize - Offset; + } + + BlockOp = Nbuf->BlockOp; + + // + // Skip to the offset. Don't make "Offset-By-One" error here. + // Cur + BLOCK.SIZE is the first sequence number of next block. + // So, (Offset < Cur + BLOCK.SIZE) means that the first byte + // is in the current block. if (Offset == Cur + BLOCK.SIZE), the + // first byte is the next block's first byte. + // + Cur = 0; + + for (Index = 0; Index < Nbuf->BlockOpNum; Index++) { + if (BlockOp[Index].Size == 0) { + continue; + } + + if (Offset < Cur + BlockOp[Index].Size) { + break; + } + + Cur += BlockOp[Index].Size; + } + + // + // Cur is the sequence number of the first byte in the block + // Offset - Cur is the number of bytes before first byte to + // to copy in the current block. + // + Skip = Offset - Cur; + Left = BlockOp[Index].Size - Skip; + + if (Len <= Left) { + CopyMem (Dest, BlockOp[Index].Head + Skip, Len); + return Len; + } + + CopyMem (Dest, BlockOp[Index].Head + Skip, Left); + + Dest += Left; + Len -= Left; + Copied = Left; + + Index++; + + for (; Index < Nbuf->BlockOpNum; Index++) { + if (Len > BlockOp[Index].Size) { + Len -= BlockOp[Index].Size; + Copied += BlockOp[Index].Size; + + CopyMem (Dest, BlockOp[Index].Head, BlockOp[Index].Size); + Dest += BlockOp[Index].Size; + } else { + Copied += Len; + CopyMem (Dest, BlockOp[Index].Head, Len); + break; + } + } + + return Copied; +} + + +/** + Initiate the net buffer queue. + + @param[in, out] NbufQue Pointer to the net buffer queue to be initialized. + +**/ +VOID +EFIAPI +NetbufQueInit ( + IN OUT NET_BUF_QUEUE *NbufQue + ) +{ + NbufQue->Signature = NET_QUE_SIGNATURE; + NbufQue->RefCnt = 1; + InitializeListHead (&NbufQue->List); + + InitializeListHead (&NbufQue->BufList); + NbufQue->BufSize = 0; + NbufQue->BufNum = 0; +} + + +/** + Allocate and initialize a net buffer queue. + + @return Pointer to the allocated net buffer queue, or NULL if the + allocation failed due to resource limit. + +**/ +NET_BUF_QUEUE * +EFIAPI +NetbufQueAlloc ( + VOID + ) +{ + NET_BUF_QUEUE *NbufQue; + + NbufQue = AllocatePool (sizeof (NET_BUF_QUEUE)); + if (NbufQue == NULL) { + return NULL; + } + + NetbufQueInit (NbufQue); + + return NbufQue; +} + + +/** + Free a net buffer queue. + + Decrease the reference count of the net buffer queue by one. The real resource + free operation isn't performed until the reference count of the net buffer + queue is decreased to 0. + + @param[in] NbufQue Pointer to the net buffer queue to be freed. + +**/ +VOID +EFIAPI +NetbufQueFree ( + IN NET_BUF_QUEUE *NbufQue + ) +{ + ASSERT (NbufQue != NULL); + NET_CHECK_SIGNATURE (NbufQue, NET_QUE_SIGNATURE); + + NbufQue->RefCnt--; + + if (NbufQue->RefCnt == 0) { + NetbufQueFlush (NbufQue); + FreePool (NbufQue); + } +} + + +/** + Append a net buffer to the net buffer queue. + + @param[in, out] NbufQue Pointer to the net buffer queue. + @param[in, out] Nbuf Pointer to the net buffer to be appended. + +**/ +VOID +EFIAPI +NetbufQueAppend ( + IN OUT NET_BUF_QUEUE *NbufQue, + IN OUT NET_BUF *Nbuf + ) +{ + NET_CHECK_SIGNATURE (NbufQue, NET_QUE_SIGNATURE); + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + InsertTailList (&NbufQue->BufList, &Nbuf->List); + + NbufQue->BufSize += Nbuf->TotalSize; + NbufQue->BufNum++; +} + + +/** + Remove a net buffer from the head in the specific queue and return it. + + @param[in, out] NbufQue Pointer to the net buffer queue. + + @return Pointer to the net buffer removed from the specific queue, + or NULL if there is no net buffer in the specific queue. + +**/ +NET_BUF * +EFIAPI +NetbufQueRemove ( + IN OUT NET_BUF_QUEUE *NbufQue + ) +{ + NET_BUF *First; + + NET_CHECK_SIGNATURE (NbufQue, NET_QUE_SIGNATURE); + + if (NbufQue->BufNum == 0) { + return NULL; + } + + First = NET_LIST_USER_STRUCT (NbufQue->BufList.ForwardLink, NET_BUF, List); + + NetListRemoveHead (&NbufQue->BufList); + + NbufQue->BufSize -= First->TotalSize; + NbufQue->BufNum--; + return First; +} + + +/** + Copy Len bytes of data from the net buffer queue at the specific offset to the + destination memory. + + The copying operation is the same as NetbufCopy but applies to the net buffer + queue instead of the net buffer. + + @param[in] NbufQue Pointer to the net buffer queue. + @param[in] Offset The sequence number of the first byte to copy. + @param[in] Len Length of the data to copy. + @param[out] Dest The destination of the data to copy to. + + @return The length of the actual copied data, or 0 if the offset + specified exceeds the total size of net buffer queue. + +**/ +UINT32 +EFIAPI +NetbufQueCopy ( + IN NET_BUF_QUEUE *NbufQue, + IN UINT32 Offset, + IN UINT32 Len, + OUT UINT8 *Dest + ) +{ + LIST_ENTRY *Entry; + NET_BUF *Nbuf; + UINT32 Skip; + UINT32 Left; + UINT32 Cur; + UINT32 Copied; + + NET_CHECK_SIGNATURE (NbufQue, NET_QUE_SIGNATURE); + ASSERT (Dest != NULL); + + if ((Len == 0) || (NbufQue->BufSize <= Offset)) { + return 0; + } + + if (NbufQue->BufSize - Offset < Len) { + Len = NbufQue->BufSize - Offset; + } + + // + // skip to the Offset + // + Cur = 0; + Nbuf = NULL; + + NET_LIST_FOR_EACH (Entry, &NbufQue->BufList) { + Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List); + + if (Offset < Cur + Nbuf->TotalSize) { + break; + } + + Cur += Nbuf->TotalSize; + } + + ASSERT (Nbuf != NULL); + + // + // Copy the data in the first buffer. + // + Skip = Offset - Cur; + Left = Nbuf->TotalSize - Skip; + + if (Len < Left) { + return NetbufCopy (Nbuf, Skip, Len, Dest); + } + + NetbufCopy (Nbuf, Skip, Left, Dest); + Dest += Left; + Len -= Left; + Copied = Left; + + // + // Iterate over the others + // + Entry = Entry->ForwardLink; + + while ((Len > 0) && (Entry != &NbufQue->BufList)) { + Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List); + + if (Len > Nbuf->TotalSize) { + Len -= Nbuf->TotalSize; + Copied += Nbuf->TotalSize; + + NetbufCopy (Nbuf, 0, Nbuf->TotalSize, Dest); + Dest += Nbuf->TotalSize; + + } else { + NetbufCopy (Nbuf, 0, Len, Dest); + Copied += Len; + break; + } + + Entry = Entry->ForwardLink; + } + + return Copied; +} + + +/** + Trim Len bytes of data from the buffer queue and free any net buffer + that is completely trimmed. + + The trimming operation is the same as NetbufTrim but applies to the net buffer + queue instead of the net buffer. + + @param[in, out] NbufQue Pointer to the net buffer queue. + @param[in] Len Length of the data to trim. + + @return The actual length of the data trimmed. + +**/ +UINT32 +EFIAPI +NetbufQueTrim ( + IN OUT NET_BUF_QUEUE *NbufQue, + IN UINT32 Len + ) +{ + LIST_ENTRY *Entry; + LIST_ENTRY *Next; + NET_BUF *Nbuf; + UINT32 Trimmed; + + NET_CHECK_SIGNATURE (NbufQue, NET_QUE_SIGNATURE); + + if (Len == 0) { + return 0; + } + + if (Len > NbufQue->BufSize) { + Len = NbufQue->BufSize; + } + + NbufQue->BufSize -= Len; + Trimmed = 0; + + NET_LIST_FOR_EACH_SAFE (Entry, Next, &NbufQue->BufList) { + Nbuf = NET_LIST_USER_STRUCT (Entry, NET_BUF, List); + + if (Len >= Nbuf->TotalSize) { + Trimmed += Nbuf->TotalSize; + Len -= Nbuf->TotalSize; + + RemoveEntryList (Entry); + NetbufFree (Nbuf); + + NbufQue->BufNum--; + + if (Len == 0) { + break; + } + + } else { + Trimmed += NetbufTrim (Nbuf, Len, NET_BUF_HEAD); + break; + } + } + + return Trimmed; +} + + +/** + Flush the net buffer queue. + + @param[in, out] NbufQue Pointer to the queue to be flushed. + +**/ +VOID +EFIAPI +NetbufQueFlush ( + IN OUT NET_BUF_QUEUE *NbufQue + ) +{ + NET_CHECK_SIGNATURE (NbufQue, NET_QUE_SIGNATURE); + + NetbufFreeList (&NbufQue->BufList); + + NbufQue->BufNum = 0; + NbufQue->BufSize = 0; +} + + +/** + Compute the checksum for a bulk of data. + + @param[in] Bulk Pointer to the data. + @param[in] Len Length of the data, in bytes. + + @return The computed checksum. + +**/ +UINT16 +EFIAPI +NetblockChecksum ( + IN UINT8 *Bulk, + IN UINT32 Len + ) +{ + register UINT32 Sum; + + Sum = 0; + + // + // Add left-over byte, if any + // + if (Len % 2 != 0) { + Sum += *(Bulk + Len - 1); + } + + while (Len > 1) { + Sum += *(UINT16 *) Bulk; + Bulk += 2; + Len -= 2; + } + + // + // Fold 32-bit sum to 16 bits + // + while ((Sum >> 16) != 0) { + Sum = (Sum & 0xffff) + (Sum >> 16); + + } + + return (UINT16) Sum; +} + + +/** + Add two checksums. + + @param[in] Checksum1 The first checksum to be added. + @param[in] Checksum2 The second checksum to be added. + + @return The new checksum. + +**/ +UINT16 +EFIAPI +NetAddChecksum ( + IN UINT16 Checksum1, + IN UINT16 Checksum2 + ) +{ + UINT32 Sum; + + Sum = Checksum1 + Checksum2; + + // + // two UINT16 can only add up to a carry of 1. + // + if ((Sum >> 16) != 0) { + Sum = (Sum & 0xffff) + 1; + + } + + return (UINT16) Sum; +} + + +/** + Compute the checksum for a NET_BUF. + + @param[in] Nbuf Pointer to the net buffer. + + @return The computed checksum. + +**/ +UINT16 +EFIAPI +NetbufChecksum ( + IN NET_BUF *Nbuf + ) +{ + NET_BLOCK_OP *BlockOp; + UINT32 Offset; + UINT16 TotalSum; + UINT16 BlockSum; + UINT32 Index; + + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + + TotalSum = 0; + Offset = 0; + BlockOp = Nbuf->BlockOp; + + for (Index = 0; Index < Nbuf->BlockOpNum; Index++) { + if (BlockOp[Index].Size == 0) { + continue; + } + + BlockSum = NetblockChecksum (BlockOp[Index].Head, BlockOp[Index].Size); + + if ((Offset & 0x01) != 0) { + // + // The checksum starts with an odd byte, swap + // the checksum before added to total checksum + // + BlockSum = SwapBytes16 (BlockSum); + } + + TotalSum = NetAddChecksum (BlockSum, TotalSum); + Offset += BlockOp[Index].Size; + } + + return TotalSum; +} + + +/** + Compute the checksum for TCP/UDP pseudo header. + + Src and Dst are in network byte order, and Len is in host byte order. + + @param[in] Src The source address of the packet. + @param[in] Dst The destination address of the packet. + @param[in] Proto The protocol type of the packet. + @param[in] Len The length of the packet. + + @return The computed checksum. + +**/ +UINT16 +EFIAPI +NetPseudoHeadChecksum ( + IN IP4_ADDR Src, + IN IP4_ADDR Dst, + IN UINT8 Proto, + IN UINT16 Len + ) +{ + NET_PSEUDO_HDR Hdr; + + // + // Zero the memory to relieve align problems + // + ZeroMem (&Hdr, sizeof (Hdr)); + + Hdr.SrcIp = Src; + Hdr.DstIp = Dst; + Hdr.Protocol = Proto; + Hdr.Len = HTONS (Len); + + return NetblockChecksum ((UINT8 *) &Hdr, sizeof (Hdr)); +} + +/** + Compute the checksum for TCP6/UDP6 pseudo header. + + Src and Dst are in network byte order, and Len is in host byte order. + + @param[in] Src The source address of the packet. + @param[in] Dst The destination address of the packet. + @param[in] NextHeader The protocol type of the packet. + @param[in] Len The length of the packet. + + @return The computed checksum. + +**/ +UINT16 +EFIAPI +NetIp6PseudoHeadChecksum ( + IN EFI_IPv6_ADDRESS *Src, + IN EFI_IPv6_ADDRESS *Dst, + IN UINT8 NextHeader, + IN UINT32 Len + ) +{ + NET_IP6_PSEUDO_HDR Hdr; + + // + // Zero the memory to relieve align problems + // + ZeroMem (&Hdr, sizeof (Hdr)); + + IP6_COPY_ADDRESS (&Hdr.SrcIp, Src); + IP6_COPY_ADDRESS (&Hdr.DstIp, Dst); + + Hdr.NextHeader = NextHeader; + Hdr.Len = HTONL (Len); + + return NetblockChecksum ((UINT8 *) &Hdr, sizeof (Hdr)); +} + +/** + The function frees the net buffer which allocated by the IP protocol. It releases + only the net buffer and doesn't call the external free function. + + This function should be called after finishing the process of mIpSec->ProcessExt() + for outbound traffic. The (EFI_IPSEC2_PROTOCOL)->ProcessExt() allocates a new + buffer for the ESP, so there needs a function to free the old net buffer. + + @param[in] Nbuf The network buffer to be freed. + +**/ +VOID +NetIpSecNetbufFree ( + NET_BUF *Nbuf + ) +{ + NET_CHECK_SIGNATURE (Nbuf, NET_BUF_SIGNATURE); + ASSERT (Nbuf->RefCnt > 0); + + Nbuf->RefCnt--; + + if (Nbuf->RefCnt == 0) { + + // + // Update Vector only when NBuf is to be released. That is, + // all the sharing of Nbuf increse Vector's RefCnt by one + // + NET_CHECK_SIGNATURE (Nbuf->Vector, NET_VECTOR_SIGNATURE); + ASSERT (Nbuf->Vector->RefCnt > 0); + + Nbuf->Vector->RefCnt--; + + if (Nbuf->Vector->RefCnt > 0) { + return; + } + + // + // If NET_VECTOR_OWN_FIRST is set, release the first block since it is + // allocated by us + // + if ((Nbuf->Vector->Flag & NET_VECTOR_OWN_FIRST) != 0) { + FreePool (Nbuf->Vector->Block[0].Bulk); + } + FreePool (Nbuf->Vector); + FreePool (Nbuf); + } +} +