/**
Remove the block number from the block range list.
@param[in] Head The block range list to remove from.
@param[in] Num The block number to remove.
@param[in] Completed Whether Num is the last block number
@param[out] TotalBlock The continuous block number in all
@retval EFI_NOT_FOUND The block number isn't in the block range list.
@retval EFI_SUCCESS The block number has been removed from the list.
@retval EFI_OUT_OF_RESOURCES Failed to allocate resources.
**/
EFI_STATUS
Mtftp6RemoveBlockNum (
IN LIST_ENTRY *Head,
IN UINT16 Num,
IN BOOLEAN Completed,
OUT UINT64 *TotalBlock
)
{
MTFTP6_BLOCK_RANGE *Range;
MTFTP6_BLOCK_RANGE *NewRange;
LIST_ENTRY *Entry;
NET_LIST_FOR_EACH (Entry, Head) {
//
// Each block represents a hole [Start, End] in the file,
// skip to the first range with End >= Num
//
Range = NET_LIST_USER_STRUCT (Entry, MTFTP6_BLOCK_RANGE, Link);
if (Range->End < Num) {
continue;
}
//
// There are three different cases for Start
// 1. (Start > Num) && (End >= Num):
// because all the holes before this one has the condition of
// End < Num, so this block number has been removed.
//
// 2. (Start == Num) && (End >= Num):
// Need to increase the Start by one, and if End == Num, this
// hole has been removed completely, remove it.
//
// 3. (Start < Num) && (End >= Num):
// if End == Num, only need to decrease the End by one because
// we have (Start < Num) && (Num == End), so (Start <= End - 1).
// if (End > Num), the hold is splited into two holes, with
// [Start, Num - 1] and [Num + 1, End].
//
if (Range->Start > Num) {
return EFI_NOT_FOUND;
} else if (Range->Start == Num) {
Range->Start++;
//
// Note that: RFC 1350 does not mention block counter roll-over,
// but several TFTP hosts implement the roll-over be able to accept
// transfers of unlimited size. There is no consensus, however, whether
// the counter should wrap around to zero or to one. Many implementations
// wrap to zero, because this is the simplest to implement. Here we choose
// this solution.
//
*TotalBlock = Num;
if (Range->Round > 0) {
*TotalBlock += Range->Bound + MultU64x32 (Range->Round - 1, (UINT32)(Range->Bound + 1)) + 1;
}
if (Range->Start > Range->Bound) {
Range->Start = 0;
Range->Round ++;
}
if ((Range->Start > Range->End) || Completed) {
RemoveEntryList (&Range->Link);
FreePool (Range);
}
return EFI_SUCCESS;
} else {
if (Range->End == Num) {
Range->End--;
} else {
NewRange = Mtftp6AllocateRange ((UINT16) (Num + 1), (UINT16) Range->End);
if (NewRange == NULL) {
return EFI_OUT_OF_RESOURCES;
}
Range->End = Num - 1;
NetListInsertAfter (&Range->Link, &NewRange->Link);
}
return EFI_SUCCESS;
}
}
EFI_STATUS
Mtftp4RemoveBlockNum (
IN NET_LIST_ENTRY *Head,
IN UINT16 Num
)
/*++
Routine Description:
Remove the block number from the block range list.
Arguments:
Head - The block range list to remove from
Num - The block number to remove
Returns:
EFI_NOT_FOUND - The block number isn't in the block range list
EFI_SUCCESS - The block number has been removed from the list
EFI_OUT_OF_RESOURCES - Failed to allocate resource
--*/
{
MTFTP4_BLOCK_RANGE *Range;
MTFTP4_BLOCK_RANGE *NewRange;
NET_LIST_ENTRY *Entry;
NET_LIST_FOR_EACH (Entry, Head) {
//
// Each block represents a hole [Start, End] in the file,
// skip to the first range with End >= Num
//
Range = NET_LIST_USER_STRUCT (Entry, MTFTP4_BLOCK_RANGE, Link);
if (Range->End < Num) {
continue;
}
//
// There are three different cases for Start
// 1. (Start > Num) && (End >= Num):
// because all the holes before this one has the condition of
// End < Num, so this block number has been removed.
//
// 2. (Start == Num) && (End >= Num):
// Need to increase the Start by one, and if End == Num, this
// hole has been removed completely, remove it.
//
// 3. (Start < Num) && (End >= Num):
// if End == Num, only need to decrease the End by one because
// we have (Start < Num) && (Num == End), so (Start <= End - 1).
// if (End > Num), the hold is splited into two holes, with
// [Start, Num - 1] and [Num + 1, End].
//
if (Range->Start > Num) {
return EFI_NOT_FOUND;
} else if (Range->Start == Num) {
Range->Start++;
if (Range->Start > Range->End) {
NetListRemoveEntry (&Range->Link);
NetFreePool (Range);
}
return EFI_SUCCESS;
} else {
if (Range->End == Num) {
Range->End--;
} else {
NewRange = Mtftp4AllocateRange (Num + 1, (UINT16) Range->End);
if (NewRange == NULL) {
return EFI_OUT_OF_RESOURCES;
}
Range->End = Num - 1;
NetListInsertAfter (&Range->Link, &NewRange->Link);
}
return EFI_SUCCESS;
}
}
