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Lester · Guest

I'm using GetIfTable API call to get information on network interfaces
([url]http://msdn.microsoft.com/library/default.asp?url=/library/en-us/iphlp/iphlp/getiftable.asp)[/url].

It fills a table (MIB_IFTABLE) with MIB_IFROW structures. (One
MIB_IFROW for each interface.)
(http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mib/mib/mib_ifrow.asp)

Now MIB_IFROW has a member wszName [MAX_INTERFACE_NAME_LEN] which is a
"Pointer to a Unicode string that contains the name of the interface".
How do I read this out from the memory, and put in (eg.) a TStrings?

=====================================

Here is some code I tried to make (see comments):

Procedure GetIFInfo(ListInterfaces:TStrings);
var
MibRow : TMibIfRow;
IntfTable: PMibIfTable;
Size : ULONG;
I : Integer;
begin
Size := 0;
//just get the size first...
if GetIfTable(nil, Size, True) <> ERROR_INSUFFICIENT_BUFFER then
Exit;

//have size, make the real call...
IntfTable := AllocMem(Size);
try
if GetIfTable(IntfTable, Size, True) = NO_ERROR then
begin
ListInterfaces.Clear;
for I := 0 to IntfTable^.dwNumEntries - 1 do
begin
//row-by-row
MibRow := IntfTable.Table[I];

//this shows perfectly...
ListInterfaces.Add('speed: ' + IntToStr(MibRow.dwSpeed));

//this shows perfectly...
ListInterfaces.Add('output octets: ' +
IntToStr(MibRow.dwOutOctets));

//PROBLEM HERE: MibRow.wszName is EMPTY!!!???
ListInterfaces.Add('name: ' + MibRow.wszName); // <-- HOW TO
READ IT???
end;
end;

finally
FreeMem(IntfTable);
end;
End;

===============

Here is the definition in IpRtrMib.pas (I'm using IPHelper from
JEDI-project):

const
MAXLEN_IFDESCR = 256;
{$EXTERNALSYM MAXLEN_IFDESCR}
MAXLEN_PHYSADDR = 8;
{$EXTERNALSYM MAXLEN_PHYSADDR}

type
PMIB_IFROW = ^MIB_IFROW;
{$EXTERNALSYM PMIB_IFROW}
_MIB_IFROW = record
wszName: array [0..MAX_INTERFACE_NAME_LEN - 1] of WCHAR;
dwIndex: DWORD;
dwType: DWORD;
dwMtu: DWORD;
dwSpeed: DWORD;
dwPhysAddrLen: DWORD;
bPhysAddr: array [0..MAXLEN_PHYSADDR - 1] of BYTE;
dwAdminStatus: DWORD;
dwOperStatus: DWORD;
dwLastChange: DWORD;
dwInOctets: DWORD;
dwInUcastPkts: DWORD;
dwInNUcastPkts: DWORD;
dwInDiscards: DWORD;
dwInErrors: DWORD;
dwInUnknownProtos: DWORD;
dwOutOctets: DWORD;
dwOutUcastPkts: DWORD;
dwOutNUcastPkts: DWORD;
dwOutDiscards: DWORD;
dwOutErrors: DWORD;
dwOutQLen: DWORD;
dwDescrLen: DWORD;
bDescr: array[0..MAXLEN_IFDESCR - 1] of BYTE;
end;
{$EXTERNALSYM _MIB_IFROW}
MIB_IFROW = _MIB_IFROW;
{$EXTERNALSYM MIB_IFROW}
TMibIfRow = MIB_IFROW;
PMibIfRow = PMIB_IFROW;

PMIB_IFTABLE = ^MIB_IFTABLE;
{$EXTERNALSYM PMIB_IFTABLE}
_MIB_IFTABLE = record
dwNumEntries: DWORD;
table: array [0..ANY_SIZE - 1] of MIB_IFROW;
end;
{$EXTERNALSYM _MIB_IFTABLE}
MIB_IFTABLE = _MIB_IFTABLE;
{$EXTERNALSYM MIB_IFTABLE}
TMibIftable = MIB_IFTABLE;
PMibIftable = PMIB_IFTABLE;

MANY thanks in advance!
L.