Announcement

**John McWilliams** · 15 May 2001, 08:41 AM

FIXED_INFO
The FIXED_INFO structure contains information that is the same across all the interfaces in a computer.

typedef struct {
char HostName[MAX_HOSTNAME_LEN + 4] ;
char DomainName[MAX_DOMAIN_NAME_LEN + 4];
PIP_ADDR_STRING CurrentDnsServer;
IP_ADDR_STRING DnsServerList;
UINT NodeType;
char ScopeId[MAX_SCOPE_ID_LEN + 4];
UINT EnableRouting;
UINT EnableProxy;
UINT EnableDns;
} FIXED_INFO, *PFIXED_INFO;
Members
HostName[MAX_HOSTNAME_LEN + 4]
Specifies the host name for the local computer.
DomainName[MAX_DOMAIN_NAME_LEN + 4]
Specifies the domain in which the local computer is registered.
CurrentDnsServer
Specifies the current DNS server.
DnsServerList
Specifies the set of DNS servers used by the local computer.
NodeType
Specifies whether the local computer uses dynamic host configuration protocol (DHCP).
ScopeId[MAX_SCOPE_ID_LEN + 4]
Specifies the DHCP scope name.
EnableRouting
Specifies whether routing is enabled on the local computer.
EnableProxy
Specifies whether the local computer is acting as an ARP proxy.
EnableDns
Specifies whether DNS is enabled on the local computer.
Requirements
Windows NT/2000: Requires Windows 2000.
Windows 95/98: Requires Windows 98.
Header: Declared in Iptypes.h.

See Also
GetNetworkParams

[This message has been edited by John McWilliams (edited May 15, 2001).]

**Michael Burns** · 15 May 2001, 07:30 PM

Thanks! That lead me in the right direction. I have kludged up a
quick and dirty demo that seems to work.

Code:

'
'   Quick & Dirty test. by Michael Burns 15-May-01
'
'
#COMPILE EXE
#DIM ALL
#INCLUDE "WIN32API.INC"
'
TYPE IP_ADDRESS_STRING
    IpAddressString(4 * 4 - 1) AS BYTE
END TYPE
'
TYPE IP_MASK_STRING
    IpMaskString(4 * 4 - 1) AS BYTE
END TYPE
'
TYPE IP_ADDR_STRING
    lNext      AS LONG
    IpAddress AS IP_ADDRESS_STRING
    IpMask    AS IP_MASK_STRING
    Context   AS LONG
END TYPE
'
%MAX_HOSTNAME_LEN = 128
%MAX_DOMAIN_NAME_LEN = 128
%MAX_SCOPE_ID_LEN = 256
'
TYPE FIXED_INFO
    HostName(%MAX_HOSTNAME_LEN + 4 - 1)AS BYTE
    DomainName(%MAX_DOMAIN_NAME_LEN + 4 - 1) AS BYTE
    CurrentDnsServer AS LONG
    DnsServerList    AS IP_ADDR_STRING
    NodeType         AS LONG
    ScopeId(%MAX_SCOPE_ID_LEN + 4 - 1) AS BYTE
    EnableRouting    AS LONG
    EnableProxy      AS LONG
    EnableDns        AS LONG
END TYPE
' Declare is done in a manner where we can use loadlibrary in case
' PC does not have iphlpapi.dll in it (like old Win 95 systems)
'
DECLARE FUNCTION GetNetworkParams ALIAS "GetNetworkParams" (BYREF pFixedInfo AS ANY, BYREF pOutBufLen AS LONG) AS LONG
'
' Declare of the movememory in a more flexable manner that winapi32.inc
' and comment out the MoveMemory in winapi32.inc
'
DECLARE FUNCTION MoveMemory LIB "KERNEL32.DLL" ALIAS "RtlMoveMemory" (lpDest AS ANY, lpSource AS ANY, BYVAL cbMove AS LONG) AS LONG
%ERROR_NOT_SUPPORTED = 50
%ERROR_BUFFER_OVERFLOW = 111
%ERROR_INVALID_PARAMETER = 87
%ERROR_NO_DATA = 232
'
FUNCTION IpToString(BYVAL ip AS LONG) AS STRING
  ' Don't remember where I got this function
  ' (I might have written it, but I might not.)
  LOCAL b AS BYTE PTR
'
  b = VARPTR(ip)
  FUNCTION = FORMAT$(@b[0]) & "." & FORMAT$(@b[1]) & "." & _
             FORMAT$(@b[2]) & "." & FORMAT$(@b[3])
'
END FUNCTION
'*********************************************
FUNCTION PBMAIN() AS LONG
    LOCAL lngFixedInfoNeeded    AS LONG
    LOCAL bytFixedInfoBuffer()  AS BYTE
    LOCAL udtFixedInfo          AS FIXED_INFO
    LOCAL strFixedInfoScopeId   AS STRING
    LOCAL lngWin32apiResultCode AS LONG
    LOCAL ProcessID AS LONG
    LOCAL hLib AS LONG
    LOCAL ProcAddr AS DWORD
    ' Here we see if iphlpapi.dll is on this machine
    ProcessID = GetCurrentProcessId()
    hLib = LoadLibrary("iphlpapi.dll")
    IF ISFALSE hLib THEN
       MSGBOX "Sorry, iphlpapi.dll not supported on this machine. Terminating program."
       EXIT FUNCTION
    END IF
    'Retrieve FUNCTION address
    ProcAddr = GetProcAddress(hLib,"GetNetworkParams")
    IF ProcAddr = %NULL THEN
       MSGBOX "Sorry, GetNetworkParams not supported on this machine. Terminating program."
       EXIT FUNCTION
    END IF
    lngFixedInfoNeeded=LEN(udtFixedInfo)
    'Call pointer to the function using function prototype
    CALL DWORD ProcAddr USING GetNetworkParams(BYVAL %NULL , lngFixedInfoNeeded) TO lngWin32apiResultCode
    IF lngWin32apiResultCode <> 0 THEN
       SELECT CASE lngWin32apiResultCode
            CASE %ERROR_BUFFER_OVERFLOW
                ' Right-size bytFixedInfoBuffer
                REDIM bytFixedInfoBuffer (lngFixedInfoNeeded)
            CASE %ERROR_INVALID_PARAMETER
                MSGBOX "Invalid parameter Error."
                EXIT FUNCTION
            CASE %ERROR_NO_DATA
                MSGBOX "No data Error."
                EXIT FUNCTION
            CASE %ERROR_NOT_SUPPORTED
                MSGBOX "Not Supported Error."
                EXIT FUNCTION
            CASE ELSE
                MSGBOX STR$(lngWin32apiResultCode) + " error code returned."
                EXIT FUNCTION
       END SELECT
    ELSE
       ' Something is horribly wrong as we should not get 0
       ' for the first pass through. Get outta here!
       MSGBOX "Unexpected result. Terminating program."
       EXIT FUNCTION
    END IF
    'Call pointer to the function using function prototype
    CALL DWORD ProcAddr USING GetNetworkParams(bytFixedInfoBuffer(0) , lngFixedInfoNeeded) TO lngWin32apiResultCode
    MoveMemory  udtFixedInfo, bytFixedInfoBuffer(0),  LEN(udtFixedInfo)
    MSGBOX "Current DNS Server: "+udtFixedInfo.DnsServerList.IpAddress
END FUNCTION

[This message has been edited by Michael Burns (edited May 15, 2001).]

**Lance Edmonds** · 16 May 2001, 04:40 AM

If you don't want to modify the MoveMemory declaration, then substitute the following line:

Code:

POKE$ VARPTR(udtFixedInfo), PEEK$(VARPTR(bytFixedInfoBuffer(0)), LEN(udtFixedInfo))

Or you can use the original MoveMemory declaration with the following line:

Code:

MoveMemory VARPTR(udtFixedInfo), VARPTR(bytFixedInfoBuffer(0)), LEN(udtFixedInfo)

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

**Michael Burns** · 16 May 2001, 07:24 AM

Thanks Lance! Here it is with your change to clean up the MoveMemory,
as well as a change at the end to enumerate any other DNS servers,
and I had forgotten above to drop the IPtoString as it is not used.
The other thing to note is this seems to work both with PC's whose
DNS assignments come from a DHCP server as well as on machines with
fixed DNS assignments made through the control panel. I suppose the
next logical step is for me to figure out how to generalize it to
multiple adapters.

Code:

'
'   Quick & Dirty test #2. by Michael Burns 16-May-01
'
'
#COMPILE EXE
#DIM ALL
#INCLUDE "WIN32API.INC"
'
TYPE IP_ADDRESS_STRING
    IpAddressString(4 * 4 - 1) AS BYTE
END TYPE
'
TYPE IP_MASK_STRING
    IpMaskString(4 * 4 - 1) AS BYTE
END TYPE
'
TYPE IP_ADDR_STRING
    lNext      AS LONG
    IpAddress AS IP_ADDRESS_STRING
    IpMask    AS IP_MASK_STRING
    Context   AS LONG
END TYPE
'
%MAX_HOSTNAME_LEN = 128
%MAX_DOMAIN_NAME_LEN = 128
%MAX_SCOPE_ID_LEN = 256
'
TYPE FIXED_INFO
    HostName(%MAX_HOSTNAME_LEN + 4 - 1)AS BYTE
    DomainName(%MAX_DOMAIN_NAME_LEN + 4 - 1) AS BYTE
    CurrentDnsServer AS LONG
    DnsServerList    AS IP_ADDR_STRING
    NodeType         AS LONG
    ScopeId(%MAX_SCOPE_ID_LEN + 4 - 1) AS BYTE
    EnableRouting    AS LONG
    EnableProxy      AS LONG
    EnableDns        AS LONG
END TYPE
' Declare is done in a manner where we can use loadlibrary in case
' PC does not have iphlpapi.dll on it (like old Win 95 systems don't).
'
DECLARE FUNCTION GetNetworkParams ALIAS "GetNetworkParams" (BYREF pFixedInfo AS ANY, BYREF pOutBufLen AS LONG) AS LONG
'
'
%ERROR_NOT_SUPPORTED = 50
%ERROR_BUFFER_OVERFLOW = 111
%ERROR_INVALID_PARAMETER = 87
%ERROR_NO_DATA = 232
'
'*********************************************
FUNCTION PBMAIN() AS LONG
    LOCAL lngFixedInfoNeeded    AS LONG
    LOCAL bytFixedInfoBuffer()  AS BYTE
    LOCAL udtFixedInfo          AS FIXED_INFO
    LOCAL Buffer AS IP_ADDR_STRING
    LOCAL strFixedInfoScopeId   AS STRING
    LOCAL lngWin32apiResultCode AS LONG
    LOCAL ProcessID AS LONG
    LOCAL hLib AS LONG
    LOCAL ProcAddr AS DWORD
    LOCAL pAddrStr AS LONG
    LOCAL I AS INTEGER
    ' Here we see if iphlpapi.dll is on this machine
    ProcessID = GetCurrentProcessId()
    hLib = LoadLibrary("iphlpapi.dll")
    IF ISFALSE hLib THEN
       MSGBOX "Sorry, iphlpapi.dll not supported on this machine. Terminating program."
       EXIT FUNCTION
    END IF
    'Retrieve FUNCTION address
    ProcAddr = GetProcAddress(hLib,"GetNetworkParams")
    IF ProcAddr = %NULL THEN
       MSGBOX "Sorry, GetNetworkParams not supported on this machine. Terminating program."
       EXIT FUNCTION
    END IF
    lngFixedInfoNeeded=LEN(udtFixedInfo)
    'Call pointer to the function using function prototype
    CALL DWORD ProcAddr USING GetNetworkParams(BYVAL %NULL , lngFixedInfoNeeded) TO lngWin32apiResultCode
    IF lngWin32apiResultCode <> 0 THEN
       SELECT CASE lngWin32apiResultCode
            CASE %ERROR_BUFFER_OVERFLOW
                ' Right-size bytFixedInfoBuffer
                REDIM bytFixedInfoBuffer (lngFixedInfoNeeded)
            CASE %ERROR_INVALID_PARAMETER
                MSGBOX "Invalid parameter Error."
                EXIT FUNCTION
            CASE %ERROR_NO_DATA
                MSGBOX "No data Error."
                EXIT FUNCTION
            CASE %ERROR_NOT_SUPPORTED
                MSGBOX "Not Supported Error."
                EXIT FUNCTION
            CASE ELSE
                MSGBOX STR$(lngWin32apiResultCode) + " error code returned."
                EXIT FUNCTION
       END SELECT
    ELSE
       ' Something is horribly wrong as we should not get 0
       ' for the first pass through. Get outta here!
       MSGBOX "Unexpected result. Terminating program."
       EXIT FUNCTION
    END IF
    'Call pointer to the function using function prototype
    CALL DWORD ProcAddr USING GetNetworkParams(bytFixedInfoBuffer(0) , lngFixedInfoNeeded) TO lngWin32apiResultCode
    MoveMemory VARPTR(udtFixedInfo), VARPTR(bytFixedInfoBuffer(0)), LEN(udtFixedInfo)
    MSGBOX "DNS Server #1:  " & udtFixedInfo.DnsServerList.IpAddress
    pAddrStr = udtFixedInfo.DnsServerList.lNext
    I=1
    DO WHILE pAddrStr <> 0
        I=I+1
        MoveMemory VARPTR(Buffer), pAddrStr, LEN(Buffer)
        MSGBOX "DNS Server#"+TRIM$(STR$(I))+":  " & Buffer.IpAddress
        pAddrStr = Buffer.lNext
    LOOP
'    
END FUNCTION

------------------
Michael Burns

[This message has been edited by Michael Burns (edited May 16, 2001).]

**Florent Heyworth** · 16 May 2001, 08:17 AM

Hi Michael

nice one - I'll add the GetNetworkParams() option to DNSQRY
- this'll round it up. Note that this method does not work
on PCs with no network adapter (like PCs connecting via a
modem to an ISP and getting a dynamic address) so that in
such cases it's still necessary to fall back on alternative
methods (such as looking in the registry, etc) to get the
DNS server(s).

Just as an aside there seemed to be a problem (the post is
date 1999 so the situation may have changed) with GetNetworkParams
in special situations. Follow this link for the discussion on
this issue:
http://www.stardust.com/hypermail/winsock2/0596.html

UPDATE: looking around it seems to be only supported on Win2000
and Win98 - I'll add it anyway

Cheers

Florent

------------------

[This message has been edited by Florent Heyworth (edited May 16, 2001).]

**Florent Heyworth** · 16 May 2001, 09:33 AM

hi michael

i added getnetworkparams to the code at http://www.powerbasic.com/support/pb...ad.php?t=24950
could you test it and tell me if my implementation works
(it returns not supported on my nt 4.0 sp6 system).

thanks!

florent heyworth

------------------

**Michael Burns** · 16 May 2001, 03:15 PM

Hi Florent

I seemed to be having a problem with it compiling. I am using PB DLL 6.00.
Does not like the print statements:
PRINT "Error: Could not find DNS server"
PRINT "specify /d<DNS_Server_Address> ON the command LINE"
So I changed them to MSGBOX statements.

With PRINT to MSGBOX change, it compiles but I get "no data" when I run it with one
email address, and get "Not implemented yet." when I run it with another. Not sure what
that all means. Maybe I need to pick friends with better email addresses?

I agree that the total "DNS finding" routine should look in all locations,
and maybe eliminate duplicates. In my application, I'll ping them as well
so that I have a list that I believe is active DNS servers. I tried to use the
loadlibrary way of using iphlpapi.dll as, from what I can find about it,
there are a lot of windows systems that don't have it at all, and it sounds
from your experience that some machines may have it, but a variation that
does not include GetNetworkParams(?) In those cases, I'll have to rely on
the System Registry.

I'll eventually have to make my application work on our testbed, which
quad-boots Win 95 OSR-2, Win 98 SE, Win ME, and Win 2k Professional. As far
as I know, Win 95 does not have iphlpapi.dll on it. I think 98 & Me do.
Not sure about Win 2k, or if it does, if it supports GetNetworkParams.

------------------
Michael Burns

[This message has been edited by Michael Burns (edited May 16, 2001).]

**Florent Heyworth** · 16 May 2001, 03:31 PM

Hi Michael

the app expects the following arguments.

<domain>|<mail address> /tMX [/d<optional dns server>]

/t represents the record type - at the moment only
MX (Mail Exchange records) are implemented

/d is an optional switch - you can use it to override the
DNS server look-up code telling it you want to use a
specific DNS server for the lookup. If this switch is not
present the program will try to look up the DNS server
using a combination GetNetworkParams and the registry.

So valid command lines would be:

dnsqry [email protected] /tMX
dnsqry domain.com /tMX
dnsqry domain.com /tMX /d193.12.1.25

When the program returns no data it means that the DNS server
could not answer the query you sent it. Did you try it with
a valid address?

Cheers

Florent

------------------

**John McWilliams** · 17 May 2001, 06:01 AM

FYI Florent, The necessary dll is installed on my NT4 SP6
+ post SP6 hotfixes, I also have IE 5 installed. So I must have
gotten it in one of those "upgrades". MSDN suggests that it's
installed in a number of SP's and IE upgrades but I couldn't
determine which one actually was responsible for the installation
of the required dll. Haven't tried the utility yet but glad I was
able to point everyone in the right direction.

**Florent Heyworth** · 17 May 2001, 07:25 AM

Hi John

thanks for the info. I'm running NT 4.0 with SP6a and iphlpapi.dll
is installed and GetNetworkParams is an exported function. However
it returns ERROR_NOT_SUPPORTED when called (it seems not to
be implemented). MSDN seems to indicate that GetNetworkParams
is only implemented on Win2000/Win98+.

Cheers

Florent

------------------

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