Hello Experts! There is a strange problem in our NDIS driver. There are some NICs in our office which the MPSendPackets function (miniport part of the driver) gets only 40-60 bytes long packages, while on other NICs this function can get up to 600 or more bytes. Is it normal or what could cause this problem? Thank you in advance!
First of all, what is a ‘package’?
NDIS 5.x has NDIS_PACKET and NDIS_BUFFER and NDIS 6.x has NET_BUFFER_LIST,
NET_BUFFER, and what is essentially the same as and NDIS_BUFFER structures.
A Miniport is given a NDIS_PACKET or a (list of) NETBUFFER to send, not a
‘package’.
As a wild assumption, I will guess you have an NDIS 5.x driver and since you
mention it has an MPSendPackets (that would be MiniportSendPackets handler,
right?) I will assume it is a LAN miniport driver.
I will further wildly assume that what you mean by ‘package’ is infact an
NDIS_BUFFER (a piece of a packet).
Yes, a bound protocol (like TCPIP.SYS) is perfectly within the norm to
describe an NDIS_PACKET for send in as many little bits and pieces it sees
fit just so long as the entire MAC header is described by the first
NDIS_BUFFER in the NDIS_PACKET.
It is not unusual to see TCP/IP generate packets like the following:
NDIS_BUFFER: [MAC Header, 0xE bytes]
NDIS_BUFFER: [IP Header, 0x14 bytes]
NDIS_BUFFER: [UDP Header, 0x8 bytes]
NDIS_BUFFER: [Payload1, n bytes]
NDIS_BUFFER: [Payload2, k bytes]
…
So, if you think there is a problem with 40-60 byte ‘packages’ where you are
expecting 600 byte ‘packages’ then you best try your question again and this
time use NDIS_PACKET an NDIS_BUFFER in the question and omit ‘package’ so we
can know what you are asking.
Good Luck,
Dave Cattley
Consulting Engineer
Systems Software Development
-----Original Message-----
From: xxxxx@lists.osr.com
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Sent: Wednesday, November 26, 2008 9:08 AM
To: Windows System Software Devs Interest List
Subject: [ntdev] NDIS miniport problem
Hello Experts! There is a strange problem in our NDIS driver. There are some
NICs in our office which the MPSendPackets function (miniport part of the
driver) gets only 40-60 bytes long packages, while on other NICs this
function can get up to 600 or more bytes. Is it normal or what could cause
this problem? Thank you in advance!
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The driver is an NDIS 5.1 driver and the package means NDIS_PACKET.
I wonder if your code might be only looking at the first buffer, instead of
following the chain of buffers, in the packet?
wrote in message news:xxxxx@ntdev…
> The driver is an NDIS 5.1 driver and the package means NDIS_PACKET.
>