lwip-users
[Top][All Lists]
Advanced
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[lwip-users] [lwip] Recent change in pbuf.c

From: David Haas
Subject: [lwip-users] [lwip] Recent change in pbuf.c
Date: Thu, 09 Jan 2003 00:15:59 -0000 
This is a multi-part message in MIME format.

------=_NextPart_000_01C2_01C29A1C.271BF2A0
Content-Type: text/plain;
        charset="Windows-1252"
Content-Transfer-Encoding: quoted-printable

There was a recent change in pbuf.c by jani which says: "fix pbuf_alloc =
for layer PBUF_LINK". This change has caused some problems for me and I =
want to explore why.

In my ethernet driver I am using PBUF_LINK when allocating pbufs for the =
receive buffers. This recent change will reserve bytes in the front of =
the pbuf, presumably for a link-level header. However, the ethernet chip =
will be putting a link-level header in the packet already. So I would =
claim that the offset for PBUF-LINK should be 0 (which it was before it =
was changed). Now, I could change my allocation to PBUF_RAW, but I would =
claim that would wrong.

Any comment?

David Haas
NBS Card Technology
70 Eisenhower Drive,
Paramus, NJ 07652
Voice: 201-845-7373 x183
Fax: 201-845-3337
email: address@hidden

------=_NextPart_000_01C2_01C29A1C.271BF2A0
Content-Type: text/html;
        charset="Windows-1252"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Dwindows-1252">
<META content=3D"MSHTML 6.00.2800.1126" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT size=3D2>There was a recent change in pbuf.c by jani which =
says: "fix=20
pbuf_alloc for layer PBUF_LINK". This change has caused some problems =
for me and=20
I want to explore why.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>In my ethernet driver I am using PBUF_LINK when =
allocating=20
pbufs for the receive buffers. This recent change will reserve bytes in =
the=20
front of the pbuf, presumably for a link-level header. However, the =
ethernet=20
chip will be putting a link-level header in the packet already. So I =
would claim=20
that the offset for PBUF-LINK should be 0 (which it was before it was =
changed).=20
Now, I could change my allocation to PBUF_RAW, but I would claim that =
would=20
wrong.</FONT></DIV>
<DIV><FONT size=3D2></FONT>&nbsp;</DIV>
<DIV><FONT size=3D2>Any comment?</FONT></DIV>
<DIV>&nbsp;</DIV>
<DIV><FONT size=3D2>David Haas<BR>NBS Card Technology<BR>70 Eisenhower=20
Drive,<BR>Paramus, NJ 07652<BR>Voice: 201-845-7373 x183<BR>Fax:=20
201-845-3337<BR>email: <A=20
href=3D"mailto:address@hidden";>address@hidden</A><BR></FONT></DIV><=
/BODY></HTML>

------=_NextPart_000_01C2_01C29A1C.271BF2A0--

[This message was sent through the lwip discussion list.]
reply via email to
[Prev in Thread] Current Thread [Next in Thread]