[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [lwip-users] pbuf_header fails in etharp_output
From: |
Kieran Mansley |
Subject: |
RE: [lwip-users] pbuf_header fails in etharp_output |
Date: |
Tue, 22 May 2007 14:51:14 +0100 |
On Tue, 2007-05-22 at 15:47 +0200, Goldschmidt Simon wrote:
> > > That would make ICMP dependent of the link layer!
> >
> > No more so than TCP, UDP, etc. It would (if there wasn't
> > enough space in the pbuf it already had) simply allocate a
> > pbuf using the PBUF_IP pbuf_layer flag, and so it would have
> > enough space reserved for the IP and link headers.
>
> But how does the ICMP code know how much space to reserve fo the
> link layer?
Look at the start of pbuf_alloc(). It increases the required length
depending on what pbuf_layer is. It uses the port-defined constants
PBUF_TRANSPORT_HLEN, PBUF_IP_HLEN and PBUF_LINK_HLEN to know how much it
needs to reserve for the headers of each layer.
Kieran
- [lwip-users] pbuf_header fails in etharp_output, Matthias Weisser, 2007/05/22
- Re: [lwip-users] pbuf_header fails in etharp_output, Kieran Mansley, 2007/05/22
- RE: [lwip-users] pbuf_header fails in etharp_output, Goldschmidt Simon, 2007/05/22
- Antw: RE: [lwip-users] pbuf_header fails in etharp_output, Matthias Weisser, 2007/05/22
- Re: Antw: RE: [lwip-users] pbuf_header fails in etharp_output, Kieran Mansley, 2007/05/22
- RE: Antw: RE: [lwip-users] pbuf_header fails in etharp_output, Goldschmidt Simon, 2007/05/22
- RE: Antw: RE: [lwip-users] pbuf_header fails in etharp_output, Kieran Mansley, 2007/05/22
- RE: [lwip-users] pbuf_header fails in etharp_output, Goldschmidt Simon, 2007/05/22
- RE: [lwip-users] pbuf_header fails in etharp_output,
Kieran Mansley <=
- RE: Antw: RE: [lwip-users] pbuf_header fails in etharp_output, Matthias Weisser, 2007/05/23
- RE: Antw: RE: [lwip-users] pbuf_header fails in etharp_output, Kieran Mansley, 2007/05/23