Re: [lwip-users] Ethernet raw frames?

[Leon Woestenberg]

Hello Mike,

> tcp_enqueue() gets called at some point <from
> tcpip_thread>. It creates two pbufs, seg->p & p.
> seg->p is of type PBUF_RAM.
> p is of type PBUF_ROM
> p is chained with seg->p. "pbuf_chain(seg->p, p);"
> seg->p carries the ACK packet with the TCP header
> p carries the pointer to the constant 'http_html_hdr'.
> And no header attached to it.
>
A chain of pbufs always represents one packet.

> Later the IP layer calls the netif->output() function
> with the pbuf (p chained to seg->p). Note: the 1st
> Packet, ACK is complete with its header & stuff. But
> the second packet has just the raw string contained in
> 'http_html_hdr'.
>
Here you indicate that the chained pbuf's are sent as seperate
packets, which is not what is supposed to happen.

I recon the chaining fails, or maybe the Ethernet device
driver fails to send a pbuf chain as one consecutive packet.

I would start adding some debug statements to see if
the pbuf chaining works and is not broken.

Regards,

Leon