[lwip-users] help configure netbuf size: requests truncated to 512 and the rest is unlinked in pbuf

[Li Eugene]

Hi

I'm using Freertos+lwip+webserver on mcf51cn128 and having a problem
receiving requests longer than 512 bytes.

I've traced it until sys_arch_mbox_fetch and i believe it is
xQueueReceive is copying truncated payload but don't see why. There is
plenty of space in pbuf pools and i've tried to play with mbox size
but it didn't make any difference.

netconn_rcv_req -> netconn_recv -> sys_arch_mbox_fetch -> xQueueReceive

I have tested it to be working fine if request fits within 512 bytes
tot_len by editing headers.

However when request is bigger, netconn always return chain of three
pbufs with sizes 202 + 256 + 54 = 512 tot_len (I have 10 pbufs size
256) and truncate the rest.

I can see the rest of the request stored somewhere further in pbufs
pool but it isn't linked to the chain.

Please point if I'm missing something or may be someone have an idea
where to dig or had similar problem?

Many thanks
Eugene