Re: uIP: bus-fault arising from use of TCP in an echo-client; reason: uip_periodic() called with a NULL buf

Paul Sokolovsky

Hello Rohit,

On Fri, 12 Aug 2016 15:09:28 +0000
Rohit Grover <Rohit.Grover(a)> wrote:

Thanks for the fix. I no longer get a bus fault. I still don’t see
client's data being received at the echo-server, but that needs to be
looked at with fresh eyes.

Please share if you have a working demo which uses TCP; it would be
useful addition to samples/net.
There's already TCP support in samples/net/echo_server , you just need
to build it with CONFIG_NETWORKING_WITH_TCP=y . While waiting for
FRDM-K64F Ethernet driver progress, I decided to try QEMU virtual
networking. After some fiddling (which I'm going to describe in a
following mail), and defining the setting above, both UDP and TCP for
echo_server work for me:

$ echo foobar | nc -6 -u 2001:db8::2 4242



$ echo foobar | nc -6 -q3 2001:db8::2 4242

(unlike UDP server, TCP one doesn't reverse data order).

Pings also work:

$ ping6 2001:db8::2
PING 2001:db8::2(2001:db8::2) 56 data bytes
64 bytes from 2001:db8::2: icmp_seq=1 ttl=64 time=4.41 ms
64 bytes from 2001:db8::2: icmp_seq=2 ttl=64 time=2.50 ms
64 bytes from 2001:db8::2: icmp_seq=3 ttl=64 time=2.72 ms


Best Regards,
Paul | Open source software for ARM SoCs
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