On Wed, 28 Feb 2024 10:20:27 +0100 Sascha Hauer <sha@xxxxxxxxxxxxxx> wrote: Hi Sascha! > On Wed, Feb 28, 2024 at 10:26:15AM +0300, Antony Pavlov wrote: > > On Sat, 17 Feb 2024 09:51:02 +0100 > > Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote: > > > > Hi All! > > > > > Hello Antony, > > > > > > On 05.02.24 10:59, Antony Pavlov wrote: > > > > On Wed, 31 Jan 2024 22:37:50 +0100 > > > > Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote: > > > > > > > > Hi All! > > > > > > > >> Hello Dan, > > > >> > > > >> On 31.01.24 22:03, Dan Shelton wrote: > > > >>> Hello! > > > >>> > > > >>> Does barebox support booting from a NFSv4 filesystem, e.g. boot from > > > >>> NFSv4 filesystem into a Linux NFSv4 netroot (diskless machine)? > > > >> > > > >> The barebox network stack only does UDP/IP. There have been attempts to > > > >> bring a TCP stack into barebox, but none have so far succeeded to > > > >> make it mainline. This is a hard requirement before we can consider > > > >> supporting NFSv4. I hope that lwIP could fill this gap in the future, > > > >> but no one is actively continuing this work as far as I am aware[1]. > > > > > > > > I have started integration on picotcp into barebox in 2015, see > > > > https://lore.barebox.org/barebox/1436991230-14251-10-git-send-email-antonynpavlov@xxxxxxxxx/T/ > > > > Actually I made the first attempt to integrate picotcp into barebox in 2014, > > see http://lists.infradead.org/pipermail/barebox/2014-May/019243.html > > > > 10 years is too long for this task :) > > > > In the message http://lists.infradead.org/pipermail/barebox/2015-July/024244.html > > if I understand correctly Sascha asked me to keep network stuff > > users (tftp, nfs, netconsole) as intact as possible. > > > > At the moment I understand that this task is too hard. > > > > The problem is: the network stuff users don't rely on "a network stack" > > in the true sense. E.g. tftp_handler() takes an ETHERNET PACKET on > > it's input, tftp_handler() skips Ethernet and IP stuff by itself > > and modifies UDP fields directly! > > > > This week I have connected picotcp code to the existing network code > > in the way that makes it possible to keep dhcp_handler() and > > ftp_handler() intact. The result is ugly: barebox netdevice driver > > receives frame from network, pass it to picotcp, picotcp parses > > network protocol headers and extracts udp payload, next > > picotcp passes udp payload back to my picotcp-to-barebox adapter, > > the adapter RECONSTRUCTS ETHERNET PACKET and give it to tftp/dhcp_handler()! > > This horrible approach creates more problems than it solves! > So if I understand correctly you tried passing *all* incoming packets to > picotcp and route some of them back to the barebox network stack. for every barebox network device I create picotcp network device which can send packets by picotcp initiative. net_receive() just calls pico_stack_recv() with corresponding picotcp network device as an argument, so no code change in drivers/net/. net_poll() just calls pico_stack_tick(). So all incoming packets go to picotcp only. Picotcp can send packet if necessary without barebox interraction. UDP datagrams processed by picotcp routed to corresponding dhcp/tftp_handler(). Are dhcp/tftp_handlers parts of barebox network stack? > Instead of passing all packets to picotcp, can't we just dispatch the > incoming packets on a per-port basis in barebox and only pass the ones > picotcp shall handle to picotcp? Good idea. I have to try. We can reroute IPv6 traffic to picotcp in net_receive() and reroute TCP/IPv4 traffic to picotcp in net_handle_ip(). > So basically a struct net_connection with the handler set to the picotcp > receive function? net_connection handler is set to the normal unamended dhcp/tftp_handlers. > That way it might be possible to have the barebox network stack and > picotcp in parallel and port the handlers over to pictotcp one by one. But I see a problem here. If there is a ARP respond in the incoming traffic I have no idea there to send it. Both barebox network code and picotcp can make ARP request. I suppose can just route ARP respond to the both stacks. But what I have to do if an ARP or ICMP echo __request__ is received? I suppose it is possible to add some simple dynamic incoming packet filtration rules that can be changed on-the-fly for testing purposes. -- Best regards, Antony Pavlov
