On Thu, Jan 10, 2019 at 05:48:26PM +0530, Sandeep K M wrote: > On Wed, Jan 9, 2019 at 10:33 PM Simon Kelley wrote: > > On 04/01/2019 06:25, Sandeep K M wrote: > > > > > > Attached are the packet captures: > > > > > > 1. Packets exchanged between client and relay (client-relay.pcap) > > > 2. Packets exchanged between relay and server (relay-server.pcap) > > > 3. strace of dnsmasq (dnsmasq.trace) > > > ... > > > > I'm sure this was tested with a relay, but the current test harnesses > > here would take some work to get into a position to test this code, so > > I'm going to try and use you as a tester, if that's OK? > > > > > > Looking at the strace output, dnsmasq logs that it's sending a > > DHCPADVERTISE reply, but it never calls sendto() to actually send the > > packet. This is definitely a dnsmasq bug, and not something in your > > network that's causing the packet to get lost: it never gets sent. > > > > > > What's confusing me is that manually tracing the code paths from what's > > known to be working (log the DHCPADVERTISE) to the sendto() call that > > should send that packet, I can't see any reason why the code should fail. > > > > Are you in a position to run dnsmasq under gdb and step through the > > relevant code? I can give you detailed instructions on where to set > > breakpoints and where the reply packet could be getting lost. The path > > is maybe 50 lines. > > > > Staring at the code has found me one bug, but it's not relevant in this > > case. (The code to avoid copying an RFC6939 link address option in a > > relay request to the reply to the relay actually sends a zero-length > > option, instead of eliding it entirely.) > > > > I will be happy to be your tester :) > > Its fairly a simple setup with two hosts and a switch. I can create this > any time you want. > > Please provide me the instructions. I am using dnsmasq version 2.78.
Keeping the ML in loop would be good. At least for the sake of the mailinglist archive. Regards Geert Stappers _______________________________________________ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
