Re-sending this one, as I don't see it appearing on the maillist list archive. I'm editing more information I got meanwhile in.
On 08.04.2018 15:21, Dominik wrote: > Dear dnsmasq enthusiasts, > > we encountered a rather strange issue with dnsmasq and Netflix on SmartTVs or > XBox (only > in this combination). > > Once Netflix is started, it queries a domain like ichnaea.netflix.com. This > query gets > answered by dnsmasq. However, sometimes, Netflix doesn't seem to be satisfied > with this > anwer over UDP and tries another query, this time over TCP. dnsmasq stalls at > this query > and does not answer any queries at all until the Netflix app is closed. > > We think the Netflix app isn't properly ending the stream (which shouldn't > happen to begin with) > but dnsmasq is not able to handle this correctly. > > Compare the following: > > Broken (X is Xbox): > > X > pi [SYN] > pi > X [SYN, ACK] > X > pi [ACK] > X > pi Standard query A api-global.netflix.com > pi > X [ACK] > pi > X Standard query response > X > pi [ACK] > > When doing a similar query from a linux machine (Y is linux machine) as dig > @pi +tcp api-global.netflix.com it looks like this: > > Y > pi [SYN] > pi > Y [SYN, ACK] > Y > pi [ACK] > Y > pi Standard query A api-global.netflix.com > pi > Y [ACK] > pi > Y Standard query response > Y > pi [ACK] > Y > pi [FIN, ACK] > Y > pi [FIN, ACK] > pi > Y [ACK] > > For seeing where it hangs with the stalling TCP request, we compiled dnsmasq > 2.79 from source and > added debug symbols (-g3). The crash is the same. When I interrupt > dnsmasq while it is stalled, I see this backtrace: > > #0 0x00007ffff7b15700 in __read_nocancel () at > ../sysdeps/unix/syscall-template.S:84 > #1 0x0000555555566533 in read_write (fd=fd@entry=13, > packet=packet@entry=0x7fffffffe334 "\002[\001", size=size@entry=1, > rw=rw@entry=1) at util.c:654 > #2 0x000055555557029c in tcp_request (confd=13, now=1523191598, > local_addr=0x7fffffffe410, netmask=..., auth_dns=0) at forward.c:1713 > #3 0x0000555555575999 in check_dns_listeners (now=1523191598) at > dnsmasq.c:1745 > #4 0x000055555555d019 in main (argc=<optimized out>, argv=<optimized > out>) at dnsmasq.c:1061 > > Please tell me if you would like to see any further information for > debugging. > > Best regards, > Dominik > _______________________________________________ Dnsmasq-discuss mailing list Dnsmasqfirstname.lastname@example.org http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss