On 9/9/18 9:16 AM, Alan Bateman wrote: > On 07/09/2018 13:22, Andre Naujoks wrote: >> : >> I have not tried joining IPv4 groups on an IPv6 socket through java, >> since we do not use IPv4 at all in this particular environment. I have >> tried setting IP_MULTICAST_ALL to 0 in the IPv6 scenario (in a C++ >> project), hoping it would help, but it did not. Hence the patch for the >> linux kernel. >> >> Would it actually help, if I tried the IPv4 multicast group bind on an >> IPv6 socket? >> >> The bind to an address would be a workaround for the missing >> IPV6_MULTICAST_ALL handling. >> > The tests that we have for the scenario of two sockets bound to the same > port but joining different multicast groups seems to be mostly using > IPv4 multicast addresses so one thing out this discussion is that we may > need to expand the tests to IPv6 multicast addresses. As the existing > tests use IPv6 sockets (when not disabled on the system or in the test > run) then it means they are exercising IP_MULTICAST_ALL=0 so I think we > can conclude that disabling IP_MULTICAST_ALL works correctly for IPv6 > sockets when joining IPv4 multicast groups. If the tests were expanded > to IPv6 multicast groups then I assume we will run into the need for > IPV6_MULTICAST_ALL too.
Yes, I would assume the same. That was the whole reason for the kernel patch. > > As regards the patch to NET_InetAddressToSockaddr to set the scope_id > then it looks correct but need testing (both for bind and connect). I > see JDK-8210493 has been picked up by Vyom. Please test it! This is my very first look into the java code-base. The patch does what it says, but I cannot rule out, that it doesn't have any unintended side effects. > > -Alan > >
