1. 20 Dec, 2017 1 commit
    • Alexey Kodanev's avatar
      ip6_vti: adjust vti mtu according to mtu of lower device · 53c81e95
      Alexey Kodanev authored
      LTP/udp6_ipsec_vti tests fail when sending large UDP datagrams over
      ip6_vti that require fragmentation and the underlying device has an
      MTU smaller than 1500 plus some extra space for headers. This happens
      because ip6_vti, by default, sets MTU to ETH_DATA_LEN and not updating
      it depending on a destination address or link parameter. Further
      attempts to send UDP packets may succeed because pmtu gets updated on
      ICMPV6_PKT_TOOBIG in vti6_err().
      
      In case the lower device has larger MTU size, e.g. 9000, ip6_vti works
      but not using the possible maximum size, output packets have 1500 limit.
      
      The above cases require manual MTU setup after ip6_vti creation. However
      ip_vti already updates MTU based on lower device with ip_tunnel_bind_dev().
      
      Here is the example when the lower device MTU is set to 9000:
      
        # ip a sh ltp_ns_veth2
            ltp_ns_veth2@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 ...
              inet 10.0.0.2/24 scope global ltp_ns_veth2
              inet6 fd00::2/64 scope global
      
        # ip li add vti6 type vti6 local fd00::2 remote fd00::1
        # ip li show vti6
            vti6@NONE: <POINTOPOINT,NOARP> mtu 1500 ...
              link/tunnel6 fd00::2 peer fd00::1
      
      After the patch:
        # ip li add vti6 type vti6 local fd00::2 remote fd00::1
        # ip li show vti6
            vti6@NONE: <POINTOPOINT,NOARP> mtu 8832 ...
              link/tunnel6 fd00::2 peer fd00::1
      Reported-by: default avatarPetr Vorel <pvorel@suse.cz>
      Signed-off-by: default avatarAlexey Kodanev <alexey.kodanev@oracle.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      53c81e95
  2. 19 Dec, 2017 33 commits
  3. 18 Dec, 2017 6 commits