On 12/28/2015 10:53 PM, Doug Ledford wrote:
The 4.4-rc7 kernel is failing for me. In my case, all of my vlan interfaces are failing to obtain a dhcp address using dhclient. I've tried a hand built 4.4-rc7, and the Fedora rawhide 4.4-rc7 kernel, both failed. I've tried NetworkManager and the old SysV network service, both fail. I tried a working dhclient from rhel7 on the Fedora rawhide install and it failed too. Running tcpdump on the interface shows the dhcp request going out, and a dhcp response coming back in. Running strace on dhclient shows that it writes the dhcp request, but it never recvs a dhcp response. If I manually bring the interface up with a static IP address then I'm able to run typical IP traffic across the link (aka, ping). It would seem that when dhclient registers a packet filter on the socket, that filter is preventing it from ever getting the dhcp response. The same dhclient works on any non-vlan interfaces in the system, so the filter must work for non-vlan interfaces. Aside from the fact that the interface is a vlan, we also use a priority egress map on the interface, and we use PFC flow control. Let me know if you need anymore to debug the issue, or email me off list and I can get you logins to my reproducer machines.
When you say 4.4-rc7 kernel is failing for you, what latest kernel version was working, where the socket filter was properly receiving the response on your vlan iface? Are you reasonably sure that the skb is dropped at the BPF filter attached to the dhcp's packet socket? Can you dump the BPF code of the filter? Are there any vlan offloading settings the filter is not taking into account (in the sense of classic BPF extensions, tcpdump/libpcap finally managed to cope with this)? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
