From: Daniel Borkmann Date: Fri, 21 Jun 2013 17:38:08 +0000 (+0200) Subject: packet: nlmon: virtual netlink monitoring device for packet sockets X-Git-Tag: v3.11-rc1~64^2~160 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e4fc408e0e99fd2e009c8b3702d9637f5554fd5c;p=pandora-kernel.git packet: nlmon: virtual netlink monitoring device for packet sockets Currently, there is no good possibility to debug netlink traffic that is being exchanged between kernel and user space. Therefore, this patch implements a netlink virtual device, so that netlink messages will be made visible to PF_PACKET sockets. Once there was an approach with a similar idea [1], but it got forgotten somehow. I think it makes most sense to accept the "overhead" of an extra netlink net device over implementing the same functionality from PF_PACKET sockets once again into netlink sockets. We have BPF filters that can already be easily applied which even have netlink extensions, we have RX_RING zero-copy between kernel- and user space that can be reused, and much more features. So instead of re-implementing all of this, we simply pass the skb to a given PF_PACKET socket for further analysis. Another nice benefit that comes from that is that no code needs to be changed in user space packet analyzers (maybe adding a dissector, but not more), thus out of the box, we can already capture pcap files of netlink traffic to debug/troubleshoot netlink problems. Also thanks goes to Thomas Graf, Flavio Leitner, Jesper Dangaard Brouer. [1] http://marc.info/?l=linux-netdev&m=113813401516110 Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- Reading git-diff-tree failed