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| author | Daniel Borkmann <dborkman@redhat.com> | 2013-06-21 21:38:08 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-06-25 03:39:05 +0400 |
| commit | e4fc408e0e99fd2e009c8b3702d9637f5554fd5c (patch) | |
| tree | f808ee97e82aaeea7c5fce0dea7ae37610ad27cb /drivers/net/Kconfig | |
| parent | bcbde0d449eda7afa8f63280b165c8300dbd00e2 (diff) | |
| download | linux-e4fc408e0e99fd2e009c8b3702d9637f5554fd5c.tar.xz | |
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 <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/Kconfig')
| -rw-r--r-- | drivers/net/Kconfig | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 00aba08f01a9..b45b240889f5 100644 --- a/drivers/net/Kconfig +++ b/drivers/net/Kconfig @@ -240,6 +240,16 @@ config VIRTIO_NET This is the virtual network driver for virtio. It can be used with lguest or QEMU based VMMs (like KVM or Xen). Say Y or M. +config NLMON + tristate "Virtual netlink monitoring device" + ---help--- + This option enables a monitoring net device for netlink skbs. The + purpose of this is to analyze netlink messages with packet sockets. + Thus applications like tcpdump will be able to see local netlink + messages if they tap into the netlink device, record pcaps for further + diagnostics, etc. This is mostly intended for developers or support + to debug netlink issues. If unsure, say N. + endif # NET_CORE config SUNGEM_PHY |