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path: root/drivers/net/nlmon.c
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2013-07-02nlmon: use standard rtnetlink link api for add/del devicesJiri Pirko1-21/+28
It is not nice when netdev is created right after module load and with some implicit name. So rather change nlmon to use standard rtnl link API. Signed-off-by: Jiri Pirko <jiri@resnulli.us> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-28nlmon: fix comparison in nlmon_is_valid_mtuDaniel Borkmann1-1/+5
This patch fixes the following warning introduced in e4fc408e0e99 ("packet: nlmon: virtual netlink monitoring device for packet sockets") reported by Dan Carpenter: warning: "drivers/net/nlmon.c:31 nlmon_is_valid_mtu() warn: always true condition '(new_mtu <= ((~0 >> 1))) => (s32min-s32max <= s32max)'" Thus, we should simply remove the test against INT_MAX. Next to that we also need to explicitly cast the sizeof() case as the comparison is type promoted to unsigned long so negative values are then valid instead of invalid. While at it, this also adds a comment about Netlink and MTUs. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-24packet: nlmon: virtual netlink monitoring device for packet socketsDaniel Borkmann1-0/+170
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>