Messages in this thread | | | Date | Tue, 27 Jan 2015 15:46:53 +0100 | From | Daniel Borkmann <> | Subject | Re: [PATCH] net: Linn Ethernet Packet Sniffer driver |
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Hi Stathis,
On 01/27/2015 12:15 PM, Stathis Voukelatos wrote: > On 26/01/15 10:10, Daniel Borkmann wrote: >>> Hello Daniel. Thank you for your feedback. >>> Packet sockets could also be used for the driver interface to >>> user space, however I think that both approaches would require the same >>> amount of maintenance. We need to maintain a protocol consisting of >>> a set of messages or commands that user space can use to communicate >>> with the driver in order to configure the H/W and retrieve results. >>> We could use packet sockets to send those messages too, but I thought >>> netlink already provides a message exchange framework that we could >>> make use of. >> >> When using packet sockets and your driver as a backend feeding them, >> users can see that there's an extra capturing/monitoring netdev present, >> all libpcap-based tools such as tcpdump et al would work out of the box >> w/o adapting any code, and as an admin you can also see what users/tools >> are making of use of the device through packet sockets. I couldn't parse >> the exact motivation from the commit message of why avoiding all this is >> better? > > Just wanted to clarify some implementation details for your approach. > - The driver would need to create and register two net_device instances. > One for sniffing Ethernet TX packets and one for RX.
Hm, I would represent the whole device as a single monitoring-only netdev. I'm somehow still missing the big advantage of all this as compared to using packet sockets on the normal netdev? I couldn't parse that from your commit message.
> - Would the control interface for the sniffer in that case need to be > through private socket ioctls (ie SIOCDEVPRIVATE + x ioctl ids)?
Nope, please have a look at Documentation/networking/packet_mmap.txt.
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