Hi Dave/all. There is quite common for drivers to speak with HW using "packet-like" messages. In our case, we put message into skb and push that out as an ordinary packet. HW then sends us reply in a packet, similar to other rx-ed packets.
It makes sense to monitor this communication. Not only for debugging during development, but mainly for collecting data for error reports from users. Very cool usecase is to teach wireshark to parse this communication so one can actually see online what is going on. Now the question is, what is the correct way to expose this communication to userspace. Naturally, this interface should be read-only. Also, the interface should be generic enough so it can be used for all drivers, including non-net drivers. 1) Special monitoring netdev. Might make sense to use a separate netdev. Is is easy to tap the communication. Driver would just create new netdev and push incoming and outgoing messages there. Downside is that there would be needed to wrap the messages with some metadata header, which seems quite odd. 2) generic Netlink (genl) interface. Easy to put metadata in, including the device identificator (pci address). User then can use nlmon in order to be able to use wireshark to see the netlink messages. Looks like 2) might be viable, well-defined, generic interface to carry this info. What do you think? Does this make sense? Thanks! Jiri -- 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
