On Fri, Mar 21, 2014 at 10:01:09AM +0000, Anton Ivanov wrote: > I am wondering how to re-organize these so that the code is not > duplicated across 3-4 drivers as well as allow people to easily add more > encaps in the future. > One way will be to pull all common routines into a common file and have > different option sets and different inits. Another will be to have > "encaps" as a parameter to a common driver. This, however will make all > params optional making option parsing ugly and prone to coding errors.
The user-visible command-line options will be different (e.g. L2TPv3 rx cookie). Therefore, I suggest having independent user-facing netdevs. In other words, give each encapsulation its own NetdevFooOptions in qapi-schema.json and a net_init_foo() function. qemu -netdev gre,... -netdev l2tp,... The actual implementation could be shared. Maybe something like: net/encap.c - common code for encapsulation/tunneling net/encap.h - header used by L2TPv3 and GRE net/l2tpv3.c - L2TPv3 specific code and net_init_l2tp() net/gre.c - GRE specific code and net_init_gre() How exactly the net/encap.h interface looks is something you need to decide based on the details. Does it make sense to have a common NetdevEncap struct that can be embedded and has function pointers for protocol-specific hooks? Or is it better to just provide common functions and let protocols use them as a library? It's up to you. Stefan
