Currently, the `ip fou` command tries to initialize a genl context even
when we just want to see the help for the command, which doesn't require
to talk to the kernel at all.
Delay genl initialization, which can fail if the module isn't loaded,
until the point where we will actually need it.
Fixes: 6928747b6e ("ip fou: Support to configure foo-over-udp RX")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
All users of genl have the same code to open a genl socket and resolve
the family for their specific protocol. Introduce a helper to initialize
the handle, and use it in all the genl code.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
There have been several instances where response from kernel
has overrun the stack buffer from the caller. Avoid future problems
by passing a size argument.
Also drop the unused peer and group arguments to rtnl_talk.
Added 'ip fou...' commands to enable/disable UDP ports for doing
foo-over-udp and Generic UDP Encapsulation variant. Arguments are port
number to bind to and IP protocol to map to port (for direct FOU).
Examples:
ip fou add port 7777 gue
ip fou add port 8888 ipproto 4
The first command creates a GUE port, the second creates a direct FOU
port for IPIP (receive payload is a assumed to be an IPv4 packet).
Signed-off-by: Tom Herbert <therbert@google.com>