On sufficiently large tailnets, even writing the peer header (~95 bytes)
can result in a large amount of data that needs to be serialized and
deserialized. Only write headers for peers that need to have their
configuration changed.
Signed-off-by: Andrew Dunham <andrew@tailscale.com>
I was working on my "dump iptables rules using only syscalls" branch and
had a bunch of C structure decoding to do. Rather than manually
calculating the padding or using unsafe trickery to actually cast
variable-length structures to Go types, I'd rather use a helper package
that deals with padding for me.
Padding rules were taken from the following article:
http://www.catb.org/esr/structure-packing/
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>