Automatically probe the path MTU to a peer when peer MTU is enabled, but do not
use the MTU information for anything yet.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
Prepare for path MTU discovery by splitting up the concept of
DefaultMTU() into the concepts of the Tailscale TUN MTU, MTUs of
underlying network interfaces, minimum "safe" TUN MTU, user configured
TUN MTU, probed path MTU to a peer, and maximum probed MTU. Add a set
of likely MTUs to probe.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
Prepare for path MTU discovery by splitting up the concept of
DefaultMTU() into the concepts of the Tailscale TUN MTU, MTUs of
underlying network interfaces, minimum "safe" TUN MTU, user configured
TUN MTU, probed path MTU to a peer, and maximum probed MTU. Add a set
of likely MTUs to probe.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
Noted on #5915 TS_DEBUG_MTU was not used consistently everywhere.
Extract the default into a function that can apply this centrally and
use it everywhere.
Added envknob.Lookup{Int,Uint}Sized to make it easier to keep CodeQL
happy when using converted values.
Updates #5915
Signed-off-by: James Tucker <james@tailscale.com>
