At least the Apple Airport Extreme doesn't allow hairpin
sends from a private socket until it's seen traffic from
that src IP:port to something else out on the internet.
See https://github.com/tailscale/tailscale/issues/188#issuecomment-600728643
And it seems that even sending to a likely-filtered RFC 5737
documentation-only IPv4 range is enough to set up the mapping.
So do that for now. In the future we might want to classify networks
that do and don't require this separately. But for now help it.
I've confirmed that this is enough to fix the hairpin check on Avery's
home network, even using the RFC 5737 IP.
Fixes#188
There's a lot of confusion around what tailscale status shows, so make it better:
show region names, last write time, and put stars around DERP too if active.
Now stars are always present if activity, and always somewhere.
* fix tailscale status for peers using discovery
* as part of that, pull out disco address selection into reusable
and testable discoEndpoint.addrForSendLocked
* truncate ping/pong logged hex txids in half to eliminate noise
* move a bunch of random time constants into named constants
with docs
* track a history of per-endpoint pong replies for future use &
status display
* add "send" and " got" prefix to discovery message logging
immediately before the frame type so it's easier to read than
searching for the "<-" or "->" arrows earlier in the line; but keep
those as the more reasily machine readable part for later.
Updates #483
This is a prelude to adding more fields, which would otherwise
become more unnamed function params.
Signed-off-by: David Anderson <danderson@tailscale.com>
It's just a config wrapper that passes "use less memory at the
expense of compression" parameters by default, so that we don't
accidentally construct resource-hungry (de)compressors.
Also includes a benchmark that measures the memory cost of the
small variants vs. the stock variants. The savings are significant
on both compressors (~8x less memory) and decompressors (~1.4x less,
not including the savings from the significantly smaller
window on the compression side - with those savings included it's
more like ~140x smaller).
BenchmarkSmallEncoder-8 56174 19354 ns/op 31 B/op 0 allocs/op
BenchmarkSmallEncoderWithBuild-8 2900 382940 ns/op 1746547 B/op 36 allocs/op
BenchmarkStockEncoder-8 48921 25761 ns/op 286 B/op 0 allocs/op
BenchmarkStockEncoderWithBuild-8 426 2630241 ns/op 13843842 B/op 124 allocs/op
BenchmarkSmallDecoder-8 123814 9344 ns/op 0 B/op 0 allocs/op
BenchmarkSmallDecoderWithBuild-8 41547 27455 ns/op 27694 B/op 31 allocs/op
BenchmarkStockDecoder-8 129832 9417 ns/op 1 B/op 0 allocs/op
BenchmarkStockDecoderWithBuild-8 25561 51751 ns/op 39607 B/op 92 allocs/op
Signed-off-by: David Anderson <danderson@tailscale.com>
Update the mapping from ip:port to discokey, so when we retrieve a
packet from the network, we can find the same conn.Endpoint that we
gave to wireguard-go previously, without making it think we've
roamed. (We did, but we're not using its roaming.)
Updates #483
Ping messages now go out somewhat regularly, pong replies are sent,
and pong replies are now partially handled enough to upgrade off DERP
to LAN.
CallMeMaybe packets are sent & received over DERP, but aren't yet
handled. That's next (and regular maintenance timers), and then WAN
should work.
Updates #483
Starting at yesterday's e96f22e560 (convering some UDPAddrs to
IPPorts), Conn.ReceiveIPv4 could return a nil addr, which would make
its way through wireguard-go and blow up later. The DERP read path
wasn't initializing the addr result parameter any more, and wgRecvAddr
wasn't checking it either.
Fixes#515
