wireguard-go uses 3 goroutines per peer (with reasonably large stacks
& buffers).
Rather than tell wireguard-go about all our peers, only tell it about
peers we're actively communicating with. That means we need hooks into
magicsock's packet receiving path and tstun's packet sending path to
lazily create a wireguard peer on demand from the network map.
This frees up lots of memory for iOS (where we have almost nothing
left for larger domains with many users).
We should ideally do this in wireguard-go itself one day, but that'd
be a pretty big change.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
sync.Pools should almost always be packate globals, even though in this
case we only have exactly 1 TUN device anyway, so it matters less.
Still, it's unusual to see a Pool that's not a package global, so move it.
We originally picked those numbers somewhat at random, but with the idea
that 8 is a traditionally lucky number in Chinese culture. Unfortunately,
"88" is also neo-nazi shorthand language.
Use 52 instead, because those are the digits above the letters
"TS" (tailscale) on a qwerty keyboard, so we're unlikely to collide with
other users. 5, 2 and 52 are also pleasantly culturally meaningless.
Signed-off-by: David Anderson <danderson@tailscale.com>
This prevents hostname being forced to os.Hostname despite override
when control is contacted for the first time after starting tailscaled.
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
Nameserver IP 10.11.12.13 would otherwise get written to resolv.conf as 13.12.11.10, as was happening on my client.
Signed-off-by: Eduardo Kienetz <eduardo@kienetz.com>
Before this patch, the 250ms sleep would not be interrupted by context cancellation,
which would result in the goroutine sometimes lingering in tests (100ms grace period).
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
Very rarely, cancellation occurs between a successful send on derpRecvCh
and a call to copyBuf on the receiving side.
Without this patch, this situation results in <-copyBuf blocking indefinitely.
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
Peers advertising a discovery key know how to speak the discovery
protocol and do their own heartbeats to get through NATs and keep NATs
open. No need for the pinger except for with legacy peers.
The new interface lets implementors more precisely distinguish
local traffic from forwarded traffic, and applies different
forwarding logic within Machines for each type. This allows
Machines to be packet forwarders, which didn't quite work
with the implementation of Inject.
Signed-off-by: David Anderson <danderson@tailscale.com>
