A new package can also later record/report which knobs are checked and
set. It also makes the code cleaner & easier to grep for env knobs.
Change-Id: Id8a123ab7539f1fadbd27e0cbeac79c2e4f09751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Only if the source address isn't on the currently active interface or
a ping of the DERP server fails.
Updates #3619
Change-Id: I6bf06503cff4d781f518b437c8744ac29577acc8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So magicsock can later ask a DERP connection whether its source IP
would've changed if it reconnected.
Updates #3619
Change-Id: Ibc8810340c511d6786b60c78c1a61c09f5800e40
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Continuing work in 434af15a04, to make it possible for magicsock to
probe whether a DERP server is still there.
Updates #3619
Change-Id: I366a77c27e93b876734e64f445b85ef01eb590f2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In prep for a future change to have client ping derp connections
when their state is questionable, rather than aggressively tearing
them down and doing a heavy reconnect when their state is unknown.
We already support ping/pong in the other direction (servers probing
clients) so we already had the two frame types, but I'd never finished
this direction.
Updates #3619
Change-Id: I024b815d9db1bc57c20f82f80f95fb55fc9e2fcc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Otherwise random browser requests to /derp cause log spam.
Change-Id: I7bdf991d2106f0323868e651156c788a877a90d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We still try the host's x509 roots first, but if that fails (like if
the host is old), we fall back to using LetsEncrypt's root and
retrying with that.
tlsdial was used in the three main places: logs, control, DERP. But it
was missing in dnsfallback. So added it there too, so we can run fine
now on a machine with no DNS config and no root CAs configured.
Also, move SSLKEYLOGFILE support out of DERP. tlsdial is the logical place
for that support.
Fixes#1609
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
On about 1 out of 500 runs, TestSendFreeze failed:
derp_test.go:416: bob: unexpected message type derp.PeerGoneMessage
Closing alice before bob created a race.
If bob closed promptly, the test passed.
If bob closed slowly, and alice's disappearance caused
bob to receive a PeerGoneMessage before closing, the test failed.
Deflake the test by closing bob first.
With this fix, the test passed 12,000 times locally.
Fixes#2668
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
A public key should only have max one connection to a given
DERP node (or really: one connection to a node in a region).
But if people clone their machine keys (e.g. clone their VM, Raspbery
Pi SD card, etc), then we can get into a situation where a public key
is connected multiple times.
Originally, the DERP server handled this by just kicking out a prior
connections whenever a new one came. But this led to reconnect fights
where 2+ nodes were in hard loops trying to reconnect and kicking out
their peer.
Then a909d37a59 tried to add rate
limiting to how often that dup-kicking can happen, but empirically it
just doesn't work and ~leaks a bunch of goroutines and TCP
connections, tying them up for hour+ while more and more accumulate
and waste memory. Mostly because we were doing a time.Sleep forever
while not reading from their TCP connections.
Instead, just accept multiple connections per public key but track
which is the most recent. And if two both are writing back & forth,
then optionally disable them both. That last part is only enabled in
tests for now. The current default policy is just last-sender-wins
while we gather the next round of stats.
Updates #2751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If a peer is connected to multiple nodes in a region (so
multiForwarder is in use) and then a node restarts and re-sends all
its additions, this bug about whether an element is in the
multiForwarder could cause a one-time flip in the which peer node we
forward to. Note a huge deal, but not written as intended.
Thanks to @lewgun for the bug report in #2141.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It was once believed that it might be useful. It wasn't. We never used it.
Remove it so we don't slowly leak memory.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The DERPTestPort int meant two things before: which port to use, and
whether to disable TLS verification. Users would like to set the port
without disabling TLS, so break it into two options.
Updates #1264
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
After allowing for custom DERP maps, it's convenient to be able to see their latency in
netcheck. This adds a query to the local tailscaled for the current DERPMap.
Updates #1264
Signed-off-by: julianknodt <julianknodt@gmail.com>
This adds a flag to the DERP server which specifies to verify clients through a local
tailscaled. It is opt-in, so should not affect existing clients, and is mainly intended for
users who want to run their own DERP servers. It assumes there is a local tailscaled running and
will attempt to hit it for peer status information.
Updates #1264
Signed-off-by: julianknodt <julianknodt@gmail.com>
Before it was using the local address and port, so fix that.
The fields in the response from `ss` are:
State, Recv-Q, Send-Q, Local Address:Port, Peer Address:Port, Process
Signed-off-by: julianknodt <julianknodt@gmail.com>
This adds a handler on the DERP server for logging bytes send and received by clients of the
server, by holding open a connection and recording if there is a difference between the number
of bytes sent and received. It sends a JSON marshalled object if there is an increase in the
number of bytes.
Signed-off-by: julianknodt <julianknodt@gmail.com>
It would be useful to know the time that packets spend inside of a queue before they are sent
off, as that can be indicative of the load the server is handling (and there was also an
existing TODO). This adds a simple exponential moving average metric to track the average packet
queue duration.
Changes during review:
Add CAS loop for recording queue timing w/ expvar.Func, rm snake_case, annotate in milliseconds,
convert
Signed-off-by: julianknodt <julianknodt@gmail.com>
No server support yet, but we want Tailscale 1.6 clients to be able to respond
to them when the server can do it.
Updates #1310
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
