They're not needed for the sockstats logger, and they're somewhat
expensive to return (since they involve the creation of a map per
label). We now have a separate GetInterfaces() method that returns
them instead (which we can still use in the PeerAPI debug endpoint).
If changing sockstatlog to sample at 10,000 Hz (instead of the default
of 10Hz), the CPU usage would go up to 59% on a iPhone XS. Removing the
per-interface stats drops it to 20% (a no-op implementation of Get that
returns a fixed value is 16%).
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
I thought our versioning scheme would make go.mod include a commit hash
even on stable builds. I was wrong. Fortunately, the rest of this code
wants anything that 'git rev-parse' understands (to convert it into a full
git hash), and tags qualify.
Signed-off-by: David Anderson <danderson@tailscale.com>
tsnet.Server.Close was calling listener.Close with the server mutex
held, but the listener close method tries to grab that mutex, resulting
in a deadlock.
Co-authored-by: David Crawshaw <crawshaw@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
We were not handling tags at all, pass them through as Impersonate-Group headers.
And use the FQDN for tagged nodes as Impersonate-User.
Updates #5055
Signed-off-by: Maisem Ali <maisem@tailscale.com>
We persist the ServeConfig, even for tsnet apps. It's quite possible for
the ServeConfig to be out of step with the code. Example: If you run
`ListenFunnel` then later turn it off, the ServeConfig will still show
it enabled, the admin console will show it enabled, but the packet
handler will reject the packets.
Workaround by clearing the ServeConfig in `tsnet.Up`
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
This lets a tsnet binary share a server out over Tailscale Funnel.
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Signed-off-by: Shayne Sweeney <shayne@tailscale.com>
Followup to #7499 to make validation a separate function (
GetWithValidation vs. Get). This way callers that don't need it don't
pay the cost of a syscall per active TCP socket.
Also clears the conn on close, so that we don't double-count the stats.
Also more consistently uses Go doc comments for the exported API of the
sockstats package.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Though not fine-grained enough to be useful for detailed analysis, we
might as well export that we gather as client metrics too, since we have
an upload/analysis pipeline for them.
clientmetric.Metric.Add is an atomic add, so it's pretty cheap to also
do per-packet.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Previously the part that handled Funnel connections was not
aware of any listeners that tsnet.Servers might have had open
so it would check against the ServeConfig and fail.
Adding a ServeConfig for a TCP proxy was also not suitable in this
scenario as that would mean creating two different listeners and have
one forward to the other, which really meant that you could not have
funnel and tailnet-only listeners on the same port.
This also introduces the ipn.FunnelConn as a way for users to identify
whether the call is coming over funnel or not. Currently it only holds
the underlying conn and the target as presented in the "Tailscale-Ingress-Target"
header.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The addition of WaitGroup.Go in the standard library has been
repeatedly proposed and rejected.
See golang/go#18022, golang/go#23538, and golang/go#39863
In summary, the argument for WaitGroup.Go is that it avoids bugs like:
go func() {
wg.Add(1)
defer wg.Done()
...
}()
where the increment happens after execution (not before)
and also (to a lesser degree) because:
wg.Go(func() {
...
})
is shorter and more readble.
The argument against WaitGroup.Go is that the provided function
takes no arguments and so inputs and outputs must closed over
by the provided function. The most common race bug for goroutines
is that the caller forgot to capture the loop iteration variable,
so this pattern may make it easier to be accidentally racy.
However, that is changing with golang/go#57969.
In my experience the probability of race bugs due to the former
still outwighs the latter, but I have no concrete evidence to prove it.
The existence of errgroup.Group.Go and frequent utility of the method
at least proves that this is a workable pattern and
the possibility of accidental races do not appear to
manifest as frequently as feared.
A reason *not* to use errgroup.Group everywhere is that there are many
situations where it doesn't make sense for the goroutine to return an error
since the error is handled in a different mechanism
(e.g., logged and ignored, formatted and printed to the frontend, etc.).
While you can use errgroup.Group by always returning nil,
the fact that you *can* return nil makes it easy to accidentally return
an error when nothing is checking the return of group.Wait.
This is not a hypothetical problem, but something that has bitten us
in usages that was only using errgroup.Group without intending to use
the error reporting part of it.
Thus, add a (yet another) variant of WaitGroup here that
is identical to sync.WaitGroup, but with an extra method.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This reverts commit 6eca47b16c and fixes forward.
Previously the first ever streaming MapRequest that a client sent would also
set ReadOnly to true as it didn't have any endpoints and expected/relied on the
map poll to restart as soon as it got endpoints. However with 48f6c1eba4,
we would no longer restart MapRequests as frequently as we used to, so control
would only ever get the first streaming MapRequest which had ReadOnly=true.
Control would treat this as an uninteresting request and would not send it
any further netmaps, while the client would happily stay in the map poll forever
while litemap updates happened in parallel.
This makes it so that we never set `ReadOnly=true` when we are doing a streaming
MapRequest. This is no longer necessary either as most endpoint discovery happens
over disco anyway.
Co-authored-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Add Value, which measures the rate at which an event occurs,
exponentially weighted towards recent activity.
It is guaranteed to occupy O(1) memory, operate in O(1) runtime,
and is safe for concurrent use.
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
withSockStats may be called before setLinkMonitor, in which case we
don't have a populated knownInterfaces map. Since we pre-populate the
per-interface counters at creation time, we would end up with an
empty map. To mitigate this, we do an on-demand request for the list of
interfaces.
This would most often happen with the logtail instrumentation, since we
initialize it very early on.
Updates tailscale/corp#9230
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Effectively reverts #249, since the server side was fixed (with #251?)
to send a 200 OK/content-length 0 response.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
We can use the TCP_CONNECTION_INFO getsockopt() on Darwin to get
OS-collected tx/rx bytes for TCP sockets. Since this API is not available
for UDP sockets (or on Linux/Android), we can't rely on it for actual
stats gathering.
However, we can use it to validate the stats that we collect ourselves
using read/write hooks, so that we can be more confident in them. We
do need additional hooks from the Go standard library (added in
tailscale/go#59) to be able to collect them.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Prior to this change, if we were in the middle of a lite map update we'd
tear down the entire map session and restart it. With this change, we'll
cancel an in-flight lite map request up to 10 times and restart before
we tear down the streaming map request. We tear down everything after 10
retries to ensure that a steady stream of calls to sendNewMapRequest
doesn't fail to make progress by repeatedly canceling and restarting.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Co-authored-by: Maisem Ali <maisem@tailscale.com>
Change-Id: I9392bf8cf674e7a58ccd1e476039300a359ef3b1
Previously, it would accept all TCP connections and then close the ones
it did not care about. Make it only ever accept the connections that it
cares about.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The main motivation for this change is to stop using the deprecated
set-output function which triggers deprecation warnings in the action.
Change-Id: I80496c44ea1166b9c40d5cd9e450129778ad4aaf
Signed-off-by: M. J. Fromberger <fromberger@tailscale.com>
This package handles cases where we need to truncate human-readable text to fit
a length constraint without leaving "ragged" multi-byte rune fragments at the
end of the truncated value.
Change-Id: Id972135d1880485f41b1fedfb65c2b8cc012d416
Signed-off-by: M. J. Fromberger <fromberger@tailscale.com>
This change adds a ringbuffer to each magicsock endpoint that keeps a
fixed set of "changes"–debug information about what updates have been
made to that endpoint.
Additionally, this adds a LocalAPI endpoint and associated
"debug peer-status" CLI subcommand to fetch the set of changes for a given
IP or hostname.
Updates tailscale/corp#9364
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I34f726a71bddd0dfa36ec05ebafffb24f6e0516a
I explained this tails/scales list to my 5yo and he looked at me like
it was the most obvious idea ever. Of course we'd make such lists at
work! What else do grown-ups do all day? And then he wouldn't stop
talking about coelacanths and I had no clue what he was saying or how
to spell it until I asked my phone and the phone apparently understood
me and I realized it was a fish and he was helping me? I think?
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
