Commit Graph
100 Commits
Author SHA1 Message Date
Brad Fitzpatrick 828aa6dcb0 stunner: add Stunner.MaxTries option 2020-05-04 23:37:01 -07:00
Brad Fitzpatrick 495796fff1 derp/derpmap: add World.ForeachServer, check STUN server validity earlier 2020-05-04 23:37:01 -07:00
Brad Fitzpatrick 3b546dc29a portlist: make two error paths have unique messages
For debugging #339
2020-05-04 07:45:15 -07:00
Brad Fitzpatrick fefd7e10dc types/structs: add structs.Incomparable annotation, use it where applicable
Shotizam before and output queries:

sqlite> select sum(size) from bin where func like 'type..%';
129067
=>
120216
2020-05-03 14:05:32 -07:00
Brad Fitzpatrick e1526b796e ipn: don't listen on the unspecified address in test
To avoid the Mac firewall dialog of (test) death.

See https://github.com/tailscale/go/commit/4521a59f30cb4272f85bc05a38785624cad3e942
which I added to help debug this.
2020-04-28 19:20:02 -07:00
Brad Fitzpatrick f4c7eb8c44 ipn: revert part of 18017f7630
In retrospect I don't trust it and I'm afraid might've caused some Mac flakiness.
I'd like more tests here before I work on this.

Updates #288
2020-04-28 14:04:45 -07:00
Brad Fitzpatrick 18017f7630 ipn, wgengine/magicsock: be more idle when in Stopped state with no peers
(Previously as #288, but with some more.)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-28 13:41:29 -07:00
Brad Fitzpatrick a464439658 control/controlclient: fix build break caused by overzealous gitting 2020-04-27 08:18:35 -07:00
Brad Fitzpatrick 2244cca5ff net/tlsdial: update package doc to say it's now somewhat useless 2020-04-27 08:17:18 -07:00
Brad Fitzpatrick 58e83d8f66 tempfork/x509: moved to tailscale/go's crypto/x509 instead 2020-04-27 08:14:54 -07:00
Brad Fitzpatrick 172d72a060 Revert "net/tlsdial: add memory-optimized TLS cert verification path for iOS"
This reverts commit 6fcbd4c4d4.

Decided to put it in tailscale/go's crypto/x509 instead.
2020-04-27 08:13:37 -07:00
Brad Fitzpatrick 5d67365cc9 logtail: add PrivateID.IsZero method 2020-04-27 07:33:23 -07:00
Brad Fitzpatrick 9497921f52 logpolicy: also set up TLS dialing (for iOS) for log uploads
This was the last of the three places that do TLS from clients (logs,
control, derp). With this, iOS should be able to use the
memory-efficient x509 root CertPool.
2020-04-26 08:31:14 -07:00
Brad Fitzpatrick c726c1eec9 logtail: add const DefaultHost with default server name 2020-04-26 08:31:07 -07:00
Brad Fitzpatrick 1a0f6fea58 go.mod, go.sum: bump wireguard-go, tidy 2020-04-26 08:06:06 -07:00
Brad Fitzpatrick 95a658e1e3 control/controlclient: also rename HTTPC in the tests 2020-04-26 07:51:54 -07:00
Brad Fitzpatrick eb6de2bd88 control/controlclient: restore Options.HTTPC as Options.HTTPTestClient
I removed the HTTPC field in b6fa5a69be but it was apparently still
used in [oss-skipped] tests.

Restore it, but name it so it's more obvious that it's only for
tests. (It currently is, and I'd like to keep it like that for now.)
2020-04-26 07:48:26 -07:00
Brad Fitzpatrick 6fcbd4c4d4 net/tlsdial: add memory-optimized TLS cert verification path for iOS
Behind a build tag for now.
2020-04-25 13:55:51 -07:00
Brad Fitzpatrick b6fa5a69be net/tlsdial: add package for TLS dials, and make DERP & controlclient use it
This will do the iOS-optimized cert checking in a following change.
2020-04-25 13:24:53 -07:00
Brad Fitzpatrick d427fc023e tempfork/x509: remove the bundle tag in our fork
We want to be able to omit from only one (not both)
2020-04-25 10:00:10 -07:00
Brad Fitzpatrick 28c632c97b tempfork/x509: store certs for iOS compressed in binary, parse lazily 2020-04-25 08:54:01 -07:00
Brad Fitzpatrick bfc1261ab6 crypto/x509: keep smaller root cert representation in memory until needed
(from patchset 1, c12c890c64dd6372b3893af1e6f5ab11802c9e81, of
https://go-review.googlesource.com/c/go/+/230025/1, with merges fixes
due to parent commit's differents from its ps1..ps3)

Instead of parsing the PEM files and then storing the *Certificate
values forever, still parse them to see if they're valid and pick out
some fields, but then only store the decoded pem.Block.Bytes until
that cert is first needed.

Saves about 500K of memory on my (Debian stable) machine after doing a
tls.Dial or calling x509.SystemCertPool.

A more aggressive version of this is still possible: we can not keep
the pem.Block.Bytes in memory either, and re-read them from disk when
necessary. But dealing with files disappearing and even large
multi-cert PEM files changing (with offsets sliding around) made this
conservative version attractive. It doesn't change the
slurp-roots-on-startup semantics. It just does so with less memory
retained.

Change-Id: I3aea333f4749ae3b0026042ec3ff7ac015c72204
2020-04-24 21:27:48 -07:00
Brad Fitzpatrick f5993f2440 crypto/x509: add support for CertPool to load certs lazily
(from patchset 1, 7cdc3c3e7427c9ef69e19224d6036c09c5ea1723, of
https://go-review.googlesource.com/c/go/+/229917/1)

This will allow building CertPools that consume less memory. (Most
certs are never accessed. Different users/programs access different
ones, but not many.)

This CL only adds the new internal mechanism (and uses it for the
old AddCert) but does not modify any existing root pool behavior.
(That is, the default Unix roots are still all slurped into memory as
of this CL)

Change-Id: Ib3a42e4050627b5e34413c595d8ced839c7bfa14
2020-04-24 21:27:48 -07:00
Brad FitzpatrickandBrad Fitzpatrick 6b232b5a79 Disable staticcheck for tempfork packages. 2020-04-24 20:46:06 -07:00
Brad FitzpatrickandBrad Fitzpatrick 0a50ecbad3 control/controlclient: add missing vlog, for consistency with other sites 2020-04-21 15:36:46 -07:00
Brad FitzpatrickandDave Anderson b8594dc937 control/controlclient: fix deadlock in timeout+keepalive race
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-21 15:22:58 -07:00
Brad Fitzpatrick 268d331cb5 wgengine/magicsock: prune key.Public-keyed on peer removals
Fixes #215
2020-04-18 08:48:01 -07:00
Brad Fitzpatrick 00d053e25a wgengine/magicsock: fix slow memory leak as peer endpoints move around
Updates #215
2020-04-18 08:28:10 -07:00
Brad Fitzpatrick 7fc97c5493 wgengine/magicsock: use netaddr more
In prep for deleting from the ever-growing maps.
2020-04-17 15:15:42 -07:00
Brad Fitzpatrick 6fb30ff543 wgengine/magicsock: start using inet.af/netaddr a bit 2020-04-17 13:51:52 -07:00
Brad Fitzpatrick adf74c75ed wgengine: also diagnose not-yet-rebooted system updates on Arch 2020-04-13 09:22:08 -07:00
Brad Fitzpatrick 3464114b88 logtail: add ParsePublicID that doesn't allocate 2020-04-13 08:54:35 -07:00
Brad Fitzpatrick 780deb9996 go.mod, go.sum: update go4.org/mem to its new home in its own module
Cleans up our go.sum, not that it really matters.
2020-04-11 14:00:48 -07:00
Brad Fitzpatrick 614eec174f derp/derphttp: avoid endless reconnect race on failure
Originally from @stablebits (Dmitry Adamushko) in:
https://github.com/tailscale/tailscale/pull/264
2020-04-11 13:37:20 -07:00
Brad Fitzpatrick 347a926ac4 control/controlclient: add opt-in netmap verbose debugging env var 2020-04-11 09:22:33 -07:00
Brad Fitzpatrick 45f2b53aca all: remove unnecessary trailing newlines in format patterns for consistency
And document on logger.Logf that it's unnecessary.
2020-04-11 08:35:34 -07:00
Brad FitzpatrickandBrad Fitzpatrick a7e7c7b548 wgengine/magicsock: close derp connections on rebind
Fixes #276

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-10 20:43:00 -07:00
Brad FitzpatrickandBrad Fitzpatrick 614261d00d wgengine/magicsock: reset AddrSet states on Rebind
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-10 20:27:35 -07:00
Brad FitzpatrickandBrad Fitzpatrick c0697e1feb net/interfaces: add IsExpensive and up state to State
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-10 20:25:12 -07:00
Brad FitzpatrickandBrad Fitzpatrick a55c4217db wgengine: diagnose why CreateTUN might've failed for users
Fixes #273

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-10 20:16:27 -07:00
Brad FitzpatrickandBrad Fitzpatrick 3a3b64301e wgengine: quiet some engine reconfig logging, make more consistent
Updates #282

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-10 13:53:01 -07:00
Brad Fitzpatrick 39ae80a2e7 version: bump date 2020-04-10 08:23:36 -07:00
Brad Fitzpatrick 1ec27dbb5b wgengine: remove an allocation in reconfig
Minor.
2020-04-10 08:22:13 -07:00
Brad Fitzpatrick b24029717b ipn: outdent some code in if that's statically always true 2020-04-10 07:52:30 -07:00
Brad Fitzpatrick fe149979e6 logpolicy: include Go version in version log 2020-04-09 14:46:19 -07:00
Brad Fitzpatrick 73249f8032 netcheck: aggregate spammy logging onto one concise line 2020-04-09 13:14:38 -07:00
Brad FitzpatrickandBrad Fitzpatrick 922d9546bf wgengine: don't allocate so much in userspaceEngine.getStatus
It was one of the top garbage producers on my phone.

It's slated to be deleted and replaced anyway, but this helps in the
meantime.

The go.sum changes look scary, but the new dep only adds 240 bytes to
the binary. The go.sum noise is just cmd/go being aggressive in
including a lot of stuff (which is being fixed in Go 1.15, for what I
understand). And I ran a go mod tidy, which added some too. (I had to
write a custom wrapper around go mod tidy because this mod tidy
normally breaks on tailscale.io/control being missing but referenced
in tests)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-09 12:49:17 -07:00
Brad Fitzpatrick 0f64d7f9cc wgengine: remove a tiny allocation
Drop in the bucket compared to the larger issues, but noticed it
when looking at pprof.
2020-04-07 22:23:40 -07:00
Brad Fitzpatrick ec0cd60fc3 portlist: fail earlier, more nicely on iOS 2020-04-06 20:11:24 -07:00
Brad Fitzpatrick 71d6738333 tstime: change an Errorf+return to Fatalf in subtest
Forgot to git add this during review. Fail.
2020-04-06 08:20:15 -07:00
Brad FitzpatrickandBrad Fitzpatrick febdac0499 tstime: write Parse3339 parse that doesn't use time.Parse
It doesn't allocate and it's half the time of time.Parse (which
allocates), and 2/3rds the time of time.ParseInLocation (which
doesn't).

Go with a UTC time:

BenchmarkGoParse3339/Z-8                 2200995               534 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339/Z-8                 2254816               554 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339/Z-8                 2159504               522 ns/op               0 B/op          0 allocs/op

Go allocates with a "-08:00" suffix instead of ending in "Z":

BenchmarkGoParse3339/TZ-8                1276491               884 ns/op             144 B/op          3 allocs/op
BenchmarkGoParse3339/TZ-8                1355858               942 ns/op             144 B/op          3 allocs/op
BenchmarkGoParse3339/TZ-8                1385484               911 ns/op             144 B/op          3 allocs/op

Go doesn't allocate if you use time.ParseInLocation, but then you need
to parse the string to find the location anyway, so might as well go
all the way (below).

BenchmarkGoParse3339InLocation-8         1912254               597 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339InLocation-8         1980043               612 ns/op               0 B/op          0 allocs/op
BenchmarkGoParse3339InLocation-8         1891366               612 ns/op               0 B/op          0 allocs/op

Parsing RFC3339 ourselves, UTC:

BenchmarkParse3339/Z-8                   3889220               307 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/Z-8                   3718500               309 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/Z-8                   3621231               303 ns/op               0 B/op          0 allocs/op

Parsing RFC3339 ourselves, with timezone (w/ *time.Location fetched
from sync.Map)

BenchmarkParse3339/TZ-8                  3019612               418 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/TZ-8                  2921618               401 ns/op               0 B/op          0 allocs/op
BenchmarkParse3339/TZ-8                  3031671               408 ns/op               0 B/op          0 allocs/op

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-06 08:19:17 -07:00
Brad Fitzpatrick 02948d2c86 Dockerfile: add some usage docs, bump to Go 1.14 2020-04-06 07:57:47 -07:00
Brad FitzpatrickandBrad Fitzpatrick d503dee6f1 tstime: add new package for time utilities, starting with Parse3339
Go's time.Parse always allocates a FixedZone for time strings not in
UTC (ending in "Z"). This avoids that allocation, at the cost of
adding a cache.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-05 20:05:49 -07:00
Brad FitzpatrickandBrad Fitzpatrick 996bf9cae7 logtail: don't send a User-Agent
Just useless bytes on the wire. Especially with HTTP/1.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-05 13:16:56 -07:00
Brad FitzpatrickandBrad Fitzpatrick 7bf436ba30 tsweb: add some Benchmarks
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-05 13:16:36 -07:00
Brad FitzpatrickandBrad Fitzpatrick 64334143a1 tsweb: rename Handler to ReturnHandler
The name's been bugging me for a long time.

I liked neither the overlap between tsweb.Handler and http.Handler,
nor the name "ServeHTTPErr" which sounds like it's an error being
returned, like it's an error handler and not sometimes a happy path.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-05 13:16:36 -07:00
Brad Fitzpatrick bdc55d7091 logtail: add ParsePrivateID 2020-04-05 09:15:15 -07:00
Brad Fitzpatrick 50aeb5b9ad wgengine: unexport some windows funcs 2020-04-05 08:23:53 -07:00
Brad FitzpatrickandBrad Fitzpatrick e71a7c7a2c logtail: read to EOF on chunked response
We'll be fixing the server so this won't trigger in practice,
but it demos the connection reuse problem.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-04 16:12:15 -07:00
Brad FitzpatrickandBrad Fitzpatrick fcb6a34f4b logtail: reduce allocations encoding text
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-04 16:12:02 -07:00
Brad FitzpatrickandBrad Fitzpatrick 2863e49db9 tsweb: don't flush, treat no-op Handler as 200, like Go
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-04 16:11:53 -07:00
Brad FitzpatrickandBrad Fitzpatrick 3b4b17d239 logpolicy: log on dials, add knob to force HTTP/1 for log uploads
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-04 14:46:41 -07:00
Brad FitzpatrickandBrad Fitzpatrick 8ca796d144 ipn, ipn/policy: filter portlist to a short list of "interesting" ports
Adds new package ipn/policy to be shared between node client & control server.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-04-01 10:03:44 -07:00
Brad Fitzpatrick c6aa5b639f tailcfg: clarify Hostinfo.OS doc 2020-04-01 09:27:35 -07:00
Brad Fitzpatrick 4524dcf51e version: move runtime.OS to tailscale OS mapping func to version
So other code can use this without duplicating the policy.
2020-04-01 08:50:56 -07:00
Brad Fitzpatrick 1df3c8d02a derp, netcheck: make tests listen on localhost only
avoid macOS firewall pop-ups
2020-03-30 11:29:08 -07:00
Brad Fitzpatrick 5362e952e1 safesocket: gofmt
Was developed on a random machine without my normal environment.
2020-03-30 11:23:18 -07:00
Brad FitzpatrickandBrad Fitzpatrick a4ef345737 cmd/tailscale: add status subcommand
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-27 20:34:36 -07:00
Brad Fitzpatrick 810c1e9704 types/key: make Public implement TextMarshaler, TextUnmarshaler
So it can be a map key with encoding/json
2020-03-27 13:03:35 -07:00
Brad Fitzpatrick f51f18b42b ipn: move FakeBackend to a test-only file 2020-03-27 13:02:33 -07:00
Brad Fitzpatrick 8ebee05fbd cmd/tailscale: remove unnecessary logpolicy/logtail logging 2020-03-27 08:27:36 -07:00
Brad FitzpatrickandBrad Fitzpatrick 8b3f6be008 control/controlclient: flip IPv6 to be on by default
The DEBUG_INCLUDE_IPV6 environment variable is now an opt-out.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-26 22:02:56 -07:00
Brad FitzpatrickandBrad Fitzpatrick 322499473e cmd/tailscaled, wgengine, ipn: add /debug/ipn handler with world state
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-26 14:26:24 -07:00
Brad FitzpatrickandBrad Fitzpatrick 7fb8d873ac logpolicy: don't log timestamp when running under systemd
It'll do it anyway.

Makes journalctl -fu cleaner.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-25 21:03:06 -07:00
Brad FitzpatrickandBrad Fitzpatrick 2d48f92a82 wgengine/magicsock: re-stun every [20,27] sec, not 28
28 is cutting it close, and we think jitter will help some spikes
we're seeing.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-25 14:25:33 -07:00
Brad Fitzpatrick 2c7ddd0828 go.mod, go.sum: tidy 2020-03-25 14:05:33 -07:00
Brad FitzpatrickandBrad Fitzpatrick 577f321c38 wgengine/magicsock: revise derp fallback logic
Revision to earlier 6284454ae5

Don't be sticky if we have no peers.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-25 13:09:18 -07:00
Brad Fitzpatrick 2e420ad8b6 wgengine, wgengine/filter: minor doc, style, performance, locking changes
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-25 08:41:01 -07:00
Brad FitzpatrickandBrad Fitzpatrick 6284454ae5 wgengine/magicsock: if UDP blocked, pick DERP where most peers are
Updates #207

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-25 08:00:44 -07:00
Brad Fitzpatrick d321190578 wgengine/magicsock: stringify [IPv6]:port normally in AddrSet.String 2020-03-24 13:40:43 -07:00
Brad Fitzpatrick 3c3ea8bc8a wgengine/magicsock: finish IPv6 transport support
DEBUG_INCLUDE_IPV6=1 is still required, but works now.

Updates #18 (fixes it, once env var gate is removed)
2020-03-24 10:56:22 -07:00
Brad Fitzpatrick 82ed7e527e wgengine/magicsock: remove log allocation
This was the whole point but I goofed at the last line.
2020-03-24 08:14:47 -07:00
Brad Fitzpatrick 8454bbbda5 wgengine/magicsock: more logging improvements
* remove endpoint discovery noise when results unchanged
* consistently spell derp nodes as "derp-N"
* replace "127.3.3.40:" with "derp-" in CreateEndpoint log output
* stop early DERP setup before SetPrivateKey is called;
  it just generates log nosie
* fix stringification of peer ShortStrings (it had an old %x on it,
  rendering it garbage)
* describe why derp routes are changing, with one of:
  shared home, their home, our home, alt
2020-03-24 08:12:55 -07:00
Brad FitzpatrickandBrad Fitzpatrick 64aff0db7b control/controlclient: add TODO to delete the UAPI method 2020-03-24 07:25:14 -07:00
Brad FitzpatrickandBrad Fitzpatrick 7740cbd8d9 ipn: call SetNetInfoCallback later, in Start
It was being called back into ultimately from magicsock before there
was a control client.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-23 22:19:40 -07:00
Brad Fitzpatrick 680311b3df wgengine/magicsock: fix few remaining logs without package prefix 2020-03-23 22:11:49 -07:00
Brad Fitzpatrick c473927558 wgengine/magicsock: clean up, add, improve DERP logs 2020-03-23 21:57:58 -07:00
Brad Fitzpatrick e749377a56 derp/derphttp: remove a redundant log message 2020-03-23 21:23:36 -07:00
Brad Fitzpatrick 1d3f45f9be derp/derphttp: ignore PeerGoneMessage in test 2020-03-23 14:13:49 -07:00
Brad Fitzpatrick ea9310403d wgengine/magicsock: re-STUN on DERP connection death
Fixes #201
2020-03-23 13:19:33 -07:00
Brad FitzpatrickandBrad Fitzpatrick 1ab5b31c4b derp, magicsock: send new "peer gone" frames when previous sender disconnects
Updates #150 (not yet enabled by default in magicsock)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-22 21:00:47 -07:00
Brad Fitzpatrick b6f77cc48d wgengine/magicsock: return early, outdent in derpWriteChanOfAddr 2020-03-22 14:08:59 -07:00
Brad Fitzpatrick 8c4cef60f8 derp: wait for send goroutine to finish before returning from run
I saw a test flake due to the sender goroutine logging (ultimately to
t.Logf) after the server was closed.

This makes sure the all goroutines are cleaned up before Server.Close
returns.
2020-03-22 13:10:07 -07:00
Brad Fitzpatrick 521ad7b0fc derp: only flush writes to clients when we're out of things to write
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-22 08:01:25 -07:00
Brad Fitzpatrick 0a25abcdaa derp: remove TODO comment
It was done in bf704a5218
2020-03-22 07:54:50 -07:00
Brad Fitzpatrick 8519a1b29f derp: revert rename of pkt to sendMsg
New plan, sorry.

Most reverts 77921a31b1, except some doc changes.
2020-03-21 22:17:22 -07:00
Brad FitzpatrickandBrad Fitzpatrick c34b350efa derp: remove the mutex around and closing of send channel
Makes it less complicated.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-21 22:00:04 -07:00
Brad Fitzpatrick 77921a31b1 derp: rename pkt to sendMsg, in prep for other types of writes
Updates #150
2020-03-21 20:34:49 -07:00
Brad Fitzpatrick 1453aecb44 derp: add sclient.done channel, simplify some context passing
This is mostly prep for a few future CLs, making sure we always have a
close-on-dead done channel available to select on when doing other
channel operations.
2020-03-21 18:28:34 -07:00
Brad FitzpatrickandDave Anderson fd824df1fa derp: export metric for server's initial MemStats.Sys reading
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2020-03-20 15:37:36 -07:00