Commit Graph

589 Commits (dd10babaed7811885a9fe946b88620be9a789909)

Author SHA1 Message Date
Brad Fitzpatrick 01098f41d0 wgengine/tstun: fix typo in comment 4 years ago
Brad Fitzpatrick 73cc2d8f89 wgengine/filter: also silently drop link-local unicast traffic
Updates #629
4 years ago
Brad Fitzpatrick 5f807c389e wgengine/filter: drop multicast packets out, don't log about them
Eventually we'll probably support multicast. For now it's just log spam.

Fixes #629
4 years ago
Brad Fitzpatrick bbb56f2303 wgengine/router: fix tests on Debian Buster as regular user on machine with IPv6 4 years ago
David Anderson fddbcb0c7b wgengine/router: support various degrees of broken IPv6.
Gracefully skips touching the v6 NAT table on systems that don't have
it, and doesn't configure IPv6 at all if IPv6 is globally disabled.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 0d80904fc2 wgengine/router: set up basic IPv6 routing/firewalling.
Part of #19.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Josh Bleecher Snyder f0ef561049 wgengine/tsdns: use netns to obtain a socket
Fixes #789

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Josh Bleecher Snyder 6e8328cba5 wgengine/tsdns: replace connections when net link changes (macOS)
When the network link changes, existing UDP sockets fail immediately
and permanently on macOS.

The forwarder set up a single UDP conn and never changed it.
As a result, any time there was a network link change,
all forwarded DNS queries failed.

To fix this, create a new connection when send requests
fail because of network unreachability.

This change is darwin-only, although extended it to other platforms
should be straightforward.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Josh Bleecher Snyder 1fd10061fd wgengine/tsdns: delegate bonjour service rdns requests
While we're here, parseQuery into a plain function.
This is helpful for fuzzing. (Which I did a bit of. Didn't find anything.)

And clean up a few minor things.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick 2d0ed99672 wgengine, wgengine/router: add a bunch of (temporary?) engine creation logging
Trying to debug what's slow on a user's machine.

Updates #785
4 years ago
Brad Fitzpatrick 7c11f71ac5 wgengine/router: ignore errors deleting 169.254.255.255/32 route on Windows
Updates #785
4 years ago
David Anderson b7e0ff598a wgengine: don't close tundev in NewUserspaceEngine.
newUserspaceEngineAdvanced closes the tun device on error already.

Fixes #783.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 5d8b88be88 control/controlclient, version/distro, wgengine: recognize OpenWrt
And help out with missing packages.

Thanks to @willangley for tips.

Updates #724
4 years ago
Brad Fitzpatrick 3528d28ed1 wgengine/router: move Tailscale's winipcfg additions into wgengine/router
Part of unforking our winipcfg-go and using upstream (#760), move our
additions into our repo. (We might upstream them later if upstream has
interest)

Originally these were:

@apenwarr: "Add ifc.SyncAddresses() and SyncRoutes()."
609dcf2df5

@bradfitz: "winipcfg: make Interface.AddRoutes do as much as possible, return combined error"
e9f93d53f3

@bradfitz: "prevent unnecessary Interface.SyncAddresses work; normalize IPNets in deltaNets"
decb9ee8e1
4 years ago
Brad Fitzpatrick fd77268770 wgengine/router: enumerate all interfaces when finding Tailscale adapter by GUID
Might fix it. I've spent too much time failing to reproduce the issue. This doesn't
seem to make it worse, though (it still runs for me), so I'll include this and
see if it helps others while I still work on a reliable way to reproduce it.

Updates tailscale/corp#474
4 years ago
Brad Fitzpatrick 5bcac4eaac net/tshttpproxy: add GetProxyForURL negative cache
Otherwise when PAC server is down, we log, and each log entry is a new
HTTP request (from logtail) and a new GetProxyForURL call, which again
logs, non-stop. This is also nicer to the WinHTTP service.

Then also hook up link change notifications to the cache to reset it
if there's a chance the network might work sooner.
4 years ago
Brad Fitzpatrick 64a24e796b wgengine/tstun: fix 32-bit alignment again 4 years ago
Brad Fitzpatrick afb2be71de wgengine: add two missing TUN close calls 4 years ago
Brad Fitzpatrick abe095f036 wgengine/tstun: make Close safe for concurrent use 4 years ago
Christina Wen f0e9dcdc0a
wgengine/router: restore /etc/resolv.conf after tailscale down is called
This change is to restore /etc/resolv.conf after tailscale down is called. This is done by setting the dns.Manager before errors occur. Error collection is also added.

Fixes #723
4 years ago
Brad Fitzpatrick acafe9811f wgengine/router: run netsh advfirewall less, rename, document setFirewall 4 years ago
Christina Wen 48fbe93e72
wgengine/magicsock: clarify pre-disco 'tailscale ping' error message
This change clarifies the error message when a user pings a peer that is using an outdated version of Tailscale.
4 years ago
Christina Wen e862f90e34
wgengine/router/router_linux.go: fixed " route del failed" error (#756)
* wgengine/router/router_linux.go: Switched `cidrDiff("addr")` and `cidrDiff("route")` order

Signed-off-by: Christina Wen <christina@tailscale.com>

Co-authored-by: Christina Wen <christina@tailscale.com>
4 years ago
Brad Fitzpatrick 7e9d1f7808 wgengine/router: tighten isMissingIPv6Err
So it doesn't false positive if misused.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson 8f5b52e571 net/netns: add windows support.
Also remove rebinding logic from the windows router. Magicsock will
instead rebind based on link change signals.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Josh Bleecher Snyder a5d701095b wgengine/magicsock: increase test timeout to reduce flakiness
Updates #654. See that issue for a discussion of why
this timeout reduces flakiness, and what next steps are.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Josh Bleecher Snyder 0c0239242c wgengine/magicsock: make discoPingPurpose a stringer
It was useful for debugging once, it'll probably be useful again.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Josh Bleecher Snyder 6e38d29485 wgengine/magicsock: improve test logging output
This fixes line numbers and reduces timestamp
precision to overwhelming the output.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick a084c44afc wgengine, wgengine/router, cmd/tailscale: force netfilter mode off on Synology
For now. Get it working again so it's not stuck on 0.98.

Subnet relay can come later.

Updates #451

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 31c13013ae wgengine/router: tolerate disabled IPv6 on Windows
Fixes #412
Updates #524 (maybe fixes?)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder 37b40b035b wgengine/router/dns: appease staticcheck (again) 4 years ago
Josh Bleecher Snyder a877dd575c wgengine/router/dns: remove unnecessary lint ignore line
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick 913c1bd04f wgengine/router: on Windows, add a firewall rule to allow Tailscale
Updates tailscale/tailscale#454
4 years ago
Josh Bleecher Snyder 57e642648f wgengine/magicsock: fix typo in comment 4 years ago
Brad Fitzpatrick 6d14678009 wgengine/router: remove unnecessary newlines in log.Printf formats 4 years ago
Brad Fitzpatrick 09d56f54a7
wgengine/router: fix Windows route sorting that caused de-dup to not work (#727)
Updates #725

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 9b07517f18 wgengine: add Engine.SetLinkChangeCallback
Start of making the IPN state machine react to link changes and down
its DNS & routes if necessary to unblock proxy resolution (e.g. for
transitioning from public to corp networks where the corp network has
mandatory proxies and WPAD PAC files that can't be resolved while
using the DNS/routes configured previously)

This change should be a no-op. Just some callback plumbing.
4 years ago
Dmytro Shynkevych cb5f3c0819
tsdns: log when settings upstreams.
It turns out that otherwise we don't know what exactly was set.

Also remove the now unused RootDomain config option.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych aa1da24f18
tsdns: remove now unused fields.
Missed in 7541982635.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 7541982635
tsdns: remove forwarding queue.
Two levels of queueing are unnecessary.
The resulting implementation performs as follows
under request bursts (`count` packets sent concurrently):

lost  count            avg latency
   0 /  256 (00.00%) - 28ms
   0 /  512 (00.00%) - 146ms
   0 /  768 (00.00%) - 166ms
   0 / 1024 (00.00%) - 416ms
  11 / 1280 (00.86%) - 430ms
 145 / 1536 (09.44%) - 715ms
 364 / 2048 (17.77%) - 836ms

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 34a7e7c12b
tsdns: be more strict with type validation.
Previously, a type AAAA query would be answered with an A record
if only an IPv4 address was available. This is irrelevant for us
while we only use IPv4, but it will be a bug one day,
so it's worth being precise about semantics.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych bc34788e65
tsdns: fix accidental rejection of all non-{A, AAAA} questions.
This is a bug introduced in a903d6c2ed.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 756d6a72bd wgengine: lazily create peer wireguard configs more explicitly
Rather than consider bigs jumps in last-received-from activity as a
signal to possibly reconfigure the set of wireguard peers to have
configured, instead just track the set of peers that are currently
excluded from the configuration. Easier to reason about.

Also adds a bit more logging.

This might fix an error we saw on a machine running a recent unstable
build:

2020-08-26 17:54:11.528033751 +0000 UTC: 8.6M/92.6M magicsock: [unexpected] lazy endpoint not created for [UcppE], d:42a770f678357249
2020-08-26 17:54:13.691305296 +0000 UTC: 8.7M/92.6M magicsock: DERP packet received from idle peer [UcppE]; created=false
2020-08-26 17:54:13.691383687 +0000 UTC: 8.7M/92.6M magicsock: DERP packet from unknown key: [UcppE]

If it does happen again, though, we'll have more logs.
4 years ago
halulu f27a57911b
cmd/tailscale: add derp and endpoints status (#703)
cmd/tailscale: add local node's information to status output (by default)

RELNOTE=yes

Updates #477

Signed-off-by: Halulu <lzjluzijie@gmail.com>
4 years ago
David Crawshaw dd2c61a519 magicsock: call RequestStatus when DERP connects
Second attempt.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
4 years ago
David Crawshaw a67b174da1 Revert "magicsock: call RequestStatus when DERP connects"
Seems to break linux CI builder. Cannot reproduce locally,
so attempting a rollback.

This reverts commit cd7bc02ab1.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
4 years ago
David Crawshaw cd7bc02ab1 magicsock: call RequestStatus when DERP connects
Without this, a freshly started ipn client will be stuck in the
"Starting" state until something triggers a call to RequestStatus.
Usually a UI does this, but until then we can sit in this state
until poked by an external event, as is evidenced by our e2e tests
locking up when DERP is attached.

(This only recently became a problem when we enabled lazy handshaking
everywhere, otherwise the wireugard tunnel creation would also
trigger a RequestStatus.)

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
4 years ago
Brad Fitzpatrick 24d1a38e81 wgengine/monitor: add a poller to the Windows link change monitor
The poller is slow by default, but speeds up for a bit after a network
change, in case WPAD/PAC files are still loading.
4 years ago
Dmytro Shynkevych a903d6c2ed
tailcfg, tsdns: derive root domains from list of nodes (#708)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Disconnect3d 44598e3e89 wgengine/monitor_freebsd.go: remove duplicated errcheck
Signed-off-by: disconnect3d <dominik.b.czarnota@gmail.com>
4 years ago
Brad Fitzpatrick 7841c97af5 wgengine: make lazy wireguard on by default
It can still be explicitly enabled or disabled via the environment variable,
then via control.

But the default is to be lazy now.
4 years ago
Dmytro Shynkevych 6c71e5b851
tsdns: copy name when loewrcasing.
The previous approach modifies name in-place in the request slice to avoid an allocation.
This is incorrect: the question section of a DNS request
must be copied verbatim, without any such modification.
Software may rely on it (we rely on other resolvers doing it it in tsdns/forwarder).

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 1886dfdca3
tsdns: lowercase the name in parseQuery.
Domains in DNS should be case-insensitive.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 9337a99dff tailcfg, wgengine, controlclient: add control-side gating of lazy WG config 4 years ago
chungdaniel 4d56d19b46
control/controlclient, wgengine/filter: extract parsePacketFilter to … (#696)
control/controlclient, wgengine/filter: extract parsePacketFilter to new constructor in wgengine/filter

Signed-off-by: chungdaniel <daniel@tailscale.com>
4 years ago
Brad Fitzpatrick 461db356b9 wgengine/router/dns: fix staticcheck error on Mac 4 years ago
Dmytro Shynkevych 1af70e2468
tsdns: delegate requests asynchronously (#687)
Signed-Off-By: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych a583e498b0
router/dns: set all domains on Windows (#672)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick f6dc47efe4 tailcfg, controlclient, magicsock: add control feature flag to enable DRPO
Updates #150
4 years ago
Brad Fitzpatrick dbb4c246fa wgengine/monitor: add Windows linkchange monitor
Updates tailscale/corp#553

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 85c3d17b3c wgengine/magicsock: use disco ping src as a candidate endpoint
Consider:

   Hard NAT (A) <---> Hard NAT w/ mapped port (B)

If A sends a packet to B's mapped port, A can disco ping B directly,
with low latency, without DERP.

But B couldn't establish a path back to A and needed to use DERP,
despite already logging about A's endpoint and adding a mapping to it
for other purposes (the wireguard conn.Endpoint lookup also needed
it).

This adds the tracking to discoEndpoint too so it'll be used for
finding a path back.

Fixes tailscale/corp#556

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 0512fd89a1 wgengine/magicsock: simplify handlePingLocked
It's no longer true that 'de may be nil'
4 years ago
Brad Fitzpatrick b983e5340f wgengine/monitor: add, clean up netlink logging on route changes
Updates #643
4 years ago
Mike Kramlich 6fa7a9a055 wgengine/router/router_userspace_bsd: on Mac the route program syntax expects delete not del -- this had caused router reconfig to fail in some cases. Fixes #673
Signed-off-by: Mike Kramlich <groglogic@gmail.com>
4 years ago
Dmytro Shynkevych 95a18f815c
router/dns: detect host endianness for NetworkManager.
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick b97aac1718 net/interfaces: include DefaultRouteInterface in interfaces.State
And log it in wgengine on change. Changing bug in #643.

Updates #643
4 years ago
Brad Fitzpatrick 84dc891843 cmd/tailscale/cli: add ping subcommand
For example:

$ tailscale ping -h
USAGE
  ping <hostname-or-IP>

FLAGS
  -c 10                   max number of pings to send
  -stop-once-direct true  stop once a direct path is established
  -verbose false          verbose output

$ tailscale ping mon.ts.tailscale.com
pong from monitoring (100.88.178.64) via DERP(sfo) in 65ms
pong from monitoring (100.88.178.64) via DERP(sfo) in 252ms
pong from monitoring (100.88.178.64) via [2604:a880:2:d1::36:d001]:41641 in 33ms

Fixes #661

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick c64a43a734 wgengine/router: set MTU on Windows to min(configured,possible)
Fixes tailscale/corp#542

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder 2622e8e082 wgenginer/router: fix build
Rebasing github.com/tailscale/wireguard-go to upstream
wireguard-go changed the API.

This commit is analogous to
https://git.zx2c4.com/wireguard-windows/commit/?id=6823cc10ffe193c0cb1d61a5d1828d563d3d0e5f
4 years ago
Dmytro Shynkevych cb01058a53
wgengine: stop giving tsdns a buffer that will be reused
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 9a346fd8b4 wgengine,magicsock: fix two lazy wireguard config issues
1) we weren't waking up a discoEndpoint that once existed and
   went idle for 5 minutes and then got a disco message again.

2) userspaceEngine.noteReceiveActivity had a buggy check; fixed
   and added a test
4 years ago
Dmytro Shynkevych 78c2e1ff83
tsdns: implement reverse DNS lookups, canonicalize names everywhere. (#640)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 41c4560592 control/controlclient: remove unused NetworkMap.UAPI method
And remove last remaining use of wgcfg.ToUAPI in a test's debug
output; replace it with JSON.
4 years ago
Brad Fitzpatrick cff737786e wgengine/magicsock: fix lazy config deadlock, document more lock ordering
This removes the atomic bool that tried to track whether we needed to acquire
the lock on a future recursive call back into magicsock. Unfortunately that
hack doesn't work because we also had a lock ordering issue between magicsock
and userspaceEngine (see issue). This documents that too.

Fixes #644
4 years ago
Brad Fitzpatrick 43bc86588e wgengine/monitor: log RTM_DELROUTE details, fix format strings
Updates #643
4 years ago
Brad Fitzpatrick 2bd9ad4b40 wgengine: fix deadlock between engine and magicsock 4 years ago
Brad Fitzpatrick 7c38db0c97 wgengine/magicsock: don't deadlock on pre-disco Endpoints w/ lazy wireguard configs
Fixes tailscale/tailscale#637
4 years ago
Brad Fitzpatrick 4987a7d46c wgengine/magicsock: when hard NAT, add stun-ipv4:static-port as candidate
If a node is behind a hard NAT and is using an explicit local port
number, assume they might've mapped a port and add their public IPv4
address with the local tailscaled's port number as a candidate endpoint.
4 years ago
Brad Fitzpatrick bfcb0aa0be wgengine/magicsock: deflake tests, Close deadlock again
Better fix than 37903a9056

Fixes tailscale/corp#533
4 years ago
Brad Fitzpatrick da3b50ad88 wgengine/filter: omit logging for all v6 multicast, remove debug panic :( 4 years ago
Dmytro Shynkevych 28e52a0492
all: dns refactor, add Proxied and PerDomain flags from control (#615)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 3e493e0417 wgengine: fix lazy wireguard config bug on sent packet minute+ later
A comparison operator was backwards.

The bad case went:

* device A send packet to B at t=1s
* B gets added to A's wireguard config
* B gets packet

(5 minutes pass)

* some other activity happens, causing B to expire
  to be removed from A's network map, since it's
  been over 5 minutes since sent or received activity
* device A sends packet to B at t=5m1s
* normally, B would get added back, but the old send
  time was not zero (we sent earlier!) and the time
  comparison was backwards, so we never regenerated
  the wireguard config.

This also refactors the code for legibility and moves constants up
top, with comments.
4 years ago
Dmytro Shynkevych 8c850947db
router: split off sandboxed path from router_darwin (#624)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick cb970539a6 wgengine/magicsock: remove TODO comment that's no longer applicable 4 years ago
Brad Fitzpatrick 915f65ddae wgengine/magicsock: stop disco activity on IPN stop
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick c180abd7cf wgengine/magicsock: merge errClosed and errConnClosed 4 years ago
Brad Fitzpatrick 7cc8fcb784 wgengine/filter: remove leftover debug knob that staticcheck doesn't like 4 years ago
Brad Fitzpatrick b4d97d2532 wgengine/filter: fix IPv4 IGMP spam omission, also omit ff02::16 spam
And add tests.

Fixes #618
Updates #402
4 years ago
Dmytro Shynkevych 2ce2b63239
router: stop iOS subprocess sandbox violations (#617)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 154d1cde05
router: reload systemd-resolved after changing /etc/resolv.conf (#619)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick b3fc61b132 wgengine: disable wireguard config trimming for now except iOS w/ many peers
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick d55fdd4669 wgengine/magicsock: update, flesh out a TODO 4 years ago
Brad Fitzpatrick d96d26c22a wgengine/filter: don't spam logs on dropped outgoing IPv6 ICMP or IPv4 IGMP
The OS (tries) to send these but we drop them. No need to worry the
user with spam that we're dropping it.

Fixes #402

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Dmytro Shynkevych c7582dc234
ipn: fix netmap change tracking and dns map generation (#609)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 3e3c24b8f6 wgengine/packet: add IPVersion field, don't use IPProto to note version
As prep for IPv6 log spam fixes in a future change.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson f8e4c75f6b wgengine/magicsock: check slightly less aggressively for connectivity.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 58b721f374 wgengine/magicsock: deflake some tests with an ugly hack
Starting with fe68841dc7, some e2e tests
got flaky. Rather than debug them (they're gnarly), just revert to the old
behavior as far as those tests are concerned. The tests were somehow
using magicsock without a private key and expecting it to do ... something.

My goal with fe68841dc7 was to stop log spam
and unnecessary work I saw on the iOS app when when stopping the app.

Instead, only stop doing that work on any transition from
once-had-a-private-key to no-longer-have-a-private-key. That fixes
what I wanted to fix while still making the mysterious e2e tests
happy.
4 years ago
David Anderson 41d0c81859 wgengine/magicsock: make disco subtest name more precise.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9beea8b314 wgengine/magicsock: remove unnecessary use of context.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson b62341d308 wgengine/magicsock: add docstring.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 9265296b33 wgengine/magicsock: don't deadlock on shutdown if sending blocks.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 0249236cc0 ipn/ipnstate: record assigned Tailscale IPs.
wgengine/magicsock: use ipnstate to find assigned Tailscale IPs.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson c3958898f1 tstest/natlab: be a bit more lenient during test shutdown.
There is a race in natlab where we might start shutdown while natlab is still running
a goroutine or two to deliver packets. This adds a small grace period to try and receive
it before continuing shutdown.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 7578c815be wgengine/magicsock: give pinger a more generous packet timeout.
The first packet to transit may take several seconds to do so, because
setup rates in wgengine may result in the initial WireGuard handshake
init to get dropped. So, we have to wait at least long enough for a
retransmit to correct the fault.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson c3994fd77c derp: remove OnlyDisco option.
Active discovery lets us introspect the state of the network stack precisely
enough that it's unnecessary, and dropping the initial DERP packets greatly
slows down tests. Additionally, it's unrealistic since our production network
will never deliver _only_ discovery packets, it'll be all or nothing.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 5455c64f1d wgengine/magicsock: add a test for two facing endpoint-independent NATs.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson f794493b4f wgengine/magicsock: explicitly check path discovery, add a firewall test.
The test proves that active discovery can traverse two facing firewalls.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson f582eeabd1 wgengine/magicsock: add a test for active path discovery.
Uses natlab only, because the point of this active discovery test is going to be
that it should get through a lot of obstacles.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 37903a9056 wgengine/magicsock: fix occasional deadlock on Conn.Close on c.derpStarted
The deadlock was:

* Conn.Close was called, which acquired c.mu
* Then this goroutine scheduled:

    if firstDerp {
        startGate = c.derpStarted
        go func() {
            dc.Connect(ctx)
            close(c.derpStarted)
        }()
    }

* The getRegion hook for that derphttp.Client then ran, which also
  tries to acquire c.mu.

This change makes that hook first see if we're already in a closing
state and then it can pretend that region doesn't exist.
4 years ago
Brad Fitzpatrick fe68841dc7 wgengine/magicsock: log better with less spam on transition to stopped state
Required a minor test update too, which now needs a private key to get far
enough to test the thing being tested.
4 years ago
Brad Fitzpatrick e298327ba8 wgengine/magicsock: remove overkill, slow reflect.DeepEqual of NetworkMap
No need to allocate or compare all the fields we don't care about.
4 years ago
Brad Fitzpatrick 4970e771ab wgengine: add debug knob to disable the watchdog during debugging
It launches goroutines and interferes with panic-based debugging,
obscuring stacks.
4 years ago
David Anderson 3669296cef wgengine/magicsock: refactor twoDevicePing to make stack construction cleaner.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 16a9cfe2f4 wgengine: configure wireguard peers lazily, as needed
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>
4 years ago
Brad Fitzpatrick 5066b824a6 wgengine/magicsock: don't log about disco ping timeouts if we have a working address
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick a89d610a3d wgengine/tstun: move sync.Pool to package global
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.
4 years ago
Dmytro Shynkevych c53ab3111d wgengine/router: support legacy resolvconf
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
David Anderson 189d86cce5 wgengine/router: don't use 88 or 8888 as table/rule numbers.
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>
4 years ago
David Anderson 972a42cb33 wgengine/router: fix router_test to match the new marks.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson d60917c0f1 wgengine/router: switch packet marks to avoid conflict with Weave Net.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick c06d2a8513 wgengine/magicsock: fix typo in comment 4 years ago
Brad Fitzpatrick bf195cd3d8 wgengine/magicsock: reduce log verbosity of discovery messages
Don't log heartbeat pings & pongs. Track the reason for pings and then
only log the ping/pong traffic if it was for initial path discovery.
4 years ago
Dmytro Shynkevych a3e7252ce6 wgengine/router: use better NetworkManager API
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Eduardo Kienetz 5df6be9d38 Use LittleEndian for correct byte order on DNS IPs
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>
4 years ago
Brad Fitzpatrick a6559a8924 wgengine/magicsock: run test DERP in mode where only disco packets allowed
So we don't accidentally pass a NAT traversal test by having DERP pick up our slack
when we really just wanted DERP as an OOB messaging channel.
4 years ago
Brad Fitzpatrick 10ac066013 all: fix vet warnings 4 years ago
Brad Fitzpatrick d74c9aa95b wgengine/magicsock: update comment, fix earlier commit
891898525c had a continue that meant the didCopy synchronization never ran.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick c976264bd1 wgengine/magicsock: gofmt 4 years ago
Dmytro Shynkevych f3e2b65637
wgengine/magicsock: time.Sleep -> time.After
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 380ee76d00
wgengine/magicsock: make time.Sleep in runDerpReader respect cancellation.
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>
4 years ago
Dmytro Shynkevych 891898525c
wgengine/magicsock: make receive from didCopy respect cancellation.
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>
4 years ago
Brad Fitzpatrick a2267aae99 wgengine: only launch pingers for peers predating the discovery protocol
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.
4 years ago
Brad Fitzpatrick cdfea347d0 wgengine: update for tailscale/wireguard-go API changes
* update to new HandshakeDone signature
* use new Device.IpcGetOperationFiltered call to avoid sending allowed_ips

See dd6c1c8fe1
4 years ago
David Anderson 45578b47f3 tstest/natlab: refactor PacketHandler into a larger interface.
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>
4 years ago
Dmytro Shynkevych 19867b2b6d
tstun: remove buggy-looking log line.
This log line looks buggy, even though lacking a filter is expected during bringup.
We already know if we forget to SetFilter: it breaks the magicsock test,
so no useful information is lost.

Resolves #559.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Wendi Yu c3736250a4
wgengine: fix macos staticcheck errors (#557)
Signed-off-by: Wendi <wendi.yu@yahoo.ca>
4 years ago
Dmytro Shynkevych 3b36400e35
tsdns: response to type ANY queries
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 2f15894a10 wgengine/magicsock: wait for derphttp client goroutine to exit
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 30bbbe9467
wgengine/router: dns: unify on *BSD, multimode on Linux, Magic DNS (#536)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 61abab999e
cmd/tailscaled: graceful shutdown (#534)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
David Anderson 88e8456e9b wgengine/magicsock: add a connectivity test for facing firewalls.
The test demonstrates that magicsock can traverse two stateful
firewalls facing each other, that each require localhost to
initiate connections.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 1f7b1a4c6c wgengine/magicsock: rearrange TwoDevicePing test for future natlab tests.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
David Anderson 977381f9cc wgengine/magicsock: make trivial natlab test pass.
Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Brad Fitzpatrick 6c74065053 wgengine/magicsock, tstest/natlab: start hooking up natlab to magicsock
Also adds ephemeral port support to natlab.

Work in progress.

Pairing with @danderson.
4 years ago
Dmytro Shynkevych 21d1dbfce0 wgengine/tsdns: local DNS server for testing
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 248d28671b
tsdns: fix race in delegate
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick bd59bba8e6 wgengine/magicsock: stop discoEndpoint timers on Close
And add some defensive early returns on c.closed.
4 years ago
Brad Fitzpatrick de875a4d87 wgengine/magicsock: remove DisableSTUNForTesting 4 years ago
Dmytro Shynkevych 67ebba90e1
tsdns: dual resolution mode, IPv6 support (#526)
This change adds to tsdns the ability to delegate lookups to upstream nameservers.
This is crucial for setting Magic DNS as the system resolver.

Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick ce1b52bb71 wgengine/monitor: fix other potential crashes on Linux
Never return "nil, nil" anymore. The caller expected a usable
interface now. I missed some of these earlier.

Also, handle address deletion now.

Updates #532
4 years ago
Brad Fitzpatrick 4b75a27969 wgengine/monitor: fix crash on Linux on type 21 messages
Fixes #532
4 years ago
Brad Fitzpatrick 724ad13fe1 wgengine/tstun: fix alignment of 64-bit atomic field
We had a test for it, but no 32-bit builder apparently. :(

Fixes #529
4 years ago
Brad Fitzpatrick 4db60a8436 wgengine/monitor: parse Linux netlink messages, ignore our own events
Fixes tailscale/corp#412 ("flood of link change events at start-up")

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 742b8b44a8 net/tsaddr: new package to hold Tailscale-specific IPs/ranges
And update existing callers with (near) duplicated cases.
4 years ago
Brad Fitzpatrick 5c6d8e3053 netcheck, tailcfg, interfaces, magicsock: survey UPnP, NAT-PMP, PCP
Don't do anything with UPnP, NAT-PMP, PCP yet, but see how common they
are in the wild.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 6196b7e658 wgengine/magicsock: change API to not permit disco key changes
Generate the disco key ourselves and give out the public half instead.

Fixes #525
4 years ago
Brad Fitzpatrick 5132edacf7 wgengine/magicsock: fix data race from undocumented wireguard-go requirement
Endpoints need to be Stringers apparently.

Fixes tailscale/corp#422
4 years ago
Brad Fitzpatrick 630379a1d0 cmd/tailscale: add tailscale status region name, last write, consistently star
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.
4 years ago
Brad Fitzpatrick 9a8700b02a wgengine/magicsock: add discoEndpoint heartbeat
Updates #483
4 years ago
Brad Fitzpatrick 9f930ef2bf wgengine/magicsock: remove the discoEndpoint.timers map
It ended up being more complicated than it was worth.
4 years ago
Brad Fitzpatrick f5f3885b5b wgengine/magicsock: bunch of misc discovery path cleanups
* 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
4 years ago
Dmytro Shynkevych e9643ae724 wgengine: prevent log after exit in watchdog test
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Dmytro Shynkevych 16b2bbbbbb wgengine: close in reverse order of bringup
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
4 years ago
Brad Fitzpatrick 6c70cf7222 wgengine/magicsock: stop ping timeout timer on pong receipt, misc log cleanup
Updates #483
4 years ago
Brad Fitzpatrick c52905abaa wgengine/magicsock: log less on no-op disco route switches
Also, renew trustBestAddrUntil even if latency isn't better.
4 years ago
Brad Fitzpatrick 0f0ed3dca0 wgengine/magicsock: clean up discovery logging
Updates #483
4 years ago
Brad Fitzpatrick 056fbee4ef wgengine/magicsock: add TS_DEBUG_OMIT_LOCAL_ADDRS knob to force STUN use only
For debugging.
4 years ago
Brad Fitzpatrick e03cc2ef57 wgengine/magicsock: populate discoOfAddr upon receiving ping frames
Updates #483
4 years ago
Brad Fitzpatrick 275a20f817 wgengine/magicsock: keep discoOfAddr populated, use it for findEndpoint
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
4 years ago
Brad Fitzpatrick 77e89c4a72 wgengine/magicsock: handle CallMeMaybe discovery mesages
Roughly feature complete now. Testing and polish remains.

Updates #483
4 years ago
Brad Fitzpatrick 710ee88e94 wgengine/magicsock: add timeout on discovery pings, clean up state
Updates #483
4 years ago
Brad Fitzpatrick 77d3ef36f4 wgengine/magicsock: hook up discovery messages, upgrade to LAN works
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
4 years ago
Brad Fitzpatrick 9b8ca219a1 wgengine/magicsock: remove allocs in UDP write, use new netaddr.PutUDPAddr
The allocs were only introduced yesterday with a TODO. Now they're gone again.
4 years ago
Brad Fitzpatrick 7b3c0bb7f6 wgengine/magicsock: fix crash reading DERP packet
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
4 years ago
Brad Fitzpatrick 47b4a19786 wgengine/magicsock: use netaddr.ParseIPPort instead of net.ResolveUDPAddr 4 years ago
Brad Fitzpatrick f7124c7f06 wgengine/magicsock: start of discoEndpoint state tracking
Updates #483
4 years ago
Brad Fitzpatrick 92252b0988 wgengine/magicsock: add a little LRU cache for netaddr.IPPort lookups
And while plumbing, a bit of discovery work I'll need: the
endpointOfAddr map to map from validated paths to the discoEndpoint.
Not being populated yet.

Updates #483
4 years ago
Brad Fitzpatrick 2d6e84e19e net/netcheck, wgengine/magicsock: replace more UDPAddr with netaddr.IPPort 4 years ago
Brad Fitzpatrick 9070aacdee wgengine/magicsock: minor comments & logging & TODO changes 4 years ago
Brad Fitzpatrick e96f22e560 wgengine/magicsock: start handling disco message, use netaddr.IPPort more
Updates #483
4 years ago
Brad Fitzpatrick a83ca9e734 wgengine/magicsock: cache precomputed nacl/box shared keys
Updates #483
4 years ago
Brad Fitzpatrick a975e86bb8 wgengine/magicsock: add new endpoint type used for discovery-supporting peers
This adds a new magicsock endpoint type only used when both sides
support discovery (that is, are advertising a discovery
key). Otherwise the old code is used.

So far the new code only communicates over DERP as proof that the new
code paths are wired up. None of the actually discovery messaging is
implemented yet.

Support for discovery (generating and advertising a key) are still
behind an environment variable for now.

Updates #483
4 years ago
Brad Fitzpatrick 6f73f2c15a wgengine, internal/deepprint: replace UAPI usage as hash func; add deepprint
The new deepprint package just walks a Go data structure and writes to
an io.Writer. It's not pretty like go-spew, etc.

We then use it to replace the use of UAPI (which we have a TODO to
remove) to generate signatures of data structures to detect whether
anything changed (without retaining the old copy).

This was necessary because the UAPI conversion ends up trying to do
DNS lookups which an upcoming change depends on not happening.
4 years ago
Brad Fitzpatrick 103c06cc68 wgengine/magicsock: open discovery naclbox messages from known peers
And track known peers.

Doesn't yet do anything with the messages. (nor does it send any yet)

Start of docs on the message format. More will come in subsequent changes.

Updates #483
4 years ago
David Crawshaw 9258d64261 wgengine/router: do not call ifconfig up if SetRoutesFunc is set
The NetworkExtension brings up the interface itself and does not have
access to `ifconfig`, which the underlying BSD userspace router attempts
to use when Up is called.

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
4 years ago
Brad Fitzpatrick 23e74a0f7a wgengine, magicsock, tstun: don't regularly STUN when idle (mobile only for now)
If there's been 5 minutes of inactivity, stop doing STUN lookups. That
means NAT mappings will expire, but they can resume later when there's
activity again.

We'll do this for all platforms later.

Updates tailscale/corp#320

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick fe50cd0c48 ipn, wgengine: plumb NetworkMap down to magicsock
Now we can have magicsock make decisions based on tailcfg.Debug
settings sent by the server.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 19d95e095a wgengine: fix blank line in interface method comment 4 years ago
Reinaldo de Souza a8635784bc wgengine: add BSD userspace router to darwin
Darwin and FreeBSD are compatible enough to share the userspace router.

The OSX router delegates to the BSD userspace router unless `SetRoutesFunc` is set.
That preserves the mechanism that allows `ipn-go-bridge` to specify its own routing behavior.

Fixes #177

Signed-off-by: Reinaldo de Souza <github@rei.nal.do>
4 years ago
Dmytro Shynkevych de5f6d70a8 magicsock: eliminate logging race in test
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
5 years ago
Brad Fitzpatrick 53fb25fc2f all: generate discovery key, plumb it around
Not actually used yet.

Updates #483
5 years ago
Brad Fitzpatrick d9054da86a wgengine: disambiguate Reconfig logging paths 5 years ago
Brad Fitzpatrick abd79ea368 derp: reduce DERP memory use; don't require callers to pass in memory to use
The magicsock derpReader was holding onto 65KB for each DERP
connection forever, just in case.

Make the derp{,http}.Client be in charge of memory instead. It can
reuse its bufio.Reader buffer space.
5 years ago
Brad Fitzpatrick 280e8884dd wgengine/magicsock: limit redundant log spam on packets from low-pri addresses
Fixes #407

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
5 years ago
David Anderson d05b0500ac wgengine: loop back tuntap packets destined for local IPs.
macOS incorrectly sends packets for the local Tailscale IP
into our tunnel interface. We have to turn the packets around
and send them back to the kernel.

Fixes tailscale/corp#189.

Signed-off-by: David Anderson <danderson@tailscale.com>
5 years ago
Avery Pennarun 51d176ecff wgengine: Remove leftover debug message.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
5 years ago
Dmytro Shynkevych 07e02ec9d3
wgengine/tsdns: add test and prevent useless updates (#449)
Signed-Off-By: Dmytro Shynkevych <dmytro@tailscale.com>
5 years ago
Dmytro Shynkevych 511840b1f6
tsdns: initial implementation of a Tailscale DNS resolver (#396)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
5 years ago
Dmytro Shynkevych 02231e968e
wgengine/tstun: add tests and benchmarks (#436)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
5 years ago
Dmytro Shynkevych 059b1d10bb
wgengine/packet: refactor and expose UDP header marshaling (#408)
Signed-off-by: Dmytro Shynkevych <dmytro@tailscale.com>
5 years ago