Commit Graph

1117 Commits (11e96760ff119dcfa60139371570f761e0c26050)

Author SHA1 Message Date
Renato Aguiar 5d07c17b93
net/dns: fix blank lines being added to resolv.conf on OpenBSD (#13928)
During resolv.conf update, old 'search' lines are cleared but '\n' is not
deleted, leaving behind a new blank line on every update.

This adds 's' flag to regexp, so '\n' is included in the match and deleted when
old lines are cleared.

Also, insert missing `\n` when updated 'search' line is appended to resolv.conf.

Signed-off-by: Renato Aguiar <renato@renatoaguiar.net>
4 weeks ago
Andrew Dunham 7fe6e50858 net/dns/resolver: fix test flake
Updates #13902

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib2def19caad17367e9a31786ac969278e65f51c6
1 month ago
Andrew Dunham b2665d9b89 net/netcheck: add a Now field to the netcheck Report
This allows us to print the time that a netcheck was run, which is
useful in debugging.

Updates #10972

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id48d30d4eb6d5208efb2b1526a71d83fe7f9320b
1 month ago
Maisem Ali 85241f8408 net/tstun: use /10 as subnet for TAP mode; read IP from netmap
Few changes to resolve TODOs in the code:
- Instead of using a hardcoded IP, get it from the netmap.
- Use 100.100.100.100 as the gateway IP
- Use the /10 CGNAT range instead of a random /24

Updates #2589

Signed-off-by: Maisem Ali <maisem@tailscale.com>
1 month ago
Maisem Ali d4d21a0bbf net/tstun: restore tap mode functionality
It had bit-rotted likely during the transition to vector io in
76389d8baf. Tested on Ubuntu 24.04
by creating a netns and doing the DHCP dance to get an IP.

Updates #2589

Signed-off-by: Maisem Ali <maisem@tailscale.com>
1 month ago
Andrea Gottardo f8f53bb6d4
health: remove SysDNSOS, add two Warnables for read+set system DNS config (#13874) 1 month ago
Andrea Gottardo fd77965f23
net/tlsdial: call out firewalls blocking Tailscale in health warnings (#13840)
Updates tailscale/tailscale#13839

Adds a new blockblame package which can detect common MITM SSL certificates used by network appliances. We use this in `tlsdial` to display a dedicated health warning when we cannot connect to control, and a network appliance MITM attack is detected.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
1 month ago
Jordan Whited 877fa504b4
net/netcheck: remove arbitrary deadlines from GetReport() tests (#13832)
GetReport() may have side effects when the caller enforces a deadline
that is shorter than ReportTimeout.

Updates #13783
Updates #13394

Signed-off-by: Jordan Whited <jordan@tailscale.com>
1 month ago
Kristoffer Dalby e0d711c478 {net/connstats,wgengine/magicsock}: fix packet counting in connstats
connstats currently increments the packet counter whenever it is called
to store a length of data, however when udp batch sending was introduced
we pass the length for a series of packages, and it is only incremented
ones, making it count wrongly if we are on a platform supporting udp
batches.

Updates tailscale/corp#22075

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
1 month ago
Nick Khyl f07ff47922 net/dns/resolver: add tests for using a forwarder with multiple upstream resolvers
If multiple upstream DNS servers are available, quad-100 sends requests to all of them
and forwards the first successful response, if any. If no successful responses are received,
it propagates the first failure from any of them.

This PR adds some test coverage for these scenarios.

Updates #13571

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2 months ago
Nick Hill c2144c44a3 net/dns/resolver: update (*forwarder).forwardWithDestChan to always return an error unless it sends a response to responseChan
We currently have two executions paths where (*forwarder).forwardWithDestChan
returns nil, rather than an error, without sending a DNS response to responseChan.

These paths are accompanied by a comment that reads:
// Returning an error will cause an internal retry, there is
// nothing we can do if parsing failed. Just drop the packet.
But it is not (or no longer longer) accurate: returning an error from forwardWithDestChan
does not currently cause a retry.

Moreover, although these paths are currently unreachable due to implementation details,
if (*forwarder).forwardWithDestChan were to return nil without sending a response to
responseChan, it would cause a deadlock at one call site and a panic at another.

Therefore, we update (*forwarder).forwardWithDestChan to return errors in those two paths
and remove comments that were no longer accurate and misleading.

Updates #cleanup
Updates #13571

Signed-off-by: Nick Hill <mykola.khyl@gmail.com>
2 months ago
Nick Hill e7545f2eac net/dns/resolver: translate 5xx DoH server errors into SERVFAIL DNS responses
If a DoH server returns an HTTP server error, rather than a SERVFAIL within
a successful HTTP response, we should handle it in the same way as SERVFAIL.

Updates #13571

Signed-off-by: Nick Hill <mykola.khyl@gmail.com>
2 months ago
Nick Hill 17335d2104 net/dns/resolver: forward SERVFAIL responses over PeerDNS
As per the docstring, (*forwarder).forwardWithDestChan should either send to responseChan
and returns nil, or returns a non-nil error (without sending to the channel).
However, this does not hold when all upstream DNS servers replied with an error.

We've been handling this special error path in (*Resolver).Query but not in (*Resolver).HandlePeerDNSQuery.
As a result, SERVFAIL responses from upstream servers were being converted into HTTP 503 responses,
instead of being properly forwarded as SERVFAIL within a successful HTTP response, as per RFC 8484, section 4.2.1:
A successful HTTP response with a 2xx status code (see Section 6.3 of [RFC7231]) is used for any valid DNS response,
regardless of the DNS response code. For example, a successful 2xx HTTP status code is used even with a DNS message
whose DNS response code indicates failure, such as SERVFAIL or NXDOMAIN.

In this PR we fix (*forwarder).forwardWithDestChan to no longer return an error when it sends a response to responseChan,
and remove the special handling in (*Resolver).Query, as it is no longer necessary.

Updates #13571

Signed-off-by: Nick Hill <mykola.khyl@gmail.com>
2 months ago
Jordan Whited 33029d4486
net/netcheck: fix netcheck cli-triggered nil pointer deref (#13782)
Updates #13780

Signed-off-by: Jordan Whited <jordan@tailscale.com>
2 months ago
Brad Fitzpatrick 841eaacb07 net/sockstats: quiet some log spam in release builds
Updates #13731

Change-Id: Ibee85426827ebb9e43a1c42a9c07c847daa50117
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 months ago
Andrew Dunham 8ee7f82bf4 net/netcheck: don't panic if a region has no Nodes
Updates #13728

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I1e8319d6b2da013ae48f15113b30c9333e69cc0b
2 months ago
Andrea Gottardo 6de6ab015f
net/dns: tweak DoH timeout, limit MaxConnsPerHost, require TLS 1.3 (#13564)
Updates tailscale/tailscale#6148

This is the result of some observations we made today with @raggi. The DNS over HTTPS client currently doesn't cap the number of connections it uses, either in-use or idle. A burst of DNS queries will open multiple connections. Idle connections remain open for 30 seconds (this interval is defined in the dohTransportTimeout constant). For DoH providers like NextDNS which send keep-alives, this means the cellular modem will remain up more than expected to send ACKs if any keep-alives are received while a connection remains idle during those 30 seconds. We can set the IdleConnTimeout to 10 seconds to ensure an idle connection is terminated if no other DNS queries come in after 10 seconds. Additionally, we can cap the number of connections to 1. This ensures that at all times there is only one open DoH connection, either active or idle. If idle, it will be terminated within 10 seconds from the last query.

We also observed all the DoH providers we support are capable of TLS 1.3. We can force this TLS version to reduce the number of packets sent/received each time a TLS connection is established.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2 months ago
Brad Fitzpatrick f49d218cfe net/dnscache: don't fall back to an IPv6 dial if we don't have IPv6
I noticed while debugging a test failure elsewhere that our failure
logs (when verbosity is cranked up) were uselessly attributing dial
failures to failure to dial an invalid IP address (this IPv6 address
we didn't have), rather than showing me the actual IPv4 connection
failure.

Updates #13597 (tangentially)

Change-Id: I45ffbefbc7e25ebfb15768006413a705b941dae5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 months ago
Andrea Gottardo ed1ac799c8
net/captivedetection: set Timeout on net.Dialer (#13613)
Updates tailscale/tailscale#1634
Updates tailscale/tailscale#13265

Captive portal detection uses a custom `net.Dialer` in its `http.Client`. This custom Dialer ensures that the socket is bound specifically to the Wi-Fi interface. This is crucial because without it, if any default routes are set, the outgoing requests for detecting a captive portal would bypass Wi-Fi and go through the default route instead.

The Dialer did not have a Timeout property configured, so the default system timeout was applied. This caused issues in #13265, where we attempted to make captive portal detection requests over an IPsec interface used for Wi-Fi Calling. The call to `connect()` would fail and remain blocked until the system timeout (approximately 1 minute) was reached.

In #13598, I simply excluded the IPsec interface from captive portal detection. This was a quick and safe mitigation for the issue. This PR is a follow-up to make the process more robust, by setting a 3 seconds timeout on any connection establishment on any interface (this is the same timeout interval we were already setting on the HTTP client).

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2 months ago
Brad Fitzpatrick 262c526c4e net/portmapper: don't treat 0.0.0.0 as a valid IP
Updates tailscale/corp#23538

Change-Id: I58b8c30abe43f1d1829f01eb9fb2c1e6e8db9476
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 months ago
Andrew Dunham 16ef88754d net/portmapper: don't return unspecified/local external IPs
We were previously not checking that the external IP that we got back
from a UPnP portmap was a valid endpoint; add minimal validation that
this endpoint is something that is routeable by another host.

Updates tailscale/corp#23538

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id9649e7683394aced326d5348f4caa24d0efd532
2 months ago
Andrea Gottardo 69be54c7b6
net/captivedetection: exclude ipsec interfaces from captive portal detection (#13598)
Updates tailscale/tailscale#1634

Logs from some iOS users indicate that we're pointlessly performing captive portal detection on certain interfaces named ipsec*. These are tunnels with the cellular carrier that do not offer Internet access, and are only used to provide internet calling functionality (VoLTE / VoWiFi).

```
attempting to do captive portal detection on interface ipsec1
attempting to do captive portal detection on interface ipsec6
```

This PR excludes interfaces with the `ipsec` prefix from captive portal detection.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2 months ago
Kristoffer Dalby 7d1160ddaa {ipn,net,tsnet}: use tsaddr helpers
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2 months ago
Kristoffer Dalby 3dc33a0a5b net/tsaddr: add WithoutExitRoutes and IsExitRoute
Updates #cleanup

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2 months ago
Kristoffer Dalby 0e0e53d3b3 util/usermetrics: make usermetrics non-global
this commit changes usermetrics to be non-global, this is a building
block for correct metrics if a go process runs multiple tsnets or
in tests.

Updates #13420
Updates tailscale/corp#22075

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2 months ago
Andrea Gottardo 8a6f48b455
cli: add `tailscale dns query` (#13368)
Updates tailscale/tailscale#13326

Adds a CLI subcommand to perform DNS queries using the internal DNS forwarder and observe its internals (namely, which upstream resolvers are being used).

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2 months ago
James Tucker af5a845a87 net/dns/resolver: fix dns-sd NXDOMAIN responses from quad-100
mdnsResponder at least as of macOS Sequoia does not find NXDOMAIN
responses to these dns-sd PTR queries acceptable unless they include the
question section in the response. This was found debugging #13511, once
we turned on additional diagnostic reporting from mdnsResponder we
witnessed:

```
Received unacceptable 12-byte response from 100.100.100.100 over UDP via utun6/27 -- id: 0x7F41 (32577), flags: 0x8183 (R/Query, RD, RA, NXDomain), counts: 0/0/0/0,
```

If the response includes a question section, the resposnes are
acceptable, e.g.:

```
Received acceptable 59-byte response from 8.8.8.8 over UDP via en0/17 -- id: 0x2E55 (11861), flags: 0x8183 (R/Query, RD, RA, NXDomain), counts: 1/0/0/0,
```

This may be contributing to an issue under diagnosis in #13511 wherein
some combination of conditions results in mdnsResponder no longer
answering DNS queries correctly to applications on the system for
extended periods of time (multiple minutes), while dig against quad-100
provides correct responses for those same domains. If additional debug
logging is enabled in mdnsResponder we see it reporting:

```
Penalizing server 100.100.100.100 for 60 seconds
```

It is also possible that the reason that macOS & iOS never "stopped
spamming" these queries is that they have never been replied to with
acceptable responses. It is not clear if this special case handling of
dns-sd PTR queries was ever beneficial, and given this evidence may have
always been harmful. If we subsequently observe that the queries settle
down now that they have acceptable responses, we should remove these
special cases - making upstream queries very occasionally isn't a lot of
battery, so we should be better off having to maintain less special
cases and avoid bugs of this class.

Updates #2442
Updates #3025
Updates #3363
Updates #3594
Updates #13511

Signed-off-by: James Tucker <james@tailscale.com>
2 months ago
Jordan Whited 951884b077
net/netcheck,wgengine/magicsock: plumb OnlyTCP443 controlknob through netcheck (#13491)
Updates tailscale/corp#17879

Signed-off-by: Jordan Whited <jordan@tailscale.com>
2 months ago
Jordan Whited afec2d41b4
wgengine/magicsock: remove redundant deadline from netcheck report call (#13395)
netcheck.Client.GetReport() applies its own deadlines. This 2s deadline
was causing GetReport() to never fall back to HTTPS/ICMP measurements
as it was shorter than netcheck.stunProbeTimeout, leaving no time
for fallbacks.

Updates #13394
Updates #6187

Signed-off-by: Jordan Whited <jordan@tailscale.com>
2 months ago
Nick Khyl 4dfde7bffc net/dns: disable DNS registration for Tailscale interface on Windows
We already disable dynamic updates by setting DisableDynamicUpdate to 1 for the Tailscale interface.
However, this does not prevent non-dynamic DNS registration from happening when `ipconfig /registerdns`
runs and in similar scenarios. Notably, dns/windowsManager.SetDNS runs `ipconfig /registerdns`,
triggering DNS registration for all interfaces that do not explicitly disable it.

In this PR, we update dns/windowsManager.disableDynamicUpdates to also set RegistrationEnabled to 0.

Fixes #13411

Signed-off-by: Nick Khyl <nickk@tailscale.com>
3 months ago
Jordan Whited 7aa766ee65
net/tstun: probe TCP GRO (#13376)
Disable TCP & UDP GRO if the probe fails.

torvalds/linux@e269d79c7d broke virtio_net
TCP & UDP GRO causing GRO writes to return EINVAL. The bug was then
resolved later in
torvalds/linux@89add40066. The offending
commit was pulled into various LTS releases.

Updates #13041

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Andrew Dunham 7dcf65a10a net/dns: fix IsZero and Equal methods on OSConfig
Discovered this while investigating the following issue; I think it's
unrelated, but might as well fix it. Also, add a test helper for
checking things that have an IsZero method using the reflect package.

Updates tailscale/support-escalations#55

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I57b7adde43bcef9483763b561da173b4c35f49e2
3 months ago
Brad Fitzpatrick 3d401c11fa all: use new Go 1.23 slices.Sorted more
Updates #12912

Change-Id: If1294e5bc7b5d3cf0067535ae10db75e8b988d8b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 months ago
Andrea Gottardo d060b3fa02
cli: implement `tailscale dns status` (#13353)
Updates tailscale/tailscale#13326

This PR begins implementing a `tailscale dns` command group in the Tailscale CLI. It provides an initial implementation of `tailscale dns status` which dumps the state of the internal DNS forwarder.

Two new endpoints were added in LocalAPI to support the CLI functionality:

- `/netmap`: dumps a copy of the last received network map (because the CLI shouldn't have to listen to the ipn bus for a copy)
- `/dns-osconfig`: dumps the OS DNS configuration (this will be very handy for the UI clients as well, as they currently do not display this information)

My plan is to implement other subcommands mentioned in tailscale/tailscale#13326, such as `query`, in later PRs.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
3 months ago
Andrea Gottardo 0112da6070
net/dns: support GetBaseConfig on Darwin OSS tailscaled (#13351)
Updates tailscale/tailscale#177

It appears that the OSS distribution of `tailscaled` is currently unable to get the current system base DNS configuration, as GetBaseConfig() in manager_darwin.go is unimplemented. This PR adds a basic implementation that reads the current values in `/etc/resolv.conf`, to at least unblock DNS resolution via Quad100 if `--accept-dns` is enabled.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
3 months ago
Andrew Dunham 1c972bc7cb wgengine/magicsock: actually use AF_PACKET socket for raw disco
Previously, despite what the commit said, we were using a raw IP socket
that was *not* an AF_PACKET socket, and thus was subject to the host
firewall rules. Switch to using a real AF_PACKET socket to actually get
the functionality we want.

Updates #13140

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: If657daeeda9ab8d967e75a4f049c66e2bca54b78
3 months ago
Jordan Whited 45c97751fb
net/tstun: clarify GROFilterFunc *gro.GRO usage (#13318)
Updates #cleanup

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Andrea Gottardo a584d04f8a
dns: increase TimeToVisible before DNS unavailable warning (#13317)
Updates tailscale/tailscale#13314

Some users are reporting 'DNS unavailable' spurious (?) warnings, especially on Android:

https://old.reddit.com/r/Tailscale/comments/1f2ow3w/health_warning_dns_unavailable_on_tailscale/
https://old.reddit.com/r/Tailscale/comments/1f3l2il/health_warnings_dns_unavailable_what_does_it_mean/

I suspect this is caused by having a too low TimeToVisible setting on the Warnable, which triggers the unhealthy state during slow network transitions.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
3 months ago
Jordan Whited 0926954cf5
net/tstun,wgengine/netstack: implement TCP GRO for local services (#13315)
Throughput improves substantially when measured via netstack loopback
(TS_DEBUG_NETSTACK_LOOPBACK_PORT).

Before (d21ebc2):
jwhited@i5-12400-2:~$ iperf3 -V -c 100.100.100.100
Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  5.77 GBytes  4.95 Gbits/sec    0 sender
[  5]   0.00-10.01  sec  5.77 GBytes  4.95 Gbits/sec      receiver

After:
jwhited@i5-12400-2:~$ iperf3 -V -c 100.100.100.100
Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  12.7 GBytes  10.9 Gbits/sec    0 sender
[  5]   0.00-10.00  sec  12.7 GBytes  10.9 Gbits/sec      receiver

Updates tailscale/corp#22754

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 31cdbd68b1
net/tstun: fix gvisor inbound GSO packet injection (#13283)
buffs[0] was not sized to hold pkt with GSO, resulting in a panic.

Updates tailscale/corp#22511

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Kristoffer Dalby a2c42d3cd4 usermetric: add initial user-facing metrics
This commit adds a new usermetric package and wires
up metrics across the tailscale client.

Updates tailscale/corp#22075

Co-authored-by: Anton Tolchanov <anton@tailscale.com>
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
3 months ago
Jordan Whited d097096ddc
net/tstun,wgengine/netstack: make inbound synthetic packet injection GSO-aware (#13266)
Updates tailscale/corp#22511

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Ilarion Kovalchuk 0cb7eb9b75 net/dns: updated gonotify dependency to v2 that supports closable context
Signed-off-by: Ilarion Kovalchuk <illarion.kovalchuk@gmail.com>
3 months ago
Brad Fitzpatrick 0ff474ff37 all: fix new lint warnings from bumping staticcheck
In prep for updating to new staticcheck required for Go 1.23.

Updates #12912

Change-Id: If77892a023b79c6fa798f936fc80428fd4ce0673
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 months ago
Jordan Whited df6014f1d7
net/tstun,wgengine{/netstack/gro}: refactor and re-enable gVisor GRO for Linux (#13172)
In 2f27319baf we disabled GRO due to a
data race around concurrent calls to tstun.Wrapper.Write(). This commit
refactors GRO to be thread-safe, and re-enables it on Linux.

This refactor now carries a GRO type across tstun and netstack APIs
with a lifetime that is scoped to a single tstun.Wrapper.Write() call.

In 25f0a3fc8f we used build tags to
prevent importation of gVisor's GRO package on iOS as at the time we
believed it was contributing to additional memory usage on that
platform. It wasn't, so this commit simplifies and removes those
build tags.

Updates tailscale/corp#22353
Updates tailscale/corp#22125
Updates #6816

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Andrea Gottardo 5cbbb48c2e
health/dns: reduce severity of DNS unavailable warning (#13152)
`DNS unavailable` was marked as a high severity warning. On Android (and other platforms), these trigger a system notification. Here we reduce the severity level to medium. A medium severity warning will still display the warning icon on platforms with a tray icon because of the `ImpactsConnectivity=true` flag being set here, but it won't show a notification anymore. If people enter an area with bad cellular reception, they're bound to receive so many of these notifications and we need to reduce notification fatigue.

Signed-off-by: Andrea Gottardo <andrea@tailscale.com>
3 months ago
Kyle Carberry 6c852fa817 go.{mod,sum}: migrate from nhooyr.io/websocket to github.com/coder/websocket
Coder has just adopted nhooyr/websocket which unfortunately changes the import path.

`github.com/coder/coder` imports `tailscale.com/net/wsconn` which was still pointing
to `nhooyr.io/websocket`, but this change updates it.

See https://coder.com/blog/websocket

Updates #13154

Change-Id: I3dec6512472b14eae337ae22c5bcc1e3758888d5
Signed-off-by: Kyle Carberry <kyle@carberry.com>
3 months ago
Brad Fitzpatrick a61825c7b8 cmd/tta, vnet: add host firewall, env var support, more tests
In particular, tests showing that #3824 works. But that test doesn't
actually work yet; it only gets a DERP connection. (why?)

Updates #13038

Change-Id: Ie1fd1b6a38d4e90fae7e72a0b9a142a95f0b2e8f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 months ago
Nick Khyl f23932bd98 net/dns/resolver: log forwarded query details when TS_DEBUG_DNS_FORWARD_SEND is enabled
Troubleshooting DNS resolution issues often requires additional information.
This PR expands the effect of the TS_DEBUG_DNS_FORWARD_SEND envknob to forwarder.forwardWithDestChan,
and includes the request type, domain name length, and the first 3 bytes of the domain's SHA-256 hash in the output.

Fixes #13070

Signed-off-by: Nick Khyl <nickk@tailscale.com>
4 months ago
Anton Tolchanov 227509547f {control,net}: close idle connections of custom transports
I noticed a few places with custom http.Transport where we are not
closing idle connections when transport is no longer used.

Updates tailscale/corp#21609

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
4 months ago