Commit Graph

1133 Commits (main)

Author SHA1 Message Date
James Tucker 7f9ebc0a83 cmd/tailscale,net/netcheck: add debug feature to force preferred DERP
This provides an interface for a user to force a preferred DERP outcome
for all future netchecks that will take precedence unless the forced
region is unreachable.

The option does not persist and will be lost when the daemon restarts.

Updates tailscale/corp#18997
Updates tailscale/corp#24755

Signed-off-by: James Tucker <james@tailscale.com>
1 hour ago
Brad Fitzpatrick 74069774be net/tstun: remove tailscaled_outbound_dropped_packets_total reason=acl metric for now
Updates #14280

Change-Id: Idff102b3d7650fc9dfbe0c340168806bdf542d76
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
9 hours ago
Brad Fitzpatrick 8d0c690f89 net/netcheck: clean up ICMP probe AddrPort lookup
Fixes #14200

Change-Id: Ib086814cf63dda5de021403fe1db4fb2a798eaae
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 days ago
James Tucker 4d33f30f91 net/netmon: improve panic reporting from #14202
I was hoping we'd catch an example input quickly, but the reporter had
rebooted their machine and it is no longer exhibiting the behavior. As
such this code may be sticking around quite a bit longer and we might
encounter other errors, so include the panic in the log entry.

Updates #14201
Updates #14202
Updates golang/go#70528

Signed-off-by: James Tucker <james@tailscale.com>
1 week ago
James Tucker f6431185b0 net/netmon: catch ParseRIB panic to gather buffer data
Updates #14201
Updates golang/go#70528

Signed-off-by: James Tucker <james@tailscale.com>
2 weeks ago
Brad Fitzpatrick 0c8c7c0f90 net/tsaddr: include test input in test failure output
https://go.dev/wiki/CodeReviewComments#useful-test-failures

(Previously it was using subtests with names including the input, but
 once those went away, there was no context left)

Updates #14169

Change-Id: Ib217028183a3d001fe4aee58f2edb746b7b3aa88
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 weeks ago
James Scott ebaf33a80c
net/tsaddr: extract IsTailscaleIPv4 from IsTailscaleIP (#14169)
Extracts tsaddr.IsTailscaleIPv4 out of tsaddr.IsTailscaleIP.

This will allow for checking valid Tailscale assigned IPv4 addresses
without checking IPv6 addresses.

Updates #14168
Updates tailscale/corp#24620

Signed-off-by: James Scott <jim@tailscale.com>
2 weeks ago
Brad Fitzpatrick 3b93fd9c44 net/captivedetection: replace 10k log lines with ... less
We see tons of logs of the form:

    2024/11/15 19:57:29 netcheck: [v2] 76 available captive portal detection endpoints: [Endpoint{URL="http://192.73.240.161/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.240.121/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.240.132/generate_204", StatusCode=204, ExpectedContent="",
11:58SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://209.177.158.246/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://209.177.158.15/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://199.38.182.118/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.243.135/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.243.229/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.243.141/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://45.159.97.144/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://45.159.97.61/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://45.159.97.233/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://45.159.98.196/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://45.159.98.253/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://45.159.98.145/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://68.183.90.120/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://209.177.156.94/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.248.83/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://209.177.156.197/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://199.38.181.104/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://209.177.145.120/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://199.38.181.93/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://199.38.181.103/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://102.67.165.90/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://102.67.165.185/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://102.67.165.36/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.90.147/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.90.207/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.90.104/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://162.248.221.199/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://162.248.221.215/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://162.248.221.248/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://185.34.3.232/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://185.34.3.207/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://185.34.3.75/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://208.83.234.151/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://208.83.233.233/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://208.72.155.133/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://185.40.234.219/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://185.40.234.113/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://185.40.234.77/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://43.245.48.220/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://43.245.48.50/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://43.245.48.250/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.252.65/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.252.134/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://208.111.34.178/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://43.245.49.105/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://43.245.49.83/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://43.245.49.144/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.92.144/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.88.183/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.92.254/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://148.163.220.129/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://148.163.220.134/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://148.163.220.210/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.242.187/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.242.28/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.242.204/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.93.248/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.93.147/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://176.58.93.154/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://192.73.244.245/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://208.111.40.12/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://208.111.40.216/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://103.6.84.152/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://205.147.105.30/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://205.147.105.78/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://102.67.167.245/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://102.67.167.37/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://102.67.167.188/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://103.84.155.178/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://103.84.155.188/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://103.84.155.46/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=true, Provider=DERPMapOther} Endpoint{URL="http://controlplane.tailscale.com/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=false, Provider=Tailscale} Endpoint{URL="http://login.tailscale.com/generate_204", StatusCode=204, ExpectedContent="", SupportsTailscaleChallenge=false, Provider=Tailscale}]

That can be much shorter.

Also add a fast exit path to the concurrency on match. Doing 5 all at
once is still pretty gratuitous, though.

Updates #1634
Fixes #13019

Change-Id: Icdbb16572fca4477b0ee9882683a3ac6eb08e2f2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 weeks ago
Brad Fitzpatrick 4e0fc037e6 all: use iterators over slice views more
This gets close to all of the remaining ones.

Updates #12912

Change-Id: I9c672bbed2654a6c5cab31e0cbece6c107d8c6fa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 weeks ago
Brad Fitzpatrick 01185e436f types/result, util/lineiter: add package for a result type, use it
This adds a new generic result type (motivated by golang/go#70084) to
try it out, and uses it in the new lineutil package (replacing the old
lineread package), changing that package to return iterators:
sometimes over []byte (when the input is all in memory), but sometimes
iterators over results of []byte, if errors might happen at runtime.

Updates #12912
Updates golang/go#70084

Change-Id: Iacdc1070e661b5fb163907b1e8b07ac7d51d3f83
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 weeks ago
VimT 43138c7a5c net/socks5: optimize UDP relay
Key changes:
- No mutex for every udp package: replace syncs.Map with regular map for udpTargetConns
- Use socksAddr as map key for better type safety
- Add test for multi udp target

Updates #7581

Change-Id: Ic3d384a9eab62dcbf267d7d6d268bf242cc8ed3c
Signed-off-by: VimT <me@vimt.me>
1 month ago
VimT b0626ff84c net/socks5: fix UDP relay in userspace-networking mode
This commit addresses an issue with the SOCKS5 UDP relay functionality
when using the --tun=userspace-networking option. Previously, UDP packets
were not being correctly routed into the Tailscale network in this mode.

Key changes:
- Replace single UDP connection with a map of connections per target
- Use c.srv.dial for creating connections to ensure proper routing

Updates #7581

Change-Id: Iaaa66f9de6a3713218014cf3f498003a7cac9832
Signed-off-by: VimT <me@vimt.me>
1 month ago
Jordan Whited 49de23cf1b
net/netcheck: add addReportHistoryAndSetPreferredDERP() test case (#13989)
Add an explicit case for exercising preferred DERP hysteresis around
the branch that compares latencies on a percentage basis.

Updates #cleanup

Signed-off-by: Jordan Whited <jordan@tailscale.com>
1 month ago
Andrea Gottardo 6985369479
net/sockstats: prevent crash in setNetMon (#13985) 1 month ago
Anton Tolchanov b4f46c31bb wgengine/magicsock: export packet drop metric for outbound errors
This required sharing the dropped packet metric between two packages
(tstun and magicsock), so I've moved its definition to util/usermetric.

Updates tailscale/corp#22075

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
1 month ago
James Tucker e1e22785b4 net/netcheck: ensure prior preferred DERP is always in netchecks
In an environment with unstable latency, such as upstream bufferbloat,
there are cases where a full netcheck could drop the prior preferred
DERP (likely home DERP) from future netcheck probe plans. This will then
likely result in a home DERP having a missing sample on the next
incremental netcheck, ultimately resulting in a home DERP move.

This change does not fix our overall response to highly unstable
latency, but it is an incremental improvement to prevent single spurious
samples during a full netcheck from alone triggering a flapping
condition, as now the prior changes to include historical latency will
still provide the desired resistance, and the home DERP should not move
unless latency is consistently worse over a 5 minute period.

Note that there is a nomenclature and semantics issue remaining in the
difference between a report preferred DERP and a home DERP. A report
preferred DERP is aspirational, it is what will be picked as a home DERP
if a home DERP connection needs to be established. A nodes home DERP may
be different than a recent preferred DERP, in which case a lot of
netcheck logic is fallible. In future enhancements much of the DERP move
logic should move to consider the home DERP, rather than recent report
preferred DERP.

Updates #8603
Updates #13969

Signed-off-by: James Tucker <james@tailscale.com>
1 month ago
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>
1 month 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>
2 months 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>
2 months 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>
2 months 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>
3 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>
3 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>
3 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