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>
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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
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>
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>
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>
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>
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>
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>
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>
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
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>
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>
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
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>
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>
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>
`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>
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>
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>
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>
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>
