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>
It is sometimes necessary to change a global lazy.SyncValue for the duration of a test. This PR adds a (*SyncValue[T]).SetForTest method to facilitate that.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The standard library includes these for strings and byte slices,
but it lacks similar functions for generic slices of comparable types.
Although they are not as commonly used, these functions are useful
in scenarios such as working with field index sequences (i.e., []int)
via reflection.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This adds support for container-like types such as Container[T] that
don't explicitly specify a view type for T. Instead, a package implementing
a container type should also implement and export a ContainerView[T, V] type
and a ContainerViewOf(*Container[T]) ContainerView[T, V] function, which
returns a view for the specified container, inferring the element view type V
from the element type T.
Updates #12736
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Windows requires routes to have a nexthop. Routes created using the interface's local IP address or an unspecified IP address ("0.0.0.0" or "::") as the nexthop are considered on-link routes. Notably, Windows treats on-link subnet routes differently, reserving the last IP in the range as the broadcast IP and therefore prohibiting TCP connections to it, resulting in WSA error 10049: "The requested address is not valid in its context. This does not happen with single-host routes, such as routes to Tailscale IP addresses, but becomes a problem with advertised subnets when all IPs in the range should be reachable.
Before Windows 8, only routes created with an unspecified IP address were considered on-link, so our previous approach of using the interface's own IP as the nexthop likely worked on Windows 7.
This PR updates configureInterface to use the TailscaleServiceIP (100.100.100.100) and its IPv6 counterpart as the nexthop for subnet routes.
Fixestailscale/support-escalations#57
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This adds support for generic types and interfaces to our cloner and viewer codegens.
It updates these packages to determine whether to make shallow or deep copies based
on the type parameter constraints. Additionally, if a template parameter or an interface
type has View() and Clone() methods, we'll use them for getters and the cloner of the
owning structure.
Updates #12736
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This adds a package with GP-related functions and types to be used in the future PRs.
It also updates nrptRuleDatabase to use the new package instead of its own gpNotificationWatcher implementation.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Without this rule, Windows 8.1 and newer devices issue parallel DNS requests to DNS servers
associated with all network adapters, even when "Override local DNS" is enabled and/or
a Mullvad exit node is being used, resulting in DNS leaks.
This also adds "disable-local-dns-override-via-nrpt" nodeAttr that can be used to disable
the new behavior if needed.
Fixestailscale/corp#20718
Signed-off-by: Nick Khyl <nickk@tailscale.com>
As quad-100 is an authoritative server for 4via6 domains, it should always return responses
with a response code of 0 (indicating no error) when resolving records for these domains.
If there's no resource record of the specified type (e.g. A), it should return a response
with an empty answer section rather than NXDomain. Such a response indicates that there
is at least one RR of a different type (e.g., AAAA), suggesting the Windows stub resolver
to look for it.
Fixestailscale/corp#20767
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Now that tsdial.Dialer.UserDial has been updated to honor the configured routes
and dial external network addresses without going through Tailscale, while also being
able to dial a node/subnet router on the tailnet, we can start using UserDial to forward
DNS requests. This is primarily needed for DNS over TCP when forwarding requests
to internal DNS servers, but we also update getKnownDoHClientForProvider to use it.
Updates tailscale/corp#18725
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We'd like to use tsdial.Dialer.UserDial instead of SystemDial for DNS over TCP.
This is primarily necessary to properly dial internal DNS servers accessible
over Tailscale and subnet routes. However, to avoid issues when switching
between Wi-Fi and cellular, we need to ensure that we don't retain connections
to any external addresses on the old interface. Therefore, we need to determine
which dialer to use internally based on the configured routes.
This plumbs routes and localRoutes from router.Config to tsdial.Dialer,
and updates UserDial to use either the peer dialer or the system dialer,
depending on the network address and the configured routes.
Updates tailscale/corp#18725
Fixes#4529
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The Network Location Awareness service identifies networks authenticated against
an Active Directory domain and categorizes them as "Domain Authenticated".
This includes the Tailscale network if a Domain Controller is reachable through it.
If a network is categories as NLM_NETWORK_CATEGORY_DOMAIN_AUTHENTICATED,
it is not possible to override its category, and we shouldn't attempt to do so.
Additionally, our Windows Firewall rules should be compatible with both private
and domain networks.
This fixes both issues.
Fixes#11813
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Package winenv provides information about the current Windows environment.
This includes details such as whether the device is a server or workstation,
and if it is AD domain-joined, MDM-registered, or neither.
Updates tailscale/corp#18342
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Tailscaled becomes inoperative if the Tailscale Tunnel wintun adapter is abruptly removed.
wireguard-go closes the device in case of a read error, but tailscaled keeps running.
This adds detection of a closed WireGuard device, triggering a graceful shutdown of tailscaled.
It is then restarted by the tailscaled watchdog service process.
Fixes#11222
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The WinTun adapter may have been removed by the time we're closing
the dns.windowsManager, and its associated interface registry key might
also have been deleted. We shouldn't use winutil.OpenKeyWait and wait
for the interface key to appear when performing a cleanup as a part of
the windowsManager shutdown.
Updates #11222
Signed-off-by: Nick Khyl <nickk@tailscale.com>
When the portable Monitor creates a winMon via newOSMon, we register
address and route change callbacks with Windows. Once a callback is hit,
it starts a goroutine that attempts to send the event into messagec and returns.
The newly started goroutine then blocks until it can send to the channel.
However, if the monitor is never started and winMon.Receive is never called,
the goroutines remain indefinitely blocked, leading to goroutine leaks and
significant memory consumption in the tailscaled service process on Windows.
Unlike the tailscaled subprocess, the service process creates but never starts
a Monitor.
This PR adds a check within the callbacks to confirm the monitor's active status,
and exits immediately if the monitor hasn't started.
Updates #9864
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this commit, we have updated the build process for our Windows DLLs
to link statically with libgcc, ensuring our Windows DLLs are self-contained.
Updates #10617
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Nick KhylandNick Khyl