This fixes a bug that was introduced in #11258 where the handling of the
per-client limit didn't properly account for the fact that the gVisor
TCP forwarder will return 'true' to indicate that it's handled a
duplicate SYN packet, but not launch the handler goroutine.
In such a case, we neither decremented our per-client limit in the
wrapper function, nor did we do so in the handler function, leading to
our per-client limit table slowly filling up without bound.
Fix this by doing the same duplicate-tracking logic that the TCP
forwarder does so we can detect such cases and appropriately decrement
our in-flight counter.
Updates tailscale/corp#12184
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib6011a71d382a10d68c0802593f34b8153d06892
The `stack.PacketBufferPtr` type no longer exists; replace it with
`*stack.PacketBuffer` instead.
Updates #8043
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib56ceff09166a042aa3d9b80f50b2aa2d34b3683
This fixes a regression introduced with 993acf4 and released in
v1.60.0.
The regression caused us to intercept all userspace traffic to port
8080 which prevented users from exposing their own services to their
tailnet at port 8080.
Now, we only intercept traffic to port 8080 if it's bound for
100.100.100.100 or fd7a:115c:a1e0::53.
Fixes#11283
Signed-off-by: Percy Wegmann <percy@tailscale.com>
(cherry picked from commit 17cd0626f3)
This is a fun one. Right now, when a client is connecting through a
subnet router, here's roughly what happens:
1. The client initiates a connection to an IP address behind a subnet
router, and sends a TCP SYN
2. The subnet router gets the SYN packet from netstack, and after
running through acceptTCP, starts DialContext-ing the destination IP,
without accepting the connection¹
3. The client retransmits the SYN packet a few times while the dial is
in progress, until either...
4. The subnet router successfully establishes a connection to the
destination IP and sends the SYN-ACK back to the client, or...
5. The subnet router times out and sends a RST to the client.
6. If the connection was successful, the client ACKs the SYN-ACK it
received, and traffic starts flowing
As a result, the notification code in forwardTCP never notices when a
new connection attempt is aborted, and it will wait until either the
connection is established, or until the OS-level connection timeout is
reached and it aborts.
To mitigate this, add a per-client limit on how many in-flight TCP
forwarding connections can be in-progress; after this, clients will see
a similar behaviour to the global limit, where new connection attempts
are aborted instead of waiting. This prevents a single misbehaving
client from blocking all other clients of a subnet router by ensuring
that it doesn't starve the global limiter.
Also, bump the global limit again to a higher value.
¹ We can't accept the connection before establishing a connection to the
remote server since otherwise we'd be opening the connection and then
immediately closing it, which breaks a bunch of stuff; see #5503 for
more details.
Updates tailscale/corp#12184
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I76e7008ddd497303d75d473f534e32309c8a5144
- add a clientmetric with a counter of TCP forwarder drops due to the
max attempts;
- fix varz metric types, as they are all counters.
Updates #8210
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
FileSystemForLocal was listening on the node's Tailscale address,
which potentially exposes the user's view of TailFS shares to other
Tailnet users. Remote nodes should connect to exported shares via
the peerapi.
This removes that code so that FileSystemForLocal is only avaialable
on 100.100.100.100:8080.
Updates tailscale/corp#16827
Signed-off-by: Percy Wegmann <percy@tailscale.com>
Adds support for node attribute tailfs:access. If this attribute is
not present, Tailscale will not accept connections to the local TailFS
server at 100.100.100.100:8080.
Updates tailscale/corp#16827
Signed-off-by: Percy Wegmann <percy@tailscale.com>
Add a WebDAV-based folder sharing mechanism that is exposed to local clients at
100.100.100.100:8080 and to remote peers via a new peerapi endpoint at
/v0/tailfs.
Add the ability to manage folder sharing via the new 'share' CLI sub-command.
Updates tailscale/corp#16827
Signed-off-by: Percy Wegmann <percy@tailscale.com>
When tailscaled is run with "-debug 127.0.0.1:12345", these metrics are
available at:
http://localhost:12345/debug/metrics
Updates #8210
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I19db6c445ac1f8344df2bc1066a3d9c9030606f8
Prior to an earlier netstack bump this code used a string conversion
path to cover multiple cases of behavior seemingly checking for
unspecified addresses, adding unspecified addresses to v6. The behavior
is now crashy in netstack, as it is enforcing address length in various
areas of the API, one in particular being address removal.
As netstack is now protocol specific, we must not create invalid
protocol addresses - an address is v4 or v6, and the address value
contained inside must match. If a control path attempts to do something
otherwise it is now logged and skipped rather than incorrect addressing
being added.
Fixestailscale/corp#15377
Signed-off-by: James Tucker <james@tailscale.com>
Prepare for path MTU discovery by splitting up the concept of
DefaultMTU() into the concepts of the Tailscale TUN MTU, MTUs of
underlying network interfaces, minimum "safe" TUN MTU, user configured
TUN MTU, probed path MTU to a peer, and maximum probed MTU. Add a set
of likely MTUs to probe.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
Use buffer pools for UDP packet forwarding to prepare for increasing the
forwarded UDP packet size for peer path MTU discovery.
Updates #311
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Val <valerie@tailscale.com>
We weren't correctly retrying truncated requests to an upstream DNS
server with TCP. Instead, we'd return a truncated request to the user,
even if the user was querying us over TCP and thus able to handle a
large response.
Also, add an envknob and controlknob to allow users/us to disable this
behaviour if it turns out to be buggy (✨ DNS ✨).
Updates #9264
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ifb04b563839a9614c0ba03e9c564e8924c1a2bfd
Prepare for path MTU discovery by splitting up the concept of
DefaultMTU() into the concepts of the Tailscale TUN MTU, MTUs of
underlying network interfaces, minimum "safe" TUN MTU, user configured
TUN MTU, probed path MTU to a peer, and maximum probed MTU. Add a set
of likely MTUs to probe.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
Use buffer pools for UDP packet forwarding to prepare for increasing the
forwarded UDP packet size for peer path MTU discovery.
Updates #311
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Val <valerie@tailscale.com>
And convert all callers over to the methods that check SelfNode.
Now we don't have multiple ways to express things in tests (setting
fields on SelfNode vs NetworkMap, sometimes inconsistently) and don't
have multiple ways to check those two fields (often only checking one
or the other).
Updates #9443
Change-Id: I2d7ba1cf6556142d219fae2be6f484f528756e3c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It had exactly one user: netstack. Just have LocalBackend notify
netstack when here's a new netmap instead, simplifying the bloated
Engine interface that has grown a bunch of non-Engine-y things.
(plenty of rando stuff remains after this, but it's a start)
Updates #cleanup
Change-Id: I45e10ab48119e962fc4967a95167656e35b141d8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The netstack code had a bunch of logic to figure out if the LocalBackend should handle an
incoming connection and then would call the function directly on LocalBackend. Move that
logic to LocalBackend and refactor the methods to return conn handlers.
Updates #cleanup
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Various BSD-derived operating systems including macOS and FreeBSD
require that ping6 be used for IPv6 destinations. The "ping" command
does not understand an IPv6 destination.
FreeBSD 13.x and later do handle IPv6 in the regular ping command,
but also retain a ping6 command. We use ping6 on all versions of
FreeBSD.
Fixes https://github.com/tailscale/tailscale/issues/8225
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
Running tailscaled with the race detector enabled immediately fires on
this field, as it is updated after first read.
Updates #cleanup
Signed-off-by: James Tucker <james@tailscale.com>
Noted on #5915 TS_DEBUG_MTU was not used consistently everywhere.
Extract the default into a function that can apply this centrally and
use it everywhere.
Added envknob.Lookup{Int,Uint}Sized to make it easier to keep CodeQL
happy when using converted values.
Updates #5915
Signed-off-by: James Tucker <james@tailscale.com>
Use the local context on Impl to check for shut down state in order to
drop rather than inject packets after close has begun.
Netstack sets endpoint.dispatcher to nil during shutdown. After the
recent adjustment in 920ec69241 we now
wait for netstack to fully shutdown before we release tests. This means
that we may continue to accept packets and attempt to inject them, which
we must prevent in order to avoid nil pointer panic.
References google/gvisor#8765Fixes#7715
Signed-off-by: James Tucker <james@tailscale.com>
Previously, it would accept all TCP connections and then close the ones
it did not care about. Make it only ever accept the connections that it
cares about.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Updates #7123
Updates #6257 (more to do in other repos)
Change-Id: I073e2a6d81a5d7fbecc29caddb7e057ff65239d0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
The macOS client was forgetting to call netstack.Impl.SetLocalBackend.
Change the API so that it can't be started without one, eliminating this
class of bug. Then update all the callers.
Updates #6764
Change-Id: I2b3a4f31fdfd9fdbbbbfe25a42db0c505373562f
Signed-off-by: Claire Wang <claire@tailscale.com>
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
All IPv6 packets for the self address were doing netip.Prefix.Contains
lookups.
If if we know they're for a self address (which we already previously
computed and have sitting in a bool), then they can't be for a 4via6
range.
Change-Id: Iaaaf1248cb3fecec229935a80548ead0eb4cb892
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It was eating TCP packets to peerapi ports to subnet routers. Some of
the TCP flow's packets went onward, some got eaten. So some TCP flows
to subnet routers, if they used an unfortunate TCP port number, got
broken.
Change-Id: Ifea036119ccfb081f4dfa18b892373416a5239f8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
