This is a prerequisite for path compression, so that insert/delete
can determine when compression occurred.
Updates #7781
Signed-off-by: David Anderson <danderson@tailscale.com>
Having `127.0.0.53` is not the only way to use `systemd-resolved`. An
alternative way is to enable `libnss_resolve` module, which seems to now
be used by default on Debian 12 bookworm.
Fixes#8549
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
If the absolute value of the difference between the current
PreferredDERP's latency and the best latency is <= 10ms, don't change
it and instead prefer the previous value.
This is in addition to the existing hysteresis that tries to remain
on the previous DERP region if the relative improvement is small, but
handles nodes that have low latency to >1 DERP region better.
Updates #8603
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I1e34c94178f8c9a68a69921c5bc0227337514c70
This allows providing additional information to the client about how to
select a home DERP region, such as preferring a given DERP region over
all others.
Updates #8603
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I7c4a270f31d8585112fab5408799ffba5b75266f
When performing a fallback DNS query, run the recursive resolver in a
separate goroutine and compare the results returned by the recursive
resolver with the results we get from "regular" bootstrap DNS. This will
allow us to gather data about whether the recursive DNS resolver works
better, worse, or about the same as "regular" bootstrap DNS.
Updates #5853
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ifa0b0cc9eeb0dccd6f7a3d91675fe44b3b34bd48
This change introduces tstime.NewClock and tstime.ClockOpts as a new way
to construct tstime.Clock. This is a subset of #8464 as a stepping stone
so that we can update our internal code to use the new API before making
the second round of changes.
Updates #8463
Change-Id: Ib26edb60e5355802aeca83ed60e4fdf806c90e27
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
This package contains platform-independent abstractions for fetching
information about an open TCP connection.
Updates #8413
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I236657b1060d7e6a45efc7a2f6aacf474547a2fe
This change is introducing new netfilterRunner interface and moving iptables manipulation to a lower leveled iptables runner.
For #391
Signed-off-by: KevinLiang10 <kevinliang@tailscale.com>
This commit updates our IP forwarding parsing logic to allow the less
common but still valid value of `2` to be parsed as `true`, which fixes
an error some users encountered.
Fixes#8375
Signed-off-by: Ross Zurowski <ross@rosszurowski.com>
Also fix a js/wasm issue with tsnet in the process. (same issue as WASI)
Updates #8320Fixes#8315
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We've talked in the past about reworking how bootstrap DNS works to
instead do recursive DNS resolution from the root; this would better
support on-prem customers and Headscale users where the DERP servers
don't currently resolve their DNS server. This package is an initial
implementation of recursive resolution for A and AAAA records.
Updates #5853
Change-Id: Ibe974d78709b4b03674b47c4ef61f9a00addf8b4
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
This test was either fixed by intermediate changes or was mis-flagged as
failing during #7876 triage.
Updates #7876
Signed-off-by: James Tucker <jftucker@gmail.com>
Wait 2 minutes before we start reporting battery usage. There is always
radio activity on initial startup, which gets reported as 100% high
power usage. Let that settle before we report usage data.
Updates tailscale/corp#9230
Signed-off-by: Will Norris <will@tailscale.com>
`interfaces.Tailscale()` returns all zero values when it finds no
Tailscale interface and encounters no errors. The netns package was
treating no error as a signal that it would receive a non-zero pointer
value leading to nil pointer dereference.
Observed in:
```
--- FAIL: TestGetInterfaceIndex (0.00s)
--- FAIL: TestGetInterfaceIndex/IP_and_port (0.00s)
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x0 pc=0x1029eb7d8]
goroutine 7 [running]:
testing.tRunner.func1.2({0x102a691e0, 0x102bc05c0})
/Users/raggi/.cache/tailscale-go/src/testing/testing.go:1526 +0x1c8
testing.tRunner.func1()
/Users/raggi/.cache/tailscale-go/src/testing/testing.go:1529 +0x384
panic({0x102a691e0, 0x102bc05c0})
/Users/raggi/.cache/tailscale-go/src/runtime/panic.go:884 +0x204
tailscale.com/net/netns.getInterfaceIndex(0x14000073f28, 0x1028d0284?, {0x1029ef3b7, 0xa})
/Users/raggi/src/github.com/tailscale/tailscale/net/netns/netns_darwin.go:114 +0x228
tailscale.com/net/netns.TestGetInterfaceIndex.func2(0x14000138000)
/Users/raggi/src/github.com/tailscale/tailscale/net/netns/netns_darwin_test.go:37 +0x54
testing.tRunner(0x14000138000, 0x140000551b0)
/Users/raggi/.cache/tailscale-go/src/testing/testing.go:1576 +0x10c
created by testing.(*T).Run
/Users/raggi/.cache/tailscale-go/src/testing/testing.go:1629 +0x368
FAIL tailscale.com/net/netns 0.824s
```
Fixes#8064
Signed-off-by: James Tucker <jftucker@gmail.com>
This is part of an effort to clean up tailscaled initialization between
tailscaled, tailscaled Windows service, tsnet, and the mac GUI.
Updates #8036
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In the case where the exit node requires SNAT, we would SNAT all traffic not just the
traffic meant to go through the exit node. This was a result of the default route being
added to the routing table which would match basically everything.
In this case, we need to account for all peers in the routing table not just the ones
that require NAT.
Fix and add a test.
Updates tailscale/corp#8020
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This change adds a v6conn to the pinger to enable sending pings to v6
addrs.
Updates #7826
Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
Looks like on some systems there's an IPv6 address, but then opening
a IPv6 UDP socket fails later. Probably some firewall. Tolerate it
better and don't crash.
To repro: check the "udp6" to something like "udp7" (something that'll
fail) and run "go run ./cmd/tailscale netcheck" on a machine with
active IPv6. It used to crash and now it doesn't.
Fixes#7949
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
On some platforms (notably macOS and iOS) we look up the default
interface to bind outgoing connections to. This is both duplicated
work and results in logspam when the default interface is not available
(i.e. when a phone has no connectivity, we log an error and thus cause
more things that we will try to upload and fail).
Fixed by passing around a netmon.Monitor to more places, so that we can
use its cached interface state.
Fixes#7850
Updates #7621
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
We're using it in more and more places, and it's not really specific to
our use of Wireguard (and does more just link/interface monitoring).
Also removes the separate interface we had for it in sockstats -- it's
a small enough package (we already pull in all of its dependencies
via other paths) that it's not worth the extra complexity.
Updates #7621
Updates #7850
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This is a follow-up to #7905 that adds two more linters and fixes the corresponding findings. As per the previous PR, this only flags things that are "obviously" wrong, and fixes the issues found.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8739bdb7bc4f75666a7385a7a26d56ec13741b7c
Found this when adding a test that does a ping over PeerAPI.
Our integration tests set up a trafficTrap to ensure that tailscaled
does not call out to the internet, and it does so via a HTTP_PROXY.
When adding a test for pings over PeerAPI, it triggered the trap and investigation
lead to the realization that we were not removing the Proxy when trying to
dial out to the PeerAPI.
Updates tailscale/corp#8020
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Exposes some internal state of the sockstats package via the C2N and
PeerAPI endpoints, so that it can be used for debugging. For now this
includes the estimated radio on percentage and a second-by-second view
of the times the radio was active.
Also fixes another off-by-one error in the radio on percentage that
was leading to >100% values (if n seconds have passed since we started
to monitor, there may be n + 1 possible seconds where the radio could
have been on).
Updates tailscale/corp#9230
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
When splitting the radio monitor usage array, we were splitting at now %
3600 to get values into chronological order. This caused the value for
the final second to be included at the beginning of the ordered slice
rather than the end. If there was activity during that final second, an
extra five seconds of high power usage would get recorded in some cases.
This could result in a final calculation of greater than 100% usage.
This corrects that by splitting values at (now+1 % 3600).
This also simplifies the percentage calculation by always rounding
values down, which is sufficient for our usage.
Signed-off-by: Will Norris <will@tailscale.com>
It's somewhat common (e.g. when a phone has no reception), and leads to
lots of logspam.
Updates #7850
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This adds an initial and intentionally minimal configuration for
golang-ci, fixes the issues reported, and adds a GitHub Action to check
new pull requests against this linter configuration.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8f38fbc315836a19a094d0d3e986758b9313f163
Exclude traffic with 100.100.100.100 (for IPv4) and
with fd7a:115c:a1e0::53 (for IPv6) since this traffic with the
Tailscale service running locally on the node.
This traffic never left the node.
It also happens to be a high volume amount of traffic since
DNS requests occur over UDP with each request coming from a
unique port, thus resulting in many discrete traffic flows.
Fixestailscale/corp#10554
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Redoes the approach from #5550 and #7539 to explicitly pass in the logf
function, instead of having global state that can be overridden.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This is a continuation of the earlier 2a67beaacf but more aggressive;
this now remembers that we failed to find the "home" router IP so we
don't try again later on the next call.
Updates #7621
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
So we're staying within the netip.Addr/AddrPort consistently and
avoiding allocs/conversions to the legacy net addr types.
Updates #5162
Change-Id: I59feba60d3de39f773e68292d759766bac98c917
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We accidentally switched to ./tool/go in
4022796484 which resulted in no longer
running Windows builds, as this is attempting to run a bash script.
I was unable to quickly fix the various tests that have regressed, so
instead I've added skips referencing #7876, which we need to back and
fix.
Updates #7262
Updates #7876
Signed-off-by: James Tucker <james@tailscale.com>
To get the tree green again for other people.
Updates #7866
Change-Id: Ibdad2e1408e5f0c97e49a148bfd77aad17c2c5e5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This also adds a bunch of tests for this function to ensure that we're
returning the proper IP(s) in all cases.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I0d9d57170dbab5f2bf07abdf78ecd17e0e635399
This makes `omitempty` actually work, and saves bytes in each map response.
Updates tailscale/corp#8020
Signed-off-by: Maisem Ali <maisem@tailscale.com>
At the current unoptimized memory utilization of the various data structures,
100k IPv6 routes consumes in the ballpark of 3-4GiB, which risks OOMing our
386 test machine.
Until we have the optimizations to (drastically) reduce that consumption,
skip the test that bloats too much for 32-bit machines.
Signed-off-by: David Anderson <danderson@tailscale.com>
Using log.Printf may end up being printed out to the console, which
is not desirable. I noticed this when I was investigating some client
logs with `sockstats: trace "NetcheckClient" was overwritten by another`.
That turns to be harmless/expected (the netcheck client will fall back
to the DERP client in some cases, which does its own sockstats trace).
However, the log output could be visible to users if running the
`tailscale netcheck` CLI command, which would be needlessly confusing.
Updates tailscale/corp#9230
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
We use it to gate code that depends on custom Go toolchain, but it's
currently only passed in the corp runners. Add a set on OSS so that we
can catch regressions earlier.
To specifically test sockstats this required adding a build tag to
explicitly enable them -- they're normally on for iOS, macOS and Android
only, and we don't run tests on those platforms normally.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
power state is very roughly approximated based on observed network
activity and AT&T's state transition timings for a typical 3G radio.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Will Norris <will@tailscale.com>
This commit implements UDP offloading for Linux. GSO size is passed to
and from the kernel via socket control messages. Support is probed at
runtime.
UDP GSO is dependent on checksum offload support on the egress netdev.
UDP GSO will be disabled in the event sendmmsg() returns EIO, which is
a strong signal that the egress netdev does not support checksum
offload.
Updates tailscale/corp#8734
Signed-off-by: Jordan Whited <jordan@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>
When running a SOCKS or HTTP proxy, configure the tshttpproxy package to
drop those addresses from any HTTP_PROXY or HTTPS_PROXY environment
variables.
Fixes#7407
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I6cd7cad7a609c639780484bad521c7514841764b
This adds support to make exit nodes and subnet routers work
when in scenarios where NAT is required.
It also updates the NATConfig to be generated from a `wgcfg.Config` as
that handles merging prefs with the netmap, so it has the required information
about whether an exit node is already configured and whether routes are accepted.
Updates tailscale/corp#8020
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This commit updates the wireguard-go dependency to pull in fixes for
the tun package, specifically 052af4a and aad7fca.
Signed-off-by: Jordan Whited <jordan@tailscale.com>
If multiple Go channels have a value (or are closed), receiving from
them all in a select will nondeterministically return one of the two
arms. In this case, it's possible that the hairpin check timer will have
expired between when we start checking and before we check at all, but
the hairpin packet has already been received. In such cases, we'd
nondeterministically set report.HairPinning.
Instead, check if we have a value in our results channel first, then
select on the value and timeout channel after. Also, add a test that
catches this particular failure.
Fixes#1795
Change-Id: I842ab0bd38d66fabc6cabf2c2c1bb9bd32febf35
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
This adds support in tstun to utitilize the SelfNodeV4MasqAddrForThisPeer and
perform the necessary modifications to the packet as it passes through tstun.
Currently this only handles ICMP, UDP and TCP traffic.
Subnet routers and Exit Nodes are also unsupported.
Updates tailscale/corp#8020
Co-authored-by: Melanie Warrick <warrick@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Followup to #7518 to also export client metrics when the active interface
is cellular.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
In May 2021, Azure App Services used 172.16.x.x addresses:
```
10: eth0@if11: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP
link/ether 02:42:ac:10:01:03 brd ff:ff:ff:ff:ff:ff
inet 172.16.1.3/24 brd 172.16.1.255 scope global eth0
valid_lft forever preferred_lft forever
```
Now it uses link-local:
```
2: eth0@if6: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP
link/ether 8a:30:1f:50:1d:23 brd ff:ff:ff:ff:ff:ff
inet 169.254.129.3/24 brd 169.254.129.255 scope global eth0
valid_lft forever preferred_lft forever
```
This is reasonable for them to choose to do, it just broke the handling in net/interfaces.
This PR proposes to:
1. Always allow link-local in LocalAddresses() if we have no better
address available.
2. Continue to make isUsableV4() conditional on an environment we know
requires it.
I don't love the idea of having to discover these environments one by
one, but I don't understand the consequences of making isUsableV4()
return true unconditionally. It makes isUsableV4() essentially always
return true and perform no function.
Fixes https://github.com/tailscale/tailscale/issues/7603
Signed-off-by: Denton Gentry <dgentry@tailscale.com>
They're not needed for the sockstats logger, and they're somewhat
expensive to return (since they involve the creation of a map per
label). We now have a separate GetInterfaces() method that returns
them instead (which we can still use in the PeerAPI debug endpoint).
If changing sockstatlog to sample at 10,000 Hz (instead of the default
of 10Hz), the CPU usage would go up to 59% on a iPhone XS. Removing the
per-interface stats drops it to 20% (a no-op implementation of Get that
returns a fixed value is 16%).
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Followup to #7499 to make validation a separate function (
GetWithValidation vs. Get). This way callers that don't need it don't
pay the cost of a syscall per active TCP socket.
Also clears the conn on close, so that we don't double-count the stats.
Also more consistently uses Go doc comments for the exported API of the
sockstats package.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Though not fine-grained enough to be useful for detailed analysis, we
might as well export that we gather as client metrics too, since we have
an upload/analysis pipeline for them.
clientmetric.Metric.Add is an atomic add, so it's pretty cheap to also
do per-packet.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
withSockStats may be called before setLinkMonitor, in which case we
don't have a populated knownInterfaces map. Since we pre-populate the
per-interface counters at creation time, we would end up with an
empty map. To mitigate this, we do an on-demand request for the list of
interfaces.
This would most often happen with the logtail instrumentation, since we
initialize it very early on.
Updates tailscale/corp#9230
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
We can use the TCP_CONNECTION_INFO getsockopt() on Darwin to get
OS-collected tx/rx bytes for TCP sockets. Since this API is not available
for UDP sockets (or on Linux/Android), we can't rely on it for actual
stats gathering.
However, we can use it to validate the stats that we collect ourselves
using read/write hooks, so that we can be more confident in them. We
do need additional hooks from the Go standard library (added in
tailscale/go#59) to be able to collect them.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Makes it cheaper/simpler to persist values, and encourages reuse of
labels as opposed to generating an arbitrary number.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Despite the fact that WSL configuration is still disabled by default, we
continue to log the machine's list of WSL distros as a diagnostic measure.
Unfortunately I have seen the "wsl.exe -l" command hang indefinitely. This patch
adds a (more than reasonable) 10s timeout to ensure that tailscaled does not get
stuck while executing this operation.
I also modified the Windows implementation of NewOSConfigurator to do the
logging asynchronously, since that information is not required in order to
continue starting up.
Fixes#7476
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
Conforms to RFC 1929.
To support Java HTTP clients via libtailscale, who offer no other
reliable hooks into their sockets.
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
Per a packet capture provided, some gateways will reply to a UPnP
discovery packet with a UDP packet with a source port that does not come
from the UPnP port. Accept these packets with a log message.
Updates #7377
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I5d4d5b2a0275009ed60f15c20b484fe2025d094b
We were previously sending a lower-case "udp" protocol, whereas other
implementations like miniupnp send an upper-case "UDP" protocol. For
compatibility, use an upper-case protocol instead.
Updates #7377
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I4aed204f94e4d51b7a256d29917af1536cb1b70f
Some devices don't let you UPnP portmap a port below 1024, so let's just
avoid that range of ports entirely.
Updates #7377
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ib7603b1c9a019162cdc4fa21744a2cae48bb1d86
Return a mock set of interfaces and a mock gateway during this test and
verify that LikelyHomeRouterIP returns the outcome we expect. Also
verify that we return an error if there are no IPv4 addresses available.
Follow-up to #7447
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I8f06989e7f1f0bebd108861cbff17b820ed2e6e4
We have many function pointers that we replace for the duration of test and
restore it on test completion, add method to do that.
Signed-off-by: Maisem Ali <maisem@tailscale.com>
We weren't filtering out IPv6 addresses from this function, so we could
be returning an IPv4 gateway IP and an IPv6 self IP. Per the function
comments, only return IPv4 addresses for the self IP.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: If19a4aadc343fbd4383fc5290befa0eff006799e
Now that we're using rand.Shuffle in a few locations, create a generic
shuffle function and use it instead. While we're at it, move the
interleaveSlices function to the same package for use.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I0b00920e5b3eea846b6cedc30bd34d978a049fd3
The debug flag on tailscaled isn't available in the macOS App Store
build, since we don't have a tailscaled binary; move it to the
'tailscale debug' CLI that is available on all platforms instead,
accessed over LocalAPI.
Updates #7377
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I47bffe4461e036fab577c2e51e173f4003592ff7
Followup to #7177 to avoid adding extra dependencies to the CLI. We
instead declare an interface for the link monitor.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This ensures that we're trying multiple returned IPs, since the DERP
servers return the same response to all queries. This should increase
the chances that we eventually reach a working IP.
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ie8d4fb93df96da910fae49ae71bf3e402b9fdecc
Uses the hooks added by tailscale/go#45 to instrument the reads and
writes on the major code paths that do network I/O in the client. The
convention is to use "<package>.<type>:<label>" as the annotation for
the responsible code path.
Enabled on iOS, macOS and Android only, since mobile platforms are the
ones we're most interested in, and we are less sensitive to any
throughput degradation due to the per-I/O callback overhead (macOS is
also enabled for ease of testing during development).
For now just exposed as counters on a /v0/sockstats PeerAPI endpoint.
We also keep track of the current interface so that we can break out
the stats by interface.
Updates tailscale/corp#9230
Updates #3363
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
Exposes the delegated interface data added by #7248 in the debug
endpoint. I would have found it useful when working on that PR, and
it may be handy in the future as well.
Also makes the interfaces table slightly easier to parse by adding
borders to it. To make then nicer-looking, the CSP was relaxed to allow
inline styles.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
With #6566 we added an external mechanism for getting the default
interface, and used it on macOS and iOS (see tailscale/corp#8201).
The goal was to be able to get the default physical interface even when
using an exit node (in which case the routing table would say that the
Tailscale utun* interface is the default).
However, the external mechanism turns out to be unreliable in some
cases, e.g. when multiple cellular interfaces are present/toggled (I
have occasionally gotten my phone into a state where it reports the pdp_ip1
interface as the default, even though it can't actually route traffic).
It was observed that `ifconfig -v` on macOS reports an "effective interface"
for the Tailscale utn* interface, which seems promising. By examining
the ifconfig source code, it turns out that this is done via a
SIOCGIFDELEGATE ioctl syscall. Though this is a private API, it appears
to have been around for a long time (e.g. it's in the 10.13 xnu release
at https://opensource.apple.com/source/xnu/xnu-4570.41.2/bsd/net/if_types.h.auto.html)
and thus is unlikely to go away.
We can thus use this ioctl if the routing table says that a utun*
interface is the default, and go back to the simpler mechanism that
we had before #6566.
Updates #7184
Updates #7188
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
As part of the work on #7248 I wanted to know all of the flags on the
RouteMessage struct that we get back from macOS. Though it doesn't turn
out to be useful (when using an exit node/Tailscale is the default route,
the flags for the physical interface routes are the same), it still seems
useful from a debugging/comprehensiveness perspective.
Adds additional Darwin flags that were output once I enabled this mode.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
