This will be used in a future change to do localhost connection
authentication. This lets us quickly map a localhost TCP connection to
a PID. (A future change will then map a pid to a user)
TODO: pull portlist's netstat code into this package. Then portlist
will be fast on Windows without requiring shelling out to netstat.exe.
We currently have a chickend-and-egg situation in some environments
where we can set up routes that WinHTTP's WPAD/PAC resolution service
needs to download the PAC file to evaluate GetProxyForURL, but the PAC
file is behind a route for which we need to call GetProxyForURL to
e.g. dial a DERP server.
As a short-term fix, just assume that the most recently returned proxy
is good enough for such situations.
iOS doesn't let you run subprocesses,
which means we can't use netstat to get routing information.
Instead, use syscalls and grub around in the results.
We keep the old netstat version around,
both for use in non-cgo builds,
and for use testing the syscall-based version.
Note that iOS doesn't ship route.h,
so we include a copy here from the macOS 10.15 SDK
(which is itself unchanged from the 10.14 SDK).
I have tested manually that this yields the correct
gateway IP address on my own macOS and iOS devices.
More coverage would be most welcome.
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
At least the Apple Airport Extreme doesn't allow hairpin
sends from a private socket until it's seen traffic from
that src IP:port to something else out on the internet.
See https://github.com/tailscale/tailscale/issues/188#issuecomment-600728643
And it seems that even sending to a likely-filtered RFC 5737
documentation-only IPv4 range is enough to set up the mapping.
So do that for now. In the future we might want to classify networks
that do and don't require this separately. But for now help it.
I've confirmed that this is enough to fix the hairpin check on Avery's
home network, even using the RFC 5737 IP.
Fixes#188
- Reuse IP length constants from net package.
- Remove beu16 to make endianness functions consistent.
Signed-off-by: Quoc-Viet Nguyen <afelion@gmail.com>
It'll be called a bunch, so worth a bit of effort. Could go further, but not yet.
(really, should hook into wgengine/monitor and only re-read on netlink changes?)
name old time/op new time/op delta
DefaultRouteInterface-8 60.8µs ±11% 44.6µs ± 5% -26.65% (p=0.000 n=20+19)
name old alloc/op new alloc/op delta
DefaultRouteInterface-8 3.29kB ± 0% 0.55kB ± 0% -83.21% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
DefaultRouteInterface-8 9.00 ± 0% 6.00 ± 0% -33.33% (p=0.000 n=20+20)
We'll use SO_BINDTODEVICE instead of fancy policy routing. This has
some limitations: for example, we will route all traffic through the
interface that has the main "default" (0.0.0.0/0) route, so machines
that have multiple physical interfaces might have to go through DERP to
get to some peers. But machines with multiple physical interfaces are
very likely to have policy routing (ip rule) support anyway.
So far, the only OS I know of that needs this feature is ChromeOS
(crostini). Fixes#245.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
My earlier 3fa58303d0 tried to implement
the net/http.Tranhsport.DialTLSContext hook, but I didn't return a
*tls.Conn, so we ended up sending a plaintext HTTP request to an HTTPS
port. The response ended up being Go telling as such, not the
/derp/latency-check handler's response (which is currently still a
404). But we didn't even get the 404.
This happened to work well enough because Go's built-in error response
was still a valid HTTP response that we can measure for timing
purposes, but it's not a great answer. Notably, it means we wouldn't
be able to get a future handler to run server-side and count those
latency requests.
tailscale netcheck was broken otherwise.
We can fix this a better way later; I'm just fixing a regression in
some way because I'm trying to work on netcheck at the moment.
This allows tailscaled's own traffic to bypass Tailscale-managed routes,
so that things like tailscale-provided default routes don't break
tailscaled itself.
Progress on #144.
Signed-off-by: David Anderson <danderson@tailscale.com>
Brad Fitzpatrick
renthraysk
Josh Bleecher Snyder
Josh Bleecher Snyder
Dmytro Shynkevych
David Anderson
Quoc-Viet Nguyen
Avery Pennarun