Commit Graph

5 Commits (d6817d0f22fe2c3dc8c6fcfe9e4d607d7ae59a76)

Author SHA1 Message Date
Brad Fitzpatrick 1237000efe control/controlhttp: don't assume port 80 upgrade response will work
Just because we get an HTTP upgrade response over port 80, don't
assume we'll be able to do bi-di Noise over it. There might be a MITM
corp proxy or anti-virus/firewall interfering. Do a bit more work to
validate the connection before proceeding to give up on the TLS port
443 dial.

Updates #4557 (probably fixes)

Change-Id: I0e1bcc195af21ad3d360ffe79daead730dfd86f1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Maisem Ali 5a1ef1bbb9 net/tsdial: add SystemDial as a wrapper on netns.Dial
The connections returned from SystemDial are automatically closed when
there is a major link change.

Also plumb through the dialer to the noise client so that connections
are auto-reset when moving from cellular to WiFi etc.

Updates #3363

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 years ago
David Anderson f570372b4d control/controlbase: don't enforce a max protocol version at handshake time.
Doing so makes development unpleasant, because we have to first break the
client by bumping to a version the control server rejects, then upgrade
the control server to make it accept the new version.

This strict rejection at handshake time is only necessary if we want to
blocklist some vulnerable protocol versions in the future. So, switch
to a default-permissive stance: until we have such a version that we
have to eagerly block early, we'll accept whatever version the client
presents, and leave it to the user of controlbase.Conn to make decisions
based on that version.

Noise still enforces that the client and server *agree* on what protocol
version is being used, and the control server still has the option to
finish the handshake and then hang up with an in-noise error, rather
than abort at the handshake level.

Updates #3488

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Anderson 02ad987e24 control/controlbase: make the protocol version number selectable.
This is so that we can plumb our client capability version through
the protocol as the Noise version. The capability version increments
more frequently than strictly required (the Noise version only needs
to change when cryptographically-significant changes are made to
the protocol, whereas the capability version also indicates changes
in non-cryptographically-significant parts of the protocol), but this
gives us a safe pre-auth way to determine if the client supports
future protocol features, while still relying on Noise's strong
assurance that the client and server have agreed on the same version.

Currently, the server executes the same protocol regardless of the
version number, and just presents the version to the caller so they
can do capability-based things in the upper RPC protocol. In future,
we may add a ratchet to disallow obsolete protocols, or vary the
Noise handshake behavior based on requested version.

Updates #3488

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago
David Anderson 96f008cf87 control/controlhttp: package to get a controlbase.Conn over HTTP(S).
Updates #3488

Signed-off-by: David Anderson <danderson@tailscale.com>
3 years ago