tree 88bd9023f941f060645381d2009fe6e54fbcba24
parent 8ead3f531445004f1122d11fa7083e8d1bcc5200
author David Benjamin <davidben@google.com> 1686849162 -0400
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> 1687200849 +0000

Pass IPv6 vs IPv4 down to the shim

The runner currently tries to listen on IPv6 and then falls back to IPv4
on error. The shim does the same. If they pick different ones, this
breaks down.

Normally, fallback happens because the system doesn't have IPv6, and
both sides will make the same decision. But if binding to IPv6 fails for
other reasons, they may mismatch. We're observing them fail due to what
seems to port exhaustion. When this happens, shim and runner don't
agree on the same address family.

Instead, just tell the shim which address to connect to. This doesn't
fix the underlying port exhaustion problem, but it does seem to fix the
flakes. Although given we are still exhausting ports and falling back to
IPv4, it doesn't truly fix it. Later CLs will address port exhaustion by
using a single server port.

This changes the runner <-> shim protocol, but hopefully in a fairly
obvious way that others using BoGo can easily follow. It shouldn't break
our cross-version tests because we keep runner and shim at the same
versio there.

To avoid needing to make an incompatible change to the shim <->
handshaker protocol, which would impact our cross-version tests, this
introduces a mechanism for the shim omit flags when talking to the
handshaker. The handshaker doesn't need to know how to connect to the
runner.

Also print the error string on Windows. Sadly this is a bit tedious.

Change-Id: Ic8bda9a854a115c206c05a659a2e34f544b844a6
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/60885
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>