commit a6a24dd292f82221e069bd497ff2a93756f63d20
author Damien Neil <dneil@google.com> Thu Feb 15 09:52:29 2024 -0800
committer Damien Neil <dneil@google.com> Wed Feb 21 20:54:12 2024 +0000
tree a2b51ecc25a335ff4dac4148fedc3280d5f1e59a
parent 2a8baeab1851a3c0f336a9185a02c177a0365232

quic: source address and ECN support in the network layer

Make the abstraction over UDP connections higher level,
and add support for setting the source address and ECN
bits in sent packets, and receving the destination
address and ECN bits in received packets.

There is no good way that I can find to identify the
source IP address of packets we send. Look up the
destination IP address of the first packet received on
each connection, and use this as the source address
for all future packets we send. This avoids unexpected
path migration, where the address we send from changes
without our knowing it.

Reject received packets sent from an unexpected peer
address.

In the future, when we support path migration, we will want
to relax these restrictions.

ECN bits may be used to detect network congestion.
We don't make use of them at this time, but this CL adds
the necessary UDP layer support to do so in the future.

This CL also lays the groundwork for using more efficient
platform APIs to send/receive packets in the future.
(sendmmsg/recvmmsg/GSO/GRO)

These features require platform-specific APIs.
Add support for Darwin and Linux to start with,
with a graceful fallback on other OSs.

For golang/go#58547

Change-Id: I1c97cc0d3e52fff18e724feaaac4a50d3df671bc
Reviewed-on: https://go-review.googlesource.com/c/net/+/565255
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>