This significantly improves throughput of a peer relay server on Linux.
Server.packetReadLoop no longer passes sockets down the stack. Instead,
packet handling methods return a netip.AddrPort and []byte, which
packetReadLoop gathers together for eventual batched writes on the
appropriate socket(s).
Updates tailscale/corp#31164
Signed-off-by: Jordan Whited <jordan@tailscale.com>
This commit adds a new type to magicsock, epAddr, which largely ends up
replacing netip.AddrPort in packet I/O paths throughout, enabling
Geneve encapsulation over UDP awareness.
The conn.ReceiveFunc for UDP has been revamped to fix and more clearly
distinguish the different classes of packets we expect to receive: naked
STUN binding messages, naked disco, naked WireGuard, Geneve-encapsulated
disco, and Geneve-encapsulated WireGuard.
Prior to this commit, STUN matching logic in the RX path could swallow
a naked WireGuard packet if the keypair index, which is randomly
generated, happened to overlap with a subset of the STUN magic cookie.
Updates tailscale/corp#27502
Updates tailscale/corp#29326
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Our conn.Bind implementation is updated to make Send() offset-aware for
future VXLAN/Geneve encapsulation support.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
This commit adds a batchingConn interface, and renames batchingUDPConn
to linuxBatchingConn. tryUpgradeToBatchingConn() may return a platform-
specific implementation of batchingConn. So far only a Linux
implementation of this interface exists, but this refactor is being
done in anticipation of a Windows implementation.
Updates tailscale/corp#21874
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Jordan Whited