mirror of
https://github.com/tailscale/tailscale.git
synced 2026-03-28 19:21:13 -04:00
607d01cdae
ReadFromUDPAddrPort worked if UDP GRO was unsupported, but we don't actually want attempted usage, nor does any exist today. Future work on tailscale/corp#37679 would have required more complexity in this method, vs clarifying the API intents. Updates tailscale/corp#37679 Signed-off-by: Jordan Whited <jordan@tailscale.com>
58 lines
2.3 KiB
Go
58 lines
2.3 KiB
Go
// Copyright (c) Tailscale Inc & contributors
|
|
// SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
// Package batching implements a socket optimized for increased throughput.
|
|
package batching
|
|
|
|
import (
|
|
"net/netip"
|
|
|
|
"golang.org/x/net/ipv4"
|
|
"golang.org/x/net/ipv6"
|
|
"tailscale.com/net/packet"
|
|
"tailscale.com/types/nettype"
|
|
)
|
|
|
|
var (
|
|
// This acts as a compile-time check for our usage of ipv6.Message in
|
|
// [Conn] for both IPv6 and IPv4 operations.
|
|
_ ipv6.Message = ipv4.Message{}
|
|
)
|
|
|
|
// Conn is a [nettype.PacketConn] that provides batched i/o using
|
|
// platform-specific optimizations, e.g. {recv,send}mmsg & UDP GSO/GRO.
|
|
//
|
|
// Conn does not support single packet reads (see ReadFromUDPAddrPort docs). It
|
|
// is the caller's responsibility to use the appropriate read API where a
|
|
// [nettype.PacketConn] has been upgraded to support batched i/o.
|
|
//
|
|
// Conn originated from (and is still used by) magicsock where its API was
|
|
// strongly influenced by [wireguard-go/conn.Bind] constraints, namely
|
|
// wireguard-go's ownership of packet memory.
|
|
type Conn interface {
|
|
nettype.PacketConn
|
|
// ReadFromUDPAddrPort always returns an error, as UDP GRO is incompatible
|
|
// with single packet reads. A single datagram may be multiple, coalesced
|
|
// datagrams, and this API lacks the ability to pass that context.
|
|
//
|
|
// TODO: consider detaching Conn from [nettype.PacketConn]
|
|
ReadFromUDPAddrPort([]byte) (int, netip.AddrPort, error)
|
|
// ReadBatch reads messages from [Conn] into msgs. It returns the number of
|
|
// messages the caller should evaluate for nonzero len, as a zero len
|
|
// message may fall on either side of a nonzero.
|
|
//
|
|
// Each [ipv6.Message.OOB] must be sized to at least MinControlMessageSize().
|
|
ReadBatch(msgs []ipv6.Message, flags int) (n int, err error)
|
|
// WriteBatchTo writes buffs to addr.
|
|
//
|
|
// If geneve.VNI.IsSet(), then geneve is encoded into the space preceding
|
|
// offset, and offset must equal [packet.GeneveFixedHeaderLength]. If
|
|
// !geneve.VNI.IsSet() then the space preceding offset is ignored.
|
|
//
|
|
// len(buffs) must be <= batchSize supplied in TryUpgradeToConn().
|
|
//
|
|
// WriteBatchTo may return a [neterror.ErrUDPGSODisabled] error if UDP GSO
|
|
// was disabled as a result of a send error.
|
|
WriteBatchTo(buffs [][]byte, addr netip.AddrPort, geneve packet.GeneveHeader, offset int) error
|
|
}
|