Remove link/packetsocket

This change removes NetworkDispatcher.DeliverOutboundPacket.

Since all packet writes go through the NIC (the only NetworkDispatcher),
we can deliver outgoing packets to interested packet endpoints before
writing the packet to the link endpoint as the stack expects that all
packets that get delivered to a link endpoint are transmitted on the
wire. That is, link endpoints no longer need to let the stack know when
it writes a packet as the stack already knows about the packet it writes
through a link endpoint.

PiperOrigin-RevId: 395761629

6 files changed, 0 insertions, 93 deletions

diff --git a/pkg/tcpip/link/nested/nested.go b/pkg/tcpip/link/nested/nested.go
index 14cb96d63..83a6c1cc8 100644
--- a/pkg/tcpip/link/nested/nested.go
+++ b/pkg/tcpip/link/nested/nested.go
@@ -60,16 +60,6 @@ func (e *Endpoint) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protoco
 	}
 }
 
-// DeliverOutboundPacket implements stack.NetworkDispatcher.DeliverOutboundPacket.
-func (e *Endpoint) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) {
-	e.mu.RLock()
-	d := e.dispatcher
-	e.mu.RUnlock()
-	if d != nil {
-		d.DeliverOutboundPacket(remote, local, protocol, pkt)
-	}
-}
-
 // Attach implements stack.LinkEndpoint.
 func (e *Endpoint) Attach(dispatcher stack.NetworkDispatcher) {
 	e.mu.Lock()
diff --git a/pkg/tcpip/link/packetsocket/BUILD b/pkg/tcpip/link/packetsocket/BUILD
deleted file mode 100644
index 6fff160ce..000000000
--- a/pkg/tcpip/link/packetsocket/BUILD
+++ /dev/null
@@ -1,14 +0,0 @@
-load("//tools:defs.bzl", "go_library")
-
-package(licenses = ["notice"])
-
-go_library(
-    name = "packetsocket",
-    srcs = ["endpoint.go"],
-    visibility = ["//visibility:public"],
-    deps = [
-        "//pkg/tcpip",
-        "//pkg/tcpip/link/nested",
-        "//pkg/tcpip/stack",
-    ],
-)
diff --git a/pkg/tcpip/link/packetsocket/endpoint.go b/pkg/tcpip/link/packetsocket/endpoint.go
deleted file mode 100644
index e01837e2d..000000000
--- a/pkg/tcpip/link/packetsocket/endpoint.go
+++ /dev/null
@@ -1,50 +0,0 @@
-// Copyright 2020 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package packetsocket provides a link layer endpoint that provides the ability
-// to loop outbound packets to any AF_PACKET sockets that may be interested in
-// the outgoing packet.
-package packetsocket
-
-import (
-	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/link/nested"
-	"gvisor.dev/gvisor/pkg/tcpip/stack"
-)
-
-type endpoint struct {
-	nested.Endpoint
-}
-
-// New creates a new packetsocket LinkEndpoint.
-func New(lower stack.LinkEndpoint) stack.LinkEndpoint {
-	e := &endpoint{}
-	e.Endpoint.Init(lower, e)
-	return e
-}
-
-// WritePacket implements stack.LinkEndpoint.WritePacket.
-func (e *endpoint) WritePacket(r stack.RouteInfo, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) tcpip.Error {
-	e.Endpoint.DeliverOutboundPacket(r.RemoteLinkAddress, r.LocalLinkAddress, protocol, pkt)
-	return e.Endpoint.WritePacket(r, protocol, pkt)
-}
-
-// WritePackets implements stack.LinkEndpoint.WritePackets.
-func (e *endpoint) WritePackets(r stack.RouteInfo, pkts stack.PacketBufferList, proto tcpip.NetworkProtocolNumber) (int, tcpip.Error) {
-	for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() {
-		e.Endpoint.DeliverOutboundPacket(r.RemoteLinkAddress, r.LocalLinkAddress, pkt.NetworkProtocolNumber, pkt)
-	}
-
-	return e.Endpoint.WritePackets(r, pkts, proto)
-}
diff --git a/pkg/tcpip/link/qdisc/fifo/endpoint.go b/pkg/tcpip/link/qdisc/fifo/endpoint.go
index dc63e5fb0..b41e3e2fa 100644
--- a/pkg/tcpip/link/qdisc/fifo/endpoint.go
+++ b/pkg/tcpip/link/qdisc/fifo/endpoint.go
@@ -108,11 +108,6 @@ func (e *endpoint) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protoco
 	e.dispatcher.DeliverNetworkPacket(remote, local, protocol, pkt)
 }
 
-// DeliverOutboundPacket implements stack.NetworkDispatcher.DeliverOutboundPacket.
-func (e *endpoint) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) {
-	e.dispatcher.DeliverOutboundPacket(remote, local, protocol, pkt)
-}
-
 // Attach implements stack.LinkEndpoint.Attach.
 func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
 	// nil means the NIC is being removed.
diff --git a/pkg/tcpip/link/sniffer/sniffer.go b/pkg/tcpip/link/sniffer/sniffer.go
index 28a172e71..2afa95af0 100644
--- a/pkg/tcpip/link/sniffer/sniffer.go
+++ b/pkg/tcpip/link/sniffer/sniffer.go
@@ -140,11 +140,6 @@ func (e *endpoint) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protoco
 	e.Endpoint.DeliverNetworkPacket(remote, local, protocol, pkt)
 }
 
-// DeliverOutboundPacket implements stack.NetworkDispatcher.DeliverOutboundPacket.
-func (e *endpoint) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) {
-	e.Endpoint.DeliverOutboundPacket(remote, local, protocol, pkt)
-}
-
 func (e *endpoint) dumpPacket(dir direction, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) {
 	writer := e.writer
 	if writer == nil && atomic.LoadUint32(&LogPackets) == 1 {
diff --git a/pkg/tcpip/link/waitable/waitable.go b/pkg/tcpip/link/waitable/waitable.go
index 13900205d..116e4defb 100644
--- a/pkg/tcpip/link/waitable/waitable.go
+++ b/pkg/tcpip/link/waitable/waitable.go
@@ -59,15 +59,6 @@ func (e *Endpoint) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protoco
 	e.dispatchGate.Leave()
 }
 
-// DeliverOutboundPacket implements stack.NetworkDispatcher.DeliverOutboundPacket.
-func (e *Endpoint) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) {
-	if !e.dispatchGate.Enter() {
-		return
-	}
-	e.dispatcher.DeliverOutboundPacket(remote, local, protocol, pkt)
-	e.dispatchGate.Leave()
-}
-
 // Attach implements stack.LinkEndpoint.Attach. It saves the dispatcher and
 // registers with the lower endpoint as its dispatcher so that "e" is called
 // for inbound packets.