netstack: Don't start endpoint goroutines too soon on restore.

Endpoint protocol goroutines were previously started as part of
loading the endpoint. This is potentially too soon, as resources used
by these goroutine may not have been loaded. Protocol goroutines may
perform meaningful work as soon as they're started (ex: incoming
connect) which can cause them to indirectly access resources that
haven't been loaded yet.

This CL defers resuming all protocol goroutines until the end of
restore.

PiperOrigin-RevId: 262409429

2 files changed, 29 insertions, 25 deletions

diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index a4527c041..9a4306011 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -136,6 +136,34 @@ func (e *endpoint) IPTables() (iptables.IPTables, error) {
 	return e.stack.IPTables(), nil
 }
 
+// Resume implements tcpip.ResumableEndpoint.Resume.
+func (e *endpoint) Resume(s *stack.Stack) {
+	e.stack = s
+
+	if e.state != stateBound && e.state != stateConnected {
+		return
+	}
+
+	var err *tcpip.Error
+	if e.state == stateConnected {
+		e.route, err = e.stack.FindRoute(e.regNICID, e.bindAddr, e.id.RemoteAddress, e.netProto, false /* multicastLoop */)
+		if err != nil {
+			panic(*err)
+		}
+
+		e.id.LocalAddress = e.route.LocalAddress
+	} else if len(e.id.LocalAddress) != 0 { // stateBound
+		if e.stack.CheckLocalAddress(e.regNICID, e.netProto, e.id.LocalAddress) == 0 {
+			panic(tcpip.ErrBadLocalAddress)
+		}
+	}
+
+	e.id, err = e.registerWithStack(e.regNICID, []tcpip.NetworkProtocolNumber{e.netProto}, e.id)
+	if err != nil {
+		panic(*err)
+	}
+}
+
 // Read reads data from the endpoint. This method does not block if
 // there is no data pending.
 func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) {
diff --git a/pkg/tcpip/transport/icmp/endpoint_state.go b/pkg/tcpip/transport/icmp/endpoint_state.go
index 99b8c4093..43551d642 100644
--- a/pkg/tcpip/transport/icmp/endpoint_state.go
+++ b/pkg/tcpip/transport/icmp/endpoint_state.go
@@ -15,7 +15,6 @@
 package icmp
 
 import (
-	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
@@ -63,28 +62,5 @@ func (e *endpoint) loadRcvBufSizeMax(max int) {
 
 // afterLoad is invoked by stateify.
 func (e *endpoint) afterLoad() {
-	e.stack = stack.StackFromEnv
-
-	if e.state != stateBound && e.state != stateConnected {
-		return
-	}
-
-	var err *tcpip.Error
-	if e.state == stateConnected {
-		e.route, err = e.stack.FindRoute(e.regNICID, e.bindAddr, e.id.RemoteAddress, e.netProto, false /* multicastLoop */)
-		if err != nil {
-			panic(*err)
-		}
-
-		e.id.LocalAddress = e.route.LocalAddress
-	} else if len(e.id.LocalAddress) != 0 { // stateBound
-		if e.stack.CheckLocalAddress(e.regNICID, e.netProto, e.id.LocalAddress) == 0 {
-			panic(tcpip.ErrBadLocalAddress)
-		}
-	}
-
-	e.id, err = e.registerWithStack(e.regNICID, []tcpip.NetworkProtocolNumber{e.netProto}, e.id)
-	if err != nil {
-		panic(*err)
-	}
+	stack.StackFromEnv.RegisterRestoredEndpoint(e)
 }