v2

internal/core/stack.go

@@ -0,0 +1,82 @@
+package core
+
+import (
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
+)
+
+// NewStack returns *stack.Stack with provided options.
+func NewStack(opts ...Option) (*stack.Stack, error) {
+	ipstack := stack.New(stack.Options{
+		NetworkProtocols: []stack.NetworkProtocolFactory{
+			ipv4.NewProtocol,
+			ipv6.NewProtocol,
+		},
+		TransportProtocols: []stack.TransportProtocolFactory{
+			tcp.NewProtocol,
+			udp.NewProtocol,
+			icmp.NewProtocol4,
+			icmp.NewProtocol6,
+		},
+	})
+
+	for _, opt := range opts {
+		if err := opt(ipstack); err != nil {
+			return nil, err
+		}
+	}
+
+	return ipstack, nil
+}
+
+// NewDefaultStack calls NewStack with default options.
+func NewDefaultStack(linkEp stack.LinkEndpoint, th tcpHandleFunc, uh udpHandleFunc) (*stack.Stack, error) {
+	return NewStack(
+		WithDefaultTTL(defaultTimeToLive),
+		WithForwarding(ipForwardingEnabled),
+
+		// Config default stack ICMP settings.
+		WithICMPBurst(icmpBurst), WithICMPLimit(icmpLimit),
+
+		// We expect no packet loss, therefore we can bump buffers.
+		// Too large buffers thrash cache, so there is little point
+		// in too large buffers.
+		//
+		// Ref: https://github.com/majek/slirpnetstack/blob/master/stack.go
+		WithTCPBufferSizeRange(minBufferSize, defaultBufferSize, maxBufferSize),
+
+		WithTCPCongestionControl(tcpCongestionControlAlgorithm),
+		WithTCPDelay(tcpDelayEnabled),
+
+		// Receive Buffer Auto-Tuning Option, see:
+		// https://github.com/google/gvisor/issues/1666
+		WithTCPModerateReceiveBuffer(tcpModerateReceiveBufferEnabled),
+
+		// TCP selective ACK Option, see:
+		// https://tools.ietf.org/html/rfc2018
+		WithTCPSACKEnabled(tcpSACKEnabled),
+
+		// Important: We must initiate transport protocol handlers
+		// before creating NIC, otherwise NIC would dispatch packets
+		// to stack and cause race condition.
+		WithICMPHandler(nil), WithTCPHandler(th), WithUDPHandler(uh),
+
+		// Create stack NIC and then bind link endpoint.
+		WithCreatingNIC(defaultNICID, linkEp),
+
+		// In past we did s.AddAddressRange to assign 0.0.0.0/0 onto
+		// the interface. We need that to be able to terminate all the
+		// incoming connections - to any ip. AddressRange API has been
+		// removed and the suggested workaround is to use Promiscuous
+		// mode. https://github.com/google/gvisor/issues/3876
+		//
+		// Ref: https://github.com/majek/slirpnetstack/blob/master/stack.go
+		WithPromiscuousMode(defaultNICID, nicPromiscuousModeEnabled),
+
+		WithSpoofing(defaultNICID, nicSpoofingEnabled),
+	)
+}