Merge pull request #1558 from kevinGC:iptables-write-input-drop

PiperOrigin-RevId: 290793754

7 files changed, 30 insertions, 12 deletions

diff --git a/pkg/tcpip/network/arp/arp.go b/pkg/tcpip/network/arp/arp.go
index 42cacb8a6..1ceaebfbd 100644
--- a/pkg/tcpip/network/arp/arp.go
+++ b/pkg/tcpip/network/arp/arp.go
@@ -137,7 +137,7 @@ func (*protocol) ParseAddresses(v buffer.View) (src, dst tcpip.Address) {
 	return tcpip.Address(h.ProtocolAddressSender()), ProtocolAddress
 }
 
-func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, sender stack.LinkEndpoint) (stack.NetworkEndpoint, *tcpip.Error) {
+func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, sender stack.LinkEndpoint, st *stack.Stack) (stack.NetworkEndpoint, *tcpip.Error) {
 	if addrWithPrefix.Address != ProtocolAddress {
 		return nil, tcpip.ErrBadLocalAddress
 	}
diff --git a/pkg/tcpip/network/ip_test.go b/pkg/tcpip/network/ip_test.go
index f1bc33adf..f4d78f8c6 100644
--- a/pkg/tcpip/network/ip_test.go
+++ b/pkg/tcpip/network/ip_test.go
@@ -212,10 +212,17 @@ func buildIPv6Route(local, remote tcpip.Address) (stack.Route, *tcpip.Error) {
 	return s.FindRoute(1, local, remote, ipv6.ProtocolNumber, false /* multicastLoop */)
 }
 
+func buildDummyStack() *stack.Stack {
+	return stack.New(stack.Options{
+		NetworkProtocols:   []stack.NetworkProtocol{ipv6.NewProtocol()},
+		TransportProtocols: []stack.TransportProtocol{udp.NewProtocol(), tcp.NewProtocol()},
+	})
+}
+
 func TestIPv4Send(t *testing.T) {
 	o := testObject{t: t, v4: true}
 	proto := ipv4.NewProtocol()
-	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, nil, &o)
+	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, nil, &o, buildDummyStack())
 	if err != nil {
 		t.Fatalf("NewEndpoint failed: %v", err)
 	}
@@ -250,7 +257,7 @@ func TestIPv4Send(t *testing.T) {
 func TestIPv4Receive(t *testing.T) {
 	o := testObject{t: t, v4: true}
 	proto := ipv4.NewProtocol()
-	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, &o, nil)
+	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, &o, nil, buildDummyStack())
 	if err != nil {
 		t.Fatalf("NewEndpoint failed: %v", err)
 	}
@@ -318,7 +325,7 @@ func TestIPv4ReceiveControl(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			o := testObject{t: t}
 			proto := ipv4.NewProtocol()
-			ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, &o, nil)
+			ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, &o, nil, buildDummyStack())
 			if err != nil {
 				t.Fatalf("NewEndpoint failed: %v", err)
 			}
@@ -385,7 +392,7 @@ func TestIPv4ReceiveControl(t *testing.T) {
 func TestIPv4FragmentationReceive(t *testing.T) {
 	o := testObject{t: t, v4: true}
 	proto := ipv4.NewProtocol()
-	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, &o, nil)
+	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv4Addr, localIpv4PrefixLen}, nil, &o, nil, buildDummyStack())
 	if err != nil {
 		t.Fatalf("NewEndpoint failed: %v", err)
 	}
@@ -456,7 +463,7 @@ func TestIPv4FragmentationReceive(t *testing.T) {
 func TestIPv6Send(t *testing.T) {
 	o := testObject{t: t}
 	proto := ipv6.NewProtocol()
-	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv6Addr, localIpv6PrefixLen}, nil, nil, &o)
+	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv6Addr, localIpv6PrefixLen}, nil, nil, &o, buildDummyStack())
 	if err != nil {
 		t.Fatalf("NewEndpoint failed: %v", err)
 	}
@@ -491,7 +498,7 @@ func TestIPv6Send(t *testing.T) {
 func TestIPv6Receive(t *testing.T) {
 	o := testObject{t: t}
 	proto := ipv6.NewProtocol()
-	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv6Addr, localIpv6PrefixLen}, nil, &o, nil)
+	ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv6Addr, localIpv6PrefixLen}, nil, &o, nil, buildDummyStack())
 	if err != nil {
 		t.Fatalf("NewEndpoint failed: %v", err)
 	}
@@ -568,7 +575,7 @@ func TestIPv6ReceiveControl(t *testing.T) {
 		t.Run(c.name, func(t *testing.T) {
 			o := testObject{t: t}
 			proto := ipv6.NewProtocol()
-			ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv6Addr, localIpv6PrefixLen}, nil, &o, nil)
+			ep, err := proto.NewEndpoint(1, tcpip.AddressWithPrefix{localIpv6Addr, localIpv6PrefixLen}, nil, &o, nil, buildDummyStack())
 			if err != nil {
 				t.Fatalf("NewEndpoint failed: %v", err)
 			}
diff --git a/pkg/tcpip/network/ipv4/BUILD b/pkg/tcpip/network/ipv4/BUILD
index aeddfcdd4..4e2aae9a3 100644
--- a/pkg/tcpip/network/ipv4/BUILD
+++ b/pkg/tcpip/network/ipv4/BUILD
@@ -15,6 +15,7 @@ go_library(
         "//pkg/tcpip",
         "//pkg/tcpip/buffer",
         "//pkg/tcpip/header",
+        "//pkg/tcpip/iptables",
         "//pkg/tcpip/network/fragmentation",
         "//pkg/tcpip/network/hash",
         "//pkg/tcpip/stack",
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 4ee3d5b45..0a1453b31 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -26,6 +26,7 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
+	"gvisor.dev/gvisor/pkg/tcpip/iptables"
 	"gvisor.dev/gvisor/pkg/tcpip/network/fragmentation"
 	"gvisor.dev/gvisor/pkg/tcpip/network/hash"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
@@ -54,10 +55,11 @@ type endpoint struct {
 	dispatcher    stack.TransportDispatcher
 	fragmentation *fragmentation.Fragmentation
 	protocol      *protocol
+	stack         *stack.Stack
 }
 
 // NewEndpoint creates a new ipv4 endpoint.
-func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint) (stack.NetworkEndpoint, *tcpip.Error) {
+func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint, st *stack.Stack) (stack.NetworkEndpoint, *tcpip.Error) {
 	e := &endpoint{
 		nicID:         nicID,
 		id:            stack.NetworkEndpointID{LocalAddress: addrWithPrefix.Address},
@@ -66,6 +68,7 @@ func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWi
 		dispatcher:    dispatcher,
 		fragmentation: fragmentation.NewFragmentation(fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout),
 		protocol:      p,
+		stack:         st,
 	}
 
 	return e, nil
@@ -350,6 +353,13 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt tcpip.PacketBuffer) {
 	}
 	pkt.NetworkHeader = headerView[:h.HeaderLength()]
 
+	// iptables filtering.
+	ipt := e.stack.IPTables()
+	if ok := ipt.Check(iptables.Input, pkt); !ok {
+		// iptables is telling us to drop the packet.
+		return
+	}
+
 	hlen := int(h.HeaderLength())
 	tlen := int(h.TotalLength())
 	pkt.Data.TrimFront(hlen)
diff --git a/pkg/tcpip/network/ipv6/icmp_test.go b/pkg/tcpip/network/ipv6/icmp_test.go
index 335f634d5..a2fdc5dcd 100644
--- a/pkg/tcpip/network/ipv6/icmp_test.go
+++ b/pkg/tcpip/network/ipv6/icmp_test.go
@@ -109,7 +109,7 @@ func TestICMPCounts(t *testing.T) {
 	if netProto == nil {
 		t.Fatalf("cannot find protocol instance for network protocol %d", ProtocolNumber)
 	}
-	ep, err := netProto.NewEndpoint(0, tcpip.AddressWithPrefix{lladdr1, netProto.DefaultPrefixLen()}, &stubLinkAddressCache{}, &stubDispatcher{}, nil)
+	ep, err := netProto.NewEndpoint(0, tcpip.AddressWithPrefix{lladdr1, netProto.DefaultPrefixLen()}, &stubLinkAddressCache{}, &stubDispatcher{}, nil, s)
 	if err != nil {
 		t.Fatalf("NewEndpoint(_) = _, %s, want = _, nil", err)
 	}
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 58c3c79b9..180a480fd 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -221,7 +221,7 @@ func (*protocol) ParseAddresses(v buffer.View) (src, dst tcpip.Address) {
 }
 
 // NewEndpoint creates a new ipv6 endpoint.
-func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint) (stack.NetworkEndpoint, *tcpip.Error) {
+func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWithPrefix, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint, st *stack.Stack) (stack.NetworkEndpoint, *tcpip.Error) {
 	return &endpoint{
 		nicID:         nicID,
 		id:            stack.NetworkEndpointID{LocalAddress: addrWithPrefix.Address},
diff --git a/pkg/tcpip/network/ipv6/ndp_test.go b/pkg/tcpip/network/ipv6/ndp_test.go
index 0dbce14a0..fe895b376 100644
--- a/pkg/tcpip/network/ipv6/ndp_test.go
+++ b/pkg/tcpip/network/ipv6/ndp_test.go
@@ -62,7 +62,7 @@ func setupStackAndEndpoint(t *testing.T, llladdr, rlladdr tcpip.Address) (*stack
 		t.Fatalf("cannot find protocol instance for network protocol %d", ProtocolNumber)
 	}
 
-	ep, err := netProto.NewEndpoint(0, tcpip.AddressWithPrefix{rlladdr, netProto.DefaultPrefixLen()}, &stubLinkAddressCache{}, &stubDispatcher{}, nil)
+	ep, err := netProto.NewEndpoint(0, tcpip.AddressWithPrefix{rlladdr, netProto.DefaultPrefixLen()}, &stubLinkAddressCache{}, &stubDispatcher{}, nil, s)
 	if err != nil {
 		t.Fatalf("NewEndpoint(_) = _, %s, want = _, nil", err)
 	}