From aeb3a4017b9bc038ebe5630fe270d5ea8691d141 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Wed, 8 Jan 2020 22:10:35 -0800
Subject: Working on filtering by protocol.

---
 pkg/tcpip/iptables/types.go    | 20 ++++++++++++++++++++
 test/iptables/iptables_test.go | 34 +++++++++++++++++-----------------
 2 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/pkg/tcpip/iptables/types.go b/pkg/tcpip/iptables/types.go
index 9f6906100..4b2a9c294 100644
--- a/pkg/tcpip/iptables/types.go
+++ b/pkg/tcpip/iptables/types.go
@@ -151,6 +151,9 @@ func (table *Table) SetMetadata(metadata interface{}) {
 // packets this rule applies to. If there are no matchers in the rule, it
 // applies to any packet.
 type Rule struct {
+	// IPHeaderFilters holds basic IP filtering fields common to every rule.
+	IPHeaderFilter IPHeaderFilter
+
 	// Matchers is the list of matchers for this rule.
 	Matchers []Matcher
 
@@ -158,6 +161,23 @@ type Rule struct {
 	Target Target
 }
 
+// TODO: This is gross.
+// TODO: Save this in SetEntries.
+// TODO: Utilize this when traversing tables.
+type IPHeaderFilter struct {
+	Source              [4]byte
+	Destination         [4]byte
+	SourceMask          [4]byte
+	DestinationMask     [4]byte
+	OutputInterface     string
+	InputInterface      string
+	OutputInterfaceMask string
+	InputInterfaceMask  string
+	Protocol            uint16
+	Flags               uint8
+	InverseFlags        uint8
+}
+
 // A Matcher is the interface for matching packets.
 type Matcher interface {
 	// Match returns whether the packet matches and whether the packet
diff --git a/test/iptables/iptables_test.go b/test/iptables/iptables_test.go
index 5927eb017..d040e971a 100644
--- a/test/iptables/iptables_test.go
+++ b/test/iptables/iptables_test.go
@@ -166,20 +166,20 @@ func TestFilterInputDropUDP(t *testing.T) {
 	}
 }
 
-func TestFilterInputDropUDPPort(t *testing.T) {
-	if err := singleTest(FilterInputDropUDPPort{}); err != nil {
-		t.Fatal(err)
-	}
-}
-
-func TestFilterInputDropDifferentUDPPort(t *testing.T) {
-	if err := singleTest(FilterInputDropDifferentUDPPort{}); err != nil {
-		t.Fatal(err)
-	}
-}
-
-func TestFilterInputDropAll(t *testing.T) {
-	if err := singleTest(FilterInputDropAll{}); err != nil {
-		t.Fatal(err)
-	}
-}
+// func TestFilterInputDropUDPPort(t *testing.T) {
+// 	if err := singleTest(FilterInputDropUDPPort{}); err != nil {
+// 		t.Fatal(err)
+// 	}
+// }
+
+// func TestFilterInputDropDifferentUDPPort(t *testing.T) {
+// 	if err := singleTest(FilterInputDropDifferentUDPPort{}); err != nil {
+// 		t.Fatal(err)
+// 	}
+// }
+
+// func TestFilterInputDropAll(t *testing.T) {
+// 	if err := singleTest(FilterInputDropAll{}); err != nil {
+// 		t.Fatal(err)
+// 	}
+// }
-- 
cgit v1.2.3


From 89d11b4d96b0c40e373f14ba72d570c9b894f976 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Thu, 9 Jan 2020 13:41:52 -0800
Subject: Added a test that we don't pass yet

---
 pkg/sentry/socket/netfilter/netfilter.go | 37 +++++++++++++++++++++++++----
 pkg/tcpip/iptables/iptables.go           |  7 ++++++
 pkg/tcpip/iptables/types.go              |  4 ++--
 test/iptables/BUILD                      |  4 ++++
 test/iptables/filter_input.go            | 30 ++++++++++++++++++++++++
 test/iptables/iptables_test.go           | 16 +++++++++----
 test/iptables/iptables_util.go           | 40 ++++++++++++++++++++++++++++++++
 test/iptables/runner/BUILD               |  1 +
 8 files changed, 127 insertions(+), 12 deletions(-)

diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go
index 014dfa625..f30461936 100644
--- a/pkg/sentry/socket/netfilter/netfilter.go
+++ b/pkg/sentry/socket/netfilter/netfilter.go
@@ -323,10 +323,9 @@ func SetEntries(stack *stack.Stack, optVal []byte) *syserr.Error {
 
 		// TODO(gvisor.dev/issue/170): We should support IPTIP
 		// filtering. We reject any nonzero IPTIP values for now.
-		emptyIPTIP := linux.IPTIP{}
-		if entry.IP != emptyIPTIP {
-			log.Warningf("netfilter: non-empty struct iptip found")
-			return syserr.ErrInvalidArgument
+		filter, err := filterFromIPTIP(entry.IP)
+		if err != nil {
+			return err
 		}
 
 		// Get the target of the rule.
@@ -336,7 +335,10 @@ func SetEntries(stack *stack.Stack, optVal []byte) *syserr.Error {
 		}
 		optVal = optVal[consumed:]
 
-		table.Rules = append(table.Rules, iptables.Rule{Target: target})
+		table.Rules = append(table.Rules, iptables.Rule{
+			Filter: filter,
+			Target: target,
+		})
 		offsets = append(offsets, offset)
 		offset += linux.SizeOfIPTEntry + consumed
 	}
@@ -447,6 +449,31 @@ func parseTarget(optVal []byte) (iptables.Target, uint32, *syserr.Error) {
 	return nil, 0, syserr.ErrInvalidArgument
 }
 
+func filterFromIPTIP(iptip linux.IPTIP) (iptables.IPHeaderFilter, *syserr.Error) {
+	if containsUnsupportedFields(iptip) {
+		log.Warningf("netfilter: unsupported fields in struct iptip: %+v")
+		return iptables.IPHeaderFilter{}, syserr.ErrInvalidArgument
+	}
+	return iptables.IPHeaderFilter{
+		Protocol: iptip.Protocol,
+	}, nil
+}
+
+func containsUnsupportedFields(iptip linux.IPTIP) bool {
+	// Currently we check that everything except protocol is zeroed.
+	var emptyInetAddr = linux.InetAddr{}
+	var emptyInterface = [linux.IFNAMSIZ]byte{}
+	return iptip.Dst != emptyInetAddr ||
+		iptip.SrcMask != emptyInetAddr ||
+		iptip.DstMask != emptyInetAddr ||
+		iptip.InputInterface != emptyInterface ||
+		iptip.OutputInterface != emptyInterface ||
+		iptip.InputInterfaceMask != emptyInterface ||
+		iptip.OutputInterfaceMask != emptyInterface ||
+		iptip.Flags != 0 ||
+		iptip.InverseFlags != 0
+}
+
 func hookFromLinux(hook int) iptables.Hook {
 	switch hook {
 	case linux.NF_INET_PRE_ROUTING:
diff --git a/pkg/tcpip/iptables/iptables.go b/pkg/tcpip/iptables/iptables.go
index 91abbbea8..b8d70ec1e 100644
--- a/pkg/tcpip/iptables/iptables.go
+++ b/pkg/tcpip/iptables/iptables.go
@@ -185,6 +185,13 @@ func (it *IPTables) checkTable(hook Hook, pkt tcpip.PacketBuffer, tablename stri
 
 func (it *IPTables) checkRule(hook Hook, pkt tcpip.PacketBuffer, table Table, ruleIdx int) Verdict {
 	rule := table.Rules[ruleIdx]
+
+	// First check whether the packet matches the IP header filter.
+	// TODO(gvisor.dev/issue/170): Support other fields of the filter.
+	// if rule.Filter.Protocol != pkt.Protocol {
+	// 	return Continue
+	// }
+
 	// Go through each rule matcher. If they all match, run
 	// the rule target.
 	for _, matcher := range rule.Matchers {
diff --git a/pkg/tcpip/iptables/types.go b/pkg/tcpip/iptables/types.go
index 4b2a9c294..4bedd9bc8 100644
--- a/pkg/tcpip/iptables/types.go
+++ b/pkg/tcpip/iptables/types.go
@@ -151,8 +151,8 @@ func (table *Table) SetMetadata(metadata interface{}) {
 // packets this rule applies to. If there are no matchers in the rule, it
 // applies to any packet.
 type Rule struct {
-	// IPHeaderFilters holds basic IP filtering fields common to every rule.
-	IPHeaderFilter IPHeaderFilter
+	// IPHeaderFilter holds basic IP filtering fields common to every rule.
+	Filter IPHeaderFilter
 
 	// Matchers is the list of matchers for this rule.
 	Matchers []Matcher
diff --git a/test/iptables/BUILD b/test/iptables/BUILD
index fa833c3b2..6a9d05828 100644
--- a/test/iptables/BUILD
+++ b/test/iptables/BUILD
@@ -4,6 +4,7 @@ package(licenses = ["notice"])
 
 go_library(
     name = "iptables",
+    testonly = 1,
     srcs = [
         "filter_input.go",
         "iptables.go",
@@ -11,6 +12,9 @@ go_library(
     ],
     importpath = "gvisor.dev/gvisor/test/iptables",
     visibility = ["//test/iptables:__subpackages__"],
+    deps = [
+        "//runsc/testutil",
+    ],
 )
 
 go_test(
diff --git a/test/iptables/filter_input.go b/test/iptables/filter_input.go
index 7c4d469fa..a3f0052b5 100644
--- a/test/iptables/filter_input.go
+++ b/test/iptables/filter_input.go
@@ -28,6 +28,7 @@ const (
 )
 
 func init() {
+	RegisterTestCase(FilterInputDropOnlyUDP{})
 	RegisterTestCase(FilterInputDropUDP{})
 	RegisterTestCase(FilterInputDropUDPPort{})
 	RegisterTestCase(FilterInputDropDifferentUDPPort{})
@@ -65,6 +66,35 @@ func (FilterInputDropUDP) LocalAction(ip net.IP) error {
 	return sendUDPLoop(ip, dropPort, sendloopDuration)
 }
 
+// FilterInputDropOnlyUDP tests that "-p udp -j DROP" only affects UDP traffic.
+type FilterInputDropOnlyUDP struct{}
+
+// Name implements TestCase.Name.
+func (FilterInputDropOnlyUDP) Name() string {
+	return "FilterInputDropOnlyUDP"
+}
+
+// ContainerAction implements TestCase.ContainerAction.
+func (FilterInputDropOnlyUDP) ContainerAction(ip net.IP) error {
+	if err := filterTable("-A", "INPUT", "-p", "udp", "-j", "DROP"); err != nil {
+		return err
+	}
+
+	// Listen for a TCP connection, which should be allowed.
+	if err := listenTCP(acceptPort, sendloopDuration); err != nil {
+		return fmt.Errorf("failed to establish a connection %v", err)
+	}
+
+	return nil
+}
+
+// LocalAction implements TestCase.LocalAction.
+func (FilterInputDropOnlyUDP) LocalAction(ip net.IP) error {
+	// Try to establish a TCP connection with the container, which should
+	// succeed.
+	return connectLoopTCP(ip, acceptPort, sendloopDuration)
+}
+
 // FilterInputDropUDPPort tests that we can drop UDP traffic by port.
 type FilterInputDropUDPPort struct{}
 
diff --git a/test/iptables/iptables_test.go b/test/iptables/iptables_test.go
index d040e971a..beaaf519c 100644
--- a/test/iptables/iptables_test.go
+++ b/test/iptables/iptables_test.go
@@ -160,11 +160,11 @@ func logContainer(output string, err error) {
 	log.Infof(msg)
 }
 
-func TestFilterInputDropUDP(t *testing.T) {
-	if err := singleTest(FilterInputDropUDP{}); err != nil {
-		t.Fatal(err)
-	}
-}
+// func TestFilterInputDropUDP(t *testing.T) {
+// 	if err := singleTest(FilterInputDropUDP{}); err != nil {
+// 		t.Fatal(err)
+// 	}
+// }
 
 // func TestFilterInputDropUDPPort(t *testing.T) {
 // 	if err := singleTest(FilterInputDropUDPPort{}); err != nil {
@@ -183,3 +183,9 @@ func TestFilterInputDropUDP(t *testing.T) {
 // 		t.Fatal(err)
 // 	}
 // }
+
+func TestFilterInputDropOnlyUDP(t *testing.T) {
+	if err := singleTest(FilterInputDropOnlyUDP{}); err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/test/iptables/iptables_util.go b/test/iptables/iptables_util.go
index 3a4d11f1a..3dcaafb79 100644
--- a/test/iptables/iptables_util.go
+++ b/test/iptables/iptables_util.go
@@ -19,6 +19,8 @@ import (
 	"net"
 	"os/exec"
 	"time"
+
+	"gvisor.dev/gvisor/runsc/testutil"
 )
 
 const iptablesBinary = "iptables"
@@ -80,3 +82,41 @@ func sendUDPLoop(ip net.IP, port int, duration time.Duration) error {
 
 	return nil
 }
+
+func listenTCP(port int, timeout time.Duration) error {
+	localAddr := net.TCPAddr{Port: acceptPort}
+	listener, err := net.ListenTCP("tcp4", &localAddr)
+	if err != nil {
+		return err
+	}
+	defer listener.Close()
+	listener.SetDeadline(time.Now().Add(timeout))
+	conn, err := listener.AcceptTCP()
+	if err != nil {
+		return fmt.Errorf("failed to establish a connection %v", err)
+	}
+	defer conn.Close()
+
+	return nil
+}
+
+func connectLoopTCP(ip net.IP, port int, timeout time.Duration) error {
+	contAddr := net.TCPAddr{
+		IP:   ip,
+		Port: port,
+	}
+	// The container may not be listening when we first connect, so retry
+	// upon error.
+	cb := func() error {
+		conn, err := net.DialTCP("tcp4", nil, &contAddr)
+		if conn != nil {
+			conn.Close()
+		}
+		return err
+	}
+	if err := testutil.Poll(cb, timeout); err != nil {
+		return fmt.Errorf("timed out waiting to send IP, most recent error: %v", err)
+	}
+
+	return nil
+}
diff --git a/test/iptables/runner/BUILD b/test/iptables/runner/BUILD
index c6c42d870..a5b6f082c 100644
--- a/test/iptables/runner/BUILD
+++ b/test/iptables/runner/BUILD
@@ -10,6 +10,7 @@ container_image(
 
 go_image(
     name = "runner",
+    testonly = 1,
     srcs = ["main.go"],
     base = ":iptables-base",
     deps = ["//test/iptables"],
-- 
cgit v1.2.3


From ff719159befaee7d2abcfeb88905a7486cd34845 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Thu, 9 Jan 2020 15:38:21 -0800
Subject: Confirmed that it works if I hardcode 17 in for pkt.Protocol. Need to
 address parsing the packet early :(

---
 pkg/tcpip/iptables/iptables.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pkg/tcpip/iptables/iptables.go b/pkg/tcpip/iptables/iptables.go
index b8d70ec1e..4e1700fdb 100644
--- a/pkg/tcpip/iptables/iptables.go
+++ b/pkg/tcpip/iptables/iptables.go
@@ -188,9 +188,9 @@ func (it *IPTables) checkRule(hook Hook, pkt tcpip.PacketBuffer, table Table, ru
 
 	// First check whether the packet matches the IP header filter.
 	// TODO(gvisor.dev/issue/170): Support other fields of the filter.
-	// if rule.Filter.Protocol != pkt.Protocol {
-	// 	return Continue
-	// }
+	if rule.Filter.Protocol != pkt.Protocol {
+		return Continue
+	}
 
 	// Go through each rule matcher. If they all match, run
 	// the rule target.
-- 
cgit v1.2.3


From d793677cd424fef10ac0b080871d181db0bcdec0 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Fri, 10 Jan 2020 18:07:15 -0800
Subject: I think INPUT works with protocol

---
 pkg/sentry/socket/netfilter/netfilter.go |  3 ++-
 pkg/tcpip/iptables/BUILD                 |  1 +
 pkg/tcpip/iptables/iptables.go           |  4 +++-
 pkg/tcpip/iptables/types.go              |  2 +-
 pkg/tcpip/network/ipv4/ipv4.go           |  3 ++-
 pkg/tcpip/packet_buffer.go               | 25 ++++++++++++++++++++++++-
 6 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go
index f30461936..175466f19 100644
--- a/pkg/sentry/socket/netfilter/netfilter.go
+++ b/pkg/sentry/socket/netfilter/netfilter.go
@@ -25,6 +25,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
 	"gvisor.dev/gvisor/pkg/syserr"
+	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/iptables"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
@@ -455,7 +456,7 @@ func filterFromIPTIP(iptip linux.IPTIP) (iptables.IPHeaderFilter, *syserr.Error)
 		return iptables.IPHeaderFilter{}, syserr.ErrInvalidArgument
 	}
 	return iptables.IPHeaderFilter{
-		Protocol: iptip.Protocol,
+		Protocol: tcpip.TransportProtocolNumber(iptip.Protocol),
 	}, nil
 }
 
diff --git a/pkg/tcpip/iptables/BUILD b/pkg/tcpip/iptables/BUILD
index 2893c80cd..297eaccaf 100644
--- a/pkg/tcpip/iptables/BUILD
+++ b/pkg/tcpip/iptables/BUILD
@@ -14,5 +14,6 @@ go_library(
     deps = [
         "//pkg/log",
         "//pkg/tcpip",
+        "//pkg/tcpip/header",
     ],
 )
diff --git a/pkg/tcpip/iptables/iptables.go b/pkg/tcpip/iptables/iptables.go
index 4e1700fdb..3cff879a2 100644
--- a/pkg/tcpip/iptables/iptables.go
+++ b/pkg/tcpip/iptables/iptables.go
@@ -21,6 +21,7 @@ import (
 
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/header"
 )
 
 const (
@@ -183,12 +184,13 @@ func (it *IPTables) checkTable(hook Hook, pkt tcpip.PacketBuffer, tablename stri
 	panic(fmt.Sprintf("Traversed past the entire list of iptables rules in table %q.", tablename))
 }
 
+// Precondition: pk.NetworkHeader is set.
 func (it *IPTables) checkRule(hook Hook, pkt tcpip.PacketBuffer, table Table, ruleIdx int) Verdict {
 	rule := table.Rules[ruleIdx]
 
 	// First check whether the packet matches the IP header filter.
 	// TODO(gvisor.dev/issue/170): Support other fields of the filter.
-	if rule.Filter.Protocol != pkt.Protocol {
+	if rule.Filter.Protocol != header.IPv4(pkt.NetworkHeader).TransportProtocol() {
 		return Continue
 	}
 
diff --git a/pkg/tcpip/iptables/types.go b/pkg/tcpip/iptables/types.go
index 4bedd9bc8..4f2a4d65e 100644
--- a/pkg/tcpip/iptables/types.go
+++ b/pkg/tcpip/iptables/types.go
@@ -173,7 +173,7 @@ type IPHeaderFilter struct {
 	InputInterface      string
 	OutputInterfaceMask string
 	InputInterfaceMask  string
-	Protocol            uint16
+	Protocol            tcpip.TransportProtocolNumber
 	Flags               uint8
 	InverseFlags        uint8
 }
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index f856081e6..5388d2549 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -353,7 +353,8 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt tcpip.PacketBuffer) {
 	}
 	pkt.NetworkHeader = headerView[:h.HeaderLength()]
 
-	// iptables filtering.
+	// iptables filtering. All packets that reach here are intended for
+	// this machine and will not be forwarded.
 	ipt := e.stack.IPTables()
 	if ok := ipt.Check(iptables.Input, pkt); !ok {
 		// iptables is telling us to drop the packet.
diff --git a/pkg/tcpip/packet_buffer.go b/pkg/tcpip/packet_buffer.go
index ab24372e7..7a036b93c 100644
--- a/pkg/tcpip/packet_buffer.go
+++ b/pkg/tcpip/packet_buffer.go
@@ -13,7 +13,9 @@
 
 package tcpip
 
-import "gvisor.dev/gvisor/pkg/tcpip/buffer"
+import (
+	"gvisor.dev/gvisor/pkg/tcpip/buffer"
+)
 
 // A PacketBuffer contains all the data of a network packet.
 //
@@ -65,3 +67,24 @@ func (pk PacketBuffer) Clone() PacketBuffer {
 	pk.Data = pk.Data.Clone(nil)
 	return pk
 }
+
+//// TransportProtocol returns the transport protocol of pk.
+////
+//// Precondition: pk.NetworkHeader is set.
+//func (pk PacketBuffer) TransportProtocolIPv4() uint16 {
+//	if pk.NetworkHeader == nil {
+//		panic("This should only be called when pk.NetworkHeader is set.")
+//	}
+//	return header.IPv4(pk.NetworkHeader).TransportProtocol()
+//}
+
+// func (pk Packet) findNetHeader() header.IPv4 {
+// 	// Inbound:
+// 	// Data holds everything, but may have had some headers shaved off.
+// 	// Figure out whether it's set or still somewhere in data and return
+// 	// appropriately.
+
+// 	// Outbound:
+// 	// NetworkHeader will be set if we've added one. Otherwise there's no
+// 	// header.
+// }
-- 
cgit v1.2.3


From bd292894097ffdf316bc78d81aebd0a2988124f3 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Mon, 13 Jan 2020 16:10:00 -0800
Subject: Protocol filtering works.

---
 pkg/tcpip/iptables/iptables.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/tcpip/iptables/iptables.go b/pkg/tcpip/iptables/iptables.go
index 921546984..5c813d8a0 100644
--- a/pkg/tcpip/iptables/iptables.go
+++ b/pkg/tcpip/iptables/iptables.go
@@ -187,7 +187,7 @@ func (it *IPTables) checkRule(hook Hook, pkt tcpip.PacketBuffer, table Table, ru
 
 	// First check whether the packet matches the IP header filter.
 	// TODO(gvisor.dev/issue/170): Support other fields of the filter.
-	if rule.Filter.Protocol != header.IPv4(pkt.NetworkHeader).TransportProtocol() {
+	if rule.Filter.Protocol != 0 && rule.Filter.Protocol != header.IPv4(pkt.NetworkHeader).TransportProtocol() {
 		return Continue
 	}
 
-- 
cgit v1.2.3


From 47bc7550c0b8fcde7b3452bf536082e955882026 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Tue, 21 Jan 2020 13:37:25 -0800
Subject: Fixing stuff

---
 pkg/sentry/socket/netfilter/netfilter.go |  3 ++
 pkg/tcpip/iptables/types.go              | 21 ++++----------
 pkg/tcpip/packet_buffer.go               | 25 +----------------
 test/iptables/iptables_test.go           | 47 ++++++++++++++++----------------
 4 files changed, 34 insertions(+), 62 deletions(-)

diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go
index 09a3276c7..4ef8123ac 100644
--- a/pkg/sentry/socket/netfilter/netfilter.go
+++ b/pkg/sentry/socket/netfilter/netfilter.go
@@ -164,6 +164,9 @@ func convertNetstackToBinary(tablename string, table iptables.Table) (linux.Kern
 		// Each rule corresponds to an entry.
 		entry := linux.KernelIPTEntry{
 			IPTEntry: linux.IPTEntry{
+				IP: linux.IPTIP{
+					Protocol: uint16(rule.Filter.Protocol),
+				},
 				NextOffset:   linux.SizeOfIPTEntry,
 				TargetOffset: linux.SizeOfIPTEntry,
 			},
diff --git a/pkg/tcpip/iptables/types.go b/pkg/tcpip/iptables/types.go
index 4f2a4d65e..a0bfc8b41 100644
--- a/pkg/tcpip/iptables/types.go
+++ b/pkg/tcpip/iptables/types.go
@@ -14,7 +14,9 @@
 
 package iptables
 
-import "gvisor.dev/gvisor/pkg/tcpip"
+import (
+	"gvisor.dev/gvisor/pkg/tcpip"
+)
 
 // A Hook specifies one of the hooks built into the network stack.
 //
@@ -161,21 +163,10 @@ type Rule struct {
 	Target Target
 }
 
-// TODO: This is gross.
-// TODO: Save this in SetEntries.
-// TODO: Utilize this when traversing tables.
+// IPHeaderFilter holds basic IP filtering data common to every rule.
 type IPHeaderFilter struct {
-	Source              [4]byte
-	Destination         [4]byte
-	SourceMask          [4]byte
-	DestinationMask     [4]byte
-	OutputInterface     string
-	InputInterface      string
-	OutputInterfaceMask string
-	InputInterfaceMask  string
-	Protocol            tcpip.TransportProtocolNumber
-	Flags               uint8
-	InverseFlags        uint8
+	// Protocol matches the transport protocol.
+	Protocol tcpip.TransportProtocolNumber
 }
 
 // A Matcher is the interface for matching packets.
diff --git a/pkg/tcpip/packet_buffer.go b/pkg/tcpip/packet_buffer.go
index 7a036b93c..ab24372e7 100644
--- a/pkg/tcpip/packet_buffer.go
+++ b/pkg/tcpip/packet_buffer.go
@@ -13,9 +13,7 @@
 
 package tcpip
 
-import (
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
-)
+import "gvisor.dev/gvisor/pkg/tcpip/buffer"
 
 // A PacketBuffer contains all the data of a network packet.
 //
@@ -67,24 +65,3 @@ func (pk PacketBuffer) Clone() PacketBuffer {
 	pk.Data = pk.Data.Clone(nil)
 	return pk
 }
-
-//// TransportProtocol returns the transport protocol of pk.
-////
-//// Precondition: pk.NetworkHeader is set.
-//func (pk PacketBuffer) TransportProtocolIPv4() uint16 {
-//	if pk.NetworkHeader == nil {
-//		panic("This should only be called when pk.NetworkHeader is set.")
-//	}
-//	return header.IPv4(pk.NetworkHeader).TransportProtocol()
-//}
-
-// func (pk Packet) findNetHeader() header.IPv4 {
-// 	// Inbound:
-// 	// Data holds everything, but may have had some headers shaved off.
-// 	// Figure out whether it's set or still somewhere in data and return
-// 	// appropriately.
-
-// 	// Outbound:
-// 	// NetworkHeader will be set if we've added one. Otherwise there's no
-// 	// header.
-// }
diff --git a/test/iptables/iptables_test.go b/test/iptables/iptables_test.go
index 63e691af6..150b44e42 100644
--- a/test/iptables/iptables_test.go
+++ b/test/iptables/iptables_test.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"flag"
+
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/runsc/dockerutil"
 	"gvisor.dev/gvisor/runsc/testutil"
@@ -160,29 +161,29 @@ func logContainer(output string, err error) {
 	log.Infof(msg)
 }
 
-// func TestFilterInputDropUDP(t *testing.T) {
-// 	if err := singleTest(FilterInputDropUDP{}); err != nil {
-// 		t.Fatal(err)
-// 	}
-// }
-
-// func TestFilterInputDropUDPPort(t *testing.T) {
-// 	if err := singleTest(FilterInputDropUDPPort{}); err != nil {
-// 		t.Fatal(err)
-// 	}
-// }
-
-// func TestFilterInputDropDifferentUDPPort(t *testing.T) {
-// 	if err := singleTest(FilterInputDropDifferentUDPPort{}); err != nil {
-// 		t.Fatal(err)
-// 	}
-// }
-
-// func TestFilterInputDropAll(t *testing.T) {
-// 	if err := singleTest(FilterInputDropAll{}); err != nil {
-// 		t.Fatal(err)
-// 	}
-// }
+func TestFilterInputDropUDP(t *testing.T) {
+	if err := singleTest(FilterInputDropUDP{}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestFilterInputDropUDPPort(t *testing.T) {
+	if err := singleTest(FilterInputDropUDPPort{}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestFilterInputDropDifferentUDPPort(t *testing.T) {
+	if err := singleTest(FilterInputDropDifferentUDPPort{}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestFilterInputDropAll(t *testing.T) {
+	if err := singleTest(FilterInputDropAll{}); err != nil {
+		t.Fatal(err)
+	}
+}
 
 func TestFilterInputDropOnlyUDP(t *testing.T) {
 	if err := singleTest(FilterInputDropOnlyUDP{}); err != nil {
-- 
cgit v1.2.3


From 9f736ac6a7747917f690596ac9b072c108b5670c Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Tue, 21 Jan 2020 13:39:48 -0800
Subject: More little fixes.

---
 pkg/sentry/socket/netfilter/netfilter.go | 4 ++--
 test/iptables/iptables_test.go           | 3 +--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/pkg/sentry/socket/netfilter/netfilter.go b/pkg/sentry/socket/netfilter/netfilter.go
index 4ef8123ac..e1f2bacce 100644
--- a/pkg/sentry/socket/netfilter/netfilter.go
+++ b/pkg/sentry/socket/netfilter/netfilter.go
@@ -325,8 +325,8 @@ func SetEntries(stack *stack.Stack, optVal []byte) *syserr.Error {
 			return syserr.ErrInvalidArgument
 		}
 
-		// TODO(gvisor.dev/issue/170): We should support IPTIP
-		// filtering. We reject any nonzero IPTIP values for now.
+		// TODO(gvisor.dev/issue/170): We should support more IPTIP
+		// filtering fields.
 		filter, err := filterFromIPTIP(entry.IP)
 		if err != nil {
 			return err
diff --git a/test/iptables/iptables_test.go b/test/iptables/iptables_test.go
index 150b44e42..679a29bef 100644
--- a/test/iptables/iptables_test.go
+++ b/test/iptables/iptables_test.go
@@ -15,6 +15,7 @@
 package iptables
 
 import (
+	"flag"
 	"fmt"
 	"net"
 	"os"
@@ -22,8 +23,6 @@ import (
 	"testing"
 	"time"
 
-	"flag"
-
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/runsc/dockerutil"
 	"gvisor.dev/gvisor/runsc/testutil"
-- 
cgit v1.2.3


From 747137c120bca27aeb259817d30ef60e01521621 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Wed, 22 Jan 2020 10:23:44 -0800
Subject: Address GitHub comments.

---
 pkg/tcpip/iptables/types.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkg/tcpip/iptables/types.go b/pkg/tcpip/iptables/types.go
index a0bfc8b41..a8b972f1b 100644
--- a/pkg/tcpip/iptables/types.go
+++ b/pkg/tcpip/iptables/types.go
@@ -153,7 +153,7 @@ func (table *Table) SetMetadata(metadata interface{}) {
 // packets this rule applies to. If there are no matchers in the rule, it
 // applies to any packet.
 type Rule struct {
-	// IPHeaderFilter holds basic IP filtering fields common to every rule.
+	// Filter holds basic IP filtering fields common to every rule.
 	Filter IPHeaderFilter
 
 	// Matchers is the list of matchers for this rule.
-- 
cgit v1.2.3