From 0aae51c6e09046e56f2d4b6064124da059731286 Mon Sep 17 00:00:00 2001
From: Kevin Krakauer <krakauer@google.com>
Date: Tue, 29 Sep 2020 22:39:37 -0700
Subject: iptables: remove unused min/max NAT range fields

PiperOrigin-RevId: 334531794
---
 pkg/tcpip/stack/conntrack.go        |  4 ++--
 pkg/tcpip/stack/iptables_targets.go | 34 ++++++++++------------------------
 2 files changed, 12 insertions(+), 26 deletions(-)

(limited to 'pkg/tcpip/stack')

diff --git a/pkg/tcpip/stack/conntrack.go b/pkg/tcpip/stack/conntrack.go
index 836682ea0..91ae7dafc 100644
--- a/pkg/tcpip/stack/conntrack.go
+++ b/pkg/tcpip/stack/conntrack.go
@@ -281,8 +281,8 @@ func (ct *ConnTrack) insertRedirectConn(pkt *PacketBuffer, hook Hook, rt Redirec
 	// rule. This tuple will be used to manipulate the packet in
 	// handlePacket.
 	replyTID := tid.reply()
-	replyTID.srcAddr = rt.MinIP
-	replyTID.srcPort = rt.MinPort
+	replyTID.srcAddr = rt.Addr
+	replyTID.srcPort = rt.Port
 	var manip manipType
 	switch hook {
 	case Prerouting:
diff --git a/pkg/tcpip/stack/iptables_targets.go b/pkg/tcpip/stack/iptables_targets.go
index 8581dd5e8..08063f6ff 100644
--- a/pkg/tcpip/stack/iptables_targets.go
+++ b/pkg/tcpip/stack/iptables_targets.go
@@ -128,26 +128,14 @@ func (ReturnTarget) Action(*PacketBuffer, *ConnTrack, Hook, *GSO, *Route, tcpip.
 const RedirectTargetName = "REDIRECT"
 
 // RedirectTarget redirects the packet by modifying the destination port/IP.
-// Min and Max values for IP and Ports in the struct indicate the range of
-// values which can be used to redirect.
+// TODO(gvisor.dev/issue/170): Other flags need to be added after we support
+// them.
 type RedirectTarget struct {
-	// TODO(gvisor.dev/issue/170): Other flags need to be added after
-	// we support them.
-	// RangeProtoSpecified flag indicates single port is specified to
-	// redirect.
-	RangeProtoSpecified bool
+	// Addr indicates address used to redirect.
+	Addr tcpip.Address
 
-	// MinIP indicates address used to redirect.
-	MinIP tcpip.Address
-
-	// MaxIP indicates address used to redirect.
-	MaxIP tcpip.Address
-
-	// MinPort indicates port used to redirect.
-	MinPort uint16
-
-	// MaxPort indicates port used to redirect.
-	MaxPort uint16
+	// Port indicates port used to redirect.
+	Port uint16
 
 	// NetworkProtocol is the network protocol the target is used with.
 	NetworkProtocol tcpip.NetworkProtocolNumber
@@ -180,11 +168,9 @@ func (rt RedirectTarget) Action(pkt *PacketBuffer, ct *ConnTrack, hook Hook, gso
 	// to primary address of the incoming interface in Prerouting.
 	switch hook {
 	case Output:
-		rt.MinIP = tcpip.Address([]byte{127, 0, 0, 1})
-		rt.MaxIP = tcpip.Address([]byte{127, 0, 0, 1})
+		rt.Addr = tcpip.Address([]byte{127, 0, 0, 1})
 	case Prerouting:
-		rt.MinIP = address
-		rt.MaxIP = address
+		rt.Addr = address
 	default:
 		panic("redirect target is supported only on output and prerouting hooks")
 	}
@@ -195,7 +181,7 @@ func (rt RedirectTarget) Action(pkt *PacketBuffer, ct *ConnTrack, hook Hook, gso
 	switch protocol := netHeader.TransportProtocol(); protocol {
 	case header.UDPProtocolNumber:
 		udpHeader := header.UDP(pkt.TransportHeader().View())
-		udpHeader.SetDestinationPort(rt.MinPort)
+		udpHeader.SetDestinationPort(rt.Port)
 
 		// Calculate UDP checksum and set it.
 		if hook == Output {
@@ -213,7 +199,7 @@ func (rt RedirectTarget) Action(pkt *PacketBuffer, ct *ConnTrack, hook Hook, gso
 			}
 		}
 		// Change destination address.
-		netHeader.SetDestinationAddress(rt.MinIP)
+		netHeader.SetDestinationAddress(rt.Addr)
 		netHeader.SetChecksum(0)
 		netHeader.SetChecksum(^netHeader.CalculateChecksum())
 		pkt.NatDone = true
-- 
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