Merge release-20210322.0-53-gd7fd00bad (automated)

3 files changed, 37 insertions, 52 deletions

diff --git a/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go b/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
index b9f129728..ac35d81e7 100644
--- a/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
+++ b/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
@@ -156,14 +156,6 @@ type GenericMulticastProtocolOptions struct {
 	//
 	// Unsolicited reports are transmitted when a group is newly joined.
 	MaxUnsolicitedReportDelay time.Duration
-
-	// AllNodesAddress is a multicast address that all nodes on a network should
-	// be a member of.
-	//
-	// This address will not have the generic multicast protocol performed on it;
-	// it will be left in the non member/listener state, and packets will never
-	// be sent for it.
-	AllNodesAddress tcpip.Address
 }
 
 // MulticastGroupProtocol is a multicast group protocol whose core state machine
@@ -188,6 +180,10 @@ type MulticastGroupProtocol interface {
 
 	// SendLeave sends a multicast leave for the specified group address.
 	SendLeave(groupAddress tcpip.Address) tcpip.Error
+
+	// ShouldPerformProtocol returns true iff the protocol should be performed for
+	// the specified group.
+	ShouldPerformProtocol(tcpip.Address) bool
 }
 
 // GenericMulticastProtocolState is the per interface generic multicast protocol
@@ -455,20 +451,7 @@ func (g *GenericMulticastProtocolState) initializeNewMemberLocked(groupAddress t
 
 	info.lastToSendReport = false
 
-	if groupAddress == g.opts.AllNodesAddress {
-		// As per RFC 2236 section 6 page 10 (for IGMPv2),
-		//
-		//   The all-systems group (address 224.0.0.1) is handled as a special
-		//   case. The host starts in Idle Member state for that group on every
-		//   interface, never transitions to another state, and never sends a
-		//   report for that group.
-		//
-		// As per RFC 2710 section 5 page 10 (for MLDv1),
-		//
-		//   The link-scope all-nodes address (FF02::1) is handled as a special
-		//   case. The node starts in Idle Listener state for that address on
-		//   every interface, never transitions to another state, and never sends
-		//   a Report or Done for that address.
+	if !g.opts.Protocol.ShouldPerformProtocol(groupAddress) {
 		info.state = idleMember
 		return
 	}
@@ -537,20 +520,7 @@ func (g *GenericMulticastProtocolState) maybeSendLeave(groupAddress tcpip.Addres
 		return
 	}
 
-	if groupAddress == g.opts.AllNodesAddress {
-		// As per RFC 2236 section 6 page 10 (for IGMPv2),
-		//
-		//   The all-systems group (address 224.0.0.1) is handled as a special
-		//   case. The host starts in Idle Member state for that group on every
-		//   interface, never transitions to another state, and never sends a
-		//   report for that group.
-		//
-		// As per RFC 2710 section 5 page 10 (for MLDv1),
-		//
-		//   The link-scope all-nodes address (FF02::1) is handled as a special
-		//   case. The node starts in Idle Listener state for that address on
-		//   every interface, never transitions to another state, and never sends
-		//   a Report or Done for that address.
+	if !g.opts.Protocol.ShouldPerformProtocol(groupAddress) {
 		return
 	}
 
@@ -627,20 +597,7 @@ func (g *GenericMulticastProtocolState) setDelayTimerForAddressRLocked(groupAddr
 		return
 	}
 
-	if groupAddress == g.opts.AllNodesAddress {
-		// As per RFC 2236 section 6 page 10 (for IGMPv2),
-		//
-		//   The all-systems group (address 224.0.0.1) is handled as a special
-		//   case. The host starts in Idle Member state for that group on every
-		//   interface, never transitions to another state, and never sends a
-		//   report for that group.
-		//
-		// As per RFC 2710 section 5 page 10 (for MLDv1),
-		//
-		//   The link-scope all-nodes address (FF02::1) is handled as a special
-		//   case. The node starts in Idle Listener state for that address on
-		//   every interface, never transitions to another state, and never sends
-		//   a Report or Done for that address.
+	if !g.opts.Protocol.ShouldPerformProtocol(groupAddress) {
 		return
 	}
 
diff --git a/pkg/tcpip/network/ipv4/igmp.go b/pkg/tcpip/network/ipv4/igmp.go
index f3fc1c87e..b1ac29294 100644
--- a/pkg/tcpip/network/ipv4/igmp.go
+++ b/pkg/tcpip/network/ipv4/igmp.go
@@ -126,6 +126,17 @@ func (igmp *igmpState) SendLeave(groupAddress tcpip.Address) tcpip.Error {
 	return err
 }
 
+// ShouldPerformProtocol implements ip.MulticastGroupProtocol.
+func (igmp *igmpState) ShouldPerformProtocol(groupAddress tcpip.Address) bool {
+	// As per RFC 2236 section 6 page 10,
+	//
+	//   The all-systems group (address 224.0.0.1) is handled as a special
+	//   case. The host starts in Idle Member state for that group on every
+	//   interface, never transitions to another state, and never sends a
+	//   report for that group.
+	return groupAddress != header.IPv4AllSystems
+}
+
 // init sets up an igmpState struct, and is required to be called before using
 // a new igmpState.
 //
@@ -137,7 +148,6 @@ func (igmp *igmpState) init(ep *endpoint) {
 		Clock:                     ep.protocol.stack.Clock(),
 		Protocol:                  igmp,
 		MaxUnsolicitedReportDelay: UnsolicitedReportIntervalMax,
-		AllNodesAddress:           header.IPv4AllSystems,
 	})
 	igmp.igmpV1Present = igmpV1PresentDefault
 	igmp.igmpV1Job = ep.protocol.stack.NewJob(&ep.mu, func() {
diff --git a/pkg/tcpip/network/ipv6/mld.go b/pkg/tcpip/network/ipv6/mld.go
index dd153466d..538590baf 100644
--- a/pkg/tcpip/network/ipv6/mld.go
+++ b/pkg/tcpip/network/ipv6/mld.go
@@ -80,6 +80,25 @@ func (mld *mldState) SendLeave(groupAddress tcpip.Address) tcpip.Error {
 	return err
 }
 
+// ShouldPerformProtocol implements ip.MulticastGroupProtocol.
+func (mld *mldState) ShouldPerformProtocol(groupAddress tcpip.Address) bool {
+	// As per RFC 2710 section 5 page 10,
+	//
+	//   The link-scope all-nodes address (FF02::1) is handled as a special
+	//   case. The node starts in Idle Listener state for that address on
+	//   every interface, never transitions to another state, and never sends
+	//   a Report or Done for that address.
+	//
+	//   MLD messages are never sent for multicast addresses whose scope is 0
+	//   (reserved) or 1 (node-local).
+	if groupAddress == header.IPv6AllNodesMulticastAddress {
+		return false
+	}
+
+	scope := header.V6MulticastScope(groupAddress)
+	return scope != header.IPv6Reserved0MulticastScope && scope != header.IPv6InterfaceLocalMulticastScope
+}
+
 // init sets up an mldState struct, and is required to be called before using
 // a new mldState.
 //
@@ -91,7 +110,6 @@ func (mld *mldState) init(ep *endpoint) {
 		Clock:                     ep.protocol.stack.Clock(),
 		Protocol:                  mld,
 		MaxUnsolicitedReportDelay: UnsolicitedReportIntervalMax,
-		AllNodesAddress:           header.IPv6AllNodesMulticastAddress,
 	})
 }