Add multicast support

PiperOrigin-RevId: 212750821
Change-Id: I822fd63e48c684b45fd91f9ce057867b7eceb792

1 files changed, 22 insertions, 0 deletions

diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index 4065fc30f..51360b11f 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -453,6 +453,28 @@ type KeepaliveIntervalOption time.Duration
 // closed.
 type KeepaliveCountOption int
 
+// MulticastTTLOption is used by SetSockOpt/GetSockOpt to control the default
+// TTL value for multicast messages. The default is 1.
+type MulticastTTLOption uint8
+
+// MembershipOption is used by SetSockOpt/GetSockOpt as an argument to
+// AddMembershipOption and RemoveMembershipOption.
+type MembershipOption struct {
+	NIC           NICID
+	InterfaceAddr Address
+	MulticastAddr Address
+}
+
+// AddMembershipOption is used by SetSockOpt/GetSockOpt to join a multicast
+// group identified by the given multicast address, on the interface matching
+// the given interface address.
+type AddMembershipOption MembershipOption
+
+// RemoveMembershipOption is used by SetSockOpt/GetSockOpt to leave a multicast
+// group identified by the given multicast address, on the interface matching
+// the given interface address.
+type RemoveMembershipOption MembershipOption
+
 // Route is a row in the routing table. It specifies through which NIC (and
 // gateway) sets of packets should be routed. A row is considered viable if the
 // masked target address matches the destination adddress in the row.