ip: add IPv6 multic. addr. to has_multicast_group

has_multicast_group was only used for IPv4 with IGMP. However, this is
also needed for IPv6, where we check the ALL_NODES, ALL_RPL_NODES and
the solicited multicast addresses.

In case of IPv4, when the `proto-igmp` feature is not enabled, this
function will return false.

src/iface/interface/igmp.rs

@@ -208,21 +208,6 @@ impl Interface {
 }
 
 impl InterfaceInner {
-    /// Check whether the interface listens to given destination multicast IP address.
-    ///
-    /// If built without feature `proto-igmp` this function will
-    /// always return `false`.
-    pub fn has_multicast_group<T: Into<IpAddress>>(&self, addr: T) -> bool {
-        match addr.into() {
-            IpAddress::Ipv4(key) => {
-                key == Ipv4Address::MULTICAST_ALL_SYSTEMS
-                    || self.ipv4_multicast_groups.get(&key).is_some()
-            }
-            #[allow(unreachable_patterns)]
-            _ => false,
-        }
-    }
-
     /// Host duties of the **IGMPv2** protocol.
     ///
     /// Sets up `igmp_report_state` for responding to IGMP general/specific membership queries.

src/iface/interface/mod.rs

@@ -1007,9 +1007,30 @@ impl InterfaceInner {
         })
     }
 
-    #[cfg(not(feature = "proto-igmp"))]
+    /// Check whether the interface listens to given destination multicast IP address.
+    ///
+    /// If built without feature `proto-igmp` this function will
+    /// always return `false` when using IPv4.
     fn has_multicast_group<T: Into<IpAddress>>(&self, addr: T) -> bool {
-        false
+        match addr.into() {
+            #[cfg(feature = "proto-igmp")]
+            IpAddress::Ipv4(key) => {
+                key == Ipv4Address::MULTICAST_ALL_SYSTEMS
+                    || self.ipv4_multicast_groups.get(&key).is_some()
+            }
+            #[cfg(feature = "proto-ipv6")]
+            IpAddress::Ipv6(Ipv6Address::LINK_LOCAL_ALL_NODES) => true,
+            #[cfg(feature = "proto-rpl")]
+            IpAddress::Ipv6(Ipv6Address::LINK_LOCAL_ALL_RPL_NODES) => true,
+            #[cfg(feature = "proto-ipv6")]
+            IpAddress::Ipv6(addr) => self.ip_addrs.iter().any(|a| match a.address() {
+                IpAddress::Ipv6(a) => a.solicited_node() == addr,
+                #[allow(unreachable_patterns)]
+                _ => false,
+            }),
+            #[allow(unreachable_patterns)]
+            _ => false,
+        }
     }
 
     #[cfg(feature = "medium-ip")]

src/iface/interface/tests/sixlowpan.rs

@@ -59,6 +59,13 @@ fn icmp_echo_request(#[case] medium: Medium) {
     ));
 
     let (mut iface, mut sockets, _device) = setup(medium);
+    iface.update_ip_addrs(|ips| {
+        ips.push(IpCidr::Ipv6(Ipv6Cidr::new(
+            Ipv6Address::from_parts(&[0xfe80, 0, 0, 0, 0x180b, 0x4242, 0x4242, 0x4242]),
+            10,
+        )))
+        .unwrap();
+    });
 
     assert_eq!(
         iface.inner.process_ieee802154(
@@ -77,6 +84,13 @@ fn test_echo_request_sixlowpan_128_bytes() {
     use crate::phy::Checksum;
 
     let (mut iface, mut sockets, mut device) = setup(Medium::Ieee802154);
+    iface.update_ip_addrs(|ips| {
+        ips.push(IpCidr::Ipv6(Ipv6Cidr::new(
+            Ipv6Address::new(0xfe80, 0x0, 0x0, 0x0, 0x92fc, 0x48c2, 0xa441, 0xfc76),
+            10,
+        )))
+        .unwrap();
+    });
     // TODO: modify the example, such that we can also test if the checksum is correctly
     // computed.
     iface.inner.caps.checksum.icmpv6 = Checksum::None;
@@ -283,6 +297,13 @@ fn test_sixlowpan_udp_with_fragmentation() {
     };
 
     let (mut iface, mut sockets, mut device) = setup(Medium::Ieee802154);
+    iface.update_ip_addrs(|ips| {
+        ips.push(IpCidr::Ipv6(Ipv6Cidr::new(
+            Ipv6Address::new(0xfe80, 0x0, 0x0, 0x0, 0x92fc, 0x48c2, 0xa441, 0xfc76),
+            10,
+        )))
+        .unwrap();
+    });
     iface.inner.caps.checksum.udp = Checksum::None;
 
     let udp_rx_buffer = udp::PacketBuffer::new(vec![udp::PacketMetadata::EMPTY], vec![0; 1024 * 4]);