link vxlan: Add IFLA_VXLAN_MC_ROUTE support and test

Added InfoVxlan::McRoute(bool) variant for IFLA_VXLAN_MC_ROUTE
attribute and a round-trip test for creating a vxlan with mcroute.

Signed-off-by: Gris Ge <cnfourt@gmail.com>

Author: cathay4t

src/link/link_info/vxlan.rs

@@ -40,6 +40,7 @@ const IFLA_VXLAN_VNIFILTER: u16 = 30;
 const IFLA_VXLAN_LOCALBYPASS: u16 = 31;
 const IFLA_VXLAN_LABEL_POLICY: u16 = 32;
 const IFLA_VXLAN_RESERVED_BITS: u16 = 33;
+const IFLA_VXLAN_MC_ROUTE: u16 = 34;
 
 #[derive(Debug, PartialEq, Eq, Clone)]
 #[non_exhaustive]
@@ -82,6 +83,7 @@ pub enum InfoVxlan {
     /// reject(drop and count as error) the VxLAN packet with that reserved
     /// bits set to 1.
     ReservedBits(u64),
+    McRoute(bool),
     Other(DefaultNla),
 }
 
@@ -104,7 +106,8 @@ impl Nla for InfoVxlan {
             | Self::TtlInherit(_)
             | Self::Df(_)
             | Self::Vnifilter(_)
-            | Self::Localbypass(_) => 1,
+            | Self::Localbypass(_)
+            | Self::McRoute(_) => 1,
             Self::Gbp(_) | Self::Gpe(_) | Self::RemCsumNoPartial(_) => 0,
             Self::Port(_) => 2,
             Self::Id(_)
@@ -149,7 +152,8 @@ impl Nla for InfoVxlan {
             | Self::UDPZeroCsumRX(value)
             | Self::RemCsumTX(value)
             | Self::RemCsumRX(value)
-            | Self::TtlInherit(value) => buffer[0] = *value as u8,
+            | Self::TtlInherit(value)
+            | Self::McRoute(value) => buffer[0] = *value as u8,
             Self::Group(value) | Self::Local(value) => {
                 buffer.copy_from_slice(&value.octets())
             }
@@ -201,6 +205,7 @@ impl Nla for InfoVxlan {
             Self::Localbypass(_) => IFLA_VXLAN_LOCALBYPASS,
             Self::LabelPolicy(_) => IFLA_VXLAN_LABEL_POLICY,
             Self::ReservedBits(_) => IFLA_VXLAN_RESERVED_BITS,
+            Self::McRoute(_) => IFLA_VXLAN_MC_ROUTE,
             Self::Other(nla) => nla.kind(),
         }
     }
@@ -372,6 +377,11 @@ impl<'a, T: AsRef<[u8]> + ?Sized> Parseable<NlaBuffer<&'a T>> for InfoVxlan {
                 parse_u64_be(payload)
                     .context("invalid IFLA_VXLAN_RESERVED_BITS value")?,
             ),
+            IFLA_VXLAN_MC_ROUTE => Self::McRoute(
+                parse_u8(payload)
+                    .context("invalid IFLA_VXLAN_MC_ROUTE value")?
+                    > 0,
+            ),
             unknown_kind => {
                 Self::Other(DefaultNla::parse(buf).context(format!(
                     "Failed to parse IFLA_INFO_DATA(vxlan) NLA type: \

src/link/tests/vxlan.rs

@@ -446,3 +446,56 @@ fn test_parsing_link_vxlan_ipv6() {
 
     assert_eq!(buf, raw);
 }
+
+// nlmon capture of netlink packet(netlink header removed) generated by command:
+//      sudo ip link add vxlan0 type \
+//          vxlan id 100 remote 192.0.2.1 dstport 10240 \
+//          ttl 16 mcroute
+#[test]
+fn test_create_vxlan_with_mcroute() {
+    let raw = vec![
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x0b, 0x00, 0x03, 0x00, 0x76, 0x78, 0x6c, 0x61,
+        0x6e, 0x30, 0x00, 0x00, 0x44, 0x00, 0x12, 0x00, 0x0a, 0x00, 0x01, 0x00,
+        0x76, 0x78, 0x6c, 0x61, 0x6e, 0x00, 0x00, 0x00, 0x34, 0x00, 0x02, 0x00,
+        0x05, 0x00, 0x05, 0x00, 0x10, 0x00, 0x00, 0x00, 0x05, 0x00, 0x22, 0x00,
+        0x01, 0x00, 0x00, 0x00, 0x08, 0x00, 0x01, 0x00, 0x64, 0x00, 0x00, 0x00,
+        0x08, 0x00, 0x02, 0x00, 0xc0, 0x00, 0x02, 0x01, 0x05, 0x00, 0x07, 0x00,
+        0x01, 0x00, 0x00, 0x00, 0x06, 0x00, 0x0f, 0x00, 0x28, 0x00, 0x00, 0x00,
+    ];
+
+    let expected = LinkMessage {
+        header: LinkHeader {
+            interface_family: AddressFamily::Unspec,
+            index: 0,
+            link_layer_type: LinkLayerType::Netrom,
+            flags: LinkFlags::empty(),
+            change_mask: LinkFlags::empty(),
+        },
+        attributes: vec![
+            LinkAttribute::IfName("vxlan0".into()),
+            LinkAttribute::LinkInfo(vec![
+                LinkInfo::Kind(InfoKind::Vxlan),
+                LinkInfo::Data(InfoData::Vxlan(vec![
+                    InfoVxlan::Ttl(16),
+                    InfoVxlan::McRoute(true),
+                    InfoVxlan::Id(100),
+                    InfoVxlan::Group(Ipv4Addr::from_str("192.0.2.1").unwrap()),
+                    InfoVxlan::Learning(true),
+                    InfoVxlan::Port(10240),
+                ])),
+            ]),
+        ],
+    };
+
+    assert_eq!(
+        expected,
+        LinkMessage::parse(&LinkMessageBuffer::new(&raw)).unwrap()
+    );
+
+    let mut buf = vec![0; expected.buffer_len()];
+
+    expected.emit(&mut buf);
+
+    assert_eq!(buf, raw);
+}