isis: implement the LSPBufferSize TLV

This TLV is primarily used for troubleshooting purposes. A warning should be emitted when receiving this TLV with a value different from the locally configured ("lsp-mtu"), which will be addressed in a separate commit along with other changes. Signed-off-by: Renato Westphal <[email protected]>
holo-routing · Jan 3, 2025 · 4a01363 · 4a01363
1 parent 0d88e2f
commit 4a01363
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Showing 7 changed files with 87 additions and 14 deletions.
diff --git a/holo-isis/src/lsdb.rs b/holo-isis/src/lsdb.rs
@@ -308,6 +308,7 @@ fn lsp_build_tlvs(
     LspTlvs::new(
         protocols_supported,
         instance.config.area_addrs.clone(),
+        Some(instance.config.lsp_mtu),
         is_reach,
         ext_is_reach,
         ipv4_addrs,
@@ -360,7 +361,7 @@ fn lsp_build_tlvs_pseudo(
         }
     }
 
-    LspTlvs::new([], [], is_reach, ext_is_reach, [], [], [], [], [], [])
+    LspTlvs::new([], [], None, is_reach, ext_is_reach, [], [], [], [], [], [])
 }
 
 fn lsp_build_fragments(

diff --git a/holo-isis/src/northbound/state.rs b/holo-isis/src/northbound/state.rs
@@ -192,6 +192,7 @@ fn load_callbacks() -> Callbacks<Instance> {
                 ipv6_te_routerid: None,
                 protocol_supported: Some(Box::new(protocol_supported)),
                 dynamic_hostname: None,
+                lsp_buffer_size: lsp.tlvs.lsp_buf_size(),
             })
         })
         .path(isis::database::levels::lsp::attributes::PATH)

diff --git a/holo-isis/src/packet/consts.rs b/holo-isis/src/packet/consts.rs
@@ -48,6 +48,7 @@ pub enum TlvType {
     Neighbors = 6,
     Padding = 8,
     LspEntries = 9,
+    LspBufferSize = 14,
     ExtIsReach = 22,
     Ipv4InternalReach = 128,
     ProtocolsSupported = 129,

diff --git a/holo-isis/src/packet/pdu.rs b/holo-isis/src/packet/pdu.rs
@@ -25,8 +25,8 @@ use crate::packet::tlv::{
     tlv_entries_split, tlv_take_max, AreaAddressesTlv, ExtIpv4Reach,
     ExtIpv4ReachTlv, ExtIsReach, ExtIsReachTlv, Ipv4AddressesTlv, Ipv4Reach,
     Ipv4ReachTlv, Ipv6AddressesTlv, Ipv6Reach, Ipv6ReachTlv, IsReach,
-    IsReachTlv, LspEntriesTlv, LspEntry, NeighborsTlv, PaddingTlv,
-    ProtocolsSupportedTlv, Tlv, UnknownTlv, TLV_HDR_SIZE,
+    IsReachTlv, LspBufferSizeTlv, LspEntriesTlv, LspEntry, NeighborsTlv,
+    PaddingTlv, ProtocolsSupportedTlv, Tlv, UnknownTlv, TLV_HDR_SIZE,
 };
 use crate::packet::{AreaAddr, LanId, LevelNumber, LevelType, LspId, SystemId};
 
@@ -102,6 +102,7 @@ pub struct Lsp {
 pub struct LspTlvs {
     pub protocols_supported: Option<ProtocolsSupportedTlv>,
     pub area_addrs: Vec<AreaAddressesTlv>,
+    pub lsp_buf_size: Option<LspBufferSizeTlv>,
     pub is_reach: Vec<IsReachTlv>,
     pub ext_is_reach: Vec<ExtIsReachTlv>,
     pub ipv4_addrs: Vec<Ipv4AddressesTlv>,
@@ -600,6 +601,10 @@ impl Lsp {
                     let tlv = AreaAddressesTlv::decode(tlv_len, &mut buf_tlv)?;
                     tlvs.area_addrs.push(tlv);
                 }
+                Some(TlvType::LspBufferSize) => {
+                    let tlv = LspBufferSizeTlv::decode(tlv_len, &mut buf_tlv)?;
+                    tlvs.lsp_buf_size = Some(tlv);
+                }
                 Some(TlvType::IsReach) => {
                     let tlv = IsReachTlv::decode(tlv_len, &mut buf_tlv)?;
                     tlvs.is_reach.push(tlv);
@@ -683,6 +688,9 @@ impl Lsp {
             for tlv in &self.tlvs.area_addrs {
                 tlv.encode(&mut buf);
             }
+            if let Some(tlv) = &self.tlvs.lsp_buf_size {
+                tlv.encode(&mut buf);
+            }
             for tlv in &self.tlvs.is_reach {
                 tlv.encode(&mut buf);
             }
@@ -807,6 +815,7 @@ impl LspTlvs {
     pub(crate) fn new(
         protocols_supported: impl IntoIterator<Item = u8>,
         area_addrs: impl IntoIterator<Item = AreaAddr>,
+        lsp_buf_size: Option<u16>,
         is_reach: impl IntoIterator<Item = IsReach>,
         ext_is_reach: impl IntoIterator<Item = ExtIsReach>,
         ipv4_addrs: impl IntoIterator<Item = Ipv4Addr>,
@@ -821,6 +830,7 @@ impl LspTlvs {
                 protocols_supported,
             )),
             area_addrs: tlv_entries_split(area_addrs),
+            lsp_buf_size: lsp_buf_size.map(|size| LspBufferSizeTlv { size }),
             is_reach: tlv_entries_split(is_reach),
             ext_is_reach: tlv_entries_split(ext_is_reach),
             ipv4_addrs: tlv_entries_split(ipv4_addrs),
@@ -840,6 +850,10 @@ impl LspTlvs {
             rem_len -= protocols_supported.len();
         }
         let area_addrs = tlv_take_max(&mut self.area_addrs, &mut rem_len);
+        let lsp_buf_size = self.lsp_buf_size.take();
+        if let Some(lsp_buf_size) = &lsp_buf_size {
+            rem_len -= lsp_buf_size.len();
+        }
         let is_reach = tlv_take_max(&mut self.is_reach, &mut rem_len);
         let ext_is_reach = tlv_take_max(&mut self.ext_is_reach, &mut rem_len);
         let ipv4_addrs = tlv_take_max(&mut self.ipv4_addrs, &mut rem_len);
@@ -858,6 +872,7 @@ impl LspTlvs {
         Some(LspTlvs {
             protocols_supported,
             area_addrs,
+            lsp_buf_size,
             is_reach,
             ext_is_reach,
             ipv4_addrs,
@@ -884,6 +899,11 @@ impl LspTlvs {
         self.area_addrs.iter().flat_map(|tlv| tlv.list.iter())
     }
 
+    // Returns the maximum sized LSP which may be generated (TLV type 14).
+    pub(crate) fn lsp_buf_size(&self) -> Option<u16> {
+        self.lsp_buf_size.as_ref().map(|tlv| tlv.size)
+    }
+
     // Returns an iterator over all IS neighbors from TLVs of type 2.
     pub(crate) fn is_reach(&self) -> impl Iterator<Item = &IsReach> {
         self.is_reach.iter().flat_map(|tlv| tlv.list.iter())

diff --git a/holo-isis/src/packet/tlv.rs b/holo-isis/src/packet/tlv.rs
@@ -79,6 +79,12 @@ pub struct PaddingTlv {
     pub length: u8,
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Deserialize, Serialize)]
+pub struct LspBufferSizeTlv {
+    pub size: u16,
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 #[derive(Deserialize, Serialize)]
 pub struct ProtocolsSupportedTlv {
@@ -359,6 +365,35 @@ impl PaddingTlv {
     }
 }
 
+// ===== impl LspBufferSizeTlv =====
+
+impl LspBufferSizeTlv {
+    const SIZE: usize = 2;
+
+    pub(crate) fn decode(tlv_len: u8, buf: &mut Bytes) -> DecodeResult<Self> {
+        // Validate the TLV length.
+        if tlv_len as usize != Self::SIZE {
+            return Err(DecodeError::InvalidTlvLength(tlv_len));
+        }
+
+        let size = buf.get_u16();
+
+        Ok(LspBufferSizeTlv { size })
+    }
+
+    pub(crate) fn encode(&self, buf: &mut BytesMut) {
+        let start_pos = tlv_encode_start(buf, TlvType::LspBufferSize);
+        buf.put_u16(self.size);
+        tlv_encode_end(buf, start_pos);
+    }
+}
+
+impl Tlv for LspBufferSizeTlv {
+    fn len(&self) -> usize {
+        TLV_HDR_SIZE + Self::SIZE
+    }
+}
+
 // ===== impl ProtocolsSupportedTlv =====
 
 impl ProtocolsSupportedTlv {

diff --git a/holo-isis/tests/packet/mod.rs b/holo-isis/tests/packet/mod.rs
@@ -19,8 +19,8 @@ use holo_isis::packet::pdu::{
 use holo_isis::packet::tlv::{
     AreaAddressesTlv, ExtIpv4Reach, ExtIpv4ReachTlv, ExtIsReach, ExtIsReachTlv,
     Ipv4AddressesTlv, Ipv4Reach, Ipv4ReachTlv, Ipv6AddressesTlv, Ipv6Reach,
-    Ipv6ReachTlv, IsReach, IsReachTlv, LspEntriesTlv, LspEntry, NeighborsTlv,
-    PaddingTlv, ProtocolsSupportedTlv,
+    Ipv6ReachTlv, IsReach, IsReachTlv, LspBufferSizeTlv, LspEntriesTlv,
+    LspEntry, NeighborsTlv, PaddingTlv, ProtocolsSupportedTlv,
 };
 use holo_isis::packet::{
     AreaAddr, LanId, LevelNumber, LevelType, LspId, SystemId,
@@ -547,6 +547,7 @@ static LSP1: Lazy<(Vec<u8>, Pdu)> = Lazy::new(|| {
                 area_addrs: vec![AreaAddressesTlv {
                     list: vec![AreaAddr::from([0x49, 0, 0].as_slice())],
                 }],
+                lsp_buf_size: None,
                 is_reach: vec![],
                 ext_is_reach: vec![ExtIsReachTlv {
                     list: vec![ExtIsReach {
@@ -614,16 +615,16 @@ static LSP1: Lazy<(Vec<u8>, Pdu)> = Lazy::new(|| {
 static LSP2: Lazy<(Vec<u8>, Pdu)> = Lazy::new(|| {
     (
         vec![
-            0x83, 0x1b, 0x01, 0x00, 0x12, 0x01, 0x00, 0x00, 0x00, 0x69, 0x04,
+            0x83, 0x1b, 0x01, 0x00, 0x12, 0x01, 0x00, 0x00, 0x00, 0x6d, 0x04,
             0xa3, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00,
-            0x00, 0x13, 0x06, 0xe2, 0x01, 0x81, 0x01, 0xcc, 0x01, 0x04, 0x03,
-            0x49, 0x00, 0x00, 0x02, 0x17, 0x00, 0x0a, 0x80, 0x80, 0x80, 0x00,
-            0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x0a, 0x80, 0x80, 0x80, 0x00,
-            0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x84, 0x04, 0x06, 0x06, 0x06,
-            0x06, 0x80, 0x24, 0x0a, 0x80, 0x80, 0x80, 0x0a, 0x00, 0x07, 0x00,
-            0xff, 0xff, 0xff, 0x00, 0x0a, 0x80, 0x80, 0x80, 0x0a, 0x00, 0x08,
-            0x00, 0xff, 0xff, 0xff, 0x00, 0x0a, 0x80, 0x80, 0x80, 0x06, 0x06,
-            0x06, 0x06, 0xff, 0xff, 0xff, 0xff,
+            0x00, 0x13, 0x0f, 0xef, 0x01, 0x81, 0x01, 0xcc, 0x01, 0x04, 0x03,
+            0x49, 0x00, 0x00, 0x0e, 0x02, 0x05, 0xd4, 0x02, 0x17, 0x00, 0x0a,
+            0x80, 0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x0a,
+            0x80, 0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x84,
+            0x04, 0x06, 0x06, 0x06, 0x06, 0x80, 0x24, 0x0a, 0x80, 0x80, 0x80,
+            0x0a, 0x00, 0x07, 0x00, 0xff, 0xff, 0xff, 0x00, 0x0a, 0x80, 0x80,
+            0x80, 0x0a, 0x00, 0x08, 0x00, 0xff, 0xff, 0xff, 0x00, 0x0a, 0x80,
+            0x80, 0x80, 0x06, 0x06, 0x06, 0x06, 0xff, 0xff, 0xff, 0xff,
         ],
         Pdu::Lsp(Lsp::new(
             LevelNumber::L1,
@@ -638,6 +639,7 @@ static LSP2: Lazy<(Vec<u8>, Pdu)> = Lazy::new(|| {
                 area_addrs: vec![AreaAddressesTlv {
                     list: vec![AreaAddr::from([0x49, 0, 0].as_slice())],
                 }],
+                lsp_buf_size: Some(LspBufferSizeTlv { size: 1492 }),
                 is_reach: vec![IsReachTlv {
                     list: vec![
                         IsReach {

diff --git a/holo-yang/modules/augmentations/holo-isis.yang b/holo-yang/modules/augmentations/holo-isis.yang
@@ -49,4 +49,17 @@ module holo-isis {
         "Interface circuit ID.";
     }
   }
+
+
+  augment "/rt:routing/rt:control-plane-protocols/"
+        + "rt:control-plane-protocol/isis:isis/isis:database/"
+        + "isis:levels/isis:lsp" {
+    leaf lsp-buffer-size {
+      type uint16;
+      units "bytes";
+      description
+        "The maximum sized LSP which may be generated.
+         The IS-IS reference is TLV 14.";
+    }
+  }
 }