isis: implement the "lsp-too-large" YANG notification

Signed-off-by: Renato Westphal <[email protected]>
holo-routing · Jan 3, 2025 · 0d88e2f · 0d88e2f
1 parent fdc02dd
commit 0d88e2f
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Showing 5 changed files with 36 additions and 13 deletions.
diff --git a/holo-isis/src/debug.rs b/holo-isis/src/debug.rs
@@ -43,6 +43,7 @@ pub enum Debug<'a> {
     PduTx(u32, MulticastAddr, &'a Pdu),
     // Flooding
     LspDiscard(LevelNumber, &'a Lsp),
+    LspTooLarge(&'a Interface, LevelNumber, &'a Lsp),
     // LSDB maintenance
     LspInstall(LevelNumber, &'a Lsp),
     LspOriginate(LevelNumber, &'a Lsp),
@@ -164,6 +165,10 @@ impl Debug<'_> {
                 // Parent span(s): isis-instance
                 debug!(?level, lsp_id = %lsp.lsp_id.to_yang(), seqno = %lsp.seqno, len = %lsp.raw.len(), "{}", self);
             }
+            Debug::LspTooLarge(iface, level, lsp) => {
+                // Parent span(s): isis-instance
+                debug!(interface = %iface.name, ?level, lsp_id = %lsp.lsp_id.to_yang(), len = %lsp.raw.len(), "{}", self);
+            }
             Debug::LspPurge(level, lsp, reason) => {
                 // Parent span(s): isis-instance
                 debug!(?level, lsp_id = %lsp.lsp_id.to_yang(), seqno = %lsp.seqno, len = %lsp.raw.len(), ?reason, "{}", self);
@@ -237,6 +242,9 @@ impl std::fmt::Display for Debug<'_> {
             Debug::LspDiscard(..) => {
                 write!(f, "discarding LSP")
             }
+            Debug::LspTooLarge(..) => {
+                write!(f, "LSP larger than interface MTU")
+            }
             Debug::LspInstall(..) => {
                 write!(f, "installing LSP")
             }

diff --git a/holo-isis/src/events.rs b/holo-isis/src/events.rs
@@ -543,7 +543,7 @@ pub(crate) fn process_pdu_lsp(
             // from the network.
             lsp.set_rem_lifetime(0);
             for iface in arenas.interfaces.iter_mut() {
-                iface.srm_list_add(level, lsp.clone());
+                iface.srm_list_add(instance, level, lsp.clone());
             }
             return Ok(());
         }
@@ -591,7 +591,7 @@ pub(crate) fn process_pdu_lsp(
                 .iter_mut()
                 .filter(|other_iface| other_iface.id != iface_id)
             {
-                other_iface.srm_list_add(level, lsp.clone());
+                other_iface.srm_list_add(instance, level, lsp.clone());
                 other_iface.ssn_list_del(level, &lsp.lsp_id);
             }
         }
@@ -632,7 +632,7 @@ pub(crate) fn process_pdu_lsp(
         Some(Ordering::Greater) => {
             // Update LSP flooding flags for the incoming interface.
             let lsp_id = lsp.lsp_id;
-            iface.srm_list_add(level, lsp);
+            iface.srm_list_add(instance, level, lsp);
             iface.ssn_list_del(level, &lsp_id);
         }
     }
@@ -753,7 +753,7 @@ pub(crate) fn process_pdu_snp(
                 }
                 Ordering::Greater => {
                     iface.ssn_list_del(level, &entry.lsp_id);
-                    iface.srm_list_add(level, lse.data.clone());
+                    iface.srm_list_add(instance, level, lse.data.clone());
                 }
                 Ordering::Less => {
                     iface.ssn_list_add(level, *entry);
@@ -789,7 +789,7 @@ pub(crate) fn process_pdu_snp(
         for lsp in instance
             .state
             .lsdb
-            .get_mut(level)
+            .get(level)
             .range(&arenas.lsp_entries, start..=end)
             .map(|lse| &lse.data)
             .filter(|lsp| !lsp_entries.contains_key(&lsp.lsp_id))
@@ -798,7 +798,7 @@ pub(crate) fn process_pdu_snp(
             // Exclude LSPs with zero sequence number.
             .filter(|lsp| lsp.seqno != 0)
         {
-            iface.srm_list_add(level, lsp.clone());
+            iface.srm_list_add(instance, level, lsp.clone());
         }
     }
 
@@ -1106,7 +1106,7 @@ pub(crate) fn process_lsp_purge(
 
     // Send purged LSP to all interfaces.
     for iface in arenas.interfaces.iter_mut() {
-        iface.srm_list_add(level, lsp.clone());
+        iface.srm_list_add(instance, level, lsp.clone());
     }
 
     // Mark the LSP as purged and start the delete timer.

diff --git a/holo-isis/src/interface.rs b/holo-isis/src/interface.rs
@@ -587,7 +587,12 @@ impl Interface {
         self.state.tasks.csnp_interval = Default::default();
     }
 
-    pub(crate) fn srm_list_add(&mut self, level: LevelNumber, mut lsp: Lsp) {
+    pub(crate) fn srm_list_add(
+        &mut self,
+        instance: &InstanceUpView<'_>,
+        level: LevelNumber,
+        mut lsp: Lsp,
+    ) {
         if !self.state.active {
             return;
         }
@@ -598,6 +603,13 @@ impl Interface {
             return;
         }
 
+        // Check if the LSP is too large to be sent on this interface.
+        if lsp.raw.len() as u32 > self.system.mtu.unwrap() {
+            Debug::LspTooLarge(self, level, &lsp).log();
+            notification::lsp_too_large(instance, self, &lsp);
+            return;
+        }
+
         // ISO 10589 - Section 7.3.16.3:
         // "A system shall decrement the Remaining Lifetime in the PDU being
         // transmitted by at least one".

diff --git a/holo-isis/src/lsdb.rs b/holo-isis/src/lsdb.rs
@@ -594,7 +594,7 @@ pub(crate) fn lsp_originate(
 
     // Flood LSP over all interfaces.
     for iface in arenas.interfaces.iter_mut() {
-        iface.srm_list_add(level, lse.data.clone());
+        iface.srm_list_add(instance, level, lse.data.clone());
     }
 
     // Schedule LSP refreshing.

diff --git a/holo-isis/src/northbound/notification.rs b/holo-isis/src/northbound/notification.rs
@@ -36,8 +36,11 @@ pub(crate) fn database_overload(instance: &InstanceUpView<'_>, overload: bool) {
     notification::send(&instance.tx.nb, path, data);
 }
 
-#[expect(unused)]
-pub(crate) fn lsp_too_large(instance: &InstanceUpView<'_>, iface: &Interface) {
+pub(crate) fn lsp_too_large(
+    instance: &InstanceUpView<'_>,
+    iface: &Interface,
+    lsp: &Lsp,
+) {
     use yang::lsp_too_large::{self, LspTooLarge};
 
     let path = lsp_too_large::PATH;
@@ -47,8 +50,8 @@ pub(crate) fn lsp_too_large(instance: &InstanceUpView<'_>, iface: &Interface) {
         interface_name: Some(Cow::Borrowed(&iface.name)),
         interface_level: Some(iface.config.level_type.resolved.to_yang()),
         extended_circuit_id: None,
-        pdu_size: None,
-        lsp_id: None,
+        pdu_size: Some(lsp.raw.len() as u32),
+        lsp_id: Some(lsp.lsp_id.to_yang()),
     };
     notification::send(&instance.tx.nb, path, data);
 }