NOC: Support the read of 'Fabrics' attribute

matter/src/data_model/sdm/noc.rs

@@ -124,6 +124,7 @@ impl NocCluster {
             base: Cluster::new(ID)?,
         });
         c.base.add_attribute(attr_currfabindex_new()?)?;
+        c.base.add_attribute(attr_fabrics_new()?)?;
         Ok(c)
     }
 
@@ -364,6 +365,15 @@ fn attr_currfabindex_new() -> Result<Attribute, Error> {
     )
 }
 
+fn attr_fabrics_new() -> Result<Attribute, Error> {
+    Attribute::new(
+        Attributes::Fabrics as u16,
+        AttrValue::Custom,
+        Access::RV | Access::FAB_SCOPED,
+        Quality::NONE,
+    )
+}
+
 impl ClusterType for NocCluster {
     fn base(&self) -> &Cluster {
         &self.base
@@ -395,6 +405,17 @@ impl ClusterType for NocCluster {
             Some(Attributes::CurrentFabricIndex) => {
                 encoder.encode(EncodeValue::Value(&attr.fab_idx))
             }
+            Some(Attributes::Fabrics) => encoder.encode(EncodeValue::Closure(&|tag, tw| {
+                let _ = tw.start_array(tag);
+                let _ = self.fabric_mgr.for_each(|entry, fab_idx| {
+                    if !attr.fab_filter || attr.fab_idx == fab_idx {
+                        let _ = entry
+                            .get_fabric_desc(fab_idx)
+                            .to_tlv(tw, TagType::Anonymous);
+                    }
+                });
+                let _ = tw.end_container();
+            })),
             _ => {
                 error!("Attribute not supported: this shouldn't happen");
             }

matter/src/fabric.rs

@@ -28,6 +28,7 @@ use crate::{
     group_keys::KeySet,
     mdns::{self, Mdns},
     sys::{Psm, SysMdnsService},
+    tlv::{OctetStr, TLVWriter, TagType, ToTLV, UtfStr},
 };
 
 const MAX_CERT_TLV_LEN: usize = 300;
@@ -61,6 +62,19 @@ pub struct Fabric {
     mdns_service: Option<SysMdnsService>,
 }
 
+#[derive(ToTLV)]
+#[tlvargs(lifetime = "'a", start = 1)]
+pub struct FabricDescriptor<'a> {
+    root_public_key: OctetStr<'a>,
+    vendor_id: u16,
+    fabric_id: u64,
+    node_id: u64,
+    label: UtfStr<'a>,
+    // TODO: Instead of the direct value, we should consider GlobalElements::FabricIndex
+    #[tagval(0xFE)]
+    pub fab_idx: Option<u8>,
+}
+
 impl Fabric {
     pub fn new(
         key_pair: KeyPair,
@@ -166,6 +180,17 @@ impl Fabric {
         self.fabric_id
     }
 
+    pub fn get_fabric_desc(&self, fab_idx: u8) -> FabricDescriptor {
+        FabricDescriptor {
+            root_public_key: OctetStr::new(self.root_ca.get_pubkey()),
+            vendor_id: self.vendor_id,
+            fabric_id: self.fabric_id,
+            node_id: self.node_id,
+            label: UtfStr::new(b""),
+            fab_idx: Some(fab_idx),
+        }
+    }
+
     fn store(&self, index: usize, psm: &MutexGuard<Psm>) -> Result<(), Error> {
         let mut key = [0u8; MAX_CERT_TLV_LEN];
         let len = self.root_ca.as_tlv(&mut key)?;
@@ -312,4 +337,18 @@ impl FabricMgr {
         }
         true
     }
+
+    // Parameters to T are the Fabric and its Fabric Index
+    pub fn for_each<T>(&self, mut f: T) -> Result<(), Error>
+    where
+        T: FnMut(&Fabric, u8),
+    {
+        let mgr = self.inner.read().unwrap();
+        for i in 1..MAX_SUPPORTED_FABRICS {
+            if let Some(fabric) = &mgr.fabrics[i] {
+                f(fabric, i as u8)
+            }
+        }
+        Ok(())
+    }
 }