bgp: implement the "clear" action for neighbors

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

holo-bgp/src/events.rs

@@ -397,10 +397,10 @@ fn process_nbr_route_refresh(
 
     match (afi, safi) {
         (Afi::Ipv4, Safi::Unicast) => {
-            process_nbr_route_refresh_af::<Ipv4Unicast>(instance, nbr)
+            nbr.resend_adj_rib_out::<Ipv4Unicast>(instance);
         }
         (Afi::Ipv6, Safi::Unicast) => {
-            process_nbr_route_refresh_af::<Ipv6Unicast>(instance, nbr)
+            nbr.resend_adj_rib_out::<Ipv6Unicast>(instance);
         }
         _ => {
             // Ignore unsupported AFI/SAFI combination.
@@ -417,36 +417,6 @@ fn process_nbr_route_refresh(
     Ok(())
 }
 
-fn process_nbr_route_refresh_af<A>(
-    instance: &mut InstanceUpView<'_>,
-    nbr: &mut Neighbor,
-) where
-    A: AddressFamily,
-{
-    let table = A::table(&mut instance.state.rib.tables);
-    for (prefix, dest) in &table.prefixes {
-        let Some(adj_rib) = dest.adj_rib.get(&nbr.remote_addr) else {
-            continue;
-        };
-        let Some(route) = adj_rib.out_post() else {
-            continue;
-        };
-
-        // Update route's attributes before transmission.
-        let mut attrs = route.attrs.get();
-        attrs_tx_update::<A>(
-            nbr,
-            instance.config.asn,
-            route.origin.is_local(),
-            &mut attrs,
-        );
-
-        // Update neighbor's Tx queue.
-        let update_queue = A::update_queue(&mut nbr.update_queues);
-        update_queue.reach.entry(attrs).or_default().insert(*prefix);
-    }
-}
-
 // ===== neighbor expired timeout =====
 
 pub(crate) fn process_nbr_timer(
@@ -592,11 +562,11 @@ where
 
                     // Update route's attributes before transmission.
                     let mut attrs = rpinfo.attrs;
-                    attrs_tx_update::<A>(
+                    rib::attrs_tx_update::<A>(
+                        &mut attrs,
                         nbr,
                         instance.config.asn,
                         rpinfo.origin.is_local(),
-                        &mut attrs,
                     );
 
                     // Update neighbor's Tx queue.
@@ -623,37 +593,6 @@ where
     Ok(())
 }
 
-fn attrs_tx_update<A>(
-    nbr: &Neighbor,
-    local_asn: u32,
-    local: bool,
-    attrs: &mut Attrs,
-) where
-    A: AddressFamily,
-{
-    match nbr.peer_type {
-        PeerType::Internal => {
-            // Attach LOCAL_PREF with default value if it's missing.
-            if attrs.base.local_pref.is_none() {
-                attrs.base.local_pref = Some(rib::DFLT_LOCAL_PREF);
-            }
-        }
-        PeerType::External => {
-            // Prepend local AS number.
-            attrs.base.as_path.prepend(local_asn);
-
-            // Do not propagate the MULTI_EXIT_DISC attribute.
-            attrs.base.med = None;
-
-            // Remove the LOCAL_PREF attribute.
-            attrs.base.local_pref = None;
-        }
-    }
-
-    // Update the next-hop attribute based on the address family if necessary.
-    A::nexthop_tx_change(nbr, local, &mut attrs.base);
-}
-
 // ===== redistribute policy import result =====
 
 pub(crate) fn process_redistribute_policy_import<A>(

holo-bgp/src/neighbor.rs

@@ -17,7 +17,7 @@ use holo_utils::ibus::IbusSender;
 use holo_utils::socket::{TcpConnInfo, TcpStream, TTL_MAX};
 use holo_utils::task::{IntervalTask, Task, TimeoutTask};
 use holo_utils::{Sender, UnboundedSender};
-use num_traits::FromPrimitive;
+use num_traits::{FromPrimitive, ToPrimitive};
 use tokio::sync::mpsc;
 
 use crate::af::{AddressFamily, Ipv4Unicast, Ipv6Unicast};
@@ -26,13 +26,14 @@ use crate::error::Error;
 use crate::instance::{Instance, InstanceUpView};
 use crate::northbound::configuration::{InstanceCfg, NeighborCfg};
 use crate::northbound::notification;
+use crate::northbound::rpc::ClearType;
 use crate::packet::attribute::Attrs;
 use crate::packet::consts::{
-    Afi, ErrorCode, FsmErrorSubcode, Safi, AS_TRANS, BGP_VERSION,
+    Afi, CeaseSubcode, ErrorCode, FsmErrorSubcode, Safi, AS_TRANS, BGP_VERSION,
 };
 use crate::packet::message::{
     Capability, DecodeCxt, EncodeCxt, KeepaliveMsg, Message,
-    NegotiatedCapability, NotificationMsg, OpenMsg,
+    NegotiatedCapability, NotificationMsg, OpenMsg, RouteRefreshMsg,
 };
 use crate::rib::{Rib, Route, RouteOrigin};
 use crate::tasks::messages::input::{NbrRxMsg, NbrTimerMsg, TcpConnectMsg};
@@ -929,6 +930,37 @@ impl Neighbor {
         );
     }
 
+    // Re-send the current Adj-RIB-Out.
+    pub(crate) fn resend_adj_rib_out<A>(
+        &mut self,
+        instance: &mut InstanceUpView<'_>,
+    ) where
+        A: AddressFamily,
+    {
+        let table = A::table(&mut instance.state.rib.tables);
+        for (prefix, dest) in &table.prefixes {
+            let Some(adj_rib) = dest.adj_rib.get(&self.remote_addr) else {
+                continue;
+            };
+            let Some(route) = adj_rib.out_post() else {
+                continue;
+            };
+
+            // Update route's attributes before transmission.
+            let mut attrs = route.attrs.get();
+            rib::attrs_tx_update::<A>(
+                &mut attrs,
+                self,
+                instance.config.asn,
+                route.origin.is_local(),
+            );
+
+            // Update neighbor's Tx queue.
+            let update_queue = A::update_queue(&mut self.update_queues);
+            update_queue.reach.entry(attrs).or_default().insert(*prefix);
+        }
+    }
+
     // Clears the Adj-RIB-In and Adj-RIB-Out for the given address family.
     fn clear_routes<A>(&mut self, rib: &mut Rib, ibus_tx: &IbusSender)
     where
@@ -959,6 +991,63 @@ impl Neighbor {
         }
     }
 
+    // Clears the neighbor session.
+    pub(crate) fn clear_session(
+        &mut self,
+        instance: &mut InstanceUpView<'_>,
+        clear_type: ClearType,
+    ) {
+        match clear_type {
+            ClearType::Admin => {
+                // Close the session with the "Administrative Reset" subcode.
+                let msg = NotificationMsg::new(
+                    ErrorCode::Cease,
+                    CeaseSubcode::AdministrativeReset,
+                );
+                self.fsm_event(instance, fsm::Event::Stop(Some(msg)));
+            }
+            ClearType::Hard => {
+                // Close the session with the "Hard Reset" subcode.
+                let msg = NotificationMsg::new(
+                    ErrorCode::Cease,
+                    CeaseSubcode::HardReset,
+                );
+                self.fsm_event(instance, fsm::Event::Stop(Some(msg)));
+            }
+            ClearType::Soft => {
+                // Re-send the current Adj-RIB-Out to this neighbor.
+                self.resend_adj_rib_out::<Ipv4Unicast>(instance);
+                self.resend_adj_rib_out::<Ipv6Unicast>(instance);
+                let msg_list = self.update_queues.build_updates();
+                if !msg_list.is_empty() {
+                    self.message_list_send(msg_list);
+                }
+            }
+            ClearType::SoftInbound => {
+                // Request the Adj-RIB-In for this neighbor to be re-sent.
+                for (afi, safi) in self
+                    .capabilities_nego
+                    .iter()
+                    .filter_map(|cap| {
+                        if let NegotiatedCapability::MultiProtocol {
+                            afi,
+                            safi,
+                        } = cap
+                        {
+                            Some((afi.to_u16().unwrap(), safi.to_u8().unwrap()))
+                        } else {
+                            None
+                        }
+                    })
+                    .collect::<Vec<_>>()
+                {
+                    let msg = RouteRefreshMsg { afi, safi };
+                    self.message_send(Message::RouteRefresh(msg));
+                }
+            }
+        }
+    }
+
     // Determines whether the given route is eligible for distribution.
     pub(crate) fn distribute_filter(&self, route: &Route) -> bool {
         // Suppress advertisements to peers if their AS number is present

holo-bgp/src/northbound/rpc.rs

@@ -7,18 +7,60 @@
 use std::sync::LazyLock as Lazy;
 
 use holo_northbound::rpc::{Callbacks, CallbacksBuilder, Provider};
+use holo_northbound::yang::control_plane_protocol::bgp;
+use holo_utils::yang::DataNodeRefExt;
+use yang2::data::Data;
 
-//use holo_utils::yang::DataNodeRefExt;
-//use yang2::data::Data;
 use crate::instance::Instance;
 
 pub static CALLBACKS: Lazy<Callbacks<Instance>> = Lazy::new(load_callbacks);
 
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum ClearType {
+    Admin,
+    Hard,
+    Soft,
+    SoftInbound,
+}
+
 // ===== callbacks =====
 
 fn load_callbacks() -> Callbacks<Instance> {
-    // TODO: YANG actions are not supported yet.
-    CallbacksBuilder::<Instance>::default().build()
+    CallbacksBuilder::<Instance>::default()
+        .path(bgp::neighbors::clear::PATH)
+        .rpc(|instance, args| {
+            Box::pin(async move {
+                let rpc = args.data.find_path(args.rpc_path).unwrap();
+
+                // Parse input parameters.
+                let remote_addr = rpc.get_ip_relative("./remote-addr");
+                let clear_type = if rpc.exists("./hard") {
+                    ClearType::Hard
+                } else if rpc.exists("./soft") {
+                    ClearType::Soft
+                } else if rpc.exists("./soft-inbound") {
+                    ClearType::SoftInbound
+                } else {
+                    ClearType::Admin
+                };
+
+                // Clear peers.
+                let Some((mut instance, neighbors)) = instance.as_up() else {
+                    return Ok(());
+                };
+                if let Some(remote_addr) = remote_addr {
+                    let nbr = neighbors.get_mut(&remote_addr).unwrap();
+                    nbr.clear_session(&mut instance, clear_type);
+                } else {
+                    for nbr in neighbors.values_mut() {
+                        nbr.clear_session(&mut instance, clear_type);
+                    }
+                }
+
+                Ok(())
+            })
+        })
+        .build()
 }
 
 // ===== impl Instance =====

holo-bgp/src/rib.rs

@@ -18,6 +18,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::af::{AddressFamily, Ipv4Unicast, Ipv6Unicast};
 use crate::debug::Debug;
+use crate::neighbor::{Neighbor, PeerType};
 use crate::northbound::configuration::{
     DistanceCfg, MultipathCfg, RouteSelectionCfg,
 };
@@ -819,6 +820,37 @@ pub(crate) fn loc_rib_update<A>(
     }
 }
 
+pub(crate) fn attrs_tx_update<A>(
+    attrs: &mut Attrs,
+    nbr: &Neighbor,
+    local_asn: u32,
+    local: bool,
+) where
+    A: AddressFamily,
+{
+    match nbr.peer_type {
+        PeerType::Internal => {
+            // Attach LOCAL_PREF with default value if it's missing.
+            if attrs.base.local_pref.is_none() {
+                attrs.base.local_pref = Some(DFLT_LOCAL_PREF);
+            }
+        }
+        PeerType::External => {
+            // Prepend local AS number.
+            attrs.base.as_path.prepend(local_asn);
+
+            // Do not propagate the MULTI_EXIT_DISC attribute.
+            attrs.base.med = None;
+
+            // Remove the LOCAL_PREF attribute.
+            attrs.base.local_pref = None;
+        }
+    }
+
+    // Update the next-hop attribute based on the address family if necessary.
+    A::nexthop_tx_change(nbr, local, &mut attrs.base);
+}
+
 pub(crate) fn nexthop_track<A>(
     nht: &mut HashMap<IpAddr, NhtEntry<A>>,
     prefix: A::IpNetwork,

holo-routing/src/northbound/rpc.rs

@@ -5,6 +5,7 @@
 //
 
 use holo_northbound::rpc::Provider;
+use holo_northbound::yang::control_plane_protocol;
 use holo_northbound::{CallbackKey, NbDaemonSender};
 use holo_utils::protocol::Protocol;
 use holo_utils::yang::DataNodeRefExt;
@@ -69,7 +70,11 @@ fn find_instance(
 ) -> Result<(Protocol, Option<String>), String> {
     let (protocol, name) = match rpc.schema().module().name() {
         "ietf-bgp" => {
-            todo!()
+            let protocol = Protocol::BGP;
+            let name = rpc.get_string_relative(
+                control_plane_protocol::name::PATH.as_ref(),
+            );
+            (protocol, name)
         }
         "ietf-mpls-ldp" => {
             let protocol = Protocol::LDP;

holo-tools/src/yang_callbacks.rs

@@ -265,6 +265,7 @@ fn main() {
 
     // Load base YANG modules that define features used by other modules.
     yang::load_module(&mut yang_ctx, "ietf-bfd-types");
+    yang::load_module(&mut yang_ctx, "iana-bgp-types");
 
     // Load provided YANG module.
     yang::load_module(&mut yang_ctx, module_name);

holo-tools/src/yang_deviations.rs

@@ -45,7 +45,11 @@ fn main() {
     // Initialize YANG context.
     let mut yang_ctx = yang::new_context();
 
-    // Load YANG module.
+    // Load base YANG modules that define features used by other modules.
+    yang::load_module(&mut yang_ctx, "ietf-bfd-types");
+    yang::load_module(&mut yang_ctx, "iana-bgp-types");
+
+    // Load requested YANG module.
     yang::load_module(&mut yang_ctx, module_name);
     let module = yang_ctx
         .get_module_latest(module_name)