IM: Include baseline support for Subscription Transaction

Currently the entire transaction goes through successfully and the other end
is notified of a successful subscription. Actual subscription part is yet to be
implemented.

matter/src/interaction_model/core.rs

@@ -100,6 +100,26 @@ impl InteractionModel {
         InteractionModel { consumer }
     }
 
+    pub fn handle_status_resp(
+        &mut self,
+        trans: &mut Transaction,
+        rx_buf: &[u8],
+        proto_tx: &mut Packet,
+    ) -> Result<ResponseRequired, Error> {
+        let root = get_root_node_struct(rx_buf)?;
+        let req = StatusResp::from_tlv(&root)?;
+
+        let mut handled = false;
+        let result = self.handle_subscription_confirm(trans, proto_tx, &mut handled);
+        if handled {
+            result
+        } else {
+            // Nothing to do for now
+            info!("Received status report with status {:?}", req.status);
+            Ok(ResponseRequired::No)
+        }
+    }
+
     pub fn handle_timed_req(
         &mut self,
         trans: &mut Transaction,
@@ -162,6 +182,8 @@ impl proto_demux::HandleProto for InteractionModel {
             OpCode::ReadRequest => self.handle_read_req(&mut trans, buf, &mut ctx.tx)?,
             OpCode::WriteRequest => self.handle_write_req(&mut trans, buf, &mut ctx.tx)?,
             OpCode::TimedRequest => self.handle_timed_req(&mut trans, buf, &mut ctx.tx)?,
+            OpCode::SubscribeRequest => self.handle_subscribe_req(&mut trans, buf, &mut ctx.tx)?,
+            OpCode::StatusResponse => self.handle_status_resp(&mut trans, buf, &mut ctx.tx)?,
             _ => {
                 error!("Opcode Not Handled: {:?}", proto_opcode);
                 return Err(Error::InvalidOpcode);

matter/src/interaction_model/messages.rs

@@ -71,7 +71,55 @@ pub mod msg {
         tlv::{FromTLV, TLVArray, TLVElement, TLVWriter, TagType, ToTLV},
     };
 
-    use super::ib::{self, AttrData, AttrPath, AttrResp, AttrStatus, CmdData, DataVersionFilter};
+    use super::ib::{
+        self, AttrData, AttrPath, AttrResp, AttrStatus, CmdData, DataVersionFilter, EventFilter,
+        EventPath,
+    };
+
+    #[derive(FromTLV)]
+    #[tlvargs(lifetime = "'a")]
+    pub struct SubscribeReq<'a> {
+        pub keep_subs: bool,
+        pub min_int_floor: u16,
+        pub max_int_ceil: u16,
+        pub attr_requests: Option<TLVArray<'a, AttrPath>>,
+        event_requests: Option<TLVArray<'a, EventPath>>,
+        event_filters: Option<TLVArray<'a, EventFilter>>,
+        // The Context Tags are discontiguous for some reason
+        _dummy: Option<bool>,
+        pub fabric_filtered: bool,
+        pub dataver_filters: Option<TLVArray<'a, DataVersionFilter>>,
+    }
+
+    impl<'a> SubscribeReq<'a> {
+        pub fn to_read_req(&self) -> ReadReq<'a> {
+            ReadReq {
+                attr_requests: self.attr_requests,
+                event_requests: self.event_requests,
+                event_filters: self.event_filters,
+                fabric_filtered: self.fabric_filtered,
+                dataver_filters: self.dataver_filters,
+            }
+        }
+    }
+
+    #[derive(ToTLV)]
+    pub struct SubscribeResp {
+        pub subs_id: u32,
+        // The Context Tags are discontiguous for some reason
+        _dummy: Option<u32>,
+        pub max_int: u16,
+    }
+
+    impl SubscribeResp {
+        pub fn new(subs_id: u32, max_int: u16) -> Self {
+            Self {
+                subs_id,
+                _dummy: None,
+                max_int,
+            }
+        }
+    }
 
     #[derive(FromTLV, ToTLV)]
     pub struct TimedReq {
@@ -115,8 +163,8 @@ pub mod msg {
     #[tlvargs(lifetime = "'a")]
     pub struct ReadReq<'a> {
         pub attr_requests: Option<TLVArray<'a, AttrPath>>,
-        event_requests: Option<bool>,
-        event_filters: Option<bool>,
+        event_requests: Option<TLVArray<'a, EventPath>>,
+        event_filters: Option<TLVArray<'a, EventFilter>>,
         pub fabric_filtered: bool,
         pub dataver_filters: Option<TLVArray<'a, DataVersionFilter>>,
     }
@@ -172,7 +220,7 @@ pub mod msg {
     }
 
     pub enum ReportDataTag {
-        _SubscriptionId = 0,
+        SubscriptionId = 0,
         AttributeReports = 1,
         _EventReport = 2,
         _MoreChunkedMsgs = 3,
@@ -472,4 +520,20 @@ pub mod ib {
         pub path: ClusterPath,
         pub data_ver: u32,
     }
+
+    #[derive(FromTLV, ToTLV, Copy, Clone)]
+    #[tlvargs(datatype = "list")]
+    pub struct EventPath {
+        pub node: Option<u64>,
+        pub endpoint: Option<u16>,
+        pub cluster: Option<u32>,
+        pub event: Option<u32>,
+        pub is_urgent: Option<bool>,
+    }
+
+    #[derive(FromTLV, ToTLV, Copy, Clone)]
+    pub struct EventFilter {
+        pub node: Option<u64>,
+        pub event_min: Option<u64>,
+    }
 }

matter/src/interaction_model/mod.rs

@@ -64,4 +64,5 @@ pub mod command;
 pub mod core;
 pub mod messages;
 pub mod read;
+pub mod subscribe;
 pub mod write;

matter/src/interaction_model/subscribe.rs

@@ -0,0 +1,115 @@
+/*
+ *
+ *    Copyright (c) 2023 Project CHIP Authors
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+use std::sync::atomic::{AtomicU32, Ordering};
+
+use crate::{
+    error::Error,
+    interaction_model::core::OpCode,
+    tlv::{get_root_node_struct, FromTLV, TLVWriter, TagType, ToTLV},
+    transport::{packet::Packet, proto_demux::ResponseRequired},
+};
+
+use log::error;
+
+use super::{
+    messages::msg::{self, SubscribeReq, SubscribeResp},
+    InteractionModel, Transaction,
+};
+
+static SUBS_ID: AtomicU32 = AtomicU32::new(1);
+
+impl InteractionModel {
+    pub fn handle_subscribe_req(
+        &mut self,
+        trans: &mut Transaction,
+        rx_buf: &[u8],
+        proto_tx: &mut Packet,
+    ) -> Result<ResponseRequired, Error> {
+        proto_tx.set_proto_opcode(OpCode::ReportData as u8);
+
+        let mut tw = TLVWriter::new(proto_tx.get_writebuf()?);
+        let root = get_root_node_struct(rx_buf)?;
+        let req = SubscribeReq::from_tlv(&root)?;
+
+        let ctx = Box::new(SubsCtx {
+            state: SubsState::Confirming,
+            // TODO
+            id: SUBS_ID.fetch_add(1, Ordering::SeqCst),
+        });
+
+        let read_req = req.to_read_req();
+        tw.start_struct(TagType::Anonymous)?;
+        tw.u32(
+            TagType::Context(msg::ReportDataTag::SubscriptionId as u8),
+            ctx.id,
+        )?;
+        self.consumer.consume_read_attr(&read_req, trans, &mut tw)?;
+        tw.bool(
+            TagType::Context(msg::ReportDataTag::SupressResponse as u8),
+            false,
+        )?;
+        tw.end_container()?;
+
+        if !trans.exch.is_data_none() {
+            error!("Exchange data already set!");
+            return Err(Error::InvalidState);
+        }
+        trans.exch.set_data_boxed(ctx);
+
+        Ok(ResponseRequired::Yes)
+    }
+
+    pub fn handle_subscription_confirm(
+        &mut self,
+        trans: &mut Transaction,
+        proto_tx: &mut Packet,
+        request_handled: &mut bool,
+    ) -> Result<ResponseRequired, Error> {
+        *request_handled = false;
+        if let Some(ctx) = trans.exch.get_data_boxed::<SubsCtx>() {
+            if ctx.state != SubsState::Confirming {
+                // Not relevant for us
+                return Err(Error::Invalid);
+            }
+            *request_handled = true;
+            ctx.state = SubsState::Confirmed;
+            proto_tx.set_proto_opcode(OpCode::SubscriptResponse as u8);
+
+            // TODO
+            let resp = SubscribeResp::new(ctx.id, 40);
+            let mut tw = TLVWriter::new(proto_tx.get_writebuf()?);
+            resp.to_tlv(&mut tw, TagType::Anonymous)?;
+            trans.complete();
+            Ok(ResponseRequired::Yes)
+        } else {
+            trans.complete();
+            Err(Error::Invalid)
+        }
+    }
+}
+
+#[derive(PartialEq)]
+enum SubsState {
+    Confirming,
+    Confirmed,
+}
+
+struct SubsCtx {
+    state: SubsState,
+    id: u32,
+}