[Store and forward] Private message storage and retrieval

Storage and retreival of messages without an origin (PR #1686)
All private/anonymous messages are stored as low priority (short TTL)
messages.

- New response type `Anonymous` for store and forward query responses
- Added some more logging
- DHT store and forward integration test
- SAF messages can never be stored in store and forward

comms/dht/src/actor.rs

@@ -299,9 +299,11 @@ impl<'a> DhtActor<'a> {
             },
             SendRequestStoredMessages => {
                 let node_identity = Arc::clone(&self.node_identity);
+                let peer_manager = Arc::clone(&self.peer_manager);
                 let outbound_requester = self.outbound_requester.clone();
                 Box::pin(Self::request_stored_messages(
                     node_identity,
+                    peer_manager,
                     outbound_requester,
                     db,
                     self.config.num_neighbouring_nodes,
@@ -359,17 +361,29 @@ impl<'a> DhtActor<'a> {
 
     async fn request_stored_messages(
         node_identity: Arc<NodeIdentity>,
+        peer_manager: Arc<PeerManager>,
         mut outbound_requester: OutboundMessageRequester,
         db: DhtDatabase,
         num_neighbouring_nodes: usize,
     ) -> Result<(), DhtActorError>
     {
-        let request = db
+        let mut request = db
             .get_value(DhtSettingKey::SafLastRequestTimestamp)
             .await?
             .map(StoredMessagesRequest::since)
             .unwrap_or_else(StoredMessagesRequest::new);
 
+        // Calculate the network region threshold for our node id.
+        // i.e. "Give me all messages that are this close to my node ID"
+        let threshold = peer_manager
+            .calc_region_threshold(
+                node_identity.node_id(),
+                num_neighbouring_nodes,
+                PeerFeatures::DHT_STORE_FORWARD,
+            )
+            .await?;
+        request.dist_threshold = threshold.to_vec();
+
         outbound_requester
             .send_message_no_header(
                 SendMessageParams::new()

comms/dht/src/config.rs

@@ -28,7 +28,7 @@ pub const SAF_MSG_CACHE_STORAGE_CAPACITY: usize = 10_000;
 /// The default time-to-live duration used for storage of low priority messages by the Store-and-forward middleware
 pub const SAF_LOW_PRIORITY_MSG_STORAGE_TTL: Duration = Duration::from_secs(6 * 60 * 60); // 6 hours
 /// The default time-to-live duration used for storage of high priority messages by the Store-and-forward middleware
-pub const SAF_HIGH_PRIORITY_MSG_STORAGE_TTL: Duration = Duration::from_secs(2 * 24 * 60 * 60); // 2 days
+pub const SAF_HIGH_PRIORITY_MSG_STORAGE_TTL: Duration = Duration::from_secs(3 * 24 * 60 * 60); // 3 days
 /// The default number of peer nodes that a message has to be closer to, to be considered a neighbour
 pub const DEFAULT_NUM_NEIGHBOURING_NODES: usize = 10;
 
@@ -55,9 +55,9 @@ pub struct DhtConfig {
     /// Default: 6 hours
     pub saf_low_priority_msg_storage_ttl: Duration,
     /// The time-to-live duration used for storage of high priority messages by the Store-and-forward middleware.
-    /// Default: 2 days
+    /// Default: 3 days
     pub saf_high_priority_msg_storage_ttl: Duration,
-    /// The limit on the message size to store in SAF storage in bytes. Default 500kb
+    /// The limit on the message size to store in SAF storage in bytes. Default 500 KiB
     pub saf_max_message_size: usize,
     /// The max capacity of the message hash cache
     /// Default: 1000
@@ -112,7 +112,7 @@ impl Default for DhtConfig {
             saf_msg_cache_storage_capacity: SAF_MSG_CACHE_STORAGE_CAPACITY,
             saf_low_priority_msg_storage_ttl: SAF_LOW_PRIORITY_MSG_STORAGE_TTL,
             saf_high_priority_msg_storage_ttl: SAF_HIGH_PRIORITY_MSG_STORAGE_TTL,
-            saf_max_message_size: 512 * 1024, // 512 kb
+            saf_max_message_size: 512 * 1024, // 500 KiB
             msg_hash_cache_capacity: 10_000,
             msg_hash_cache_ttl: Duration::from_secs(300),
             broadcast_cooldown_max_attempts: 3,

comms/dht/src/inbound/dedup.rs

@@ -26,6 +26,7 @@ use futures::{task::Context, Future};
 use log::*;
 use std::task::Poll;
 use tari_comms::{pipeline::PipelineError, types::Challenge};
+use tari_crypto::tari_utilities::hex::Hex;
 use tower::{layer::Layer, Service, ServiceExt};
 
 const LOG_TARGET: &str = "comms::dht::dedup";
@@ -77,6 +78,7 @@ where S: Service<DhtInboundMessage, Response = (), Error = PipelineError>
     {
         trace!(target: LOG_TARGET, "Checking inbound message cache for duplicates");
         let hash = Self::hash_message(&message);
+        trace!(target: LOG_TARGET, "Inserting message hash {}", hash.to_hex());
         if dht_requester
             .insert_message_hash(hash)
             .await
@@ -88,6 +90,8 @@ where S: Service<DhtInboundMessage, Response = (), Error = PipelineError>
             );
             return Ok(());
         }
+
+        trace!(target: LOG_TARGET, "Passing message onto next service");
         next_service.oneshot(message).await
     }
 

comms/dht/src/inbound/message.rs

@@ -52,7 +52,7 @@ impl Display for DhtInboundMessage {
     fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
         write!(
             f,
-            "\n---- DhtInboundMessage ---- \nSize: {} byte(s)\nType: {}\nPeer: {}\nHeader: {}\n----",
+            "\n---- Inbound Message ---- \nSize: {} byte(s)\nType: {}\nPeer: {}\nHeader: {}\n----",
             self.body.len(),
             self.dht_header.message_type,
             self.source_peer,

comms/dht/src/outbound/broadcast.rs

@@ -222,6 +222,7 @@ where S: Service<DhtOutboundMessage, Response = (), Error = PipelineError>
         reply_tx: oneshot::Sender<SendMessageResponse>,
     ) -> Result<Vec<DhtOutboundMessage>, DhtOutboundError>
     {
+        trace!(target: LOG_TARGET, "Send params: {:?}", params);
         if params
             .broadcast_strategy
             .direct_public_key()

comms/dht/src/outbound/message.rs

@@ -168,7 +168,7 @@ impl fmt::Display for DhtOutboundMessage {
         let header_str = self
             .custom_header
             .as_ref()
-            .and_then(|h| Some(format!("{} (Propagated)", h)))
+            .map(|h| format!("{} (Propagated)", h))
             .unwrap_or_else(|| {
                 format!(
                     "Network: {:?}, Flags: {:?}, Destination: {}",

comms/dht/src/proto/store_forward.proto

@@ -12,6 +12,7 @@ package tari.dht.store_forward;
 message StoredMessagesRequest {
     google.protobuf.Timestamp since = 1;
     uint32 request_id = 2;
+    bytes dist_threshold = 3;
 }
 
 // Storage for a single message envelope, including the date and time when the element was stored
@@ -27,14 +28,16 @@ message StoredMessagesResponse {
     repeated StoredMessage messages = 1;
     uint32 request_id = 2;
     enum SafResponseType {
-        // All applicable messages
-        General = 0;
-        // Send messages explicitly addressed to the requesting node or within the requesting node's region
-        ExplicitlyAddressed = 1;
-        // Send Discovery messages that could be for the requester
-        Discovery = 2;
-        // Send Join messages that the requester could be interested in
-        Join = 3;
+        // Messages for the requested public key or node ID
+        ForMe = 0;
+        // Discovery messages that could be for the requester
+        Discovery = 1;
+        // Join messages that the requester could be interested in
+        Join = 2;
+        // Messages without an explicit destination and with an unidentified encrypted source
+        Anonymous = 3;
+        // Messages within the requesting node's region
+        InRegion = 4;
     }
     SafResponseType response_type = 3;
 }

comms/dht/src/proto/tari.dht.store_forward.rs

@@ -7,6 +7,8 @@ pub struct StoredMessagesRequest {
     pub since: ::std::option::Option<::prost_types::Timestamp>,
     #[prost(uint32, tag = "2")]
     pub request_id: u32,
+    #[prost(bytes, tag = "3")]
+    pub dist_threshold: std::vec::Vec<u8>,
 }
 /// Storage for a single message envelope, including the date and time when the element was stored
 #[derive(Clone, PartialEq, ::prost::Message)]
@@ -34,13 +36,15 @@ pub mod stored_messages_response {
     #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, ::prost::Enumeration)]
     #[repr(i32)]
     pub enum SafResponseType {
-        /// All applicable messages
-        General = 0,
-        /// Send messages explicitly addressed to the requesting node or within the requesting node's region
-        ExplicitlyAddressed = 1,
-        /// Send Discovery messages that could be for the requester
-        Discovery = 2,
-        /// Send Join messages that the requester could be interested in
-        Join = 3,
+        /// Messages for the requested public key
+        ForMe = 0,
+        /// Discovery messages that could be for the requester
+        Discovery = 1,
+        /// Join messages that the requester could be interested in
+        Join = 2,
+        /// Messages without an explicit destination and with an unidentified encrypted source
+        Anonymous = 3,
+        /// Messages within the requesting node's region
+        InRegion = 4,
     }
 }

comms/dht/src/store_forward/database/mod.rs

@@ -31,7 +31,10 @@ use crate::{
 };
 use chrono::{DateTime, NaiveDateTime, Utc};
 use diesel::{BoolExpressionMethods, ExpressionMethods, QueryDsl, RunQueryDsl};
-use tari_comms::types::CommsPublicKey;
+use tari_comms::{
+    peer_manager::{node_id::NodeDistance, NodeId},
+    types::CommsPublicKey,
+};
 use tari_crypto::tari_utilities::hex::Hex;
 
 pub struct StoreAndForwardDatabase {
@@ -54,19 +57,106 @@ impl StoreAndForwardDatabase {
             .await
     }
 
-    pub async fn find_messages_for_public_key(
+    pub async fn find_messages_for_peer(
         &self,
         public_key: &CommsPublicKey,
+        node_id: &NodeId,
         since: Option<DateTime<Utc>>,
         limit: i64,
     ) -> Result<Vec<StoredMessage>, StorageError>
     {
         let pk_hex = public_key.to_hex();
+        let node_id_hex = node_id.to_hex();
+        self.connection
+            .with_connection_async::<_, Vec<StoredMessage>>(move |conn| {
+                let mut query = stored_messages::table
+                    .select(stored_messages::all_columns)
+                    .filter(
+                        stored_messages::destination_pubkey
+                            .eq(pk_hex)
+                            .or(stored_messages::destination_node_id.eq(node_id_hex)),
+                    )
+                    .into_boxed();
+
+                if let Some(since) = since {
+                    query = query.filter(stored_messages::stored_at.ge(since.naive_utc()));
+                }
+
+                query
+                    .order_by(stored_messages::stored_at.asc())
+                    .limit(limit)
+                    .get_results(conn)
+                    .map_err(Into::into)
+            })
+            .await
+    }
+
+    pub async fn find_regional_messages(
+        &self,
+        node_id: &NodeId,
+        dist_threshold: Option<Box<NodeDistance>>,
+        since: Option<DateTime<Utc>>,
+        limit: i64,
+    ) -> Result<Vec<StoredMessage>, StorageError>
+    {
+        let node_id_hex = node_id.to_hex();
+        let results = self
+            .connection
+            .with_connection_async::<_, Vec<StoredMessage>>(move |conn| {
+                let mut query = stored_messages::table
+                    .select(stored_messages::all_columns)
+                    .filter(stored_messages::destination_node_id.ne(node_id_hex))
+                    .filter(stored_messages::destination_node_id.is_not_null())
+                    .filter(stored_messages::message_type.eq(DhtMessageType::None as i32))
+                    .into_boxed();
+
+                if let Some(since) = since {
+                    query = query.filter(stored_messages::stored_at.ge(since.naive_utc()));
+                }
+
+                query
+                    .order_by(stored_messages::stored_at.asc())
+                    .limit(limit)
+                    .get_results(conn)
+                    .map_err(Into::into)
+            })
+            .await?;
+
+        match dist_threshold {
+            Some(dist_threshold) => {
+                // Filter node ids that are within the distance threshold from the source node id
+                let results = results
+                    .into_iter()
+                    // TODO: Investigate if we could do this in sqlite using XOR (^)
+                    .filter(|message| match message.destination_node_id {
+                        Some(ref dest_node_id) => match NodeId::from_hex(dest_node_id).ok() {
+                            Some(dest_node_id) => {
+                                &dest_node_id == node_id || &dest_node_id.distance(node_id) <= &*dist_threshold
+                            },
+                            None => false,
+                        },
+                        None => true,
+                    })
+                    .collect();
+                Ok(results)
+            },
+            None => Ok(results),
+        }
+    }
+
+    pub async fn find_anonymous_messages(
+        &self,
+        since: Option<DateTime<Utc>>,
+        limit: i64,
+    ) -> Result<Vec<StoredMessage>, StorageError>
+    {
         self.connection
             .with_connection_async(move |conn| {
                 let mut query = stored_messages::table
                     .select(stored_messages::all_columns)
-                    .filter(stored_messages::destination_pubkey.eq(pk_hex))
+                    .filter(stored_messages::origin_pubkey.is_null())
+                    .filter(stored_messages::destination_pubkey.is_null())
+                    .filter(stored_messages::is_encrypted.eq(true))
                     .filter(stored_messages::message_type.eq(DhtMessageType::None as i32))
                     .into_boxed();
 
@@ -75,7 +165,7 @@ impl StoreAndForwardDatabase {
                 }
 
                 query
-                    .order_by(stored_messages::stored_at.desc())
+                    .order_by(stored_messages::stored_at.asc())
                     .limit(limit)
                     .get_results(conn)
                     .map_err(Into::into)
@@ -109,7 +199,7 @@ impl StoreAndForwardDatabase {
                 }
 
                 query
-                    .order_by(stored_messages::stored_at.desc())
+                    .order_by(stored_messages::stored_at.asc())
                     .limit(limit)
                     .get_results(conn)
                     .map_err(Into::into)

comms/dht/src/store_forward/error.rs

@@ -71,4 +71,6 @@ pub enum StoreAndForwardError {
     /// The envelope version is invalid
     InvalidEnvelopeVersion,
     MalformedNodeId(ByteArrayError),
+    /// NodeDistance threshold was invalid
+    InvalidNodeDistanceThreshold,
 }

comms/dht/src/store_forward/message.rs

@@ -55,13 +55,15 @@ impl StoredMessagesRequest {
         Self {
             since: None,
             request_id: OsRng.next_u32(),
+            dist_threshold: Vec::new(),
         }
     }
 
     pub fn since(since: DateTime<Utc>) -> Self {
         Self {
             since: Some(datetime_to_timestamp(since)),
             request_id: OsRng.next_u32(),
+            dist_threshold: Vec::new(),
         }
     }
 }