feat: disable default dht discovery forwarding (#7128)

Description
---
- Disabled default forwarding of DHT discovery messages as this is not
required for the proper operation of the network. A config option has
been added to enable or disable this, but the default is false.
- Adjusted the DHT dedup cache default config to be a lot more
conservative before starting new dedup cycle - the amount of time an
identical inbound message will be ignored before being processed again.

Motivation and Context
---
Mainnet is being flooded with messages that do not contribute to the
blockchain.

How Has This Been Tested?
---
System-level testing shows markedly reduced overheads, inbound pipeline
finish times and overall memory usage. The dedup cache also does its job
much better now so the base node does not can ignore the endless round
robbin of the messages.

What process can a PR reviewer use to test or verify this change?
---
Code review.
System-level testing.

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Breaking Changes
---

- [x] None
- [ ] Requires data directory on base node to be deleted
- [ ] Requires hard fork
- [ ] Other - Please specify

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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Introduced a new configuration option to enable or disable message
forwarding in the network's DHT. This option is disabled by default and
can be enabled for communication nodes.

- **Improvements**
- Increased the default cache capacity for deduplication and extended
the default cache trim interval, enhancing overall message handling
efficiency.

- **Documentation**
- Updated configuration files and documentation comments to reflect the
new forwarding option and revised cache settings.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: SW van Heerden <swvheerden@gmail.com>

Author: hansieodendaal

common/config/presets/c_base_node_c.toml

@@ -331,6 +331,8 @@ database_url = "data/base_node/dht.db"
 #                or
 #   `excluded_dial_addresses = ["/ip4/127.0:0.1/tcp/122", "/ip4/127.0:0.1/tcp/1000:2000"]`
 excluded_dial_addresses = []
+# Enables the DHT to forward messages to other nodes in the network - communication nodes only (Default: false)
+#enable_forwarding = false
 
 # setting this to some version will reject peers that dont meet the min version or the agent string in the correct string.
 # peer string should match X/X/X/X/{VERSION} where the last segment is the version in semer versioning scheme

common/config/presets/d_console_wallet.toml

@@ -369,6 +369,8 @@ ban_duration_short = 60 # 1 min
 #                or
 #   `excluded_dial_addresses = ["/ip4/127.0:0.1/tcp/122", "/ip4/127.0:0.1/tcp/1000:2000"]`
 excluded_dial_addresses = []
+# Enables the DHT to forward messages to other nodes in the network - communication nodes only (Default: false)
+#enable_forwarding = false
 
 # setting this to some version will reject peers that dont meet the min version or the agent string in the correct string.
 # peer string should match X/X/X/X/{VERSION} where the last segment is the version in semer versioning scheme

comms/dht/src/config.rs

@@ -52,10 +52,10 @@ pub struct DhtConfig {
     /// Default: 4
     pub propagation_factor: usize,
     /// The max capacity of the message hash cache
-    /// Default: 2,500
+    /// Default: 50,000
     pub dedup_cache_capacity: usize,
     /// The periodic trim interval for items in the message hash cache
-    /// Default: 300s (5 mins)
+    /// Default: 12 x 60 x 60s (12 hours)
     #[serde(with = "serializers::seconds")]
     pub dedup_cache_trim_interval: Duration,
     /// The number of occurrences of a message is allowed to pass through the DHT pipeline before being
@@ -111,6 +111,9 @@ pub struct DhtConfig {
     ///                or
     ///   `excluded_dial_addresses = ["/ip4/127.0:0.1/tcp/122", "/ip4/127.0:0.1/tcp/1000:2000"]`
     pub excluded_dial_addresses: MultiaddrRangeList,
+    /// Enables the DHT to forward messages to other nodes in the network - communication nodes only
+    /// Default: false
+    pub enable_forwarding: bool,
 }
 
 impl DhtConfig {
@@ -140,6 +143,7 @@ impl DhtConfig {
                 ..Default::default()
             },
             excluded_dial_addresses: vec![].into(),
+            enable_forwarding: true,
             ..Default::default()
         }
     }
@@ -168,8 +172,8 @@ impl Default for DhtConfig {
             minimize_connections: false,
             propagation_factor: 20,
             broadcast_factor: 8,
-            dedup_cache_capacity: 2_500,
-            dedup_cache_trim_interval: Duration::from_secs(5 * 60),
+            dedup_cache_capacity: 50_000,
+            dedup_cache_trim_interval: Duration::from_secs(12 * 60 * 60), // 12 hours
             dedup_allowed_message_occurrences: 1,
             database_url: DbConnectionUrl::Memory,
             discovery_request_timeout: Duration::from_secs(2 * 60),
@@ -185,6 +189,7 @@ impl Default for DhtConfig {
             offline_peer_cooldown: Duration::from_secs(24 * 60 * 60),
             peer_validator_config: Default::default(),
             excluded_dial_addresses: vec![].into(),
+            enable_forwarding: false,
         }
     }
 }

comms/dht/src/dht.rs

@@ -272,7 +272,8 @@ impl Dht {
             .layer(ForwardLayer::new(
                 self.dht_requester(),
                 self.outbound_requester(),
-                self.node_identity.features().contains(PeerFeatures::DHT_STORE_FORWARD),
+                self.node_identity.features().contains(PeerFeatures::DHT_STORE_FORWARD) &&
+                    self.config.enable_forwarding,
             ))
             .layer(inbound::DhtHandlerLayer::new(
                 self.config.clone(),
@@ -532,6 +533,7 @@ mod test {
         // Send all outbound requests to the mock
         let dht = Dht::builder()
             .with_outbound_sender(oms_requester.get_mpsc_sender())
+            .with_config(DhtConfig::default_local_test())
             .build(
                 Arc::clone(&node_identity),
                 peer_manager,