feat: add support for ultrasound validator preferences (#831)

## 📝 Summary

Add support for ultrasound validator preferences.

## ✅ I have completed the following steps:

* [x] Run `make lint`
* [x] Run `make test`
* [ ] Added tests (if applicable)

Author: efbig

crates/rbuilder-primitives/src/mev_boost/mod.rs

@@ -183,7 +183,7 @@ pub struct ValidatorSlotData {
     pub regional_endpoints: Vec<BloxrouteRegionalEndpoint>,
     /// (Titan) Validator preferences.
     #[serde(default)]
-    pub preferences: Option<TitanValidatorPreferences>,
+    pub preferences: Option<ValidatorPreferences>,
 }
 
 /// Bloxroute validator RProxy details.
@@ -201,6 +201,36 @@ pub struct BloxrouteRegionalEndpoint {
     pub websocket_endpoint: String,
 }
 
+/// Relay validator preferences.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Hash)]
+#[serde(untagged)]
+pub enum ValidatorPreferences {
+    Ultrasound(UltrasoundValidatorPreferences),
+    Titan(TitanValidatorPreferences),
+}
+
+impl ValidatorPreferences {
+    /// Returns [`TitanValidatorPreferences`] if the variant matches.
+    pub fn as_titan(&self) -> Option<&TitanValidatorPreferences> {
+        if let Self::Titan(preferences) = self {
+            Some(preferences)
+        } else {
+            None
+        }
+    }
+}
+
+/// Ultrasound validator preferences.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Hash)]
+pub struct UltrasoundValidatorPreferences {
+    /// Indicator whether the validator is filtering. Values: "none", "ofac".
+    filtering: String,
+    /// Flag indicating whether the validator is integrated with MEV Protect.
+    is_mev_protect: bool,
+    /// Flag indicating whether the validator is integrated with Primev.
+    is_primev: bool,
+}
+
 /// Titan validator preferences.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Hash)]
 pub struct TitanValidatorPreferences {
@@ -292,6 +322,26 @@ mod tests {
                     }
                 }
             "#,
+            r#"
+                {
+                    "slot": "123",
+                    "validator_index": "123",
+                    "entry": {
+                        "message": {
+                            "fee_recipient": "0x0000000000000000000000000000000000000000",
+                            "gas_limit": "60000000",
+                            "timestamp": "123",
+                            "pubkey": "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
+                        },
+                        "signature": "0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
+                    },
+                    "preferences": {
+                        "filtering": "none",
+                        "is_mev_protect": false,
+                        "is_primev": false
+                    }
+                }
+            "#,
         ];
         for raw in registrations {
             assert!(serde_json::from_str::<ValidatorSlotData>(raw).is_ok());

crates/rbuilder/src/mev_boost/mod.rs

@@ -7,8 +7,8 @@ use flate2::{write::GzEncoder, Compression};
 use governor::{DefaultDirectRateLimiter, Quota, RateLimiter};
 use rbuilder_primitives::mev_boost::{
     KnownRelay, MevBoostRelayID, RelayMode, SubmitBlockRequestNoBlobs,
-    SubmitBlockRequestWithMetadata, SubmitHeaderRequestWithMetadata, ValidatorRegistration,
-    ValidatorSlotData, MEV_BOOST_SLOT_INFO_REQUEST_TIMEOUT,
+    SubmitBlockRequestWithMetadata, SubmitHeaderRequestWithMetadata, ValidatorPreferences,
+    ValidatorRegistration, ValidatorSlotData, MEV_BOOST_SLOT_INFO_REQUEST_TIMEOUT,
 };
 use reqwest::{
     header::{HeaderMap, HeaderValue, AUTHORIZATION, CONTENT_ENCODING, CONTENT_TYPE},
@@ -691,6 +691,7 @@ impl RelayClient {
                     .filter(|r| {
                         r.preferences
                             .as_ref()
+                            .and_then(ValidatorPreferences::as_titan)
                             .is_none_or(|p| !p.censoring || self.ask_for_filtering_validators)
                     })
                     .collect();