adds extensions to contact-info (solana-labs#32309)

The commit adds a Vec<Extension> to ContactInfo so that future additions
to ContactInfo can be done by only adding new Extensions instead of
modifying the entire ContactInfo.

gossip/src/cluster_info.rs

@@ -271,7 +271,7 @@ pub fn make_accounts_hashes_message(
 pub(crate) type Ping = ping_pong::Ping<[u8; GOSSIP_PING_TOKEN_SIZE]>;
 
 // TODO These messages should go through the gpu pipeline for spam filtering
-#[frozen_abi(digest = "3U6DqJ4X4UE1DxRP1sbwP5QtyFxexMxzjLSKXXRDrt4q")]
+#[frozen_abi(digest = "9eS1agTwFQxCcCWgoBYhPfEVBfXkppan1zbob5rRRu7u")]
 #[derive(Serialize, Deserialize, Debug, AbiEnumVisitor, AbiExample)]
 #[allow(clippy::large_enum_variant)]
 pub(crate) enum Protocol {

gossip/src/contact_info.rs

@@ -66,7 +66,7 @@ pub enum Error {
     UnusedIpAddr(IpAddr),
 }
 
-#[derive(Clone, Debug, Eq, PartialEq, AbiExample, Serialize)]
+#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
 pub struct ContactInfo {
     pubkey: Pubkey,
     #[serde(with = "serde_varint")]
@@ -82,6 +82,8 @@ pub struct ContactInfo {
     // All sockets have a unique key and a valid IP address index.
     #[serde(with = "short_vec")]
     sockets: Vec<SocketEntry>,
+    #[serde(with = "short_vec")]
+    extensions: Vec<Extension>,
     #[serde(skip_serializing)]
     cache: [SocketAddr; SOCKET_CACHE_SIZE],
 }
@@ -94,6 +96,9 @@ struct SocketEntry {
     offset: u16, // Port offset with respect to the previous entry.
 }
 
+#[derive(Clone, Debug, Eq, PartialEq, Deserialize, Serialize)]
+enum Extension {}
+
 // As part of deserialization, self.addrs and self.sockets should be cross
 // verified and self.cache needs to be populated. This type serves as a
 // workaround since serde does not have an initializer.
@@ -110,6 +115,8 @@ struct ContactInfoLite {
     addrs: Vec<IpAddr>,
     #[serde(with = "short_vec")]
     sockets: Vec<SocketEntry>,
+    #[serde(with = "short_vec")]
+    extensions: Vec<Extension>,
 }
 
 macro_rules! get_socket {
@@ -183,6 +190,7 @@ impl ContactInfo {
             version: solana_version::Version::default(),
             addrs: Vec::<IpAddr>::default(),
             sockets: Vec::<SocketEntry>::default(),
+            extensions: Vec::<Extension>::default(),
             cache: [SOCKET_ADDR_UNSPECIFIED; SOCKET_CACHE_SIZE],
         }
     }
@@ -415,6 +423,7 @@ impl TryFrom<ContactInfoLite> for ContactInfo {
             version,
             addrs,
             sockets,
+            extensions,
         } = node;
         sanitize_entries(&addrs, &sockets)?;
         let mut node = ContactInfo {
@@ -425,6 +434,7 @@ impl TryFrom<ContactInfoLite> for ContactInfo {
             version,
             addrs,
             sockets,
+            extensions,
             cache: [SOCKET_ADDR_UNSPECIFIED; SOCKET_CACHE_SIZE],
         };
         // Populate node.cache.
@@ -540,6 +550,23 @@ pub(crate) fn get_quic_socket(socket: &SocketAddr) -> Result<SocketAddr, Error>
     ))
 }
 
+#[cfg(all(test, RUSTC_WITH_SPECIALIZATION))]
+impl solana_frozen_abi::abi_example::AbiExample for ContactInfo {
+    fn example() -> Self {
+        Self {
+            pubkey: Pubkey::example(),
+            wallclock: u64::example(),
+            outset: u64::example(),
+            shred_version: u16::example(),
+            version: solana_version::Version::example(),
+            addrs: Vec::<IpAddr>::example(),
+            sockets: Vec::<SocketEntry>::example(),
+            extensions: vec![],
+            cache: <[SocketAddr; SOCKET_CACHE_SIZE]>::example(),
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use {
@@ -679,6 +706,7 @@ mod tests {
             version: solana_version::Version::default(),
             addrs: Vec::default(),
             sockets: Vec::default(),
+            extensions: Vec::default(),
             cache: [SOCKET_ADDR_UNSPECIFIED; SOCKET_CACHE_SIZE],
         };
         let mut sockets = HashMap::<u8, SocketAddr>::new();