introduce async_mining_allowed as JDS config parameter

before issue #853 was reported, JDS would simply support async jobs by default and completely ignore this flag.

but checking this flag implies that JDS could either support async jobs or not, and that is what this commit does.

a new `asyn_mining_allowed` parameter is introduced to the TOML config files, and that is used when:
- checking for the flags of `SetupConnection` messages
- responding to `AllocateMiningJobToken` messages

roles/jd-server/config-examples/jds-config-hosted-example.toml

@@ -1,3 +1,6 @@
+# Async Job Support
+async_mining_allowed = true
+
 # SRI Pool config
 authority_public_key = "9auqWEzQDVyd2oe1JVGFLMLHZtCo2FFqZwtKA5gd9xbuEu7PH72"
 authority_secret_key = "mkDLTBBRxdBv998612qipDYoTK3YUrqLe8uWw7gu3iXbSrn2n"

roles/jd-server/config-examples/jds-config-local-example.toml

@@ -1,3 +1,6 @@
+# Async Job Support
+async_mining_allowed = true
+
 # SRI Pool config
 authority_public_key = "9auqWEzQDVyd2oe1JVGFLMLHZtCo2FFqZwtKA5gd9xbuEu7PH72"
 authority_secret_key = "mkDLTBBRxdBv998612qipDYoTK3YUrqLe8uWw7gu3iXbSrn2n"

roles/jd-server/src/lib/job_declarator/message_handler.rs

@@ -49,7 +49,7 @@ impl ParseClientJobDeclarationMessages for JobDeclaratorDownstream {
             request_id: message.request_id,
             mining_job_token: token.to_le_bytes().to_vec().try_into().unwrap(),
             coinbase_output_max_additional_size: 100,
-            async_mining_allowed: true,
+            async_mining_allowed: self.async_mining_allowed,
             coinbase_output: self.coinbase_output.clone().try_into().unwrap(),
         };
         let message_enum = JobDeclaration::AllocateMiningJobTokenSuccess(message_success);

roles/jd-server/src/lib/job_declarator/mod.rs

@@ -47,6 +47,7 @@ pub struct AddTrasactionsToMempool {
 
 #[derive(Debug)]
 pub struct JobDeclaratorDownstream {
+    async_mining_allowed: bool,
     sender: Sender<EitherFrame>,
     receiver: Receiver<EitherFrame>,
     // TODO this should be computed for each new template so that fees are included
@@ -70,6 +71,7 @@ pub struct JobDeclaratorDownstream {
 
 impl JobDeclaratorDownstream {
     pub fn new(
+        async_mining_allowed: bool,
         receiver: Receiver<EitherFrame>,
         sender: Sender<EitherFrame>,
         config: &Configuration,
@@ -89,6 +91,7 @@ impl JobDeclaratorDownstream {
             .expect("Invalid coinbase output in config");
 
         Self {
+            async_mining_allowed,
             receiver,
             sender,
             coinbase_output,
@@ -477,14 +480,14 @@ impl JobDeclarator {
                             let flag = setup_connection.flags;
                             let is_valid = SetupConnection::check_flags(
                                 Protocol::JobDeclarationProtocol,
-                                1,
+                                config.async_mining_allowed as u32,
                                 flag,
                             );
 
                             if is_valid {
                                 let success_message = SetupConnectionSuccess {
                                     used_version: 2,
-                                    flags: 0b_0000_0000_0000_0000_0000_0000_0000_0001,
+                                    flags: (setup_connection.flags & 1u32),
                                 };
                                 info!("Sending success message for proxy");
                                 let sv2_frame: StdFrame = JdsMessages::Common(success_message.into())
@@ -495,6 +498,7 @@ impl JobDeclarator {
 
                                 let jddownstream =
                                     Arc::new(Mutex::new(JobDeclaratorDownstream::new(
+                                        (setup_connection.flags & 1u32) != 0u32, // this takes a bool instead of u32
                                         receiver.clone(),
                                         sender.clone(),
                                         &config,

roles/jd-server/src/lib/mod.rs

@@ -57,6 +57,8 @@ pub struct CoinbaseOutput {
 
 #[derive(Debug, Deserialize, Clone)]
 pub struct Configuration {
+    #[serde(default = "default_true")]
+    pub async_mining_allowed: bool,
     pub listen_jd_address: String,
     pub authority_public_key: Secp256k1PublicKey,
     pub authority_secret_key: Secp256k1SecretKey,
@@ -70,6 +72,10 @@ pub struct Configuration {
     pub mempool_update_interval: Duration,
 }
 
+fn default_true() -> bool {
+    true
+}
+
 fn duration_from_toml<'de, D>(deserializer: D) -> Result<Duration, D::Error>
 where
     D: serde::Deserializer<'de>,