Detect tracer key in sigverify (#25579)

* Mark the tracer transaction

* simplify tracer check

(cherry picked from commit 90a3315)

core/src/sigverify.rs

@@ -64,6 +64,7 @@ impl SigVerifier for TransactionSigVerifier {
         removed_before_sigverify_stage: bool,
         is_dup: bool,
     ) {
+        sigverify::check_for_tracer_packet(packet);
         if packet.meta.is_tracer_packet() {
             if removed_before_sigverify_stage {
                 self.tracer_packet_stats

perf/src/sigverify.rs

@@ -41,6 +41,7 @@ const TRACER_KEY_BYTES: [u8; 32] = [
     155, 90, 30, 39, 116, 115, 238, 38, 126, 21, 232, 133,
 ];
 const TRACER_KEY: Pubkey = Pubkey::new_from_array(TRACER_KEY_BYTES);
+const TRACER_KEY_OFFSET_IN_TRANSACTION: usize = 69;
 
 lazy_static! {
     static ref PAR_THREAD_POOL: ThreadPool = rayon::ThreadPoolBuilder::new()
@@ -155,13 +156,6 @@ fn verify_packet(packet: &mut Packet, reject_non_vote: bool) {
             return;
         }
 
-        // Check for tracer pubkey
-        if !packet.meta.is_tracer_packet()
-            && &packet.data[pubkey_start..pubkey_end] == TRACER_KEY.as_ref()
-        {
-            packet.meta.flags |= PacketFlags::TRACER_PACKET;
-        }
-
         pubkey_start = pubkey_end;
         sig_start = sig_end;
     }
@@ -318,6 +312,22 @@ fn do_get_packet_offsets(
     ))
 }
 
+pub fn check_for_tracer_packet(packet: &mut Packet) -> bool {
+    let first_pubkey_start: usize = TRACER_KEY_OFFSET_IN_TRANSACTION;
+    let first_pubkey_end = first_pubkey_start.saturating_add(size_of::<Pubkey>());
+    // Check for tracer pubkey
+    if packet.meta.size > first_pubkey_start {
+        let is_tracer_packet =
+            &packet.data()[first_pubkey_start..first_pubkey_end] == TRACER_KEY.as_ref();
+        if is_tracer_packet {
+            packet.meta.flags |= PacketFlags::TRACER_PACKET;
+        }
+        is_tracer_packet
+    } else {
+        false
+    }
+}
+
 fn get_packet_offsets(
     packet: &mut Packet,
     current_offset: usize,