5 files changed, 36 insertions, 22 deletions
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index c10f85b94c4..57d0c52a840 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -468,11 +468,11 @@ static void repairDatabasesAndCheckVersion(OperationContext* txn) {
 static void _initWireSpec() {
     WireSpec& spec = WireSpec::instance();
     // accept from any version
-    spec.minWireVersionIncoming = RELEASE_2_4_AND_BEFORE;
-    spec.maxWireVersionIncoming = COMMANDS_ACCEPT_WRITE_CONCERN;
+    spec.incoming.minWireVersion = RELEASE_2_4_AND_BEFORE;
+    spec.incoming.maxWireVersion = COMMANDS_ACCEPT_WRITE_CONCERN;
     // connect to any version
-    spec.minWireVersionOutgoing = RELEASE_2_4_AND_BEFORE;
-    spec.maxWireVersionOutgoing = COMMANDS_ACCEPT_WRITE_CONCERN;
+    spec.outgoing.minWireVersion = RELEASE_2_4_AND_BEFORE;
+    spec.outgoing.maxWireVersion = COMMANDS_ACCEPT_WRITE_CONCERN;
 }
 
 
diff --git a/src/mongo/db/dbdirectclient.cpp b/src/mongo/db/dbdirectclient.cpp
index 06c06991722..f4bf62ed644 100644
--- a/src/mongo/db/dbdirectclient.cpp
+++ b/src/mongo/db/dbdirectclient.cpp
@@ -89,12 +89,12 @@ std::string DBDirectClient::getServerAddress() const {
 
 // Returned version should match the incoming connections restrictions.
 int DBDirectClient::getMinWireVersion() {
-    return WireSpec::instance().minWireVersionIncoming;
+    return WireSpec::instance().incoming.minWireVersion;
 }
 
 // Returned version should match the incoming connections restrictions.
 int DBDirectClient::getMaxWireVersion() {
-    return WireSpec::instance().maxWireVersionIncoming;
+    return WireSpec::instance().incoming.maxWireVersion;
 }
 
 ConnectionString::ConnectionType DBDirectClient::type() const {
diff --git a/src/mongo/db/repl/replication_info.cpp b/src/mongo/db/repl/replication_info.cpp
index 90dd3fb451a..d27257a8eb0 100644
--- a/src/mongo/db/repl/replication_info.cpp
+++ b/src/mongo/db/repl/replication_info.cpp
@@ -286,8 +286,8 @@ public:
         result.appendNumber("maxMessageSizeBytes", MaxMessageSizeBytes);
         result.appendNumber("maxWriteBatchSize", BatchedCommandRequest::kMaxWriteBatchSize);
         result.appendDate("localTime", jsTime());
-        result.append("maxWireVersion", WireSpec::instance().maxWireVersionIncoming);
-        result.append("minWireVersion", WireSpec::instance().minWireVersionIncoming);
+        result.append("maxWireVersion", WireSpec::instance().incoming.maxWireVersion);
+        result.append("minWireVersion", WireSpec::instance().incoming.minWireVersion);
         result.append("readOnly", storageGlobalParams.readOnly);
 
         const auto parameter = mapFindWithDefault(ServerParameterSet::getGlobal()->getMap(),
diff --git a/src/mongo/db/s/set_shard_version_command.cpp b/src/mongo/db/s/set_shard_version_command.cpp
index b19e72c9489..de56695a4cb 100644
--- a/src/mongo/db/s/set_shard_version_command.cpp
+++ b/src/mongo/db/s/set_shard_version_command.cpp
@@ -148,8 +148,8 @@ public:
 
             // TODO: SERVER-21397 remove post v3.3.
             // Send back wire version to let mongos know what protocol we can speak
-            result.append("minWireVersion", WireSpec::instance().minWireVersionIncoming);
-            result.append("maxWireVersion", WireSpec::instance().maxWireVersionIncoming);
+            result.append("minWireVersion", WireSpec::instance().incoming.minWireVersion);
+            result.append("maxWireVersion", WireSpec::instance().incoming.maxWireVersion);
 
             return true;
         }
diff --git a/src/mongo/db/wire_version.h b/src/mongo/db/wire_version.h
index 86f629e0ca7..de816c0ae1b 100644
--- a/src/mongo/db/wire_version.h
+++ b/src/mongo/db/wire_version.h
@@ -26,6 +26,10 @@
 *    it in the license file.
 */
 
+#pragma once
+
+#include "mongo/base/disallow_copying.h"
+
 namespace mongo {
 
 /**
@@ -63,6 +67,14 @@ enum WireVersion {
     COMMANDS_ACCEPT_WRITE_CONCERN = 5,
 };
 
+/**
+ * Struct to pass around information about wire version.
+ */
+struct WireVersionInfo {
+    int minWireVersion;
+    int maxWireVersion;
+};
+
 struct WireSpec {
     MONGO_DISALLOW_COPYING(WireSpec);
 
@@ -71,18 +83,20 @@ struct WireSpec {
         return instance;
     }
 
-    // Minimum version that the server accepts on incoming requests. We should bump this whenever
-    // we don't want to allow incoming connections from clients that are too old.
-    int minWireVersionIncoming;
-    // Latest version that the server accepts on incoming requests. This should always be at the
-    // latest entry in WireVersion.
-    int maxWireVersionIncoming;
-
-    // Minimum version allowed on remote nodes when the server sends requests. We should bump this
-    // whenever we don't want to connect to clients that are too old.
-    int minWireVersionOutgoing;
-    // Latest version allowed on remote nodes when the server sends requests.
-    int maxWireVersionOutgoing;
+    // incoming.minWireVersion - Minimum version that the server accepts on incoming requests. We
+    // should bump this whenever we don't want to allow incoming connections from clients that are
+    // too old.
+
+    // incoming.maxWireVersion - Latest version that the server accepts on incoming requests. This
+    // should always be at the latest entry in WireVersion.
+    WireVersionInfo incoming;
+
+    // outgoing.minWireVersion - Minimum version allowed on remote nodes when the server sends
+    // requests. We should bump this whenever we don't want to connect to clients that are too old.
+
+    // outgoing.maxWireVersion - Latest version allowed on remote nodes when the server sends
+    // requests.
+    WireVersionInfo outgoing;
 
 private:
     WireSpec() = default;