From 93f7b0d0a13df9037cade1e5b57936f3c9d6a2d0 Mon Sep 17 00:00:00 2001
From: Cole Eason <cole@expensify.com>
Date: Fri, 19 Jul 2024 17:07:11 +0000
Subject: [PATCH] More fixes for mysql clients

1. Updates version to a higher version for clients that check for supported modern version numbers
2. Adds support for more SHOW DATABASE equivalent queries
3. Adds support for selecting version, needs to be DRY'd with (1)
---
 plugins/MySQL.cpp | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/plugins/MySQL.cpp b/plugins/MySQL.cpp
index e185ae4f5..6d61e6295 100644
--- a/plugins/MySQL.cpp
+++ b/plugins/MySQL.cpp
@@ -87,7 +87,7 @@ string MySQLPacket::serializeHandshake() {
     // Just hard code the values for now
     MySQLPacket handshake;
     handshake.payload += lenEncInt(10);      // protocol version
-    handshake.payload += "5.0.0"s; // server version
+    handshake.payload += "8.0.0"s; // server version
     handshake.payload += lenEncInt(0);       // NULL
     uint32_t connectionID = 1;
     SAppend(handshake.payload, &connectionID, 4); // connection_id
@@ -249,12 +249,12 @@ void BedrockPlugin_MySQL::onPortRecv(STCPManager::Socket* s, SData& request) {
     MySQLPacket packet;
     while ((packetSize = packet.deserialize(s->recvBuffer.c_str(), s->recvBuffer.size()))) {
         // Got a packet, process it
-        SDEBUG("Received command #" << (int)packet.sequenceID << ": '" << SToHex(packet.serialize()) << "'");
+        SDEBUG("Received command #" << packet.payload[0] << ", sequenceID #" << (int)packet.sequenceID << " : '" << SToHex(packet.serialize()) << "'");
         s->recvBuffer.consumeFront(packetSize);
+        SDEBUG("Packet payload " + packet.payload);
         switch (packet.payload[0]) {
         case 3: { // COM_QUERY
             // Decode the query
-            SDEBUG("Packet payload " + packet.payload);
             string query = STrim(packet.payload.substr(1, packet.payload.size() - 1));
             if (!SEndsWith(query, ";")) {
                 // We translate our query to one we can pass to `DB`, for which this is mandatory.
@@ -302,7 +302,9 @@ void BedrockPlugin_MySQL::onPortRecv(STCPManager::Socket* s, SData& request) {
                     result.rows.back()[1] = g_MySQLVariables[c][1];
                 }
                 s->send(MySQLPacket::serializeQueryResponse(packet.sequenceID, result));
-            } else if (SIEquals(query, "SHOW DATABASES;")) {
+            } else if (SIEquals(query, "SHOW DATABASES;") ||
+                       SIEquals(SToUpper(query), "SELECT DATABASE();") ||
+                       SIEquals(SToUpper(query), "select * from (select DATABASE() as DATABASE_NAME) a where a.DATABASE_NAME is not null;")) {
                 // Return a fake "main" database
                 SINFO("Responding with fake database list");
                 SQResult result;
@@ -337,6 +339,14 @@ void BedrockPlugin_MySQL::onPortRecv(STCPManager::Socket* s, SData& request) {
                 // response or else the client will hang.
                 SINFO("Responding OK to $$ query.");
                 s->send(MySQLPacket::serializeOK(packet.sequenceID));
+            } else if (SIEquals(SToUpper(query), "SELECT VERSION();")) {
+                // Return our fake version
+                SINFO("Responding with fake database list");
+                SQResult result;
+                result.headers.push_back("version()");
+                result.rows.resize(1);
+                result.rows.back().push_back("8.0.0");
+                s->send(MySQLPacket::serializeQueryResponse(packet.sequenceID, result));
             } else {
                 // Transform this into an internal request
                 request.methodLine = "Query";