From 1bd6117db875932583fb3cf052cfa469f5929703 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20Canna=C3=B2?= <rene.cannao@gmail.com>
Date: Wed, 9 Oct 2019 03:07:32 +1100
Subject: [PATCH] Handle large queries with SSL enabled

This commit fixes the following bug:
if a client connection uses SSL and sends a query larger than 32KB, the query is never executed and the connection hang
---
 include/MySQL_Data_Stream.h |  2 ++
 lib/MySQL_Thread.cpp        | 13 ++++++++++++-
 lib/mysql_data_stream.cpp   | 15 +++++++++++++--
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/include/MySQL_Data_Stream.h b/include/MySQL_Data_Stream.h
index 6962ef003..eb212b796 100644
--- a/include/MySQL_Data_Stream.h
+++ b/include/MySQL_Data_Stream.h
@@ -210,5 +210,7 @@ class MySQL_Data_Stream
 	void free_mysql_real_query();	
 	void reinit_queues();
 	void destroy_queues();
+
+	bool data_in_rbio();
 };
 #endif /* __CLASS_MYSQL_DATA_STREAM_H */
diff --git a/lib/MySQL_Thread.cpp b/lib/MySQL_Thread.cpp
index 87b65345b..55d9e57dc 100644
--- a/lib/MySQL_Thread.cpp
+++ b/lib/MySQL_Thread.cpp
@@ -4139,7 +4139,18 @@ bool MySQL_Thread::process_data_on_data_stream(MySQL_Data_Stream *myds, unsigned
 									rb = 0; // exit loop
 								}
 							} else {
-								rb = 0; // exit loop
+								bool set_rb_zero = true;
+								if (rb > 0 && myds->myds_type == MYDS_FRONTEND) {
+									if (myds->encrypted == true) {
+										if (SSL_is_init_finished(myds->ssl)) {
+											if (myds->data_in_rbio()) {
+												set_rb_zero = false;
+											}
+										}
+									}
+								}
+								if (set_rb_zero)
+									rb = 0; // exit loop
 							}
 						} while (rb > 0);
 
diff --git a/lib/mysql_data_stream.cpp b/lib/mysql_data_stream.cpp
index aec768218..e73d9f4a1 100644
--- a/lib/mysql_data_stream.cpp
+++ b/lib/mysql_data_stream.cpp
@@ -437,6 +437,7 @@ int MySQL_Data_Stream::read_from_net() {
 			r = SSL_read (ssl, queue_w_ptr(queueIN), s);
 		}
 */
+		PROXY_TRACE();
 		if (s < MY_SSL_BUFFER) {
 			return 0;	// no enough space for reads
 		}
@@ -444,7 +445,8 @@ int MySQL_Data_Stream::read_from_net() {
 		//ssize_t n = read(fd, buf, sizeof(buf));
 		int n = recv(fd, buf, sizeof(buf), 0);
 		//proxy_info("SSL recv of %d bytes\n", n);
-		if (n > 0) {
+		proxy_debug(PROXY_DEBUG_NET, 7, "Session=%p: recv() read %d bytes. num_write: %u ,  num_read: %u\n", sess, n,  rbio_ssl->num_write , rbio_ssl->num_read);
+		if (n > 0 || rbio_ssl->num_write > rbio_ssl->num_read) {
 			//on_read_cb(buf, (size_t)n);
 
 			char buf2[MY_SSL_BUFFER];
@@ -452,8 +454,9 @@ int MySQL_Data_Stream::read_from_net() {
 			enum sslstatus status;
 			char *src = buf;
 			int len = n;
-			while (len) {
+			while (len > 0) {
 				n2 = BIO_write(rbio_ssl, src, len);
+				proxy_debug(PROXY_DEBUG_NET, 5, "Session=%p: write %d bytes into BIO %p, len=%d\n", sess, n2, rbio_ssl, len);
 				//proxy_info("BIO_write with len = %d and %d bytes\n", len , n2);
 				if (n2 <= 0) {
 					shut_soft();
@@ -477,6 +480,7 @@ int MySQL_Data_Stream::read_from_net() {
 				}
 			}
 			n2 = SSL_read (ssl, queue_w_ptr(queueIN), s);
+			proxy_debug(PROXY_DEBUG_NET, 5, "Session=%p: read %d bytes from BIO %p into a buffer with %d bytes free\n", sess, n2, rbio_ssl, s);
 			r = n2;
 			//proxy_info("Read %d bytes from SSL\n", r);
 			if (n2 > 0) {
@@ -1398,3 +1402,10 @@ void MySQL_Data_Stream::destroy_MySQL_Connection_From_Pool(bool sq) {
 	mc->send_quit=sq;
 	MyHGM->destroy_MyConn_from_pool(mc);
 }
+
+bool MySQL_Data_Stream::data_in_rbio() {
+	if (rbio_ssl->num_write > rbio_ssl->num_read) {
+		return true;
+	}
+	return false;
+}