Fixed bug which could cause a redirect loop with improperly configured

listener redirects.

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -18,6 +18,8 @@ Thin Mode Changes
 #)  Fixed bug which caused a cursor leak if an error was thrown while
     processing the execution of a query.
 #)  Fixed bugs in the implementation of the statement cache.
+#)  Fixed bug which could cause a redirect loop with improperly configured
+    listener redirects.
 #)  Eliminated unneeded round trip when using token authentication to connect
     to the database.
 

src/oracledb/impl/thin/constants.pxi

@@ -40,6 +40,7 @@ DEF TNS_PACKET_TYPE_CONTROL = 14
 DEF TNS_PACKET_TYPE_REDIRECT = 5
 
 # packet flags
+DEF TNS_PACKET_FLAG_REDIRECT = 0x04
 DEF TNS_PACKET_FLAG_TLS_RENEG = 0x08
 
 # data flags

src/oracledb/impl/thin/messages.pyx

@@ -1746,7 +1746,7 @@ cdef class ConnectMessage(Message):
         if buf._caps.supports_oob:
             service_options |= TNS_GSO_CAN_RECV_ATTENTION
             connect_flags_2 |= TNS_CHECK_OOB
-        buf.start_request(TNS_PACKET_TYPE_CONNECT)
+        buf.start_request(TNS_PACKET_TYPE_CONNECT, self.packet_flags)
         buf.write_uint16(TNS_VERSION_DESIRED)
         buf.write_uint16(TNS_VERSION_MINIMUM)
         buf.write_uint16(service_options)

src/oracledb/impl/thin/packet.pyx

@@ -587,6 +587,7 @@ cdef class WriteBuffer(Buffer):
 
     cdef:
         uint8_t _packet_type
+        uint8_t _packet_flags
         Capabilities _caps
         object _socket
         uint8_t _seq_num
@@ -610,7 +611,7 @@ cdef class WriteBuffer(Buffer):
             self.write_uint16(size)
             self.write_uint16(0)
         self.write_uint8(self._packet_type)
-        self.write_uint8(0)
+        self.write_uint8(self._packet_flags)
         self.write_uint16(0)
         self._pos = size
         if DEBUG_PACKETS:
@@ -650,7 +651,8 @@ cdef class WriteBuffer(Buffer):
         """
         return self._max_size - PACKET_HEADER_SIZE - 2
 
-    cdef void start_request(self, uint8_t packet_type, uint16_t data_flags=0):
+    cdef void start_request(self, uint8_t packet_type, uint8_t packet_flags=0,
+                            uint16_t data_flags=0):
         """
         Indicates that a request from the client is starting. The packet type
         is retained just in case a request spans multiple packets. The packet
@@ -659,6 +661,7 @@ cdef class WriteBuffer(Buffer):
         """
         self._packet_sent = False
         self._packet_type = packet_type
+        self._packet_flags = packet_flags
         self._pos = PACKET_HEADER_SIZE
         if packet_type == TNS_PACKET_TYPE_DATA:
             self.write_uint16(data_flags)

src/oracledb/impl/thin/protocol.pyx

@@ -133,11 +133,11 @@ cdef class Protocol:
         """
         cdef:
             ConnectMessage connect_message = None
+            uint8_t packet_type, packet_flags = 0
             object ssl_context, connect_info
             ConnectParamsImpl temp_params
             str host, redirect_data
             Address temp_address
-            uint8_t packet_type
             int port, pos
 
         # store whether OOB processing is possible or not
@@ -163,6 +163,7 @@ cdef class Protocol:
                 connect_message.connect_string_bytes = connect_string.encode()
                 connect_message.connect_string_len = \
                         <uint16_t> len(connect_message.connect_string_bytes)
+                connect_message.packet_flags = packet_flags
 
             # process connection message
             self._process_message(connect_message)
@@ -180,6 +181,7 @@ cdef class Protocol:
                 connect_string = redirect_data[pos + 1:]
                 self._connect_tcp(params, description, address, host, port)
                 connect_message = None
+                packet_flags = TNS_PACKET_FLAG_REDIRECT
             elif connect_message.packet_type == TNS_PACKET_TYPE_ACCEPT:
                 break
 
@@ -293,7 +295,7 @@ cdef class Protocol:
         """
         Send the final close packet to the server and close the socket.
         """
-        buf.start_request(TNS_PACKET_TYPE_DATA, TNS_DATA_FLAGS_EOF)
+        buf.start_request(TNS_PACKET_TYPE_DATA, 0, TNS_DATA_FLAGS_EOF)
         buf.end_request()
         self._socket.shutdown(socket.SHUT_RDWR)
         self._socket.close()