By iterating over the servers and sending the master's charset we are
guaranteed a "known good" charset. This also solves the problem where a
deactivated server reference would be used as the charset and server
version source.
Some SQL clients may default to a different authentication plugin than
"mysql_native_password". Since this is the only one supported by MySQL-
authenticator, the client is instructed to swap its plugin.
If an ignorable packet was followed by more than one queued packets, they
would all get routed in the same batch. This would cause unexpected
replies from the server if multiple ignorable packets were queued up.
The prefix was always added even when the original version would've been
acceptable. For example, a version string of 5.5.40 would get converted to
5.5.5-5.5.40 which is quite confusing for older client applications.
When a response to a prepared statement was processed, the number of EOF
packets was used to see whether the response was complete. This code used
a function that does not work with the special packet returned by a PS
preparation that is similar to an OK packet.
The correct method is to count the total number of packets in the
response.
Under heavy load some of the basic network operations could fail which led
to some of the allocated memory to leak.
Also the backend protocol never freed the current protocol command if it
was not completed. This would happen if a user executed a session command
as the first command but backend authentication would fail.
If the client sends two different sets of capability bits during the
authentication phase of an SSL enabled connection, both sets need to be
combined. This prevents capabilities from degrading mid-connection which
is the case when Oracle Connector/J drops the SSL capability bit
mid-authentication.
If the service doesn't require collection of complete packets, the user
reauthentication done with COM_CHANGE_USER would be skipped. This caused
the change_user test to fail.
By temporarily switching to full packet collection mode for the duration
of the COM_CHANGE_USER, we avoid duplicating the code for the streaming
router types.
The intention was to send the lowest backend version string automatically
to the client instead of the default handshake version. This did not work
as the service version string was used instead of the server version.
The collection of resultsets needs to be disabled by default when a
response is received to cover the cases where an error is returned.
The collection of results should also not be set for queries that do not
generate any responses.
By storing the data gathere by readwritesplit inside the session, the
protocol will be aware of the state of the LOAD DATA LOCAL INFILE
execution. This prevents misinterpretation of the data which previously
led to closed connections, effectively rendering LOAD DATA LOCAL INFILE
unusable.
This change is a temporary solution to a problem that needs to be solved
at the protocol level. The changes required to implement this are too big
to add into a bug fix release.
If a large packet is received, the stack would overflow when the username
size was determined from the packet size. The code must not assume
anything about the size of the packet being read.
The LocalClient micro-client required a reference to the session that was
valid at construction time. This is the reason why the previous
implementation used dcb_foreach to first gather the targets and then
execute queries on them. By replacing this reference with pointers to the
raw data it requires, we lift the requirement of the orignating session
being alive at construction time.
Now that the LocalClient no longer holds a reference to the session, the
killing of the connection does not have to be done on the same thread that
started the process. This prevents the deadlock that occurred when
concurrect dcb_foreach calls were made.
Replaced the unused dcb_foreach_parallel with a version of dcb_foreach
that allows iteration of DCBs local to this worker. The dcb_foreach_local
is the basis upon which all DCB access outside of administrative tasks
should be built on.
This change will introduce a regression in functionality: The client will
no longer receive an error if no connections match the KILL query
criteria. This is done to avoid having to synchronize the workers after
they have performed the killing of their own connections.
If a client is executing a COM_CHANGE_USER command and the
reauthentication of the client fails, no error message would be logged
about the failure of the reauthentication process and only a routing
failure message would be logged.
The protocol could leak memory in rare cases where several commands were
queued at the same time. Readwritesplit also didn't free the memory it
acquired via qc_get_table_names.
The function implemented redundant functionality and replacement with
modutil_get_next_MySQL_packet was planned.
When faced with a packet header spread over multiple buffers, the packet
length calculation would read past the buffer end. This is fixed by taking
modutil_get_next_MySQL_packet into use.
Identical behavior to the old function is achieved by calling
gwbuf_make_contiguous for each packet to store them in a contiguous area
of memory. This should be either removed and only done when
RCAP_TYPE_CONTIGUOUS_INPUT is requested or be made an innate feature of
statement based routing.
The debug assertion introduced by commit 3d1c2b421a fails when a
COM_CHANGE_USER was executed. This was caused by the fact that the
authentication data was being interpreted as a command when it should've
been ignored.
Added a debug assertion into the reauthentication code to make sure the
current command remains the same.
When a client connection is closed by MaxScale before the client initiates
a controlled closing of the connection, an error message is sent. This
error message now also explains why the connection was closed to make
problem resolution easier.
The default database was not extracted correctly as the length of the
user's name did not include the null terminator. Also the comparison for
database name length used the smaller than operator instead of the correct
larger than operator.
When the client reauthenticates via COM_CHANGE_USER the new SHA1 needs to
be stored as the backend connections rely on it being up-to-date.
This commit fixes the regression of the mxs548_short_session_change_user
test.
The re-authentication done in MaxScale caused multiple error packets to be
sent for the same COM_CHANGE_USER. In addition to this, the failure of
authentication did not terminate the client connection.
The change in behavior requires the test case to be changed as well.
If a connection is killed but the backend DCBs have not yet received their
thread IDs, the connections can be forcibly closed. This removes the
possibility of stale connections caused by an unfortunately timed KILL
query to a session that has partially connected to some servers.
To support a wider range of client connectors, MaxScale should respond
with an AuthSwitchRequest packet to all COM_CHANGE_USER commands. Only
MariaDB connectors understand the OK packet as the only response to a
COM_CHANGE_USER but all connectors understand the AuthSwitchRequest
packet.
The mysql_create_standard_error function accepted a packet number as a
parameter but did not use it as the actual packet number. As the value it
used happened to coincide with 50% of the use-cases, it went unnoticed.
The remaining 50% occurred when a KILL command was executed with an
unknown connection ID.
The COM_STMT_FETCH command will create a response. This was a
readwritesplit-specific interpretation of the command and it was wrong.
Also record the currently executed command event for session commands.
The current command needs to be updated before the queries are actually
routed. This allows the KILL command detection and processing to correctly
work.
