MySQL Bugs: #29991: assertion in network-mysqld-proto.c:99 when auto

Bug #29991	assertion in network-mysqld-proto.c:99 when auto_increment key > 65534
Submitted:	23 Jul 2007 22:21	Modified:	31 Aug 2007 5:01
Reporter:	Justin Swanhart	Email Updates:
Status:	No Feedback	Impact on me:	None
Category:	MySQL Proxy: Core	Severity:	S1 (Critical)
Version:	0.5.1	OS:	Linux
Assigned to:	Jan Kneschke	CPU Architecture:	Any
Tags:	assertion

Description:
When a query comes into read_query() I inject an INSERT INTO.

Once my test table (with a BIGINT key) hits 65534 entries, the proxy stops with an assertion:
./mysql-proxy --proxy-lua-script=proxy_test.lua
file network-mysqld-proto.c: line 99 (network_mysqld_proto_get_int_len): assertion failed: (*_off + size <= packet->len)
Aborted

to duplicate:
run the proxy with the lua script from 'how to repeat', then execute 65535+ queries.  here is a PHP script to run the queries easily:

<?php
###
### CREATE THE TEST TABLE NOT USING THE PROXY CONNECTION
###
$conn = mysql_connect('127.0.0.1:3306');
mysql_query("DROP TABLE IF EXISTS test.proxytest");
$table = mysql_query("CREATE TABLE test.proxytest (pk bigint auto_increment primary key, col varchar(10))");
$conn = false;
###
### EXECUTE LOTS OF SELECT 1; THROUGH THE PROXY
###
$conn = mysql_connect('127.0.0.1:4040');
for($i=0;$i<70000;$i++) {
  $result = mysql_query("SELECT 1");
  if (!$result) {
        echo mysql_error($conn);
        exit;
  }

}
?>

How to repeat:
-- use the following script for --proxy-lua-script
-- then run 65535+_ queries
-- -----------------------------------------------------------

-- this function makes a COM_QUERY packet from a SQL statement
function make_query(sql) 
--      print (sql .. "\n")
        return string.char(proxy.COM_QUERY) .. sql
end

-- this function adds a query to the query queue
-- the id for the query is automatically incremented
-- and returned by the function 
_G.packet_id = 0
function add_query(packet) 
        _G.packet_id = _G.packet_id + 1
--      print(string.sub(packet,2))
        proxy.queries:append(_G.packet_id, packet)
        return _G.packet_id
end

-- when a query comes in from the client, this event fires
function read_query(packet)
        --INJECT OUR TEST QUERY
        -- THIS BREAKS AFTER 65534 INSERT INTO statements....
        add_query(make_query("INSERT INTO test.proxytest (pk) values (NULL)"))
        _G.orig_query_id = add_query(packet)
        return proxy.PROXY_SEND_QUERY
end

-- answer to any injected queries 
-- this won't fire unless we answer read_query with PROXY_SEND_QUERY....
function read_query_result(inj)
        -- send the result of the original SQL statement
        if inj.id == _G.orig_query_id then
                return proxy.PROXY_SEND_RESULT;
        end

        return proxy.PROXY_IGNORE_RESULT;
end

I can't reproduce the problem with the latest SVN code.

The script has to be adjusted with work with the svn-code. If you return SEND_RESULT you have to set proxy.response to send a hand-crafted result. If you just want to pass a result on to the client, return nothing.

Instead of the _G.query_id you can also just use 1 and 2 as the packet-id only has be be unique per client-query

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".

I'm getting the same error while I'm using the mysql 5.0 library. In my case this error is appearing in an insert query that is inserting record in a table containing an auto_increment column as a result of which mysql-proxy crashes. If I remove the auto_increment from the column definition then mysql-proxy doesn't crash on this query.