System Administration Guide

The MQ_CONNX_EXIT function interface described here is used for both the MQCONN call and the MQCONNX call. However, separate entry points are defined for these two calls. To intercept both calls, the MQXEP call must be used at least twice - once with function identifier MQXF_CONN, and again with MQXF_CONNX.
Because the MQ_CONNX_EXIT interface is the same for MQCONN and MQCONNX , a single exit function can be used for both calls; the Function field in the MQAXP structure indicates which call is in progress. Alternatively, the MQXEP call can be used to register different exit functions for the two calls.
When a message channel agent (MCA) responds to an inbound client connection, the MCA can issue a number of MQ calls before the client state is fully known. These MQ calls result in the API exit functions being invoked with the MQAXC structure containing data relating to the MCA, and not to the client (for example, user identifier and connection name). However, once the client state is fully known, subsequent MQ calls result in the API exit functions being invoked with the appropriate client data in the MQAXC structure.
All MQXR_BEFORE exit functions are invoked before any parameter validation is performed by the queue manager. The parameters may therefore be invalid (including invalid pointers for the addresses of parameters).
The MQ_CONNX_EXIT function is invoked before any authorization checks are performed by the queue manager.
The exit function must not change the name of the queue manager specified on the MQCONN or MQCONNX call. If the name is changed by the exit function, the results are undefined.
An MQXR_BEFORE exit function for the MQ_CONNX_EXIT cannot issue MQ calls other than MQXEP .

C invocation

MQ_CONNX_EXIT (&ExitParms, &ExitContext, QMgrName,
              &pConnectOpts, &pHconn, &CompCode,
              &Reason);

The parameters passed to the exit are declared as follows:

PMQAXP     pExitParms;     /* Exit parameter structure */
PMQAXC     pExitContext;   /* Exit context structure */
PMQCHAR48  pQMgrName;      /* Name of queue manager */
PPMQCNO    ppConnectOpts;  /* Options that control the action of
                              MQCONNX */
PPMQHCONN  ppHconn;        /* Connection handle */
PMQLONG    pCompCode;      /* Completion code */
PMQLONG    pReason;        /* Reason code qualifying CompCode */