PM82226: WMQ V7.1: A CHANNEL RECEIVE EXIT FAILS WITH RC2537 BECAUSE A 4K BUFFER IS RECEIVED BY THE EXIT.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After migration from WebSphere MQ V6 to V710 the channel
  receive exit fails with RC2537 'MQRC_CHANNEL_NOT_AVAILABLE',
  because it receives a 4K buffer instead of the real data send by
  the channel send exit.
  
  The problem occurs with MQI clients connected over SVRCONN
  channels using data encryption.
  
  At MQCONN the channel receive exit is called to process the
  request that decrypts the data send by the send exit of the
  partner channel. It returns decrypted data back to the caller.
  
  Then the MQCONN reply is passed back to the channel send exit
  which encrypts the data before being send to the MQ Client.
  
  This works fine with WebSphere MQ V6, but with V710 the
  MQCONN reply is send in a 4K message buffer instead of the
  460 bytes encrypted data as it was in WMQ V6 .
  .
  This causes incorrout and reason code 2537 on the channel exits.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
  *                 Release 1 Modification 0.                    *
  ****************************************************************
  * PROBLEM DESCRIPTION: After migrating to V710 a channel       *
  *                      receive exit fails with RC2537          *
  *                      'MQRC_CHANNEL_NOT_AVAILABLE', because   *
  *                      it receives the length of the buffer    *
  *                      holding the data instead of the length  *
  *                      of the data.                            *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The customer had a send and receive pair of channel exits that
  worked at MQ V6, but failed at V710.
  The exits were invoked on a SVRCONN channel using data
  encryption. The send exit increases the size of the data to
  be sent, and acquires a new buffer to hold the data since the
  send buffer is no longer big enough. But CSQXREXT then passes
  on the size of the new buffer instead of the size of the
  data to the receive exit, which causes that exit to fail with
  MQRC 2537, MQRC_CHANNEL_NOT_AVAILABLE.
  

Problem conclusion

• The function rriCallSndExit in CSQXREXT has been altered to
  correctly pass back the size of the data and not of the buffer.
  CSQXBPAC has also been updated to show the correct buffer length
  on exit.
  100Y
  CSQXBPAL
  CSQXREXT
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UK93507

Modules/Macros

• CSQXBPAL CSQXREXT
  

Fix information

• Fixed component name

  WMQ Z/OS V7

• Fixed component ID

  5655R3600

Applicable component levels

• R100 PSY UK93507

     UP13/06/14 P F306

Fix is available

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