PQ55451: CALL TO GETSOCKOPT() FOR SO_ERROR RETURNS WITH ERRNO=0 WHEN SOCKET IS NON-BLOCKING AND CONNECT FAILS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Call to getsockopt() for SO_ERROR returns with errno=0 when
  connect() fails on a non-blocking socket.
  A non-blocking connect() is issued and returns with EINPROGRESS
  because the call did not complete. A select() is issued to
  monitor the socket for the competion of the connect().  The
  connect() request times out, causing the select() to complete.
  The application issues getsockopt() for SO_ERROR to get the
  status of the connect(), and errno=0 is returned instead of
  ETIMEDOUT.
  KEYWORDS:
  GETSOCKOPT GETSOCKOPT() BPX1OPT SO_ERROR SOCKET ERROR ERRNO
  ETIMEDOUT 1127 x'467' 60 x'3C'
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for OS/390 Release 10 IP and                 *
  *                 z/OS Version 1 Release 2 IP                  *
  ****************************************************************
  * PROBLEM DESCRIPTION: GETSOCKOPT for SO_ERROR returns an      *
  *                      incorrect ERRNO after a CONNECT times   *
  *                      out                                     *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An application program issues a non-blocking CONNECT.  As
  expected, the CONNECT returns RETCODE -1 and ERRNO EINPROGRESS
  (36) which indicates that the CONNECT is in progress.  The
  application program then issues a SELECT in order to wait until
  the CONNECT is no longer in progress.  Because the remote system
  is not receiving, the CONNECT times out.  EZBTCPTM sets an error
  value of ETIMEDOUT (60) but does not propagate it to the SCB
  that represents the connecting socket.  The SELECT completes and
  the application program issues a GETSOCKOPT for SO_ERROR in
  order to determine whether or not the CONNECT succeeded.  Since
  the SCB does not contain the correct ERRNO, the GETSOCKOPT
  returns an ERRNO of 0 which causes the application program to
  erroneously determine that the CONNECT succeeded.
  +-------------------------------------------------------------+
  + Please check our Communications Server for OS/390 homepages +
  + for common networking tips and fixes.  The URL for these    +
  + homepages can be found in Informational APAR II11334.       +
  +-------------------------------------------------------------+
  

Problem conclusion

• EZBTCPTM has been amended to propagate an ETIMEDOUT error to the
  SCB.
  
  * Cross Reference between External and Internal Names
  

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:

  UQ61332 UQ61333

Modules/Macros

• EZBTCPTM
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R120 PSY UQ61332

     UP02/01/15 P F201

• R50A PSY UQ61333

     UP02/01/15 P F201

Fix is available

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