PI32127: TCP ASYNC SEND WITH SO_SNDTIMEO SET DOES NOT WORK CORRECTLY

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Asychronous send operation on a TCP socket with a setsockopt
  for SO_SNDTIMEO set on may not complete correctly.
  
  
  Other symptoms:
  
  - TCB lock held by a process (DUCB) that is no longer running
    (verified in a dump).  This will present externally as NETSTAT
    commands hanging, or the inability to STOP the TCPIP address
    space.
  
  - S0C4 or S4C5 ABENDs in a routine trying to reference a TCB,
    typically EZBTCRD, EZBTCUTL, EZBTCSTR, EZBTCICT, or EZBTCITS.
    There will likely be several of these ABENDs.  This can
    potentially be accompanied by an IST1578I DEVICE INOP DETECTED
    FOR osatrlename BY IUTLLCDQ CODE = 001 message from VTAM.
  
  - Loop in TCPIP code, including socket calls from other address
    spaces.  Examination of a dump will show it is in an ITEVENT
    macro, referencing an EVNT control block whose
    itevent_e_nextactive field (+4) points to itself.
  
  - Also see APAR PI28400.
  
  - DISPLAY TCPIP command does not respond, causes backup in z/OS
    Command CLASS2 (IEE822E IEE806A).  This results in other
    commands not working, such a LOGON and START. A  CMDS DISPLAY
    command will show the commands that are backed up (IEE062I).
  
  Keywords:
  
   ABENDS00C4  ABENDS04C5 76690402 769E0402
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * All users of the IBM Communications Server for z/OS Version  *
  * 2 Release 1: IP                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * TCP socket applications can see incorrect data written out   *
  * when the SO_SNDTIMEO socket option is set.                   *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply PTF                                                    *
  ****************************************************************
  When the TCP socket application hangs waiting on a send type
  socket call to complete when the SO_SNDTIMEO socket option is
  set, incorrect data can be transmitted when the send completes.
  

Problem conclusion

• The stack code is changed to transmit the correct data when
  completing the TCP socket application which was hung waiting on
  a send type socket call to complete when the SO_SNDTIMEO socket
  option is set.
  

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:

  106PC1Ÿ UI24538 106PC1Ÿ

Modules/Macros

• EZBT6FWR EZBTSFWR EZBTCFWR EZBT6LWR EZBTLFWR EZBTCFRD EZBRWWRI
  EZBUDWRT
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R210 PSY UI24538

     UP15/02/23 P F502

Fix is available

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