PI94075: UNKNOWN_CLIENT_HOSTNAME WHEN CICS ISSUES GETADDRINFO ON S8 TCB, DD SYSTCPD IS NOT USED.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CICS TS 5.3 has is not always using SYSTCPD DD statement in
  preference to /etc/resolv.conf and this causes failures as seen
  in CICS trace:
  
  S8000 SO 0427 SOIS  EVENT GETADDRINFO_ENTRY
  S8000 SO 0428 SOIS  EVENT GETADDRINFO_EXIT      -1,1,78AE1004
  S8000 SO 0429 SOIS  *EXC* GETADDRINFO_ERROR     -1,1,78AE1004
  S8000 SO 0402 SOIS  EXIT  VERIFY_IP_ADDRESS/EXCEPTION
                      UNKNOWN_CLIENT_HOSTNAME.
  The problem was originally fixed by APARs:
  PM48597 (CICS) and OA37056(TCP/IP).
  "IP addresses cannot be resolved by function GETHOSTBYNAME
  when using DD SYSTCPD. A new bit is added to the BPXYPRLI for
  use by CICS and TCP/IP to determine proper search order
  for gethostbyname."
  This fix works fine when the call is on the CICS SO TCB.
  From a CICS dump, bit setting PRLICICS is set
  (x'04' at offset x'18') into the PRLI :
  Address
     7F50EAB0
                  Hex                                 EBCDIC
         D7D9D3C9 E6000070 0203042C FD7FFFFF *PRLIW.
    +10  84000000 172EE450 2C7B5A00 00000000 *d.....
                           [[
  When we check the PRLI's for the S8 TCBs we find that it is not
  set. This causes /etc/resolv.conf to be used in preference
  to SYSTCPD DD.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: Outbound web request using SSL fails    *
  *                      and message DFHSO0113 is issued.        *
  *                                                              *
  ****************************************************************
  z/OS has been configured with access to multiple different DNS
  servers.  CICS needs to use the DNS servers (and other resolver
  information) specified in the parameter file named on the
  SYSTCPD DD statement in the CICS job.
  
  A CICS application makes an outbound web request that uses SSL.
  CICS uses the BPX1GAI service to lookup the supplied hostname.
  This service checks bit PRLICICS to determine if the call was
  made by CICS or not.  If the flag is set then SYSTCPD would be
  used first to locate resolver information.  CICS has only set
  the flag for the SO TCB.  This request is made using an S8 TCB
  and so does not have the flag set on.  The BPX1GAI service uses
  /etc/resolv.conf instead of SYSTCPD to obtain the DNS server
  address and the hostname lookup fails.  This causes CICS to
  issue message DFHSO0113 and for the outbound web request to
  fail.
  
  Keywords: SO0429  SO0113  msgDFHSO0113
  

Problem conclusion

• CICS has been changed to ensure that the PRLICICS Bit is set on
  for S8 TCBs in addition to the SO TCB.
  

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:

  UI56094 UI56095 UI56096

Modules/Macros

• DFHDSBR  DFHDSIT  DFHLEPT@ DFHLEPTC DFHLEPTD
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R000 PSY UI56095

     UP18/05/29 P F805

• R003 PSY UI56096

     UP18/05/29 P F805

• R100 PSY UI56094

     UP18/06/02 P F806

Fix is available

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