PM77862: GETADDRINFO LOOPS CALLING BPX1RED

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• The resolver is configured to use TCP sockets and has two name
  servers defined.  A getaddrinfo call is issued by an
  application. The first name server returns more information
  than can be returned to the caller, causing a truncation bit to
  be set.  An error occurs trying to read the data returned by the
  first name server.  The second name server is queried.  An
  answer is returned which can fit in the supplied buffer, but the
  truncation bit was not cleared.  This causes a loop in EZBRERSN
  trying to read a negative amount of data.  The getaddrinfo will
  not return to the caller.
  .
  VERIFICATION STEPS:
  1) ip systrace shows repeated calls to BPX1RED
  2) ip summ format will show that task in a resolver call such as
  getaddrinfo.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release(s) 12 and 13 IP   *
  *                 Resolver                                     *
  ****************************************************************
  * PROBLEM DESCRIPTION: A loop occurs during GetHostByAddr      *
  *                      function processing while reading data  *
  *                      from a TCP socket connected to a name   *
  *                      server that has returned only partial   *
  *                      results.                                *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The checks for a truncated packet allowed a loop control
  variable to become negative and a loop occurred.
  +-------------------------------------------------------------+
  + 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

• EZBRERSN has been amended to correctly check for a truncated
  packet and discontinue processing with the current name
  server and continue onto the next.
  
  * 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:

  UK90683 UK90684

Modules/Macros

• EZBRERSN
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R1C0 PSY UK90683

     UP13/02/02 P F302

• R1D0 PSY UK90684

     UP13/02/02 P F302

Fix is available

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