PM59618: FTCHKCMD USER EXIT SCRATCHPAD BUFFER CLEARED AFTER PASS COMMAND ACCEPTED.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A FTCHKCMD user exit is being used by the FTP server.  The last
  parameter to the user exit is the address of a 256-byte
  scratchpad, which is passed to the user exit each time and
  should not be altered or cleared by the FTP server.  The buffer
  is being cleared after a PASS command is successfully processed
  by the FTP server.  Any information in the scratchpad will not
  be available when the exit is invoked for the next command.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release(s) 12 and 13      *
  *                 IP: FTP                                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: When the user implements the FTCHKCMD   *
  *                      exit and changes the scratchpad area    *
  *                      between calls to the exit. This area    *
  *                      is being cleared out after the PASS     *
  *                      command. It should not be changed by    *
  *                      FTP at any time.                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A PASS command will generate another execv() of ftpdns. This
  causes the main() routine in EZAFTPRX to be entered multiple
  times. Code is in place to copy control blocks into storage
  which is tied to the address space, so it is not freed during
  the execv processing. This is managed by copyCtrlBlks() and
  initReExec(). The problem is the storage for the user exit,
  pointed to by ftip->uexwaptr, is not copied.
  +-------------------------------------------------------------+
  + 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

• The scratchpad area of server FTCHKCMD exit has been preserved.
  
  The following document has been updated to add a restriction.
  
  IBM Communications Server:
  IP Configuration Reference
  SC318776
  
  Change the contents in section "The FTCHKCMD user exit"
  
  From:
  
  +52 Pointer to a 256-byte scratchpad buffer, which can be used
      to pass information between user exits. All exits receive a
      pointer to this buffer except FTCHKIP and FTCHKPWD. FTP
      does not query or alter the contents of the scratchpad at
      any time.
  
  To:
  
  +52 Pointer to a 256-byte scratchpad buffer, which can be used
      to pass information between user exits. All exits receive a
      pointer to this buffer except FTCHKIP and FTCHKPWD. FTP
      does not query or alter the contents of the scratchpad at
      any time. The extended tracing (DUMP) identifier of the
      scratchpad is 87. If extended tracing of the scratchpad is
      requested, the contents are dumped after execution of the
      user exit.
  
      Restriction: When the exit is being used for USER/PASS
      command processing, the scratchpad buffer should not contain
      a pointer unless the storage location being referenced is
      available to all address spaces.
  
  * Cross Reference between External and Internal Names
  EZAECCMD (FTCHKCMD)  EZAECCM1 (FTCHKCM1)  EZAECCM2 (FTCHKCM2)
  EZAECCM3 (FTPOSTPR)  EZAEC046 (FTCHKJES)  EZAFTPPO (FTPOSTPA)
  EZAFTPSM (FTPDMSG )  EZAECCMD (FTCHKCMD)  EZAECCM1 (FTCHKCM1)
  EZAECCM2 (FTCHKCM2)  EZAECCM3 (FTPOSTPR)  EZAEC046 (FTCHKJES)
  EZAFTPPO (FTPOSTPA)  EZAFTPSM (FTPDMSG )
  

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:

  UK78146 UK78147

Modules/Macros

• EZAECCMD EZAECCM1 EZAECCM2 EZAECCM3 EZAEC046
  EZAFTPAC EZAFTPCG EZAFTPCL EZAFTPCP EZAFTPCY EZAFTPDM EZAFTPEA
  EZAFTPEH EZAFTPEP EZAFTPGL EZAFTPGM EZAFTPMK EZAFTPM9 EZAFTPPO
  EZAFTPRM EZAFTPRX EZAFTPSM EZAFTPSR EZAFTPTO
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R1C0 PSY UK78146

     UP12/05/30 P F205

• R1D0 PSY UK78147

     UP12/05/30 P F205

Fix is available

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