[YDBTest#598] Fix various issues in SOCKET USE command (GT.M V7.0-003 regression)

Background

• See !1524 (comment 1901072557) for more details. But basically the below test case failed an assert.

  $ $gtm_dist/mumps -run %XCMD 'open "socket":(listen="9999:TCP":IOERROR="NOTRAP")::"SOCKET" use "socket":(options="KEEPINTVL=0") '
  %YDB-F-ASSERT, Assert failed in sr_unix/gtm_fd_trace.c line 185 for expression (FALSE)

Issue

• The issue was that a close(socketptr->sd); was done in sr_port/iosocket_tcp_keepalive.c after commit 0e138473 because freesocket was TRUE. But in this case, iosocket_use() had called iosocket_tcp_keepalive() with a copy of the socket device (curr_socketptr variable in sr_port/iosocket_use.c) while keeping the original socket device still accessible using the variable socketptr in iosocket_use.c. This meant that close() in iosocket_tcp_keepalive closed curr_socketptr->sd and reset it to be FD_INVALID but did not do the same to the copy socketptr->sd.

• And when halting, the process looked at all open devices and found socketptr->sd as a valid fd and so tried to close it resulting in the close() failing and causing the assert.

• There is a pre-existing comment which says SOCKET_FREE should not be used on the copy (line 537 below).

  sr_port/iosocket_use.c

    536                 /* Make a copy of the socket_struct so most errors leave the previous structure as is.
    537                  * SOCKET_FREE should not be used on this copy since it frees other things such as buffers
    538                  * DELIMITER is an exception due to how iosocket_delimiter manages storage.

• Inspite of this, we end up doing a SOCKET_FREE() on the copy when called through iosocket_tcp_keepalive() in iosocket_use().

• This is incorrect and is the cause of the issue.

• Additionally, after the call to iosocket_tcp_keepalive(), iosocket_use.c does a free(curr_socketptr) again. This would end up being a double-free.

Fix

• The fix is simple and is to pass FALSE as the freesocket argument to iosocket_tcp_keepalive() in sr_port/iosocket_use.c.

• And to do the close(socketptr->sd) and SOCKET_FREE(socketptr) calls only if freesocket argument is TRUE (previously this happened if freesocket || trap was TRUE).

• Note that we still issue a rts_error if freesocket || trap is TRUE.

• This will take care of all the above described problems.

Tests

• Below were the tests done to test OPEN/USE with IOERROR=NOTRAP/TRAP. Including scenarios tested during commit 0e138473.

  YDB>open "socket":(listen="9999:TCP":IOERROR="NOTRAP":options="KEEPINTVL=0")::"SOCKET" set x=$DEVICE zwrite x
  %YDB-E-SETSOCKOPTERR, Setting the socket attribute TCP_KEEPINTVL failed: (errno == 22) Invalid argument
  
  YDB>open "socket":(listen="9999:TCP":IOERROR="TRAP":options="KEEPINTVL=0")::"SOCKET" set x=$DEVICE zwrite x
  %YDB-E-SETSOCKOPTERR, Setting the socket attribute TCP_KEEPINTVL failed: (errno == 22) Invalid argument
  
  YDB>open "socket":(listen="9999:TCP":IOERROR="NOTRAP")::"SOCKET" use "socket":(options="KEEPINTVL=0") set x=$device use $principal zwrite x zshow "d"
  x="1,Invalid argument"
  /dev/pts/1 OPEN TERMINAL NOPAST NOESCA NOREADONLY TYPE WIDTH=124 LENG=51 TTSYNC NOHOSTSYNC
  socket OPEN SOCKET TOTAL=1 CURRENT=0
          SOCKET[0]=h1715372292002 DESC=3 LISTENING PASSIVE  NOTRAP  PORT=9999
                  ZDELAY  ZBFSIZE=1024 ZIBFSIZE=131072 NODELIMITER
  
  YDB>open "socket":(listen="9998:TCP":IOERROR="TRAP")::"SOCKET" use "socket":(options="KEEPINTVL=0")
  %YDB-E-SETSOCKOPTERR, Setting the socket attribute TCP_KEEPINTVL failed: (errno == 22) Invalid argument