src/rmr/si/src/si95/siwait.c

   1 // vim: noet sw=4 ts=4:
   2 /*
   3 ==================================================================================
   4     Copyright (c) 2020 Nokia
   5     Copyright (c) 2020 AT&T Intellectual Property.
   6
   7    Licensed under the Apache License, Version 2.0 (the "License");
   8    you may not use this file except in compliance with the License.
   9    You may obtain a copy of the License at
  10
  11        http://www.apache.org/licenses/LICENSE-2.0
  12
  13    Unless required by applicable law or agreed to in writing, software
  14    distributed under the License is distributed on an "AS IS" BASIS,
  15    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16    See the License for the specific language governing permissions and
  17    limitations under the License.
  18 ==================================================================================
  19 */
  20
  21 /*
  22 **************************************************************************
  23 *  Mnemonic: SIwait
  24 *  Abstract: This  routine will wait for an event to occur on the
  25 *            connections in tplist. When an event is received on a fd
  26 *            the status of the fd is checked and the event handled, driving
  27 *            a callback routine if necessary. The system call poll is usd
  28 *            to wait, and will be interrupted if a signal is caught,
  29 *            therefore the routine will handle any work that is required
  30 *            when a signal is received. The routine continues to loop
  31 *            until the shutdown flag is set, or until there are no open
  32 *            file descriptors on which to wait.
  33 *  Parms:    gptr - Pointer to the global information block
  34 *  Returns:  SI_OK if the caller can continue, SI_ERROR if all sessions have been
  35 *            stopped, or the interface cannot proceed. When SI_ERROR is
  36 *            returned the caller should cleanup and exit immediatly (we
  37 *            have probably received a sigter or sigquit.
  38 *  Date:     28 March 1995
  39 *  Author:   E. Scott Daniels
  40 *
  41 *  Modified: 11 Apr 1995 - To pass execption to select when no keyboard
  42 *            19 Apr 1995 - To call do key to do better keyboard editing
  43 *            18 Aug 1995 - To init kstat to 0 to prevent key hold if
  44 *                          network data pending prior to entry.
  45 *                       31 Jul 2016 - Major formatting clean up in the main while loop.
  46 **************************************************************************
  47 */
  48 #include  "sisetup.h"     //  get the setup stuff
  49 #include "sitransport.h"
  50 #include        <sys/wait.h>
  51
  52
  53 extern int SIwait( struct ginfo_blk *gptr ) {
  54         int fd;                                                 //  file descriptor for use in this routine
  55         int ((*cbptr)());                               //  pointer to callback routine to call
  56         int status = SI_OK;                             //  return status
  57         int addrlen;                                    //  length of address from recvfrom call
  58         int i;                                                  //  loop index
  59         struct tp_blk *tpptr;                   //  pointer at tp stuff
  60         struct tp_blk *nextone;                 //  point at next block to process in loop
  61         int pstat;                                              //  poll status
  62         struct timeval  timeout;                //  delay to use on select call
  63         char *buf;
  64         char *ibuf;
  65
  66         ibuf = (char *) malloc( 2048 );
  67
  68         gptr->sierr = SI_ERR_SHUTD;
  69
  70         if( gptr->flags & GIF_SHUTDOWN ) {                              //  cannot do if we should shutdown
  71                 fprintf( stderr, ">>> wait: shutdown on entry????\n" );
  72                 return SI_ERROR;                                                        //  so just get out
  73         }
  74
  75         gptr->sierr = SI_ERR_HANDLE;
  76
  77         if( gptr->magicnum != MAGICNUM ) {                              //  if not a valid ginfo block
  78                 fprintf( stderr, ">>> wait: bad magic on entry????\n" );
  79                 return SI_ERROR;
  80         }
  81
  82         timeout.tv_sec = 0;
  83         timeout.tv_usec = 500000;                               // pop every 500ms to ensure we pick up new outbound connections in list
  84
  85         do {                                                                    // main wait/process loop
  86
  87                 SIbldpoll( gptr );                                      // build the fdlist for poll
  88                 pstat = select( gptr->fdcount, &gptr->readfds, &gptr->writefds, &gptr->execpfds, &timeout );
  89
  90                 if( (pstat < 0 && errno != EINTR)  ) {
  91                         gptr->fdcount = 0;                              //  prevent trying to look at a session
  92                         gptr->flags |= GIF_SHUTDOWN;    //  cause cleanup and exit at end
  93                 }
  94
  95                 if( pstat > 0  &&  (! (gptr->flags & GIF_SHUTDOWN)) ) {
  96                         for( tpptr = gptr->tplist; tpptr != NULL; tpptr = nextone ) {
  97                                 nextone = tpptr->next;                          //  prevent issues if we delete the block during loop
  98
  99                                 if( tpptr->fd >= 0 ) {
 100                                         if( tpptr->squeue != NULL && (FD_ISSET( tpptr->fd, &gptr->writefds )) ) {
 101                                                 SIsend( gptr, tpptr );                  //  send if clear to send
 102                                         }
 103
 104                                         if( FD_ISSET( tpptr->fd, &gptr->execpfds ) ) {
 105                                                         ;                               // sunos seems to set the except flag for unknown reasons; ignore it
 106                                         } else {
 107                                                 if( FD_ISSET( tpptr->fd, &gptr->readfds ) ) {                   // ready to read
 108                                                         fd = tpptr->fd;
 109                                                         tpptr->rcvd++;
 110
 111                                                         if( tpptr->flags & TPF_LISTENFD ) {                                     // new session request
 112                                                                 errno=0;
 113                                                                 status = SInewsession( gptr, tpptr );                   // accept connection
 114                                                         } else  {                                                                                       //  data received on a regular port (we support just tcp now
 115                                                                 status = RECV( fd, gptr->rbuf, MAX_RBUF, 0 );   //  read data
 116                                                                 //fprintf( stderr, ">>>>> wait popped status =%d\n", status );
 117                                                                 if( status > 0  &&  ! (tpptr->flags & TPF_DRAIN) ) {
 118                                                                         if( (cbptr = gptr->cbtab[SI_CB_CDATA].cbrtn) != NULL ) {
 119                                                                                 status = (*cbptr)( gptr->cbtab[SI_CB_CDATA].cbdata, fd, gptr->rbuf, status );
 120                                                                                 SIcbstat( gptr, status, SI_CB_CDATA );  //  handle cb status
 121                                                                         }
 122                                                                 } else {                                                                                // no bites, but read flagged indicates disconnect
 123                                                                         if( (cbptr = gptr->cbtab[SI_CB_DISC].cbrtn) != NULL ) {
 124                                                                                 status = (*cbptr)( gptr->cbtab[SI_CB_DISC].cbdata, tpptr->fd );
 125                                                                                 SIcbstat( gptr, status, SI_CB_DISC );   //  handle status
 126                                                                         }
 127                                                                         SIterm( gptr, tpptr );
 128                                                                 }
 129                                                         }
 130                                                 }
 131                                         }
 132                                 }                                                               //  if still good fd
 133                         }
 134                 }
 135         } while( gptr->tplist != NULL && !(gptr->flags & GIF_SHUTDOWN) );
 136
 137         free( ibuf );
 138         if( gptr->tplist == NULL )                                      //  indicate all fds closed
 139                 gptr->sierr = SI_ERR_NOFDS;
 140
 141         if( gptr->flags & GIF_SHUTDOWN ) {                      //  we need to stop for some reason
 142                 gptr->sierr = SI_ERR_SHUTD;                             //  indicate error exit status
 143                 status = SI_ERROR;                                              //  status should indicate to user to die
 144                 SIshutdown( gptr );                                             //  clean things up
 145         } else {
 146                 status = SI_OK;                                                 //  user can continue to process
 147         }
 148
 149         return status;
 150 }