git.sur5r.net Git - openldap/blob - servers/slapd/cancel.c

   1 /* cancel.c - LDAP cancel extended operation */
   2 /* $OpenLDAP$ */
   3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   4  *
   5  * Copyright 1998-2017 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16
  17 #include "portable.h"
  18
  19 #include <stdio.h>
  20
  21 #include <ac/socket.h>
  22 #include <ac/string.h>
  23 #include <ac/unistd.h>
  24
  25 #include "slap.h"
  26
  27 #include <lber_pvt.h>
  28 #include <lutil.h>
  29
  30 const struct berval slap_EXOP_CANCEL = BER_BVC(LDAP_EXOP_CANCEL);
  31
  32 int cancel_extop( Operation *op, SlapReply *rs )
  33 {
  34         Operation *o;
  35         int rc;
  36         int opid;
  37         BerElement *ber;
  38
  39         assert( ber_bvcmp( &slap_EXOP_CANCEL, &op->ore_reqoid ) == 0 );
  40
  41         if ( op->ore_reqdata == NULL ) {
  42                 rs->sr_text = "no message ID supplied";
  43                 return LDAP_PROTOCOL_ERROR;
  44         }
  45
  46         ber = ber_init( op->ore_reqdata );
  47         if ( ber == NULL ) {
  48                 rs->sr_text = "internal error";
  49                 return LDAP_OTHER;
  50         }
  51
  52         if ( ber_scanf( ber, "{i}", &opid ) == LBER_ERROR ) {
  53                 rs->sr_text = "message ID parse failed";
  54                 return LDAP_PROTOCOL_ERROR;
  55         }
  56
  57         (void) ber_free( ber, 1 );
  58
  59         Statslog( LDAP_DEBUG_STATS, "%s CANCEL msg=%d\n",
  60                 op->o_log_prefix, opid, 0, 0, 0 );
  61
  62         if ( opid < 0 ) {
  63                 rs->sr_text = "message ID invalid";
  64                 return LDAP_PROTOCOL_ERROR;
  65         }
  66
  67         ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
  68
  69         if ( op->o_abandon ) {
  70                 /* FIXME: Should instead reject the cancel/abandon of this op, but
  71                  * it seems unsafe to reset op->o_abandon once it is set. ITS#6138.
  72                  */
  73                 rc = LDAP_OPERATIONS_ERROR;
  74                 rs->sr_text = "tried to abandon or cancel this operation";
  75                 goto out;
  76         }
  77
  78         LDAP_STAILQ_FOREACH( o, &op->o_conn->c_pending_ops, o_next ) {
  79                 if ( o->o_msgid == opid ) {
  80                         /* TODO: We could instead remove the cancelled operation
  81                          * from c_pending_ops like Abandon does, and send its
  82                          * response here.  Not if it is pending because of a
  83                          * congested connection though.
  84                          */
  85                         rc = LDAP_CANNOT_CANCEL;
  86                         rs->sr_text = "too busy for Cancel, try Abandon instead";
  87                         goto out;
  88                 }
  89         }
  90
  91         LDAP_STAILQ_FOREACH( o, &op->o_conn->c_ops, o_next ) {
  92                 if ( o->o_msgid == opid ) {
  93                         break;
  94                 }
  95         }
  96
  97         if ( o == NULL ) {
  98                 rc = LDAP_NO_SUCH_OPERATION;
  99                 rs->sr_text = "message ID not found";
 100
 101         } else if ( o->o_tag == LDAP_REQ_BIND
 102                         || o->o_tag == LDAP_REQ_UNBIND
 103                         || o->o_tag == LDAP_REQ_ABANDON ) {
 104                 rc = LDAP_CANNOT_CANCEL;
 105
 106         } else if ( o->o_cancel != SLAP_CANCEL_NONE ) {
 107                 rc = LDAP_OPERATIONS_ERROR;
 108                 rs->sr_text = "message ID already being cancelled";
 109
 110 #if 0
 111         } else if ( o->o_abandon ) {
 112                 /* TODO: Would this break something when
 113                  * o_abandon="suppress response"? (ITS#6138)
 114                  */
 115                 rc = LDAP_TOO_LATE;
 116 #endif
 117
 118         } else {
 119                 rc = LDAP_SUCCESS;
 120                 o->o_cancel = SLAP_CANCEL_REQ;
 121                 o->o_abandon = 1;
 122         }
 123
 124  out:
 125         ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
 126
 127         if ( rc == LDAP_SUCCESS ) {
 128                 LDAP_STAILQ_FOREACH( op->o_bd, &backendDB, be_next ) {
 129                         if( !op->o_bd->be_cancel ) continue;
 130
 131                         op->oq_cancel.rs_msgid = opid;
 132                         if ( op->o_bd->be_cancel( op, rs ) == LDAP_SUCCESS ) {
 133                                 return LDAP_SUCCESS;
 134                         }
 135                 }
 136
 137                 do {
 138                         /* Fake a cond_wait with thread_yield, then
 139                          * verify the result properly mutex-protected.
 140                          */
 141                         while ( o->o_cancel == SLAP_CANCEL_REQ )
 142                                 ldap_pvt_thread_yield();
 143                         ldap_pvt_thread_mutex_lock( &op->o_conn->c_mutex );
 144                         rc = o->o_cancel;
 145                         ldap_pvt_thread_mutex_unlock( &op->o_conn->c_mutex );
 146                 } while ( rc == SLAP_CANCEL_REQ );
 147
 148                 if ( rc == SLAP_CANCEL_ACK ) {
 149                         rc = LDAP_SUCCESS;
 150                 }
 151
 152                 o->o_cancel = SLAP_CANCEL_DONE;
 153         }
 154
 155         return rc;
 156 }