source4/cluster/ctdb/common/ctdb_message.c

   1 /*
   2    ctdb_message protocol code
   3
   4    Copyright (C) Andrew Tridgell  2007
   5
   6    This library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2 of the License, or (at your option) any later version.
  10
  11    This library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with this library; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19 */
  20 /*
  21   see http://wiki.samba.org/index.php/Samba_%26_Clustering for
  22   protocol design and packet details
  23 */
  24 #include "includes.h"
  25 #include "lib/events/events.h"
  26 #include "lib/tdb/include/tdb.h"
  27 #include "system/network.h"
  28 #include "system/filesys.h"
  29 #include "../include/ctdb_private.h"
  30
  31
  32 /*
  33   called when a CTDB_REQ_MESSAGE packet comes in
  34
  35   this dispatches the messages to the registered ctdb message handler
  36 */
  37 void ctdb_request_message(struct ctdb_context *ctdb, struct ctdb_req_header *hdr)
  38 {
  39         struct ctdb_req_message *c = (struct ctdb_req_message *)hdr;
  40         TDB_DATA data;
  41         if (ctdb->message_handler == NULL) {
  42                 /* no registered message handler */
  43                 talloc_free(hdr);
  44                 return;
  45         }
  46         data.dptr = &c->data[0];
  47         data.dsize = c->datalen;
  48         ctdb->message_handler(ctdb, c->srvid, data, ctdb->message_private);
  49         talloc_free(hdr);
  50 }
  51
  52
  53 /*
  54   send a ctdb message
  55 */
  56 int ctdb_send_message(struct ctdb_context *ctdb, uint32_t vnn,
  57                       uint32_t srvid, TDB_DATA data)
  58 {
  59         struct ctdb_req_message *r;
  60         int len;
  61
  62         len = offsetof(struct ctdb_req_message, data) + data.dsize;
  63         r = ctdb->methods->allocate_pkt(ctdb, len);
  64         CTDB_NO_MEMORY(ctdb, r);
  65
  66         r->hdr.length    = len;
  67         r->hdr.operation = CTDB_REQ_MESSAGE;
  68         r->hdr.destnode  = vnn;
  69         r->hdr.srcnode   = ctdb->vnn;
  70         r->hdr.reqid     = 0;
  71         r->srvid         = srvid;
  72         r->datalen       = data.dsize;
  73         memcpy(&r->data[0], data.dptr, data.dsize);
  74
  75         ctdb_queue_packet(ctdb, &r->hdr);
  76
  77         talloc_free(r);
  78         return 0;
  79 }
  80
  81 /*
  82   setup handler for receipt of ctdb messages from ctdb_send_message()
  83 */
  84 int ctdb_set_message_handler(struct ctdb_context *ctdb, ctdb_message_fn_t handler,
  85                              void *private)
  86 {
  87         ctdb->message_handler = handler;
  88         ctdb->message_private = private;
  89         return 0;
  90 }
  91