source: vendor/current/ctdb/server/ctdb_banning.c

/* 
   ctdb banning code

   Copyright (C) Ronnie Sahlberg  2009

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "system/time.h"
#include "system/network.h"
#include "system/filesys.h"
#include "system/wait.h"

#include <talloc.h>
#include <tevent.h>

#include "lib/util/debug.h"
#include "lib/util/samba_util.h"

#include "ctdb_private.h"
#include "ctdb_client.h"

#include "common/common.h"
#include "common/logging.h"

static void ctdb_ban_node_event(struct tevent_context *ev,
                                struct tevent_timer *te,
                                struct timeval t, void *private_data)
{
        struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);

        /* Make sure we were able to freeze databases during banning */
        if (!ctdb_db_all_frozen(ctdb)) {
                DEBUG(DEBUG_ERR, ("Banning timedout, but still unable to freeze databases\n"));
                ctdb_ban_self(ctdb);
                return;
        }

        DEBUG(DEBUG_ERR,("Banning timedout\n"));
        ctdb->nodes[ctdb->pnn]->flags &= ~NODE_FLAGS_BANNED;

        if (ctdb->banning_ctx != NULL) {
                talloc_free(ctdb->banning_ctx);
                ctdb->banning_ctx = NULL;
        }
}

void ctdb_local_node_got_banned(struct ctdb_context *ctdb)
{
        struct ctdb_db_context *ctdb_db;

        DEBUG(DEBUG_NOTICE,("This node has been banned - forcing recovery\n"));

        /* Reset the generation id to 1 to make us ignore any
           REQ/REPLY CALL/DMASTER someone sends to us.
           We are now banned so we shouldnt service database calls
           anymore.
        */
        ctdb->vnn_map->generation = INVALID_GENERATION;
        for (ctdb_db = ctdb->db_list; ctdb_db != NULL; ctdb_db = ctdb_db->next) {
                ctdb_db->generation = INVALID_GENERATION;
        }

        /* Recovery daemon will set the recovery mode ACTIVE and freeze
         * databases.
         */

        ctdb_release_all_ips(ctdb);
}

int32_t ctdb_control_set_ban_state(struct ctdb_context *ctdb, TDB_DATA indata)
{
        struct ctdb_ban_state *bantime = (struct ctdb_ban_state *)indata.dptr;
        bool already_banned;

        DEBUG(DEBUG_INFO,("SET BAN STATE\n"));

        if (bantime->pnn != ctdb->pnn) {
                DEBUG(DEBUG_WARNING,
                      ("SET_BAN_STATE control for PNN %d ignored\n",
                       bantime->pnn));
                return -1;
        }

        already_banned = false;
        if (ctdb->banning_ctx != NULL) {
                talloc_free(ctdb->banning_ctx);
                ctdb->banning_ctx = NULL;
                already_banned = true;
        }

        if (bantime->time == 0) {
                DEBUG(DEBUG_ERR,("Unbanning this node\n"));
                ctdb->nodes[bantime->pnn]->flags &= ~NODE_FLAGS_BANNED;
                return 0;
        }

        if (ctdb->tunable.enable_bans == 0) {
                DEBUG(DEBUG_ERR,("Bans are disabled - ignoring ban of node %u\n", bantime->pnn));
                return 0;
        }

        ctdb->banning_ctx = talloc(ctdb, struct ctdb_ban_state);
        if (ctdb->banning_ctx == NULL) {
                DEBUG(DEBUG_CRIT,(__location__ " ERROR Failed to allocate new banning state\n"));
                return -1;
        }
        *((struct ctdb_ban_state *)(ctdb->banning_ctx)) = *bantime;


        DEBUG(DEBUG_ERR,("Banning this node for %d seconds\n", bantime->time));
        ctdb->nodes[bantime->pnn]->flags |= NODE_FLAGS_BANNED;

        tevent_add_timer(ctdb->ev, ctdb->banning_ctx,
                         timeval_current_ofs(bantime->time,0),
                         ctdb_ban_node_event, ctdb);

        if (!already_banned) {
                ctdb_local_node_got_banned(ctdb);
        }
        return 0;
}

int32_t ctdb_control_get_ban_state(struct ctdb_context *ctdb, TDB_DATA *outdata)
{
        struct ctdb_ban_state *bantime;

        bantime = talloc(outdata, struct ctdb_ban_state);
        CTDB_NO_MEMORY(ctdb, bantime);

        if (ctdb->banning_ctx != NULL) {
                *bantime = *(struct ctdb_ban_state *)(ctdb->banning_ctx);
        } else {
                bantime->pnn = ctdb->pnn;
                bantime->time = 0;
        }

        outdata->dptr  = (uint8_t *)bantime;
        outdata->dsize = sizeof(struct ctdb_ban_state);

        return 0;
}

/* Routine to ban ourselves for a while when trouble strikes. */
void ctdb_ban_self(struct ctdb_context *ctdb)
{
        TDB_DATA data;
        struct ctdb_ban_state bantime;

        bantime.pnn  = ctdb->pnn;
        bantime.time = ctdb->tunable.recovery_ban_period;

        data.dsize = sizeof(bantime);
        data.dptr  = (uint8_t *)&bantime;

        ctdb_control_set_ban_state(ctdb, data);
}