source: trunk/server/source4/wrepl_server/wrepl_server.c

/* 
   Unix SMB/CIFS implementation.
   
   WINS Replication server
   
   Copyright (C) Stefan Metzmacher      2005
   
   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 "includes.h"
#include "../lib/util/dlinklist.h"
#include "smbd/service_task.h"
#include "smbd/service.h"
#include "lib/messaging/irpc.h"
#include "librpc/gen_ndr/winsrepl.h"
#include "wrepl_server/wrepl_server.h"
#include "nbt_server/wins/winsdb.h"
#include <ldb.h>
#include <ldb_errors.h>
#include "auth/auth.h"
#include "ldb_wrap.h"
#include "param/param.h"
#include "lib/socket/netif.h"

static struct ldb_context *wins_config_db_connect(TALLOC_CTX *mem_ctx, 
                                                  struct tevent_context *ev_ctx,
                                                  struct loadparm_context *lp_ctx)
{
        return ldb_wrap_connect(mem_ctx, ev_ctx, lp_ctx, private_path(mem_ctx,
                                lp_ctx, lpcfg_wins_config_url(lp_ctx)),
                                system_session(lp_ctx), NULL, 0);
}

static uint64_t wins_config_db_get_seqnumber(struct ldb_context *ldb)
{
        int ret;
        struct ldb_dn *dn;
        struct ldb_result *res = NULL;
        TALLOC_CTX *tmp_ctx = talloc_new(ldb);
        uint64_t seqnumber = 0;

        dn = ldb_dn_new(tmp_ctx, ldb, "@BASEINFO");
        if (!dn) goto failed;

        /* find the record in the WINS database */
        ret = ldb_search(ldb, tmp_ctx, &res, dn, LDB_SCOPE_BASE, NULL, NULL);
        if (ret != LDB_SUCCESS) goto failed;
        if (res->count > 1) goto failed;

        if (res->count == 1) {
                seqnumber = ldb_msg_find_attr_as_uint64(res->msgs[0], "sequenceNumber", 0);
        }

failed:
        talloc_free(tmp_ctx);
        return seqnumber;
}

/*
  open winsdb
*/
static NTSTATUS wreplsrv_open_winsdb(struct wreplsrv_service *service, 
                                     struct loadparm_context *lp_ctx)
{
        const char *owner = lpcfg_parm_string(lp_ctx, NULL, "winsdb", "local_owner");

        if (owner == NULL) {
                struct interface *ifaces;
                load_interfaces(service, lpcfg_interfaces(lp_ctx), &ifaces);
                owner = iface_n_ip(ifaces, 0);
        }

        service->wins_db     = winsdb_connect(service, service->task->event_ctx, lp_ctx, owner, WINSDB_HANDLE_CALLER_WREPL);
        if (!service->wins_db) {
                return NT_STATUS_INTERNAL_DB_ERROR;
        }

        service->config.ldb = wins_config_db_connect(service, service->task->event_ctx, lp_ctx);
        if (!service->config.ldb) {
                return NT_STATUS_INTERNAL_DB_ERROR;
        }

        /* the default renew interval is 6 days */
        service->config.renew_interval    = lpcfg_parm_int(lp_ctx, NULL,"wreplsrv","renew_interval", 6*24*60*60);

        /* the default tombstone (extinction) interval is 6 days */
        service->config.tombstone_interval= lpcfg_parm_int(lp_ctx, NULL,"wreplsrv","tombstone_interval", 6*24*60*60);

        /* the default tombstone (extinction) timeout is 1 day */
        service->config.tombstone_timeout = lpcfg_parm_int(lp_ctx, NULL,"wreplsrv","tombstone_timeout", 1*24*60*60);

        /* the default tombstone extra timeout is 3 days */
        service->config.tombstone_extra_timeout = lpcfg_parm_int(lp_ctx, NULL,"wreplsrv","tombstone_extra_timeout", 3*24*60*60);

        /* the default verify interval is 24 days */
        service->config.verify_interval   = lpcfg_parm_int(lp_ctx, NULL,"wreplsrv","verify_interval", 24*24*60*60);

        /* the default scavenging interval is 'renew_interval/2' */
        service->config.scavenging_interval=lpcfg_parm_int(lp_ctx, NULL,"wreplsrv","scavenging_interval",
                                                        service->config.renew_interval/2);

        /* the maximun interval to the next periodic processing event */
        service->config.periodic_interval = lpcfg_parm_int(lp_ctx, NULL,"wreplsrv","periodic_interval", 15);

        return NT_STATUS_OK;
}

struct wreplsrv_partner *wreplsrv_find_partner(struct wreplsrv_service *service, const char *peer_addr)
{
        struct wreplsrv_partner *cur;

        for (cur = service->partners; cur; cur = cur->next) {
                if (strcmp(cur->address, peer_addr) == 0) {
                        return cur;
                }
        }

        return NULL;
}

/*
  load our replication partners
*/
NTSTATUS wreplsrv_load_partners(struct wreplsrv_service *service)
{
        struct wreplsrv_partner *partner;
        struct ldb_result *res = NULL;
        int ret;
        TALLOC_CTX *tmp_ctx;
        unsigned int i;
        uint64_t new_seqnumber;

        new_seqnumber = wins_config_db_get_seqnumber(service->config.ldb);

        /* if it's not the first run and nothing changed we're done */
        if (service->config.seqnumber != 0 && service->config.seqnumber == new_seqnumber) {
                return NT_STATUS_OK;
        }

        tmp_ctx = talloc_new(service);
        NT_STATUS_HAVE_NO_MEMORY(tmp_ctx);

        service->config.seqnumber = new_seqnumber;

        /* find the record in the WINS database */
        ret = ldb_search(service->config.ldb, tmp_ctx, &res,
                         ldb_dn_new(tmp_ctx, service->config.ldb, "CN=PARTNERS"),
                         LDB_SCOPE_SUBTREE, NULL, "(objectClass=wreplPartner)");
        if (ret != LDB_SUCCESS) goto failed;

        /* first disable all existing partners */
        for (partner=service->partners; partner; partner = partner->next) {
                partner->type = WINSREPL_PARTNER_NONE;
        }

        for (i=0; i < res->count; i++) {
                const char *address;

                address = ldb_msg_find_attr_as_string(res->msgs[i], "address", NULL);
                if (!address) {
                        goto failed;
                }

                partner = wreplsrv_find_partner(service, address);
                if (partner) {
                        if (partner->name != partner->address) {
                                talloc_free(discard_const(partner->name));
                        }
                        partner->name = NULL;
                        talloc_free(discard_const(partner->our_address));
                        partner->our_address = NULL;

                        /* force rescheduling of pulling */
                        partner->pull.next_run = timeval_zero();
                } else {
                        partner = talloc_zero(service, struct wreplsrv_partner);
                        if (partner == NULL) goto failed;

                        partner->service = service;
                        partner->address = address;
                        talloc_steal(partner, partner->address);

                        DLIST_ADD_END(service->partners, partner, struct wreplsrv_partner *);
                }

                partner->name                   = ldb_msg_find_attr_as_string(res->msgs[i], "name", partner->address);
                talloc_steal(partner, partner->name);
                partner->our_address            = ldb_msg_find_attr_as_string(res->msgs[i], "ourAddress", NULL);
                talloc_steal(partner, partner->our_address);

                partner->type                   = ldb_msg_find_attr_as_uint(res->msgs[i], "type", WINSREPL_PARTNER_BOTH);
                partner->pull.interval          = ldb_msg_find_attr_as_uint(res->msgs[i], "pullInterval",
                                                                    WINSREPL_DEFAULT_PULL_INTERVAL);
                partner->pull.retry_interval    = ldb_msg_find_attr_as_uint(res->msgs[i], "pullRetryInterval",
                                                                    WINSREPL_DEFAULT_PULL_RETRY_INTERVAL);
                partner->push.change_count      = ldb_msg_find_attr_as_uint(res->msgs[i], "pushChangeCount",
                                                                    WINSREPL_DEFAULT_PUSH_CHANGE_COUNT);
                partner->push.use_inform        = ldb_msg_find_attr_as_uint(res->msgs[i], "pushUseInform", true);

                DEBUG(3,("wreplsrv_load_partners: found partner: %s type: 0x%X\n",
                        partner->address, partner->type));
        }

        DEBUG(2,("wreplsrv_load_partners: %u partners found: wins_config_db seqnumber %llu\n",
                res->count, (unsigned long long)service->config.seqnumber));

        talloc_free(tmp_ctx);
        return NT_STATUS_OK;
failed:
        talloc_free(tmp_ctx);
        return NT_STATUS_FOOBAR;
}

NTSTATUS wreplsrv_fill_wrepl_table(struct wreplsrv_service *service,
                                   TALLOC_CTX *mem_ctx,
                                   struct wrepl_table *table_out,
                                   const char *initiator,
                                   bool full_table)
{
        struct wreplsrv_owner *cur;
        uint32_t i = 0;

        table_out->partner_count        = 0;
        table_out->partners             = NULL;
        table_out->initiator            = initiator;

        for (cur = service->table; cur; cur = cur->next) {
                if (full_table) {
                        table_out->partner_count++;
                        continue;
                }

                if (strcmp(initiator, cur->owner.address) != 0) continue;

                table_out->partner_count++;
                break;
        }

        table_out->partners = talloc_array(mem_ctx, struct wrepl_wins_owner, table_out->partner_count);
        NT_STATUS_HAVE_NO_MEMORY(table_out->partners);

        for (cur = service->table; cur && i < table_out->partner_count; cur = cur->next) {
                /*
                 * if it's our local entry
                 * update the max version
                 */
                if (cur == service->owner) {
                        cur->owner.max_version = winsdb_get_maxVersion(service->wins_db);
                }

                if (full_table) {
                        table_out->partners[i] = cur->owner;
                        i++;
                        continue;
                }

                if (strcmp(initiator, cur->owner.address) != 0) continue;

                table_out->partners[i] = cur->owner;
                i++;
                break;
        }

        return NT_STATUS_OK;
}

struct wreplsrv_owner *wreplsrv_find_owner(struct wreplsrv_service *service,
                                           struct wreplsrv_owner *table,
                                           const char *wins_owner)
{
        struct wreplsrv_owner *cur;

        for (cur = table; cur; cur = cur->next) {
                if (strcmp(cur->owner.address, wins_owner) == 0) {
                        /*
                         * if it's our local entry
                         * update the max version
                         */
                        if (cur == service->owner) {
                                cur->owner.max_version = winsdb_get_maxVersion(service->wins_db);
                        }
                        return cur;
                }
        }

        return NULL;
}

/*
 update the wins_owner_table max_version, if the given version is the highest version
 if no entry for the wins_owner exists yet, create one
*/
NTSTATUS wreplsrv_add_table(struct wreplsrv_service *service,
                            TALLOC_CTX *mem_ctx, struct wreplsrv_owner **_table,
                            const char *wins_owner, uint64_t version)
{
        struct wreplsrv_owner *table = *_table;
        struct wreplsrv_owner *cur;

        if (!wins_owner || strcmp(wins_owner, "0.0.0.0") == 0) {
                wins_owner = service->wins_db->local_owner;
        }

        cur = wreplsrv_find_owner(service, table, wins_owner);

        /* if it doesn't exists yet, create one */
        if (!cur) {
                cur = talloc_zero(mem_ctx, struct wreplsrv_owner);
                NT_STATUS_HAVE_NO_MEMORY(cur);

                cur->owner.address      = talloc_strdup(cur, wins_owner);
                NT_STATUS_HAVE_NO_MEMORY(cur->owner.address);
                cur->owner.min_version  = 0;
                cur->owner.max_version  = 0;
                cur->owner.type         = 1; /* don't know why this is always 1 */

                cur->partner            = wreplsrv_find_partner(service, wins_owner);

                DLIST_ADD_END(table, cur, struct wreplsrv_owner *);
                *_table = table;
        }

        /* the min_version is always 0 here, and won't be updated */

        /* if the given version is higher than the current max_version, update */
        if (cur->owner.max_version < version) {
                cur->owner.max_version = version;
                /* if it's for our local db, we need to update the wins.ldb too */
                if (cur == service->owner) {
                        uint64_t ret;
                        ret = winsdb_set_maxVersion(service->wins_db, cur->owner.max_version);
                        if (ret != cur->owner.max_version) {
                                DEBUG(0,("winsdb_set_maxVersion(%llu) failed: %llu\n",
                                         (unsigned long long)cur->owner.max_version, 
                                         (unsigned long long)ret));
                                return NT_STATUS_INTERNAL_DB_CORRUPTION;
                        }
                }
        }

        return NT_STATUS_OK;
}

/*
  load the partner table
*/
static NTSTATUS wreplsrv_load_table(struct wreplsrv_service *service)
{
        struct ldb_result *res = NULL;
        int ret;
        NTSTATUS status;
        TALLOC_CTX *tmp_ctx = talloc_new(service);
        struct ldb_context *ldb = service->wins_db->ldb;
        unsigned int i;
        struct wreplsrv_owner *local_owner;
        const char *wins_owner;
        uint64_t version;
        const char * const attrs[] = {
                "winsOwner",
                "versionID",
                NULL
        };

        /*
         * make sure we have our local entry in the list,
         * but we set service->owner when we're done
         * to avoid to many calls to wreplsrv_local_max_version()
         */
        status = wreplsrv_add_table(service,
                                    service, &service->table,
                                    service->wins_db->local_owner, 0);
        if (!NT_STATUS_IS_OK(status)) goto failed;
        local_owner = wreplsrv_find_owner(service, service->table, service->wins_db->local_owner);
        if (!local_owner) {
                status = NT_STATUS_INTERNAL_ERROR;
                goto failed;
        }

        /* find the record in the WINS database */
        ret = ldb_search(ldb, tmp_ctx, &res, NULL, LDB_SCOPE_SUBTREE,
                         attrs, "(objectClass=winsRecord)");
        status = NT_STATUS_INTERNAL_DB_CORRUPTION;
        if (ret != LDB_SUCCESS) goto failed;

        for (i=0; i < res->count; i++) {
                wins_owner     = ldb_msg_find_attr_as_string(res->msgs[i], "winsOwner", NULL);
                version        = ldb_msg_find_attr_as_uint64(res->msgs[i], "versionID", 0);

                status = wreplsrv_add_table(service,
                                            service, &service->table,
                                            wins_owner, version);
                if (!NT_STATUS_IS_OK(status)) goto failed;
                talloc_free(res->msgs[i]);
        }

        /*
         * this makes sure we call wreplsrv_local_max_version() before returning in
         * wreplsrv_find_owner()
         */
        service->owner = local_owner;

        /*
         * this makes sure the maxVersion in the database is updated,
         * with the highest version we found, if this is higher than the current stored one
         */
        status = wreplsrv_add_table(service,
                                    service, &service->table,
                                    service->wins_db->local_owner, local_owner->owner.max_version);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        talloc_free(tmp_ctx);
        return NT_STATUS_OK;
failed:
        talloc_free(tmp_ctx);
        return status;
}

/*
  setup our replication partners
*/
static NTSTATUS wreplsrv_setup_partners(struct wreplsrv_service *service)
{
        NTSTATUS status;

        status = wreplsrv_load_partners(service);
        NT_STATUS_NOT_OK_RETURN(status);

        status = wreplsrv_load_table(service);
        NT_STATUS_NOT_OK_RETURN(status);

        return NT_STATUS_OK;
}

/*
  startup the wrepl task
*/
static void wreplsrv_task_init(struct task_server *task)
{
        NTSTATUS status;
        struct wreplsrv_service *service;

        if (!lpcfg_wins_support(task->lp_ctx)) {
                return;
        }

        task_server_set_title(task, "task[wreplsrv]");

        service = talloc_zero(task, struct wreplsrv_service);
        if (!service) {
                task_server_terminate(task, "wreplsrv_task_init: out of memory", true);
                return;
        }
        service->task           = task;
        service->startup_time   = timeval_current();
        task->private_data      = service;

        /*
         * setup up all partners, and open the winsdb
         */
        status = wreplsrv_open_winsdb(service, task->lp_ctx);
        if (!NT_STATUS_IS_OK(status)) {
                task_server_terminate(task, "wreplsrv_task_init: wreplsrv_open_winsdb() failed", true);
                return;
        }

        /*
         * setup timed events for each partner we want to pull from
         */
        status = wreplsrv_setup_partners(service);
        if (!NT_STATUS_IS_OK(status)) {
                task_server_terminate(task, "wreplsrv_task_init: wreplsrv_setup_partners() failed", true);
                return;
        }

        /* 
         * setup listen sockets, so we can answer requests from our partners,
         * which pull from us
         */
        status = wreplsrv_setup_sockets(service, task->lp_ctx);
        if (!NT_STATUS_IS_OK(status)) {
                task_server_terminate(task, "wreplsrv_task_init: wreplsrv_setup_sockets() failed", true);
                return;
        }

        status = wreplsrv_setup_periodic(service);
        if (!NT_STATUS_IS_OK(status)) {
                task_server_terminate(task, "wreplsrv_task_init: wreplsrv_setup_periodic() failed", true);
                return;
        }

        irpc_add_name(task->msg_ctx, "wrepl_server");
}

/*
  register ourselves as a available server
*/
NTSTATUS server_service_wrepl_init(void)
{
        return register_server_service("wrepl", wreplsrv_task_init);
}