ldb_tdb: Call talloc_free(options_dn) as soon as we are done with options_dn

[Samba.git] / lib / ldb / ldb_tdb / ldb_cache.c

/* 
   ldb database library

   Copyright (C) Andrew Tridgell  2004

     ** NOTE! The following LGPL license applies to the ldb
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL
   
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 3 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/

/*
 *  Name: ldb
 *
 *  Component: ldb tdb cache functions
 *
 *  Description: cache special records in a ldb/tdb
 *
 *  Author: Andrew Tridgell
 */

#include "ldb_tdb.h"
#include "ldb_private.h"

#define LTDB_FLAG_CASE_INSENSITIVE (1<<0)
#define LTDB_FLAG_INTEGER          (1<<1)
#define LTDB_FLAG_HIDDEN           (1<<2)

/* valid attribute flags */
static const struct {
        const char *name;
        int value;
} ltdb_valid_attr_flags[] = {
        { "CASE_INSENSITIVE", LTDB_FLAG_CASE_INSENSITIVE },
        { "INTEGER", LTDB_FLAG_INTEGER },
        { "HIDDEN", LTDB_FLAG_HIDDEN },
        { "NONE", 0 },
        { NULL, 0 }
};


/*
  de-register any special handlers for @ATTRIBUTES
*/
static void ltdb_attributes_unload(struct ldb_module *module)
{
        struct ldb_context *ldb = ldb_module_get_ctx(module);

        ldb_schema_attribute_remove_flagged(ldb, LDB_ATTR_FLAG_FROM_DB);

}

/*
  add up the attrib flags for a @ATTRIBUTES element
*/
static int ltdb_attributes_flags(struct ldb_message_element *el, unsigned *v)
{
        unsigned int i;
        unsigned value = 0;
        for (i=0;i<el->num_values;i++) {
                unsigned int j;
                for (j=0;ltdb_valid_attr_flags[j].name;j++) {
                        if (strcmp(ltdb_valid_attr_flags[j].name, 
                                   (char *)el->values[i].data) == 0) {
                                value |= ltdb_valid_attr_flags[j].value;
                                break;
                        }
                }
                if (ltdb_valid_attr_flags[j].name == NULL) {
                        return -1;
                }
        }
        *v = value;
        return 0;
}

static int ldb_schema_attribute_compare(const void *p1, const void *p2)
{
        const struct ldb_schema_attribute *sa1 = (const struct ldb_schema_attribute *)p1;
        const struct ldb_schema_attribute *sa2 = (const struct ldb_schema_attribute *)p2;
        return ldb_attr_cmp(sa1->name, sa2->name);
}

/*
  register any special handlers from @ATTRIBUTES
*/
static int ltdb_attributes_load(struct ldb_module *module)
{
        struct ldb_schema_attribute *attrs;
        struct ldb_context *ldb;
        struct ldb_message *attrs_msg = NULL;
        struct ldb_dn *dn;
        unsigned int i;
        unsigned int num_loaded_attrs = 0;
        int r;

        ldb = ldb_module_get_ctx(module);

        if (ldb->schema.attribute_handler_override) {
                /* we skip loading the @ATTRIBUTES record when a module is supplying
                   its own attribute handling */
                return 0;
        }

        attrs_msg = ldb_msg_new(module);
        if (attrs_msg == NULL) {
                goto failed;
        }

        dn = ldb_dn_new(module, ldb, LTDB_ATTRIBUTES);
        if (dn == NULL) goto failed;

        r = ltdb_search_dn1(module, dn, attrs_msg,
                            LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC
                            |LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC
                            |LDB_UNPACK_DATA_FLAG_NO_DN);
        talloc_free(dn);
        if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
                goto failed;
        }
        if (r == LDB_ERR_NO_SUCH_OBJECT || attrs_msg->num_elements == 0) {
                TALLOC_FREE(attrs_msg);
                return 0;
        }

        attrs = talloc_array(attrs_msg,
                             struct ldb_schema_attribute,
                             attrs_msg->num_elements
                             + ldb->schema.num_attributes);
        if (attrs == NULL) {
                goto failed;
        }

        memcpy(attrs,
               ldb->schema.attributes,
               sizeof(ldb->schema.attributes[0]) * ldb->schema.num_attributes);

        /* mapping these flags onto ldap 'syntaxes' isn't strictly correct,
           but its close enough for now */
        for (i=0;i<attrs_msg->num_elements;i++) {
                unsigned flags;
                const char *syntax;
                const struct ldb_schema_syntax *s;
                const struct ldb_schema_attribute *a =
                        ldb_schema_attribute_by_name(ldb,
                                                     attrs_msg->elements[i].name);
                if (a != NULL && a->flags & LDB_ATTR_FLAG_FIXED) {
                        /* Must already be set in the array, and kept */
                        continue;
                }

                if (ltdb_attributes_flags(&attrs_msg->elements[i], &flags) != 0) {
                        ldb_debug(ldb, LDB_DEBUG_ERROR,
                                  "Invalid @ATTRIBUTES element for '%s'",
                                  attrs_msg->elements[i].name);
                        goto failed;
                }
                switch (flags & ~LTDB_FLAG_HIDDEN) {
                case 0:
                        syntax = LDB_SYNTAX_OCTET_STRING;
                        break;
                case LTDB_FLAG_CASE_INSENSITIVE:
                        syntax = LDB_SYNTAX_DIRECTORY_STRING;
                        break;
                case LTDB_FLAG_INTEGER:
                        syntax = LDB_SYNTAX_INTEGER;
                        break;
                default:
                        ldb_debug(ldb, LDB_DEBUG_ERROR, 
                                  "Invalid flag combination 0x%x for '%s' "
                                  "in @ATTRIBUTES",
                                  flags, attrs_msg->elements[i].name);
                        goto failed;
                }

                s = ldb_standard_syntax_by_name(ldb, syntax);
                if (s == NULL) {
                        ldb_debug(ldb, LDB_DEBUG_ERROR, 
                                  "Invalid attribute syntax '%s' for '%s' "
                                  "in @ATTRIBUTES",
                                  syntax, attrs_msg->elements[i].name);
                        goto failed;
                }

                flags |= LDB_ATTR_FLAG_ALLOCATED | LDB_ATTR_FLAG_FROM_DB;

                r = ldb_schema_attribute_fill_with_syntax(ldb,
                                                          attrs,
                                                          attrs_msg->elements[i].name,
                                                          flags, s,
                                                          &attrs[num_loaded_attrs + ldb->schema.num_attributes]);
                if (r != 0) {
                        goto failed;
                }
                num_loaded_attrs++;
        }

        attrs = talloc_realloc(attrs_msg,
                               attrs, struct ldb_schema_attribute,
                               num_loaded_attrs + ldb->schema.num_attributes);
        if (attrs == NULL) {
                goto failed;
        }
        TYPESAFE_QSORT(attrs, num_loaded_attrs + ldb->schema.num_attributes,
                       ldb_schema_attribute_compare);
        talloc_unlink(ldb, ldb->schema.attributes);
        ldb->schema.attributes = talloc_steal(ldb, attrs);
        ldb->schema.num_attributes = num_loaded_attrs + ldb->schema.num_attributes;
        TALLOC_FREE(attrs_msg);

        return 0;
failed:
        TALLOC_FREE(attrs_msg);
        return -1;
}


/*
  initialise the baseinfo record
*/
static int ltdb_baseinfo_init(struct ldb_module *module)
{
        struct ldb_context *ldb;
        void *data = ldb_module_get_private(module);
        struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
        struct ldb_message *msg;
        struct ldb_message_element el;
        struct ldb_val val;
        int ret;
        /* the initial sequence number must be different from the one
           set in ltdb_cache_free(). Thanks to Jon for pointing this
           out. */
        const char *initial_sequence_number = "1";

        ldb = ldb_module_get_ctx(module);

        ltdb->sequence_number = atof(initial_sequence_number);

        msg = ldb_msg_new(ltdb);
        if (msg == NULL) {
                goto failed;
        }

        msg->num_elements = 1;
        msg->elements = &el;
        msg->dn = ldb_dn_new(msg, ldb, LTDB_BASEINFO);
        if (!msg->dn) {
                goto failed;
        }
        el.name = talloc_strdup(msg, LTDB_SEQUENCE_NUMBER);
        if (!el.name) {
                goto failed;
        }
        el.values = &val;
        el.num_values = 1;
        el.flags = 0;
        val.data = (uint8_t *)talloc_strdup(msg, initial_sequence_number);
        if (!val.data) {
                goto failed;
        }
        val.length = 1;
        
        ret = ltdb_store(module, msg, TDB_INSERT);

        talloc_free(msg);

        return ret;

failed:
        talloc_free(msg);
        errno = ENOMEM;
        return LDB_ERR_OPERATIONS_ERROR;
}

/*
  free any cache records
 */
static void ltdb_cache_free(struct ldb_module *module)
{
        void *data = ldb_module_get_private(module);
        struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);

        ltdb->sequence_number = 0;
        talloc_free(ltdb->cache);
        ltdb->cache = NULL;
}

/*
  force a cache reload
*/
int ltdb_cache_reload(struct ldb_module *module)
{
        ltdb_attributes_unload(module);
        ltdb_cache_free(module);
        return ltdb_cache_load(module);
}

/*
  load the cache records
*/
int ltdb_cache_load(struct ldb_module *module)
{
        struct ldb_context *ldb;
        void *data = ldb_module_get_private(module);
        struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
        struct ldb_dn *baseinfo_dn = NULL, *options_dn = NULL;
        struct ldb_dn *indexlist_dn = NULL;
        uint64_t seq;
        struct ldb_message *baseinfo = NULL, *options = NULL;
        int r;

        ldb = ldb_module_get_ctx(module);

        /* a very fast check to avoid extra database reads */
        if (ltdb->cache != NULL && 
            tdb_get_seqnum(ltdb->tdb) == ltdb->tdb_seqnum) {
                return 0;
        }

        if (ltdb->cache == NULL) {
                ltdb->cache = talloc_zero(ltdb, struct ltdb_cache);
                if (ltdb->cache == NULL) goto failed;
                ltdb->cache->indexlist = ldb_msg_new(ltdb->cache);
                if (ltdb->cache->indexlist == NULL) {
                        goto failed;
                }
        }

        baseinfo = ldb_msg_new(ltdb->cache);
        if (baseinfo == NULL) goto failed;

        baseinfo_dn = ldb_dn_new(baseinfo, ldb, LTDB_BASEINFO);
        if (baseinfo_dn == NULL) goto failed;

        r= ltdb_search_dn1(module, baseinfo_dn, baseinfo, 0);
        if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
                goto failed;
        }
        
        /* possibly initialise the baseinfo */
        if (r == LDB_ERR_NO_SUCH_OBJECT) {

                if (tdb_transaction_start(ltdb->tdb) != 0) {
                        goto failed;
                }

                /* error handling for ltdb_baseinfo_init() is by
                   looking for the record again. */
                ltdb_baseinfo_init(module);

                tdb_transaction_commit(ltdb->tdb);

                if (ltdb_search_dn1(module, baseinfo_dn, baseinfo, 0) != LDB_SUCCESS) {
                        goto failed;
                }
        }

        ltdb->tdb_seqnum = tdb_get_seqnum(ltdb->tdb);

        /* if the current internal sequence number is the same as the one
           in the database then assume the rest of the cache is OK */
        seq = ldb_msg_find_attr_as_uint64(baseinfo, LTDB_SEQUENCE_NUMBER, 0);
        if (seq == ltdb->sequence_number) {
                goto done;
        }
        ltdb->sequence_number = seq;

        /* Read an interpret database options */
        options = ldb_msg_new(ltdb->cache);
        if (options == NULL) goto failed;

        options_dn = ldb_dn_new(options, ldb, LTDB_OPTIONS);
        if (options_dn == NULL) goto failed;

        r= ltdb_search_dn1(module, options_dn, options, 0);
        talloc_free(options_dn);
        if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
                goto failed;
        }
        
        /* set flags if they do exist */
        if (r == LDB_SUCCESS) {
                ltdb->check_base = ldb_msg_find_attr_as_bool(options,
                                                             LTDB_CHECK_BASE,
                                                             false);
                ltdb->disallow_dn_filter = ldb_msg_find_attr_as_bool(options,
                                                                     LTDB_DISALLOW_DN_FILTER,
                                                                     false);
        } else {
                ltdb->check_base = false;
                ltdb->disallow_dn_filter = false;
        }

        talloc_free(ltdb->cache->indexlist);
        /*
         * ltdb_attributes_unload() calls internally talloc_free() on
         * any non-fixed elemnts in ldb->schema.attributes.
         *
         * NOTE WELL: This is per-ldb, not per module, so overwrites
         * the handlers across all databases when used under Samba's
         * partition module.
         */
        ltdb_attributes_unload(module);
        ltdb->cache->indexlist = ldb_msg_new(ltdb->cache);
        if (ltdb->cache->indexlist == NULL) {
                goto failed;
        }
        ltdb->cache->one_level_indexes = false;
        ltdb->cache->attribute_indexes = false;
            
        indexlist_dn = ldb_dn_new(module, ldb, LTDB_INDEXLIST);
        if (indexlist_dn == NULL) goto failed;

        r = ltdb_search_dn1(module, indexlist_dn, ltdb->cache->indexlist,
                            LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC
                            |LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC
                            |LDB_UNPACK_DATA_FLAG_NO_DN);
        if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
                goto failed;
        }

        if (ldb_msg_find_element(ltdb->cache->indexlist, LTDB_IDXONE) != NULL) {
                ltdb->cache->one_level_indexes = true;
        }
        if (ldb_msg_find_element(ltdb->cache->indexlist, LTDB_IDXATTR) != NULL) {
                ltdb->cache->attribute_indexes = true;
        }

        /*
         * NOTE WELL: This is per-ldb, not per module, so overwrites
         * the handlers across all databases when used under Samba's
         * partition module.
         */
        if (ltdb_attributes_load(module) == -1) {
                goto failed;
        }

done:
        talloc_free(options);
        talloc_free(baseinfo);
        talloc_free(indexlist_dn);
        return 0;

failed:
        talloc_free(options);
        talloc_free(baseinfo);
        talloc_free(indexlist_dn);
        return -1;
}


/*
  increase the sequence number to indicate a database change
*/
int ltdb_increase_sequence_number(struct ldb_module *module)
{
        struct ldb_context *ldb;
        void *data = ldb_module_get_private(module);
        struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
        struct ldb_message *msg;
        struct ldb_message_element el[2];
        struct ldb_val val;
        struct ldb_val val_time;
        time_t t = time(NULL);
        char *s = NULL;
        int ret;

        ldb = ldb_module_get_ctx(module);

        msg = ldb_msg_new(ltdb);
        if (msg == NULL) {
                errno = ENOMEM;
                return LDB_ERR_OPERATIONS_ERROR;
        }

        s = talloc_asprintf(msg, "%llu", ltdb->sequence_number+1);
        if (!s) {
                talloc_free(msg);
                errno = ENOMEM;
                return LDB_ERR_OPERATIONS_ERROR;
        }

        msg->num_elements = ARRAY_SIZE(el);
        msg->elements = el;
        msg->dn = ldb_dn_new(msg, ldb, LTDB_BASEINFO);
        if (msg->dn == NULL) {
                talloc_free(msg);
                errno = ENOMEM;
                return LDB_ERR_OPERATIONS_ERROR;
        }
        el[0].name = talloc_strdup(msg, LTDB_SEQUENCE_NUMBER);
        if (el[0].name == NULL) {
                talloc_free(msg);
                errno = ENOMEM;
                return LDB_ERR_OPERATIONS_ERROR;
        }
        el[0].values = &val;
        el[0].num_values = 1;
        el[0].flags = LDB_FLAG_MOD_REPLACE;
        val.data = (uint8_t *)s;
        val.length = strlen(s);

        el[1].name = talloc_strdup(msg, LTDB_MOD_TIMESTAMP);
        if (el[1].name == NULL) {
                talloc_free(msg);
                errno = ENOMEM;
                return LDB_ERR_OPERATIONS_ERROR;
        }
        el[1].values = &val_time;
        el[1].num_values = 1;
        el[1].flags = LDB_FLAG_MOD_REPLACE;

        s = ldb_timestring(msg, t);
        if (s == NULL) {
                talloc_free(msg);
                return LDB_ERR_OPERATIONS_ERROR;
        }

        val_time.data = (uint8_t *)s;
        val_time.length = strlen(s);

        ret = ltdb_modify_internal(module, msg, NULL);

        talloc_free(msg);

        if (ret == LDB_SUCCESS) {
                ltdb->sequence_number += 1;
        }

        /* updating the tdb_seqnum here avoids us reloading the cache
           records due to our own modification */
        ltdb->tdb_seqnum = tdb_get_seqnum(ltdb->tdb);

        return ret;
}

int ltdb_check_at_attributes_values(const struct ldb_val *value)
{
        unsigned int i;

        for (i = 0; ltdb_valid_attr_flags[i].name != NULL; i++) {
                if ((strcmp(ltdb_valid_attr_flags[i].name, (char *)value->data) == 0)) {
                        return 0;
                }
        }

        return -1;
}