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samba-mirror/lib/ldb/ldb_key_value/ldb_kv_search.c
Jo Sutton 4e8ca6140a ldb: Attach appropriate ldb context to returned result
This is done by adding a new API that avoids the problems of
ldb_dn_copy() and makes it clear that a struct ldb_context *
pointer will be stored in the new copy.

Signed-off-by: Jo Sutton <josutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
2024-06-11 04:32:30 +00:00

796 lines
20 KiB
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 search functions
*
* Description: functions to search ldb+tdb databases
*
* Author: Andrew Tridgell
*/
#include "ldb_kv.h"
#include "ldb_private.h"
#include "lib/util/attr.h"
/*
search the database for a single simple dn.
return LDB_ERR_NO_SUCH_OBJECT on record-not-found
and LDB_SUCCESS on success
*/
int ldb_kv_search_base(struct ldb_module *module,
TALLOC_CTX *mem_ctx,
struct ldb_dn *dn,
struct ldb_dn **ret_dn)
{
int exists;
int ret;
struct ldb_message *msg = NULL;
if (ldb_dn_is_null(dn)) {
return LDB_ERR_NO_SUCH_OBJECT;
}
/*
* We can't use tdb_exists() directly on a key when the TDB
* key is the GUID one, not the DN based one. So we just do a
* normal search and avoid most of the allocation with the
* LDB_UNPACK_DATA_FLAG_NO_ATTRS flag
*/
msg = ldb_msg_new(module);
if (msg == NULL) {
return LDB_ERR_OPERATIONS_ERROR;
}
ret = ldb_kv_search_dn1(module, dn, msg, LDB_UNPACK_DATA_FLAG_NO_ATTRS);
if (ret == LDB_SUCCESS) {
const char *dn_linearized
= ldb_dn_get_linearized(dn);
const char *msg_dn_linearized
= ldb_dn_get_linearized(msg->dn);
if (strcmp(dn_linearized, msg_dn_linearized) == 0) {
/*
* Re-use the full incoming DN for
* subtree checks
*/
*ret_dn = dn;
} else {
/*
* Use the string DN from the unpack, so that
* we have a case-exact match of the base
*/
*ret_dn = talloc_steal(mem_ctx, msg->dn);
}
exists = true;
} else if (ret == LDB_ERR_NO_SUCH_OBJECT) {
exists = false;
} else {
talloc_free(msg);
return ret;
}
talloc_free(msg);
if (exists) {
return LDB_SUCCESS;
}
return LDB_ERR_NO_SUCH_OBJECT;
}
struct ldb_kv_parse_data_unpack_ctx {
struct ldb_message *msg;
struct ldb_module *module;
struct ldb_kv_private *ldb_kv;
unsigned int unpack_flags;
};
static int ldb_kv_parse_data_unpack(struct ldb_val key,
struct ldb_val data,
void *private_data)
{
struct ldb_kv_parse_data_unpack_ctx *ctx = private_data;
int ret;
struct ldb_context *ldb = ldb_module_get_ctx(ctx->module);
struct ldb_val data_parse = data;
struct ldb_kv_private *ldb_kv = ctx->ldb_kv;
if ((ldb_kv->kv_ops->options & LDB_KV_OPTION_STABLE_READ_LOCK) &&
(ctx->unpack_flags & LDB_UNPACK_DATA_FLAG_READ_LOCKED) &&
!ldb_kv->kv_ops->transaction_active(ldb_kv)) {
/*
* In the case where no transactions are active and
* we're in a read-lock, we can point directly into
* database memory.
*
* The database can't be changed underneath us and we
* will duplicate this data in the call to filter.
*
* This is seen in:
* - ldb_kv_index_filter
* - ldb_kv_search_and_return_base
*/
} else {
/*
* In every other case, since unpack doesn't memdup, we need
* to at least do a memdup on the whole data buffer as that
* may change later and the caller needs a stable result.
*
* During transactions, pointers could change and in
* TDB, there just aren't the same guarantees.
*/
data_parse.data = talloc_memdup(ctx->msg,
data.data,
data.length);
if (data_parse.data == NULL) {
ldb_debug(ldb, LDB_DEBUG_ERROR,
"Unable to allocate data(%d) for %*.*s\n",
(int)data.length,
(int)key.length, (int)key.length, key.data);
return LDB_ERR_OPERATIONS_ERROR;
}
}
ret = ldb_unpack_data_flags(ldb, &data_parse,
ctx->msg, ctx->unpack_flags);
if (ret == -1) {
if (data_parse.data != data.data) {
talloc_free(data_parse.data);
}
ldb_debug(ldb, LDB_DEBUG_ERROR,
__location__ ": Invalid data for index %*.*s\n",
(int)key.length, (int)key.length, key.data);
return LDB_ERR_OPERATIONS_ERROR;
}
return ret;
}
/*
search the database for a single simple dn, returning all attributes
in a single message
return LDB_ERR_NO_SUCH_OBJECT on record-not-found
and LDB_SUCCESS on success
*/
int ldb_kv_search_key(struct ldb_module *module,
struct ldb_kv_private *ldb_kv,
const struct ldb_val ldb_key,
struct ldb_message *msg,
unsigned int unpack_flags)
{
int ret;
struct ldb_kv_parse_data_unpack_ctx ctx = {
.msg = msg,
.module = module,
.unpack_flags = unpack_flags,
.ldb_kv = ldb_kv
};
memset(msg, 0, sizeof(*msg));
msg->num_elements = 0;
msg->elements = NULL;
ret = ldb_kv->kv_ops->fetch_and_parse(
ldb_kv, ldb_key, ldb_kv_parse_data_unpack, &ctx);
if (ret == -1) {
ret = ldb_kv->kv_ops->error(ldb_kv);
if (ret == LDB_SUCCESS) {
/*
* Just to be sure we don't turn errors
* into success
*/
return LDB_ERR_OPERATIONS_ERROR;
}
return ret;
} else if (ret != LDB_SUCCESS) {
return ret;
}
return LDB_SUCCESS;
}
/*
search the database for a single simple dn, returning all attributes
in a single message
return LDB_ERR_NO_SUCH_OBJECT on record-not-found
and LDB_SUCCESS on success
*/
int ldb_kv_search_dn1(struct ldb_module *module,
struct ldb_dn *dn,
struct ldb_message *msg,
unsigned int unpack_flags)
{
void *data = ldb_module_get_private(module);
struct ldb_kv_private *ldb_kv =
talloc_get_type(data, struct ldb_kv_private);
int ret;
uint8_t guid_key[LDB_KV_GUID_KEY_SIZE];
struct ldb_val key = {
.data = guid_key,
.length = sizeof(guid_key)
};
TALLOC_CTX *tdb_key_ctx = NULL;
bool valid_dn = ldb_dn_validate(dn);
if (valid_dn == false) {
ldb_asprintf_errstring(ldb_module_get_ctx(module),
"Invalid Base DN: %s",
ldb_dn_get_linearized(dn));
return LDB_ERR_INVALID_DN_SYNTAX;
}
if (ldb_kv->cache->GUID_index_attribute == NULL ||
ldb_dn_is_special(dn)) {
tdb_key_ctx = talloc_new(msg);
if (!tdb_key_ctx) {
return ldb_module_oom(module);
}
/* form the key */
key = ldb_kv_key_dn(tdb_key_ctx, dn);
if (!key.data) {
TALLOC_FREE(tdb_key_ctx);
return LDB_ERR_OPERATIONS_ERROR;
}
} else {
/*
* Look in the index to find the key for this DN.
*
* the tdb_key memory is allocated above, msg is just
* used for internal memory.
*
*/
ret = ldb_kv_key_dn_from_idx(module, ldb_kv, msg, dn, &key);
if (ret != LDB_SUCCESS) {
return ret;
}
}
ret = ldb_kv_search_key(module, ldb_kv, key, msg, unpack_flags);
TALLOC_FREE(tdb_key_ctx);
if (ret != LDB_SUCCESS) {
return ret;
}
if ((unpack_flags & LDB_UNPACK_DATA_FLAG_NO_DN) == 0) {
if (!msg->dn) {
msg->dn = ldb_dn_copy(msg, dn);
}
if (!msg->dn) {
return LDB_ERR_OPERATIONS_ERROR;
}
}
return LDB_SUCCESS;
}
/*
* filter the specified list of attributes from msg,
* adding requested attributes, and perhaps all for *.
* The DN will not be added if it is missing.
*/
int ldb_kv_filter_attrs_in_place(struct ldb_message *msg,
const char *const *attrs)
{
return ldb_filter_attrs_in_place(msg, attrs);
}
/*
search function for a non-indexed search
*/
static int search_func(_UNUSED_ struct ldb_kv_private *ldb_kv,
struct ldb_val key,
struct ldb_val val,
void *state)
{
struct ldb_context *ldb;
struct ldb_kv_context *ac;
struct ldb_message *msg;
struct timeval now;
int ret, timeval_cmp;
bool matched;
ac = talloc_get_type(state, struct ldb_kv_context);
ldb = ldb_module_get_ctx(ac->module);
/*
* We want to skip @ records early in a search full scan
*
* @ records like @IDXLIST are only available via a base
* search on the specific name but the method by which they
* were excluded was expensive, after the unpack the DN is
* exploded and ldb_match_msg_error() would reject it for
* failing to match the scope.
*
* ldb_kv_key_is_normal_record() uses the fact that @ records
* have the DN=@ prefix on their TDB/LMDB key to quickly
* exclude them from consideration.
*
* (any other non-records are also excluded by the same key
* match)
*/
if (ldb_kv_key_is_normal_record(key) == false) {
return 0;
}
/*
* Check the time every 64 records, to reduce calls to
* gettimeofday(). This is a compromise, not all calls to
* ldb_match_message() will take the same time, most will fail
* quickly but by luck it might be possible to have 64 records
* that are slow, doing a recursive search via
* LDAP_MATCHING_RULE_IN_CHAIN.
*/
if (ac->timeout_counter++ % 64 == 0) {
now = tevent_timeval_current();
timeval_cmp = tevent_timeval_compare(&ac->timeout_timeval,
&now);
/*
* The search has taken too long. This is the most
* likely place for our time to expire, as we are in
* an un-indexed search and we return the data from
* within this loop. The tevent based timeout is not
* likely to be hit, sadly.
*
* ldb_match_msg_error() can be quite expensive if a
* LDAP_MATCHING_RULE_IN_CHAIN extended match was
* specified.
*/
if (timeval_cmp <= 0) {
ac->error = LDB_ERR_TIME_LIMIT_EXCEEDED;
return -1;
}
}
msg = ldb_msg_new(ac);
if (!msg) {
ac->error = LDB_ERR_OPERATIONS_ERROR;
return -1;
}
/* unpack the record */
ret = ldb_unpack_data_flags(ldb, &val, msg,
LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC);
if (ret == -1) {
talloc_free(msg);
ac->error = LDB_ERR_OPERATIONS_ERROR;
return -1;
}
if (!msg->dn) {
msg->dn = ldb_dn_new(msg, ldb,
(char *)key.data + 3);
if (msg->dn == NULL) {
talloc_free(msg);
ac->error = LDB_ERR_OPERATIONS_ERROR;
return -1;
}
}
/*
* The redaction callback may be expensive to call if it fetches a
* security descriptor. Check the DN early and bail out if it doesn't
* match the base.
*/
if (!ldb_match_scope(ldb, ac->base, msg->dn, ac->scope)) {
talloc_free(msg);
return 0;
}
if (ldb->redact.callback != NULL) {
ret = ldb->redact.callback(ldb->redact.module, ac->req, msg);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
return ret;
}
}
/* see if it matches the given expression */
ret = ldb_match_message(ldb, msg,
ac->tree, ac->scope, &matched);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
ac->error = LDB_ERR_OPERATIONS_ERROR;
return -1;
}
if (!matched) {
talloc_free(msg);
return 0;
}
ret = ldb_msg_add_distinguished_name(msg);
if (ret == -1) {
talloc_free(msg);
return LDB_ERR_OPERATIONS_ERROR;
}
/* filter the attributes that the user wants */
ret = ldb_kv_filter_attrs_in_place(msg, ac->attrs);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
ac->error = LDB_ERR_OPERATIONS_ERROR;
return -1;
}
ldb_msg_shrink_to_fit(msg);
/* Ensure the message elements are all talloc'd. */
ret = ldb_msg_elements_take_ownership(msg);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
ac->error = LDB_ERR_OPERATIONS_ERROR;
return -1;
}
ret = ldb_module_send_entry(ac->req, msg, NULL);
if (ret != LDB_SUCCESS) {
ac->request_terminated = true;
/* the callback failed, abort the operation */
ac->error = LDB_ERR_OPERATIONS_ERROR;
return -1;
}
return 0;
}
/*
* Key pointing to just before the first GUID indexed record for
* iterate_range
*/
struct ldb_val start_of_db_key = {.data=discard_const_p(uint8_t, "GUID<"),
.length=6};
/*
* Key pointing to just after the last GUID indexed record for
* iterate_range
*/
struct ldb_val end_of_db_key = {.data=discard_const_p(uint8_t, "GUID>"),
.length=6};
/*
search the database with a LDAP-like expression.
this is the "full search" non-indexed variant
*/
static int ldb_kv_search_full(struct ldb_kv_context *ctx)
{
void *data = ldb_module_get_private(ctx->module);
struct ldb_kv_private *ldb_kv =
talloc_get_type(data, struct ldb_kv_private);
int ret;
/*
* If the backend has an iterate_range op, use it to start the search
* at the first GUID indexed record, skipping the indexes section.
*/
ctx->error = LDB_SUCCESS;
ret = ldb_kv->kv_ops->iterate_range(ldb_kv,
start_of_db_key,
end_of_db_key,
search_func,
ctx);
if (ret == LDB_ERR_OPERATIONS_ERROR) {
/*
* If iterate_range isn't defined, it'll return an error,
* so just iterate over the whole DB.
*/
ret = ldb_kv->kv_ops->iterate(ldb_kv, search_func, ctx);
}
if (ret < 0) {
return LDB_ERR_OPERATIONS_ERROR;
}
return ctx->error;
}
static int ldb_kv_search_and_return_base(struct ldb_kv_private *ldb_kv,
struct ldb_kv_context *ctx)
{
struct ldb_message *msg;
struct ldb_context *ldb = ldb_module_get_ctx(ctx->module);
const char *dn_linearized;
const char *msg_dn_linearized;
int ret;
bool matched;
msg = ldb_msg_new(ctx);
if (!msg) {
return LDB_ERR_OPERATIONS_ERROR;
}
ret = ldb_kv_search_dn1(ctx->module,
ctx->base,
msg,
LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC |
LDB_UNPACK_DATA_FLAG_READ_LOCKED);
if (ret == LDB_ERR_NO_SUCH_OBJECT) {
if (ldb_kv->check_base == false) {
/*
* In this case, we are done, as no base
* checking is allowed in this DB
*/
talloc_free(msg);
return LDB_SUCCESS;
}
ldb_asprintf_errstring(ldb,
"No such Base DN: %s",
ldb_dn_get_linearized(ctx->base));
}
if (ret != LDB_SUCCESS) {
talloc_free(msg);
return ret;
}
if (ldb->redact.callback != NULL) {
ret = ldb->redact.callback(ldb->redact.module, ctx->req, msg);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
return ret;
}
}
/*
* We use this, not ldb_match_msg_error() as we know
* we matched on the scope BASE, as we just fetched
* the base DN
*/
ret = ldb_match_message(ldb, msg,
ctx->tree,
ctx->scope,
&matched);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
return ret;
}
if (!matched) {
talloc_free(msg);
return LDB_SUCCESS;
}
dn_linearized = ldb_dn_get_linearized(ctx->base);
msg_dn_linearized = ldb_dn_get_linearized(msg->dn);
if (strcmp(dn_linearized, msg_dn_linearized) == 0) {
/*
* If the DN is exactly the same string, then
* re-use the full incoming DN for the
* returned result, as it has already been
* casefolded
*/
struct ldb_dn *dn = ldb_dn_copy_with_ldb_context(msg, ctx->base, ldb);
if (dn != NULL) {
msg->dn = dn;
}
}
ret = ldb_msg_add_distinguished_name(msg);
if (ret == -1) {
talloc_free(msg);
return LDB_ERR_OPERATIONS_ERROR;
}
/*
* filter the attributes that the user wants.
*/
ret = ldb_kv_filter_attrs_in_place(msg, ctx->attrs);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
return LDB_ERR_OPERATIONS_ERROR;
}
ldb_msg_shrink_to_fit(msg);
/* Ensure the message elements are all talloc'd. */
ret = ldb_msg_elements_take_ownership(msg);
if (ret != LDB_SUCCESS) {
talloc_free(msg);
return LDB_ERR_OPERATIONS_ERROR;
}
/*
* Remove any extended components, we just want the casefold components
*/
ldb_dn_remove_extended_components(msg->dn);
ret = ldb_module_send_entry(ctx->req, msg, NULL);
if (ret != LDB_SUCCESS) {
/* Regardless of success or failure, the msg
* is the callbacks responsibility, and should
* not be talloc_free()'ed */
ctx->request_terminated = true;
return ret;
}
return LDB_SUCCESS;
}
/*
search the database with a LDAP-like expression.
choses a search method
*/
int ldb_kv_search(struct ldb_kv_context *ctx)
{
struct ldb_context *ldb;
struct ldb_module *module = ctx->module;
struct ldb_request *req = ctx->req;
void *data = ldb_module_get_private(module);
struct ldb_kv_private *ldb_kv =
talloc_get_type(data, struct ldb_kv_private);
int ret;
ldb = ldb_module_get_ctx(module);
ldb_request_set_state(req, LDB_ASYNC_PENDING);
if (ldb_kv->kv_ops->lock_read(module) != 0) {
return LDB_ERR_OPERATIONS_ERROR;
}
if (ldb_kv_cache_load(module) != 0) {
ldb_kv->kv_ops->unlock_read(module);
return LDB_ERR_OPERATIONS_ERROR;
}
if (req->op.search.tree == NULL) {
ldb_kv->kv_ops->unlock_read(module);
return LDB_ERR_OPERATIONS_ERROR;
}
ctx->tree = req->op.search.tree;
ctx->scope = req->op.search.scope;
ctx->base = req->op.search.base;
ctx->attrs = req->op.search.attrs;
if ((req->op.search.base == NULL) || (ldb_dn_is_null(req->op.search.base) == true)) {
/* Check what we should do with a NULL dn */
switch (req->op.search.scope) {
case LDB_SCOPE_BASE:
ldb_asprintf_errstring(ldb,
"NULL Base DN invalid for a base search");
ret = LDB_ERR_INVALID_DN_SYNTAX;
break;
case LDB_SCOPE_ONELEVEL:
ldb_asprintf_errstring(ldb,
"NULL Base DN invalid for a one-level search");
ret = LDB_ERR_INVALID_DN_SYNTAX;
break;
case LDB_SCOPE_SUBTREE:
default:
/* We accept subtree searches from a NULL base DN, ie over the whole DB */
ret = LDB_SUCCESS;
}
} else if (req->op.search.scope == LDB_SCOPE_BASE) {
/*
* If we are LDB_SCOPE_BASE, do just one search and
* return early. This is critical to ensure we do not
* go into the index code for special DNs, as that
* will try to look up an index record for a special
* record (which doesn't exist).
*/
ret = ldb_kv_search_and_return_base(ldb_kv, ctx);
ldb_kv->kv_ops->unlock_read(module);
return ret;
} else if (ldb_kv->check_base) {
/*
* This database has been marked as
* 'checkBaseOnSearch', so do a spot check of the base
* dn. Also optimise the subsequent filter by filling
* in the ctx->base to be exactly case correct
*/
ret = ldb_kv_search_base(
module, ctx, req->op.search.base, &ctx->base);
if (ret == LDB_ERR_NO_SUCH_OBJECT) {
ldb_asprintf_errstring(ldb,
"No such Base DN: %s",
ldb_dn_get_linearized(req->op.search.base));
}
} else if (ldb_dn_validate(req->op.search.base) == false) {
/* We don't want invalid base DNs here */
ldb_asprintf_errstring(ldb,
"Invalid Base DN: %s",
ldb_dn_get_linearized(req->op.search.base));
ret = LDB_ERR_INVALID_DN_SYNTAX;
} else {
/* If we are not checking the base DN life is easy */
ret = LDB_SUCCESS;
}
if (ret == LDB_SUCCESS) {
uint32_t match_count = 0;
ret = ldb_kv_search_indexed(ctx, &match_count);
if (ret == LDB_ERR_NO_SUCH_OBJECT) {
/* Not in the index, therefore OK! */
ret = LDB_SUCCESS;
}
/* Check if we got just a normal error.
* In that case proceed to a full search unless we got a
* callback error */
if (!ctx->request_terminated && ret != LDB_SUCCESS) {
/* Not indexed, so we need to do a full scan */
if (ldb_kv->warn_unindexed ||
ldb_kv->disable_full_db_scan) {
/* useful for debugging when slow performance
* is caused by unindexed searches */
char *expression = ldb_filter_from_tree(ctx, ctx->tree);
ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb FULL SEARCH: %s SCOPE: %s DN: %s",
expression,
req->op.search.scope==LDB_SCOPE_BASE?"base":
req->op.search.scope==LDB_SCOPE_ONELEVEL?"one":
req->op.search.scope==LDB_SCOPE_SUBTREE?"sub":"UNKNOWN",
ldb_dn_get_linearized(req->op.search.base));
talloc_free(expression);
}
if (match_count != 0) {
/* the indexing code gave an error
* after having returned at least one
* entry. This means the indexes are
* corrupt or a database record is
* corrupt. We cannot continue with a
* full search or we may return
* duplicate entries
*/
ldb_kv->kv_ops->unlock_read(module);
return LDB_ERR_OPERATIONS_ERROR;
}
if (ldb_kv->disable_full_db_scan) {
ldb_set_errstring(ldb,
"ldb FULL SEARCH disabled");
ldb_kv->kv_ops->unlock_read(module);
return LDB_ERR_INAPPROPRIATE_MATCHING;
}
ret = ldb_kv_search_full(ctx);
if (ret != LDB_SUCCESS) {
ldb_set_errstring(ldb, "Indexed and full searches both failed!\n");
}
}
}
ldb_kv->kv_ops->unlock_read(module);
return ret;
}