diff options
Diffstat (limited to 'source4/dsdb/samdb/ldb_modules/paged_results.c')
| -rw-r--r-- | source4/dsdb/samdb/ldb_modules/paged_results.c | 888 |
1 files changed, 888 insertions, 0 deletions
diff --git a/source4/dsdb/samdb/ldb_modules/paged_results.c b/source4/dsdb/samdb/ldb_modules/paged_results.c new file mode 100644 index 0000000..83729b0 --- /dev/null +++ b/source4/dsdb/samdb/ldb_modules/paged_results.c @@ -0,0 +1,888 @@ +/* + ldb database library + + Copyright (C) Simo Sorce 2005-2008 + Copyright (C) Andrew Bartlett <abartlet@samba.org> 2018 + + ** 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: paged_result + * + * Component: ldb paged results control module + * + * Description: this module caches a complete search and sends back + * results in chunks as asked by the client + * + * Author: Garming Sam and Aaron Haslett + * + * Note: Based on the original paged_results.c by Simo Sorce and + * vlv_pagination.c by Douglas Bagnall and Garming Sam. + */ + +#include "includes.h" +#include "auth/auth.h" +#include <ldb.h> +#include "dsdb/samdb/samdb.h" +#include "libcli/security/security.h" +#include "libcli/ldap/ldap_errors.h" +#include "replace.h" +#include "system/filesys.h" +#include "system/time.h" +#include "ldb_module.h" +#include "dsdb/samdb/samdb.h" + +#include "dsdb/common/util.h" +#include "lib/util/dlinklist.h" + +/* Referrals are temporarily stored in a linked list */ +struct referral_store { + char *ref; + struct referral_store *next; +}; + +struct private_data; + +struct results_store { + struct results_store *prev, *next; + + struct private_data *priv; + + char *cookie; + time_t timestamp; + + struct referral_store *first_ref; + struct referral_store *last_ref; + + struct ldb_control **controls; + + /* from VLV */ + struct GUID *results; + size_t num_entries; + size_t result_array_size; + + struct ldb_control **down_controls; + const char * const *attrs; + + unsigned last_i; + struct ldb_parse_tree *expr; + char *expr_str; +}; + +struct private_data { + uint32_t next_free_id; + size_t num_stores; + struct results_store *store; +}; + +static int store_destructor(struct results_store *del) +{ + struct private_data *priv = del->priv; + DLIST_REMOVE(priv->store, del); + + priv->num_stores -= 1; + + return 0; +} + +static struct results_store *new_store(struct private_data *priv) +{ + struct results_store *newr; + uint32_t new_id = priv->next_free_id++; + + /* TODO: we should have a limit on the number of + * outstanding paged searches + */ + + newr = talloc_zero(priv, struct results_store); + if (!newr) return NULL; + + newr->priv = priv; + + newr->cookie = talloc_asprintf(newr, "%d", new_id); + if (!newr->cookie) { + talloc_free(newr); + return NULL; + } + + newr->timestamp = time(NULL); + + DLIST_ADD(priv->store, newr); + + priv->num_stores += 1; + + talloc_set_destructor(newr, store_destructor); + + if (priv->num_stores > 10) { + struct results_store *last; + /* + * 10 is the default for MaxResultSetsPerConn -- + * possibly need to parameterize it. + */ + last = DLIST_TAIL(priv->store); + TALLOC_FREE(last); + } + + return newr; +} + +struct paged_context { + struct ldb_module *module; + struct ldb_request *req; + + struct results_store *store; + int size; + struct ldb_control **controls; +}; + +static int send_referrals(struct results_store *store, + struct ldb_request *req) +{ + int ret; + struct referral_store *node; + while (store->first_ref != NULL) { + node = store->first_ref; + ret = ldb_module_send_referral(req, node->ref); + if (ret != LDB_SUCCESS) { + return ret; + } + store->first_ref = node->next; + talloc_free(node); + } + return LDB_SUCCESS; +} + +/* Start an ldb request for a single object by GUID */ +static int paged_search_by_dn_guid(struct ldb_module *module, + struct paged_context *ac, + struct ldb_result **result, + const struct GUID *guid, + const char * const *attrs, + struct ldb_parse_tree *expr) +{ + struct ldb_dn *dn; + struct ldb_request *req; + struct ldb_result *res; + int ret; + struct GUID_txt_buf guid_str; + + /* Use controls passed in on the downreq */ + struct ldb_control **controls = ac->store->down_controls; + + struct ldb_context *ldb = ldb_module_get_ctx(module); + + dn = ldb_dn_new_fmt(ac, ldb, "<GUID=%s>", + GUID_buf_string(guid, &guid_str)); + if (dn == NULL) { + return ldb_oom(ldb); + } + + res = talloc_zero(ac, struct ldb_result); + if (res == NULL) { + TALLOC_FREE(dn); + return ldb_oom(ldb); + } + + ret = ldb_build_search_req_ex(&req, ldb, ac, + dn, + LDB_SCOPE_BASE, + expr, + attrs, + controls, + res, + ldb_search_default_callback, + ac->req); + if (ret != LDB_SUCCESS) { + TALLOC_FREE(dn); + TALLOC_FREE(res); + return ret; + } + + /* + * Ensure the dn lasts only as long as the request, + * as we will have a lot of these (one per object + * being returned) + */ + + talloc_steal(req, dn); + + ret = ldb_request(ldb, req); + if (ret == LDB_SUCCESS) { + ret = ldb_wait(req->handle, LDB_WAIT_ALL); + } + + talloc_free(req); + if (ret != LDB_SUCCESS) { + talloc_free(res); + return ret; + } + + *result = res; + return ret; +} + +static int paged_results(struct paged_context *ac, struct ldb_reply *ares) +{ + struct ldb_extended *response = (ares != NULL ? ares->response : NULL); + struct ldb_paged_control *paged; + unsigned int i, num_ctrls; + int ret; + + if (ac->store == NULL) { + ret = LDB_ERR_OPERATIONS_ERROR; + return ldb_module_done( + ac->req, ac->controls, response, ret); + } + + while (ac->store->last_i < ac->store->num_entries && ac->size > 0) { + struct GUID *guid = &ac->store->results[ac->store->last_i++]; + struct ldb_result *result = NULL; + + ac->size--; + + /* + * Note: In the case that an object has been moved to a + * different place in the LDAP tree, we might expect the object + * to disappear from paged results. If we were going to + * implement that behaviour, we would do it here by passing + * down the original container DN to the search. + * However, testing shows that, on Windows, the moved object + * remains in the paged results. So, we are matching Windows + * behaviour here by leaving out the scope. + */ + ret = paged_search_by_dn_guid(ac->module, ac, &result, guid, + ac->req->op.search.attrs, + ac->store->expr); + if (ret == LDAP_NO_SUCH_OBJECT || + (ret == LDB_SUCCESS && result->count == 0)) { + /* The thing isn't there TODO, which we quietly + ignore and go on to send an extra one + instead. */ + continue; + } else if (ret != LDB_SUCCESS) { + return ldb_module_done( + ac->req, ac->controls, response, ret); + } + + ret = ldb_module_send_entry(ac->req, result->msgs[0], + NULL); + if (ret != LDB_SUCCESS) { + /* + * ldb_module_send_entry will have called + * ldb_module_done if an error occurred. + */ + return ret; + } + } + + if (ac->store->first_ref) { + /* There is no right place to put references in the sorted + results, so we send them as soon as possible. + */ + ret = send_referrals(ac->store, ac->req); + if (ret != LDB_SUCCESS) { + /* + * send_referrals will have called ldb_module_done + * if an error occurred. + */ + return ret; + } + } + + /* return result done */ + num_ctrls = 1; + i = 0; + + if (ac->store->controls != NULL) { + while (ac->store->controls[i]) i++; /* counting */ + + num_ctrls += i; + } + + ac->controls = talloc_array(ac, struct ldb_control *, num_ctrls +1); + if (ac->controls == NULL) { + ret = LDB_ERR_OPERATIONS_ERROR; + return ldb_module_done( + ac->req, ac->controls, response, ret); + } + ac->controls[num_ctrls] = NULL; + + for (i = 0; i < (num_ctrls -1); i++) { + ac->controls[i] = talloc_reference(ac->controls, + ac->store->controls[i]); + } + + ac->controls[i] = talloc(ac->controls, struct ldb_control); + if (ac->controls[i] == NULL) { + ret = LDB_ERR_OPERATIONS_ERROR; + return ldb_module_done( + ac->req, ac->controls, response, ret); + } + + ac->controls[i]->oid = talloc_strdup(ac->controls[i], + LDB_CONTROL_PAGED_RESULTS_OID); + if (ac->controls[i]->oid == NULL) { + ret = LDB_ERR_OPERATIONS_ERROR; + return ldb_module_done( + ac->req, ac->controls, response, ret); + } + + ac->controls[i]->critical = 0; + + paged = talloc(ac->controls[i], struct ldb_paged_control); + if (paged == NULL) { + ret = LDB_ERR_OPERATIONS_ERROR; + return ldb_module_done( + ac->req, ac->controls, response, ret); + } + + ac->controls[i]->data = paged; + + if (ac->size > 0) { + paged->size = 0; + paged->cookie = NULL; + paged->cookie_len = 0; + } else { + paged->size = ac->store->num_entries; + paged->cookie = talloc_strdup(paged, ac->store->cookie); + paged->cookie_len = strlen(paged->cookie) + 1; + } + + return LDB_SUCCESS; +} + +static int save_referral(struct results_store *store, char *ref) +{ + struct referral_store *node = talloc(store, + struct referral_store); + if (node == NULL) { + return LDB_ERR_OPERATIONS_ERROR; + } + node->next = NULL; + node->ref = talloc_steal(node, ref); + + if (store->first_ref == NULL) { + store->first_ref = node; + } else { + store->last_ref->next = node; + } + store->last_ref = node; + return LDB_SUCCESS; +} + +static int paged_search_callback(struct ldb_request *req, + struct ldb_reply *ares) +{ + struct paged_context *ac; + struct results_store *store; + int ret; + const struct ldb_val *guid_blob; + struct GUID guid; + NTSTATUS status; + + ac = talloc_get_type(req->context, struct paged_context); + store = ac->store; + + if (!ares) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + if (ares->error != LDB_SUCCESS) { + return ldb_module_done(ac->req, ares->controls, + ares->response, ares->error); + } + + switch (ares->type) { + case LDB_REPLY_ENTRY: + if (store->results == NULL) { + store->num_entries = 0; + store->result_array_size = 16; + store->results = talloc_array(store, struct GUID, + store->result_array_size); + if (store->results == NULL) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + } else if (store->num_entries == store->result_array_size) { + if (store->result_array_size > INT_MAX/2) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + store->result_array_size *= 2; + store->results = talloc_realloc(store, store->results, + struct GUID, + store->result_array_size); + if (store->results == NULL) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + } + + guid_blob = ldb_dn_get_extended_component(ares->message->dn, + "GUID"); + if (guid_blob == NULL) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + status = GUID_from_ndr_blob(guid_blob, &guid); + if (!NT_STATUS_IS_OK(status)) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + + /* Redundant paranoid check */ + if (store->num_entries > store->result_array_size) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + + store->results[store->num_entries] = guid; + store->num_entries++; + break; + + case LDB_REPLY_REFERRAL: + ret = save_referral(store, ares->referral); + if (ret != LDB_SUCCESS) { + return ldb_module_done(ac->req, NULL, NULL, ret); + } + break; + + case LDB_REPLY_DONE: + if (store->num_entries != 0) { + store->results = talloc_realloc(store, store->results, + struct GUID, + store->num_entries); + if (store->results == NULL) { + return ldb_module_done(ac->req, NULL, NULL, + LDB_ERR_OPERATIONS_ERROR); + } + } + store->result_array_size = store->num_entries; + + ac->store->controls = talloc_move(ac->store, &ares->controls); + ret = paged_results(ac, ares); + if (ret != LDB_SUCCESS) { + /* paged_results will have called ldb_module_done + * if an error occurred + */ + return ret; + } + return ldb_module_done(ac->req, ac->controls, + ares->response, ret); + } + + return LDB_SUCCESS; +} + +static struct ldb_control ** +paged_results_copy_down_controls(TALLOC_CTX *mem_ctx, + struct ldb_control **controls) +{ + + struct ldb_control **new_controls; + unsigned int i, j, num_ctrls; + if (controls == NULL) { + return NULL; + } + + for (num_ctrls = 0; controls[num_ctrls]; num_ctrls++); + + new_controls = talloc_array(mem_ctx, struct ldb_control *, num_ctrls); + if (new_controls == NULL) { + return NULL; + } + + for (j = 0, i = 0; i < (num_ctrls); i++) { + struct ldb_control *control = controls[i]; + if (control->oid == NULL) { + continue; + } + if (strcmp(control->oid, LDB_CONTROL_PAGED_RESULTS_OID) == 0) { + continue; + } + /* + * ASQ changes everything, do not copy it down for the + * per-GUID search + */ + if (strcmp(control->oid, LDB_CONTROL_ASQ_OID) == 0) { + continue; + } + new_controls[j] = talloc_steal(new_controls, control); + + /* + * Sadly the caller is not obliged to make this a + * proper talloc tree, so we do so here. + */ + if (control->data) { + talloc_steal(control, control->data); + } + j++; + } + new_controls[j] = NULL; + return new_controls; +} + +static const char * const *paged_copy_attrs(TALLOC_CTX *mem_ctx, + const char * const *attrs) { + int i; + const char **new_attrs; + if (attrs == NULL) { + return NULL; + } + new_attrs = ldb_attr_list_copy(mem_ctx, attrs); + + for (i=0; attrs[i] != NULL; i++) { + new_attrs[i] = talloc_strdup(mem_ctx, attrs[i]); + } + new_attrs[i] = NULL; + return new_attrs; +} + +/* + * Check if two sets of controls are the same except for the paged results + * control in the request controls. This function is messy because request + * control lists can contain controls that were NULL'd by the rootdse. We + * must ignore those entries. This function is not portable. + */ +static bool paged_controls_same(struct ldb_request *req, + struct ldb_control **down_controls) { + int i; + unsigned int num_down_controls, num_non_null_req_controls; + struct ldb_control *ctrl; + + num_down_controls = 0; + for (i=0; down_controls[i] != NULL; i++) { + num_down_controls++; + + ctrl = ldb_request_get_control(req, down_controls[i]->oid); + if (ctrl == NULL) { + return false; + } + } + + num_non_null_req_controls = 0; + for (i=0; req->controls[i] != NULL; i++) { + if (req->controls[i]->oid != NULL && + strcmp(req->controls[i]->oid, + LDB_CONTROL_ASQ_OID) != 0) { + num_non_null_req_controls++; + } + } + + /* At this point we have the number of non-null entries for both + * control lists and we know that: + * 1. down_controls does not contain the paged control or ASQ + * (because paged_results_copy_down_controls excludes it) + * 2. req->controls does contain the paged control + * (because this function is only called if this is true) + * 3. down_controls is a subset of non-null controls in req->controls + * (checked above) + * So to confirm that the two lists are identical except for the paged + * control and possibly ASQ, all we need to check is: */ + if (num_non_null_req_controls == num_down_controls + 1) { + return true; + } + return false; +} + +static bool paged_attrs_same(const char * const *attrs_1, + const char * const *attrs_2) { + int i; + if (attrs_1 == NULL || attrs_2 == NULL) { + if (attrs_1 == NULL && attrs_2 == NULL) { + return true; + } + return false; + } + + for (i=0; attrs_1[i] != NULL; i++) { + if (!ldb_attr_in_list(attrs_2, attrs_1[i])) { + return false; + } + } + return true; +} + +static int paged_search(struct ldb_module *module, struct ldb_request *req) +{ + struct ldb_context *ldb; + struct ldb_control *control; + struct ldb_control *vlv_control; + struct private_data *private_data; + struct ldb_paged_control *paged_ctrl; + struct ldb_request *search_req; + struct paged_context *ac; + int ret; + + ldb = ldb_module_get_ctx(module); + + /* check if there's a paged request control */ + control = ldb_request_get_control(req, LDB_CONTROL_PAGED_RESULTS_OID); + if (control == NULL) { + /* not found go on */ + return ldb_next_request(module, req); + } + + paged_ctrl = talloc_get_type(control->data, struct ldb_paged_control); + if (!paged_ctrl) { + return LDB_ERR_PROTOCOL_ERROR; + } + + private_data = talloc_get_type(ldb_module_get_private(module), + struct private_data); + + vlv_control = ldb_request_get_control(req, LDB_CONTROL_VLV_REQ_OID); + if (vlv_control != NULL) { + /* + * VLV and paged_results are not allowed at the same + * time + */ + return LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION; + } + + ac = talloc_zero(req, struct paged_context); + if (ac == NULL) { + ldb_set_errstring(ldb, "Out of Memory"); + return LDB_ERR_OPERATIONS_ERROR; + } + + ac->module = module; + ac->req = req; + ac->size = paged_ctrl->size; + if (ac->size < 0) { + /* + * Apparently some clients send more than 2^31. This + * violates the ldap standard, but we need to cope. + * In the future, if maximum result sizes are implemented in + * Samba, we should also clamp the page size to the maximum + * result size. + */ + ac->size = 0x7FFFFFFF; + } + + /* check if it is a continuation search the store */ + if (paged_ctrl->cookie_len == 0) { + struct ldb_control *ext_ctrl; + struct ldb_control **controls; + static const char * const attrs[1] = { NULL }; + void *ref = NULL; + + if (paged_ctrl->size == 0) { + return LDB_ERR_OPERATIONS_ERROR; + } + + ac->store = new_store(private_data); + if (ac->store == NULL) { + return LDB_ERR_OPERATIONS_ERROR; + } + + controls = req->controls; + ext_ctrl = ldb_request_get_control(req, + LDB_CONTROL_EXTENDED_DN_OID); + if (ext_ctrl == NULL) { + /* + * Add extended_dn control to the request if there + * isn't already one. We'll get the GUID out of it in + * the callback. This is a workaround for the case + * where ntsecuritydescriptor forbids fetching GUIDs + * for the current user. + */ + struct ldb_request *req_extended_dn; + struct ldb_extended_dn_control *ext_ctrl_data; + req_extended_dn = talloc_zero(req, struct ldb_request); + if (req_extended_dn == NULL) { + return ldb_module_oom(module); + } + req_extended_dn->controls = req->controls; + ext_ctrl_data = talloc_zero(req, + struct ldb_extended_dn_control); + if (ext_ctrl_data == NULL) { + return ldb_module_oom(module); + } + ext_ctrl_data->type = 1; + + ret = ldb_request_add_control(req_extended_dn, + LDB_CONTROL_EXTENDED_DN_OID, + true, + ext_ctrl_data); + if (ret != LDB_SUCCESS) { + return ret; + } + controls = req_extended_dn->controls; + } + + ret = ldb_build_search_req_ex(&search_req, ldb, ac, + req->op.search.base, + req->op.search.scope, + req->op.search.tree, + attrs, + controls, + ac, + paged_search_callback, + req); + if (ret != LDB_SUCCESS) { + return ret; + } + + /* + * LDB does not have a function to take a full copy of + * this, but at least take a shallow copy + */ + ac->store->expr = ldb_parse_tree_copy_shallow(ac->store, + req->op.search.tree); + + if (ac->store->expr == NULL) { + return ldb_operr(ldb); + } + + /* + * As the above is only a shallow copy, take a + * reference to ensure the values are kept around + */ + ref = talloc_reference(ac->store, req->op.search.tree); + if (ref == NULL) { + return ldb_module_oom(module); + } + ac->store->expr_str = ldb_filter_from_tree(ac->store, + req->op.search.tree); + if (ac->store->expr_str == NULL) { + return ldb_module_oom(module); + } + if (req->op.search.attrs != NULL) { + ac->store->attrs = paged_copy_attrs(ac->store, + req->op.search.attrs); + if (ac->store->attrs == NULL) { + return ldb_module_oom(module); + } + } + + /* save it locally and remove it from the list */ + /* we do not need to replace them later as we + * are keeping the original req intact */ + if (!ldb_save_controls(control, search_req, NULL)) { + return LDB_ERR_OPERATIONS_ERROR; + } + ac->store->down_controls = + paged_results_copy_down_controls(ac->store, req->controls); + if (ac->store->down_controls == NULL) { + return LDB_ERR_OPERATIONS_ERROR; + } + + return ldb_next_request(module, search_req); + + } else { + struct results_store *current = NULL; + char *expr_str; + bool bool_ret; + + /* TODO: age out old outstanding requests */ + for (current = private_data->store; current != NULL; + current = current->next) { + if (strcmp(current->cookie, paged_ctrl->cookie) == 0) { + current->timestamp = time(NULL); + break; + } + } + if (current == NULL) { + return LDB_ERR_UNWILLING_TO_PERFORM; + } + + /* Get the expression string and make sure it didn't change */ + expr_str = ldb_filter_from_tree(ac, req->op.search.tree); + if (expr_str == NULL) { + return LDB_ERR_OPERATIONS_ERROR; + } + + ret = strcmp(current->expr_str, expr_str); + if (ret != 0) { + return LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION; + } + + bool_ret = paged_controls_same(req, current->down_controls); + if (bool_ret == false) { + return LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION; + } + + bool_ret = paged_attrs_same(req->op.search.attrs, + current->attrs); + if (bool_ret == false) { + return LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION; + } + + DLIST_PROMOTE(private_data->store, current); + + ac->store = current; + + /* check if it is an abandon */ + if (ac->size == 0) { + return ldb_module_done(req, NULL, NULL, + LDB_SUCCESS); + } + + ret = paged_results(ac, NULL); + if (ret != LDB_SUCCESS) { + /* + * paged_results() will have called ldb_module_done + * if an error occurred + */ + return ret; + } + return ldb_module_done(req, ac->controls, NULL, LDB_SUCCESS); + } +} + +static int paged_request_init(struct ldb_module *module) +{ + struct ldb_context *ldb; + struct private_data *data; + int ret; + + ldb = ldb_module_get_ctx(module); + + data = talloc(module, struct private_data); + if (data == NULL) { + return LDB_ERR_OTHER; + } + + data->next_free_id = 1; + data->num_stores = 0; + data->store = NULL; + ldb_module_set_private(module, data); + + ret = ldb_mod_register_control(module, LDB_CONTROL_PAGED_RESULTS_OID); + if (ret != LDB_SUCCESS) { + ldb_debug(ldb, LDB_DEBUG_WARNING, + "paged_results:" + "Unable to register control with rootdse!"); + } + + return ldb_next_init(module); +} + +static const struct ldb_module_ops ldb_paged_results_module_ops = { + .name = "dsdb_paged_results", + .search = paged_search, + .init_context = paged_request_init +}; + +int ldb_dsdb_paged_results_init(const char *version) +{ + LDB_MODULE_CHECK_VERSION(version); + return ldb_register_module(&ldb_paged_results_module_ops); +} |