samba-mirror/lib/ldb/include/ldb_module.h

/*
   ldb database library

   Copyright (C) Simo Sorce         2008

     ** 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 module header
 *
 *  Description: defines ldb modules structures and helpers
 *
 */

#ifndef _LDB_MODULE_H_
#define _LDB_MODULE_H_

#include <ldb.h>

#if defined(_SAMBA_BUILD_) && defined(USING_SYSTEM_LDB)

/*
 * Versions before 1.2.0 doesn't define these values
 * so we assime 1.1.29 (which was used in Samba 4.6)
 *
 * See https://bugzilla.samba.org/show_bug.cgi?id=12859
 */
#ifndef EXPECTED_SYSTEM_LDB_VERSION_MAJOR
#define EXPECTED_SYSTEM_LDB_VERSION_MAJOR 1
#endif
#ifndef EXPECTED_SYSTEM_LDB_VERSION_MINOR
#define EXPECTED_SYSTEM_LDB_VERSION_MINOR 1
#endif
#ifndef EXPECTED_SYSTEM_LDB_VERSION_MINOR
#define EXPECTED_SYSTEM_LDB_VERSION_MINOR 29
#endif

/*
 * Only Samba versions which expect ldb >= 1.4.0
 * reopen the ldb after each fork().
 *
 * See https://bugzilla.samba.org/show_bug.cgi?id=13519
 */
#if EXPECTED_SYSTEM_LDB_VERSION_MAJOR > 1
#define __LDB_FORK_COMPATIBLE__ 1
#elif EXPECTED_SYSTEM_LDB_VERSION_MINOR > 3
#define __LDB_FORK_COMPATIBLE__ 1
#endif
#ifndef __LDB_FORK_COMPATIBLE__
#error "Samba < 4.9 is not compatible with this version of ldb due to assumptions around fork() behaviour"
#endif

#endif /* defined(_SAMBA_BUILD_) && defined(USING_SYSTEM_LDB) */

struct ldb_context;
struct ldb_module;

/**
   internal flag bits on message elements. Must be within LDB_FLAG_INTERNAL_MASK
 */
#define LDB_FLAG_INTERNAL_DISABLE_VALIDATION 0x10

/* disable any single value checking on this attribute */
#define LDB_FLAG_INTERNAL_DISABLE_SINGLE_VALUE_CHECK 0x20

/* attribute has failed access check and must not be exposed */
#define LDB_FLAG_INTERNAL_INACCESSIBLE_ATTRIBUTE 0x40

/* force single value checking on this attribute */
#define LDB_FLAG_INTERNAL_FORCE_SINGLE_VALUE_CHECK 0x80

/*
 * ensure that this value is unique on an index
 * (despite the index not otherwise being configured as UNIQUE).
 * For example, all words starting with 'a' must be unique, but duplicates of
 * words starting with b are allowed.  This is specifically for Samba's
 * objectSid index which is unique in the primary domain only.
 */
#define LDB_FLAG_INTERNAL_FORCE_UNIQUE_INDEX 0x100

/* an extended match rule that always fails to match */
#define SAMBA_LDAP_MATCH_ALWAYS_FALSE "1.3.6.1.4.1.7165.4.5.1"

/* The const char * const * pointer to a list of secret (password)
 * attributes, not to be printed in trace messages */
#define LDB_SECRET_ATTRIBUTE_LIST_OPAQUE "LDB_SECRET_ATTRIBUTE_LIST"

/*
   these function pointers define the operations that a ldb module can intercept
*/
struct ldb_module_ops {
	const char *name;
	int (*init_context) (struct ldb_module *);
	int (*search)(struct ldb_module *, struct ldb_request *); /* search */
	int (*add)(struct ldb_module *, struct ldb_request *); /* add */
	int (*modify)(struct ldb_module *, struct ldb_request *); /* modify */
	int (*del)(struct ldb_module *, struct ldb_request *); /* delete */
	int (*rename)(struct ldb_module *, struct ldb_request *); /* rename */
	int (*request)(struct ldb_module *, struct ldb_request *); /* match any other operation */
	int (*extended)(struct ldb_module *, struct ldb_request *); /* extended operations */
	int (*start_transaction)(struct ldb_module *);
	int (*prepare_commit)(struct ldb_module *);
	int (*end_transaction)(struct ldb_module *);
	int (*del_transaction)(struct ldb_module *);
	int (*sequence_number)(struct ldb_module *, struct ldb_request *);
	int (*read_lock)(struct ldb_module *);
	int (*read_unlock)(struct ldb_module *);
	void *private_data;
};


/* The following definitions come from lib/ldb/common/ldb_debug.c  */
void ldb_debug(struct ldb_context *ldb, enum ldb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
void ldb_debug_set(struct ldb_context *ldb, enum ldb_debug_level level, 
		   const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
void ldb_debug_add(struct ldb_context *ldb, const char *fmt, ...) PRINTF_ATTRIBUTE(2, 3);
void ldb_debug_end(struct ldb_context *ldb, enum ldb_debug_level level);
void ldb_vdebug(struct ldb_context *ldb, enum ldb_debug_level level, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(3, 0);

#define ldb_error(ldb, ecode, reason) ldb_error_at(ldb, ecode, reason, __FILE__, __LINE__)
#define ldb_module_error(module, ecode, reason) ldb_error_at(ldb_module_get_ctx(module), ecode, reason, __FILE__, __LINE__)

#define ldb_oom(ldb) ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR, "ldb out of memory")
#define ldb_module_oom(module) ldb_oom(ldb_module_get_ctx(module))
#define ldb_operr(ldb) ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR, "operations error")
#define ldb_module_operr(module) ldb_error(ldb_module_get_ctx(module), LDB_ERR_OPERATIONS_ERROR, "operations error")

/* The following definitions come from lib/ldb/common/ldb.c  */

void ldb_request_set_state(struct ldb_request *req, int state);
int ldb_request_get_status(struct ldb_request *req);

unsigned int ldb_get_create_perms(struct ldb_context *ldb);

const struct ldb_schema_syntax *ldb_standard_syntax_by_name(struct ldb_context *ldb,
							    const char *syntax);

/* The following definitions come from lib/ldb/common/ldb_attributes.c  */

int ldb_schema_attribute_add_with_syntax(struct ldb_context *ldb,
					 const char *name,
					 unsigned flags,
					 const struct ldb_schema_syntax *syntax);
int ldb_schema_attribute_add(struct ldb_context *ldb, 
			     const char *name,
			     unsigned flags,
			     const char *syntax);
void ldb_schema_attribute_remove(struct ldb_context *ldb, const char *name);

/* we allow external code to override the name -> schema_attribute function */
typedef const struct ldb_schema_attribute *(*ldb_attribute_handler_override_fn_t)(struct ldb_context *, void *, const char *);

/**
  Allow the caller to define a callback for the attribute handler

  \param ldb The ldb context
  \param override The callback to be used for attribute lookups
  \param private_data Private data for the callback

*/
void ldb_schema_attribute_set_override_handler(struct ldb_context *ldb,
					       ldb_attribute_handler_override_fn_t override,
					       void *private_data);

/**
  Allow the caller to define that the callback for the attribute handler
  also overrides the index list

  \param ldb The ldb context
  \param one_level_indexes Indicates that the index for SCOPE_ONELEVEL
         should also be maintained

*/
void ldb_schema_set_override_indexlist(struct ldb_context *ldb,
				       bool one_level_indexes);

/**

  \param ldb The ldb context
  \param GUID_index_attribute The globally attribute (eg objectGUID)
         on each entry
  \param GUID_index_attribute The DN component matching the
         globally attribute on each entry (eg GUID)

 The caller must ensure the supplied strings do not go out of
 scope (they are typically constant memory).

*/
void ldb_schema_set_override_GUID_index(struct ldb_context *ldb,
					const char *GUID_index_attribute,
					const char *GUID_index_dn_component);

/* A useful function to build comparison functions with */
int ldb_any_comparison(struct ldb_context *ldb, void *mem_ctx, 
		       ldb_attr_handler_t canonicalise_fn, 
		       const struct ldb_val *v1,
		       const struct ldb_val *v2);

/* The following definitions come from lib/ldb/common/ldb_controls.c  */
int ldb_save_controls(struct ldb_control *exclude, struct ldb_request *req, struct ldb_control ***saver);
/* Returns a list of controls, except the one specified.  Included
 * controls become a child of returned list if they were children of
 * controls_in */
struct ldb_control **ldb_controls_except_specified(struct ldb_control **controls_in, 
					       TALLOC_CTX *mem_ctx, 
					       struct ldb_control *exclude);
int ldb_check_critical_controls(struct ldb_control **controls);

/* The following definitions come from lib/ldb/common/ldb_ldif.c  */
int ldb_should_b64_encode(struct ldb_context *ldb, const struct ldb_val *val);

/* The following definitions come from lib/ldb/common/ldb_match.c  */
int ldb_match_msg(struct ldb_context *ldb,
		  const struct ldb_message *msg,
		  const struct ldb_parse_tree *tree,
		  struct ldb_dn *base,
		  enum ldb_scope scope);

int ldb_match_msg_error(struct ldb_context *ldb,
			const struct ldb_message *msg,
			const struct ldb_parse_tree *tree,
			struct ldb_dn *base,
			enum ldb_scope scope,
			bool *matched);

int ldb_match_msg_objectclass(const struct ldb_message *msg,
			      const char *objectclass);

int ldb_register_extended_match_rules(struct ldb_context *ldb);

/* The following definitions come from lib/ldb/common/ldb_modules.c  */

struct ldb_module *ldb_module_new(TALLOC_CTX *memctx,
				  struct ldb_context *ldb,
				  const char *module_name,
				  const struct ldb_module_ops *ops);

const char * ldb_module_get_name(struct ldb_module *module);
struct ldb_context *ldb_module_get_ctx(struct ldb_module *module);
void *ldb_module_get_private(struct ldb_module *module);
void ldb_module_set_private(struct ldb_module *module, void *private_data);
const struct ldb_module_ops *ldb_module_get_ops(struct ldb_module *module);

int ldb_next_request(struct ldb_module *module, struct ldb_request *request);
int ldb_next_start_trans(struct ldb_module *module);
int ldb_next_end_trans(struct ldb_module *module);
int ldb_next_del_trans(struct ldb_module *module);
int ldb_next_prepare_commit(struct ldb_module *module);
int ldb_next_init(struct ldb_module *module);
int ldb_next_read_lock(struct ldb_module *module);
int ldb_next_read_unlock(struct ldb_module *module);

void ldb_set_errstring(struct ldb_context *ldb, const char *err_string);
void ldb_asprintf_errstring(struct ldb_context *ldb, const char *format, ...) PRINTF_ATTRIBUTE(2,3);
void ldb_reset_err_string(struct ldb_context *ldb);
int ldb_error_at(struct ldb_context *ldb, int ecode, const char *reason, const char *file, int line);

const char *ldb_default_modules_dir(void);

int ldb_register_module(const struct ldb_module_ops *);

typedef int (*ldb_connect_fn)(struct ldb_context *ldb, const char *url,
			      unsigned int flags, const char *options[],
			      struct ldb_module **module);

/**
 Require that LDB use a private event context for each request

 A private event context may need to be created to avoid nested event
 loops during ldb_tdb with the locks held.  This indicates that a
 backend is in use that requires this to hold locks safely.

 \param handle The ldb handle to set the flag on
 */
void ldb_set_require_private_event_context(struct ldb_context *ldb);

struct ldb_backend_ops {
	const char *name;
	ldb_connect_fn connect_fn;
};

const char *ldb_default_modules_dir(void);

int ldb_register_backend(const char *url_prefix, ldb_connect_fn, bool);

struct ldb_handle *ldb_handle_new(TALLOC_CTX *mem_ctx, struct ldb_context *ldb);

/**
 Obtains the private event context for the handle,

 A private event context may have been created to avoid nested event
 loops during ldb_tdb with the locks held.  Otherwise return the
 global one.

 \param handle The ldb handle to obtain the event context for
 \return the tevent event context for this handle (private or global)
 */
struct tevent_context *ldb_handle_get_event_context(struct ldb_handle *handle);

int ldb_module_send_entry(struct ldb_request *req,
			  struct ldb_message *msg,
			  struct ldb_control **ctrls);

int ldb_module_send_referral(struct ldb_request *req,
					   char *ref);

int ldb_module_done(struct ldb_request *req,
		    struct ldb_control **ctrls,
		    struct ldb_extended *response,
		    int error);

int ldb_mod_register_control(struct ldb_module *module, const char *oid);

void ldb_set_default_dns(struct ldb_context *ldb);
/**
  Add a ldb_control to a ldb_reply

  \param ares the reply struct where to add the control
  \param oid the object identifier of the control as string
  \param critical whether the control should be critical or not
  \param data a talloc pointer to the control specific data

  \return result code (LDB_SUCCESS on success, or a failure code)
*/
int ldb_reply_add_control(struct ldb_reply *ares, const char *oid, bool critical, void *data);

/**
  mark a request as untrusted.

  This tells the rootdse module to remove unregistered controls

  \param req the request to mark as untrusted
*/
void ldb_req_mark_untrusted(struct ldb_request *req);

/**
  mark a request as trusted.

  This tells the rootdse module to allow unregistered controls

  \param req the request to mark as trusted
*/
void ldb_req_mark_trusted(struct ldb_request *req);

/**
   return true is a request is untrusted

   This indicates the request came across a trust boundary
   for example over LDAP

  \param req the request check
  \return is req trusted
*/
bool ldb_req_is_untrusted(struct ldb_request *req);

/**
  set custom flags. Those flags are set by applications using ldb,
  they are application dependent and the same bit can have different
  meaning in different application.
 */
void ldb_req_set_custom_flags(struct ldb_request *req, uint32_t flags);

/**
  get custom flags. Those flags are set by applications using ldb,
  they are application dependent and the same bit can have different
  meaning in different application.
 */
uint32_t ldb_req_get_custom_flags(struct ldb_request *req);

/* load all modules from the given directory */
int ldb_modules_load(const char *modules_path, const char *version);

/* init functions prototype */
typedef int (*ldb_module_init_fn)(const char *);

/*
  general ldb hook function
 */
enum ldb_module_hook_type { LDB_MODULE_HOOK_CMDLINE_OPTIONS     = 1,
			    LDB_MODULE_HOOK_CMDLINE_PRECONNECT  = 2,
			    LDB_MODULE_HOOK_CMDLINE_POSTCONNECT = 3 };

typedef int (*ldb_hook_fn)(struct ldb_context *, enum ldb_module_hook_type );

/*
  register a ldb hook function
 */
int ldb_register_hook(ldb_hook_fn hook_fn);

/*
  call ldb hooks of a given type
 */
int ldb_modules_hook(struct ldb_context *ldb, enum ldb_module_hook_type t);

#define LDB_MODULE_CHECK_VERSION(version) do { \
 if (strcmp(version, LDB_VERSION) != 0) { \
	fprintf(stderr, "ldb: module version mismatch in %s : ldb_version=%s module_version=%s\n", \
			__FILE__, version, LDB_VERSION); \
        return LDB_ERR_UNAVAILABLE; \
 }} while (0)


/*
  return a string representation of the calling chain for the given
  ldb request
 */
char *ldb_module_call_chain(struct ldb_request *req, TALLOC_CTX *mem_ctx);

/*
  return the next module in the chain
 */
struct ldb_module *ldb_module_next(struct ldb_module *module);

/*
  set the next module in the module chain
 */
void ldb_module_set_next(struct ldb_module *module, struct ldb_module *next);

/*
  load a list of modules
 */
int ldb_module_load_list(struct ldb_context *ldb, const char **module_list,
			 struct ldb_module *backend, struct ldb_module **out);

/*
  get the popt_options pointer in the ldb structure. This allows a ldb
  module to change the command line parsing
 */
struct poptOption **ldb_module_popt_options(struct ldb_context *ldb);

/* modules are called in inverse order on the stack.
   Lets place them as an admin would think the right order is.
   Modules order is important */
const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string);

/*
  return the current ldb flags LDB_FLG_*
 */
uint32_t ldb_module_flags(struct ldb_context *ldb);

int ldb_module_connect_backend(struct ldb_context *ldb,
			       const char *url,
			       const char *options[],
			       struct ldb_module **backend_module);

/*
  initialise a chain of modules
 */
int ldb_module_init_chain(struct ldb_context *ldb, struct ldb_module *module);

/*
 * prototype for the init function defined by dynamically loaded modules
 */
int ldb_init_module(const char *version);

/* replace the components of a DN with those from another DN, without
 * touching the extended components
 *
 * return true if successful and false if not
 * if false is returned the dn may be marked invalid
 */
bool ldb_dn_replace_components(struct ldb_dn *dn, struct ldb_dn *new_dn);

/*
  walk a parse tree, calling the provided callback on each node
*/
int ldb_parse_tree_walk(struct ldb_parse_tree *tree,
			int (*callback)(struct ldb_parse_tree *tree, void *),
			void *private_context);

/* compare two message elements with ordering - used by modify */
bool ldb_msg_element_equal_ordered(const struct ldb_message_element *el1,
				   const struct ldb_message_element *el2);


struct ldb_extended_match_rule
{
	const char *oid;
	int (*callback)(struct ldb_context *, const char *oid,
			const struct ldb_message *, const char *,
			const struct ldb_val *, bool *);
};

int ldb_register_extended_match_rule(struct ldb_context *ldb,
				     const struct ldb_extended_match_rule *rule);

/*
 * these pack/unpack functions are exposed in the library for use by
 * ldb tools like ldbdump and for use in tests,
 * but are not part of the public API
 */
int ldb_pack_data(struct ldb_context *ldb,
		  const struct ldb_message *message,
		  struct ldb_val *data);
/*
 * Unpack a ldb message from a linear buffer in ldb_val
 *
 * Providing a list of attributes to this function allows selective unpacking.
 * Giving a NULL list (or a list_size of 0) unpacks all the attributes.
 */
int ldb_unpack_data_only_attr_list(struct ldb_context *ldb,
				   const struct ldb_val *data,
				   struct ldb_message *message,
				   const char* const * list,
				   unsigned int list_size,
				   unsigned int *nb_attributes_indb);
int ldb_unpack_data(struct ldb_context *ldb,
		    const struct ldb_val *data,
		    struct ldb_message *message);
/*
 * Unpack a ldb message from a linear buffer in ldb_val
 *
 * Providing a list of attributes to this function allows selective unpacking.
 * Giving a NULL list (or a list_size of 0) unpacks all the attributes.
 *
 * Flags allow control of allocation, so that if
 * LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC is specified, then data in values are
 * not allocated, instead they point into the supplier constant buffer.
 *
 * If LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC is specified, then values
 * array are not allocated individually (for single-valued
 * attributes), instead they point into a single buffer per message.
 *
 * LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC is only valid when
 * LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC is also specified.
 *
 * Likewise if LDB_UNPACK_DATA_FLAG_NO_DN is specified, the DN is omitted.
 *
 * If LDB_UNPACK_DATA_FLAG_NO_ATTRS is specified, then no attributes
 * are unpacked or returned.
 *
 */
int ldb_unpack_data_only_attr_list_flags(struct ldb_context *ldb,
					 const struct ldb_val *data,
					 struct ldb_message *message,
					 const char * const *list,
					 unsigned int list_size,
					 unsigned int flags,
					 unsigned int *nb_elements_in_db);

#define LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC   0x0001
#define LDB_UNPACK_DATA_FLAG_NO_DN           0x0002
#define LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC 0x0004
#define LDB_UNPACK_DATA_FLAG_NO_ATTRS        0x0008

/**
 Forces a specific ldb handle to use the global event context.

 This allows a nested event loop to operate, so any open
 transaction also needs to be aborted.

 Any events on this event context will be lost.

 This is used in Samba when sending an IRPC to another part of the
 same process instead of making a local DB modification.

 \param handle The ldb handle to force to use the global context

 */
void ldb_handle_use_global_event_context(struct ldb_handle *handle);

#endif