idmap.c

samba最新软件

/*
   Unix SMB/CIFS implementation.

   Map SIDs to unixids and back

   Copyright (C) Kai Blin 2008

   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 "auth/auth.h"
#include "librpc/gen_ndr/lsa.h"
#include "librpc/gen_ndr/samr.h"
#include "librpc/gen_ndr/ndr_security.h"
#include "lib/ldb/include/ldb.h"
#include "lib/ldb/include/ldb_errors.h"
#include "lib/ldb_wrap.h"
#include "param/param.h"
#include "winbind/idmap.h"
#include "libcli/security/proto.h"
#include "libcli/ldap/ldap_ndr.h"

/**
 * Get uid/gid bounds from idmap database
 *
 * \param idmap_ctx idmap context to use
 * \param low lower uid/gid bound is stored here
 * \param high upper uid/gid bound is stored here
 * \return 0 on success, nonzero on failure
 */
static int idmap_get_bounds(struct idmap_context *idmap_ctx, uint32_t *low,
		uint32_t *high)
{
	int ret = -1;
	struct ldb_context *ldb = idmap_ctx->ldb_ctx;
	struct ldb_dn *dn;
	struct ldb_result *res = NULL;
	TALLOC_CTX *tmp_ctx = talloc_new(idmap_ctx);
	uint32_t lower_bound = (uint32_t) -1;
	uint32_t upper_bound = (uint32_t) -1;

	dn = ldb_dn_new(tmp_ctx, ldb, "CN=CONFIG");
	if (dn == NULL) goto failed;

	ret = ldb_search(ldb, dn, LDB_SCOPE_BASE, NULL, NULL, &res);
	if (ret != LDB_SUCCESS) goto failed;

	talloc_steal(tmp_ctx, res);

	if (res->count != 1) {
		ret = -1;
		goto failed;
	}

	lower_bound = ldb_msg_find_attr_as_uint(res->msgs[0], "lowerBound", -1);
	if (lower_bound != (uint32_t) -1) {
		ret = LDB_SUCCESS;
	} else {
		ret = -1;
		goto failed;
	}

	upper_bound = ldb_msg_find_attr_as_uint(res->msgs[0], "upperBound", -1);
	if (upper_bound != (uint32_t) -1) {
		ret = LDB_SUCCESS;
	} else {
		ret = -1;
	}

failed:
	talloc_free(tmp_ctx);
	*low  = lower_bound;
	*high = upper_bound;
	return ret;
}

/**
 * Add a dom_sid structure to a ldb_message
 * \param idmap_ctx idmap context to use
 * \param mem_ctx talloc context to use
 * \param ldb_message ldb message to add dom_sid to
 * \param attr_name name of the attribute to store the dom_sid in
 * \param sid dom_sid to store
 * \return 0 on success, an ldb error code on failure.
 */
static int idmap_msg_add_dom_sid(struct idmap_context *idmap_ctx,
		TALLOC_CTX *mem_ctx, struct ldb_message *msg,
		const char *attr_name, const struct dom_sid *sid)
{
	struct ldb_val val;
	enum ndr_err_code ndr_err;

	ndr_err = ndr_push_struct_blob(&val, mem_ctx,
				       lp_iconv_convenience(idmap_ctx->lp_ctx),
				       sid,
				       (ndr_push_flags_fn_t)ndr_push_dom_sid);

	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		return -1;
	}

	return ldb_msg_add_value(msg, attr_name, &val, NULL);
}

/**
 * Get a dom_sid structure from a ldb message.
 *
 * \param mem_ctx talloc context to allocate dom_sid memory in
 * \param msg ldb_message to get dom_sid from
 * \param attr_name key that has the dom_sid as data
 * \return dom_sid structure on success, NULL on failure
 */
static struct dom_sid *idmap_msg_get_dom_sid(TALLOC_CTX *mem_ctx,
		struct ldb_message *msg, const char *attr_name)
{
	struct dom_sid *sid;
	const struct ldb_val *val;
	enum ndr_err_code ndr_err;

	val = ldb_msg_find_ldb_val(msg, attr_name);
	if (val == NULL) {
		return NULL;
	}

	sid = talloc(mem_ctx, struct dom_sid);
	if (sid == NULL) {
		return NULL;
	}

	ndr_err = ndr_pull_struct_blob(val, sid, NULL, sid,
				       (ndr_pull_flags_fn_t)ndr_pull_dom_sid);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		talloc_free(sid);
		return NULL;
	}

	return sid;
}

/**
 * Initialize idmap context
 *
 * talloc_free to close.
 *
 * \param mem_ctx talloc context to use.
 * \return allocated idmap_context on success, NULL on error
 */
struct idmap_context *idmap_init(TALLOC_CTX *mem_ctx,
				 struct event_context *ev_ctx,
		struct loadparm_context *lp_ctx)
{
	struct idmap_context *idmap_ctx;

	idmap_ctx = talloc(mem_ctx, struct idmap_context);
	if (idmap_ctx == NULL) {
		return NULL;
	}

	idmap_ctx->lp_ctx = lp_ctx;

	idmap_ctx->ldb_ctx = ldb_wrap_connect(mem_ctx, ev_ctx, lp_ctx,
					      lp_idmap_url(lp_ctx),
					      system_session(mem_ctx, lp_ctx),
					      NULL, 0, NULL);
	if (idmap_ctx->ldb_ctx == NULL) {
		return NULL;
	}

	idmap_ctx->unix_groups_sid = dom_sid_parse_talloc(mem_ctx, "S-1-22-2");
	if (idmap_ctx->unix_groups_sid == NULL) {
		return NULL;
	}

	idmap_ctx->unix_users_sid = dom_sid_parse_talloc(mem_ctx, "S-1-22-1");
	if (idmap_ctx->unix_users_sid == NULL) {
		return NULL;
	}

	return idmap_ctx;
}

/**
 * Convert an unixid to the corresponding SID
 *
 * \param idmap_ctx idmap context to use
 * \param mem_ctx talloc context the memory for the struct dom_sid is allocated
 * from.
 * \param unixid pointer to a unixid struct to convert
 * \param sid pointer that will take the struct dom_sid pointer if the mapping
 * succeeds.
 * \return NT_STATUS_OK on success, NT_STATUS_NONE_MAPPED if mapping not
 * possible or some other NTSTATUS that is more descriptive on failure.
 */

NTSTATUS idmap_xid_to_sid(struct idmap_context *idmap_ctx, TALLOC_CTX *mem_ctx,
		const struct unixid *unixid, struct dom_sid **sid)
{
	int ret;
	NTSTATUS status = NT_STATUS_NONE_MAPPED;
	struct ldb_context *ldb = idmap_ctx->ldb_ctx;
	struct ldb_result *res = NULL;
	struct dom_sid *unix_sid, *new_sid;
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	const char *id_type;

	switch (unixid->type) {
		case ID_TYPE_UID:
			id_type = "ID_TYPE_UID";
			break;
		case ID_TYPE_GID:
			id_type = "ID_TYPE_GID";
			break;
		default:
			DEBUG(1, ("unixid->type must be type gid or uid\n"));
			status = NT_STATUS_NONE_MAPPED;
			goto failed;
	}

	ret = ldb_search_exp_fmt(ldb, tmp_ctx, &res, NULL, LDB_SCOPE_SUBTREE,
				 NULL, "(&(|(type=ID_TYPE_BOTH)(type=%s))"
				 "(xidNumber=%u))", id_type, unixid->id);
	if (ret != LDB_SUCCESS) {
		DEBUG(1, ("Search failed: %s\n", ldb_errstring(ldb)));
		status = NT_STATUS_NONE_MAPPED;
		goto failed;
	}

	if (res->count == 1) {
		*sid = idmap_msg_get_dom_sid(mem_ctx, res->msgs[0],
					     "objectSid");
		if (*sid == NULL) {
			DEBUG(1, ("Failed to get sid from db: %u\n", ret));
			status = NT_STATUS_NONE_MAPPED;
			goto failed;
		}
		talloc_free(tmp_ctx);
		return NT_STATUS_OK;
	}

	DEBUG(6, ("xid not found in idmap db, create S-1-22- SID.\n"));

	/* For local users/groups , we just create a rid = uid/gid */
	if (unixid->type == ID_TYPE_UID) {
		unix_sid = dom_sid_parse_talloc(tmp_ctx, "S-1-22-1");
	} else {
		unix_sid = dom_sid_parse_talloc(tmp_ctx, "S-1-22-2");
	}
	if (unix_sid == NULL) {
		status = NT_STATUS_NO_MEMORY;
		goto failed;
	}

	new_sid = dom_sid_add_rid(mem_ctx, unix_sid, unixid->id);
	if (new_sid == NULL) {
		status = NT_STATUS_NO_MEMORY;
		goto failed;
	}

	*sid = new_sid;
	talloc_free(tmp_ctx);
	return NT_STATUS_OK;

failed:
	talloc_free(tmp_ctx);
	return status;
}


/**
 * Map a SID to an unixid struct.
 *
 * If no mapping exists, a new mapping will be created.
 *
 * \todo Check if SIDs can be resolved if lp_idmap_trusted_only() == true
 * \todo Fix backwards compatibility for Samba3
 *
 * \param idmap_ctx idmap context to use
 * \param mem_ctx talloc context to use
 * \param sid SID to map to an unixid struct
 * \param unixid pointer to a unixid struct pointer
 * \return NT_STATUS_OK on success, NT_STATUS_INVALID_SID if the sid is not from
 * a trusted domain and idmap trusted only = true, NT_STATUS_NONE_MAPPED if the
 * mapping failed.
 */
NTSTATUS idmap_sid_to_xid(struct idmap_context *idmap_ctx, TALLOC_CTX *mem_ctx,
		const struct dom_sid *sid, struct unixid **unixid)
{
	int ret;
	NTSTATUS status = NT_STATUS_NONE_MAPPED;
	struct ldb_context *ldb = idmap_ctx->ldb_ctx;
	struct ldb_dn *dn;
	struct ldb_message *hwm_msg, *map_msg;
	struct ldb_result *res = NULL;
	int trans;
	uint32_t low, high, hwm, new_xid;
	char *sid_string, *unixid_string, *hwm_string;
	bool hwm_entry_exists;
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);

	if (dom_sid_in_domain(idmap_ctx->unix_users_sid, sid)) {
		uint32_t rid;
		DEBUG(6, ("This is a local unix uid, just calculate that.\n"));
		status = dom_sid_split_rid(tmp_ctx, sid, NULL, &rid);
		if (!NT_STATUS_IS_OK(status)) goto failed;

		*unixid = talloc(mem_ctx, struct unixid);
		if (*unixid == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto failed;
		}
		(*unixid)->id = rid;
		(*unixid)->type = ID_TYPE_UID;

		talloc_free(tmp_ctx);
		return NT_STATUS_OK;
	}

	if (dom_sid_in_domain(idmap_ctx->unix_groups_sid, sid)) {
		uint32_t rid;
		DEBUG(6, ("This is a local unix gid, just calculate that.\n"));
		status = dom_sid_split_rid(tmp_ctx, sid, NULL, &rid);
		if (!NT_STATUS_IS_OK(status)) goto failed;

		*unixid = talloc(mem_ctx, struct unixid);
		if (*unixid == NULL) {
			status = NT_STATUS_NO_MEMORY;
			goto failed;
		}
		(*unixid)->id = rid;
		(*unixid)->type = ID_TYPE_GID;

		talloc_free(tmp_ctx);
		return NT_STATUS_OK;
	 }

	ret = ldb_search_exp_fmt(ldb, tmp_ctx, &res, NULL, LDB_SCOPE_SUBTREE,
				 NULL, "(&(objectClass=sidMap)(objectSid=%s))",
				 ldap_encode_ndr_dom_sid(tmp_ctx, sid));
	if (ret != LDB_SUCCESS) {
		DEBUG(1, ("Search failed: %s\n", ldb_errstring(ldb)));
		status = NT_STATUS_NONE_MAPPED;
		goto failed;
	}

	if (res->count == 1) {
		const char *type = ldb_msg_find_attr_as_string(res->msgs[0],
							       "type", NULL);
		new_xid = ldb_msg_find_attr_as_uint(res->msgs[0], "xidNumber",