Add Group Policy extension infrastructure.

Guenther
(This used to be commit 6d543b1a1a5a7af98affc9aea2edf650cb476379)

3 files changed, 858 insertions, 0 deletions

diff --git a/source3/libgpo/gpext/gpext.c b/source3/libgpo/gpext/gpext.c
new file mode 100644
index 00000000000..184a2fa185d
--- /dev/null
+++ b/source3/libgpo/gpext/gpext.c
@@ -0,0 +1,746 @@
+/*
+ *  Unix SMB/CIFS implementation.
+ *  Group Policy Support
+ *  Copyright (C) Guenther Deschner 2007-2008
+ *
+ *  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"
+
+static struct gp_extension *extensions = NULL;
+
+/****************************************************************
+****************************************************************/
+
+struct gp_extension *get_gp_extension_list(void)
+{
+	return extensions;
+}
+
+/****************************************************************
+****************************************************************/
+
+/* see http://support.microsoft.com/kb/216358/en-us/ for more info */
+
+struct gp_extension_reg_table gpext_reg_vals[] = {
+	{ "DllName", REG_EXPAND_SZ },
+	{ "ProcessGroupPolicy", REG_SZ },
+	{ "NoMachinePolicy", REG_DWORD },
+	{ "NoUserPolicy", REG_DWORD },
+	{ "NoSlowLink", REG_DWORD },
+	{ "NoBackgroundPolicy", REG_DWORD },
+	{ "NoGPOListChanges", REG_DWORD },
+	{ "PerUserLocalSettings", REG_DWORD },
+	{ "RequiresSuccessfulRegistry", REG_DWORD },
+	{ "EnableAsynchronousProcessing", REG_DWORD },
+	{ "ExtensionDebugLevel", REG_DWORD },
+	/* new */
+	{ "GenerateGroupPolicy", REG_SZ }, /* not supported on w2k */
+	{ "NotifyLinkTransition", REG_DWORD },
+	{ "ProcessGroupPolicyEx", REG_SZ }, /* not supported on w2k */
+	{ "ExtensionEventSource", REG_MULTI_SZ }, /* not supported on w2k */
+	{ "GenerateGroupPolicy", REG_SZ },
+	{ "MaxNoGPOListChangesInterval", REG_DWORD },
+	{ NULL, REG_NONE }
+};
+
+/****************************************************************
+****************************************************************/
+
+static struct gp_extension *get_extension_by_name(struct gp_extension *be,
+						  const char *name)
+{
+	struct gp_extension *b;
+
+	for (b = be; b; b = b->next) {
+		if (strequal(b->name, name)) {
+			return b;
+		}
+	}
+
+	return NULL;
+}
+
+/****************************************************************
+****************************************************************/
+
+static struct gp_extension_methods *get_methods_by_name(struct gp_extension *be,
+							const char *name)
+{
+	struct gp_extension *b;
+
+	for (b = be; b; b = b->next) {
+		if (strequal(b->name, name)) {
+			return b->methods;
+		}
+	}
+
+	return NULL;
+}
+
+/****************************************************************
+****************************************************************/
+
+NTSTATUS unregister_gp_extension(const char *name)
+{
+	struct gp_extension *ext;
+
+	ext = get_extension_by_name(extensions, name);
+	if (!ext) {
+		return NT_STATUS_OK;
+	}
+
+	DLIST_REMOVE(extensions, ext);
+	TALLOC_FREE(ext);
+
+	DEBUG(2,("Successfully removed GP extension '%s'\n", name));
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+NTSTATUS register_gp_extension(TALLOC_CTX *gpext_ctx,
+			       int version,
+			       const char *name,
+			       const char *guid,
+			       struct gp_extension_methods *methods)
+{
+	struct gp_extension_methods *test;
+	struct gp_extension *entry;
+	NTSTATUS status;
+
+	if (!gpext_ctx) {
+		return NT_STATUS_INTERNAL_DB_ERROR;
+	}
+
+	if ((version != SMB_GPEXT_INTERFACE_VERSION)) {
+		DEBUG(0,("Failed to register gp extension.\n"
+		         "The module was compiled against "
+			 "SMB_GPEXT_INTERFACE_VERSION %d,\n"
+		         "current SMB_GPEXT_INTERFACE_VERSION is %d.\n"
+		         "Please recompile against the current "
+			 "version of samba!\n",
+			 version, SMB_GPEXT_INTERFACE_VERSION));
+		return NT_STATUS_OBJECT_TYPE_MISMATCH;
+	}
+
+	if (!guid || !name || !name[0] || !methods) {
+		DEBUG(0,("Called with NULL pointer or empty name!\n"));
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
+	test = get_methods_by_name(extensions, name);
+	if (test) {
+		DEBUG(0,("GP extension module %s already registered!\n",
+			name));
+		return NT_STATUS_OBJECT_NAME_COLLISION;
+	}
+
+	entry = TALLOC_ZERO_P(gpext_ctx, struct gp_extension);
+	NT_STATUS_HAVE_NO_MEMORY(entry);
+
+	entry->name = talloc_strdup(gpext_ctx, name);
+	NT_STATUS_HAVE_NO_MEMORY(entry->name);
+
+	entry->guid = TALLOC_ZERO_P(gpext_ctx, struct GUID);
+	NT_STATUS_HAVE_NO_MEMORY(entry->guid);
+	status = GUID_from_string(guid, entry->guid);
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	entry->methods = methods;
+	DLIST_ADD(extensions, entry);
+
+	DEBUG(2,("Successfully added GP extension '%s' %s\n",
+		name, GUID_string2(gpext_ctx, entry->guid)));
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+static NTSTATUS gp_extension_init_module(TALLOC_CTX *mem_ctx,
+					 const char *name,
+					 struct gp_extension **gpext)
+{
+	NTSTATUS status;
+	struct gp_extension *ext = NULL;
+
+	ext = TALLOC_ZERO_P(mem_ctx, struct gp_extension);
+	NT_STATUS_HAVE_NO_MEMORY(gpext);
+
+	ext->methods = get_methods_by_name(extensions, name);
+	if (!ext->methods) {
+
+		status = smb_probe_module(SAMBA_SUBSYSTEM_GPEXT,
+					  name);
+		if (!NT_STATUS_IS_OK(status)) {
+			return status;
+		}
+
+		ext->methods = get_methods_by_name(extensions, name);
+		if (!ext->methods) {
+			return NT_STATUS_DLL_INIT_FAILED;
+		}
+	}
+
+	*gpext = ext;
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+static bool add_gp_extension_reg_entry_to_array(TALLOC_CTX *mem_ctx,
+						struct gp_extension_reg_entry *entry,
+						struct gp_extension_reg_entry **entries,
+						size_t *num)
+{
+	*entries = TALLOC_REALLOC_ARRAY(mem_ctx, *entries,
+					struct gp_extension_reg_entry,
+					(*num)+1);
+	if (*entries == NULL) {
+		*num = 0;
+		return false;
+	}
+
+	(*entries)[*num].value = entry->value;
+	(*entries)[*num].data = entry->data;
+
+	*num += 1;
+	return true;
+}
+
+/****************************************************************
+****************************************************************/
+
+static bool add_gp_extension_reg_info_entry_to_array(TALLOC_CTX *mem_ctx,
+						     struct gp_extension_reg_info_entry *entry,
+						     struct gp_extension_reg_info_entry **entries,
+						     size_t *num)
+{
+	*entries = TALLOC_REALLOC_ARRAY(mem_ctx, *entries,
+					struct gp_extension_reg_info_entry,
+					(*num)+1);
+	if (*entries == NULL) {
+		*num = 0;
+		return false;
+	}
+
+	(*entries)[*num].guid = entry->guid;
+	(*entries)[*num].num_entries = entry->num_entries;
+	(*entries)[*num].entries = entry->entries;
+
+	*num += 1;
+	return true;
+}
+
+/****************************************************************
+****************************************************************/
+
+static NTSTATUS gp_ext_info_add_reg(TALLOC_CTX *mem_ctx,
+				    struct gp_extension_reg_info_entry *entry,
+				    const char *value,
+				    enum winreg_Type type,
+				    const char *data_s)
+{
+	struct gp_extension_reg_entry *reg_entry = NULL;
+	struct registry_value *data = NULL;
+
+	reg_entry = TALLOC_ZERO_P(mem_ctx, struct gp_extension_reg_entry);
+	NT_STATUS_HAVE_NO_MEMORY(reg_entry);
+
+	data = TALLOC_ZERO_P(mem_ctx, struct registry_value);
+	NT_STATUS_HAVE_NO_MEMORY(data);
+
+	data->type = type;
+
+	switch (type) {
+		case REG_SZ:
+		case REG_EXPAND_SZ:
+			data->v.sz.str = talloc_strdup(mem_ctx, data_s);
+			NT_STATUS_HAVE_NO_MEMORY(data->v.sz.str);
+			data->v.sz.len = strlen(data_s);
+			break;
+		case REG_DWORD:
+			data->v.dword = atoi(data_s);
+			break;
+		default:
+			return NT_STATUS_NOT_SUPPORTED;
+	}
+
+	reg_entry->value = value;
+	reg_entry->data = data;
+
+	if (!add_gp_extension_reg_entry_to_array(mem_ctx, reg_entry,
+						 &entry->entries,
+						 &entry->num_entries)) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+static NTSTATUS gp_ext_info_add_reg_table(TALLOC_CTX *mem_ctx,
+					  const char *module,
+					  struct gp_extension_reg_info_entry *entry,
+					  struct gp_extension_reg_table *table)
+{
+	NTSTATUS status;
+	const char *module_name = NULL;
+	int i;
+
+	module_name = talloc_asprintf(mem_ctx, "%s.%s", module, shlib_ext());
+	NT_STATUS_HAVE_NO_MEMORY(module_name);
+
+	status = gp_ext_info_add_reg(mem_ctx, entry,
+				     "DllName", REG_EXPAND_SZ, module_name);
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	for (i=0; table[i].val; i++) {
+		status = gp_ext_info_add_reg(mem_ctx, entry,
+					     table[i].val,
+					     table[i].type,
+					     table[i].data);
+		NT_STATUS_NOT_OK_RETURN(status);
+	}
+
+	return status;
+}
+
+/****************************************************************
+****************************************************************/
+
+NTSTATUS gp_ext_info_add_entry(TALLOC_CTX *mem_ctx,
+			       const char *module,
+			       const char *ext_guid,
+			       struct gp_extension_reg_table *table,
+			       struct gp_extension_reg_info *info)
+{
+	NTSTATUS status;
+	struct gp_extension_reg_info_entry *entry = NULL;
+
+	entry = TALLOC_ZERO_P(mem_ctx, struct gp_extension_reg_info_entry);
+	NT_STATUS_HAVE_NO_MEMORY(entry);
+
+	status = GUID_from_string(ext_guid, &entry->guid);
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	status = gp_ext_info_add_reg_table(mem_ctx, module, entry, table);
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	if (!add_gp_extension_reg_info_entry_to_array(mem_ctx, entry,
+						      &info->entries,
+						      &info->num_entries)) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+static bool gp_extension_reg_info_verify_entry(struct gp_extension_reg_entry *entry)
+{
+	int i;
+
+	for (i=0; gpext_reg_vals[i].val; i++) {
+
+		if ((strequal(entry->value, gpext_reg_vals[i].val)) &&
+		    (entry->data->type == gpext_reg_vals[i].type)) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/****************************************************************
+****************************************************************/
+
+static bool gp_extension_reg_info_verify(struct gp_extension_reg_info_entry *entry)
+{
+	int i;
+
+	for (i=0; i < entry->num_entries; i++) {
+		if (!gp_extension_reg_info_verify_entry(&entry->entries[i])) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+/****************************************************************
+****************************************************************/
+
+static WERROR gp_extension_store_reg_vals(TALLOC_CTX *mem_ctx,
+					  struct registry_key *key,
+					  struct gp_extension_reg_info_entry *entry)
+{
+	WERROR werr = WERR_OK;
+	size_t i;
+
+	for (i=0; i < entry->num_entries; i++) {
+
+		werr = reg_setvalue(key,
+				    entry->entries[i].value,
+				    entry->entries[i].data);
+		W_ERROR_NOT_OK_RETURN(werr);
+	}
+
+	return werr;
+}
+
+/****************************************************************
+****************************************************************/
+
+static WERROR gp_extension_store_reg_entry(TALLOC_CTX *mem_ctx,
+					   struct gp_registry_context *reg_ctx,
+					   struct gp_extension_reg_info_entry *entry)
+{
+	WERROR werr;
+	struct registry_key *key = NULL;
+	const char *subkeyname = NULL;
+
+	if (!gp_extension_reg_info_verify(entry)) {
+		return WERR_INVALID_PARAM;
+	}
+
+	subkeyname = GUID_string2(mem_ctx, &entry->guid);
+	W_ERROR_HAVE_NO_MEMORY(subkeyname);
+
+	strupper_m(CONST_DISCARD(char *,subkeyname));
+
+	werr = gp_store_reg_subkey(mem_ctx,
+				   subkeyname,
+				   reg_ctx->curr_key,
+				   &key);
+	W_ERROR_NOT_OK_RETURN(werr);
+
+	werr = gp_extension_store_reg_vals(mem_ctx,
+					   key,
+					   entry);
+	W_ERROR_NOT_OK_RETURN(werr);
+
+	return werr;
+}
+
+/****************************************************************
+****************************************************************/
+
+static WERROR gp_extension_store_reg(TALLOC_CTX *mem_ctx,
+				     struct gp_registry_context *reg_ctx,
+				     struct gp_extension_reg_info *info)
+{
+	WERROR werr = WERR_OK;
+	int i;
+
+	if (!info) {
+		return WERR_OK;
+	}
+
+	for (i=0; i < info->num_entries; i++) {
+		werr = gp_extension_store_reg_entry(mem_ctx,
+						    reg_ctx,
+						    &info->entries[i]);
+		W_ERROR_NOT_OK_RETURN(werr);
+	}
+
+	return werr;
+}
+
+/****************************************************************
+****************************************************************/
+
+static NTSTATUS gp_glob_ext_list(TALLOC_CTX *mem_ctx,
+				 const char ***ext_list,
+				 size_t *ext_list_len)
+{
+	SMB_STRUCT_DIR *dir = NULL;
+	SMB_STRUCT_DIRENT *dirent = NULL;
+
+	dir = sys_opendir(lib_path(SAMBA_SUBSYSTEM_GPEXT));
+	if (!dir) {
+		return map_nt_error_from_unix(errno);
+	}
+
+	while ((dirent = sys_readdir(dir))) {
+
+		fstring name; /* forgive me... */
+		char *p;
+
+		if ((strequal(dirent->d_name, ".")) ||
+		    (strequal(dirent->d_name, ".."))) {
+			continue;
+		}
+
+		p = strrchr(dirent->d_name, '.');
+		if (!p) {
+			sys_closedir(dir);
+			return NT_STATUS_NO_MEMORY;
+		}
+
+		if (!strcsequal(p+1, shlib_ext())) {
+			DEBUG(10,("gp_glob_ext_list: not a *.so file: %s\n",
+				dirent->d_name));
+			continue;
+		}
+
+		fstrcpy(name, dirent->d_name);
+		name[PTR_DIFF(p, dirent->d_name)] = 0;
+
+		if (!add_string_to_array(mem_ctx, name, ext_list,
+					 (int *)ext_list_len)) {
+			sys_closedir(dir);
+			return NT_STATUS_NO_MEMORY;
+		}
+	}
+
+	sys_closedir(dir);
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+NTSTATUS shutdown_gp_extensions(void)
+{
+	struct gp_extension *ext = NULL;
+
+	for (ext = extensions; ext; ext = ext->next) {
+		if (ext->methods && ext->methods->shutdown) {
+			ext->methods->shutdown();
+		}
+	}
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+NTSTATUS init_gp_extensions(TALLOC_CTX *mem_ctx)
+{
+	NTSTATUS status;
+	WERROR werr;
+	int i = 0;
+	const char **ext_array = NULL;
+	size_t ext_array_len = 0;
+	struct gp_extension *gpext = NULL;
+	struct gp_registry_context *reg_ctx = NULL;
+
+	if (get_gp_extension_list()) {
+		return NT_STATUS_OK;
+	}
+
+	status = gp_glob_ext_list(mem_ctx, &ext_array, &ext_array_len);
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	for (i=0; i<ext_array_len; i++) {
+
+		struct gp_extension_reg_info *info = NULL;
+
+		status = gp_extension_init_module(mem_ctx, ext_array[i],
+						  &gpext);
+		if (!NT_STATUS_IS_OK(status)) {
+			goto out;
+		}
+
+		if (gpext->methods->get_reg_config) {
+
+			status = gpext->methods->initialize(mem_ctx);
+			if (!NT_STATUS_IS_OK(status)) {
+				gpext->methods->shutdown();
+				goto out;
+			}
+
+			status = gpext->methods->get_reg_config(mem_ctx,
+								&info);
+			if (!NT_STATUS_IS_OK(status)) {
+				gpext->methods->shutdown();
+				goto out;
+			}
+
+			if (!reg_ctx) {
+				struct nt_user_token *token;
+
+				token = registry_create_system_token(mem_ctx);
+				NT_STATUS_HAVE_NO_MEMORY(token);
+
+				werr = gp_init_reg_ctx(mem_ctx,
+						       KEY_WINLOGON_GPEXT_PATH,
+						       REG_KEY_WRITE,
+						       token,
+						       &reg_ctx);
+				if (!W_ERROR_IS_OK(werr)) {
+					status = werror_to_ntstatus(werr);
+					gpext->methods->shutdown();
+					goto out;
+				}
+			}
+
+			werr = gp_extension_store_reg(mem_ctx, reg_ctx, info);
+			if (!W_ERROR_IS_OK(werr)) {
+				DEBUG(1,("gp_extension_store_reg failed: %s\n",
+					dos_errstr(werr)));
+				TALLOC_FREE(info);
+				gpext->methods->shutdown();
+				status = werror_to_ntstatus(werr);
+				goto out;
+			}
+			TALLOC_FREE(info);
+		}
+
+	}
+
+ out:
+	TALLOC_FREE(reg_ctx);
+
+	return status;
+}
+
+/****************************************************************
+****************************************************************/
+
+NTSTATUS free_gp_extensions(void)
+{
+	struct gp_extension *ext, *ext_next = NULL;
+
+	for (ext = extensions; ext; ext = ext_next) {
+		ext_next = ext->next;
+		DLIST_REMOVE(extensions, ext);
+		TALLOC_FREE(ext);
+	}
+
+	extensions = NULL;
+
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+void debug_gpext_header(int lvl,
+			const char *name,
+			uint32_t flags,
+			struct GROUP_POLICY_OBJECT *gpo,
+			const char *extension_guid,
+			const char *snapin_guid)
+{
+	char *flags_str = NULL;
+
+	DEBUG(lvl,("%s\n", name));
+	DEBUGADD(lvl,("\tgpo:           %s (%s)\n", gpo->name,
+		gpo->display_name));
+	DEBUGADD(lvl,("\tcse extension: %s (%s)\n", extension_guid,
+		cse_gpo_guid_string_to_name(extension_guid)));
+	DEBUGADD(lvl,("\tgplink:        %s\n", gpo->link));
+	DEBUGADD(lvl,("\tsnapin:        %s (%s)\n", snapin_guid,
+		cse_snapin_gpo_guid_string_to_name(snapin_guid)));
+
+	flags_str = gpo_flag_str(flags);
+	DEBUGADD(lvl,("\tflags:         0x%08x %s\n", flags, flags_str));
+	SAFE_FREE(flags_str);
+}
+
+NTSTATUS process_gpo_list_with_extension(ADS_STRUCT *ads,
+			   TALLOC_CTX *mem_ctx,
+			   uint32_t flags,
+			   const struct nt_user_token *token,
+			   struct GROUP_POLICY_OBJECT *gpo_list,
+			   const char *extension_guid,
+			   const char *snapin_guid)
+{
+	return NT_STATUS_OK;
+}
+
+/****************************************************************
+****************************************************************/
+
+NTSTATUS gpext_process_extension(ADS_STRUCT *ads,
+				 TALLOC_CTX *mem_ctx,
+				 uint32_t flags,
+				 const struct nt_user_token *token,
+				 struct registry_key *root_key,
+				 struct GROUP_POLICY_OBJECT *gpo,
+				 const char *extension_guid,
+				 const char *snapin_guid)
+{
+	NTSTATUS status;
+	struct gp_extension *ext = NULL;
+	struct GUID guid;
+	bool cse_found = false;
+
+	status = init_gp_extensions(mem_ctx);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1,("init_gp_extensions failed: %s\n",
+			nt_errstr(status)));
+		return status;
+	}
+
+	status = GUID_from_string(extension_guid, &guid);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	for (ext = extensions; ext; ext = ext->next) {
+
+		if (GUID_equal(ext->guid, &guid)) {
+			cse_found = true;
+			break;
+		}
+	}
+
+	if (!cse_found) {
+		goto no_ext;
+	}
+
+	status = ext->methods->initialize(mem_ctx);
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	status = ext->methods->process_group_policy(ads,
+						    mem_ctx,
+						    flags,
+						    root_key,
+						    token,
+						    gpo,
+						    extension_guid,
+						    snapin_guid);
+	if (!NT_STATUS_IS_OK(status)) {
+		ext->methods->shutdown();
+	}
+
+	return status;
+
+ no_ext:
+	if (flags & GPO_INFO_FLAG_VERBOSE) {
+		DEBUG(0,("process_extension: no extension available for:\n"));
+		DEBUGADD(0,("%s (%s) (snapin: %s)\n",
+			extension_guid,
+			cse_gpo_guid_string_to_name(extension_guid),
+			snapin_guid));
+	}
+
+	return NT_STATUS_OK;
+}
diff --git a/source3/libgpo/gpext/gpext.h b/source3/libgpo/gpext/gpext.h
new file mode 100644
index 00000000000..0f0445701d9
--- /dev/null
+++ b/source3/libgpo/gpext/gpext.h
@@ -0,0 +1,79 @@
+/*
+ *  Unix SMB/CIFS implementation.
+ *  Group Policy Support
+ *  Copyright (C) Guenther Deschner 2007-2008
+ *
+ *  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/>.
+ */
+
+#define KEY_WINLOGON_GPEXT_PATH "HKLM\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\GPExtensions"
+
+#define SAMBA_SUBSYSTEM_GPEXT "gpext"
+
+#define SMB_GPEXT_INTERFACE_VERSION 1
+
+struct gp_extension {
+	struct GUID *guid;
+	const char *name;
+	struct gp_extension_methods *methods;
+	struct gp_extension *prev, *next;
+};
+
+struct gp_extension_reg_table {
+	const char *val;
+	enum winreg_Type type;
+	const char *data;
+};
+
+struct gp_extension_reg_entry {
+	const char *value;
+	struct registry_value *data;
+};
+
+struct gp_extension_reg_info_entry {
+	struct GUID guid;
+	size_t num_entries;
+	struct gp_extension_reg_entry *entries;
+};
+
+struct gp_extension_reg_info {
+	size_t num_entries;
+	struct gp_extension_reg_info_entry *entries;
+};
+
+struct gp_extension_methods {
+
+	NTSTATUS (*initialize)(TALLOC_CTX *mem_ctx);
+
+	NTSTATUS (*process_group_policy)(ADS_STRUCT *ads,
+					 TALLOC_CTX *mem_ctx,
+					 uint32_t flags,
+					 struct registry_key *root_key,
+					 const struct nt_user_token *token,
+					 struct GROUP_POLICY_OBJECT *gpo,
+					 const char *extension_guid,
+					 const char *snapin_guid);
+
+	NTSTATUS (*process_group_policy2)(ADS_STRUCT *ads,
+					 TALLOC_CTX *mem_ctx,
+					 uint32_t flags,
+					 const struct nt_user_token *token,
+					 struct GROUP_POLICY_OBJECT *gpo_list,
+					 const char *extension_guid);
+
+	NTSTATUS (*get_reg_config)(TALLOC_CTX *mem_ctx,
+				   struct gp_extension_reg_info **info);
+
+	NTSTATUS (*shutdown)(void);
+};
diff --git a/source3/libgpo/gpo_util.c b/source3/libgpo/gpo_util.c
index cd532da48b3..bc6c35726c2 100644
--- a/source3/libgpo/gpo_util.c
+++ b/source3/libgpo/gpo_util.c
@@ -668,6 +668,39 @@ NTSTATUS check_refresh_gpo_list(ADS_STRUCT *ads,
 /****************************************************************
 ****************************************************************/
 
+char *gpo_flag_str(uint32_t flags)
+{
+	fstring str = "";
+
+	if (flags == 0) {
+		return NULL;
+	}
+
+	if (flags & GPO_INFO_FLAG_SLOWLINK)
+		fstrcat(str, "GPO_INFO_FLAG_SLOWLINK ");
+	if (flags & GPO_INFO_FLAG_VERBOSE)
+		fstrcat(str, "GPO_INFO_FLAG_VERBOSE ");
+	if (flags & GPO_INFO_FLAG_SAFEMODE_BOOT)
+		fstrcat(str, "GPO_INFO_FLAG_SAFEMODE_BOOT ");
+	if (flags & GPO_INFO_FLAG_NOCHANGES)
+		fstrcat(str, "GPO_INFO_FLAG_NOCHANGES ");
+	if (flags & GPO_INFO_FLAG_MACHINE)
+		fstrcat(str, "GPO_INFO_FLAG_MACHINE ");
+	if (flags & GPO_INFO_FLAG_LOGRSOP_TRANSITION)
+		fstrcat(str, "GPO_INFO_FLAG_LOGRSOP_TRANSITION ");
+	if (flags & GPO_INFO_FLAG_LINKTRANSITION)
+		fstrcat(str, "GPO_INFO_FLAG_LINKTRANSITION ");
+	if (flags & GPO_INFO_FLAG_FORCED_REFRESH)
+		fstrcat(str, "GPO_INFO_FLAG_FORCED_REFRESH ");
+	if (flags & GPO_INFO_FLAG_BACKGROUND)
+		fstrcat(str, "GPO_INFO_FLAG_BACKGROUND ");
+
+	return SMB_STRDUP(str);
+}
+
+/****************************************************************
+****************************************************************/
+
 NTSTATUS gp_find_file(TALLOC_CTX *mem_ctx,
 		      uint32_t flags,
 		      const char *filename,