lib: Add server_id_db

This is a mapping from names to server_ids. In the future, this will
replace the namedb in source4/messaging.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

3 files changed, 360 insertions, 0 deletions

diff --git a/lib/util/server_id_db.c b/lib/util/server_id_db.c
new file mode 100644
index 0000000000..7f5b055f17
--- /dev/null
+++ b/lib/util/server_id_db.c
@@ -0,0 +1,308 @@
+/*
+ * Map names to server_ids
+ *
+ * Copyright Volker Lendecke <vl@samba.org> 2014
+ *
+ * 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 "replace.h"
+#include "system/filesys.h"
+#include "lib/util/server_id_db.h"
+#include "lib/tdb_wrap/tdb_wrap.h"
+#include "lib/util/strv.h"
+#include "lib/util/util_tdb.h"
+#include "lib/util/samba_util.h"
+
+static TDB_DATA talloc_tdb_data(void *ptr)
+{
+	return (TDB_DATA) { .dptr = ptr, .dsize = talloc_get_size(ptr) };
+}
+
+struct server_id_db {
+	struct server_id pid;
+	struct tdb_wrap *tdb;
+	char *names;
+};
+
+static int server_id_db_destructor(struct server_id_db *db);
+
+struct server_id_db *server_id_db_init(TALLOC_CTX *mem_ctx,
+				       struct server_id pid,
+				       const char *base_path,
+				       int hash_size, int tdb_flags)
+{
+	struct server_id_db *db;
+	size_t pathlen = strlen(base_path) + 11;
+	char path[pathlen];
+
+	db = talloc(mem_ctx, struct server_id_db);
+	if (db == NULL) {
+		return NULL;
+	}
+	db->pid = pid;
+	db->names = NULL;
+
+	snprintf(path, pathlen, "%s/names.tdb", base_path);
+
+	db->tdb = tdb_wrap_open(db, path, hash_size, tdb_flags,
+				O_RDWR|O_CREAT, 0660);
+	if (db->tdb == NULL) {
+		TALLOC_FREE(db);
+		return NULL;
+	}
+
+	talloc_set_destructor(db, server_id_db_destructor);
+
+	return db;
+}
+
+void server_id_db_reinit(struct server_id_db *db, struct server_id pid)
+{
+	db->pid = pid;
+	TALLOC_FREE(db->names);
+}
+
+static int server_id_db_destructor(struct server_id_db *db)
+{
+	char *name = NULL;
+
+	while ((name = strv_next(db->names, name)) != NULL) {
+		server_id_db_remove(db, name);
+	}
+
+	return 0;
+}
+
+int server_id_db_add(struct server_id_db *db, const char *name)
+{
+	struct tdb_context *tdb = db->tdb->tdb;
+	struct server_id_buf buf;
+	TDB_DATA key, data;
+	char *n;
+	int ret;
+
+	n = strv_find(db->names, name);
+	if (n != NULL) {
+		return EEXIST;
+	}
+
+	ret = strv_add(db, &db->names, name);
+	if (ret != 0) {
+		return ret;
+	}
+
+	key = string_term_tdb_data(name);
+
+	server_id_str_buf(db->pid, &buf);
+	data = string_term_tdb_data(buf.buf);
+
+	ret = tdb_append(tdb, key, data);
+	if (ret != 0) {
+		enum TDB_ERROR err = tdb_error(tdb);
+		strv_delete(&db->names, strv_find(db->names, name));
+		return map_unix_error_from_tdb(err);
+	}
+
+	return 0;
+}
+
+int server_id_db_remove(struct server_id_db *db, const char *name)
+{
+	struct tdb_context *tdb = db->tdb->tdb;
+	struct server_id_buf buf;
+	TDB_DATA key;
+	uint8_t *data;
+	char *ids, *n, *id;
+	int ret;
+
+	n = strv_find(db->names, name);
+	if (n == NULL) {
+		return ENOENT;
+	}
+
+	key = string_term_tdb_data(name);
+	server_id_str_buf(db->pid, &buf);
+
+	ret = tdb_chainlock(tdb, key);
+	if (ret == -1) {
+		enum TDB_ERROR err = tdb_error(tdb);
+		return map_unix_error_from_tdb(err);
+	}
+
+	ret = tdb_fetch_talloc(tdb, key, db, &data);
+	if (ret != 0) {
+		tdb_chainunlock(tdb, key);
+		return ret;
+	}
+
+	ids = (char *)data;
+
+	id = strv_find(ids, buf.buf);
+	if (id == NULL) {
+		tdb_chainunlock(tdb, key);
+		TALLOC_FREE(data);
+		return ENOENT;
+	}
+
+	strv_delete(&ids, id);
+	ret = tdb_store(tdb, key, talloc_tdb_data(ids), TDB_MODIFY);
+	TALLOC_FREE(data);
+
+	tdb_chainunlock(tdb, key);
+
+	if (ret == -1) {
+		enum TDB_ERROR err = tdb_error(tdb);
+		return map_unix_error_from_tdb(err);
+	}
+
+	strv_delete(&db->names, n);
+	return 0;
+}
+
+int server_id_db_lookup(struct server_id_db *db, const char *name,
+			TALLOC_CTX *mem_ctx, unsigned *pnum_servers,
+			struct server_id **pservers)
+{
+	struct tdb_context *tdb = db->tdb->tdb;
+	TDB_DATA key;
+	uint8_t *data;
+	char *ids, *id;
+	unsigned num_servers;
+	struct server_id *servers;
+	int i, ret;
+
+	key = string_term_tdb_data(name);
+
+	ret = tdb_fetch_talloc(tdb, key, mem_ctx, &data);
+	if (ret != 0) {
+		return ret;
+	}
+
+	ids = (char *)data;
+	num_servers = strv_count(ids);
+
+	servers = talloc_array(mem_ctx, struct server_id, num_servers);
+	if (servers == NULL) {
+		TALLOC_FREE(data);
+		return ENOMEM;
+	}
+
+	i = 0;
+
+	for (id = ids; id != NULL; id = strv_next(ids, id)) {
+		servers[i++] = server_id_from_string(NONCLUSTER_VNN, id);
+	}
+
+	TALLOC_FREE(data);
+
+	*pnum_servers = num_servers;
+	*pservers = servers;
+
+	return 0;
+}
+
+bool server_id_db_lookup_one(struct server_id_db *db, const char *name,
+			     struct server_id *server)
+{
+	int ret;
+	unsigned num_servers;
+	struct server_id *servers;
+
+	ret = server_id_db_lookup(db, name, db, &num_servers, &servers);
+	if (ret != 0) {
+		return false;
+	}
+	if (num_servers == 0) {
+		TALLOC_FREE(servers);
+		return false;
+	}
+	*server = servers[0];
+	TALLOC_FREE(servers);
+	return true;
+}
+
+struct server_id_db_traverse_state {
+	TALLOC_CTX *mem_ctx;
+	int (*fn)(const char *name,
+		  unsigned num_servers,
+		  const struct server_id *servers,
+		  void *private_data);
+	void *private_data;
+};
+
+static int server_id_db_traverse_fn(struct tdb_context *tdb,
+				    TDB_DATA key, TDB_DATA data,
+				    void *private_data)
+{
+	struct server_id_db_traverse_state *state = private_data;
+	const char *name;
+	char *ids, *id;
+	unsigned num_servers;
+	struct server_id *servers;
+	int i, ret;
+
+	if (key.dsize == 0) {
+		return 0;
+	}
+	if (key.dptr[key.dsize-1] != '\0') {
+		return 0;
+	}
+	name = (const char *)key.dptr;
+
+	ids = (char *)talloc_memdup(state->mem_ctx, data.dptr, data.dsize);
+	if (ids == NULL) {
+		return 0;
+	}
+
+	num_servers = strv_count(ids);
+	servers = talloc_array(ids, struct server_id, num_servers);
+
+	i = 0;
+
+	for (id = ids; id != NULL; id = strv_next(ids, id)) {
+		servers[i++] = server_id_from_string(NONCLUSTER_VNN, id);
+	}
+
+	ret = state->fn(name, num_servers, servers, state->private_data);
+
+	TALLOC_FREE(ids);
+
+	return ret;
+}
+
+int server_id_db_traverse_read(struct server_id_db *db,
+			       int (*fn)(const char *name,
+					 unsigned num_servers,
+					 const struct server_id *servers,
+					 void *private_data),
+			       void *private_data)
+{
+	struct server_id_db_traverse_state state;
+	int ret;
+
+	state = (struct server_id_db_traverse_state) {
+		.fn = fn, .private_data = private_data,
+		.mem_ctx = talloc_new(db)
+	};
+
+	if (state.mem_ctx == NULL) {
+		return ENOMEM;
+	}
+
+	ret = tdb_traverse_read(db->tdb->tdb, server_id_db_traverse_fn,
+				&state);
+	TALLOC_FREE(state.mem_ctx);
+	return ret;
+}
diff --git a/lib/util/server_id_db.h b/lib/util/server_id_db.h
new file mode 100644
index 0000000000..31b3305f47
--- /dev/null
+++ b/lib/util/server_id_db.h
@@ -0,0 +1,47 @@
+/*
+ * Namedb
+ *
+ * Copyright Volker Lendecke <vl@samba.org> 2014
+ *
+ * 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/>.
+ */
+
+#ifndef _SERVER_ID_DB_H_
+#define _SERVER_ID_DB_H_
+
+#include "talloc.h"
+#include "librpc/gen_ndr/server_id.h"
+
+struct server_id_db;
+
+struct server_id_db *server_id_db_init(TALLOC_CTX *mem_ctx,
+				       struct server_id pid,
+				       const char *base_path,
+				       int hash_size, int tdb_flags);
+void server_id_db_reinit(struct server_id_db *db, struct server_id pid);
+int server_id_db_add(struct server_id_db *db, const char *name);
+int server_id_db_remove(struct server_id_db *db, const char *name);
+int server_id_db_lookup(struct server_id_db *db, const char *name,
+			TALLOC_CTX *mem_ctx, unsigned *num_servers,
+			struct server_id **servers);
+bool server_id_db_lookup_one(struct server_id_db *db, const char *name,
+			     struct server_id *server);
+int server_id_db_traverse_read(struct server_id_db *db,
+			       int (*fn)(const char *name,
+					 unsigned num_servers,
+					 const struct server_id *servers,
+					 void *private_data),
+			       void *private_data);
+
+#endif
diff --git a/lib/util/wscript_build b/lib/util/wscript_build
index 83d0bf1d15..c0d07e70f8 100755
--- a/lib/util/wscript_build
+++ b/lib/util/wscript_build
@@ -139,3 +139,8 @@ if not bld.env.SAMBA_UTIL_CORE_ONLY:
                         public_deps='talloc'
 	                )
 
+    bld.SAMBA_LIBRARY('server_id_db',
+                      source='server_id_db.c',
+                      deps='talloc tdb strv util_tdb tdb-wrap samba-util',
+                      local_include=False,
+                      private_library=True)