r24283: added a dbwrap API for temporary databases, based on the one from the

s3 clustering code.

This commit just establishes the API. The ctdb backend for this will
come soon.
(This used to be commit 3767e755db7b58aee4ff375896beb00b133cc413)

5 files changed, 357 insertions, 0 deletions

diff --git a/source4/lib/basic.mk b/source4/lib/basic.mk
index 823057fbc7..0f61ac6549 100644
--- a/source4/lib/basic.mk
+++ b/source4/lib/basic.mk
@@ -13,6 +13,7 @@ include appweb/config.mk
 include stream/config.mk
 include util/config.mk
 include tdr/config.mk
+include dbwrap/config.mk
 
 ##############################
 # Start SUBSYSTEM LIBCRYPTO
diff --git a/source4/lib/dbwrap/config.mk b/source4/lib/dbwrap/config.mk
new file mode 100644
index 0000000000..e2df04ac96
--- /dev/null
+++ b/source4/lib/dbwrap/config.mk
@@ -0,0 +1,5 @@
+[SUBSYSTEM::LIBDBWRAP]
+OBJ_FILES = dbwrap.o \
+		dbwrap_tdb.o
+PUBLIC_DEPENDENCIES = \
+		LIBTDB
diff --git a/source4/lib/dbwrap/dbwrap.c b/source4/lib/dbwrap/dbwrap.c
new file mode 100644
index 0000000000..e853967aa2
--- /dev/null
+++ b/source4/lib/dbwrap/dbwrap.c
@@ -0,0 +1,33 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   database wrapper code
+
+   Copyright (C) Andrew Tridgell 2007
+   Copyright (C) Volker Lendecke 2005
+   
+   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 "lib/tdb/include/tdb.h"
+#include "lib/dbwrap/dbwrap.h"
+
+/*
+  open a temporary database
+ */
+struct db_context *db_tmp_open(TALLOC_CTX *mem_ctx, const char *name, int tdb_flags)
+{
+	return db_tmp_open_tdb(mem_ctx, name, tdb_flags);
+}
diff --git a/source4/lib/dbwrap/dbwrap.h b/source4/lib/dbwrap/dbwrap.h
new file mode 100644
index 0000000000..4b9654b8cf
--- /dev/null
+++ b/source4/lib/dbwrap/dbwrap.h
@@ -0,0 +1,53 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   database wrapper code
+
+   Copyright (C) Volker Lendecks 2005-2007
+   Copyright (C) Andrew Tridgell 2007
+   
+   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/>.
+*/
+
+struct db_record {
+	TDB_DATA key, value;
+	NTSTATUS (*store)(struct db_record *rec, TDB_DATA data, int flag);
+	NTSTATUS (*delete_rec)(struct db_record *rec);
+	void *private_data;
+};
+
+struct db_context {
+	struct db_record *(*fetch_locked)(struct db_context *db,
+					  TALLOC_CTX *mem_ctx,
+					  TDB_DATA key);
+	int (*fetch)(struct db_context *db, TALLOC_CTX *mem_ctx,
+		     TDB_DATA key, TDB_DATA *data);
+	int (*traverse)(struct db_context *db,
+			int (*f)(struct db_record *db,
+				 void *private_data),
+			void *private_data);
+	int (*traverse_read)(struct db_context *db,
+			     int (*f)(struct db_record *db,
+				      void *private_data),
+			     void *private_data);
+	int (*get_seqnum)(struct db_context *db);
+	void *private_data;
+};
+
+struct db_context *db_tmp_open(TALLOC_CTX *mem_ctx, const char *name, int tdb_flags);
+
+
+/* backends */
+struct db_context *db_tmp_open_tdb(TALLOC_CTX *mem_ctx, const char *name, int tdb_flags);
+
diff --git a/source4/lib/dbwrap/dbwrap_tdb.c b/source4/lib/dbwrap/dbwrap_tdb.c
new file mode 100644
index 0000000000..dedb344e0b
--- /dev/null
+++ b/source4/lib/dbwrap/dbwrap_tdb.c
@@ -0,0 +1,265 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   Database interface wrapper around tdb
+
+   Copyright (C) Volker Lendecke 2005
+   Copyright (C) Andrew Tridgell 2007
+   
+   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 "lib/tdb/include/tdb.h"
+#include "lib/dbwrap/dbwrap.h"
+#include "system/filesys.h"
+#include "db_wrap.h"
+
+struct db_tdb_ctx {
+	struct tdb_wrap *wtdb;
+};
+
+static NTSTATUS db_tdb_store(struct db_record *rec, TDB_DATA data, int flag);
+static NTSTATUS db_tdb_delete(struct db_record *rec);
+
+static int db_tdb_record_destr(struct db_record* data)
+{
+	struct db_tdb_ctx *ctx = talloc_get_type(data->private_data, struct db_tdb_ctx);
+
+	if (tdb_chainunlock(ctx->wtdb->tdb, data->key) != 0) {
+		DEBUG(0, ("tdb_chainunlock failed\n"));
+		return -1;
+	}
+	return 0;
+}
+
+static int db_tdb_fetch(struct db_context *db, TALLOC_CTX *mem_ctx, TDB_DATA key, TDB_DATA *data)
+{
+	struct db_tdb_ctx *ctx = talloc_get_type(db->private_data, struct db_tdb_ctx);
+	TDB_DATA value;
+
+	value = tdb_fetch(ctx->wtdb->tdb, key);
+	if (value.dptr == NULL) {
+		return -1;
+	}
+
+	data->dsize = value.dsize;
+	data->dptr  = (uint8_t *)talloc_memdup(mem_ctx, value.dptr, value.dsize);
+	free(value.dptr);
+	if (data->dptr == NULL) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	return 0;
+}
+
+static struct db_record *db_tdb_fetch_locked(struct db_context *db,
+				     TALLOC_CTX *mem_ctx, TDB_DATA key)
+{
+	struct db_tdb_ctx *ctx = talloc_get_type(db->private_data, struct db_tdb_ctx);
+	struct db_record *result;
+	TDB_DATA value;
+
+	result = talloc(mem_ctx, struct db_record);
+	if (result == NULL) {
+		return NULL;
+	}
+
+	result->key.dsize = key.dsize;
+	result->key.dptr = (uint8_t *)talloc_memdup(result, key.dptr, key.dsize);
+	if (result->key.dptr == NULL) {
+		talloc_free(result);
+		return NULL;
+	}
+
+	result->value.dptr = NULL;
+	result->value.dsize = 0;
+	result->private_data = talloc_reference(result, ctx);
+	result->store = db_tdb_store;
+	result->delete_rec = db_tdb_delete;
+
+	if (tdb_chainlock(ctx->wtdb->tdb, key) != 0) {
+		talloc_free(result);
+		return NULL;
+	}
+
+	talloc_set_destructor(result, db_tdb_record_destr);
+
+	value = tdb_fetch(ctx->wtdb->tdb, key);
+
+	if (value.dptr == NULL) {
+		return result;
+	}
+
+	result->value.dsize = value.dsize;
+	result->value.dptr = (uint8_t *)talloc_memdup(result, value.dptr,
+						    value.dsize);
+	free(value.dptr);
+	if (result->value.dptr == NULL) {
+		talloc_free(result);
+		return NULL;
+	}
+
+	return result;
+}
+
+static NTSTATUS db_tdb_store(struct db_record *rec, TDB_DATA data, int flag)
+{
+	struct db_tdb_ctx *ctx = talloc_get_type(rec->private_data, struct db_tdb_ctx);
+
+	/*
+	 * This has a bug: We need to replace rec->value for correct
+	 * operation, but right now brlock and locking don't use the value
+	 * anymore after it was stored.
+	 */
+
+	return (tdb_store(ctx->wtdb->tdb, rec->key, data, flag) == 0) ?
+		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
+}
+
+static NTSTATUS db_tdb_delete(struct db_record *rec)
+{
+	struct db_tdb_ctx *ctx = talloc_get_type(rec->private_data, struct db_tdb_ctx);
+
+	return (tdb_delete(ctx->wtdb->tdb, rec->key) == 0) ?
+		NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL;
+}
+
+struct db_tdb_traverse_ctx {
+	struct db_context *db;
+	int (*f)(struct db_record *rec, void *private_data);
+	void *private_data;
+};
+
+static int db_tdb_traverse_func(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
+				void *private_data)
+{
+	struct db_tdb_traverse_ctx *ctx =
+		(struct db_tdb_traverse_ctx *)private_data;
+	struct db_record rec;
+
+	rec.key = kbuf;
+	rec.value = dbuf;
+	rec.store = db_tdb_store;
+	rec.delete_rec = db_tdb_delete;
+	rec.private_data = ctx->db->private_data;
+
+	return ctx->f(&rec, ctx->private_data);
+}
+
+static int db_tdb_traverse(struct db_context *db,
+			   int (*f)(struct db_record *rec, void *private_data),
+			   void *private_data)
+{
+	struct db_tdb_ctx *db_ctx =
+		talloc_get_type(db->private_data, struct db_tdb_ctx);
+	struct db_tdb_traverse_ctx ctx;
+
+	ctx.db = db;
+	ctx.f = f;
+	ctx.private_data = private_data;
+	return tdb_traverse(db_ctx->wtdb->tdb, db_tdb_traverse_func, &ctx);
+}
+
+static NTSTATUS db_tdb_store_deny(struct db_record *rec, TDB_DATA data, int flag)
+{
+	return NT_STATUS_MEDIA_WRITE_PROTECTED;
+}
+
+static NTSTATUS db_tdb_delete_deny(struct db_record *rec)
+{
+	return NT_STATUS_MEDIA_WRITE_PROTECTED;
+}
+
+static int db_tdb_traverse_read_func(TDB_CONTEXT *tdb, TDB_DATA kbuf, TDB_DATA dbuf,
+				void *private_data)
+{
+	struct db_tdb_traverse_ctx *ctx =
+		(struct db_tdb_traverse_ctx *)private_data;
+	struct db_record rec;
+
+	rec.key = kbuf;
+	rec.value = dbuf;
+	rec.store = db_tdb_store_deny;
+	rec.delete_rec = db_tdb_delete_deny;
+	rec.private_data = ctx->db->private_data;
+
+	return ctx->f(&rec, ctx->private_data);
+}
+
+static int db_tdb_traverse_read(struct db_context *db,
+			   int (*f)(struct db_record *rec, void *private_data),
+			   void *private_data)
+{
+	struct db_tdb_ctx *db_ctx =
+		talloc_get_type(db->private_data, struct db_tdb_ctx);
+	struct db_tdb_traverse_ctx ctx;
+
+	ctx.db = db;
+	ctx.f = f;
+	ctx.private_data = private_data;
+	return tdb_traverse_read(db_ctx->wtdb->tdb, db_tdb_traverse_read_func, &ctx);
+}
+
+static int db_tdb_get_seqnum(struct db_context *db)
+
+{
+	struct db_tdb_ctx *db_ctx =
+		talloc_get_type(db->private_data, struct db_tdb_ctx);
+	return tdb_get_seqnum(db_ctx->wtdb->tdb);
+}
+
+/*
+  open a temporary database
+ */
+struct db_context *db_tmp_open_tdb(TALLOC_CTX *mem_ctx, const char *name, int tdb_flags)
+{
+	struct db_context *result;
+	struct db_tdb_ctx *db_tdb;
+	char *path;
+
+	result = talloc_zero(mem_ctx, struct db_context);
+	if (result == NULL) goto failed;
+
+	db_tdb = talloc(result, struct db_tdb_ctx);
+	if (db_tdb == NULL) goto failed;
+
+	result->private_data = db_tdb;
+
+	/* the name passed in should not be a full path, it should be
+	   just be the db name */
+	path = smbd_tmp_path(result, name);
+
+	db_tdb->wtdb = tdb_wrap_open(db_tdb, path, 0, tdb_flags,
+				     O_CREAT|O_RDWR, 0666);
+	if (db_tdb->wtdb == NULL) {
+		DEBUG(3, ("Could not open tdb '%s': %s\n", path, strerror(errno)));
+		goto failed;
+	}
+	
+	talloc_free(path);
+
+	result->fetch_locked  = db_tdb_fetch_locked;
+	result->fetch         = db_tdb_fetch;
+	result->traverse      = db_tdb_traverse;
+	result->traverse_read = db_tdb_traverse_read;
+	result->get_seqnum    = db_tdb_get_seqnum;
+
+	return result;
+
+ failed:
+	talloc_free(result);
+	return NULL;
+}