r13839: Use registration mechanism for backends as well (in the same sense

my previous patch added it for modules). This is the next step towards
LDB backends and modules as run-time loadable .so files.
(This used to be commit fb2f70de4f6c4a9b13ad590cb4d3a9c858cede49)

8 files changed, 88 insertions, 38 deletions

diff --git a/source4/lib/ldb/common/ldb.c b/source4/lib/ldb/common/ldb.c
index 9d8783324c..b664ba680d 100644
--- a/source4/lib/ldb/common/ldb.c
+++ b/source4/lib/ldb/common/ldb.c
@@ -55,6 +55,40 @@ struct ldb_context *ldb_init(void *mem_ctx)
 	return ldb;
 }
 
+static struct ldb_backend {
+	const char *name;
+	ldb_connect_fn connect_fn;
+	struct ldb_backend *prev, *next;
+} *ldb_backends = NULL;
+/*
+ register a new ldb backend
+*/
+int ldb_register_backend(const char *url_prefix, ldb_connect_fn connectfn)
+{
+	struct ldb_backend *backend = talloc(talloc_autofree_context(), struct ldb_backend);
+
+	/* Maybe check for duplicity here later on? */
+
+	backend->name = talloc_strdup(backend, url_prefix);
+	backend->connect_fn = connectfn;
+	DLIST_ADD(ldb_backends, backend);
+
+	return LDB_SUCCESS;
+}
+
+static ldb_connect_fn ldb_find_backend(const char *url)
+{
+	struct ldb_backend *backend;
+
+	for (backend = ldb_backends; backend; backend = backend->next) {
+		if (strncmp(backend->name, url, strlen(backend->name)) == 0) {
+			return backend->connect_fn;
+		}
+	}
+
+	return NULL;
+}
+
 /* 
  connect to a database. The URL can either be one of the following forms
    ldb://path
@@ -68,31 +102,22 @@ struct ldb_context *ldb_init(void *mem_ctx)
 int ldb_connect(struct ldb_context *ldb, const char *url, unsigned int flags, const char *options[])
 {
 	int ret;
+	ldb_connect_fn fn;
 
-	if (strncmp(url, "tdb:", 4) == 0 ||
-	    strchr(url, ':') == NULL) {
-		ret = ltdb_connect(ldb, url, flags, options);
+	if (strchr(url, ':') != NULL) {
+		fn = ldb_find_backend(url);
+	} else {
+		/* Default to tdb */
+		fn = ldb_find_backend("tdb:");
 	}
 
-#if HAVE_ILDAP
-	else if (strncmp(url, "ldap", 4) == 0) {
-		ret = ildb_connect(ldb, url, flags, options);
-	}
-#elif HAVE_LDAP
-	else if (strncmp(url, "ldap", 4) == 0) {
-		ret = lldb_connect(ldb, url, flags, options);
-	}
-#endif
-#if HAVE_SQLITE3
-	else if (strncmp(url, "sqlite:", 7) == 0) {
-                ret = lsqlite3_connect(ldb, url, flags, options);
-	}
-#endif
-	else {
+	if (fn == NULL) {
 		ldb_debug(ldb, LDB_DEBUG_FATAL, "Unable to find backend for '%s'\n", url);
 		return LDB_ERR_OTHER;
 	}
 
+	ret = fn(ldb, url, flags, options);
+
 	if (ret != LDB_SUCCESS) {
 		ldb_debug(ldb, LDB_DEBUG_ERROR, "Failed to connect to '%s'\n", url);
 		return ret;
diff --git a/source4/lib/ldb/common/ldb_modules.c b/source4/lib/ldb/common/ldb_modules.c
index 17c5231e54..53394e7047 100644
--- a/source4/lib/ldb/common/ldb_modules.c
+++ b/source4/lib/ldb/common/ldb_modules.c
@@ -126,10 +126,24 @@ static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
 	return NULL;
 }
 
-	
+#ifdef HAVE_LDAP
+#define LDAP_INIT ldb_ldap_init,
+#else
+#define LDAP_INIT
+#endif
+
+#ifdef HAVE_SQLITE3
+#define SQLITE3_INIT ldb_sqlite3_init,
+#else
+#define SQLITE3_INIT
+#endif
+
 #ifndef STATIC_LIBLDB_MODULES
 #define STATIC_LIBLDB_MODULES \
 	{	\
+		LDAP_INIT \
+		SQLITE3_INIT \
+		ldb_tdb_init, 	\
 		ldb_schema_init,	\
 		ldb_operational_init,	\
 		ldb_rdn_name_init,	\
diff --git a/source4/lib/ldb/config.mk b/source4/lib/ldb/config.mk
index 82b98fa123..fe7b03251d 100644
--- a/source4/lib/ldb/config.mk
+++ b/source4/lib/ldb/config.mk
@@ -80,6 +80,7 @@ OBJ_FILES = \
 [MODULE::libldb_ildap]
 SUBSYSTEM = LIBLDB
 OUTPUT_TYPE = MERGEDOBJ
+INIT_FUNCTION = ldb_ildap_init
 OBJ_FILES = \
 		ldb_ildap/ldb_ildap.o
 REQUIRED_SUBSYSTEMS = \
@@ -112,6 +113,7 @@ OBJ_FILES = modules/skel.o
 [MODULE::libldb_sqlite3]
 SUBSYSTEM = LIBLDB
 OUTPUT_TYPE = MERGEDOBJ
+INIT_FUNCTION = ldb_sqlite3_init
 OBJ_FILES = \
 		ldb_sqlite3/ldb_sqlite3.o
 REQUIRED_SUBSYSTEMS = \
@@ -124,6 +126,7 @@ NOPROTO = YES
 # Start MODULE libldb_tdb
 [MODULE::libldb_tdb]
 SUBSYSTEM = LIBLDB
+INIT_FUNCTION = ldb_tdb_init
 OUTPUT_TYPE = MERGEDOBJ
 OBJ_FILES = \
 		ldb_tdb/ldb_tdb.o \
diff --git a/source4/lib/ldb/include/ldb_private.h b/source4/lib/ldb/include/ldb_private.h
index ba6823559f..52ea0f833d 100644
--- a/source4/lib/ldb/include/ldb_private.h
+++ b/source4/lib/ldb/include/ldb_private.h
@@ -64,6 +64,7 @@ struct ldb_module_ops {
 	int (*async_wait)(struct ldb_module *, struct ldb_async_handle *, enum ldb_async_wait_type);
 };
 
+typedef int (*ldb_connect_fn) (struct ldb_context *ldb, const char *url, unsigned int flags, const char *options[]);
 
 /*
   schema related information needed for matching rules
@@ -133,6 +134,7 @@ void ldb_set_errstring(struct ldb_context *ldb, char *err_string);
 void ldb_reset_err_string(struct ldb_context *ldb);
 
 int ldb_register_module(const struct ldb_module_ops *);
+int ldb_register_backend(const char *url_prefix, ldb_connect_fn);
 
 /* 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);
@@ -142,27 +144,16 @@ void ldb_debug_set(struct ldb_context *ldb, enum ldb_debug_level level,
 /* The following definitions come from lib/ldb/common/ldb_ldif.c  */
 int ldb_should_b64_encode(const struct ldb_val *val);
 
-int ltdb_connect(struct ldb_context *ldb, const char *url, 
-		 unsigned int flags, 
-		 const char *options[]);
-int lldb_connect(struct ldb_context *ldb, const char *url, 
-		 unsigned int flags, 
-		 const char *options[]);
-int ildb_connect(struct ldb_context *ldb,
-		 const char *url, 
-		 unsigned int flags, 
-		 const char *options[]);
-int lsqlite3_connect(struct ldb_context *ldb,
-		     const char *url, 
-		     unsigned int flags, 
-		     const char *options[]);
-
 int ldb_objectclass_init(void);
 int ldb_operational_init(void);
 int ldb_paged_results_init(void);
 int ldb_rdn_name_init(void);
 int ldb_schema_init(void);
 int ldb_sort_init(void);
+int ldb_ldap_init(void);
+int ldb_ildap_init(void);
+int ldb_tdb_init(void);
+int ldb_sqlite3_init(void);
 
 int ldb_match_msg(struct ldb_context *ldb,
 		  struct ldb_message *msg,
diff --git a/source4/lib/ldb/ldb_ildap/ldb_ildap.c b/source4/lib/ldb/ldb_ildap/ldb_ildap.c
index 3467e65bf9..ab37ab7570 100644
--- a/source4/lib/ldb/ldb_ildap/ldb_ildap.c
+++ b/source4/lib/ldb/ldb_ildap/ldb_ildap.c
@@ -987,7 +987,7 @@ static const struct ldb_module_ops ildb_ops = {
 /*
   connect to the database
 */
-int ildb_connect(struct ldb_context *ldb, const char *url, 
+static int ildb_connect(struct ldb_context *ldb, const char *url, 
 		 unsigned int flags, const char *options[])
 {
 	struct ildb_private *ildb = NULL;
@@ -1065,3 +1065,7 @@ failed:
 	return -1;
 }
 
+int ldb_ildap_init(void)
+{
+	return ldb_register_backend("ldap", ildb_connect);
+}
diff --git a/source4/lib/ldb/ldb_ldap/ldb_ldap.c b/source4/lib/ldb/ldb_ldap/ldb_ldap.c
index d671afb953..3a5039ddc0 100644
--- a/source4/lib/ldb/ldb_ldap/ldb_ldap.c
+++ b/source4/lib/ldb/ldb_ldap/ldb_ldap.c
@@ -1042,7 +1042,7 @@ static int lldb_destructor(void *p)
 /*
   connect to the database
 */
-int lldb_connect(struct ldb_context *ldb,
+static int lldb_connect(struct ldb_context *ldb,
 		 const char *url, 
 		 unsigned int flags, 
 		 const char *options[])
@@ -1093,3 +1093,7 @@ failed:
 	return -1;
 }
 
+int ldb_ldap_init(void)
+{
+	return ldb_register_backend("ldap", lldb_connect);
+}
diff --git a/source4/lib/ldb/ldb_sqlite3/ldb_sqlite3.c b/source4/lib/ldb/ldb_sqlite3/ldb_sqlite3.c
index bf6cf0951b..883b21e0b5 100644
--- a/source4/lib/ldb/ldb_sqlite3/ldb_sqlite3.c
+++ b/source4/lib/ldb/ldb_sqlite3/ldb_sqlite3.c
@@ -2070,7 +2070,7 @@ static const struct ldb_module_ops lsqlite3_ops = {
 /*
  * connect to the database
  */
-int lsqlite3_connect(struct ldb_context *ldb,
+static int lsqlite3_connect(struct ldb_context *ldb,
 		     const char *url, 
 		     unsigned int flags, 
 		     const char *options[])
@@ -2137,3 +2137,7 @@ failed:
 	return -1;
 }
 
+int ldb_sqlite3_init(void)
+{
+	return ldb_register_backend("sqlite3", lsqlite3_connect);
+}
diff --git a/source4/lib/ldb/ldb_tdb/ldb_tdb.c b/source4/lib/ldb/ldb_tdb/ldb_tdb.c
index 0825348658..5470fccb97 100644
--- a/source4/lib/ldb/ldb_tdb/ldb_tdb.c
+++ b/source4/lib/ldb/ldb_tdb/ldb_tdb.c
@@ -1033,7 +1033,7 @@ static const struct ldb_module_ops ltdb_ops = {
 /*
   connect to the database
 */
-int ltdb_connect(struct ldb_context *ldb, const char *url, 
+static int ltdb_connect(struct ldb_context *ldb, const char *url, 
 		 unsigned int flags, const char *options[])
 {
 	const char *path;
@@ -1094,3 +1094,8 @@ int ltdb_connect(struct ldb_context *ldb, const char *url,
 
 	return 0;
 }
+
+int ldb_tdb_init(void)
+{
+	return ldb_register_backend("tdb:", ltdb_connect);
+}