s4-ldb: added support for general ldb hooks in modules

this allows a ldb module to register a hook function called at various
stages of processing. It will be initially used for ldb command line
hooks, but should work generally.

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/lib/ldb/common/ldb_modules.c b/source4/lib/ldb/common/ldb_modules.c
index 4590842d8f8642c82566bf744134f46c40b1e25f..5f01082e1dc8e0125290a5af702bc5aff751e96e 100644 (file)
--- a/source4/lib/ldb/common/ldb_modules.c
+++ b/source4/lib/ldb/common/ldb_modules.c
@@ -131,13 +131,12 @@ static struct ops_list_entry {
        struct ops_list_entry *next;
 } *registered_modules = NULL;
 
-static backends_list_entry *ldb_find_backend(const char *url)
+static struct backends_list_entry *ldb_find_backend(const char *url_prefix)
 {
        struct backends_list_entry *backend;
 
        for (backend = ldb_backends; backend; backend = backend->next) {
-               if (strncmp(backend->ops->name, url,
-                           strlen(backend->ops->name)) == 0) {
+               if (strcmp(backend->ops->name, url_prefix) == 0) {
                        return backend;
                }
        }
@@ -152,7 +151,6 @@ static backends_list_entry *ldb_find_backend(const char *url)
 */
 int ldb_register_backend(const char *url_prefix, ldb_connect_fn connectfn, bool override)
 {
-       struct ldb_backend_ops *backend;
        struct backends_list_entry *be;
 
        be = ldb_find_backend(url_prefix);
@@ -161,16 +159,16 @@ int ldb_register_backend(const char *url_prefix, ldb_connect_fn connectfn, bool
                        return LDB_SUCCESS;
                }
        } else {
-               be = talloc(ldb_backends, struct backends_list_entry);
+               be = talloc_zero(ldb_backends, struct backends_list_entry);
                if (!be) {
                        return LDB_ERR_OPERATIONS_ERROR;
                }
-               be->ops = talloc(be, struct ldb_backend_ops);
-               if (!backend) {
+               be->ops = talloc_zero(be, struct ldb_backend_ops);
+               if (!be->ops) {
                        talloc_free(be);
                        return LDB_ERR_OPERATIONS_ERROR;
                }
-               DLIST_ADD_END(ldb_backends, entry, struct backends_list_entry);
+               DLIST_ADD_END(ldb_backends, be, struct backends_list_entry);
        }
 
        be->ops->name = url_prefix;
@@ -229,6 +227,42 @@ int ldb_connect_backend(struct ldb_context *ldb,
        return ret;
 }
 
+static struct ldb_hooks {
+       struct ldb_hooks *next, *prev;
+       ldb_hook_fn hook_fn;
+} *ldb_hooks;
+
+/*
+  register a ldb hook function
+ */
+int ldb_register_hook(ldb_hook_fn hook_fn)
+{
+       struct ldb_hooks *lc;
+       lc = talloc_zero(ldb_hooks, struct ldb_hooks);
+       if (lc == NULL) {
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+       lc->hook_fn = hook_fn;
+       DLIST_ADD_END(ldb_hooks, lc, struct ldb_hooks);
+       return LDB_SUCCESS;
+}
+
+/*
+  call ldb hooks of a given type
+ */
+int ldb_modules_hook(struct ldb_context *ldb, enum ldb_module_hook_type t)
+{
+       struct ldb_hooks *lc;
+       for (lc = ldb_hooks; lc; lc=lc->next) {
+               int ret = lc->hook_fn(ldb, t);
+               if (ret != LDB_SUCCESS) {
+                       return ret;
+               }
+       }
+       return LDB_SUCCESS;
+}
+
+
 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
 {
        struct ops_list_entry *e;
@@ -855,7 +889,7 @@ static int ldb_modules_load_one(const char *path, const char *version)
 
        handle = dlopen(path, RTLD_NOW);
        if (handle == NULL) {
-               fprintf(stderr, "ldb: unable to dlopen %s : %s", path, dlerror());
+               fprintf(stderr, "ldb: unable to dlopen %s : %s\n", path, dlerror());
                return LDB_SUCCESS;
        }
 
@@ -932,7 +966,7 @@ static int ldb_modules_load_dir(const char *modules_dir, const char *version)
        for (i=0; i<num_modules; i++) {
                int ret = ldb_modules_load_one(modlist[i], version);
                if (ret != LDB_SUCCESS) {
-                       fprintf(stderr, "ldb: failed to initialise module %s : %s",
+                       fprintf(stderr, "ldb: failed to initialise module %s : %s\n",
                                modlist[i], ldb_strerror(ret));
                        talloc_free(tmp_ctx);
                        return ret;
@@ -987,7 +1021,7 @@ int ldb_modules_load(const char *modules_path, const char *version)
 
        path = talloc_strdup(NULL, modules_path);
        if (path == NULL) {
-               fprintf(stderr, "ldb: failed to allocate modules_path");
+               fprintf(stderr, "ldb: failed to allocate modules_path\n");
                return LDB_ERR_UNAVAILABLE;
        }
 

diff --git a/source4/lib/ldb/include/ldb_module.h b/source4/lib/ldb/include/ldb_module.h
index 71c3cd8f7b938a75c4ae5a560387e3fb7f1f1525..800bf72e446979add53cf99c00943c48042b479d 100644 (file)
--- a/source4/lib/ldb/include/ldb_module.h
+++ b/source4/lib/ldb/include/ldb_module.h
@@ -185,7 +185,7 @@ struct ldb_backend_ops {
 
 const char *ldb_default_modules_dir(void);
 
-int ldb_register_backend(const char *url_prefix, ldb_connect_fn);
+int ldb_register_backend(const char *url_prefix, ldb_connect_fn, bool);
 
 struct ldb_handle *ldb_handle_new(TALLOC_CTX *mem_ctx, struct ldb_context *ldb);
 
@@ -233,4 +233,23 @@ int ldb_modules_load(const char *modules_path, const char *version);
 /* init functions prototype */
 typedef int (*ldb_module_init_fn)(const char *);
 
+/*
+  general ldb hook function
+ */
+enum ldb_module_hook_type { LDB_MODULE_HOOK_CMDLINE_OPTIONS     = 1,
+                           LDB_MODULE_HOOK_CMDLINE_PRECONNECT  = 2,
+                           LDB_MODULE_HOOK_CMDLINE_POSTCONNECT = 3 };
+
+typedef int (*ldb_hook_fn)(struct ldb_context *, enum ldb_module_hook_type );
+
+/*
+  register a ldb hook function
+ */
+int ldb_register_hook(ldb_hook_fn hook_fn);
+
+/*
+  call ldb hooks of a given type
+ */
+int ldb_modules_hook(struct ldb_context *ldb, enum ldb_module_hook_type t);
+
 #endif