lib: add hook infrastructure

Please refer to lib/hook.h for a description/documentation.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/lib/hook.c b/lib/hook.c
new file mode 100644
index 0000000000..04d803cd8d
--- /dev/null
+++ b/lib/hook.c
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2016  David Lamparter, for NetDEF, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "memory.h"
+#include "hook.h"
+
+DEFINE_MTYPE_STATIC(LIB, HOOK_ENTRY, "Hook entry")
+
+void _hook_register(struct hook *hook, void *funcptr, void *arg, bool has_arg,
+		    struct frrmod_runtime *module, const char *funcname)
+{
+	struct hookent *he = XCALLOC(MTYPE_HOOK_ENTRY, sizeof(*he));
+	he->hookfn = funcptr;
+	he->hookarg = arg;
+	he->has_arg = has_arg;
+	he->module = module;
+	he->fnname = funcname;
+
+	he->next = hook->entries;
+	hook->entries = he;
+}
+
+void _hook_unregister(struct hook *hook, void *funcptr,
+		      void *arg, bool has_arg)
+{
+	struct hookent *he, **prev;
+
+	for (prev = &hook->entries; (he = *prev) != NULL; prev = &he->next)
+		if (he->hookfn == funcptr && he->hookarg == arg
+				&& he->has_arg == has_arg)
+		{
+			*prev = he->next;
+			XFREE(MTYPE_HOOK_ENTRY, he);
+			break;
+		}
+}
+