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authorTom Tucker <tom@opengridcomputing.com>2006-07-30 20:43:26 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2006-08-02 13:38:20 -0700
commit792d1932e319ff8ba01361e7d151b1794c55c31f (patch)
treee4259bbccab44d311f7fd3d3ffc18557ae52c49c
parent3687b1dc6fe83a500ba4d3235704594f6a111a2d (diff)
[NET]: Network Event Notifier Mechanism.
This patch uses notifier blocks to implement a network event notifier mechanism. Clients register their callback function by calling register_netevent_notifier() like this: static struct notifier_block nb = { .notifier_call = my_callback_func }; ... register_netevent_notifier(&nb); Signed-off-by: Tom Tucker <tom@opengridcomputing.com> Signed-off-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/netevent.h33
-rw-r--r--net/core/netevent.c69
2 files changed, 102 insertions, 0 deletions
diff --git a/include/net/netevent.h b/include/net/netevent.h
new file mode 100644
index 00000000000..e5d21624142
--- /dev/null
+++ b/include/net/netevent.h
@@ -0,0 +1,33 @@
+#ifndef _NET_EVENT_H
+#define _NET_EVENT_H
+
+/*
+ * Generic netevent notifiers
+ *
+ * Authors:
+ * Tom Tucker <tom@opengridcomputing.com>
+ * Steve Wise <swise@opengridcomputing.com>
+ *
+ * Changes:
+ */
+#ifdef __KERNEL__
+
+#include <net/dst.h>
+
+struct netevent_redirect {
+ struct dst_entry *old;
+ struct dst_entry *new;
+};
+
+enum netevent_notif_type {
+ NETEVENT_NEIGH_UPDATE = 1, /* arg is struct neighbour ptr */
+ NETEVENT_PMTU_UPDATE, /* arg is struct dst_entry ptr */
+ NETEVENT_REDIRECT, /* arg is struct netevent_redirect ptr */
+};
+
+extern int register_netevent_notifier(struct notifier_block *nb);
+extern int unregister_netevent_notifier(struct notifier_block *nb);
+extern int call_netevent_notifiers(unsigned long val, void *v);
+
+#endif
+#endif
diff --git a/net/core/netevent.c b/net/core/netevent.c
new file mode 100644
index 00000000000..35d02c38554
--- /dev/null
+++ b/net/core/netevent.c
@@ -0,0 +1,69 @@
+/*
+ * Network event notifiers
+ *
+ * Authors:
+ * Tom Tucker <tom@opengridcomputing.com>
+ * Steve Wise <swise@opengridcomputing.com>
+ *
+ * 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
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Fixes:
+ */
+
+#include <linux/rtnetlink.h>
+#include <linux/notifier.h>
+
+static ATOMIC_NOTIFIER_HEAD(netevent_notif_chain);
+
+/**
+ * register_netevent_notifier - register a netevent notifier block
+ * @nb: notifier
+ *
+ * Register a notifier to be called when a netevent occurs.
+ * The notifier passed is linked into the kernel structures and must
+ * not be reused until it has been unregistered. A negative errno code
+ * is returned on a failure.
+ */
+int register_netevent_notifier(struct notifier_block *nb)
+{
+ int err;
+
+ err = atomic_notifier_chain_register(&netevent_notif_chain, nb);
+ return err;
+}
+
+/**
+ * netevent_unregister_notifier - unregister a netevent notifier block
+ * @nb: notifier
+ *
+ * Unregister a notifier previously registered by
+ * register_neigh_notifier(). The notifier is unlinked into the
+ * kernel structures and may then be reused. A negative errno code
+ * is returned on a failure.
+ */
+
+int unregister_netevent_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&netevent_notif_chain, nb);
+}
+
+/**
+ * call_netevent_notifiers - call all netevent notifier blocks
+ * @val: value passed unmodified to notifier function
+ * @v: pointer passed unmodified to notifier function
+ *
+ * Call all neighbour notifier blocks. Parameters and return value
+ * are as for notifier_call_chain().
+ */
+
+int call_netevent_notifiers(unsigned long val, void *v)
+{
+ return atomic_notifier_call_chain(&netevent_notif_chain, val, v);
+}
+
+EXPORT_SYMBOL_GPL(register_netevent_notifier);
+EXPORT_SYMBOL_GPL(unregister_netevent_notifier);
+EXPORT_SYMBOL_GPL(call_netevent_notifiers);