1 files changed, 61 insertions, 0 deletions
diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c
new file mode 100644
index 00000000..9ae5c01c
--- /dev/null
+++ b/net/ipv4/protocol.c
@@ -0,0 +1,61 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		INET protocol dispatch tables.
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ * Fixes:
+ *		Alan Cox	: Ahah! udp icmp errors don't work because
+ *				  udp_err is never called!
+ *		Alan Cox	: Added new fields for init and ready for
+ *				  proper fragmentation (_NO_ 4K limits!)
+ *		Richard Colella	: Hang on hash collision
+ *		Vince Laviano	: Modified inet_del_protocol() to correctly
+ *				  maintain copy bit.
+ *
+ *		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.
+ */
+#include <linux/cache.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/spinlock.h>
+#include <net/protocol.h>
+
+const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
+
+/*
+ *	Add a protocol handler to the hash tables
+ */
+
+int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
+{
+	int hash = protocol & (MAX_INET_PROTOS - 1);
+
+	return !cmpxchg((const struct net_protocol **)&inet_protos[hash],
+			NULL, prot) ? 0 : -1;
+}
+EXPORT_SYMBOL(inet_add_protocol);
+
+/*
+ *	Remove a protocol from the hash tables.
+ */
+
+int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
+{
+	int ret, hash = protocol & (MAX_INET_PROTOS - 1);
+
+	ret = (cmpxchg((const struct net_protocol **)&inet_protos[hash],
+		       prot, NULL) == prot) ? 0 : -1;
+
+	synchronize_net();
+
+	return ret;
+}
+EXPORT_SYMBOL(inet_del_protocol);