/* * 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. * * Version:	$Id: protocol.c,v 1.14 2001/05/18 02:25:49 davem Exp $ * * 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 <asm/uaccess.h>#include <asm/system.h>#include <linux/module.h>#include <linux/types.h>#include <linux/kernel.h>#include <linux/sched.h>#include <linux/string.h>#include <linux/config.h>#include <linux/socket.h>#include <linux/in.h>#include <linux/inet.h>#include <linux/netdevice.h>#include <linux/timer.h>#include <net/ip.h>#include <net/protocol.h>#include <linux/skbuff.h>#include <net/sock.h>#include <net/icmp.h>#include <net/udp.h>#include <net/ipip.h>#include <linux/igmp.h> struct net_protocol *inet_protos[MAX_INET_PROTOS];static DEFINE_SPINLOCK(inet_proto_lock); /* *	Add a protocol handler to the hash tables */ int inet_add_protocol(struct net_protocol *prot, unsigned char protocol){	int hash, ret; 	hash = protocol & (MAX_INET_PROTOS - 1); 	spin_lock_bh(&inet_proto_lock);	if (inet_protos[hash]) {		ret = -1;	} else {		inet_protos[hash] = prot;		ret = 0;	}	spin_unlock_bh(&inet_proto_lock); 	return ret;} /* *	Remove a protocol from the hash tables. */ int inet_del_protocol(struct net_protocol *prot, unsigned char protocol){	int hash, ret; 	hash = protocol & (MAX_INET_PROTOS - 1); 	spin_lock_bh(&inet_proto_lock);	if (inet_protos[hash] == prot) {		inet_protos[hash] = NULL;		ret = 0;	} else {		ret = -1;	}	spin_unlock_bh(&inet_proto_lock); 	synchronize_net(); 	return ret;} EXPORT_SYMBOL(inet_add_protocol);EXPORT_SYMBOL(inet_del_protocol);