82 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * INET		An implementation of the TCP/IP protocol suite for the LINUX
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 *		operating system.  INET is implemented using the  BSD Socket
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 *		interface as the means of communication with the user level.
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 *
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 *		INET protocol dispatch tables.
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 *
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 * Authors:	Ross Biro
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 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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 *
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 * Fixes:
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 *		Alan Cox	: Ahah! udp icmp errors don't work because
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 *				  udp_err is never called!
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 *		Alan Cox	: Added new fields for init and ready for
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 *				  proper fragmentation (_NO_ 4K limits!)
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 *		Richard Colella	: Hang on hash collision
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 *		Vince Laviano	: Modified inet_del_protocol() to correctly
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 *				  maintain copy bit.
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 *
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 *		This program is free software; you can redistribute it and/or
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 *		modify it under the terms of the GNU General Public License
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 *		as published by the Free Software Foundation; either version
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 *		2 of the License, or (at your option) any later version.
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 */
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#include <linux/cache.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/spinlock.h>
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#include <net/protocol.h>
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const struct net_protocol *inet_protos[MAX_INET_PROTOS] ____cacheline_aligned_in_smp;
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static DEFINE_SPINLOCK(inet_proto_lock);
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/*
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 *	Add a protocol handler to the hash tables
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 */
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int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
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{
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	int hash, ret;
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	hash = protocol & (MAX_INET_PROTOS - 1);
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	spin_lock_bh(&inet_proto_lock);
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	if (inet_protos[hash]) {
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		ret = -1;
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	} else {
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		inet_protos[hash] = prot;
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		ret = 0;
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	}
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	spin_unlock_bh(&inet_proto_lock);
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	return ret;
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}
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/*
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 *	Remove a protocol from the hash tables.
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 */
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int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
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{
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	int hash, ret;
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	hash = protocol & (MAX_INET_PROTOS - 1);
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	spin_lock_bh(&inet_proto_lock);
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	if (inet_protos[hash] == prot) {
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		inet_protos[hash] = NULL;
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		ret = 0;
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	} else {
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		ret = -1;
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	}
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	spin_unlock_bh(&inet_proto_lock);
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	synchronize_net();
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	return ret;
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}
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EXPORT_SYMBOL(inet_add_protocol);
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EXPORT_SYMBOL(inet_del_protocol);
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