1/*
 2 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 3 *		operating system.  INET is implemented using the  BSD Socket
 4 *		interface as the means of communication with the user level.
 5 *
 6 *		INET protocol dispatch tables.
 7 *
 8 * Authors:	Ross Biro
 9 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 *
11 * Fixes:
12 *		Alan Cox	: Ahah! udp icmp errors don't work because
13 *				  udp_err is never called!
14 *		Alan Cox	: Added new fields for init and ready for
15 *				  proper fragmentation (_NO_ 4K limits!)
16 *		Richard Colella	: Hang on hash collision
17 *		Vince Laviano	: Modified inet_del_protocol() to correctly
18 *				  maintain copy bit.
19 *
20 *		This program is free software; you can redistribute it and/or
21 *		modify it under the terms of the GNU General Public License
22 *		as published by the Free Software Foundation; either version
23 *		2 of the License, or (at your option) any later version.
24 */
25#include <linux/cache.h>
26#include <linux/module.h>
27#include <linux/netdevice.h>
28#include <linux/spinlock.h>
29#include <net/protocol.h>
30
31const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
32
33/*
34 *	Add a protocol handler to the hash tables
35 */
36
37int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
38{
39	int hash = protocol & (MAX_INET_PROTOS - 1);
 
 
 
 
40
41	return !cmpxchg((const struct net_protocol **)&inet_protos[hash],
42			NULL, prot) ? 0 : -1;
43}
44EXPORT_SYMBOL(inet_add_protocol);
45
46/*
47 *	Remove a protocol from the hash tables.
48 */
 
 
 
49
50int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
51{
52	int ret, hash = protocol & (MAX_INET_PROTOS - 1);
53
54	ret = (cmpxchg((const struct net_protocol **)&inet_protos[hash],
55		       prot, NULL) == prot) ? 0 : -1;
56
57	synchronize_net();
58
59	return ret;
60}
61EXPORT_SYMBOL(inet_del_protocol);

 1/*
 2 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 3 *		operating system.  INET is implemented using the  BSD Socket
 4 *		interface as the means of communication with the user level.
 5 *
 6 *		INET protocol dispatch tables.
 7 *
 8 * Authors:	Ross Biro
 9 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 *
11 * Fixes:
12 *		Alan Cox	: Ahah! udp icmp errors don't work because
13 *				  udp_err is never called!
14 *		Alan Cox	: Added new fields for init and ready for
15 *				  proper fragmentation (_NO_ 4K limits!)
16 *		Richard Colella	: Hang on hash collision
17 *		Vince Laviano	: Modified inet_del_protocol() to correctly
18 *				  maintain copy bit.
19 *
20 *		This program is free software; you can redistribute it and/or
21 *		modify it under the terms of the GNU General Public License
22 *		as published by the Free Software Foundation; either version
23 *		2 of the License, or (at your option) any later version.
24 */
25#include <linux/cache.h>
26#include <linux/module.h>
27#include <linux/netdevice.h>
28#include <linux/spinlock.h>
29#include <net/protocol.h>
30
31const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
32const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;
33EXPORT_SYMBOL(inet_offloads);
 
 
34
35int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
36{
37	if (!prot->netns_ok) {
38		pr_err("Protocol %u is not namespace aware, cannot register.\n",
39			protocol);
40		return -EINVAL;
41	}
42
43	return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
44			NULL, prot) ? 0 : -1;
45}
46EXPORT_SYMBOL(inet_add_protocol);
47
48int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
49{
50	return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
51			NULL, prot) ? 0 : -1;
52}
53EXPORT_SYMBOL(inet_add_offload);
54
55int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
56{
57	int ret;
58
59	ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
60		       prot, NULL) == prot) ? 0 : -1;
61
62	synchronize_net();
63
64	return ret;
65}
66EXPORT_SYMBOL(inet_del_protocol);
67
68int inet_del_offload(const struct net_offload *prot, unsigned char protocol)
69{
70	int ret;
71
72	ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol],
73		       prot, NULL) == prot) ? 0 : -1;
74
75	synchronize_net();
76
77	return ret;
78}
79EXPORT_SYMBOL(inet_del_offload);