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;
 
 
 
33
34int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
35{
36	if (!prot->netns_ok) {
37		pr_err("Protocol %u is not namespace aware, cannot register.\n",
38			protocol);
39		return -EINVAL;
40	}
41
42	return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
43			NULL, prot) ? 0 : -1;
44}
45EXPORT_SYMBOL(inet_add_protocol);
46
47int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
48{
49	return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
50			NULL, prot) ? 0 : -1;
51}
52EXPORT_SYMBOL(inet_add_offload);
53
54int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
55{
56	int ret;
57
58	ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
59		       prot, NULL) == prot) ? 0 : -1;
60
61	synchronize_net();
62
63	return ret;
64}
65EXPORT_SYMBOL(inet_del_protocol);
66
67int inet_del_offload(const struct net_offload *prot, unsigned char protocol)
68{
69	int ret;
70
71	ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol],
72		       prot, NULL) == prot) ? 0 : -1;
73
74	synchronize_net();
75
76	return ret;
77}
78EXPORT_SYMBOL(inet_del_offload);

 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);