1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
4 *		operating system.  INET is implemented using the  BSD Socket
5 *		interface as the means of communication with the user level.
6 *
7 *		INET protocol dispatch tables.
8 *
9 * Authors:	Ross Biro
10 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11 *
12 * Fixes:
13 *		Alan Cox	: Ahah! udp icmp errors don't work because
14 *				  udp_err is never called!
15 *		Alan Cox	: Added new fields for init and ready for
16 *				  proper fragmentation (_NO_ 4K limits!)
17 *		Richard Colella	: Hang on hash collision
18 *		Vince Laviano	: Modified inet_del_protocol() to correctly
19 *				  maintain copy bit.
20 */
21#include <linux/cache.h>
22#include <linux/module.h>
23#include <linux/netdevice.h>
24#include <linux/spinlock.h>
25#include <net/protocol.h>
26
27struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
28EXPORT_SYMBOL(inet_protos);
29const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;
30EXPORT_SYMBOL(inet_offloads);
31
32int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
33{
34	return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
35			NULL, prot) ? 0 : -1;
36}
37EXPORT_SYMBOL(inet_add_protocol);
38
39int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
40{
41	return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
42			NULL, prot) ? 0 : -1;
43}
44EXPORT_SYMBOL(inet_add_offload);
45
46int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
47{
48	int ret;
49
50	ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
51		       prot, NULL) == prot) ? 0 : -1;
52
53	synchronize_net();
54
55	return ret;
56}
57EXPORT_SYMBOL(inet_del_protocol);
58
59int inet_del_offload(const struct net_offload *prot, unsigned char protocol)
60{
61	int ret;
62
63	ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol],
64		       prot, NULL) == prot) ? 0 : -1;
65
66	synchronize_net();
67
68	return ret;
69}
70EXPORT_SYMBOL(inet_del_offload);
71