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1da177e4 LT |
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 | * | |
02c30a84 | 8 | * Authors: Ross Biro |
1da177e4 LT |
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 | */ | |
fa1a9c68 | 25 | #include <linux/cache.h> |
1da177e4 | 26 | #include <linux/module.h> |
1da177e4 | 27 | #include <linux/netdevice.h> |
fa1a9c68 | 28 | #include <linux/spinlock.h> |
1da177e4 | 29 | #include <net/protocol.h> |
1da177e4 | 30 | |
e0ad61ec | 31 | const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly; |
1da177e4 LT |
32 | |
33 | /* | |
34 | * Add a protocol handler to the hash tables | |
35 | */ | |
36 | ||
32613090 | 37 | int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol) |
1da177e4 | 38 | { |
e0386005 | 39 | int hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 | 40 | |
e0ad61ec ED |
41 | return !cmpxchg((const struct net_protocol **)&inet_protos[hash], |
42 | NULL, prot) ? 0 : -1; | |
1da177e4 | 43 | } |
4bc2f18b | 44 | EXPORT_SYMBOL(inet_add_protocol); |
1da177e4 LT |
45 | |
46 | /* | |
47 | * Remove a protocol from the hash tables. | |
48 | */ | |
e905a9ed | 49 | |
32613090 | 50 | int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol) |
1da177e4 | 51 | { |
e0386005 | 52 | int ret, hash = protocol & (MAX_INET_PROTOS - 1); |
1da177e4 | 53 | |
e0ad61ec ED |
54 | ret = (cmpxchg((const struct net_protocol **)&inet_protos[hash], |
55 | prot, NULL) == prot) ? 0 : -1; | |
1da177e4 LT |
56 | |
57 | synchronize_net(); | |
58 | ||
59 | return ret; | |
60 | } | |
1da177e4 | 61 | EXPORT_SYMBOL(inet_del_protocol); |