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 31 const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly; 32 const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly; 33 34 /* 35 * Add a protocol handler to the hash tables 36 */ 37 38 int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol) 39 { 40 return !cmpxchg((const struct net_protocol **)&inet_protos[protocol], 41 NULL, prot) ? 0 : -1; 42 } 43 EXPORT_SYMBOL(inet_add_protocol); 44 45 int inet_add_offload(const struct net_offload *prot, unsigned char protocol) 46 { 47 return !cmpxchg((const struct net_offload **)&inet_offloads[protocol], 48 NULL, prot) ? 0 : -1; 49 } 50 EXPORT_SYMBOL(inet_add_offload); 51 52 /* 53 * Remove a protocol from the hash tables. 54 */ 55 56 int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol) 57 { 58 int ret; 59 60 ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol], 61 prot, NULL) == prot) ? 0 : -1; 62 63 synchronize_net(); 64 65 return ret; 66 } 67 EXPORT_SYMBOL(inet_del_protocol); 68 69 int inet_del_offload(const struct net_offload *prot, unsigned char protocol) 70 { 71 int ret; 72 73 ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol], 74 prot, NULL) == prot) ? 0 : -1; 75 76 synchronize_net(); 77 78 return ret; 79 } 80 EXPORT_SYMBOL(inet_del_offload); 81