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 27 struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly; 28 EXPORT_SYMBOL(inet_protos); 29 const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly; 30 EXPORT_SYMBOL(inet_offloads); 31 32 int 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 } 37 EXPORT_SYMBOL(inet_add_protocol); 38 39 int 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 } 44 EXPORT_SYMBOL(inet_add_offload); 45 46 int 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 } 57 EXPORT_SYMBOL(inet_del_protocol); 58 59 int 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 } 70 EXPORT_SYMBOL(inet_del_offload); 71