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 26 #include <asm/uaccess.h> 27 #include <asm/system.h> 28 #include <linux/module.h> 29 #include <linux/types.h> 30 #include <linux/kernel.h> 31 #include <linux/string.h> 32 #include <linux/socket.h> 33 #include <linux/in.h> 34 #include <linux/inet.h> 35 #include <linux/netdevice.h> 36 #include <linux/timer.h> 37 #include <net/ip.h> 38 #include <net/protocol.h> 39 #include <linux/skbuff.h> 40 #include <net/sock.h> 41 #include <net/icmp.h> 42 #include <net/udp.h> 43 #include <net/ipip.h> 44 #include <linux/igmp.h> 45 46 struct net_protocol *inet_protos[MAX_INET_PROTOS] ____cacheline_aligned_in_smp; 47 static DEFINE_SPINLOCK(inet_proto_lock); 48 49 /* 50 * Add a protocol handler to the hash tables 51 */ 52 53 int inet_add_protocol(struct net_protocol *prot, unsigned char protocol) 54 { 55 int hash, ret; 56 57 hash = protocol & (MAX_INET_PROTOS - 1); 58 59 spin_lock_bh(&inet_proto_lock); 60 if (inet_protos[hash]) { 61 ret = -1; 62 } else { 63 inet_protos[hash] = prot; 64 ret = 0; 65 } 66 spin_unlock_bh(&inet_proto_lock); 67 68 return ret; 69 } 70 71 /* 72 * Remove a protocol from the hash tables. 73 */ 74 75 int inet_del_protocol(struct net_protocol *prot, unsigned char protocol) 76 { 77 int hash, ret; 78 79 hash = protocol & (MAX_INET_PROTOS - 1); 80 81 spin_lock_bh(&inet_proto_lock); 82 if (inet_protos[hash] == prot) { 83 inet_protos[hash] = NULL; 84 ret = 0; 85 } else { 86 ret = -1; 87 } 88 spin_unlock_bh(&inet_proto_lock); 89 90 synchronize_net(); 91 92 return ret; 93 } 94 95 EXPORT_SYMBOL(inet_add_protocol); 96 EXPORT_SYMBOL(inet_del_protocol); 97