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 * Version: $Id: protocol.c,v 1.14 2001/05/18 02:25:49 davem Exp $ 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 12 * 13 * Fixes: 14 * Alan Cox : Ahah! udp icmp errors don't work because 15 * udp_err is never called! 16 * Alan Cox : Added new fields for init and ready for 17 * proper fragmentation (_NO_ 4K limits!) 18 * Richard Colella : Hang on hash collision 19 * Vince Laviano : Modified inet_del_protocol() to correctly 20 * maintain copy bit. 21 * 22 * This program is free software; you can redistribute it and/or 23 * modify it under the terms of the GNU General Public License 24 * as published by the Free Software Foundation; either version 25 * 2 of the License, or (at your option) any later version. 26 */ 27 28 #include <asm/uaccess.h> 29 #include <asm/system.h> 30 #include <linux/module.h> 31 #include <linux/types.h> 32 #include <linux/kernel.h> 33 #include <linux/string.h> 34 #include <linux/socket.h> 35 #include <linux/in.h> 36 #include <linux/inet.h> 37 #include <linux/netdevice.h> 38 #include <linux/timer.h> 39 #include <net/ip.h> 40 #include <net/protocol.h> 41 #include <linux/skbuff.h> 42 #include <net/sock.h> 43 #include <net/icmp.h> 44 #include <net/udp.h> 45 #include <net/ipip.h> 46 #include <linux/igmp.h> 47 48 struct net_protocol *inet_protos[MAX_INET_PROTOS] ____cacheline_aligned_in_smp; 49 static DEFINE_SPINLOCK(inet_proto_lock); 50 51 /* 52 * Add a protocol handler to the hash tables 53 */ 54 55 int inet_add_protocol(struct net_protocol *prot, unsigned char protocol) 56 { 57 int hash, ret; 58 59 hash = protocol & (MAX_INET_PROTOS - 1); 60 61 spin_lock_bh(&inet_proto_lock); 62 if (inet_protos[hash]) { 63 ret = -1; 64 } else { 65 inet_protos[hash] = prot; 66 ret = 0; 67 } 68 spin_unlock_bh(&inet_proto_lock); 69 70 return ret; 71 } 72 73 /* 74 * Remove a protocol from the hash tables. 75 */ 76 77 int inet_del_protocol(struct net_protocol *prot, unsigned char protocol) 78 { 79 int hash, ret; 80 81 hash = protocol & (MAX_INET_PROTOS - 1); 82 83 spin_lock_bh(&inet_proto_lock); 84 if (inet_protos[hash] == prot) { 85 inet_protos[hash] = NULL; 86 ret = 0; 87 } else { 88 ret = -1; 89 } 90 spin_unlock_bh(&inet_proto_lock); 91 92 synchronize_net(); 93 94 return ret; 95 } 96 97 EXPORT_SYMBOL(inet_add_protocol); 98 EXPORT_SYMBOL(inet_del_protocol); 99