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/sched.h> 34 #include <linux/string.h> 35 #include <linux/socket.h> 36 #include <linux/in.h> 37 #include <linux/inet.h> 38 #include <linux/netdevice.h> 39 #include <linux/timer.h> 40 #include <net/ip.h> 41 #include <net/protocol.h> 42 #include <linux/skbuff.h> 43 #include <net/sock.h> 44 #include <net/icmp.h> 45 #include <net/udp.h> 46 #include <net/ipip.h> 47 #include <linux/igmp.h> 48 49 struct net_protocol *inet_protos[MAX_INET_PROTOS]; 50 static DEFINE_SPINLOCK(inet_proto_lock); 51 52 /* 53 * Add a protocol handler to the hash tables 54 */ 55 56 int inet_add_protocol(struct net_protocol *prot, unsigned char protocol) 57 { 58 int hash, ret; 59 60 hash = protocol & (MAX_INET_PROTOS - 1); 61 62 spin_lock_bh(&inet_proto_lock); 63 if (inet_protos[hash]) { 64 ret = -1; 65 } else { 66 inet_protos[hash] = prot; 67 ret = 0; 68 } 69 spin_unlock_bh(&inet_proto_lock); 70 71 return ret; 72 } 73 74 /* 75 * Remove a protocol from the hash tables. 76 */ 77 78 int inet_del_protocol(struct net_protocol *prot, unsigned char protocol) 79 { 80 int hash, ret; 81 82 hash = protocol & (MAX_INET_PROTOS - 1); 83 84 spin_lock_bh(&inet_proto_lock); 85 if (inet_protos[hash] == prot) { 86 inet_protos[hash] = NULL; 87 ret = 0; 88 } else { 89 ret = -1; 90 } 91 spin_unlock_bh(&inet_proto_lock); 92 93 synchronize_net(); 94 95 return ret; 96 } 97 98 EXPORT_SYMBOL(inet_add_protocol); 99 EXPORT_SYMBOL(inet_del_protocol); 100