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, <bir7@leland.Stanford.Edu> 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/config.h> 36 #include <linux/socket.h> 37 #include <linux/in.h> 38 #include <linux/inet.h> 39 #include <linux/netdevice.h> 40 #include <linux/timer.h> 41 #include <net/ip.h> 42 #include <net/protocol.h> 43 #include <net/tcp.h> 44 #include <linux/skbuff.h> 45 #include <net/sock.h> 46 #include <net/icmp.h> 47 #include <net/udp.h> 48 #include <net/ipip.h> 49 #include <linux/igmp.h> 50 51 struct net_protocol *inet_protos[MAX_INET_PROTOS]; 52 static DEFINE_SPINLOCK(inet_proto_lock); 53 54 /* 55 * Add a protocol handler to the hash tables 56 */ 57 58 int inet_add_protocol(struct net_protocol *prot, unsigned char protocol) 59 { 60 int hash, ret; 61 62 hash = protocol & (MAX_INET_PROTOS - 1); 63 64 spin_lock_bh(&inet_proto_lock); 65 if (inet_protos[hash]) { 66 ret = -1; 67 } else { 68 inet_protos[hash] = prot; 69 ret = 0; 70 } 71 spin_unlock_bh(&inet_proto_lock); 72 73 return ret; 74 } 75 76 /* 77 * Remove a protocol from the hash tables. 78 */ 79 80 int inet_del_protocol(struct net_protocol *prot, unsigned char protocol) 81 { 82 int hash, ret; 83 84 hash = protocol & (MAX_INET_PROTOS - 1); 85 86 spin_lock_bh(&inet_proto_lock); 87 if (inet_protos[hash] == prot) { 88 inet_protos[hash] = NULL; 89 ret = 0; 90 } else { 91 ret = -1; 92 } 93 spin_unlock_bh(&inet_proto_lock); 94 95 synchronize_net(); 96 97 return ret; 98 } 99 100 EXPORT_SYMBOL(inet_add_protocol); 101 EXPORT_SYMBOL(inet_del_protocol); 102