/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * Version: 0.0.7 * * Thu 21 Mar 2002 Harald Welte <laforge@gnumonks.org> * 	- port to newnat API * */#include <linux/module.h>#include <linux/ip.h>#include <linux/udp.h>#include <linux/netfilter.h>#include <linux/netfilter_ipv4/ip_tables.h>#include <linux/netfilter_ipv4/ip_conntrack_helper.h>#include <linux/netfilter_ipv4/ip_conntrack_tftp.h>MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");MODULE_DESCRIPTION("tftp connection tracking helper");MODULE_LICENSE("GPL");#define MAX_PORTS 8static int ports[MAX_PORTS];static int ports_c;MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");MODULE_PARM_DESC(ports, "port numbers of tftp servers");#if 0#define DEBUGP(format, args...) printk("%s:%s:" format, \                                       __FILE__, __FUNCTION__ , ## args)#else#define DEBUGP(format, args...)#endifstatic int tftp_help(struct sk_buff *skb,		     struct ip_conntrack *ct,		     enum ip_conntrack_info ctinfo){	struct tftphdr tftph;	struct ip_conntrack_expect *exp;	if (skb_copy_bits(skb, skb->nh.iph->ihl * 4 + sizeof(struct udphdr),			  &tftph, sizeof(tftph)) != 0)		return NF_ACCEPT;	switch (ntohs(tftph.opcode)) {	/* RRQ and WRQ works the same way */	case TFTP_OPCODE_READ:	case TFTP_OPCODE_WRITE:		DEBUGP("");		DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);		DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);		exp = ip_conntrack_expect_alloc();		if (exp == NULL)			return NF_ACCEPT;		exp->tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;		exp->mask.src.ip = 0xffffffff;		exp->mask.dst.ip = 0xffffffff;		exp->mask.dst.u.udp.port = 0xffff;		exp->mask.dst.protonum = 0xffff;		exp->expectfn = NULL;		DEBUGP("expect: ");		DUMP_TUPLE(&exp->tuple);		DUMP_TUPLE(&exp->mask);		ip_conntrack_expect_related(exp, ct);		break;	case TFTP_OPCODE_DATA:	case TFTP_OPCODE_ACK:		DEBUGP("Data/ACK opcode\n");		break;	case TFTP_OPCODE_ERROR:		DEBUGP("Error opcode\n");		break;	default:		DEBUGP("Unknown opcode\n");	}	return NF_ACCEPT;}static struct ip_conntrack_helper tftp[MAX_PORTS];static char tftp_names[MAX_PORTS][10];static void fini(void){	int i;	for (i = 0 ; i < ports_c; i++) {		DEBUGP("unregistering helper for port %d\n",			ports[i]);		ip_conntrack_helper_unregister(&tftp[i]);	} }static int __init init(void){	int i, ret;	char *tmpname;	if (!ports[0])		ports[0]=TFTP_PORT;	for (i = 0 ; (i < MAX_PORTS) && ports[i] ; i++) {		/* Create helper structure */		memset(&tftp[i], 0, sizeof(struct ip_conntrack_helper));		tftp[i].tuple.dst.protonum = IPPROTO_UDP;		tftp[i].tuple.src.u.udp.port = htons(ports[i]);		tftp[i].mask.dst.protonum = 0xFFFF;		tftp[i].mask.src.u.udp.port = 0xFFFF;		tftp[i].max_expected = 1;		tftp[i].timeout = 0;		tftp[i].flags = IP_CT_HELPER_F_REUSE_EXPECT;		tftp[i].me = THIS_MODULE;		tftp[i].help = tftp_help;		tmpname = &tftp_names[i][0];		if (ports[i] == TFTP_PORT)			sprintf(tmpname, "tftp");		else			sprintf(tmpname, "tftp-%d", i);		tftp[i].name = tmpname;		DEBUGP("port #%d: %d\n", i, ports[i]);		ret=ip_conntrack_helper_register(&tftp[i]);		if (ret) {			printk("ERROR registering helper for port %d\n",				ports[i]);			fini();			return(ret);		}		ports_c++;	}	return(0);}PROVIDES_CONNTRACK(tftp);module_init(init);module_exit(fini);