/* Amanda extension for IP connection tracking, Version 0.2 * (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca> * based on HW's ip_conntrack_irc.c as well as other modules * *      This program is free software; you can redistribute it and/or *      modify it under the terms of the GNU General Public License *      as published by the Free Software Foundation; either version *      2 of the License, or (at your option) any later version. * *	Module load syntax: * 	insmod ip_conntrack_amanda.o [master_timeout=n] *	 *	Where master_timeout is the timeout (in seconds) of the master *	connection (port 10080).  This defaults to 5 minutes but if *	your clients take longer than 5 minutes to do their work *	before getting back to the Amanda server, you can increase *	this value. * */#include <linux/kernel.h>#include <linux/module.h>#include <linux/netfilter.h>#include <linux/ip.h>#include <net/checksum.h>#include <net/udp.h>#include <linux/netfilter_ipv4/lockhelp.h>#include <linux/netfilter_ipv4/ip_conntrack_helper.h>#include <linux/netfilter_ipv4/ip_conntrack_amanda.h>static unsigned int master_timeout = 300;MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");MODULE_DESCRIPTION("Amanda connection tracking module");MODULE_LICENSE("GPL");MODULE_PARM(master_timeout, "i");MODULE_PARM_DESC(master_timeout, "timeout for the master connection");static char *conns[] = { "DATA ", "MESG ", "INDEX " };/* This is slow, but it's simple. --RR */static char amanda_buffer[65536];static DECLARE_LOCK(amanda_buffer_lock);static int help(struct sk_buff *skb,                struct ip_conntrack *ct, enum ip_conntrack_info ctinfo){	struct ip_conntrack_expect *exp;	struct ip_ct_amanda_expect *exp_amanda_info;	char *data, *data_limit, *tmp;	unsigned int dataoff, i;	u_int16_t port, len;	/* Only look at packets from the Amanda server */	if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)		return NF_ACCEPT;	/* increase the UDP timeout of the master connection as replies from	 * Amanda clients to the server can be quite delayed */	ip_ct_refresh(ct, master_timeout * HZ);	/* No data? */	dataoff = skb->nh.iph->ihl*4 + sizeof(struct udphdr);	if (dataoff >= skb->len) {		if (net_ratelimit())			printk("amanda_help: skblen = %u\n", skb->len);		return NF_ACCEPT;	}	LOCK_BH(&amanda_buffer_lock);	skb_copy_bits(skb, dataoff, amanda_buffer, skb->len - dataoff);	data = amanda_buffer;	data_limit = amanda_buffer + skb->len - dataoff;	*data_limit = '\0';	/* Search for the CONNECT string */	data = strstr(data, "CONNECT ");	if (!data)		goto out;	data += strlen("CONNECT ");	/* Only search first line. */		if ((tmp = strchr(data, '\n')))		*tmp = '\0';	for (i = 0; i < ARRAY_SIZE(conns); i++) {		char *match = strstr(data, conns[i]);		if (!match)			continue;		tmp = data = match + strlen(conns[i]);		port = simple_strtoul(data, &data, 10);		len = data - tmp;		if (port == 0 || len > 5)			break;		exp = ip_conntrack_expect_alloc();		if (exp == NULL)			goto out;		exp->tuple.src.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;		exp->tuple.dst.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;		exp->tuple.dst.protonum = IPPROTO_TCP;		exp->mask.src.ip = 0xFFFFFFFF;		exp->mask.dst.ip = 0xFFFFFFFF;		exp->mask.dst.protonum = 0xFFFF;		exp->mask.dst.u.tcp.port = 0xFFFF;		exp_amanda_info = &exp->help.exp_amanda_info;		exp_amanda_info->offset = tmp - amanda_buffer;		exp_amanda_info->port   = port;		exp_amanda_info->len    = len;		exp->tuple.dst.u.tcp.port = htons(port);		ip_conntrack_expect_related(exp, ct);	}out:	UNLOCK_BH(&amanda_buffer_lock);	return NF_ACCEPT;}static struct ip_conntrack_helper amanda_helper = {	.max_expected = ARRAY_SIZE(conns),	.timeout = 180,	.flags = IP_CT_HELPER_F_REUSE_EXPECT,	.me = THIS_MODULE,	.help = help,	.name = "amanda",	.tuple = { .src = { .u = { __constant_htons(10080) } },		   .dst = { .protonum = IPPROTO_UDP },	},	.mask = { .src = { .u = { 0xFFFF } },		 .dst = { .protonum = 0xFFFF },	},};static void __exit fini(void){	ip_conntrack_helper_unregister(&amanda_helper);}static int __init init(void){	return ip_conntrack_helper_register(&amanda_helper);}PROVIDES_CONNTRACK(amanda);module_init(init);module_exit(fini);