Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 59eecdfb authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

[NETFILTER]: nf_conntrack: UDPLITE support 



Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 61075af5

net/netfilter/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -102,6 +102,16 @@ config NF_CT_PROTO_SCTP 
	  If you want to compile it as a module, say M here and read

	  <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.



config NF_CT_PROTO_UDPLITE

	tristate 'UDP-Lite protocol connection tracking support (EXPERIMENTAL)'

	depends on EXPERIMENTAL && NF_CONNTRACK

	help

	  With this option enabled, the layer 3 independent connection

	  tracking code will be able to do state tracking on UDP-Lite

	  connections.



	  To compile it as a module, choose M here.  If unsure, say N.



config NF_CONNTRACK_AMANDA

	tristate "Amanda backup protocol support"

	depends on NF_CONNTRACK

net/netfilter/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ obj-$(CONFIG_NF_CONNTRACK) += nf_conntrack.o 
# SCTP protocol connection tracking

obj-$(CONFIG_NF_CT_PROTO_GRE) += nf_conntrack_proto_gre.o

obj-$(CONFIG_NF_CT_PROTO_SCTP) += nf_conntrack_proto_sctp.o

obj-$(CONFIG_NF_CT_PROTO_UDPLITE) += nf_conntrack_proto_udplite.o



# netlink interface for nf_conntrack

obj-$(CONFIG_NF_CT_NETLINK) += nf_conntrack_netlink.o

net/netfilter/nf_conntrack_proto_udplite.c

0 → 100644
+266 −0
Original line number Diff line number Diff line 
/* (C) 1999-2001 Paul `Rusty' Russell

 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>

 * (C) 2007 Patrick McHardy <kaber@trash.net>

 *

 * 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.

 */



#include <linux/types.h>

#include <linux/timer.h>

#include <linux/module.h>

#include <linux/netfilter.h>

#include <linux/udp.h>

#include <linux/seq_file.h>

#include <linux/skbuff.h>

#include <linux/ipv6.h>

#include <net/ip6_checksum.h>

#include <net/checksum.h>



#include <linux/netfilter.h>

#include <linux/netfilter_ipv4.h>

#include <linux/netfilter_ipv6.h>

#include <net/netfilter/nf_conntrack_l4proto.h>

#include <net/netfilter/nf_conntrack_ecache.h>



static unsigned int nf_ct_udplite_timeout __read_mostly = 30*HZ;

static unsigned int nf_ct_udplite_timeout_stream __read_mostly = 180*HZ;



static int udplite_pkt_to_tuple(const struct sk_buff *skb,

				unsigned int dataoff,

				struct nf_conntrack_tuple *tuple)

{

	struct udphdr _hdr, *hp;



	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);

	if (hp == NULL)

		return 0;



	tuple->src.u.udp.port = hp->source;

	tuple->dst.u.udp.port = hp->dest;

	return 1;

}



static int udplite_invert_tuple(struct nf_conntrack_tuple *tuple,

				const struct nf_conntrack_tuple *orig)

{

	tuple->src.u.udp.port = orig->dst.u.udp.port;

	tuple->dst.u.udp.port = orig->src.u.udp.port;

	return 1;

}



/* Print out the per-protocol part of the tuple. */

static int udplite_print_tuple(struct seq_file *s,

			       const struct nf_conntrack_tuple *tuple)

{

	return seq_printf(s, "sport=%hu dport=%hu ",

			  ntohs(tuple->src.u.udp.port),

			  ntohs(tuple->dst.u.udp.port));

}



/* Print out the private part of the conntrack. */

static int udplite_print_conntrack(struct seq_file *s,

				   const struct nf_conn *conntrack)

{

	return 0;

}



/* Returns verdict for packet, and may modify conntracktype */

static int udplite_packet(struct nf_conn *conntrack,

			  const struct sk_buff *skb,

			  unsigned int dataoff,

			  enum ip_conntrack_info ctinfo,

			  int pf,

			  unsigned int hooknum)

{

	/* If we've seen traffic both ways, this is some kind of UDP

	   stream.  Extend timeout. */

	if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) {

		nf_ct_refresh_acct(conntrack, ctinfo, skb,

				   nf_ct_udplite_timeout_stream);

		/* Also, more likely to be important, and not a probe */

		if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status))

			nf_conntrack_event_cache(IPCT_STATUS, skb);

	} else

		nf_ct_refresh_acct(conntrack, ctinfo, skb,

				   nf_ct_udplite_timeout);



	return NF_ACCEPT;

}



/* Called when a new connection for this protocol found. */

static int udplite_new(struct nf_conn *conntrack, const struct sk_buff *skb,

		       unsigned int dataoff)

{

	return 1;

}



static int udplite_error(struct sk_buff *skb, unsigned int dataoff,

			 enum ip_conntrack_info *ctinfo,

			 int pf,

			 unsigned int hooknum)

{

	unsigned int udplen = skb->len - dataoff;

	struct udphdr _hdr, *hdr;

	unsigned int cscov;



	/* Header is too small? */

	hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);

	if (hdr == NULL) {

		if (LOG_INVALID(IPPROTO_UDPLITE))

			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,

				      "nf_ct_udplite: short packet ");

		return -NF_ACCEPT;

	}



	cscov = ntohs(hdr->len);

	if (cscov == 0)

		cscov = udplen;

	else if (cscov < sizeof(*hdr) || cscov > udplen) {

		if (LOG_INVALID(IPPROTO_UDPLITE))

			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,

				"nf_ct_udplite: invalid checksum coverage ");

		return -NF_ACCEPT;

	}



	/* UDPLITE mandates checksums */

	if (!hdr->check) {

		if (LOG_INVALID(IPPROTO_UDPLITE))

			nf_log_packet(pf, 0, skb, NULL, NULL, NULL,

				      "nf_ct_udplite: checksum missing ");

		return -NF_ACCEPT;

	}



	/* Checksum invalid? Ignore. */

	if (nf_conntrack_checksum && !skb_csum_unnecessary(skb) &&

	    ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||

	     (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING))) {

		if (pf == PF_INET) {

			struct iphdr *iph = ip_hdr(skb);



			skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,

						       udplen, IPPROTO_UDPLITE, 0);

		} else {

			struct ipv6hdr *ipv6h = ipv6_hdr(skb);

			__wsum hsum = skb_checksum(skb, 0, dataoff, 0);



			skb->csum = ~csum_unfold(

				csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,

						udplen, IPPROTO_UDPLITE,

						csum_sub(0, hsum)));

		}



		skb->ip_summed = CHECKSUM_NONE;

		if (__skb_checksum_complete_head(skb, dataoff + cscov)) {

			if (LOG_INVALID(IPPROTO_UDPLITE))

				nf_log_packet(pf, 0, skb, NULL, NULL, NULL,

					      "nf_ct_udplite: bad UDPLite "

					      "checksum ");

			return -NF_ACCEPT;

		}

		skb->ip_summed = CHECKSUM_UNNECESSARY;

	}



	return NF_ACCEPT;

}



#ifdef CONFIG_SYSCTL

static unsigned int udplite_sysctl_table_users;

static struct ctl_table_header *udplite_sysctl_header;

static struct ctl_table udplite_sysctl_table[] = {

	{

		.ctl_name	= CTL_UNNUMBERED,

		.procname	= "nf_conntrack_udplite_timeout",

		.data		= &nf_ct_udplite_timeout,

		.maxlen		= sizeof(unsigned int),

		.mode		= 0644,

		.proc_handler	= &proc_dointvec_jiffies,

	},

	{

		.ctl_name	= CTL_UNNUMBERED,

		.procname	= "nf_conntrack_udplite_timeout_stream",

		.data		= &nf_ct_udplite_timeout_stream,

		.maxlen		= sizeof(unsigned int),

		.mode		= 0644,

		.proc_handler	= &proc_dointvec_jiffies,

	},

	{

		.ctl_name	= 0

	}

};

#endif /* CONFIG_SYSCTL */



static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly =

{

	.l3proto		= PF_INET,

	.l4proto		= IPPROTO_UDPLITE,

	.name			= "udplite",

	.pkt_to_tuple		= udplite_pkt_to_tuple,

	.invert_tuple		= udplite_invert_tuple,

	.print_tuple		= udplite_print_tuple,

	.print_conntrack	= udplite_print_conntrack,

	.packet			= udplite_packet,

	.new			= udplite_new,

	.error			= udplite_error,

#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)

	.tuple_to_nfattr	= nf_ct_port_tuple_to_nfattr,

	.nfattr_to_tuple	= nf_ct_port_nfattr_to_tuple,

#endif

#ifdef CONFIG_SYSCTL

	.ctl_table_users	= &udplite_sysctl_table_users,

	.ctl_table_header	= &udplite_sysctl_header,

	.ctl_table		= udplite_sysctl_table,

#endif

};



static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly =

{

	.l3proto		= PF_INET6,

	.l4proto		= IPPROTO_UDPLITE,

	.name			= "udplite",

	.pkt_to_tuple		= udplite_pkt_to_tuple,

	.invert_tuple		= udplite_invert_tuple,

	.print_tuple		= udplite_print_tuple,

	.print_conntrack	= udplite_print_conntrack,

	.packet			= udplite_packet,

	.new			= udplite_new,

	.error			= udplite_error,

#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)

	.tuple_to_nfattr	= nf_ct_port_tuple_to_nfattr,

	.nfattr_to_tuple	= nf_ct_port_nfattr_to_tuple,

#endif

#ifdef CONFIG_SYSCTL

	.ctl_table_users	= &udplite_sysctl_table_users,

	.ctl_table_header	= &udplite_sysctl_header,

	.ctl_table		= udplite_sysctl_table,

#endif

};



static int __init nf_conntrack_proto_udplite_init(void)

{

	int err;



	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4);

	if (err < 0)

		goto err1;

	err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6);

	if (err < 0)

		goto err2;

	return 0;

err2:

	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);

err1:

	return err;

}



static void __exit nf_conntrack_proto_udplite_exit(void)

{

	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6);

	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4);

}



module_init(nf_conntrack_proto_udplite_init);

module_exit(nf_conntrack_proto_udplite_exit);



MODULE_LICENSE("GPL");