[NETFILTER]: nf_conntrack: UDPLITE support

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2007-07-14 20:48:44 -07:00 committed by David S. Miller
parent 61075af51f
commit 59eecdfb16
3 changed files with 277 additions and 0 deletions

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@ -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

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@ -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

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@ -0,0 +1,266 @@
/* (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");