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/*
* ebt_ip6
*
* Authors:
* Manohar Castelino <manohar.r.castelino@intel.com>
* Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
* Jan Engelhardt <jengelh@computergmbh.de>
*
* Summary:
* This is just a modification of the IPv4 code written by
* Bart De Schuymer <bdschuym@pandora.be>
* with the changes required to support IPv6
*
* Jan, 2008
*/
#include <linux/ipv6.h>
#include <net/ipv6.h>
#include <linux/in.h>
#include <linux/module.h>
#include <net/dsfield.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_bridge/ebtables.h>
#include <linux/netfilter_bridge/ebt_ip6.h>
struct tcpudphdr {
__be16 src;
__be16 dst;
};
static bool ebt_filter_ip6(const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out, const void *data,
unsigned int datalen)
{
const struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
const struct ipv6hdr *ih6;
struct ipv6hdr _ip6h;
const struct tcpudphdr *pptr;
struct tcpudphdr _ports;
struct in6_addr tmp_addr;
int i;
ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h);
if (ih6 == NULL)
return false;
if (info->bitmask & EBT_IP6_TCLASS &&
FWINV(info->tclass != ipv6_get_dsfield(ih6), EBT_IP6_TCLASS))
return false;
for (i = 0; i < 4; i++)
tmp_addr.in6_u.u6_addr32[i] = ih6->saddr.in6_u.u6_addr32[i] &
info->smsk.in6_u.u6_addr32[i];
if (info->bitmask & EBT_IP6_SOURCE &&
FWINV((ipv6_addr_cmp(&tmp_addr, &info->saddr) != 0),
EBT_IP6_SOURCE))
return false;
for (i = 0; i < 4; i++)
tmp_addr.in6_u.u6_addr32[i] = ih6->daddr.in6_u.u6_addr32[i] &
info->dmsk.in6_u.u6_addr32[i];
if (info->bitmask & EBT_IP6_DEST &&
FWINV((ipv6_addr_cmp(&tmp_addr, &info->daddr) != 0), EBT_IP6_DEST))
return false;
if (info->bitmask & EBT_IP6_PROTO) {
uint8_t nexthdr = ih6->nexthdr;
int offset_ph;
offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr);
if (offset_ph == -1)
return false;
if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
return false;
if (!(info->bitmask & EBT_IP6_DPORT) &&
!(info->bitmask & EBT_IP6_SPORT))
return true;
pptr = skb_header_pointer(skb, offset_ph, sizeof(_ports),
&_ports);
if (pptr == NULL)
return false;
if (info->bitmask & EBT_IP6_DPORT) {
u32 dst = ntohs(pptr->dst);
if (FWINV(dst < info->dport[0] ||
dst > info->dport[1], EBT_IP6_DPORT))
return false;
}
if (info->bitmask & EBT_IP6_SPORT) {
u32 src = ntohs(pptr->src);
if (FWINV(src < info->sport[0] ||
src > info->sport[1], EBT_IP6_SPORT))
return false;
}
return true;
}
return true;
}
static bool ebt_ip6_check(const char *tablename, unsigned int hookmask,
const struct ebt_entry *e, void *data, unsigned int datalen)
{
struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
return false;
if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
return false;
if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
if (info->invflags & EBT_IP6_PROTO)
return false;
if (info->protocol != IPPROTO_TCP &&
info->protocol != IPPROTO_UDP &&
info->protocol != IPPROTO_UDPLITE &&
info->protocol != IPPROTO_SCTP &&
info->protocol != IPPROTO_DCCP)
return false;
}
if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
return false;
if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
return false;
return true;
}
static struct ebt_match filter_ip6 =
{
.name = EBT_IP6_MATCH,
.revision = 0,
.family = NFPROTO_BRIDGE,
.match = ebt_filter_ip6,
.check = ebt_ip6_check,
.matchsize = XT_ALIGN(sizeof(struct ebt_ip6_info)),
.me = THIS_MODULE,
};
static int __init ebt_ip6_init(void)
{
return ebt_register_match(&filter_ip6);
}
static void __exit ebt_ip6_fini(void)
{
ebt_unregister_match(&filter_ip6);
}
module_init(ebt_ip6_init);
module_exit(ebt_ip6_fini);
MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
MODULE_LICENSE("GPL");
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