75f2811c64
While parsing through IPv6 extension headers, fragment headers are skipped making them invisible to the caller. This reports the fragment offset of the last header in order to make it possible to determine whether the packet is fragmented and, if so whether it is a first or last fragment. Signed-off-by: Jesse Gross <jesse@nicira.com>
157 lines
4.2 KiB
C
157 lines
4.2 KiB
C
/*
|
|
* ebt_ip6
|
|
*
|
|
* Authors:
|
|
* Manohar Castelino <manohar.r.castelino@intel.com>
|
|
* Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
|
|
* Jan Engelhardt <jengelh@medozas.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>
|
|
|
|
union pkthdr {
|
|
struct {
|
|
__be16 src;
|
|
__be16 dst;
|
|
} tcpudphdr;
|
|
struct {
|
|
u8 type;
|
|
u8 code;
|
|
} icmphdr;
|
|
};
|
|
|
|
static bool
|
|
ebt_ip6_mt(const struct sk_buff *skb, struct xt_action_param *par)
|
|
{
|
|
const struct ebt_ip6_info *info = par->matchinfo;
|
|
const struct ipv6hdr *ih6;
|
|
struct ipv6hdr _ip6h;
|
|
const union pkthdr *pptr;
|
|
union pkthdr _pkthdr;
|
|
|
|
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;
|
|
if (FWINV(ipv6_masked_addr_cmp(&ih6->saddr, &info->smsk,
|
|
&info->saddr), EBT_IP6_SOURCE) ||
|
|
FWINV(ipv6_masked_addr_cmp(&ih6->daddr, &info->dmsk,
|
|
&info->daddr), EBT_IP6_DEST))
|
|
return false;
|
|
if (info->bitmask & EBT_IP6_PROTO) {
|
|
uint8_t nexthdr = ih6->nexthdr;
|
|
__be16 frag_off;
|
|
int offset_ph;
|
|
|
|
offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr, &frag_off);
|
|
if (offset_ph == -1)
|
|
return false;
|
|
if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
|
|
return false;
|
|
if (!(info->bitmask & ( EBT_IP6_DPORT |
|
|
EBT_IP6_SPORT | EBT_IP6_ICMP6)))
|
|
return true;
|
|
|
|
/* min icmpv6 headersize is 4, so sizeof(_pkthdr) is ok. */
|
|
pptr = skb_header_pointer(skb, offset_ph, sizeof(_pkthdr),
|
|
&_pkthdr);
|
|
if (pptr == NULL)
|
|
return false;
|
|
if (info->bitmask & EBT_IP6_DPORT) {
|
|
u16 dst = ntohs(pptr->tcpudphdr.dst);
|
|
if (FWINV(dst < info->dport[0] ||
|
|
dst > info->dport[1], EBT_IP6_DPORT))
|
|
return false;
|
|
}
|
|
if (info->bitmask & EBT_IP6_SPORT) {
|
|
u16 src = ntohs(pptr->tcpudphdr.src);
|
|
if (FWINV(src < info->sport[0] ||
|
|
src > info->sport[1], EBT_IP6_SPORT))
|
|
return false;
|
|
}
|
|
if ((info->bitmask & EBT_IP6_ICMP6) &&
|
|
FWINV(pptr->icmphdr.type < info->icmpv6_type[0] ||
|
|
pptr->icmphdr.type > info->icmpv6_type[1] ||
|
|
pptr->icmphdr.code < info->icmpv6_code[0] ||
|
|
pptr->icmphdr.code > info->icmpv6_code[1],
|
|
EBT_IP6_ICMP6))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static int ebt_ip6_mt_check(const struct xt_mtchk_param *par)
|
|
{
|
|
const struct ebt_entry *e = par->entryinfo;
|
|
struct ebt_ip6_info *info = par->matchinfo;
|
|
|
|
if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
|
|
return -EINVAL;
|
|
if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
|
|
return -EINVAL;
|
|
if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
|
|
if (info->invflags & EBT_IP6_PROTO)
|
|
return -EINVAL;
|
|
if (info->protocol != IPPROTO_TCP &&
|
|
info->protocol != IPPROTO_UDP &&
|
|
info->protocol != IPPROTO_UDPLITE &&
|
|
info->protocol != IPPROTO_SCTP &&
|
|
info->protocol != IPPROTO_DCCP)
|
|
return -EINVAL;
|
|
}
|
|
if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
|
|
return -EINVAL;
|
|
if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
|
|
return -EINVAL;
|
|
if (info->bitmask & EBT_IP6_ICMP6) {
|
|
if ((info->invflags & EBT_IP6_PROTO) ||
|
|
info->protocol != IPPROTO_ICMPV6)
|
|
return -EINVAL;
|
|
if (info->icmpv6_type[0] > info->icmpv6_type[1] ||
|
|
info->icmpv6_code[0] > info->icmpv6_code[1])
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct xt_match ebt_ip6_mt_reg __read_mostly = {
|
|
.name = "ip6",
|
|
.revision = 0,
|
|
.family = NFPROTO_BRIDGE,
|
|
.match = ebt_ip6_mt,
|
|
.checkentry = ebt_ip6_mt_check,
|
|
.matchsize = sizeof(struct ebt_ip6_info),
|
|
.me = THIS_MODULE,
|
|
};
|
|
|
|
static int __init ebt_ip6_init(void)
|
|
{
|
|
return xt_register_match(&ebt_ip6_mt_reg);
|
|
}
|
|
|
|
static void __exit ebt_ip6_fini(void)
|
|
{
|
|
xt_unregister_match(&ebt_ip6_mt_reg);
|
|
}
|
|
|
|
module_init(ebt_ip6_init);
|
|
module_exit(ebt_ip6_fini);
|
|
MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
|
|
MODULE_AUTHOR("Kuo-Lang Tseng <kuo-lang.tseng@intel.com>");
|
|
MODULE_LICENSE("GPL");
|