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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@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 ((info->bitmask & EBT_IP6_SOURCE &&
- FWINV(ipv6_masked_addr_cmp(&ih6->saddr, &info->smsk,
- &info->saddr), EBT_IP6_SOURCE)) ||
- (info->bitmask & EBT_IP6_DEST &&
- 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");
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