149 lines
4.0 KiB
C
149 lines
4.0 KiB
C
/*
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* ebt_ip6
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*
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* Authors:
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* Manohar Castelino <manohar.r.castelino@intel.com>
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* Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
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* Jan Engelhardt <jengelh@computergmbh.de>
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*
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* Summary:
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* This is just a modification of the IPv4 code written by
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* Bart De Schuymer <bdschuym@pandora.be>
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* with the changes required to support IPv6
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*
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* Jan, 2008
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*/
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#include <linux/ipv6.h>
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#include <net/ipv6.h>
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#include <linux/in.h>
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#include <linux/module.h>
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#include <net/dsfield.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter_bridge/ebtables.h>
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#include <linux/netfilter_bridge/ebt_ip6.h>
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struct tcpudphdr {
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__be16 src;
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__be16 dst;
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};
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static bool
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ebt_ip6_mt(const struct sk_buff *skb, const struct net_device *in,
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const struct net_device *out, const struct xt_match *match,
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const void *data, int offset, unsigned int protoff, bool *hotdrop)
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{
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const struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
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const struct ipv6hdr *ih6;
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struct ipv6hdr _ip6h;
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const struct tcpudphdr *pptr;
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struct tcpudphdr _ports;
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struct in6_addr tmp_addr;
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int i;
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ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h);
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if (ih6 == NULL)
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return false;
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if (info->bitmask & EBT_IP6_TCLASS &&
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FWINV(info->tclass != ipv6_get_dsfield(ih6), EBT_IP6_TCLASS))
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return false;
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for (i = 0; i < 4; i++)
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tmp_addr.in6_u.u6_addr32[i] = ih6->saddr.in6_u.u6_addr32[i] &
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info->smsk.in6_u.u6_addr32[i];
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if (info->bitmask & EBT_IP6_SOURCE &&
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FWINV((ipv6_addr_cmp(&tmp_addr, &info->saddr) != 0),
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EBT_IP6_SOURCE))
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return false;
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for (i = 0; i < 4; i++)
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tmp_addr.in6_u.u6_addr32[i] = ih6->daddr.in6_u.u6_addr32[i] &
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info->dmsk.in6_u.u6_addr32[i];
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if (info->bitmask & EBT_IP6_DEST &&
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FWINV((ipv6_addr_cmp(&tmp_addr, &info->daddr) != 0), EBT_IP6_DEST))
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return false;
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if (info->bitmask & EBT_IP6_PROTO) {
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uint8_t nexthdr = ih6->nexthdr;
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int offset_ph;
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offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr);
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if (offset_ph == -1)
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return false;
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if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
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return false;
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if (!(info->bitmask & EBT_IP6_DPORT) &&
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!(info->bitmask & EBT_IP6_SPORT))
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return true;
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pptr = skb_header_pointer(skb, offset_ph, sizeof(_ports),
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&_ports);
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if (pptr == NULL)
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return false;
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if (info->bitmask & EBT_IP6_DPORT) {
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u32 dst = ntohs(pptr->dst);
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if (FWINV(dst < info->dport[0] ||
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dst > info->dport[1], EBT_IP6_DPORT))
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return false;
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}
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if (info->bitmask & EBT_IP6_SPORT) {
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u32 src = ntohs(pptr->src);
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if (FWINV(src < info->sport[0] ||
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src > info->sport[1], EBT_IP6_SPORT))
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return false;
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}
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return true;
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}
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return true;
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}
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static bool
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ebt_ip6_mt_check(const char *table, const void *entry,
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const struct xt_match *match, void *data,
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unsigned int hook_mask)
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{
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const struct ebt_entry *e = entry;
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struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
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if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
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return false;
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if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
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return false;
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if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
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if (info->invflags & EBT_IP6_PROTO)
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return false;
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if (info->protocol != IPPROTO_TCP &&
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info->protocol != IPPROTO_UDP &&
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info->protocol != IPPROTO_UDPLITE &&
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info->protocol != IPPROTO_SCTP &&
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info->protocol != IPPROTO_DCCP)
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return false;
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}
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if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
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return false;
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if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
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return false;
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return true;
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}
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static struct ebt_match filter_ip6 =
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{
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.name = EBT_IP6_MATCH,
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.revision = 0,
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.family = NFPROTO_BRIDGE,
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.match = ebt_ip6_mt,
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.checkentry = ebt_ip6_mt_check,
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.matchsize = XT_ALIGN(sizeof(struct ebt_ip6_info)),
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.me = THIS_MODULE,
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};
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static int __init ebt_ip6_init(void)
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{
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return ebt_register_match(&filter_ip6);
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}
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static void __exit ebt_ip6_fini(void)
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{
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ebt_unregister_match(&filter_ip6);
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}
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module_init(ebt_ip6_init);
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module_exit(ebt_ip6_fini);
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MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
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MODULE_LICENSE("GPL");
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