// SPDX-License-Identifier: GPL-2.0-only
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/*
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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@medozas.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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union pkthdr {
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struct {
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__be16 src;
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__be16 dst;
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} tcpudphdr;
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struct {
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u8 type;
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u8 code;
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} icmphdr;
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};
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static bool
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ebt_ip6_mt(const struct sk_buff *skb, struct xt_action_param *par)
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{
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const struct ebt_ip6_info *info = par->matchinfo;
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const struct ipv6hdr *ih6;
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struct ipv6hdr _ip6h;
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const union pkthdr *pptr;
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union pkthdr _pkthdr;
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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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NF_INVF(info, EBT_IP6_TCLASS,
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info->tclass != ipv6_get_dsfield(ih6)))
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return false;
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if (((info->bitmask & EBT_IP6_SOURCE) &&
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NF_INVF(info, EBT_IP6_SOURCE,
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ipv6_masked_addr_cmp(&ih6->saddr, &info->smsk,
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&info->saddr))) ||
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((info->bitmask & EBT_IP6_DEST) &&
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NF_INVF(info, EBT_IP6_DEST,
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ipv6_masked_addr_cmp(&ih6->daddr, &info->dmsk,
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&info->daddr))))
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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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__be16 frag_off;
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int offset_ph;
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offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr, &frag_off);
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if (offset_ph == -1)
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return false;
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if (NF_INVF(info, EBT_IP6_PROTO, info->protocol != nexthdr))
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return false;
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if (!(info->bitmask & (EBT_IP6_DPORT |
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EBT_IP6_SPORT | EBT_IP6_ICMP6)))
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return true;
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/* min icmpv6 headersize is 4, so sizeof(_pkthdr) is ok. */
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pptr = skb_header_pointer(skb, offset_ph, sizeof(_pkthdr),
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&_pkthdr);
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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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u16 dst = ntohs(pptr->tcpudphdr.dst);
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if (NF_INVF(info, EBT_IP6_DPORT,
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dst < info->dport[0] ||
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dst > info->dport[1]))
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return false;
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}
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if (info->bitmask & EBT_IP6_SPORT) {
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u16 src = ntohs(pptr->tcpudphdr.src);
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if (NF_INVF(info, EBT_IP6_SPORT,
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src < info->sport[0] ||
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src > info->sport[1]))
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return false;
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}
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if ((info->bitmask & EBT_IP6_ICMP6) &&
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NF_INVF(info, EBT_IP6_ICMP6,
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pptr->icmphdr.type < info->icmpv6_type[0] ||
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pptr->icmphdr.type > info->icmpv6_type[1] ||
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pptr->icmphdr.code < info->icmpv6_code[0] ||
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pptr->icmphdr.code > info->icmpv6_code[1]))
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return false;
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}
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return true;
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}
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static int ebt_ip6_mt_check(const struct xt_mtchk_param *par)
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{
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const struct ebt_entry *e = par->entryinfo;
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struct ebt_ip6_info *info = par->matchinfo;
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if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
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return -EINVAL;
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if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
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return -EINVAL;
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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 -EINVAL;
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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 -EINVAL;
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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 -EINVAL;
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if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
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return -EINVAL;
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if (info->bitmask & EBT_IP6_ICMP6) {
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if ((info->invflags & EBT_IP6_PROTO) ||
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info->protocol != IPPROTO_ICMPV6)
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return -EINVAL;
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if (info->icmpv6_type[0] > info->icmpv6_type[1] ||
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info->icmpv6_code[0] > info->icmpv6_code[1])
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return -EINVAL;
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}
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return 0;
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}
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static struct xt_match ebt_ip6_mt_reg __read_mostly = {
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.name = "ip6",
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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 = 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 xt_register_match(&ebt_ip6_mt_reg);
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}
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static void __exit ebt_ip6_fini(void)
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{
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xt_unregister_match(&ebt_ip6_mt_reg);
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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_AUTHOR("Kuo-Lang Tseng <kuo-lang.tseng@intel.com>");
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MODULE_LICENSE("GPL");
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