f01ffbd6e7
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
292 lines
8.2 KiB
C
292 lines
8.2 KiB
C
/*
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* Copyright (C)2003,2004 USAGI/WIDE Project
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Author:
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* Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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*/
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#include <linux/types.h>
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#include <linux/timer.h>
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#include <linux/module.h>
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#include <linux/netfilter.h>
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#include <linux/in6.h>
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#include <linux/icmpv6.h>
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#include <linux/ipv6.h>
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#include <net/ipv6.h>
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#include <net/ip6_checksum.h>
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#include <linux/seq_file.h>
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#include <linux/netfilter_ipv6.h>
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#include <net/netfilter/nf_conntrack_tuple.h>
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#include <net/netfilter/nf_conntrack_l4proto.h>
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#include <net/netfilter/nf_conntrack_core.h>
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#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
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#include <net/netfilter/nf_log.h>
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static unsigned long nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
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static int icmpv6_pkt_to_tuple(const struct sk_buff *skb,
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unsigned int dataoff,
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struct nf_conntrack_tuple *tuple)
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{
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struct icmp6hdr _hdr, *hp;
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hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
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if (hp == NULL)
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return 0;
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tuple->dst.u.icmp.type = hp->icmp6_type;
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tuple->src.u.icmp.id = hp->icmp6_identifier;
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tuple->dst.u.icmp.code = hp->icmp6_code;
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return 1;
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}
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/* Add 1; spaces filled with 0. */
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static u_int8_t invmap[] = {
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[ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
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[ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
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[ICMPV6_NI_QUERY - 128] = ICMPV6_NI_QUERY + 1,
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[ICMPV6_NI_REPLY - 128] = ICMPV6_NI_REPLY +1
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};
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static int icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
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const struct nf_conntrack_tuple *orig)
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{
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int type = orig->dst.u.icmp.type - 128;
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if (type < 0 || type >= sizeof(invmap) || !invmap[type])
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return 0;
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tuple->src.u.icmp.id = orig->src.u.icmp.id;
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tuple->dst.u.icmp.type = invmap[type] - 1;
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tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
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return 1;
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}
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/* Print out the per-protocol part of the tuple. */
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static int icmpv6_print_tuple(struct seq_file *s,
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const struct nf_conntrack_tuple *tuple)
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{
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return seq_printf(s, "type=%u code=%u id=%u ",
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tuple->dst.u.icmp.type,
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tuple->dst.u.icmp.code,
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ntohs(tuple->src.u.icmp.id));
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}
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/* Print out the private part of the conntrack. */
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static int icmpv6_print_conntrack(struct seq_file *s,
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const struct nf_conn *conntrack)
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{
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return 0;
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}
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/* Returns verdict for packet, or -1 for invalid. */
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static int icmpv6_packet(struct nf_conn *ct,
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const struct sk_buff *skb,
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unsigned int dataoff,
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enum ip_conntrack_info ctinfo,
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int pf,
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unsigned int hooknum)
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{
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/* Try to delete connection immediately after all replies:
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won't actually vanish as we still have skb, and del_timer
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means this will only run once even if count hits zero twice
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(theoretically possible with SMP) */
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if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
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if (atomic_dec_and_test(&ct->proto.icmp.count)
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&& del_timer(&ct->timeout))
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ct->timeout.function((unsigned long)ct);
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} else {
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atomic_inc(&ct->proto.icmp.count);
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nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
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nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
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}
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return NF_ACCEPT;
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}
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/* Called when a new connection for this protocol found. */
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static int icmpv6_new(struct nf_conn *conntrack,
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const struct sk_buff *skb,
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unsigned int dataoff)
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{
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static u_int8_t valid_new[] = {
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[ICMPV6_ECHO_REQUEST - 128] = 1,
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[ICMPV6_NI_QUERY - 128] = 1
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};
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int type = conntrack->tuplehash[0].tuple.dst.u.icmp.type - 128;
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if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
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/* Can't create a new ICMPv6 `conn' with this. */
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pr_debug("icmpv6: can't create new conn with type %u\n",
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type + 128);
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NF_CT_DUMP_TUPLE(&conntrack->tuplehash[0].tuple);
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return 0;
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}
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atomic_set(&conntrack->proto.icmp.count, 0);
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return 1;
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}
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static int
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icmpv6_error_message(struct sk_buff *skb,
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unsigned int icmp6off,
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enum ip_conntrack_info *ctinfo,
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unsigned int hooknum)
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{
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struct nf_conntrack_tuple intuple, origtuple;
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struct nf_conntrack_tuple_hash *h;
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struct nf_conntrack_l4proto *inproto;
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NF_CT_ASSERT(skb->nfct == NULL);
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/* Are they talking about one of our connections? */
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if (!nf_ct_get_tuplepr(skb,
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skb_network_offset(skb)
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+ sizeof(struct ipv6hdr)
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+ sizeof(struct icmp6hdr),
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PF_INET6, &origtuple)) {
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pr_debug("icmpv6_error: Can't get tuple\n");
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return -NF_ACCEPT;
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}
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/* rcu_read_lock()ed by nf_hook_slow */
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inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
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/* Ordinarily, we'd expect the inverted tupleproto, but it's
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been preserved inside the ICMP. */
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if (!nf_ct_invert_tuple(&intuple, &origtuple,
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&nf_conntrack_l3proto_ipv6, inproto)) {
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pr_debug("icmpv6_error: Can't invert tuple\n");
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return -NF_ACCEPT;
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}
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*ctinfo = IP_CT_RELATED;
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h = nf_conntrack_find_get(&intuple);
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if (!h) {
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pr_debug("icmpv6_error: no match\n");
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return -NF_ACCEPT;
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} else {
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if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
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*ctinfo += IP_CT_IS_REPLY;
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}
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/* Update skb to refer to this connection */
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skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
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skb->nfctinfo = *ctinfo;
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return -NF_ACCEPT;
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}
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static int
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icmpv6_error(struct sk_buff *skb, unsigned int dataoff,
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enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum)
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{
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struct icmp6hdr _ih, *icmp6h;
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icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
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if (icmp6h == NULL) {
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if (LOG_INVALID(IPPROTO_ICMPV6))
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nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
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"nf_ct_icmpv6: short packet ");
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return -NF_ACCEPT;
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}
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if (nf_conntrack_checksum && hooknum == NF_INET_PRE_ROUTING &&
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nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
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nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
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"nf_ct_icmpv6: ICMPv6 checksum failed\n");
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return -NF_ACCEPT;
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}
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/* is not error message ? */
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if (icmp6h->icmp6_type >= 128)
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return NF_ACCEPT;
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return icmpv6_error_message(skb, dataoff, ctinfo, hooknum);
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}
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#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nfnetlink_conntrack.h>
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static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
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const struct nf_conntrack_tuple *t)
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{
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NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
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NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
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NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
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return 0;
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nla_put_failure:
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return -1;
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}
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static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
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[CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
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[CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
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[CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
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};
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static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
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struct nf_conntrack_tuple *tuple)
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{
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if (!tb[CTA_PROTO_ICMPV6_TYPE]
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|| !tb[CTA_PROTO_ICMPV6_CODE]
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|| !tb[CTA_PROTO_ICMPV6_ID])
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return -EINVAL;
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tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
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tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
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tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
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if (tuple->dst.u.icmp.type < 128
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|| tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
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|| !invmap[tuple->dst.u.icmp.type - 128])
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return -EINVAL;
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return 0;
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}
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#endif
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#ifdef CONFIG_SYSCTL
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static struct ctl_table_header *icmpv6_sysctl_header;
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static struct ctl_table icmpv6_sysctl_table[] = {
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{
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.procname = "nf_conntrack_icmpv6_timeout",
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.data = &nf_ct_icmpv6_timeout,
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.maxlen = sizeof(unsigned int),
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.mode = 0644,
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.proc_handler = &proc_dointvec_jiffies,
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},
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{
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.ctl_name = 0
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}
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};
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#endif /* CONFIG_SYSCTL */
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struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
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{
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.l3proto = PF_INET6,
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.l4proto = IPPROTO_ICMPV6,
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.name = "icmpv6",
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.pkt_to_tuple = icmpv6_pkt_to_tuple,
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.invert_tuple = icmpv6_invert_tuple,
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.print_tuple = icmpv6_print_tuple,
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.print_conntrack = icmpv6_print_conntrack,
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.packet = icmpv6_packet,
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.new = icmpv6_new,
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.error = icmpv6_error,
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#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
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.tuple_to_nlattr = icmpv6_tuple_to_nlattr,
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.nlattr_to_tuple = icmpv6_nlattr_to_tuple,
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.nla_policy = icmpv6_nla_policy,
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#endif
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#ifdef CONFIG_SYSCTL
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.ctl_table_header = &icmpv6_sysctl_header,
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.ctl_table = icmpv6_sysctl_table,
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#endif
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};
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