// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C)2003,2004 USAGI/WIDE Project
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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/nf_conntrack_timeout.h>
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#include <net/netfilter/nf_conntrack_zones.h>
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#include <net/netfilter/nf_log.h>
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#include "nf_internals.h"
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static const unsigned int nf_ct_icmpv6_timeout = 30*HZ;
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bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
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unsigned int dataoff,
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struct net *net,
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struct nf_conntrack_tuple *tuple)
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{
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const struct icmp6hdr *hp;
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struct icmp6hdr _hdr;
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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 false;
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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 true;
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}
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/* Add 1; spaces filled with 0. */
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static const 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_REPLY + 1,
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[ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY + 1
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};
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static const u_int8_t noct_valid_new[] = {
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[ICMPV6_MGM_QUERY - 130] = 1,
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[ICMPV6_MGM_REPORT - 130] = 1,
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[ICMPV6_MGM_REDUCTION - 130] = 1,
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[NDISC_ROUTER_SOLICITATION - 130] = 1,
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[NDISC_ROUTER_ADVERTISEMENT - 130] = 1,
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[NDISC_NEIGHBOUR_SOLICITATION - 130] = 1,
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[NDISC_NEIGHBOUR_ADVERTISEMENT - 130] = 1,
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[ICMPV6_MLD2_REPORT - 130] = 1
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};
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bool nf_conntrack_invert_icmpv6_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 false;
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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 true;
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}
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static unsigned int *icmpv6_get_timeouts(struct net *net)
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{
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return &nf_icmpv6_pernet(net)->timeout;
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}
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/* Returns verdict for packet, or -1 for invalid. */
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int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
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struct sk_buff *skb,
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enum ip_conntrack_info ctinfo,
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const struct nf_hook_state *state)
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{
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unsigned int *timeout = nf_ct_timeout_lookup(ct);
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static const u8 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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if (state->pf != NFPROTO_IPV6)
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return -NF_ACCEPT;
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if (!nf_ct_is_confirmed(ct)) {
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int type = ct->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_ipv6(&ct->tuplehash[0].tuple);
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return -NF_ACCEPT;
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}
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}
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if (!timeout)
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timeout = icmpv6_get_timeouts(nf_ct_net(ct));
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/* Do not immediately delete the connection after the first
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successful reply to avoid excessive conntrackd traffic
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and also to handle correctly ICMP echo reply duplicates. */
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nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
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return NF_ACCEPT;
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}
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static void icmpv6_error_log(const struct sk_buff *skb,
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const struct nf_hook_state *state,
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const char *msg)
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{
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nf_l4proto_log_invalid(skb, state->net, state->pf,
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IPPROTO_ICMPV6, "%s", msg);
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}
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int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
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struct sk_buff *skb,
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unsigned int dataoff,
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const struct nf_hook_state *state)
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{
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union nf_inet_addr outer_daddr;
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const struct icmp6hdr *icmp6h;
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struct icmp6hdr _ih;
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int type;
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icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
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if (icmp6h == NULL) {
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icmpv6_error_log(skb, state, "short packet");
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return -NF_ACCEPT;
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}
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if (state->hook == NF_INET_PRE_ROUTING &&
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state->net->ct.sysctl_checksum &&
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nf_ip6_checksum(skb, state->hook, dataoff, IPPROTO_ICMPV6)) {
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icmpv6_error_log(skb, state, "ICMPv6 checksum failed");
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return -NF_ACCEPT;
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}
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type = icmp6h->icmp6_type - 130;
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if (type >= 0 && type < sizeof(noct_valid_new) &&
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noct_valid_new[type]) {
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nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
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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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memcpy(&outer_daddr.ip6, &ipv6_hdr(skb)->daddr,
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sizeof(outer_daddr.ip6));
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dataoff += sizeof(*icmp6h);
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return nf_conntrack_inet_error(tmpl, skb, dataoff, state,
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IPPROTO_ICMPV6, &outer_daddr);
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}
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#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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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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if (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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goto nla_put_failure;
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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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u_int32_t flags)
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{
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if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_TYPE)) {
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if (!tb[CTA_PROTO_ICMPV6_TYPE])
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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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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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}
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if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_CODE)) {
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if (!tb[CTA_PROTO_ICMPV6_CODE])
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return -EINVAL;
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tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
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}
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if (flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_ID)) {
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if (!tb[CTA_PROTO_ICMPV6_ID])
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return -EINVAL;
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tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
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}
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return 0;
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}
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static unsigned int icmpv6_nlattr_tuple_size(void)
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{
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static unsigned int size __read_mostly;
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if (!size)
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size = nla_policy_len(icmpv6_nla_policy, CTA_PROTO_MAX + 1);
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return size;
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}
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#endif
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#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
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#include <linux/netfilter/nfnetlink.h>
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#include <linux/netfilter/nfnetlink_cttimeout.h>
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static int icmpv6_timeout_nlattr_to_obj(struct nlattr *tb[],
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struct net *net, void *data)
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{
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unsigned int *timeout = data;
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struct nf_icmp_net *in = nf_icmpv6_pernet(net);
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if (!timeout)
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timeout = icmpv6_get_timeouts(net);
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if (tb[CTA_TIMEOUT_ICMPV6_TIMEOUT]) {
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*timeout =
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ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMPV6_TIMEOUT])) * HZ;
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} else {
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/* Set default ICMPv6 timeout. */
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*timeout = in->timeout;
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}
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return 0;
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}
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static int
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icmpv6_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
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{
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const unsigned int *timeout = data;
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if (nla_put_be32(skb, CTA_TIMEOUT_ICMPV6_TIMEOUT, htonl(*timeout / HZ)))
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -ENOSPC;
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}
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static const struct nla_policy
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icmpv6_timeout_nla_policy[CTA_TIMEOUT_ICMPV6_MAX+1] = {
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[CTA_TIMEOUT_ICMPV6_TIMEOUT] = { .type = NLA_U32 },
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};
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#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
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void nf_conntrack_icmpv6_init_net(struct net *net)
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{
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struct nf_icmp_net *in = nf_icmpv6_pernet(net);
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in->timeout = nf_ct_icmpv6_timeout;
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}
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const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
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{
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.l4proto = IPPROTO_ICMPV6,
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#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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.tuple_to_nlattr = icmpv6_tuple_to_nlattr,
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.nlattr_tuple_size = icmpv6_nlattr_tuple_size,
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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_NF_CONNTRACK_TIMEOUT
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.ctnl_timeout = {
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.nlattr_to_obj = icmpv6_timeout_nlattr_to_obj,
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.obj_to_nlattr = icmpv6_timeout_obj_to_nlattr,
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.nlattr_max = CTA_TIMEOUT_ICMP_MAX,
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.obj_size = sizeof(unsigned int),
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.nla_policy = icmpv6_timeout_nla_policy,
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},
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#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
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};
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