/*      $FreeBSD: src/sys/netinet6/in6_proto.c,v 1.6.2.9 2003/01/24 05:11:35 sam Exp $  */
/*      $KAME: in6_proto.c,v 1.91 2001/05/27 13:28:35 itojun Exp $      */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (c) 1982, 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)in_proto.c  8.1 (Berkeley) 6/10/93
 */

#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_carp.h"

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/kernel.h>
#include <sys/domain.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/radix.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip_encap.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>

#include <netinet/tcp.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet6/tcp6_var.h>
#include <netinet6/raw_ip6.h>
#include <netinet6/udp6_var.h>
#include <netinet6/pim6_var.h>
#include <netinet6/nd6.h>

#include <netinet6/ip6protosw.h>

#include <net/net_osdep.h>

#ifdef CARP
#include <netinet/ip_carp.h>
#endif


/*
 * TCP/IP protocol family: IP6, ICMP6, UDP, TCP.
 */

extern  struct domain inet6domain;
static struct pr_usrreqs nousrreqs;

#define PR_LISTEN       0
#define PR_ABRTACPTDIS  0

struct protosw inet6sw[] = {
    {
        .pr_type = 0,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_IPV6,
        .pr_flags = 0,

        .pr_init = ip6_init,
        .pr_drain = frag6_drain,
        .pr_usrreqs = &nousrreqs
    },
    {
        .pr_type = SOCK_DGRAM,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_UDP,
        .pr_flags = PR_ATOMIC | PR_ADDR | PR_MPSAFE | PR_LASTHDR,

        .pr_input = udp6_input,
        .pr_output = 0,
        .pr_ctlinput = udp6_ctlinput,
        .pr_ctloutput = ip6_ctloutput_dispatch,

        .pr_ctlport = cpu0_ctlport,
        .pr_usrreqs = &udp6_usrreqs
    },
    {
        .pr_type = SOCK_STREAM,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_TCP,
        .pr_flags = PR_CONNREQUIRED | PR_WANTRCVD | PR_LISTEN |
                    PR_MPSAFE | PR_LASTHDR | PR_ASYNC_SEND | PR_ASYNC_RCVD,

        .pr_input = tcp6_input,
        .pr_output = NULL,
        .pr_ctlinput = tcp6_ctlinput,
        .pr_ctloutput = tcp_ctloutput,

        .pr_ctlport = cpu0_ctlport,
#ifndef INET
        /* don't call initialization and timeout routines twice */
        .pr_init = tcp_init,
#endif
        .pr_drain = tcp_drain,
        .pr_usrreqs = &tcp6_usrreqs
    },
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_RAW,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,

        .pr_input = rip6_input,
        .pr_output = rip6_output,
        .pr_ctlinput = rip6_ctlinput,
        .pr_ctloutput = rip6_ctloutput,

        .pr_ctlport = cpu0_ctlport,
        .pr_usrreqs = &rip6_usrreqs
    },
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_ICMPV6,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,

        .pr_input = icmp6_input,
        .pr_output = rip6_output,
        .pr_ctlinput = rip6_ctlinput,
        .pr_ctloutput = rip6_ctloutput,

        .pr_ctlport = cpu0_ctlport,
        .pr_init = icmp6_init,
        .pr_drain = NULL,

        .pr_usrreqs = &rip6_usrreqs
    },
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_DSTOPTS, PR_ATOMIC|PR_ADDR,

        .pr_input = dest6_input,
        .pr_output = NULL,
        .pr_ctlinput = NULL,
        .pr_ctloutput = NULL,

        .pr_usrreqs = &nousrreqs
    },
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_ROUTING, PR_ATOMIC|PR_ADDR,

        .pr_input = route6_input,
        .pr_output = NULL,
        .pr_ctlinput = NULL,
        .pr_ctloutput = NULL,

        .pr_usrreqs = &nousrreqs
    },
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_FRAGMENT, PR_ATOMIC|PR_ADDR,

        .pr_input = frag6_input,
        .pr_output = NULL,
        .pr_ctlinput = NULL,
        .pr_ctloutput = NULL,

        .pr_usrreqs = &nousrreqs
    },
#ifdef INET
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_IPV4,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,

        .pr_input = encap6_input,
        .pr_output = rip6_output,
        .pr_ctlinput = NULL,
        .pr_ctloutput = rip6_ctloutput,

        .pr_init = encap_init,
        .pr_usrreqs = &rip6_usrreqs
    },
#endif /* INET */
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_IPV6,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,

        .pr_input = encap6_input,
        .pr_output = rip6_output,
        .pr_ctlinput = NULL,
        .pr_ctloutput = rip6_ctloutput,

        .pr_init = encap_init,
        .pr_usrreqs = &rip6_usrreqs
    },
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_PIM,
        .pr_flags = PR_ATOMIC|PR_ADDR|PR_LASTHDR,

        .pr_input = pim6_input,
        .pr_output = rip6_output,
        .pr_ctlinput = NULL,
        .pr_ctloutput = rip6_ctloutput,

        .pr_usrreqs = &rip6_usrreqs
    },
#ifdef CARP
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = IPPROTO_CARP,
        .pr_flags = PR_ATOMIC|PR_ADDR,

        .pr_input = carp6_proto_input,
        .pr_output = rip6_output,
        .pr_ctlinput = NULL,
        .pr_ctloutput = rip6_ctloutput,

        .pr_usrreqs = &rip6_usrreqs
    },
#endif /* CARP */

    /* raw wildcard */
    {
        .pr_type = SOCK_RAW,
        .pr_domain = &inet6domain,
        .pr_protocol = 0,
        .pr_flags = PR_ATOMIC|PR_ADDR,

        .pr_input = rip6_input,
        .pr_output = rip6_output,
        .pr_ctlinput = NULL,
        .pr_ctloutput = rip6_ctloutput,

        .pr_usrreqs = &rip6_usrreqs
    },
};

extern int in6_inithead (void **, int);

struct domain inet6domain = {
        .dom_family             = AF_INET6,
        .dom_name               = "internet6",
        .dom_init               = NULL,
        .dom_externalize        = NULL,
        .dom_dispose            = NULL,
        .dom_protosw            = inet6sw,
        .dom_protoswNPROTOSW    = &inet6sw[NELEM(inet6sw)],
        .dom_next               = SLIST_ENTRY_INITIALIZER,
        .dom_rtattach           = in6_inithead,
        .dom_rtoffset           = offsetof(struct sockaddr_in6, sin6_addr),
        .dom_maxrtkey           = sizeof(struct sockaddr_in6),
        .dom_ifattach           = in6_domifattach,
        .dom_ifdetach           = in6_domifdetach,
        .dom_if_up              = in6_if_up,
        .dom_if_down            = in6_if_down
};

DOMAIN_SET(inet6);

/*
 * Internet configuration info
 */
#ifndef IPV6FORWARDING
#ifdef GATEWAY6
#define IPV6FORWARDING  1       /* forward IP6 packets not for us */
#else
#define IPV6FORWARDING  0       /* don't forward IP6 packets not for us */
#endif /* GATEWAY6 */
#endif /* !IPV6FORWARDING */

#ifndef IPV6_SENDREDIRECTS
#define IPV6_SENDREDIRECTS      1
#endif

int     nd6_onlink_ns_rfc4861 = 0; /* allow 'on-link' NS/NA (as in RFC 4861) */

int     ip6_forwarding = IPV6FORWARDING;        /* act as router? */
int     ip6_sendredirects = IPV6_SENDREDIRECTS;
int     ip6_defhlim = IPV6_DEFHLIM;
int     ip6_minhlim = IPV6_MINHLIM;
int     ip6_defmcasthlim = IPV6_DEFAULT_MULTICAST_HOPS;
int     ip6_accept_rtadv = 0;   /* "IPV6FORWARDING ? 0 : 1" is dangerous */
int     ip6_maxfragpackets;     /* initialized in frag6.c:frag6_init() */
int     ip6_maxfrags;           /* initialized in frag6.c:frag6_init() */
int     ip6_log_interval = 5;
int     ip6_hdrnestlimit = 50;  /* appropriate? */
int     ip6_dad_count = 1;      /* DupAddrDetectionTransmits */
u_int32_t ip6_flow_seq;
int     ip6_auto_flowlabel = 1;
int     ip6_gif_hlim = 0;
int     ip6_use_deprecated = 1; /* allow deprecated addr (RFC2462 5.5.4) */
int     ip6_rr_prune = 5;       /* router renumbering prefix
                                 * walk list every 5 sec. */

#ifdef IP6_AUTO_LINKLOCAL
int ip6_auto_linklocal = IP6_AUTO_LINKLOCAL;
#else
int ip6_auto_linklocal = 1;     /* enable by default */
#endif

u_int32_t ip6_id = 0UL;
time_t  ip6_log_time = (time_t)0L;

/* icmp6 */
/*
 * BSDI4 defines these variables in in_proto.c...
 * XXX: what if we don't define INET? Should we define pmtu6_expire
 * or so? (jinmei@kame.net 19990310)
 */
int pmtu_expire = 60*10;
int pmtu_probe = 60*2;

/* raw IP6 parameters */
/*
 * Nominal space allocated to a raw ip socket.
 */
#define RIPV6SNDQ       8192
#define RIPV6RCVQ       8192

u_long  rip6_sendspace = RIPV6SNDQ;
u_long  rip6_recvspace = RIPV6RCVQ;

/* ICMPV6 parameters */
int     icmp6_rediraccept = 1;          /* accept and process redirects */
int     icmp6_redirtimeout = 10 * 60;   /* 10 minutes */
int     icmp6errppslim = 100;           /* 100pps */
int     icmp6_nodeinfo = 3;             /* enable/disable NI response */

/* UDP on IP6 parameters */
int     udp6_sendspace = 9216;          /* really max datagram size */
int     udp6_recvspace = 40 * (1024 + sizeof(struct sockaddr_in6));
                                        /* 40 1K datagrams */

/*
 * sysctl related items.
 */
SYSCTL_NODE(_net,       PF_INET6,       inet6,  CTLFLAG_RW,     0,
        "Internet6 Family");

/* net.inet6 */
SYSCTL_NODE(_net_inet6, IPPROTO_IPV6,   ip6,    CTLFLAG_RW, 0,  "IP6");
SYSCTL_NODE(_net_inet6, IPPROTO_ICMPV6, icmp6,  CTLFLAG_RW, 0,  "ICMP6");
SYSCTL_NODE(_net_inet6, IPPROTO_UDP,    udp6,   CTLFLAG_RW, 0,  "UDP6");
SYSCTL_NODE(_net_inet6, IPPROTO_TCP,    tcp6,   CTLFLAG_RW, 0,  "TCP6");

/* net.inet6.ip6 */
static int
sysctl_ip6_temppltime(SYSCTL_HANDLER_ARGS)
{
        int error = 0;
        int old;

        error = SYSCTL_OUT(req, arg1, sizeof(int));
        if (error || !req->newptr)
                return (error);
        old = ip6_temp_preferred_lifetime;
        error = SYSCTL_IN(req, arg1, sizeof(int));
        if (ip6_temp_preferred_lifetime <
            ip6_desync_factor + ip6_temp_regen_advance) {
                ip6_temp_preferred_lifetime = old;
                return (EINVAL);
        }
        return (error);
}

static int
sysctl_ip6_tempvltime(SYSCTL_HANDLER_ARGS)
{
        int error = 0;
        int old;

        error = SYSCTL_OUT(req, arg1, sizeof(int));
        if (error || !req->newptr)
                return (error);
        old = ip6_temp_valid_lifetime;
        error = SYSCTL_IN(req, arg1, sizeof(int));
        if (ip6_temp_valid_lifetime < ip6_temp_preferred_lifetime) {
                ip6_temp_preferred_lifetime = old;
                return (EINVAL);
        }
        return (error);
}

SYSCTL_INT(_net_inet6_ip6, IPV6CTL_FORWARDING, forwarding, CTLFLAG_RW,
    &ip6_forwarding, 0, "Enable IP forwarding between interfaces");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
    &ip6_sendredirects, 0, "Enable sending IP redirects");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_DEFHLIM,
    hlim, CTLFLAG_RW, &ip6_defhlim, 0, "Default hop limit");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_MINHLIM,
    minhlim, CTLFLAG_RW, &ip6_minhlim, 0, "Default hop limit");
SYSCTL_STRUCT(_net_inet6_ip6, IPV6CTL_STATS, stats, CTLFLAG_RD,
    &ip6stat, ip6stat, "IP stats");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_MAXFRAGPACKETS, maxfragpackets,
    CTLFLAG_RW, &ip6_maxfragpackets, 0, "Maximum packets in reassembly queue");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_ACCEPT_RTADV, accept_rtadv,
    CTLFLAG_RW, &ip6_accept_rtadv, 0,
    "Default value of per-interface flag for accepting "
    "ICMPv6 Router Advertisement messages");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_LOG_INTERVAL, log_interval,
    CTLFLAG_RW, &ip6_log_interval, 0, "");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_HDRNESTLIMIT, hdrnestlimit, CTLFLAG_RW,
    &ip6_hdrnestlimit, 0, "Upper limit of # of extension headers");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_DAD_COUNT, dad_count, CTLFLAG_RW,
    &ip6_dad_count, 0, "Number of times to perform duplicate address detectione");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_AUTO_FLOWLABEL, auto_flowlabel, CTLFLAG_RW,
    &ip6_auto_flowlabel, 0, "Enable attaching flowlabel automatically");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_DEFMCASTHLIM, defmcasthlim, CTLFLAG_RW,
    &ip6_defmcasthlim, 0, "Default multicast hop limit");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_RW,
    &ip6_gif_hlim, 0, "Hop limit for gif encap packet");
SYSCTL_STRING(_net_inet6_ip6, IPV6CTL_KAME_VERSION, kame_version,
    CTLFLAG_RD, __KAME_VERSION, 0, "KAME version");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_USE_DEPRECATED, use_deprecated, CTLFLAG_RW,
    &ip6_use_deprecated, 0, "Allow deprecated addr as source");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RR_PRUNE, rr_prune, CTLFLAG_RW,
    &ip6_rr_prune, 0, "Walk timer for router renumbering");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_USETEMPADDR, use_tempaddr, CTLFLAG_RW,
    &ip6_use_tempaddr, 0, "Whether to use temporary addresses");
SYSCTL_OID(_net_inet6_ip6, IPV6CTL_TEMPPLTIME, temppltime,
    CTLTYPE_INT|CTLFLAG_RW, &ip6_temp_preferred_lifetime, 0,
    sysctl_ip6_temppltime, "I",
    "Preferred lifetime for tmpaddrs");
SYSCTL_OID(_net_inet6_ip6, IPV6CTL_TEMPVLTIME, tempvltime,
    CTLTYPE_INT|CTLFLAG_RW, &ip6_temp_valid_lifetime, 0,
    sysctl_ip6_tempvltime, "I",
    "Valid lifetime for tmpaddrs");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_AUTO_LINKLOCAL, auto_linklocal,
    CTLFLAG_RW, &ip6_auto_linklocal, 0,
    "Default value of per-interface flag for auto-assigning "
    "a link-local address");
SYSCTL_STRUCT(_net_inet6_ip6, IPV6CTL_RIP6STATS, rip6stats, CTLFLAG_RD,
    &rip6stat, rip6stat, "Raw stats");
SYSCTL_INT(_net_inet6_ip6, IPV6CTL_MAXFRAGS, maxfrags, CTLFLAG_RW,
    &ip6_maxfrags, 0, "Maximum fragments in reassembly queues");

/* net.inet6.icmp6 */
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRACCEPT, rediraccept, CTLFLAG_RW,
    &icmp6_rediraccept, 0, "If enabled, accept and process redirects");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_REDIRTIMEOUT, redirtimeout, CTLFLAG_RW,
    &icmp6_redirtimeout, 0, "Cache time for redirect routes");
SYSCTL_STRUCT(_net_inet6_icmp6, ICMPV6CTL_STATS, stats, CTLFLAG_RD,
    &icmp6stat, icmp6stat, "Stats");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_PRUNE, nd6_prune, CTLFLAG_RW,
    &nd6_prune, 0, "Prune interval");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DELAY, nd6_delay, CTLFLAG_RW,
    &nd6_delay, 0, "Reachability timeout for stale neighbors");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_UMAXTRIES, nd6_umaxtries, CTLFLAG_RW,
    &nd6_umaxtries, 0, "Maximum unicast query");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MMAXTRIES, nd6_mmaxtries, CTLFLAG_RW,
    &nd6_mmaxtries, 0, "Maximum multicast query");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_USELOOPBACK, nd6_useloopback, CTLFLAG_RW,
    &nd6_useloopback, 0, "Use loopback interface for local traffic");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_NODEINFO,
    nodeinfo, CTLFLAG_RW, &icmp6_nodeinfo, 0, "Enable/disable NI response");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ERRPPSLIMIT,
    errppslimit, CTLFLAG_RW, &icmp6errppslim, 0,
    "ICMPv6 error maximum packet-per-second value (default: 100pps)");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXNUDHINT, nd6_maxnudhint, CTLFLAG_RW,
    &nd6_maxnudhint, 0, "Max # of subsequent upper layer hints");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DEBUG, nd6_debug, CTLFLAG_RW,
    &nd6_debug, 0, "Enable debug output");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_ONLINKNSRFC4861, nd6_onlink_ns_rfc4861, CTLFLAG_RW,
    &nd6_onlink_ns_rfc4861, 0, "Accept 'on-link' NS/NA in compliance with RFC 4861.");