Merge pull request #8138 from ckishimo/ospfv3_prefix

[mirror_frr.git] / zebra / rt_netlink.c

/* Kernel routing table updates using netlink over GNU/Linux system.
 * Copyright (C) 1997, 98, 99 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * GNU Zebra is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#ifdef HAVE_NETLINK

#include <net/if_arp.h>
#include <linux/lwtunnel.h>
#include <linux/mpls_iptunnel.h>
#include <linux/neighbour.h>
#include <linux/rtnetlink.h>
#include <linux/nexthop.h>

/* Hack for GNU libc version 2. */
#ifndef MSG_TRUNC
#define MSG_TRUNC      0x20
#endif /* MSG_TRUNC */

#include "linklist.h"
#include "if.h"
#include "log.h"
#include "prefix.h"
#include "connected.h"
#include "table.h"
#include "memory.h"
#include "zebra_memory.h"
#include "rib.h"
#include "thread.h"
#include "privs.h"
#include "nexthop.h"
#include "vrf.h"
#include "vty.h"
#include "mpls.h"
#include "vxlan.h"
#include "printfrr.h"

#include "zebra/zapi_msg.h"
#include "zebra/zebra_ns.h"
#include "zebra/zebra_vrf.h"
#include "zebra/rt.h"
#include "zebra/redistribute.h"
#include "zebra/interface.h"
#include "zebra/debug.h"
#include "zebra/rtadv.h"
#include "zebra/zebra_ptm.h"
#include "zebra/zebra_mpls.h"
#include "zebra/kernel_netlink.h"
#include "zebra/rt_netlink.h"
#include "zebra/zebra_nhg.h"
#include "zebra/zebra_mroute.h"
#include "zebra/zebra_vxlan.h"
#include "zebra/zebra_errors.h"
#include "zebra/zebra_evpn_mh.h"

#ifndef AF_MPLS
#define AF_MPLS 28
#endif

/* Re-defining as I am unable to include <linux/if_bridge.h> which has the
 * UAPI for MAC sync. */
#ifndef _UAPI_LINUX_IF_BRIDGE_H
#define BR_SPH_LIST_SIZE 10
#endif

static vlanid_t filter_vlan = 0;

/* We capture whether the current kernel supports nexthop ids; by
 * default, we'll use them if possible. There's also a configuration
 * available to _disable_ use of kernel nexthops.
 */
static bool supports_nh;

struct gw_family_t {
        uint16_t filler;
        uint16_t family;
        union g_addr gate;
};

static const char ipv4_ll_buf[16] = "169.254.0.1";
static struct in_addr ipv4_ll;

/* Is this a ipv4 over ipv6 route? */
static bool is_route_v4_over_v6(unsigned char rtm_family,
                                enum nexthop_types_t nexthop_type)
{
        if (rtm_family == AF_INET
            && (nexthop_type == NEXTHOP_TYPE_IPV6
                || nexthop_type == NEXTHOP_TYPE_IPV6_IFINDEX))
                return true;

        return false;
}

/* Helper to control use of kernel-level nexthop ids */
static bool kernel_nexthops_supported(void)
{
        return (supports_nh && !vrf_is_backend_netns()
                && zebra_nhg_kernel_nexthops_enabled());
}

/*
 * Some people may only want to use NHGs created by protos and not
 * implicitly created by Zebra. This check accounts for that.
 */
static bool proto_nexthops_only(void)
{
        return zebra_nhg_proto_nexthops_only();
}

/* Is this a proto created NHG? */
static bool is_proto_nhg(uint32_t id, int type)
{
        /* If type is available, use it as the source of truth */
        if (type) {
                if (type != ZEBRA_ROUTE_NHG)
                        return true;
                return false;
        }

        if (id >= ZEBRA_NHG_PROTO_LOWER)
                return true;

        return false;
}

/*
 * The ipv4_ll data structure is used for all 5549
 * additions to the kernel.  Let's figure out the
 * correct value one time instead for every
 * install/remove of a 5549 type route
 */
void rt_netlink_init(void)
{
        inet_pton(AF_INET, ipv4_ll_buf, &ipv4_ll);
}

/*
 * Mapping from dataplane neighbor flags to netlink flags
 */
static uint8_t neigh_flags_to_netlink(uint8_t dplane_flags)
{
        uint8_t flags = 0;

        if (dplane_flags & DPLANE_NTF_EXT_LEARNED)
                flags |= NTF_EXT_LEARNED;
        if (dplane_flags & DPLANE_NTF_ROUTER)
                flags |= NTF_ROUTER;
        if (dplane_flags & DPLANE_NTF_USE)
                flags |= NTF_USE;

        return flags;
}

/*
 * Mapping from dataplane neighbor state to netlink state
 */
static uint16_t neigh_state_to_netlink(uint16_t dplane_state)
{
        uint16_t state = 0;

        if (dplane_state & DPLANE_NUD_REACHABLE)
                state |= NUD_REACHABLE;
        if (dplane_state & DPLANE_NUD_STALE)
                state |= NUD_STALE;
        if (dplane_state & DPLANE_NUD_NOARP)
                state |= NUD_NOARP;
        if (dplane_state & DPLANE_NUD_PROBE)
                state |= NUD_PROBE;
        if (dplane_state & DPLANE_NUD_INCOMPLETE)
                state |= NUD_INCOMPLETE;

        return state;
}


static inline bool is_selfroute(int proto)
{
        if ((proto == RTPROT_BGP) || (proto == RTPROT_OSPF)
            || (proto == RTPROT_ZSTATIC) || (proto == RTPROT_ZEBRA)
            || (proto == RTPROT_ISIS) || (proto == RTPROT_RIPNG)
            || (proto == RTPROT_NHRP) || (proto == RTPROT_EIGRP)
            || (proto == RTPROT_LDP) || (proto == RTPROT_BABEL)
            || (proto == RTPROT_RIP) || (proto == RTPROT_SHARP)
            || (proto == RTPROT_PBR) || (proto == RTPROT_OPENFABRIC)
            || (proto == RTPROT_SRTE)) {
                return true;
        }

        return false;
}

static inline int zebra2proto(int proto)
{
        switch (proto) {
        case ZEBRA_ROUTE_BABEL:
                proto = RTPROT_BABEL;
                break;
        case ZEBRA_ROUTE_BGP:
                proto = RTPROT_BGP;
                break;
        case ZEBRA_ROUTE_OSPF:
        case ZEBRA_ROUTE_OSPF6:
                proto = RTPROT_OSPF;
                break;
        case ZEBRA_ROUTE_STATIC:
                proto = RTPROT_ZSTATIC;
                break;
        case ZEBRA_ROUTE_ISIS:
                proto = RTPROT_ISIS;
                break;
        case ZEBRA_ROUTE_RIP:
                proto = RTPROT_RIP;
                break;
        case ZEBRA_ROUTE_RIPNG:
                proto = RTPROT_RIPNG;
                break;
        case ZEBRA_ROUTE_NHRP:
                proto = RTPROT_NHRP;
                break;
        case ZEBRA_ROUTE_EIGRP:
                proto = RTPROT_EIGRP;
                break;
        case ZEBRA_ROUTE_LDP:
                proto = RTPROT_LDP;
                break;
        case ZEBRA_ROUTE_SHARP:
                proto = RTPROT_SHARP;
                break;
        case ZEBRA_ROUTE_PBR:
                proto = RTPROT_PBR;
                break;
        case ZEBRA_ROUTE_OPENFABRIC:
                proto = RTPROT_OPENFABRIC;
                break;
        case ZEBRA_ROUTE_SRTE:
                proto = RTPROT_SRTE;
                break;
        case ZEBRA_ROUTE_TABLE:
        case ZEBRA_ROUTE_NHG:
                proto = RTPROT_ZEBRA;
                break;
        case ZEBRA_ROUTE_CONNECT:
        case ZEBRA_ROUTE_KERNEL:
                proto = RTPROT_KERNEL;
                break;
        default:
                /*
                 * When a user adds a new protocol this will show up
                 * to let them know to do something about it.  This
                 * is intentionally a warn because we should see
                 * this as part of development of a new protocol
                 */
                zlog_debug(
                        "%s: Please add this protocol(%d) to proper rt_netlink.c handling",
                        __func__, proto);
                proto = RTPROT_ZEBRA;
                break;
        }

        return proto;
}

static inline int proto2zebra(int proto, int family, bool is_nexthop)
{
        switch (proto) {
        case RTPROT_BABEL:
                proto = ZEBRA_ROUTE_BABEL;
                break;
        case RTPROT_BGP:
                proto = ZEBRA_ROUTE_BGP;
                break;
        case RTPROT_OSPF:
                proto = (family == AF_INET) ? ZEBRA_ROUTE_OSPF
                                            : ZEBRA_ROUTE_OSPF6;
                break;
        case RTPROT_ISIS:
                proto = ZEBRA_ROUTE_ISIS;
                break;
        case RTPROT_RIP:
                proto = ZEBRA_ROUTE_RIP;
                break;
        case RTPROT_RIPNG:
                proto = ZEBRA_ROUTE_RIPNG;
                break;
        case RTPROT_NHRP:
                proto = ZEBRA_ROUTE_NHRP;
                break;
        case RTPROT_EIGRP:
                proto = ZEBRA_ROUTE_EIGRP;
                break;
        case RTPROT_LDP:
                proto = ZEBRA_ROUTE_LDP;
                break;
        case RTPROT_STATIC:
        case RTPROT_ZSTATIC:
                proto = ZEBRA_ROUTE_STATIC;
                break;
        case RTPROT_SHARP:
                proto = ZEBRA_ROUTE_SHARP;
                break;
        case RTPROT_PBR:
                proto = ZEBRA_ROUTE_PBR;
                break;
        case RTPROT_OPENFABRIC:
                proto = ZEBRA_ROUTE_OPENFABRIC;
                break;
        case RTPROT_SRTE:
                proto = ZEBRA_ROUTE_SRTE;
                break;
        case RTPROT_ZEBRA:
                if (is_nexthop) {
                        proto = ZEBRA_ROUTE_NHG;
                        break;
                }
                /* Intentional fall thru */
        default:
                /*
                 * When a user adds a new protocol this will show up
                 * to let them know to do something about it.  This
                 * is intentionally a warn because we should see
                 * this as part of development of a new protocol
                 */
                zlog_debug(
                        "%s: Please add this protocol(%d) to proper rt_netlink.c handling",
                        __func__, proto);
                proto = ZEBRA_ROUTE_KERNEL;
                break;
        }
        return proto;
}

/*
Pending: create an efficient table_id (in a tree/hash) based lookup)
 */
vrf_id_t vrf_lookup_by_table(uint32_t table_id, ns_id_t ns_id)
{
        struct vrf *vrf;
        struct zebra_vrf *zvrf;

        RB_FOREACH (vrf, vrf_id_head, &vrfs_by_id) {
                zvrf = vrf->info;
                if (zvrf == NULL)
                        continue;
                /* case vrf with netns : match the netnsid */
                if (vrf_is_backend_netns()) {
                        if (ns_id == zvrf_id(zvrf))
                                return zvrf_id(zvrf);
                } else {
                        /* VRF is VRF_BACKEND_VRF_LITE */
                        if (zvrf->table_id != table_id)
                                continue;
                        return zvrf_id(zvrf);
                }
        }

        return VRF_DEFAULT;
}

/**
 * @parse_encap_mpls() - Parses encapsulated mpls attributes
 * @tb:         Pointer to rtattr to look for nested items in.
 * @labels:     Pointer to store labels in.
 *
 * Return:      Number of mpls labels found.
 */
static int parse_encap_mpls(struct rtattr *tb, mpls_label_t *labels)
{
        struct rtattr *tb_encap[MPLS_IPTUNNEL_MAX + 1] = {0};
        mpls_lse_t *lses = NULL;
        int num_labels = 0;
        uint32_t ttl = 0;
        uint32_t bos = 0;
        uint32_t exp = 0;
        mpls_label_t label = 0;

        netlink_parse_rtattr_nested(tb_encap, MPLS_IPTUNNEL_MAX, tb);
        lses = (mpls_lse_t *)RTA_DATA(tb_encap[MPLS_IPTUNNEL_DST]);
        while (!bos && num_labels < MPLS_MAX_LABELS) {
                mpls_lse_decode(lses[num_labels], &label, &ttl, &exp, &bos);
                labels[num_labels++] = label;
        }

        return num_labels;
}

static struct nexthop
parse_nexthop_unicast(ns_id_t ns_id, struct rtmsg *rtm, struct rtattr **tb,
                      enum blackhole_type bh_type, int index, void *prefsrc,
                      void *gate, afi_t afi, vrf_id_t vrf_id)
{
        struct interface *ifp = NULL;
        struct nexthop nh = {0};
        mpls_label_t labels[MPLS_MAX_LABELS] = {0};
        int num_labels = 0;

        vrf_id_t nh_vrf_id = vrf_id;
        size_t sz = (afi == AFI_IP) ? 4 : 16;

        if (bh_type == BLACKHOLE_UNSPEC) {
                if (index && !gate)
                        nh.type = NEXTHOP_TYPE_IFINDEX;
                else if (index && gate)
                        nh.type = (afi == AFI_IP) ? NEXTHOP_TYPE_IPV4_IFINDEX
                                                  : NEXTHOP_TYPE_IPV6_IFINDEX;
                else if (!index && gate)
                        nh.type = (afi == AFI_IP) ? NEXTHOP_TYPE_IPV4
                                                  : NEXTHOP_TYPE_IPV6;
                else {
                        nh.type = NEXTHOP_TYPE_BLACKHOLE;
                        nh.bh_type = bh_type;
                }
        } else {
                nh.type = NEXTHOP_TYPE_BLACKHOLE;
                nh.bh_type = bh_type;
        }
        nh.ifindex = index;
        if (prefsrc)
                memcpy(&nh.src, prefsrc, sz);
        if (gate)
                memcpy(&nh.gate, gate, sz);

        if (index) {
                ifp = if_lookup_by_index_per_ns(zebra_ns_lookup(ns_id), index);
                if (ifp)
                        nh_vrf_id = ifp->vrf_id;
        }
        nh.vrf_id = nh_vrf_id;

        if (tb[RTA_ENCAP] && tb[RTA_ENCAP_TYPE]
            && *(uint16_t *)RTA_DATA(tb[RTA_ENCAP_TYPE])
                       == LWTUNNEL_ENCAP_MPLS) {
                num_labels = parse_encap_mpls(tb[RTA_ENCAP], labels);
        }

        if (rtm->rtm_flags & RTNH_F_ONLINK)
                SET_FLAG(nh.flags, NEXTHOP_FLAG_ONLINK);

        if (num_labels)
                nexthop_add_labels(&nh, ZEBRA_LSP_STATIC, num_labels, labels);

        return nh;
}

static uint8_t parse_multipath_nexthops_unicast(ns_id_t ns_id,
                                                struct nexthop_group *ng,
                                                struct rtmsg *rtm,
                                                struct rtnexthop *rtnh,
                                                struct rtattr **tb,
                                                void *prefsrc, vrf_id_t vrf_id)
{
        void *gate = NULL;
        struct interface *ifp = NULL;
        int index = 0;
        /* MPLS labels */
        mpls_label_t labels[MPLS_MAX_LABELS] = {0};
        int num_labels = 0;
        struct rtattr *rtnh_tb[RTA_MAX + 1] = {};

        int len = RTA_PAYLOAD(tb[RTA_MULTIPATH]);
        vrf_id_t nh_vrf_id = vrf_id;

        for (;;) {
                struct nexthop *nh = NULL;

                if (len < (int)sizeof(*rtnh) || rtnh->rtnh_len > len)
                        break;

                index = rtnh->rtnh_ifindex;
                if (index) {
                        /*
                         * Yes we are looking this up
                         * for every nexthop and just
                         * using the last one looked
                         * up right now
                         */
                        ifp = if_lookup_by_index_per_ns(zebra_ns_lookup(ns_id),
                                                        index);
                        if (ifp)
                                nh_vrf_id = ifp->vrf_id;
                        else {
                                flog_warn(
                                        EC_ZEBRA_UNKNOWN_INTERFACE,
                                        "%s: Unknown interface %u specified, defaulting to VRF_DEFAULT",
                                        __func__, index);
                                nh_vrf_id = VRF_DEFAULT;
                        }
                } else
                        nh_vrf_id = vrf_id;

                if (rtnh->rtnh_len > sizeof(*rtnh)) {
                        memset(rtnh_tb, 0, sizeof(rtnh_tb));

                        netlink_parse_rtattr(rtnh_tb, RTA_MAX, RTNH_DATA(rtnh),
                                             rtnh->rtnh_len - sizeof(*rtnh));
                        if (rtnh_tb[RTA_GATEWAY])
                                gate = RTA_DATA(rtnh_tb[RTA_GATEWAY]);
                        if (rtnh_tb[RTA_ENCAP] && rtnh_tb[RTA_ENCAP_TYPE]
                            && *(uint16_t *)RTA_DATA(rtnh_tb[RTA_ENCAP_TYPE])
                                       == LWTUNNEL_ENCAP_MPLS) {
                                num_labels = parse_encap_mpls(
                                        rtnh_tb[RTA_ENCAP], labels);
                        }
                }

                if (gate && rtm->rtm_family == AF_INET) {
                        if (index)
                                nh = nexthop_from_ipv4_ifindex(
                                        gate, prefsrc, index, nh_vrf_id);
                        else
                                nh = nexthop_from_ipv4(gate, prefsrc,
                                                       nh_vrf_id);
                } else if (gate && rtm->rtm_family == AF_INET6) {
                        if (index)
                                nh = nexthop_from_ipv6_ifindex(
                                        gate, index, nh_vrf_id);
                        else
                                nh = nexthop_from_ipv6(gate, nh_vrf_id);
                } else
                        nh = nexthop_from_ifindex(index, nh_vrf_id);

                if (nh) {
                        nh->weight = rtnh->rtnh_hops + 1;

                        if (num_labels)
                                nexthop_add_labels(nh, ZEBRA_LSP_STATIC,
                                                   num_labels, labels);

                        if (rtnh->rtnh_flags & RTNH_F_ONLINK)
                                SET_FLAG(nh->flags, NEXTHOP_FLAG_ONLINK);

                        /* Add to temporary list */
                        nexthop_group_add_sorted(ng, nh);
                }

                if (rtnh->rtnh_len == 0)
                        break;

                len -= NLMSG_ALIGN(rtnh->rtnh_len);
                rtnh = RTNH_NEXT(rtnh);
        }

        uint8_t nhop_num = nexthop_group_nexthop_num(ng);

        return nhop_num;
}

/* Looking up routing table by netlink interface. */
static int netlink_route_change_read_unicast(struct nlmsghdr *h, ns_id_t ns_id,
                                             int startup)
{
        int len;
        struct rtmsg *rtm;
        struct rtattr *tb[RTA_MAX + 1];
        uint32_t flags = 0;
        struct prefix p;
        struct prefix_ipv6 src_p = {};
        vrf_id_t vrf_id;
        bool selfroute;

        char anyaddr[16] = {0};

        int proto = ZEBRA_ROUTE_KERNEL;
        int index = 0;
        int table;
        int metric = 0;
        uint32_t mtu = 0;
        uint8_t distance = 0;
        route_tag_t tag = 0;
        uint32_t nhe_id = 0;

        void *dest = NULL;
        void *gate = NULL;
        void *prefsrc = NULL; /* IPv4 preferred source host address */
        void *src = NULL;     /* IPv6 srcdest   source prefix */
        enum blackhole_type bh_type = BLACKHOLE_UNSPEC;

        rtm = NLMSG_DATA(h);

        if (startup && h->nlmsg_type != RTM_NEWROUTE)
                return 0;
        switch (rtm->rtm_type) {
        case RTN_UNICAST:
                break;
        case RTN_BLACKHOLE:
                bh_type = BLACKHOLE_NULL;
                break;
        case RTN_UNREACHABLE:
                bh_type = BLACKHOLE_REJECT;
                break;
        case RTN_PROHIBIT:
                bh_type = BLACKHOLE_ADMINPROHIB;
                break;
        default:
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("Route rtm_type: %s(%d) intentionally ignoring",
                                   nl_rttype_to_str(rtm->rtm_type),
                                   rtm->rtm_type);
                return 0;
        }

        len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct rtmsg));
        if (len < 0) {
                zlog_err(
                        "%s: Message received from netlink is of a broken size %d %zu",
                        __func__, h->nlmsg_len,
                        (size_t)NLMSG_LENGTH(sizeof(struct rtmsg)));
                return -1;
        }

        memset(tb, 0, sizeof(tb));
        netlink_parse_rtattr(tb, RTA_MAX, RTM_RTA(rtm), len);

        if (rtm->rtm_flags & RTM_F_CLONED)
                return 0;
        if (rtm->rtm_protocol == RTPROT_REDIRECT)
                return 0;
        if (rtm->rtm_protocol == RTPROT_KERNEL)
                return 0;

        selfroute = is_selfroute(rtm->rtm_protocol);

        if (!startup && selfroute
            && h->nlmsg_type == RTM_NEWROUTE
            && !zrouter.asic_offloaded) {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("Route type: %d Received that we think we have originated, ignoring",
                                   rtm->rtm_protocol);
                return 0;
        }

        /* We don't care about change notifications for the MPLS table. */
        /* TODO: Revisit this. */
        if (rtm->rtm_family == AF_MPLS)
                return 0;

        /* Table corresponding to route. */
        if (tb[RTA_TABLE])
                table = *(int *)RTA_DATA(tb[RTA_TABLE]);
        else
                table = rtm->rtm_table;

        /* Map to VRF */
        vrf_id = vrf_lookup_by_table(table, ns_id);
        if (vrf_id == VRF_DEFAULT) {
                if (!is_zebra_valid_kernel_table(table)
                    && !is_zebra_main_routing_table(table))
                        return 0;
        }

        if (rtm->rtm_flags & RTM_F_TRAP)
                flags |= ZEBRA_FLAG_TRAPPED;
        if (rtm->rtm_flags & RTM_F_OFFLOAD)
                flags |= ZEBRA_FLAG_OFFLOADED;
        if (rtm->rtm_flags & RTM_F_OFFLOAD_FAILED)
                flags |= ZEBRA_FLAG_OFFLOAD_FAILED;

        /* Route which inserted by Zebra. */
        if (selfroute) {
                flags |= ZEBRA_FLAG_SELFROUTE;
                proto = proto2zebra(rtm->rtm_protocol, rtm->rtm_family, false);
        }
        if (tb[RTA_OIF])
                index = *(int *)RTA_DATA(tb[RTA_OIF]);

        if (tb[RTA_DST])
                dest = RTA_DATA(tb[RTA_DST]);
        else
                dest = anyaddr;

        if (tb[RTA_SRC])
                src = RTA_DATA(tb[RTA_SRC]);
        else
                src = anyaddr;

        if (tb[RTA_PREFSRC])
                prefsrc = RTA_DATA(tb[RTA_PREFSRC]);

        if (tb[RTA_GATEWAY])
                gate = RTA_DATA(tb[RTA_GATEWAY]);

        if (tb[RTA_NH_ID])
                nhe_id = *(uint32_t *)RTA_DATA(tb[RTA_NH_ID]);

        if (tb[RTA_PRIORITY])
                metric = *(int *)RTA_DATA(tb[RTA_PRIORITY]);

#if defined(SUPPORT_REALMS)
        if (tb[RTA_FLOW])
                tag = *(uint32_t *)RTA_DATA(tb[RTA_FLOW]);
#endif

        if (tb[RTA_METRICS]) {
                struct rtattr *mxrta[RTAX_MAX + 1];

                memset(mxrta, 0, sizeof(mxrta));
                netlink_parse_rtattr(mxrta, RTAX_MAX, RTA_DATA(tb[RTA_METRICS]),
                                     RTA_PAYLOAD(tb[RTA_METRICS]));

                if (mxrta[RTAX_MTU])
                        mtu = *(uint32_t *)RTA_DATA(mxrta[RTAX_MTU]);
        }

        if (rtm->rtm_family == AF_INET) {
                p.family = AF_INET;
                if (rtm->rtm_dst_len > IPV4_MAX_BITLEN) {
                        zlog_err(
                                "Invalid destination prefix length: %u received from kernel route change",
                                rtm->rtm_dst_len);
                        return -1;
                }
                memcpy(&p.u.prefix4, dest, 4);
                p.prefixlen = rtm->rtm_dst_len;

                if (rtm->rtm_src_len != 0) {
                        flog_warn(
                                EC_ZEBRA_UNSUPPORTED_V4_SRCDEST,
                                "unsupported IPv4 sourcedest route (dest %pFX vrf %u)",
                                &p, vrf_id);
                        return 0;
                }

                /* Force debug below to not display anything for source */
                src_p.prefixlen = 0;
        } else if (rtm->rtm_family == AF_INET6) {
                p.family = AF_INET6;
                if (rtm->rtm_dst_len > IPV6_MAX_BITLEN) {
                        zlog_err(
                                "Invalid destination prefix length: %u received from kernel route change",
                                rtm->rtm_dst_len);
                        return -1;
                }
                memcpy(&p.u.prefix6, dest, 16);
                p.prefixlen = rtm->rtm_dst_len;

                src_p.family = AF_INET6;
                if (rtm->rtm_src_len > IPV6_MAX_BITLEN) {
                        zlog_err(
                                "Invalid source prefix length: %u received from kernel route change",
                                rtm->rtm_src_len);
                        return -1;
                }
                memcpy(&src_p.prefix, src, 16);
                src_p.prefixlen = rtm->rtm_src_len;
        }

        /*
         * For ZEBRA_ROUTE_KERNEL types:
         *
         * The metric/priority of the route received from the kernel
         * is a 32 bit number.  We are going to interpret the high
         * order byte as the Admin Distance and the low order 3 bytes
         * as the metric.
         *
         * This will allow us to do two things:
         * 1) Allow the creation of kernel routes that can be
         *    overridden by zebra.
         * 2) Allow the old behavior for 'most' kernel route types
         *    if a user enters 'ip route ...' v4 routes get a metric
         *    of 0 and v6 routes get a metric of 1024.  Both of these
         *    values will end up with a admin distance of 0, which
         *    will cause them to win for the purposes of zebra.
         */
        if (proto == ZEBRA_ROUTE_KERNEL) {
                distance = (metric >> 24) & 0xFF;
                metric = (metric & 0x00FFFFFF);
        }

        if (IS_ZEBRA_DEBUG_KERNEL) {
                char buf2[PREFIX_STRLEN];

                zlog_debug(
                        "%s %pFX%s%s vrf %s(%u) table_id: %u metric: %d Admin Distance: %d",
                        nl_msg_type_to_str(h->nlmsg_type), &p,
                        src_p.prefixlen ? " from " : "",
                        src_p.prefixlen ? prefix2str(&src_p, buf2, sizeof(buf2))
                                        : "",
                        vrf_id_to_name(vrf_id), vrf_id, table, metric,
                        distance);
        }

        afi_t afi = AFI_IP;
        if (rtm->rtm_family == AF_INET6)
                afi = AFI_IP6;

        if (h->nlmsg_type == RTM_NEWROUTE) {

                if (!tb[RTA_MULTIPATH]) {
                        struct nexthop nh = {0};

                        if (!nhe_id) {
                                nh = parse_nexthop_unicast(
                                        ns_id, rtm, tb, bh_type, index, prefsrc,
                                        gate, afi, vrf_id);
                        }
                        rib_add(afi, SAFI_UNICAST, vrf_id, proto, 0, flags, &p,
                                &src_p, &nh, nhe_id, table, metric, mtu,
                                distance, tag);
                } else {
                        /* This is a multipath route */
                        struct route_entry *re;
                        struct nexthop_group *ng = NULL;
                        struct rtnexthop *rtnh =
                                (struct rtnexthop *)RTA_DATA(tb[RTA_MULTIPATH]);

                        re = XCALLOC(MTYPE_RE, sizeof(struct route_entry));
                        re->type = proto;
                        re->distance = distance;
                        re->flags = flags;
                        re->metric = metric;
                        re->mtu = mtu;
                        re->vrf_id = vrf_id;
                        re->table = table;
                        re->uptime = monotime(NULL);
                        re->tag = tag;
                        re->nhe_id = nhe_id;

                        if (!nhe_id) {
                                uint8_t nhop_num;

                                /* Use temporary list of nexthops; parse
                                 * message payload's nexthops.
                                 */
                                ng = nexthop_group_new();
                                nhop_num =
                                        parse_multipath_nexthops_unicast(
                                                ns_id, ng, rtm, rtnh, tb,
                                                prefsrc, vrf_id);

                                zserv_nexthop_num_warn(
                                        __func__, (const struct prefix *)&p,
                                        nhop_num);

                                if (nhop_num == 0) {
                                        nexthop_group_delete(&ng);
                                        ng = NULL;
                                }
                        }

                        if (nhe_id || ng)
                                rib_add_multipath(afi, SAFI_UNICAST, &p,
                                                  &src_p, re, ng);
                        else
                                XFREE(MTYPE_RE, re);
                }
        } else {
                if (nhe_id) {
                        rib_delete(afi, SAFI_UNICAST, vrf_id, proto, 0, flags,
                                   &p, &src_p, NULL, nhe_id, table, metric,
                                   distance, true);
                } else {
                        if (!tb[RTA_MULTIPATH]) {
                                struct nexthop nh;

                                nh = parse_nexthop_unicast(
                                        ns_id, rtm, tb, bh_type, index, prefsrc,
                                        gate, afi, vrf_id);
                                rib_delete(afi, SAFI_UNICAST, vrf_id, proto, 0,
                                           flags, &p, &src_p, &nh, 0, table,
                                           metric, distance, true);
                        } else {
                                /* XXX: need to compare the entire list of
                                 * nexthops here for NLM_F_APPEND stupidity */
                                rib_delete(afi, SAFI_UNICAST, vrf_id, proto, 0,
                                           flags, &p, &src_p, NULL, 0, table,
                                           metric, distance, true);
                        }
                }
        }

        return 0;
}

static struct mcast_route_data *mroute = NULL;

static int netlink_route_change_read_multicast(struct nlmsghdr *h,
                                               ns_id_t ns_id, int startup)
{
        int len;
        struct rtmsg *rtm;
        struct rtattr *tb[RTA_MAX + 1];
        struct mcast_route_data *m;
        struct mcast_route_data mr;
        int iif = 0;
        int count;
        int oif[256];
        int oif_count = 0;
        char oif_list[256] = "\0";
        vrf_id_t vrf;
        int table;

        if (mroute)
                m = mroute;
        else {
                memset(&mr, 0, sizeof(mr));
                m = &mr;
        }

        rtm = NLMSG_DATA(h);

        len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct rtmsg));

        memset(tb, 0, sizeof(tb));
        netlink_parse_rtattr(tb, RTA_MAX, RTM_RTA(rtm), len);

        if (tb[RTA_TABLE])
                table = *(int *)RTA_DATA(tb[RTA_TABLE]);
        else
                table = rtm->rtm_table;

        vrf = vrf_lookup_by_table(table, ns_id);

        if (tb[RTA_IIF])
                iif = *(int *)RTA_DATA(tb[RTA_IIF]);

        if (tb[RTA_SRC])
                m->sg.src = *(struct in_addr *)RTA_DATA(tb[RTA_SRC]);

        if (tb[RTA_DST])
                m->sg.grp = *(struct in_addr *)RTA_DATA(tb[RTA_DST]);

        if (tb[RTA_EXPIRES])
                m->lastused = *(unsigned long long *)RTA_DATA(tb[RTA_EXPIRES]);

        if (tb[RTA_MULTIPATH]) {
                struct rtnexthop *rtnh =
                        (struct rtnexthop *)RTA_DATA(tb[RTA_MULTIPATH]);

                len = RTA_PAYLOAD(tb[RTA_MULTIPATH]);
                for (;;) {
                        if (len < (int)sizeof(*rtnh) || rtnh->rtnh_len > len)
                                break;

                        oif[oif_count] = rtnh->rtnh_ifindex;
                        oif_count++;

                        if (rtnh->rtnh_len == 0)
                                break;

                        len -= NLMSG_ALIGN(rtnh->rtnh_len);
                        rtnh = RTNH_NEXT(rtnh);
                }
        }

        if (IS_ZEBRA_DEBUG_KERNEL) {
                struct interface *ifp = NULL;
                struct zebra_vrf *zvrf = NULL;

                for (count = 0; count < oif_count; count++) {
                        ifp = if_lookup_by_index(oif[count], vrf);
                        char temp[256];

                        snprintf(temp, sizeof(temp), "%s(%d) ",
                                 ifp ? ifp->name : "Unknown", oif[count]);
                        strlcat(oif_list, temp, sizeof(oif_list));
                }
                zvrf = zebra_vrf_lookup_by_id(vrf);
                ifp = if_lookup_by_index(iif, vrf);
                zlog_debug(
                        "MCAST VRF: %s(%d) %s (%pI4,%pI4) IIF: %s(%d) OIF: %s jiffies: %lld",
                        zvrf_name(zvrf), vrf, nl_msg_type_to_str(h->nlmsg_type),
                        &m->sg.src, &m->sg.grp, ifp ? ifp->name : "Unknown",
                        iif, oif_list,
                        m->lastused);
        }
        return 0;
}

int netlink_route_change(struct nlmsghdr *h, ns_id_t ns_id, int startup)
{
        int len;
        struct rtmsg *rtm;

        rtm = NLMSG_DATA(h);

        if (!(h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE)) {
                /* If this is not route add/delete message print warning. */
                zlog_debug("Kernel message: %s NS %u",
                           nl_msg_type_to_str(h->nlmsg_type), ns_id);
                return 0;
        }

        if (!(rtm->rtm_family == AF_INET ||
              rtm->rtm_family == AF_INET6 ||
              rtm->rtm_family == RTNL_FAMILY_IPMR )) {
                flog_warn(
                        EC_ZEBRA_UNKNOWN_FAMILY,
                        "Invalid address family: %u received from kernel route change: %s",
                        rtm->rtm_family, nl_msg_type_to_str(h->nlmsg_type));
                return 0;
        }

        /* Connected route. */
        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("%s %s %s proto %s NS %u",
                           nl_msg_type_to_str(h->nlmsg_type),
                           nl_family_to_str(rtm->rtm_family),
                           nl_rttype_to_str(rtm->rtm_type),
                           nl_rtproto_to_str(rtm->rtm_protocol), ns_id);


        len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct rtmsg));
        if (len < 0) {
                zlog_err(
                        "%s: Message received from netlink is of a broken size: %d %zu",
                        __func__, h->nlmsg_len,
                        (size_t)NLMSG_LENGTH(sizeof(struct rtmsg)));
                return -1;
        }

        if (rtm->rtm_type == RTN_MULTICAST)
                netlink_route_change_read_multicast(h, ns_id, startup);
        else
                netlink_route_change_read_unicast(h, ns_id, startup);
        return 0;
}

/* Request for specific route information from the kernel */
static int netlink_request_route(struct zebra_ns *zns, int family, int type)
{
        struct {
                struct nlmsghdr n;
                struct rtmsg rtm;
        } req;

        /* Form the request, specifying filter (rtattr) if needed. */
        memset(&req, 0, sizeof(req));
        req.n.nlmsg_type = type;
        req.n.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
        req.rtm.rtm_family = family;

        return netlink_request(&zns->netlink_cmd, &req);
}

/* Routing table read function using netlink interface.  Only called
   bootstrap time. */
int netlink_route_read(struct zebra_ns *zns)
{
        int ret;
        struct zebra_dplane_info dp_info;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        /* Get IPv4 routing table. */
        ret = netlink_request_route(zns, AF_INET, RTM_GETROUTE);
        if (ret < 0)
                return ret;
        ret = netlink_parse_info(netlink_route_change_read_unicast,
                                 &zns->netlink_cmd, &dp_info, 0, 1);
        if (ret < 0)
                return ret;

        /* Get IPv6 routing table. */
        ret = netlink_request_route(zns, AF_INET6, RTM_GETROUTE);
        if (ret < 0)
                return ret;
        ret = netlink_parse_info(netlink_route_change_read_unicast,
                                 &zns->netlink_cmd, &dp_info, 0, 1);
        if (ret < 0)
                return ret;

        return 0;
}

/*
 * The function returns true if the gateway info could be added
 * to the message, otherwise false is returned.
 */
static bool _netlink_route_add_gateway_info(uint8_t route_family,
                                            uint8_t gw_family,
                                            struct nlmsghdr *nlmsg,
                                            size_t req_size, int bytelen,
                                            const struct nexthop *nexthop)
{
        if (route_family == AF_MPLS) {
                struct gw_family_t gw_fam;

                gw_fam.family = gw_family;
                if (gw_family == AF_INET)
                        memcpy(&gw_fam.gate.ipv4, &nexthop->gate.ipv4, bytelen);
                else
                        memcpy(&gw_fam.gate.ipv6, &nexthop->gate.ipv6, bytelen);
                if (!nl_attr_put(nlmsg, req_size, RTA_VIA, &gw_fam.family,
                                 bytelen + 2))
                        return false;
        } else {
                if (!(nexthop->rparent
                      && IS_MAPPED_IPV6(&nexthop->rparent->gate.ipv6))) {
                        if (gw_family == AF_INET) {
                                if (!nl_attr_put(nlmsg, req_size, RTA_GATEWAY,
                                                 &nexthop->gate.ipv4, bytelen))
                                        return false;
                        } else {
                                if (!nl_attr_put(nlmsg, req_size, RTA_GATEWAY,
                                                 &nexthop->gate.ipv6, bytelen))
                                        return false;
                        }
                }
        }

        return true;
}

static int build_label_stack(struct mpls_label_stack *nh_label,
                             mpls_lse_t *out_lse, char *label_buf,
                             size_t label_buf_size)
{
        char label_buf1[20];
        int num_labels = 0;

        for (int i = 0; nh_label && i < nh_label->num_labels; i++) {
                if (nh_label->label[i] == MPLS_LABEL_IMPLICIT_NULL)
                        continue;

                if (IS_ZEBRA_DEBUG_KERNEL) {
                        if (!num_labels)
                                snprintf(label_buf, label_buf_size, "label %u",
                                         nh_label->label[i]);
                        else {
                                snprintf(label_buf1, sizeof(label_buf1), "/%u",
                                         nh_label->label[i]);
                                strlcat(label_buf, label_buf1, label_buf_size);
                        }
                }

                out_lse[num_labels] =
                        mpls_lse_encode(nh_label->label[i], 0, 0, 0);
                num_labels++;
        }

        return num_labels;
}

static bool _netlink_route_encode_label_info(struct mpls_label_stack *nh_label,
                                             struct nlmsghdr *nlmsg,
                                             size_t buflen, struct rtmsg *rtmsg,
                                             char *label_buf,
                                             size_t label_buf_size)
{
        mpls_lse_t out_lse[MPLS_MAX_LABELS];
        int num_labels;

        /*
         * label_buf is *only* currently used within debugging.
         * As such when we assign it we are guarding it inside
         * a debug test.  If you want to change this make sure
         * you fix this assumption
         */
        label_buf[0] = '\0';

        num_labels =
                build_label_stack(nh_label, out_lse, label_buf, label_buf_size);

        if (num_labels) {
                /* Set the BoS bit */
                out_lse[num_labels - 1] |= htonl(1 << MPLS_LS_S_SHIFT);

                if (rtmsg->rtm_family == AF_MPLS) {
                        if (!nl_attr_put(nlmsg, buflen, RTA_NEWDST, &out_lse,
                                         num_labels * sizeof(mpls_lse_t)))
                                return false;
                } else {
                        struct rtattr *nest;

                        if (!nl_attr_put16(nlmsg, buflen, RTA_ENCAP_TYPE,
                                           LWTUNNEL_ENCAP_MPLS))
                                return false;

                        nest = nl_attr_nest(nlmsg, buflen, RTA_ENCAP);
                        if (!nest)
                                return false;

                        if (!nl_attr_put(nlmsg, buflen, MPLS_IPTUNNEL_DST,
                                         &out_lse,
                                         num_labels * sizeof(mpls_lse_t)))
                                return false;
                        nl_attr_nest_end(nlmsg, nest);
                }
        }

        return true;
}

static bool _netlink_route_encode_nexthop_src(const struct nexthop *nexthop,
                                              int family,
                                              struct nlmsghdr *nlmsg,
                                              size_t buflen, int bytelen)
{
        if (family == AF_INET) {
                if (nexthop->rmap_src.ipv4.s_addr != INADDR_ANY) {
                        if (!nl_attr_put(nlmsg, buflen, RTA_PREFSRC,
                                         &nexthop->rmap_src.ipv4, bytelen))
                                return false;
                } else if (nexthop->src.ipv4.s_addr != INADDR_ANY) {
                        if (!nl_attr_put(nlmsg, buflen, RTA_PREFSRC,
                                         &nexthop->src.ipv4, bytelen))
                                return false;
                }
        } else if (family == AF_INET6) {
                if (!IN6_IS_ADDR_UNSPECIFIED(&nexthop->rmap_src.ipv6)) {
                        if (!nl_attr_put(nlmsg, buflen, RTA_PREFSRC,
                                         &nexthop->rmap_src.ipv6, bytelen))
                                return false;
                } else if (!IN6_IS_ADDR_UNSPECIFIED(&nexthop->src.ipv6)) {
                        if (!nl_attr_put(nlmsg, buflen, RTA_PREFSRC,
                                         &nexthop->src.ipv6, bytelen))
                                return false;
                }
        }

        return true;
}

/* This function takes a nexthop as argument and adds
 * the appropriate netlink attributes to an existing
 * netlink message.
 *
 * @param routedesc: Human readable description of route type
 *                   (direct/recursive, single-/multipath)
 * @param bytelen: Length of addresses in bytes.
 * @param nexthop: Nexthop information
 * @param nlmsg: nlmsghdr structure to fill in.
 * @param req_size: The size allocated for the message.
 *
 * The function returns true if the nexthop could be added
 * to the message, otherwise false is returned.
 */
static bool _netlink_route_build_singlepath(const struct prefix *p,
                                            const char *routedesc, int bytelen,
                                            const struct nexthop *nexthop,
                                            struct nlmsghdr *nlmsg,
                                            struct rtmsg *rtmsg,
                                            size_t req_size, int cmd)
{

        char label_buf[256];
        struct vrf *vrf;
        char addrstr[INET6_ADDRSTRLEN];

        assert(nexthop);

        vrf = vrf_lookup_by_id(nexthop->vrf_id);

        if (!_netlink_route_encode_label_info(nexthop->nh_label, nlmsg,
                                              req_size, rtmsg, label_buf,
                                              sizeof(label_buf)))
                return false;

        if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ONLINK))
                rtmsg->rtm_flags |= RTNH_F_ONLINK;

        if (is_route_v4_over_v6(rtmsg->rtm_family, nexthop->type)) {
                rtmsg->rtm_flags |= RTNH_F_ONLINK;
                if (!nl_attr_put(nlmsg, req_size, RTA_GATEWAY, &ipv4_ll, 4))
                        return false;
                if (!nl_attr_put32(nlmsg, req_size, RTA_OIF, nexthop->ifindex))
                        return false;

                if (cmd == RTM_NEWROUTE) {
                        if (!_netlink_route_encode_nexthop_src(
                                    nexthop, AF_INET, nlmsg, req_size, bytelen))
                                return false;
                }

                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s: 5549 (%s): %pFX nexthop via %s %s if %u vrf %s(%u)",
                                   __func__, routedesc, p, ipv4_ll_buf,
                                   label_buf, nexthop->ifindex,
                                   VRF_LOGNAME(vrf), nexthop->vrf_id);
                return true;
        }

        if (nexthop->type == NEXTHOP_TYPE_IPV4
            || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX) {
                /* Send deletes to the kernel without specifying the next-hop */
                if (cmd != RTM_DELROUTE) {
                        if (!_netlink_route_add_gateway_info(
                                    rtmsg->rtm_family, AF_INET, nlmsg, req_size,
                                    bytelen, nexthop))
                                return false;
                }

                if (cmd == RTM_NEWROUTE) {
                        if (!_netlink_route_encode_nexthop_src(
                                    nexthop, AF_INET, nlmsg, req_size, bytelen))
                                return false;
                }

                if (IS_ZEBRA_DEBUG_KERNEL) {
                        inet_ntop(AF_INET, &nexthop->gate.ipv4, addrstr,
                                  sizeof(addrstr));
                        zlog_debug("%s: (%s): %pFX nexthop via %s %s if %u vrf %s(%u)",
                                   __func__, routedesc, p, addrstr, label_buf,
                                   nexthop->ifindex, VRF_LOGNAME(vrf),
                                   nexthop->vrf_id);
                }
        }

        if (nexthop->type == NEXTHOP_TYPE_IPV6
            || nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX) {
                if (!_netlink_route_add_gateway_info(rtmsg->rtm_family,
                                                     AF_INET6, nlmsg, req_size,
                                                     bytelen, nexthop))
                        return false;

                if (cmd == RTM_NEWROUTE) {
                        if (!_netlink_route_encode_nexthop_src(
                                    nexthop, AF_INET6, nlmsg, req_size,
                                    bytelen))
                                return false;
                }

                if (IS_ZEBRA_DEBUG_KERNEL) {
                        inet_ntop(AF_INET6, &nexthop->gate.ipv6, addrstr,
                                  sizeof(addrstr));
                        zlog_debug("%s: (%s): %pFX nexthop via %s %s if %u vrf %s(%u)",
                                   __func__, routedesc, p, addrstr, label_buf,
                                   nexthop->ifindex, VRF_LOGNAME(vrf),
                                   nexthop->vrf_id);
                }
        }

        /*
         * We have the ifindex so we should always send it
         * This is especially useful if we are doing route
         * leaking.
         */
        if (nexthop->type != NEXTHOP_TYPE_BLACKHOLE) {
                if (!nl_attr_put32(nlmsg, req_size, RTA_OIF, nexthop->ifindex))
                        return false;
        }

        if (nexthop->type == NEXTHOP_TYPE_IFINDEX) {
                if (cmd == RTM_NEWROUTE) {
                        if (!_netlink_route_encode_nexthop_src(
                                    nexthop, AF_INET, nlmsg, req_size, bytelen))
                                return false;
                }

                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s: (%s): %pFX nexthop via if %u vrf %s(%u)",
                                   __func__, routedesc, p, nexthop->ifindex,
                                   VRF_LOGNAME(vrf), nexthop->vrf_id);
        }

        return true;
}

/* This function takes a nexthop as argument and
 * appends to the given netlink msg. If the nexthop
 * defines a preferred source, the src parameter
 * will be modified to point to that src, otherwise
 * it will be kept unmodified.
 *
 * @param routedesc: Human readable description of route type
 *                   (direct/recursive, single-/multipath)
 * @param bytelen: Length of addresses in bytes.
 * @param nexthop: Nexthop information
 * @param nlmsg: nlmsghdr structure to fill in.
 * @param req_size: The size allocated for the message.
 * @param src: pointer pointing to a location where
 *             the prefsrc should be stored.
 *
 * The function returns true if the nexthop could be added
 * to the message, otherwise false is returned.
 */
static bool _netlink_route_build_multipath(const struct prefix *p,
                                           const char *routedesc, int bytelen,
                                           const struct nexthop *nexthop,
                                           struct nlmsghdr *nlmsg,
                                           size_t req_size, struct rtmsg *rtmsg,
                                           const union g_addr **src)
{
        char label_buf[256];
        struct vrf *vrf;
        struct rtnexthop *rtnh;

        rtnh = nl_attr_rtnh(nlmsg, req_size);
        if (rtnh == NULL)
                return false;

        assert(nexthop);

        vrf = vrf_lookup_by_id(nexthop->vrf_id);

        if (!_netlink_route_encode_label_info(nexthop->nh_label, nlmsg,
                                              req_size, rtmsg, label_buf,
                                              sizeof(label_buf)))
                return false;

        if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ONLINK))
                rtnh->rtnh_flags |= RTNH_F_ONLINK;

        if (is_route_v4_over_v6(rtmsg->rtm_family, nexthop->type)) {
                rtnh->rtnh_flags |= RTNH_F_ONLINK;
                if (!nl_attr_put(nlmsg, req_size, RTA_GATEWAY, &ipv4_ll, 4))
                        return false;
                rtnh->rtnh_ifindex = nexthop->ifindex;
                if (nexthop->weight)
                        rtnh->rtnh_hops = nexthop->weight - 1;

                if (nexthop->rmap_src.ipv4.s_addr != INADDR_ANY)
                        *src = &nexthop->rmap_src;
                else if (nexthop->src.ipv4.s_addr != INADDR_ANY)
                        *src = &nexthop->src;

                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug(
                                "%s: 5549 (%s): %pFX nexthop via %s %s if %u vrf %s(%u)",
                                __func__, routedesc, p, ipv4_ll_buf, label_buf,
                                nexthop->ifindex, VRF_LOGNAME(vrf),
                                nexthop->vrf_id);
                nl_attr_rtnh_end(nlmsg, rtnh);
                return true;
        }

        if (nexthop->type == NEXTHOP_TYPE_IPV4
            || nexthop->type == NEXTHOP_TYPE_IPV4_IFINDEX) {
                if (!_netlink_route_add_gateway_info(rtmsg->rtm_family, AF_INET,
                                                     nlmsg, req_size, bytelen,
                                                     nexthop))
                        return false;

                if (nexthop->rmap_src.ipv4.s_addr != INADDR_ANY)
                        *src = &nexthop->rmap_src;
                else if (nexthop->src.ipv4.s_addr != INADDR_ANY)
                        *src = &nexthop->src;

                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s: (%s): %pFX nexthop via %pI4 %s if %u vrf %s(%u)",
                                   __func__, routedesc, p, &nexthop->gate.ipv4,
                                   label_buf, nexthop->ifindex,
                                   VRF_LOGNAME(vrf), nexthop->vrf_id);
        }
        if (nexthop->type == NEXTHOP_TYPE_IPV6
            || nexthop->type == NEXTHOP_TYPE_IPV6_IFINDEX) {
                if (!_netlink_route_add_gateway_info(rtmsg->rtm_family,
                                                     AF_INET6, nlmsg, req_size,
                                                     bytelen, nexthop))
                        return false;

                if (!IN6_IS_ADDR_UNSPECIFIED(&nexthop->rmap_src.ipv6))
                        *src = &nexthop->rmap_src;
                else if (!IN6_IS_ADDR_UNSPECIFIED(&nexthop->src.ipv6))
                        *src = &nexthop->src;

                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s: (%s): %pFX nexthop via %pI6 %s if %u vrf %s(%u)",
                                   __func__, routedesc, p, &nexthop->gate.ipv6,
                                   label_buf, nexthop->ifindex,
                                   VRF_LOGNAME(vrf), nexthop->vrf_id);
        }

        /*
         * We have figured out the ifindex so we should always send it
         * This is especially useful if we are doing route
         * leaking.
         */
        if (nexthop->type != NEXTHOP_TYPE_BLACKHOLE)
                rtnh->rtnh_ifindex = nexthop->ifindex;

        /* ifindex */
        if (nexthop->type == NEXTHOP_TYPE_IFINDEX) {
                if (nexthop->rmap_src.ipv4.s_addr != INADDR_ANY)
                        *src = &nexthop->rmap_src;
                else if (nexthop->src.ipv4.s_addr != INADDR_ANY)
                        *src = &nexthop->src;

                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s: (%s): %pFX nexthop via if %u vrf %s(%u)",
                                   __func__, routedesc, p, nexthop->ifindex,
                                   VRF_LOGNAME(vrf), nexthop->vrf_id);
        }

        if (nexthop->weight)
                rtnh->rtnh_hops = nexthop->weight - 1;

        nl_attr_rtnh_end(nlmsg, rtnh);
        return true;
}

static inline bool _netlink_mpls_build_singlepath(const struct prefix *p,
                                                  const char *routedesc,
                                                  const zebra_nhlfe_t *nhlfe,
                                                  struct nlmsghdr *nlmsg,
                                                  struct rtmsg *rtmsg,
                                                  size_t req_size, int cmd)
{
        int bytelen;
        uint8_t family;

        family = NHLFE_FAMILY(nhlfe);
        bytelen = (family == AF_INET ? 4 : 16);
        return _netlink_route_build_singlepath(p, routedesc, bytelen,
                                               nhlfe->nexthop, nlmsg, rtmsg,
                                               req_size, cmd);
}


static inline bool
_netlink_mpls_build_multipath(const struct prefix *p, const char *routedesc,
                              const zebra_nhlfe_t *nhlfe,
                              struct nlmsghdr *nlmsg, size_t req_size,
                              struct rtmsg *rtmsg, const union g_addr **src)
{
        int bytelen;
        uint8_t family;

        family = NHLFE_FAMILY(nhlfe);
        bytelen = (family == AF_INET ? 4 : 16);
        return _netlink_route_build_multipath(p, routedesc, bytelen,
                                              nhlfe->nexthop, nlmsg, req_size,
                                              rtmsg, src);
}

static void _netlink_mpls_debug(int cmd, uint32_t label, const char *routedesc)
{
        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("netlink_mpls_multipath_msg_encode() (%s): %s %u/20",
                           routedesc, nl_msg_type_to_str(cmd), label);
}

static int netlink_neigh_update(int cmd, int ifindex, uint32_t addr, char *lla,
                                int llalen, ns_id_t ns_id)
{
        uint8_t protocol = RTPROT_ZEBRA;
        struct {
                struct nlmsghdr n;
                struct ndmsg ndm;
                char buf[256];
        } req;

        struct zebra_ns *zns = zebra_ns_lookup(ns_id);

        memset(&req, 0, sizeof(req));

        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
        req.n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST;
        req.n.nlmsg_type = cmd; // RTM_NEWNEIGH or RTM_DELNEIGH
        req.n.nlmsg_pid = zns->netlink_cmd.snl.nl_pid;

        req.ndm.ndm_family = AF_INET;
        req.ndm.ndm_state = NUD_PERMANENT;
        req.ndm.ndm_ifindex = ifindex;
        req.ndm.ndm_type = RTN_UNICAST;

        nl_attr_put(&req.n, sizeof(req), NDA_PROTOCOL, &protocol,
                    sizeof(protocol));
        nl_attr_put32(&req.n, sizeof(req), NDA_DST, addr);
        nl_attr_put(&req.n, sizeof(req), NDA_LLADDR, lla, llalen);

        return netlink_talk(netlink_talk_filter, &req.n, &zns->netlink_cmd, zns,
                            0);
}

static bool nexthop_set_src(const struct nexthop *nexthop, int family,
                            union g_addr *src)
{
        if (family == AF_INET) {
                if (nexthop->rmap_src.ipv4.s_addr != INADDR_ANY) {
                        src->ipv4 = nexthop->rmap_src.ipv4;
                        return true;
                } else if (nexthop->src.ipv4.s_addr != INADDR_ANY) {
                        src->ipv4 = nexthop->src.ipv4;
                        return true;
                }
        } else if (family == AF_INET6) {
                if (!IN6_IS_ADDR_UNSPECIFIED(&nexthop->rmap_src.ipv6)) {
                        src->ipv6 = nexthop->rmap_src.ipv6;
                        return true;
                } else if (!IN6_IS_ADDR_UNSPECIFIED(&nexthop->src.ipv6)) {
                        src->ipv6 = nexthop->src.ipv6;
                        return true;
                }
        }

        return false;
}

/*
 * The function returns true if the attribute could be added
 * to the message, otherwise false is returned.
 */
static int netlink_route_nexthop_encap(struct nlmsghdr *n, size_t nlen,
                                       struct nexthop *nh)
{
        struct rtattr *nest;

        switch (nh->nh_encap_type) {
        case NET_VXLAN:
                if (!nl_attr_put16(n, nlen, RTA_ENCAP_TYPE, nh->nh_encap_type))
                        return false;

                nest = nl_attr_nest(n, nlen, RTA_ENCAP);
                if (!nest)
                        return false;

                if (!nl_attr_put32(n, nlen, 0 /* VXLAN_VNI */,
                                   nh->nh_encap.vni))
                        return false;
                nl_attr_nest_end(n, nest);
                break;
        }

        return true;
}

/*
 * Routing table change via netlink interface, using a dataplane context object
 *
 * Returns -1 on failure, 0 when the msg doesn't fit entirely in the buffer
 * otherwise the number of bytes written to buf.
 */
ssize_t netlink_route_multipath_msg_encode(int cmd,
                                           struct zebra_dplane_ctx *ctx,
                                           uint8_t *data, size_t datalen,
                                           bool fpm, bool force_nhg)
{
        int bytelen;
        struct nexthop *nexthop = NULL;
        unsigned int nexthop_num;
        const char *routedesc;
        bool setsrc = false;
        union g_addr src;
        const struct prefix *p, *src_p;
        uint32_t table_id;

        struct {
                struct nlmsghdr n;
                struct rtmsg r;
                char buf[];
        } *req = (void *)data;

        p = dplane_ctx_get_dest(ctx);
        src_p = dplane_ctx_get_src(ctx);

        if (datalen < sizeof(*req))
                return 0;

        memset(req, 0, sizeof(*req));

        bytelen = (p->family == AF_INET ? 4 : 16);

        req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
        req->n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST;

        if ((cmd == RTM_NEWROUTE) &&
            ((p->family == AF_INET) || v6_rr_semantics))
                req->n.nlmsg_flags |= NLM_F_REPLACE;

        req->n.nlmsg_type = cmd;

        req->n.nlmsg_pid = dplane_ctx_get_ns(ctx)->nls.snl.nl_pid;

        req->r.rtm_family = p->family;
        req->r.rtm_dst_len = p->prefixlen;
        req->r.rtm_src_len = src_p ? src_p->prefixlen : 0;
        req->r.rtm_scope = RT_SCOPE_UNIVERSE;

        if (cmd == RTM_DELROUTE)
                req->r.rtm_protocol = zebra2proto(dplane_ctx_get_old_type(ctx));
        else
                req->r.rtm_protocol = zebra2proto(dplane_ctx_get_type(ctx));

        /*
         * blackhole routes are not RTN_UNICAST, they are
         * RTN_ BLACKHOLE|UNREACHABLE|PROHIBIT
         * so setting this value as a RTN_UNICAST would
         * cause the route lookup of just the prefix
         * to fail.  So no need to specify this for
         * the RTM_DELROUTE case
         */
        if (cmd != RTM_DELROUTE)
                req->r.rtm_type = RTN_UNICAST;

        if (!nl_attr_put(&req->n, datalen, RTA_DST, &p->u.prefix, bytelen))
                return 0;
        if (src_p) {
                if (!nl_attr_put(&req->n, datalen, RTA_SRC, &src_p->u.prefix,
                                 bytelen))
                        return 0;
        }

        /* Metric. */
        /* Hardcode the metric for all routes coming from zebra. Metric isn't
         * used
         * either by the kernel or by zebra. Its purely for calculating best
         * path(s)
         * by the routing protocol and for communicating with protocol peers.
         */
        if (!nl_attr_put32(&req->n, datalen, RTA_PRIORITY,
                           NL_DEFAULT_ROUTE_METRIC))
                return 0;

#if defined(SUPPORT_REALMS)
        {
                route_tag_t tag;

                if (cmd == RTM_DELROUTE)
                        tag = dplane_ctx_get_old_tag(ctx);
                else
                        tag = dplane_ctx_get_tag(ctx);

                if (tag > 0 && tag <= 255) {
                        if (!nl_attr_put32(&req->n, datalen, RTA_FLOW, tag))
                                return 0;
                }
        }
#endif
        /* Table corresponding to this route. */
        table_id = dplane_ctx_get_table(ctx);
        if (table_id < 256)
                req->r.rtm_table = table_id;
        else {
                req->r.rtm_table = RT_TABLE_UNSPEC;
                if (!nl_attr_put32(&req->n, datalen, RTA_TABLE, table_id))
                        return 0;
        }

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug(
                        "%s: %s %pFX vrf %u(%u)", __func__,
                        nl_msg_type_to_str(cmd), p, dplane_ctx_get_vrf(ctx),
                        table_id);

        /*
         * If we are not updating the route and we have received
         * a route delete, then all we need to fill in is the
         * prefix information to tell the kernel to schwack
         * it.
         */
        if (cmd == RTM_DELROUTE)
                return NLMSG_ALIGN(req->n.nlmsg_len);

        if (dplane_ctx_get_mtu(ctx) || dplane_ctx_get_nh_mtu(ctx)) {
                struct rtattr *nest;
                uint32_t mtu = dplane_ctx_get_mtu(ctx);
                uint32_t nexthop_mtu = dplane_ctx_get_nh_mtu(ctx);

                if (!mtu || (nexthop_mtu && nexthop_mtu < mtu))
                        mtu = nexthop_mtu;

                nest = nl_attr_nest(&req->n, datalen, RTA_METRICS);
                if (nest == NULL)
                        return 0;

                if (!nl_attr_put(&req->n, datalen, RTAX_MTU, &mtu, sizeof(mtu)))
                        return 0;
                nl_attr_nest_end(&req->n, nest);
        }

        /*
         * Always install blackhole routes without using nexthops, because of
         * the following kernel problems:
         * 1. Kernel nexthops don't suport unreachable/prohibit route types.
         * 2. Blackhole kernel nexthops are deleted when loopback is down.
         */
        nexthop = dplane_ctx_get_ng(ctx)->nexthop;
        if (nexthop) {
                if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
                        nexthop = nexthop->resolved;

                if (nexthop->type == NEXTHOP_TYPE_BLACKHOLE) {
                        switch (nexthop->bh_type) {
                        case BLACKHOLE_ADMINPROHIB:
                                req->r.rtm_type = RTN_PROHIBIT;
                                break;
                        case BLACKHOLE_REJECT:
                                req->r.rtm_type = RTN_UNREACHABLE;
                                break;
                        default:
                                req->r.rtm_type = RTN_BLACKHOLE;
                                break;
                        }
                        return NLMSG_ALIGN(req->n.nlmsg_len);
                }
        }

        if ((!fpm && kernel_nexthops_supported()
             && (!proto_nexthops_only()
                 || is_proto_nhg(dplane_ctx_get_nhe_id(ctx), 0)))
            || (fpm && force_nhg)) {
                /* Kernel supports nexthop objects */
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s: %pFX nhg_id is %u", __func__, p,
                                   dplane_ctx_get_nhe_id(ctx));

                if (!nl_attr_put32(&req->n, datalen, RTA_NH_ID,
                                   dplane_ctx_get_nhe_id(ctx)))
                        return 0;

                /* Have to determine src still */
                for (ALL_NEXTHOPS_PTR(dplane_ctx_get_ng(ctx), nexthop)) {
                        if (setsrc)
                                break;

                        setsrc = nexthop_set_src(nexthop, p->family, &src);
                }

                if (setsrc) {
                        if (p->family == AF_INET) {
                                if (!nl_attr_put(&req->n, datalen, RTA_PREFSRC,
                                                 &src.ipv4, bytelen))
                                        return 0;
                        } else if (p->family == AF_INET6) {
                                if (!nl_attr_put(&req->n, datalen, RTA_PREFSRC,
                                                 &src.ipv6, bytelen))
                                        return 0;
                        }
                }

                return NLMSG_ALIGN(req->n.nlmsg_len);
        }

        /* Count overall nexthops so we can decide whether to use singlepath
         * or multipath case.
         */
        nexthop_num = 0;
        for (ALL_NEXTHOPS_PTR(dplane_ctx_get_ng(ctx), nexthop)) {
                if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
                        continue;
                if (!NEXTHOP_IS_ACTIVE(nexthop->flags))
                        continue;

                nexthop_num++;
        }

        /* Singlepath case. */
        if (nexthop_num == 1) {
                nexthop_num = 0;
                for (ALL_NEXTHOPS_PTR(dplane_ctx_get_ng(ctx), nexthop)) {
                        if (CHECK_FLAG(nexthop->flags,
                                       NEXTHOP_FLAG_RECURSIVE)) {

                                if (setsrc)
                                        continue;

                                setsrc = nexthop_set_src(nexthop, p->family,
                                                         &src);
                                continue;
                        }

                        if (NEXTHOP_IS_ACTIVE(nexthop->flags)) {
                                routedesc = nexthop->rparent
                                                    ? "recursive, single-path"
                                                    : "single-path";

                                if (!_netlink_route_build_singlepath(
                                            p, routedesc, bytelen, nexthop,
                                            &req->n, &req->r, datalen, cmd))
                                        return 0;
                                nexthop_num++;
                                break;
                        }

                        /*
                         * Add encapsulation information when installing via
                         * FPM.
                         */
                        if (fpm) {
                                if (!netlink_route_nexthop_encap(
                                            &req->n, datalen, nexthop))
                                        return 0;
                        }
                }

                if (setsrc) {
                        if (p->family == AF_INET) {
                                if (!nl_attr_put(&req->n, datalen, RTA_PREFSRC,
                                                 &src.ipv4, bytelen))
                                        return 0;
                        } else if (p->family == AF_INET6) {
                                if (!nl_attr_put(&req->n, datalen, RTA_PREFSRC,
                                                 &src.ipv6, bytelen))
                                        return 0;
                        }
                }
        } else {    /* Multipath case */
                struct rtattr *nest;
                const union g_addr *src1 = NULL;

                nest = nl_attr_nest(&req->n, datalen, RTA_MULTIPATH);
                if (nest == NULL)
                        return 0;

                nexthop_num = 0;
                for (ALL_NEXTHOPS_PTR(dplane_ctx_get_ng(ctx), nexthop)) {
                        if (CHECK_FLAG(nexthop->flags,
                                       NEXTHOP_FLAG_RECURSIVE)) {
                                /* This only works for IPv4 now */
                                if (setsrc)
                                        continue;

                                setsrc = nexthop_set_src(nexthop, p->family,
                                                         &src);
                                continue;
                        }

                        if (NEXTHOP_IS_ACTIVE(nexthop->flags)) {
                                routedesc = nexthop->rparent
                                                    ? "recursive, multipath"
                                                    : "multipath";
                                nexthop_num++;

                                if (!_netlink_route_build_multipath(
                                            p, routedesc, bytelen, nexthop,
                                            &req->n, datalen, &req->r, &src1))
                                        return 0;

                                if (!setsrc && src1) {
                                        if (p->family == AF_INET)
                                                src.ipv4 = src1->ipv4;
                                        else if (p->family == AF_INET6)
                                                src.ipv6 = src1->ipv6;

                                        setsrc = 1;
                                }
                        }
                }

                nl_attr_nest_end(&req->n, nest);

                /*
                 * Add encapsulation information when installing via
                 * FPM.
                 */
                if (fpm) {
                        for (ALL_NEXTHOPS_PTR(dplane_ctx_get_ng(ctx),
                                              nexthop)) {
                                if (CHECK_FLAG(nexthop->flags,
                                               NEXTHOP_FLAG_RECURSIVE))
                                        continue;
                                if (!netlink_route_nexthop_encap(
                                            &req->n, datalen, nexthop))
                                        return 0;
                        }
                }


                if (setsrc) {
                        if (p->family == AF_INET) {
                                if (!nl_attr_put(&req->n, datalen, RTA_PREFSRC,
                                                 &src.ipv4, bytelen))
                                        return 0;
                        } else if (p->family == AF_INET6) {
                                if (!nl_attr_put(&req->n, datalen, RTA_PREFSRC,
                                                 &src.ipv6, bytelen))
                                        return 0;
                        }
                        if (IS_ZEBRA_DEBUG_KERNEL)
                                zlog_debug("Setting source");
                }
        }

        /* If there is no useful nexthop then return. */
        if (nexthop_num == 0) {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s: No useful nexthop.", __func__);
        }

        return NLMSG_ALIGN(req->n.nlmsg_len);
}

int kernel_get_ipmr_sg_stats(struct zebra_vrf *zvrf, void *in)
{
        uint32_t actual_table;
        int suc = 0;
        struct mcast_route_data *mr = (struct mcast_route_data *)in;
        struct {
                struct nlmsghdr n;
                struct ndmsg ndm;
                char buf[256];
        } req;

        mroute = mr;
        struct zebra_ns *zns;

        zns = zvrf->zns;
        memset(&req, 0, sizeof(req));

        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
        req.n.nlmsg_flags = NLM_F_REQUEST;
        req.n.nlmsg_pid = zns->netlink_cmd.snl.nl_pid;

        req.ndm.ndm_family = RTNL_FAMILY_IPMR;
        req.n.nlmsg_type = RTM_GETROUTE;

        nl_attr_put32(&req.n, sizeof(req), RTA_IIF, mroute->ifindex);
        nl_attr_put32(&req.n, sizeof(req), RTA_OIF, mroute->ifindex);
        nl_attr_put32(&req.n, sizeof(req), RTA_SRC, mroute->sg.src.s_addr);
        nl_attr_put32(&req.n, sizeof(req), RTA_DST, mroute->sg.grp.s_addr);
        /*
         * What?
         *
         * So during the namespace cleanup we started storing
         * the zvrf table_id for the default table as RT_TABLE_MAIN
         * which is what the normal routing table for ip routing is.
         * This change caused this to break our lookups of sg data
         * because prior to this change the zvrf->table_id was 0
         * and when the pim multicast kernel code saw a 0,
         * it was auto-translated to RT_TABLE_DEFAULT.  But since
         * we are now passing in RT_TABLE_MAIN there is no auto-translation
         * and the kernel goes screw you and the delicious cookies you
         * are trying to give me.  So now we have this little hack.
         */
        actual_table = (zvrf->table_id == RT_TABLE_MAIN) ? RT_TABLE_DEFAULT :
                zvrf->table_id;
        nl_attr_put32(&req.n, sizeof(req), RTA_TABLE, actual_table);

        suc = netlink_talk(netlink_route_change_read_multicast, &req.n,
                           &zns->netlink_cmd, zns, 0);

        mroute = NULL;
        return suc;
}

/* Char length to debug ID with */
#define ID_LENGTH 10

static bool _netlink_nexthop_build_group(struct nlmsghdr *n, size_t req_size,
                                         uint32_t id,
                                         const struct nh_grp *z_grp,
                                         const uint8_t count)
{
        struct nexthop_grp grp[count];
        /* Need space for max group size, "/", and null term */
        char buf[(MULTIPATH_NUM * (ID_LENGTH + 1)) + 1];
        char buf1[ID_LENGTH + 2];

        buf[0] = '\0';

        memset(grp, 0, sizeof(grp));

        if (count) {
                for (int i = 0; i < count; i++) {
                        grp[i].id = z_grp[i].id;
                        grp[i].weight = z_grp[i].weight - 1;

                        if (IS_ZEBRA_DEBUG_KERNEL) {
                                if (i == 0)
                                        snprintf(buf, sizeof(buf1), "group %u",
                                                 grp[i].id);
                                else {
                                        snprintf(buf1, sizeof(buf1), "/%u",
                                                 grp[i].id);
                                        strlcat(buf, buf1, sizeof(buf));
                                }
                        }
                }
                if (!nl_attr_put(n, req_size, NHA_GROUP, grp,
                                 count * sizeof(*grp)))
                        return false;
        }

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("%s: ID (%u): %s", __func__, id, buf);

        return true;
}

/**
 * Next hop packet encoding helper function.
 *
 * \param[in] cmd netlink command.
 * \param[in] ctx dataplane context (information snapshot).
 * \param[out] buf buffer to hold the packet.
 * \param[in] buflen amount of buffer bytes.
 *
 * \returns -1 on failure, 0 when the msg doesn't fit entirely in the buffer
 * otherwise the number of bytes written to buf.
 */
ssize_t netlink_nexthop_msg_encode(uint16_t cmd,
                                   const struct zebra_dplane_ctx *ctx,
                                   void *buf, size_t buflen)
{
        struct {
                struct nlmsghdr n;
                struct nhmsg nhm;
                char buf[];
        } *req = buf;

        mpls_lse_t out_lse[MPLS_MAX_LABELS];
        char label_buf[256];
        int num_labels = 0;
        uint32_t id = dplane_ctx_get_nhe_id(ctx);
        int type = dplane_ctx_get_nhe_type(ctx);
        struct rtattr *nest;
        uint16_t encap;

        if (!id) {
                flog_err(
                        EC_ZEBRA_NHG_FIB_UPDATE,
                        "Failed trying to update a nexthop group in the kernel that does not have an ID");
                return -1;
        }

        /*
         * Nothing to do if the kernel doesn't support nexthop objects or
         * we dont want to install this type of NHG
         */
        if (!kernel_nexthops_supported()) {
                if (IS_ZEBRA_DEBUG_KERNEL || IS_ZEBRA_DEBUG_NHG)
                        zlog_debug(
                                "%s: nhg_id %u (%s): kernel nexthops not supported, ignoring",
                                __func__, id, zebra_route_string(type));
                return 0;
        }

        if (proto_nexthops_only() && !is_proto_nhg(id, type)) {
                if (IS_ZEBRA_DEBUG_KERNEL || IS_ZEBRA_DEBUG_NHG)
                        zlog_debug(
                                "%s: nhg_id %u (%s): proto-based nexthops only, ignoring",
                                __func__, id, zebra_route_string(type));
                return 0;
        }

        label_buf[0] = '\0';

        if (buflen < sizeof(*req))
                return 0;

        memset(req, 0, sizeof(*req));

        req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg));
        req->n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST;

        if (cmd == RTM_NEWNEXTHOP)
                req->n.nlmsg_flags |= NLM_F_REPLACE;

        req->n.nlmsg_type = cmd;
        req->n.nlmsg_pid = dplane_ctx_get_ns(ctx)->nls.snl.nl_pid;

        req->nhm.nh_family = AF_UNSPEC;
        /* TODO: Scope? */

        if (!nl_attr_put32(&req->n, buflen, NHA_ID, id))
                return 0;

        if (cmd == RTM_NEWNEXTHOP) {
                /*
                 * We distinguish between a "group", which is a collection
                 * of ids, and a singleton nexthop with an id. The
                 * group is installed as an id that just refers to a list of
                 * other ids.
                 */
                if (dplane_ctx_get_nhe_nh_grp_count(ctx)) {
                        if (!_netlink_nexthop_build_group(
                                    &req->n, buflen, id,
                                    dplane_ctx_get_nhe_nh_grp(ctx),
                                    dplane_ctx_get_nhe_nh_grp_count(ctx)))
                                return 0;
                } else {
                        const struct nexthop *nh =
                                dplane_ctx_get_nhe_ng(ctx)->nexthop;
                        afi_t afi = dplane_ctx_get_nhe_afi(ctx);

                        if (afi == AFI_IP)
                                req->nhm.nh_family = AF_INET;
                        else if (afi == AFI_IP6)
                                req->nhm.nh_family = AF_INET6;

                        switch (nh->type) {
                        case NEXTHOP_TYPE_IPV4:
                        case NEXTHOP_TYPE_IPV4_IFINDEX:
                                if (!nl_attr_put(&req->n, buflen, NHA_GATEWAY,
                                                 &nh->gate.ipv4,
                                                 IPV4_MAX_BYTELEN))
                                        return 0;
                                break;
                        case NEXTHOP_TYPE_IPV6:
                        case NEXTHOP_TYPE_IPV6_IFINDEX:
                                if (!nl_attr_put(&req->n, buflen, NHA_GATEWAY,
                                                 &nh->gate.ipv6,
                                                 IPV6_MAX_BYTELEN))
                                        return 0;
                                break;
                        case NEXTHOP_TYPE_BLACKHOLE:
                                if (!nl_attr_put(&req->n, buflen, NHA_BLACKHOLE,
                                                 NULL, 0))
                                        return 0;
                                /* Blackhole shouldn't have anymore attributes
                                 */
                                goto nexthop_done;
                        case NEXTHOP_TYPE_IFINDEX:
                                /* Don't need anymore info for this */
                                break;
                        }

                        if (!nh->ifindex) {
                                flog_err(
                                        EC_ZEBRA_NHG_FIB_UPDATE,
                                        "Context received for kernel nexthop update without an interface");
                                return -1;
                        }

                        if (!nl_attr_put32(&req->n, buflen, NHA_OIF,
                                           nh->ifindex))
                                return 0;

                        if (CHECK_FLAG(nh->flags, NEXTHOP_FLAG_ONLINK))
                                req->nhm.nh_flags |= RTNH_F_ONLINK;

                        num_labels =
                                build_label_stack(nh->nh_label, out_lse,
                                                  label_buf, sizeof(label_buf));

                        if (num_labels) {
                                /* Set the BoS bit */
                                out_lse[num_labels - 1] |=
                                        htonl(1 << MPLS_LS_S_SHIFT);

                                /*
                                 * TODO: MPLS unsupported for now in kernel.
                                 */
                                if (req->nhm.nh_family == AF_MPLS)
                                        goto nexthop_done;

                                encap = LWTUNNEL_ENCAP_MPLS;
                                if (!nl_attr_put16(&req->n, buflen,
                                                   NHA_ENCAP_TYPE, encap))
                                        return 0;
                                nest = nl_attr_nest(&req->n, buflen, NHA_ENCAP);
                                if (!nest)
                                        return 0;
                                if (!nl_attr_put(
                                            &req->n, buflen, MPLS_IPTUNNEL_DST,
                                            &out_lse,
                                            num_labels * sizeof(mpls_lse_t)))
                                        return 0;

                                nl_attr_nest_end(&req->n, nest);
                        }

nexthop_done:

                        if (IS_ZEBRA_DEBUG_KERNEL)
                                zlog_debug("%s: ID (%u): %pNHv(%d) vrf %s(%u) %s ",
                                           __func__, id, nh, nh->ifindex,
                                           vrf_id_to_name(nh->vrf_id),
                                           nh->vrf_id, label_buf);
                }

                req->nhm.nh_protocol = zebra2proto(type);

        } else if (cmd != RTM_DELNEXTHOP) {
                flog_err(
                        EC_ZEBRA_NHG_FIB_UPDATE,
                        "Nexthop group kernel update command (%d) does not exist",
                        cmd);
                return -1;
        }

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("%s: %s, id=%u", __func__, nl_msg_type_to_str(cmd),
                           id);

        return NLMSG_ALIGN(req->n.nlmsg_len);
}

static ssize_t netlink_nexthop_msg_encoder(struct zebra_dplane_ctx *ctx,
                                           void *buf, size_t buflen)
{
        enum dplane_op_e op;
        int cmd = 0;

        op = dplane_ctx_get_op(ctx);
        if (op == DPLANE_OP_NH_INSTALL || op == DPLANE_OP_NH_UPDATE)
                cmd = RTM_NEWNEXTHOP;
        else if (op == DPLANE_OP_NH_DELETE)
                cmd = RTM_DELNEXTHOP;
        else {
                flog_err(EC_ZEBRA_NHG_FIB_UPDATE,
                         "Context received for kernel nexthop update with incorrect OP code (%u)",
                         op);
                return -1;
        }

        return netlink_nexthop_msg_encode(cmd, ctx, buf, buflen);
}

enum netlink_msg_status
netlink_put_nexthop_update_msg(struct nl_batch *bth,
                               struct zebra_dplane_ctx *ctx)
{
        /* Nothing to do if the kernel doesn't support nexthop objects */
        if (!kernel_nexthops_supported())
                return FRR_NETLINK_SUCCESS;

        return netlink_batch_add_msg(bth, ctx, netlink_nexthop_msg_encoder,
                                     false);
}

static ssize_t netlink_newroute_msg_encoder(struct zebra_dplane_ctx *ctx,
                                            void *buf, size_t buflen)
{
        return netlink_route_multipath_msg_encode(RTM_NEWROUTE, ctx, buf,
                                                  buflen, false, false);
}

static ssize_t netlink_delroute_msg_encoder(struct zebra_dplane_ctx *ctx,
                                            void *buf, size_t buflen)
{
        return netlink_route_multipath_msg_encode(RTM_DELROUTE, ctx, buf,
                                                  buflen, false, false);
}

enum netlink_msg_status
netlink_put_route_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx)
{
        int cmd;
        const struct prefix *p = dplane_ctx_get_dest(ctx);

        if (dplane_ctx_get_op(ctx) == DPLANE_OP_ROUTE_DELETE) {
                cmd = RTM_DELROUTE;
        } else if (dplane_ctx_get_op(ctx) == DPLANE_OP_ROUTE_INSTALL) {
                cmd = RTM_NEWROUTE;
        } else if (dplane_ctx_get_op(ctx) == DPLANE_OP_ROUTE_UPDATE) {

                if (p->family == AF_INET || v6_rr_semantics) {
                        /* Single 'replace' operation */

                        /*
                         * With route replace semantics in place
                         * for v4 routes and the new route is a system
                         * route we do not install anything.
                         * The problem here is that the new system
                         * route should cause us to withdraw from
                         * the kernel the old non-system route
                         */
                        if (RSYSTEM_ROUTE(dplane_ctx_get_type(ctx))
                            && !RSYSTEM_ROUTE(dplane_ctx_get_old_type(ctx)))
                                netlink_batch_add_msg(
                                        bth, ctx, netlink_delroute_msg_encoder,
                                        true);
                } else {
                        /*
                         * So v6 route replace semantics are not in
                         * the kernel at this point as I understand it.
                         * so let's do a delete then an add.
                         * In the future once v6 route replace semantics
                         * are in we can figure out what to do here to
                         * allow working with old and new kernels.
                         *
                         * I'm also intentionally ignoring the failure case
                         * of the route delete.  If that happens yeah we're
                         * screwed.
                         */
                        if (!RSYSTEM_ROUTE(dplane_ctx_get_old_type(ctx)))
                                netlink_batch_add_msg(
                                        bth, ctx, netlink_delroute_msg_encoder,
                                        true);
                }

                cmd = RTM_NEWROUTE;
        } else
                return FRR_NETLINK_ERROR;

        if (RSYSTEM_ROUTE(dplane_ctx_get_type(ctx)))
                return FRR_NETLINK_SUCCESS;

        return netlink_batch_add_msg(bth, ctx,
                                     cmd == RTM_NEWROUTE
                                             ? netlink_newroute_msg_encoder
                                             : netlink_delroute_msg_encoder,
                                     false);
}

/**
 * netlink_nexthop_process_nh() - Parse the gatway/if info from a new nexthop
 *
 * @tb:         Netlink RTA data
 * @family:     Address family in the nhmsg
 * @ifp:        Interface connected - this should be NULL, we fill it in
 * @ns_id:      Namspace id
 *
 * Return:      New nexthop
 */
static struct nexthop netlink_nexthop_process_nh(struct rtattr **tb,
                                                 unsigned char family,
                                                 struct interface **ifp,
                                                 ns_id_t ns_id)
{
        struct nexthop nh = {};
        void *gate = NULL;
        enum nexthop_types_t type = 0;
        int if_index = 0;
        size_t sz = 0;
        struct interface *ifp_lookup;

        if_index = *(int *)RTA_DATA(tb[NHA_OIF]);


        if (tb[NHA_GATEWAY]) {
                switch (family) {
                case AF_INET:
                        type = NEXTHOP_TYPE_IPV4_IFINDEX;
                        sz = 4;
                        break;
                case AF_INET6:
                        type = NEXTHOP_TYPE_IPV6_IFINDEX;
                        sz = 16;
                        break;
                default:
                        flog_warn(
                                EC_ZEBRA_BAD_NHG_MESSAGE,
                                "Nexthop gateway with bad address family (%d) received from kernel",
                                family);
                        return nh;
                }
                gate = RTA_DATA(tb[NHA_GATEWAY]);
        } else
                type = NEXTHOP_TYPE_IFINDEX;

        if (type)
                nh.type = type;

        if (gate)
                memcpy(&(nh.gate), gate, sz);

        if (if_index)
                nh.ifindex = if_index;

        ifp_lookup =
                if_lookup_by_index_per_ns(zebra_ns_lookup(ns_id), nh.ifindex);

        if (ifp)
                *ifp = ifp_lookup;
        if (ifp_lookup)
                nh.vrf_id = ifp_lookup->vrf_id;
        else {
                flog_warn(
                        EC_ZEBRA_UNKNOWN_INTERFACE,
                        "%s: Unknown nexthop interface %u received, defaulting to VRF_DEFAULT",
                        __func__, nh.ifindex);

                nh.vrf_id = VRF_DEFAULT;
        }

        if (tb[NHA_ENCAP] && tb[NHA_ENCAP_TYPE]) {
                uint16_t encap_type = *(uint16_t *)RTA_DATA(tb[NHA_ENCAP_TYPE]);
                int num_labels = 0;

                mpls_label_t labels[MPLS_MAX_LABELS] = {0};

                if (encap_type == LWTUNNEL_ENCAP_MPLS)
                        num_labels = parse_encap_mpls(tb[NHA_ENCAP], labels);

                if (num_labels)
                        nexthop_add_labels(&nh, ZEBRA_LSP_STATIC, num_labels,
                                           labels);
        }

        return nh;
}

static int netlink_nexthop_process_group(struct rtattr **tb,
                                         struct nh_grp *z_grp, int z_grp_size)
{
        uint8_t count = 0;
        /* linux/nexthop.h group struct */
        struct nexthop_grp *n_grp = NULL;

        n_grp = (struct nexthop_grp *)RTA_DATA(tb[NHA_GROUP]);
        count = (RTA_PAYLOAD(tb[NHA_GROUP]) / sizeof(*n_grp));

        if (!count || (count * sizeof(*n_grp)) != RTA_PAYLOAD(tb[NHA_GROUP])) {
                flog_warn(EC_ZEBRA_BAD_NHG_MESSAGE,
                          "Invalid nexthop group received from the kernel");
                return count;
        }

        for (int i = 0; ((i < count) && (i < z_grp_size)); i++) {
                z_grp[i].id = n_grp[i].id;
                z_grp[i].weight = n_grp[i].weight + 1;
        }
        return count;
}

/**
 * netlink_nexthop_change() - Read in change about nexthops from the kernel
 *
 * @h:          Netlink message header
 * @ns_id:      Namspace id
 * @startup:    Are we reading under startup conditions?
 *
 * Return:      Result status
 */
int netlink_nexthop_change(struct nlmsghdr *h, ns_id_t ns_id, int startup)
{
        int len;
        /* nexthop group id */
        uint32_t id;
        unsigned char family;
        int type;
        afi_t afi = AFI_UNSPEC;
        vrf_id_t vrf_id = VRF_DEFAULT;
        struct interface *ifp = NULL;
        struct nhmsg *nhm = NULL;
        struct nexthop nh = {};
        struct nh_grp grp[MULTIPATH_NUM] = {};
        /* Count of nexthops in group array */
        uint8_t grp_count = 0;
        struct rtattr *tb[NHA_MAX + 1] = {};

        nhm = NLMSG_DATA(h);

        if (ns_id)
                vrf_id = ns_id;

        if (startup && h->nlmsg_type != RTM_NEWNEXTHOP)
                return 0;

        len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct nhmsg));
        if (len < 0) {
                zlog_warn(
                        "%s: Message received from netlink is of a broken size %d %zu",
                        __func__, h->nlmsg_len,
                        (size_t)NLMSG_LENGTH(sizeof(struct nhmsg)));
                return -1;
        }

        netlink_parse_rtattr(tb, NHA_MAX, RTM_NHA(nhm), len);


        if (!tb[NHA_ID]) {
                flog_warn(
                        EC_ZEBRA_BAD_NHG_MESSAGE,
                        "Nexthop group without an ID received from the kernel");
                return -1;
        }

        /* We use the ID key'd nhg table for kernel updates */
        id = *((uint32_t *)RTA_DATA(tb[NHA_ID]));

        if (zebra_evpn_mh_is_fdb_nh(id)) {
                /* If this is a L2 NH just ignore it */
                if (IS_ZEBRA_DEBUG_KERNEL || IS_ZEBRA_DEBUG_EVPN_MH_NH) {
                        zlog_debug("Ignore kernel update (%u) for fdb-nh 0x%x",
                                        h->nlmsg_type, id);
                }
                return 0;
        }

        family = nhm->nh_family;
        afi = family2afi(family);

        type = proto2zebra(nhm->nh_protocol, 0, true);

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("%s ID (%u) %s NS %u",
                           nl_msg_type_to_str(h->nlmsg_type), id,
                           nl_family_to_str(family), ns_id);


        if (h->nlmsg_type == RTM_NEWNEXTHOP) {
                if (tb[NHA_GROUP]) {
                        /**
                         * If this is a group message its only going to have
                         * an array of nexthop IDs associated with it
                         */
                        grp_count = netlink_nexthop_process_group(
                                tb, grp, array_size(grp));
                } else {
                        if (tb[NHA_BLACKHOLE]) {
                                /**
                                 * This nexthop is just for blackhole-ing
                                 * traffic, it should not have an OIF, GATEWAY,
                                 * or ENCAP
                                 */
                                nh.type = NEXTHOP_TYPE_BLACKHOLE;
                                nh.bh_type = BLACKHOLE_UNSPEC;
                        } else if (tb[NHA_OIF])
                                /**
                                 * This is a true new nexthop, so we need
                                 * to parse the gateway and device info
                                 */
                                nh = netlink_nexthop_process_nh(tb, family,
                                                                &ifp, ns_id);
                        else {

                                flog_warn(
                                        EC_ZEBRA_BAD_NHG_MESSAGE,
                                        "Invalid Nexthop message received from the kernel with ID (%u)",
                                        id);
                                return -1;
                        }
                        SET_FLAG(nh.flags, NEXTHOP_FLAG_ACTIVE);
                        if (nhm->nh_flags & RTNH_F_ONLINK)
                                SET_FLAG(nh.flags, NEXTHOP_FLAG_ONLINK);
                        vrf_id = nh.vrf_id;
                }

                if (zebra_nhg_kernel_find(id, &nh, grp, grp_count, vrf_id, afi,
                                          type, startup))
                        return -1;

        } else if (h->nlmsg_type == RTM_DELNEXTHOP)
                zebra_nhg_kernel_del(id, vrf_id);

        return 0;
}

/**
 * netlink_request_nexthop() - Request nextop information from the kernel
 * @zns:        Zebra namespace
 * @family:     AF_* netlink family
 * @type:       RTM_* route type
 *
 * Return:      Result status
 */
static int netlink_request_nexthop(struct zebra_ns *zns, int family, int type)
{
        struct {
                struct nlmsghdr n;
                struct nhmsg nhm;
        } req;

        /* Form the request, specifying filter (rtattr) if needed. */
        memset(&req, 0, sizeof(req));
        req.n.nlmsg_type = type;
        req.n.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg));
        req.nhm.nh_family = family;

        return netlink_request(&zns->netlink_cmd, &req);
}


/**
 * netlink_nexthop_read() - Nexthop read function using netlink interface
 *
 * @zns:        Zebra name space
 *
 * Return:      Result status
 * Only called at bootstrap time.
 */
int netlink_nexthop_read(struct zebra_ns *zns)
{
        int ret;
        struct zebra_dplane_info dp_info;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        /* Get nexthop objects */
        ret = netlink_request_nexthop(zns, AF_UNSPEC, RTM_GETNEXTHOP);
        if (ret < 0)
                return ret;
        ret = netlink_parse_info(netlink_nexthop_change, &zns->netlink_cmd,
                                 &dp_info, 0, 1);

        if (!ret)
                /* If we succesfully read in nexthop objects,
                 * this kernel must support them.
                 */
                supports_nh = true;

        if (IS_ZEBRA_DEBUG_KERNEL || IS_ZEBRA_DEBUG_NHG)
                zlog_debug("Nexthop objects %ssupported on this kernel",
                           supports_nh ? "" : "not ");

        return ret;
}


int kernel_neigh_update(int add, int ifindex, uint32_t addr, char *lla,
                        int llalen, ns_id_t ns_id)
{
        return netlink_neigh_update(add ? RTM_NEWNEIGH : RTM_DELNEIGH, ifindex,
                                    addr, lla, llalen, ns_id);
}

/**
 * netlink_neigh_update_msg_encode() - Common helper api for encoding
 * evpn neighbor update as netlink messages using dataplane context object.
 * Here, a neighbor refers to a bridge forwarding database entry for
 * either unicast forwarding or head-end replication or an IP neighbor
 * entry.
 * @ctx:                Dataplane context
 * @cmd:                Netlink command (RTM_NEWNEIGH or RTM_DELNEIGH)
 * @mac:                A neighbor cache link layer address
 * @ip:         A neighbor cache n/w layer destination address
 *                      In the case of bridge FDB, this represnts the remote
 *                      VTEP IP.
 * @replace_obj:        Whether NEW request should replace existing object or
 *                      add to the end of the list
 * @family:             AF_* netlink family
 * @type:               RTN_* route type
 * @flags:              NTF_* flags
 * @state:              NUD_* states
 * @data:               data buffer pointer
 * @datalen:            total amount of data buffer space
 *
 * Return:              0 when the msg doesn't fit entirely in the buffer
 *                              otherwise the number of bytes written to buf.
 */
static ssize_t netlink_neigh_update_msg_encode(
        const struct zebra_dplane_ctx *ctx, int cmd, const struct ethaddr *mac,
        const struct ipaddr *ip, bool replace_obj, uint8_t family, uint8_t type,
        uint8_t flags, uint16_t state, uint32_t nhg_id, bool nfy,
        uint8_t nfy_flags, bool ext, uint32_t ext_flags, void *data,
        size_t datalen)
{
        uint8_t protocol = RTPROT_ZEBRA;
        struct {
                struct nlmsghdr n;
                struct ndmsg ndm;
                char buf[];
        } *req = data;
        int ipa_len;
        enum dplane_op_e op;

        if (datalen < sizeof(*req))
                return 0;
        memset(req, 0, sizeof(*req));

        op = dplane_ctx_get_op(ctx);

        req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
        req->n.nlmsg_flags = NLM_F_REQUEST;
        if (cmd == RTM_NEWNEIGH)
                req->n.nlmsg_flags |=
                        NLM_F_CREATE
                        | (replace_obj ? NLM_F_REPLACE : NLM_F_APPEND);
        req->n.nlmsg_type = cmd;
        req->ndm.ndm_family = family;
        req->ndm.ndm_type = type;
        req->ndm.ndm_state = state;
        req->ndm.ndm_flags = flags;
        req->ndm.ndm_ifindex = dplane_ctx_get_ifindex(ctx);

        if (!nl_attr_put(&req->n, datalen, NDA_PROTOCOL, &protocol,
                         sizeof(protocol)))
                return 0;

        if (mac) {
                if (!nl_attr_put(&req->n, datalen, NDA_LLADDR, mac, 6))
                        return 0;
        }

        if (nfy) {
                struct rtattr *nest;

                nest = nl_attr_nest(&req->n, datalen,
                                    NDA_FDB_EXT_ATTRS | NLA_F_NESTED);
                if (!nest)
                        return 0;

                if (!nl_attr_put(&req->n, datalen, NFEA_ACTIVITY_NOTIFY,
                                 &nfy_flags, sizeof(nfy_flags)))
                        return 0;
                if (!nl_attr_put(&req->n, datalen, NFEA_DONT_REFRESH, NULL, 0))
                        return 0;

                nl_attr_nest_end(&req->n, nest);
        }


        if (ext) {
                if (!nl_attr_put(&req->n, datalen, NDA_EXT_FLAGS, &ext_flags,
                                 sizeof(ext_flags)))
                        return 0;
        }

        if (nhg_id) {
                if (!nl_attr_put32(&req->n, datalen, NDA_NH_ID, nhg_id))
                        return 0;
        } else {
                ipa_len =
                        IS_IPADDR_V4(ip) ? IPV4_MAX_BYTELEN : IPV6_MAX_BYTELEN;
                if (!nl_attr_put(&req->n, datalen, NDA_DST, &ip->ip.addr,
                                 ipa_len))
                        return 0;
        }

        if (op == DPLANE_OP_MAC_INSTALL || op == DPLANE_OP_MAC_DELETE) {
                vlanid_t vid = dplane_ctx_mac_get_vlan(ctx);

                if (vid > 0) {
                        if (!nl_attr_put16(&req->n, datalen, NDA_VLAN, vid))
                                return 0;
                }

                if (!nl_attr_put32(&req->n, datalen, NDA_MASTER,
                                   dplane_ctx_mac_get_br_ifindex(ctx)))
                        return 0;
        }

        return NLMSG_ALIGN(req->n.nlmsg_len);
}

/*
 * Add remote VTEP to the flood list for this VxLAN interface (VNI). This
 * is done by adding an FDB entry with a MAC of 00:00:00:00:00:00.
 */
static ssize_t
netlink_vxlan_flood_update_ctx(const struct zebra_dplane_ctx *ctx, int cmd,
                               void *buf, size_t buflen)
{
        struct ethaddr dst_mac = {.octet = {0}};

        return netlink_neigh_update_msg_encode(
                ctx, cmd, &dst_mac, dplane_ctx_neigh_get_ipaddr(ctx), false,
                PF_BRIDGE, 0, NTF_SELF, (NUD_NOARP | NUD_PERMANENT), 0 /*nhg*/,
                false /*nfy*/, 0 /*nfy_flags*/, false /*ext*/, 0 /*ext_flags*/,
                buf, buflen);
}

#ifndef NDA_RTA
#define NDA_RTA(r)                                                             \
        ((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
#endif

static int netlink_macfdb_change(struct nlmsghdr *h, int len, ns_id_t ns_id)
{
        struct ndmsg *ndm;
        struct interface *ifp;
        struct zebra_if *zif;
        struct rtattr *tb[NDA_MAX + 1];
        struct interface *br_if;
        struct ethaddr mac;
        vlanid_t vid = 0;
        struct in_addr vtep_ip;
        int vid_present = 0, dst_present = 0;
        char buf[ETHER_ADDR_STRLEN];
        char vid_buf[20];
        char dst_buf[30];
        bool sticky;
        bool local_inactive = false;
        bool dp_static = false;
        uint32_t nhg_id = 0;

        ndm = NLMSG_DATA(h);

        /* We only process macfdb notifications if EVPN is enabled */
        if (!is_evpn_enabled())
                return 0;

        /* Parse attributes and extract fields of interest. Do basic
         * validation of the fields.
         */
        memset(tb, 0, sizeof tb);
        netlink_parse_rtattr_flags(tb, NDA_MAX, NDA_RTA(ndm), len,
                                   NLA_F_NESTED);

        if (!tb[NDA_LLADDR]) {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("%s AF_BRIDGE IF %u - no LLADDR",
                                   nl_msg_type_to_str(h->nlmsg_type),
                                   ndm->ndm_ifindex);
                return 0;
        }

        if (RTA_PAYLOAD(tb[NDA_LLADDR]) != ETH_ALEN) {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug(
                                "%s AF_BRIDGE IF %u - LLADDR is not MAC, len %lu",
                                nl_msg_type_to_str(h->nlmsg_type), ndm->ndm_ifindex,
                                (unsigned long)RTA_PAYLOAD(tb[NDA_LLADDR]));
                return 0;
        }

        memcpy(&mac, RTA_DATA(tb[NDA_LLADDR]), ETH_ALEN);

        if ((NDA_VLAN <= NDA_MAX) && tb[NDA_VLAN]) {
                vid_present = 1;
                vid = *(uint16_t *)RTA_DATA(tb[NDA_VLAN]);
                snprintf(vid_buf, sizeof(vid_buf), " VLAN %u", vid);
        }

        if (tb[NDA_DST]) {
                /* TODO: Only IPv4 supported now. */
                dst_present = 1;
                memcpy(&vtep_ip.s_addr, RTA_DATA(tb[NDA_DST]),
                       IPV4_MAX_BYTELEN);
                snprintfrr(dst_buf, sizeof(dst_buf), " dst %pI4",
                           &vtep_ip);
        }

        if (tb[NDA_NH_ID])
                nhg_id = *(uint32_t *)RTA_DATA(tb[NDA_NH_ID]);

        if (ndm->ndm_state & NUD_STALE)
                local_inactive = true;

        if (tb[NDA_FDB_EXT_ATTRS]) {
                struct rtattr *attr = tb[NDA_FDB_EXT_ATTRS];
                struct rtattr *nfea_tb[NFEA_MAX + 1] = {0};

                netlink_parse_rtattr_nested(nfea_tb, NFEA_MAX, attr);
                if (nfea_tb[NFEA_ACTIVITY_NOTIFY]) {
                        uint8_t nfy_flags;

                        nfy_flags = *(uint8_t *)RTA_DATA(
                                nfea_tb[NFEA_ACTIVITY_NOTIFY]);
                        if (nfy_flags & FDB_NOTIFY_BIT)
                                dp_static = true;
                        if (nfy_flags & FDB_NOTIFY_INACTIVE_BIT)
                                local_inactive = true;
                }
        }

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("Rx %s AF_BRIDGE IF %u%s st 0x%x fl 0x%x MAC %s%s nhg %d",
                           nl_msg_type_to_str(h->nlmsg_type),
                           ndm->ndm_ifindex, vid_present ? vid_buf : "",
                           ndm->ndm_state, ndm->ndm_flags,
                           prefix_mac2str(&mac, buf, sizeof(buf)),
                           dst_present ? dst_buf : "", nhg_id);

        /* The interface should exist. */
        ifp = if_lookup_by_index_per_ns(zebra_ns_lookup(ns_id),
                                        ndm->ndm_ifindex);
        if (!ifp || !ifp->info)
                return 0;

        /* The interface should be something we're interested in. */
        if (!IS_ZEBRA_IF_BRIDGE_SLAVE(ifp))
                return 0;

        zif = (struct zebra_if *)ifp->info;
        if ((br_if = zif->brslave_info.br_if) == NULL) {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug(
                                "%s AF_BRIDGE IF %s(%u) brIF %u - no bridge master",
                                nl_msg_type_to_str(h->nlmsg_type), ifp->name,
                                ndm->ndm_ifindex,
                                zif->brslave_info.bridge_ifindex);
                return 0;
        }

        sticky = !!(ndm->ndm_flags & NTF_STICKY);

        if (filter_vlan && vid != filter_vlan) {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug("        Filtered due to filter vlan: %d",
                                   filter_vlan);
                return 0;
        }

        /* If add or update, do accordingly if learnt on a "local" interface; if
         * the notification is over VxLAN, this has to be related to
         * multi-homing,
         * so perform an implicit delete of any local entry (if it exists).
         */
        if (h->nlmsg_type == RTM_NEWNEIGH) {
                /* Drop "permanent" entries. */
                if (ndm->ndm_state & NUD_PERMANENT) {
                        if (IS_ZEBRA_DEBUG_KERNEL)
                                zlog_debug(
                                        "        Dropping entry because of NUD_PERMANENT");
                        return 0;
                }

                if (IS_ZEBRA_IF_VXLAN(ifp))
                        return zebra_vxlan_dp_network_mac_add(
                                ifp, br_if, &mac, vid, nhg_id, sticky,
                                !!(ndm->ndm_flags & NTF_EXT_LEARNED));

                return zebra_vxlan_local_mac_add_update(ifp, br_if, &mac, vid,
                                sticky, local_inactive, dp_static);
        }

        /* This is a delete notification.
         * Ignore the notification with IP dest as it may just signify that the
         * MAC has moved from remote to local. The exception is the special
         * all-zeros MAC that represents the BUM flooding entry; we may have
         * to readd it. Otherwise,
         *  1. For a MAC over VxLan, check if it needs to be refreshed(readded)
         *  2. For a MAC over "local" interface, delete the mac
         * Note: We will get notifications from both bridge driver and VxLAN
         * driver.
         */
        if (nhg_id)
                return 0;

        if (dst_present) {
                u_char zero_mac[6] = {0x0, 0x0, 0x0, 0x0, 0x0, 0x0};

                if (!memcmp(zero_mac, mac.octet, ETH_ALEN))
                        return zebra_vxlan_check_readd_vtep(ifp, vtep_ip);
                return 0;
        }

        if (IS_ZEBRA_IF_VXLAN(ifp))
                return zebra_vxlan_dp_network_mac_del(ifp, br_if, &mac, vid);

        return zebra_vxlan_local_mac_del(ifp, br_if, &mac, vid);
}

static int netlink_macfdb_table(struct nlmsghdr *h, ns_id_t ns_id, int startup)
{
        int len;
        struct ndmsg *ndm;

        if (h->nlmsg_type != RTM_NEWNEIGH)
                return 0;

        /* Length validity. */
        len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct ndmsg));
        if (len < 0)
                return -1;

        /* We are interested only in AF_BRIDGE notifications. */
        ndm = NLMSG_DATA(h);
        if (ndm->ndm_family != AF_BRIDGE)
                return 0;

        return netlink_macfdb_change(h, len, ns_id);
}

/* Request for MAC FDB information from the kernel */
static int netlink_request_macs(struct nlsock *netlink_cmd, int family,
                                int type, ifindex_t master_ifindex)
{
        struct {
                struct nlmsghdr n;
                struct ifinfomsg ifm;
                char buf[256];
        } req;

        /* Form the request, specifying filter (rtattr) if needed. */
        memset(&req, 0, sizeof(req));
        req.n.nlmsg_type = type;
        req.n.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
        req.ifm.ifi_family = family;
        if (master_ifindex)
                nl_attr_put32(&req.n, sizeof(req), IFLA_MASTER, master_ifindex);

        return netlink_request(netlink_cmd, &req);
}

/*
 * MAC forwarding database read using netlink interface. This is invoked
 * at startup.
 */
int netlink_macfdb_read(struct zebra_ns *zns)
{
        int ret;
        struct zebra_dplane_info dp_info;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        /* Get bridge FDB table. */
        ret = netlink_request_macs(&zns->netlink_cmd, AF_BRIDGE, RTM_GETNEIGH,
                                   0);
        if (ret < 0)
                return ret;
        /* We are reading entire table. */
        filter_vlan = 0;
        ret = netlink_parse_info(netlink_macfdb_table, &zns->netlink_cmd,
                                 &dp_info, 0, 1);

        return ret;
}

/*
 * MAC forwarding database read using netlink interface. This is for a
 * specific bridge and matching specific access VLAN (if VLAN-aware bridge).
 */
int netlink_macfdb_read_for_bridge(struct zebra_ns *zns, struct interface *ifp,
                                   struct interface *br_if)
{
        struct zebra_if *br_zif;
        struct zebra_if *zif;
        struct zebra_l2info_vxlan *vxl;
        struct zebra_dplane_info dp_info;
        int ret = 0;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        /* Save VLAN we're filtering on, if needed. */
        br_zif = (struct zebra_if *)br_if->info;
        zif = (struct zebra_if *)ifp->info;
        vxl = &zif->l2info.vxl;
        if (IS_ZEBRA_IF_BRIDGE_VLAN_AWARE(br_zif))
                filter_vlan = vxl->access_vlan;

        /* Get bridge FDB table for specific bridge - we do the VLAN filtering.
         */
        ret = netlink_request_macs(&zns->netlink_cmd, AF_BRIDGE, RTM_GETNEIGH,
                                   br_if->ifindex);
        if (ret < 0)
                return ret;
        ret = netlink_parse_info(netlink_macfdb_table, &zns->netlink_cmd,
                                 &dp_info, 0, 0);

        /* Reset VLAN filter. */
        filter_vlan = 0;
        return ret;
}


/* Request for MAC FDB for a specific MAC address in VLAN from the kernel */
static int netlink_request_specific_mac_in_bridge(struct zebra_ns *zns,
                                                  int family,
                                                  int type,
                                                  struct interface *br_if,
                                                  struct ethaddr *mac,
                                                  vlanid_t vid)
{
        struct {
                struct nlmsghdr n;
                struct ndmsg ndm;
                char buf[256];
        } req;
        struct zebra_if *br_zif;
        char buf[ETHER_ADDR_STRLEN];

        memset(&req, 0, sizeof(req));
        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
        req.n.nlmsg_type = type;        /* RTM_GETNEIGH */
        req.n.nlmsg_flags = NLM_F_REQUEST;
        req.ndm.ndm_family = family;    /* AF_BRIDGE */
        /* req.ndm.ndm_state = NUD_REACHABLE; */

        nl_attr_put(&req.n, sizeof(req), NDA_LLADDR, mac, 6);

        br_zif = (struct zebra_if *)br_if->info;
        if (IS_ZEBRA_IF_BRIDGE_VLAN_AWARE(br_zif) && vid > 0)
                nl_attr_put16(&req.n, sizeof(req), NDA_VLAN, vid);

        nl_attr_put32(&req.n, sizeof(req), NDA_MASTER, br_if->ifindex);

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug(
                        "%s: Tx family %s IF %s(%u) vrf %s(%u) MAC %s vid %u",
                        __func__, nl_family_to_str(req.ndm.ndm_family),
                        br_if->name, br_if->ifindex,
                        vrf_id_to_name(br_if->vrf_id), br_if->vrf_id,
                        prefix_mac2str(mac, buf, sizeof(buf)), vid);

        return netlink_request(&zns->netlink_cmd, &req);
}

int netlink_macfdb_read_specific_mac(struct zebra_ns *zns,
                                     struct interface *br_if,
                                     struct ethaddr *mac, vlanid_t vid)
{
        int ret = 0;
        struct zebra_dplane_info dp_info;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        /* Get bridge FDB table for specific bridge - we do the VLAN filtering.
         */
        ret = netlink_request_specific_mac_in_bridge(zns, AF_BRIDGE,
                                                     RTM_GETNEIGH,
                                                     br_if, mac, vid);
        if (ret < 0)
                return ret;

        ret = netlink_parse_info(netlink_macfdb_table, &zns->netlink_cmd,
                                 &dp_info, 1, 0);

        return ret;
}

/*
 * Netlink-specific handler for MAC updates using dataplane context object.
 */
ssize_t netlink_macfdb_update_ctx(struct zebra_dplane_ctx *ctx, void *data,
                                  size_t datalen)
{
        struct ipaddr vtep_ip;
        vlanid_t vid;
        ssize_t total;
        int cmd;
        uint8_t flags;
        uint16_t state;
        uint32_t nhg_id;
        uint32_t update_flags;
        bool nfy = false;
        uint8_t nfy_flags = 0;

        cmd = dplane_ctx_get_op(ctx) == DPLANE_OP_MAC_INSTALL
                          ? RTM_NEWNEIGH : RTM_DELNEIGH;

        flags = NTF_MASTER;
        state = NUD_REACHABLE;

        update_flags = dplane_ctx_mac_get_update_flags(ctx);
        if (update_flags & DPLANE_MAC_REMOTE) {
                flags |= NTF_SELF;
                if (dplane_ctx_mac_is_sticky(ctx)) {
                        /* NUD_NOARP prevents the entry from expiring */
                        state |= NUD_NOARP;
                        /* sticky the entry from moving */
                        flags |= NTF_STICKY;
                } else {
                        flags |= NTF_EXT_LEARNED;
                }
                /* if it was static-local previously we need to clear the
                 * notify flags on replace with remote
                 */
                if (update_flags & DPLANE_MAC_WAS_STATIC)
                        nfy = true;
        } else {
                /* local mac */
                if (update_flags & DPLANE_MAC_SET_STATIC) {
                        nfy_flags |= FDB_NOTIFY_BIT;
                        state |= NUD_NOARP;
                }

                if (update_flags & DPLANE_MAC_SET_INACTIVE)
                        nfy_flags |= FDB_NOTIFY_INACTIVE_BIT;

                nfy = true;
        }

        nhg_id = dplane_ctx_mac_get_nhg_id(ctx);
        vtep_ip.ipaddr_v4 = *(dplane_ctx_mac_get_vtep_ip(ctx));
        SET_IPADDR_V4(&vtep_ip);

        if (IS_ZEBRA_DEBUG_KERNEL) {
                char ipbuf[PREFIX_STRLEN];
                char buf[ETHER_ADDR_STRLEN];
                char vid_buf[20];
                const struct ethaddr *mac = dplane_ctx_mac_get_addr(ctx);

                vid = dplane_ctx_mac_get_vlan(ctx);
                if (vid > 0)
                        snprintf(vid_buf, sizeof(vid_buf), " VLAN %u", vid);
                else
                        vid_buf[0] = '\0';

                zlog_debug(
                        "Tx %s family %s IF %s(%u)%s %sMAC %s dst %s nhg %u%s%s%s%s%s",
                        nl_msg_type_to_str(cmd), nl_family_to_str(AF_BRIDGE),
                        dplane_ctx_get_ifname(ctx), dplane_ctx_get_ifindex(ctx),
                        vid_buf, dplane_ctx_mac_is_sticky(ctx) ? "sticky " : "",
                        prefix_mac2str(mac, buf, sizeof(buf)),
                        ipaddr2str(&vtep_ip, ipbuf, sizeof(ipbuf)), nhg_id,
                        (update_flags & DPLANE_MAC_REMOTE) ? " rem" : "",
                        (update_flags & DPLANE_MAC_WAS_STATIC) ? " clr_sync"
                                                               : "",
                        (update_flags & DPLANE_MAC_SET_STATIC) ? " static" : "",
                        (update_flags & DPLANE_MAC_SET_INACTIVE) ? " inactive"
                                                                 : "",
                        nfy ? " nfy" : "");
        }

        total = netlink_neigh_update_msg_encode(
                ctx, cmd, dplane_ctx_mac_get_addr(ctx), &vtep_ip, true,
                AF_BRIDGE, 0, flags, state, nhg_id, nfy, nfy_flags,
                false /*ext*/, 0 /*ext_flags*/, data, datalen);

        return total;
}

/*
 * In the event the kernel deletes ipv4 link-local neighbor entries created for
 * 5549 support, re-install them.
 */
static void netlink_handle_5549(struct ndmsg *ndm, struct zebra_if *zif,
                                struct interface *ifp, struct ipaddr *ip,
                                bool handle_failed)
{
        if (ndm->ndm_family != AF_INET)
                return;

        if (!zif->v6_2_v4_ll_neigh_entry)
                return;

        if (ipv4_ll.s_addr != ip->ip._v4_addr.s_addr)
                return;

        if (handle_failed && ndm->ndm_state & NUD_FAILED) {
                zlog_info("Neighbor Entry for %s has entered a failed state, not reinstalling",
                          ifp->name);
                return;
        }

        if_nbr_ipv6ll_to_ipv4ll_neigh_update(ifp, &zif->v6_2_v4_ll_addr6, true);
}

#define NUD_VALID                                                              \
        (NUD_PERMANENT | NUD_NOARP | NUD_REACHABLE | NUD_PROBE | NUD_STALE     \
         | NUD_DELAY)
#define NUD_LOCAL_ACTIVE                                                 \
        (NUD_PERMANENT | NUD_NOARP | NUD_REACHABLE)

static int netlink_ipneigh_change(struct nlmsghdr *h, int len, ns_id_t ns_id)
{
        struct ndmsg *ndm;
        struct interface *ifp;
        struct zebra_if *zif;
        struct rtattr *tb[NDA_MAX + 1];
        struct interface *link_if;
        struct ethaddr mac;
        struct ipaddr ip;
        struct vrf *vrf;
        char buf[ETHER_ADDR_STRLEN];
        char buf2[INET6_ADDRSTRLEN];
        int mac_present = 0;
        bool is_ext;
        bool is_router;
        bool local_inactive;
        uint32_t ext_flags = 0;
        bool dp_static = false;

        ndm = NLMSG_DATA(h);

        /* The interface should exist. */
        ifp = if_lookup_by_index_per_ns(zebra_ns_lookup(ns_id),
                                        ndm->ndm_ifindex);
        if (!ifp || !ifp->info)
                return 0;

        vrf = vrf_lookup_by_id(ifp->vrf_id);
        zif = (struct zebra_if *)ifp->info;

        /* Parse attributes and extract fields of interest. */
        memset(tb, 0, sizeof(tb));
        netlink_parse_rtattr(tb, NDA_MAX, NDA_RTA(ndm), len);

        if (!tb[NDA_DST]) {
                zlog_debug("%s family %s IF %s(%u) vrf %s(%u) - no DST",
                           nl_msg_type_to_str(h->nlmsg_type),
                           nl_family_to_str(ndm->ndm_family), ifp->name,
                           ndm->ndm_ifindex, VRF_LOGNAME(vrf), ifp->vrf_id);
                return 0;
        }

        memset(&ip, 0, sizeof(struct ipaddr));
        ip.ipa_type = (ndm->ndm_family == AF_INET) ? IPADDR_V4 : IPADDR_V6;
        memcpy(&ip.ip.addr, RTA_DATA(tb[NDA_DST]), RTA_PAYLOAD(tb[NDA_DST]));

        /* if kernel deletes our rfc5549 neighbor entry, re-install it */
        if (h->nlmsg_type == RTM_DELNEIGH && (ndm->ndm_state & NUD_PERMANENT)) {
                netlink_handle_5549(ndm, zif, ifp, &ip, false);
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug(
                                "    Neighbor Entry Received is a 5549 entry, finished");
                return 0;
        }

        /* if kernel marks our rfc5549 neighbor entry invalid, re-install it */
        if (h->nlmsg_type == RTM_NEWNEIGH && !(ndm->ndm_state & NUD_VALID))
                netlink_handle_5549(ndm, zif, ifp, &ip, true);

        /* The neighbor is present on an SVI. From this, we locate the
         * underlying
         * bridge because we're only interested in neighbors on a VxLAN bridge.
         * The bridge is located based on the nature of the SVI:
         * (a) In the case of a VLAN-aware bridge, the SVI is a L3 VLAN
         * interface
         * and is linked to the bridge
         * (b) In the case of a VLAN-unaware bridge, the SVI is the bridge
         * inteface
         * itself
         */
        if (IS_ZEBRA_IF_VLAN(ifp)) {
                link_if = if_lookup_by_index_per_ns(zebra_ns_lookup(ns_id),
                                                    zif->link_ifindex);
                if (!link_if)
                        return 0;
        } else if (IS_ZEBRA_IF_BRIDGE(ifp))
                link_if = ifp;
        else {
                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug(
                                "    Neighbor Entry received is not on a VLAN or a BRIDGE, ignoring");
                return 0;
        }

        memset(&mac, 0, sizeof(struct ethaddr));
        if (h->nlmsg_type == RTM_NEWNEIGH) {
                if (tb[NDA_LLADDR]) {
                        if (RTA_PAYLOAD(tb[NDA_LLADDR]) != ETH_ALEN) {
                                if (IS_ZEBRA_DEBUG_KERNEL)
                                        zlog_debug(
                                                "%s family %s IF %s(%u) vrf %s(%u) - LLADDR is not MAC, len %lu",
                                                nl_msg_type_to_str(
                                                        h->nlmsg_type),
                                                nl_family_to_str(
                                                        ndm->ndm_family),
                                                ifp->name, ndm->ndm_ifindex,
                                                VRF_LOGNAME(vrf), ifp->vrf_id,
                                                (unsigned long)RTA_PAYLOAD(
                                                        tb[NDA_LLADDR]));
                                return 0;
                        }

                        mac_present = 1;
                        memcpy(&mac, RTA_DATA(tb[NDA_LLADDR]), ETH_ALEN);
                }

                is_ext = !!(ndm->ndm_flags & NTF_EXT_LEARNED);
                is_router = !!(ndm->ndm_flags & NTF_ROUTER);

                if (tb[NDA_EXT_FLAGS]) {
                        ext_flags = *(uint32_t *)RTA_DATA(tb[NDA_EXT_FLAGS]);
                        if (ext_flags & NTF_E_MH_PEER_SYNC)
                                dp_static = true;
                }

                if (IS_ZEBRA_DEBUG_KERNEL)
                        zlog_debug(
                                "Rx %s family %s IF %s(%u) vrf %s(%u) IP %s MAC %s state 0x%x flags 0x%x ext_flags 0x%x",
                                nl_msg_type_to_str(h->nlmsg_type),
                                nl_family_to_str(ndm->ndm_family), ifp->name,
                                ndm->ndm_ifindex, VRF_LOGNAME(vrf), ifp->vrf_id,
                                ipaddr2str(&ip, buf2, sizeof(buf2)),
                                mac_present
                                        ? prefix_mac2str(&mac, buf, sizeof(buf))
                                        : "",
                                ndm->ndm_state, ndm->ndm_flags, ext_flags);

                /* If the neighbor state is valid for use, process as an add or
                 * update
                 * else process as a delete. Note that the delete handling may
                 * result
                 * in re-adding the neighbor if it is a valid "remote" neighbor.
                 */
                if (ndm->ndm_state & NUD_VALID) {
                        if (zebra_evpn_mh_do_adv_reachable_neigh_only())
                                local_inactive =
                                        !(ndm->ndm_state & NUD_LOCAL_ACTIVE);
                        else
                                /* If EVPN-MH is not enabled we treat STALE
                                 * neighbors as locally-active and advertise
                                 * them
                                 */
                                local_inactive = false;

                        return zebra_vxlan_handle_kernel_neigh_update(
                                ifp, link_if, &ip, &mac, ndm->ndm_state, is_ext,
                                is_router, local_inactive, dp_static);
                }

                return zebra_vxlan_handle_kernel_neigh_del(ifp, link_if, &ip);
        }

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("Rx %s family %s IF %s(%u) vrf %s(%u) IP %s",
                           nl_msg_type_to_str(h->nlmsg_type),
                           nl_family_to_str(ndm->ndm_family), ifp->name,
                           ndm->ndm_ifindex, VRF_LOGNAME(vrf), ifp->vrf_id,
                           ipaddr2str(&ip, buf2, sizeof(buf2)));

        /* Process the delete - it may result in re-adding the neighbor if it is
         * a valid "remote" neighbor.
         */
        return zebra_vxlan_handle_kernel_neigh_del(ifp, link_if, &ip);
}

static int netlink_neigh_table(struct nlmsghdr *h, ns_id_t ns_id, int startup)
{
        int len;
        struct ndmsg *ndm;

        if (h->nlmsg_type != RTM_NEWNEIGH)
                return 0;

        /* Length validity. */
        len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct ndmsg));
        if (len < 0)
                return -1;

        /* We are interested only in AF_INET or AF_INET6 notifications. */
        ndm = NLMSG_DATA(h);
        if (ndm->ndm_family != AF_INET && ndm->ndm_family != AF_INET6)
                return 0;

        return netlink_neigh_change(h, len);
}

/* Request for IP neighbor information from the kernel */
static int netlink_request_neigh(struct nlsock *netlink_cmd, int family,
                                 int type, ifindex_t ifindex)
{
        struct {
                struct nlmsghdr n;
                struct ndmsg ndm;
                char buf[256];
        } req;

        /* Form the request, specifying filter (rtattr) if needed. */
        memset(&req, 0, sizeof(req));
        req.n.nlmsg_type = type;
        req.n.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
        req.ndm.ndm_family = family;
        if (ifindex)
                nl_attr_put32(&req.n, sizeof(req), NDA_IFINDEX, ifindex);

        return netlink_request(netlink_cmd, &req);
}

/*
 * IP Neighbor table read using netlink interface. This is invoked
 * at startup.
 */
int netlink_neigh_read(struct zebra_ns *zns)
{
        int ret;
        struct zebra_dplane_info dp_info;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        /* Get IP neighbor table. */
        ret = netlink_request_neigh(&zns->netlink_cmd, AF_UNSPEC, RTM_GETNEIGH,
                                    0);
        if (ret < 0)
                return ret;
        ret = netlink_parse_info(netlink_neigh_table, &zns->netlink_cmd,
                                 &dp_info, 0, 1);

        return ret;
}

/*
 * IP Neighbor table read using netlink interface. This is for a specific
 * VLAN device.
 */
int netlink_neigh_read_for_vlan(struct zebra_ns *zns, struct interface *vlan_if)
{
        int ret = 0;
        struct zebra_dplane_info dp_info;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        ret = netlink_request_neigh(&zns->netlink_cmd, AF_UNSPEC, RTM_GETNEIGH,
                                    vlan_if->ifindex);
        if (ret < 0)
                return ret;
        ret = netlink_parse_info(netlink_neigh_table, &zns->netlink_cmd,
                                 &dp_info, 0, 0);

        return ret;
}

/*
 * Request for a specific IP in VLAN (SVI) device from IP Neighbor table,
 * read using netlink interface.
 */
static int netlink_request_specific_neigh_in_vlan(struct zebra_ns *zns,
                                                  int type, struct ipaddr *ip,
                                                  ifindex_t ifindex)
{
        struct {
                struct nlmsghdr n;
                struct ndmsg ndm;
                char buf[256];
        } req;
        int ipa_len;

        /* Form the request, specifying filter (rtattr) if needed. */
        memset(&req, 0, sizeof(req));
        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
        req.n.nlmsg_flags = NLM_F_REQUEST;
        req.n.nlmsg_type = type; /* RTM_GETNEIGH */
        req.ndm.ndm_ifindex = ifindex;

        if (IS_IPADDR_V4(ip)) {
                ipa_len = IPV4_MAX_BYTELEN;
                req.ndm.ndm_family = AF_INET;

        } else {
                ipa_len = IPV6_MAX_BYTELEN;
                req.ndm.ndm_family = AF_INET6;
        }

        nl_attr_put(&req.n, sizeof(req), NDA_DST, &ip->ip.addr, ipa_len);

        if (IS_ZEBRA_DEBUG_KERNEL) {
                char buf[INET6_ADDRSTRLEN];

                zlog_debug("%s: Tx %s family %s IF %u IP %s flags 0x%x",
                           __func__, nl_msg_type_to_str(type),
                           nl_family_to_str(req.ndm.ndm_family), ifindex,
                           ipaddr2str(ip, buf, sizeof(buf)), req.n.nlmsg_flags);
        }

        return netlink_request(&zns->netlink_cmd, &req);
}

int netlink_neigh_read_specific_ip(struct ipaddr *ip,
                                  struct interface *vlan_if)
{
        int ret = 0;
        struct zebra_ns *zns;
        struct zebra_vrf *zvrf = zebra_vrf_lookup_by_id(vlan_if->vrf_id);
        char buf[INET6_ADDRSTRLEN];
        struct zebra_dplane_info dp_info;

        zns = zvrf->zns;

        zebra_dplane_info_from_zns(&dp_info, zns, true /*is_cmd*/);

        if (IS_ZEBRA_DEBUG_KERNEL)
                zlog_debug("%s: neigh request IF %s(%u) IP %s vrf %s(%u)",
                           __func__, vlan_if->name, vlan_if->ifindex,
                           ipaddr2str(ip, buf, sizeof(buf)),
                           vrf_id_to_name(vlan_if->vrf_id), vlan_if->vrf_id);

        ret = netlink_request_specific_neigh_in_vlan(zns, RTM_GETNEIGH, ip,
                                            vlan_if->ifindex);
        if (ret < 0)
                return ret;

        ret = netlink_parse_info(netlink_neigh_table, &zns->netlink_cmd,
                                 &dp_info, 1, 0);

        return ret;
}

int netlink_neigh_change(struct nlmsghdr *h, ns_id_t ns_id)
{
        int len;
        struct ndmsg *ndm;

        if (!(h->nlmsg_type == RTM_NEWNEIGH || h->nlmsg_type == RTM_DELNEIGH))
                return 0;

        /* Length validity. */
        len = h->nlmsg_len - NLMSG_LENGTH(sizeof(struct ndmsg));
        if (len < 0) {
                zlog_err(
                        "%s: Message received from netlink is of a broken size %d %zu",
                        __func__, h->nlmsg_len,
                        (size_t)NLMSG_LENGTH(sizeof(struct ndmsg)));
                return -1;
        }

        /* Is this a notification for the MAC FDB or IP neighbor table? */
        ndm = NLMSG_DATA(h);
        if (ndm->ndm_family == AF_BRIDGE)
                return netlink_macfdb_change(h, len, ns_id);

        if (ndm->ndm_type != RTN_UNICAST)
                return 0;

        if (ndm->ndm_family == AF_INET || ndm->ndm_family == AF_INET6)
                return netlink_ipneigh_change(h, len, ns_id);
        else {
                flog_warn(
                        EC_ZEBRA_UNKNOWN_FAMILY,
                        "Invalid address family: %u received from kernel neighbor change: %s",
                        ndm->ndm_family, nl_msg_type_to_str(h->nlmsg_type));
                return 0;
        }

        return 0;
}

/*
 * Utility neighbor-update function, using info from dplane context.
 */
static ssize_t netlink_neigh_update_ctx(const struct zebra_dplane_ctx *ctx,
                                        int cmd, void *buf, size_t buflen)
{
        const struct ipaddr *ip;
        const struct ethaddr *mac;
        uint8_t flags;
        uint16_t state;
        uint8_t family;
        uint32_t update_flags;
        uint32_t ext_flags = 0;
        bool ext = false;

        ip = dplane_ctx_neigh_get_ipaddr(ctx);
        mac = dplane_ctx_neigh_get_mac(ctx);
        if (is_zero_mac(mac))
                mac = NULL;

        update_flags = dplane_ctx_neigh_get_update_flags(ctx);
        flags = neigh_flags_to_netlink(dplane_ctx_neigh_get_flags(ctx));
        state = neigh_state_to_netlink(dplane_ctx_neigh_get_state(ctx));

        family = IS_IPADDR_V4(ip) ? AF_INET : AF_INET6;

        if (update_flags & DPLANE_NEIGH_REMOTE) {
                flags |= NTF_EXT_LEARNED;
                /* if it was static-local previously we need to clear the
                 * ext flags on replace with remote
                 */
                if (update_flags & DPLANE_NEIGH_WAS_STATIC)
                        ext = true;
        } else {
                ext = true;
                /* local neigh */
                if (update_flags & DPLANE_NEIGH_SET_STATIC)
                        ext_flags |= NTF_E_MH_PEER_SYNC;
        }
        if (IS_ZEBRA_DEBUG_KERNEL) {
                char buf[INET6_ADDRSTRLEN];
                char buf2[ETHER_ADDR_STRLEN];

                zlog_debug(
                        "Tx %s family %s IF %s(%u) Neigh %s MAC %s flags 0x%x state 0x%x %sext_flags 0x%x",
                        nl_msg_type_to_str(cmd), nl_family_to_str(family),
                        dplane_ctx_get_ifname(ctx), dplane_ctx_get_ifindex(ctx),
                        ipaddr2str(ip, buf, sizeof(buf)),
                        mac ? prefix_mac2str(mac, buf2, sizeof(buf2)) : "null",
                        flags, state, ext ? "ext " : "", ext_flags);
        }

        return netlink_neigh_update_msg_encode(
                ctx, cmd, mac, ip, true, family, RTN_UNICAST, flags, state,
                0 /*nhg*/, false /*nfy*/, 0 /*nfy_flags*/, ext, ext_flags, buf,
                buflen);
}

static ssize_t netlink_neigh_msg_encoder(struct zebra_dplane_ctx *ctx,
                                         void *buf, size_t buflen)
{
        ssize_t ret;

        switch (dplane_ctx_get_op(ctx)) {
        case DPLANE_OP_NEIGH_INSTALL:
        case DPLANE_OP_NEIGH_UPDATE:
        case DPLANE_OP_NEIGH_DISCOVER:
                ret = netlink_neigh_update_ctx(ctx, RTM_NEWNEIGH, buf, buflen);
                break;
        case DPLANE_OP_NEIGH_DELETE:
                ret = netlink_neigh_update_ctx(ctx, RTM_DELNEIGH, buf, buflen);
                break;
        case DPLANE_OP_VTEP_ADD:
                ret = netlink_vxlan_flood_update_ctx(ctx, RTM_NEWNEIGH, buf,
                                                     buflen);
                break;
        case DPLANE_OP_VTEP_DELETE:
                ret = netlink_vxlan_flood_update_ctx(ctx, RTM_DELNEIGH, buf,
                                                     buflen);
                break;
        default:
                ret = -1;
        }

        return ret;
}

/*
 * Update MAC, using dataplane context object.
 */

enum netlink_msg_status netlink_put_mac_update_msg(struct nl_batch *bth,
                                                   struct zebra_dplane_ctx *ctx)
{
        return netlink_batch_add_msg(bth, ctx, netlink_macfdb_update_ctx,
                                     false);
}

enum netlink_msg_status
netlink_put_neigh_update_msg(struct nl_batch *bth, struct zebra_dplane_ctx *ctx)
{
        return netlink_batch_add_msg(bth, ctx, netlink_neigh_msg_encoder,
                                     false);
}

/*
 * MPLS label forwarding table change via netlink interface, using dataplane
 * context information.
 */
ssize_t netlink_mpls_multipath_msg_encode(int cmd, struct zebra_dplane_ctx *ctx,
                                          void *buf, size_t buflen)
{
        mpls_lse_t lse;
        const struct nhlfe_list_head *head;
        const zebra_nhlfe_t *nhlfe;
        struct nexthop *nexthop = NULL;
        unsigned int nexthop_num;
        const char *routedesc;
        int route_type;
        struct prefix p = {0};

        struct {
                struct nlmsghdr n;
                struct rtmsg r;
                char buf[0];
        } *req = buf;

        if (buflen < sizeof(*req))
                return 0;

        memset(req, 0, sizeof(*req));

        /*
         * Count # nexthops so we can decide whether to use singlepath
         * or multipath case.
         */
        nexthop_num = 0;
        head = dplane_ctx_get_nhlfe_list(ctx);
        frr_each(nhlfe_list_const, head, nhlfe) {
                nexthop = nhlfe->nexthop;
                if (!nexthop)
                        continue;
                if (cmd == RTM_NEWROUTE) {
                        /* Count all selected NHLFEs */
                        if (CHECK_FLAG(nhlfe->flags, NHLFE_FLAG_SELECTED)
                            && CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_ACTIVE))
                                nexthop_num++;
                } else { /* DEL */
                        /* Count all installed NHLFEs */
                        if (CHECK_FLAG(nhlfe->flags, NHLFE_FLAG_INSTALLED)
                            && CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_FIB))
                                nexthop_num++;
                }
        }

        if ((nexthop_num == 0) ||
            (!dplane_ctx_get_best_nhlfe(ctx) && (cmd != RTM_DELROUTE)))
                return 0;

        req->n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
        req->n.nlmsg_flags = NLM_F_CREATE | NLM_F_REQUEST;
        req->n.nlmsg_type = cmd;
        req->n.nlmsg_pid = dplane_ctx_get_ns(ctx)->nls.snl.nl_pid;

        req->r.rtm_family = AF_MPLS;
        req->r.rtm_table = RT_TABLE_MAIN;
        req->r.rtm_dst_len = MPLS_LABEL_LEN_BITS;
        req->r.rtm_scope = RT_SCOPE_UNIVERSE;
        req->r.rtm_type = RTN_UNICAST;

        if (cmd == RTM_NEWROUTE) {
                /* We do a replace to handle update. */
                req->n.nlmsg_flags |= NLM_F_REPLACE;

                /* set the protocol value if installing */
                route_type = re_type_from_lsp_type(
                        dplane_ctx_get_best_nhlfe(ctx)->type);
                req->r.rtm_protocol = zebra2proto(route_type);
        }

        /* Fill destination */
        lse = mpls_lse_encode(dplane_ctx_get_in_label(ctx), 0, 0, 1);
        if (!nl_attr_put(&req->n, buflen, RTA_DST, &lse, sizeof(mpls_lse_t)))
                return 0;

        /* Fill nexthops (paths) based on single-path or multipath. The paths
         * chosen depend on the operation.
         */
        if (nexthop_num == 1) {
                routedesc = "single-path";
                _netlink_mpls_debug(cmd, dplane_ctx_get_in_label(ctx),
                                    routedesc);

                nexthop_num = 0;
                frr_each(nhlfe_list_const, head, nhlfe) {
                        nexthop = nhlfe->nexthop;
                        if (!nexthop)
                                continue;

                        if ((cmd == RTM_NEWROUTE
                             && (CHECK_FLAG(nhlfe->flags, NHLFE_FLAG_SELECTED)
                                 && CHECK_FLAG(nexthop->flags,
                                               NEXTHOP_FLAG_ACTIVE)))
                            || (cmd == RTM_DELROUTE
                                && (CHECK_FLAG(nhlfe->flags,
                                               NHLFE_FLAG_INSTALLED)
                                    && CHECK_FLAG(nexthop->flags,
                                                  NEXTHOP_FLAG_FIB)))) {
                                /* Add the gateway */
                                if (!_netlink_mpls_build_singlepath(
                                            &p, routedesc, nhlfe, &req->n,
                                            &req->r, buflen, cmd))
                                        return false;

                                nexthop_num++;
                                break;
                        }
                }
        } else { /* Multipath case */
                struct rtattr *nest;
                const union g_addr *src1 = NULL;

                nest = nl_attr_nest(&req->n, buflen, RTA_MULTIPATH);
                if (!nest)
                        return 0;

                routedesc = "multipath";
                _netlink_mpls_debug(cmd, dplane_ctx_get_in_label(ctx),
                                    routedesc);

                nexthop_num = 0;
                frr_each(nhlfe_list_const, head, nhlfe) {
                        nexthop = nhlfe->nexthop;
                        if (!nexthop)
                                continue;

                        if ((cmd == RTM_NEWROUTE
                             && (CHECK_FLAG(nhlfe->flags, NHLFE_FLAG_SELECTED)
                                 && CHECK_FLAG(nexthop->flags,
                                               NEXTHOP_FLAG_ACTIVE)))
                            || (cmd == RTM_DELROUTE
                                && (CHECK_FLAG(nhlfe->flags,
                                               NHLFE_FLAG_INSTALLED)
                                    && CHECK_FLAG(nexthop->flags,
                                                  NEXTHOP_FLAG_FIB)))) {
                                nexthop_num++;

                                /* Build the multipath */
                                if (!_netlink_mpls_build_multipath(
                                            &p, routedesc, nhlfe, &req->n,
                                            buflen, &req->r, &src1))
                                        return 0;
                        }
                }

                /* Add the multipath */
                nl_attr_nest_end(&req->n, nest);
        }

        return NLMSG_ALIGN(req->n.nlmsg_len);
}

/****************************************************************************
* This code was developed in a branch that didn't have dplane APIs for
* MAC updates. Hence the use of the legacy style. It will be moved to
* the new dplane style pre-merge to master. XXX
*/
static int netlink_fdb_nh_update(uint32_t nh_id, struct in_addr vtep_ip)
{
        struct {
                struct nlmsghdr n;
                struct nhmsg nhm;
                char buf[256];
        } req;
        int cmd = RTM_NEWNEXTHOP;
        struct zebra_vrf *zvrf;
        struct zebra_ns *zns;

        zvrf = zebra_vrf_get_evpn();
        if (!zvrf)
                return -1;
        zns = zvrf->zns;

        memset(&req, 0, sizeof(req));

        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg));
        req.n.nlmsg_flags = NLM_F_REQUEST;
        req.n.nlmsg_flags |= (NLM_F_CREATE | NLM_F_REPLACE);
        req.n.nlmsg_type = cmd;
        req.nhm.nh_family = AF_INET;

        if (!nl_attr_put32(&req.n, sizeof(req), NHA_ID, nh_id))
                return -1;
        if (!nl_attr_put(&req.n, sizeof(req), NHA_FDB, NULL, 0))
                return -1;
        if (!nl_attr_put(&req.n, sizeof(req), NHA_GATEWAY,
                        &vtep_ip, IPV4_MAX_BYTELEN))
                return -1;

        if (IS_ZEBRA_DEBUG_KERNEL || IS_ZEBRA_DEBUG_EVPN_MH_NH) {
                zlog_debug("Tx %s fdb-nh 0x%x %pI4",
                           nl_msg_type_to_str(cmd), nh_id, &vtep_ip);
        }

        return netlink_talk(netlink_talk_filter, &req.n, &zns->netlink_cmd, zns,
                            0);
}

static int netlink_fdb_nh_del(uint32_t nh_id)
{
        struct {
                struct nlmsghdr n;
                struct nhmsg nhm;
                char buf[256];
        } req;
        int cmd = RTM_DELNEXTHOP;
        struct zebra_vrf *zvrf;
        struct zebra_ns *zns;

        zvrf = zebra_vrf_get_evpn();
        if (!zvrf)
                return -1;
        zns = zvrf->zns;

        memset(&req, 0, sizeof(req));

        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg));
        req.n.nlmsg_flags = NLM_F_REQUEST;
        req.n.nlmsg_type = cmd;
        req.nhm.nh_family = AF_UNSPEC;

        if (!nl_attr_put32(&req.n, sizeof(req), NHA_ID, nh_id))
                return -1;

        if (IS_ZEBRA_DEBUG_KERNEL || IS_ZEBRA_DEBUG_EVPN_MH_NH) {
                zlog_debug("Tx %s fdb-nh 0x%x",
                           nl_msg_type_to_str(cmd), nh_id);
        }

        return netlink_talk(netlink_talk_filter, &req.n, &zns->netlink_cmd, zns,
                            0);
}

static int netlink_fdb_nhg_update(uint32_t nhg_id, uint32_t nh_cnt,
                struct nh_grp *nh_ids)
{
        struct {
                struct nlmsghdr n;
                struct nhmsg nhm;
                char buf[256];
        } req;
        int cmd = RTM_NEWNEXTHOP;
        struct zebra_vrf *zvrf;
        struct zebra_ns *zns;
        struct nexthop_grp grp[nh_cnt];
        uint32_t i;

        zvrf = zebra_vrf_get_evpn();
        if (!zvrf)
                return -1;
        zns = zvrf->zns;

        memset(&req, 0, sizeof(req));

        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg));
        req.n.nlmsg_flags = NLM_F_REQUEST;
        req.n.nlmsg_flags |= (NLM_F_CREATE | NLM_F_REPLACE);
        req.n.nlmsg_type = cmd;
        req.nhm.nh_family = AF_UNSPEC;

        if (!nl_attr_put32(&req.n, sizeof(req), NHA_ID, nhg_id))
                return -1;
        if (!nl_attr_put(&req.n, sizeof(req), NHA_FDB, NULL, 0))
                return -1;
        memset(&grp, 0, sizeof(grp));
        for (i = 0; i < nh_cnt; ++i) {
                grp[i].id = nh_ids[i].id;
                grp[i].weight = nh_ids[i].weight;
        }
        if (!nl_attr_put(&req.n, sizeof(req), NHA_GROUP,
                        grp, nh_cnt * sizeof(struct nexthop_grp)))
                return -1;


        if (IS_ZEBRA_DEBUG_KERNEL || IS_ZEBRA_DEBUG_EVPN_MH_NH) {
                char vtep_str[ES_VTEP_LIST_STR_SZ];
                char nh_buf[16];

                vtep_str[0] = '\0';
                for (i = 0; i < nh_cnt; ++i) {
                        snprintf(nh_buf, sizeof(nh_buf), "%u ",
                                        grp[i].id);
                        strlcat(vtep_str, nh_buf, sizeof(vtep_str));
                }

                zlog_debug("Tx %s fdb-nhg 0x%x %s",
                           nl_msg_type_to_str(cmd), nhg_id, vtep_str);
        }

        return netlink_talk(netlink_talk_filter, &req.n, &zns->netlink_cmd, zns,
                            0);
}

static int netlink_fdb_nhg_del(uint32_t nhg_id)
{
        return netlink_fdb_nh_del(nhg_id);
}

int kernel_upd_mac_nh(uint32_t nh_id, struct in_addr vtep_ip)
{
        return netlink_fdb_nh_update(nh_id, vtep_ip);
}

int kernel_del_mac_nh(uint32_t nh_id)
{
        return netlink_fdb_nh_del(nh_id);
}

int kernel_upd_mac_nhg(uint32_t nhg_id, uint32_t nh_cnt,
                struct nh_grp *nh_ids)
{
        return netlink_fdb_nhg_update(nhg_id, nh_cnt, nh_ids);
}

int kernel_del_mac_nhg(uint32_t nhg_id)
{
        return netlink_fdb_nhg_del(nhg_id);
}

#endif /* HAVE_NETLINK */