Merge pull request #1591 from qlyoung/bgpd-ringbuf

[mirror_frr.git] / bgpd / bgp_evpn.c

/* Ethernet-VPN Packet and vty Processing File
 * Copyright (C) 2016 6WIND
 * Copyright (C) 2017 Cumulus Networks, Inc.
 *
 * This file is part of FRR.
 *
 * FRRouting 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.
 *
 * FRRouting 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>

#include "command.h"
#include "filter.h"
#include "prefix.h"
#include "log.h"
#include "memory.h"
#include "stream.h"
#include "hash.h"
#include "jhash.h"
#include "bitfield.h"
#include "zclient.h"

#include "bgpd/bgp_attr_evpn.h"
#include "bgpd/bgpd.h"
#include "bgpd/bgp_table.h"
#include "bgpd/bgp_route.h"
#include "bgpd/bgp_attr.h"
#include "bgpd/bgp_mplsvpn.h"
#include "bgpd/bgp_label.h"
#include "bgpd/bgp_evpn.h"
#include "bgpd/bgp_evpn_private.h"
#include "bgpd/bgp_ecommunity.h"
#include "bgpd/bgp_encap_types.h"
#include "bgpd/bgp_debug.h"
#include "bgpd/bgp_aspath.h"
#include "bgpd/bgp_zebra.h"
#include "bgpd/bgp_nexthop.h"

/*
 * Definitions and external declarations.
 */
extern struct zclient *zclient;

DEFINE_QOBJ_TYPE(bgpevpn)


/*
 * Static function declarations
 */
static void delete_evpn_route_entry(struct bgp *bgp, struct bgpevpn *vpn,
                                    afi_t afi, safi_t safi, struct bgp_node *rn,
                                    struct bgp_info **ri);
static int delete_all_vni_routes(struct bgp *bgp, struct bgpevpn *vpn);

/*
 * Private functions.
 */

/*
 * Make vni hash key.
 */
static unsigned int vni_hash_key_make(void *p)
{
        struct bgpevpn *vpn = p;
        return (jhash_1word(vpn->vni, 0));
}

/*
 * Comparison function for vni hash
 */
static int vni_hash_cmp(const void *p1, const void *p2)
{
        const struct bgpevpn *vpn1 = p1;
        const struct bgpevpn *vpn2 = p2;

        if (!vpn1 && !vpn2)
                return 1;
        if (!vpn1 || !vpn2)
                return 0;
        return (vpn1->vni == vpn2->vni);
}

/*
 * Make import route target hash key.
 */
static unsigned int import_rt_hash_key_make(void *p)
{
        struct irt_node *irt = p;
        char *pnt = irt->rt.val;
        unsigned int key = 0;
        int c = 0;

        key += pnt[c];
        key += pnt[c + 1];
        key += pnt[c + 2];
        key += pnt[c + 3];
        key += pnt[c + 4];
        key += pnt[c + 5];
        key += pnt[c + 6];
        key += pnt[c + 7];

        return (key);
}

/*
 * Comparison function for import rt hash
 */
static int import_rt_hash_cmp(const void *p1, const void *p2)
{
        const struct irt_node *irt1 = p1;
        const struct irt_node *irt2 = p2;

        if (irt1 == NULL && irt2 == NULL)
                return 1;

        if (irt1 == NULL || irt2 == NULL)
                return 0;

        return (memcmp(irt1->rt.val, irt2->rt.val, ECOMMUNITY_SIZE) == 0);
}

/*
 * Create a new import_rt
 */
static struct irt_node *import_rt_new(struct bgp *bgp,
                                      struct ecommunity_val *rt)
{
        struct irt_node *irt;

        if (!bgp)
                return NULL;

        irt = XCALLOC(MTYPE_BGP_EVPN_IMPORT_RT, sizeof(struct irt_node));
        if (!irt)
                return NULL;

        irt->rt = *rt;
        irt->vnis = list_new();

        /* Add to hash */
        if (!hash_get(bgp->import_rt_hash, irt, hash_alloc_intern)) {
                XFREE(MTYPE_BGP_EVPN_IMPORT_RT, irt);
                return NULL;
        }

        return irt;
}

/*
 * Free the import rt node
 */
static void import_rt_free(struct bgp *bgp, struct irt_node *irt)
{
        hash_release(bgp->import_rt_hash, irt);
        XFREE(MTYPE_BGP_EVPN_IMPORT_RT, irt);
}

/*
 * Function to lookup Import RT node - used to map a RT to set of
 * VNIs importing routes with that RT.
 */
static struct irt_node *lookup_import_rt(struct bgp *bgp,
                                         struct ecommunity_val *rt)
{
        struct irt_node *irt;
        struct irt_node tmp;

        memset(&tmp, 0, sizeof(struct irt_node));
        memcpy(&tmp.rt, rt, ECOMMUNITY_SIZE);
        irt = hash_lookup(bgp->import_rt_hash, &tmp);
        return irt;
}

/*
 * Is specified VNI present on the RT's list of "importing" VNIs?
 */
static int is_vni_present_in_irt_vnis(struct list *vnis, struct bgpevpn *vpn)
{
        struct listnode *node, *nnode;
        struct bgpevpn *tmp_vpn;

        for (ALL_LIST_ELEMENTS(vnis, node, nnode, tmp_vpn)) {
                if (tmp_vpn == vpn)
                        return 1;
        }

        return 0;
}

/*
 * Compare Route Targets.
 */
static int evpn_route_target_cmp(struct ecommunity *ecom1,
                                 struct ecommunity *ecom2)
{
        if (ecom1 && !ecom2)
                return -1;

        if (!ecom1 && ecom2)
                return 1;

        if (!ecom1 && !ecom2)
                return 0;

        if (ecom1->str && !ecom2->str)
                return -1;

        if (!ecom1->str && ecom2->str)
                return 1;

        if (!ecom1->str && !ecom2->str)
                return 0;

        return strcmp(ecom1->str, ecom2->str);
}

/*
 * Mask off global-admin field of specified extended community (RT),
 * just retain the local-admin field.
 */
static inline void mask_ecom_global_admin(struct ecommunity_val *dst,
                                          struct ecommunity_val *src)
{
        u_char type;

        type = src->val[0];
        dst->val[0] = 0;
        if (type == ECOMMUNITY_ENCODE_AS) {
                dst->val[2] = dst->val[3] = 0;
        } else if (type == ECOMMUNITY_ENCODE_AS4
                   || type == ECOMMUNITY_ENCODE_IP) {
                dst->val[2] = dst->val[3] = 0;
                dst->val[4] = dst->val[5] = 0;
        }
}

/*
 * Map one RT to specified VNI.
 */
static void map_vni_to_rt(struct bgp *bgp, struct bgpevpn *vpn,
                          struct ecommunity_val *eval)
{
        struct irt_node *irt;
        struct ecommunity_val eval_tmp;

        /* If using "automatic" RT, we only care about the local-admin
         * sub-field.
         * This is to facilitate using VNI as the RT for EBGP peering too.
         */
        memcpy(&eval_tmp, eval, ECOMMUNITY_SIZE);
        if (!is_import_rt_configured(vpn))
                mask_ecom_global_admin(&eval_tmp, eval);

        irt = lookup_import_rt(bgp, &eval_tmp);
        if (irt && irt->vnis)
                if (is_vni_present_in_irt_vnis(irt->vnis, vpn))
                        /* Already mapped. */
                        return;

        if (!irt) {
                irt = import_rt_new(bgp, &eval_tmp);
                assert(irt);
        }

        /* Add VNI to the hash list for this RT. */
        listnode_add(irt->vnis, vpn);
}

/*
 * Unmap specified VNI from specified RT. If there are no other
 * VNIs for this RT, then the RT hash is deleted.
 */
static void unmap_vni_from_rt(struct bgp *bgp, struct bgpevpn *vpn,
                              struct irt_node *irt)
{
        /* Delete VNI from hash list for this RT. */
        listnode_delete(irt->vnis, vpn);
        if (!listnode_head(irt->vnis)) {
                list_delete_and_null(&irt->vnis);
                import_rt_free(bgp, irt);
        }
}

/*
 * Create RT extended community automatically from passed information:
 * of the form AS:VNI.
 * NOTE: We use only the lower 16 bits of the AS. This is sufficient as
 * the need is to get a RT value that will be unique across different
 * VNIs but the same across routers (in the same AS) for a particular
 * VNI.
 */
static void form_auto_rt(struct bgp *bgp, struct bgpevpn *vpn, struct list *rtl)
{
        struct ecommunity_val eval;
        struct ecommunity *ecomadd;

        encode_route_target_as((bgp->as & 0xFFFF), vpn->vni, &eval);

        ecomadd = ecommunity_new();
        ecommunity_add_val(ecomadd, &eval);
        listnode_add_sort(rtl, ecomadd);
}

/*
 * Derive RD and RT for a VNI automatically. Invoked at the time of
 * creation of a VNI.
 */
static void derive_rd_rt_for_vni(struct bgp *bgp, struct bgpevpn *vpn)
{
        bgp_evpn_derive_auto_rd(bgp, vpn);
        bgp_evpn_derive_auto_rt_import(bgp, vpn);
        bgp_evpn_derive_auto_rt_export(bgp, vpn);
}

/*
 * Add (update) or delete MACIP from zebra.
 */
static int bgp_zebra_send_remote_macip(struct bgp *bgp, struct bgpevpn *vpn,
                                       struct prefix_evpn *p,
                                       struct in_addr remote_vtep_ip, int add,
                                       u_char sticky)
{
        struct stream *s;
        int ipa_len;
        char buf1[ETHER_ADDR_STRLEN];
        char buf2[INET6_ADDRSTRLEN];
        char buf3[INET6_ADDRSTRLEN];

        /* Check socket. */
        if (!zclient || zclient->sock < 0)
                return 0;

        /* Don't try to register if Zebra doesn't know of this instance. */
        if (!IS_BGP_INST_KNOWN_TO_ZEBRA(bgp))
                return 0;

        s = zclient->obuf;
        stream_reset(s);

        zclient_create_header(s, add ? ZEBRA_REMOTE_MACIP_ADD
                                     : ZEBRA_REMOTE_MACIP_DEL,
                              bgp->vrf_id);
        stream_putl(s, vpn->vni);
        stream_put(s, &p->prefix.mac.octet, ETH_ALEN); /* Mac Addr */
        /* IP address length and IP address, if any. */
        if (IS_EVPN_PREFIX_IPADDR_NONE(p))
                stream_putl(s, 0);
        else {
                ipa_len = IS_EVPN_PREFIX_IPADDR_V4(p) ? IPV4_MAX_BYTELEN
                                                      : IPV6_MAX_BYTELEN;
                stream_putl(s, ipa_len);
                stream_put(s, &p->prefix.ip.ip.addr, ipa_len);
        }
        stream_put_in_addr(s, &remote_vtep_ip);

        /* TX MAC sticky status */
        if (add)
                stream_putc(s, sticky);

        stream_putw_at(s, 0, stream_get_endp(s));

        if (bgp_debug_zebra(NULL))
                zlog_debug("Tx %s MACIP, VNI %u %sMAC %s IP %s remote VTEP %s",
                           add ? "ADD" : "DEL", vpn->vni,
                           sticky ? "sticky " : "",
                           prefix_mac2str(&p->prefix.mac, buf1, sizeof(buf1)),
                           ipaddr2str(&p->prefix.ip, buf3, sizeof(buf3)),
                           inet_ntop(AF_INET, &remote_vtep_ip, buf2,
                                     sizeof(buf2)));

        return zclient_send_message(zclient);
}

/*
 * Add (update) or delete remote VTEP from zebra.
 */
static int bgp_zebra_send_remote_vtep(struct bgp *bgp, struct bgpevpn *vpn,
                                      struct prefix_evpn *p, int add)
{
        struct stream *s;

        /* Check socket. */
        if (!zclient || zclient->sock < 0)
                return 0;

        /* Don't try to register if Zebra doesn't know of this instance. */
        if (!IS_BGP_INST_KNOWN_TO_ZEBRA(bgp))
                return 0;

        s = zclient->obuf;
        stream_reset(s);

        zclient_create_header(s, add ? ZEBRA_REMOTE_VTEP_ADD
                                     : ZEBRA_REMOTE_VTEP_DEL,
                              bgp->vrf_id);
        stream_putl(s, vpn->vni);
        if (IS_EVPN_PREFIX_IPADDR_V4(p))
                stream_put_in_addr(s, &p->prefix.ip.ipaddr_v4);
        else if (IS_EVPN_PREFIX_IPADDR_V6(p)) {
                zlog_err(
                        "Bad remote IP when trying to %s remote VTEP for VNI %u",
                        add ? "ADD" : "DEL", vpn->vni);
                return -1;
        }

        stream_putw_at(s, 0, stream_get_endp(s));

        if (bgp_debug_zebra(NULL))
                zlog_debug("Tx %s Remote VTEP, VNI %u remote VTEP %s",
                           add ? "ADD" : "DEL", vpn->vni,
                           inet_ntoa(p->prefix.ip.ipaddr_v4));

        return zclient_send_message(zclient);
}

/*
 * Build extended communities for EVPN route. RT and ENCAP are
 * applicable to all routes.
 */
static void build_evpn_route_extcomm(struct bgpevpn *vpn, struct attr *attr)
{
        struct ecommunity ecom_encap;
        struct ecommunity ecom_sticky;
        struct ecommunity_val eval;
        struct ecommunity_val eval_sticky;
        bgp_encap_types tnl_type;
        struct listnode *node, *nnode;
        struct ecommunity *ecom;
        u_int32_t seqnum;

        /* Encap */
        tnl_type = BGP_ENCAP_TYPE_VXLAN;
        memset(&ecom_encap, 0, sizeof(ecom_encap));
        encode_encap_extcomm(tnl_type, &eval);
        ecom_encap.size = 1;
        ecom_encap.val = (u_int8_t *)eval.val;

        /* Add Encap */
        attr->ecommunity = ecommunity_dup(&ecom_encap);

        /* Add the export RTs */
        for (ALL_LIST_ELEMENTS(vpn->export_rtl, node, nnode, ecom))
                attr->ecommunity = ecommunity_merge(attr->ecommunity, ecom);

        if (attr->sticky) {
                seqnum = 0;
                memset(&ecom_sticky, 0, sizeof(ecom_sticky));
                encode_mac_mobility_extcomm(1, seqnum, &eval_sticky);
                ecom_sticky.size = 1;
                ecom_sticky.val = (u_int8_t *)eval_sticky.val;
                attr->ecommunity =
                        ecommunity_merge(attr->ecommunity, &ecom_sticky);
        }

        attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES);
}

/*
 * Add MAC mobility extended community to attribute.
 */
static void add_mac_mobility_to_attr(u_int32_t seq_num, struct attr *attr)
{
        struct ecommunity ecom_tmp;
        struct ecommunity_val eval;
        u_int8_t *ecom_val_ptr;
        int i;
        u_int8_t *pnt;
        int type = 0;
        int sub_type = 0;

        /* Build MM */
        encode_mac_mobility_extcomm(0, seq_num, &eval);

        /* Find current MM ecommunity */
        ecom_val_ptr = NULL;

        if (attr->ecommunity) {
                for (i = 0; i < attr->ecommunity->size; i++) {
                        pnt = attr->ecommunity->val + (i * 8);
                        type = *pnt++;
                        sub_type = *pnt++;

                        if (type == ECOMMUNITY_ENCODE_EVPN
                            && sub_type
                                       == ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY) {
                                ecom_val_ptr =
                                        (u_int8_t *)(attr->ecommunity->val
                                                     + (i * 8));
                                break;
                        }
                }
        }

        /* Update the existing MM ecommunity */
        if (ecom_val_ptr) {
                memcpy(ecom_val_ptr, eval.val, sizeof(char) * ECOMMUNITY_SIZE);
        }
        /* Add MM to existing */
        else {
                memset(&ecom_tmp, 0, sizeof(ecom_tmp));
                ecom_tmp.size = 1;
                ecom_tmp.val = (u_int8_t *)eval.val;

                attr->ecommunity =
                        ecommunity_merge(attr->ecommunity, &ecom_tmp);
        }
}

/* Install EVPN route into zebra. */
static int evpn_zebra_install(struct bgp *bgp, struct bgpevpn *vpn,
                              struct prefix_evpn *p,
                              struct in_addr remote_vtep_ip, u_char sticky)
{
        int ret;

        if (p->prefix.route_type == BGP_EVPN_MAC_IP_ROUTE)
                ret = bgp_zebra_send_remote_macip(bgp, vpn, p, remote_vtep_ip,
                                                  1, sticky);
        else
                ret = bgp_zebra_send_remote_vtep(bgp, vpn, p, 1);

        return ret;
}

/* Uninstall EVPN route from zebra. */
static int evpn_zebra_uninstall(struct bgp *bgp, struct bgpevpn *vpn,
                                struct prefix_evpn *p,
                                struct in_addr remote_vtep_ip)
{
        int ret;

        if (p->prefix.route_type == BGP_EVPN_MAC_IP_ROUTE)
                ret = bgp_zebra_send_remote_macip(bgp, vpn, p, remote_vtep_ip,
                                                  0, 0);
        else
                ret = bgp_zebra_send_remote_vtep(bgp, vpn, p, 0);

        return ret;
}

/*
 * Due to MAC mobility, the prior "local" best route has been supplanted
 * by a "remote" best route. The prior route has to be deleted and withdrawn
 * from peers.
 */
static void evpn_delete_old_local_route(struct bgp *bgp, struct bgpevpn *vpn,
                                        struct bgp_node *rn,
                                        struct bgp_info *old_local)
{
        struct bgp_node *global_rn;
        struct bgp_info *ri;
        afi_t afi = AFI_L2VPN;
        safi_t safi = SAFI_EVPN;

        /* Locate route node in the global EVPN routing table. Note that
         * this table is a 2-level tree (RD-level + Prefix-level) similar to
         * L3VPN routes.
         */
        global_rn = bgp_afi_node_lookup(bgp->rib[afi][safi], afi, safi,
                                        (struct prefix *)&rn->p, &vpn->prd);
        if (global_rn) {
                /* Delete route entry in the global EVPN table. */
                delete_evpn_route_entry(bgp, vpn, afi, safi, global_rn, &ri);

                /* Schedule for processing - withdraws to peers happen from
                 * this table.
                 */
                if (ri)
                        bgp_process(bgp, global_rn, afi, safi);
                bgp_unlock_node(global_rn);
        }

        /* Delete route entry in the VNI route table, caller to remove. */
        bgp_info_delete(rn, old_local);
}

/*
 * Calculate the best path for an EVPN route. Install/update best path in zebra,
 * if appropriate.
 */
static int evpn_route_select_install(struct bgp *bgp, struct bgpevpn *vpn,
                                     struct bgp_node *rn)
{
        struct bgp_info *old_select, *new_select;
        struct bgp_info_pair old_and_new;
        afi_t afi = AFI_L2VPN;
        safi_t safi = SAFI_EVPN;
        int ret = 0;

        /* Compute the best path. */
        bgp_best_selection(bgp, rn, &bgp->maxpaths[afi][safi], &old_and_new,
                           afi, safi);
        old_select = old_and_new.old;
        new_select = old_and_new.new;

        /* If the best path hasn't changed - see if there is still something to
         * update
         * to zebra RIB.
         */
        if (old_select && old_select == new_select
            && old_select->type == ZEBRA_ROUTE_BGP
            && old_select->sub_type == BGP_ROUTE_NORMAL
            && !CHECK_FLAG(rn->flags, BGP_NODE_USER_CLEAR)
            && !CHECK_FLAG(old_select->flags, BGP_INFO_ATTR_CHANGED)
            && !bgp->addpath_tx_used[afi][safi]) {
                if (bgp_zebra_has_route_changed(rn, old_select))
                        ret = evpn_zebra_install(bgp, vpn,
                                                 (struct prefix_evpn *)&rn->p,
                                                 old_select->attr->nexthop,
                                                 old_select->attr->sticky);
                UNSET_FLAG(old_select->flags, BGP_INFO_MULTIPATH_CHG);
                bgp_zebra_clear_route_change_flags(rn);
                return ret;
        }

        /* If the user did a "clear" this flag will be set */
        UNSET_FLAG(rn->flags, BGP_NODE_USER_CLEAR);

        /* bestpath has changed; update relevant fields and install or uninstall
         * into the zebra RIB.
         */
        if (old_select || new_select)
                bgp_bump_version(rn);

        if (old_select)
                bgp_info_unset_flag(rn, old_select, BGP_INFO_SELECTED);
        if (new_select) {
                bgp_info_set_flag(rn, new_select, BGP_INFO_SELECTED);
                bgp_info_unset_flag(rn, new_select, BGP_INFO_ATTR_CHANGED);
                UNSET_FLAG(new_select->flags, BGP_INFO_MULTIPATH_CHG);
        }

        if (new_select && new_select->type == ZEBRA_ROUTE_BGP
            && new_select->sub_type == BGP_ROUTE_NORMAL) {
                ret = evpn_zebra_install(bgp, vpn, (struct prefix_evpn *)&rn->p,
                                         new_select->attr->nexthop,
                                         new_select->attr->sticky);
                /* If an old best existed and it was a "local" route, the only
                 * reason
                 * it would be supplanted is due to MAC mobility procedures. So,
                 * we
                 * need to do an implicit delete and withdraw that route from
                 * peers.
                 */
                if (old_select && old_select->peer == bgp->peer_self
                    && old_select->type == ZEBRA_ROUTE_BGP
                    && old_select->sub_type == BGP_ROUTE_STATIC)
                        evpn_delete_old_local_route(bgp, vpn, rn, old_select);
        } else {
                if (old_select && old_select->type == ZEBRA_ROUTE_BGP
                    && old_select->sub_type == BGP_ROUTE_NORMAL)
                        ret = evpn_zebra_uninstall(bgp, vpn,
                                                   (struct prefix_evpn *)&rn->p,
                                                   old_select->attr->nexthop);
        }

        /* Clear any route change flags. */
        bgp_zebra_clear_route_change_flags(rn);

        /* Reap old select bgp_info, if it has been removed */
        if (old_select && CHECK_FLAG(old_select->flags, BGP_INFO_REMOVED))
                bgp_info_reap(rn, old_select);

        return ret;
}


/*
 * Return true if the local ri for this rn has sticky set
 */
static int evpn_route_is_sticky(struct bgp *bgp, struct bgp_node *rn)
{
        struct bgp_info *tmp_ri;
        struct bgp_info *local_ri;

        local_ri = NULL;
        for (tmp_ri = rn->info; tmp_ri; tmp_ri = tmp_ri->next) {
                if (tmp_ri->peer == bgp->peer_self
                    && tmp_ri->type == ZEBRA_ROUTE_BGP
                    && tmp_ri->sub_type == BGP_ROUTE_STATIC)
                        local_ri = tmp_ri;
        }

        if (!local_ri)
                return 0;

        return local_ri->attr->sticky;
}

/*
 * Create or update EVPN route entry. This could be in the VNI route table
 * or the global route table.
 */
static int update_evpn_route_entry(struct bgp *bgp, struct bgpevpn *vpn,
                                   afi_t afi, safi_t safi, struct bgp_node *rn,
                                   struct attr *attr, int add, int vni_table,
                                   struct bgp_info **ri, u_char flags)
{
        struct bgp_info *tmp_ri;
        struct bgp_info *local_ri, *remote_ri;
        struct attr *attr_new;
        mpls_label_t label = MPLS_INVALID_LABEL;
        int route_change = 1;
        u_char sticky = 0;

        *ri = NULL;

        /* See if this is an update of an existing route, or a new add. Also,
         * identify if already known from remote, and if so, the one with the
         * highest sequence number; this is only when adding to the VNI routing
         * table.
         */
        local_ri = remote_ri = NULL;
        for (tmp_ri = rn->info; tmp_ri; tmp_ri = tmp_ri->next) {
                if (tmp_ri->peer == bgp->peer_self
                    && tmp_ri->type == ZEBRA_ROUTE_BGP
                    && tmp_ri->sub_type == BGP_ROUTE_STATIC)
                        local_ri = tmp_ri;
                if (vni_table) {
                        if (tmp_ri->type == ZEBRA_ROUTE_BGP
                            && tmp_ri->sub_type == BGP_ROUTE_NORMAL
                            && CHECK_FLAG(tmp_ri->flags, BGP_INFO_VALID)) {
                                if (!remote_ri)
                                        remote_ri = tmp_ri;
                                else if (mac_mobility_seqnum(tmp_ri->attr)
                                         > mac_mobility_seqnum(remote_ri->attr))
                                        remote_ri = tmp_ri;
                        }
                }
        }

        /* If route doesn't exist already, create a new one, if told to.
         * Otherwise act based on whether the attributes of the route have
         * changed or not.
         */
        if (!local_ri && !add)
                return 0;

        if (!local_ri) {
                /* When learnt locally for the first time but already known from
                 * remote, we have to initiate appropriate MAC mobility steps.
                 * This
                 * is applicable when updating the VNI routing table.
                 * We need to skip mobility steps for g/w macs (local mac on g/w
                 * SVI) advertised in EVPN.
                 * This will ensure that local routes are preferred for g/w macs
                 */
                if (remote_ri && !CHECK_FLAG(flags, ZEBRA_MAC_TYPE_GW)) {
                        u_int32_t cur_seqnum;

                        /* Add MM extended community to route. */
                        cur_seqnum = mac_mobility_seqnum(remote_ri->attr);
                        add_mac_mobility_to_attr(cur_seqnum + 1, attr);
                }

                /* Add (or update) attribute to hash. */
                attr_new = bgp_attr_intern(attr);

                /* Extract MAC mobility sequence number, if any. */
                attr_new->mm_seqnum =
                        bgp_attr_mac_mobility_seqnum(attr_new, &sticky);
                attr_new->sticky = sticky;

                /* Create new route with its attribute. */
                tmp_ri = info_make(ZEBRA_ROUTE_BGP, BGP_ROUTE_STATIC, 0,
                                   bgp->peer_self, attr_new, rn);
                SET_FLAG(tmp_ri->flags, BGP_INFO_VALID);
                bgp_info_extra_get(tmp_ri);

                /* The VNI goes into the 'label' field of the route */
                vni2label(vpn->vni, &label);

                memcpy(&tmp_ri->extra->label, &label, BGP_LABEL_BYTES);
                bgp_info_add(rn, tmp_ri);
        } else {
                tmp_ri = local_ri;
                if (attrhash_cmp(tmp_ri->attr, attr)
                    && !CHECK_FLAG(tmp_ri->flags, BGP_INFO_REMOVED))
                        route_change = 0;
                else {
                        /* The attribute has changed. */
                        /* Add (or update) attribute to hash. */
                        attr_new = bgp_attr_intern(attr);
                        bgp_info_set_flag(rn, tmp_ri, BGP_INFO_ATTR_CHANGED);

                        /* Restore route, if needed. */
                        if (CHECK_FLAG(tmp_ri->flags, BGP_INFO_REMOVED))
                                bgp_info_restore(rn, tmp_ri);

                        /* Unintern existing, set to new. */
                        bgp_attr_unintern(&tmp_ri->attr);
                        tmp_ri->attr = attr_new;
                        tmp_ri->uptime = bgp_clock();
                }
        }

        /* Return back the route entry. */
        *ri = tmp_ri;
        return route_change;
}

/*
 * Create or update EVPN route (of type based on prefix) for specified VNI
 * and schedule for processing.
 */
static int update_evpn_route(struct bgp *bgp, struct bgpevpn *vpn,
                             struct prefix_evpn *p, u_char flags)
{
        struct bgp_node *rn;
        struct attr attr;
        struct attr *attr_new;
        struct bgp_info *ri;
        afi_t afi = AFI_L2VPN;
        safi_t safi = SAFI_EVPN;
        int route_change;

        memset(&attr, 0, sizeof(struct attr));

        /* Build path-attribute for this route. */
        bgp_attr_default_set(&attr, BGP_ORIGIN_IGP);
        attr.nexthop = vpn->originator_ip;
        attr.mp_nexthop_global_in = vpn->originator_ip;
        attr.mp_nexthop_len = BGP_ATTR_NHLEN_IPV4;
        attr.sticky = CHECK_FLAG(flags, ZEBRA_MAC_TYPE_STICKY) ? 1 : 0;
        attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_PMSI_TUNNEL);
        vni2label(vpn->vni, &(attr.label));

        /* Set up RT and ENCAP extended community. */
        build_evpn_route_extcomm(vpn, &attr);

        /* First, create (or fetch) route node within the VNI. */
        /* NOTE: There is no RD here. */
        rn = bgp_node_get(vpn->route_table, (struct prefix *)p);

        /* Create or update route entry. */
        route_change = update_evpn_route_entry(bgp, vpn, afi, safi, rn, &attr,
                                               1, 1, &ri, flags);
        assert(ri);
        attr_new = ri->attr;

        /* Perform route selection; this is just to set the flags correctly
         * as local route in the VNI always wins.
         */
        evpn_route_select_install(bgp, vpn, rn);
        bgp_unlock_node(rn);

        /* If this is a new route or some attribute has changed, export the
         * route to the global table. The route will be advertised to peers
         * from there. Note that this table is a 2-level tree (RD-level +
         * Prefix-level) similar to L3VPN routes.
         */
        if (route_change) {
                struct bgp_info *global_ri;

                rn = bgp_afi_node_get(bgp->rib[afi][safi], afi, safi,
                                      (struct prefix *)p, &vpn->prd);
                update_evpn_route_entry(bgp, vpn, afi, safi, rn, attr_new, 1, 0,
                                        &global_ri, flags);

                /* Schedule for processing and unlock node. */
                bgp_process(bgp, rn, afi, safi);
                bgp_unlock_node(rn);
        }

        /* Unintern temporary. */
        aspath_unintern(&attr.aspath);

        return 0;
}

/*
 * Delete EVPN route entry. This could be in the VNI route table
 * or the global route table.
 */
static void delete_evpn_route_entry(struct bgp *bgp, struct bgpevpn *vpn,
                                    afi_t afi, safi_t safi, struct bgp_node *rn,
                                    struct bgp_info **ri)
{
        struct bgp_info *tmp_ri;

        *ri = NULL;

        /* Now, find matching route. */
        for (tmp_ri = rn->info; tmp_ri; tmp_ri = tmp_ri->next)
                if (tmp_ri->peer == bgp->peer_self
                    && tmp_ri->type == ZEBRA_ROUTE_BGP
                    && tmp_ri->sub_type == BGP_ROUTE_STATIC)
                        break;

        *ri = tmp_ri;

        /* Mark route for delete. */
        if (tmp_ri)
                bgp_info_delete(rn, tmp_ri);
}

/*
 * Delete EVPN route (of type based on prefix) for specified VNI and
 * schedule for processing.
 */
static int delete_evpn_route(struct bgp *bgp, struct bgpevpn *vpn,
                             struct prefix_evpn *p)
{
        struct bgp_node *rn, *global_rn;
        struct bgp_info *ri;
        afi_t afi = AFI_L2VPN;
        safi_t safi = SAFI_EVPN;

        /* First, locate the route node within the VNI. If it doesn't exist,
         * there
         * is nothing further to do.
         */
        /* NOTE: There is no RD here. */
        rn = bgp_node_lookup(vpn->route_table, (struct prefix *)p);
        if (!rn)
                return 0;

        /* Next, locate route node in the global EVPN routing table. Note that
         * this table is a 2-level tree (RD-level + Prefix-level) similar to
         * L3VPN routes.
         */
        global_rn = bgp_afi_node_lookup(bgp->rib[afi][safi], afi, safi,
                                        (struct prefix *)p, &vpn->prd);
        if (global_rn) {
                /* Delete route entry in the global EVPN table. */
                delete_evpn_route_entry(bgp, vpn, afi, safi, global_rn, &ri);

                /* Schedule for processing - withdraws to peers happen from
                 * this table.
                 */
                if (ri)
                        bgp_process(bgp, global_rn, afi, safi);
                bgp_unlock_node(global_rn);
        }

        /* Delete route entry in the VNI route table. This can just be removed.
         */
        delete_evpn_route_entry(bgp, vpn, afi, safi, rn, &ri);
        if (ri)
                bgp_info_reap(rn, ri);
        bgp_unlock_node(rn);

        return 0;
}

/*
 * Update all type-2 (MACIP) local routes for this VNI - these should also
 * be scheduled for advertise to peers.
 */
static int update_all_type2_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        afi_t afi;
        safi_t safi;
        struct bgp_node *rn;
        struct bgp_info *ri;
        struct attr attr;
        struct attr attr_sticky;
        struct attr *attr_new;

        afi = AFI_L2VPN;
        safi = SAFI_EVPN;
        memset(&attr, 0, sizeof(struct attr));
        memset(&attr_sticky, 0, sizeof(struct attr));

        /* Build path-attribute - all type-2 routes for this VNI will share the
         * same path attribute.
         */
        bgp_attr_default_set(&attr, BGP_ORIGIN_IGP);
        bgp_attr_default_set(&attr_sticky, BGP_ORIGIN_IGP);
        attr.nexthop = vpn->originator_ip;
        attr.mp_nexthop_global_in = vpn->originator_ip;
        attr.mp_nexthop_len = BGP_ATTR_NHLEN_IPV4;
        attr_sticky.nexthop = vpn->originator_ip;
        attr_sticky.mp_nexthop_global_in = vpn->originator_ip;
        attr_sticky.mp_nexthop_len = BGP_ATTR_NHLEN_IPV4;
        attr_sticky.sticky = 1;

        /* Set up RT, ENCAP and sticky MAC extended community. */
        build_evpn_route_extcomm(vpn, &attr);
        build_evpn_route_extcomm(vpn, &attr_sticky);

        /* Walk this VNI's route table and update local type-2 routes. For any
         * routes updated, update corresponding entry in the global table too.
         */
        for (rn = bgp_table_top(vpn->route_table); rn;
             rn = bgp_route_next(rn)) {
                struct prefix_evpn *evp = (struct prefix_evpn *)&rn->p;
                struct bgp_node *rd_rn;
                struct bgp_info *global_ri;

                if (evp->prefix.route_type != BGP_EVPN_MAC_IP_ROUTE)
                        continue;

                if (evpn_route_is_sticky(bgp, rn))
                        update_evpn_route_entry(bgp, vpn, afi, safi, rn,
                                                &attr_sticky, 0, 1, &ri, 0);
                else
                        update_evpn_route_entry(bgp, vpn, afi, safi, rn, &attr,
                                                0, 1, &ri, 0);

                /* If a local route exists for this prefix, we need to update
                 * the global routing table too.
                 */
                if (!ri)
                        continue;

                /* Perform route selection; this is just to set the flags
                 * correctly
                 * as local route in the VNI always wins.
                 */
                evpn_route_select_install(bgp, vpn, rn);

                attr_new = ri->attr;

                /* Update route in global routing table. */
                rd_rn = bgp_afi_node_get(bgp->rib[afi][safi], afi, safi,
                                         (struct prefix *)evp, &vpn->prd);
                assert(rd_rn);
                update_evpn_route_entry(bgp, vpn, afi, safi, rd_rn, attr_new, 0,
                                        0, &global_ri, 0);

                /* Schedule for processing and unlock node. */
                bgp_process(bgp, rd_rn, afi, safi);
                bgp_unlock_node(rd_rn);
        }

        /* Unintern temporary. */
        aspath_unintern(&attr.aspath);
        aspath_unintern(&attr_sticky.aspath);

        return 0;
}

/*
 * Delete all type-2 (MACIP) local routes for this VNI - only from the
 * global routing table. These are also scheduled for withdraw from peers.
 */
static int delete_global_type2_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        afi_t afi;
        safi_t safi;
        struct bgp_node *rdrn, *rn;
        struct bgp_table *table;
        struct bgp_info *ri;

        afi = AFI_L2VPN;
        safi = SAFI_EVPN;

        rdrn = bgp_node_lookup(bgp->rib[afi][safi], (struct prefix *)&vpn->prd);
        if (rdrn && rdrn->info) {
                table = (struct bgp_table *)rdrn->info;
                for (rn = bgp_table_top(table); rn; rn = bgp_route_next(rn)) {
                        struct prefix_evpn *evp = (struct prefix_evpn *)&rn->p;

                        if (evp->prefix.route_type != BGP_EVPN_MAC_IP_ROUTE)
                                continue;

                        delete_evpn_route_entry(bgp, vpn, afi, safi, rn, &ri);
                        if (ri)
                                bgp_process(bgp, rn, afi, safi);
                }
        }

        /* Unlock RD node. */
        if (rdrn)
                bgp_unlock_node(rdrn);

        return 0;
}

/*
 * Delete all type-2 (MACIP) local routes for this VNI - from the global
 * table as well as the per-VNI route table.
 */
static int delete_all_type2_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        afi_t afi;
        safi_t safi;
        struct bgp_node *rn;
        struct bgp_info *ri;

        afi = AFI_L2VPN;
        safi = SAFI_EVPN;

        /* First, walk the global route table for this VNI's type-2 local
         * routes.
         * EVPN routes are a 2-level table, first get the RD table.
         */
        delete_global_type2_routes(bgp, vpn);

        /* Next, walk this VNI's route table and delete local type-2 routes. */
        for (rn = bgp_table_top(vpn->route_table); rn;
             rn = bgp_route_next(rn)) {
                struct prefix_evpn *evp = (struct prefix_evpn *)&rn->p;

                if (evp->prefix.route_type != BGP_EVPN_MAC_IP_ROUTE)
                        continue;

                delete_evpn_route_entry(bgp, vpn, afi, safi, rn, &ri);

                /* Route entry in local table gets deleted immediately. */
                if (ri)
                        bgp_info_reap(rn, ri);
        }

        return 0;
}

/*
 * Delete all routes in the per-VNI route table.
 */
static int delete_all_vni_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        struct bgp_node *rn;
        struct bgp_info *ri, *nextri;

        /* Walk this VNI's route table and delete all routes. */
        for (rn = bgp_table_top(vpn->route_table); rn;
             rn = bgp_route_next(rn)) {
                for (ri = rn->info; (ri != NULL) && (nextri = ri->next, 1);
                     ri = nextri) {
                        bgp_info_delete(rn, ri);
                        bgp_info_reap(rn, ri);
                }
        }

        return 0;
}

/*
 * Update (and advertise) local routes for a VNI. Invoked upon the VNI
 * export RT getting modified or change to tunnel IP. Note that these
 * situations need the route in the per-VNI table as well as the global
 * table to be updated (as attributes change).
 */
static int update_routes_for_vni(struct bgp *bgp, struct bgpevpn *vpn)
{
        int ret;
        struct prefix_evpn p;

        /* Update and advertise the type-3 route (only one) followed by the
         * locally learnt type-2 routes (MACIP) - for this VNI.
         */
        build_evpn_type3_prefix(&p, vpn->originator_ip);
        ret = update_evpn_route(bgp, vpn, &p, 0);
        if (ret)
                return ret;

        return update_all_type2_routes(bgp, vpn);
}

/*
 * Delete (and withdraw) local routes for specified VNI from the global
 * table and per-VNI table. After this, remove all other routes from
 * the per-VNI table. Invoked upon the VNI being deleted or EVPN
 * (advertise-all-vni) being disabled.
 */
static int delete_routes_for_vni(struct bgp *bgp, struct bgpevpn *vpn)
{
        int ret;
        struct prefix_evpn p;

        /* Delete and withdraw locally learnt type-2 routes (MACIP)
         * followed by type-3 routes (only one) - for this VNI.
         */
        ret = delete_all_type2_routes(bgp, vpn);
        if (ret)
                return ret;

        build_evpn_type3_prefix(&p, vpn->originator_ip);
        ret = delete_evpn_route(bgp, vpn, &p);
        if (ret)
                return ret;

        /* Delete all routes from the per-VNI table. */
        return delete_all_vni_routes(bgp, vpn);
}

/*
 * There is a tunnel endpoint IP address change for this VNI,
 * need to re-advertise routes with the new nexthop.
 */
static int handle_tunnel_ip_change(struct bgp *bgp, struct bgpevpn *vpn,
                                   struct in_addr originator_ip)
{
        struct prefix_evpn p;

        /* If VNI is not live, we only need to update the originator ip */
        if (!is_vni_live(vpn)) {
                vpn->originator_ip = originator_ip;
                return 0;
        }

        /* Update the tunnel-ip hash */
        bgp_tip_del(bgp, &vpn->originator_ip);
        bgp_tip_add(bgp, &originator_ip);

        /* filter routes as martian nexthop db has changed */
        bgp_filter_evpn_routes_upon_martian_nh_change(bgp);

        /* Need to withdraw type-3 route as the originator IP is part
         * of the key.
         */
        build_evpn_type3_prefix(&p, vpn->originator_ip);
        delete_evpn_route(bgp, vpn, &p);

        /* Update the tunnel IP and re-advertise all routes for this VNI. */
        vpn->originator_ip = originator_ip;
        return update_routes_for_vni(bgp, vpn);
}

/*
 * Install route entry into the VNI routing table and invoke route selection.
 */
static int install_evpn_route_entry(struct bgp *bgp, struct bgpevpn *vpn,
                                    struct prefix_evpn *p,
                                    struct bgp_info *parent_ri)
{
        struct bgp_node *rn;
        struct bgp_info *ri;
        struct attr *attr_new;
        int ret;

        /* Create (or fetch) route within the VNI. */
        /* NOTE: There is no RD here. */
        rn = bgp_node_get(vpn->route_table, (struct prefix *)p);

        /* Check if route entry is already present. */
        for (ri = rn->info; ri; ri = ri->next)
                if (ri->extra
                    && (struct bgp_info *)ri->extra->parent == parent_ri)
                        break;

        if (!ri) {
                /* Add (or update) attribute to hash. */
                attr_new = bgp_attr_intern(parent_ri->attr);

                /* Create new route with its attribute. */
                ri = info_make(parent_ri->type, parent_ri->sub_type, 0,
                               parent_ri->peer, attr_new, rn);
                SET_FLAG(ri->flags, BGP_INFO_VALID);
                bgp_info_extra_get(ri);
                ri->extra->parent = parent_ri;
                if (parent_ri->extra)
                        memcpy(&ri->extra->label, &parent_ri->extra->label,
                               BGP_LABEL_BYTES);
                bgp_info_add(rn, ri);
        } else {
                if (attrhash_cmp(ri->attr, parent_ri->attr)
                    && !CHECK_FLAG(ri->flags, BGP_INFO_REMOVED)) {
                        bgp_unlock_node(rn);
                        return 0;
                }
                /* The attribute has changed. */
                /* Add (or update) attribute to hash. */
                attr_new = bgp_attr_intern(parent_ri->attr);

                /* Restore route, if needed. */
                if (CHECK_FLAG(ri->flags, BGP_INFO_REMOVED))
                        bgp_info_restore(rn, ri);

                /* Mark if nexthop has changed. */
                if (!IPV4_ADDR_SAME(&ri->attr->nexthop, &attr_new->nexthop))
                        SET_FLAG(ri->flags, BGP_INFO_IGP_CHANGED);

                /* Unintern existing, set to new. */
                bgp_attr_unintern(&ri->attr);
                ri->attr = attr_new;
                ri->uptime = bgp_clock();
        }

        /* Perform route selection and update zebra, if required. */
        ret = evpn_route_select_install(bgp, vpn, rn);

        return ret;
}

/*
 * Uninstall route entry from the VNI routing table and send message
 * to zebra, if appropriate.
 */
static int uninstall_evpn_route_entry(struct bgp *bgp, struct bgpevpn *vpn,
                                      struct prefix_evpn *p,
                                      struct bgp_info *parent_ri)
{
        struct bgp_node *rn;
        struct bgp_info *ri;
        int ret;

        /* Locate route within the VNI. */
        /* NOTE: There is no RD here. */
        rn = bgp_node_lookup(vpn->route_table, (struct prefix *)p);
        if (!rn)
                return 0;

        /* Find matching route entry. */
        for (ri = rn->info; ri; ri = ri->next)
                if (ri->extra
                    && (struct bgp_info *)ri->extra->parent == parent_ri)
                        break;

        if (!ri)
                return 0;

        /* Mark entry for deletion */
        bgp_info_delete(rn, ri);

        /* Perform route selection and update zebra, if required. */
        ret = evpn_route_select_install(bgp, vpn, rn);

        /* Unlock route node. */
        bgp_unlock_node(rn);

        return ret;
}

/*
 * Given a route entry and a VNI, see if this route entry should be
 * imported into the VNI i.e., RTs match.
 */
static int is_route_matching_for_vni(struct bgp *bgp, struct bgpevpn *vpn,
                                     struct bgp_info *ri)
{
        struct attr *attr = ri->attr;
        struct ecommunity *ecom;
        int i;

        assert(attr);
        /* Route should have valid RT to be even considered. */
        if (!(attr->flag & ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES)))
                return 0;

        ecom = attr->ecommunity;
        if (!ecom || !ecom->size)
                return 0;

        /* For each extended community RT, see if it matches this VNI. If any RT
         * matches, we're done.
         */
        for (i = 0; i < ecom->size; i++) {
                u_char *pnt;
                u_char type, sub_type;
                struct ecommunity_val *eval;
                struct ecommunity_val eval_tmp;
                struct irt_node *irt;

                /* Only deal with RTs */
                pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
                eval = (struct ecommunity_val *)(ecom->val
                                                 + (i * ECOMMUNITY_SIZE));
                type = *pnt++;
                sub_type = *pnt++;
                if (sub_type != ECOMMUNITY_ROUTE_TARGET)
                        continue;

                /* See if this RT matches specified VNIs import RTs */
                irt = lookup_import_rt(bgp, eval);
                if (irt && irt->vnis)
                        if (is_vni_present_in_irt_vnis(irt->vnis, vpn))
                                return 1;

                /* Also check for non-exact match. In this, we mask out the AS
                 * and
                 * only check on the local-admin sub-field. This is to
                 * facilitate using
                 * VNI as the RT for EBGP peering too.
                 */
                irt = NULL;
                if (type == ECOMMUNITY_ENCODE_AS
                    || type == ECOMMUNITY_ENCODE_AS4
                    || type == ECOMMUNITY_ENCODE_IP) {
                        memcpy(&eval_tmp, eval, ECOMMUNITY_SIZE);
                        mask_ecom_global_admin(&eval_tmp, eval);
                        irt = lookup_import_rt(bgp, &eval_tmp);
                }
                if (irt && irt->vnis)
                        if (is_vni_present_in_irt_vnis(irt->vnis, vpn))
                                return 1;
        }

        return 0;
}

/*
 * Install or uninstall routes of specified type that are appropriate for this
 * particular VNI.
 */
static int install_uninstall_routes_for_vni(struct bgp *bgp,
                                            struct bgpevpn *vpn,
                                            bgp_evpn_route_type rtype,
                                            int install)
{
        afi_t afi;
        safi_t safi;
        struct bgp_node *rd_rn, *rn;
        struct bgp_table *table;
        struct bgp_info *ri;
        int ret;

        afi = AFI_L2VPN;
        safi = SAFI_EVPN;

        /* Walk entire global routing table and evaluate routes which could be
         * imported into this VPN. Note that we cannot just look at the routes
         * for
         * the VNI's RD - remote routes applicable for this VNI could have any
         * RD.
         */
        /* EVPN routes are a 2-level table. */
        for (rd_rn = bgp_table_top(bgp->rib[afi][safi]); rd_rn;
             rd_rn = bgp_route_next(rd_rn)) {
                table = (struct bgp_table *)(rd_rn->info);
                if (!table)
                        continue;

                for (rn = bgp_table_top(table); rn; rn = bgp_route_next(rn)) {
                        struct prefix_evpn *evp = (struct prefix_evpn *)&rn->p;

                        if (evp->prefix.route_type != rtype)
                                continue;

                        for (ri = rn->info; ri; ri = ri->next) {
                                /* Consider "valid" remote routes applicable for
                                 * this VNI. */
                                if (!(CHECK_FLAG(ri->flags, BGP_INFO_VALID)
                                      && ri->type == ZEBRA_ROUTE_BGP
                                      && ri->sub_type == BGP_ROUTE_NORMAL))
                                        continue;

                                if (is_route_matching_for_vni(bgp, vpn, ri)) {
                                        if (install)
                                                ret = install_evpn_route_entry(
                                                        bgp, vpn, evp, ri);
                                        else
                                                ret = uninstall_evpn_route_entry(
                                                        bgp, vpn, evp, ri);

                                        if (ret) {
                                                zlog_err(
                                                        "%u: Failed to %s EVPN %s route in VNI %u",
                                                        bgp->vrf_id,
                                                        install ? "install"
                                                                : "uninstall",
                                                        rtype == BGP_EVPN_MAC_IP_ROUTE
                                                                ? "MACIP"
                                                                : "IMET",
                                                        vpn->vni);
                                                return ret;
                                        }
                                }
                        }
                }
        }

        return 0;
}

/*
 * Install any existing remote routes applicable for this VNI into its
 * routing table. This is invoked when a VNI becomes "live" or its Import
 * RT is changed.
 */
static int install_routes_for_vni(struct bgp *bgp, struct bgpevpn *vpn)
{
        int ret;

        /* Install type-3 routes followed by type-2 routes - the ones applicable
         * for this VNI.
         */
        ret = install_uninstall_routes_for_vni(bgp, vpn, BGP_EVPN_IMET_ROUTE,
                                               1);
        if (ret)
                return ret;

        return install_uninstall_routes_for_vni(bgp, vpn, BGP_EVPN_MAC_IP_ROUTE,
                                                1);
}

/*
 * Uninstall any existing remote routes for this VNI. One scenario in which
 * this is invoked is upon an import RT change.
 */
static int uninstall_routes_for_vni(struct bgp *bgp, struct bgpevpn *vpn)
{
        int ret;

        /* Uninstall type-2 routes followed by type-3 routes - the ones
         * applicable
         * for this VNI.
         */
        ret = install_uninstall_routes_for_vni(bgp, vpn, BGP_EVPN_MAC_IP_ROUTE,
                                               0);
        if (ret)
                return ret;

        return install_uninstall_routes_for_vni(bgp, vpn, BGP_EVPN_IMET_ROUTE,
                                                0);
}

/*
 * Install or uninstall route in matching VNIs (list).
 */
static int install_uninstall_route_in_vnis(struct bgp *bgp, afi_t afi,
                                           safi_t safi, struct prefix_evpn *evp,
                                           struct bgp_info *ri,
                                           struct list *vnis, int install)
{
        struct bgpevpn *vpn;
        struct listnode *node, *nnode;

        for (ALL_LIST_ELEMENTS(vnis, node, nnode, vpn)) {
                int ret;

                if (!is_vni_live(vpn))
                        continue;

                if (install)
                        ret = install_evpn_route_entry(bgp, vpn, evp, ri);
                else
                        ret = uninstall_evpn_route_entry(bgp, vpn, evp, ri);

                if (ret) {
                        zlog_err("%u: Failed to %s EVPN %s route in VNI %u",
                                 bgp->vrf_id, install ? "install" : "uninstall",
                                 evp->prefix.route_type == BGP_EVPN_MAC_IP_ROUTE
                                         ? "MACIP"
                                         : "IMET",
                                 vpn->vni);
                        return ret;
                }
        }

        return 0;
}

/*
 * Install or uninstall route for appropriate VNIs.
 */
static int install_uninstall_evpn_route(struct bgp *bgp, afi_t afi, safi_t safi,
                                        struct prefix *p, struct bgp_info *ri,
                                        int import)
{
        struct prefix_evpn *evp = (struct prefix_evpn *)p;
        struct attr *attr = ri->attr;
        struct ecommunity *ecom;
        int i;

        assert(attr);

        /* Only type-2 and type-3 routes go into a L2 VNI. */
        if (!(evp->prefix.route_type == BGP_EVPN_MAC_IP_ROUTE
              || evp->prefix.route_type == BGP_EVPN_IMET_ROUTE))
                return 0;

        /* If we don't have Route Target, nothing much to do. */
        if (!(attr->flag & ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES)))
                return 0;

        ecom = attr->ecommunity;
        if (!ecom || !ecom->size)
                return -1;

        /* For each extended community RT, see which VNIs match and import
         * the route into matching VNIs.
         */
        for (i = 0; i < ecom->size; i++) {
                u_char *pnt;
                u_char type, sub_type;
                struct ecommunity_val *eval;
                struct ecommunity_val eval_tmp;
                struct irt_node *irt;

                /* Only deal with RTs */
                pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
                eval = (struct ecommunity_val *)(ecom->val
                                                 + (i * ECOMMUNITY_SIZE));
                type = *pnt++;
                sub_type = *pnt++;
                if (sub_type != ECOMMUNITY_ROUTE_TARGET)
                        continue;

                /* Are we interested in this RT? */
                irt = lookup_import_rt(bgp, eval);
                if (irt && irt->vnis)
                        install_uninstall_route_in_vnis(bgp, afi, safi, evp, ri,
                                                        irt->vnis, import);

                /* Also check for non-exact match. In this, we mask out the AS
                 * and
                 * only check on the local-admin sub-field. This is to
                 * facilitate using
                 * VNI as the RT for EBGP peering too.
                 */
                irt = NULL;
                if (type == ECOMMUNITY_ENCODE_AS
                    || type == ECOMMUNITY_ENCODE_AS4
                    || type == ECOMMUNITY_ENCODE_IP) {
                        memcpy(&eval_tmp, eval, ECOMMUNITY_SIZE);
                        mask_ecom_global_admin(&eval_tmp, eval);
                        irt = lookup_import_rt(bgp, &eval_tmp);
                }
                if (irt && irt->vnis)
                        install_uninstall_route_in_vnis(bgp, afi, safi, evp, ri,
                                                        irt->vnis, import);
        }

        return 0;
}

/*
 * Update and advertise local routes for a VNI. Invoked upon router-id
 * change. Note that the processing is done only on the global route table
 * using routes that already exist in the per-VNI table.
 */
static int update_advertise_vni_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        struct prefix_evpn p;
        struct bgp_node *rn, *global_rn;
        struct bgp_info *ri, *global_ri;
        struct attr *attr;
        afi_t afi = AFI_L2VPN;
        safi_t safi = SAFI_EVPN;

        /* Locate type-3 route for VNI in the per-VNI table and use its
         * attributes to create and advertise the type-3 route for this VNI
         * in the global table.
         */
        build_evpn_type3_prefix(&p, vpn->originator_ip);
        rn = bgp_node_lookup(vpn->route_table, (struct prefix *)&p);
        if (!rn) /* unexpected */
                return 0;
        for (ri = rn->info; ri; ri = ri->next)
                if (ri->peer == bgp->peer_self && ri->type == ZEBRA_ROUTE_BGP
                    && ri->sub_type == BGP_ROUTE_STATIC)
                        break;
        if (!ri) /* unexpected */
                return 0;
        attr = ri->attr;

        global_rn = bgp_afi_node_get(bgp->rib[afi][safi], afi, safi,
                                     (struct prefix *)&p, &vpn->prd);
        update_evpn_route_entry(bgp, vpn, afi, safi, global_rn, attr, 1, 0, &ri,
                                0);

        /* Schedule for processing and unlock node. */
        bgp_process(bgp, global_rn, afi, safi);
        bgp_unlock_node(global_rn);

        /* Now, walk this VNI's route table and use the route and its attribute
         * to create and schedule route in global table.
         */
        for (rn = bgp_table_top(vpn->route_table); rn;
             rn = bgp_route_next(rn)) {
                struct prefix_evpn *evp = (struct prefix_evpn *)&rn->p;

                /* Identify MAC-IP local routes. */
                if (evp->prefix.route_type != BGP_EVPN_MAC_IP_ROUTE)
                        continue;

                for (ri = rn->info; ri; ri = ri->next)
                        if (ri->peer == bgp->peer_self
                            && ri->type == ZEBRA_ROUTE_BGP
                            && ri->sub_type == BGP_ROUTE_STATIC)
                                break;
                if (!ri)
                        continue;

                /* Create route in global routing table using this route entry's
                 * attribute.
                 */
                attr = ri->attr;
                global_rn = bgp_afi_node_get(bgp->rib[afi][safi], afi, safi,
                                             (struct prefix *)evp, &vpn->prd);
                assert(global_rn);
                update_evpn_route_entry(bgp, vpn, afi, safi, global_rn, attr, 1,
                                        0, &global_ri, 0);

                /* Schedule for processing and unlock node. */
                bgp_process(bgp, global_rn, afi, safi);
                bgp_unlock_node(global_rn);
        }

        return 0;
}

/*
 * Delete (and withdraw) local routes for a VNI - only from the global
 * table. Invoked upon router-id change.
 */
static int delete_withdraw_vni_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        int ret;
        struct prefix_evpn p;
        struct bgp_node *global_rn;
        struct bgp_info *ri;
        afi_t afi = AFI_L2VPN;
        safi_t safi = SAFI_EVPN;

        /* Delete and withdraw locally learnt type-2 routes (MACIP)
         * for this VNI - from the global table.
         */
        ret = delete_global_type2_routes(bgp, vpn);
        if (ret)
                return ret;

        /* Remove type-3 route for this VNI from global table. */
        build_evpn_type3_prefix(&p, vpn->originator_ip);
        global_rn = bgp_afi_node_lookup(bgp->rib[afi][safi], afi, safi,
                                        (struct prefix *)&p, &vpn->prd);
        if (global_rn) {
                /* Delete route entry in the global EVPN table. */
                delete_evpn_route_entry(bgp, vpn, afi, safi, global_rn, &ri);

                /* Schedule for processing - withdraws to peers happen from
                 * this table.
                 */
                if (ri)
                        bgp_process(bgp, global_rn, afi, safi);
                bgp_unlock_node(global_rn);
        }

        return 0;
}

/*
 * Handle router-id change. Update and advertise local routes corresponding
 * to this VNI from peers. Note that this is invoked after updating the
 * router-id. The routes in the per-VNI table are used to create routes in
 * the global table and schedule them.
 */
static void update_router_id_vni(struct hash_backet *backet, struct bgp *bgp)
{
        struct bgpevpn *vpn;

        vpn = (struct bgpevpn *)backet->data;

        if (!vpn) {
                zlog_warn("%s: VNI hash entry for VNI not found", __FUNCTION__);
                return;
        }

        /* Skip VNIs with configured RD. */
        if (is_rd_configured(vpn))
                return;

        bgp_evpn_derive_auto_rd(bgp, vpn);
        update_advertise_vni_routes(bgp, vpn);
}

/*
 * Handle router-id change. Delete and withdraw local routes corresponding
 * to this VNI from peers. Note that this is invoked prior to updating
 * the router-id and is done only on the global route table, the routes
 * are needed in the per-VNI table to re-advertise with new router id.
 */
static void withdraw_router_id_vni(struct hash_backet *backet, struct bgp *bgp)
{
        struct bgpevpn *vpn;

        vpn = (struct bgpevpn *)backet->data;

        if (!vpn) {
                zlog_warn("%s: VNI hash entry for VNI not found", __FUNCTION__);
                return;
        }

        /* Skip VNIs with configured RD. */
        if (is_rd_configured(vpn))
                return;

        delete_withdraw_vni_routes(bgp, vpn);
}

/*
 * Process received EVPN type-2 route (advertise or withdraw).
 */
static int process_type2_route(struct peer *peer, afi_t afi, safi_t safi,
                               struct attr *attr, u_char *pfx, int psize,
                               u_int32_t addpath_id)
{
        struct prefix_rd prd;
        struct prefix_evpn p;
        u_char ipaddr_len;
        u_char macaddr_len;
        mpls_label_t *label_pnt;
        int ret;

        /* Type-2 route should be either 33, 37 or 49 bytes or an
         * additional 3 bytes if there is a second label (VNI):
         * RD (8), ESI (10), Eth Tag (4), MAC Addr Len (1),
         * MAC Addr (6), IP len (1), IP (0, 4 or 16),
         * MPLS Lbl1 (3), MPLS Lbl2 (0 or 3)
         */
        if (psize != 33 && psize != 37 && psize != 49 && psize != 36
            && psize != 40 && psize != 52) {
                zlog_err("%u:%s - Rx EVPN Type-2 NLRI with invalid length %d",
                         peer->bgp->vrf_id, peer->host, psize);
                return -1;
        }

        /* Make prefix_rd */
        prd.family = AF_UNSPEC;
        prd.prefixlen = 64;
        memcpy(&prd.val, pfx, 8);
        pfx += 8;

        /* Make EVPN prefix. */
        memset(&p, 0, sizeof(struct prefix_evpn));
        p.family = AF_EVPN;
        p.prefixlen = EVPN_TYPE_2_ROUTE_PREFIXLEN;
        p.prefix.route_type = BGP_EVPN_MAC_IP_ROUTE;

        /* Skip over Ethernet Seg Identifier for now. */
        pfx += 10;

        /* Skip over Ethernet Tag for now. */
        pfx += 4;

        /* Get the MAC Addr len */
        macaddr_len = *pfx++;

        /* Get the MAC Addr */
        if (macaddr_len == (ETH_ALEN * 8)) {
                memcpy(&p.prefix.mac.octet, pfx, ETH_ALEN);
                pfx += ETH_ALEN;
        } else {
                zlog_err(
                        "%u:%s - Rx EVPN Type-2 NLRI with unsupported MAC address length %d",
                        peer->bgp->vrf_id, peer->host, macaddr_len);
                return -1;
        }


        /* Get the IP. */
        ipaddr_len = *pfx++;
        if (ipaddr_len != 0 && ipaddr_len != IPV4_MAX_BITLEN
            && ipaddr_len != IPV6_MAX_BITLEN) {
                zlog_err(
                        "%u:%s - Rx EVPN Type-2 NLRI with unsupported IP address length %d",
                        peer->bgp->vrf_id, peer->host, ipaddr_len);
                return -1;
        }

        if (ipaddr_len) {
                ipaddr_len /= 8; /* Convert to bytes. */
                p.prefix.ip.ipa_type = (ipaddr_len == IPV4_MAX_BYTELEN)
                                               ? IPADDR_V4
                                               : IPADDR_V6;
                memcpy(&p.prefix.ip.ip.addr, pfx, ipaddr_len);
        }
        pfx += ipaddr_len;

        /* Get the VNI (in MPLS label field). */
        /* Note: We ignore the second VNI, if any. */
        label_pnt = (mpls_label_t *)pfx;

        /* Process the route. */
        if (attr)
                ret = bgp_update(peer, (struct prefix *)&p, addpath_id, attr,
                                 afi, safi, ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL,
                                 &prd, label_pnt, 0, NULL);
        else
                ret = bgp_withdraw(peer, (struct prefix *)&p, addpath_id, attr,
                                   afi, safi, ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL,
                                   &prd, label_pnt, NULL);
        return ret;
}

/*
 * Process received EVPN type-3 route (advertise or withdraw).
 */
static int process_type3_route(struct peer *peer, afi_t afi, safi_t safi,
                               struct attr *attr, u_char *pfx, int psize,
                               u_int32_t addpath_id)
{
        struct prefix_rd prd;
        struct prefix_evpn p;
        u_char ipaddr_len;
        int ret;

        /* Type-3 route should be either 17 or 29 bytes: RD (8), Eth Tag (4),
         * IP len (1) and IP (4 or 16).
         */
        if (psize != 17 && psize != 29) {
                zlog_err("%u:%s - Rx EVPN Type-3 NLRI with invalid length %d",
                         peer->bgp->vrf_id, peer->host, psize);
                return -1;
        }

        /* Make prefix_rd */
        prd.family = AF_UNSPEC;
        prd.prefixlen = 64;
        memcpy(&prd.val, pfx, 8);
        pfx += 8;

        /* Make EVPN prefix. */
        memset(&p, 0, sizeof(struct prefix_evpn));
        p.family = AF_EVPN;
        p.prefixlen = EVPN_TYPE_3_ROUTE_PREFIXLEN;
        p.prefix.route_type = BGP_EVPN_IMET_ROUTE;

        /* Skip over Ethernet Tag for now. */
        pfx += 4;

        /* Get the IP. */
        ipaddr_len = *pfx++;
        if (ipaddr_len == IPV4_MAX_BITLEN) {
                p.prefix.ip.ipa_type = IPADDR_V4;
                memcpy(&p.prefix.ip.ip.addr, pfx, IPV4_MAX_BYTELEN);
        } else {
                zlog_err(
                        "%u:%s - Rx EVPN Type-3 NLRI with unsupported IP address length %d",
                        peer->bgp->vrf_id, peer->host, ipaddr_len);
                return -1;
        }

        /* Process the route. */
        if (attr)
                ret = bgp_update(peer, (struct prefix *)&p, addpath_id, attr,
                                 afi, safi, ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL,
                                 &prd, NULL, 0, NULL);
        else
                ret = bgp_withdraw(peer, (struct prefix *)&p, addpath_id, attr,
                                   afi, safi, ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL,
                                   &prd, NULL, NULL);
        return ret;
}

/*
 * Process received EVPN type-5 route (advertise or withdraw).
 */
static int process_type5_route(struct peer *peer, afi_t afi, safi_t safi,
                               struct attr *attr, u_char *pfx, int psize,
                               u_int32_t addpath_id, int withdraw)
{
        struct prefix_rd prd;
        struct prefix_evpn p;
        struct bgp_route_evpn evpn;
        u_char ippfx_len;
        u_int32_t eth_tag;
        mpls_label_t *label_pnt;
        int ret;

        /* Type-5 route should be 34 or 58 bytes:
         * RD (8), ESI (10), Eth Tag (4), IP len (1), IP (4 or 16),
         * GW (4 or 16) and VNI (3).
         * Note that the IP and GW should both be IPv4 or both IPv6.
         */
        if (psize != 34 && psize != 58) {
                zlog_err("%u:%s - Rx EVPN Type-5 NLRI with invalid length %d",
                         peer->bgp->vrf_id, peer->host, psize);
                return -1;
        }

        /* Make prefix_rd */
        prd.family = AF_UNSPEC;
        prd.prefixlen = 64;
        memcpy(&prd.val, pfx, 8);
        pfx += 8;

        /* Make EVPN prefix. */
        memset(&p, 0, sizeof(struct prefix_evpn));
        p.family = AF_EVPN;
        p.prefix.route_type = BGP_EVPN_IP_PREFIX_ROUTE;

        /* Additional information outside of prefix - ESI and GW IP */
        memset(&evpn, 0, sizeof(evpn));

        /* Fetch ESI */
        memcpy(&evpn.eth_s_id.val, pfx, 10);
        pfx += 10;

        /* Fetch Ethernet Tag. */
        memcpy(&eth_tag, pfx, 4);
        p.prefix.eth_tag = ntohl(eth_tag);
        pfx += 4;

        /* Fetch IP prefix length. */
        ippfx_len = *pfx++;
        if (ippfx_len > IPV6_MAX_BITLEN) {
                zlog_err(
                        "%u:%s - Rx EVPN Type-5 NLRI with invalid IP Prefix length %d",
                        peer->bgp->vrf_id, peer->host, ippfx_len);
                return -1;
        }
        p.prefix.ip_prefix_length = ippfx_len;

        /* Determine IPv4 or IPv6 prefix */
        /* Since the address and GW are from the same family, this just becomes
         * a simple check on the total size.
         */
        if (psize == 34) {
                SET_IPADDR_V4(&p.prefix.ip);
                memcpy(&p.prefix.ip.ipaddr_v4, pfx, 4);
                pfx += 4;
                memcpy(&evpn.gw_ip.ipv4, pfx, 4);
                pfx += 4;
                p.prefixlen = PREFIX_LEN_ROUTE_TYPE_5_IPV4;
        } else {
                SET_IPADDR_V6(&p.prefix.ip);
                memcpy(&p.prefix.ip.ipaddr_v6, pfx, 16);
                pfx += 16;
                memcpy(&evpn.gw_ip.ipv6, pfx, 16);
                pfx += 16;
                p.prefixlen = PREFIX_LEN_ROUTE_TYPE_5_IPV6;
        }

        label_pnt = (mpls_label_t *)pfx;

        /* Process the route. */
        if (!withdraw)
                ret = bgp_update(peer, (struct prefix *)&p, addpath_id, attr,
                                 afi, safi, ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL,
                                 &prd, label_pnt, 0, &evpn);
        else
                ret = bgp_withdraw(peer, (struct prefix *)&p, addpath_id, attr,
                                   afi, safi, ZEBRA_ROUTE_BGP, BGP_ROUTE_NORMAL,
                                   &prd, label_pnt, &evpn);

        return ret;
}

static void evpn_mpattr_encode_type5(struct stream *s, struct prefix *p,
                                     struct prefix_rd *prd, mpls_label_t *label,
                                     struct attr *attr)
{
        int len;
        char temp[16];
        struct evpn_addr *p_evpn_p;

        memset(&temp, 0, 16);
        if (p->family != AF_EVPN)
                return;
        p_evpn_p = &(p->u.prefix_evpn);

        if (IS_IPADDR_V4(&p_evpn_p->ip))
                len = 8; /* ipv4 */
        else
                len = 32; /* ipv6 */
        /* Prefix contains RD, ESI, EthTag, IP length, IP, GWIP and VNI */
        stream_putc(s, 8 + 10 + 4 + 1 + len + 3);
        stream_put(s, prd->val, 8);
        if (attr)
                stream_put(s, &(attr->evpn_overlay.eth_s_id), 10);
        else
                stream_put(s, &temp, 10);
        stream_putl(s, p_evpn_p->eth_tag);
        stream_putc(s, p_evpn_p->ip_prefix_length);
        if (IS_IPADDR_V4(&p_evpn_p->ip))
                stream_put_ipv4(s, p_evpn_p->ip.ipaddr_v4.s_addr);
        else
                stream_put(s, &p_evpn_p->ip.ipaddr_v6, 16);
        if (attr) {
                if (IS_IPADDR_V4(&p_evpn_p->ip))
                        stream_put_ipv4(s,
                                        attr->evpn_overlay.gw_ip.ipv4.s_addr);
                else
                        stream_put(s, &(attr->evpn_overlay.gw_ip.ipv6), 16);
        } else {
                if (IS_IPADDR_V4(&p_evpn_p->ip))
                        stream_put_ipv4(s, 0);
                else
                        stream_put(s, &temp, 16);
        }

        if (label)
                stream_put(s, label, 3);
        else
                stream_put3(s, 0);
}

/*
 * Cleanup specific VNI upon EVPN (advertise-all-vni) being disabled.
 */
static void cleanup_vni_on_disable(struct hash_backet *backet, struct bgp *bgp)
{
        struct bgpevpn *vpn = (struct bgpevpn *)backet->data;

        /* Remove EVPN routes and schedule for processing. */
        delete_routes_for_vni(bgp, vpn);

        /* Clear "live" flag and see if hash needs to be freed. */
        UNSET_FLAG(vpn->flags, VNI_FLAG_LIVE);
        if (!is_vni_configured(vpn))
                bgp_evpn_free(bgp, vpn);
}

/*
 * Free a VNI entry; iterator function called during cleanup.
 */
static void free_vni_entry(struct hash_backet *backet, struct bgp *bgp)
{
        struct bgpevpn *vpn;

        vpn = (struct bgpevpn *)backet->data;
        delete_all_vni_routes(bgp, vpn);
        bgp_evpn_free(bgp, vpn);
}


/*
 * Public functions.
 */

/*
 * Handle change to BGP router id. This is invoked twice by the change
 * handler, first before the router id has been changed and then after
 * the router id has been changed. The first invocation will result in
 * local routes for all VNIs being deleted and withdrawn and the next
 * will result in the routes being re-advertised.
 */
void bgp_evpn_handle_router_id_update(struct bgp *bgp, int withdraw)
{
        if (withdraw)
                hash_iterate(bgp->vnihash,
                             (void (*)(struct hash_backet *,
                                       void *))withdraw_router_id_vni,
                             bgp);
        else
                hash_iterate(bgp->vnihash,
                             (void (*)(struct hash_backet *,
                                       void *))update_router_id_vni,
                             bgp);
}

/*
 * Handle change to export RT - update and advertise local routes.
 */
int bgp_evpn_handle_export_rt_change(struct bgp *bgp, struct bgpevpn *vpn)
{
        return update_routes_for_vni(bgp, vpn);
}

/*
 * Handle change to RD. This is invoked twice by the change handler,
 * first before the RD has been changed and then after the RD has
 * been changed. The first invocation will result in local routes
 * of this VNI being deleted and withdrawn and the next will result
 * in the routes being re-advertised.
 */
void bgp_evpn_handle_rd_change(struct bgp *bgp, struct bgpevpn *vpn,
                               int withdraw)
{
        if (withdraw)
                delete_withdraw_vni_routes(bgp, vpn);
        else
                update_advertise_vni_routes(bgp, vpn);
}

/*
 * Install routes for this VNI. Invoked upon change to Import RT.
 */
int bgp_evpn_install_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        return install_routes_for_vni(bgp, vpn);
}

/*
 * Uninstall all routes installed for this VNI. Invoked upon change
 * to Import RT.
 */
int bgp_evpn_uninstall_routes(struct bgp *bgp, struct bgpevpn *vpn)
{
        return uninstall_routes_for_vni(bgp, vpn);
}

/*
 * Function to display "tag" in route as a VNI.
 */
char *bgp_evpn_label2str(mpls_label_t *label, char *buf, int len)
{
        vni_t vni;

        vni = label2vni(label);
        snprintf(buf, len, "%u", vni);
        return buf;
}

/*
 * Function to convert evpn route to json format.
 * NOTE: We don't use prefix2str as the output here is a bit different.
 */
void bgp_evpn_route2json(struct prefix_evpn *p, json_object *json)
{
        char buf1[ETHER_ADDR_STRLEN];
        char buf2[PREFIX2STR_BUFFER];

        if (!json)
                return;

        if (p->prefix.route_type == BGP_EVPN_IMET_ROUTE) {
                json_object_int_add(json, "routeType", p->prefix.route_type);
                json_object_int_add(json, "ethTag", 0);
                json_object_int_add(json, "ipLen",
                                    IS_EVPN_PREFIX_IPADDR_V4(p)
                                            ? IPV4_MAX_BITLEN
                                            : IPV6_MAX_BITLEN);
                json_object_string_add(json, "ip",
                                       inet_ntoa(p->prefix.ip.ipaddr_v4));
        } else if (p->prefix.route_type == BGP_EVPN_MAC_IP_ROUTE) {
                if (IS_EVPN_PREFIX_IPADDR_NONE(p)) {
                        json_object_int_add(json, "routeType",
                                            p->prefix.route_type);
                        json_object_int_add(
                                json, "esi",
                                0); /* TODO: we don't support esi yet */
                        json_object_int_add(json, "ethTag", 0);
                        json_object_int_add(json, "macLen", 8 * ETH_ALEN);
                        json_object_string_add(json, "mac",
                                               prefix_mac2str(&p->prefix.mac,
                                                              buf1,
                                                              sizeof(buf1)));
                } else {
                        u_char family;

                        family = IS_EVPN_PREFIX_IPADDR_V4(p) ? AF_INET
                                                             : AF_INET6;

                        json_object_int_add(json, "routeType",
                                            p->prefix.route_type);
                        json_object_int_add(
                                json, "esi",
                                0); /* TODO: we don't support esi yet */
                        json_object_int_add(json, "ethTag", 0);
                        json_object_int_add(json, "macLen", 8 * ETH_ALEN);
                        json_object_string_add(json, "mac",
                                               prefix_mac2str(&p->prefix.mac,
                                                              buf1,
                                                              sizeof(buf1)));
                        json_object_int_add(json, "ipLen",
                                            IS_EVPN_PREFIX_IPADDR_V4(p)
                                                    ? IPV4_MAX_BITLEN
                                                    : IPV6_MAX_BITLEN);
                        json_object_string_add(
                                json, "ip",
                                inet_ntop(family, &p->prefix.ip.ip.addr, buf2,
                                          PREFIX2STR_BUFFER));
                }
        } else {
                /* Currently, this is to cater to other AF_ETHERNET code. */
        }
}

/*
 * Function to convert evpn route to string.
 * NOTE: We don't use prefix2str as the output here is a bit different.
 */
char *bgp_evpn_route2str(struct prefix_evpn *p, char *buf, int len)
{
        char buf1[ETHER_ADDR_STRLEN];
        char buf2[PREFIX2STR_BUFFER];

        if (p->prefix.route_type == BGP_EVPN_IMET_ROUTE) {
                snprintf(buf, len, "[%d]:[0]:[%d]:[%s]", p->prefix.route_type,
                         IS_EVPN_PREFIX_IPADDR_V4(p) ? IPV4_MAX_BITLEN
                                                     : IPV6_MAX_BITLEN,
                         inet_ntoa(p->prefix.ip.ipaddr_v4));
        } else if (p->prefix.route_type == BGP_EVPN_MAC_IP_ROUTE) {
                if (IS_EVPN_PREFIX_IPADDR_NONE(p))
                        snprintf(buf, len, "[%d]:[0]:[0]:[%d]:[%s]",
                                 p->prefix.route_type, 8 * ETH_ALEN,
                                 prefix_mac2str(&p->prefix.mac, buf1,
                                                sizeof(buf1)));
                else {
                        u_char family;

                        family = IS_EVPN_PREFIX_IPADDR_V4(p) ? AF_INET
                                                             : AF_INET6;
                        snprintf(buf, len, "[%d]:[0]:[0]:[%d]:[%s]:[%d]:[%s]",
                                 p->prefix.route_type, 8 * ETH_ALEN,
                                 prefix_mac2str(&p->prefix.mac, buf1,
                                                sizeof(buf1)),
                                 family == AF_INET ? IPV4_MAX_BITLEN
                                                   : IPV6_MAX_BITLEN,
                                 inet_ntop(family, &p->prefix.ip.ip.addr, buf2,
                                           PREFIX2STR_BUFFER));
                }
        } else {
                /* For EVPN route types not supported yet. */
                snprintf(buf, len, "(unsupported route type %d)",
                         p->prefix.route_type);
        }

        return (buf);
}

/*
 * Encode EVPN prefix in Update (MP_REACH)
 */
void bgp_evpn_encode_prefix(struct stream *s, struct prefix *p,
                            struct prefix_rd *prd, mpls_label_t *label,
                            struct attr *attr, int addpath_encode,
                            u_int32_t addpath_tx_id)
{
        struct prefix_evpn *evp = (struct prefix_evpn *)p;
        int ipa_len = 0;

        if (addpath_encode)
                stream_putl(s, addpath_tx_id);

        /* Route type */
        stream_putc(s, evp->prefix.route_type);

        switch (evp->prefix.route_type) {
        case BGP_EVPN_MAC_IP_ROUTE:
                if (IS_EVPN_PREFIX_IPADDR_V4(evp))
                        ipa_len = IPV4_MAX_BYTELEN;
                else if (IS_EVPN_PREFIX_IPADDR_V6(evp))
                        ipa_len = IPV6_MAX_BYTELEN;
                stream_putc(s, 33 + ipa_len);       // 1 VNI
                stream_put(s, prd->val, 8);      /* RD */
                stream_put(s, 0, 10);               /* ESI */
                stream_putl(s, 0);                  /* Ethernet Tag ID */
                stream_putc(s, 8 * ETH_ALEN); /* Mac Addr Len - bits */
                stream_put(s, evp->prefix.mac.octet, 6); /* Mac Addr */
                stream_putc(s, 8 * ipa_len);             /* IP address Length */
                if (ipa_len)
                        stream_put(s, &evp->prefix.ip.ip.addr,
                                   ipa_len); /* IP */
                stream_put(s, label,
                           BGP_LABEL_BYTES); /* VNI is contained in 'tag' */
                break;

        case BGP_EVPN_IMET_ROUTE:
                stream_putc(s, 17); // TODO: length - assumes IPv4 address
                stream_put(s, prd->val, 8);      /* RD */
                stream_putl(s, 0);               /* Ethernet Tag ID */
                stream_putc(s, IPV4_MAX_BITLEN); /* IP address Length - bits */
                /* Originating Router's IP Addr */
                stream_put_in_addr(s, &evp->prefix.ip.ipaddr_v4);
                break;

        case BGP_EVPN_IP_PREFIX_ROUTE:
                /* TODO: AddPath support. */
                evpn_mpattr_encode_type5(s, p, prd, label, attr);
                break;

        default:
                break;
        }
}

int bgp_nlri_parse_evpn(struct peer *peer, struct attr *attr,
                        struct bgp_nlri *packet, int withdraw)
{
        u_char *pnt;
        u_char *lim;
        afi_t afi;
        safi_t safi;
        u_int32_t addpath_id;
        int addpath_encoded;
        int psize = 0;
        u_char rtype;
        u_char rlen;
        struct prefix p;

        /* Check peer status. */
        if (peer->status != Established) {
                zlog_err("%u:%s - EVPN update received in state %d",
                         peer->bgp->vrf_id, peer->host, peer->status);
                return -1;
        }

        /* Start processing the NLRI - there may be multiple in the MP_REACH */
        pnt = packet->nlri;
        lim = pnt + packet->length;
        afi = packet->afi;
        safi = packet->safi;
        addpath_id = 0;

        addpath_encoded =
                (CHECK_FLAG(peer->af_cap[afi][safi], PEER_CAP_ADDPATH_AF_RX_ADV)
                 && CHECK_FLAG(peer->af_cap[afi][safi],
                               PEER_CAP_ADDPATH_AF_TX_RCV));

        for (; pnt < lim; pnt += psize) {
                /* Clear prefix structure. */
                memset(&p, 0, sizeof(struct prefix));

                /* Deal with path-id if AddPath is supported. */
                if (addpath_encoded) {
                        /* When packet overflow occurs return immediately. */
                        if (pnt + BGP_ADDPATH_ID_LEN > lim)
                                return -1;

                        addpath_id = ntohl(*((uint32_t *)pnt));
                        pnt += BGP_ADDPATH_ID_LEN;
                }

                /* All EVPN NLRI types start with type and length. */
                if (pnt + 2 > lim)
                        return -1;

                rtype = *pnt++;
                psize = rlen = *pnt++;

                /* When packet overflow occur return immediately. */
                if (pnt + psize > lim)
                        return -1;

                switch (rtype) {
                case BGP_EVPN_MAC_IP_ROUTE:
                        if (process_type2_route(peer, afi, safi,
                                                withdraw ? NULL : attr, pnt,
                                                psize, addpath_id)) {
                                zlog_err(
                                        "%u:%s - Error in processing EVPN type-2 NLRI size %d",
                                        peer->bgp->vrf_id, peer->host, psize);
                                return -1;
                        }
                        break;

                case BGP_EVPN_IMET_ROUTE:
                        if (process_type3_route(peer, afi, safi,
                                                withdraw ? NULL : attr, pnt,
                                                psize, addpath_id)) {
                                zlog_err(
                                        "%u:%s - Error in processing EVPN type-3 NLRI size %d",
                                        peer->bgp->vrf_id, peer->host, psize);
                                return -1;
                        }
                        break;

                case BGP_EVPN_IP_PREFIX_ROUTE:
                        if (process_type5_route(peer, afi, safi, attr, pnt,
                                                psize, addpath_id, withdraw)) {
                                zlog_err(
                                        "%u:%s - Error in processing EVPN type-5 NLRI size %d",
                                        peer->bgp->vrf_id, peer->host, psize);
                                return -1;
                        }
                        break;

                default:
                        break;
                }
        }

        /* Packet length consistency check. */
        if (pnt != lim)
                return -1;

        return 0;
}


/*
 * Map the RTs (configured or automatically derived) of a VNI to the VNI.
 * The mapping will be used during route processing.
 */
void bgp_evpn_map_vni_to_its_rts(struct bgp *bgp, struct bgpevpn *vpn)
{
        int i;
        struct ecommunity_val *eval;
        struct listnode *node, *nnode;
        struct ecommunity *ecom;

        for (ALL_LIST_ELEMENTS(vpn->import_rtl, node, nnode, ecom)) {
                for (i = 0; i < ecom->size; i++) {
                        eval = (struct ecommunity_val *)(ecom->val
                                                         + (i
                                                            * ECOMMUNITY_SIZE));
                        map_vni_to_rt(bgp, vpn, eval);
                }
        }
}

/*
 * Unmap the RTs (configured or automatically derived) of a VNI from the VNI.
 */
void bgp_evpn_unmap_vni_from_its_rts(struct bgp *bgp, struct bgpevpn *vpn)
{
        int i;
        struct ecommunity_val *eval;
        struct listnode *node, *nnode;
        struct ecommunity *ecom;

        for (ALL_LIST_ELEMENTS(vpn->import_rtl, node, nnode, ecom)) {
                for (i = 0; i < ecom->size; i++) {
                        struct irt_node *irt;
                        struct ecommunity_val eval_tmp;

                        eval = (struct ecommunity_val *)(ecom->val
                                                         + (i
                                                            * ECOMMUNITY_SIZE));
                        /* If using "automatic" RT, we only care about the
                         * local-admin sub-field.
                         * This is to facilitate using VNI as the RT for EBGP
                         * peering too.
                         */
                        memcpy(&eval_tmp, eval, ECOMMUNITY_SIZE);
                        if (!is_import_rt_configured(vpn))
                                mask_ecom_global_admin(&eval_tmp, eval);

                        irt = lookup_import_rt(bgp, &eval_tmp);
                        if (irt)
                                unmap_vni_from_rt(bgp, vpn, irt);
                }
        }
}

/*
 * Derive Import RT automatically for VNI and map VNI to RT.
 * The mapping will be used during route processing.
 */
void bgp_evpn_derive_auto_rt_import(struct bgp *bgp, struct bgpevpn *vpn)
{
        form_auto_rt(bgp, vpn, vpn->import_rtl);
        UNSET_FLAG(vpn->flags, VNI_FLAG_IMPRT_CFGD);

        /* Map RT to VNI */
        bgp_evpn_map_vni_to_its_rts(bgp, vpn);
}

/*
 * Derive Export RT automatically for VNI.
 */
void bgp_evpn_derive_auto_rt_export(struct bgp *bgp, struct bgpevpn *vpn)
{
        form_auto_rt(bgp, vpn, vpn->export_rtl);
        UNSET_FLAG(vpn->flags, VNI_FLAG_EXPRT_CFGD);
}

/*
 * Derive RD automatically for VNI using passed information - it
 * is of the form RouterId:unique-id-for-vni.
 */
void bgp_evpn_derive_auto_rd(struct bgp *bgp, struct bgpevpn *vpn)
{
        char buf[100];

        vpn->prd.family = AF_UNSPEC;
        vpn->prd.prefixlen = 64;
        sprintf(buf, "%s:%hu", inet_ntoa(bgp->router_id), vpn->rd_id);
        (void)str2prefix_rd(buf, &vpn->prd);
        UNSET_FLAG(vpn->flags, VNI_FLAG_RD_CFGD);
}

/*
 * Lookup VNI.
 */
struct bgpevpn *bgp_evpn_lookup_vni(struct bgp *bgp, vni_t vni)
{
        struct bgpevpn *vpn;
        struct bgpevpn tmp;

        memset(&tmp, 0, sizeof(struct bgpevpn));
        tmp.vni = vni;
        vpn = hash_lookup(bgp->vnihash, &tmp);
        return vpn;
}

/*
 * Create a new vpn - invoked upon configuration or zebra notification.
 */
struct bgpevpn *bgp_evpn_new(struct bgp *bgp, vni_t vni,
                             struct in_addr originator_ip)
{
        struct bgpevpn *vpn;

        if (!bgp)
                return NULL;

        vpn = XCALLOC(MTYPE_BGP_EVPN, sizeof(struct bgpevpn));
        if (!vpn)
                return NULL;

        /* Set values - RD and RT set to defaults. */
        vpn->vni = vni;
        vpn->originator_ip = originator_ip;

        /* Initialize route-target import and export lists */
        vpn->import_rtl = list_new();
        vpn->import_rtl->cmp = (int (*)(void *, void *))evpn_route_target_cmp;
        vpn->export_rtl = list_new();
        vpn->export_rtl->cmp = (int (*)(void *, void *))evpn_route_target_cmp;
        bf_assign_index(bgp->rd_idspace, vpn->rd_id);
        derive_rd_rt_for_vni(bgp, vpn);

        /* Initialize EVPN route table. */
        vpn->route_table = bgp_table_init(AFI_L2VPN, SAFI_EVPN);

        /* Add to hash */
        if (!hash_get(bgp->vnihash, vpn, hash_alloc_intern)) {
                XFREE(MTYPE_BGP_EVPN, vpn);
                return NULL;
        }
        QOBJ_REG(vpn, bgpevpn);
        return vpn;
}

/*
 * Free a given VPN - called in multiple scenarios such as zebra
 * notification, configuration being deleted, advertise-all-vni disabled etc.
 * This just frees appropriate memory, caller should have taken other
 * needed actions.
 */
void bgp_evpn_free(struct bgp *bgp, struct bgpevpn *vpn)
{
        bgp_table_unlock(vpn->route_table);
        bgp_evpn_unmap_vni_from_its_rts(bgp, vpn);
        list_delete_and_null(&vpn->import_rtl);
        list_delete_and_null(&vpn->export_rtl);
        bf_release_index(bgp->rd_idspace, vpn->rd_id);
        hash_release(bgp->vnihash, vpn);
        QOBJ_UNREG(vpn);
        XFREE(MTYPE_BGP_EVPN, vpn);
}

/*
 * Import route into matching VNI(s).
 */
int bgp_evpn_import_route(struct bgp *bgp, afi_t afi, safi_t safi,
                          struct prefix *p, struct bgp_info *ri)
{
        return install_uninstall_evpn_route(bgp, afi, safi, p, ri, 1);
}

/*
 * Unimport route from matching VNI(s).
 */
int bgp_evpn_unimport_route(struct bgp *bgp, afi_t afi, safi_t safi,
                            struct prefix *p, struct bgp_info *ri)
{
        return install_uninstall_evpn_route(bgp, afi, safi, p, ri, 0);
}

/* filter routes which have martian next hops */
int bgp_filter_evpn_routes_upon_martian_nh_change(struct bgp *bgp)
{
        afi_t afi;
        safi_t safi;
        struct bgp_node *rd_rn, *rn;
        struct bgp_table *table;
        struct bgp_info *ri;

        afi = AFI_L2VPN;
        safi = SAFI_EVPN;

        /* Walk entire global routing table and evaluate routes which could be
         * imported into this VPN. Note that we cannot just look at the routes
         * for the VNI's RD -
         * remote routes applicable for this VNI could have any RD.
         */
        /* EVPN routes are a 2-level table. */
        for (rd_rn = bgp_table_top(bgp->rib[afi][safi]); rd_rn;
             rd_rn = bgp_route_next(rd_rn)) {
                table = (struct bgp_table *)(rd_rn->info);
                if (!table)
                        continue;

                for (rn = bgp_table_top(table); rn; rn = bgp_route_next(rn)) {

                        for (ri = rn->info; ri; ri = ri->next) {

                                /* Consider "valid" remote routes applicable for
                                 * this VNI. */
                                if (!(ri->type == ZEBRA_ROUTE_BGP
                                      && ri->sub_type == BGP_ROUTE_NORMAL))
                                        continue;

                                if (bgp_nexthop_self(bgp, ri->attr->nexthop)) {

                                        char attr_str[BUFSIZ];
                                        char pbuf[PREFIX_STRLEN];

                                        bgp_dump_attr(ri->attr, attr_str,
                                                      BUFSIZ);

                                        if (bgp_debug_update(ri->peer, &rn->p,
                                                             NULL, 1))
                                                zlog_debug(
                                                        "%u: prefix %s with attr %s - DENIED due to martian or self nexthop",
                                                        bgp->vrf_id,
                                                        prefix2str(
                                                                &rn->p, pbuf,
                                                                sizeof(pbuf)),
                                                        attr_str);

                                        bgp_evpn_unimport_route(bgp, afi, safi,
                                                                &rn->p, ri);

                                        bgp_rib_remove(rn, ri, ri->peer, afi,
                                                       safi);
                                }
                        }
                }
        }

        return 0;
}

/*
 * Handle del of a local MACIP.
 */
int bgp_evpn_local_macip_del(struct bgp *bgp, vni_t vni, struct ethaddr *mac,
                             struct ipaddr *ip)
{
        struct bgpevpn *vpn;
        struct prefix_evpn p;

        if (!bgp->vnihash) {
                zlog_err("%u: VNI hash not created", bgp->vrf_id);
                return -1;
        }

        /* Lookup VNI hash - should exist. */
        vpn = bgp_evpn_lookup_vni(bgp, vni);
        if (!vpn || !is_vni_live(vpn)) {
                zlog_warn("%u: VNI hash entry for VNI %u %s at MACIP DEL",
                          bgp->vrf_id, vni, vpn ? "not live" : "not found");
                return -1;
        }

        /* Remove EVPN type-2 route and schedule for processing. */
        build_evpn_type2_prefix(&p, mac, ip);
        delete_evpn_route(bgp, vpn, &p);

        return 0;
}

/*
 * Handle add of a local MACIP.
 */
int bgp_evpn_local_macip_add(struct bgp *bgp, vni_t vni, struct ethaddr *mac,
                             struct ipaddr *ip, u_char flags)
{
        struct bgpevpn *vpn;
        struct prefix_evpn p;

        if (!bgp->vnihash) {
                zlog_err("%u: VNI hash not created", bgp->vrf_id);
                return -1;
        }

        /* Lookup VNI hash - should exist. */
        vpn = bgp_evpn_lookup_vni(bgp, vni);
        if (!vpn || !is_vni_live(vpn)) {
                zlog_warn("%u: VNI hash entry for VNI %u %s at MACIP ADD",
                          bgp->vrf_id, vni, vpn ? "not live" : "not found");
                return -1;
        }

        /* Create EVPN type-2 route and schedule for processing. */
        build_evpn_type2_prefix(&p, mac, ip);
        if (update_evpn_route(bgp, vpn, &p, flags)) {
                char buf[ETHER_ADDR_STRLEN];
                char buf2[INET6_ADDRSTRLEN];

                zlog_err(
                        "%u:Failed to create Type-2 route, VNI %u %s MAC %s IP %s",
                        bgp->vrf_id, vpn->vni,
                        CHECK_FLAG(flags, ZEBRA_MAC_TYPE_STICKY) ? "sticky gateway"
                                                                 : "",
                        prefix_mac2str(mac, buf, sizeof(buf)),
                        ipaddr2str(ip, buf2, sizeof(buf2)));
                return -1;
        }

        return 0;
}

/*
 * Handle del of a local VNI.
 */
int bgp_evpn_local_vni_del(struct bgp *bgp, vni_t vni)
{
        struct bgpevpn *vpn;

        if (!bgp->vnihash) {
                zlog_err("%u: VNI hash not created", bgp->vrf_id);
                return -1;
        }

        /* Locate VNI hash */
        vpn = bgp_evpn_lookup_vni(bgp, vni);
        if (!vpn) {
                zlog_warn("%u: VNI hash entry for VNI %u not found at DEL",
                          bgp->vrf_id, vni);
                return 0;
        }

        /* Remove all local EVPN routes and schedule for processing (to
         * withdraw from peers).
         */
        delete_routes_for_vni(bgp, vpn);

        /*
         * tunnel is no longer active, del tunnel ip address from tip_hash
         */
        bgp_tip_del(bgp, &vpn->originator_ip);

        /* Clear "live" flag and see if hash needs to be freed. */
        UNSET_FLAG(vpn->flags, VNI_FLAG_LIVE);
        if (!is_vni_configured(vpn))
                bgp_evpn_free(bgp, vpn);

        return 0;
}

/*
 * Handle add (or update) of a local VNI. The only VNI change we care
 * about is change to local-tunnel-ip.
 */
int bgp_evpn_local_vni_add(struct bgp *bgp, vni_t vni,
                           struct in_addr originator_ip)
{
        struct bgpevpn *vpn;
        struct prefix_evpn p;

        if (!bgp->vnihash) {
                zlog_err("%u: VNI hash not created", bgp->vrf_id);
                return -1;
        }

        /* Lookup VNI. If present and no change, exit. */
        vpn = bgp_evpn_lookup_vni(bgp, vni);
        if (vpn) {
                if (is_vni_live(vpn)
                    && IPV4_ADDR_SAME(&vpn->originator_ip, &originator_ip))
                        /* Probably some other param has changed that we don't
                         * care about. */
                        return 0;

                /* Local tunnel endpoint IP address has changed */
                handle_tunnel_ip_change(bgp, vpn, originator_ip);
        }

        /* Create or update as appropriate. */
        if (!vpn) {
                vpn = bgp_evpn_new(bgp, vni, originator_ip);
                if (!vpn) {
                        zlog_err(
                                "%u: Failed to allocate VNI entry for VNI %u - at Add",
                                bgp->vrf_id, vni);
                        return -1;
                }
        }

        /* if the VNI is live already, there is nothing more to do */
        if (is_vni_live(vpn))
                return 0;

        /* Mark as "live" */
        SET_FLAG(vpn->flags, VNI_FLAG_LIVE);

        /* tunnel is now active, add tunnel-ip to db */
        bgp_tip_add(bgp, &originator_ip);

        /* filter routes as nexthop database has changed */
        bgp_filter_evpn_routes_upon_martian_nh_change(bgp);

        /* Create EVPN type-3 route and schedule for processing. */
        build_evpn_type3_prefix(&p, vpn->originator_ip);
        if (update_evpn_route(bgp, vpn, &p, 0)) {
                zlog_err("%u: Type3 route creation failure for VNI %u",
                         bgp->vrf_id, vni);
                return -1;
        }

        /* If we have learnt and retained remote routes (VTEPs, MACs) for this
         * VNI,
         * install them.
         */
        install_routes_for_vni(bgp, vpn);

        /* If we are advertising gateway mac-ip
           It needs to be conveyed again to zebra */
        bgp_zebra_advertise_gw_macip(bgp, vpn->advertise_gw_macip, vpn->vni);

        return 0;
}

/*
 * Cleanup EVPN information on disable - Need to delete and withdraw
 * EVPN routes from peers.
 */
void bgp_evpn_cleanup_on_disable(struct bgp *bgp)
{
        hash_iterate(bgp->vnihash, (void (*)(struct hash_backet *,
                                             void *))cleanup_vni_on_disable,
                     bgp);
}

/*
 * Cleanup EVPN information - invoked at the time of bgpd exit or when the
 * BGP instance (default) is being freed.
 */
void bgp_evpn_cleanup(struct bgp *bgp)
{
        if (bgp->vnihash)
                hash_iterate(bgp->vnihash, (void (*)(struct hash_backet *,
                                                     void *))free_vni_entry,
                             bgp);
        if (bgp->import_rt_hash)
                hash_free(bgp->import_rt_hash);
        bgp->import_rt_hash = NULL;
        if (bgp->vnihash)
                hash_free(bgp->vnihash);
        bgp->vnihash = NULL;
        bf_free(bgp->rd_idspace);
}

/*
 * Initialization for EVPN
 * Create
 *  VNI hash table
 *  hash for RT to VNI
 *  unique rd id space for auto derivation of RD for VNIs
 */
void bgp_evpn_init(struct bgp *bgp)
{
        bgp->vnihash =
                hash_create(vni_hash_key_make, vni_hash_cmp, "BGP VNI Hash");
        bgp->import_rt_hash =
                hash_create(import_rt_hash_key_make, import_rt_hash_cmp,
                            "BGP Import RT Hash");
        bf_init(bgp->rd_idspace, UINT16_MAX);
        /*assign 0th index in the bitfield, so that we start with id 1*/
        bf_assign_zero_index(bgp->rd_idspace);
}