Merge pull request #2823 from opensourcerouting/snap-staticd

[mirror_frr.git] / ospfd / ospf_sr.c

/*
 * This is an implementation of Segment Routing
 * as per draft draft-ietf-ospf-segment-routing-extensions-24
 *
 * Module name: Segment Routing
 *
 * Author: Olivier Dugeon <olivier.dugeon@orange.com>
 * Author: Anselme Sawadogo <anselmesawadogo@gmail.com>
 *
 * Copyright (C) 2016 - 2018 Orange Labs http://www.orange.com
 *
 * This program 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 of the License, or (at your option)
 * any later version.
 *
 * This program 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 <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <zebra.h>

#include "command.h"
#include "hash.h"
#include "if.h"
#include "if.h"
#include "jhash.h"
#include "libospf.h" /* for ospf interface types */
#include "linklist.h"
#include "log.h"
#include "memory.h"
#include "monotime.h"
#include "network.h"
#include "prefix.h"
#include "sockunion.h" /* for inet_aton() */
#include "stream.h"
#include "table.h"
#include "thread.h"
#include "vty.h"
#include "zclient.h"
#include <lib/json.h>

#include "ospfd/ospfd.h"
#include "ospfd/ospf_interface.h"
#include "ospfd/ospf_ism.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_lsa.h"
#include "ospfd/ospf_lsdb.h"
#include "ospfd/ospf_neighbor.h"
#include "ospfd/ospf_nsm.h"
#include "ospfd/ospf_flood.h"
#include "ospfd/ospf_packet.h"
#include "ospfd/ospf_spf.h"
#include "ospfd/ospf_dump.h"
#include "ospfd/ospf_route.h"
#include "ospfd/ospf_ase.h"
#include "ospfd/ospf_sr.h"
#include "ospfd/ospf_ri.h"
#include "ospfd/ospf_ext.h"
#include "ospfd/ospf_zebra.h"

/*
 * Global variable to manage Segment Routing on this node.
 * Note that all parameter values are stored in network byte order.
 */
static struct ospf_sr_db OspfSR;
static void ospf_sr_register_vty(void);
static inline void del_sid_nhlfe(struct sr_nhlfe nhlfe);

/*
 * Segment Routing Data Base functions
 */

/* Hash function for Segment Routing entry */
static unsigned int sr_hash(void *p)
{
        const struct in_addr *rid = p;

        return jhash_1word(rid->s_addr, 0);
}

/* Compare 2 Router ID hash entries based on SR Node */
static int sr_cmp(const void *p1, const void *p2)
{
        const struct sr_node *srn = p1;
        const struct in_addr *rid = p2;

        return IPV4_ADDR_SAME(&srn->adv_router, rid);
}

/* Functions to remove an SR Link */
static void del_sr_link(void *val)
{
        struct sr_link *srl = (struct sr_link *)val;

        del_sid_nhlfe(srl->nhlfe[0]);
        del_sid_nhlfe(srl->nhlfe[1]);
        XFREE(MTYPE_OSPF_SR_PARAMS, val);
}

/* Functions to remove an SR Prefix */
static void del_sr_pref(void *val)
{
        struct sr_prefix *srp = (struct sr_prefix *)val;

        del_sid_nhlfe(srp->nhlfe);
        XFREE(MTYPE_OSPF_SR_PARAMS, val);
}

/* Allocate new Segment Routine node */
static struct sr_node *sr_node_new(struct in_addr *rid)
{

        if (rid == NULL)
                return NULL;

        struct sr_node *new;

        /* Allocate Segment Routing node memory */
        new = XCALLOC(MTYPE_OSPF_SR_PARAMS, sizeof(struct sr_node));

        /* Default Algorithm, SRGB and MSD */
        for (int i = 0; i < ALGORITHM_COUNT; i++)
                new->algo[i] = SR_ALGORITHM_UNSET;

        new->srgb.range_size = 0;
        new->srgb.lower_bound = 0;
        new->msd = 0;

        /* Create Link, Prefix and Range TLVs list */
        new->ext_link = list_new();
        new->ext_prefix = list_new();
        new->ext_link->del = del_sr_link;
        new->ext_prefix->del = del_sr_pref;

        IPV4_ADDR_COPY(&new->adv_router, rid);
        new->neighbor = NULL;
        new->instance = 0;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("  |-  Created new SR node for %s",
                           inet_ntoa(new->adv_router));
        return new;
}

/* Delete Segment Routing node */
static void sr_node_del(struct sr_node *srn)
{
        /* Sanity Check */
        if (srn == NULL)
                return;

        /* Clean Extended Link */
        list_delete_and_null(&srn->ext_link);

        /* Clean Prefix List */
        list_delete_and_null(&srn->ext_prefix);

        XFREE(MTYPE_OSPF_SR_PARAMS, srn);
}

/* Get SR Node for a given nexthop */
static struct sr_node *get_sr_node_by_nexthop(struct ospf *ospf,
                                              struct in_addr nexthop)
{
        struct ospf_interface *oi = NULL;
        struct ospf_neighbor *nbr = NULL;
        struct listnode *node;
        struct route_node *rn;
        struct sr_node *srn;
        bool found;

        /* Sanity check */
        if (OspfSR.neighbors == NULL)
                return NULL;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("      |-  Search SR-Node for nexthop %s",
                           inet_ntoa(nexthop));

        /* First, search neighbor Router ID for this nexthop */
        found = false;
        for (ALL_LIST_ELEMENTS_RO(ospf->oiflist, node, oi)) {
                for (rn = route_top(oi->nbrs); rn; rn = route_next(rn)) {
                        nbr = rn->info;
                        if ((nbr) && (IPV4_ADDR_SAME(&nexthop, &nbr->src))) {
                                found = true;
                                break;
                        }
                }
                if (found)
                        break;
        }

        if (!found)
                return NULL;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("      |-  Found nexthop Router ID %s",
                           inet_ntoa(nbr->router_id));
        /* Then, search SR Node */
        srn = (struct sr_node *)hash_lookup(OspfSR.neighbors, &nbr->router_id);

        return srn;
}

/*
 * Segment Routing Initialization functions
 */

/* Segment Routing starter function */
static int ospf_sr_start(struct ospf *ospf)
{
        struct route_node *rn;
        struct ospf_lsa *lsa;
        struct sr_node *srn;
        int rc = 0;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): Start Segment Routing", __func__);

        /* Initialize self SR Node */
        srn = hash_get(OspfSR.neighbors, (void *)&(ospf->router_id),
                       (void *)sr_node_new);

        /* Sanity Check */
        if (srn == NULL)
                return rc;

        /* Complete & Store self SR Node */
        srn->srgb.range_size = OspfSR.srgb.range_size;
        srn->srgb.lower_bound = OspfSR.srgb.lower_bound;
        srn->algo[0] = OspfSR.algo[0];
        srn->msd = OspfSR.msd;
        OspfSR.self = srn;

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("SR (%s): Update SR-DB from LSDB", __func__);

        /* Start by looking to Router Info & Extended LSA in lsdb */
        if ((ospf != NULL) && (ospf->backbone != NULL)) {
                LSDB_LOOP (OPAQUE_AREA_LSDB(ospf->backbone), rn, lsa) {
                        if (IS_LSA_MAXAGE(lsa) || IS_LSA_SELF(lsa))
                                continue;
                        int lsa_id =
                                GET_OPAQUE_TYPE(ntohl(lsa->data->id.s_addr));
                        switch (lsa_id) {
                        case OPAQUE_TYPE_ROUTER_INFORMATION_LSA:
                                ospf_sr_ri_lsa_update(lsa);
                                break;
                        case OPAQUE_TYPE_EXTENDED_PREFIX_LSA:
                                ospf_sr_ext_prefix_lsa_update(lsa);
                                break;
                        case OPAQUE_TYPE_EXTENDED_LINK_LSA:
                                ospf_sr_ext_link_lsa_update(lsa);
                                break;
                        default:
                                break;
                        }
                }
        }

        rc = 1;
        return rc;
}

/* Stop Segment Routing */
static void ospf_sr_stop(void)
{

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): Stop Segment Routing", __func__);

        /*
         * Remove all SR Nodes from the Hash table. Prefix and Link SID will
         * be remove though list_delete_and_null() call. See sr_node_del()
         */
        hash_clean(OspfSR.neighbors, (void *)sr_node_del);
}

/*
 * Segment Routing initialize function
 *
 * @param - nothing
 *
 * @return 0 if OK, -1 otherwise
 */
int ospf_sr_init(void)
{
        int rc = -1;

        if (IS_DEBUG_OSPF_SR)
                zlog_info("SR (%s): Initialize SR Data Base", __func__);

        memset(&OspfSR, 0, sizeof(struct ospf_sr_db));
        OspfSR.enabled = false;
        /* Only AREA flooding is supported in this release */
        OspfSR.scope = OSPF_OPAQUE_AREA_LSA;

        /* Initialize SRGB, Algorithms and MSD TLVs */
        /* Only Algorithm SPF is supported */
        OspfSR.algo[0] = SR_ALGORITHM_SPF;
        for (int i = 1; i < ALGORITHM_COUNT; i++)
                OspfSR.algo[i] = SR_ALGORITHM_UNSET;

        OspfSR.srgb.range_size = MPLS_DEFAULT_MAX_SRGB_SIZE;
        OspfSR.srgb.lower_bound = MPLS_DEFAULT_MIN_SRGB_LABEL;
        OspfSR.msd = 0;

        /* Initialize Hash table for neighbor SR nodes */
        OspfSR.neighbors = hash_create(sr_hash, sr_cmp, "OSPF_SR");
        if (OspfSR.neighbors == NULL)
                return rc;

        /* Initialize Route Table for prefix */
        OspfSR.prefix = route_table_init();
        if (OspfSR.prefix == NULL)
                return rc;

        /* Register Segment Routing VTY command */
        ospf_sr_register_vty();

        rc = 0;
        return rc;
}

/*
 * Segment Routing termination function
 *
 * @param - nothing
 * @return - nothing
 */
void ospf_sr_term(void)
{

        /* Stop Segment Routing */
        ospf_sr_stop();

        /* Clear SR Node Table */
        if (OspfSR.neighbors)
                hash_free(OspfSR.neighbors);

        /* Clear Prefix Table */
        if (OspfSR.prefix)
                route_table_finish(OspfSR.prefix);

        OspfSR.enabled = false;
        OspfSR.self = NULL;
}

/*
 * Segment Routing finish function
 *
 * @param - nothing
 * @return - nothing
 */
void ospf_sr_finish(void)
{
        /* Stop Segment Routing */
        ospf_sr_stop();

        OspfSR.enabled = false;
}

/*
 * Following functions are used to manipulate the
 * Next Hop Label Forwarding entry (NHLFE)
 */

/* Compute label from index */
static mpls_label_t index2label(uint32_t index, struct sr_srgb srgb)
{
        mpls_label_t label;

        label = srgb.lower_bound + index;
        if (label > (srgb.lower_bound + srgb.range_size))
                return MPLS_INVALID_LABEL;
        else
                return label;
}

/* Get neighbor full structure from address */
static struct ospf_neighbor *get_neighbor_by_addr(struct ospf *top,
                                                  struct in_addr addr)
{
        struct ospf_neighbor *nbr;
        struct ospf_interface *oi;
        struct listnode *node;
        struct route_node *rn;

        /* Sanity Check */
        if (top == NULL)
                return NULL;

        for (ALL_LIST_ELEMENTS_RO(top->oiflist, node, oi))
                for (rn = route_top(oi->nbrs); rn; rn = route_next(rn)) {
                        nbr = rn->info;
                        if (nbr)
                                if (IPV4_ADDR_SAME(&nbr->address.u.prefix4,
                                                   &addr)
                                    || IPV4_ADDR_SAME(&nbr->router_id, &addr)) {
                                        route_unlock_node(rn);
                                        return nbr;
                                }
                }
        return NULL;
}

/* Get OSPF Path from address */
static struct ospf_path *get_nexthop_by_addr(struct ospf *top,
                                             struct prefix_ipv4 p)
{
        struct ospf_route * or ;
        struct ospf_path *path;
        struct listnode *node;
        struct route_node *rn;

        /* Sanity Check */
        if (top == NULL)
                return NULL;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("      |-  Search Nexthop for prefix %s/%u",
                           inet_ntoa(p.prefix), p.prefixlen);

        rn = route_node_lookup(top->new_table, (struct prefix *)&p);

        /*
         * Check if we found an OSPF route. May be NULL if SPF has not
         * yet populate routing table for this prefix.
         */
        if (rn == NULL)
                return NULL;

        route_unlock_node(rn);
        or = rn->info;
        if (or == NULL)
                return NULL;

        /* Then search path from this route */
        for (ALL_LIST_ELEMENTS_RO(or->paths, node, path))
                if (path->nexthop.s_addr != INADDR_ANY || path->ifindex != 0)
                        return path;

        return NULL;
}

/* Compute NHLFE entry for Extended Link */
static int compute_link_nhlfe(struct sr_link *srl)
{
        struct ospf *top = ospf_lookup_by_vrf_id(VRF_DEFAULT);
        struct ospf_neighbor *nh;
        int rc = 0;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  Compute NHLFE for link %s/%u",
                           inet_ntoa(srl->nhlfe[0].prefv4.prefix),
                           srl->nhlfe[0].prefv4.prefixlen);

        /* First determine the OSPF Neighbor */
        nh = get_neighbor_by_addr(top, srl->nhlfe[0].nexthop);

        /* Neighbor could be not found when OSPF Adjacency just fire up
         * because SPF don't yet populate routing table. This NHLFE will
         * be fixed later when SR SPF schedule will be called.
         */
        if (nh == NULL)
                return rc;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  Found nexthop NHLFE %s",
                           inet_ntoa(nh->router_id));

        /* Set ifindex for this neighbor */
        srl->nhlfe[0].ifindex = nh->oi->ifp->ifindex;
        srl->nhlfe[1].ifindex = nh->oi->ifp->ifindex;

        /* Update neighbor address for LAN_ADJ_SID */
        if (srl->type == LAN_ADJ_SID) {
                IPV4_ADDR_COPY(&srl->nhlfe[0].nexthop, &nh->src);
                IPV4_ADDR_COPY(&srl->nhlfe[1].nexthop, &nh->src);
        }

        /* Set Input & Output Label */
        if (CHECK_FLAG(srl->flags[0], EXT_SUBTLV_LINK_ADJ_SID_VFLG))
                srl->nhlfe[0].label_in = srl->sid[0];
        else
                srl->nhlfe[0].label_in =
                        index2label(srl->sid[0], srl->srn->srgb);
        if (CHECK_FLAG(srl->flags[1], EXT_SUBTLV_LINK_ADJ_SID_VFLG))
                srl->nhlfe[1].label_in = srl->sid[1];
        else
                srl->nhlfe[1].label_in =
                        index2label(srl->sid[1], srl->srn->srgb);

        srl->nhlfe[0].label_out = MPLS_LABEL_IMPLICIT_NULL;
        srl->nhlfe[1].label_out = MPLS_LABEL_IMPLICIT_NULL;

        rc = 1;
        return rc;
}

/*
 * Compute NHLFE entry for Extended Prefix
 *
 * @param srp - Segment Routing Prefix
 *
 * @return -1 if next hop is not found, 0 if nexthop has not changed
 *         and 1 if success
 */
static int compute_prefix_nhlfe(struct sr_prefix *srp)
{
        struct ospf *top = ospf_lookup_by_vrf_id(VRF_DEFAULT);
        struct ospf_path *nh = NULL;
        struct sr_node *srnext;
        int rc = -1;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  Compute NHLFE for prefix %s/%u",
                           inet_ntoa(srp->nhlfe.prefv4.prefix),
                           srp->nhlfe.prefv4.prefixlen);

        /* First determine the nexthop */
        nh = get_nexthop_by_addr(top, srp->nhlfe.prefv4);

        /* Nexthop could be not found when OSPF Adjacency just fire up
         * because SPF don't yet populate routing table. This NHLFE will
         * be fixed later when SR SPF schedule will be called.
         */
        if (nh == NULL)
                return rc;

        /* Check if NextHop has changed when call after running a new SPF */
        if (IPV4_ADDR_SAME(&nh->nexthop, &srp->nhlfe.nexthop)
            && (nh->ifindex == srp->nhlfe.ifindex))
                return 0;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  Found new next hop for this NHLFE: %s",
                           inet_ntoa(nh->nexthop));

        /*
         * Get SR-Node for this nexthop. Could be not yet available
         * as Extende Link / Prefix and Router Information are flooded
         * after LSA Type 1 & 2 which populate the OSPF Route Table
         */
        srnext = get_sr_node_by_nexthop(top, nh->nexthop);
        if (srnext == NULL)
                return rc;

        /* And store this information for later update if SR Node is found */
        srnext->neighbor = OspfSR.self;
        if (IPV4_ADDR_SAME(&srnext->adv_router, &srp->adv_router))
                srp->nexthop = NULL;
        else
                srp->nexthop = srnext;

        /*
         * SR Node could be known, but SRGB could be not initialize
         * This is due to the fact that Extended Link / Prefix could
         * be received before corresponding Router Information LSA
         */
        if ((srnext == NULL) || (srnext->srgb.lower_bound == 0)
            || (srnext->srgb.range_size == 0))
                return rc;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  Found SRGB %u/%u for next hop SR-Node %s",
                           srnext->srgb.range_size, srnext->srgb.lower_bound,
                           inet_ntoa(srnext->adv_router));

        /* Set ip addr & ifindex for this neighbor */
        IPV4_ADDR_COPY(&srp->nhlfe.nexthop, &nh->nexthop);
        srp->nhlfe.ifindex = nh->ifindex;

        /* Compute Input Label with self SRGB */
        srp->nhlfe.label_in = index2label(srp->sid, OspfSR.srgb);
        /*
         * and Output Label with Next hop SR Node SRGB or Implicit Null label
         * if next hop is the destination and request PHP
         */
        if ((srp->nexthop == NULL)
            && (!CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_NPFLG)))
                srp->nhlfe.label_out = MPLS_LABEL_IMPLICIT_NULL;
        else if (CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_VFLG))
                srp->nhlfe.label_out = srp->sid;
        else
                srp->nhlfe.label_out = index2label(srp->sid, srnext->srgb);

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  Computed new labels in: %u out: %u",
                           srp->nhlfe.label_in, srp->nhlfe.label_out);

        rc = 1;
        return rc;
}

/* Send MPLS Label entry to Zebra for installation or deletion */
static int ospf_zebra_send_mpls_labels(int cmd, struct sr_nhlfe nhlfe)
{
        struct stream *s;

        /* Reset stream. */
        s = zclient->obuf;
        stream_reset(s);

        zclient_create_header(s, cmd, VRF_DEFAULT);
        stream_putc(s, ZEBRA_LSP_SR);
        /* OSPF Segment Routing currently support only IPv4 */
        stream_putl(s, nhlfe.prefv4.family);
        stream_put_in_addr(s, &nhlfe.prefv4.prefix);
        stream_putc(s, nhlfe.prefv4.prefixlen);
        stream_put_in_addr(s, &nhlfe.nexthop);
        stream_putl(s, nhlfe.ifindex);
        stream_putc(s, OSPF_SR_PRIORITY_DEFAULT);
        stream_putl(s, nhlfe.label_in);
        stream_putl(s, nhlfe.label_out);

        /* Put length at the first point of the stream. */
        stream_putw_at(s, 0, stream_get_endp(s));

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  %s LSP %u/%u for %s/%u via %u",
                           cmd == ZEBRA_MPLS_LABELS_ADD ? "Add" : "Delete",
                           nhlfe.label_in, nhlfe.label_out,
                           inet_ntoa(nhlfe.prefv4.prefix),
                           nhlfe.prefv4.prefixlen, nhlfe.ifindex);

        return zclient_send_message(zclient);
}

/* Request zebra to install/remove FEC in FIB */
static int ospf_zebra_send_mpls_ftn(int cmd, struct sr_nhlfe nhlfe)
{
        struct zapi_route api;
        struct zapi_nexthop *api_nh;

        /* Support only IPv4 */
        if (nhlfe.prefv4.family != AF_INET)
                return -1;

        memset(&api, 0, sizeof(api));
        api.vrf_id = VRF_DEFAULT;
        api.type = ZEBRA_ROUTE_OSPF;
        api.safi = SAFI_UNICAST;
        memcpy(&api.prefix, &nhlfe.prefv4, sizeof(struct prefix_ipv4));

        if (cmd == ZEBRA_ROUTE_ADD) {
                /* Metric value. */
                SET_FLAG(api.message, ZAPI_MESSAGE_METRIC);
                api.metric = OSPF_SR_DEFAULT_METRIC;
                /* Nexthop */
                SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
                api_nh = &api.nexthops[0];
                IPV4_ADDR_COPY(&api_nh->gate.ipv4, &nhlfe.nexthop);
                api_nh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
                api_nh->ifindex = nhlfe.ifindex;
                /* MPLS labels */
                SET_FLAG(api.message, ZAPI_MESSAGE_LABEL);
                api_nh->labels[0] = nhlfe.label_out;
                api_nh->label_num = 1;
                api_nh->vrf_id = VRF_DEFAULT;
                api.nexthop_num = 1;
        }

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("    |-  %s FEC %u for %s/%u via %u",
                           cmd == ZEBRA_ROUTE_ADD ? "Add" : "Delete",
                           nhlfe.label_out, inet_ntoa(nhlfe.prefv4.prefix),
                           nhlfe.prefv4.prefixlen, nhlfe.ifindex);

        return zclient_route_send(cmd, zclient, &api);
}

/* Add new NHLFE entry for SID */
static inline void add_sid_nhlfe(struct sr_nhlfe nhlfe)
{
        if ((nhlfe.label_in != 0) && (nhlfe.label_out != 0)) {
                ospf_zebra_send_mpls_labels(ZEBRA_MPLS_LABELS_ADD, nhlfe);
                if (nhlfe.label_out != MPLS_LABEL_IMPLICIT_NULL)
                        ospf_zebra_send_mpls_ftn(ZEBRA_ROUTE_ADD, nhlfe);
        }
}

/* Remove NHLFE entry for SID */
static inline void del_sid_nhlfe(struct sr_nhlfe nhlfe)
{
        if ((nhlfe.label_in != 0) && (nhlfe.label_out != 0)) {
                ospf_zebra_send_mpls_labels(ZEBRA_MPLS_LABELS_DELETE, nhlfe);
                if (nhlfe.label_out != MPLS_LABEL_IMPLICIT_NULL)
                        ospf_zebra_send_mpls_ftn(ZEBRA_ROUTE_DELETE, nhlfe);
        }
}

/* Update NHLFE entry for SID */
static inline void update_sid_nhlfe(struct sr_nhlfe n1, struct sr_nhlfe n2)
{

        del_sid_nhlfe(n1);
        add_sid_nhlfe(n2);
}

/*
 * Functions to parse and get Extended Link / Prefix
 * TLVs and SubTLVs
 */

/* Extended Link SubTLVs Getter */
static struct sr_link *get_ext_link_sid(struct tlv_header *tlvh)
{

        struct sr_link *srl;
        struct ext_tlv_link *link = (struct ext_tlv_link *)tlvh;
        struct ext_subtlv_adj_sid *adj_sid;
        struct ext_subtlv_lan_adj_sid *lan_sid;
        struct ext_subtlv_rmt_itf_addr *rmt_itf;

        struct tlv_header *sub_tlvh;
        uint16_t length = 0, sum = 0, i = 0;

        srl = XCALLOC(MTYPE_OSPF_SR_PARAMS, sizeof(struct sr_link));

        /* Initialize TLV browsing */
        length = ntohs(tlvh->length) - EXT_TLV_LINK_SIZE;
        sub_tlvh = (struct tlv_header *)((char *)(tlvh) + TLV_HDR_SIZE
                                         + EXT_TLV_LINK_SIZE);
        for (; sum < length; sub_tlvh = TLV_HDR_NEXT(sub_tlvh)) {
                switch (ntohs(sub_tlvh->type)) {
                case EXT_SUBTLV_ADJ_SID:
                        adj_sid = (struct ext_subtlv_adj_sid *)sub_tlvh;
                        srl->type = ADJ_SID;
                        i = CHECK_FLAG(adj_sid->flags,
                                       EXT_SUBTLV_LINK_ADJ_SID_BFLG)
                                    ? 1
                                    : 0;
                        srl->flags[i] = adj_sid->flags;
                        if (CHECK_FLAG(adj_sid->flags,
                                       EXT_SUBTLV_LINK_ADJ_SID_VFLG))
                                srl->sid[i] = GET_LABEL(ntohl(adj_sid->value));
                        else
                                srl->sid[i] = ntohl(adj_sid->value);
                        IPV4_ADDR_COPY(&srl->nhlfe[i].nexthop, &link->link_id);
                        break;
                case EXT_SUBTLV_LAN_ADJ_SID:
                        lan_sid = (struct ext_subtlv_lan_adj_sid *)sub_tlvh;
                        srl->type = LAN_ADJ_SID;
                        i = CHECK_FLAG(lan_sid->flags,
                                       EXT_SUBTLV_LINK_ADJ_SID_BFLG)
                                    ? 1
                                    : 0;
                        srl->flags[i] = lan_sid->flags;
                        if (CHECK_FLAG(lan_sid->flags,
                                       EXT_SUBTLV_LINK_ADJ_SID_VFLG))
                                srl->sid[i] = GET_LABEL(ntohl(lan_sid->value));
                        else
                                srl->sid[i] = ntohl(lan_sid->value);
                        IPV4_ADDR_COPY(&srl->nhlfe[i].nexthop,
                                       &lan_sid->neighbor_id);
                        break;
                case EXT_SUBTLV_RMT_ITF_ADDR:
                        rmt_itf = (struct ext_subtlv_rmt_itf_addr *)sub_tlvh;
                        IPV4_ADDR_COPY(&srl->nhlfe[0].nexthop, &rmt_itf->value);
                        IPV4_ADDR_COPY(&srl->nhlfe[1].nexthop, &rmt_itf->value);
                        break;
                default:
                        break;
                }
                sum += TLV_SIZE(sub_tlvh);
        }

        IPV4_ADDR_COPY(&srl->nhlfe[0].prefv4.prefix, &link->link_data);
        srl->nhlfe[0].prefv4.prefixlen = IPV4_MAX_PREFIXLEN;
        srl->nhlfe[0].prefv4.family = AF_INET;
        apply_mask_ipv4(&srl->nhlfe[0].prefv4);
        IPV4_ADDR_COPY(&srl->nhlfe[1].prefv4.prefix, &link->link_data);
        srl->nhlfe[1].prefv4.prefixlen = IPV4_MAX_PREFIXLEN;
        srl->nhlfe[1].prefv4.family = AF_INET;
        apply_mask_ipv4(&srl->nhlfe[1].prefv4);

        if (IS_DEBUG_OSPF_SR) {
                zlog_debug("  |-  Found primary Adj/Lan Sid %u for %s/%u",
                           srl->sid[0], inet_ntoa(srl->nhlfe[0].prefv4.prefix),
                           srl->nhlfe[0].prefv4.prefixlen);
                zlog_debug("  |-  Found backup Adj/Lan Sid %u for %s/%u",
                           srl->sid[1], inet_ntoa(srl->nhlfe[1].prefv4.prefix),
                           srl->nhlfe[1].prefv4.prefixlen);
        }

        return srl;
}

/* Extended Prefix SubTLVs Getter */
static struct sr_prefix *get_ext_prefix_sid(struct tlv_header *tlvh)
{

        struct sr_prefix *srp;
        struct ext_tlv_prefix *pref = (struct ext_tlv_prefix *)tlvh;
        struct ext_subtlv_prefix_sid *psid;

        struct tlv_header *sub_tlvh;
        uint16_t length = 0, sum = 0;

        srp = XCALLOC(MTYPE_OSPF_SR_PARAMS, sizeof(struct sr_prefix));

        /* Initialize TLV browsing */
        length = ntohs(tlvh->length) - EXT_TLV_PREFIX_SIZE;
        sub_tlvh = (struct tlv_header *)((char *)(tlvh) + TLV_HDR_SIZE
                                         + EXT_TLV_PREFIX_SIZE);
        for (; sum < length; sub_tlvh = TLV_HDR_NEXT(sub_tlvh)) {
                switch (ntohs(sub_tlvh->type)) {
                case EXT_SUBTLV_PREFIX_SID:
                        psid = (struct ext_subtlv_prefix_sid *)sub_tlvh;
                        if (psid->algorithm != SR_ALGORITHM_SPF) {
                                zlog_err("SR (%s): Unsupported Algorithm",
                                         __func__);
                                XFREE(MTYPE_OSPF_SR_PARAMS, srp);
                                return NULL;
                        }
                        srp->type = PREF_SID;
                        srp->flags = psid->flags;
                        if (CHECK_FLAG(psid->flags, EXT_SUBTLV_PREFIX_SID_VFLG))
                                srp->sid = GET_LABEL(ntohl(psid->value));
                        else
                                srp->sid = ntohl(psid->value);
                        IPV4_ADDR_COPY(&srp->nhlfe.prefv4.prefix,
                                       &pref->address);
                        srp->nhlfe.prefv4.prefixlen = pref->pref_length;
                        srp->nhlfe.prefv4.family = AF_INET;
                        apply_mask_ipv4(&srp->nhlfe.prefv4);
                        break;
                default:
                        break;
                }
                sum += TLV_SIZE(sub_tlvh);
        }

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("  |-  Found SID %u for prefix %s/%u", srp->sid,
                           inet_ntoa(srp->nhlfe.prefv4.prefix),
                           srp->nhlfe.prefv4.prefixlen);
        return srp;
}

/*
 * Functions to manipulate Segment Routing Link & Prefix structures
 */

/* Compare two Segment Link: return 0 if equal, 1 otherwise */
static inline int sr_link_cmp(struct sr_link *srl1, struct sr_link *srl2)
{
        if ((srl1->sid[0] == srl2->sid[0]) && (srl1->sid[1] == srl2->sid[1])
            && (srl1->type == srl2->type) && (srl1->flags[0] == srl2->flags[0])
            && (srl1->flags[1] == srl2->flags[1]))
                return 0;
        else
                return 1;
}

/* Compare two Segment Prefix: return 0 if equal, 1 otherwise */
static inline int sr_prefix_cmp(struct sr_prefix *srp1, struct sr_prefix *srp2)
{
        if ((srp1->sid == srp2->sid) && (srp1->flags == srp2->flags))
                return 0;
        else
                return 1;
}

/* Update Segment Link of given Segment Routing Node */
static void update_ext_link_sid(struct sr_node *srn, struct sr_link *srl,
                                uint8_t lsa_flags)
{
        struct listnode *node;
        struct sr_link *lk;
        bool found = false;

        /* Sanity check */
        if ((srn == NULL) || (srl == NULL))
                return;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("  |-  Process Extended Link Adj/Lan-SID");

        /* Process only Local Adj/Lan_Adj SID coming from LSA SELF */
        if (!CHECK_FLAG(srl->flags[0], EXT_SUBTLV_LINK_ADJ_SID_LFLG)
            || !CHECK_FLAG(srl->flags[1], EXT_SUBTLV_LINK_ADJ_SID_LFLG)
            || !CHECK_FLAG(lsa_flags, OSPF_LSA_SELF))
                return;

        /* Search for existing Segment Link */
        for (ALL_LIST_ELEMENTS_RO(srn->ext_link, node, lk))
                if (lk->instance == srl->instance) {
                        found = true;
                        break;
                }

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("  |-  %s SR Link 8.0.0.%u for SR node %s",
                           found ? "Update" : "Add",
                           GET_OPAQUE_ID(srl->instance),
                           inet_ntoa(srn->adv_router));

        /* if not found, add new Segment Link and install NHLFE */
        if (!found) {
                /* Complete SR-Link and add it to SR-Node list */
                srl->srn = srn;
                IPV4_ADDR_COPY(&srl->adv_router, &srn->adv_router);
                listnode_add(srn->ext_link, srl);
                /* Try to set MPLS table */
                if (compute_link_nhlfe(srl)) {
                        add_sid_nhlfe(srl->nhlfe[0]);
                        add_sid_nhlfe(srl->nhlfe[1]);
                }
        } else {
                if (sr_link_cmp(lk, srl)) {
                        if (compute_link_nhlfe(srl)) {
                                update_sid_nhlfe(lk->nhlfe[0], srl->nhlfe[0]);
                                update_sid_nhlfe(lk->nhlfe[1], srl->nhlfe[1]);
                                /* Replace Segment List */
                                listnode_delete(srn->ext_link, lk);
                                XFREE(MTYPE_OSPF_SR_PARAMS, lk);
                                srl->srn = srn;
                                IPV4_ADDR_COPY(&srl->adv_router,
                                               &srn->adv_router);
                                listnode_add(srn->ext_link, srl);
                        } else {
                                /* New NHLFE was not found.
                                 * Just free the SR Link
                                 */
                                XFREE(MTYPE_OSPF_SR_PARAMS, srl);
                        }
                } else {
                        /*
                         * This is just an LSA refresh.
                         * Stop processing and free SR Link
                         */
                        XFREE(MTYPE_OSPF_SR_PARAMS, srl);
                }
        }
}

/* Update Segment Prefix of given Segment Routing Node */
static void update_ext_prefix_sid(struct sr_node *srn, struct sr_prefix *srp)
{

        struct listnode *node;
        struct sr_prefix *pref;
        bool found = false;

        /* Sanity check */
        if (srn == NULL || srp == NULL)
                return;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("  |-  Process Extended Prefix SID %u", srp->sid);

        /* Process only Global Prefix SID */
        if (CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_LFLG))
                return;

        /* Search for existing Segment Prefix */
        for (ALL_LIST_ELEMENTS_RO(srn->ext_prefix, node, pref))
                if (pref->instance == srp->instance) {
                        found = true;
                        break;
                }

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("  |-  %s SR LSA ID 7.0.0.%u for SR node %s",
                           found ? "Update" : "Add",
                           GET_OPAQUE_ID(srp->instance),
                           inet_ntoa(srn->adv_router));

        /* if not found, add new Segment Prefix and install NHLFE */
        if (!found) {
                /* Complete SR-Prefix and add it to SR-Node list */
                srp->srn = srn;
                IPV4_ADDR_COPY(&srp->adv_router, &srn->adv_router);
                listnode_add(srn->ext_prefix, srp);
                /* Try to set MPLS table */
                if (compute_prefix_nhlfe(srp) == 1)
                        add_sid_nhlfe(srp->nhlfe);
        } else {
                if (sr_prefix_cmp(pref, srp)) {
                        if (compute_prefix_nhlfe(srp) == 1) {
                                update_sid_nhlfe(pref->nhlfe, srp->nhlfe);
                                /* Replace Segment Prefix */
                                listnode_delete(srn->ext_prefix, pref);
                                XFREE(MTYPE_OSPF_SR_PARAMS, pref);
                                srp->srn = srn;
                                IPV4_ADDR_COPY(&srp->adv_router,
                                               &srn->adv_router);
                                listnode_add(srn->ext_prefix, srp);
                        } else {
                                /* New NHLFE was not found.
                                 * Just free the SR Prefix
                                 */
                                XFREE(MTYPE_OSPF_SR_PARAMS, srp);
                        }
                } else {
                        /* This is just an LSA refresh.
                         * Stop processing and free SR Prefix
                         */
                        XFREE(MTYPE_OSPF_SR_PARAMS, srp);
                }
        }
}

/*
 * When change the FRR Self SRGB, update the NHLFE Input Label
 * for all Extended Prefix with SID index through hash_iterate()
 */
static void update_in_nhlfe(struct hash_backet *backet, void *args)
{
        struct listnode *node;
        struct sr_node *srn = (struct sr_node *)backet->data;
        struct sr_prefix *srp;
        struct sr_nhlfe new;

        /* Process Every Extended Prefix for this SR-Node */
        for (ALL_LIST_ELEMENTS_RO(srn->ext_prefix, node, srp)) {
                /* Process Self SRN only if NO-PHP is requested */
                if ((srn == OspfSR.self)
                    && !CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_NPFLG))
                        continue;

                /* Process only SID Index */
                if (CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_VFLG))
                        continue;

                /* OK. Compute new NHLFE */
                memcpy(&new, &srp->nhlfe, sizeof(struct sr_nhlfe));
                new.label_in = index2label(srp->sid, OspfSR.srgb);
                /* Update MPLS LFIB */
                update_sid_nhlfe(srp->nhlfe, new);
                /* Finally update Input Label */
                srp->nhlfe.label_in = new.label_in;
        }
}

/*
 * When SRGB has changed, update NHLFE Output Label for all Extended Prefix
 * with SID index which use the given SR-Node as nexthop though hash_iterate()
 */
static void update_out_nhlfe(struct hash_backet *backet, void *args)
{
        struct listnode *node;
        struct sr_node *srn = (struct sr_node *)backet->data;
        struct sr_node *srnext = (struct sr_node *)args;
        struct sr_prefix *srp;
        struct sr_nhlfe new;

        for (ALL_LIST_ELEMENTS_RO(srn->ext_prefix, node, srp)) {
                /* Process only SID Index for next hop without PHP */
                if ((srp->nexthop == NULL)
                    && (!CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_NPFLG)))
                        continue;
                memcpy(&new, &srp->nhlfe, sizeof(struct sr_nhlfe));
                new.label_out = index2label(srp->sid, srnext->srgb);
                update_sid_nhlfe(srp->nhlfe, new);
                srp->nhlfe.label_out = new.label_out;
        }
}

/*
 * Following functions are call when new Segment Routing LSA are received
 *  - Router Information: ospf_sr_ri_lsa_update() & ospf_sr_ri_lsa_delete()
 *  - Extended Link: ospf_sr_ext_link_update() & ospf_sr_ext_link_delete()
 *  - Extended Prefix: ospf_ext_prefix_update() & ospf_sr_ext_prefix_delete()
 */

/* Update Segment Routing from Router Information LSA */
void ospf_sr_ri_lsa_update(struct ospf_lsa *lsa)
{
        struct sr_node *srn;
        struct tlv_header *tlvh;
        struct lsa_header *lsah = (struct lsa_header *)lsa->data;
        struct ri_sr_tlv_sid_label_range *ri_srgb;
        struct ri_sr_tlv_sr_algorithm *algo;
        struct sr_srgb srgb;
        uint16_t length = 0, sum = 0;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug(
                        "SR (%s): Process Router "
                        "Information LSA 4.0.0.%u from %s",
                        __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                        inet_ntoa(lsah->adv_router));

        /* Sanity check */
        if (IS_LSA_SELF(lsa))
                return;

        if (OspfSR.neighbors == NULL) {
                zlog_err("SR (%s): Abort! no valid SR DataBase", __func__);
                return;
        }

        /* Get SR Node in hash table from Router ID */
        srn = hash_get(OspfSR.neighbors, (void *)&(lsah->adv_router),
                       (void *)sr_node_new);

        /* Sanity check */
        if (srn == NULL) {
                zlog_err("SR (%s): Abort! can't create SR node in hash table",
                         __func__);
                return;
        }

        if ((srn->instance != 0) && (srn->instance != ntohl(lsah->id.s_addr))) {
                zlog_err(
                        "SR (%s): Abort! Wrong "
                        "LSA ID 4.0.0.%u for SR node %s/%u",
                        __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                        inet_ntoa(lsah->adv_router), srn->instance);
                return;
        }

        /* Collect Router Information Sub TLVs */
        /* Initialize TLV browsing */
        length = ntohs(lsah->length) - OSPF_LSA_HEADER_SIZE;
        srgb.range_size = 0;
        srgb.lower_bound = 0;

        for (tlvh = TLV_HDR_TOP(lsah); (sum < length) && (tlvh != NULL);
             tlvh = TLV_HDR_NEXT(tlvh)) {
                switch (ntohs(tlvh->type)) {
                case RI_SR_TLV_SR_ALGORITHM:
                        algo = (struct ri_sr_tlv_sr_algorithm *)tlvh;
                        int i;

                        for (i = 0; i < ntohs(algo->header.length); i++)
                                srn->algo[i] = algo->value[0];
                        for (; i < ALGORITHM_COUNT; i++)
                                srn->algo[i] = SR_ALGORITHM_UNSET;
                        sum += TLV_SIZE(tlvh);
                        break;
                case RI_SR_TLV_SID_LABEL_RANGE:
                        ri_srgb = (struct ri_sr_tlv_sid_label_range *)tlvh;
                        srgb.range_size = GET_RANGE_SIZE(ntohl(ri_srgb->size));
                        srgb.lower_bound =
                                GET_LABEL(ntohl(ri_srgb->lower.value));
                        sum += TLV_SIZE(tlvh);
                        break;
                case RI_SR_TLV_NODE_MSD:
                        srn->msd = ((struct ri_sr_tlv_node_msd *)(tlvh))->value;
                        sum += TLV_SIZE(tlvh);
                        break;
                default:
                        sum += TLV_SIZE(tlvh);
                        break;
                }
        }

        /* Check that we collect mandatory parameters */
        if (srn->algo[0] == SR_ALGORITHM_UNSET || srgb.range_size == 0
            || srgb.lower_bound == 0) {
                zlog_warn("SR (%s): Missing mandatory parameters. Abort!",
                          __func__);
                hash_release(OspfSR.neighbors, &(srn->adv_router));
                XFREE(MTYPE_OSPF_SR_PARAMS, srn);
                return;
        }

        /* Check if it is a new SR Node or not */
        if (srn->instance == 0) {
                /* update LSA ID */
                srn->instance = ntohl(lsah->id.s_addr);
                /* Copy SRGB */
                srn->srgb.range_size = srgb.range_size;
                srn->srgb.lower_bound = srgb.lower_bound;
        }

        /* Check if SRGB has changed */
        if ((srn->srgb.range_size != srgb.range_size)
            || (srn->srgb.lower_bound != srgb.lower_bound)) {
                srn->srgb.range_size = srgb.range_size;
                srn->srgb.lower_bound = srgb.lower_bound;
                /* Update NHLFE if it is a neighbor SR node */
                if (srn->neighbor == OspfSR.self)
                        hash_iterate(OspfSR.neighbors,
                                     (void (*)(struct hash_backet *,
                                               void *))update_out_nhlfe,
                                     (void *)srn);
        }
}

/*
 * Delete SR Node entry in hash table information corresponding to an expired
 * Router Information LSA
 */
void ospf_sr_ri_lsa_delete(struct ospf_lsa *lsa)
{
        struct sr_node *srn;
        struct lsa_header *lsah = (struct lsa_header *)lsa->data;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): Remove SR node %s from lsa_id 4.0.0.%u",
                           __func__, inet_ntoa(lsah->adv_router),
                           GET_OPAQUE_ID(ntohl(lsah->id.s_addr)));

        /* Sanity check */
        if (OspfSR.neighbors == NULL) {
                zlog_err("SR (%s): Abort! no valid SR Data Base", __func__);
                return;
        }

        /* Release Router ID entry in SRDB hash table */
        srn = hash_release(OspfSR.neighbors, &(lsah->adv_router));

        /* Sanity check */
        if (srn == NULL) {
                zlog_err("SR (%s): Abort! no entry in SRDB for SR Node %s",
                         __func__, inet_ntoa(lsah->adv_router));
                return;
        }

        if ((srn->instance != 0) && (srn->instance != ntohl(lsah->id.s_addr))) {
                zlog_err("SR (%s): Abort! Wrong LSA ID 4.0.0.%u for SR node %s",
                         __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                         inet_ntoa(lsah->adv_router));
                return;
        }

        /* Remove SR node */
        sr_node_del(srn);
}

/* Update Segment Routing from Extended Link LSA */
void ospf_sr_ext_link_lsa_update(struct ospf_lsa *lsa)
{
        struct sr_node *srn;
        struct tlv_header *tlvh;
        struct lsa_header *lsah = (struct lsa_header *)lsa->data;
        struct sr_link *srl;

        uint16_t length, sum;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug(
                        "SR (%s): Process Extended Link LSA 8.0.0.%u from %s",
                        __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                        inet_ntoa(lsah->adv_router));

        /* Sanity check */
        if (OspfSR.neighbors == NULL) {
                zlog_err("SR (%s): Abort! no valid SR DataBase", __func__);
                return;
        }

        /* Get SR Node in hash table from Router ID */
        srn = (struct sr_node *)hash_get(OspfSR.neighbors,
                                         (void *)&(lsah->adv_router),
                                         (void *)sr_node_new);

        /* Sanity check */
        if (srn == NULL) {
                zlog_err("SR (%s): Abort! can't create SR node in hash table",
                         __func__);
                return;
        }

        /* Initialize TLV browsing */
        length = ntohs(lsah->length) - OSPF_LSA_HEADER_SIZE;
        sum = 0;
        for (tlvh = TLV_HDR_TOP(lsah); (sum < length) && (tlvh != NULL);
             tlvh = TLV_HDR_NEXT(tlvh)) {
                if (ntohs(tlvh->type) == EXT_TLV_LINK) {
                        /* Got Extended Link information */
                        srl = get_ext_link_sid(tlvh);
                        /* Update SID if not null */
                        if (srl != NULL) {
                                srl->instance = ntohl(lsah->id.s_addr);
                                update_ext_link_sid(srn, srl, lsa->flags);
                        }
                }
                sum += TLV_SIZE(tlvh);
        }
}

/* Delete Segment Routing from Extended Link LSA */
void ospf_sr_ext_link_lsa_delete(struct ospf_lsa *lsa)
{
        struct listnode *node;
        struct sr_link *srl;
        struct sr_node *srn;
        struct lsa_header *lsah = (struct lsa_header *)lsa->data;
        uint32_t instance = ntohl(lsah->id.s_addr);

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): Remove Extended Link LSA 8.0.0.%u from %s",
                           __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                           inet_ntoa(lsah->adv_router));

        /* Sanity check */
        if (OspfSR.neighbors == NULL) {
                zlog_err("SR (%s): Abort! no valid SR DataBase", __func__);
                return;
        }

        /* Search SR Node in hash table from Router ID */
        srn = (struct sr_node *)hash_lookup(OspfSR.neighbors,
                                            (void *)&(lsah->adv_router));

        /*
         * SR-Node may be NULL if it has been remove previously when
         * processing Router Information LSA deletion
         */
        if (srn == NULL) {
                zlog_warn("SR (%s): Stop! no entry in SRDB for SR Node %s",
                          __func__, inet_ntoa(lsah->adv_router));
                return;
        }

        /* Search for corresponding Segment Link */
        for (ALL_LIST_ELEMENTS_RO(srn->ext_link, node, srl))
                if (srl->instance == instance)
                        break;

        /* Remove Segment Link if found */
        if ((srl != NULL) && (srl->instance == instance)) {
                del_sid_nhlfe(srl->nhlfe[0]);
                del_sid_nhlfe(srl->nhlfe[1]);
                listnode_delete(srn->ext_link, srl);
                XFREE(MTYPE_OSPF_SR_PARAMS, srl);
        } else {
                zlog_warn(
                        "SR (%s): Didn't found corresponding SR Link 8.0.0.%u "
                        "for SR Node %s",
                        __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                        inet_ntoa(lsah->adv_router));
        }
}

/* Update Segment Routing from Extended Prefix LSA */
void ospf_sr_ext_prefix_lsa_update(struct ospf_lsa *lsa)
{
        struct sr_node *srn;
        struct tlv_header *tlvh;
        struct lsa_header *lsah = (struct lsa_header *)lsa->data;
        struct sr_prefix *srp;

        uint16_t length, sum;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug(
                        "SR (%s): Process Extended Prefix LSA "
                        "7.0.0.%u from %s",
                        __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                        inet_ntoa(lsah->adv_router));

        /* Sanity check */
        if (OspfSR.neighbors == NULL) {
                zlog_err("SR (%s): Abort! no valid SR DataBase", __func__);
                return;
        }

        /* Get SR Node in hash table from Router ID */
        srn = (struct sr_node *)hash_get(OspfSR.neighbors,
                                         (void *)&(lsah->adv_router),
                                         (void *)sr_node_new);

        /* Sanity check */
        if (srn == NULL) {
                zlog_err("SR (%s): Abort! can't create SR node in hash table",
                         __func__);
                return;
        }

        /* Initialize TLV browsing */
        length = ntohs(lsah->length) - OSPF_LSA_HEADER_SIZE;
        sum = 0;
        for (tlvh = TLV_HDR_TOP(lsah); sum < length;
             tlvh = TLV_HDR_NEXT(tlvh)) {
                if (ntohs(tlvh->type) == EXT_TLV_LINK) {
                        /* Got Extended Link information */
                        srp = get_ext_prefix_sid(tlvh);
                        /* Update SID if not null */
                        if (srp != NULL) {
                                srp->instance = ntohl(lsah->id.s_addr);
                                update_ext_prefix_sid(srn, srp);
                        }
                }
                sum += TLV_SIZE(tlvh);
        }
}

/* Delete Segment Routing from Extended Prefix LSA */
void ospf_sr_ext_prefix_lsa_delete(struct ospf_lsa *lsa)
{
        struct listnode *node;
        struct sr_prefix *srp;
        struct sr_node *srn;
        struct lsa_header *lsah = (struct lsa_header *)lsa->data;
        uint32_t instance = ntohl(lsah->id.s_addr);

        if (IS_DEBUG_OSPF_SR)
                zlog_debug(
                        "SR (%s): Remove Extended Prefix LSA 7.0.0.%u from %s",
                        __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                        inet_ntoa(lsah->adv_router));

        /* Sanity check */
        if (OspfSR.neighbors == NULL) {
                zlog_err("SR (%s): Abort! no valid SR DataBase", __func__);
                return;
        }

        /* Search SR Node in hash table from Router ID */
        srn = (struct sr_node *)hash_lookup(OspfSR.neighbors,
                                            (void *)&(lsah->adv_router));

        /*
         * SR-Node may be NULL if it has been remove previously when
         * processing Router Information LSA deletion
         */
        if (srn == NULL) {
                zlog_warn("SR (%s):  Stop! no entry in SRDB for SR Node %s",
                          __func__, inet_ntoa(lsah->adv_router));
                return;
        }

        /* Search for corresponding Segment Link */
        for (ALL_LIST_ELEMENTS_RO(srn->ext_prefix, node, srp))
                if (srp->instance == instance)
                        break;

        /* Remove Segment Link if found */
        if ((srp != NULL) && (srp->instance == instance)) {
                del_sid_nhlfe(srp->nhlfe);
                listnode_delete(srn->ext_link, srp);
                XFREE(MTYPE_OSPF_SR_PARAMS, srp);
        } else {
                zlog_warn(
                        "SR (%s): Didn't found corresponding SR Prefix "
                        "7.0.0.%u for SR Node %s",
                        __func__, GET_OPAQUE_ID(ntohl(lsah->id.s_addr)),
                        inet_ntoa(lsah->adv_router));
        }
}

/* Get Label for Extended Link SID */
/* TODO: To be replace by Zebra Label Manager */
uint32_t get_ext_link_label_value(void)
{
        static uint32_t label = ADJ_SID_MIN - 1;

        if (label < ADJ_SID_MAX)
                label += 1;

        return label;
}

/*
 * Update Prefix SID. Call by ospf_ext_pref_ism_change to
 * complete initial CLI command at startutp.
 *
 * @param ifp - Loopback interface
 * @param pref - Prefix address of this interface
 *
 * @return - void
 */
void ospf_sr_update_prefix(struct interface *ifp, struct prefix *p)
{
        struct listnode *node;
        struct sr_prefix *srp;

        /* Sanity Check */
        if ((ifp == NULL) || (p == NULL))
                return;

        /*
         * Search if there is a Segment Prefix that correspond to this
         * interface or prefix, and update it if found
         */
        for (ALL_LIST_ELEMENTS_RO(OspfSR.self->ext_prefix, node, srp)) {
                if ((srp->nhlfe.ifindex == ifp->ifindex)
                    || ((IPV4_ADDR_SAME(&srp->nhlfe.prefv4.prefix,
                                        &p->u.prefix4))
                        && (srp->nhlfe.prefv4.prefixlen == p->prefixlen))) {

                        /* Update Interface & Prefix info */
                        srp->nhlfe.ifindex = ifp->ifindex;
                        IPV4_ADDR_COPY(&srp->nhlfe.prefv4.prefix,
                                       &p->u.prefix4);
                        srp->nhlfe.prefv4.prefixlen = p->prefixlen;
                        srp->nhlfe.prefv4.family = p->family;
                        IPV4_ADDR_COPY(&srp->nhlfe.nexthop, &p->u.prefix4);

                        /* OK. Let's Schedule Extended Prefix LSA */
                        srp->instance = ospf_ext_schedule_prefix_index(
                                ifp, srp->sid, &srp->nhlfe.prefv4, srp->flags);

                        /* Install NHLFE if NO-PHP is requested */
                        if (CHECK_FLAG(srp->flags,
                                       EXT_SUBTLV_PREFIX_SID_NPFLG)) {
                                srp->nhlfe.label_in = index2label(
                                        srp->sid, OspfSR.self->srgb);
                                srp->nhlfe.label_out = MPLS_LABEL_IMPLICIT_NULL;
                                add_sid_nhlfe(srp->nhlfe);
                        }
                }
        }
}

/*
 * Following functions are used to update MPLS LFIB after a SPF run
 */

static void ospf_sr_nhlfe_update(struct hash_backet *backet, void *args)
{

        struct sr_node *srn = (struct sr_node *)backet->data;
        struct listnode *node;
        struct sr_prefix *srp;
        struct sr_nhlfe old;
        int rc;

        /* Sanity Check */
        if (srn == NULL)
                return;

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("  |-  Update Prefix for SR Node %s",
                           inet_ntoa(srn->adv_router));

        /* Skip Self SR Node */
        if (srn == OspfSR.self)
                return;

        /* Update Extended Prefix */
        for (ALL_LIST_ELEMENTS_RO(srn->ext_prefix, node, srp)) {

                /* Backup current NHLFE */
                memcpy(&old, &srp->nhlfe, sizeof(struct sr_nhlfe));

                /* Compute the new NHLFE */
                rc = compute_prefix_nhlfe(srp);

                /* Check computation result */
                switch (rc) {
                /* next hop is not know, remove old NHLFE to avoid loop */
                case -1:
                        del_sid_nhlfe(srp->nhlfe);
                        break;
                /* next hop has not changed, skip it */
                case 0:
                        break;
                /* there is a new next hop, update NHLFE */
                case 1:
                        update_sid_nhlfe(old, srp->nhlfe);
                        break;
                default:
                        break;
                }
        }
}

static int ospf_sr_update_schedule(struct thread *t)
{

        struct ospf *ospf;
        struct timeval start_time, stop_time;

        ospf = THREAD_ARG(t);
        ospf->t_sr_update = NULL;

        if (!OspfSR.update)
                return 0;

        monotime(&start_time);

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): Start SPF update", __func__);

        hash_iterate(OspfSR.neighbors, (void (*)(struct hash_backet *,
                                                 void *))ospf_sr_nhlfe_update,
                     NULL);

        monotime(&stop_time);

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): SPF Processing Time(usecs): %lld\n",
                           __func__,
                           (stop_time.tv_sec - start_time.tv_sec) * 1000000LL
                                   + (stop_time.tv_usec - start_time.tv_usec));

        OspfSR.update = false;
        return 1;
}

#define OSPF_SR_UPDATE_INTERVAL 1

void ospf_sr_update_timer_add(struct ospf *ospf)
{

        if (ospf == NULL)
                return;

        /* Check if an update is not alreday engage */
        if (OspfSR.update)
                return;

        OspfSR.update = true;

        thread_add_timer(master, ospf_sr_update_schedule, ospf,
                         OSPF_SR_UPDATE_INTERVAL, &ospf->t_sr_update);
}

/*
 * --------------------------------------
 * Followings are vty command functions.
 * --------------------------------------
 */

/*
 * Segment Routing Router configuration
 *
 * Must be centralize as it concerns both Extended Link/Prefix LSA
 * and Router Information LSA. Choose to call it from Extended Prefix
 * write_config() call back.
 *
 * @param vty VTY output
 *
 * @return none
 */
void ospf_sr_config_write_router(struct vty *vty)
{
        struct listnode *node;
        struct sr_prefix *srp;

        if (OspfSR.enabled) {
                vty_out(vty, " segment-routing on\n");

                if ((OspfSR.srgb.lower_bound != MPLS_DEFAULT_MIN_SRGB_LABEL)
                    || (OspfSR.srgb.range_size != MPLS_DEFAULT_MAX_SRGB_SIZE)) {
                        vty_out(vty, " segment-routing global-block %u %u\n",
                                OspfSR.srgb.lower_bound,
                                OspfSR.srgb.lower_bound + OspfSR.srgb.range_size
                                        - 1);
                }
                if (OspfSR.msd != 0)
                        vty_out(vty, " segment-routing node-msd %u\n",
                                OspfSR.msd);

                if (OspfSR.self != NULL) {
                        for (ALL_LIST_ELEMENTS_RO(OspfSR.self->ext_prefix, node,
                                                  srp)) {
                                vty_out(vty,
                                        " segment-routing prefix %s/%u "
                                        "index %u%s\n",
                                        inet_ntoa(srp->nhlfe.prefv4.prefix),
                                        srp->nhlfe.prefv4.prefixlen, srp->sid,
                                        CHECK_FLAG(srp->flags,
                                                   EXT_SUBTLV_PREFIX_SID_NPFLG)
                                                ? " no-php-flag"
                                                : "");
                        }
                }
        }
}

DEFUN(ospf_sr_enable,
       ospf_sr_enable_cmd,
       "segment-routing on",
       SR_STR
       "Enable Segment Routing\n")
{

        VTY_DECLVAR_INSTANCE_CONTEXT(ospf, ospf);

        if (OspfSR.enabled)
                return CMD_SUCCESS;

        if (ospf->vrf_id != VRF_DEFAULT) {
                vty_out(vty,
                        "Segment Routing is only supported in default "
                        "VRF\n");
                return CMD_WARNING_CONFIG_FAILED;
        }

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("SR: Segment Routing: OFF -> ON");

        /* Start Segment Routing */
        OspfSR.enabled = true;
        if (!ospf_sr_start(ospf)) {
                zlog_warn("SR: Unable to start Segment Routing. Abort!");
                return CMD_WARNING;
        }

        /* Set Router Information SR parameters */
        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("SR: Activate SR for Router Information LSA");

        ospf_router_info_update_sr(true, OspfSR.srgb, OspfSR.msd);

        /* Update Ext LSA */
        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("SR: Activate SR for Extended Link/Prefix LSA");

        ospf_ext_update_sr(true);

        return CMD_SUCCESS;
}

DEFUN (no_ospf_sr_enable,
       no_ospf_sr_enable_cmd,
       "no segment-routing [on]",
       NO_STR
       SR_STR
       "Disable Segment Routing\n")
{

        if (!OspfSR.enabled)
                return CMD_SUCCESS;

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("SR: Segment Routing: ON -> OFF");

        /* Start by Disabling Extended Link & Prefix LSA */
        ospf_ext_update_sr(false);

        /* then, disable Router Information SR parameters */
        ospf_router_info_update_sr(false, OspfSR.srgb, OspfSR.msd);

        /* Finally, stop Segment Routing */
        ospf_sr_stop();
        OspfSR.enabled = false;

        return CMD_SUCCESS;
}

static int ospf_sr_enabled(struct vty *vty)
{
        if (OspfSR.enabled)
                return 1;

        if (vty)
                vty_out(vty, "%% OSPF SR is not turned on\n");

        return 0;
}

DEFUN (sr_sid_label_range,
       sr_sid_label_range_cmd,
       "segment-routing global-block (0-1048575) (0-1048575)",
       SR_STR
       "Segment Routing Global Block label range\n"
       "Lower-bound range in decimal (0-1048575)\n"
       "Upper-bound range in decimal (0-1048575)\n")
{
        uint32_t upper;
        uint32_t lower;
        uint32_t size;
        int idx_low = 2;
        int idx_up = 3;

        if (!ospf_sr_enabled(vty))
                return CMD_WARNING_CONFIG_FAILED;

        /* Get lower and upper bound */
        lower = strtoul(argv[idx_low]->arg, NULL, 10);
        upper = strtoul(argv[idx_up]->arg, NULL, 10);
        size = upper - lower + 1;

        if (size > MPLS_DEFAULT_MAX_SRGB_SIZE || size <= 0) {
                vty_out(vty,
                        "Range size cannot be less than 0 or more than %u\n",
                        MPLS_DEFAULT_MAX_SRGB_SIZE);
                return CMD_WARNING_CONFIG_FAILED;
        }

        if (upper > MPLS_DEFAULT_MAX_SRGB_LABEL) {
                vty_out(vty, "Upper-bound cannot exceed %u\n",
                        MPLS_DEFAULT_MAX_SRGB_LABEL);
                return CMD_WARNING_CONFIG_FAILED;
        }

        if (upper < MPLS_DEFAULT_MIN_SRGB_LABEL) {
                vty_out(vty, "Upper-bound cannot be lower than %u\n",
                        MPLS_DEFAULT_MIN_SRGB_LABEL);
                return CMD_WARNING_CONFIG_FAILED;
        }

        /* Check if values have changed */
        if ((OspfSR.srgb.range_size == size)
            && (OspfSR.srgb.lower_bound == lower))
                return CMD_SUCCESS;

        /* Set SID/Label range SRGB */
        OspfSR.srgb.range_size = size;
        OspfSR.srgb.lower_bound = lower;
        if (OspfSR.self != NULL) {
                OspfSR.self->srgb.range_size = size;
                OspfSR.self->srgb.lower_bound = lower;
        }

        /* Set Router Information SR parameters */
        ospf_router_info_update_sr(true, OspfSR.srgb, OspfSR.msd);

        /* Update NHLFE entries */
        hash_iterate(OspfSR.neighbors,
                     (void (*)(struct hash_backet *, void *))update_in_nhlfe,
                     NULL);

        return CMD_SUCCESS;
}

DEFUN (no_sr_sid_label_range,
        no_sr_sid_label_range_cmd,
        "no segment-routing global-block [(0-1048575) (0-1048575)]",
        NO_STR
        SR_STR
        "Segment Routing Global Block label range\n"
        "Lower-bound range in decimal (0-1048575)\n"
        "Upper-bound range in decimal (0-1048575)\n")
{

        if (!ospf_sr_enabled(vty))
                return CMD_WARNING_CONFIG_FAILED;

        /* Revert to default SRGB value */
        OspfSR.srgb.range_size = MPLS_DEFAULT_MIN_SRGB_SIZE;
        OspfSR.srgb.lower_bound = MPLS_DEFAULT_MIN_SRGB_LABEL;
        if (OspfSR.self != NULL) {
                OspfSR.self->srgb.range_size = OspfSR.srgb.range_size;
                OspfSR.self->srgb.lower_bound = OspfSR.srgb.lower_bound;
        }

        /* Set Router Information SR parameters */
        ospf_router_info_update_sr(true, OspfSR.srgb, OspfSR.msd);

        /* Update NHLFE entries */
        hash_iterate(OspfSR.neighbors,
                     (void (*)(struct hash_backet *, void *))update_in_nhlfe,
                     NULL);

        return CMD_SUCCESS;
}

DEFUN (sr_node_msd,
       sr_node_msd_cmd,
       "segment-routing node-msd (1-16)",
       SR_STR
       "Maximum Stack Depth for this router\n"
       "Maximum number of label that could be stack (1-16)\n")
{
        uint32_t msd;
        int idx = 1;

        if (!ospf_sr_enabled(vty))
                return CMD_WARNING_CONFIG_FAILED;

        /* Get MSD */
        argv_find(argv, argc, "(1-16)", &idx);
        msd = strtoul(argv[idx]->arg, NULL, 10);
        if (msd < 1 || msd > MPLS_MAX_LABELS) {
                vty_out(vty, "MSD must be comprise between 1 and %u\n",
                        MPLS_MAX_LABELS);
                return CMD_WARNING_CONFIG_FAILED;
        }

        /* Check if value has changed */
        if (OspfSR.msd == msd)
                return CMD_SUCCESS;

        /* Set this router MSD */
        OspfSR.msd = msd;
        if (OspfSR.self != NULL)
                OspfSR.self->msd = msd;

        /* Set Router Information SR parameters */
        ospf_router_info_update_sr(true, OspfSR.srgb, OspfSR.msd);

        return CMD_SUCCESS;
}

DEFUN (no_sr_node_msd,
        no_sr_node_msd_cmd,
        "no segment-routing node-msd [(1-16)]",
        NO_STR
        SR_STR
        "Maximum Stack Depth for this router\n"
        "Maximum number of label that could be stack (1-16)\n")
{

        if (!ospf_sr_enabled(vty))
                return CMD_WARNING_CONFIG_FAILED;

        /* unset this router MSD */
        OspfSR.msd = 0;
        if (OspfSR.self != NULL)
                OspfSR.self->msd = 0;

        /* Set Router Information SR parameters */
        ospf_router_info_update_sr(true, OspfSR.srgb, 0);

        return CMD_SUCCESS;
}

DEFUN (sr_prefix_sid,
       sr_prefix_sid_cmd,
       "segment-routing prefix A.B.C.D/M index (0-65535) [no-php-flag]",
       SR_STR
       "Prefix SID\n"
       "IPv4 Prefix as A.B.C.D/M\n"
       "SID index for this prefix in decimal (0-65535)\n"
       "Index value inside SRGB (lower_bound < index < upper_bound)\n"
       "Don't request Penultimate Hop Popping (PHP)\n")
{
        int idx = 0;
        struct prefix p;
        uint32_t index;
        struct listnode *node;
        struct sr_prefix *srp, *new;
        struct interface *ifp;

        if (!ospf_sr_enabled(vty))
                return CMD_WARNING_CONFIG_FAILED;

        /* Get network prefix */
        argv_find(argv, argc, "A.B.C.D/M", &idx);
        if (!str2prefix(argv[idx]->arg, &p)) {
                vty_out(vty, "Invalid prefix format %s\n", argv[idx]->arg);
                return CMD_WARNING_CONFIG_FAILED;
        }

        /* Get & verify index value */
        argv_find(argv, argc, "(0-65535)", &idx);
        index = strtoul(argv[idx]->arg, NULL, 10);
        if (index > OspfSR.srgb.range_size - 1) {
                vty_out(vty, "Index %u must be lower than range size %u\n",
                        index, OspfSR.srgb.range_size);
                return CMD_WARNING_CONFIG_FAILED;
        }

        /* check that the index is not already used */
        for (ALL_LIST_ELEMENTS_RO(OspfSR.self->ext_prefix, node, srp)) {
                if (srp->sid == index) {
                        vty_out(vty, "Index %u is already used\n", index);
                        return CMD_WARNING_CONFIG_FAILED;
                }
        }

        /* Create new Extended Prefix to SRDB if not found */
        new = XCALLOC(MTYPE_OSPF_SR_PARAMS, sizeof(struct sr_prefix));
        IPV4_ADDR_COPY(&new->nhlfe.prefv4.prefix, &p.u.prefix4);
        IPV4_ADDR_COPY(&new->nhlfe.nexthop, &p.u.prefix4);
        new->nhlfe.prefv4.prefixlen = p.prefixlen;
        new->nhlfe.prefv4.family = p.family;
        new->sid = index;
        /* Set NO PHP flag if present and compute NHLFE */
        if (argv_find(argv, argc, "no-php-flag", &idx)) {
                SET_FLAG(new->flags, EXT_SUBTLV_PREFIX_SID_NPFLG);
                new->nhlfe.label_in = index2label(new->sid, OspfSR.self->srgb);
                new->nhlfe.label_out = MPLS_LABEL_IMPLICIT_NULL;
        }

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): Add new index %u to Prefix %s/%u",
                           __func__, index, inet_ntoa(new->nhlfe.prefv4.prefix),
                           new->nhlfe.prefv4.prefixlen);

        /* Get Interface and check if it is a Loopback */
        ifp = if_lookup_prefix(&p, VRF_DEFAULT);
        if (ifp == NULL) {
                /*
                 * Interface could be not yet available i.e. when this
                 * command is in the configuration file, OSPF is not yet
                 * ready. In this case, store the prefix SID for latter
                 * update of this Extended Prefix
                 */
                listnode_add(OspfSR.self->ext_prefix, new);
                zlog_warn(
                        "Interface for prefix %s/%u not found. Deferred LSA "
                        "flooding",
                        inet_ntoa(p.u.prefix4), p.prefixlen);
                return CMD_SUCCESS;
        }

        if (!if_is_loopback(ifp)) {
                vty_out(vty, "interface %s is not a Loopback\n", ifp->name);
                XFREE(MTYPE_OSPF_SR_PARAMS, new);
                return CMD_WARNING_CONFIG_FAILED;
        }
        new->nhlfe.ifindex = ifp->ifindex;

        /* Search if this prefix already exist */
        for (ALL_LIST_ELEMENTS_RO(OspfSR.self->ext_prefix, node, srp)) {
                if ((IPV4_ADDR_SAME(&srp->nhlfe.prefv4.prefix, &p.u.prefix4)
                     && srp->nhlfe.prefv4.prefixlen == p.prefixlen))
                        break;
                else
                        srp = NULL;
        }

        /* Update or Add this new SR Prefix */
        if (srp) {
                update_sid_nhlfe(srp->nhlfe, new->nhlfe);
                listnode_delete(OspfSR.self->ext_prefix, srp);
                listnode_add(OspfSR.self->ext_prefix, new);
        } else {
                listnode_add(OspfSR.self->ext_prefix, new);
                add_sid_nhlfe(new->nhlfe);
        }

        /* Finally, update Extended Prefix LSA */
        new->instance = ospf_ext_schedule_prefix_index(
                ifp, new->sid, &new->nhlfe.prefv4, new->flags);
        if (new->instance == 0) {
                vty_out(vty, "Unable to set index %u for prefix %s/%u\n", index,
                        inet_ntoa(p.u.prefix4), p.prefixlen);
                return CMD_WARNING;
        }

        return CMD_SUCCESS;
}

DEFUN (no_sr_prefix_sid,
       no_sr_prefix_sid_cmd,
       "no segment-routing prefix A.B.C.D/M [index (0-65535) no-php-flag]",
       NO_STR
       SR_STR
       "Prefix SID\n"
       "IPv4 Prefix as A.B.C.D/M\n"
       "SID index for this prefix in decimal (0-65535)\n"
       "Index value inside SRGB (lower_bound < index < upper_bound)\n"
       "Don't request Penultimate Hop Popping (PHP)\n")
{
        int idx = 0;
        struct prefix p;
        struct listnode *node;
        struct sr_prefix *srp;
        struct interface *ifp;
        bool found = false;
        int rc;

        /* Get network prefix */
        argv_find(argv, argc, "A.B.C.D/M", &idx);
        rc = str2prefix(argv[idx]->arg, &p);
        if (!rc) {
                vty_out(vty, "Invalid prefix format %s\n", argv[idx]->arg);
                return CMD_WARNING_CONFIG_FAILED;
        }

        /* check that the prefix is already set */
        for (ALL_LIST_ELEMENTS_RO(OspfSR.self->ext_prefix, node, srp))
                if (IPV4_ADDR_SAME(&srp->nhlfe.prefv4.prefix, &p.u.prefix4)
                    && (srp->nhlfe.prefv4.prefixlen == p.prefixlen)) {
                        found = true;
                        break;
                }

        if (!found) {
                vty_out(vty, "Prefix %s is not found. Abort!\n",
                        argv[idx]->arg);
                return CMD_WARNING_CONFIG_FAILED;
        }

        /* Get Interface */
        ifp = if_lookup_by_index(srp->nhlfe.ifindex, VRF_DEFAULT);
        if (ifp == NULL) {
                vty_out(vty, "interface for prefix %s not found.\n",
                        argv[idx]->arg);
                return CMD_WARNING_CONFIG_FAILED;
        }

        /* Update Extended Prefix LSA */
        if (!ospf_ext_schedule_prefix_index(ifp, 0, NULL, 0)) {
                vty_out(vty, "No corresponding loopback interface. Abort!\n");
                return CMD_WARNING;
        }

        if (IS_DEBUG_OSPF_SR)
                zlog_debug("SR (%s): Remove Prefix %s/%u with index %u",
                           __func__, inet_ntoa(srp->nhlfe.prefv4.prefix),
                           srp->nhlfe.prefv4.prefixlen, srp->sid);

        /* Delete NHLFE is NO-PHP is set */
        if (CHECK_FLAG(srp->flags, EXT_SUBTLV_PREFIX_SID_NPFLG))
                del_sid_nhlfe(srp->nhlfe);

        /* OK, all is clean, remove SRP from SRDB */
        listnode_delete(OspfSR.self->ext_prefix, srp);
        XFREE(MTYPE_OSPF_SR_PARAMS, srp);

        return CMD_SUCCESS;
}


static void show_sr_node(struct vty *vty, struct json_object *json,
                         struct sr_node *srn)
{

        struct listnode *node;
        struct sr_link *srl;
        struct sr_prefix *srp;
        struct interface *itf;
        char pref[19];
        char sid[22];
        char label[8];
        json_object *json_node = NULL, *json_algo, *json_obj;
        json_object *json_prefix = NULL, *json_link = NULL;

        /* Sanity Check */
        if (srn == NULL)
                return;

        if (json) {
                json_node = json_object_new_object();
                json_object_string_add(json_node, "routerID",
                                       inet_ntoa(srn->adv_router));
                json_object_int_add(json_node, "srgbSize",
                                    srn->srgb.range_size);
                json_object_int_add(json_node, "srgbLabel",
                                    srn->srgb.lower_bound);
                json_algo = json_object_new_array();
                json_object_object_add(json_node, "algorithms", json_algo);
                for (int i = 0; i < ALGORITHM_COUNT; i++) {
                        if (srn->algo[i] == SR_ALGORITHM_UNSET)
                                continue;
                        json_obj = json_object_new_object();
                        char tmp[2];

                        snprintf(tmp, 2, "%u", i);
                        json_object_string_add(json_obj, tmp,
                                               srn->algo[i] == SR_ALGORITHM_SPF
                                                       ? "SPF"
                                                       : "S-SPF");
                        json_object_array_add(json_algo, json_obj);
                }
                if (srn->msd != 0)
                        json_object_int_add(json_node, "nodeMsd", srn->msd);
        } else {
                vty_out(vty, "SR-Node: %s", inet_ntoa(srn->adv_router));
                vty_out(vty, "\tSRGB (Size/Label): %u/%u", srn->srgb.range_size,
                        srn->srgb.lower_bound);
                vty_out(vty, "\tAlgorithm(s): %s",
                        srn->algo[0] == SR_ALGORITHM_SPF ? "SPF" : "S-SPF");
                for (int i = 1; i < ALGORITHM_COUNT; i++) {
                        if (srn->algo[i] == SR_ALGORITHM_UNSET)
                                continue;
                        vty_out(vty, "/%s",
                                srn->algo[i] == SR_ALGORITHM_SPF ? "SPF"
                                                                 : "S-SPF");
                }
                if (srn->msd != 0)
                        vty_out(vty, "\tMSD: %u", srn->msd);
        }

        if (!json) {
                vty_out(vty,
                        "\n\n    Prefix or Link  Label In  Label Out       "
                        "Node or Adj. SID  Interface          Nexthop\n");
                vty_out(vty,
                        "------------------  --------  ---------  "
                        "---------------------  ---------  ---------------\n");
        }
        for (ALL_LIST_ELEMENTS_RO(srn->ext_prefix, node, srp)) {
                snprintf(pref, 19, "%s/%u", inet_ntoa(srp->nhlfe.prefv4.prefix),
                         srp->nhlfe.prefv4.prefixlen);
                snprintf(sid, 22, "SR Pfx (idx %u)", srp->sid);
                if (srp->nhlfe.label_out == MPLS_LABEL_IMPLICIT_NULL)
                        sprintf(label, "pop");
                else
                        sprintf(label, "%u", srp->nhlfe.label_out);
                itf = if_lookup_by_index(srp->nhlfe.ifindex, VRF_DEFAULT);
                if (json) {
                        if (!json_prefix) {
                                json_prefix = json_object_new_array();
                                json_object_object_add(json_node,
                                                       "extendedPrefix",
                                                       json_prefix);
                        }
                        json_obj = json_object_new_object();
                        json_object_string_add(json_obj, "prefix", pref);
                        json_object_int_add(json_obj, "sid", srp->sid);
                        json_object_int_add(json_obj, "inputLabel",
                                            srp->nhlfe.label_in);
                        json_object_string_add(json_obj, "outputLabel", label);
                        json_object_string_add(json_obj, "interface",
                                               itf ? itf->name : "-");
                        json_object_string_add(json_obj, "nexthop",
                                               inet_ntoa(srp->nhlfe.nexthop));
                        json_object_array_add(json_prefix, json_obj);
                } else {
                        vty_out(vty, "%18s  %8u  %9s  %21s  %9s  %15s\n", pref,
                                srp->nhlfe.label_in, label, sid,
                                itf ? itf->name : "-",
                                inet_ntoa(srp->nhlfe.nexthop));
                }
        }

        for (ALL_LIST_ELEMENTS_RO(srn->ext_link, node, srl)) {
                snprintf(pref, 19, "%s/%u",
                         inet_ntoa(srl->nhlfe[0].prefv4.prefix),
                         srl->nhlfe[0].prefv4.prefixlen);
                snprintf(sid, 22, "SR Adj. (lbl %u)", srl->sid[0]);
                if (srl->nhlfe[0].label_out == MPLS_LABEL_IMPLICIT_NULL)
                        sprintf(label, "pop");
                else
                        sprintf(label, "%u", srl->nhlfe[0].label_out);
                itf = if_lookup_by_index(srl->nhlfe[0].ifindex, VRF_DEFAULT);
                if (json) {
                        if (!json_link) {
                                json_link = json_object_new_array();
                                json_object_object_add(
                                        json_node, "extendedLink", json_link);
                        }
                        /* Primary Link */
                        json_obj = json_object_new_object();
                        json_object_string_add(json_obj, "prefix", pref);
                        json_object_int_add(json_obj, "sid", srl->sid[0]);
                        json_object_int_add(json_obj, "inputLabel",
                                            srl->nhlfe[0].label_in);
                        json_object_string_add(json_obj, "outputLabel", label);
                        json_object_string_add(json_obj, "interface",
                                               itf ? itf->name : "-");
                        json_object_string_add(
                                json_obj, "nexthop",
                                inet_ntoa(srl->nhlfe[0].nexthop));
                        json_object_array_add(json_link, json_obj);
                        /* Backup Link */
                        json_obj = json_object_new_object();
                        snprintf(sid, 22, "SR Adj. (lbl %u)", srl->sid[1]);
                        if (srl->nhlfe[1].label_out == MPLS_LABEL_IMPLICIT_NULL)
                                sprintf(label, "pop");
                        else
                                sprintf(label, "%u", srl->nhlfe[0].label_out);
                        json_object_string_add(json_obj, "prefix", pref);
                        json_object_int_add(json_obj, "sid", srl->sid[1]);
                        json_object_int_add(json_obj, "inputLabel",
                                            srl->nhlfe[1].label_in);
                        json_object_string_add(json_obj, "outputLabel", label);
                        json_object_string_add(json_obj, "interface",
                                               itf ? itf->name : "-");
                        json_object_string_add(
                                json_obj, "nexthop",
                                inet_ntoa(srl->nhlfe[1].nexthop));
                        json_object_array_add(json_link, json_obj);
                } else {
                        vty_out(vty, "%18s  %8u  %9s  %21s  %9s  %15s\n", pref,
                                srl->nhlfe[0].label_in, label, sid,
                                itf ? itf->name : "-",
                                inet_ntoa(srl->nhlfe[0].nexthop));
                        snprintf(sid, 22, "SR Adj. (lbl %u)", srl->sid[1]);
                        if (srl->nhlfe[1].label_out == MPLS_LABEL_IMPLICIT_NULL)
                                sprintf(label, "pop");
                        else
                                sprintf(label, "%u", srl->nhlfe[1].label_out);
                        vty_out(vty, "%18s  %8u  %9s  %21s  %9s  %15s\n", pref,
                                srl->nhlfe[1].label_in, label, sid,
                                itf ? itf->name : "-",
                                inet_ntoa(srl->nhlfe[1].nexthop));
                }
        }
        if (json)
                json_object_array_add(json, json_node);
        else
                vty_out(vty, "\n");
}

static void show_vty_srdb(struct hash_backet *backet, void *args)
{
        struct vty *vty = (struct vty *)args;
        struct sr_node *srn = (struct sr_node *)backet->data;

        show_sr_node(vty, NULL, srn);
}

static void show_json_srdb(struct hash_backet *backet, void *args)
{
        struct json_object *json = (struct json_object *)args;
        struct sr_node *srn = (struct sr_node *)backet->data;

        show_sr_node(NULL, json, srn);
}

DEFUN (show_ip_opsf_srdb,
       show_ip_ospf_srdb_cmd,
       "show ip ospf database segment-routing [adv-router A.B.C.D|self-originate] [json]",
       SHOW_STR
       IP_STR
       OSPF_STR
       "Database summary\n"
       "Show Segment Routing Data Base\n"
       "Advertising SR node\n"
       "Advertising SR node ID (as an IP address)\n"
       "Self-originated SR node\n"
       JSON_STR)
{
        int idx = 0;
        struct in_addr rid;
        struct sr_node *srn;
        uint8_t uj = use_json(argc, argv);
        json_object *json = NULL, *json_node_array = NULL;

        if (!OspfSR.enabled) {
                vty_out(vty, "Segment Routing is disabled on this router\n");
                return CMD_WARNING;
        }

        if (uj) {
                json = json_object_new_object();
                json_node_array = json_object_new_array();
                json_object_string_add(json, "srdbID",
                                       inet_ntoa(OspfSR.self->adv_router));
                json_object_object_add(json, "srNodes", json_node_array);
        } else {
                vty_out(vty,
                        "\n\t\tOSPF Segment Routing database for ID %s\n\n",
                        inet_ntoa(OspfSR.self->adv_router));
        }

        if (argv_find(argv, argc, "self-originate", &idx)) {
                srn = OspfSR.self;
                show_sr_node(vty, json_node_array, srn);
                if (uj) {
                        vty_out(vty, "%s\n",
                                json_object_to_json_string_ext(
                                        json, JSON_C_TO_STRING_PRETTY));
                        json_object_free(json);
                }
                return CMD_SUCCESS;
        }

        if (argv_find(argv, argc, "A.B.C.D", &idx)) {
                if (!inet_aton(argv[idx]->arg, &rid)) {
                        vty_out(vty, "Specified Router ID %s is invalid\n",
                                argv[idx]->arg);
                        return CMD_WARNING_CONFIG_FAILED;
                }
                /* Get the SR Node from the SRDB */
                srn = (struct sr_node *)hash_lookup(OspfSR.neighbors,
                                                    (void *)&rid);
                show_sr_node(vty, json_node_array, srn);
                if (uj) {
                        vty_out(vty, "%s\n",
                                json_object_to_json_string_ext(
                                        json, JSON_C_TO_STRING_PRETTY));
                        json_object_free(json);
                }
                return CMD_SUCCESS;
        }

        /* No parameters have been provided, Iterate through all the SRDB */
        if (uj) {
                hash_iterate(OspfSR.neighbors, (void (*)(struct hash_backet *,
                                                         void *))show_json_srdb,
                             (void *)json_node_array);
                vty_out(vty, "%s\n", json_object_to_json_string_ext(
                                             json, JSON_C_TO_STRING_PRETTY));
                json_object_free(json);
        } else {
                hash_iterate(OspfSR.neighbors, (void (*)(struct hash_backet *,
                                                         void *))show_vty_srdb,
                             (void *)vty);
        }
        return CMD_SUCCESS;
}

/* Install new CLI commands */
void ospf_sr_register_vty(void)
{
        install_element(VIEW_NODE, &show_ip_ospf_srdb_cmd);

        install_element(OSPF_NODE, &ospf_sr_enable_cmd);
        install_element(OSPF_NODE, &no_ospf_sr_enable_cmd);
        install_element(OSPF_NODE, &sr_sid_label_range_cmd);
        install_element(OSPF_NODE, &no_sr_sid_label_range_cmd);
        install_element(OSPF_NODE, &sr_node_msd_cmd);
        install_element(OSPF_NODE, &no_sr_node_msd_cmd);
        install_element(OSPF_NODE, &sr_prefix_sid_cmd);
        install_element(OSPF_NODE, &no_sr_prefix_sid_cmd);
}