Merge pull request #13227 from mjstapp/ospf_sock_bufsizes

[mirror_frr.git] / isisd / isis_lsp.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * IS-IS Rout(e)ing protocol - isis_lsp.c
 *                             LSP processing
 *
 * Copyright (C) 2001,2002   Sampo Saaristo
 *                           Tampere University of Technology
 *                           Institute of Communications Engineering
 * Copyright (C) 2013-2015   Christian Franke <chris@opensourcerouting.org>
 */

#include <zebra.h>

#include "linklist.h"
#include "frrevent.h"
#include "vty.h"
#include "stream.h"
#include "memory.h"
#include "log.h"
#include "prefix.h"
#include "command.h"
#include "hash.h"
#include "if.h"
#include "checksum.h"
#include "md5.h"
#include "table.h"
#include "srcdest_table.h"
#include "lib_errors.h"

#include "isisd/isis_constants.h"
#include "isisd/isis_common.h"
#include "isisd/isis_flags.h"
#include "isisd/isis_circuit.h"
#include "isisd/isisd.h"
#include "isisd/isis_lsp.h"
#include "isisd/isis_pdu.h"
#include "isisd/isis_dynhn.h"
#include "isisd/isis_misc.h"
#include "isisd/isis_csm.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_spf.h"
#include "isisd/isis_mt.h"
#include "isisd/isis_tlvs.h"
#include "isisd/isis_te.h"
#include "isisd/isis_sr.h"
#include "isisd/fabricd.h"
#include "isisd/isis_tx_queue.h"
#include "isisd/isis_nb.h"

DEFINE_MTYPE_STATIC(ISISD, ISIS_LSP, "ISIS LSP");

static void lsp_refresh(struct event *thread);
static void lsp_l1_refresh_pseudo(struct event *thread);
static void lsp_l2_refresh_pseudo(struct event *thread);

static void lsp_destroy(struct isis_lsp *lsp);

static bool device_startup;

int lsp_id_cmp(uint8_t *id1, uint8_t *id2)
{
        return memcmp(id1, id2, ISIS_SYS_ID_LEN + 2);
}

int lspdb_compare(const struct isis_lsp *a, const struct isis_lsp *b)
{
        return memcmp(a->hdr.lsp_id, b->hdr.lsp_id, sizeof(a->hdr.lsp_id));
}

void lsp_db_init(struct lspdb_head *head)
{
        lspdb_init(head);
}

void lsp_db_fini(struct lspdb_head *head)
{
        struct isis_lsp *lsp;

        while ((lsp = lspdb_pop(head)))
                lsp_destroy(lsp);
        lspdb_fini(head);
}

struct isis_lsp *lsp_search(struct lspdb_head *head, const uint8_t *id)
{
        struct isis_lsp searchfor;
        memcpy(searchfor.hdr.lsp_id, id, sizeof(searchfor.hdr.lsp_id));

        return lspdb_find(head, &searchfor);
}

static void lsp_clear_data(struct isis_lsp *lsp)
{
        if (!lsp)
                return;

        isis_free_tlvs(lsp->tlvs);
        lsp->tlvs = NULL;
}

static void lsp_remove_frags(struct lspdb_head *head, struct list *frags);

static void lsp_destroy(struct isis_lsp *lsp)
{
        struct listnode *cnode;
        struct isis_circuit *circuit;

        if (!lsp)
                return;

        for (ALL_LIST_ELEMENTS_RO(lsp->area->circuit_list, cnode, circuit))
                isis_tx_queue_del(circuit->tx_queue, lsp);

        ISIS_FLAGS_CLEAR_ALL(lsp->SSNflags);

        isis_te_lsp_event(lsp, LSP_DEL);

        lsp_clear_data(lsp);

        if (!LSP_FRAGMENT(lsp->hdr.lsp_id)) {
                if (lsp->lspu.frags) {
                        lsp_remove_frags(&lsp->area->lspdb[lsp->level - 1],
                                        lsp->lspu.frags);
                        list_delete(&lsp->lspu.frags);
                }
        } else {
                if (lsp->lspu.zero_lsp
                    && lsp->lspu.zero_lsp->lspu.frags) {
                        listnode_delete(lsp->lspu.zero_lsp->lspu.frags, lsp);
                }
        }

        isis_spf_schedule(lsp->area, lsp->level);

        if (lsp->pdu)
                stream_free(lsp->pdu);

        fabricd_lsp_free(lsp);
        XFREE(MTYPE_ISIS_LSP, lsp);
}

/*
 * Remove all the frags belonging to the given lsp
 */
static void lsp_remove_frags(struct lspdb_head *head, struct list *frags)
{
        struct listnode *lnode, *lnnode;
        struct isis_lsp *lsp;

        for (ALL_LIST_ELEMENTS(frags, lnode, lnnode, lsp)) {
                lsp = lsp_search(head, lsp->hdr.lsp_id);
                lspdb_del(head, lsp);
                lsp_destroy(lsp);
        }
}

void lsp_search_and_destroy(struct lspdb_head *head, const uint8_t *id)
{
        struct isis_lsp *lsp;

        lsp = lsp_search(head, id);
        if (lsp) {
                lspdb_del(head, lsp);
                /*
                 * If this is a zero lsp, remove all the frags now
                 */
                if (LSP_FRAGMENT(lsp->hdr.lsp_id) == 0) {
                        if (lsp->lspu.frags)
                                lsp_remove_frags(head, lsp->lspu.frags);
                } else {
                        /*
                         * else just remove this frag, from the zero lsps' frag
                         * list
                         */
                        if (lsp->lspu.zero_lsp
                            && lsp->lspu.zero_lsp->lspu.frags)
                                listnode_delete(lsp->lspu.zero_lsp->lspu.frags,
                                                lsp);
                }
                lsp_destroy(lsp);
        }
}

/*
 * Compares a LSP to given values
 * Params are given in net order
 */
int lsp_compare(char *areatag, struct isis_lsp *lsp, uint32_t seqno,
                uint16_t checksum, uint16_t rem_lifetime)
{
        if (lsp->hdr.seqno == seqno && lsp->hdr.checksum == checksum
            && ((lsp->hdr.rem_lifetime == 0 && rem_lifetime == 0)
                || (lsp->hdr.rem_lifetime != 0 && rem_lifetime != 0))) {
                if (IS_DEBUG_SNP_PACKETS) {
                        zlog_debug(
                                "ISIS-Snp (%s): Compare LSP %s seq 0x%08x, cksum 0x%04hx, lifetime %hus",
                                areatag, rawlspid_print(lsp->hdr.lsp_id),
                                lsp->hdr.seqno, lsp->hdr.checksum,
                                lsp->hdr.rem_lifetime);
                        zlog_debug(
                                "ISIS-Snp (%s):         is equal to ours seq 0x%08x, cksum 0x%04hx, lifetime %hus",
                                areatag, seqno, checksum, rem_lifetime);
                }
                return LSP_EQUAL;
        }

        /*
         * LSPs with identical checksums should only be treated as newer if:
         * a) The current LSP has a remaining lifetime != 0 and the other LSP
         * has a
         *    remaining lifetime == 0. In this case, we should participate in
         * the purge
         *    and should not treat the current LSP with remaining lifetime == 0
         * as older.
         * b) The LSP has an incorrect checksum. In this case, we need to react
         * as given
         *    in 7.3.16.2.
         */
        if (seqno > lsp->hdr.seqno
            || (seqno == lsp->hdr.seqno
                && ((lsp->hdr.rem_lifetime != 0 && rem_lifetime == 0)
                    || (lsp->hdr.checksum != checksum
                        && lsp->hdr.rem_lifetime)))) {
                if (IS_DEBUG_SNP_PACKETS) {
                        zlog_debug(
                                "ISIS-Snp (%s): Compare LSP %s seq 0x%08x, cksum 0x%04hx, lifetime %hus",
                                areatag, rawlspid_print(lsp->hdr.lsp_id), seqno,
                                checksum, rem_lifetime);
                        zlog_debug(
                                "ISIS-Snp (%s):       is newer than ours seq 0x%08x, cksum 0x%04hx, lifetime %hus",
                                areatag, lsp->hdr.seqno, lsp->hdr.checksum,
                                lsp->hdr.rem_lifetime);
                }
                return LSP_NEWER;
        }
        if (IS_DEBUG_SNP_PACKETS) {
                zlog_debug("ISIS-Snp (%s): Compare LSP %s seq 0x%08x, cksum 0x%04hx, lifetime %hus",
                           areatag, rawlspid_print(lsp->hdr.lsp_id), seqno,
                           checksum, rem_lifetime);
                zlog_debug(
                        "ISIS-Snp (%s):       is older than ours seq 0x%08x, cksum 0x%04hx, lifetime %hus",
                        areatag, lsp->hdr.seqno, lsp->hdr.checksum,
                        lsp->hdr.rem_lifetime);
        }

        return LSP_OLDER;
}

static void put_lsp_hdr(struct isis_lsp *lsp, size_t *len_pointer, bool keep)
{
        uint8_t pdu_type =
                (lsp->level == IS_LEVEL_1) ? L1_LINK_STATE : L2_LINK_STATE;
        struct isis_lsp_hdr *hdr = &lsp->hdr;
        struct stream *stream = lsp->pdu;
        size_t orig_getp = 0, orig_endp = 0;

        if (keep) {
                orig_getp = stream_get_getp(lsp->pdu);
                orig_endp = stream_get_endp(lsp->pdu);
        }

        stream_set_getp(lsp->pdu, 0);
        stream_set_endp(lsp->pdu, 0);

        fill_fixed_hdr(pdu_type, stream);

        if (len_pointer)
                *len_pointer = stream_get_endp(stream);
        stream_putw(stream, hdr->pdu_len);
        stream_putw(stream, hdr->rem_lifetime);
        stream_put(stream, hdr->lsp_id, sizeof(hdr->lsp_id));
        stream_putl(stream, hdr->seqno);
        stream_putw(stream, hdr->checksum);
        stream_putc(stream, hdr->lsp_bits);

        if (keep) {
                stream_set_endp(lsp->pdu, orig_endp);
                stream_set_getp(lsp->pdu, orig_getp);
        }
}

static void lsp_add_auth(struct isis_lsp *lsp)
{
        struct isis_passwd *passwd;
        passwd = (lsp->level == IS_LEVEL_1) ? &lsp->area->area_passwd
                                            : &lsp->area->domain_passwd;
        isis_tlvs_add_auth(lsp->tlvs, passwd);
}

static void lsp_pack_pdu(struct isis_lsp *lsp)
{
        if (!lsp->tlvs)
                lsp->tlvs = isis_alloc_tlvs();

        lsp_add_auth(lsp);

        size_t len_pointer;
        put_lsp_hdr(lsp, &len_pointer, false);
        isis_pack_tlvs(lsp->tlvs, lsp->pdu, len_pointer, false, true);

        lsp->hdr.pdu_len = stream_get_endp(lsp->pdu);
        lsp->hdr.checksum =
                ntohs(fletcher_checksum(STREAM_DATA(lsp->pdu) + 12,
                                        stream_get_endp(lsp->pdu) - 12, 12));
}

void lsp_inc_seqno(struct isis_lsp *lsp, uint32_t seqno)
{
        uint32_t newseq;

        if (seqno == 0 || lsp->hdr.seqno > seqno)
                newseq = lsp->hdr.seqno + 1;
        else
                newseq = seqno + 1;

#ifndef FABRICD
        /* check for overflow */
        if (newseq < lsp->hdr.seqno) {
                /* send northbound notification */
                lsp->area->lsp_exceeded_max_counter++;
                isis_notif_lsp_exceed_max(lsp->area, lsp->hdr.lsp_id);
        }
#endif /* ifndef FABRICD */

        lsp->hdr.seqno = newseq;

        lsp_pack_pdu(lsp);
        isis_spf_schedule(lsp->area, lsp->level);
        isis_te_lsp_event(lsp, LSP_INC);
}

static void lsp_purge_add_poi(struct isis_lsp *lsp,
                              const uint8_t *sender)
{
        if (lsp->area == NULL)
                return;

        if (!lsp->area->purge_originator)
                return;

        /* add purge originator identification */
        if (!lsp->tlvs)
                lsp->tlvs = isis_alloc_tlvs();
        isis_tlvs_set_purge_originator(lsp->tlvs, lsp->area->isis->sysid,
                                       sender);
        isis_tlvs_set_dynamic_hostname(lsp->tlvs, cmd_hostname_get());
}

static void lsp_purge(struct isis_lsp *lsp, int level,
                      const uint8_t *sender)
{
        /* reset stream */
        lsp_clear_data(lsp);
        stream_reset(lsp->pdu);

        /* update header */
        lsp->hdr.checksum = 0;
        lsp->hdr.rem_lifetime = 0;
        lsp->level = level;
        lsp->age_out = lsp->area->max_lsp_lifetime[level - 1];
        lsp->area->lsp_purge_count[level - 1]++;

        lsp_purge_add_poi(lsp, sender);

        lsp_pack_pdu(lsp);
        lsp_flood(lsp, NULL);
}

/*
 * Generates checksum for LSP and its frags
 */
static void lsp_seqno_update(struct isis_lsp *lsp0)
{
        struct isis_lsp *lsp;
        struct listnode *node;

        lsp_inc_seqno(lsp0, 0);

        if (!lsp0->lspu.frags)
                return;

        for (ALL_LIST_ELEMENTS_RO(lsp0->lspu.frags, node, lsp)) {
                if (lsp->tlvs)
                        lsp_inc_seqno(lsp, 0);
                else if (lsp->hdr.rem_lifetime) {
                        /* Purge should only be applied when the fragment has
                         * non-zero remaining lifetime.
                         */
                        lsp_purge(lsp, lsp0->level, NULL);
                }
        }

        return;
}

bool isis_level2_adj_up(struct isis_area *area)
{
        struct listnode *node, *cnode;
        struct isis_circuit *circuit;
        struct list *adjdb;
        struct isis_adjacency *adj;

        if (area->is_type == IS_LEVEL_1)
                return false;

        for (ALL_LIST_ELEMENTS_RO(area->circuit_list, cnode, circuit)) {
                if (circuit->circ_type == CIRCUIT_T_BROADCAST) {
                        adjdb = circuit->u.bc.adjdb[1];
                        if (!adjdb || !adjdb->count)
                                continue;

                        for (ALL_LIST_ELEMENTS_RO(adjdb, node, adj)) {
                                if (adj->level != ISIS_ADJ_LEVEL1
                                    && adj->adj_state == ISIS_ADJ_UP)
                                        return true;
                        }
                } else if (circuit->circ_type == CIRCUIT_T_P2P
                           && circuit->u.p2p.neighbor) {
                        adj = circuit->u.p2p.neighbor;
                        if (adj->level != ISIS_ADJ_LEVEL1
                            && adj->adj_state == ISIS_ADJ_UP)
                                return true;
                }
        }

        return false;
}

/*
 * Unset the overload bit after the timer expires
 */
void set_overload_on_start_timer(struct event *thread)
{
        struct isis_area *area = EVENT_ARG(thread);
        assert(area);

        area->t_overload_on_startup_timer = NULL;

        /* Check if set-overload-bit is not currently configured */
        if (!area->overload_configured)
                isis_area_overload_bit_set(area, false);
}

static void isis_reset_attach_bit(struct isis_adjacency *adj)
{
        struct isis_area *area = adj->circuit->area;
        struct lspdb_head *head;
        struct isis_lsp *lsp;
        uint8_t lspid[ISIS_SYS_ID_LEN + 2];

        /*
         * If an L2 adjacency changed its state in L-1-2 area, we have to:
         * - set the attached bit in L1 LSPs if it's the first L2 adjacency
         * - remove the attached bit in L1 LSPs if it's the last L2 adjacency
         */

        if (area->is_type != IS_LEVEL_1_AND_2 || adj->level == ISIS_ADJ_LEVEL1)
                return;

        if (!area->attached_bit_send)
                return;

        head = &area->lspdb[IS_LEVEL_1 - 1];
        memset(lspid, 0, ISIS_SYS_ID_LEN + 2);
        memcpy(lspid, area->isis->sysid, ISIS_SYS_ID_LEN);

        lsp = lsp_search(head, lspid);
        if (!lsp)
                return;

        if (adj->adj_state == ISIS_ADJ_UP
            && !(lsp->hdr.lsp_bits & LSPBIT_ATT)) {
                sched_debug("ISIS (%s): adj going up regenerate lsp-bits",
                            area->area_tag);
                lsp_regenerate_schedule(area, IS_LEVEL_1, 0);
        } else if (adj->adj_state == ISIS_ADJ_DOWN
                   && (lsp->hdr.lsp_bits & LSPBIT_ATT)
                   && !isis_level2_adj_up(area)) {
                sched_debug("ISIS (%s): adj going down regenerate lsp-bits",
                            area->area_tag);
                lsp_regenerate_schedule(area, IS_LEVEL_1, 0);
        }
}

static uint8_t lsp_bits_generate(int level, int overload_bit, int attached_bit,
                                 struct isis_area *area)
{
        uint8_t lsp_bits = 0;
        if (area->is_type == IS_LEVEL_1)
                lsp_bits = IS_LEVEL_1;
        else
                lsp_bits = IS_LEVEL_1_AND_2;
        if (overload_bit)
                lsp_bits |= overload_bit;

        /* only set the attach bit if we are a level-1-2 router and this is
         * a level-1 LSP and we have a level-2 adjacency up from another area
         */
        if (area->is_type == IS_LEVEL_1_AND_2 && level == IS_LEVEL_1
            && attached_bit && isis_level2_adj_up(area))
                lsp_bits |= LSPBIT_ATT;
        return lsp_bits;
}

static void lsp_update_data(struct isis_lsp *lsp, struct isis_lsp_hdr *hdr,
                            struct isis_tlvs *tlvs, struct stream *stream,
                            struct isis_area *area, int level)
{
        /* free the old lsp data */
        lsp_clear_data(lsp);

        /* copying only the relevant part of our stream */
        if (lsp->pdu != NULL)
                stream_free(lsp->pdu);
        lsp->pdu = stream_dup(stream);

        memcpy(&lsp->hdr, hdr, sizeof(lsp->hdr));
        lsp->area = area;
        lsp->level = level;
        lsp->age_out = ZERO_AGE_LIFETIME;
        lsp->installed = time(NULL);

        lsp->tlvs = tlvs;

        if (area->dynhostname && lsp->tlvs->hostname
            && lsp->hdr.rem_lifetime) {
                isis_dynhn_insert(
                        area->isis, lsp->hdr.lsp_id, lsp->tlvs->hostname,
                        (lsp->hdr.lsp_bits & LSPBIT_IST) == IS_LEVEL_1_AND_2
                                ? IS_LEVEL_2
                                : IS_LEVEL_1);
        }

        return;
}

static void lsp_link_fragment(struct isis_lsp *lsp, struct isis_lsp *lsp0)
{
        if (!LSP_FRAGMENT(lsp->hdr.lsp_id)) {
                /* zero lsp -> create list to store fragments */
                lsp->lspu.frags = list_new();
        } else {
                /* fragment -> set backpointer and add to zero lsps list */
                assert(lsp0);
                lsp->lspu.zero_lsp = lsp0;
                listnode_add(lsp0->lspu.frags, lsp);
        }
}

void lsp_update(struct isis_lsp *lsp, struct isis_lsp_hdr *hdr,
                struct isis_tlvs *tlvs, struct stream *stream,
                struct isis_area *area, int level, bool confusion)
{
        if (lsp->own_lsp) {
                flog_err(
                        EC_LIB_DEVELOPMENT,
                        "ISIS-Upd (%s): BUG updating LSP %s still marked as own LSP",
                        area->area_tag, rawlspid_print(lsp->hdr.lsp_id));
                lsp_clear_data(lsp);
                lsp->own_lsp = 0;
        }

        if (confusion) {
                lsp_purge(lsp, level, NULL);
        } else {
                lsp_update_data(lsp, hdr, tlvs, stream, area, level);
        }

        if (LSP_FRAGMENT(lsp->hdr.lsp_id) && !lsp->lspu.zero_lsp) {
                uint8_t lspid[ISIS_SYS_ID_LEN + 2];
                struct isis_lsp *lsp0;

                memcpy(lspid, lsp->hdr.lsp_id, ISIS_SYS_ID_LEN + 1);
                LSP_FRAGMENT(lspid) = 0;
                lsp0 = lsp_search(&area->lspdb[level - 1], lspid);
                if (lsp0)
                        lsp_link_fragment(lsp, lsp0);
        }

        if (lsp->hdr.seqno) {
                isis_spf_schedule(lsp->area, lsp->level);
                isis_te_lsp_event(lsp, LSP_UPD);
        }
}

/* creation of LSP directly from what we received */
struct isis_lsp *lsp_new_from_recv(struct isis_lsp_hdr *hdr,
                                   struct isis_tlvs *tlvs,
                                   struct stream *stream, struct isis_lsp *lsp0,
                                   struct isis_area *area, int level)
{
        struct isis_lsp *lsp;

        lsp = XCALLOC(MTYPE_ISIS_LSP, sizeof(struct isis_lsp));
        lsp_update_data(lsp, hdr, tlvs, stream, area, level);
        lsp_link_fragment(lsp, lsp0);

        return lsp;
}

static void lsp_adjust_stream(struct isis_lsp *lsp)
{
        if (lsp->pdu) {
                if (STREAM_SIZE(lsp->pdu) == LLC_LEN + lsp->area->lsp_mtu)
                        return;
                stream_free(lsp->pdu);
        }

        lsp->pdu = stream_new(LLC_LEN + lsp->area->lsp_mtu);
}

struct isis_lsp *lsp_new(struct isis_area *area, uint8_t *lsp_id,
                         uint16_t rem_lifetime, uint32_t seqno,
                         uint8_t lsp_bits, uint16_t checksum,
                         struct isis_lsp *lsp0, int level)
{
        struct isis_lsp *lsp;

        lsp = XCALLOC(MTYPE_ISIS_LSP, sizeof(struct isis_lsp));
        lsp->area = area;

        lsp_adjust_stream(lsp);

        /* Minimal LSP PDU size */
        lsp->hdr.pdu_len = ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN;
        memcpy(lsp->hdr.lsp_id, lsp_id, sizeof(lsp->hdr.lsp_id));
        lsp->hdr.checksum = checksum;
        lsp->hdr.seqno = seqno;
        lsp->hdr.rem_lifetime = rem_lifetime;
        lsp->hdr.lsp_bits = lsp_bits;
        lsp->level = level;
        lsp->age_out = ZERO_AGE_LIFETIME;
        lsp_link_fragment(lsp, lsp0);
        put_lsp_hdr(lsp, NULL, false);

        if (IS_DEBUG_EVENTS)
                zlog_debug("New LSP with ID %s-%02x-%02x len %d seqnum %08x",
                           sysid_print(lsp_id), LSP_PSEUDO_ID(lsp->hdr.lsp_id),
                           LSP_FRAGMENT(lsp->hdr.lsp_id), lsp->hdr.pdu_len,
                           lsp->hdr.seqno);

        return lsp;
}

void lsp_insert(struct lspdb_head *head, struct isis_lsp *lsp)
{
        lspdb_add(head, lsp);
        if (lsp->hdr.seqno) {
                isis_spf_schedule(lsp->area, lsp->level);
                isis_te_lsp_event(lsp, LSP_ADD);
        }
}

/*
 * Build a list of LSPs with non-zero ht and seqno bounded by start and stop ids
 */
void lsp_build_list_nonzero_ht(struct lspdb_head *head, const uint8_t *start_id,
                               const uint8_t *stop_id, struct list *list)
{
        struct isis_lsp searchfor;
        struct isis_lsp *lsp, *start;

        memcpy(&searchfor.hdr.lsp_id, start_id, sizeof(searchfor.hdr.lsp_id));

        start = lspdb_find_gteq(head, &searchfor);
        frr_each_from (lspdb, head, lsp, start) {
                if (memcmp(lsp->hdr.lsp_id, stop_id,
                           ISIS_SYS_ID_LEN + 2) > 0)
                        break;

                if (lsp->hdr.rem_lifetime && lsp->hdr.seqno)
                        listnode_add(list, lsp);
        }
}

static void lsp_set_time(struct isis_lsp *lsp)
{
        assert(lsp);

        if (lsp->hdr.rem_lifetime == 0) {
                if (lsp->age_out > 0)
                        lsp->age_out--;
                return;
        }

        lsp->hdr.rem_lifetime--;
        if (lsp->pdu && stream_get_endp(lsp->pdu) >= 12)
                stream_putw_at(lsp->pdu, 10, lsp->hdr.rem_lifetime);
}

void lspid_print(uint8_t *lsp_id, char *dest, size_t dest_len, char dynhost,
                 char frag, struct isis *isis)
{
        struct isis_dynhn *dyn = NULL;
        char id[SYSID_STRLEN];

        if (dynhost)
                dyn = dynhn_find_by_id(isis, lsp_id);
        else
                dyn = NULL;

        if (dyn)
                snprintf(id, sizeof(id), "%.14s", dyn->hostname);
        else if (!memcmp(isis->sysid, lsp_id, ISIS_SYS_ID_LEN) && dynhost)
                snprintf(id, sizeof(id), "%.14s", cmd_hostname_get());
        else
                memcpy(id, sysid_print(lsp_id), 15);

        if (frag)
                snprintf(dest, dest_len, "%s.%02x-%02x", id,
                         LSP_PSEUDO_ID(lsp_id), LSP_FRAGMENT(lsp_id));
        else
                snprintf(dest, dest_len, "%s.%02x", id, LSP_PSEUDO_ID(lsp_id));
}

/* Convert the lsp attribute bits to attribute string */
static const char *lsp_bits2string(uint8_t lsp_bits, char *buf, size_t buf_size)
{
        char *pos = buf;

        if (!lsp_bits)
                return " none";

        if (buf_size < 2 * 3)
                return " error";

        /* we only focus on the default metric */
        pos += snprintf(pos, buf_size, "%d/",
                        ISIS_MASK_LSP_ATT_BITS(lsp_bits) ? 1 : 0);

        pos += snprintf(pos, buf_size, "%d/",
                        ISIS_MASK_LSP_PARTITION_BIT(lsp_bits) ? 1 : 0);

        snprintf(pos, buf_size, "%d", ISIS_MASK_LSP_OL_BIT(lsp_bits) ? 1 : 0);

        return buf;
}

/* this function prints the lsp on show isis database */
void lsp_print_common(struct isis_lsp *lsp, struct vty *vty, struct json_object *json,
               char dynhost, struct isis *isis)
{
        if (json) {
                return lsp_print_json(lsp, json, dynhost, isis);
        } else {
                return lsp_print_vty(lsp, vty, dynhost, isis);
        }
}

void lsp_print_json(struct isis_lsp *lsp, struct json_object *json,
               char dynhost, struct isis *isis)
{
        char LSPid[255];
        char age_out[8];
        char b[200];
        json_object *own_json;
        char buf[256];

        lspid_print(lsp->hdr.lsp_id, LSPid, sizeof(LSPid), dynhost, 1, isis);
        own_json = json_object_new_object();
        json_object_object_add(json, "lsp", own_json);
        json_object_string_add(own_json, "id", LSPid);
        json_object_string_add(own_json, "own", lsp->own_lsp ? "*" : " ");
        json_object_int_add(json, "pdu-len", lsp->hdr.pdu_len);
        snprintfrr(buf, sizeof(buf), "0x%08x", lsp->hdr.seqno);
        json_object_string_add(json, "seq-number", buf);
        snprintfrr(buf, sizeof(buf), "0x%04hx", lsp->hdr.checksum);
        json_object_string_add(json, "chksum", buf);
        if (lsp->hdr.rem_lifetime == 0) {
                snprintf(age_out, sizeof(age_out), "(%d)", lsp->age_out);
                age_out[7] = '\0';
                json_object_string_add(json, "holdtime", age_out);
        } else {
                json_object_int_add(json, "holdtime", lsp->hdr.rem_lifetime);
        }
        json_object_string_add(
                json, "att-p-ol", lsp_bits2string(lsp->hdr.lsp_bits, b, sizeof(b)));
}

void lsp_print_vty(struct isis_lsp *lsp, struct vty *vty,
               char dynhost, struct isis *isis)
{
        char LSPid[255];
        char age_out[8];
        char b[200];

        lspid_print(lsp->hdr.lsp_id, LSPid, sizeof(LSPid), dynhost, 1, isis);
        vty_out(vty, "%-21s%c  ", LSPid, lsp->own_lsp ? '*' : ' ');
        vty_out(vty, "%5hu   ", lsp->hdr.pdu_len);
        vty_out(vty, "0x%08x  ", lsp->hdr.seqno);
        vty_out(vty, "0x%04hx  ", lsp->hdr.checksum);
        if (lsp->hdr.rem_lifetime == 0) {
                snprintf(age_out, sizeof(age_out), "(%d)", lsp->age_out);
                age_out[7] = '\0';
                vty_out(vty, "%7s   ", age_out);
        } else
                vty_out(vty, " %5hu    ", lsp->hdr.rem_lifetime);
        vty_out(vty, "%s\n", lsp_bits2string(lsp->hdr.lsp_bits, b, sizeof(b)));
}

void lsp_print_detail(struct isis_lsp *lsp, struct vty *vty,
                             struct json_object *json, char dynhost,
                             struct isis *isis)
{
        if (json) {
                lsp_print_json(lsp, json, dynhost, isis);
                if (lsp->tlvs) {
                        isis_format_tlvs(lsp->tlvs, json);
                }
        } else {
                lsp_print_vty(lsp, vty, dynhost, isis);
                if (lsp->tlvs)
                        vty_multiline(vty, "  ", "%s",
                                      isis_format_tlvs(lsp->tlvs, NULL));
                vty_out(vty, "\n");
        }
}

/* print all the lsps info in the local lspdb */
int lsp_print_all(struct vty *vty, struct json_object *json,
                  struct lspdb_head *head, char detail, char dynhost,
                  struct isis *isis)
{
        struct isis_lsp *lsp;
        int lsp_count = 0;

        if (detail == ISIS_UI_LEVEL_BRIEF) {
                frr_each (lspdb, head, lsp) {
                        lsp_print_common(lsp, vty, json, dynhost, isis);
                        lsp_count++;
                }
        } else if (detail == ISIS_UI_LEVEL_DETAIL) {
                frr_each (lspdb, head, lsp) {
                        lsp_print_detail(lsp, vty, json, dynhost, isis);
                        lsp_count++;
                }
        }

        return lsp_count;
}

static uint16_t lsp_rem_lifetime(struct isis_area *area, int level)
{
        uint16_t rem_lifetime;

        /* Add jitter to configured LSP lifetime */
        rem_lifetime =
                isis_jitter(area->max_lsp_lifetime[level - 1], MAX_AGE_JITTER);

        /* No jitter if the max refresh will be less than configure gen interval
         */
        /* N.B. this calucation is acceptable since rem_lifetime is in
         * [332,65535] at
         * this point */
        if (area->lsp_gen_interval[level - 1] > (rem_lifetime - 300))
                rem_lifetime = area->max_lsp_lifetime[level - 1];

        return rem_lifetime;
}

static uint16_t lsp_refresh_time(struct isis_lsp *lsp, uint16_t rem_lifetime)
{
        struct isis_area *area = lsp->area;
        int level = lsp->level;
        uint16_t refresh_time;

        /* Add jitter to LSP refresh time */
        refresh_time =
                isis_jitter(area->lsp_refresh[level - 1], MAX_LSP_GEN_JITTER);

        /* RFC 4444 : make sure the refresh time is at least less than 300
         * of the remaining lifetime and more than gen interval */
        if (refresh_time <= area->lsp_gen_interval[level - 1]
            || refresh_time > (rem_lifetime - 300))
                refresh_time = rem_lifetime - 300;

        /* In cornercases, refresh_time might be <= lsp_gen_interval, however
         * we accept this violation to satisfy refresh_time <= rem_lifetime -
         * 300 */

        return refresh_time;
}

static void lsp_build_ext_reach_ipv4(struct isis_lsp *lsp,
                                     struct isis_area *area)
{
        struct route_table *er_table = get_ext_reach(area, AF_INET, lsp->level);
        if (!er_table)
                return;

        for (struct route_node *rn = route_top(er_table); rn;
             rn = route_next(rn)) {
                if (!rn->info)
                        continue;

                struct prefix_ipv4 *ipv4 = (struct prefix_ipv4 *)&rn->p;
                struct isis_ext_info *info = rn->info;

                uint32_t metric = info->metric;
                if (metric > MAX_WIDE_PATH_METRIC)
                        metric = MAX_WIDE_PATH_METRIC;
                if (area->oldmetric && metric > 0x3f)
                        metric = 0x3f;

                if (area->oldmetric)
                        isis_tlvs_add_oldstyle_ip_reach(lsp->tlvs, ipv4,
                                                        metric);
                if (area->newmetric) {
                        struct sr_prefix_cfg *pcfg = NULL;

                        if (area->srdb.enabled)
                                pcfg = isis_sr_cfg_prefix_find(area, ipv4);

                        isis_tlvs_add_extended_ip_reach(lsp->tlvs, ipv4, metric,
                                                        true, pcfg);
                }
        }
}

static void lsp_build_ext_reach_ipv6(struct isis_lsp *lsp,
                                     struct isis_area *area)
{
        struct route_table *er_table =
                get_ext_reach(area, AF_INET6, lsp->level);
        if (!er_table)
                return;

        for (struct route_node *rn = route_top(er_table); rn;
             rn = srcdest_route_next(rn)) {
                if (!rn->info)
                        continue;
                struct isis_ext_info *info = rn->info;
                struct prefix_ipv6 *p, *src_p;

                srcdest_rnode_prefixes(rn, (const struct prefix **)&p,
                                       (const struct prefix **)&src_p);

                uint32_t metric = info->metric;
                if (info->metric > MAX_WIDE_PATH_METRIC)
                        metric = MAX_WIDE_PATH_METRIC;

                if (!src_p || !src_p->prefixlen) {
                        struct sr_prefix_cfg *pcfg = NULL;

                        if (area->srdb.enabled)
                                pcfg = isis_sr_cfg_prefix_find(area, p);

                        isis_tlvs_add_ipv6_reach(lsp->tlvs,
                                                 isis_area_ipv6_topology(area),
                                                 p, metric, true, pcfg);
                } else if (isis_area_ipv6_dstsrc_enabled(area)) {
                        isis_tlvs_add_ipv6_dstsrc_reach(lsp->tlvs,
                                                        ISIS_MT_IPV6_DSTSRC,
                                                        p, src_p, metric);
                }
        }
}

static void lsp_build_ext_reach(struct isis_lsp *lsp, struct isis_area *area)
{
        lsp_build_ext_reach_ipv4(lsp, area);
        lsp_build_ext_reach_ipv6(lsp, area);
}

static struct isis_lsp *lsp_next_frag(uint8_t frag_num, struct isis_lsp *lsp0,
                                      struct isis_area *area, int level)
{
        struct isis_lsp *lsp;
        uint8_t frag_id[ISIS_SYS_ID_LEN + 2];

        memcpy(frag_id, lsp0->hdr.lsp_id, ISIS_SYS_ID_LEN + 1);
        LSP_FRAGMENT(frag_id) = frag_num;

        lsp = lsp_search(&area->lspdb[level - 1], frag_id);
        if (lsp) {
                lsp_clear_data(lsp);
                if (!lsp->lspu.zero_lsp)
                        lsp_link_fragment(lsp, lsp0);
                return lsp;
        }

        lsp = lsp_new(area, frag_id, lsp0->hdr.rem_lifetime, 0,
                      lsp_bits_generate(level, area->overload_bit,
                                        area->attached_bit_send, area),
                      0, lsp0, level);
        lsp->own_lsp = 1;
        lsp_insert(&area->lspdb[level - 1], lsp);
        return lsp;
}

/*
 * Builds the LSP data part. This func creates a new frag whenever
 * area->lsp_frag_threshold is exceeded.
 */
static void lsp_build(struct isis_lsp *lsp, struct isis_area *area)
{
        int level = lsp->level;
        struct listnode *node;
        struct isis_lsp *frag;

        lsp_clear_data(lsp);
        for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag))
                lsp_clear_data(frag);

        lsp->tlvs = isis_alloc_tlvs();
        lsp_debug("ISIS (%s): Constructing local system LSP for level %d",
                  area->area_tag, level);

        lsp->hdr.lsp_bits = lsp_bits_generate(level, area->overload_bit,
                                              area->attached_bit_send, area);

        lsp_add_auth(lsp);

        isis_tlvs_add_area_addresses(lsp->tlvs, area->area_addrs);

        /* Protocols Supported */
        if (area->ip_circuits > 0 || area->ipv6_circuits > 0) {
                struct nlpids nlpids = {.count = 0};

                if (area->ip_circuits > 0) {
                        lsp_debug(
                                "ISIS (%s): Found IPv4 circuit, adding IPv4 to NLPIDs",
                                area->area_tag);
                        nlpids.nlpids[nlpids.count] = NLPID_IP;
                        nlpids.count++;
                }
                if (area->ipv6_circuits > 0) {
                        lsp_debug(
                                "ISIS (%s): Found IPv6 circuit, adding IPv6 to NLPIDs",
                                area->area_tag);
                        nlpids.nlpids[nlpids.count] = NLPID_IPV6;
                        nlpids.count++;
                }
                isis_tlvs_set_protocols_supported(lsp->tlvs, &nlpids);
        }

        if (area_is_mt(area)) {
                lsp_debug("ISIS (%s): Adding MT router tlv...", area->area_tag);

                struct isis_area_mt_setting **mt_settings;
                unsigned int mt_count;

                mt_settings = area_mt_settings(area, &mt_count);
                for (unsigned int i = 0; i < mt_count; i++) {
                        isis_tlvs_add_mt_router_info(
                                lsp->tlvs, mt_settings[i]->mtid,
                                mt_settings[i]->overload, false);
                        lsp_debug("ISIS (%s):   MT %s", area->area_tag,
                                  isis_mtid2str(mt_settings[i]->mtid));
                }
        } else {
                lsp_debug("ISIS (%s): Not adding MT router tlv (disabled)",
                          area->area_tag);
        }
        /* Dynamic Hostname */
        if (area->dynhostname) {
                isis_tlvs_set_dynamic_hostname(lsp->tlvs, cmd_hostname_get());
                lsp_debug("ISIS (%s): Adding dynamic hostname '%s'",
                          area->area_tag, cmd_hostname_get());
        } else {
                lsp_debug("ISIS (%s): Not adding dynamic hostname (disabled)",
                          area->area_tag);
        }

        /* Add Router Capability TLV. */
        if (area->isis->router_id != 0) {
                struct isis_router_cap cap = {};

                cap.router_id.s_addr = area->isis->router_id;

                /* Add SR Sub-TLVs if SR is enabled. */
                if (area->srdb.enabled) {
                        struct isis_sr_db *srdb = &area->srdb;
                        uint32_t range_size;

                        /* SRGB first */
                        range_size = srdb->config.srgb_upper_bound
                                     - srdb->config.srgb_lower_bound + 1;
                        cap.srgb.flags = ISIS_SUBTLV_SRGB_FLAG_I
                                         | ISIS_SUBTLV_SRGB_FLAG_V;
                        cap.srgb.range_size = range_size;
                        cap.srgb.lower_bound = srdb->config.srgb_lower_bound;
                        /* Then Algorithm */
                        cap.algo[0] = SR_ALGORITHM_SPF;
                        cap.algo[1] = SR_ALGORITHM_UNSET;
                        /* SRLB */
                        cap.srlb.flags = 0;
                        range_size = srdb->config.srlb_upper_bound
                                     - srdb->config.srlb_lower_bound + 1;
                        cap.srlb.range_size = range_size;
                        cap.srlb.lower_bound = srdb->config.srlb_lower_bound;
                        /* And finally MSD */
                        cap.msd = srdb->config.msd;
                } else {
                        /* Disable SR Algorithm */
                        cap.algo[0] = SR_ALGORITHM_UNSET;
                        cap.algo[1] = SR_ALGORITHM_UNSET;
                }

                isis_tlvs_set_router_capability(lsp->tlvs, &cap);
                lsp_debug("ISIS (%s): Adding Router Capabilities information",
                          area->area_tag);
        }

        /* IPv4 address and TE router ID TLVs.
         * In case of the first one we don't follow "C" vendor,
         * but "J" vendor behavior - one IPv4 address is put
         * into LSP. TE router ID will be the same if MPLS-TE
         * is not activate or MPLS-TE router-id not specified
         */
        if (area->isis->router_id != 0) {
                struct in_addr id = {.s_addr = area->isis->router_id};
                lsp_debug("ISIS (%s): Adding router ID %pI4 as IPv4 tlv.",
                          area->area_tag, &id);
                isis_tlvs_add_ipv4_address(lsp->tlvs, &id);

                /* If new style TLV's are in use, add TE router ID TLV
                 * Check if MPLS-TE is activate and mpls-te router-id set
                 * otherwise add exactly same data as for IPv4 address
                 */
                if (area->newmetric) {
                        if (IS_MPLS_TE(area->mta)
                            && area->mta->router_id.s_addr != INADDR_ANY)
                                id.s_addr = area->mta->router_id.s_addr;
                        lsp_debug(
                                "ISIS (%s): Adding router ID also as TE router ID tlv.",
                                area->area_tag);
                        isis_tlvs_set_te_router_id(lsp->tlvs, &id);
                }
        } else {
                lsp_debug("ISIS (%s): Router ID is unset. Not adding tlv.",
                          area->area_tag);
        }

        if (IS_MPLS_TE(area->mta)
            && !IN6_IS_ADDR_UNSPECIFIED(&area->mta->router_id_ipv6)) {
                lsp_debug("ISIS (%s): Adding IPv6 TE Router ID tlv.",
                          area->area_tag);
                isis_tlvs_set_te_router_id_ipv6(lsp->tlvs,
                                                &area->mta->router_id_ipv6);
        }

        lsp_debug("ISIS (%s): Adding circuit specific information.",
                  area->area_tag);

        if (fabricd) {
                lsp_debug(
                        "ISIS (%s): Adding tier %hhu spine-leaf-extension tlv.",
                        area->area_tag, fabricd_tier(area));
                isis_tlvs_add_spine_leaf(lsp->tlvs, fabricd_tier(area), true,
                                         false, false, false);
        }

        struct isis_circuit *circuit;
        for (ALL_LIST_ELEMENTS_RO(area->circuit_list, node, circuit)) {
                if (!circuit->interface)
                        lsp_debug(
                                "ISIS (%s): Processing %s circuit %p with unknown interface",
                                area->area_tag,
                                circuit_type2string(circuit->circ_type),
                                circuit);
                else
                        lsp_debug("ISIS (%s): Processing %s circuit %s",
                                  area->area_tag,
                                  circuit_type2string(circuit->circ_type),
                                  circuit->interface->name);

                if (circuit->state != C_STATE_UP) {
                        lsp_debug("ISIS (%s): Circuit is not up, ignoring.",
                                  area->area_tag);
                        continue;
                }

                if (area->advertise_passive_only && !circuit->is_passive) {
                        lsp_debug(
                                "ISIS (%s): Circuit is not passive, ignoring.",
                                area->area_tag);
                        continue;
                }

                uint32_t metric = area->oldmetric
                                          ? circuit->metric[level - 1]
                                          : circuit->te_metric[level - 1];

                if (circuit->ip_router && circuit->ip_addrs->count > 0) {
                        lsp_debug(
                                "ISIS (%s): Circuit has IPv4 active, adding respective TLVs.",
                                area->area_tag);
                        struct listnode *ipnode;
                        struct prefix_ipv4 *ipv4;
                        for (ALL_LIST_ELEMENTS_RO(circuit->ip_addrs, ipnode,
                                                  ipv4)) {
                                if (area->oldmetric) {
                                        lsp_debug(
                                                "ISIS (%s): Adding old-style IP reachability for %pFX",
                                                area->area_tag, ipv4);
                                        isis_tlvs_add_oldstyle_ip_reach(
                                                lsp->tlvs, ipv4, metric);
                                }

                                if (area->newmetric) {
                                        struct sr_prefix_cfg *pcfg = NULL;

                                        lsp_debug(
                                                "ISIS (%s): Adding te-style IP reachability for %pFX",
                                                area->area_tag, ipv4);

                                        if (area->srdb.enabled)
                                                pcfg = isis_sr_cfg_prefix_find(
                                                        area, ipv4);

                                        isis_tlvs_add_extended_ip_reach(
                                                lsp->tlvs, ipv4, metric, false,
                                                pcfg);
                                }
                        }
                }

                if (circuit->ipv6_router && circuit->ipv6_non_link->count > 0) {
                        struct listnode *ipnode;
                        struct prefix_ipv6 *ipv6;

                        for (ALL_LIST_ELEMENTS_RO(circuit->ipv6_non_link,
                                                  ipnode, ipv6)) {
                                struct sr_prefix_cfg *pcfg = NULL;

                                lsp_debug(
                                        "ISIS (%s): Adding IPv6 reachability for %pFX",
                                        area->area_tag, ipv6);

                                if (area->srdb.enabled)
                                        pcfg = isis_sr_cfg_prefix_find(area,
                                                                       ipv6);

                                isis_tlvs_add_ipv6_reach(
                                        lsp->tlvs,
                                        isis_area_ipv6_topology(area), ipv6,
                                        metric, false, pcfg);
                        }
                }

                switch (circuit->circ_type) {
                case CIRCUIT_T_BROADCAST:
                        if (level & circuit->is_type) {
                                uint8_t *ne_id =
                                        (level == IS_LEVEL_1)
                                                ? circuit->u.bc.l1_desig_is
                                                : circuit->u.bc.l2_desig_is;

                                if (LSP_PSEUDO_ID(ne_id)) {
                                        if (area->oldmetric) {
                                                lsp_debug(
                                                        "ISIS (%s): Adding DIS %s.%02x as old-style neighbor",
                                                        area->area_tag,
                                                        sysid_print(ne_id),
                                                        LSP_PSEUDO_ID(ne_id));
                                                isis_tlvs_add_oldstyle_reach(
                                                        lsp->tlvs, ne_id,
                                                        metric);
                                        }
                                        if (area->newmetric)
                                                tlvs_add_mt_bcast(
                                                        lsp->tlvs, circuit,
                                                        level, ne_id, metric);
                                }
                        } else {
                                lsp_debug(
                                        "ISIS (%s): Circuit is not active for current level. Not adding IS neighbors",
                                        area->area_tag);
                        }
                        break;
                case CIRCUIT_T_P2P: {
                        struct isis_adjacency *nei = circuit->u.p2p.neighbor;
                        if (nei && nei->adj_state == ISIS_ADJ_UP
                            && (level & nei->circuit_t)) {
                                uint8_t ne_id[7];
                                memcpy(ne_id, nei->sysid, ISIS_SYS_ID_LEN);
                                LSP_PSEUDO_ID(ne_id) = 0;

                                if (area->oldmetric) {
                                        lsp_debug(
                                                "ISIS (%s): Adding old-style is reach for %s",
                                                area->area_tag,
                                                sysid_print(ne_id));
                                        isis_tlvs_add_oldstyle_reach(
                                                lsp->tlvs, ne_id, metric);
                                }
                                if (area->newmetric) {
                                        uint32_t neighbor_metric;
                                        if (fabricd_tier(area) == 0) {
                                                neighbor_metric = 0xffe;
                                        } else {
                                                neighbor_metric = metric;
                                        }

                                        tlvs_add_mt_p2p(lsp->tlvs, circuit,
                                                        ne_id, neighbor_metric);
                                }
                        } else {
                                lsp_debug(
                                        "ISIS (%s): No adjacency for given level on this circuit. Not adding IS neighbors",
                                        area->area_tag);
                        }
                } break;
                case CIRCUIT_T_LOOPBACK:
                        break;
                default:
                        zlog_warn("lsp_area_create: unknown circuit type");
                }
        }

        lsp_build_ext_reach(lsp, area);

        struct isis_tlvs *tlvs = lsp->tlvs;
        lsp->tlvs = NULL;

        lsp_adjust_stream(lsp);
        lsp_pack_pdu(lsp);
        size_t tlv_space = STREAM_WRITEABLE(lsp->pdu) - LLC_LEN;
        lsp_clear_data(lsp);

        struct list *fragments = isis_fragment_tlvs(tlvs, tlv_space);
        if (!fragments) {
                zlog_warn("BUG: could not fragment own LSP:");
                log_multiline(LOG_WARNING, "    ", "%s",
                              isis_format_tlvs(tlvs, NULL));
                isis_free_tlvs(tlvs);
                return;
        }
        isis_free_tlvs(tlvs);

        bool fragment_overflow = false;
        frag = lsp;
        for (ALL_LIST_ELEMENTS_RO(fragments, node, tlvs)) {
                if (node != listhead(fragments)) {
                        if (LSP_FRAGMENT(frag->hdr.lsp_id) == 255) {
                                if (!fragment_overflow) {
                                        fragment_overflow = true;
                                        zlog_warn(
                                                "ISIS (%s): Too much information for 256 fragments",
                                                area->area_tag);
                                }
                                isis_free_tlvs(tlvs);
                                continue;
                        }

                        frag = lsp_next_frag(LSP_FRAGMENT(frag->hdr.lsp_id) + 1,
                                             lsp, area, level);
                        lsp_adjust_stream(frag);
                }
                frag->tlvs = tlvs;
        }

        list_delete(&fragments);
        lsp_debug("ISIS (%s): LSP construction is complete. Serializing...",
                  area->area_tag);
        return;
}

/*
 * 7.3.7 and 7.3.9 Generation on non-pseudonode LSPs
 */
int lsp_generate(struct isis_area *area, int level)
{
        struct isis_lsp *oldlsp, *newlsp;
        uint32_t seq_num = 0;
        uint8_t lspid[ISIS_SYS_ID_LEN + 2];
        uint16_t rem_lifetime, refresh_time;
        uint32_t overload_time;

        if ((area == NULL) || (area->is_type & level) != level)
                return ISIS_ERROR;

        /* Check if config is still being processed */
        if (event_is_scheduled(t_isis_cfg))
                return ISIS_OK;

        memset(&lspid, 0, ISIS_SYS_ID_LEN + 2);

        memcpy(&lspid, area->isis->sysid, ISIS_SYS_ID_LEN);

        /* Check if device should be overloaded on startup */
        if (device_startup) {
                overload_time = isis_restart_read_overload_time(area);
                if (overload_time > 0) {
                        isis_area_overload_bit_set(area, true);
                        event_add_timer(master, set_overload_on_start_timer,
                                        area, overload_time,
                                        &area->t_overload_on_startup_timer);
                }
                device_startup = false;
        }

        /* only builds the lsp if the area shares the level */
        oldlsp = lsp_search(&area->lspdb[level - 1], lspid);
        if (oldlsp) {
                /* FIXME: we should actually initiate a purge */
                seq_num = oldlsp->hdr.seqno;
                lsp_search_and_destroy(&area->lspdb[level - 1],
                                       oldlsp->hdr.lsp_id);
        }
        rem_lifetime = lsp_rem_lifetime(area, level);
        newlsp = lsp_new(area, lspid, rem_lifetime, seq_num,
                         lsp_bits_generate(area->is_type, area->overload_bit,
                                           area->attached_bit_send, area),
                         0, NULL, level);
        newlsp->area = area;
        newlsp->own_lsp = 1;

        lsp_insert(&area->lspdb[level - 1], newlsp);
        /* build_lsp_data (newlsp, area); */
        lsp_build(newlsp, area);
        /* time to calculate our checksum */
        lsp_seqno_update(newlsp);
        newlsp->last_generated = time(NULL);
        lsp_flood(newlsp, NULL);
        area->lsp_gen_count[level - 1]++;

        refresh_time = lsp_refresh_time(newlsp, rem_lifetime);

        EVENT_OFF(area->t_lsp_refresh[level - 1]);
        area->lsp_regenerate_pending[level - 1] = 0;
        event_add_timer(master, lsp_refresh, &area->lsp_refresh_arg[level - 1],
                        refresh_time, &area->t_lsp_refresh[level - 1]);

        if (IS_DEBUG_UPDATE_PACKETS) {
                zlog_debug("ISIS-Upd (%s): Building L%d LSP %s, len %hu, seq 0x%08x, cksum 0x%04hx, lifetime %hus refresh %hus",
                           area->area_tag, level,
                           rawlspid_print(newlsp->hdr.lsp_id),
                           newlsp->hdr.pdu_len, newlsp->hdr.seqno,
                           newlsp->hdr.checksum, newlsp->hdr.rem_lifetime,
                           refresh_time);
        }
        sched_debug(
                "ISIS (%s): Built L%d LSP. Set triggered regenerate to non-pending.",
                area->area_tag, level);

#ifndef FABRICD
        /* send northbound notification */
        isis_notif_lsp_gen(area, newlsp->hdr.lsp_id, newlsp->hdr.seqno,
                           newlsp->last_generated);
#endif /* ifndef FABRICD */

        return ISIS_OK;
}

/*
 * Search own LSPs, update holding time and flood
 */
static int lsp_regenerate(struct isis_area *area, int level)
{
        struct lspdb_head *head;
        struct isis_lsp *lsp, *frag;
        struct listnode *node;
        uint8_t lspid[ISIS_SYS_ID_LEN + 2];
        uint16_t rem_lifetime, refresh_time;

        if ((area == NULL) || (area->is_type & level) != level)
                return ISIS_ERROR;

        head = &area->lspdb[level - 1];
        memset(lspid, 0, ISIS_SYS_ID_LEN + 2);
        memcpy(lspid, area->isis->sysid, ISIS_SYS_ID_LEN);

        lsp = lsp_search(head, lspid);

        if (!lsp) {
                flog_err(EC_LIB_DEVELOPMENT,
                         "ISIS-Upd (%s): lsp_regenerate: no L%d LSP found!",
                         area->area_tag, level);
                return ISIS_ERROR;
        }

        lsp_clear_data(lsp);
        lsp_build(lsp, area);
        rem_lifetime = lsp_rem_lifetime(area, level);
        lsp->hdr.rem_lifetime = rem_lifetime;
        lsp->last_generated = time(NULL);
        lsp_flood(lsp, NULL);
        area->lsp_gen_count[level - 1]++;
        for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag)) {
                if (!frag->tlvs) {
                        /* Updating and flooding should only affect fragments
                         * carrying data
                         */
                        continue;
                }

                frag->hdr.lsp_bits =
                        lsp_bits_generate(level, area->overload_bit,
                                          area->attached_bit_send, area);
                /* Set the lifetime values of all the fragments to the same
                 * value,
                 * so that no fragment expires before the lsp is refreshed.
                 */
                frag->hdr.rem_lifetime = rem_lifetime;
                frag->age_out = ZERO_AGE_LIFETIME;
                lsp_flood(frag, NULL);
        }
        lsp_seqno_update(lsp);

        refresh_time = lsp_refresh_time(lsp, rem_lifetime);
        event_add_timer(master, lsp_refresh, &area->lsp_refresh_arg[level - 1],
                        refresh_time, &area->t_lsp_refresh[level - 1]);
        area->lsp_regenerate_pending[level - 1] = 0;

        if (IS_DEBUG_UPDATE_PACKETS) {
                zlog_debug(
                        "ISIS-Upd (%s): Refreshed our L%d LSP %s, len %hu, seq 0x%08x, cksum 0x%04hx, lifetime %hus refresh %hus",
                        area->area_tag, level, rawlspid_print(lsp->hdr.lsp_id),
                        lsp->hdr.pdu_len, lsp->hdr.seqno, lsp->hdr.checksum,
                        lsp->hdr.rem_lifetime, refresh_time);
        }
        sched_debug(
                "ISIS (%s): Rebuilt L%d LSP. Set triggered regenerate to non-pending.",
                area->area_tag, level);

        return ISIS_OK;
}

/*
 * Something has changed or periodic refresh -> regenerate LSP
 */
static void lsp_refresh(struct event *thread)
{
        struct lsp_refresh_arg *arg = EVENT_ARG(thread);

        assert(arg);

        struct isis_area *area = arg->area;

        assert(area);

        int level = arg->level;

        area->t_lsp_refresh[level - 1] = NULL;
        area->lsp_regenerate_pending[level - 1] = 0;

        if ((area->is_type & level) == 0)
                return;

        /*
         * Throttle regeneration of LSPs (but not when BFD signalled a 'down'
         * message)
         */
        if (monotime_since(&area->last_lsp_refresh_event[level - 1], NULL)
                    < 100000L
            && !(area->bfd_force_spf_refresh)) {
                sched_debug("ISIS (%s): Still unstable, postpone LSP L%d refresh",
                            area->area_tag, level);
                _lsp_regenerate_schedule(area, level, 0, false,
                                         __func__, __FILE__, __LINE__);
                return;
        }

        sched_debug(
                "ISIS (%s): LSP L%d refresh timer expired. Refreshing LSP...",
                area->area_tag, level);
        lsp_regenerate(area, level);
}

int _lsp_regenerate_schedule(struct isis_area *area, int level,
                             int all_pseudo, bool postpone,
                             const char *func, const char *file,
                             int line)
{
        struct isis_lsp *lsp;
        uint8_t id[ISIS_SYS_ID_LEN + 2];
        time_t now, diff;
        long timeout;
        struct listnode *cnode;
        struct isis_circuit *circuit;
        int lvl;

        if (area == NULL)
                return ISIS_ERROR;

        sched_debug(
                "ISIS (%s): Scheduling regeneration of %s LSPs, %sincluding PSNs Caller: %s %s:%d",
                area->area_tag, circuit_t2string(level),
                all_pseudo ? "" : "not ",
                func, file, line);

        memcpy(id, area->isis->sysid, ISIS_SYS_ID_LEN);
        LSP_PSEUDO_ID(id) = LSP_FRAGMENT(id) = 0;
        now = time(NULL);

        for (lvl = IS_LEVEL_1; lvl <= IS_LEVEL_2; lvl++) {
                if (!((level & lvl) && (area->is_type & lvl)))
                        continue;

                if (postpone) {
                        monotime(&area->last_lsp_refresh_event[lvl - 1]);
                }

                sched_debug(
                        "ISIS (%s): Checking whether L%d needs to be scheduled",
                        area->area_tag, lvl);

                if (area->lsp_regenerate_pending[lvl - 1]
                    && !(area->bfd_signalled_down)) {
                        /*
                         * Note: in case of a BFD 'down' message the refresh is
                         * scheduled once again just to be sure
                         */
                        struct timeval remain = event_timer_remain(
                                area->t_lsp_refresh[lvl - 1]);
                        sched_debug(
                                "ISIS (%s): Regeneration is already pending, nothing todo. (Due in %lld.%03lld seconds)",
                                area->area_tag, (long long)remain.tv_sec,
                                (long long)remain.tv_usec / 1000);
                        continue;
                }

                lsp = lsp_search(&area->lspdb[lvl - 1], id);
                if (!lsp) {
                        sched_debug(
                                "ISIS (%s): We do not have any LSPs to regenerate, nothing todo.",
                                area->area_tag);
                        continue;
                }

                /*
                 * Throttle avoidance
                 */
                sched_debug(
                        "ISIS (%s): Will schedule regen timer. Last run was: %lld, Now is: %lld",
                        area->area_tag, (long long)lsp->last_generated,
                        (long long)now);
                EVENT_OFF(area->t_lsp_refresh[lvl - 1]);
                diff = now - lsp->last_generated;
                if (diff < area->lsp_gen_interval[lvl - 1]
                    && !(area->bfd_signalled_down)) {
                        timeout =
                                1000 * (area->lsp_gen_interval[lvl - 1] - diff);
                        sched_debug(
                                "ISIS (%s): Scheduling in %ld ms to match configured lsp_gen_interval",
                                area->area_tag, timeout);
                } else {
                        /*
                         * Schedule LSP refresh ASAP
                         */
                        if (area->bfd_signalled_down) {
                                sched_debug(
                                        "ISIS (%s): Scheduling immediately due to BFD 'down' message.",
                                        area->area_tag);
                                area->bfd_signalled_down = false;
                                area->bfd_force_spf_refresh = true;
                                timeout = 0;
                        } else {
                                int64_t time_since_last = monotime_since(
                                        &area->last_lsp_refresh_event[lvl - 1],
                                        NULL);
                                timeout = time_since_last < 100000L
                                                  ? (100000L - time_since_last)/1000
                                                  : 0;
                                if (timeout > 0)
                                        sched_debug(
                                                "ISIS (%s): Last generation was more than lsp_gen_interval ago. Scheduling for execution in %ld ms due to the instability timer.",
                                                area->area_tag, timeout);
                                else
                                        sched_debug(
                                                "ISIS (%s): Last generation was more than lsp_gen_interval ago. Scheduling for execution now.",
                                                area->area_tag);
                        }
                }

                area->lsp_regenerate_pending[lvl - 1] = 1;
                event_add_timer_msec(master, lsp_refresh,
                                     &area->lsp_refresh_arg[lvl - 1], timeout,
                                     &area->t_lsp_refresh[lvl - 1]);
        }

        if (all_pseudo) {
                for (ALL_LIST_ELEMENTS_RO(area->circuit_list, cnode, circuit))
                        lsp_regenerate_schedule_pseudo(circuit, level);
        }

        return ISIS_OK;
}

/*
 * Funcs for pseudonode LSPs
 */

/*
 * 7.3.8 and 7.3.10 Generation of level 1 and 2 pseudonode LSPs
 */
static void lsp_build_pseudo(struct isis_lsp *lsp, struct isis_circuit *circuit,
                             int level)
{
        struct isis_adjacency *adj;
        struct list *adj_list;
        struct listnode *node;
        struct isis_area *area = circuit->area;
        uint16_t mtid;

        lsp_clear_data(lsp);
        lsp->tlvs = isis_alloc_tlvs();
        lsp_debug(
                "ISIS (%s): Constructing pseudo LSP %s for interface %s level %d",
                area->area_tag, rawlspid_print(lsp->hdr.lsp_id),
                circuit->interface->name, level);

        lsp->level = level;
        /* RFC3787  section 4 SHOULD not set overload bit in pseudo LSPs */
        lsp->hdr.lsp_bits = lsp_bits_generate(
                level, 0, circuit->area->attached_bit_send, area);

        /*
         * add self to IS neighbours
         */
        uint8_t ne_id[ISIS_SYS_ID_LEN + 1];

        memcpy(ne_id, area->isis->sysid, ISIS_SYS_ID_LEN);
        LSP_PSEUDO_ID(ne_id) = 0;

        if (circuit->area->oldmetric) {
                isis_tlvs_add_oldstyle_reach(lsp->tlvs, ne_id, 0);
                lsp_debug(
                        "ISIS (%s): Adding %s.%02x as old-style neighbor (self)",
                        area->area_tag, sysid_print(ne_id),
                        LSP_PSEUDO_ID(ne_id));
        }
        if (circuit->area->newmetric) {
                if (area_is_mt(circuit->area))
                        mtid = ISIS_MT_IPV4_UNICAST;
                else
                        mtid = ISIS_MT_DISABLE;
                isis_tlvs_add_extended_reach(lsp->tlvs, mtid, ne_id, 0, NULL);
                lsp_debug(
                        "ISIS (%s): Adding %s.%02x as te-style neighbor (self)",
                        area->area_tag, sysid_print(ne_id),
                        LSP_PSEUDO_ID(ne_id));
        }

        adj_list = list_new();
        isis_adj_build_up_list(circuit->u.bc.adjdb[level - 1], adj_list);

        for (ALL_LIST_ELEMENTS_RO(adj_list, node, adj)) {
                if (!(adj->level & level)) {
                        lsp_debug(
                                "ISIS (%s): Ignoring neighbor %s, level does not intersect",
                                area->area_tag, sysid_print(adj->sysid));
                        continue;
                }

                if (!(level == IS_LEVEL_1
                      && adj->sys_type == ISIS_SYSTYPE_L1_IS)
                    && !(level == IS_LEVEL_1
                         && adj->sys_type == ISIS_SYSTYPE_L2_IS
                         && adj->adj_usage == ISIS_ADJ_LEVEL1AND2)
                    && !(level == IS_LEVEL_2
                         && adj->sys_type == ISIS_SYSTYPE_L2_IS)) {
                        lsp_debug(
                                "ISIS (%s): Ignoring neighbor %s, level does not match",
                                area->area_tag, sysid_print(adj->sysid));
                        continue;
                }

                memcpy(ne_id, adj->sysid, ISIS_SYS_ID_LEN);
                if (circuit->area->oldmetric) {
                        isis_tlvs_add_oldstyle_reach(lsp->tlvs, ne_id, 0);
                        lsp_debug(
                                "ISIS (%s): Adding %s.%02x as old-style neighbor (peer)",
                                area->area_tag, sysid_print(ne_id),
                                LSP_PSEUDO_ID(ne_id));
                }
                if (circuit->area->newmetric) {
                        isis_tlvs_add_extended_reach(lsp->tlvs,
                                                     ISIS_MT_IPV4_UNICAST,
                                                     ne_id, 0, NULL);
                        lsp_debug(
                                "ISIS (%s): Adding %s.%02x as te-style neighbor (peer)",
                                area->area_tag, sysid_print(ne_id),
                                LSP_PSEUDO_ID(ne_id));
                }
        }
        list_delete(&adj_list);
        return;
}

int lsp_generate_pseudo(struct isis_circuit *circuit, int level)
{
        struct lspdb_head *head = &circuit->area->lspdb[level - 1];
        struct isis_lsp *lsp;
        uint8_t lsp_id[ISIS_SYS_ID_LEN + 2];
        uint16_t rem_lifetime, refresh_time;

        if ((circuit->is_type & level) != level
            || (circuit->state != C_STATE_UP)
            || (circuit->circ_type != CIRCUIT_T_BROADCAST)
            || (circuit->u.bc.is_dr[level - 1] == 0))
                return ISIS_ERROR;

        memcpy(lsp_id, circuit->isis->sysid, ISIS_SYS_ID_LEN);
        LSP_FRAGMENT(lsp_id) = 0;
        LSP_PSEUDO_ID(lsp_id) = circuit->circuit_id;

        /*
         * If for some reason have a pseudo LSP in the db already -> regenerate
         */
        if (lsp_search(head, lsp_id))
                return lsp_regenerate_schedule_pseudo(circuit, level);

        rem_lifetime = lsp_rem_lifetime(circuit->area, level);
        /* RFC3787  section 4 SHOULD not set overload bit in pseudo LSPs */
        lsp = lsp_new(circuit->area, lsp_id, rem_lifetime, 1,
                      lsp_bits_generate(circuit->area->is_type, 0,
                                        circuit->area->attached_bit_send,
                                        circuit->area),
                      0, NULL, level);
        lsp->area = circuit->area;

        lsp_build_pseudo(lsp, circuit, level);
        lsp_pack_pdu(lsp);
        lsp->own_lsp = 1;
        lsp_insert(head, lsp);
        lsp_flood(lsp, NULL);

        refresh_time = lsp_refresh_time(lsp, rem_lifetime);
        EVENT_OFF(circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);
        circuit->lsp_regenerate_pending[level - 1] = 0;
        if (level == IS_LEVEL_1)
                event_add_timer(master, lsp_l1_refresh_pseudo, circuit,
                                refresh_time,
                                &circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);
        else if (level == IS_LEVEL_2)
                event_add_timer(master, lsp_l2_refresh_pseudo, circuit,
                                refresh_time,
                                &circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);

        if (IS_DEBUG_UPDATE_PACKETS) {
                zlog_debug(
                        "ISIS-Upd (%s): Built L%d Pseudo LSP %s, len %hu, seq 0x%08x, cksum 0x%04hx, lifetime %hus, refresh %hus",
                        circuit->area->area_tag, level,
                        rawlspid_print(lsp->hdr.lsp_id), lsp->hdr.pdu_len,
                        lsp->hdr.seqno, lsp->hdr.checksum,
                        lsp->hdr.rem_lifetime, refresh_time);
        }

        return ISIS_OK;
}

static int lsp_regenerate_pseudo(struct isis_circuit *circuit, int level)
{
        struct lspdb_head *head = &circuit->area->lspdb[level - 1];
        struct isis_lsp *lsp;
        uint8_t lsp_id[ISIS_SYS_ID_LEN + 2];
        uint16_t rem_lifetime, refresh_time;

        if ((circuit->is_type & level) != level
            || (circuit->state != C_STATE_UP)
            || (circuit->circ_type != CIRCUIT_T_BROADCAST)
            || (circuit->u.bc.is_dr[level - 1] == 0))
                return ISIS_ERROR;

        memcpy(lsp_id, circuit->isis->sysid, ISIS_SYS_ID_LEN);
        LSP_PSEUDO_ID(lsp_id) = circuit->circuit_id;
        LSP_FRAGMENT(lsp_id) = 0;

        lsp = lsp_search(head, lsp_id);

        if (!lsp) {
                flog_err(EC_LIB_DEVELOPMENT,
                         "lsp_regenerate_pseudo: no l%d LSP %s found!", level,
                         rawlspid_print(lsp_id));
                return ISIS_ERROR;
        }

        rem_lifetime = lsp_rem_lifetime(circuit->area, level);
        lsp->hdr.rem_lifetime = rem_lifetime;
        lsp_build_pseudo(lsp, circuit, level);
        lsp_inc_seqno(lsp, 0);
        lsp->last_generated = time(NULL);
        lsp_flood(lsp, NULL);

        refresh_time = lsp_refresh_time(lsp, rem_lifetime);
        if (level == IS_LEVEL_1)
                event_add_timer(master, lsp_l1_refresh_pseudo, circuit,
                                refresh_time,
                                &circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);
        else if (level == IS_LEVEL_2)
                event_add_timer(master, lsp_l2_refresh_pseudo, circuit,
                                refresh_time,
                                &circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);

        if (IS_DEBUG_UPDATE_PACKETS) {
                zlog_debug(
                        "ISIS-Upd (%s): Refreshed L%d Pseudo LSP %s, len %hu, seq 0x%08x, cksum 0x%04hx, lifetime %hus, refresh %hus",
                        circuit->area->area_tag, level,
                        rawlspid_print(lsp->hdr.lsp_id), lsp->hdr.pdu_len,
                        lsp->hdr.seqno, lsp->hdr.checksum,
                        lsp->hdr.rem_lifetime, refresh_time);
        }

        return ISIS_OK;
}

/*
 * Something has changed or periodic refresh -> regenerate pseudo LSP
 */
static void lsp_l1_refresh_pseudo(struct event *thread)
{
        struct isis_circuit *circuit;
        uint8_t id[ISIS_SYS_ID_LEN + 2];

        circuit = EVENT_ARG(thread);

        circuit->u.bc.t_refresh_pseudo_lsp[0] = NULL;
        circuit->lsp_regenerate_pending[0] = 0;

        if ((circuit->u.bc.is_dr[0] == 0)
            || (circuit->is_type & IS_LEVEL_1) == 0) {
                memcpy(id, circuit->isis->sysid, ISIS_SYS_ID_LEN);
                LSP_PSEUDO_ID(id) = circuit->circuit_id;
                LSP_FRAGMENT(id) = 0;
                lsp_purge_pseudo(id, circuit, IS_LEVEL_1);
                return;
        }

        lsp_regenerate_pseudo(circuit, IS_LEVEL_1);
}

static void lsp_l2_refresh_pseudo(struct event *thread)
{
        struct isis_circuit *circuit;
        uint8_t id[ISIS_SYS_ID_LEN + 2];

        circuit = EVENT_ARG(thread);

        circuit->u.bc.t_refresh_pseudo_lsp[1] = NULL;
        circuit->lsp_regenerate_pending[1] = 0;

        if ((circuit->u.bc.is_dr[1] == 0)
            || (circuit->is_type & IS_LEVEL_2) == 0) {
                memcpy(id, circuit->isis->sysid, ISIS_SYS_ID_LEN);
                LSP_PSEUDO_ID(id) = circuit->circuit_id;
                LSP_FRAGMENT(id) = 0;
                lsp_purge_pseudo(id, circuit, IS_LEVEL_2);
                return;
        }

        lsp_regenerate_pseudo(circuit, IS_LEVEL_2);
}

int lsp_regenerate_schedule_pseudo(struct isis_circuit *circuit, int level)
{
        struct isis_lsp *lsp;
        uint8_t lsp_id[ISIS_SYS_ID_LEN + 2];
        time_t now, diff;
        long timeout;
        int lvl;
        struct isis_area *area = circuit->area;

        if (circuit->circ_type != CIRCUIT_T_BROADCAST
            || circuit->state != C_STATE_UP)
                return ISIS_OK;

        sched_debug(
                "ISIS (%s): Scheduling regeneration of %s pseudo LSP for interface %s",
                area->area_tag, circuit_t2string(level),
                circuit->interface->name);

        memcpy(lsp_id, area->isis->sysid, ISIS_SYS_ID_LEN);
        LSP_PSEUDO_ID(lsp_id) = circuit->circuit_id;
        LSP_FRAGMENT(lsp_id) = 0;
        now = time(NULL);

        for (lvl = IS_LEVEL_1; lvl <= IS_LEVEL_2; lvl++) {
                sched_debug(
                        "ISIS (%s): Checking whether L%d pseudo LSP needs to be scheduled",
                        area->area_tag, lvl);

                if (!((level & lvl) && (circuit->is_type & lvl))) {
                        sched_debug("ISIS (%s): Level is not active on circuit",
                                    area->area_tag);
                        continue;
                }

                if (circuit->u.bc.is_dr[lvl - 1] == 0) {
                        sched_debug(
                                "ISIS (%s): This IS is not DR, nothing to do.",
                                area->area_tag);
                        continue;
                }

                if (circuit->lsp_regenerate_pending[lvl - 1]) {
                        struct timeval remain = event_timer_remain(
                                circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1]);
                        sched_debug(
                                "ISIS (%s): Regenerate is already pending, nothing todo. (Due in %lld.%03lld seconds)",
                                area->area_tag, (long long)remain.tv_sec,
                                (long long)remain.tv_usec / 1000);
                        continue;
                }

                lsp = lsp_search(&circuit->area->lspdb[lvl - 1], lsp_id);
                if (!lsp) {
                        sched_debug(
                                "ISIS (%s): Pseudonode LSP does not exist yet, nothing to regenerate.",
                                area->area_tag);
                        continue;
                }

                /*
                 * Throttle avoidance
                 */
                sched_debug(
                        "ISIS (%s): Will schedule PSN regen timer. Last run was: %lld, Now is: %lld",
                        area->area_tag, (long long)lsp->last_generated,
                        (long long)now);
                EVENT_OFF(circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1]);
                diff = now - lsp->last_generated;
                if (diff < circuit->area->lsp_gen_interval[lvl - 1]) {
                        timeout =
                                1000 * (circuit->area->lsp_gen_interval[lvl - 1]
                                        - diff);
                        sched_debug(
                                "ISIS (%s): Sechduling in %ld ms to match configured lsp_gen_interval",
                                area->area_tag, timeout);
                } else {
                        timeout = 100;
                        sched_debug(
                                "ISIS (%s): Last generation was more than lsp_gen_interval ago. Scheduling for execution in %ld ms.",
                                area->area_tag, timeout);
                }

                circuit->lsp_regenerate_pending[lvl - 1] = 1;

                if (lvl == IS_LEVEL_1) {
                        event_add_timer_msec(
                                master, lsp_l1_refresh_pseudo, circuit, timeout,
                                &circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1]);
                } else if (lvl == IS_LEVEL_2) {
                        event_add_timer_msec(
                                master, lsp_l2_refresh_pseudo, circuit, timeout,
                                &circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1]);
                }
        }

        return ISIS_OK;
}

/*
 * Walk through LSPs for an area
 *  - set remaining lifetime
 */
void lsp_tick(struct event *thread)
{
        struct isis_area *area;
        struct isis_lsp *lsp;
        int level;
        uint16_t rem_lifetime;
        bool fabricd_sync_incomplete = false;

        area = EVENT_ARG(thread);
        assert(area);
        area->t_tick = NULL;
        event_add_timer(master, lsp_tick, area, 1, &area->t_tick);

        struct isis_circuit *fabricd_init_c = fabricd_initial_sync_circuit(area);

        /*
         * Remove LSPs which have aged out
         */
        for (level = 0; level < ISIS_LEVELS; level++) {
                struct isis_lsp *next = lspdb_first(&area->lspdb[level]);
                frr_each_from (lspdb, &area->lspdb[level], lsp, next) {
                        /*
                         * The lsp rem_lifetime is kept at 0 for MaxAge
                         * or
                         * ZeroAgeLifetime depending on explicit purge
                         * or
                         * natural age out. So schedule spf only once
                         * when
                         * the first time rem_lifetime becomes 0.
                         */
                        rem_lifetime = lsp->hdr.rem_lifetime;
                        lsp_set_time(lsp);

                        /*
                         * Schedule may run spf which should be done
                         * only after
                         * the lsp rem_lifetime becomes 0 for the first
                         * time.
                         * ISO 10589 - 7.3.16.4 first paragraph.
                         */
                        if (rem_lifetime == 1 && lsp->hdr.seqno != 0) {
                                /* 7.3.16.4 a) set SRM flags on all */
                                /* 7.3.16.4 b) retain only the header */
                                if (lsp->area->purge_originator)
                                        lsp_purge(lsp, lsp->level, NULL);
                                else
                                        lsp_flood(lsp, NULL);
                                /* 7.3.16.4 c) record the time to purge
                                 * FIXME */
                                isis_spf_schedule(lsp->area, lsp->level);
                                isis_te_lsp_event(lsp, LSP_TICK);
                        }

                        if (lsp->age_out == 0) {
                                zlog_debug(
                                        "ISIS-Upd (%s): L%u LSP %s seq 0x%08x aged out",
                                        area->area_tag, lsp->level,
                                        rawlspid_print(lsp->hdr.lsp_id),
                                        lsp->hdr.seqno);

                                /* if we're aging out fragment 0, lsp_destroy()
                                 * below will delete all other fragments too,
                                 * so we need to skip over those
                                 */
                                if (!LSP_FRAGMENT(lsp->hdr.lsp_id))
                                        while (next &&
                                                !memcmp(next->hdr.lsp_id,
                                                        lsp->hdr.lsp_id,
                                                        ISIS_SYS_ID_LEN + 1))
                                                next = lspdb_next(
                                                        &area->lspdb[level],
                                                        next);

                                lspdb_del(&area->lspdb[level], lsp);
                                lsp_destroy(lsp);
                                lsp = NULL;
                        }

                        if (fabricd_init_c && lsp) {
                                fabricd_sync_incomplete |=
                                        ISIS_CHECK_FLAG(lsp->SSNflags,
                                                        fabricd_init_c);
                        }
                }
        }

        if (fabricd_init_c
            && !fabricd_sync_incomplete
            && !isis_tx_queue_len(fabricd_init_c->tx_queue)) {
                fabricd_initial_sync_finish(area);
        }
}

void lsp_purge_pseudo(uint8_t *id, struct isis_circuit *circuit, int level)
{
        struct isis_lsp *lsp;

        lsp = lsp_search(&circuit->area->lspdb[level - 1], id);
        if (!lsp)
                return;

        lsp_purge(lsp, level, NULL);
}

/*
 * Purge own LSP that is received and we don't have.
 * -> Do as in 7.3.16.4
 */
void lsp_purge_non_exist(int level, struct isis_lsp_hdr *hdr,
                         struct isis_area *area)
{
        struct isis_lsp *lsp;

        /*
         * We need to create the LSP to be purged
         */
        lsp = XCALLOC(MTYPE_ISIS_LSP, sizeof(struct isis_lsp));
        lsp->area = area;
        lsp->level = level;
        lsp_adjust_stream(lsp);
        lsp->age_out = ZERO_AGE_LIFETIME;
        lsp->area->lsp_purge_count[level - 1]++;

        memcpy(&lsp->hdr, hdr, sizeof(lsp->hdr));
        lsp->hdr.rem_lifetime = 0;

        lsp_purge_add_poi(lsp, NULL);

        lsp_pack_pdu(lsp);

        lsp_insert(&area->lspdb[lsp->level - 1], lsp);
        lsp_flood(lsp, NULL);

        return;
}

void lsp_set_all_srmflags(struct isis_lsp *lsp, bool set)
{
        struct listnode *node;
        struct isis_circuit *circuit;

        assert(lsp);

        if (!lsp->area)
                return;

        struct list *circuit_list = lsp->area->circuit_list;
        for (ALL_LIST_ELEMENTS_RO(circuit_list, node, circuit)) {
                if (set) {
                        isis_tx_queue_add(circuit->tx_queue, lsp,
                                          TX_LSP_NORMAL);
                } else {
                        isis_tx_queue_del(circuit->tx_queue, lsp);
                }
        }
}

void _lsp_flood(struct isis_lsp *lsp, struct isis_circuit *circuit,
                const char *func, const char *file, int line)
{
        if (IS_DEBUG_FLOODING) {
                zlog_debug("Flooding LSP %s%s%s (From %s %s:%d)",
                           rawlspid_print(lsp->hdr.lsp_id),
                           circuit ? " except on " : "",
                           circuit ? circuit->interface->name : "",
                           func, file, line);
        }

        if (!fabricd)
                lsp_set_all_srmflags(lsp, true);
        else
                fabricd_lsp_flood(lsp, circuit);

        if (circuit)
                isis_tx_queue_del(circuit->tx_queue, lsp);
}

static int lsp_handle_adj_state_change(struct isis_adjacency *adj)
{
        lsp_regenerate_schedule(adj->circuit->area, IS_LEVEL_1 | IS_LEVEL_2, 0);

        /* when an adjacency state changes determine if we need to
         * change attach_bits in other area's LSPs
         */
        isis_reset_attach_bit(adj);

        return 0;
}

/*
 * Iterate over all IP reachability TLVs in a LSP (all fragments) of the given
 * address-family and MT-ID.
 */
int isis_lsp_iterate_ip_reach(struct isis_lsp *lsp, int family, uint16_t mtid,
                              lsp_ip_reach_iter_cb cb, void *arg)
{
        bool pseudo_lsp = LSP_PSEUDO_ID(lsp->hdr.lsp_id);
        struct isis_lsp *frag;
        struct listnode *node;

        if (lsp->hdr.seqno == 0 || lsp->hdr.rem_lifetime == 0)
                return LSP_ITER_CONTINUE;

        /* Parse LSP */
        if (lsp->tlvs) {
                if (!fabricd && !pseudo_lsp && family == AF_INET
                    && mtid == ISIS_MT_IPV4_UNICAST) {
                        struct isis_item_list *reachs[] = {
                                &lsp->tlvs->oldstyle_ip_reach,
                                &lsp->tlvs->oldstyle_ip_reach_ext};

                        for (unsigned int i = 0; i < array_size(reachs); i++) {
                                struct isis_oldstyle_ip_reach *r;

                                for (r = (struct isis_oldstyle_ip_reach *)
                                                 reachs[i]
                                                         ->head;
                                     r; r = r->next) {
                                        bool external = i ? true : false;

                                        if ((*cb)((struct prefix *)&r->prefix,
                                                  r->metric, external, NULL,
                                                  arg)
                                            == LSP_ITER_STOP)
                                                return LSP_ITER_STOP;
                                }
                        }
                }

                if (!pseudo_lsp && family == AF_INET) {
                        struct isis_item_list *ipv4_reachs;

                        if (mtid == ISIS_MT_IPV4_UNICAST)
                                ipv4_reachs = &lsp->tlvs->extended_ip_reach;
                        else
                                ipv4_reachs = isis_lookup_mt_items(
                                        &lsp->tlvs->mt_ip_reach, mtid);

                        struct isis_extended_ip_reach *r;
                        for (r = ipv4_reachs ? (struct isis_extended_ip_reach *)
                                                       ipv4_reachs->head
                                             : NULL;
                             r; r = r->next) {
                                if ((*cb)((struct prefix *)&r->prefix,
                                          r->metric, false, r->subtlvs, arg)
                                    == LSP_ITER_STOP)
                                        return LSP_ITER_STOP;
                        }
                }

                if (!pseudo_lsp && family == AF_INET6) {
                        struct isis_item_list *ipv6_reachs;
                        struct isis_ipv6_reach *r;

                        if (mtid == ISIS_MT_IPV4_UNICAST)
                                ipv6_reachs = &lsp->tlvs->ipv6_reach;
                        else
                                ipv6_reachs = isis_lookup_mt_items(
                                        &lsp->tlvs->mt_ipv6_reach, mtid);

                        for (r = ipv6_reachs ? (struct isis_ipv6_reach *)
                                                       ipv6_reachs->head
                                             : NULL;
                             r; r = r->next) {
                                if ((*cb)((struct prefix *)&r->prefix,
                                          r->metric, r->external, r->subtlvs,
                                          arg)
                                    == LSP_ITER_STOP)
                                        return LSP_ITER_STOP;
                        }
                }
        }

        /* Parse LSP fragments if it is not a fragment itself */
        if (!LSP_FRAGMENT(lsp->hdr.lsp_id))
                for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag)) {
                        if (!frag->tlvs)
                                continue;

                        if (isis_lsp_iterate_ip_reach(frag, family, mtid, cb,
                                                      arg)
                            == LSP_ITER_STOP)
                                return LSP_ITER_STOP;
                }

        return LSP_ITER_CONTINUE;
}

/*
 * Iterate over all IS reachability TLVs in a LSP (all fragments) of the given
 * MT-ID.
 */
int isis_lsp_iterate_is_reach(struct isis_lsp *lsp, uint16_t mtid,
                              lsp_is_reach_iter_cb cb, void *arg)
{
        bool pseudo_lsp = LSP_PSEUDO_ID(lsp->hdr.lsp_id);
        struct isis_lsp *frag;
        struct listnode *node;
        struct isis_item *head;
        struct isis_item_list *te_neighs;

        if (lsp->hdr.seqno == 0 || lsp->hdr.rem_lifetime == 0)
                return LSP_ITER_CONTINUE;

        /* Parse LSP */
        if (lsp->tlvs) {
                if (pseudo_lsp || mtid == ISIS_MT_IPV4_UNICAST) {
                        head = lsp->tlvs->oldstyle_reach.head;
                        for (struct isis_oldstyle_reach *reach =
                                     (struct isis_oldstyle_reach *)head;
                             reach; reach = reach->next) {
                                if ((*cb)(reach->id, reach->metric, true, NULL,
                                          arg)
                                    == LSP_ITER_STOP)
                                        return LSP_ITER_STOP;
                        }
                }

                if (pseudo_lsp || mtid == ISIS_MT_IPV4_UNICAST)
                        te_neighs = &lsp->tlvs->extended_reach;
                else
                        te_neighs =
                                isis_get_mt_items(&lsp->tlvs->mt_reach, mtid);
                if (te_neighs) {
                        head = te_neighs->head;
                        for (struct isis_extended_reach *reach =
                                     (struct isis_extended_reach *)head;
                             reach; reach = reach->next) {
                                if ((*cb)(reach->id, reach->metric, false,
                                          reach->subtlvs, arg)
                                    == LSP_ITER_STOP)
                                        return LSP_ITER_STOP;
                        }
                }
        }

        /* Parse LSP fragments if it not a fragment itself. */
        if (!LSP_FRAGMENT(lsp->hdr.lsp_id))
                for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag)) {
                        if (!frag->tlvs)
                                continue;

                        if (isis_lsp_iterate_is_reach(frag, mtid, cb, arg)
                            == LSP_ITER_STOP)
                                return LSP_ITER_STOP;
                }

        return LSP_ITER_CONTINUE;
}

void lsp_init(void)
{
        device_startup = true;
        hook_register(isis_adj_state_change_hook,
                      lsp_handle_adj_state_change);
}