Merge pull request #3509 from faickermo/fix_bgp_ipv6_default_nexthop

[mirror_frr.git] / isisd / isis_tlvs.c

/*
 * IS-IS TLV Serializer/Deserializer
 *
 * Copyright (C) 2015,2017 Christian Franke
 *
 * This file is part of FRR.
 *
 * FRR is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * FRR is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with FRR; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */
#include <zebra.h>

#include "md5.h"
#include "memory.h"
#include "stream.h"
#include "sbuf.h"

#include "isisd/isisd.h"
#include "isisd/isis_memory.h"
#include "isisd/isis_tlvs.h"
#include "isisd/isis_common.h"
#include "isisd/isis_mt.h"
#include "isisd/isis_misc.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_circuit.h"
#include "isisd/isis_pdu.h"
#include "isisd/isis_lsp.h"
#include "isisd/isis_te.h"

DEFINE_MTYPE_STATIC(ISISD, ISIS_TLV, "ISIS TLVs")
DEFINE_MTYPE_STATIC(ISISD, ISIS_SUBTLV, "ISIS Sub-TLVs")
DEFINE_MTYPE_STATIC(ISISD, ISIS_MT_ITEM_LIST, "ISIS MT Item Lists")

typedef int (*unpack_tlv_func)(enum isis_tlv_context context, uint8_t tlv_type,
                               uint8_t tlv_len, struct stream *s,
                               struct sbuf *log, void *dest, int indent);
typedef int (*pack_item_func)(struct isis_item *item, struct stream *s);
typedef void (*free_item_func)(struct isis_item *i);
typedef int (*unpack_item_func)(uint16_t mtid, uint8_t len, struct stream *s,
                                struct sbuf *log, void *dest, int indent);
typedef void (*format_item_func)(uint16_t mtid, struct isis_item *i,
                                 struct sbuf *buf, int indent);
typedef struct isis_item *(*copy_item_func)(struct isis_item *i);

struct tlv_ops {
        const char *name;
        unpack_tlv_func unpack;

        pack_item_func pack_item;
        free_item_func free_item;
        unpack_item_func unpack_item;
        format_item_func format_item;
        copy_item_func copy_item;
};

enum how_to_pack {
        ISIS_ITEMS,
        ISIS_MT_ITEMS,
};

struct pack_order_entry {
        enum isis_tlv_context context;
        enum isis_tlv_type type;
        enum how_to_pack how_to_pack;
        size_t what_to_pack;
};
#define PACK_ENTRY(t, h, w)                                                    \
        {                                                                      \
                .context = ISIS_CONTEXT_LSP, .type = ISIS_TLV_##t,             \
                .how_to_pack = (h),                                            \
                .what_to_pack = offsetof(struct isis_tlvs, w),                 \
        }

static struct pack_order_entry pack_order[] = {
        PACK_ENTRY(OLDSTYLE_REACH, ISIS_ITEMS, oldstyle_reach),
        PACK_ENTRY(LAN_NEIGHBORS, ISIS_ITEMS, lan_neighbor),
        PACK_ENTRY(LSP_ENTRY, ISIS_ITEMS, lsp_entries),
        PACK_ENTRY(EXTENDED_REACH, ISIS_ITEMS, extended_reach),
        PACK_ENTRY(MT_REACH, ISIS_MT_ITEMS, mt_reach),
        PACK_ENTRY(OLDSTYLE_IP_REACH, ISIS_ITEMS, oldstyle_ip_reach),
        PACK_ENTRY(OLDSTYLE_IP_REACH_EXT, ISIS_ITEMS, oldstyle_ip_reach_ext),
        PACK_ENTRY(IPV4_ADDRESS, ISIS_ITEMS, ipv4_address),
        PACK_ENTRY(IPV6_ADDRESS, ISIS_ITEMS, ipv6_address),
        PACK_ENTRY(EXTENDED_IP_REACH, ISIS_ITEMS, extended_ip_reach),
        PACK_ENTRY(MT_IP_REACH, ISIS_MT_ITEMS, mt_ip_reach),
        PACK_ENTRY(IPV6_REACH, ISIS_ITEMS, ipv6_reach),
        PACK_ENTRY(MT_IPV6_REACH, ISIS_MT_ITEMS, mt_ipv6_reach)};

/* This is a forward definition. The table is actually initialized
 * in at the bottom. */
static const struct tlv_ops *tlv_table[ISIS_CONTEXT_MAX][ISIS_TLV_MAX];

/* End of _ops forward definition. */

/* Prototypes */
static void append_item(struct isis_item_list *dest, struct isis_item *item);

/* Functions for Sub-TLV 3 SR Prefix-SID */

static struct isis_item *copy_item_prefix_sid(struct isis_item *i)
{
        struct isis_prefix_sid *sid = (struct isis_prefix_sid *)i;
        struct isis_prefix_sid *rv = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*rv));

        rv->flags = sid->flags;
        rv->algorithm = sid->algorithm;
        rv->value = sid->value;
        return (struct isis_item *)rv;
}

static void format_item_prefix_sid(uint16_t mtid, struct isis_item *i,
                                   struct sbuf *buf, int indent)
{
        struct isis_prefix_sid *sid = (struct isis_prefix_sid *)i;

        sbuf_push(buf, indent, "SR Prefix-SID:\n");
        sbuf_push(buf, indent, "  Flags:%s%s%s%s%s%s\n",
                  sid->flags & ISIS_PREFIX_SID_READVERTISED ? " READVERTISED" : "",
                  sid->flags & ISIS_PREFIX_SID_NODE ? " NODE" : "",
                  sid->flags & ISIS_PREFIX_SID_NO_PHP ? " NO_PHP" : "",
                  sid->flags & ISIS_PREFIX_SID_EXPLICIT_NULL ? " EXPLICIT-NULL" : "",
                  sid->flags & ISIS_PREFIX_SID_VALUE ? " VALUE" : "",
                  sid->flags & ISIS_PREFIX_SID_LOCAL ? " LOCAL" : "");
        sbuf_push(buf, indent, "  Algorithm: %" PRIu8 "\n", sid->algorithm);
        if (sid->flags & ISIS_PREFIX_SID_VALUE) {
                sbuf_push(buf, indent,  "Label: %" PRIu32 "\n", sid->value);
        } else {
                sbuf_push(buf, indent,  "Index: %" PRIu32 "\n", sid->value);
        }
}

static void free_item_prefix_sid(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_SUBTLV, i);
}

static int pack_item_prefix_sid(struct isis_item *i, struct stream *s)
{
        struct isis_prefix_sid *sid = (struct isis_prefix_sid *)i;

        uint8_t size = (sid->flags & ISIS_PREFIX_SID_VALUE) ? 5 : 6;

        if (STREAM_WRITEABLE(s) < size)
                return 1;

        stream_putc(s, sid->flags);
        stream_putc(s, sid->algorithm);

        if (sid->flags & ISIS_PREFIX_SID_VALUE) {
                stream_put3(s, sid->value);
        } else {
                stream_putl(s, sid->value);
        }

        return 0;
}

static int unpack_item_prefix_sid(uint16_t mtid, uint8_t len, struct stream *s,
                                  struct sbuf *log, void *dest, int indent)
{
        struct isis_subtlvs *subtlvs = dest;
        struct isis_prefix_sid sid = {
        };

        sbuf_push(log, indent, "Unpacking SR Prefix-SID...\n");

        if (len < 5) {
                sbuf_push(log, indent,
                          "Not enough data left. (expected 5 or more bytes, got %" PRIu8 ")\n",
                          len);
                return 1;
        }

        sid.flags = stream_getc(s);
        if ((sid.flags & ISIS_PREFIX_SID_VALUE)
            != (sid.flags & ISIS_PREFIX_SID_LOCAL)) {
                sbuf_push(log, indent, "Flags inplausible: Local Flag needs to match Value Flag\n");
                return 0;
        }

        sid.algorithm = stream_getc(s);

        uint8_t expected_size = (sid.flags & ISIS_PREFIX_SID_VALUE) ? 5 : 6;
        if (len != expected_size) {
                sbuf_push(log, indent,
                          "TLV size differs from expected size. "
                          "(expected %u but got %" PRIu8 ")\n",
                          expected_size, len);
                return 1;
        }

        if (sid.flags & ISIS_PREFIX_SID_VALUE) {
                sid.value = stream_get3(s);
        } else {
                sid.value = stream_getl(s);
        }

        format_item_prefix_sid(mtid, (struct isis_item *)&sid, log, indent + 2);
        append_item(&subtlvs->prefix_sids, copy_item_prefix_sid((struct isis_item *)&sid));
        return 0;
}

/* Functions for Sub-TVL ??? IPv6 Source Prefix */

static struct prefix_ipv6 *copy_subtlv_ipv6_source_prefix(struct prefix_ipv6 *p)
{
        if (!p)
                return NULL;

        struct prefix_ipv6 *rv = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*rv));
        rv->family = p->family;
        rv->prefixlen = p->prefixlen;
        memcpy(&rv->prefix, &p->prefix, sizeof(rv->prefix));
        return rv;
}

static void format_subtlv_ipv6_source_prefix(struct prefix_ipv6 *p,
                                             struct sbuf *buf, int indent)
{
        if (!p)
                return;

        char prefixbuf[PREFIX2STR_BUFFER];
        sbuf_push(buf, indent, "IPv6 Source Prefix: %s\n",
                  prefix2str(p, prefixbuf, sizeof(prefixbuf)));
}

static int pack_subtlv_ipv6_source_prefix(struct prefix_ipv6 *p,
                                          struct stream *s)
{
        if (!p)
                return 0;

        if (STREAM_WRITEABLE(s) < 3 + (unsigned)PSIZE(p->prefixlen))
                return 1;

        stream_putc(s, ISIS_SUBTLV_IPV6_SOURCE_PREFIX);
        stream_putc(s, 1 + PSIZE(p->prefixlen));
        stream_putc(s, p->prefixlen);
        stream_put(s, &p->prefix, PSIZE(p->prefixlen));
        return 0;
}

static int unpack_subtlv_ipv6_source_prefix(enum isis_tlv_context context,
                                            uint8_t tlv_type, uint8_t tlv_len,
                                            struct stream *s, struct sbuf *log,
                                            void *dest, int indent)
{
        struct isis_subtlvs *subtlvs = dest;
        struct prefix_ipv6 p = {
                .family = AF_INET6,
        };

        sbuf_push(log, indent, "Unpacking IPv6 Source Prefix Sub-TLV...\n");

        if (tlv_len < 1) {
                sbuf_push(log, indent,
                          "Not enough data left. (expected 1 or more bytes, got %" PRIu8 ")\n",
                          tlv_len);
                return 1;
        }

        p.prefixlen = stream_getc(s);
        if (p.prefixlen > 128) {
                sbuf_push(log, indent, "Prefixlen %u is inplausible for IPv6\n",
                          p.prefixlen);
                return 1;
        }

        if (tlv_len != 1 + PSIZE(p.prefixlen)) {
                sbuf_push(
                        log, indent,
                        "TLV size differs from expected size for the prefixlen. "
                        "(expected %u but got %" PRIu8 ")\n",
                        1 + PSIZE(p.prefixlen), tlv_len);
                return 1;
        }

        stream_get(&p.prefix, s, PSIZE(p.prefixlen));

        if (subtlvs->source_prefix) {
                sbuf_push(
                        log, indent,
                        "WARNING: source prefix Sub-TLV present multiple times.\n");
                /* Ignore all but first occurrence of the source prefix Sub-TLV
                 */
                return 0;
        }

        subtlvs->source_prefix = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(p));
        memcpy(subtlvs->source_prefix, &p, sizeof(p));
        return 0;
}
static void init_item_list(struct isis_item_list *items);
static struct isis_item *copy_item(enum isis_tlv_context context,
                                   enum isis_tlv_type type,
                                   struct isis_item *item);
static void copy_items(enum isis_tlv_context context, enum isis_tlv_type type,
                       struct isis_item_list *src, struct isis_item_list *dest);
static void format_items_(uint16_t mtid, enum isis_tlv_context context,
                          enum isis_tlv_type type, struct isis_item_list *items,
                          struct sbuf *buf, int indent);
#define format_items(...) format_items_(ISIS_MT_IPV4_UNICAST, __VA_ARGS__)
static void free_items(enum isis_tlv_context context, enum isis_tlv_type type,
                       struct isis_item_list *items);
static int pack_items_(uint16_t mtid, enum isis_tlv_context context,
                       enum isis_tlv_type type, struct isis_item_list *items,
                       struct stream *s, struct isis_tlvs **fragment_tlvs,
                       struct pack_order_entry *pe,
                       struct isis_tlvs *(*new_fragment)(struct list *l),
                       struct list *new_fragment_arg);
#define pack_items(...) pack_items_(ISIS_MT_IPV4_UNICAST, __VA_ARGS__)

/* Functions related to subtlvs */

static struct isis_subtlvs *isis_alloc_subtlvs(enum isis_tlv_context context)
{
        struct isis_subtlvs *result;

        result = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*result));
        result->context = context;

        init_item_list(&result->prefix_sids);

        return result;
}

static struct isis_subtlvs *copy_subtlvs(struct isis_subtlvs *subtlvs)
{
        if (!subtlvs)
                return NULL;

        struct isis_subtlvs *rv = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*rv));

        rv->context = subtlvs->context;

        copy_items(subtlvs->context, ISIS_SUBTLV_PREFIX_SID,
                   &subtlvs->prefix_sids, &rv->prefix_sids);

        rv->source_prefix =
                copy_subtlv_ipv6_source_prefix(subtlvs->source_prefix);
        return rv;
}

static void format_subtlvs(struct isis_subtlvs *subtlvs, struct sbuf *buf,
                           int indent)
{
        format_items(subtlvs->context, ISIS_SUBTLV_PREFIX_SID,
                     &subtlvs->prefix_sids, buf, indent);

        format_subtlv_ipv6_source_prefix(subtlvs->source_prefix, buf, indent);
}

static void isis_free_subtlvs(struct isis_subtlvs *subtlvs)
{
        if (!subtlvs)
                return;

        free_items(subtlvs->context, ISIS_SUBTLV_PREFIX_SID,
                   &subtlvs->prefix_sids);

        XFREE(MTYPE_ISIS_SUBTLV, subtlvs->source_prefix);

        XFREE(MTYPE_ISIS_SUBTLV, subtlvs);
}

static int pack_subtlvs(struct isis_subtlvs *subtlvs, struct stream *s)
{
        int rv;
        size_t subtlv_len_pos = stream_get_endp(s);

        if (STREAM_WRITEABLE(s) < 1)
                return 1;

        stream_putc(s, 0); /* Put 0 as subtlvs length, filled in later */

        rv = pack_items(subtlvs->context, ISIS_SUBTLV_PREFIX_SID,
                        &subtlvs->prefix_sids, s, NULL, NULL, NULL, NULL);
        if (rv)
                return rv;

        rv = pack_subtlv_ipv6_source_prefix(subtlvs->source_prefix, s);
        if (rv)
                return rv;

        size_t subtlv_len = stream_get_endp(s) - subtlv_len_pos - 1;
        if (subtlv_len > 255)
                return 1;

        stream_putc_at(s, subtlv_len_pos, subtlv_len);
        return 0;
}

static int unpack_tlvs(enum isis_tlv_context context, size_t avail_len,
                       struct stream *stream, struct sbuf *log, void *dest,
                       int indent, bool *unpacked_known_tlvs);

/* Functions related to TLVs 1 Area Addresses */

static struct isis_item *copy_item_area_address(struct isis_item *i)
{
        struct isis_area_address *addr = (struct isis_area_address *)i;
        struct isis_area_address *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->len = addr->len;
        memcpy(rv->addr, addr->addr, addr->len);
        return (struct isis_item *)rv;
}

static void format_item_area_address(uint16_t mtid, struct isis_item *i,
                                     struct sbuf *buf, int indent)
{
        struct isis_area_address *addr = (struct isis_area_address *)i;

        sbuf_push(buf, indent, "Area Address: %s\n",
                  isonet_print(addr->addr, addr->len));
}

static void free_item_area_address(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_area_address(struct isis_item *i, struct stream *s)
{
        struct isis_area_address *addr = (struct isis_area_address *)i;

        if (STREAM_WRITEABLE(s) < (unsigned)1 + addr->len)
                return 1;
        stream_putc(s, addr->len);
        stream_put(s, addr->addr, addr->len);
        return 0;
}

static int unpack_item_area_address(uint16_t mtid, uint8_t len,
                                    struct stream *s, struct sbuf *log,
                                    void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;
        struct isis_area_address *rv = NULL;

        sbuf_push(log, indent, "Unpack area address...\n");
        if (len < 1) {
                sbuf_push(
                        log, indent,
                        "Not enough data left. (Expected 1 byte of address length, got %" PRIu8
                        ")\n",
                        len);
                goto out;
        }

        rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        rv->len = stream_getc(s);

        if (len < 1 + rv->len) {
                sbuf_push(log, indent, "Not enough data left. (Expected %" PRIu8
                                       " bytes of address, got %" PRIu8 ")\n",
                          rv->len, len - 1);
                goto out;
        }

        if (rv->len < 1 || rv->len > 20) {
                sbuf_push(log, indent,
                          "Implausible area address length %" PRIu8 "\n",
                          rv->len);
                goto out;
        }

        stream_get(rv->addr, s, rv->len);

        format_item_area_address(ISIS_MT_IPV4_UNICAST, (struct isis_item *)rv,
                                 log, indent + 2);
        append_item(&tlvs->area_addresses, (struct isis_item *)rv);
        return 0;
out:
        XFREE(MTYPE_ISIS_TLV, rv);
        return 1;
}

/* Functions related to TLV 2 (Old-Style) IS Reach */
static struct isis_item *copy_item_oldstyle_reach(struct isis_item *i)
{
        struct isis_oldstyle_reach *r = (struct isis_oldstyle_reach *)i;
        struct isis_oldstyle_reach *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        memcpy(rv->id, r->id, 7);
        rv->metric = r->metric;
        return (struct isis_item *)rv;
}

static void format_item_oldstyle_reach(uint16_t mtid, struct isis_item *i,
                                       struct sbuf *buf, int indent)
{
        struct isis_oldstyle_reach *r = (struct isis_oldstyle_reach *)i;

        sbuf_push(buf, indent, "IS Reachability: %s (Metric: %" PRIu8 ")\n",
                  isis_format_id(r->id, 7), r->metric);
}

static void free_item_oldstyle_reach(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_oldstyle_reach(struct isis_item *i, struct stream *s)
{
        struct isis_oldstyle_reach *r = (struct isis_oldstyle_reach *)i;

        if (STREAM_WRITEABLE(s) < 11)
                return 1;

        stream_putc(s, r->metric);
        stream_putc(s, 0x80); /* delay metric - unsupported */
        stream_putc(s, 0x80); /* expense metric - unsupported */
        stream_putc(s, 0x80); /* error metric - unsupported */
        stream_put(s, r->id, 7);

        return 0;
}

static int unpack_item_oldstyle_reach(uint16_t mtid, uint8_t len,
                                      struct stream *s, struct sbuf *log,
                                      void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpack oldstyle reach...\n");
        if (len < 11) {
                sbuf_push(
                        log, indent,
                        "Not enough data left.(Expected 11 bytes of reach information, got %" PRIu8
                        ")\n",
                        len);
                return 1;
        }

        struct isis_oldstyle_reach *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        rv->metric = stream_getc(s);
        if ((rv->metric & 0x3f) != rv->metric) {
                sbuf_push(log, indent, "Metric has unplausible format\n");
                rv->metric &= 0x3f;
        }
        stream_forward_getp(s, 3); /* Skip other metrics */
        stream_get(rv->id, s, 7);

        format_item_oldstyle_reach(mtid, (struct isis_item *)rv, log,
                                   indent + 2);
        append_item(&tlvs->oldstyle_reach, (struct isis_item *)rv);
        return 0;
}

/* Functions related to TLV 6 LAN Neighbors */
static struct isis_item *copy_item_lan_neighbor(struct isis_item *i)
{
        struct isis_lan_neighbor *n = (struct isis_lan_neighbor *)i;
        struct isis_lan_neighbor *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        memcpy(rv->mac, n->mac, 6);
        return (struct isis_item *)rv;
}

static void format_item_lan_neighbor(uint16_t mtid, struct isis_item *i,
                                     struct sbuf *buf, int indent)
{
        struct isis_lan_neighbor *n = (struct isis_lan_neighbor *)i;

        sbuf_push(buf, indent, "LAN Neighbor: %s\n", isis_format_id(n->mac, 6));
}

static void free_item_lan_neighbor(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_lan_neighbor(struct isis_item *i, struct stream *s)
{
        struct isis_lan_neighbor *n = (struct isis_lan_neighbor *)i;

        if (STREAM_WRITEABLE(s) < 6)
                return 1;

        stream_put(s, n->mac, 6);

        return 0;
}

static int unpack_item_lan_neighbor(uint16_t mtid, uint8_t len,
                                    struct stream *s, struct sbuf *log,
                                    void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpack LAN neighbor...\n");
        if (len < 6) {
                sbuf_push(
                        log, indent,
                        "Not enough data left.(Expected 6 bytes of mac, got %" PRIu8
                        ")\n",
                        len);
                return 1;
        }

        struct isis_lan_neighbor *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        stream_get(rv->mac, s, 6);

        format_item_lan_neighbor(mtid, (struct isis_item *)rv, log, indent + 2);
        append_item(&tlvs->lan_neighbor, (struct isis_item *)rv);
        return 0;
}

/* Functions related to TLV 9 LSP Entry */
static struct isis_item *copy_item_lsp_entry(struct isis_item *i)
{
        struct isis_lsp_entry *e = (struct isis_lsp_entry *)i;
        struct isis_lsp_entry *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->rem_lifetime = e->rem_lifetime;
        memcpy(rv->id, e->id, sizeof(rv->id));
        rv->seqno = e->seqno;
        rv->checksum = e->checksum;

        return (struct isis_item *)rv;
}

static void format_item_lsp_entry(uint16_t mtid, struct isis_item *i,
                                  struct sbuf *buf, int indent)
{
        struct isis_lsp_entry *e = (struct isis_lsp_entry *)i;

        sbuf_push(buf, indent,
                  "LSP Entry: %s, seq 0x%08" PRIx32 ", cksum 0x%04" PRIx16
                  ", lifetime %" PRIu16 "s\n",
                  isis_format_id(e->id, 8), e->seqno, e->checksum,
                  e->rem_lifetime);
}

static void free_item_lsp_entry(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_lsp_entry(struct isis_item *i, struct stream *s)
{
        struct isis_lsp_entry *e = (struct isis_lsp_entry *)i;

        if (STREAM_WRITEABLE(s) < 16)
                return 1;

        stream_putw(s, e->rem_lifetime);
        stream_put(s, e->id, 8);
        stream_putl(s, e->seqno);
        stream_putw(s, e->checksum);

        return 0;
}

static int unpack_item_lsp_entry(uint16_t mtid, uint8_t len, struct stream *s,
                                 struct sbuf *log, void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpack LSP entry...\n");
        if (len < 16) {
                sbuf_push(
                        log, indent,
                        "Not enough data left. (Expected 16 bytes of LSP info, got %" PRIu8,
                        len);
                return 1;
        }

        struct isis_lsp_entry *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        rv->rem_lifetime = stream_getw(s);
        stream_get(rv->id, s, 8);
        rv->seqno = stream_getl(s);
        rv->checksum = stream_getw(s);

        format_item_lsp_entry(mtid, (struct isis_item *)rv, log, indent + 2);
        append_item(&tlvs->lsp_entries, (struct isis_item *)rv);
        return 0;
}

/* Functions related to TLVs 22/222 Extended Reach/MT Reach */

static struct isis_item *copy_item_extended_reach(struct isis_item *i)
{
        struct isis_extended_reach *r = (struct isis_extended_reach *)i;
        struct isis_extended_reach *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        memcpy(rv->id, r->id, 7);
        rv->metric = r->metric;

        if (r->subtlvs && r->subtlv_len) {
                rv->subtlvs = XCALLOC(MTYPE_ISIS_TLV, r->subtlv_len);
                memcpy(rv->subtlvs, r->subtlvs, r->subtlv_len);
                rv->subtlv_len = r->subtlv_len;
        }

        return (struct isis_item *)rv;
}

static void format_item_extended_reach(uint16_t mtid, struct isis_item *i,
                                       struct sbuf *buf, int indent)
{
        struct isis_extended_reach *r = (struct isis_extended_reach *)i;

        sbuf_push(buf, indent, "%s Reachability: %s (Metric: %u)",
                  (mtid == ISIS_MT_IPV4_UNICAST) ? "Extended" : "MT",
                  isis_format_id(r->id, 7), r->metric);
        if (mtid != ISIS_MT_IPV4_UNICAST)
                sbuf_push(buf, 0, " %s", isis_mtid2str(mtid));
        sbuf_push(buf, 0, "\n");

        if (r->subtlv_len && r->subtlvs)
                mpls_te_print_detail(buf, indent + 2, r->subtlvs,
                                     r->subtlv_len);
}

static void free_item_extended_reach(struct isis_item *i)
{
        struct isis_extended_reach *item = (struct isis_extended_reach *)i;
        XFREE(MTYPE_ISIS_TLV, item->subtlvs);
        XFREE(MTYPE_ISIS_TLV, item);
}

static int pack_item_extended_reach(struct isis_item *i, struct stream *s)
{
        struct isis_extended_reach *r = (struct isis_extended_reach *)i;

        if (STREAM_WRITEABLE(s) < 11 + (unsigned)r->subtlv_len)
                return 1;
        stream_put(s, r->id, sizeof(r->id));
        stream_put3(s, r->metric);
        stream_putc(s, r->subtlv_len);
        stream_put(s, r->subtlvs, r->subtlv_len);
        return 0;
}

static int unpack_item_extended_reach(uint16_t mtid, uint8_t len,
                                      struct stream *s, struct sbuf *log,
                                      void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;
        struct isis_extended_reach *rv = NULL;
        uint8_t subtlv_len;
        struct isis_item_list *items;

        if (mtid == ISIS_MT_IPV4_UNICAST) {
                items = &tlvs->extended_reach;
        } else {
                items = isis_get_mt_items(&tlvs->mt_reach, mtid);
        }

        sbuf_push(log, indent, "Unpacking %s reachability...\n",
                  (mtid == ISIS_MT_IPV4_UNICAST) ? "extended" : "mt");

        if (len < 11) {
                sbuf_push(log, indent,
                          "Not enough data left. (expected 11 or more bytes, got %"
                          PRIu8 ")\n",
                          len);
                goto out;
        }

        rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        stream_get(rv->id, s, 7);
        rv->metric = stream_get3(s);
        subtlv_len = stream_getc(s);

        format_item_extended_reach(mtid, (struct isis_item *)rv, log,
                                   indent + 2);

        if ((size_t)len < ((size_t)11) + subtlv_len) {
                sbuf_push(log, indent,
                          "Not enough data left for subtlv size %" PRIu8
                          ", there are only %" PRIu8 " bytes left.\n",
                          subtlv_len, len - 11);
                goto out;
        }

        sbuf_push(log, indent, "Storing %" PRIu8 " bytes of subtlvs\n",
                  subtlv_len);

        if (subtlv_len) {
                size_t subtlv_start = stream_get_getp(s);

                if (unpack_tlvs(ISIS_CONTEXT_SUBTLV_NE_REACH, subtlv_len, s,
                                log, NULL, indent + 4, NULL)) {
                        goto out;
                }

                stream_set_getp(s, subtlv_start);

                rv->subtlvs = XCALLOC(MTYPE_ISIS_TLV, subtlv_len);
                stream_get(rv->subtlvs, s, subtlv_len);
                rv->subtlv_len = subtlv_len;
        }

        append_item(items, (struct isis_item *)rv);
        return 0;
out:
        if (rv)
                free_item_extended_reach((struct isis_item *)rv);

        return 1;
}

/* Functions related to TLV 128 (Old-Style) IP Reach */
static struct isis_item *copy_item_oldstyle_ip_reach(struct isis_item *i)
{
        struct isis_oldstyle_ip_reach *r = (struct isis_oldstyle_ip_reach *)i;
        struct isis_oldstyle_ip_reach *rv =
                XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->metric = r->metric;
        rv->prefix = r->prefix;
        return (struct isis_item *)rv;
}

static void format_item_oldstyle_ip_reach(uint16_t mtid, struct isis_item *i,
                                          struct sbuf *buf, int indent)
{
        struct isis_oldstyle_ip_reach *r = (struct isis_oldstyle_ip_reach *)i;
        char prefixbuf[PREFIX2STR_BUFFER];

        sbuf_push(buf, indent, "IP Reachability: %s (Metric: %" PRIu8 ")\n",
                  prefix2str(&r->prefix, prefixbuf, sizeof(prefixbuf)),
                  r->metric);
}

static void free_item_oldstyle_ip_reach(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_oldstyle_ip_reach(struct isis_item *i, struct stream *s)
{
        struct isis_oldstyle_ip_reach *r = (struct isis_oldstyle_ip_reach *)i;

        if (STREAM_WRITEABLE(s) < 12)
                return 1;

        stream_putc(s, r->metric);
        stream_putc(s, 0x80); /* delay metric - unsupported */
        stream_putc(s, 0x80); /* expense metric - unsupported */
        stream_putc(s, 0x80); /* error metric - unsupported */
        stream_put(s, &r->prefix.prefix, 4);

        struct in_addr mask;
        masklen2ip(r->prefix.prefixlen, &mask);
        stream_put(s, &mask, sizeof(mask));

        return 0;
}

static int unpack_item_oldstyle_ip_reach(uint16_t mtid, uint8_t len,
                                         struct stream *s, struct sbuf *log,
                                         void *dest, int indent)
{
        sbuf_push(log, indent, "Unpack oldstyle ip reach...\n");
        if (len < 12) {
                sbuf_push(
                        log, indent,
                        "Not enough data left.(Expected 12 bytes of reach information, got %" PRIu8
                        ")\n",
                        len);
                return 1;
        }

        struct isis_oldstyle_ip_reach *rv =
                XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        rv->metric = stream_getc(s);
        if ((rv->metric & 0x7f) != rv->metric) {
                sbuf_push(log, indent, "Metric has unplausible format\n");
                rv->metric &= 0x7f;
        }
        stream_forward_getp(s, 3); /* Skip other metrics */
        rv->prefix.family = AF_INET;
        stream_get(&rv->prefix.prefix, s, 4);

        struct in_addr mask;
        stream_get(&mask, s, 4);
        rv->prefix.prefixlen = ip_masklen(mask);

        format_item_oldstyle_ip_reach(mtid, (struct isis_item *)rv, log,
                                      indent + 2);
        append_item(dest, (struct isis_item *)rv);
        return 0;
}


/* Functions related to TLV 129 protocols supported */

static void copy_tlv_protocols_supported(struct isis_protocols_supported *src,
                                         struct isis_protocols_supported *dest)
{
        if (!src->protocols || !src->count)
                return;
        dest->count = src->count;
        dest->protocols = XCALLOC(MTYPE_ISIS_TLV, src->count);
        memcpy(dest->protocols, src->protocols, src->count);
}

static void format_tlv_protocols_supported(struct isis_protocols_supported *p,
                                           struct sbuf *buf, int indent)
{
        if (!p || !p->count || !p->protocols)
                return;

        sbuf_push(buf, indent, "Protocols Supported: ");
        for (uint8_t i = 0; i < p->count; i++) {
                sbuf_push(buf, 0, "%s%s", nlpid2str(p->protocols[i]),
                          (i + 1 < p->count) ? ", " : "");
        }
        sbuf_push(buf, 0, "\n");
}

static void free_tlv_protocols_supported(struct isis_protocols_supported *p)
{
        XFREE(MTYPE_ISIS_TLV, p->protocols);
}

static int pack_tlv_protocols_supported(struct isis_protocols_supported *p,
                                        struct stream *s)
{
        if (!p || !p->count || !p->protocols)
                return 0;

        if (STREAM_WRITEABLE(s) < (unsigned)(p->count + 2))
                return 1;

        stream_putc(s, ISIS_TLV_PROTOCOLS_SUPPORTED);
        stream_putc(s, p->count);
        stream_put(s, p->protocols, p->count);
        return 0;
}

static int unpack_tlv_protocols_supported(enum isis_tlv_context context,
                                          uint8_t tlv_type, uint8_t tlv_len,
                                          struct stream *s, struct sbuf *log,
                                          void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpacking Protocols Supported TLV...\n");
        if (!tlv_len) {
                sbuf_push(log, indent, "WARNING: No protocols included\n");
                return 0;
        }
        if (tlvs->protocols_supported.protocols) {
                sbuf_push(
                        log, indent,
                        "WARNING: protocols supported TLV present multiple times.\n");
                stream_forward_getp(s, tlv_len);
                return 0;
        }

        tlvs->protocols_supported.count = tlv_len;
        tlvs->protocols_supported.protocols = XCALLOC(MTYPE_ISIS_TLV, tlv_len);
        stream_get(tlvs->protocols_supported.protocols, s, tlv_len);

        format_tlv_protocols_supported(&tlvs->protocols_supported, log,
                                       indent + 2);
        return 0;
}

/* Functions related to TLV 132 IPv4 Interface addresses */
static struct isis_item *copy_item_ipv4_address(struct isis_item *i)
{
        struct isis_ipv4_address *a = (struct isis_ipv4_address *)i;
        struct isis_ipv4_address *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->addr = a->addr;
        return (struct isis_item *)rv;
}

static void format_item_ipv4_address(uint16_t mtid, struct isis_item *i,
                                     struct sbuf *buf, int indent)
{
        struct isis_ipv4_address *a = (struct isis_ipv4_address *)i;
        char addrbuf[INET_ADDRSTRLEN];

        inet_ntop(AF_INET, &a->addr, addrbuf, sizeof(addrbuf));
        sbuf_push(buf, indent, "IPv4 Interface Address: %s\n", addrbuf);
}

static void free_item_ipv4_address(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_ipv4_address(struct isis_item *i, struct stream *s)
{
        struct isis_ipv4_address *a = (struct isis_ipv4_address *)i;

        if (STREAM_WRITEABLE(s) < 4)
                return 1;

        stream_put(s, &a->addr, 4);

        return 0;
}

static int unpack_item_ipv4_address(uint16_t mtid, uint8_t len,
                                    struct stream *s, struct sbuf *log,
                                    void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpack IPv4 Interface address...\n");
        if (len < 4) {
                sbuf_push(
                        log, indent,
                        "Not enough data left.(Expected 4 bytes of IPv4 address, got %" PRIu8
                        ")\n",
                        len);
                return 1;
        }

        struct isis_ipv4_address *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        stream_get(&rv->addr, s, 4);

        format_item_ipv4_address(mtid, (struct isis_item *)rv, log, indent + 2);
        append_item(&tlvs->ipv4_address, (struct isis_item *)rv);
        return 0;
}


/* Functions related to TLV 232 IPv6 Interface addresses */
static struct isis_item *copy_item_ipv6_address(struct isis_item *i)
{
        struct isis_ipv6_address *a = (struct isis_ipv6_address *)i;
        struct isis_ipv6_address *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->addr = a->addr;
        return (struct isis_item *)rv;
}

static void format_item_ipv6_address(uint16_t mtid, struct isis_item *i,
                                     struct sbuf *buf, int indent)
{
        struct isis_ipv6_address *a = (struct isis_ipv6_address *)i;
        char addrbuf[INET6_ADDRSTRLEN];

        inet_ntop(AF_INET6, &a->addr, addrbuf, sizeof(addrbuf));
        sbuf_push(buf, indent, "IPv6 Interface Address: %s\n", addrbuf);
}

static void free_item_ipv6_address(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_ipv6_address(struct isis_item *i, struct stream *s)
{
        struct isis_ipv6_address *a = (struct isis_ipv6_address *)i;

        if (STREAM_WRITEABLE(s) < 16)
                return 1;

        stream_put(s, &a->addr, 16);

        return 0;
}

static int unpack_item_ipv6_address(uint16_t mtid, uint8_t len,
                                    struct stream *s, struct sbuf *log,
                                    void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpack IPv6 Interface address...\n");
        if (len < 16) {
                sbuf_push(
                        log, indent,
                        "Not enough data left.(Expected 16 bytes of IPv6 address, got %" PRIu8
                        ")\n",
                        len);
                return 1;
        }

        struct isis_ipv6_address *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        stream_get(&rv->addr, s, 16);

        format_item_ipv6_address(mtid, (struct isis_item *)rv, log, indent + 2);
        append_item(&tlvs->ipv6_address, (struct isis_item *)rv);
        return 0;
}


/* Functions related to TLV 229 MT Router information */
static struct isis_item *copy_item_mt_router_info(struct isis_item *i)
{
        struct isis_mt_router_info *info = (struct isis_mt_router_info *)i;
        struct isis_mt_router_info *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->overload = info->overload;
        rv->attached = info->attached;
        rv->mtid = info->mtid;
        return (struct isis_item *)rv;
}

static void format_item_mt_router_info(uint16_t mtid, struct isis_item *i,
                                       struct sbuf *buf, int indent)
{
        struct isis_mt_router_info *info = (struct isis_mt_router_info *)i;

        sbuf_push(buf, indent, "MT Router Info: %s%s%s\n",
                  isis_mtid2str(info->mtid),
                  info->overload ? " Overload" : "",
                  info->attached ? " Attached" : "");
}

static void free_item_mt_router_info(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_mt_router_info(struct isis_item *i, struct stream *s)
{
        struct isis_mt_router_info *info = (struct isis_mt_router_info *)i;

        if (STREAM_WRITEABLE(s) < 2)
                return 1;

        uint16_t entry = info->mtid;

        if (info->overload)
                entry |= ISIS_MT_OL_MASK;
        if (info->attached)
                entry |= ISIS_MT_AT_MASK;

        stream_putw(s, entry);

        return 0;
}

static int unpack_item_mt_router_info(uint16_t mtid, uint8_t len,
                                      struct stream *s, struct sbuf *log,
                                      void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpack MT Router info...\n");
        if (len < 2) {
                sbuf_push(
                        log, indent,
                        "Not enough data left.(Expected 2 bytes of MT info, got %" PRIu8
                        ")\n",
                        len);
                return 1;
        }

        struct isis_mt_router_info *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        uint16_t entry = stream_getw(s);
        rv->overload = entry & ISIS_MT_OL_MASK;
        rv->attached = entry & ISIS_MT_AT_MASK;
        rv->mtid = entry & ISIS_MT_MASK;

        format_item_mt_router_info(mtid, (struct isis_item *)rv, log,
                                   indent + 2);
        append_item(&tlvs->mt_router_info, (struct isis_item *)rv);
        return 0;
}

/* Functions related to TLV 134 TE Router ID */

static struct in_addr *copy_tlv_te_router_id(const struct in_addr *id)
{
        if (!id)
                return NULL;

        struct in_addr *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        memcpy(rv, id, sizeof(*rv));
        return rv;
}

static void format_tlv_te_router_id(const struct in_addr *id, struct sbuf *buf,
                                    int indent)
{
        if (!id)
                return;

        char addrbuf[INET_ADDRSTRLEN];
        inet_ntop(AF_INET, id, addrbuf, sizeof(addrbuf));
        sbuf_push(buf, indent, "TE Router ID: %s\n", addrbuf);
}

static void free_tlv_te_router_id(struct in_addr *id)
{
        XFREE(MTYPE_ISIS_TLV, id);
}

static int pack_tlv_te_router_id(const struct in_addr *id, struct stream *s)
{
        if (!id)
                return 0;

        if (STREAM_WRITEABLE(s) < (unsigned)(2 + sizeof(*id)))
                return 1;

        stream_putc(s, ISIS_TLV_TE_ROUTER_ID);
        stream_putc(s, 4);
        stream_put(s, id, 4);
        return 0;
}

static int unpack_tlv_te_router_id(enum isis_tlv_context context,
                                   uint8_t tlv_type, uint8_t tlv_len,
                                   struct stream *s, struct sbuf *log,
                                   void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpacking TE Router ID TLV...\n");
        if (tlv_len != 4) {
                sbuf_push(log, indent, "WARNING: Length invalid\n");
                return 1;
        }

        if (tlvs->te_router_id) {
                sbuf_push(log, indent,
                          "WARNING: TE Router ID present multiple times.\n");
                stream_forward_getp(s, tlv_len);
                return 0;
        }

        tlvs->te_router_id = XCALLOC(MTYPE_ISIS_TLV, 4);
        stream_get(tlvs->te_router_id, s, 4);
        format_tlv_te_router_id(tlvs->te_router_id, log, indent + 2);
        return 0;
}


/* Functions related to TLVs 135/235 extended IP reach/MT IP Reach */

static struct isis_item *copy_item_extended_ip_reach(struct isis_item *i)
{
        struct isis_extended_ip_reach *r = (struct isis_extended_ip_reach *)i;
        struct isis_extended_ip_reach *rv =
                XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->metric = r->metric;
        rv->down = r->down;
        rv->prefix = r->prefix;

        return (struct isis_item *)rv;
}

static void format_item_extended_ip_reach(uint16_t mtid, struct isis_item *i,
                                          struct sbuf *buf, int indent)
{
        struct isis_extended_ip_reach *r = (struct isis_extended_ip_reach *)i;
        char prefixbuf[PREFIX2STR_BUFFER];

        sbuf_push(buf, indent, "%s IP Reachability: %s (Metric: %u)%s",
                  (mtid == ISIS_MT_IPV4_UNICAST) ? "Extended" : "MT",
                  prefix2str(&r->prefix, prefixbuf, sizeof(prefixbuf)), r->metric,
                  r->down ? " Down" : "");
        if (mtid != ISIS_MT_IPV4_UNICAST)
                sbuf_push(buf, 0, " %s", isis_mtid2str(mtid));
        sbuf_push(buf, 0, "\n");

        if (r->subtlvs) {
                sbuf_push(buf, indent, "  Subtlvs:\n");
                format_subtlvs(r->subtlvs, buf, indent + 4);
        }
}

static void free_item_extended_ip_reach(struct isis_item *i)
{
        struct isis_extended_ip_reach *item =
                (struct isis_extended_ip_reach *)i;
        isis_free_subtlvs(item->subtlvs);
        XFREE(MTYPE_ISIS_TLV, item);
}

static int pack_item_extended_ip_reach(struct isis_item *i, struct stream *s)
{
        struct isis_extended_ip_reach *r = (struct isis_extended_ip_reach *)i;
        uint8_t control;

        if (STREAM_WRITEABLE(s) < 5)
                return 1;
        stream_putl(s, r->metric);

        control = r->down ? ISIS_EXTENDED_IP_REACH_DOWN : 0;
        control |= r->prefix.prefixlen;
        control |= r->subtlvs ? ISIS_EXTENDED_IP_REACH_SUBTLV : 0;

        stream_putc(s, control);

        if (STREAM_WRITEABLE(s) < (unsigned)PSIZE(r->prefix.prefixlen))
                return 1;
        stream_put(s, &r->prefix.prefix.s_addr, PSIZE(r->prefix.prefixlen));

        if (r->subtlvs)
                return pack_subtlvs(r->subtlvs, s);
        return 0;
}

static int unpack_item_extended_ip_reach(uint16_t mtid, uint8_t len,
                                         struct stream *s, struct sbuf *log,
                                         void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;
        struct isis_extended_ip_reach *rv = NULL;
        size_t consume;
        uint8_t control, subtlv_len;
        struct isis_item_list *items;

        if (mtid == ISIS_MT_IPV4_UNICAST) {
                items = &tlvs->extended_ip_reach;
        } else {
                items = isis_get_mt_items(&tlvs->mt_ip_reach, mtid);
        }

        sbuf_push(log, indent, "Unpacking %s IPv4 reachability...\n",
                  (mtid == ISIS_MT_IPV4_UNICAST) ? "extended" : "mt");

        consume = 5;
        if (len < consume) {
                sbuf_push(log, indent,
                          "Not enough data left. (expected 5 or more bytes, got %" PRIu8 ")\n",
                          len);
                goto out;
        }

        rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->metric = stream_getl(s);
        control = stream_getc(s);
        rv->down = (control & ISIS_EXTENDED_IP_REACH_DOWN);
        rv->prefix.family = AF_INET;
        rv->prefix.prefixlen = control & 0x3f;
        if (rv->prefix.prefixlen > 32) {
                sbuf_push(log, indent, "Prefixlen %u is inplausible for IPv4\n",
                          rv->prefix.prefixlen);
                goto out;
        }

        consume += PSIZE(rv->prefix.prefixlen);
        if (len < consume) {
                sbuf_push(log, indent,
                          "Expected %u bytes of prefix, but only %u bytes available.\n",
                          PSIZE(rv->prefix.prefixlen), len - 5);
                goto out;
        }
        stream_get(&rv->prefix.prefix.s_addr, s, PSIZE(rv->prefix.prefixlen));
        in_addr_t orig_prefix = rv->prefix.prefix.s_addr;
        apply_mask_ipv4(&rv->prefix);
        if (orig_prefix != rv->prefix.prefix.s_addr)
                sbuf_push(log, indent + 2,
                          "WARNING: Prefix had hostbits set.\n");
        format_item_extended_ip_reach(mtid, (struct isis_item *)rv, log,
                                      indent + 2);

        if (control & ISIS_EXTENDED_IP_REACH_SUBTLV) {
                consume += 1;
                if (len < consume) {
                        sbuf_push(log, indent,
                                  "Expected 1 byte of subtlv len, but no more data present.\n");
                        goto out;
                }
                subtlv_len = stream_getc(s);

                if (!subtlv_len) {
                        sbuf_push(log, indent + 2,
                                  "  WARNING: subtlv bit is set, but there are no subtlvs.\n");
                }
                consume += subtlv_len;
                if (len < consume) {
                        sbuf_push(log, indent,
                                  "Expected %" PRIu8
                                  " bytes of subtlvs, but only %u bytes available.\n",
                                  subtlv_len,
                                  len - 6 - PSIZE(rv->prefix.prefixlen));
                        goto out;
                }

                rv->subtlvs = isis_alloc_subtlvs(ISIS_CONTEXT_SUBTLV_IP_REACH);
                bool unpacked_known_tlvs = false;

                if (unpack_tlvs(ISIS_CONTEXT_SUBTLV_IP_REACH, subtlv_len, s,
                                log, rv->subtlvs, indent + 4, &unpacked_known_tlvs)) {
                        goto out;
                }
                if (!unpacked_known_tlvs) {
                        isis_free_subtlvs(rv->subtlvs);
                        rv->subtlvs = NULL;
                }
        }

        append_item(items, (struct isis_item *)rv);
        return 0;
out:
        if (rv)
                free_item_extended_ip_reach((struct isis_item *)rv);
        return 1;
}

/* Functions related to TLV 137 Dynamic Hostname */

static char *copy_tlv_dynamic_hostname(const char *hostname)
{
        if (!hostname)
                return NULL;

        return XSTRDUP(MTYPE_ISIS_TLV, hostname);
}

static void format_tlv_dynamic_hostname(const char *hostname, struct sbuf *buf,
                                        int indent)
{
        if (!hostname)
                return;

        sbuf_push(buf, indent, "Hostname: %s\n", hostname);
}

static void free_tlv_dynamic_hostname(char *hostname)
{
        XFREE(MTYPE_ISIS_TLV, hostname);
}

static int pack_tlv_dynamic_hostname(const char *hostname, struct stream *s)
{
        if (!hostname)
                return 0;

        uint8_t name_len = strlen(hostname);

        if (STREAM_WRITEABLE(s) < (unsigned)(2 + name_len))
                return 1;

        stream_putc(s, ISIS_TLV_DYNAMIC_HOSTNAME);
        stream_putc(s, name_len);
        stream_put(s, hostname, name_len);
        return 0;
}

static int unpack_tlv_dynamic_hostname(enum isis_tlv_context context,
                                       uint8_t tlv_type, uint8_t tlv_len,
                                       struct stream *s, struct sbuf *log,
                                       void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpacking Dynamic Hostname TLV...\n");
        if (!tlv_len) {
                sbuf_push(log, indent, "WARNING: No hostname included\n");
                return 0;
        }

        if (tlvs->hostname) {
                sbuf_push(log, indent,
                          "WARNING: Hostname present multiple times.\n");
                stream_forward_getp(s, tlv_len);
                return 0;
        }

        tlvs->hostname = XCALLOC(MTYPE_ISIS_TLV, tlv_len + 1);
        stream_get(tlvs->hostname, s, tlv_len);
        tlvs->hostname[tlv_len] = '\0';

        bool sane = true;
        for (uint8_t i = 0; i < tlv_len; i++) {
                if ((unsigned char)tlvs->hostname[i] > 127
                    || !isprint((int)tlvs->hostname[i])) {
                        sane = false;
                        tlvs->hostname[i] = '?';
                }
        }
        if (!sane) {
                sbuf_push(
                        log, indent,
                        "WARNING: Hostname contained non-printable/non-ascii characters.\n");
        }

        return 0;
}

/* Functions related to TLV 150 Spine-Leaf-Extension */

static struct isis_spine_leaf *copy_tlv_spine_leaf(
                                const struct isis_spine_leaf *spine_leaf)
{
        if (!spine_leaf)
                return NULL;

        struct isis_spine_leaf *rv = XMALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        memcpy(rv, spine_leaf, sizeof(*rv));

        return rv;
}

static void format_tlv_spine_leaf(const struct isis_spine_leaf *spine_leaf,
                                  struct sbuf *buf, int indent)
{
        if (!spine_leaf)
                return;

        sbuf_push(buf, indent, "Spine-Leaf-Extension:\n");
        if (spine_leaf->has_tier) {
                if (spine_leaf->tier == ISIS_TIER_UNDEFINED) {
                        sbuf_push(buf, indent, "  Tier: undefined\n");
                } else {
                        sbuf_push(buf, indent, "  Tier: %" PRIu8 "\n",
                                  spine_leaf->tier);
                }
        }

        sbuf_push(buf, indent, "  Flags:%s%s%s\n",
                  spine_leaf->is_leaf ? " LEAF" : "",
                  spine_leaf->is_spine ? " SPINE" : "",
                  spine_leaf->is_backup ? " BACKUP" : "");

}

static void free_tlv_spine_leaf(struct isis_spine_leaf *spine_leaf)
{
        XFREE(MTYPE_ISIS_TLV, spine_leaf);
}

#define ISIS_SPINE_LEAF_FLAG_TIER 0x08
#define ISIS_SPINE_LEAF_FLAG_BACKUP 0x04
#define ISIS_SPINE_LEAF_FLAG_SPINE 0x02
#define ISIS_SPINE_LEAF_FLAG_LEAF 0x01

static int pack_tlv_spine_leaf(const struct isis_spine_leaf *spine_leaf,
                               struct stream *s)
{
        if (!spine_leaf)
                return 0;

        uint8_t tlv_len = 2;

        if (STREAM_WRITEABLE(s) < (unsigned)(2 + tlv_len))
                return 1;

        stream_putc(s, ISIS_TLV_SPINE_LEAF_EXT);
        stream_putc(s, tlv_len);

        uint16_t spine_leaf_flags = 0;

        if (spine_leaf->has_tier) {
                spine_leaf_flags |= ISIS_SPINE_LEAF_FLAG_TIER;
                spine_leaf_flags |= spine_leaf->tier << 12;
        }

        if (spine_leaf->is_leaf)
                spine_leaf_flags |= ISIS_SPINE_LEAF_FLAG_LEAF;

        if (spine_leaf->is_spine)
                spine_leaf_flags |= ISIS_SPINE_LEAF_FLAG_SPINE;

        if (spine_leaf->is_backup)
                spine_leaf_flags |= ISIS_SPINE_LEAF_FLAG_BACKUP;

        stream_putw(s, spine_leaf_flags);

        return 0;
}

static int unpack_tlv_spine_leaf(enum isis_tlv_context context,
                                 uint8_t tlv_type, uint8_t tlv_len,
                                 struct stream *s, struct sbuf *log,
                                 void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpacking Spine Leaf Extension TLV...\n");
        if (tlv_len < 2) {
                sbuf_push(log, indent, "WARNING: Unexepected TLV size\n");
                stream_forward_getp(s, tlv_len);
                return 0;
        }

        if (tlvs->spine_leaf) {
                sbuf_push(log, indent,
                          "WARNING: Spine Leaf Extension TLV present multiple times.\n");
                stream_forward_getp(s, tlv_len);
                return 0;
        }

        tlvs->spine_leaf = XCALLOC(MTYPE_ISIS_TLV, sizeof(*tlvs->spine_leaf));

        uint16_t spine_leaf_flags = stream_getw(s);

        if (spine_leaf_flags & ISIS_SPINE_LEAF_FLAG_TIER) {
                tlvs->spine_leaf->has_tier = true;
                tlvs->spine_leaf->tier = spine_leaf_flags >> 12;
        }

        tlvs->spine_leaf->is_leaf = spine_leaf_flags & ISIS_SPINE_LEAF_FLAG_LEAF;
        tlvs->spine_leaf->is_spine = spine_leaf_flags & ISIS_SPINE_LEAF_FLAG_SPINE;
        tlvs->spine_leaf->is_backup = spine_leaf_flags & ISIS_SPINE_LEAF_FLAG_BACKUP;

        stream_forward_getp(s, tlv_len - 2);
        return 0;
}

/* Functions related to TLV 240 P2P Three-Way Adjacency */

const char *isis_threeway_state_name(enum isis_threeway_state state)
{
        switch (state) {
        case ISIS_THREEWAY_DOWN:
                return "Down";
        case ISIS_THREEWAY_INITIALIZING:
                return "Initializing";
        case ISIS_THREEWAY_UP:
                return "Up";
        default:
                return "Invalid!";
        }
}

static struct isis_threeway_adj *copy_tlv_threeway_adj(
                                const struct isis_threeway_adj *threeway_adj)
{
        if (!threeway_adj)
                return NULL;

        struct isis_threeway_adj *rv = XMALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        memcpy(rv, threeway_adj, sizeof(*rv));

        return rv;
}

static void format_tlv_threeway_adj(const struct isis_threeway_adj *threeway_adj,
                                     struct sbuf *buf, int indent)
{
        if (!threeway_adj)
                return;

        sbuf_push(buf, indent, "P2P Three-Way Adjacency:\n");
        sbuf_push(buf, indent, "  State: %s (%d)\n",
                  isis_threeway_state_name(threeway_adj->state),
                  threeway_adj->state);
        sbuf_push(buf, indent, "  Extended Local Circuit ID: %" PRIu32 "\n",
                  threeway_adj->local_circuit_id);
        if (!threeway_adj->neighbor_set)
                return;

        sbuf_push(buf, indent, "  Neighbor System ID: %s\n",
                  isis_format_id(threeway_adj->neighbor_id, 6));
        sbuf_push(buf, indent, "  Neighbor Extended Circuit ID: %" PRIu32 "\n",
                  threeway_adj->neighbor_circuit_id);
}

static void free_tlv_threeway_adj(struct isis_threeway_adj *threeway_adj)
{
        XFREE(MTYPE_ISIS_TLV, threeway_adj);
}

static int pack_tlv_threeway_adj(const struct isis_threeway_adj *threeway_adj,
                                  struct stream *s)
{
        if (!threeway_adj)
                return 0;

        uint8_t tlv_len = (threeway_adj->neighbor_set) ? 15 : 5;

        if (STREAM_WRITEABLE(s) < (unsigned)(2 + tlv_len))
                return 1;

        stream_putc(s, ISIS_TLV_THREE_WAY_ADJ);
        stream_putc(s, tlv_len);
        stream_putc(s, threeway_adj->state);
        stream_putl(s, threeway_adj->local_circuit_id);

        if (threeway_adj->neighbor_set) {
                stream_put(s, threeway_adj->neighbor_id, 6);
                stream_putl(s, threeway_adj->neighbor_circuit_id);
        }

        return 0;
}

static int unpack_tlv_threeway_adj(enum isis_tlv_context context,
                                       uint8_t tlv_type, uint8_t tlv_len,
                                       struct stream *s, struct sbuf *log,
                                       void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpacking P2P Three-Way Adjacency TLV...\n");
        if (tlv_len != 5 && tlv_len != 15) {
                sbuf_push(log, indent, "WARNING: Unexepected TLV size\n");
                stream_forward_getp(s, tlv_len);
                return 0;
        }

        if (tlvs->threeway_adj) {
                sbuf_push(log, indent,
                          "WARNING: P2P Three-Way Adjacency TLV present multiple times.\n");
                stream_forward_getp(s, tlv_len);
                return 0;
        }

        tlvs->threeway_adj = XCALLOC(MTYPE_ISIS_TLV, sizeof(*tlvs->threeway_adj));

        tlvs->threeway_adj->state = stream_getc(s);
        tlvs->threeway_adj->local_circuit_id = stream_getl(s);

        if (tlv_len == 15) {
                tlvs->threeway_adj->neighbor_set = true;
                stream_get(tlvs->threeway_adj->neighbor_id, s, 6);
                tlvs->threeway_adj->neighbor_circuit_id = stream_getl(s);
        }

        return 0;
}

/* Functions related to TLVs 236/237 IPv6/MT-IPv6 reach */

static struct isis_item *copy_item_ipv6_reach(struct isis_item *i)
{
        struct isis_ipv6_reach *r = (struct isis_ipv6_reach *)i;
        struct isis_ipv6_reach *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        rv->metric = r->metric;
        rv->down = r->down;
        rv->external = r->external;
        rv->prefix = r->prefix;
        rv->subtlvs = copy_subtlvs(r->subtlvs);

        return (struct isis_item *)rv;
}

static void format_item_ipv6_reach(uint16_t mtid, struct isis_item *i,
                                   struct sbuf *buf, int indent)
{
        struct isis_ipv6_reach *r = (struct isis_ipv6_reach *)i;
        char prefixbuf[PREFIX2STR_BUFFER];

        sbuf_push(buf, indent, "%sIPv6 Reachability: %s (Metric: %u)%s%s",
                  (mtid == ISIS_MT_IPV4_UNICAST) ? "" : "MT ",
                  prefix2str(&r->prefix, prefixbuf, sizeof(prefixbuf)),
                  r->metric,
                  r->down ? " Down" : "",
                  r->external ? " External" : "");
        if (mtid != ISIS_MT_IPV4_UNICAST)
                sbuf_push(buf, 0, " %s", isis_mtid2str(mtid));
        sbuf_push(buf, 0, "\n");

        if (r->subtlvs) {
                sbuf_push(buf, indent, "  Subtlvs:\n");
                format_subtlvs(r->subtlvs, buf, indent + 4);
        }
}

static void free_item_ipv6_reach(struct isis_item *i)
{
        struct isis_ipv6_reach *item = (struct isis_ipv6_reach *)i;

        isis_free_subtlvs(item->subtlvs);
        XFREE(MTYPE_ISIS_TLV, item);
}

static int pack_item_ipv6_reach(struct isis_item *i, struct stream *s)
{
        struct isis_ipv6_reach *r = (struct isis_ipv6_reach *)i;
        uint8_t control;

        if (STREAM_WRITEABLE(s) < 6)
                return 1;
        stream_putl(s, r->metric);

        control = r->down ? ISIS_IPV6_REACH_DOWN : 0;
        control |= r->external ? ISIS_IPV6_REACH_EXTERNAL : 0;
        control |= r->subtlvs ? ISIS_IPV6_REACH_SUBTLV : 0;

        stream_putc(s, control);
        stream_putc(s, r->prefix.prefixlen);

        if (STREAM_WRITEABLE(s) < (unsigned)PSIZE(r->prefix.prefixlen))
                return 1;
        stream_put(s, &r->prefix.prefix.s6_addr, PSIZE(r->prefix.prefixlen));

        if (r->subtlvs)
                return pack_subtlvs(r->subtlvs, s);

        return 0;
}

static int unpack_item_ipv6_reach(uint16_t mtid, uint8_t len, struct stream *s,
                                  struct sbuf *log, void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;
        struct isis_ipv6_reach *rv = NULL;
        size_t consume;
        uint8_t control, subtlv_len;
        struct isis_item_list *items;

        if (mtid == ISIS_MT_IPV4_UNICAST) {
                items = &tlvs->ipv6_reach;
        } else {
                items = isis_get_mt_items(&tlvs->mt_ipv6_reach, mtid);
        }

        sbuf_push(log, indent, "Unpacking %sIPv6 reachability...\n",
                  (mtid == ISIS_MT_IPV4_UNICAST) ? "" : "mt ");
        consume = 6;
        if (len < consume) {
                sbuf_push(log, indent,
                          "Not enough data left. (expected 6 or more bytes, got %"
                          PRIu8 ")\n",
                          len);
                goto out;
        }

        rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->metric = stream_getl(s);
        control = stream_getc(s);
        rv->down = (control & ISIS_IPV6_REACH_DOWN);
        rv->external = (control & ISIS_IPV6_REACH_EXTERNAL);

        rv->prefix.family = AF_INET6;
        rv->prefix.prefixlen = stream_getc(s);
        if (rv->prefix.prefixlen > 128) {
                sbuf_push(log, indent, "Prefixlen %u is inplausible for IPv6\n",
                          rv->prefix.prefixlen);
                goto out;
        }

        consume += PSIZE(rv->prefix.prefixlen);
        if (len < consume) {
                sbuf_push(log, indent,
                          "Expected %u bytes of prefix, but only %u bytes available.\n",
                          PSIZE(rv->prefix.prefixlen), len - 6);
                goto out;
        }
        stream_get(&rv->prefix.prefix.s6_addr, s, PSIZE(rv->prefix.prefixlen));
        struct in6_addr orig_prefix = rv->prefix.prefix;
        apply_mask_ipv6(&rv->prefix);
        if (memcmp(&orig_prefix, &rv->prefix.prefix, sizeof(orig_prefix)))
                sbuf_push(log, indent + 2,
                          "WARNING: Prefix had hostbits set.\n");
        format_item_ipv6_reach(mtid, (struct isis_item *)rv, log, indent + 2);

        if (control & ISIS_IPV6_REACH_SUBTLV) {
                consume += 1;
                if (len < consume) {
                        sbuf_push(log, indent,
                                  "Expected 1 byte of subtlv len, but no more data persent.\n");
                        goto out;
                }
                subtlv_len = stream_getc(s);

                if (!subtlv_len) {
                        sbuf_push(log, indent + 2,
                                  "  WARNING: subtlv bit set, but there are no subtlvs.\n");
                }
                consume += subtlv_len;
                if (len < consume) {
                        sbuf_push(log, indent,
                                  "Expected %" PRIu8
                                  " bytes of subtlvs, but only %u bytes available.\n",
                                  subtlv_len,
                                  len - 6 - PSIZE(rv->prefix.prefixlen));
                        goto out;
                }

                rv->subtlvs = isis_alloc_subtlvs(ISIS_CONTEXT_SUBTLV_IPV6_REACH);
                bool unpacked_known_tlvs = false;

                if (unpack_tlvs(ISIS_CONTEXT_SUBTLV_IPV6_REACH, subtlv_len, s,
                                log, rv->subtlvs, indent + 4, &unpacked_known_tlvs)) {
                        goto out;
                }
                if (!unpacked_known_tlvs) {
                        isis_free_subtlvs(rv->subtlvs);
                        rv->subtlvs = NULL;
                }
        }

        append_item(items, (struct isis_item *)rv);
        return 0;
out:
        if (rv)
                free_item_ipv6_reach((struct isis_item *)rv);
        return 1;
}

/* Functions related to TLV 10 Authentication */
static struct isis_item *copy_item_auth(struct isis_item *i)
{
        struct isis_auth *auth = (struct isis_auth *)i;
        struct isis_auth *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->type = auth->type;
        rv->length = auth->length;
        memcpy(rv->value, auth->value, sizeof(rv->value));
        return (struct isis_item *)rv;
}

static void format_item_auth(uint16_t mtid, struct isis_item *i,
                             struct sbuf *buf, int indent)
{
        struct isis_auth *auth = (struct isis_auth *)i;
        char obuf[768];

        sbuf_push(buf, indent, "Authentication:\n");
        switch (auth->type) {
        case ISIS_PASSWD_TYPE_CLEARTXT:
                zlog_sanitize(obuf, sizeof(obuf), auth->value, auth->length);
                sbuf_push(buf, indent, "  Password: %s\n", obuf);
                break;
        case ISIS_PASSWD_TYPE_HMAC_MD5:
                for (unsigned int j = 0; j < 16; j++) {
                        snprintf(obuf + 2 * j, sizeof(obuf) - 2 * j,
                                 "%02" PRIx8, auth->value[j]);
                }
                sbuf_push(buf, indent, "  HMAC-MD5: %s\n", obuf);
                break;
        default:
                sbuf_push(buf, indent, "  Unknown (%" PRIu8 ")\n", auth->type);
                break;
        }
}

static void free_item_auth(struct isis_item *i)
{
        XFREE(MTYPE_ISIS_TLV, i);
}

static int pack_item_auth(struct isis_item *i, struct stream *s)
{
        struct isis_auth *auth = (struct isis_auth *)i;

        if (STREAM_WRITEABLE(s) < 1)
                return 1;
        stream_putc(s, auth->type);

        switch (auth->type) {
        case ISIS_PASSWD_TYPE_CLEARTXT:
                if (STREAM_WRITEABLE(s) < auth->length)
                        return 1;
                stream_put(s, auth->passwd, auth->length);
                break;
        case ISIS_PASSWD_TYPE_HMAC_MD5:
                if (STREAM_WRITEABLE(s) < 16)
                        return 1;
                auth->offset = stream_get_endp(s);
                stream_put(s, NULL, 16);
                break;
        default:
                return 1;
        }

        return 0;
}

static int unpack_item_auth(uint16_t mtid, uint8_t len, struct stream *s,
                            struct sbuf *log, void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;

        sbuf_push(log, indent, "Unpack Auth TLV...\n");
        if (len < 1) {
                sbuf_push(
                        log, indent,
                        "Not enough data left.(Expected 1 bytes of auth type, got %" PRIu8
                        ")\n",
                        len);
                return 1;
        }

        struct isis_auth *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        rv->type = stream_getc(s);
        rv->length = len - 1;

        if (rv->type == ISIS_PASSWD_TYPE_HMAC_MD5 && rv->length != 16) {
                sbuf_push(
                        log, indent,
                        "Unexpected auth length for HMAC-MD5 (expected 16, got %" PRIu8
                        ")\n",
                        rv->length);
                XFREE(MTYPE_ISIS_TLV, rv);
                return 1;
        }

        rv->offset = stream_get_getp(s);
        stream_get(rv->value, s, rv->length);
        format_item_auth(mtid, (struct isis_item *)rv, log, indent + 2);
        append_item(&tlvs->isis_auth, (struct isis_item *)rv);
        return 0;
}

/* Functions related to TLV 13 Purge Originator */

static struct isis_purge_originator *copy_tlv_purge_originator(
                                        struct isis_purge_originator *poi)
{
        if (!poi)
                return NULL;

        struct isis_purge_originator *rv;

        rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));
        rv->sender_set = poi->sender_set;
        memcpy(rv->generator, poi->generator, sizeof(rv->generator));
        if (poi->sender_set)
                memcpy(rv->sender, poi->sender, sizeof(rv->sender));
        return rv;
}

static void format_tlv_purge_originator(struct isis_purge_originator *poi,
                                        struct sbuf *buf, int indent)
{
        if (!poi)
                return;

        sbuf_push(buf, indent, "Purge Originator Identification:\n");
        sbuf_push(buf, indent, "  Generator: %s\n",
                  isis_format_id(poi->generator, sizeof(poi->generator)));
        if (poi->sender_set) {
                sbuf_push(buf, indent, "  Received-From: %s\n",
                          isis_format_id(poi->sender, sizeof(poi->sender)));
        }
}

static void free_tlv_purge_originator(struct isis_purge_originator *poi)
{
        XFREE(MTYPE_ISIS_TLV, poi);
}

static int pack_tlv_purge_originator(struct isis_purge_originator *poi,
                                     struct stream *s)
{
        if (!poi)
                return 0;

        uint8_t data_len = 1 + sizeof(poi->generator);

        if (poi->sender_set)
                data_len += sizeof(poi->sender);

        if (STREAM_WRITEABLE(s) < (unsigned)(2 + data_len))
                return 1;

        stream_putc(s, ISIS_TLV_PURGE_ORIGINATOR);
        stream_putc(s, data_len);
        stream_putc(s, poi->sender_set ? 2 : 1);
        stream_put(s, poi->generator, sizeof(poi->generator));
        if (poi->sender_set)
                stream_put(s, poi->sender, sizeof(poi->sender));
        return 0;
}

static int unpack_tlv_purge_originator(enum isis_tlv_context context,
                                       uint8_t tlv_type, uint8_t tlv_len,
                                       struct stream *s, struct sbuf *log,
                                       void *dest, int indent)
{
        struct isis_tlvs *tlvs = dest;
        struct isis_purge_originator poi = {};

        sbuf_push(log, indent, "Unpacking Purge Originator Identification TLV...\n");
        if (tlv_len < 7) {
                sbuf_push(log, indent, "Not enough data left. (Expected at least 7 bytes, got %"
                          PRIu8 ")\n", tlv_len);
                return 1;
        }

        uint8_t number_of_ids = stream_getc(s);

        if (number_of_ids == 1) {
                poi.sender_set = false;
        } else if (number_of_ids == 2) {
                poi.sender_set = true;
        } else {
                sbuf_push(log, indent, "Got invalid value for number of system IDs: %"
                          PRIu8 ")\n", number_of_ids);
                return 1;
        }

        if (tlv_len != 1 + 6 * number_of_ids) {
                sbuf_push(log, indent, "Incorrect tlv len for number of IDs.\n");
                return 1;
        }

        stream_get(poi.generator, s, sizeof(poi.generator));
        if (poi.sender_set)
                stream_get(poi.sender, s, sizeof(poi.sender));

        if (tlvs->purge_originator) {
                sbuf_push(log, indent,
                          "WARNING: Purge originator present multiple times, ignoring.\n");
                return 0;
        }

        tlvs->purge_originator = copy_tlv_purge_originator(&poi);
        return 0;
}


/* Functions relating to item TLVs */

static void init_item_list(struct isis_item_list *items)
{
        items->head = NULL;
        items->tail = &items->head;
        items->count = 0;
}

static struct isis_item *copy_item(enum isis_tlv_context context,
                                   enum isis_tlv_type type,
                                   struct isis_item *item)
{
        const struct tlv_ops *ops = tlv_table[context][type];

        if (ops && ops->copy_item)
                return ops->copy_item(item);

        assert(!"Unknown item tlv type!");
        return NULL;
}

static void copy_items(enum isis_tlv_context context, enum isis_tlv_type type,
                       struct isis_item_list *src, struct isis_item_list *dest)
{
        struct isis_item *item;

        init_item_list(dest);

        for (item = src->head; item; item = item->next) {
                append_item(dest, copy_item(context, type, item));
        }
}

static void format_item(uint16_t mtid, enum isis_tlv_context context,
                        enum isis_tlv_type type, struct isis_item *i,
                        struct sbuf *buf, int indent)
{
        const struct tlv_ops *ops = tlv_table[context][type];

        if (ops && ops->format_item) {
                ops->format_item(mtid, i, buf, indent);
                return;
        }

        assert(!"Unknown item tlv type!");
}

static void format_items_(uint16_t mtid, enum isis_tlv_context context,
                          enum isis_tlv_type type, struct isis_item_list *items,
                          struct sbuf *buf, int indent)
{
        struct isis_item *i;

        for (i = items->head; i; i = i->next)
                format_item(mtid, context, type, i, buf, indent);
}

static void free_item(enum isis_tlv_context tlv_context,
                      enum isis_tlv_type tlv_type, struct isis_item *item)
{
        const struct tlv_ops *ops = tlv_table[tlv_context][tlv_type];

        if (ops && ops->free_item) {
                ops->free_item(item);
                return;
        }

        assert(!"Unknown item tlv type!");
}

static void free_items(enum isis_tlv_context context, enum isis_tlv_type type,
                       struct isis_item_list *items)
{
        struct isis_item *item, *next_item;

        for (item = items->head; item; item = next_item) {
                next_item = item->next;
                free_item(context, type, item);
        }
}

static int pack_item(enum isis_tlv_context context, enum isis_tlv_type type,
                     struct isis_item *i, struct stream *s,
                     struct isis_tlvs **fragment_tlvs,
                     struct pack_order_entry *pe, uint16_t mtid)
{
        const struct tlv_ops *ops = tlv_table[context][type];

        if (ops && ops->pack_item) {
                return ops->pack_item(i, s);
        }

        assert(!"Unknown item tlv type!");
        return 1;
}

static void add_item_to_fragment(struct isis_item *i, struct pack_order_entry *pe,
                                 struct isis_tlvs *fragment_tlvs, uint16_t mtid)
{
        struct isis_item_list *l;

        if (pe->how_to_pack == ISIS_ITEMS) {
                l = (struct isis_item_list *)(((char *)fragment_tlvs) + pe->what_to_pack);
        } else {
                struct isis_mt_item_list *m;
                m = (struct isis_mt_item_list *)(((char *)fragment_tlvs) + pe->what_to_pack);
                l = isis_get_mt_items(m, mtid);
        }

        append_item(l, copy_item(pe->context, pe->type, i));
}

static int pack_items_(uint16_t mtid, enum isis_tlv_context context,
                       enum isis_tlv_type type, struct isis_item_list *items,
                       struct stream *s, struct isis_tlvs **fragment_tlvs,
                       struct pack_order_entry *pe,
                       struct isis_tlvs *(*new_fragment)(struct list *l),
                       struct list *new_fragment_arg)
{
        size_t len_pos, last_len, len;
        struct isis_item *item = NULL;
        int rv;

        if (!items->head)
                return 0;

top:
        if (STREAM_WRITEABLE(s) < 2)
                goto too_long;

        stream_putc(s, type);
        len_pos = stream_get_endp(s);
        stream_putc(s, 0); /* Put 0 as length for now */

        if (context == ISIS_CONTEXT_LSP && IS_COMPAT_MT_TLV(type)
            && mtid != ISIS_MT_IPV4_UNICAST) {
                if (STREAM_WRITEABLE(s) < 2)
                        goto too_long;
                stream_putw(s, mtid);
        }

        if (context == ISIS_CONTEXT_LSP && type == ISIS_TLV_OLDSTYLE_REACH) {
                if (STREAM_WRITEABLE(s) < 1)
                        goto too_long;
                stream_putc(s, 0); /* Virtual flag is set to 0 */
        }

        last_len = len = 0;
        for (item = item ? item : items->head; item; item = item->next) {
                rv = pack_item(context, type, item, s, fragment_tlvs, pe, mtid);
                if (rv)
                        goto too_long;

                len = stream_get_endp(s) - len_pos - 1;

                /* Multiple auths don't go into one TLV, so always break */
                if (context == ISIS_CONTEXT_LSP && type == ISIS_TLV_AUTH) {
                        item = item->next;
                        break;
                }

                /* Multiple prefix-sids don't go into one TLV, so always break */
                if (type == ISIS_SUBTLV_PREFIX_SID
                    && (context == ISIS_CONTEXT_SUBTLV_IP_REACH
                        || context == ISIS_CONTEXT_SUBTLV_IPV6_REACH)) {
                        item = item->next;
                        break;
                }

                if (len > 255) {
                        if (!last_len) /* strange, not a single item fit */
                                return 1;
                        /* drop last tlv, otherwise, its too long */
                        stream_set_endp(s, len_pos + 1 + last_len);
                        len = last_len;
                        break;
                }

                if (fragment_tlvs)
                        add_item_to_fragment(item, pe, *fragment_tlvs, mtid);

                last_len = len;
        }

        stream_putc_at(s, len_pos, len);
        if (item)
                goto top;

        return 0;
too_long:
        if (!fragment_tlvs)
                return 1;
        stream_reset(s);
        *fragment_tlvs = new_fragment(new_fragment_arg);
        goto top;
}
#define pack_items(...) pack_items_(ISIS_MT_IPV4_UNICAST, __VA_ARGS__)

static void append_item(struct isis_item_list *dest, struct isis_item *item)
{
        *dest->tail = item;
        dest->tail = &(*dest->tail)->next;
        dest->count++;
}

static struct isis_item *last_item(struct isis_item_list *list)
{
        return container_of(list->tail, struct isis_item, next);
}

static int unpack_item(uint16_t mtid, enum isis_tlv_context context,
                       uint8_t tlv_type, uint8_t len, struct stream *s,
                       struct sbuf *log, void *dest, int indent)
{
        const struct tlv_ops *ops = tlv_table[context][tlv_type];

        if (ops && ops->unpack_item)
                return ops->unpack_item(mtid, len, s, log, dest, indent);

        assert(!"Unknown item tlv type!");
        sbuf_push(log, indent, "Unknown item tlv type!\n");
        return 1;
}

static int unpack_tlv_with_items(enum isis_tlv_context context,
                                 uint8_t tlv_type, uint8_t tlv_len,
                                 struct stream *s, struct sbuf *log, void *dest,
                                 int indent)
{
        size_t tlv_start;
        size_t tlv_pos;
        int rv;
        uint16_t mtid;

        tlv_start = stream_get_getp(s);
        tlv_pos = 0;

        if (context == ISIS_CONTEXT_LSP && IS_COMPAT_MT_TLV(tlv_type)) {
                if (tlv_len < 2) {
                        sbuf_push(log, indent,
                                  "TLV is too short to contain MTID\n");
                        return 1;
                }
                mtid = stream_getw(s) & ISIS_MT_MASK;
                tlv_pos += 2;
                sbuf_push(log, indent, "Unpacking as MT %s item TLV...\n",
                          isis_mtid2str(mtid));
        } else {
                sbuf_push(log, indent, "Unpacking as item TLV...\n");
                mtid = ISIS_MT_IPV4_UNICAST;
        }

        if (context == ISIS_CONTEXT_LSP
            && tlv_type == ISIS_TLV_OLDSTYLE_REACH) {
                if (tlv_len - tlv_pos < 1) {
                        sbuf_push(log, indent,
                                  "TLV is too short for old style reach\n");
                        return 1;
                }
                stream_forward_getp(s, 1);
                tlv_pos += 1;
        }

        if (context == ISIS_CONTEXT_LSP
            && tlv_type == ISIS_TLV_OLDSTYLE_IP_REACH) {
                struct isis_tlvs *tlvs = dest;
                dest = &tlvs->oldstyle_ip_reach;
        } else if (context == ISIS_CONTEXT_LSP
                   && tlv_type == ISIS_TLV_OLDSTYLE_IP_REACH_EXT) {
                struct isis_tlvs *tlvs = dest;
                dest = &tlvs->oldstyle_ip_reach_ext;
        }

        if (context == ISIS_CONTEXT_LSP
            && tlv_type == ISIS_TLV_MT_ROUTER_INFO) {
                struct isis_tlvs *tlvs = dest;
                tlvs->mt_router_info_empty = (tlv_pos >= (size_t)tlv_len);
        }

        while (tlv_pos < (size_t)tlv_len) {
                rv = unpack_item(mtid, context, tlv_type, tlv_len - tlv_pos, s,
                                 log, dest, indent + 2);
                if (rv)
                        return rv;

                tlv_pos = stream_get_getp(s) - tlv_start;
        }

        return 0;
}

/* Functions to manipulate mt_item_lists */

static int isis_mt_item_list_cmp(const struct isis_item_list *a,
                                 const struct isis_item_list *b)
{
        if (a->mtid < b->mtid)
                return -1;
        if (a->mtid > b->mtid)
                return 1;
        return 0;
}

RB_PROTOTYPE(isis_mt_item_list, isis_item_list, mt_tree, isis_mt_item_list_cmp);
RB_GENERATE(isis_mt_item_list, isis_item_list, mt_tree, isis_mt_item_list_cmp);

struct isis_item_list *isis_get_mt_items(struct isis_mt_item_list *m,
                                         uint16_t mtid)
{
        struct isis_item_list *rv;

        rv = isis_lookup_mt_items(m, mtid);
        if (!rv) {
                rv = XCALLOC(MTYPE_ISIS_MT_ITEM_LIST, sizeof(*rv));
                init_item_list(rv);
                rv->mtid = mtid;
                RB_INSERT(isis_mt_item_list, m, rv);
        }

        return rv;
}

struct isis_item_list *isis_lookup_mt_items(struct isis_mt_item_list *m,
                                            uint16_t mtid)
{
        struct isis_item_list key = {.mtid = mtid};

        return RB_FIND(isis_mt_item_list, m, &key);
}

static void free_mt_items(enum isis_tlv_context context,
                          enum isis_tlv_type type, struct isis_mt_item_list *m)
{
        struct isis_item_list *n, *nnext;

        RB_FOREACH_SAFE (n, isis_mt_item_list, m, nnext) {
                free_items(context, type, n);
                RB_REMOVE(isis_mt_item_list, m, n);
                XFREE(MTYPE_ISIS_MT_ITEM_LIST, n);
        }
}

static void format_mt_items(enum isis_tlv_context context,
                            enum isis_tlv_type type,
                            struct isis_mt_item_list *m, struct sbuf *buf,
                            int indent)
{
        struct isis_item_list *n;

        RB_FOREACH (n, isis_mt_item_list, m) {
                format_items_(n->mtid, context, type, n, buf, indent);
        }
}

static int pack_mt_items(enum isis_tlv_context context, enum isis_tlv_type type,
                         struct isis_mt_item_list *m, struct stream *s,
                         struct isis_tlvs **fragment_tlvs,
                         struct pack_order_entry *pe,
                         struct isis_tlvs *(*new_fragment)(struct list *l),
                         struct list *new_fragment_arg)
{
        struct isis_item_list *n;

        RB_FOREACH (n, isis_mt_item_list, m) {
                int rv;

                rv = pack_items_(n->mtid, context, type, n, s, fragment_tlvs,
                                 pe, new_fragment, new_fragment_arg);
                if (rv)
                        return rv;
        }

        return 0;
}

static void copy_mt_items(enum isis_tlv_context context,
                          enum isis_tlv_type type,
                          struct isis_mt_item_list *src,
                          struct isis_mt_item_list *dest)
{
        struct isis_item_list *n;

        RB_INIT(isis_mt_item_list, dest);

        RB_FOREACH (n, isis_mt_item_list, src) {
                copy_items(context, type, n, isis_get_mt_items(dest, n->mtid));
        }
}

/* Functions related to tlvs in general */

struct isis_tlvs *isis_alloc_tlvs(void)
{
        struct isis_tlvs *result;

        result = XCALLOC(MTYPE_ISIS_TLV, sizeof(*result));

        init_item_list(&result->isis_auth);
        init_item_list(&result->area_addresses);
        init_item_list(&result->mt_router_info);
        init_item_list(&result->oldstyle_reach);
        init_item_list(&result->lan_neighbor);
        init_item_list(&result->lsp_entries);
        init_item_list(&result->extended_reach);
        RB_INIT(isis_mt_item_list, &result->mt_reach);
        init_item_list(&result->oldstyle_ip_reach);
        init_item_list(&result->oldstyle_ip_reach_ext);
        init_item_list(&result->ipv4_address);
        init_item_list(&result->ipv6_address);
        init_item_list(&result->extended_ip_reach);
        RB_INIT(isis_mt_item_list, &result->mt_ip_reach);
        init_item_list(&result->ipv6_reach);
        RB_INIT(isis_mt_item_list, &result->mt_ipv6_reach);

        return result;
}

struct isis_tlvs *isis_copy_tlvs(struct isis_tlvs *tlvs)
{
        struct isis_tlvs *rv = XCALLOC(MTYPE_ISIS_TLV, sizeof(*rv));

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_AUTH, &tlvs->isis_auth,
                   &rv->isis_auth);

        rv->purge_originator =
                        copy_tlv_purge_originator(tlvs->purge_originator);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_AREA_ADDRESSES,
                   &tlvs->area_addresses, &rv->area_addresses);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_ROUTER_INFO,
                   &tlvs->mt_router_info, &rv->mt_router_info);

        rv->mt_router_info_empty = tlvs->mt_router_info_empty;

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_REACH,
                   &tlvs->oldstyle_reach, &rv->oldstyle_reach);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_LAN_NEIGHBORS,
                   &tlvs->lan_neighbor, &rv->lan_neighbor);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_LSP_ENTRY, &tlvs->lsp_entries,
                   &rv->lsp_entries);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_EXTENDED_REACH,
                   &tlvs->extended_reach, &rv->extended_reach);

        copy_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_REACH, &tlvs->mt_reach,
                      &rv->mt_reach);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_IP_REACH,
                   &tlvs->oldstyle_ip_reach, &rv->oldstyle_ip_reach);

        copy_tlv_protocols_supported(&tlvs->protocols_supported,
                                     &rv->protocols_supported);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_IP_REACH_EXT,
                   &tlvs->oldstyle_ip_reach_ext, &rv->oldstyle_ip_reach_ext);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV4_ADDRESS, &tlvs->ipv4_address,
                   &rv->ipv4_address);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV6_ADDRESS, &tlvs->ipv6_address,
                   &rv->ipv6_address);

        rv->te_router_id = copy_tlv_te_router_id(tlvs->te_router_id);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_EXTENDED_IP_REACH,
                   &tlvs->extended_ip_reach, &rv->extended_ip_reach);

        copy_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_IP_REACH,
                      &tlvs->mt_ip_reach, &rv->mt_ip_reach);

        rv->hostname = copy_tlv_dynamic_hostname(tlvs->hostname);

        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV6_REACH, &tlvs->ipv6_reach,
                   &rv->ipv6_reach);

        copy_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_IPV6_REACH,
                      &tlvs->mt_ipv6_reach, &rv->mt_ipv6_reach);

        rv->threeway_adj = copy_tlv_threeway_adj(tlvs->threeway_adj);

        rv->spine_leaf = copy_tlv_spine_leaf(tlvs->spine_leaf);

        return rv;
}

static void format_tlvs(struct isis_tlvs *tlvs, struct sbuf *buf, int indent)
{
        format_tlv_protocols_supported(&tlvs->protocols_supported, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_AUTH, &tlvs->isis_auth, buf,
                     indent);

        format_tlv_purge_originator(tlvs->purge_originator, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_AREA_ADDRESSES,
                     &tlvs->area_addresses, buf, indent);

        if (tlvs->mt_router_info_empty) {
                sbuf_push(buf, indent, "MT Router Info: None\n");
        } else {
                format_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_ROUTER_INFO,
                             &tlvs->mt_router_info, buf, indent);
        }

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_REACH,
                     &tlvs->oldstyle_reach, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_LAN_NEIGHBORS,
                     &tlvs->lan_neighbor, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_LSP_ENTRY, &tlvs->lsp_entries,
                     buf, indent);

        format_tlv_dynamic_hostname(tlvs->hostname, buf, indent);
        format_tlv_te_router_id(tlvs->te_router_id, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_EXTENDED_REACH,
                     &tlvs->extended_reach, buf, indent);

        format_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_REACH, &tlvs->mt_reach,
                        buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_IP_REACH,
                     &tlvs->oldstyle_ip_reach, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_IP_REACH_EXT,
                     &tlvs->oldstyle_ip_reach_ext, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV4_ADDRESS,
                     &tlvs->ipv4_address, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV6_ADDRESS,
                     &tlvs->ipv6_address, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_EXTENDED_IP_REACH,
                     &tlvs->extended_ip_reach, buf, indent);

        format_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_IP_REACH,
                        &tlvs->mt_ip_reach, buf, indent);

        format_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV6_REACH, &tlvs->ipv6_reach,
                     buf, indent);

        format_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_IPV6_REACH,
                        &tlvs->mt_ipv6_reach, buf, indent);

        format_tlv_threeway_adj(tlvs->threeway_adj, buf, indent);

        format_tlv_spine_leaf(tlvs->spine_leaf, buf, indent);
}

const char *isis_format_tlvs(struct isis_tlvs *tlvs)
{
        static struct sbuf buf;

        if (!sbuf_buf(&buf))
                sbuf_init(&buf, NULL, 0);

        sbuf_reset(&buf);
        format_tlvs(tlvs, &buf, 0);
        return sbuf_buf(&buf);
}

void isis_free_tlvs(struct isis_tlvs *tlvs)
{
        if (!tlvs)
                return;

        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_AUTH, &tlvs->isis_auth);
        free_tlv_purge_originator(tlvs->purge_originator);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_AREA_ADDRESSES,
                   &tlvs->area_addresses);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_ROUTER_INFO,
                   &tlvs->mt_router_info);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_REACH,
                   &tlvs->oldstyle_reach);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_LAN_NEIGHBORS,
                   &tlvs->lan_neighbor);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_LSP_ENTRY, &tlvs->lsp_entries);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_EXTENDED_REACH,
                   &tlvs->extended_reach);
        free_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_REACH, &tlvs->mt_reach);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_IP_REACH,
                   &tlvs->oldstyle_ip_reach);
        free_tlv_protocols_supported(&tlvs->protocols_supported);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_OLDSTYLE_IP_REACH_EXT,
                   &tlvs->oldstyle_ip_reach_ext);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV4_ADDRESS,
                   &tlvs->ipv4_address);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV6_ADDRESS,
                   &tlvs->ipv6_address);
        free_tlv_te_router_id(tlvs->te_router_id);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_EXTENDED_IP_REACH,
                   &tlvs->extended_ip_reach);
        free_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_IP_REACH,
                      &tlvs->mt_ip_reach);
        free_tlv_dynamic_hostname(tlvs->hostname);
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_IPV6_REACH, &tlvs->ipv6_reach);
        free_mt_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_IPV6_REACH,
                      &tlvs->mt_ipv6_reach);
        free_tlv_threeway_adj(tlvs->threeway_adj);
        free_tlv_spine_leaf(tlvs->spine_leaf);

        XFREE(MTYPE_ISIS_TLV, tlvs);
}

static void add_padding(struct stream *s)
{
        while (STREAM_WRITEABLE(s)) {
                if (STREAM_WRITEABLE(s) == 1)
                        break;
                uint32_t padding_len = STREAM_WRITEABLE(s) - 2;

                if (padding_len > 255) {
                        if (padding_len == 256)
                                padding_len = 254;
                        else
                                padding_len = 255;
                }

                stream_putc(s, ISIS_TLV_PADDING);
                stream_putc(s, padding_len);
                stream_put(s, NULL, padding_len);
        }
}

#define LSP_REM_LIFETIME_OFF 10
#define LSP_CHECKSUM_OFF 24
static void safe_auth_md5(struct stream *s, uint16_t *checksum,
                          uint16_t *rem_lifetime)
{
        memcpy(rem_lifetime, STREAM_DATA(s) + LSP_REM_LIFETIME_OFF,
               sizeof(*rem_lifetime));
        memset(STREAM_DATA(s) + LSP_REM_LIFETIME_OFF, 0, sizeof(*rem_lifetime));
        memcpy(checksum, STREAM_DATA(s) + LSP_CHECKSUM_OFF, sizeof(*checksum));
        memset(STREAM_DATA(s) + LSP_CHECKSUM_OFF, 0, sizeof(*checksum));
}

static void restore_auth_md5(struct stream *s, uint16_t checksum,
                             uint16_t rem_lifetime)
{
        memcpy(STREAM_DATA(s) + LSP_REM_LIFETIME_OFF, &rem_lifetime,
               sizeof(rem_lifetime));
        memcpy(STREAM_DATA(s) + LSP_CHECKSUM_OFF, &checksum, sizeof(checksum));
}

static void update_auth_hmac_md5(struct isis_auth *auth, struct stream *s,
                                 bool is_lsp)
{
        uint8_t digest[16];
        uint16_t checksum, rem_lifetime;

        if (is_lsp)
                safe_auth_md5(s, &checksum, &rem_lifetime);

        memset(STREAM_DATA(s) + auth->offset, 0, 16);
        hmac_md5(STREAM_DATA(s), stream_get_endp(s), auth->passwd,
                 auth->plength, digest);
        memcpy(auth->value, digest, 16);
        memcpy(STREAM_DATA(s) + auth->offset, digest, 16);

        if (is_lsp)
                restore_auth_md5(s, checksum, rem_lifetime);
}

static void update_auth(struct isis_tlvs *tlvs, struct stream *s, bool is_lsp)
{
        struct isis_auth *auth_head = (struct isis_auth *)tlvs->isis_auth.head;

        for (struct isis_auth *auth = auth_head; auth; auth = auth->next) {
                if (auth->type == ISIS_PASSWD_TYPE_HMAC_MD5)
                        update_auth_hmac_md5(auth, s, is_lsp);
        }
}

static int handle_pack_entry(struct pack_order_entry *pe,
                             struct isis_tlvs *tlvs, struct stream *stream,
                             struct isis_tlvs **fragment_tlvs,
                             struct isis_tlvs *(*new_fragment)(struct list *l),
                             struct list *new_fragment_arg)
{
        int rv;

        if (pe->how_to_pack == ISIS_ITEMS) {
                struct isis_item_list *l;
                l = (struct isis_item_list *)(((char *)tlvs)
                                              + pe->what_to_pack);
                rv = pack_items(pe->context, pe->type, l, stream, fragment_tlvs,
                                pe, new_fragment, new_fragment_arg);
        } else {
                struct isis_mt_item_list *l;
                l = (struct isis_mt_item_list *)(((char *)tlvs)
                                                 + pe->what_to_pack);
                rv = pack_mt_items(pe->context, pe->type, l, stream,
                                   fragment_tlvs, pe, new_fragment,
                                   new_fragment_arg);
        }

        return rv;
}

static int pack_tlvs(struct isis_tlvs *tlvs, struct stream *stream,
                     struct isis_tlvs *fragment_tlvs,
                     struct isis_tlvs *(*new_fragment)(struct list *l),
                     struct list *new_fragment_arg)
{
        int rv;

        /* When fragmenting, don't add auth as it's already accounted for in the
         * size we are given. */
        if (!fragment_tlvs) {
                rv = pack_items(ISIS_CONTEXT_LSP, ISIS_TLV_AUTH,
                                &tlvs->isis_auth, stream, NULL, NULL, NULL,
                                NULL);
                if (rv)
                        return rv;
        }

        rv = pack_tlv_purge_originator(tlvs->purge_originator, stream);
        if (rv)
                return rv;
        if (fragment_tlvs) {
                fragment_tlvs->purge_originator =
                        copy_tlv_purge_originator(tlvs->purge_originator);
        }

        rv = pack_tlv_protocols_supported(&tlvs->protocols_supported, stream);
        if (rv)
                return rv;
        if (fragment_tlvs) {
                copy_tlv_protocols_supported(
                        &tlvs->protocols_supported,
                        &fragment_tlvs->protocols_supported);
        }

        rv = pack_items(ISIS_CONTEXT_LSP, ISIS_TLV_AREA_ADDRESSES,
                        &tlvs->area_addresses, stream, NULL, NULL, NULL, NULL);
        if (rv)
                return rv;
        if (fragment_tlvs) {
                copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_AREA_ADDRESSES,
                           &tlvs->area_addresses,
                           &fragment_tlvs->area_addresses);
        }


        if (tlvs->mt_router_info_empty) {
                if (STREAM_WRITEABLE(stream) < 2)
                        return 1;
                stream_putc(stream, ISIS_TLV_MT_ROUTER_INFO);
                stream_putc(stream, 0);
                if (fragment_tlvs)
                        fragment_tlvs->mt_router_info_empty = true;
        } else {
                rv = pack_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_ROUTER_INFO,
                                &tlvs->mt_router_info, stream, NULL, NULL, NULL,
                                NULL);
                if (rv)
                        return rv;
                if (fragment_tlvs) {
                        copy_items(ISIS_CONTEXT_LSP, ISIS_TLV_MT_ROUTER_INFO,
                                   &tlvs->mt_router_info,
                                   &fragment_tlvs->mt_router_info);
                }
        }

        rv = pack_tlv_dynamic_hostname(tlvs->hostname, stream);
        if (rv)
                return rv;
        if (fragment_tlvs)
                fragment_tlvs->hostname =
                        copy_tlv_dynamic_hostname(tlvs->hostname);

        rv = pack_tlv_te_router_id(tlvs->te_router_id, stream);
        if (rv)
                return rv;
        if (fragment_tlvs) {
                fragment_tlvs->te_router_id =
                        copy_tlv_te_router_id(tlvs->te_router_id);
        }

        rv = pack_tlv_threeway_adj(tlvs->threeway_adj, stream);
        if (rv)
                return rv;
        if (fragment_tlvs) {
                fragment_tlvs->threeway_adj =
                        copy_tlv_threeway_adj(tlvs->threeway_adj);
        }

        rv = pack_tlv_spine_leaf(tlvs->spine_leaf, stream);
        if (rv)
                return rv;
        if (fragment_tlvs) {
                fragment_tlvs->spine_leaf =
                        copy_tlv_spine_leaf(tlvs->spine_leaf);
        }

        for (size_t pack_idx = 0; pack_idx < array_size(pack_order);
             pack_idx++) {
                rv = handle_pack_entry(&pack_order[pack_idx], tlvs, stream,
                                       fragment_tlvs ? &fragment_tlvs : NULL,
                                       new_fragment, new_fragment_arg);

                if (rv)
                        return rv;
        }

        return 0;
}

int isis_pack_tlvs(struct isis_tlvs *tlvs, struct stream *stream,
                   size_t len_pointer, bool pad, bool is_lsp)
{
        int rv;

        rv = pack_tlvs(tlvs, stream, NULL, NULL, NULL);
        if (rv)
                return rv;

        if (pad)
                add_padding(stream);

        if (len_pointer != (size_t)-1) {
                stream_putw_at(stream, len_pointer, stream_get_endp(stream));
        }

        update_auth(tlvs, stream, is_lsp);

        return 0;
}

static struct isis_tlvs *new_fragment(struct list *l)
{
        struct isis_tlvs *rv = isis_alloc_tlvs();

        listnode_add(l, rv);
        return rv;
}

struct list *isis_fragment_tlvs(struct isis_tlvs *tlvs, size_t size)
{
        struct stream *dummy_stream = stream_new(size);
        struct list *rv = list_new();
        struct isis_tlvs *fragment_tlvs = new_fragment(rv);

        if (pack_tlvs(tlvs, dummy_stream, fragment_tlvs, new_fragment, rv)) {
                struct listnode *node;
                for (ALL_LIST_ELEMENTS_RO(rv, node, fragment_tlvs))
                        isis_free_tlvs(fragment_tlvs);
                list_delete(&rv);
        }

        stream_free(dummy_stream);
        return rv;
}

static int unpack_tlv_unknown(enum isis_tlv_context context, uint8_t tlv_type,
                              uint8_t tlv_len, struct stream *s,
                              struct sbuf *log, int indent)
{
        stream_forward_getp(s, tlv_len);
        sbuf_push(log, indent,
                  "Skipping unknown TLV %" PRIu8 " (%" PRIu8 " bytes)\n",
                  tlv_type, tlv_len);
        return 0;
}

static int unpack_tlv(enum isis_tlv_context context, size_t avail_len,
                      struct stream *stream, struct sbuf *log, void *dest,
                      int indent, bool *unpacked_known_tlvs)
{
        uint8_t tlv_type, tlv_len;
        const struct tlv_ops *ops;

        sbuf_push(log, indent, "Unpacking TLV...\n");

        if (avail_len < 2) {
                sbuf_push(
                        log, indent + 2,
                        "Available data %zu too short to contain a TLV header.\n",
                        avail_len);
                return 1;
        }

        tlv_type = stream_getc(stream);
        tlv_len = stream_getc(stream);

        sbuf_push(log, indent + 2,
                  "Found TLV of type %" PRIu8 " and len %" PRIu8 ".\n",
                  tlv_type, tlv_len);

        if (avail_len < ((size_t)tlv_len) + 2) {
                sbuf_push(log, indent + 2,
                          "Available data %zu too short for claimed TLV len %" PRIu8 ".\n",
                          avail_len - 2, tlv_len);
                return 1;
        }

        ops = tlv_table[context][tlv_type];
        if (ops && ops->unpack) {
                if (unpacked_known_tlvs)
                        *unpacked_known_tlvs = true;
                return ops->unpack(context, tlv_type, tlv_len, stream, log,
                                   dest, indent + 2);
        }

        return unpack_tlv_unknown(context, tlv_type, tlv_len, stream, log,
                                  indent + 2);
}

static int unpack_tlvs(enum isis_tlv_context context, size_t avail_len,
                       struct stream *stream, struct sbuf *log, void *dest,
                       int indent, bool *unpacked_known_tlvs)
{
        int rv;
        size_t tlv_start, tlv_pos;

        tlv_start = stream_get_getp(stream);
        tlv_pos = 0;

        sbuf_push(log, indent, "Unpacking %zu bytes of %s...\n", avail_len,
                  (context == ISIS_CONTEXT_LSP) ? "TLVs" : "sub-TLVs");

        while (tlv_pos < avail_len) {
                rv = unpack_tlv(context, avail_len - tlv_pos, stream, log, dest,
                                indent + 2, unpacked_known_tlvs);
                if (rv)
                        return rv;

                tlv_pos = stream_get_getp(stream) - tlv_start;
        }

        return 0;
}

int isis_unpack_tlvs(size_t avail_len, struct stream *stream,
                     struct isis_tlvs **dest, const char **log)
{
        static struct sbuf logbuf;
        int indent = 0;
        int rv;
        struct isis_tlvs *result;

        if (!sbuf_buf(&logbuf))
                sbuf_init(&logbuf, NULL, 0);

        sbuf_reset(&logbuf);
        if (avail_len > STREAM_READABLE(stream)) {
                sbuf_push(&logbuf, indent,
                          "Stream doesn't contain sufficient data. "
                          "Claimed %zu, available %zu\n",
                          avail_len, STREAM_READABLE(stream));
                return 1;
        }

        result = isis_alloc_tlvs();
        rv = unpack_tlvs(ISIS_CONTEXT_LSP, avail_len, stream, &logbuf, result,
                         indent, NULL);

        *log = sbuf_buf(&logbuf);
        *dest = result;

        return rv;
}

#define TLV_OPS(_name_, _desc_)                                                \
        static const struct tlv_ops tlv_##_name_##_ops = {                     \
                .name = _desc_, .unpack = unpack_tlv_##_name_,                 \
        }

#define ITEM_TLV_OPS(_name_, _desc_)                                           \
        static const struct tlv_ops tlv_##_name_##_ops = {                     \
                .name = _desc_,                                                \
                .unpack = unpack_tlv_with_items,                               \
                                                                               \
                .pack_item = pack_item_##_name_,                               \
                .free_item = free_item_##_name_,                               \
                .unpack_item = unpack_item_##_name_,                           \
                .format_item = format_item_##_name_,                           \
                .copy_item = copy_item_##_name_}

#define SUBTLV_OPS(_name_, _desc_)                                             \
        static const struct tlv_ops subtlv_##_name_##_ops = {                  \
                .name = _desc_, .unpack = unpack_subtlv_##_name_,              \
        }

#define ITEM_SUBTLV_OPS(_name_, _desc_) \
        ITEM_TLV_OPS(_name_, _desc_)

ITEM_TLV_OPS(area_address, "TLV 1 Area Addresses");
ITEM_TLV_OPS(oldstyle_reach, "TLV 2 IS Reachability");
ITEM_TLV_OPS(lan_neighbor, "TLV 6 LAN Neighbors");
ITEM_TLV_OPS(lsp_entry, "TLV 9 LSP Entries");
ITEM_TLV_OPS(auth, "TLV 10 IS-IS Auth");
TLV_OPS(purge_originator, "TLV 13 Purge Originator Identification");
ITEM_TLV_OPS(extended_reach, "TLV 22 Extended Reachability");
ITEM_TLV_OPS(oldstyle_ip_reach, "TLV 128/130 IP Reachability");
TLV_OPS(protocols_supported, "TLV 129 Protocols Supported");
ITEM_TLV_OPS(ipv4_address, "TLV 132 IPv4 Interface Address");
TLV_OPS(te_router_id, "TLV 134 TE Router ID");
ITEM_TLV_OPS(extended_ip_reach, "TLV 135 Extended IP Reachability");
TLV_OPS(dynamic_hostname, "TLV 137 Dynamic Hostname");
TLV_OPS(spine_leaf, "TLV 150 Spine Leaf Extensions");
ITEM_TLV_OPS(mt_router_info, "TLV 229 MT Router Information");
TLV_OPS(threeway_adj, "TLV 240 P2P Three-Way Adjacency");
ITEM_TLV_OPS(ipv6_address, "TLV 232 IPv6 Interface Address");
ITEM_TLV_OPS(ipv6_reach, "TLV 236 IPv6 Reachability");

ITEM_SUBTLV_OPS(prefix_sid, "Sub-TLV 3 SR Prefix-SID");
SUBTLV_OPS(ipv6_source_prefix, "Sub-TLV 22 IPv6 Source Prefix");

static const struct tlv_ops *tlv_table[ISIS_CONTEXT_MAX][ISIS_TLV_MAX] = {
        [ISIS_CONTEXT_LSP] = {
                [ISIS_TLV_AREA_ADDRESSES] = &tlv_area_address_ops,
                [ISIS_TLV_OLDSTYLE_REACH] = &tlv_oldstyle_reach_ops,
                [ISIS_TLV_LAN_NEIGHBORS] = &tlv_lan_neighbor_ops,
                [ISIS_TLV_LSP_ENTRY] = &tlv_lsp_entry_ops,
                [ISIS_TLV_AUTH] = &tlv_auth_ops,
                [ISIS_TLV_PURGE_ORIGINATOR] = &tlv_purge_originator_ops,
                [ISIS_TLV_EXTENDED_REACH] = &tlv_extended_reach_ops,
                [ISIS_TLV_MT_REACH] = &tlv_extended_reach_ops,
                [ISIS_TLV_OLDSTYLE_IP_REACH] = &tlv_oldstyle_ip_reach_ops,
                [ISIS_TLV_PROTOCOLS_SUPPORTED] = &tlv_protocols_supported_ops,
                [ISIS_TLV_OLDSTYLE_IP_REACH_EXT] = &tlv_oldstyle_ip_reach_ops,
                [ISIS_TLV_IPV4_ADDRESS] = &tlv_ipv4_address_ops,
                [ISIS_TLV_TE_ROUTER_ID] = &tlv_te_router_id_ops,
                [ISIS_TLV_EXTENDED_IP_REACH] = &tlv_extended_ip_reach_ops,
                [ISIS_TLV_MT_IP_REACH] = &tlv_extended_ip_reach_ops,
                [ISIS_TLV_DYNAMIC_HOSTNAME] = &tlv_dynamic_hostname_ops,
                [ISIS_TLV_SPINE_LEAF_EXT] = &tlv_spine_leaf_ops,
                [ISIS_TLV_MT_ROUTER_INFO] = &tlv_mt_router_info_ops,
                [ISIS_TLV_THREE_WAY_ADJ] = &tlv_threeway_adj_ops,
                [ISIS_TLV_IPV6_ADDRESS] = &tlv_ipv6_address_ops,
                [ISIS_TLV_IPV6_REACH] = &tlv_ipv6_reach_ops,
                [ISIS_TLV_MT_IPV6_REACH] = &tlv_ipv6_reach_ops,
        },
        [ISIS_CONTEXT_SUBTLV_NE_REACH] = {},
        [ISIS_CONTEXT_SUBTLV_IP_REACH] = {
                [ISIS_SUBTLV_PREFIX_SID] = &tlv_prefix_sid_ops,
        },
        [ISIS_CONTEXT_SUBTLV_IPV6_REACH] = {
                [ISIS_SUBTLV_PREFIX_SID] = &tlv_prefix_sid_ops,
                [ISIS_SUBTLV_IPV6_SOURCE_PREFIX] = &subtlv_ipv6_source_prefix_ops,
        }
};

/* Accessor functions */

void isis_tlvs_add_auth(struct isis_tlvs *tlvs, struct isis_passwd *passwd)
{
        free_items(ISIS_CONTEXT_LSP, ISIS_TLV_AUTH, &tlvs->isis_auth);
        init_item_list(&tlvs->isis_auth);

        if (passwd->type == ISIS_PASSWD_TYPE_UNUSED)
                return;

        struct isis_auth *auth = XCALLOC(MTYPE_ISIS_TLV, sizeof(*auth));

        auth->type = passwd->type;

        auth->plength = passwd->len;
        memcpy(auth->passwd, passwd->passwd,
               MIN(sizeof(auth->passwd), sizeof(passwd->passwd)));

        if (auth->type == ISIS_PASSWD_TYPE_CLEARTXT) {
                auth->length = passwd->len;
                memcpy(auth->value, passwd->passwd,
                       MIN(sizeof(auth->value), sizeof(passwd->passwd)));
        }

        append_item(&tlvs->isis_auth, (struct isis_item *)auth);
}

void isis_tlvs_add_area_addresses(struct isis_tlvs *tlvs,
                                  struct list *addresses)
{
        struct listnode *node;
        struct area_addr *area_addr;

        for (ALL_LIST_ELEMENTS_RO(addresses, node, area_addr)) {
                struct isis_area_address *a =
                        XCALLOC(MTYPE_ISIS_TLV, sizeof(*a));

                a->len = area_addr->addr_len;
                memcpy(a->addr, area_addr->area_addr, 20);
                append_item(&tlvs->area_addresses, (struct isis_item *)a);
        }
}

void isis_tlvs_add_lan_neighbors(struct isis_tlvs *tlvs, struct list *neighbors)
{
        struct listnode *node;
        uint8_t *snpa;

        for (ALL_LIST_ELEMENTS_RO(neighbors, node, snpa)) {
                struct isis_lan_neighbor *n =
                        XCALLOC(MTYPE_ISIS_TLV, sizeof(*n));

                memcpy(n->mac, snpa, 6);
                append_item(&tlvs->lan_neighbor, (struct isis_item *)n);
        }
}

void isis_tlvs_set_protocols_supported(struct isis_tlvs *tlvs,
                                       struct nlpids *nlpids)
{
        tlvs->protocols_supported.count = nlpids->count;
        XFREE(MTYPE_ISIS_TLV, tlvs->protocols_supported.protocols);
        if (nlpids->count) {
                tlvs->protocols_supported.protocols =
                        XCALLOC(MTYPE_ISIS_TLV, nlpids->count);
                memcpy(tlvs->protocols_supported.protocols, nlpids->nlpids,
                       nlpids->count);
        } else {
                tlvs->protocols_supported.protocols = NULL;
        }
}

void isis_tlvs_add_mt_router_info(struct isis_tlvs *tlvs, uint16_t mtid,
                                  bool overload, bool attached)
{
        struct isis_mt_router_info *i = XCALLOC(MTYPE_ISIS_TLV, sizeof(*i));

        i->overload = overload;
        i->attached = attached;
        i->mtid = mtid;
        append_item(&tlvs->mt_router_info, (struct isis_item *)i);
}

void isis_tlvs_add_ipv4_address(struct isis_tlvs *tlvs, struct in_addr *addr)
{
        struct isis_ipv4_address *a = XCALLOC(MTYPE_ISIS_TLV, sizeof(*a));
        a->addr = *addr;
        append_item(&tlvs->ipv4_address, (struct isis_item *)a);
}


void isis_tlvs_add_ipv4_addresses(struct isis_tlvs *tlvs,
                                  struct list *addresses)
{
        struct listnode *node;
        struct prefix_ipv4 *ip_addr;
        unsigned int addr_count = 0;

        for (ALL_LIST_ELEMENTS_RO(addresses, node, ip_addr)) {
                isis_tlvs_add_ipv4_address(tlvs, &ip_addr->prefix);
                addr_count++;
                if (addr_count >= 63)
                        break;
        }
}

void isis_tlvs_add_ipv6_addresses(struct isis_tlvs *tlvs,
                                  struct list *addresses)
{
        struct listnode *node;
        struct prefix_ipv6 *ip_addr;
        unsigned int addr_count = 0;

        for (ALL_LIST_ELEMENTS_RO(addresses, node, ip_addr)) {
                if (addr_count >= 15)
                        break;

                struct isis_ipv6_address *a =
                        XCALLOC(MTYPE_ISIS_TLV, sizeof(*a));

                a->addr = ip_addr->prefix;
                append_item(&tlvs->ipv6_address, (struct isis_item *)a);
                addr_count++;
        }
}

typedef bool (*auth_validator_func)(struct isis_passwd *passwd,
                                    struct stream *stream,
                                    struct isis_auth *auth, bool is_lsp);

static bool auth_validator_cleartxt(struct isis_passwd *passwd,
                                    struct stream *stream,
                                    struct isis_auth *auth, bool is_lsp)
{
        return (auth->length == passwd->len
                && !memcmp(auth->value, passwd->passwd, passwd->len));
}

static bool auth_validator_hmac_md5(struct isis_passwd *passwd,
                                    struct stream *stream,
                                    struct isis_auth *auth, bool is_lsp)
{
        uint8_t digest[16];
        uint16_t checksum;
        uint16_t rem_lifetime;

        if (is_lsp)
                safe_auth_md5(stream, &checksum, &rem_lifetime);

        memset(STREAM_DATA(stream) + auth->offset, 0, 16);
        hmac_md5(STREAM_DATA(stream), stream_get_endp(stream), passwd->passwd,
                 passwd->len, digest);
        memcpy(STREAM_DATA(stream) + auth->offset, auth->value, 16);

        bool rv = !memcmp(digest, auth->value, 16);

        if (is_lsp)
                restore_auth_md5(stream, checksum, rem_lifetime);

        return rv;
}

static const auth_validator_func auth_validators[] = {
                [ISIS_PASSWD_TYPE_CLEARTXT] = auth_validator_cleartxt,
                [ISIS_PASSWD_TYPE_HMAC_MD5] = auth_validator_hmac_md5,
};

int isis_tlvs_auth_is_valid(struct isis_tlvs *tlvs, struct isis_passwd *passwd,
                            struct stream *stream, bool is_lsp)
{
        /* If no auth is set, always pass authentication */
        if (!passwd->type)
                return ISIS_AUTH_OK;

        /* If we don't known how to validate the auth, return invalid */
        if (passwd->type >= array_size(auth_validators)
            || !auth_validators[passwd->type])
                return ISIS_AUTH_NO_VALIDATOR;

        struct isis_auth *auth_head = (struct isis_auth *)tlvs->isis_auth.head;
        struct isis_auth *auth;
        for (auth = auth_head; auth; auth = auth->next) {
                if (auth->type == passwd->type)
                        break;
        }

        /* If matching auth TLV could not be found, return invalid */
        if (!auth)
                return ISIS_AUTH_TYPE_FAILURE;


        /* Perform validation and return result */
        if (auth_validators[passwd->type](passwd, stream, auth, is_lsp))
                return ISIS_AUTH_OK;
        else
                return ISIS_AUTH_FAILURE;
}

bool isis_tlvs_area_addresses_match(struct isis_tlvs *tlvs,
                                    struct list *addresses)
{
        struct isis_area_address *addr_head;

        addr_head = (struct isis_area_address *)tlvs->area_addresses.head;
        for (struct isis_area_address *addr = addr_head; addr;
             addr = addr->next) {
                struct listnode *node;
                struct area_addr *a;

                for (ALL_LIST_ELEMENTS_RO(addresses, node, a)) {
                        if (a->addr_len == addr->len
                            && !memcmp(a->area_addr, addr->addr, addr->len))
                                return true;
                }
        }

        return false;
}

static void tlvs_area_addresses_to_adj(struct isis_tlvs *tlvs,
                                       struct isis_adjacency *adj,
                                       bool *changed)
{
        if (adj->area_address_count != tlvs->area_addresses.count) {
                *changed = true;
                adj->area_address_count = tlvs->area_addresses.count;
                adj->area_addresses = XREALLOC(
                        MTYPE_ISIS_ADJACENCY_INFO, adj->area_addresses,
                        adj->area_address_count * sizeof(*adj->area_addresses));
        }

        struct isis_area_address *addr = NULL;
        for (unsigned int i = 0; i < tlvs->area_addresses.count; i++) {
                if (!addr)
                        addr = (struct isis_area_address *)
                                       tlvs->area_addresses.head;
                else
                        addr = addr->next;

                if (adj->area_addresses[i].addr_len == addr->len
                    && !memcmp(adj->area_addresses[i].area_addr, addr->addr,
                               addr->len)) {
                        continue;
                }

                *changed = true;
                adj->area_addresses[i].addr_len = addr->len;
                memcpy(adj->area_addresses[i].area_addr, addr->addr, addr->len);
        }
}

static void tlvs_protocols_supported_to_adj(struct isis_tlvs *tlvs,
                                            struct isis_adjacency *adj,
                                            bool *changed)
{
        bool ipv4_supported = false, ipv6_supported = false;

        for (uint8_t i = 0; i < tlvs->protocols_supported.count; i++) {
                if (tlvs->protocols_supported.protocols[i] == NLPID_IP)
                        ipv4_supported = true;
                if (tlvs->protocols_supported.protocols[i] == NLPID_IPV6)
                        ipv6_supported = true;
        }

        struct nlpids reduced = {};

        if (ipv4_supported && ipv6_supported) {
                reduced.count = 2;
                reduced.nlpids[0] = NLPID_IP;
                reduced.nlpids[1] = NLPID_IPV6;
        } else if (ipv4_supported) {
                reduced.count = 1;
                reduced.nlpids[0] = NLPID_IP;
        } else if (ipv6_supported) {
                reduced.count = 1;
                reduced.nlpids[0] = NLPID_IPV6;
        } else {
                reduced.count = 0;
        }

        if (adj->nlpids.count == reduced.count
            && !memcmp(adj->nlpids.nlpids, reduced.nlpids, reduced.count))
                return;

        *changed = true;
        adj->nlpids.count = reduced.count;
        memcpy(adj->nlpids.nlpids, reduced.nlpids, reduced.count);
}

static void tlvs_ipv4_addresses_to_adj(struct isis_tlvs *tlvs,
                                       struct isis_adjacency *adj,
                                       bool *changed)
{
        if (adj->ipv4_address_count != tlvs->ipv4_address.count) {
                *changed = true;
                adj->ipv4_address_count = tlvs->ipv4_address.count;
                adj->ipv4_addresses = XREALLOC(
                        MTYPE_ISIS_ADJACENCY_INFO, adj->ipv4_addresses,
                        adj->ipv4_address_count * sizeof(*adj->ipv4_addresses));
        }

        struct isis_ipv4_address *addr = NULL;
        for (unsigned int i = 0; i < tlvs->ipv4_address.count; i++) {
                if (!addr)
                        addr = (struct isis_ipv4_address *)
                                       tlvs->ipv4_address.head;
                else
                        addr = addr->next;

                if (!memcmp(&adj->ipv4_addresses[i], &addr->addr,
                            sizeof(addr->addr)))
                        continue;

                *changed = true;
                adj->ipv4_addresses[i] = addr->addr;
        }
}

static void tlvs_ipv6_addresses_to_adj(struct isis_tlvs *tlvs,
                                       struct isis_adjacency *adj,
                                       bool *changed)
{
        if (adj->ipv6_address_count != tlvs->ipv6_address.count) {
                *changed = true;
                adj->ipv6_address_count = tlvs->ipv6_address.count;
                adj->ipv6_addresses = XREALLOC(
                        MTYPE_ISIS_ADJACENCY_INFO, adj->ipv6_addresses,
                        adj->ipv6_address_count * sizeof(*adj->ipv6_addresses));
        }

        struct isis_ipv6_address *addr = NULL;
        for (unsigned int i = 0; i < tlvs->ipv6_address.count; i++) {
                if (!addr)
                        addr = (struct isis_ipv6_address *)
                                       tlvs->ipv6_address.head;
                else
                        addr = addr->next;

                if (!memcmp(&adj->ipv6_addresses[i], &addr->addr,
                            sizeof(addr->addr)))
                        continue;

                *changed = true;
                adj->ipv6_addresses[i] = addr->addr;
        }
}

void isis_tlvs_to_adj(struct isis_tlvs *tlvs, struct isis_adjacency *adj,
                      bool *changed)
{
        *changed = false;

        tlvs_area_addresses_to_adj(tlvs, adj, changed);
        tlvs_protocols_supported_to_adj(tlvs, adj, changed);
        tlvs_ipv4_addresses_to_adj(tlvs, adj, changed);
        tlvs_ipv6_addresses_to_adj(tlvs, adj, changed);
}

bool isis_tlvs_own_snpa_found(struct isis_tlvs *tlvs, uint8_t *snpa)
{
        struct isis_lan_neighbor *ne_head;

        ne_head = (struct isis_lan_neighbor *)tlvs->lan_neighbor.head;
        for (struct isis_lan_neighbor *ne = ne_head; ne; ne = ne->next) {
                if (!memcmp(ne->mac, snpa, ETH_ALEN))
                        return true;
        }

        return false;
}

void isis_tlvs_add_lsp_entry(struct isis_tlvs *tlvs, struct isis_lsp *lsp)
{
        struct isis_lsp_entry *entry = XCALLOC(MTYPE_ISIS_TLV, sizeof(*entry));

        entry->rem_lifetime = lsp->hdr.rem_lifetime;
        memcpy(entry->id, lsp->hdr.lsp_id, ISIS_SYS_ID_LEN + 2);
        entry->checksum = lsp->hdr.checksum;
        entry->seqno = lsp->hdr.seqno;
        entry->lsp = lsp;

        append_item(&tlvs->lsp_entries, (struct isis_item *)entry);
}

void isis_tlvs_add_csnp_entries(struct isis_tlvs *tlvs, uint8_t *start_id,
                                uint8_t *stop_id, uint16_t num_lsps,
                                struct lspdb_head *head,
                                struct isis_lsp **last_lsp)
{
        struct isis_lsp searchfor;
        struct isis_lsp *first, *lsp;

        memcpy(&searchfor.hdr.lsp_id, start_id, sizeof(searchfor.hdr.lsp_id));
        first = lspdb_find_gteq(head, &searchfor);
        if (!first)
                return;

        frr_each_from (lspdb, head, lsp, first) {
                if (memcmp(lsp->hdr.lsp_id, stop_id, sizeof(lsp->hdr.lsp_id))
                        > 0 || tlvs->lsp_entries.count == num_lsps)
                        break;

                isis_tlvs_add_lsp_entry(tlvs, lsp);
                *last_lsp = lsp;
        }
}

void isis_tlvs_set_dynamic_hostname(struct isis_tlvs *tlvs,
                                    const char *hostname)
{
        XFREE(MTYPE_ISIS_TLV, tlvs->hostname);
        if (hostname)
                tlvs->hostname = XSTRDUP(MTYPE_ISIS_TLV, hostname);
}

void isis_tlvs_set_te_router_id(struct isis_tlvs *tlvs,
                                const struct in_addr *id)
{
        XFREE(MTYPE_ISIS_TLV, tlvs->te_router_id);
        if (!id)
                return;
        tlvs->te_router_id = XCALLOC(MTYPE_ISIS_TLV, sizeof(*id));
        memcpy(tlvs->te_router_id, id, sizeof(*id));
}

void isis_tlvs_add_oldstyle_ip_reach(struct isis_tlvs *tlvs,
                                     struct prefix_ipv4 *dest, uint8_t metric)
{
        struct isis_oldstyle_ip_reach *r = XCALLOC(MTYPE_ISIS_TLV, sizeof(*r));

        r->metric = metric;
        memcpy(&r->prefix, dest, sizeof(*dest));
        apply_mask_ipv4(&r->prefix);
        append_item(&tlvs->oldstyle_ip_reach, (struct isis_item *)r);
}

void isis_tlvs_add_extended_ip_reach(struct isis_tlvs *tlvs,
                                     struct prefix_ipv4 *dest, uint32_t metric)
{
        struct isis_extended_ip_reach *r = XCALLOC(MTYPE_ISIS_TLV, sizeof(*r));

        r->metric = metric;
        memcpy(&r->prefix, dest, sizeof(*dest));
        apply_mask_ipv4(&r->prefix);
        append_item(&tlvs->extended_ip_reach, (struct isis_item *)r);
}

void isis_tlvs_add_ipv6_reach(struct isis_tlvs *tlvs, uint16_t mtid,
                              struct prefix_ipv6 *dest, uint32_t metric)
{
        struct isis_ipv6_reach *r = XCALLOC(MTYPE_ISIS_TLV, sizeof(*r));

        r->metric = metric;
        memcpy(&r->prefix, dest, sizeof(*dest));
        apply_mask_ipv6(&r->prefix);

        struct isis_item_list *l;
        l = (mtid == ISIS_MT_IPV4_UNICAST)
                    ? &tlvs->ipv6_reach
                    : isis_get_mt_items(&tlvs->mt_ipv6_reach, mtid);
        append_item(l, (struct isis_item *)r);
}

void isis_tlvs_add_ipv6_dstsrc_reach(struct isis_tlvs *tlvs, uint16_t mtid,
                                     struct prefix_ipv6 *dest,
                                     struct prefix_ipv6 *src,
                                     uint32_t metric)
{
        isis_tlvs_add_ipv6_reach(tlvs, mtid, dest, metric);
        struct isis_item_list *l = isis_get_mt_items(&tlvs->mt_ipv6_reach,
                                                     mtid);

        struct isis_ipv6_reach *r = (struct isis_ipv6_reach*)last_item(l);
        r->subtlvs = isis_alloc_subtlvs(ISIS_CONTEXT_SUBTLV_IPV6_REACH);
        r->subtlvs->source_prefix = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*src));
        memcpy(r->subtlvs->source_prefix, src, sizeof(*src));
}

void isis_tlvs_add_oldstyle_reach(struct isis_tlvs *tlvs, uint8_t *id,
                                  uint8_t metric)
{
        struct isis_oldstyle_reach *r = XCALLOC(MTYPE_ISIS_TLV, sizeof(*r));

        r->metric = metric;
        memcpy(r->id, id, sizeof(r->id));
        append_item(&tlvs->oldstyle_reach, (struct isis_item *)r);
}

void isis_tlvs_add_extended_reach(struct isis_tlvs *tlvs, uint16_t mtid,
                                  uint8_t *id, uint32_t metric,
                                  uint8_t *subtlvs, uint8_t subtlv_len)
{
        struct isis_extended_reach *r = XCALLOC(MTYPE_ISIS_TLV, sizeof(*r));

        memcpy(r->id, id, sizeof(r->id));
        r->metric = metric;
        if (subtlvs && subtlv_len) {
                r->subtlvs = XCALLOC(MTYPE_ISIS_TLV, subtlv_len);
                memcpy(r->subtlvs, subtlvs, subtlv_len);
                r->subtlv_len = subtlv_len;
        }

        struct isis_item_list *l;
        if (mtid == ISIS_MT_IPV4_UNICAST)
                l = &tlvs->extended_reach;
        else
                l = isis_get_mt_items(&tlvs->mt_reach, mtid);
        append_item(l, (struct isis_item *)r);
}

void isis_tlvs_add_threeway_adj(struct isis_tlvs *tlvs,
                                enum isis_threeway_state state,
                                uint32_t local_circuit_id,
                                const uint8_t *neighbor_id,
                                uint32_t neighbor_circuit_id)
{
        assert(!tlvs->threeway_adj);

        tlvs->threeway_adj = XCALLOC(MTYPE_ISIS_TLV, sizeof(*tlvs->threeway_adj));
        tlvs->threeway_adj->state = state;
        tlvs->threeway_adj->local_circuit_id = local_circuit_id;

        if (neighbor_id) {
                tlvs->threeway_adj->neighbor_set = true;
                memcpy(tlvs->threeway_adj->neighbor_id, neighbor_id, 6);
                tlvs->threeway_adj->neighbor_circuit_id = neighbor_circuit_id;
        }
}

void isis_tlvs_add_spine_leaf(struct isis_tlvs *tlvs, uint8_t tier,
                              bool has_tier, bool is_leaf, bool is_spine,
                              bool is_backup)
{
        assert(!tlvs->spine_leaf);

        tlvs->spine_leaf = XCALLOC(MTYPE_ISIS_TLV, sizeof(*tlvs->spine_leaf));

        if (has_tier) {
                tlvs->spine_leaf->tier = tier;
        }

        tlvs->spine_leaf->has_tier = has_tier;
        tlvs->spine_leaf->is_leaf = is_leaf;
        tlvs->spine_leaf->is_spine = is_spine;
        tlvs->spine_leaf->is_backup = is_backup;
}

struct isis_mt_router_info *
isis_tlvs_lookup_mt_router_info(struct isis_tlvs *tlvs, uint16_t mtid)
{
        if (tlvs->mt_router_info_empty)
                return NULL;

        struct isis_mt_router_info *rv;
        for (rv = (struct isis_mt_router_info *)tlvs->mt_router_info.head; rv;
             rv = rv->next) {
                if (rv->mtid == mtid)
                        return rv;
        }

        return NULL;
}

void isis_tlvs_set_purge_originator(struct isis_tlvs *tlvs,
                                    const uint8_t *generator,
                                    const uint8_t *sender)
{
        assert(!tlvs->purge_originator);

        tlvs->purge_originator = XCALLOC(MTYPE_ISIS_TLV,
                                         sizeof(*tlvs->purge_originator));
        memcpy(tlvs->purge_originator->generator, generator,
               sizeof(tlvs->purge_originator->generator));
        if (sender) {
                tlvs->purge_originator->sender_set = true;
                memcpy(tlvs->purge_originator->sender, sender,
                       sizeof(tlvs->purge_originator->sender));
        }
}