Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3459 insertions, 0 deletions

diff --git a/isisd/isis_snmp.c b/isisd/isis_snmp.c
new file mode 100644
index 0000000..f9e3780
--- /dev/null
+++ b/isisd/isis_snmp.c
@@ -0,0 +1,3459 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ISIS SNMP support
+ * Copyright (C) 2020 Volta Networks, Inc.
+ *                    Aleksey Romanov
+ */
+
+/*
+ * This is minimal read-only implementations providing isisReadOnlyCompliance
+ */
+
+#include <zebra.h>
+
+#include <net-snmp/net-snmp-config.h>
+#include <net-snmp/net-snmp-includes.h>
+
+#include "vrf.h"
+#include "if.h"
+#include "log.h"
+#include "prefix.h"
+#include "table.h"
+#include "command.h"
+#include "memory.h"
+#include "smux.h"
+#include "libfrr.h"
+#include "lib/version.h"
+#include "lib/zclient.h"
+
+#include "isisd/isis_constants.h"
+#include "isisd/isis_common.h"
+#include "isisd/isis_flags.h"
+#include "isisd/isis_circuit.h"
+#include "isisd/isis_lsp.h"
+#include "isisd/isis_pdu.h"
+#include "isisd/isis_network.h"
+#include "isisd/isis_misc.h"
+#include "isisd/isis_constants.h"
+#include "isisd/isis_adjacency.h"
+#include "isisd/isis_dynhn.h"
+#include "isisd/isis_te.h"
+#include "isisd/isis_dr.h"
+#include "isisd/isis_nb.h"
+#include "isisd/isisd.h"
+
+/* ISIS-MIB. */
+#define ISIS_MIB 1, 3, 6, 1, 2, 1, 138
+
+#define ISIS_OBJECTS 1
+#define ISIS_SYSTEM 1, 1
+#define ISIS_SYSLEVEL 1, 2
+#define ISIS_CIRC 1, 3
+#define ISIS_CIRC_LEVEL_VALUES 1, 4
+#define ISIS_COUNTERS 1, 5
+#define ISIS_ISADJ 1, 6
+
+/************************ isisSystemGroup ************************/
+
+/* isisSysObject  */
+#define ISIS_SYS_OBJECT 1, 1, 1
+#define ISIS_SYS_VERSION 1
+#define ISIS_SYS_LEVELTYPE 2
+#define ISIS_SYS_ID 3
+#define ISIS_SYS_MAXPATHSPLITS 4
+#define ISIS_SYS_MAXLSPGENINT 5
+#define ISIS_SYS_POLLESHELLORATE 6
+#define ISIS_SYS_WAITTIME 7
+#define ISIS_SYS_ADMINSTATE 8
+#define ISIS_SYS_L2TOL1LEAKING 9
+#define ISIS_SYS_MAXAGE 10
+#define ISIS_SYS_RECEIVELSPBUFFERSIZE 11
+#define ISIS_SYS_PROTSUPPORTED 12
+#define ISIS_SYS_NOTIFICATIONENABLE 13
+
+/* isisManAreaAddrEntry */
+#define ISIS_MANAREA_ADDRENTRY 1, 1, 2, 1
+#define ISIS_MANAREA_ADDREXISTSTATE 2
+
+/* isisAreaAddrEntry */
+#define ISIS_AREA_ADDRENTRY 1, 1, 3, 1
+#define ISIS_AREA_ADDR 1
+
+/* isisSummAddrEntry */
+#define ISIS_SUMM_ADDRENTRY 1, 1, 4, 1
+#define ISIS_SUMM_ADDREXISTSTATE 4
+#define ISIS_SUMM_ADDRMETRIC 5
+#define ISIS_SUMM_ADDRFULLMETRIC 6
+
+/* isisRedistributeAddrEntry */
+#define ISIS_REDISTRIBUTE_ADDRENTRY 1, 1, 5, 1
+#define ISIS_REDISTRIBUTE_ADDREXISTSTATE 3
+
+/* isisRouterEntry */
+#define ISIS_ROUTER_ENTRY 1, 1, 6, 1
+#define ISIS_ROUTER_HOSTNAME 3
+#define ISIS_ROUTER_ID 4
+
+/* isisSysLevelTable */
+#define ISIS_SYSLEVEL_ENTRY 1, 2, 1, 1
+#define ISIS_SYSLEVEL_ORIGLSPBUFFSIZE 2
+#define ISIS_SYSLEVEL_MINLSPGENINT 3
+#define ISIS_SYSLEVEL_STATE 4
+#define ISIS_SYSLEVEL_SETOVERLOAD 5
+#define ISIS_SYSLEVEL_SETOVERLOADUNTIL 6
+#define ISIS_SYSLEVEL_METRICSTYLE 7
+#define ISIS_SYSLEVEL_SPFCONSIDERS 8
+#define ISIS_SYSLEVEL_TEENABLED 9
+
+
+/* isisSystemCounterEntry */
+#define ISIS_SYSTEM_COUNTER_ENTRY 1, 5, 1, 1
+#define ISIS_SYSSTAT_CORRLSPS 2
+#define ISIS_SYSSTAT_AUTHTYPEFAILS 3
+#define ISIS_SYSSTAT_AUTHFAILS 4
+#define ISIS_SYSSTAT_LSPDBASEOLOADS 5
+#define ISIS_SYSSTAT_MANADDRDROPFROMAREAS 6
+#define ISIS_SYSSTAT_ATTMPTTOEXMAXSEQNUMS 7
+#define ISIS_SYSSTAT_SEQNUMSKIPS 8
+#define ISIS_SYSSTAT_OWNLSPPURGES 9
+#define ISIS_SYSSTAT_IDFIELDLENMISMATCHES 10
+#define ISIS_SYSSTAT_PARTCHANGES 11
+#define ISIS_SYSSTAT_SPFRUNS 12
+#define ISIS_SYSSTAT_LSPERRORS 13
+
+
+/************************ isisCircuitGroup ************************/
+
+/* Scalar directly under isisCirc */
+#define ISIS_NEXTCIRC_INDEX 1
+
+/* isisCircEntry */
+#define ISIS_CIRC_ENTRY 1, 3, 2, 1
+#define ISIS_CIRC_IFINDEX 2
+#define ISIS_CIRC_ADMINSTATE 3
+#define ISIS_CIRC_EXISTSTATE 4
+#define ISIS_CIRC_TYPE 5
+#define ISIS_CIRC_EXTDOMAIN 6
+#define ISIS_CIRC_LEVELTYPE 7
+#define ISIS_CIRC_PASSIVECIRCUIT 8
+#define ISIS_CIRC_MESHGROUPENABLED 9
+#define ISIS_CIRC_MESHGROUP 10
+#define ISIS_CIRC_SMALLHELLOS 11
+#define ISIS_CIRC_LASTUPTIME 12
+#define ISIS_CIRC_3WAYENABLED 13
+#define ISIS_CIRC_EXTENDEDCIRCID 14
+
+/* isisCircLevelEntry */
+#define ISIS_CIRCLEVEL_ENTRY 1, 4, 1, 1
+#define ISIS_CIRCLEVEL_METRIC 2
+#define ISIS_CIRCLEVEL_WIDEMETRIC 3
+#define ISIS_CIRCLEVEL_ISPRIORITY 4
+#define ISIS_CIRCLEVEL_IDOCTET 5
+#define ISIS_CIRCLEVEL_ID 6
+#define ISIS_CIRCLEVEL_DESIS 7
+#define ISIS_CIRCLEVEL_HELLOMULTIPLIER 8
+#define ISIS_CIRCLEVEL_HELLOTIMER 9
+#define ISIS_CIRCLEVEL_DRHELLOTIMER 10
+#define ISIS_CIRCLEVEL_LSPTHROTTLE 11
+#define ISIS_CIRCLEVEL_MINLSPRETRANSINT 12
+#define ISIS_CIRCLEVEL_CSNPINTERVAL 13
+#define ISIS_CIRCLEVEL_PARTSNPINTERVAL 14
+
+/* isisCircuitCounterEntry */
+#define ISIS_CIRC_COUNTER_ENTRY 1, 5, 2, 1
+#define ISIS_CIRC_ADJCHANGES 2
+#define ISIS_CIRC_NUMADJ 3
+#define ISIS_CIRC_INITFAILS 4
+#define ISIS_CIRC_REJADJS 5
+#define ISIS_CIRC_IDFIELDLENMISMATCHES 6
+#define ISIS_CIRC_MAXAREAADDRMISMATCHES 7
+#define ISIS_CIRC_AUTHTYPEFAILS 8
+#define ISIS_CIRC_AUTHFAILS 9
+#define ISIS_CIRC_LANDESISCHANGES 10
+
+
+/************************ isisISAdjGroup ************************/
+
+/* isisISAdjEntry */
+#define ISIS_ISADJ_ENTRY 1, 6, 1, 1
+#define ISIS_ISADJ_STATE 2
+#define ISIS_ISADJ_3WAYSTATE 3
+#define ISIS_ISADJ_NEIGHSNPAADDRESS 4
+#define ISIS_ISADJ_NEIGHSYSTYPE 5
+#define ISIS_ISADJ_NEIGHSYSID 6
+#define ISIS_ISADJ_NBREXTENDEDCIRCID 7
+#define ISIS_ISADJ_USAGE 8
+#define ISIS_ISADJ_HOLDTIMER 9
+#define ISIS_ISADJ_NEIGHPRIORITY 10
+#define ISIS_ISADJ_LASTUPTIME 11
+
+/* isisISAdjAreadAddrEntry */
+#define ISIS_ISADJAREA_ADDRENTRY 1, 6, 2, 1
+#define ISIS_ISADJAREA_ADDRESS 2
+
+/* isisISAdjIPAddrEntry*/
+#define ISIS_ISADJIPADDR_ENTRY 1, 6, 3, 1
+#define ISIS_ISADJIPADDR_TYPE 2
+#define ISIS_ISADJIPADDR_ADDRESS 3
+
+
+/* isisISAdjProtSuppEntty */
+
+#define ISIS_ISADJPROTSUPP_ENTRY 1, 6, 4, 1
+#define ISIS_ISADJPROTSUPP_PROTOCOL 1
+
+
+/************************ Trap data variables ************************/
+#define ISIS_NOTIFICATION_ENTRY 1, 10, 1
+#define ISIS_NOTIF_SYLELVELINDEX 1
+#define ISIS_NOTIF_CIRCIFINDEX 2
+#define ISIS_PDU_LSPID 3
+#define ISIS_PDU_FRAGMENT 4
+#define ISIS_PDU_FIELDLEN 5
+#define ISIS_PDU_MAXAREAADDR 6
+#define ISIS_PDU_PROTOVER 7
+#define ISIS_PDU_LSPSIZE 8
+#define ISIS_PDU_ORIGBUFFERSIZE 9
+#define ISIS_PDU_BUFFERSIZE 10
+#define ISIS_PDU_PROTSUPP 11
+#define ISIS_ADJ_STATE 12
+#define ISIS_ERROR_OFFSET 13
+#define ISIS_ERROR_TLVTYPE 14
+#define ISIS_NOTIF_AREAADDR 15
+
+/************************ Traps ************************/
+#define ISIS_NOTIFICATIONS ISIS_MIB, 0
+#define ISIS_TRAP_DB_OVERLOAD 1
+#define ISIS_TRAP_MAN_ADDR_DROP 2
+#define ISIS_TRAP_CORRUPTED_LSP 3
+#define ISIS_TRAP_LSP_EXCEED_MAX 4
+#define ISIS_TRAP_ID_LEN_MISMATCH 5
+#define ISIS_TRAP_MAX_AREA_ADDR_MISMATCH 6
+#define ISIS_TRAP_OWN_LSP_PURGE 7
+#define ISIS_TRAP_SEQNO_SKIPPED 8
+#define ISIS_TRAP_AUTHEN_TYPE_FAILURE 9
+#define ISIS_TRAP_AUTHEN_FAILURE 10
+#define ISIS_TRAP_VERSION_SKEW 11
+#define ISIS_TRAP_AREA_MISMATCH 12
+#define ISIS_TRAP_REJ_ADJACENCY 13
+#define ISIS_TRAP_LSP_TOO_LARGE 14
+#define ISIS_TRAP_LSP_BUFFSIZE_MISMATCH 15
+#define ISIS_TRAP_PROTSUPP_MISMATCH 16
+#define ISIS_TRAP_ADJ_STATE_CHANGE 17
+#define ISIS_TRAP_LSP_ERROR 18
+
+/* Change this definition if number of traps changes */
+#define ISIS_TRAP_LAST_TRAP ISIS_TRAP_LSP_ERROR + 1
+
+#define ISIS_SNMP_TRAP_VAR 1, 3, 6, 1, 6, 3, 1, 1, 4, 1, 0
+
+
+/* SNMP value hack. */
+#define COUNTER32 ASN_COUNTER
+#define INTEGER ASN_INTEGER
+#define UNSIGNED32 ASN_GAUGE
+#define TIMESTAMP ASN_TIMETICKS
+#define TIMETICKS ASN_TIMETICKS
+#define STRING ASN_OCTET_STR
+
+/* Declare static local variables for convenience. */
+SNMP_LOCAL_VARIABLES
+
+/*
+ * Define time function, it serves two purposes
+ * 1. Uses unint32_t for unix time and encapsulates
+ *    sing extension issues in conversion from time_t
+ *
+ * 2. I could be replaced in unit test environment
+ */
+
+/* ISIS-MIB instances. */
+static oid isis_oid[] = {ISIS_MIB};
+
+/* SNMP trap variable */
+static oid isis_snmp_trap_var[] = {ISIS_SNMP_TRAP_VAR};
+
+/* SNMP trap values (others are calculated on the fly */
+static oid isis_snmp_notifications[] = {ISIS_NOTIFICATIONS};
+static oid isis_snmp_trap_val_db_overload[] = {ISIS_NOTIFICATIONS,
+					       ISIS_TRAP_DB_OVERLOAD};
+static oid isis_snmp_trap_val_lsp_exceed_max[] = {ISIS_NOTIFICATIONS,
+						  ISIS_TRAP_LSP_EXCEED_MAX};
+static oid isis_snmp_trap_val_area_mismatch[] = {ISIS_NOTIFICATIONS,
+						 ISIS_TRAP_AREA_MISMATCH};
+static oid isis_snmp_trap_val_lsp_error[] = {ISIS_NOTIFICATIONS,
+					     ISIS_TRAP_LSP_ERROR};
+
+/*
+ * Trap vars under 'isisNotifications': note: we use full names of variables
+ * scalar index
+ */
+static oid isis_snmp_trap_data_var_sys_level_index[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_NOTIF_SYLELVELINDEX, 0};
+static oid isis_snmp_trap_data_var_circ_if_index[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_NOTIF_CIRCIFINDEX, 0};
+static oid isis_snmp_trap_data_var_pdu_lsp_id[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_PDU_LSPID, 0};
+static oid isis_snmp_trap_data_var_pdu_fragment[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_PDU_FRAGMENT, 0};
+static oid isis_snmp_trap_data_var_pdu_field_len[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_PDU_FIELDLEN, 0};
+static oid isis_snmp_trap_data_var_pdu_max_area_addr[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_PDU_MAXAREAADDR, 0};
+static oid isis_snmp_trap_data_var_pdu_proto_ver[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_PDU_PROTOVER, 0};
+static oid isis_snmp_trap_data_var_pdu_lsp_size[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_PDU_LSPSIZE, 0};
+static oid isis_snmp_trap_data_var_adj_state[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_ADJ_STATE, 0};
+static oid isis_snmp_trap_data_var_error_offset[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_ERROR_OFFSET, 0};
+static oid isis_snmp_trap_data_var_error_tlv_type[] = {
+	ISIS_MIB, ISIS_NOTIFICATION_ENTRY, ISIS_ERROR_TLVTYPE, 0};
+
+/*
+ * Other variables used by traps: note we use full names of variables and
+ * reserve space for index
+ */
+static oid isis_snmp_trap_data_var_sys_level_state[] = {
+	ISIS_MIB, ISIS_SYSLEVEL_ENTRY, ISIS_SYSLEVEL_STATE, 0};
+
+/* Throttle time values for traps */
+static time_t isis_snmp_trap_timestamp[ISIS_TRAP_LAST_TRAP]; /* ?? 1 */
+
+/* Max len of raw-pdu in traps */
+#define ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN (64)
+
+/*
+ * Just to save on typing we have a shortcut structure
+ * to specify mib layout as prefix/leaf combination
+ */
+#define ISIS_SNMP_PREF_LEN_MAX 10
+struct isis_var_prefix {
+	FindVarMethod *findVar;
+	uint8_t ivd_pref_len;
+	oid ivd_pref[ISIS_SNMP_PREF_LEN_MAX];
+};
+
+
+/* Find-val functions */
+static uint8_t *isis_snmp_find_sys_object(struct variable *, oid *, size_t *,
+					  int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_man_area(struct variable *, oid *, size_t *, int,
+					size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_area_addr(struct variable *, oid *, size_t *,
+					 int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_summ_addr(struct variable *, oid *, size_t *,
+					 int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_redistribute_addr(struct variable *, oid *,
+						 size_t *, int, size_t *,
+						 WriteMethod **);
+
+static uint8_t *isis_snmp_find_router(struct variable *, oid *, size_t *, int,
+				      size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_sys_level(struct variable *, oid *, size_t *,
+					 int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_system_counter(struct variable *, oid *,
+					      size_t *, int, size_t *,
+					      WriteMethod **);
+
+static uint8_t *isis_snmp_find_next_circ_index(struct variable *, oid *,
+					       size_t *, int, size_t *,
+					       WriteMethod **);
+
+static uint8_t *isis_snmp_find_circ(struct variable *, oid *, size_t *, int,
+				    size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_circ_level(struct variable *, oid *, size_t *,
+					  int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_circ_counter(struct variable *, oid *, size_t *,
+					    int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_isadj(struct variable *, oid *, size_t *, int,
+				     size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_isadj_area(struct variable *, oid *, size_t *,
+					  int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_isadj_ipaddr(struct variable *, oid *, size_t *,
+					    int, size_t *, WriteMethod **);
+
+static uint8_t *isis_snmp_find_isadj_prot_supp(struct variable *, oid *,
+					       size_t *, int, size_t *,
+					       WriteMethod **);
+
+/*
+ * Just to save on typing we have a shortcut structure
+ * to specify mib layout, we populate the rest of the data
+ * during initialization
+ */
+#define ISIS_PREF_LEN_MAX (6)
+
+struct isis_func_to_prefix {
+	FindVarMethod *ihtp_func;
+	oid ihtp_pref_oid[ISIS_PREF_LEN_MAX];
+	uint8_t ihtp_pref_len;
+};
+
+static struct isis_func_to_prefix isis_func_to_prefix_arr[] = {
+	{isis_snmp_find_sys_object, {ISIS_SYS_OBJECT}, 3},
+	{isis_snmp_find_man_area, {ISIS_MANAREA_ADDRENTRY}, 4},
+	{isis_snmp_find_area_addr, {ISIS_AREA_ADDRENTRY}, 4},
+	{isis_snmp_find_summ_addr, {ISIS_SUMM_ADDRENTRY}, 4},
+	{isis_snmp_find_redistribute_addr, {ISIS_REDISTRIBUTE_ADDRENTRY}, 4},
+	{isis_snmp_find_router, {ISIS_ROUTER_ENTRY}, 4},
+	{isis_snmp_find_sys_level, {ISIS_SYSLEVEL_ENTRY}, 4},
+	{isis_snmp_find_system_counter, {ISIS_SYSTEM_COUNTER_ENTRY}, 4},
+	{isis_snmp_find_next_circ_index, {ISIS_CIRC}, 2},
+	{isis_snmp_find_circ, {ISIS_CIRC_ENTRY}, 4},
+	{isis_snmp_find_circ_level, {ISIS_CIRCLEVEL_ENTRY}, 4},
+	{isis_snmp_find_circ_counter, {ISIS_CIRC_COUNTER_ENTRY}, 4},
+	{isis_snmp_find_isadj, {ISIS_ISADJ_ENTRY}, 4},
+	{isis_snmp_find_isadj_area, {ISIS_ISADJAREA_ADDRENTRY}, 4},
+	{isis_snmp_find_isadj_ipaddr, {ISIS_ISADJIPADDR_ENTRY}, 4},
+	{isis_snmp_find_isadj_prot_supp, {ISIS_ISADJPROTSUPP_ENTRY}, 4},
+};
+static size_t isis_func_to_prefix_count = array_size(isis_func_to_prefix_arr);
+
+static struct variable isis_var_arr[] = {
+	{ISIS_SYS_VERSION, INTEGER, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_LEVELTYPE, INTEGER, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_ID, STRING, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_MAXPATHSPLITS, UNSIGNED32, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_MAXLSPGENINT, UNSIGNED32, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_POLLESHELLORATE, UNSIGNED32, RONLY,
+	 isis_snmp_find_sys_object},
+	{ISIS_SYS_WAITTIME, UNSIGNED32, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_ADMINSTATE, INTEGER, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_L2TOL1LEAKING, INTEGER, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_MAXAGE, UNSIGNED32, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_RECEIVELSPBUFFERSIZE, UNSIGNED32, RONLY,
+	 isis_snmp_find_sys_object},
+	{ISIS_SYS_PROTSUPPORTED, STRING, RONLY, isis_snmp_find_sys_object},
+	{ISIS_SYS_NOTIFICATIONENABLE, INTEGER, RONLY,
+	 isis_snmp_find_sys_object},
+	{ISIS_MANAREA_ADDREXISTSTATE, INTEGER, RONLY, isis_snmp_find_man_area},
+	{ISIS_AREA_ADDR, STRING, RONLY, isis_snmp_find_area_addr},
+	{ISIS_SUMM_ADDREXISTSTATE, INTEGER, RONLY, isis_snmp_find_summ_addr},
+	{ISIS_SUMM_ADDRMETRIC, UNSIGNED32, RONLY, isis_snmp_find_summ_addr},
+	{ISIS_SUMM_ADDRFULLMETRIC, UNSIGNED32, RONLY, isis_snmp_find_summ_addr},
+	{ISIS_REDISTRIBUTE_ADDREXISTSTATE, INTEGER, RONLY,
+	 isis_snmp_find_redistribute_addr},
+	{ISIS_ROUTER_HOSTNAME, STRING, RONLY, isis_snmp_find_router},
+	{ISIS_ROUTER_ID, UNSIGNED32, RONLY, isis_snmp_find_router},
+	{ISIS_SYSLEVEL_ORIGLSPBUFFSIZE, UNSIGNED32, RONLY,
+	 isis_snmp_find_sys_level},
+	{ISIS_SYSLEVEL_MINLSPGENINT, UNSIGNED32, RONLY,
+	 isis_snmp_find_sys_level},
+	{ISIS_SYSLEVEL_STATE, INTEGER, RONLY, isis_snmp_find_sys_level},
+	{ISIS_SYSLEVEL_SETOVERLOAD, INTEGER, RONLY, isis_snmp_find_sys_level},
+	{ISIS_SYSLEVEL_SETOVERLOADUNTIL, UNSIGNED32, RONLY,
+	 isis_snmp_find_sys_level},
+	{ISIS_SYSLEVEL_METRICSTYLE, INTEGER, RONLY, isis_snmp_find_sys_level},
+	{ISIS_SYSLEVEL_SPFCONSIDERS, INTEGER, RONLY, isis_snmp_find_sys_level},
+	{ISIS_SYSLEVEL_TEENABLED, INTEGER, RONLY, isis_snmp_find_sys_level},
+	{ISIS_SYSSTAT_CORRLSPS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_AUTHTYPEFAILS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_AUTHFAILS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_LSPDBASEOLOADS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_MANADDRDROPFROMAREAS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_ATTMPTTOEXMAXSEQNUMS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_SEQNUMSKIPS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_OWNLSPPURGES, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_IDFIELDLENMISMATCHES, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_PARTCHANGES, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_SPFRUNS, COUNTER32, RONLY, isis_snmp_find_system_counter},
+	{ISIS_SYSSTAT_LSPERRORS, COUNTER32, RONLY,
+	 isis_snmp_find_system_counter},
+	{ISIS_NEXTCIRC_INDEX, UNSIGNED32, RONLY,
+	 isis_snmp_find_next_circ_index},
+	{ISIS_CIRC_IFINDEX, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_ADMINSTATE, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_EXISTSTATE, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_TYPE, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_EXTDOMAIN, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_LEVELTYPE, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_PASSIVECIRCUIT, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_MESHGROUPENABLED, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_MESHGROUP, UNSIGNED32, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_SMALLHELLOS, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_LASTUPTIME, TIMESTAMP, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_3WAYENABLED, INTEGER, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRC_EXTENDEDCIRCID, UNSIGNED32, RONLY, isis_snmp_find_circ},
+	{ISIS_CIRCLEVEL_METRIC, UNSIGNED32, RONLY, isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_WIDEMETRIC, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_ISPRIORITY, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_IDOCTET, UNSIGNED32, RONLY, isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_ID, STRING, RONLY, isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_DESIS, STRING, RONLY, isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_HELLOMULTIPLIER, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_HELLOTIMER, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_DRHELLOTIMER, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_LSPTHROTTLE, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_MINLSPRETRANSINT, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_CSNPINTERVAL, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRCLEVEL_PARTSNPINTERVAL, UNSIGNED32, RONLY,
+	 isis_snmp_find_circ_level},
+	{ISIS_CIRC_ADJCHANGES, COUNTER32, RONLY, isis_snmp_find_circ_counter},
+	{ISIS_CIRC_NUMADJ, UNSIGNED32, RONLY, isis_snmp_find_circ_counter},
+	{ISIS_CIRC_INITFAILS, COUNTER32, RONLY, isis_snmp_find_circ_counter},
+	{ISIS_CIRC_REJADJS, COUNTER32, RONLY, isis_snmp_find_circ_counter},
+	{ISIS_CIRC_IDFIELDLENMISMATCHES, COUNTER32, RONLY,
+	 isis_snmp_find_circ_counter},
+	{ISIS_CIRC_MAXAREAADDRMISMATCHES, COUNTER32, RONLY,
+	 isis_snmp_find_circ_counter},
+	{ISIS_CIRC_AUTHTYPEFAILS, COUNTER32, RONLY,
+	 isis_snmp_find_circ_counter},
+	{ISIS_CIRC_AUTHFAILS, COUNTER32, RONLY, isis_snmp_find_circ_counter},
+	{ISIS_CIRC_LANDESISCHANGES, COUNTER32, RONLY,
+	 isis_snmp_find_circ_counter},
+	{ISIS_ISADJ_STATE, INTEGER, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_3WAYSTATE, INTEGER, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_NEIGHSNPAADDRESS, STRING, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_NEIGHSYSTYPE, INTEGER, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_NEIGHSYSID, STRING, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_NBREXTENDEDCIRCID, UNSIGNED32, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_USAGE, INTEGER, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_HOLDTIMER, UNSIGNED32, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_NEIGHPRIORITY, UNSIGNED32, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJ_LASTUPTIME, TIMESTAMP, RONLY, isis_snmp_find_isadj},
+	{ISIS_ISADJAREA_ADDRESS, STRING, RONLY, isis_snmp_find_isadj_area},
+	{ISIS_ISADJIPADDR_TYPE, INTEGER, RONLY, isis_snmp_find_isadj_ipaddr},
+	{ISIS_ISADJIPADDR_ADDRESS, STRING, RONLY, isis_snmp_find_isadj_ipaddr},
+	{ISIS_ISADJPROTSUPP_PROTOCOL, INTEGER, RONLY,
+	 isis_snmp_find_isadj_prot_supp},
+};
+
+static const size_t isis_var_count = array_size(isis_var_arr);
+
+/* Minimal set of hard-coded data */
+#define ISIS_VERSION (1)
+
+/* If sys-id is not set use this value */
+static uint8_t isis_null_sysid[ISIS_SYS_ID_LEN];
+
+/* OSI addr-len */
+#define ISIS_SNMP_OSI_ADDR_LEN_MAX (20)
+
+/*
+ * The implementation has a fixed max-path splits value
+ * of 64 (see ISIS_MAX_PATH_SPLITS), the max mib value
+ * is 32.
+ *
+ * FIXME(aromanov): should we return 32 or 64?
+ */
+#define ISIS_SNMP_MAX_PATH_SPLITS (32)
+
+#define ISIS_SNMP_ADMIN_STATE_ON (1)
+
+#define ISIS_SNMP_ROW_STATUS_ACTIVE (1)
+
+#define ISIS_SNMP_LEVEL_STATE_OFF (1)
+#define ISIS_SNMP_LEVEL_STATE_ON (2)
+#define ISIS_SNMP_LEVEL_STATE_WAITING (3)
+#define ISIS_SNMP_LEVEL_STATE_OVERLOADED (4)
+
+#define ISIS_SNMP_TRUTH_VALUE_TRUE (1)
+#define ISIS_SNMP_TRUTH_VALUE_FALSE (2)
+
+#define ISIS_SNMP_METRIC_STYLE_NARROW (1)
+#define ISIS_SNMP_METRIC_STYLE_WIDE (2)
+#define ISIS_SNMP_METRIC_STYLE_BOTH (3)
+
+#define ISIS_SNMP_MESH_GROUP_INACTIVE (1)
+
+#define ISIS_SNMP_ADJ_STATE_DOWN (1)
+#define ISIS_SNMP_ADJ_STATE_INITIALIZING (2)
+#define ISIS_SNMP_ADJ_STATE_UP (3)
+#define ISIS_SNMP_ADJ_STATE_FAILED (4)
+
+static inline uint32_t isis_snmp_adj_state(enum isis_adj_state state)
+{
+	switch (state) {
+	case ISIS_ADJ_UNKNOWN:
+		return ISIS_SNMP_ADJ_STATE_DOWN;
+	case ISIS_ADJ_INITIALIZING:
+		return ISIS_SNMP_ADJ_STATE_INITIALIZING;
+	case ISIS_ADJ_UP:
+		return ISIS_SNMP_ADJ_STATE_UP;
+	case ISIS_ADJ_DOWN:
+		return ISIS_SNMP_ADJ_STATE_FAILED;
+	}
+
+	return 0; /* not reached */
+}
+
+#define ISIS_SNMP_ADJ_NEIGHTYPE_IS_L1 (1)
+#define ISIS_SNMP_ADJ_NEIGHTYPE_IS_L2 (2)
+#define ISIS_SNMP_ADJ_NEIGHTYPE_IS_L1_L2 (3)
+#define ISIS_SNMP_ADJ_NEIGHTYPE_UNKNOWN (4)
+
+static inline uint32_t isis_snmp_adj_neightype(enum isis_system_type type)
+{
+	switch (type) {
+	case ISIS_SYSTYPE_UNKNOWN:
+	case ISIS_SYSTYPE_ES:
+		return ISIS_SNMP_ADJ_NEIGHTYPE_UNKNOWN;
+	case ISIS_SYSTYPE_IS:
+		return ISIS_SNMP_ADJ_NEIGHTYPE_IS_L1_L2;
+	case ISIS_SYSTYPE_L1_IS:
+		return ISIS_SNMP_ADJ_NEIGHTYPE_IS_L1;
+	case ISIS_SYSTYPE_L2_IS:
+		return ISIS_SNMP_ADJ_NEIGHTYPE_IS_L2;
+	}
+
+	return 0; /* not reached */
+}
+
+#define ISIS_SNMP_INET_TYPE_V4 (1)
+#define ISIS_SNMP_INET_TYPE_V6 (2)
+
+#define ISIS_SNMP_P2P_CIRCUIT (3)
+
+/* Protocols supported value */
+static uint8_t isis_snmp_protocols_supported = 0x7; /* All: iso, ipv4, ipv6 */
+
+#define SNMP_CIRCUITS_MAX (512)
+
+static struct isis_circuit *snmp_circuits[SNMP_CIRCUITS_MAX];
+static uint32_t snmp_circuit_id_last;
+
+static int isis_circuit_snmp_id_gen(struct isis_circuit *circuit)
+{
+	uint32_t id;
+	uint32_t i;
+
+	id = snmp_circuit_id_last;
+	id++;
+
+	/* find next unused entry */
+	for (i = 0; i < SNMP_CIRCUITS_MAX; i++) {
+		if (id >= SNMP_CIRCUITS_MAX) {
+			id = 0;
+			continue;
+		}
+
+		if (id == 0)
+			continue;
+
+		if (snmp_circuits[id] == NULL)
+			break;
+
+		id++;
+	}
+
+	if (i == SNMP_CIRCUITS_MAX) {
+		zlog_warn("Could not allocate a smmp-circuit-id");
+		return 0;
+	}
+
+	snmp_circuits[id] = circuit;
+	snmp_circuit_id_last = id;
+	circuit->snmp_id = id;
+
+	return 0;
+}
+
+static int isis_circuit_snmp_id_free(struct isis_circuit *circuit)
+{
+	snmp_circuits[circuit->snmp_id] = NULL;
+	circuit->snmp_id = 0;
+	return 0;
+}
+
+/*
+ * Convenience function to move to the next circuit,
+ */
+static struct isis_circuit *isis_snmp_circuit_next(struct isis_circuit *circuit)
+{
+	uint32_t start;
+	uint32_t off;
+
+	start = 1;
+
+	if (circuit != NULL)
+		start = circuit->snmp_id + 1;
+
+	for (off = start; off < SNMP_CIRCUITS_MAX; off++) {
+		circuit = snmp_circuits[off];
+
+		if (circuit != NULL)
+			return circuit;
+	}
+
+	return NULL;
+}
+
+/*
+ * Convenience function to get the first matching level
+ */
+static int isis_snmp_circuit_get_level_lo(struct isis_circuit *circuit)
+{
+	if (circuit->is_type == IS_LEVEL_2)
+		return IS_LEVEL_2;
+
+	return IS_LEVEL_1;
+}
+
+/* Check level match */
+static int isis_snmp_get_level_match(int is_type, int level)
+{
+	if (is_type != IS_LEVEL_1 && is_type != IS_LEVEL_2
+	    && is_type != IS_LEVEL_1_AND_2)
+		return 0;
+
+	if (level != IS_LEVEL_1 && level != IS_LEVEL_2)
+		return 0;
+
+
+	if (is_type == IS_LEVEL_1) {
+		if (level == IS_LEVEL_1)
+			return 1;
+
+		return 0;
+	}
+
+	if (is_type == IS_LEVEL_2) {
+		if (level == IS_LEVEL_2)
+			return 1;
+
+		return 0;
+	}
+
+	return 1;
+}
+/*
+ * Helper function to convert oid index representing
+ * octet-string index (e.g. isis-sys-id) to byte string
+ * representing the same index.
+ *
+ * Also we do not fail if idx is longer than max_len,
+ * so we can use the same function to check compound
+ * indexes.
+ */
+static int isis_snmp_conv_exact(uint8_t *buf, size_t max_len, size_t *out_len,
+				const oid *idx, size_t idx_len)
+{
+	size_t off;
+	size_t len;
+
+	/* Oid representation: length followed by bytes */
+	if (idx == NULL || idx_len == 0)
+		return 0;
+
+	len = idx[0];
+
+	if (len > max_len)
+		return 0;
+
+	if (idx_len < len + 1)
+		return 0;
+
+	for (off = 0; off < len; off++) {
+		if (idx[off + 1] > 0xff)
+			return 0;
+
+		buf[off] = (uint8_t)(idx[off + 1] & 0xff);
+	}
+
+	*out_len = len;
+
+	return 1;
+}
+
+static int isis_snmp_conv_next(uint8_t *buf, size_t max_len, size_t *out_len,
+			       int *try_exact, const oid *idx, size_t idx_len)
+{
+	size_t off;
+	size_t len;
+	size_t cmp_len;
+
+	if (idx == NULL || idx_len == 0) {
+		*out_len = 0;
+		*try_exact = 1;
+		return 1;
+	}
+
+	len = idx[0];
+
+	if (len > max_len)
+		return 0;
+
+	cmp_len = len;
+
+	if ((idx_len - 1) < cmp_len)
+		cmp_len = idx_len - 1;
+
+	for (off = 0; off < cmp_len; off++) {
+		if (idx[off + 1] > 0xff) {
+			memset(buf + off, 0xff, len - off);
+			*out_len = len;
+			*try_exact = 1;
+			return 1;
+		}
+
+		buf[off] = (uint8_t)(idx[off + 1] & 0xff);
+	}
+
+	if (cmp_len < len)
+		memset(buf + cmp_len, 0, len - cmp_len);
+
+	*out_len = len;
+	*try_exact = cmp_len < len ? 1 : 0;
+	return 1;
+}
+
+/*
+ * Helper functions to find area address from snmp index
+ */
+static int isis_snmp_area_addr_lookup_exact(oid *oid_idx, size_t oid_idx_len,
+					    struct isis_area **ret_area,
+					    struct iso_address **ret_addr)
+{
+	uint8_t cmp_buf[ISIS_SNMP_OSI_ADDR_LEN_MAX];
+	size_t addr_len;
+	struct isis_area *area = NULL;
+	struct iso_address *addr = NULL;
+	struct listnode *addr_node;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL)
+		return 0;
+
+	if (list_isempty(isis->area_list)) {
+		/* Area is not configured yet */
+		return 0;
+	}
+
+	area = listgetdata(listhead(isis->area_list));
+
+	int res = isis_snmp_conv_exact(cmp_buf, sizeof(cmp_buf), &addr_len,
+				       oid_idx, oid_idx_len);
+
+
+	if (!res || addr_len == 0 || oid_idx_len != (addr_len + 1)) {
+		/* Bad conversion, empty address or extra oids at the end */
+		return 0;
+	}
+
+	for (ALL_LIST_ELEMENTS_RO(area->area_addrs, addr_node, addr)) {
+		if (addr->addr_len != addr_len)
+			continue;
+
+		if (memcmp(addr->area_addr, cmp_buf, addr_len) == 0) {
+			if (ret_area != 0)
+				*ret_area = area;
+
+			if (ret_addr != 0)
+				*ret_addr = addr;
+
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static int isis_snmp_area_addr_lookup_next(oid *oid_idx, size_t oid_idx_len,
+					   struct isis_area **ret_area,
+					   struct iso_address **ret_addr)
+{
+	uint8_t cmp_buf[ISIS_SNMP_OSI_ADDR_LEN_MAX];
+	size_t addr_len;
+	int try_exact = 0;
+	struct isis_area *found_area = NULL;
+	struct isis_area *area = NULL;
+	struct iso_address *found_addr = NULL;
+	struct iso_address *addr = NULL;
+	struct listnode *addr_node;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL)
+		return 0;
+
+	if (list_isempty(isis->area_list)) {
+		/* Area is not configured yet */
+		return 0;
+	}
+
+	area = listgetdata(listhead(isis->area_list));
+
+	int res = isis_snmp_conv_next(cmp_buf, sizeof(cmp_buf), &addr_len,
+				      &try_exact, oid_idx, oid_idx_len);
+
+	if (!res)
+		return 0;
+
+	for (ALL_LIST_ELEMENTS_RO(area->area_addrs, addr_node, addr)) {
+		if (addr->addr_len < addr_len)
+			continue;
+
+		if (addr->addr_len == addr_len) {
+			if (addr_len == 0)
+				continue;
+
+			res = memcmp(addr->area_addr, cmp_buf, addr_len);
+
+			if (res < 0)
+				continue;
+
+			if (res == 0 && addr->addr_len == addr_len) {
+				if (try_exact) {
+					/*
+					 * This is the best match no point
+					 * to look further
+					 */
+					found_area = area;
+					found_addr = addr;
+					break;
+				}
+				continue;
+			}
+		}
+
+		if (found_addr == NULL || addr->addr_len < found_addr->addr_len
+		    || (addr->addr_len == found_addr->addr_len
+			&& memcmp(addr->area_addr, found_addr->area_addr,
+				  addr->addr_len)
+				   < 0)) {
+			found_area = area;
+			found_addr = addr;
+		}
+	}
+
+	if (found_area == NULL)
+		return 0;
+
+	if (ret_area != 0)
+		*ret_area = found_area;
+
+	if (ret_addr != 0)
+		*ret_addr = found_addr;
+
+	return 1;
+}
+
+/*
+ * Helper functions to find circuit from
+ * snmp index
+ */
+static int isis_snmp_circuit_lookup_exact(oid *oid_idx, size_t oid_idx_len,
+					  struct isis_circuit **ret_circuit)
+{
+	struct isis_circuit *circuit;
+
+	if (oid_idx == NULL || oid_idx_len < 1
+	    || oid_idx[0] > SNMP_CIRCUITS_MAX)
+		return 0;
+
+	circuit = snmp_circuits[oid_idx[0]];
+	if (circuit == NULL)
+		return 0;
+
+	if (ret_circuit != NULL)
+		*ret_circuit = circuit;
+
+	return 1;
+}
+
+static int isis_snmp_circuit_lookup_next(oid *oid_idx, size_t oid_idx_len,
+					 struct isis_circuit **ret_circuit)
+{
+	oid off;
+	oid start;
+	struct isis_circuit *circuit;
+
+	start = 0;
+
+	if (oid_idx != NULL && oid_idx_len != 0) {
+		if (oid_idx[0] > SNMP_CIRCUITS_MAX)
+			return 0;
+
+		start = oid_idx[0];
+	}
+
+	for (off = start; off < SNMP_CIRCUITS_MAX; ++off) {
+		circuit = snmp_circuits[off];
+
+		if (circuit != NULL && off > start) {
+			if (ret_circuit != NULL)
+				*ret_circuit = circuit;
+
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Helper functions to find circuit level
+ * combination from snmp index
+ */
+static int isis_snmp_circuit_level_lookup_exact(
+	oid *oid_idx, size_t oid_idx_len, int check_match,
+	struct isis_circuit **ret_circuit, int *ret_level)
+{
+	int level;
+	int res;
+	struct isis_circuit *circuit;
+
+	/* Minor optimization: check level first */
+	if (oid_idx == NULL || oid_idx_len < 2)
+		return 0;
+
+	if (oid_idx[1] < IS_LEVEL_1 || oid_idx[1] > IS_LEVEL_2)
+		return 0;
+
+	level = (int)oid_idx[1];
+
+	res = isis_snmp_circuit_lookup_exact(oid_idx, oid_idx_len, &circuit);
+
+	if (!res)
+		return 0;
+
+	if (check_match && !isis_snmp_get_level_match(circuit->is_type, level))
+		return 0;
+
+	if (ret_circuit != NULL)
+		*ret_circuit = circuit;
+
+	if (ret_level != NULL)
+		*ret_level = level;
+
+	return 1;
+}
+
+static int isis_snmp_circuit_level_lookup_next(
+	oid *oid_idx, size_t oid_idx_len, int check_match,
+	struct isis_circuit **ret_circuit, int *ret_level)
+{
+	oid off;
+	oid start;
+	struct isis_circuit *circuit = NULL;
+	int level;
+
+	start = 0;
+
+	if (oid_idx != NULL && oid_idx_len != 0) {
+		if (oid_idx[0] > SNMP_CIRCUITS_MAX)
+			return 0;
+
+		start = oid_idx[0];
+	}
+
+	for (off = start; off < SNMP_CIRCUITS_MAX; off++) {
+		circuit = snmp_circuits[off];
+
+		if (circuit == NULL)
+			continue;
+
+		if (off > start || oid_idx_len < 2) {
+			/* Found and can use level 1 */
+			level = IS_LEVEL_1;
+			break;
+		}
+
+		assert(oid_idx != NULL);
+
+		/* We have to check level specified by index */
+		if (oid_idx[1] < IS_LEVEL_1) {
+			level = IS_LEVEL_1;
+			break;
+		}
+
+		if (oid_idx[1] < IS_LEVEL_2) {
+			level = IS_LEVEL_2;
+			break;
+		}
+
+		/* Try next */
+		circuit = NULL;
+	}
+
+	if (circuit == NULL)
+		return 0;
+
+	if (check_match
+	    && !isis_snmp_get_level_match(circuit->is_type, level)) {
+		if (level == IS_LEVEL_1) {
+			/*
+			 * We can simply advance level because
+			 * at least one level should match
+			 */
+			level = IS_LEVEL_2;
+		} else {
+			/* We have to move to the next circuit */
+			circuit = isis_snmp_circuit_next(circuit);
+			if (circuit == NULL)
+				return 0;
+
+			level = isis_snmp_circuit_get_level_lo(circuit);
+		}
+	}
+
+	if (ret_circuit != NULL)
+		*ret_circuit = circuit;
+
+	if (ret_level != NULL)
+		*ret_level = level;
+
+	return 1;
+}
+
+/*
+ * Helper functions to find adjacency
+ * from snmp index.
+ *
+ * We have 4 tables related to adjacency
+ * looking up adjacency is quite expensive
+ * in case of bcast interfaces.
+ *
+ * It is pain to have 4 very similar functions
+ * hence we pass in and out additional data
+ * we are looking for.
+ *
+ * Note: we  use data-len value to distinguish
+ * between ipv4 and ipv6 addresses
+ */
+#define ISIS_SNMP_ADJ_DATA_NONE (1)
+#define ISIS_SNMP_ADJ_DATA_AREA_ADDR (2)
+#define ISIS_SNMP_ADJ_DATA_IP_ADDR (3)
+#define ISIS_SNMP_ADJ_DATA_PROTO (4)
+
+/*
+ * Helper function to process data associated
+ * with adjacency
+ */
+static int isis_snmp_adj_helper(struct isis_adjacency *adj, int data_id,
+				oid data_off, uint8_t **ret_data,
+				size_t *ret_data_len)
+{
+	uint8_t *data = NULL;
+	size_t data_len = 0;
+
+	switch (data_id) {
+	case ISIS_SNMP_ADJ_DATA_NONE:
+		break;
+
+	case ISIS_SNMP_ADJ_DATA_AREA_ADDR:
+		if (data_off >= adj->area_address_count)
+			return 0;
+
+		data = adj->area_addresses[data_off].area_addr;
+		data_len = adj->area_addresses[data_off].addr_len;
+		break;
+
+	case ISIS_SNMP_ADJ_DATA_IP_ADDR:
+		if (data_off >= (adj->ipv4_address_count + adj->ll_ipv6_count))
+			return 0;
+
+		if (data_off >= adj->ipv4_address_count) {
+			data = (uint8_t *)&adj->ll_ipv6_addrs
+				       [data_off - adj->ipv4_address_count];
+			data_len = sizeof(adj->ll_ipv6_addrs[0]);
+		} else {
+			data = (uint8_t *)&adj->ipv4_addresses[data_off];
+			data_len = sizeof(adj->ipv4_addresses[0]);
+		}
+
+		break;
+
+
+	case ISIS_SNMP_ADJ_DATA_PROTO:
+		if (data_off >= adj->nlpids.count)
+			return 0;
+
+		data = &adj->nlpids.nlpids[data_off];
+		data_len = sizeof(adj->nlpids.nlpids[0]);
+		break;
+
+	default:
+		assert(0);
+		return 0;
+	}
+
+	if (ret_data != NULL)
+		*ret_data = data;
+
+	if (ret_data_len != NULL)
+		*ret_data_len = data_len;
+
+	return 1;
+}
+
+static int isis_snmp_adj_lookup_exact(oid *oid_idx, size_t oid_idx_len,
+				      int data_id,
+				      struct isis_adjacency **ret_adj,
+				      oid *ret_data_idx, uint8_t **ret_data,
+				      size_t *ret_data_len)
+{
+	int res;
+	struct listnode *node;
+	struct isis_circuit *circuit;
+	struct isis_adjacency *adj;
+	struct isis_adjacency *tmp_adj;
+	oid adj_idx;
+	oid data_off;
+	uint8_t *data;
+	size_t data_len;
+
+	res = isis_snmp_circuit_lookup_exact(oid_idx, oid_idx_len, &circuit);
+
+	if (!res)
+		return 0;
+
+	if (oid_idx == NULL || oid_idx_len < 2
+	    || (data_id != ISIS_SNMP_ADJ_DATA_NONE && oid_idx_len < 3))
+		return 0;
+
+	adj_idx = oid_idx[1];
+
+	if (data_id != ISIS_SNMP_ADJ_DATA_NONE) {
+		if (oid_idx[2] == 0)
+			return 0;
+
+		data_off = oid_idx[2] - 1;
+	} else {
+		/*
+		 * Data-off is not used if data-id is none
+		 * but we set it just for consistency
+		 */
+		data_off = 0;
+	}
+
+	adj = NULL;
+	data = NULL;
+	data_len = 0;
+
+	for (ALL_LIST_ELEMENTS_RO(circuit->snmp_adj_list, node, tmp_adj)) {
+		if (tmp_adj->snmp_idx > adj_idx) {
+			/*
+			 * Adjacencies are ordered in the list
+			 * no point to look further
+			 */
+			break;
+		}
+
+		if (tmp_adj->snmp_idx == adj_idx) {
+			res = isis_snmp_adj_helper(tmp_adj, data_id, data_off,
+						   &data, &data_len);
+			if (res)
+				adj = tmp_adj;
+
+			break;
+		}
+	}
+
+	if (adj == NULL)
+		return 0;
+
+	if (ret_adj != NULL)
+		*ret_adj = adj;
+
+	if (ret_data_idx != NULL)
+		*ret_data_idx = data_off + 1;
+
+	if (ret_data)
+		*ret_data = data;
+
+	if (ret_data_len)
+		*ret_data_len = data_len;
+
+	return 1;
+}
+
+static int isis_snmp_adj_lookup_next(oid *oid_idx, size_t oid_idx_len,
+				     int data_id,
+				     struct isis_adjacency **ret_adj,
+				     oid *ret_data_idx, uint8_t **ret_data,
+				     size_t *ret_data_len)
+{
+	struct listnode *node;
+	struct isis_circuit *circuit;
+	struct isis_adjacency *adj;
+	struct isis_adjacency *tmp_adj;
+	oid circ_idx;
+	oid adj_idx;
+	oid data_idx;
+	uint8_t *data;
+	size_t data_len;
+
+	adj = NULL;
+	data = NULL;
+	data_len = 0;
+
+	/*
+	 * Note: we rely on the fact that data indexes are consequtive
+	 * starting from 1
+	 */
+
+	if (oid_idx == 0 || oid_idx_len == 0) {
+		circ_idx = 0;
+		adj_idx = 0;
+		data_idx = 0;
+	} else if (oid_idx_len == 1) {
+		circ_idx = oid_idx[0];
+		adj_idx = 0;
+		data_idx = 0;
+	} else if (oid_idx_len == 2) {
+		circ_idx = oid_idx[0];
+		adj_idx = oid_idx[1];
+		data_idx = 0;
+	} else {
+		circ_idx = oid_idx[0];
+		adj_idx = oid_idx[1];
+
+		if (data_id == ISIS_SNMP_ADJ_DATA_NONE)
+			data_idx = 0;
+		else
+			data_idx = oid_idx[2];
+	}
+
+	if (!isis_snmp_circuit_lookup_exact(&circ_idx, 1, &circuit)
+	    && !isis_snmp_circuit_lookup_next(&circ_idx, 1, &circuit))
+		/* No circuit */
+		return 0;
+
+	if (circuit->snmp_id != circ_idx) {
+		/* Match is not exact */
+		circ_idx = 0;
+		adj_idx = 0;
+		data_idx = 0;
+	}
+
+	/*
+	 * Note: the simple loop  below will work in all cases
+	 */
+	while (circuit != NULL) {
+		for (ALL_LIST_ELEMENTS_RO(circuit->snmp_adj_list, node,
+					  tmp_adj)) {
+			if (tmp_adj->snmp_idx < adj_idx)
+				continue;
+
+			if (tmp_adj->snmp_idx == adj_idx
+			    && data_id == ISIS_SNMP_ADJ_DATA_NONE)
+				continue;
+
+			if (adj_idx != 0 && tmp_adj->snmp_idx > adj_idx)
+				data_idx = 0;
+
+			if (isis_snmp_adj_helper(tmp_adj, data_id, data_idx,
+						 &data, &data_len)) {
+				adj = tmp_adj;
+				break;
+			}
+		}
+
+		if (adj != NULL)
+			break;
+
+		circuit = isis_snmp_circuit_next(circuit);
+		circ_idx = 0;
+		adj_idx = 0;
+		data_idx = 0;
+	}
+
+	if (adj == NULL)
+		return 0;
+
+	if (ret_adj != NULL)
+		*ret_adj = adj;
+
+	if (ret_data_idx != 0) {
+		if (data_id == ISIS_SNMP_ADJ_DATA_NONE)
+			/*
+			 * Value does not matter but let us set
+			 * it to zero for consistency
+			 */
+			*ret_data_idx = 0;
+		else
+			*ret_data_idx = data_idx + 1;
+	}
+
+	if (ret_data != 0)
+		*ret_data = data;
+
+	if (ret_data_len != 0)
+		*ret_data_len = data_len;
+
+	return 1;
+}
+
+static uint8_t *isis_snmp_find_sys_object(struct variable *v, oid *name,
+					  size_t *length, int exact,
+					  size_t *var_len,
+					  WriteMethod **write_method)
+{
+	struct isis_area *area = NULL;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL)
+		return NULL;
+
+	if (!list_isempty(isis->area_list))
+		area = listgetdata(listhead(isis->area_list));
+
+	/* Check whether the instance identifier is valid */
+	if (smux_header_generic(v, name, length, exact, var_len, write_method)
+	    == MATCH_FAILED)
+		return NULL;
+
+	switch (v->magic) {
+	case ISIS_SYS_VERSION:
+		return SNMP_INTEGER(ISIS_VERSION);
+
+	case ISIS_SYS_LEVELTYPE:
+		/*
+		 * If we do not have areas use 1&2 otherwise use settings
+		 * from the first area in the list
+		 */
+		if (area == NULL)
+			return SNMP_INTEGER(IS_LEVEL_1_AND_2);
+
+		return SNMP_INTEGER(area->is_type);
+
+	case ISIS_SYS_ID:
+		if (!isis->sysid_set) {
+			*var_len = ISIS_SYS_ID_LEN;
+			return isis_null_sysid;
+		}
+
+		*var_len = ISIS_SYS_ID_LEN;
+		return isis->sysid;
+
+	case ISIS_SYS_MAXPATHSPLITS:
+		return SNMP_INTEGER(ISIS_SNMP_MAX_PATH_SPLITS);
+
+	case ISIS_SYS_MAXLSPGENINT:
+		return SNMP_INTEGER(DEFAULT_MAX_LSP_GEN_INTERVAL);
+
+	case ISIS_SYS_POLLESHELLORATE:
+		return SNMP_INTEGER(DEFAULT_HELLO_INTERVAL);
+
+	case ISIS_SYS_WAITTIME:
+		/* Note: it seems that we have same fixed delay time */
+		return SNMP_INTEGER(DEFAULT_MIN_LSP_GEN_INTERVAL);
+
+	case ISIS_SYS_ADMINSTATE:
+		/* If daemon is running it admin state is on */
+		return SNMP_INTEGER(ISIS_SNMP_ADMIN_STATE_ON);
+
+
+	case ISIS_SYS_L2TOL1LEAKING:
+		/* We do not allow l2-to-l1 leaking */
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+	case ISIS_SYS_MAXAGE:
+		return SNMP_INTEGER(MAX_AGE);
+
+	case ISIS_SYS_RECEIVELSPBUFFERSIZE:
+		if (area == NULL)
+			return SNMP_INTEGER(DEFAULT_LSP_MTU);
+
+		return SNMP_INTEGER(area->lsp_mtu);
+
+	case ISIS_SYS_PROTSUPPORTED:
+		*var_len = 1;
+		return &isis_snmp_protocols_supported;
+
+	case ISIS_SYS_NOTIFICATIONENABLE:
+		if (isis->snmp_notifications)
+			return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_TRUE);
+
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+
+static uint8_t *isis_snmp_find_man_area(struct variable *v, oid *name,
+					size_t *length, int exact,
+					size_t *var_len,
+					WriteMethod **write_method)
+{
+	int res;
+	struct iso_address *area_addr = NULL;
+	oid *oid_idx;
+	size_t oid_idx_len;
+	size_t off = 0;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+
+	if (exact) {
+		res = isis_snmp_area_addr_lookup_exact(oid_idx, oid_idx_len,
+						       NULL, &area_addr);
+
+		if (!res)
+			return NULL;
+
+	} else {
+		res = isis_snmp_area_addr_lookup_next(oid_idx, oid_idx_len,
+						      NULL, &area_addr);
+
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = area_addr->addr_len;
+
+		for (off = 0; off < area_addr->addr_len; off++)
+			name[v->namelen + 1 + off] = area_addr->area_addr[off];
+
+		*length = v->namelen + 1 + area_addr->addr_len;
+	}
+
+	switch (v->magic) {
+	case ISIS_MANAREA_ADDREXISTSTATE:
+		return SNMP_INTEGER(ISIS_SNMP_ROW_STATUS_ACTIVE);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_area_addr(struct variable *v, oid *name,
+					 size_t *length, int exact,
+					 size_t *var_len,
+					 WriteMethod **write_method)
+{
+	/*
+	 * Area addresses in sense of addresses reported by L1 lsps
+	 * are not supported yet.
+	 */
+	(void)v;
+	(void)name;
+	(void)length;
+	(void)exact;
+	(void)var_len;
+
+
+	*write_method = NULL;
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_summ_addr(struct variable *v, oid *name,
+					 size_t *length, int exact,
+					 size_t *var_len,
+					 WriteMethod **write_method)
+{
+	/*
+	 * So far there is no way to set summary table values through cli
+	 * and snmp operations are read-only, hence there are no entries
+	 */
+	(void)v;
+	(void)name;
+	(void)length;
+	(void)exact;
+	(void)var_len;
+	*write_method = NULL;
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_redistribute_addr(struct variable *v, oid *name,
+						 size_t *length, int exact,
+						 size_t *var_len,
+						 WriteMethod **write_method)
+{
+	/*
+	 * It is not clear at the point whether redist code in isis is actually
+	 * used for now we will consider that entries are not present
+	 */
+	(void)v;
+	(void)name;
+	(void)length;
+	(void)exact;
+	(void)var_len;
+	*write_method = NULL;
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_router(struct variable *v, oid *name,
+				      size_t *length, int exact,
+				      size_t *var_len,
+				      WriteMethod **write_method)
+{
+	uint8_t cmp_buf[ISIS_SYS_ID_LEN];
+	size_t cmp_len;
+	int try_exact;
+	int cmp_level;
+	int res;
+	struct isis_dynhn *dyn = NULL;
+	oid *oid_idx;
+	size_t oid_idx_len;
+	size_t off = 0;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL)
+		return NULL;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+
+	if (exact) {
+		res = isis_snmp_conv_exact(cmp_buf, sizeof(cmp_buf), &cmp_len,
+					   oid_idx, oid_idx_len);
+
+		if (!res || cmp_len != ISIS_SYS_ID_LEN
+		    || oid_idx_len != (cmp_len + 2))
+			/*
+			 * Bad conversion, or bad length,
+			 * or extra oids at the end
+			 */
+			return NULL;
+
+		if (oid_idx[ISIS_SYS_ID_LEN + 1] < IS_LEVEL_1
+		    || oid_idx[ISIS_SYS_ID_LEN + 1] > IS_LEVEL_2)
+			/* Level part of the index is out of range */
+			return NULL;
+
+		cmp_level = (int)oid_idx[ISIS_SYS_ID_LEN + 1];
+
+		dyn = dynhn_find_by_id(isis, cmp_buf);
+
+		if (dyn == NULL || dyn->level != cmp_level)
+			return NULL;
+
+		switch (v->magic) {
+		case ISIS_ROUTER_HOSTNAME:
+			*var_len = strlen(dyn->hostname);
+			return (uint8_t *)dyn->hostname;
+
+		case ISIS_ROUTER_ID:
+			/* It seems that we do no know router-id in lsps */
+			return SNMP_INTEGER(0);
+
+		default:
+			break;
+		}
+
+		return NULL;
+	}
+
+	res = isis_snmp_conv_next(cmp_buf, sizeof(cmp_buf), &cmp_len,
+				  &try_exact, oid_idx, oid_idx_len);
+
+
+	if (!res)
+		/* Bad conversion */
+		return NULL;
+
+	if (cmp_len != ISIS_SYS_ID_LEN) {
+		/* We do not have valid index oids */
+		memset(cmp_buf, 0, sizeof(cmp_buf));
+		cmp_level = 0;
+	} else if (try_exact)
+		/*
+		 * We have no valid level index.
+		 * Let start from non-existing level 0 and
+		 * hence not need to do exact match
+		 */
+		cmp_level = 0;
+	else if (oid_idx_len < (ISIS_SYS_ID_LEN + 2))
+		cmp_level = 0;
+	else if (oid_idx[ISIS_SYS_ID_LEN + 1] <= IS_LEVEL_2)
+		cmp_level = (int)oid_idx[ISIS_SYS_ID_LEN + 1];
+	else
+		/*
+		 * Any value greater than 2 will have the same result
+		 * but we can have integer overflows, hence 3 is a reasonable
+		 * choice
+		 */
+		cmp_level = (int)(IS_LEVEL_2 + 1);
+
+	dyn = dynhn_snmp_next(isis, cmp_buf, cmp_level);
+
+	if (dyn == NULL)
+		return NULL;
+
+	/* Copy the name out */
+	memcpy(name, v->name, v->namelen * sizeof(oid));
+
+	/* Append index */
+	name[v->namelen] = ISIS_SYS_ID_LEN;
+
+	for (off = 0; off < ISIS_SYS_ID_LEN; off++)
+		name[v->namelen + 1 + off] = dyn->id[off];
+
+	name[v->namelen + 1 + ISIS_SYS_ID_LEN] = (oid)dyn->level;
+
+	/* Set length */
+	*length = v->namelen + 1 + ISIS_SYS_ID_LEN + 1;
+
+	switch (v->magic) {
+	case ISIS_ROUTER_HOSTNAME:
+		*var_len = strlen(dyn->hostname);
+		return (uint8_t *)dyn->hostname;
+
+	case ISIS_ROUTER_ID:
+		/* It seems that we do no know router-id in lsps */
+		return SNMP_INTEGER(0);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_sys_level(struct variable *v, oid *name,
+					 size_t *length, int exact,
+					 size_t *var_len,
+					 WriteMethod **write_method)
+{
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int level;
+	int level_match;
+	struct isis_area *area = NULL;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL)
+		return NULL;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+
+	if (exact) {
+		if (oid_idx == NULL || oid_idx_len != 1)
+			return NULL;
+
+		if (oid_idx[0] == IS_LEVEL_1)
+			level = IS_LEVEL_1;
+		else if (oid_idx[0] == IS_LEVEL_2)
+			level = IS_LEVEL_2;
+		else
+			return NULL;
+
+	} else {
+		if (oid_idx == NULL)
+			level = IS_LEVEL_1;
+		else if (oid_idx_len == 0)
+			level = IS_LEVEL_1;
+		else if (oid_idx[0] < IS_LEVEL_1)
+			level = IS_LEVEL_1;
+		else if (oid_idx[0] < IS_LEVEL_2)
+			level = IS_LEVEL_2;
+		else
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = level;
+
+		/* Set length */
+		*length = v->namelen + 1;
+	}
+
+	area = NULL;
+
+	if (!list_isempty(isis->area_list))
+		area = listgetdata(listhead(isis->area_list));
+
+	level_match = 0;
+
+	if (area != NULL)
+		level_match = isis_snmp_get_level_match(area->is_type, level);
+
+	switch (v->magic) {
+	case ISIS_SYSLEVEL_ORIGLSPBUFFSIZE:
+		if (level_match)
+			return SNMP_INTEGER(area->lsp_mtu);
+
+		return SNMP_INTEGER(DEFAULT_LSP_MTU);
+
+	case ISIS_SYSLEVEL_MINLSPGENINT:
+		if (level_match)
+			return SNMP_INTEGER(area->lsp_gen_interval[level - 1]);
+		else
+			return SNMP_INTEGER(DEFAULT_MIN_LSP_GEN_INTERVAL);
+
+	case ISIS_SYSLEVEL_STATE:
+		if (level_match) {
+			if (area->overload_bit)
+				return SNMP_INTEGER(
+					ISIS_SNMP_LEVEL_STATE_OVERLOADED);
+
+			return SNMP_INTEGER(ISIS_SNMP_LEVEL_STATE_ON);
+		}
+		return SNMP_INTEGER(ISIS_SNMP_LEVEL_STATE_OFF);
+
+	case ISIS_SYSLEVEL_SETOVERLOAD:
+		if (level_match && area->overload_bit)
+			return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_TRUE);
+
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+	case ISIS_SYSLEVEL_SETOVERLOADUNTIL:
+		/* We do not have automatic cleanup of overload bit */
+		return SNMP_INTEGER(0);
+
+	case ISIS_SYSLEVEL_METRICSTYLE:
+		if (level_match) {
+			if (area->newmetric && area->oldmetric)
+				return SNMP_INTEGER(
+					ISIS_SNMP_METRIC_STYLE_BOTH);
+
+			if (area->newmetric)
+				return SNMP_INTEGER(
+					ISIS_SNMP_METRIC_STYLE_WIDE);
+
+			return SNMP_INTEGER(ISIS_SNMP_METRIC_STYLE_NARROW);
+		}
+		return SNMP_INTEGER(ISIS_SNMP_METRIC_STYLE_NARROW);
+
+	case ISIS_SYSLEVEL_SPFCONSIDERS:
+		return SNMP_INTEGER(ISIS_SNMP_METRIC_STYLE_BOTH);
+
+	case ISIS_SYSLEVEL_TEENABLED:
+		if (level_match && IS_MPLS_TE(area->mta))
+			return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_TRUE);
+
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_system_counter(struct variable *v, oid *name,
+					      size_t *length, int exact,
+					      size_t *var_len,
+					      WriteMethod **write_method)
+{
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int level;
+	int level_match;
+	struct isis_area *area = NULL;
+	uint32_t val;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL)
+		return NULL;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+
+	if (exact) {
+		if (oid_idx == NULL || oid_idx_len != 1)
+			return 0;
+
+		if (oid_idx[0] == IS_LEVEL_1)
+			level = IS_LEVEL_1;
+		else if (oid_idx[0] == IS_LEVEL_2)
+			level = IS_LEVEL_2;
+		else
+			return NULL;
+
+	} else {
+		if (oid_idx == NULL)
+			level = IS_LEVEL_1;
+		else if (oid_idx_len == 0)
+			level = IS_LEVEL_1;
+		else if (oid_idx[0] < IS_LEVEL_1)
+			level = IS_LEVEL_1;
+		else if (oid_idx[0] < IS_LEVEL_2)
+			level = IS_LEVEL_2;
+		else
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = level;
+
+		/* Set length */
+		*length = v->namelen + 1;
+	}
+
+	area = NULL;
+
+	if (!list_isempty(isis->area_list))
+		area = listgetdata(listhead(isis->area_list));
+
+	level_match = 0;
+
+	if (area != NULL)
+		level_match = isis_snmp_get_level_match(area->is_type, level);
+
+	if (!level_match)
+		/* If level does not match all counters are zeros */
+		return SNMP_INTEGER(0);
+
+	switch (v->magic) {
+	case ISIS_SYSSTAT_CORRLSPS:
+		val = 0;
+		break;
+
+	case ISIS_SYSSTAT_AUTHTYPEFAILS:
+		val = (uint32_t)area->auth_type_failures[level - 1];
+		break;
+
+	case ISIS_SYSSTAT_AUTHFAILS:
+		val = (uint32_t)area->auth_failures[level - 1];
+		break;
+
+	case ISIS_SYSSTAT_LSPDBASEOLOADS:
+		val = area->overload_counter;
+		break;
+
+	case ISIS_SYSSTAT_MANADDRDROPFROMAREAS:
+		/* We do not support manual addresses */
+		val = 0;
+		break;
+
+	case ISIS_SYSSTAT_ATTMPTTOEXMAXSEQNUMS:
+		val = area->lsp_exceeded_max_counter;
+		break;
+
+	case ISIS_SYSSTAT_SEQNUMSKIPS:
+		val = area->lsp_seqno_skipped_counter;
+		break;
+
+	case ISIS_SYSSTAT_OWNLSPPURGES:
+		if (!area->purge_originator)
+			val = 0;
+		else
+			val = area->lsp_purge_count[level - 1];
+		break;
+
+	case ISIS_SYSSTAT_IDFIELDLENMISMATCHES:
+		val = (uint32_t)area->id_len_mismatches[level - 1];
+		break;
+
+	case ISIS_SYSSTAT_PARTCHANGES:
+		/* Not supported */
+		val = 0;
+		break;
+
+	case ISIS_SYSSTAT_SPFRUNS:
+		val = (uint32_t)area->spf_run_count[level - 1];
+		break;
+
+	case ISIS_SYSSTAT_LSPERRORS:
+		val = (uint32_t)area->lsp_error_counter[level - 1];
+		break;
+
+	default:
+		return NULL;
+	}
+
+	return SNMP_INTEGER(val);
+}
+
+static uint8_t *isis_snmp_find_next_circ_index(struct variable *v, oid *name,
+					       size_t *length, int exact,
+					       size_t *var_len,
+					       WriteMethod **write_method)
+{
+	/* Check whether the instance identifier is valid */
+	if (smux_header_generic(v, name, length, exact, var_len, write_method)
+	    == MATCH_FAILED)
+		return NULL;
+
+	switch (v->magic) {
+	case ISIS_NEXTCIRC_INDEX:
+		/*
+		 * We do not support circuit creation through snmp
+		 */
+		return SNMP_INTEGER(0);
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static uint8_t *isis_snmp_find_circ(struct variable *v, oid *name,
+				    size_t *length, int exact, size_t *var_len,
+				    WriteMethod **write_method)
+{
+	/* Index is circuit-id: 1-255 */
+	oid *oid_idx;
+	size_t oid_idx_len;
+	struct isis_circuit *circuit;
+	uint32_t up_ticks;
+	uint32_t delta_ticks;
+	time_t now_time;
+	int res;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+	if (exact) {
+		res = isis_snmp_circuit_lookup_exact(oid_idx, oid_idx_len,
+						     &circuit);
+
+		if (!res || oid_idx_len != 1)
+			return NULL;
+
+	} else {
+		res = isis_snmp_circuit_lookup_next(oid_idx, oid_idx_len,
+						    &circuit);
+
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = circuit->snmp_id;
+
+		/* Set length */
+		*length = v->namelen + 1;
+	}
+
+	switch (v->magic) {
+	case ISIS_CIRC_IFINDEX:
+		if (circuit->interface == NULL)
+			return SNMP_INTEGER(0);
+
+		return SNMP_INTEGER(circuit->interface->ifindex);
+
+	case ISIS_CIRC_ADMINSTATE:
+		return SNMP_INTEGER(ISIS_SNMP_ADMIN_STATE_ON);
+
+	case ISIS_CIRC_EXISTSTATE:
+		return SNMP_INTEGER(ISIS_SNMP_ROW_STATUS_ACTIVE);
+
+	case ISIS_CIRC_TYPE:
+		/*
+		 * Note: values do not match 100%:
+		 *
+		 * 1. From isis_circuit.h:
+		 *        CIRCUIT_T_UNKNOWN    0
+		 *        CIRCUIT_T_BROADCAST  1
+		 *        CIRCUIT_T_P2P        2
+		 *        CIRCUIT_T_LOOPBACK   3
+		 *
+		 * 2. From rfc:
+		 *        broadcast(1),
+		 *        ptToPt(2),
+		 *        staticIn(3),
+		 *        staticOut(4),
+		 */
+
+		return SNMP_INTEGER(circuit->circ_type);
+
+	case ISIS_CIRC_EXTDOMAIN:
+		if (circuit->ext_domain)
+			return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_TRUE);
+
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+	case ISIS_CIRC_LEVELTYPE:
+		return SNMP_INTEGER(circuit->is_type);
+
+	case ISIS_CIRC_PASSIVECIRCUIT:
+		if (circuit->is_passive)
+			return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_TRUE);
+
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+	case ISIS_CIRC_MESHGROUPENABLED:
+		/* Not supported */
+		return SNMP_INTEGER(ISIS_SNMP_MESH_GROUP_INACTIVE);
+
+	case ISIS_CIRC_MESHGROUP:
+		/* Not supported */
+		return SNMP_INTEGER(0);
+
+	case ISIS_CIRC_SMALLHELLOS:
+		/*
+		 * return false if lan hellos must be padded
+		 */
+		if (circuit->pad_hellos == ISIS_HELLO_PADDING_ALWAYS ||
+		    (circuit->pad_hellos ==
+			     ISIS_HELLO_PADDING_DURING_ADJACENCY_FORMATION &&
+		     circuit->upadjcount[0] + circuit->upadjcount[1] == 0))
+			return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_TRUE);
+
+	case ISIS_CIRC_LASTUPTIME:
+		if (circuit->last_uptime == 0)
+			return SNMP_INTEGER(0);
+
+		up_ticks = (uint32_t)netsnmp_get_agent_uptime();
+		now_time = time(NULL);
+
+		if (circuit->last_uptime >= now_time)
+			return SNMP_INTEGER(up_ticks);
+
+		delta_ticks = (now_time - circuit->last_uptime) * 10;
+
+		if (up_ticks < delta_ticks)
+			return SNMP_INTEGER(up_ticks);
+
+		return SNMP_INTEGER(up_ticks - delta_ticks);
+
+	case ISIS_CIRC_3WAYENABLED:
+		/* Not supported */
+		return SNMP_INTEGER(ISIS_SNMP_TRUTH_VALUE_FALSE);
+
+	case ISIS_CIRC_EXTENDEDCIRCID:
+		/* Used for 3-way hand shake only */
+		return SNMP_INTEGER(0);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_circ_level(struct variable *v, oid *name,
+					  size_t *length, int exact,
+					  size_t *var_len,
+					  WriteMethod **write_method)
+{
+	static uint8_t circuit_id_val[ISIS_SYS_ID_LEN + 1];
+	/* Index is circuit-id: 1-255 + level: 1-2 */
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int res;
+	struct isis_circuit *circuit;
+	int level;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL)
+		return NULL;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+	if (exact) {
+		res = isis_snmp_circuit_level_lookup_exact(oid_idx, oid_idx_len,
+							   1, &circuit, &level);
+
+		if (!res || oid_idx_len != 2)
+			return NULL;
+
+	} else {
+		res = isis_snmp_circuit_level_lookup_next(oid_idx, oid_idx_len,
+							  1, &circuit, &level);
+
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = circuit->snmp_id;
+		name[v->namelen + 1] = level;
+
+		/* Set length */
+		*length = v->namelen + 2;
+	}
+
+	switch (v->magic) {
+	case ISIS_CIRCLEVEL_METRIC:
+		return SNMP_INTEGER(circuit->metric[level - 1]);
+
+	case ISIS_CIRCLEVEL_WIDEMETRIC:
+		if (circuit->area == NULL || !circuit->area->newmetric) {
+			/* What should we do if wide metric is not supported? */
+			return SNMP_INTEGER(0);
+		}
+		return SNMP_INTEGER(circuit->te_metric[level - 1]);
+
+	case ISIS_CIRCLEVEL_ISPRIORITY:
+		return SNMP_INTEGER(circuit->priority[level - 1]);
+
+	case ISIS_CIRCLEVEL_IDOCTET:
+		return SNMP_INTEGER(circuit->circuit_id);
+
+	case ISIS_CIRCLEVEL_ID:
+		if (circuit->circ_type != CIRCUIT_T_P2P) {
+			/*
+			 * Unless it is point-to-point circuit, the value is and
+			 * empty octet string
+			 */
+			*var_len = 0;
+			return circuit_id_val;
+		}
+
+		/* !!!!!! Circuit-id is zero for p2p links */
+		if (circuit->u.p2p.neighbor == NULL
+		    || circuit->u.p2p.neighbor->adj_state != ISIS_ADJ_UP) {
+			/* No adjacency or adjacency not fully up yet */
+			memcpy(circuit_id_val, isis->sysid, ISIS_SYS_ID_LEN);
+			circuit_id_val[ISIS_SYS_ID_LEN] = circuit->circuit_id;
+			*var_len = ISIS_SYS_ID_LEN + 1;
+			return circuit_id_val;
+		}
+
+		/* Adjacency fully-up */
+		memcpy(circuit_id_val, circuit->u.p2p.neighbor->sysid,
+		       ISIS_SYS_ID_LEN);
+		circuit_id_val[ISIS_SYS_ID_LEN] = 0;
+		*var_len = ISIS_SYS_ID_LEN + 1;
+		return circuit_id_val;
+
+	case ISIS_CIRCLEVEL_DESIS:
+		if (circuit->circ_type != CIRCUIT_T_BROADCAST
+		    || !circuit->u.bc.is_dr[level - 1]) {
+			/*
+			 * Unless it is lan circuit participating in dis process
+			 * the value is an empty octet string
+			 */
+			*var_len = 0;
+			return circuit_id_val;
+		}
+
+		*var_len = ISIS_SYS_ID_LEN + 1;
+
+		if (level == IS_LEVEL_1)
+			return circuit->u.bc.l1_desig_is;
+
+		return circuit->u.bc.l2_desig_is;
+
+	case ISIS_CIRCLEVEL_HELLOMULTIPLIER:
+		return SNMP_INTEGER(circuit->hello_multiplier[level - 1]);
+
+	case ISIS_CIRCLEVEL_HELLOTIMER:
+		return SNMP_INTEGER(circuit->hello_interval[level - 1] * 1000);
+
+	case ISIS_CIRCLEVEL_DRHELLOTIMER:
+		return SNMP_INTEGER(circuit->hello_interval[level - 1] * 1000);
+
+	case ISIS_CIRCLEVEL_LSPTHROTTLE:
+		if (circuit->area)
+			return SNMP_INTEGER(
+				circuit->area->min_spf_interval[level - 1]
+				* 1000);
+		else
+			return SNMP_INTEGER(0);
+
+	case ISIS_CIRCLEVEL_MINLSPRETRANSINT:
+		if (circuit->area)
+			return SNMP_INTEGER(
+				circuit->area->min_spf_interval[level - 1]);
+		else
+			return SNMP_INTEGER(0);
+
+	case ISIS_CIRCLEVEL_CSNPINTERVAL:
+		return SNMP_INTEGER(circuit->csnp_interval[level - 1]);
+
+	case ISIS_CIRCLEVEL_PARTSNPINTERVAL:
+		return SNMP_INTEGER(circuit->psnp_interval[level - 1]);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_circ_counter(struct variable *v, oid *name,
+					    size_t *length, int exact,
+					    size_t *var_len,
+					    WriteMethod **write_method)
+{
+	/* Index circuit-id 1-255 + level */
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int res;
+	struct isis_circuit *circuit;
+	int level;
+	uint32_t val = 0;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+	if (exact) {
+		res = isis_snmp_circuit_level_lookup_exact(oid_idx, oid_idx_len,
+							   1, &circuit, &level);
+
+		if (!res || oid_idx_len != 2)
+			return NULL;
+
+	} else {
+		res = isis_snmp_circuit_level_lookup_next(oid_idx, oid_idx_len,
+							  1, &circuit, &level);
+
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = circuit->snmp_id;
+		if (circuit->circ_type == CIRCUIT_T_P2P)
+			name[v->namelen + 1] = ISIS_SNMP_P2P_CIRCUIT;
+		else
+			name[v->namelen + 1] = level;
+
+		/* Set length */
+		*length = v->namelen + 2;
+	}
+
+	switch (v->magic) {
+	case ISIS_CIRC_ADJCHANGES:
+		val = circuit->adj_state_changes;
+		break;
+
+	case ISIS_CIRC_NUMADJ:
+		if (circuit->circ_type == CIRCUIT_T_P2P) {
+			val = circuit->u.p2p.neighbor == NULL ? 0 : 1;
+			break;
+		}
+
+		if (circuit->circ_type != CIRCUIT_T_BROADCAST) {
+			val = 0;
+			break;
+		}
+
+		if (level == IS_LEVEL_1) {
+			if (circuit->u.bc.adjdb[0] == NULL)
+				val = 0;
+			else
+				val = listcount(circuit->u.bc.adjdb[0]);
+			break;
+		}
+
+		if (circuit->u.bc.adjdb[1] == NULL)
+			val = 0;
+		else
+			val = listcount(circuit->u.bc.adjdb[1]);
+
+		break;
+
+	case ISIS_CIRC_INITFAILS:
+		val = circuit->init_failures; /* counter never incremented */
+		break;
+
+	case ISIS_CIRC_REJADJS:
+		val = circuit->rej_adjacencies;
+		break;
+
+	case ISIS_CIRC_IDFIELDLENMISMATCHES:
+		val = circuit->id_len_mismatches;
+		break;
+
+	case ISIS_CIRC_MAXAREAADDRMISMATCHES:
+		val = circuit->max_area_addr_mismatches;
+		break;
+
+	case ISIS_CIRC_AUTHTYPEFAILS:
+		val = circuit->auth_type_failures;
+		break;
+
+	case ISIS_CIRC_AUTHFAILS:
+		val = circuit->auth_failures;
+		break;
+
+	case ISIS_CIRC_LANDESISCHANGES:
+		if (circuit->circ_type == CIRCUIT_T_P2P)
+			val = 0;
+		else
+			val = circuit->desig_changes[level - 1];
+		break;
+
+	default:
+		return NULL;
+	}
+
+	return SNMP_INTEGER(val);
+}
+
+static uint8_t *isis_snmp_find_isadj(struct variable *v, oid *name,
+				     size_t *length, int exact, size_t *var_len,
+				     WriteMethod **write_method)
+{
+	/* Index is circuit-id: 1-255 + adj-id: 1-... */
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int res;
+	time_t val;
+	struct isis_adjacency *adj;
+	uint32_t up_ticks;
+	uint32_t delta_ticks;
+	time_t now_time;
+
+	/* Ring buffer to print SNPA */
+#define FORMAT_BUF_COUNT 4
+	static char snpa[FORMAT_BUF_COUNT][ISO_SYSID_STRLEN];
+	static size_t cur_buf = 0;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+	if (exact) {
+		res = isis_snmp_adj_lookup_exact(oid_idx, oid_idx_len,
+						 ISIS_SNMP_ADJ_DATA_NONE, &adj,
+						 NULL, NULL, NULL);
+
+		if (!res || oid_idx_len != 2)
+			return NULL;
+
+	} else {
+		res = isis_snmp_adj_lookup_next(oid_idx, oid_idx_len,
+						ISIS_SNMP_ADJ_DATA_NONE, &adj,
+						NULL, NULL, NULL);
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = adj->circuit->snmp_id;
+		name[v->namelen + 1] = adj->snmp_idx;
+
+		/* Set length */
+		*length = v->namelen + 2;
+	}
+
+	switch (v->magic) {
+	case ISIS_ISADJ_STATE:
+		return SNMP_INTEGER(isis_snmp_adj_state(adj->adj_state));
+
+	case ISIS_ISADJ_3WAYSTATE:
+		return SNMP_INTEGER(adj->threeway_state);
+
+	case ISIS_ISADJ_NEIGHSNPAADDRESS: {
+		cur_buf = (cur_buf + 1) % FORMAT_BUF_COUNT;
+		snprintfrr(snpa[cur_buf], ISO_SYSID_STRLEN, "%pSY", adj->snpa);
+		*var_len = strlen(snpa[cur_buf]);
+		return (uint8_t *)snpa[cur_buf];
+	}
+
+	case ISIS_ISADJ_NEIGHSYSTYPE:
+		return SNMP_INTEGER(isis_snmp_adj_neightype(adj->sys_type));
+
+	case ISIS_ISADJ_NEIGHSYSID:
+		*var_len = sizeof(adj->sysid);
+		return adj->sysid;
+
+	case ISIS_ISADJ_NBREXTENDEDCIRCID:
+		return SNMP_INTEGER(adj->ext_circuit_id != 0 ? 1 : 0);
+
+	case ISIS_ISADJ_USAGE:
+		/* It seems that no value conversion is required */
+		return SNMP_INTEGER(adj->adj_usage);
+
+	case ISIS_ISADJ_HOLDTIMER:
+		/*
+		 * It seems that we want remaining timer
+		 */
+		if (adj->last_upd != 0) {
+			val = time(NULL);
+			if (val < (adj->last_upd + adj->hold_time))
+				return SNMP_INTEGER(adj->last_upd
+						    + adj->hold_time - val);
+		}
+		/* Not running or just expired */
+		return SNMP_INTEGER(0);
+
+	case ISIS_ISADJ_NEIGHPRIORITY:
+		return SNMP_INTEGER(adj->prio[adj->level - 1]);
+
+	case ISIS_ISADJ_LASTUPTIME:
+		if (adj->flaps == 0)
+			return SNMP_INTEGER(0);
+
+		up_ticks = (uint32_t)netsnmp_get_agent_uptime();
+
+		now_time = time(NULL);
+
+		if (adj->last_flap >= now_time)
+			return SNMP_INTEGER(up_ticks);
+
+		delta_ticks = (now_time - adj->last_flap) * 10;
+
+		if (up_ticks < delta_ticks)
+			return SNMP_INTEGER(up_ticks);
+
+		return SNMP_INTEGER(up_ticks - delta_ticks);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_isadj_area(struct variable *v, oid *name,
+					  size_t *length, int exact,
+					  size_t *var_len,
+					  WriteMethod **write_method)
+{
+	/* Index circuit-id: 1-255 + adj-id: 1-... */
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int res;
+	struct isis_adjacency *adj;
+	oid data_idx;
+	uint8_t *data;
+	size_t data_len;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+	if (exact) {
+		res = isis_snmp_adj_lookup_exact(oid_idx, oid_idx_len,
+						 ISIS_SNMP_ADJ_DATA_AREA_ADDR,
+						 &adj, NULL, &data, &data_len);
+
+		if (!res || oid_idx_len != 3)
+			return NULL;
+
+	} else {
+		res = isis_snmp_adj_lookup_next(
+			oid_idx, oid_idx_len, ISIS_SNMP_ADJ_DATA_AREA_ADDR,
+			&adj, &data_idx, &data, &data_len);
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = adj->circuit->snmp_id;
+		name[v->namelen + 1] = adj->snmp_idx;
+		name[v->namelen + 2] = data_idx;
+
+		/* Set length */
+		*length = v->namelen + 3;
+	}
+
+	switch (v->magic) {
+	case ISIS_ISADJAREA_ADDRESS:
+		*var_len = data_len;
+		return data;
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_isadj_ipaddr(struct variable *v, oid *name,
+					    size_t *length, int exact,
+					    size_t *var_len,
+					    WriteMethod **write_method)
+{
+	/* Index circuit-id 1-255 + adj-id 1-... */
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int res;
+	struct isis_adjacency *adj;
+	oid data_idx;
+	uint8_t *data;
+	size_t data_len;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+	if (exact) {
+		res = isis_snmp_adj_lookup_exact(oid_idx, oid_idx_len,
+						 ISIS_SNMP_ADJ_DATA_IP_ADDR,
+						 &adj, NULL, &data, &data_len);
+
+		if (!res || oid_idx_len != 3)
+			return NULL;
+	} else {
+		res = isis_snmp_adj_lookup_next(
+			oid_idx, oid_idx_len, ISIS_SNMP_ADJ_DATA_IP_ADDR, &adj,
+			&data_idx, &data, &data_len);
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = adj->circuit->snmp_id;
+		name[v->namelen + 1] = adj->snmp_idx;
+		name[v->namelen + 2] = data_idx;
+
+		/* Set length */
+		*length = v->namelen + 3;
+	}
+
+	switch (v->magic) {
+	case ISIS_ISADJIPADDR_TYPE:
+		if (data_len == 4)
+			return SNMP_INTEGER(ISIS_SNMP_INET_TYPE_V4);
+
+		return SNMP_INTEGER(ISIS_SNMP_INET_TYPE_V6);
+
+	case ISIS_ISADJIPADDR_ADDRESS:
+		*var_len = data_len;
+		return data;
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+static uint8_t *isis_snmp_find_isadj_prot_supp(struct variable *v, oid *name,
+					       size_t *length, int exact,
+					       size_t *var_len,
+					       WriteMethod **write_method)
+{
+	/* Index circuit-id 1-255 + adj-id 1-... */
+	oid *oid_idx;
+	size_t oid_idx_len;
+	int res;
+	struct isis_adjacency *adj;
+	oid data_idx;
+	uint8_t *data;
+	size_t data_len;
+
+	*write_method = NULL;
+
+	if (*length <= v->namelen) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else if (memcmp(name, v->name, v->namelen * sizeof(oid)) != 0) {
+		oid_idx = NULL;
+		oid_idx_len = 0;
+	} else {
+		oid_idx = name + v->namelen;
+		oid_idx_len = *length - v->namelen;
+	}
+	if (exact) {
+		res = isis_snmp_adj_lookup_exact(oid_idx, oid_idx_len,
+						 ISIS_SNMP_ADJ_DATA_PROTO, &adj,
+						 NULL, &data, &data_len);
+
+		if (!res || oid_idx_len != 3)
+			return NULL;
+
+	} else {
+		res = isis_snmp_adj_lookup_next(oid_idx, oid_idx_len,
+						ISIS_SNMP_ADJ_DATA_PROTO, &adj,
+						&data_idx, &data, &data_len);
+		if (!res)
+			return NULL;
+
+		/* Copy the name out */
+		memcpy(name, v->name, v->namelen * sizeof(oid));
+
+		/* Append index */
+		name[v->namelen] = adj->circuit->snmp_id;
+		name[v->namelen + 1] = adj->snmp_idx;
+		name[v->namelen + 2] = data_idx;
+
+		/* Set length */
+		*length = v->namelen + 3;
+	}
+
+	switch (v->magic) {
+	case ISIS_ISADJPROTSUPP_PROTOCOL:
+		return SNMP_INTEGER(*data);
+
+	default:
+		break;
+	}
+
+	return NULL;
+}
+
+
+/* Register ISIS-MIB. */
+static int isis_snmp_init(struct event_loop *tm)
+{
+	struct isis_func_to_prefix *h2f = isis_func_to_prefix_arr;
+	struct variable *v;
+
+	for (size_t off = 0; off < isis_var_count; off++) {
+		v = &isis_var_arr[off];
+
+		if (v->findVar != h2f->ihtp_func) {
+			/* Next table */
+			h2f++;
+			assert(h2f < (isis_func_to_prefix_arr
+				      + isis_func_to_prefix_count));
+			assert(v->findVar == h2f->ihtp_func);
+		}
+
+		v->namelen = h2f->ihtp_pref_len + 1;
+		memcpy(v->name, h2f->ihtp_pref_oid,
+		       h2f->ihtp_pref_len * sizeof(oid));
+		v->name[h2f->ihtp_pref_len] = v->magic;
+	}
+
+
+	smux_init(tm);
+	REGISTER_MIB("mibII/isis", isis_var_arr, variable, isis_oid);
+	return 0;
+}
+
+/*
+ * ISIS notification functions: we have one function per notification
+ */
+static int isis_snmp_trap_throttle(oid trap_id)
+{
+	time_t time_now;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL || !isis->snmp_notifications || !smux_enabled())
+		return 0;
+
+	time_now = time(NULL);
+
+	if ((isis_snmp_trap_timestamp[trap_id] + 5) > time_now)
+		/* Throttle trap rate at 1 in 5 secs */
+		return 0;
+
+	isis_snmp_trap_timestamp[trap_id] = time_now;
+	return 1;
+}
+
+static int isis_snmp_db_overload_update(const struct isis_area *area)
+{
+	netsnmp_variable_list *notification_vars;
+	long val;
+	uint32_t off;
+
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_DB_OVERLOAD))
+		return 0;
+
+	notification_vars = NULL;
+
+	/* Put in trap value */
+	snmp_varlist_add_variable(&notification_vars, isis_snmp_trap_var,
+				  array_size(isis_snmp_trap_var), ASN_OBJECT_ID,
+				  (uint8_t *)&isis_snmp_trap_val_db_overload,
+				  sizeof(isis_snmp_trap_val_db_overload));
+
+	/* Prepare data */
+	val = area->is_type;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_sys_level_index,
+		array_size(isis_snmp_trap_data_var_sys_level_index), INTEGER,
+		(uint8_t *)&val, sizeof(val));
+
+	/* Patch sys_level_state with proper index */
+	off = array_size(isis_snmp_trap_data_var_sys_level_state) - 1;
+	isis_snmp_trap_data_var_sys_level_state[off] = val;
+
+	/* Prepare data */
+	if (area->overload_bit)
+		val = ISIS_SNMP_LEVEL_STATE_OVERLOADED;
+	else
+		val = ISIS_SNMP_LEVEL_STATE_ON;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_sys_level_state,
+		array_size(isis_snmp_trap_data_var_sys_level_state), INTEGER,
+		(uint8_t *)&val, sizeof(val));
+
+	send_v2trap(notification_vars);
+	snmp_free_varbind(notification_vars);
+	smux_events_update();
+	return 0;
+}
+
+static int isis_snmp_lsp_exceed_max_update(const struct isis_area *area,
+					   const uint8_t *lsp_id)
+{
+	netsnmp_variable_list *notification_vars;
+	long val;
+
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_LSP_EXCEED_MAX))
+		return 0;
+
+	notification_vars = NULL;
+
+	/* Put in trap value */
+	snmp_varlist_add_variable(&notification_vars, isis_snmp_trap_var,
+				  array_size(isis_snmp_trap_var), ASN_OBJECT_ID,
+				  (uint8_t *)&isis_snmp_trap_val_lsp_exceed_max,
+				  sizeof(isis_snmp_trap_val_lsp_exceed_max));
+
+	/* Prepare data */
+	val = area->is_type;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_sys_level_index,
+		array_size(isis_snmp_trap_data_var_sys_level_index), INTEGER,
+		(uint8_t *)&val, sizeof(val));
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_pdu_lsp_id,
+		array_size(isis_snmp_trap_data_var_pdu_lsp_id), STRING, lsp_id,
+		ISIS_SYS_ID_LEN + 2);
+
+	send_v2trap(notification_vars);
+	snmp_free_varbind(notification_vars);
+	smux_events_update();
+	return 0;
+}
+
+
+/*
+ * A common function to handle popular combination of trap objects
+ * isisNotificationSysLevelIndex,
+ * optional-object-a
+ * isisNotificationCircIfIndex,
+ * optional-object-b
+ */
+static void isis_snmp_update_worker_a(const struct isis_circuit *circuit,
+				      oid trap_id, const oid *oid_a,
+				      size_t oid_a_len, uint8_t type_a,
+				      const void *data_a, size_t data_a_len,
+				      const oid *oid_b, size_t oid_b_len,
+				      uint8_t type_b, const void *data_b,
+				      size_t data_b_len)
+{
+	netsnmp_variable_list *notification_vars = NULL;
+	oid var_name[MAX_OID_LEN];
+	size_t var_count;
+	long val;
+
+	/* Sanity */
+	if (trap_id != ISIS_TRAP_ID_LEN_MISMATCH
+	    && trap_id != ISIS_TRAP_MAX_AREA_ADDR_MISMATCH
+	    && trap_id != ISIS_TRAP_OWN_LSP_PURGE
+	    && trap_id != ISIS_TRAP_SEQNO_SKIPPED
+	    && trap_id != ISIS_TRAP_AUTHEN_TYPE_FAILURE
+	    && trap_id != ISIS_TRAP_AUTHEN_FAILURE
+	    && trap_id != ISIS_TRAP_REJ_ADJACENCY)
+		return;
+
+	/* Put in trap value */
+	memcpy(var_name, isis_snmp_notifications,
+	       sizeof(isis_snmp_notifications));
+	var_count = array_size(isis_snmp_notifications);
+	var_name[var_count++] = trap_id;
+
+	/* Put in trap value */
+	snmp_varlist_add_variable(&notification_vars, isis_snmp_trap_var,
+				  array_size(isis_snmp_trap_var), ASN_OBJECT_ID,
+				  (uint8_t *)var_name, var_count * sizeof(oid));
+
+	val = circuit->is_type;
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_sys_level_index,
+		array_size(isis_snmp_trap_data_var_sys_level_index), INTEGER,
+		(uint8_t *)&val, sizeof(val));
+
+	if (oid_a_len != 0) {
+		if (oid_a == NULL || data_a == NULL || data_a_len == 0)
+			return;
+
+		snmp_varlist_add_variable(&notification_vars, oid_a, oid_a_len,
+					  type_a, (uint8_t *)data_a,
+					  data_a_len);
+	}
+
+	if (circuit->interface == NULL)
+		val = 0;
+	else
+		val = circuit->interface->ifindex;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_circ_if_index,
+		array_size(isis_snmp_trap_data_var_circ_if_index), UNSIGNED32,
+		(uint8_t *)&val, sizeof(val));
+
+
+	if (oid_b_len != 0) {
+		if (oid_b == NULL || data_b == NULL || data_b_len == 0)
+			return;
+
+		snmp_varlist_add_variable(&notification_vars, oid_b, oid_b_len,
+					  type_b, (uint8_t *)data_b,
+					  data_b_len);
+	}
+
+	send_v2trap(notification_vars);
+	snmp_free_varbind(notification_vars);
+	smux_events_update();
+}
+
+/*
+ * A common function to handle popular combination of trap objects
+ * isisNotificationSysLevelIndex,
+ * isisNotificationCircIfIndex,
+ * optional-var-a
+ * optional-var-b
+ *
+ * Note: the only difference with worker_a is order of circ-if-index vs
+ * optional-var-a
+ */
+static void isis_snmp_update_worker_b(const struct isis_circuit *circuit,
+				      oid trap_id, const oid *oid_a,
+				      size_t oid_a_len, uint8_t type_a,
+				      const void *data_a, size_t data_a_len,
+				      const oid *oid_b, size_t oid_b_len,
+				      uint8_t type_b, const void *data_b,
+				      size_t data_b_len)
+{
+	netsnmp_variable_list *notification_vars = NULL;
+	oid var_name[MAX_OID_LEN];
+	size_t var_count;
+	long val;
+
+	/* Sanity */
+	if (trap_id != ISIS_TRAP_VERSION_SKEW
+	    && trap_id != ISIS_TRAP_LSP_TOO_LARGE
+	    && trap_id != ISIS_TRAP_ADJ_STATE_CHANGE)
+		return;
+
+	/* Put in trap value */
+	memcpy(var_name, isis_snmp_notifications,
+	       sizeof(isis_snmp_notifications));
+	var_count = array_size(isis_snmp_notifications);
+	var_name[var_count++] = trap_id;
+
+	/* Put in trap value */
+	snmp_varlist_add_variable(&notification_vars, isis_snmp_trap_var,
+				  array_size(isis_snmp_trap_var), ASN_OBJECT_ID,
+				  (uint8_t *)var_name, var_count * sizeof(oid));
+
+	val = circuit->is_type;
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_sys_level_index,
+		array_size(isis_snmp_trap_data_var_sys_level_index), INTEGER,
+		(uint8_t *)&val, sizeof(val));
+
+	if (circuit->interface == NULL)
+		val = 0;
+	else
+		val = circuit->interface->ifindex;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_circ_if_index,
+		array_size(isis_snmp_trap_data_var_circ_if_index), UNSIGNED32,
+		(uint8_t *)&val, sizeof(val));
+
+
+	if (oid_a_len != 0) {
+		if (oid_a == NULL || data_a == NULL || data_a_len == 0)
+			return;
+
+		snmp_varlist_add_variable(&notification_vars, oid_a, oid_a_len,
+					  type_a, (uint8_t *)data_a,
+					  data_a_len);
+	}
+
+	if (oid_b_len != 0) {
+		if (oid_b == NULL || data_b == NULL || data_b_len == 0)
+			return;
+
+		snmp_varlist_add_variable(&notification_vars, oid_b, oid_b_len,
+					  type_b, (uint8_t *)data_b,
+					  data_b_len);
+	}
+
+	send_v2trap(notification_vars);
+	snmp_free_varbind(notification_vars);
+	smux_events_update();
+}
+
+
+static int isis_snmp_id_len_mismatch_update(const struct isis_circuit *circuit,
+					    uint8_t rcv_id, const char *raw_pdu,
+					    size_t raw_pdu_len)
+{
+	long val;
+
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_ID_LEN_MISMATCH))
+		return 0;
+
+	val = rcv_id;
+
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	isis_snmp_update_worker_a(
+		circuit, ISIS_TRAP_ID_LEN_MISMATCH,
+		isis_snmp_trap_data_var_pdu_field_len,
+		array_size(isis_snmp_trap_data_var_pdu_field_len), UNSIGNED32,
+		&val, sizeof(val), isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+	return 0;
+}
+
+static int
+isis_snmp_max_area_addr_mismatch_update(const struct isis_circuit *circuit,
+					uint8_t max_addrs, const char *raw_pdu,
+					size_t raw_pdu_len)
+{
+	long val;
+
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_MAX_AREA_ADDR_MISMATCH))
+		return 0;
+
+	val = max_addrs;
+
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	isis_snmp_update_worker_a(
+		circuit, ISIS_TRAP_MAX_AREA_ADDR_MISMATCH,
+		isis_snmp_trap_data_var_pdu_max_area_addr,
+		array_size(isis_snmp_trap_data_var_pdu_max_area_addr),
+		UNSIGNED32, &val, sizeof(val),
+		isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+	return 0;
+}
+
+static int isis_snmp_own_lsp_purge_update(const struct isis_circuit *circuit,
+					  const uint8_t *lsp_id)
+{
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_OWN_LSP_PURGE))
+		return 0;
+
+	isis_snmp_update_worker_a(
+		circuit, ISIS_TRAP_OWN_LSP_PURGE, NULL, 0, STRING, NULL, 0,
+		isis_snmp_trap_data_var_pdu_lsp_id,
+		array_size(isis_snmp_trap_data_var_pdu_lsp_id), STRING, lsp_id,
+		ISIS_SYS_ID_LEN + 2);
+	return 0;
+}
+
+static int isis_snmp_seqno_skipped_update(const struct isis_circuit *circuit,
+					  const uint8_t *lsp_id)
+{
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_SEQNO_SKIPPED))
+		return 0;
+
+	isis_snmp_update_worker_a(
+		circuit, ISIS_TRAP_SEQNO_SKIPPED, NULL, 0, STRING, NULL, 0,
+		isis_snmp_trap_data_var_pdu_lsp_id,
+		array_size(isis_snmp_trap_data_var_pdu_lsp_id), STRING, lsp_id,
+		ISIS_SYS_ID_LEN + 2);
+	return 0;
+}
+
+static int
+isis_snmp_authentication_type_failure_update(const struct isis_circuit *circuit,
+					     const char *raw_pdu,
+					     size_t raw_pdu_len)
+{
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_AUTHEN_TYPE_FAILURE))
+		return 0;
+
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	isis_snmp_update_worker_a(
+		circuit, ISIS_TRAP_AUTHEN_TYPE_FAILURE, NULL, 0, STRING, NULL,
+		0, isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+	return 0;
+}
+
+static int
+isis_snmp_authentication_failure_update(const struct isis_circuit *circuit,
+					char const *raw_pdu, size_t raw_pdu_len)
+{
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_AUTHEN_FAILURE))
+		return 0;
+
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	isis_snmp_update_worker_a(
+		circuit, ISIS_TRAP_AUTHEN_FAILURE, NULL, 0, STRING, NULL, 0,
+		isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+	return 0;
+}
+
+static int isis_snmp_version_skew_update(const struct isis_circuit *circuit,
+					 uint8_t version, const char *raw_pdu,
+					 size_t raw_pdu_len)
+{
+	long val;
+
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_VERSION_SKEW))
+		return 0;
+
+	val = version;
+
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	isis_snmp_update_worker_b(
+		circuit, ISIS_TRAP_VERSION_SKEW,
+		isis_snmp_trap_data_var_pdu_proto_ver,
+		array_size(isis_snmp_trap_data_var_pdu_proto_ver), UNSIGNED32,
+		&val, sizeof(val), isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+	return 0;
+}
+
+static int isis_snmp_area_mismatch_update(const struct isis_circuit *circuit,
+					  const char *raw_pdu,
+					  size_t raw_pdu_len)
+{
+	/*
+	 * This is a special case because
+	 * it does not include isisNotificationSysLevelIndex
+	 */
+	netsnmp_variable_list *notification_vars;
+	long val;
+
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_AREA_MISMATCH))
+		return 0;
+
+	notification_vars = NULL;
+
+	/* Put in trap value */
+	snmp_varlist_add_variable(&notification_vars, isis_snmp_trap_var,
+				  array_size(isis_snmp_trap_var), ASN_OBJECT_ID,
+				  (uint8_t *)&isis_snmp_trap_val_area_mismatch,
+				  sizeof(isis_snmp_trap_val_area_mismatch));
+
+
+	if (circuit->interface == NULL)
+		val = 0;
+	else
+		val = circuit->interface->ifindex;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_circ_if_index,
+		array_size(isis_snmp_trap_data_var_circ_if_index), UNSIGNED32,
+		(uint8_t *)&val, sizeof(val));
+
+
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+
+	send_v2trap(notification_vars);
+	snmp_free_varbind(notification_vars);
+	smux_events_update();
+
+	return 0;
+}
+
+static int isis_snmp_reject_adjacency_update(const struct isis_circuit *circuit,
+					     const char *raw_pdu,
+					     size_t raw_pdu_len)
+{
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_REJ_ADJACENCY))
+		return 0;
+
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	isis_snmp_update_worker_a(
+		circuit, ISIS_TRAP_REJ_ADJACENCY, NULL, 0, STRING, NULL, 0,
+		isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+	return 0;
+}
+
+static int isis_snmp_lsp_too_large_update(const struct isis_circuit *circuit,
+					  uint32_t pdu_size,
+					  const uint8_t *lsp_id)
+{
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_LSP_TOO_LARGE))
+		return 0;
+
+	isis_snmp_update_worker_b(
+		circuit, ISIS_TRAP_LSP_TOO_LARGE,
+		isis_snmp_trap_data_var_pdu_lsp_size,
+		array_size(isis_snmp_trap_data_var_pdu_lsp_size), UNSIGNED32,
+		&pdu_size, sizeof(pdu_size), isis_snmp_trap_data_var_pdu_lsp_id,
+		array_size(isis_snmp_trap_data_var_pdu_lsp_id), STRING, lsp_id,
+		ISIS_SYS_ID_LEN + 2);
+	return 0;
+}
+
+
+static int isis_snmp_adj_state_change_update(const struct isis_adjacency *adj)
+{
+	uint8_t lsp_id[ISIS_SYS_ID_LEN + 2];
+	long val;
+	struct isis *isis = isis_lookup_by_vrfid(VRF_DEFAULT);
+
+	if (isis == NULL || !isis->snmp_notifications || !smux_enabled())
+		return 0;
+
+	/* Prepare data */
+	memcpy(lsp_id, adj->sysid, ISIS_SYS_ID_LEN);
+	lsp_id[ISIS_SYS_ID_LEN] = 0;
+	lsp_id[ISIS_SYS_ID_LEN + 1] = 0;
+
+	val = isis_snmp_adj_state(adj->adj_state);
+
+	isis_snmp_update_worker_b(
+		adj->circuit, ISIS_TRAP_ADJ_STATE_CHANGE,
+		isis_snmp_trap_data_var_pdu_lsp_id,
+		array_size(isis_snmp_trap_data_var_pdu_lsp_id), STRING, lsp_id,
+		ISIS_SYS_ID_LEN + 2, isis_snmp_trap_data_var_adj_state,
+		array_size(isis_snmp_trap_data_var_adj_state), INTEGER, &val,
+		sizeof(val));
+	return 0;
+}
+
+static int isis_snmp_lsp_error_update(const struct isis_circuit *circuit,
+				      const uint8_t *lsp_id,
+				      char const *raw_pdu, size_t raw_pdu_len)
+{
+	/*
+	 * This is a special case because
+	 * it have more variables
+	 */
+	netsnmp_variable_list *notification_vars;
+	long val;
+
+	if (!isis_snmp_trap_throttle(ISIS_TRAP_LSP_ERROR))
+		return 0;
+
+	notification_vars = NULL;
+
+	/* Put in trap value */
+	snmp_varlist_add_variable(&notification_vars, isis_snmp_trap_var,
+				  array_size(isis_snmp_trap_var), ASN_OBJECT_ID,
+				  (uint8_t *)&isis_snmp_trap_val_lsp_error,
+				  sizeof(isis_snmp_trap_val_lsp_error));
+
+	/* Prepare data */
+	val = circuit->is_type;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_sys_level_index,
+		array_size(isis_snmp_trap_data_var_sys_level_index), INTEGER,
+		(uint8_t *)&val, sizeof(val));
+
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_pdu_lsp_id,
+		array_size(isis_snmp_trap_data_var_pdu_lsp_id), STRING, lsp_id,
+		ISIS_SYS_ID_LEN + 2);
+
+	/* Prepare data */
+	if (circuit->interface == NULL)
+		val = 0;
+	else
+		val = circuit->interface->ifindex;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_circ_if_index,
+		array_size(isis_snmp_trap_data_var_circ_if_index), UNSIGNED32,
+		(uint8_t *)&val, sizeof(val));
+
+	/* Prepare data */
+	if (raw_pdu_len > ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN)
+		raw_pdu_len = ISIS_SNMP_TRAP_PDU_FRAGMENT_MAX_LEN;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_pdu_fragment,
+		array_size(isis_snmp_trap_data_var_pdu_fragment), STRING,
+		raw_pdu, raw_pdu_len);
+
+	/* Prepare data */
+	val = 0;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_error_offset,
+		array_size(isis_snmp_trap_data_var_error_offset), UNSIGNED32,
+		(uint8_t *)&val, sizeof(val));
+
+	/* Prepare data */
+	val = 0;
+
+	snmp_varlist_add_variable(
+		&notification_vars, isis_snmp_trap_data_var_error_tlv_type,
+		array_size(isis_snmp_trap_data_var_error_tlv_type), UNSIGNED32,
+		(uint8_t *)&val, sizeof(val));
+
+	send_v2trap(notification_vars);
+	snmp_free_varbind(notification_vars);
+	smux_events_update();
+	return 0;
+}
+
+
+static int isis_snmp_module_init(void)
+{
+	hook_register(isis_hook_db_overload, isis_snmp_db_overload_update);
+	hook_register(isis_hook_lsp_exceed_max,
+		      isis_snmp_lsp_exceed_max_update);
+	hook_register(isis_hook_id_len_mismatch,
+		      isis_snmp_id_len_mismatch_update);
+	hook_register(isis_hook_max_area_addr_mismatch,
+		      isis_snmp_max_area_addr_mismatch_update);
+	hook_register(isis_hook_own_lsp_purge, isis_snmp_own_lsp_purge_update);
+	hook_register(isis_hook_seqno_skipped, isis_snmp_seqno_skipped_update);
+	hook_register(isis_hook_authentication_type_failure,
+		      isis_snmp_authentication_type_failure_update);
+	hook_register(isis_hook_authentication_failure,
+		      isis_snmp_authentication_failure_update);
+	hook_register(isis_hook_version_skew, isis_snmp_version_skew_update);
+	hook_register(isis_hook_area_mismatch, isis_snmp_area_mismatch_update);
+	hook_register(isis_hook_reject_adjacency,
+		      isis_snmp_reject_adjacency_update);
+	hook_register(isis_hook_lsp_too_large, isis_snmp_lsp_too_large_update);
+	hook_register(isis_hook_adj_state_change,
+		      isis_snmp_adj_state_change_update);
+	hook_register(isis_hook_lsp_error, isis_snmp_lsp_error_update);
+	hook_register(isis_circuit_new_hook, isis_circuit_snmp_id_gen);
+	hook_register(isis_circuit_del_hook, isis_circuit_snmp_id_free);
+
+	hook_register(frr_late_init, isis_snmp_init);
+	return 0;
+}
+
+FRR_MODULE_SETUP(
+	.name = "isis_snmp",
+	.version = FRR_VERSION,
+	.description = "isis AgentX SNMP module",
+	.init = isis_snmp_module_init,
+);