isisd: add new tlv parser

Signed-off-by: Christian Franke <chris@opensourcerouting.org>

isisd/Makefile.am

@@ -8,7 +8,7 @@ LIBS = @LIBS@
 AM_CFLAGS = $(WERROR)
 
 noinst_LIBRARIES = libisis.a
-sbin_PROGRAMS = isisd 
+sbin_PROGRAMS = isisd
 
 libisis_a_SOURCES = \
 	isis_memory.c \
@@ -16,7 +16,8 @@ libisis_a_SOURCES = \
 	isis_tlv.c isisd.c isis_misc.c isis_zebra.c isis_dr.c \
 	isis_flags.c isis_dynhn.c iso_checksum.c isis_csm.c isis_events.c \
 	isis_spf.c isis_redist.c isis_route.c isis_routemap.c isis_te.c \
-	isis_vty.c isis_mt.c
+	isis_vty.c isis_mt.c \
+	isis_tlvs2.c
 
 
 noinst_HEADERS = \
@@ -25,7 +26,8 @@ noinst_HEADERS = \
 	isis_lsp.h dict.h isis_circuit.h isis_misc.h isis_network.h \
 	isis_zebra.h isis_dr.h isis_flags.h isis_dynhn.h isis_common.h \
 	iso_checksum.h isis_csm.h isis_events.h isis_spf.h isis_redist.h \
-	isis_route.h isis_routemap.h isis_te.h isis_mt.h
+	isis_route.h isis_routemap.h isis_te.h isis_mt.h \
+	isis_tlvs2.h
 
 isisd_SOURCES = \
 	isis_main.c $(libisis_a_SOURCES) \

isisd/isis_mt.h

@@ -24,6 +24,7 @@
 
 #define ISIS_MT_MASK           0x0fff
 #define ISIS_MT_OL_MASK        0x8000
+#define ISIS_MT_AT_MASK        0x4000
 
 #define ISIS_MT_IPV4_UNICAST   0
 #define ISIS_MT_IPV4_MGMT      1

isisd/isis_tlvs2.h

@@ -0,0 +1,308 @@
+/*
+ * 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.
+ */
+#ifndef ISIS_TLVS2_H
+#define ISIS_TLVS2_H
+
+#include "openbsd-tree.h"
+#include "prefix.h"
+#include "isisd/dict.h"
+
+struct isis_subtlvs;
+
+struct isis_area_address;
+struct isis_area_address {
+	struct isis_area_address *next;
+
+	uint8_t addr[20];
+	uint8_t len;
+};
+
+struct isis_oldstyle_reach;
+struct isis_oldstyle_reach {
+	struct isis_oldstyle_reach *next;
+
+	uint8_t id[7];
+	uint8_t metric;
+};
+
+struct isis_oldstyle_ip_reach;
+struct isis_oldstyle_ip_reach {
+	struct isis_oldstyle_ip_reach *next;
+
+	uint8_t metric;
+	struct prefix_ipv4 prefix;
+};
+
+struct isis_lsp_entry;
+struct isis_lsp_entry {
+	struct isis_lsp_entry *next;
+
+	uint16_t rem_lifetime;
+	uint8_t id[8];
+	uint16_t checksum;
+	uint32_t seqno;
+
+	struct isis_lsp *lsp;
+};
+
+struct isis_extended_reach;
+struct isis_extended_reach {
+	struct isis_extended_reach *next;
+
+	uint8_t id[7];
+	uint32_t metric;
+
+	uint8_t *subtlvs;
+	uint8_t subtlv_len;
+};
+
+struct isis_extended_ip_reach;
+struct isis_extended_ip_reach {
+	struct isis_extended_ip_reach *next;
+
+	uint32_t metric;
+	bool down;
+	struct prefix_ipv4 prefix;
+};
+
+struct isis_ipv6_reach;
+struct isis_ipv6_reach {
+	struct isis_ipv6_reach *next;
+
+	uint32_t metric;
+	bool down;
+	bool external;
+
+	struct prefix_ipv6 prefix;
+
+	struct isis_subtlvs *subtlvs;
+};
+
+struct isis_protocols_supported {
+	uint8_t count;
+	uint8_t *protocols;
+};
+
+struct isis_item;
+struct isis_item {
+	struct isis_item *next;
+};
+
+struct isis_lan_neighbor;
+struct isis_lan_neighbor {
+	struct isis_lan_neighbor *next;
+
+	uint8_t mac[6];
+};
+
+struct isis_ipv4_address;
+struct isis_ipv4_address {
+	struct isis_ipv4_address *next;
+
+	struct in_addr addr;
+};
+
+struct isis_ipv6_address;
+struct isis_ipv6_address {
+	struct isis_ipv6_address *next;
+
+	struct in6_addr addr;
+};
+
+struct isis_mt_router_info;
+struct isis_mt_router_info {
+	struct isis_mt_router_info *next;
+
+	bool overload;
+	bool attached;
+	uint16_t mtid;
+};
+
+struct isis_auth;
+struct isis_auth {
+	struct isis_auth *next;
+
+	uint8_t type;
+	uint8_t length;
+	uint8_t value[256];
+
+	uint8_t plength;
+	uint8_t passwd[256];
+
+	size_t offset; /* Only valid after packing */
+};
+
+struct isis_item_list;
+struct isis_item_list {
+	struct isis_item *head;
+	struct isis_item **tail;
+
+	RB_ENTRY(isis_item_list) mt_tree;
+	uint16_t mtid;
+	unsigned int count;
+};
+
+RB_HEAD(isis_mt_item_list, isis_item_list);
+
+struct isis_item_list *isis_get_mt_items(struct isis_mt_item_list *m,
+					 uint16_t mtid);
+struct isis_item_list *isis_lookup_mt_items(struct isis_mt_item_list *m,
+					    uint16_t mtid);
+
+struct isis_tlvs {
+	struct isis_item_list isis_auth;
+	struct isis_item_list area_addresses;
+	struct isis_item_list oldstyle_reach;
+	struct isis_item_list lan_neighbor;
+	struct isis_item_list lsp_entries;
+	struct isis_item_list extended_reach;
+	struct isis_mt_item_list mt_reach;
+	struct isis_item_list oldstyle_ip_reach;
+	struct isis_protocols_supported protocols_supported;
+	struct isis_item_list oldstyle_ip_reach_ext;
+	struct isis_item_list ipv4_address;
+	struct isis_item_list ipv6_address;
+	struct isis_item_list mt_router_info;
+	bool mt_router_info_empty;
+	struct in_addr *te_router_id;
+	struct isis_item_list extended_ip_reach;
+	struct isis_mt_item_list mt_ip_reach;
+	char *hostname;
+	struct isis_item_list ipv6_reach;
+	struct isis_mt_item_list mt_ipv6_reach;
+};
+
+struct isis_subtlvs {
+	/* draft-baker-ipv6-isis-dst-src-routing-06 */
+	struct prefix_ipv6 *source_prefix;
+};
+
+enum isis_tlv_context {
+	ISIS_CONTEXT_LSP,
+	ISIS_CONTEXT_SUBTLV_NE_REACH,
+	ISIS_CONTEXT_SUBTLV_IP_REACH,
+	ISIS_CONTEXT_SUBTLV_IPV6_REACH,
+	ISIS_CONTEXT_MAX
+};
+
+enum isis_tlv_type {
+	ISIS_TLV_AREA_ADDRESSES = 1,
+	ISIS_TLV_OLDSTYLE_REACH = 2,
+	ISIS_TLV_LAN_NEIGHBORS = 6,
+	ISIS_TLV_PADDING = 8,
+	ISIS_TLV_LSP_ENTRY = 9,
+	ISIS_TLV_AUTH = 10,
+	ISIS_TLV_EXTENDED_REACH = 22,
+
+	ISIS_TLV_OLDSTYLE_IP_REACH = 128,
+	ISIS_TLV_PROTOCOLS_SUPPORTED = 129,
+	ISIS_TLV_OLDSTYLE_IP_REACH_EXT = 130,
+	ISIS_TLV_IPV4_ADDRESS = 132,
+	ISIS_TLV_TE_ROUTER_ID = 134,
+	ISIS_TLV_EXTENDED_IP_REACH = 135,
+	ISIS_TLV_DYNAMIC_HOSTNAME = 137,
+	ISIS_TLV_MT_REACH = 222,
+	ISIS_TLV_MT_ROUTER_INFO = 229,
+	ISIS_TLV_IPV6_ADDRESS = 232,
+	ISIS_TLV_MT_IP_REACH = 235,
+	ISIS_TLV_IPV6_REACH = 236,
+	ISIS_TLV_MT_IPV6_REACH = 237,
+	ISIS_TLV_MAX = 256,
+
+	ISIS_SUBTLV_IPV6_SOURCE_PREFIX = 22
+};
+
+#define IS_COMPAT_MT_TLV(tlv_type)                                             \
+	((tlv_type == ISIS_TLV_MT_REACH) || (tlv_type == ISIS_TLV_MT_IP_REACH) \
+	 || (tlv_type == ISIS_TLV_MT_IPV6_REACH))
+
+struct stream;
+int isis_pack_tlvs(struct isis_tlvs *tlvs, struct stream *stream,
+		   size_t len_pointer, bool pad, bool is_lsp);
+void isis_free_tlvs(struct isis_tlvs *tlvs);
+struct isis_tlvs *isis_alloc_tlvs(void);
+int isis_unpack_tlvs(size_t avail_len, struct stream *stream,
+		     struct isis_tlvs **dest, const char **error_log);
+const char *isis_format_tlvs(struct isis_tlvs *tlvs);
+struct isis_tlvs *isis_copy_tlvs(struct isis_tlvs *tlvs);
+struct list *isis_fragment_tlvs(struct isis_tlvs *tlvs, size_t size);
+
+#define ISIS_EXTENDED_IP_REACH_DOWN 0x80
+#define ISIS_EXTENDED_IP_REACH_SUBTLV 0x40
+
+#define ISIS_IPV6_REACH_DOWN 0x80
+#define ISIS_IPV6_REACH_EXTERNAL 0x40
+#define ISIS_IPV6_REACH_SUBTLV 0x20
+
+#ifndef ISIS_MT_MASK
+#define ISIS_MT_MASK           0x0fff
+#define ISIS_MT_OL_MASK        0x8000
+#define ISIS_MT_AT_MASK        0x4000
+#endif
+
+
+void isis_tlvs_add_auth(struct isis_tlvs *tlvs, struct isis_passwd *passwd);
+void isis_tlvs_add_area_addresses(struct isis_tlvs *tlvs,
+				  struct list *addresses);
+void isis_tlvs_add_lan_neighbors(struct isis_tlvs *tlvs,
+				 struct list *neighbors);
+void isis_tlvs_set_protocols_supported(struct isis_tlvs *tlvs,
+				       struct nlpids *nlpids);
+void isis_tlvs_add_mt_router_info(struct isis_tlvs *tlvs, uint16_t mtid,
+				  bool overload, bool attached);
+void isis_tlvs_add_ipv4_address(struct isis_tlvs *tlvs, struct in_addr *addr);
+void isis_tlvs_add_ipv4_addresses(struct isis_tlvs *tlvs,
+				  struct list *addresses);
+void isis_tlvs_add_ipv6_addresses(struct isis_tlvs *tlvs,
+				  struct list *addresses);
+bool isis_tlvs_auth_is_valid(struct isis_tlvs *tlvs, struct isis_passwd *passwd,
+			     struct stream *stream, bool is_lsp);
+bool isis_tlvs_area_addresses_match(struct isis_tlvs *tlvs,
+				    struct list *addresses);
+struct isis_adjacency;
+void isis_tlvs_to_adj(struct isis_tlvs *tlvs, struct isis_adjacency *adj,
+		      bool *changed);
+bool isis_tlvs_own_snpa_found(struct isis_tlvs *tlvs, uint8_t *snpa);
+void isis_tlvs_add_lsp_entry(struct isis_tlvs *tlvs, struct isis_lsp *lsp);
+void isis_tlvs_add_csnp_entries(struct isis_tlvs *tlvs, uint8_t *start_id,
+				uint8_t *stop_id, uint16_t num_lsps,
+				dict_t *lspdb, struct isis_lsp **last_lsp);
+void isis_tlvs_set_dynamic_hostname(struct isis_tlvs *tlvs,
+				    const char *hostname);
+void isis_tlvs_set_te_router_id(struct isis_tlvs *tlvs,
+				const struct in_addr *id);
+void isis_tlvs_add_oldstyle_ip_reach(struct isis_tlvs *tlvs,
+				     struct prefix_ipv4 *dest, uint8_t metric);
+void isis_tlvs_add_extended_ip_reach(struct isis_tlvs *tlvs,
+				     struct prefix_ipv4 *dest, uint32_t metric);
+void isis_tlvs_add_ipv6_reach(struct isis_tlvs *tlvs, uint16_t mtid,
+			      struct prefix_ipv6 *dest, uint32_t metric);
+void isis_tlvs_add_oldstyle_reach(struct isis_tlvs *tlvs, uint8_t *id,
+				  uint8_t metric);
+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_mt_router_info *
+isis_tlvs_lookup_mt_router_info(struct isis_tlvs *tlvs, uint16_t mtid);
+#endif

tests/.gitignore

@@ -25,6 +25,8 @@ __pycache__
 /bgpd/test_ecommunity
 /bgpd/test_mp_attr
 /bgpd/test_mpath
+/isisd/test_fuzz_isis_tlv
+/isisd/test_fuzz_isis_tlv_tests.h
 /lib/cli/test_cli
 /lib/cli/test_commands
 /lib/cli/test_commands_defun.c

tests/Makefile.am

@@ -24,6 +24,13 @@ else
 TESTS_BGPD =
 endif
 
+if ISISD
+TESTS_ISISD = \
+	isisd/test_fuzz_isis_tlv
+else
+TESTS_ISISD =
+endif
+
 if OSPF6D
 TESTS_OSPF6D = \
 	ospf6d/test_lsdb \
@@ -61,6 +68,7 @@ check_PROGRAMS = \
 	lib/cli/test_cli \
 	lib/cli/test_commands \
 	$(TESTS_BGPD) \
+	$(TESTS_ISISD) \
 	$(TESTS_OSPF6D) \
 	# end
 
@@ -75,7 +83,12 @@ lib/cli/test_commands_defun.c: ../vtysh/vtysh_cmd.c
 		< ../vtysh/vtysh_cmd.c \
 		> "$@"
 
-BUILT_SOURCES = lib/cli/test_commands_defun.c
+isisd/test_fuzz_isis_tlv_tests.h: $(top_srcdir)/tests/isisd/test_fuzz_isis_tlv_tests.h.gz
+	gzip -d < $(top_srcdir)/tests/isisd/test_fuzz_isis_tlv_tests.h.gz > "$@"
+
+BUILT_SOURCES = \
+	lib/cli/test_commands_defun.c \
+	isisd/test_fuzz_isis_tlv_tests.h
 
 noinst_HEADERS = \
 	./helpers/c/prng.h \
@@ -110,11 +123,14 @@ bgpd_test_capability_SOURCES = bgpd/test_capability.c
 bgpd_test_ecommunity_SOURCES = bgpd/test_ecommunity.c
 bgpd_test_mp_attr_SOURCES = bgpd/test_mp_attr.c
 bgpd_test_mpath_SOURCES = bgpd/test_mpath.c
+isisd_test_fuzz_isis_tlv_SOURCES = isisd/test_fuzz_isis_tlv.c
+isisd_test_fuzz_isis_tlv_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_builddir)/tests/isisd
 
 ospf6d_test_lsdb_SOURCES = ospf6d/test_lsdb.c lib/cli/common_cli.c
 
 ALL_TESTS_LDADD = ../lib/libfrr.la @LIBCAP@
 BGP_TEST_LDADD = ../bgpd/libbgp.a $(BGP_VNC_RFP_LIB) $(ALL_TESTS_LDADD) -lm
+ISISD_TEST_LDADD = ../isisd/libisis.a $(ALL_TESTS_LDADD)
 OSPF6_TEST_LDADD = ../ospf6d/libospf6.a $(ALL_TESTS_LDADD)
 
 lib_test_buffer_LDADD = $(ALL_TESTS_LDADD)
@@ -140,6 +156,7 @@ bgpd_test_capability_LDADD = $(BGP_TEST_LDADD)
 bgpd_test_ecommunity_LDADD = $(BGP_TEST_LDADD)
 bgpd_test_mp_attr_LDADD = $(BGP_TEST_LDADD)
 bgpd_test_mpath_LDADD = $(BGP_TEST_LDADD)
+isisd_test_fuzz_isis_tlv_LDADD = $(ISISD_TEST_LDADD)
 ospf6d_test_lsdb_LDADD = $(OSPF6_TEST_LDADD)
 
 EXTRA_DIST = \
@@ -151,6 +168,8 @@ EXTRA_DIST = \
     bgpd/test_mpath.py \
     helpers/python/frrsix.py \
     helpers/python/frrtest.py \
+    isisd/test_fuzz_isis_tlv.py \
+    isisd/test_fuzz_isis_tlv_tests.h.gz \
     lib/cli/test_commands.in \
     lib/cli/test_commands.py \
     lib/cli/test_commands.refout \

tests/isisd/.gitignore

@@ -0,0 +1 @@
+/*_afl/*

tests/isisd/test_fuzz_isis_tlv.c

@@ -0,0 +1,188 @@
+#include "test_fuzz_isis_tlv_tests.h"
+
+#include <zebra.h>
+
+#include "memory.h"
+#include "sbuf.h"
+#include "stream.h"
+#include "thread.h"
+
+#include "isisd/isis_circuit.h"
+#include "isisd/isis_tlvs2.h"
+
+#define TEST_STREAM_SIZE 1500
+
+struct thread_master *master;
+int isis_sock_init(struct isis_circuit *circuit);
+int isis_sock_init(struct isis_circuit *circuit)
+{
+	return 0;
+}
+
+static bool atexit_registered;
+
+static void show_meminfo_at_exit(void)
+{
+	log_memstats_stderr("isis fuzztest");
+}
+
+static int comp_line(const void *p1, const void *p2)
+{
+	return strcmp(*(char * const *)p1, *(char * const *)p2);
+}
+
+static char *sortlines(char *in)
+{
+	size_t line_count = 1;
+	size_t rv_len = strlen(in) + 1;
+	size_t rv_pos = 0;
+	char *rv = XMALLOC(MTYPE_TMP, rv_len);
+
+	for (char *c = in; *c; c++) {
+		if (*c == '\n')
+			line_count++;
+	}
+
+	if (line_count == 1) {
+		strncpy(rv, in, rv_len);
+		return rv;
+	}
+
+	char **lines = XCALLOC(MTYPE_TMP, sizeof(char *)*line_count);
+	char *saveptr = NULL;
+	size_t i = 0;
+
+	for (char *line = strtok_r(in, "\n", &saveptr); line;
+	     line = strtok_r(NULL, "\n", &saveptr)) {
+		lines[i++] = line;
+		assert(i <= line_count);
+	}
+
+	line_count = i;
+
+	qsort(lines, line_count, sizeof(char *), comp_line);
+
+	for (i = 0; i < line_count; i++) {
+		int printf_rv = snprintf(rv + rv_pos, rv_len - rv_pos, "%s\n", lines[i]);
+		assert(printf_rv >= 0);
+		rv_pos += printf_rv;
+	}
+
+	XFREE(MTYPE_TMP, lines);
+	return rv;
+}
+
+static int test(FILE *input, FILE *output)
+{
+	struct stream *s = stream_new(TEST_STREAM_SIZE);
+	char buf[TEST_STREAM_SIZE];
+	size_t bytes_read = 0;
+
+	if (!atexit_registered) {
+		atexit(show_meminfo_at_exit);
+		atexit_registered = true;
+	}
+
+	while (STREAM_WRITEABLE(s) && !feof(input)) {
+		bytes_read = fread(buf, 1, STREAM_WRITEABLE(s), input);
+		if (bytes_read == 0)
+			break;
+		stream_put(s, buf, bytes_read);
+	}
+
+	if (bytes_read && !feof(input)) {
+		fprintf(output, "Too much input data.\n");
+		stream_free(s);
+		return 1;
+	}
+
+	stream_set_getp(s, 0);
+	struct isis_tlvs *tlvs;
+	const char *log;
+	int rv = isis_unpack_tlvs(STREAM_READABLE(s), s, &tlvs, &log);
+
+	if (rv) {
+		fprintf(output, "Could not unpack TLVs:\n%s\n", log);
+		isis_free_tlvs(tlvs);
+		stream_free(s);
+		return 2;
+	}
+
+	fprintf(output, "Unpack log:\n%s", log);
+	const char *s_tlvs = isis_format_tlvs(tlvs);
+	fprintf(output, "Unpacked TLVs:\n%s", s_tlvs);
+
+	struct isis_tlvs *tlv_copy = isis_copy_tlvs(tlvs);
+	isis_free_tlvs(tlvs);
+
+	struct stream *s2 = stream_new(TEST_STREAM_SIZE);
+
+	if (isis_pack_tlvs(tlv_copy, s2, (size_t)-1, false, false)) {
+		fprintf(output, "Could not pack TLVs.\n");
+		assert(0);
+	}
+
+	stream_set_getp(s2, 0);
+	rv = isis_unpack_tlvs(STREAM_READABLE(s2), s2, &tlvs, &log);
+	if (rv) {
+		fprintf(output, "Could not unpack own TLVs:\n%s\n", log);
+		assert(0);
+	}
+
+	char *orig_tlvs = XSTRDUP(MTYPE_TMP, s_tlvs);
+	s_tlvs = isis_format_tlvs(tlvs);
+
+	if (strcmp(orig_tlvs, s_tlvs)) {
+		fprintf(output,
+			"Deserialized and Serialized LSP seem to differ.\n");
+		fprintf(output, "Re-Unpacked TLVs:\n%s", s_tlvs);
+		assert(0);
+	}
+
+	isis_free_tlvs(tlv_copy);
+	stream_free(s);
+	stream_free(s2);
+
+	struct list *fragments = isis_fragment_tlvs(tlvs, 550);
+	isis_free_tlvs(tlvs);
+	if (!fragments) {
+		XFREE(MTYPE_TMP, orig_tlvs);
+		return 0;
+	}
+
+	s = stream_new(550);
+
+	struct sbuf fragment_format;
+	sbuf_init(&fragment_format, NULL, 0);
+
+	struct listnode *node;
+	for (ALL_LIST_ELEMENTS_RO(fragments, node, tlvs)) {
+		stream_reset(s);
+		int rv = isis_pack_tlvs(tlvs, s, (size_t)-1, false, false);
+		if (rv) {
+			fprintf(output, "Could not pack fragment, too large.\n");
+			assert(0);
+		}
+		sbuf_push(&fragment_format, 0, "%s", isis_format_tlvs(tlvs));
+		isis_free_tlvs(tlvs);
+	}
+	list_delete(fragments);
+	stream_free(s);
+
+	char *fragment_content = sortlines((char *)sbuf_buf(&fragment_format));
+	sbuf_free(&fragment_format);
+	char *orig_tlv_content = sortlines(orig_tlvs);
+	XFREE(MTYPE_TMP, orig_tlvs);
+
+	if (strcmp(fragment_content, orig_tlv_content)) {
+		fprintf(output, "Fragmented and unfragmented LSP seem to differ.\n");
+		fprintf(output, "Original:\n%s\nFragmented:\n%s\n",
+			orig_tlv_content, fragment_content);
+		assert(0);
+	}
+
+	XFREE(MTYPE_TMP, fragment_content);
+	XFREE(MTYPE_TMP, orig_tlv_content);
+
+	return 0;
+}

tests/isisd/test_fuzz_isis_tlv.py

@@ -0,0 +1,6 @@
+import frrtest
+
+class TestFuzzIsisTLV(frrtest.TestMultiOut):
+    program = './test_fuzz_isis_tlv'
+
+TestFuzzIsisTLV.exit_cleanly()