]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-isoclns.c
display the DIS lan-id of an IIH in non-verbose mode
[tcpdump] / print-isoclns.c
index bf832fb6465166b918cf6b905e2f5b7631b6541e..f610fd323a28122d1a20028b9a1a092dcf3915d9 100644 (file)
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
  * Original code by Matt Thomas, Digital Equipment Corporation
+ *
+ * Extensively modified by Hannes Gredler ([email protected]) for more
+ * complete IS-IS support.
  */
 
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-isoclns.c,v 1.17 2000-07-01 03:39:06 assar Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-isoclns.c,v 1.102 2003-10-28 19:10:15 hannes Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <sys/types.h>
-#include <sys/time.h>
-#include <sys/socket.h>
-
-struct mbuf;
-struct rtentry;
-#include <net/if.h>
-
-#include <netinet/in.h>
-#include <netinet/if_ether.h>
+#include <tcpdump-stdinc.h>
 
 #include <stdio.h>
+#include <string.h>
 
 #include "interface.h"
 #include "addrtoname.h"
 #include "ethertype.h"
+#include "ether.h"
+#include "extract.h"
+#include "gmpls.h"
+
+#define        NLPID_CLNS      129     /* 0x81 */
+#define        NLPID_ESIS      130     /* 0x82 */
+#define        NLPID_ISIS      131     /* 0x83 */
+#define NLPID_IP6       0x8e
+#define NLPID_IP        0xcc
+#define        NLPID_NULLNS    0
+
+#define IPV4            1       /* AFI value */
+#define IPV6            2       /* AFI value */
+
+/*
+ * IS-IS is defined in ISO 10589.  Look there for protocol definitions.
+ */
+
+#define SYSTEM_ID_LEN  ETHER_ADDR_LEN
+#define NODE_ID_LEN     SYSTEM_ID_LEN+1
+#define LSP_ID_LEN      SYSTEM_ID_LEN+2
+
+#define ISIS_VERSION   1
+#define PDU_TYPE_MASK  0x1F
+#define PRIORITY_MASK  0x7F
+
+#define L1_LAN_IIH     15
+#define L2_LAN_IIH     16
+#define PTP_IIH                17
+#define L1_LSP         18
+#define L2_LSP         20
+#define L1_CSNP        24
+#define L2_CSNP        25
+#define L1_PSNP                26
+#define L2_PSNP                27
+
+static struct tok isis_pdu_values[] = {
+    { L1_LAN_IIH,       "L1 Lan IIH"},
+    { L2_LAN_IIH,       "L2 Lan IIH"},
+    { PTP_IIH,          "p2p IIH"},
+    { L1_LSP,           "L1 LSP"},
+    { L2_LSP,           "L2 LSP"},
+    { L1_CSNP,          "L1 CSNP"},
+    { L2_CSNP,          "L2 CSNP"},
+    { L1_PSNP,          "L1 PSNP"},
+    { L2_PSNP,          "L2 PSNP"},
+    { 0, NULL}
+};
+
+/*
+ * A TLV is a tuple of a type, length and a value and is normally used for
+ * encoding information in all sorts of places.  This is an enumeration of
+ * the well known types.
+ *
+ * list taken from rfc3359 plus some memory from veterans ;-)
+ */
+
+#define TLV_AREA_ADDR           1   /* iso10589 */
+#define TLV_IS_REACH            2   /* iso10589 */
+#define TLV_ESNEIGH             3   /* iso10589 */
+#define TLV_PART_DIS            4   /* iso10589 */
+#define TLV_PREFIX_NEIGH        5   /* iso10589 */
+#define TLV_ISNEIGH             6   /* iso10589 */
+#define TLV_ISNEIGH_VARLEN      7   /* iso10589 */
+#define TLV_PADDING             8   /* iso10589 */
+#define TLV_LSP                 9   /* iso10589 */
+#define TLV_AUTH                10  /* iso10589, rfc3567 */
+#define TLV_CHECKSUM            12  /* rfc3358 */
+#define TLV_LSP_BUFFERSIZE      14  /* iso10589 rev2 */
+#define TLV_EXT_IS_REACH        22  /* draft-ietf-isis-traffic-05 */
+#define TLV_IS_ALIAS_ID         24  /* draft-ietf-isis-ext-lsp-frags-02 */
+#define TLV_DECNET_PHASE4       42
+#define TLV_LUCENT_PRIVATE      66
+#define TLV_IP_REACH            128 /* rfc1195, rfc2966 */
+#define TLV_PROTOCOLS           129 /* rfc1195 */
+#define TLV_IP_REACH_EXT        130 /* rfc1195, rfc2966 */
+#define TLV_IDRP_INFO           131 /* rfc1195 */
+#define TLV_IPADDR              132 /* rfc1195 */
+#define TLV_IPAUTH              133 /* rfc1195 */
+#define TLV_TE_ROUTER_ID        134 /* draft-ietf-isis-traffic-05 */
+#define TLV_EXT_IP_REACH        135 /* draft-ietf-isis-traffic-05 */
+#define TLV_HOSTNAME            137 /* rfc2763 */
+#define TLV_SHARED_RISK_GROUP   138 /* draft-ietf-isis-gmpls-extensions */
+#define TLV_NORTEL_PRIVATE1     176
+#define TLV_NORTEL_PRIVATE2     177
+#define TLV_HOLDTIME            198 /* ES-IS */
+#define TLV_RESTART_SIGNALING   211 /* draft-ietf-isis-restart-01 */
+#define TLV_MT_IS_REACH         222 /* draft-ietf-isis-wg-multi-topology-05 */
+#define TLV_MT_SUPPORTED        229 /* draft-ietf-isis-wg-multi-topology-05 */
+#define TLV_IP6ADDR             232 /* draft-ietf-isis-ipv6-02 */
+#define TLV_MT_IP_REACH         235 /* draft-ietf-isis-wg-multi-topology-05 */
+#define TLV_IP6_REACH           236 /* draft-ietf-isis-ipv6-02 */
+#define TLV_MT_IP6_REACH        237 /* draft-ietf-isis-wg-multi-topology-05 */
+#define TLV_PTP_ADJ             240 /* rfc3373 */
+#define TLV_IIH_SEQNR           241 /* draft-shen-isis-iih-sequence-00 */
+#define TLV_VENDOR_PRIVATE      250 /* draft-ietf-isis-proprietary-tlv-00 */
+
+static struct tok isis_tlv_values[] = {
+    { TLV_AREA_ADDR,        "Area address(es)"},
+    { TLV_IS_REACH,          "IS Reachability"},
+    { TLV_ESNEIGH,           "ES Neighbor(s)"},
+    { TLV_PART_DIS,          "Partition DIS"},
+    { TLV_PREFIX_NEIGH,      "Prefix Neighbors"},
+    { TLV_ISNEIGH,           "IS Neighbor(s)"},
+    { TLV_ISNEIGH_VARLEN,    "IS Neighbor(s) (variable length)"},
+    { TLV_PADDING,           "Padding"},
+    { TLV_LSP,               "LSP entries"},
+    { TLV_AUTH,              "Authentication"},
+    { TLV_CHECKSUM,          "Checksum"},
+    { TLV_LSP_BUFFERSIZE,    "LSP Buffersize"},
+    { TLV_EXT_IS_REACH,      "Extended IS Reachability"},
+    { TLV_IS_ALIAS_ID,       "IS Alias ID"},
+    { TLV_DECNET_PHASE4,     "DECnet Phase IV"},
+    { TLV_LUCENT_PRIVATE,    "Lucent Proprietary"},
+    { TLV_IP_REACH,          "IPv4 Internal Reachability"},
+    { TLV_PROTOCOLS,         "Protocols supported"},
+    { TLV_IP_REACH_EXT,      "IPv4 External Reachability"},
+    { TLV_IDRP_INFO,         "Inter-Domain Information Type"},
+    { TLV_IPADDR,            "IPv4 Interface address(es)"},
+    { TLV_IPAUTH,            "IPv4 authentication (deprecated)"},
+    { TLV_TE_ROUTER_ID,      "Traffic Engineering Router ID"},
+    { TLV_EXT_IP_REACH,      "Extended IPv4 Reachability"},
+    { TLV_HOSTNAME,          "Hostname"},
+    { TLV_SHARED_RISK_GROUP, "Shared Risk Link Group"},
+    { TLV_NORTEL_PRIVATE1,   "Nortel Proprietary"},
+    { TLV_NORTEL_PRIVATE2,   "Nortel Proprietary"},
+    { TLV_HOLDTIME,          "Holdtime"},
+    { TLV_RESTART_SIGNALING, "Restart Signaling"},
+    { TLV_MT_IS_REACH,       "Multi Topology IS Reachability"},
+    { TLV_MT_SUPPORTED,      "Multi Topology"},
+    { TLV_IP6ADDR,           "IPv6 Interface address(es)"},
+    { TLV_MT_IP_REACH,       "Multi-Topology IPv4 Reachability"},
+    { TLV_IP6_REACH,         "IPv6 reachability"},
+    { TLV_MT_IP6_REACH,      "Multi-Topology IP6 Reachability"},
+    { TLV_PTP_ADJ,           "Point-to-point Adjacency State"},
+    { TLV_IIH_SEQNR,         "Hello PDU Sequence Number"},
+    { TLV_VENDOR_PRIVATE,    "Vendor Private"},
+    { 0, NULL }
+};
+
+#define SUBTLV_EXT_IS_REACH_ADMIN_GROUP           3 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_LINK_LOCAL_REMOTE_ID  4 /* draft-ietf-isis-gmpls-extensions */
+#define SUBTLV_EXT_IS_REACH_LINK_REMOTE_ID        5 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_IPV4_INTF_ADDR        6 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_IPV4_NEIGHBOR_ADDR    8 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_MAX_LINK_BW           9 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_RESERVABLE_BW        10 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_UNRESERVED_BW        11 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_TE_METRIC            18 /* draft-ietf-isis-traffic-05 */
+#define SUBTLV_EXT_IS_REACH_LINK_PROTECTION_TYPE 20 /* draft-ietf-isis-gmpls-extensions */
+#define SUBTLV_EXT_IS_REACH_INTF_SW_CAP_DESCR    21 /* draft-ietf-isis-gmpls-extensions */
+
+static struct tok isis_ext_is_reach_subtlv_values[] = {
+    { SUBTLV_EXT_IS_REACH_ADMIN_GROUP,            "Administrative groups" },
+    { SUBTLV_EXT_IS_REACH_LINK_LOCAL_REMOTE_ID,   "Link Local/Remote Identifier" },
+    { SUBTLV_EXT_IS_REACH_LINK_REMOTE_ID,         "Link Remote Identifier" },
+    { SUBTLV_EXT_IS_REACH_IPV4_INTF_ADDR,         "IPv4 interface address" },
+    { SUBTLV_EXT_IS_REACH_IPV4_NEIGHBOR_ADDR,     "IPv4 neighbor address" },
+    { SUBTLV_EXT_IS_REACH_MAX_LINK_BW,            "Maximum link bandwidth" },
+    { SUBTLV_EXT_IS_REACH_RESERVABLE_BW,          "Reservable link bandwidth" },
+    { SUBTLV_EXT_IS_REACH_UNRESERVED_BW,          "Unreserved bandwidth" },
+    { SUBTLV_EXT_IS_REACH_TE_METRIC,              "Traffic Engineering Metric" },
+    { SUBTLV_EXT_IS_REACH_LINK_PROTECTION_TYPE,   "Link Protection Type" },
+    { SUBTLV_EXT_IS_REACH_INTF_SW_CAP_DESCR,      "Interface Switching Capability" },
+    { 250,                                        "Reserved for cisco specific extensions" },
+    { 251,                                        "Reserved for cisco specific extensions" },
+    { 252,                                        "Reserved for cisco specific extensions" },
+    { 253,                                        "Reserved for cisco specific extensions" },
+    { 254,                                        "Reserved for cisco specific extensions" },
+    { 255,                                        "Reserved for future expansion" },
+    { 0, NULL }
+};
+
+#define SUBTLV_IP_REACH_ADMIN_TAG32               1
+#define SUBTLV_IP_REACH_ADMIN_TAG64               2
+
+static struct tok isis_ext_ip_reach_subtlv_values[] = {
+    { SUBTLV_IP_REACH_ADMIN_TAG32,                "32-Bit Administrative tag" },
+    { SUBTLV_IP_REACH_ADMIN_TAG64,                "64-Bit Administrative tag" },
+    { 0, NULL }
+};
+
+#define SUBTLV_AUTH_SIMPLE        1
+#define SUBTLV_AUTH_MD5          54
+#define SUBTLV_AUTH_MD5_LEN      16
+#define SUBTLV_AUTH_PRIVATE     255
+
+static struct tok isis_subtlv_auth_values[] = {
+    { SUBTLV_AUTH_SIMPLE,      "simple text password"},
+    { SUBTLV_AUTH_MD5,         "HMAC-MD5 password"},
+    { SUBTLV_AUTH_PRIVATE,     "Routing Domain private password"},
+    { 0, NULL }
+};
+
+#define SUBTLV_IDRP_RES           0
+#define SUBTLV_IDRP_LOCAL         1
+#define SUBTLV_IDRP_ASN           2
+
+static struct tok isis_subtlv_idrp_values[] = {
+    { SUBTLV_IDRP_RES,         "Reserved"},
+    { SUBTLV_IDRP_LOCAL,       "Routing-Domain Specific"},
+    { SUBTLV_IDRP_ASN,         "AS Number Tag"},
+    { 0, NULL}
+};
+
+#define ISIS_8BIT_MASK(x)                  ((x)&0xff)
+
+#define ISIS_MASK_LSP_OL_BIT(x)            ((x)&0x4)
+#define ISIS_MASK_LSP_ISTYPE_BITS(x)       ((x)&0x3)
+#define ISIS_MASK_LSP_PARTITION_BIT(x)     ((x)&0x80)
+#define ISIS_MASK_LSP_ATT_BITS(x)          ((x)&0x78)
+#define ISIS_MASK_LSP_ATT_ERROR_BIT(x)     ((x)&0x40)
+#define ISIS_MASK_LSP_ATT_EXPENSE_BIT(x)   ((x)&0x20)
+#define ISIS_MASK_LSP_ATT_DELAY_BIT(x)     ((x)&0x10)
+#define ISIS_MASK_LSP_ATT_DEFAULT_BIT(x)   ((x)&0x8)
+
+#define ISIS_MASK_MTID(x)                  ((x)&0x0fff)
+#define ISIS_MASK_MTFLAGS(x)               ((x)&0xf000)
+
+static struct tok isis_mt_flag_values[] = {
+    { 0x4000,                  "sub-TLVs present"},
+    { 0x8000,                  "ATT bit set"},
+    { 0, NULL}
+};
+
+#define ISIS_MASK_TLV_EXT_IP_UPDOWN(x)     ((x)&0x80)
+#define ISIS_MASK_TLV_EXT_IP_SUBTLV(x)     ((x)&0x40)
+
+#define ISIS_MASK_TLV_EXT_IP6_IE(x)        ((x)&0x40)
+#define ISIS_MASK_TLV_EXT_IP6_SUBTLV(x)    ((x)&0x20)
+
+#define ISIS_LSP_TLV_METRIC_SUPPORTED(x)   ((x)&0x80)
+#define ISIS_LSP_TLV_METRIC_IE(x)          ((x)&0x40)
+#define ISIS_LSP_TLV_METRIC_UPDOWN(x)      ((x)&0x80)
+#define ISIS_LSP_TLV_METRIC_VALUE(x)      ((x)&0x3f)
+
+#define ISIS_MASK_TLV_SHARED_RISK_GROUP(x) ((x)&0x1)
+
+static struct tok isis_mt_values[] = {
+    { 0,    "IPv4 unicast"},
+    { 1,    "In-Band Management"},
+    { 2,    "IPv6 unicast"},
+    { 3,    "Multicast"},
+    { 4095, "Development, Experimental or Proprietary"},
+    { 0, NULL }
+};
+
+static struct tok isis_iih_circuit_type_values[] = {
+    { 1,    "Level 1 only"},
+    { 2,    "Level 2 only"},
+    { 3,    "Level 1, Level 2"},
+    { 0, NULL}
+};
+
+#define ISIS_LSP_TYPE_UNUSED0   0
+#define ISIS_LSP_TYPE_LEVEL_1   1
+#define ISIS_LSP_TYPE_UNUSED2   2
+#define ISIS_LSP_TYPE_LEVEL_2   3
+
+static struct tok isis_lsp_istype_values[] = {
+    { ISIS_LSP_TYPE_UNUSED0,   "Unused 0x0 (invalid)"},
+    { ISIS_LSP_TYPE_LEVEL_1,   "L1 IS"},
+    { ISIS_LSP_TYPE_UNUSED2,   "Unused 0x2 (invalid)"},
+    { ISIS_LSP_TYPE_LEVEL_2,   "L1L2 IS"},
+    { 0, NULL }
+};
+
+static struct tok osi_nlpid_values[] = {
+    { NLPID_CLNS,   "CLNS"},
+    { NLPID_IP,     "IPv4"},
+    { NLPID_IP6,    "IPv6"},
+    { 0, NULL }
+};
+
+/*
+ * Katz's point to point adjacency TLV uses codes to tell us the state of
+ * the remote adjacency.  Enumerate them.
+ */
+
+#define ISIS_PTP_ADJ_UP   0
+#define ISIS_PTP_ADJ_INIT 1
+#define ISIS_PTP_ADJ_DOWN 2
+
+
+static struct tok isis_ptp_adjancey_values[] = {
+    { ISIS_PTP_ADJ_UP,    "Up" },
+    { ISIS_PTP_ADJ_INIT,  "Initializing" },
+    { ISIS_PTP_ADJ_DOWN,  "Down" },
+    { 0, NULL}
+};
+
+struct isis_tlv_ptp_adj {
+    u_int8_t adjacency_state;
+    u_int8_t extd_local_circuit_id[4];
+    u_int8_t neighbor_sysid[SYSTEM_ID_LEN];
+    u_int8_t neighbor_extd_local_circuit_id[4];
+};
+
+static int osi_cksum(const u_int8_t *, u_int);
+static void esis_print(const u_int8_t *, u_int);
+static int isis_print(const u_int8_t *, u_int);
+
+struct isis_metric_block {
+    u_int8_t metric_default;
+    u_int8_t metric_delay;
+    u_int8_t metric_expense;
+    u_int8_t metric_error;
+};
+
+struct isis_tlv_is_reach {
+    struct isis_metric_block isis_metric_block;
+    u_int8_t neighbor_nodeid[NODE_ID_LEN];
+};
+
+struct isis_tlv_es_reach {
+    struct isis_metric_block isis_metric_block;
+    u_int8_t neighbor_sysid[SYSTEM_ID_LEN];
+};
+
+struct isis_tlv_ip_reach {
+    struct isis_metric_block isis_metric_block;
+    u_int8_t prefix[4];
+    u_int8_t mask[4];
+};
+
+static struct tok isis_is_reach_virtual_values[] = {
+    { 0,    "IsNotVirtual"},
+    { 1,    "IsVirtual"},
+    { 0, NULL }
+};
+
+static struct tok isis_restart_flag_values[] = {
+    { 0x1,  "Restart Request"},
+    { 0x2,  "Restart Acknowledgement"},
+    { 0, NULL }
+};
+
+struct isis_common_header {
+    u_int8_t nlpid;
+    u_int8_t fixed_len;
+    u_int8_t version;                  /* Protocol version */
+    u_int8_t id_length;
+    u_int8_t pdu_type;                 /* 3 MSbits are reserved */
+    u_int8_t pdu_version;              /* Packet format version */
+    u_int8_t reserved;
+    u_int8_t max_area;
+};
+
+struct isis_iih_lan_header {
+    u_int8_t circuit_type;
+    u_int8_t source_id[SYSTEM_ID_LEN];
+    u_int8_t holding_time[2];
+    u_int8_t pdu_len[2];
+    u_int8_t priority;
+    u_int8_t lan_id[NODE_ID_LEN];
+};
+
+struct isis_iih_ptp_header {
+    u_int8_t circuit_type;
+    u_int8_t source_id[SYSTEM_ID_LEN];
+    u_int8_t holding_time[2];
+    u_int8_t pdu_len[2];
+    u_int8_t circuit_id;
+};
+
+struct isis_lsp_header {
+    u_int8_t pdu_len[2];
+    u_int8_t remaining_lifetime[2];
+    u_int8_t lsp_id[LSP_ID_LEN];
+    u_int8_t sequence_number[4];
+    u_int8_t checksum[2];
+    u_int8_t typeblock;
+};
+
+struct isis_csnp_header {
+    u_int8_t pdu_len[2];
+    u_int8_t source_id[NODE_ID_LEN];
+    u_int8_t start_lsp_id[LSP_ID_LEN];
+    u_int8_t end_lsp_id[LSP_ID_LEN];
+};
+
+struct isis_psnp_header {
+    u_int8_t pdu_len[2];
+    u_int8_t source_id[NODE_ID_LEN];
+};
 
-#define        CLNS    129
-#define        ESIS    130
-#define        ISIS    131
-#define        NULLNS  0
+struct isis_tlv_lsp {
+    u_int8_t remaining_lifetime[2];
+    u_int8_t lsp_id[LSP_ID_LEN];
+    u_int8_t sequence_number[4];
+    u_int8_t checksum[2];
+};
 
-static int osi_cksum(const u_char *, u_int, const u_char *, u_char *, u_char *);
-static void esis_print(const u_char *, u_int);
 
-void
-isoclns_print(const u_char *p, u_int length, u_int caplen,
-             const u_char *esrc, const u_char *edst)
+/* allocate space for the following string
+ * xx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xx
+ * 50 bytes plus one termination byte */
+static char *
+print_nsap(register const u_int8_t *pptr, register int nsap_length)
 {
-       if (caplen < 1) {
-               printf("[|iso-clns] ");
-               if (!eflag)
-                       printf("%s > %s",
-                              etheraddr_string(esrc),
-                              etheraddr_string(edst));
-               return;
+       int nsap_idx;
+       static char nsap_ascii_output[51];
+        char *junk_buf = nsap_ascii_output;
+
+        if (nsap_length < 1 || nsap_length > 20) {
+                snprintf(nsap_ascii_output, sizeof(nsap_ascii_output),
+                    "illegal length");
+                return (nsap_ascii_output);
+        }
+
+       for (nsap_idx = 0; nsap_idx < nsap_length; nsap_idx++) {
+               if (!TTEST2(*pptr, 1))
+                       return (0);
+               snprintf(junk_buf,
+                   sizeof(nsap_ascii_output) - (junk_buf - nsap_ascii_output),
+                   "%02x", *pptr++);
+               junk_buf += strlen(junk_buf);
+               if (((nsap_idx & 1) == 0) &&
+                     (nsap_idx + 1 < nsap_length)) {
+                       *junk_buf++ = '.';
+               }
        }
+        *(junk_buf) = '\0';
+       return (nsap_ascii_output);
+}
+
+#define ISIS_COMMON_HEADER_SIZE (sizeof(struct isis_common_header))
+#define ISIS_IIH_LAN_HEADER_SIZE (sizeof(struct isis_iih_lan_header))
+#define ISIS_IIH_PTP_HEADER_SIZE (sizeof(struct isis_iih_ptp_header))
+#define ISIS_LSP_HEADER_SIZE (sizeof(struct isis_lsp_header))
+#define ISIS_CSNP_HEADER_SIZE (sizeof(struct isis_csnp_header))
+#define ISIS_PSNP_HEADER_SIZE (sizeof(struct isis_psnp_header))
+
+void isoclns_print(const u_int8_t *p, u_int length, u_int caplen)
+{
+       u_int8_t pdu_type;
+       const struct isis_common_header *header;
+
+       header = (const struct isis_common_header *)p;
+       pdu_type = header->pdu_type & PDU_TYPE_MASK;
+
+        printf("%sOSI", caplen < 1 ? "|" : "");
+
+        if (caplen < 1) /* enough bytes on the wire ? */
+                return;
 
        switch (*p) {
 
-       case CLNS:
-               /* esis_print(&p, &length); */
-               printf("iso-clns");
-               if (!eflag)
-                       (void)printf(" %s > %s",
-                                    etheraddr_string(esrc),
-                                    etheraddr_string(edst));
+       case NLPID_CLNS:
+               (void)printf(", CLNS, length %u", length);
                break;
 
-       case ESIS:
-               printf("iso-esis");
-               if (!eflag)
-                       (void)printf(" %s > %s",
-                                    etheraddr_string(esrc),
-                                    etheraddr_string(edst));
+       case NLPID_ESIS:
                esis_print(p, length);
                return;
 
-       case ISIS:
-               printf("iso-isis");
-               if (!eflag)
-                       (void)printf(" %s > %s",
-                                    etheraddr_string(esrc),
-                                    etheraddr_string(edst));
-               /* isis_print(&p, &length); */
-               (void)printf(" len=%d ", length);
-               if (caplen > 1)
-                       default_print_unaligned(p, caplen);
+       case NLPID_ISIS:
+               if (!isis_print(p, length))
+                        print_unknown_data(p,"\n\t",caplen);
                break;
 
-       case NULLNS:
-               printf("iso-nullns");
-               if (!eflag)
-                       (void)printf(" %s > %s",
-                                    etheraddr_string(esrc),
-                                    etheraddr_string(edst));
+       case NLPID_NULLNS:
+               (void)printf(", ISO NULLNS, length: %u", length);
                break;
 
        default:
-               printf("iso-clns %02x", p[0]);
-               if (!eflag)
-                       (void)printf(" %s > %s",
-                                    etheraddr_string(esrc),
-                                    etheraddr_string(edst));
-               (void)printf(" len=%d ", length);
+               (void)printf(", Unknown NLPID 0x%02x, length: %u", p[0], length);
                if (caplen > 1)
-                       default_print_unaligned(p, caplen);
+                        print_unknown_data(p,"\n\t",caplen);
                break;
        }
 }
@@ -125,30 +518,37 @@ isoclns_print(const u_char *p, u_int length, u_int caplen,
 #define        ESIS_ESH        2
 #define        ESIS_ISH        4
 
+static struct tok esis_values[] = {
+    { ESIS_REDIRECT, "redirect"},
+    { ESIS_ESH,      "ESH"},
+    { ESIS_ISH,      "ISH"},
+    { 0, NULL }
+};
+
 struct esis_hdr {
-       u_char version;
-       u_char reserved;
-       u_char type;
-       u_char tmo[2];
-       u_char cksum[2];
+       u_int8_t version;
+       u_int8_t reserved;
+       u_int8_t type;
+       u_int8_t tmo[2];
+       u_int8_t cksum[2];
 };
 
 static void
-esis_print(const u_char *p, u_int length)
+esis_print(const u_int8_t *p, u_int length)
 {
-       const u_char *ep;
-       int li = p[1];
-       const struct esis_hdr *eh = (const struct esis_hdr *) &p[2];
-       u_char cksum[2];
-       u_char off[2];
+       const u_int8_t *ep;
+       u_int li;
+       const struct esis_hdr *eh;
 
-       if (length == 2) {
+       if (length <= 2) {
                if (qflag)
                        printf(" bad pkt!");
                else
                        printf(" no header at all!");
                return;
        }
+       li = p[1];
+       eh = (const struct esis_hdr *) &p[2];
        ep = p + li;
        if (li > length) {
                if (qflag)
@@ -167,29 +567,18 @@ esis_print(const u_char *p, u_int length)
                }
                return;
        }
-       switch (eh->type & 0x1f) {
 
-       case ESIS_REDIRECT:
-               printf(" redirect");
-               break;
+        printf(", ES-IS, %s, length %u",
+               tok2str(esis_values,"unknown type: %u",eh->type & 0x1f),
+               length);
 
-       case ESIS_ESH:
-               printf(" esh");
-               break;
-
-       case ESIS_ISH:
-               printf(" ish");
-               break;
+        if(vflag < 1)
+               return;
 
-       default:
-               printf(" type %d", eh->type & 0x1f);
-               break;
-       }
-       off[0] = eh->cksum[0];
-       off[1] = eh->cksum[1];
-       if (vflag && osi_cksum(p, li, eh->cksum, cksum, off)) {
-               printf(" bad cksum (got %02x%02x want %02x%02x)",
-                      eh->cksum[1], eh->cksum[0], cksum[1], cksum[0]);
+       if (vflag && osi_cksum(p, li)) {
+               printf(" bad cksum (got 0x%02x%02x)",
+                      eh->cksum[1], eh->cksum[0]);
+               default_print(p, length);
                return;
        }
        if (eh->version != 1) {
@@ -201,12 +590,12 @@ esis_print(const u_char *p, u_int length)
 
        switch (eh->type & 0x1f) {
        case ESIS_REDIRECT: {
-               const u_char *dst, *snpa, *is;
+               const u_int8_t *dst, *snpa, *is;
 
                dst = p; p += *p + 1;
                if (p > snapend)
                        return;
-               printf(" %s", isonsap_string(dst));
+               printf("\n\t\t %s", isonsap_string(dst));
                snpa = p; p += *p + 1;
                is = p;   p += *p + 1;
                if (p > snapend)
@@ -222,13 +611,12 @@ esis_print(const u_char *p, u_int length)
                li = ep - p;
                break;
        }
-#if 0
+
        case ESIS_ESH:
-               printf(" esh");
                break;
-#endif
+
        case ESIS_ISH: {
-               const u_char *is;
+               const u_int8_t *is;
 
                is = p; p += *p + 1;
                if (p > ep) {
@@ -237,83 +625,1394 @@ esis_print(const u_char *p, u_int length)
                }
                if (p > snapend)
                        return;
-               printf(" %s", isonsap_string(is));
+               if (!qflag)
+                       printf("\n\tNET: %s", print_nsap(is+1,*is));
                li = ep - p;
                break;
        }
 
        default:
-               (void)printf(" len=%d", length);
-               if (length && p < snapend) {
-                       length = snapend - p;
-                       default_print(p, length);
-               }
-               return;
+            if (vflag <= 1) {
+                   if (p < snapend) 
+                            print_unknown_data(p,"\n\t  ",snapend-p);
+            }
+            return;
        }
+
+        /* hexdump - FIXME ? */
+        if (vflag > 1) {
+                    if (p < snapend)
+                            print_unknown_data(p,"\n\t  ",snapend-p);
+        }
        if (vflag)
                while (p < ep && li) {
-                       int op, opli;
-                       const u_char *q;
+                       u_int op, opli;
+                       const u_int8_t *q;
 
                        if (snapend - p < 2)
                                return;
                        if (li < 2) {
-                               printf(" bad opts/li");
+                               printf(", bad opts/li");
                                return;
                        }
                        op = *p++;
                        opli = *p++;
                        li -= 2;
                        if (opli > li) {
-                               printf(" opt (%d) too long", op);
+                               printf(", opt (%d) too long", op);
                                return;
                        }
                        li -= opli;
                        q = p;
                        p += opli;
+
                        if (snapend < p)
                                return;
-                       if (op == 198 && opli == 2) {
-                               printf(" tmo=%d", q[0] * 256 + q[1]);
+
+                       if (op == TLV_HOLDTIME && opli == 2) {
+                               printf("\n\tholdtime: %us", EXTRACT_16BITS(q));
                                continue;
                        }
-                       printf (" %d:<", op);
-                       while (--opli >= 0)
-                               printf("%02x", *q++);
-                       printf (">");
+
+                       if (op == TLV_PROTOCOLS && opli >= 1) {
+                               printf("\n\t%s (length: %u): %s",
+                                       tok2str(isis_tlv_values, "unknown", op),
+                                       opli,
+                                       tok2str(osi_nlpid_values,"Unknown 0x%02x",*q));
+                               continue;
+                       }
+
+                        print_unknown_data(q,"\n\t  ",opli);
                }
 }
 
+/* shared routine for printing system, node and lsp-ids
+ * allocate space for the worst-case string
+ * xxxx.xxxx.xxxx.yy-zz
+ * 20 bytes plus one termination byte */
+static char *
+isis_print_id(const u_int8_t *cp, int id_len)
+{
+    int i;
+    static char id[sizeof("xxxx.xxxx.xxxx.yy-zz")];
+    char *pos = id;
+
+    for (i = 1; i <= SYSTEM_ID_LEN; i++) {
+        snprintf(pos, sizeof(id) - (pos - id), "%02x", *cp++);
+       pos += strlen(pos);
+       if (i == 2 || i == 4)
+           *pos++ = '.';
+       }
+    if (id_len >= NODE_ID_LEN) {
+        snprintf(pos, sizeof(id) - (pos - id), ".%02x", *cp++);
+       pos += strlen(pos);
+    }
+    if (id_len == LSP_ID_LEN)
+        snprintf(pos, sizeof(id) - (pos - id), "-%02x", *cp);
+    return (id);
+}
+
+/* print the 4-byte metric block which is common found in the old-style TLVs */
 static int
-osi_cksum(register const u_char *p, register u_int len,
-         const u_char *toff, u_char *cksum, u_char *off)
+isis_print_metric_block (const struct isis_metric_block *isis_metric_block)
 {
-       int x, y, f = (len - ((toff - p) + 1));
-       int32_t c0 = 0, c1 = 0;
+    printf(", Default Metric: %d, %s",
+           ISIS_LSP_TLV_METRIC_VALUE(isis_metric_block->metric_default),
+           ISIS_LSP_TLV_METRIC_IE(isis_metric_block->metric_default) ? "External" : "Internal");
+    if (!ISIS_LSP_TLV_METRIC_SUPPORTED(isis_metric_block->metric_delay))
+        printf("\n\t\t  Delay Metric: %d, %s",
+               ISIS_LSP_TLV_METRIC_VALUE(isis_metric_block->metric_delay),
+               ISIS_LSP_TLV_METRIC_IE(isis_metric_block->metric_delay) ? "External" : "Internal");
+    if (!ISIS_LSP_TLV_METRIC_SUPPORTED(isis_metric_block->metric_expense))
+        printf("\n\t\t  Expense Metric: %d, %s",
+               ISIS_LSP_TLV_METRIC_VALUE(isis_metric_block->metric_expense),
+               ISIS_LSP_TLV_METRIC_IE(isis_metric_block->metric_expense) ? "External" : "Internal");
+    if (!ISIS_LSP_TLV_METRIC_SUPPORTED(isis_metric_block->metric_error))
+        printf("\n\t\t  Error Metric: %d, %s",
+               ISIS_LSP_TLV_METRIC_VALUE(isis_metric_block->metric_error),
+               ISIS_LSP_TLV_METRIC_IE(isis_metric_block->metric_error) ? "External" : "Internal");
+
+    return(1); /* everything is ok */
+}
+
+static int
+isis_print_tlv_ip_reach (const u_int8_t *cp, const char *ident, int length)
+{
+       int prefix_len;
+       const struct isis_tlv_ip_reach *tlv_ip_reach;
+
+       tlv_ip_reach = (const struct isis_tlv_ip_reach *)cp;
+
+       while (length > 0) {
+               if ((size_t)length < sizeof(*tlv_ip_reach)) {
+                       printf("short IPv4 Reachability (%d vs %lu)",
+                               length,
+                               (unsigned long)sizeof(*tlv_ip_reach));
+                       return (0);
+               }
+
+               if (!TTEST(*tlv_ip_reach))
+                   return (0);
+
+               prefix_len = mask2plen(EXTRACT_32BITS(tlv_ip_reach->mask));
+
+               if (prefix_len == -1)
+                       printf("%sIPv4 prefix: %s mask %s",
+                               ident,
+                              ipaddr_string((tlv_ip_reach->prefix)),
+                              ipaddr_string((tlv_ip_reach->mask)));
+               else
+                       printf("%sIPv4 prefix: %15s/%u",
+                               ident,
+                              ipaddr_string((tlv_ip_reach->prefix)),
+                              prefix_len);
+
+               printf(", Distribution: %s, Metric: %u, %s",
+                       ISIS_LSP_TLV_METRIC_UPDOWN(tlv_ip_reach->isis_metric_block.metric_default) ? "down" : "up",
+                       ISIS_LSP_TLV_METRIC_VALUE(tlv_ip_reach->isis_metric_block.metric_default),
+                       ISIS_LSP_TLV_METRIC_IE(tlv_ip_reach->isis_metric_block.metric_default) ? "External" : "Internal");
+
+               if (!ISIS_LSP_TLV_METRIC_SUPPORTED(tlv_ip_reach->isis_metric_block.metric_delay))
+                    printf("%s  Delay Metric: %u, %s",
+                           ident,
+                           ISIS_LSP_TLV_METRIC_VALUE(tlv_ip_reach->isis_metric_block.metric_delay),
+                           ISIS_LSP_TLV_METRIC_IE(tlv_ip_reach->isis_metric_block.metric_delay) ? "External" : "Internal");
+                
+               if (!ISIS_LSP_TLV_METRIC_SUPPORTED(tlv_ip_reach->isis_metric_block.metric_expense))
+                    printf("%s  Expense Metric: %u, %s",
+                           ident,
+                           ISIS_LSP_TLV_METRIC_VALUE(tlv_ip_reach->isis_metric_block.metric_expense),
+                           ISIS_LSP_TLV_METRIC_IE(tlv_ip_reach->isis_metric_block.metric_expense) ? "External" : "Internal");
+                
+               if (!ISIS_LSP_TLV_METRIC_SUPPORTED(tlv_ip_reach->isis_metric_block.metric_error))
+                    printf("%s  Error Metric: %u, %s",
+                           ident,
+                           ISIS_LSP_TLV_METRIC_VALUE(tlv_ip_reach->isis_metric_block.metric_error),
+                           ISIS_LSP_TLV_METRIC_IE(tlv_ip_reach->isis_metric_block.metric_error) ? "External" : "Internal");
+
+               length -= sizeof(struct isis_tlv_ip_reach);
+               tlv_ip_reach++;
+       }
+       return (1);
+}
+
+/*
+ * this is the common IP-REACH subTLV decoder it is called
+ * from various EXTD-IP REACH TLVs (135,235,236,237)
+ */
+
+static int
+isis_print_ip_reach_subtlv (const u_int8_t *tptr,int subt,int subl,const char *ident) {
+
+        /* first lets see if we know the subTLVs name*/
+       printf("%s%s subTLV #%u, length: %u",
+              ident,
+               tok2str(isis_ext_ip_reach_subtlv_values,
+                       "unknown",
+                       subt),
+               subt,
+               subl);
+
+       if (!TTEST2(*tptr,subl))
+           goto trunctlv;
+
+    switch(subt) {
+    case SUBTLV_IP_REACH_ADMIN_TAG32:
+        while (subl >= 4) {
+           printf(", 0x%08x (=%u)",
+                  EXTRACT_32BITS(tptr),
+                  EXTRACT_32BITS(tptr));
+           tptr+=4;
+           subl-=4;
+       }
+       break;
+    case SUBTLV_IP_REACH_ADMIN_TAG64:
+        while (subl >= 8) {
+           printf(", 0x%08x%08x",
+                  EXTRACT_32BITS(tptr),
+                  EXTRACT_32BITS(tptr+4));
+           tptr+=8;
+           subl-=8;
+       }
+       break;
+    default:
+       if(!print_unknown_data(tptr,"\n\t\t    ",
+                              subl))
+         return(0);
+       break;
+    }
+    return(1);
+       
+trunctlv:
+    printf("%spacket exceeded snapshot",ident);
+    return(0);
+}
+
+/*
+ * this is the common IS-REACH subTLV decoder it is called
+ * from isis_print_ext_is_reach()
+ */
+
+static int
+isis_print_is_reach_subtlv (const u_int8_t *tptr,int subt,int subl,const char *ident) {
+
+        int priority_level;
+        union { /* int to float conversion buffer for several subTLVs */
+            float f; 
+            u_int32_t i;
+        } bw;
+
+        /* first lets see if we know the subTLVs name*/
+       printf("%s%s subTLV #%u, length: %u",
+              ident,
+               tok2str(isis_ext_is_reach_subtlv_values,
+                       "unknown",
+                       subt),
+               subt,
+               subl);
+
+       if (!TTEST2(*tptr,subl))
+           goto trunctlv;
+
+        switch(subt) {
+        case SUBTLV_EXT_IS_REACH_ADMIN_GROUP:      
+        case SUBTLV_EXT_IS_REACH_LINK_LOCAL_REMOTE_ID:
+        case SUBTLV_EXT_IS_REACH_LINK_REMOTE_ID:
+            printf(", 0x%08x", EXTRACT_32BITS(tptr));
+           if (subl == 8) /* draft-ietf-isis-gmpls-extensions */
+             printf(", 0x%08x", EXTRACT_32BITS(tptr+4));
+           break;
+        case SUBTLV_EXT_IS_REACH_IPV4_INTF_ADDR:
+        case SUBTLV_EXT_IS_REACH_IPV4_NEIGHBOR_ADDR:
+            printf(", %s", ipaddr_string(tptr));
+            break;
+        case SUBTLV_EXT_IS_REACH_MAX_LINK_BW :
+       case SUBTLV_EXT_IS_REACH_RESERVABLE_BW:  
+            bw.i = EXTRACT_32BITS(tptr);
+            printf(", %.3f Mbps", bw.f*8/1000000 );
+            break;
+        case SUBTLV_EXT_IS_REACH_UNRESERVED_BW :
+            for (priority_level = 0; priority_level < 8; priority_level++) {
+                bw.i = EXTRACT_32BITS(tptr);
+                printf("%s  priority level %d: %.3f Mbps",
+                       ident,
+                       priority_level,
+                       bw.f*8/1000000 );
+               tptr+=4;
+            }
+            break;
+        case SUBTLV_EXT_IS_REACH_TE_METRIC:
+            printf(", %u", EXTRACT_24BITS(tptr));
+            break;
+        case SUBTLV_EXT_IS_REACH_LINK_PROTECTION_TYPE:
+            printf(", %s, Priority %u",
+                  bittok2str(gmpls_link_prot_values, "none", *tptr),
+                   *(tptr+1));
+            break;
+        case SUBTLV_EXT_IS_REACH_INTF_SW_CAP_DESCR:
+            printf("%s  Interface Switching Capability:%s",
+                   ident,
+                   tok2str(gmpls_switch_cap_values, "Unknown", *(tptr)));
+            printf(", LSP Encoding: %s",
+                   tok2str(gmpls_encoding_values, "Unknown", *(tptr+1)));
+           tptr+=4;
+            printf("%s  Max LSP Bandwidth:",ident);
+            for (priority_level = 0; priority_level < 8; priority_level++) {
+                bw.i = EXTRACT_32BITS(tptr);
+                printf("%s    priority level %d: %.3f Mbps",
+                       ident,
+                       priority_level,
+                       bw.f*8/1000000 );
+               tptr+=4;
+            }
+            subl-=36;
+            /* there is some optional stuff left to decode but this is as of yet
+               not specified so just lets hexdump what is left */
+            if(subl>0){
+                if(!print_unknown_data(tptr,"\n\t\t    ",
+                                      subl-36))
+                    return(0);
+            }
+            break;
+        default:
+            if(!print_unknown_data(tptr,"\n\t\t    ",
+                                  subl))
+                return(0);
+            break;
+        }
+        return(1);
+
+trunctlv:
+    printf("%spacket exceeded snapshot",ident);
+    return(0);
+}
+
+
+/*
+ * this is the common IS-REACH decoder it is called
+ * from various EXTD-IS REACH style TLVs (22,24,222)
+ */
+
+static int
+isis_print_ext_is_reach (const u_int8_t *tptr,const char *ident, int tlv) {
+
+    char ident_buffer[20];
+    int subt,subl,tslen;
+    int proc_bytes = 0; /* how many bytes did we process ? */
+    
+    if (!TTEST2(*tptr, NODE_ID_LEN))
+        return(0);
+
+    printf("%sIS Neighbor: %s", ident, isis_print_id(tptr, NODE_ID_LEN));
+    tptr+=(NODE_ID_LEN);
+
+    if (tlv != TLV_IS_ALIAS_ID) {
+        if (!TTEST2(*tptr, 3))
+           return(0);
+       printf(", Metric: %d",EXTRACT_24BITS(tptr));
+       tptr+=3;
+    }
+        
+    if (!TTEST2(*tptr, 1))
+        return(0);
+    tslen=*(tptr++); /* read out subTLV length */
+    proc_bytes=NODE_ID_LEN+3+1;
+    printf(", %ssub-TLVs present",tslen ? "" : "no ");
+    if (tslen) {
+        printf(" (%u)",tslen);
+        while (tslen>0) {
+            if (!TTEST2(*tptr,2))
+                return(0);
+            subt=*(tptr++);
+            subl=*(tptr++);
+            /* prepend the ident string */
+            snprintf(ident_buffer, sizeof(ident_buffer), "%s  ",ident);
+            if(!isis_print_is_reach_subtlv(tptr,subt,subl,ident_buffer))
+                return(0);
+            tptr+=subl;
+            tslen-=(subl+2);
+            proc_bytes+=(subl+2);
+        }
+    }
+    return(proc_bytes);
+}
+
+/*
+ * this is the common Multi Topology ID decoder
+ * it is called from various MT-TLVs (222,229,235,237)
+ */
+
+static int
+isis_print_mtid (const u_int8_t *tptr,const char *ident) {
+    
+    if (!TTEST2(*tptr, 2))
+        return(0);
+
+    printf("%s%s",
+           ident,
+           tok2str(isis_mt_values,
+                   "Reserved for IETF Consensus",
+                   ISIS_MASK_MTID(EXTRACT_16BITS(tptr))));
+
+    printf(" Topology (0x%03x), Flags: [%s]",
+           ISIS_MASK_MTID(EXTRACT_16BITS(tptr)),
+           bittok2str(isis_mt_flag_values, "none",ISIS_MASK_MTFLAGS(EXTRACT_16BITS(tptr))));
+
+    return(2);
+}
+
+/*
+ * this is the common extended IP reach decoder
+ * it is called from TLVs (135,235,236,237)
+ * we process the TLV and optional subTLVs and return
+ * the amount of processed bytes
+ */
+
+static int
+isis_print_extd_ip_reach (const u_int8_t *tptr, const char *ident, u_int16_t afi) {
+
+    char ident_buffer[20];
+    u_int8_t prefix[16]; /* shared copy buffer for IPv4 and IPv6 prefixes */
+    u_int metric, status_byte, bit_length, byte_length, sublen, processed, subtlvtype, subtlvlen;
+
+    if (!TTEST2(*tptr, 4))
+        return (0);
+    metric = EXTRACT_32BITS(tptr);
+    processed=4;
+    tptr+=4;
+    
+    if (afi == IPV4) {
+        if (!TTEST2(*tptr, 1)) /* fetch status byte */
+            return (0);
+        status_byte=*(tptr++);
+        bit_length = status_byte&0x3f;
+        processed++;
+#ifdef INET6
+    } else if (afi == IPV6) {
+        if (!TTEST2(*tptr, 1)) /* fetch status & prefix_len byte */
+            return (0);
+        status_byte=*(tptr++);
+        bit_length=*(tptr++);
+        processed+=2;
+#endif
+    } else
+        return (0); /* somebody is fooling us */
+
+    byte_length = (bit_length + 7) / 8; /* prefix has variable length encoding */
+   
+    if (!TTEST2(*tptr, byte_length))
+        return (0);
+    memset(prefix, 0, 16);              /* clear the copy buffer */
+    memcpy(prefix,tptr,byte_length);    /* copy as much as is stored in the TLV */
+    tptr+=byte_length;
+    processed+=byte_length;
+
+    if (afi == IPV4)
+        printf("%sIPv4 prefix: %15s/%u",
+               ident,
+               ipaddr_string(prefix),
+               bit_length);
+#ifdef INET6
+    if (afi == IPV6)
+        printf("%sIPv6 prefix: %s/%u",
+               ident,
+               ip6addr_string(prefix),
+               bit_length);
+#endif 
+   
+    printf(", Distribution: %s, Metric: %u",
+           ISIS_MASK_TLV_EXT_IP_UPDOWN(status_byte) ? "down" : "up",
+           metric);
+
+    if (afi == IPV4 && ISIS_MASK_TLV_EXT_IP_SUBTLV(status_byte))
+        printf(", sub-TLVs present");
+#ifdef INET6
+    if (afi == IPV6)
+        printf(", %s%s",
+               ISIS_MASK_TLV_EXT_IP6_IE(status_byte) ? "External" : "Internal",
+               ISIS_MASK_TLV_EXT_IP6_SUBTLV(status_byte) ? ", sub-TLVs present" : "");
+#endif
+    
+    if ((ISIS_MASK_TLV_EXT_IP_SUBTLV(status_byte)  && afi == IPV4) ||
+        (ISIS_MASK_TLV_EXT_IP6_SUBTLV(status_byte) && afi == IPV6)) {
+        /* assume that one prefix can hold more
+           than one subTLV - therefore the first byte must reflect
+           the aggregate bytecount of the subTLVs for this prefix
+        */
+        if (!TTEST2(*tptr, 1))
+            return (0);
+        sublen=*(tptr++);
+        processed+=sublen+1;
+        printf(" (%u)",sublen);   /* print out subTLV length */
+        
+        while (sublen>0) {
+            if (!TTEST2(*tptr,2))
+                return (0);
+            subtlvtype=*(tptr++);
+            subtlvlen=*(tptr++);
+            /* prepend the ident string */
+            snprintf(ident_buffer, sizeof(ident_buffer), "%s  ",ident);
+            if(!isis_print_ip_reach_subtlv(tptr,subtlvtype,subtlvlen,ident_buffer))
+                return(0);
+            tptr+=subtlvlen;
+            sublen-=(subtlvlen+2);
+        }
+    }
+    return (processed);
+}
+
+/*
+ * isis_print
+ * Decode IS-IS packets.  Return 0 on error.
+ */
+
+static int isis_print (const u_int8_t *p, u_int length)
+{
+    const struct isis_common_header *header;
+
+    const struct isis_iih_lan_header *header_iih_lan;
+    const struct isis_iih_ptp_header *header_iih_ptp;
+    const struct isis_lsp_header *header_lsp;
+    const struct isis_csnp_header *header_csnp;
+    const struct isis_psnp_header *header_psnp;
+
+    const struct isis_tlv_lsp *tlv_lsp;
+    const struct isis_tlv_ptp_adj *tlv_ptp_adj;
+    const struct isis_tlv_is_reach *tlv_is_reach;
+    const struct isis_tlv_es_reach *tlv_es_reach;
+
+    u_int8_t pdu_type, max_area, id_length, tlv_type, tlv_len, tmp, alen, lan_alen, prefix_len;
+    u_int8_t ext_is_len, ext_ip_len, mt_len;
+    const u_int8_t *optr, *pptr, *tptr;
+    u_short packet_len,pdu_len;
+    u_int i;
+
+    packet_len=length;
+    optr = p; /* initialize the _o_riginal pointer to the packet start -
+                 need it for parsing the checksum TLV */
+    header = (const struct isis_common_header *)p;
+    TCHECK(*header);
+    pptr = p+(ISIS_COMMON_HEADER_SIZE);
+    header_iih_lan = (const struct isis_iih_lan_header *)pptr;
+    header_iih_ptp = (const struct isis_iih_ptp_header *)pptr;
+    header_lsp = (const struct isis_lsp_header *)pptr;
+    header_csnp = (const struct isis_csnp_header *)pptr;
+    header_psnp = (const struct isis_psnp_header *)pptr;
+
+    /*
+     * Sanity checking of the header.
+     */
+
+    if (header->version != ISIS_VERSION) {
+       printf(", version %d packet not supported", header->version);
+       return (0);
+    }
+
+    if ((header->id_length != SYSTEM_ID_LEN) && (header->id_length != 0)) {
+       printf(", system ID length of %d is not supported",
+              header->id_length);
+       return (0);
+    }
+
+    if (header->pdu_version != ISIS_VERSION) {
+       printf(", version %d packet not supported", header->pdu_version);
+       return (0);
+    }
+
+    max_area = header->max_area;
+    switch(max_area) {
+    case 0:
+       max_area = 3;    /* silly shit */
+       break;
+    case 255:
+       printf(", bad packet -- 255 areas");
+       return (0);
+    default:
+       break;
+    }
+
+    id_length = header->id_length;
+    switch(id_length) {
+    case 0:
+        id_length = 6;  /* silly shit again */
+       break;
+    case 1:              /* 1-8 are valid sys-ID lenghts */
+    case 2:
+    case 3:
+    case 4:
+    case 5:
+    case 6:
+    case 7:
+    case 8:
+        break;
+    case 255:
+        id_length = 0;   /* entirely useless */
+       break;
+    default:
+        break;
+    }
+
+    /* toss any non 6-byte sys-ID len PDUs */
+    if (id_length != 6 ) { 
+       printf(", bad packet -- illegal sys-ID length (%u)", id_length);
+       return (0);
+    }
+
+    pdu_type=header->pdu_type;
+
+    /* in non-verbose mode print the basic PDU Type plus PDU specific brief information*/
+    if (vflag < 1) {
+        printf(", IS-IS, %s",
+               tok2str(isis_pdu_values,"unknown PDU-Type %u",pdu_type));
+
+       switch (pdu_type) {
+
+       case L1_LAN_IIH:
+       case L2_LAN_IIH:
+           printf(", source-id %s",
+                   isis_print_id(header_iih_lan->source_id,SYSTEM_ID_LEN));
+           printf(", DIS lan-id %s",
+                   isis_print_id(header_iih_lan->lan_id,NODE_ID_LEN));
+           break;
+       case PTP_IIH:
+           printf(", source-id %s", isis_print_id(header_iih_ptp->source_id,SYSTEM_ID_LEN));
+           break;
+       case L1_LSP:
+       case L2_LSP:
+           printf(", lsp-id %s, seq 0x%08x, lifetime %5us",
+                  isis_print_id(header_lsp->lsp_id, LSP_ID_LEN),
+                  EXTRACT_32BITS(header_lsp->sequence_number),
+                  EXTRACT_16BITS(header_lsp->remaining_lifetime));
+           break;
+       case L1_CSNP:
+       case L2_CSNP:
+           printf(", source-id %s", isis_print_id(header_csnp->source_id,SYSTEM_ID_LEN));
+           break;
+       case L1_PSNP:
+       case L2_PSNP:
+           printf(", source-id %s", isis_print_id(header_psnp->source_id,SYSTEM_ID_LEN));
+           break;
+
+       }
+       printf(", length %u", length);
+
+        return(1);
+    }
+
+    /* ok they seem to want to know everything - lets fully decode it */
+    printf(", IS-IS, length: %u",length);
+
+    printf("\n\t%s, hlen: %u, v: %u, pdu-v: %u, sys-id-len: %u (%u), max-area: %u (%u)",
+           tok2str(isis_pdu_values,
+                   "unknown, type %u",
+                   pdu_type),
+           header->fixed_len,
+           header->version,
+           header->pdu_version,
+          id_length,
+          header->id_length,
+           max_area,
+           header->max_area);
+
+    if (vflag > 1) {
+        if(!print_unknown_data(optr,"\n\t",8)) /* provide the _o_riginal pointer */
+            return(0);                         /* for optionally debugging the common header */
+    }
+
+    switch (pdu_type) {
+
+    case L1_LAN_IIH:
+    case L2_LAN_IIH:
+       if (header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE)) {
+           printf(", bogus fixed header length %u should be %lu",
+                  header->fixed_len, (unsigned long)ISIS_IIH_LAN_HEADER_SIZE);
+           return (0);
+       }
+
+       pdu_len=EXTRACT_16BITS(header_iih_lan->pdu_len);
+       if (packet_len>pdu_len) {
+            packet_len=pdu_len; /* do TLV decoding as long as it makes sense */
+            length=pdu_len;
+       }
+
+       TCHECK(*header_iih_lan);
+       printf("\n\t  source-id:  %s,  holding time: %us, Flags: [%s]",
+               isis_print_id(header_iih_lan->source_id,SYSTEM_ID_LEN),
+               EXTRACT_16BITS(header_iih_lan->holding_time),
+               tok2str(isis_iih_circuit_type_values,
+                       "unknown circuit type 0x%02x",
+                       header_iih_lan->circuit_type));
+
+       printf("\n\t  DIS lan-id: %s, Priority: %u, PDU length: %u",
+               isis_print_id(header_iih_lan->lan_id, NODE_ID_LEN),
+               (header_iih_lan->priority) & PRIORITY_MASK,
+               pdu_len);
+
+        if (vflag > 1) {
+            if(!print_unknown_data(pptr,"\n\t  ",ISIS_IIH_LAN_HEADER_SIZE))
+                return(0);
+        }
+
+       packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE);
+       pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE);
+       break;
+
+    case PTP_IIH:
+       if (header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE)) {
+           printf(", bogus fixed header length %u should be %lu",
+                  header->fixed_len, (unsigned long)ISIS_IIH_PTP_HEADER_SIZE);
+           return (0);
+       }
+
+       pdu_len=EXTRACT_16BITS(header_iih_ptp->pdu_len);
+       if (packet_len>pdu_len) {
+            packet_len=pdu_len; /* do TLV decoding as long as it makes sense */
+            length=pdu_len;
+       }
+
+       TCHECK(*header_iih_ptp);
+       printf("\n\t  source-id: %s, holding time: %us, Flags: [%s]",
+               isis_print_id(header_iih_ptp->source_id,SYSTEM_ID_LEN),
+               EXTRACT_16BITS(header_iih_ptp->holding_time),
+               tok2str(isis_iih_circuit_type_values,
+                       "unknown circuit type 0x%02x",
+                       header_iih_ptp->circuit_type));
+
+       printf("\n\t  circuit-id: 0x%02x, PDU length: %u",
+               header_iih_ptp->circuit_id,
+               pdu_len);
+
+        if (vflag > 1) {
+            if(!print_unknown_data(pptr,"\n\t  ",ISIS_IIH_PTP_HEADER_SIZE))
+                return(0);
+        }
+
+       packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE);
+       pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE);
+       break;
+
+    case L1_LSP:
+    case L2_LSP:
+       if (header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE)) {
+           printf(", bogus fixed header length %u should be %lu",
+                  header->fixed_len, (unsigned long)ISIS_LSP_HEADER_SIZE);
+           return (0);
+       }
+
+       pdu_len=EXTRACT_16BITS(header_lsp->pdu_len);
+       if (packet_len>pdu_len) {
+            packet_len=pdu_len; /* do TLV decoding as long as it makes sense */
+            length=pdu_len;
+       }
+
+       TCHECK(*header_lsp);
+       printf("\n\t  lsp-id: %s, seq: 0x%08x, lifetime: %5us",
+               isis_print_id(header_lsp->lsp_id, LSP_ID_LEN),
+               EXTRACT_32BITS(header_lsp->sequence_number),
+               EXTRACT_16BITS(header_lsp->remaining_lifetime));
+        /* verify the checksum -
+         * checking starts at the lsp-id field
+         * which is 12 bytes after the packet start*/
+       printf("\n\t  chksum: 0x%04x (%s), PDU length: %u",
+               EXTRACT_16BITS(header_lsp->checksum),
+               (osi_cksum(optr+12, length-12)) ? "incorrect" : "correct",
+               pdu_len);
+
+       printf(", %s", ISIS_MASK_LSP_OL_BIT(header_lsp->typeblock) ? "Overload bit set, " : "");
+
+       if (ISIS_MASK_LSP_ATT_BITS(header_lsp->typeblock)) {
+           printf("%s", ISIS_MASK_LSP_ATT_DEFAULT_BIT(header_lsp->typeblock) ? "default " : "");
+           printf("%s", ISIS_MASK_LSP_ATT_DELAY_BIT(header_lsp->typeblock) ? "delay " : "");
+           printf("%s", ISIS_MASK_LSP_ATT_EXPENSE_BIT(header_lsp->typeblock) ? "expense " : "");
+           printf("%s", ISIS_MASK_LSP_ATT_ERROR_BIT(header_lsp->typeblock) ? "error " : "");
+           printf("ATT bit set, ");
+       }
+       printf("%s", ISIS_MASK_LSP_PARTITION_BIT(header_lsp->typeblock) ? "P bit set, " : "");
+       printf("%s", tok2str(isis_lsp_istype_values,"Unknown(0x%x)",ISIS_MASK_LSP_ISTYPE_BITS(header_lsp->typeblock)));
+
+        if (vflag > 1) {
+            if(!print_unknown_data(pptr,"\n\t  ",ISIS_LSP_HEADER_SIZE))
+                return(0);
+        }
+
+       packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE);
+       pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE);
+       break;
+
+    case L1_CSNP:
+    case L2_CSNP:
+       if (header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE)) {
+           printf(", bogus fixed header length %u should be %lu",
+                  header->fixed_len, (unsigned long)ISIS_CSNP_HEADER_SIZE);
+           return (0);
+       }
 
-       if ((cksum[0] = off[0]) == 0 && (cksum[1] = off[1]) == 0)
-               return 0;
+       pdu_len=EXTRACT_16BITS(header_csnp->pdu_len);
+       if (packet_len>pdu_len) {
+            packet_len=pdu_len; /* do TLV decoding as long as it makes sense */
+            length=pdu_len;
+       }
+
+       TCHECK(*header_csnp);
+       printf("\n\t  source-id:    %s, PDU length: %u",
+               isis_print_id(header_csnp->source_id, NODE_ID_LEN),
+               pdu_len);
+       printf("\n\t  start lsp-id: %s",
+               isis_print_id(header_csnp->start_lsp_id, LSP_ID_LEN));
+       printf("\n\t  end lsp-id:   %s",
+               isis_print_id(header_csnp->end_lsp_id, LSP_ID_LEN));
+
+        if (vflag > 1) {
+            if(!print_unknown_data(pptr,"\n\t  ",ISIS_CSNP_HEADER_SIZE))
+                return(0);
+        }
+
+       packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE);
+       pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE);
+        break;
+
+    case L1_PSNP:
+    case L2_PSNP:
+       if (header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_PSNP_HEADER_SIZE)) {
+           printf("- bogus fixed header length %u should be %lu",
+                  header->fixed_len, (unsigned long)ISIS_PSNP_HEADER_SIZE);
+           return (0);
+       }
+
+       pdu_len=EXTRACT_16BITS(header_psnp->pdu_len);
+       if (packet_len>pdu_len) {
+            packet_len=pdu_len; /* do TLV decoding as long as it makes sense */
+            length=pdu_len;
+       }
+
+       TCHECK(*header_psnp);
+       printf("\n\t  source-id:    %s, PDU length: %u",
+               isis_print_id(header_psnp->source_id, NODE_ID_LEN),
+               pdu_len);
+
+        if (vflag > 1) {
+            if(!print_unknown_data(pptr,"\n\t  ",ISIS_PSNP_HEADER_SIZE))
+                return(0);
+        }
+
+       packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_PSNP_HEADER_SIZE);
+       pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_PSNP_HEADER_SIZE);
+       break;
+
+    default:
+       if(!print_unknown_data(pptr,"\n\t  ",length))
+           return(0);
+       return (0);
+    }
+
+    /*
+     * Now print the TLV's.
+     */
+
+    while (packet_len >= 2) {
+        if (pptr == snapend) {
+           return (1);
+        }
+
+       if (!TTEST2(*pptr, 2)) {
+           printf("\n\t\t packet exceeded snapshot (%ld) bytes",
+                   (long)(pptr-snapend));
+           return (1);
+       }
+       tlv_type = *pptr++;
+       tlv_len = *pptr++;
+        tmp =tlv_len; /* copy temporary len & pointer to packet data */
+        tptr = pptr;
+       packet_len -= 2;
+       if (tlv_len > packet_len) {
+           break;
+       }
+
+        /* first lets see if we know the TLVs name*/
+       printf("\n\t    %s TLV #%u, length: %u",
+               tok2str(isis_tlv_values,
+                       "unknown",
+                       tlv_type),
+               tlv_type,
+               tlv_len);
+
+        /* now check if we have a decoder otherwise do a hexdump at the end*/
+       switch (tlv_type) {
+       case TLV_AREA_ADDR:
+           if (!TTEST2(*tptr, 1))
+               goto trunctlv;
+           alen = *tptr++;
+           while (tmp && alen < tmp) {
+               printf("\n\t      Area address (length: %u): %s",
+                       alen,
+                       print_nsap(tptr, alen));
+               tptr += alen;
+               tmp -= alen + 1;
+               if (tmp==0) /* if this is the last area address do not attemt a boundary check */
+                    break;
+               if (!TTEST2(*tptr, 1))
+                   goto trunctlv;
+               alen = *tptr++;
+           }
+           break;
+       case TLV_ISNEIGH:
+           while (tmp >= ETHER_ADDR_LEN) {
+                if (!TTEST2(*tptr, ETHER_ADDR_LEN))
+                    goto trunctlv;
+                printf("\n\t      SNPA: %s",isis_print_id(tptr,ETHER_ADDR_LEN));
+                tmp -= ETHER_ADDR_LEN;
+                tptr += ETHER_ADDR_LEN;
+           }
+           break;
+
+        case TLV_ISNEIGH_VARLEN:
+            if (!TTEST2(*tptr, 1))
+               goto trunctlv;
+           lan_alen = *tptr++; /* LAN adress length */
+            tmp --;
+            printf("\n\t      LAN address length %u bytes ",lan_alen);
+           while (tmp >= lan_alen) {
+                if (!TTEST2(*tptr, lan_alen))
+                    goto trunctlv;
+                printf("\n\t\tIS Neighbor: %s",isis_print_id(tptr,lan_alen));
+                tmp -= lan_alen;
+                tptr +=lan_alen;
+            }
+            break;
+
+       case TLV_PADDING:
+           break;
+
+        case TLV_MT_IS_REACH:
+            while (tmp >= 2+NODE_ID_LEN+3+1) {
+                mt_len = isis_print_mtid(tptr, "\n\t      ");
+                if (mt_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                tptr+=mt_len;
+                tmp-=mt_len;
+
+                ext_is_len = isis_print_ext_is_reach(tptr,"\n\t      ",tlv_type);
+                if (ext_is_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                   
+                tmp-=ext_is_len;
+                tptr+=ext_is_len;
+            }
+            break;
+
+        case TLV_IS_ALIAS_ID:
+           while (tmp >= NODE_ID_LEN+1) { /* is it worth attempting a decode ? */
+               ext_is_len = isis_print_ext_is_reach(tptr,"\n\t      ",tlv_type);
+               if (ext_is_len == 0) /* did something go wrong ? */
+                   goto trunctlv;
+               tmp-=ext_is_len;
+               tptr+=ext_is_len;
+           }
+           break;
+
+        case TLV_EXT_IS_REACH:
+            while (tmp >= NODE_ID_LEN+3+1) { /* is it worth attempting a decode ? */
+                ext_is_len = isis_print_ext_is_reach(tptr,"\n\t      ",tlv_type);
+                if (ext_is_len == 0) /* did something go wrong ? */
+                    goto trunctlv;                   
+                tmp-=ext_is_len;
+                tptr+=ext_is_len;
+            }
+            break;
+        case TLV_IS_REACH:
+           if (!TTEST2(*tptr,1))  /* check if there is one byte left to read out the virtual flag */
+                goto trunctlv;
+            printf("\n\t      %s",
+                   tok2str(isis_is_reach_virtual_values,
+                           "bogus virtual flag 0x%02x",
+                           *tptr++));
+           tlv_is_reach = (const struct isis_tlv_is_reach *)tptr;
+            while (tmp >= sizeof(struct isis_tlv_is_reach)) {
+               if (!TTEST(*tlv_is_reach))
+                   goto trunctlv;
+               printf("\n\t      IS Neighbor: %s",
+                      isis_print_id(tlv_is_reach->neighbor_nodeid, NODE_ID_LEN));
+                isis_print_metric_block(&tlv_is_reach->isis_metric_block);
+               tmp -= sizeof(struct isis_tlv_is_reach);
+               tlv_is_reach++;
+           }
+            break;
+
+        case TLV_ESNEIGH:
+           tlv_es_reach = (const struct isis_tlv_es_reach *)tptr;
+            while (tmp >= sizeof(struct isis_tlv_es_reach)) {
+               if (!TTEST(*tlv_es_reach))
+                   goto trunctlv;
+               printf("\n\t      ES Neighbor: %s",
+                       isis_print_id(tlv_es_reach->neighbor_sysid,SYSTEM_ID_LEN));
+                isis_print_metric_block(&tlv_es_reach->isis_metric_block);
+               tmp -= sizeof(struct isis_tlv_es_reach);
+               tlv_es_reach++;
+           }
+            break;
+
+            /* those two TLVs share the same format */
+       case TLV_IP_REACH:
+       case TLV_IP_REACH_EXT:
+           if (!isis_print_tlv_ip_reach(pptr, "\n\t      ", tlv_len))
+               return (1);
+           break;
+
+       case TLV_EXT_IP_REACH:
+           while (tmp>0) {
+                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", IPV4);
+                if (ext_ip_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                tptr+=ext_ip_len;
+               tmp-=ext_ip_len;
+           }
+           break;
+
+        case TLV_MT_IP_REACH:
+           while (tmp>0) {
+                mt_len = isis_print_mtid(tptr, "\n\t      ");
+                if (mt_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                tptr+=mt_len;
+                tmp-=mt_len;
+
+                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", IPV4);
+                if (ext_ip_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                tptr+=ext_ip_len;
+               tmp-=ext_ip_len;
+           }
+           break;
+
+#ifdef INET6
+       case TLV_IP6_REACH:
+           while (tmp>0) {
+                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", IPV6);
+                if (ext_ip_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                tptr+=ext_ip_len;
+               tmp-=ext_ip_len;
+           }
+           break;
+
+       case TLV_MT_IP6_REACH:
+           while (tmp>0) {
+                mt_len = isis_print_mtid(tptr, "\n\t      ");
+                if (mt_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                tptr+=mt_len;
+                tmp-=mt_len;
+
+                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", IPV6);
+                if (ext_ip_len == 0) /* did something go wrong ? */
+                    goto trunctlv;
+                tptr+=ext_ip_len;
+               tmp-=ext_ip_len;
+           }
+           break;
+
+       case TLV_IP6ADDR:
+           while (tmp>0) {
+               if (!TTEST2(*tptr, 16))
+                   goto trunctlv;
+
+                printf("\n\t      IPv6 interface address: %s",
+                      ip6addr_string(tptr));
+
+               tptr += 16;
+               tmp -= 16;
+           }
+           break;
+#endif
+       case TLV_AUTH:
+           if (!TTEST2(*tptr, 1))
+               goto trunctlv;
+
+            printf("\n\t      %s: ",
+                   tok2str(isis_subtlv_auth_values,
+                           "unknown Authentication type 0x%02x",
+                           *tptr));
+
+           switch (*tptr) {
+           case SUBTLV_AUTH_SIMPLE:
+               for(i=1;i<tlv_len;i++) {
+                   if (!TTEST2(*(tptr+i), 1))
+                       goto trunctlv;
+                   printf("%c",*(tptr+i));
+               }
+               break;
+           case SUBTLV_AUTH_MD5:
+               for(i=1;i<tlv_len;i++) {
+                   if (!TTEST2(*(tptr+i), 1))
+                       goto trunctlv;
+                   printf("%02x",*(tptr+i));
+               }
+               if (tlv_len != SUBTLV_AUTH_MD5_LEN+1)
+                    printf(", (malformed subTLV) ");
+               break;
+           case SUBTLV_AUTH_PRIVATE:
+           default:
+               if(!print_unknown_data(tptr+1,"\n\t\t  ",tlv_len-1))
+                   return(0);
+               break;
+           }
+           break;
+
+       case TLV_PTP_ADJ:
+           tlv_ptp_adj = (const struct isis_tlv_ptp_adj *)tptr;
+           if(tmp>=1) {
+               if (!TTEST2(*tptr, 1))
+                   goto trunctlv;
+               printf("\n\t      Adjacency State: %s",
+                      tok2str(isis_ptp_adjancey_values, "0x%02x", *tptr));
+               tmp--;
+           }
+           if(tmp>sizeof(tlv_ptp_adj->extd_local_circuit_id)) {
+               if (!TTEST2(tlv_ptp_adj->extd_local_circuit_id,
+                            sizeof(tlv_ptp_adj->extd_local_circuit_id)))
+                   goto trunctlv;
+               printf("\n\t      Extended Local circuit ID: 0x%08x",
+                      EXTRACT_32BITS(tlv_ptp_adj->extd_local_circuit_id));
+               tmp-=sizeof(tlv_ptp_adj->extd_local_circuit_id);
+           }
+           if(tmp>=SYSTEM_ID_LEN) {
+               if (!TTEST2(tlv_ptp_adj->neighbor_sysid, SYSTEM_ID_LEN))
+                   goto trunctlv;
+               printf("\n\t      Neighbor SystemID: %s",
+                      isis_print_id(tlv_ptp_adj->neighbor_sysid,SYSTEM_ID_LEN));
+               tmp-=SYSTEM_ID_LEN;
+           }
+           if(tmp>=sizeof(tlv_ptp_adj->neighbor_extd_local_circuit_id)) {
+               if (!TTEST2(tlv_ptp_adj->neighbor_extd_local_circuit_id,
+                            sizeof(tlv_ptp_adj->neighbor_extd_local_circuit_id)))
+                   goto trunctlv;
+               printf("\n\t      Neighbor Extended Local circuit ID: 0x%08x",
+                      EXTRACT_32BITS(tlv_ptp_adj->neighbor_extd_local_circuit_id));
+           }
+           break;
+
+       case TLV_PROTOCOLS:
+           printf("\n\t      NLPID(s): ");
+           while (tmp>0) {
+               if (!TTEST2(*(tptr), 1))
+                   goto trunctlv;
+               printf("%s",
+                       tok2str(osi_nlpid_values,
+                               "Unknown 0x%02x",
+                               *tptr++));
+               if (tmp>1) /* further NPLIDs ? - put comma */
+                   printf(", ");
+                tmp--;
+           }
+           break;
+
+       case TLV_TE_ROUTER_ID:
+           if (!TTEST2(*pptr, 4))
+               goto trunctlv;
+           printf("\n\t      Traffic Engineering Router ID: %s", ipaddr_string(pptr));
+           break;
+
+       case TLV_IPADDR:
+           while (tmp>0) {
+               if (!TTEST2(*tptr, 4))
+                   goto trunctlv;
+               printf("\n\t      IPv4 interface address: %s", ipaddr_string(tptr));
+               tptr += 4;
+               tmp -= 4;
+           }
+           break;
+
+       case TLV_HOSTNAME:
+           printf("\n\t      Hostname: ");
+           while (tmp>0) {
+               if (!TTEST2(*tptr, 1))
+                   goto trunctlv;
+               printf("%c",*tptr++);
+                tmp--;
+           }
+           break;
+
+       case TLV_SHARED_RISK_GROUP:
+           if (!TTEST2(*tptr, NODE_ID_LEN))
+                goto trunctlv;
+           printf("\n\t      IS Neighbor: %s", isis_print_id(tptr, NODE_ID_LEN));
+           tptr+=(NODE_ID_LEN);
+           tmp-=(NODE_ID_LEN);
+
+           if (!TTEST2(*tptr, 1))
+                goto trunctlv;
+           printf(", Flags: [%s]", ISIS_MASK_TLV_SHARED_RISK_GROUP(*tptr++) ? "numbered" : "unnumbered");
+           tmp--;
+
+           if (!TTEST2(*tptr,4))
+                goto trunctlv;
+           printf("\n\t      IPv4 interface address: %s", ipaddr_string(tptr));
+           tptr+=4;
+           tmp-=4;
+
+           if (!TTEST2(*tptr,4))
+                goto trunctlv;
+           printf("\n\t      IPv4 neighbor address: %s", ipaddr_string(tptr));
+           tptr+=4;
+           tmp-=4;
+
+           while (tmp>0) {
+                if (!TTEST2(*tptr, 4))
+                    goto trunctlv;
+                printf("\n\t      Link-ID: 0x%08x", EXTRACT_32BITS(tptr));
+                tptr+=4;
+                tmp-=4;
+           }
+           break;
+
+       case TLV_LSP:
+           tlv_lsp = (const struct isis_tlv_lsp *)tptr;
+           while(tmp>0) {
+               if (!TTEST((tlv_lsp->lsp_id)[LSP_ID_LEN]))
+                   goto trunctlv;
+               printf("\n\t      lsp-id: %s",
+                       isis_print_id(tlv_lsp->lsp_id, LSP_ID_LEN));
+               if (!TTEST2(tlv_lsp->sequence_number, 4))
+                   goto trunctlv;
+               printf(", seq: 0x%08x",EXTRACT_32BITS(tlv_lsp->sequence_number));
+               if (!TTEST2(tlv_lsp->remaining_lifetime, 2))
+                   goto trunctlv;
+               printf(", lifetime: %5ds",EXTRACT_16BITS(tlv_lsp->remaining_lifetime));
+               if (!TTEST2(tlv_lsp->checksum, 2))
+                   goto trunctlv;
+               printf(", chksum: 0x%04x",EXTRACT_16BITS(tlv_lsp->checksum));
+               tmp-=sizeof(struct isis_tlv_lsp);
+               tlv_lsp++;
+           }
+           break;
+
+       case TLV_CHECKSUM:
+           if (!TTEST2(*tptr, 2))
+               goto trunctlv;
+           printf("\n\t      checksum: 0x%04x (%s)",
+                  EXTRACT_16BITS(tptr),
+                   (osi_cksum(optr, length)) ? "incorrect" : "correct");
+           break;
+
+       case TLV_MT_SUPPORTED:
+           while (tmp>1) {
+               /* length can only be a multiple of 2, otherwise there is
+                  something broken -> so decode down until length is 1 */
+               if (tmp!=1) {
+                    mt_len = isis_print_mtid(tptr, "\n\t      ");
+                    if (mt_len == 0) /* did something go wrong ? */
+                        goto trunctlv;
+                    tptr+=mt_len;
+                    tmp-=mt_len;
+               } else {
+                   printf("\n\t      malformed MT-ID");
+                   break;
+               }
+           }
+           break;
+
+       case TLV_RESTART_SIGNALING:
+            if (!TTEST2(*tptr, 3))
+                goto trunctlv;
+            printf("\n\t      Flags [%s], Remaining holding time %us",
+                   bittok2str(isis_restart_flag_values, "none", *tptr),
+                   EXTRACT_16BITS(tptr+1));
+           tptr+=3;
+           break;
+
+        case TLV_IDRP_INFO:
+            if (!TTEST2(*tptr, 1))
+                goto trunctlv;
+            printf("\n\t      Inter-Domain Information Type: %s",
+                   tok2str(isis_subtlv_idrp_values,
+                           "Unknown (0x%02x)",
+                           *tptr));
+            switch (*tptr++) {
+            case SUBTLV_IDRP_ASN:
+                if (!TTEST2(*tptr, 2)) /* fetch AS number */
+                    goto trunctlv;
+                printf("AS Number: %u",EXTRACT_16BITS(tptr));
+                break;
+            case SUBTLV_IDRP_LOCAL:
+            case SUBTLV_IDRP_RES:
+            default:
+                if(!print_unknown_data(tptr,"\n\t      ",tlv_len-1))
+                    return(0);
+                break;
+            }
+            break;
+
+        case TLV_LSP_BUFFERSIZE:
+            if (!TTEST2(*tptr, 2))
+                goto trunctlv;
+            printf("\n\t      LSP Buffersize: %u",EXTRACT_16BITS(tptr));
+            break;
+
+        case TLV_PART_DIS:
+            while (tmp >= SYSTEM_ID_LEN) {
+                if (!TTEST2(*tptr, SYSTEM_ID_LEN))
+                    goto trunctlv;
+                printf("\n\t      %s",isis_print_id(tptr,SYSTEM_ID_LEN));
+                tptr+=SYSTEM_ID_LEN;
+                tmp-=SYSTEM_ID_LEN;
+            }
+            break;
+
+        case TLV_PREFIX_NEIGH:
+            if (!TTEST2(*tptr, sizeof(struct isis_metric_block)))
+                goto trunctlv;
+            printf("\n\t      Metric Block");
+            isis_print_metric_block((const struct isis_metric_block *)tptr);
+            tptr+=sizeof(struct isis_metric_block);
+            tmp-=sizeof(struct isis_metric_block);
+
+            while(tmp>0) {
+                if (!TTEST2(*tptr, 1))
+                    goto trunctlv;
+                prefix_len=*tptr++; /* read out prefix length in semioctets*/
+                tmp--;
+                if (!TTEST2(*tptr, prefix_len/2))
+                    goto trunctlv;
+                printf("\n\t\tAddress: %s/%u",
+                       print_nsap(tptr,prefix_len/2),
+                       prefix_len*4);
+                tptr+=prefix_len/2;
+                tmp-=prefix_len/2;
+            }
+            break;
+
+        case TLV_IIH_SEQNR:
+            if (!TTEST2(*tptr, 4)) /* check if four bytes are on the wire */
+                goto trunctlv;
+            printf("\n\t      Sequence number: %u", EXTRACT_32BITS(tptr) );
+            break;
+
+        case TLV_VENDOR_PRIVATE:
+            if (!TTEST2(*tptr, 3)) /* check if enough byte for a full oui */
+                goto trunctlv;
+            printf("\n\t      Vendor OUI Code: 0x%06x", EXTRACT_24BITS(tptr) );
+            tptr+=3;
+            tmp-=3;
+            if (tmp > 0) /* hexdump the rest */
+                if(!print_unknown_data(tptr,"\n\t\t",tmp))
+                    return(0);
+            break;
+            /*
+             * FIXME those are the defined TLVs that lack a decoder
+             * you are welcome to contribute code ;-)
+             */
+
+        case TLV_DECNET_PHASE4:
+        case TLV_LUCENT_PRIVATE:
+        case TLV_IPAUTH:
+        case TLV_NORTEL_PRIVATE1:
+        case TLV_NORTEL_PRIVATE2:
+
+       default:
+            if (vflag <= 1) {
+                if(!print_unknown_data(pptr,"\n\t\t",tlv_len))
+                    return(0);
+            }
+           break;
+       }
+        /* do we want to see an additionally hexdump ? */
+        if (vflag> 1) {
+           if(!print_unknown_data(pptr,"\n\t      ",tlv_len))
+               return(0);
+        }
+
+       pptr += tlv_len;
+       packet_len -= tlv_len;
+    }
+
+    if (packet_len != 0) {
+       printf("\n\t      %u straggler bytes", packet_len);
+    }
+    return (1);
+
+ trunc:
+    fputs("[|isis]", stdout);
+    return (1);
+
+ trunctlv:
+    printf("\n\t\t packet exceeded snapshot");
+    return(1);
+}
+
+/*
+ * Verify the checksum.  See 8473-1, Appendix C, section C.4.
+ */
+
+static int
+osi_cksum(const u_int8_t *tptr, u_int len)
+{
+       int32_t c0 = 0, c1 = 0;
 
-       off[0] = off[1] = 0;
        while ((int)--len >= 0) {
-               c0 += *p++;
-               c1 += c0;
+               c0 += *tptr++;
                c0 %= 255;
+               c1 += c0;
                c1 %= 255;
        }
-       x = (c0 * f - c1);
-       if (x < 0)
-               x = 255 - (-x % 255);
-       else
-               x %= 255;
-       y = -1 * (x + c0);
-       if (y < 0)
-               y = 255 - (-y % 255);
-       else
-               y %= 255;
-
-       off[0] = x;
-       off[1] = y;
-
-       return (off[0] != cksum[0] || off[1] != cksum[1]);
+       return (c0 | c1);
 }