]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-isoclns.c
Use more the ND_TTEST_1() macro
[tcpdump] / print-isoclns.c
index cc441c11409f38e881a2aace5d68ddaf22f39cc7..3d09f994eb564184b275af7d40feafd19e96c891 100644 (file)
  *
  * Original code by Matt Thomas, Digital Equipment Corporation
  *
- * Extensively modified by Hannes Gredler (hannes@juniper.net) for more
+ * Extensively modified by Hannes Gredler (hannes@gredler.at) for more
  * complete IS-IS & CLNP support.
  */
 
-#ifndef lint
-static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-isoclns.c,v 1.165 2008-08-16 13:38:15 hannes Exp $ (LBL)";
-#endif
+/* \summary: ISO CLNS, ESIS, and ISIS printer */
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
 
-#include <stdio.h>
 #include <string.h>
 
-#include "interface.h"
+#include "netdissect.h"
 #include "addrtoname.h"
-#include "ethertype.h"
-#include "ether.h"
 #include "nlpid.h"
 #include "extract.h"
 #include "gmpls.h"
 #include "oui.h"
 #include "signature.h"
 
+static const char tstr[] = " [|isis]";
+
 /*
  * 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 SYSTEM_ID_LEN  MAC_ADDR_LEN
+#define NODE_ID_LEN     (SYSTEM_ID_LEN+1)
+#define LSP_ID_LEN      (SYSTEM_ID_LEN+2)
 
 #define ISIS_VERSION   1
 #define ESIS_VERSION   1
@@ -109,9 +105,10 @@ static const struct tok isis_pdu_values[] = {
 #define ISIS_TLV_AUTH                10  /* iso10589, rfc3567 */
 #define ISIS_TLV_CHECKSUM            12  /* rfc3358 */
 #define ISIS_TLV_CHECKSUM_MINLEN 2
+#define ISIS_TLV_POI                 13  /* rfc6232 */
 #define ISIS_TLV_LSP_BUFFERSIZE      14  /* iso10589 rev2 */
 #define ISIS_TLV_LSP_BUFFERSIZE_MINLEN 2
-#define ISIS_TLV_EXT_IS_REACH        22  /* draft-ietf-isis-traffic-05 */
+#define ISIS_TLV_EXT_IS_REACH        22  /* rfc5305 */
 #define ISIS_TLV_IS_ALIAS_ID         24  /* draft-ietf-isis-ext-lsp-frags-02 */
 #define ISIS_TLV_DECNET_PHASE4       42
 #define ISIS_TLV_LUCENT_PRIVATE      66
@@ -122,8 +119,8 @@ static const struct tok isis_pdu_values[] = {
 #define ISIS_TLV_IDRP_INFO_MINLEN      1
 #define ISIS_TLV_IPADDR              132 /* rfc1195 */
 #define ISIS_TLV_IPAUTH              133 /* rfc1195 */
-#define ISIS_TLV_TE_ROUTER_ID        134 /* draft-ietf-isis-traffic-05 */
-#define ISIS_TLV_EXTD_IP_REACH       135 /* draft-ietf-isis-traffic-05 */
+#define ISIS_TLV_TE_ROUTER_ID        134 /* rfc5305 */
+#define ISIS_TLV_EXTD_IP_REACH       135 /* rfc5305 */
 #define ISIS_TLV_HOSTNAME            137 /* rfc2763 */
 #define ISIS_TLV_SHARED_RISK_GROUP   138 /* draft-ietf-isis-gmpls-extensions */
 #define ISIS_TLV_MT_PORT_CAP         143 /* rfc6165 */
@@ -158,6 +155,7 @@ static const struct tok isis_tlv_values[] = {
     { ISIS_TLV_LSP,                "LSP entries"},
     { ISIS_TLV_AUTH,               "Authentication"},
     { ISIS_TLV_CHECKSUM,           "Checksum"},
+    { ISIS_TLV_POI,                "Purge Originator Identifier"},
     { ISIS_TLV_LSP_BUFFERSIZE,     "LSP Buffersize"},
     { ISIS_TLV_EXT_IS_REACH,       "Extended IS Reachability"},
     { ISIS_TLV_IS_ALIAS_ID,        "IS Alias ID"},
@@ -339,16 +337,16 @@ static const struct tok clnp_option_qos_global_values[] = {
     { 0, NULL }
 };
 
-#define ISIS_SUBTLV_EXT_IS_REACH_ADMIN_GROUP           3 /* draft-ietf-isis-traffic-05 */
+#define ISIS_SUBTLV_EXT_IS_REACH_ADMIN_GROUP           3 /* rfc5305 */
 #define ISIS_SUBTLV_EXT_IS_REACH_LINK_LOCAL_REMOTE_ID  4 /* rfc4205 */
-#define ISIS_SUBTLV_EXT_IS_REACH_LINK_REMOTE_ID        5 /* draft-ietf-isis-traffic-05 */
-#define ISIS_SUBTLV_EXT_IS_REACH_IPV4_INTF_ADDR        6 /* draft-ietf-isis-traffic-05 */
-#define ISIS_SUBTLV_EXT_IS_REACH_IPV4_NEIGHBOR_ADDR    8 /* draft-ietf-isis-traffic-05 */
-#define ISIS_SUBTLV_EXT_IS_REACH_MAX_LINK_BW           9 /* draft-ietf-isis-traffic-05 */
-#define ISIS_SUBTLV_EXT_IS_REACH_RESERVABLE_BW        10 /* draft-ietf-isis-traffic-05 */
+#define ISIS_SUBTLV_EXT_IS_REACH_LINK_REMOTE_ID        5 /* rfc5305 */
+#define ISIS_SUBTLV_EXT_IS_REACH_IPV4_INTF_ADDR        6 /* rfc5305 */
+#define ISIS_SUBTLV_EXT_IS_REACH_IPV4_NEIGHBOR_ADDR    8 /* rfc5305 */
+#define ISIS_SUBTLV_EXT_IS_REACH_MAX_LINK_BW           9 /* rfc5305 */
+#define ISIS_SUBTLV_EXT_IS_REACH_RESERVABLE_BW        10 /* rfc5305 */
 #define ISIS_SUBTLV_EXT_IS_REACH_UNRESERVED_BW        11 /* rfc4124 */
 #define ISIS_SUBTLV_EXT_IS_REACH_BW_CONSTRAINTS_OLD   12 /* draft-ietf-tewg-diff-te-proto-06 */
-#define ISIS_SUBTLV_EXT_IS_REACH_TE_METRIC            18 /* draft-ietf-isis-traffic-05 */
+#define ISIS_SUBTLV_EXT_IS_REACH_TE_METRIC            18 /* rfc5305 */
 #define ISIS_SUBTLV_EXT_IS_REACH_LINK_ATTRIBUTE       19 /* draft-ietf-isis-link-attr-01 */
 #define ISIS_SUBTLV_EXT_IS_REACH_LINK_PROTECTION_TYPE 20 /* rfc4205 */
 #define ISIS_SUBTLV_EXT_IS_REACH_INTF_SW_CAP_DESCR    21 /* rfc4205 */
@@ -452,10 +450,10 @@ static const struct tok isis_mt_capability_subtlv_values[] = {
 };
 
 struct isis_spb_mcid {
-  u_int8_t  format_id;
-  u_int8_t  name[32];
-  u_int8_t  revision_lvl[2];
-  u_int8_t  digest[16];
+  uint8_t  format_id;
+  uint8_t  name[32];
+  uint8_t  revision_lvl[2];
+  uint8_t  digest[16];
 };
 
 struct isis_subtlv_spb_mcid {
@@ -464,11 +462,11 @@ struct isis_subtlv_spb_mcid {
 };
 
 struct isis_subtlv_spb_instance {
-  u_int8_t cist_root_id[8];
-  u_int8_t cist_external_root_path_cost[4];
-  u_int8_t bridge_priority[2];
-  u_int8_t spsourceid[4];
-  u_int8_t no_of_trees;
+  uint8_t cist_root_id[8];
+  uint8_t cist_external_root_path_cost[4];
+  uint8_t bridge_priority[2];
+  uint8_t spsourceid[4];
+  uint8_t no_of_trees;
 };
 
 #define CLNP_SEGMENT_PART  0x80
@@ -559,39 +557,39 @@ static const struct tok isis_ptp_adjancey_values[] = {
 };
 
 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];
+    uint8_t adjacency_state;
+    uint8_t extd_local_circuit_id[4];
+    uint8_t neighbor_sysid[SYSTEM_ID_LEN];
+    uint8_t neighbor_extd_local_circuit_id[4];
 };
 
-static void osi_print_cksum(const u_int8_t *pptr, u_int16_t checksum,
-                            u_int checksum_offset, u_int length);
-static int clnp_print(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);
+static void osi_print_cksum(netdissect_options *, const uint8_t *pptr,
+                           uint16_t checksum, int checksum_offset, u_int length);
+static int clnp_print(netdissect_options *, const uint8_t *, u_int);
+static void esis_print(netdissect_options *, const uint8_t *, u_int);
+static int isis_print(netdissect_options *, const uint8_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;
+    uint8_t metric_default;
+    uint8_t metric_delay;
+    uint8_t metric_expense;
+    uint8_t metric_error;
 };
 
 struct isis_tlv_is_reach {
     struct isis_metric_block isis_metric_block;
-    u_int8_t neighbor_nodeid[NODE_ID_LEN];
+    uint8_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];
+    uint8_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];
+    uint8_t prefix[4];
+    uint8_t mask[4];
 };
 
 static const struct tok isis_is_reach_virtual_values[] = {
@@ -608,59 +606,59 @@ static const struct tok isis_restart_flag_values[] = {
 };
 
 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;
+    uint8_t nlpid;
+    uint8_t fixed_len;
+    uint8_t version;                   /* Protocol version */
+    uint8_t id_length;
+    uint8_t pdu_type;                  /* 3 MSbits are reserved */
+    uint8_t pdu_version;               /* Packet format version */
+    uint8_t reserved;
+    uint8_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];
+    uint8_t circuit_type;
+    uint8_t source_id[SYSTEM_ID_LEN];
+    uint8_t holding_time[2];
+    uint8_t pdu_len[2];
+    uint8_t priority;
+    uint8_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;
+    uint8_t circuit_type;
+    uint8_t source_id[SYSTEM_ID_LEN];
+    uint8_t holding_time[2];
+    uint8_t pdu_len[2];
+    uint8_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;
+    uint8_t pdu_len[2];
+    uint8_t remaining_lifetime[2];
+    uint8_t lsp_id[LSP_ID_LEN];
+    uint8_t sequence_number[4];
+    uint8_t checksum[2];
+    uint8_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];
+    uint8_t pdu_len[2];
+    uint8_t source_id[NODE_ID_LEN];
+    uint8_t start_lsp_id[LSP_ID_LEN];
+    uint8_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];
+    uint8_t pdu_len[2];
+    uint8_t source_id[NODE_ID_LEN];
 };
 
 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];
+    uint8_t remaining_lifetime[2];
+    uint8_t lsp_id[LSP_ID_LEN];
+    uint8_t sequence_number[4];
+    uint8_t checksum[2];
 };
 
 #define ISIS_COMMON_HEADER_SIZE (sizeof(struct isis_common_header))
@@ -670,66 +668,59 @@ struct isis_tlv_lsp {
 #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)
+void
+isoclns_print(netdissect_options *ndo, const uint8_t *p, u_int length)
 {
-        if (caplen <= 1) { /* enough bytes on the wire ? */
-            printf("|OSI");
-            return;
-        }
+       if (!ND_TTEST_1(p)) { /* enough bytes on the wire ? */
+               ND_PRINT((ndo, "|OSI"));
+               return;
+       }
 
-        if (eflag)
-            printf("OSI NLPID %s (0x%02x): ",
-                   tok2str(nlpid_values,"Unknown",*p),
-                   *p);
+       if (ndo->ndo_eflag)
+               ND_PRINT((ndo, "OSI NLPID %s (0x%02x): ", tok2str(nlpid_values, "Unknown", EXTRACT_U_1(p)), EXTRACT_U_1(p)));
 
-       switch (*p) {
+       switch (EXTRACT_U_1(p)) {
 
        case NLPID_CLNP:
-               if (!clnp_print(p, length))
-                        print_unknown_data(gndo,p,"\n\t",caplen);
+               if (!clnp_print(ndo, p, length))
+                       print_unknown_data(ndo, p, "\n\t", length);
                break;
 
        case NLPID_ESIS:
-               esis_print(p, length);
+               esis_print(ndo, p, length);
                return;
 
        case NLPID_ISIS:
-               if (!isis_print(p, length))
-                        print_unknown_data(gndo,p,"\n\t",caplen);
+               if (!isis_print(ndo, p, length))
+                       print_unknown_data(ndo, p, "\n\t", length);
                break;
 
        case NLPID_NULLNS:
-               (void)printf("%slength: %u",
-                            eflag ? "" : ", ",
-                             length);
+               ND_PRINT((ndo, "%slength: %u", ndo->ndo_eflag ? "" : ", ", length));
                break;
 
-        case NLPID_Q933:
-                q933_print(p+1, length-1);
-                break;
+       case NLPID_Q933:
+               q933_print(ndo, p + 1, length - 1);
+               break;
 
-        case NLPID_IP:
-               ip_print(gndo, p+1, length-1);
-                break;
+       case NLPID_IP:
+               ip_print(ndo, p + 1, length - 1);
+               break;
 
-#ifdef INET6
-        case NLPID_IP6:
-                ip6_print(gndo, p+1, length-1);
-                break;
-#endif
+       case NLPID_IP6:
+               ip6_print(ndo, p + 1, length - 1);
+               break;
 
-        case NLPID_PPP:
-                ppp_print(p+1, length-1);
-                break;
+       case NLPID_PPP:
+               ppp_print(ndo, p + 1, length - 1);
+               break;
 
        default:
-                if (!eflag)
-                    printf("OSI NLPID 0x%02x unknown",*p);
-               (void)printf("%slength: %u",
-                            eflag ? "" : ", ",
-                             length);
-               if (caplen > 1)
-                        print_unknown_data(gndo,p,"\n\t",caplen);
+               if (!ndo->ndo_eflag)
+                       ND_PRINT((ndo, "OSI NLPID 0x%02x unknown", EXTRACT_U_1(p)));
+               ND_PRINT((ndo, "%slength: %u", ndo->ndo_eflag ? "" : ", ", length));
+               if (length > 1)
+                       print_unknown_data(ndo, p, "\n\t", length);
                break;
        }
 }
@@ -750,19 +741,19 @@ static const struct tok clnp_pdu_values[] = {
 };
 
 struct clnp_header_t {
-    u_int8_t nlpid;
-    u_int8_t length_indicator;
-    u_int8_t version;
-    u_int8_t lifetime; /* units of 500ms */
-    u_int8_t type;
-    u_int8_t segment_length[2];
-    u_int8_t cksum[2];
+    uint8_t nlpid;
+    uint8_t length_indicator;
+    uint8_t version;
+    uint8_t lifetime; /* units of 500ms */
+    uint8_t type;
+    uint8_t segment_length[2];
+    uint8_t cksum[2];
 };
 
 struct clnp_segment_header_t {
-    u_int8_t data_unit_id[2];
-    u_int8_t segment_offset[2];
-    u_int8_t total_length[2];
+    uint8_t data_unit_id[2];
+    uint8_t segment_offset[2];
+    uint8_t total_length[2];
 };
 
 /*
@@ -770,29 +761,45 @@ struct clnp_segment_header_t {
  * Decode CLNP packets.  Return 0 on error.
  */
 
-static int clnp_print (const u_int8_t *pptr, u_int length)
+static int
+clnp_print(netdissect_options *ndo,
+           const uint8_t *pptr, u_int length)
 {
-       const u_int8_t *optr,*source_address,*dest_address;
+       const uint8_t *optr,*source_address,*dest_address;
         u_int li,tlen,nsap_offset,source_address_length,dest_address_length, clnp_pdu_type, clnp_flags;
        const struct clnp_header_t *clnp_header;
        const struct clnp_segment_header_t *clnp_segment_header;
-        u_int8_t rfd_error_major,rfd_error_minor;
+        uint8_t rfd_error,rfd_error_major,rfd_error_minor;
 
        clnp_header = (const struct clnp_header_t *) pptr;
-        TCHECK(*clnp_header);
+        ND_TCHECK(*clnp_header);
 
         li = clnp_header->length_indicator;
         optr = pptr;
 
-        if (!eflag)
-            printf("CLNP");
+        if (!ndo->ndo_eflag)
+            ND_PRINT((ndo, "CLNP"));
 
         /*
          * Sanity checking of the header.
          */
 
         if (clnp_header->version != CLNP_VERSION) {
-            printf("version %d packet not supported", clnp_header->version);
+            ND_PRINT((ndo, "version %d packet not supported", clnp_header->version));
+            return (0);
+        }
+
+       if (li > length) {
+            ND_PRINT((ndo, " length indicator(%u) > PDU size (%u)!", li, length));
+            return (0);
+       }
+
+        if (li < sizeof(struct clnp_header_t)) {
+            ND_PRINT((ndo, " length indicator %u < min PDU size:", li));
+            while (pptr < ndo->ndo_snapend) {
+                ND_PRINT((ndo, "%02X", EXTRACT_U_1(pptr)));
+                pptr++;
+            }
             return (0);
         }
 
@@ -803,157 +810,216 @@ static int clnp_print (const u_int8_t *pptr, u_int length)
 
         pptr += sizeof(struct clnp_header_t);
         li -= sizeof(struct clnp_header_t);
-        dest_address_length = *pptr;
-        dest_address = pptr + 1;
-
-        pptr += (1 + dest_address_length);
-        li -= (1 + dest_address_length);
-        source_address_length = *pptr;
-        source_address = pptr +1;
-
-        pptr += (1 + source_address_length);
-        li -= (1 + source_address_length);
-
-        if (vflag < 1) {
-            printf("%s%s > %s, %s, length %u",
-                   eflag ? "" : ", ",
-                   isonsap_string(source_address, source_address_length),
-                   isonsap_string(dest_address, dest_address_length),
+
+        if (li < 1) {
+            ND_PRINT((ndo, "li < size of fixed part of CLNP header and addresses"));
+            return (0);
+        }
+       ND_TCHECK_1(pptr);
+        dest_address_length = EXTRACT_U_1(pptr);
+        pptr += 1;
+        li -= 1;
+        if (li < dest_address_length) {
+            ND_PRINT((ndo, "li < size of fixed part of CLNP header and addresses"));
+            return (0);
+        }
+        ND_TCHECK_LEN(pptr, dest_address_length);
+        dest_address = pptr;
+        pptr += dest_address_length;
+        li -= dest_address_length;
+
+        if (li < 1) {
+            ND_PRINT((ndo, "li < size of fixed part of CLNP header and addresses"));
+            return (0);
+        }
+       ND_TCHECK_1(pptr);
+        source_address_length = EXTRACT_U_1(pptr);
+        pptr += 1;
+        li -= 1;
+        if (li < source_address_length) {
+            ND_PRINT((ndo, "li < size of fixed part of CLNP header and addresses"));
+            return (0);
+        }
+        ND_TCHECK_LEN(pptr, source_address_length);
+        source_address = pptr;
+        pptr += source_address_length;
+        li -= source_address_length;
+
+        if (ndo->ndo_vflag < 1) {
+            ND_PRINT((ndo, "%s%s > %s, %s, length %u",
+                   ndo->ndo_eflag ? "" : ", ",
+                   isonsap_string(ndo, source_address, source_address_length),
+                   isonsap_string(ndo, dest_address, dest_address_length),
                    tok2str(clnp_pdu_values,"unknown (%u)",clnp_pdu_type),
-                   length);
+                   length));
             return (1);
         }
-        printf("%slength %u",eflag ? "" : ", ",length);
+        ND_PRINT((ndo, "%slength %u", ndo->ndo_eflag ? "" : ", ", length));
 
-        printf("\n\t%s PDU, hlen: %u, v: %u, lifetime: %u.%us, Segment PDU length: %u, checksum: 0x%04x",
+        ND_PRINT((ndo, "\n\t%s PDU, hlen: %u, v: %u, lifetime: %u.%us, Segment PDU length: %u, checksum: 0x%04x",
                tok2str(clnp_pdu_values, "unknown (%u)",clnp_pdu_type),
                clnp_header->length_indicator,
                clnp_header->version,
                clnp_header->lifetime/2,
                (clnp_header->lifetime%2)*5,
-               EXTRACT_16BITS(clnp_header->segment_length),
-               EXTRACT_16BITS(clnp_header->cksum));
+               EXTRACT_BE_U_2(clnp_header->segment_length),
+               EXTRACT_BE_U_2(clnp_header->cksum)));
 
-        osi_print_cksum(optr, EXTRACT_16BITS(clnp_header->cksum), 7,
+        osi_print_cksum(ndo, optr, EXTRACT_BE_U_2(clnp_header->cksum), 7,
                         clnp_header->length_indicator);
 
-        printf("\n\tFlags [%s]",
-               bittok2str(clnp_flag_values,"none",clnp_flags));
+        ND_PRINT((ndo, "\n\tFlags [%s]",
+               bittok2str(clnp_flag_values, "none", clnp_flags)));
 
-        printf("\n\tsource address (length %u): %s\n\tdest   address (length %u): %s",
+        ND_PRINT((ndo, "\n\tsource address (length %u): %s\n\tdest   address (length %u): %s",
                source_address_length,
-               isonsap_string(source_address, source_address_length),
+               isonsap_string(ndo, source_address, source_address_length),
                dest_address_length,
-               isonsap_string(dest_address,dest_address_length));
+               isonsap_string(ndo, dest_address, dest_address_length)));
 
         if (clnp_flags & CLNP_SEGMENT_PART) {
+                if (li < sizeof(struct clnp_segment_header_t)) {
+                    ND_PRINT((ndo, "li < size of fixed part of CLNP header, addresses, and segment part"));
+                    return (0);
+                }
                clnp_segment_header = (const struct clnp_segment_header_t *) pptr;
-                TCHECK(*clnp_segment_header);
-                printf("\n\tData Unit ID: 0x%04x, Segment Offset: %u, Total PDU Length: %u",
-                       EXTRACT_16BITS(clnp_segment_header->data_unit_id),
-                       EXTRACT_16BITS(clnp_segment_header->segment_offset),
-                       EXTRACT_16BITS(clnp_segment_header->total_length));
-                pptr+=sizeof(const struct clnp_segment_header_t);
-                li-=sizeof(const struct clnp_segment_header_t);
+                ND_TCHECK(*clnp_segment_header);
+                ND_PRINT((ndo, "\n\tData Unit ID: 0x%04x, Segment Offset: %u, Total PDU Length: %u",
+                       EXTRACT_BE_U_2(clnp_segment_header->data_unit_id),
+                       EXTRACT_BE_U_2(clnp_segment_header->segment_offset),
+                       EXTRACT_BE_U_2(clnp_segment_header->total_length)));
+                pptr+=sizeof(struct clnp_segment_header_t);
+                li-=sizeof(struct clnp_segment_header_t);
         }
 
         /* now walk the options */
         while (li >= 2) {
             u_int op, opli;
-            const u_int8_t *tptr;
+            const uint8_t *tptr;
 
-            TCHECK2(*pptr, 2);
             if (li < 2) {
-                printf(", bad opts/li");
+                ND_PRINT((ndo, ", bad opts/li"));
                 return (0);
             }
-            op = *pptr++;
-            opli = *pptr++;
+            ND_TCHECK_2(pptr);
+            op = EXTRACT_U_1(pptr);
+            opli = EXTRACT_U_1(pptr + 1);
+            pptr += 2;
             li -= 2;
-            TCHECK2(*pptr, opli);
             if (opli > li) {
-                printf(", opt (%d) too long", op);
+                ND_PRINT((ndo, ", opt (%d) too long", op));
                 return (0);
             }
+            ND_TCHECK_LEN(pptr, opli);
             li -= opli;
             tptr = pptr;
             tlen = opli;
 
-            printf("\n\t  %s Option #%u, length %u, value: ",
+            ND_PRINT((ndo, "\n\t  %s Option #%u, length %u, value: ",
                    tok2str(clnp_option_values,"Unknown",op),
                    op,
-                   opli);
+                   opli));
 
+            /*
+             * We've already checked that the entire option is present
+             * in the captured packet with the ND_TCHECK_LEN() call.
+             * Therefore, we don't need to do ND_TCHECK()/ND_TCHECK_LEN()
+             * checks.
+             * We do, however, need to check tlen, to make sure we
+             * don't run past the end of the option.
+            */
             switch (op) {
 
 
             case CLNP_OPTION_ROUTE_RECORDING: /* those two options share the format */
             case CLNP_OPTION_SOURCE_ROUTING:
-                    printf("%s %s",
-                           tok2str(clnp_option_sr_rr_values,"Unknown",*tptr),
-                           tok2str(clnp_option_sr_rr_string_values,"Unknown Option %u",op));
-                    nsap_offset=*(tptr+1);
+                    if (tlen < 2) {
+                            ND_PRINT((ndo, ", bad opt len"));
+                            return (0);
+                    }
+                    ND_PRINT((ndo, "%s %s",
+                           tok2str(clnp_option_sr_rr_values,"Unknown",EXTRACT_U_1(tptr)),
+                           tok2str(clnp_option_sr_rr_string_values, "Unknown Option %u", op)));
+                    nsap_offset=EXTRACT_U_1(tptr + 1);
                     if (nsap_offset == 0) {
-                            printf(" Bad NSAP offset (0)");
+                            ND_PRINT((ndo, " Bad NSAP offset (0)"));
                             break;
                     }
                     nsap_offset-=1; /* offset to nsap list */
                     if (nsap_offset > tlen) {
-                            printf(" Bad NSAP offset (past end of option)");
+                            ND_PRINT((ndo, " Bad NSAP offset (past end of option)"));
                             break;
                     }
                     tptr+=nsap_offset;
                     tlen-=nsap_offset;
                     while (tlen > 0) {
-                            source_address_length=*tptr;
+                            source_address_length=EXTRACT_U_1(tptr);
                             if (tlen < source_address_length+1) {
-                                    printf("\n\t    NSAP address goes past end of option");
+                                    ND_PRINT((ndo, "\n\t    NSAP address goes past end of option"));
                                     break;
                             }
                             if (source_address_length > 0) {
                                     source_address=(tptr+1);
-                                    TCHECK2(*source_address, source_address_length);
-                                    printf("\n\t    NSAP address (length %u): %s",
+                                    ND_TCHECK_LEN(source_address,
+                                                  source_address_length);
+                                    ND_PRINT((ndo, "\n\t    NSAP address (length %u): %s",
                                            source_address_length,
-                                           isonsap_string(source_address, source_address_length));
+                                           isonsap_string(ndo, source_address, source_address_length)));
                             }
                             tlen-=source_address_length+1;
                     }
                     break;
 
             case CLNP_OPTION_PRIORITY:
-                    printf("0x%1x", *tptr&0x0f);
+                    if (tlen < 1) {
+                            ND_PRINT((ndo, ", bad opt len"));
+                            return (0);
+                    }
+                    ND_PRINT((ndo, "0x%1x", EXTRACT_U_1(tptr)&0x0f));
                     break;
 
             case CLNP_OPTION_QOS_MAINTENANCE:
-                    printf("\n\t    Format Code: %s",
-                           tok2str(clnp_option_scope_values,"Reserved",*tptr&CLNP_OPTION_SCOPE_MASK));
+                    if (tlen < 1) {
+                            ND_PRINT((ndo, ", bad opt len"));
+                            return (0);
+                    }
+                    ND_PRINT((ndo, "\n\t    Format Code: %s",
+                           tok2str(clnp_option_scope_values, "Reserved", EXTRACT_U_1(tptr) & CLNP_OPTION_SCOPE_MASK)));
 
-                    if ((*tptr&CLNP_OPTION_SCOPE_MASK) == CLNP_OPTION_SCOPE_GLOBAL)
-                            printf("\n\t    QoS Flags [%s]",
+                    if ((EXTRACT_U_1(tptr)&CLNP_OPTION_SCOPE_MASK) == CLNP_OPTION_SCOPE_GLOBAL)
+                            ND_PRINT((ndo, "\n\t    QoS Flags [%s]",
                                    bittok2str(clnp_option_qos_global_values,
                                               "none",
-                                              *tptr&CLNP_OPTION_OPTION_QOS_MASK));
+                                              EXTRACT_U_1(tptr)&CLNP_OPTION_OPTION_QOS_MASK)));
                     break;
 
             case CLNP_OPTION_SECURITY:
-                    printf("\n\t    Format Code: %s, Security-Level %u",
-                           tok2str(clnp_option_scope_values,"Reserved",*tptr&CLNP_OPTION_SCOPE_MASK),
-                           *(tptr+1));
+                    if (tlen < 2) {
+                            ND_PRINT((ndo, ", bad opt len"));
+                            return (0);
+                    }
+                    ND_PRINT((ndo, "\n\t    Format Code: %s, Security-Level %u",
+                           tok2str(clnp_option_scope_values,"Reserved",EXTRACT_U_1(tptr)&CLNP_OPTION_SCOPE_MASK),
+                           EXTRACT_U_1(tptr + 1)));
                     break;
 
             case CLNP_OPTION_DISCARD_REASON:
-                rfd_error_major = (*tptr&0xf0) >> 4;
-                rfd_error_minor = *tptr&0x0f;
-                printf("\n\t    Class: %s Error (0x%01x), %s (0x%01x)",
+                if (tlen < 1) {
+                        ND_PRINT((ndo, ", bad opt len"));
+                        return (0);
+                }
+                rfd_error = EXTRACT_U_1(tptr);
+                rfd_error_major = (rfd_error&0xf0) >> 4;
+                rfd_error_minor = rfd_error&0x0f;
+                ND_PRINT((ndo, "\n\t    Class: %s Error (0x%01x), %s (0x%01x)",
                        tok2str(clnp_option_rfd_class_values,"Unknown",rfd_error_major),
                        rfd_error_major,
                        tok2str(clnp_option_rfd_error_class[rfd_error_major],"Unknown",rfd_error_minor),
-                       rfd_error_minor);
+                       rfd_error_minor));
                 break;
 
             case CLNP_OPTION_PADDING:
-                    printf("padding data");
+                    ND_PRINT((ndo, "padding data"));
                 break;
 
                 /*
@@ -962,11 +1028,11 @@ static int clnp_print (const u_int8_t *pptr, u_int length)
                  */
 
             default:
-                print_unknown_data(gndo,tptr,"\n\t  ",opli);
+                print_unknown_data(ndo, tptr, "\n\t  ", opli);
                 break;
             }
-            if (vflag > 1)
-                print_unknown_data(gndo,pptr,"\n\t  ",opli);
+            if (ndo->ndo_vflag > 1)
+                print_unknown_data(ndo, pptr, "\n\t  ", opli);
             pptr += opli;
         }
 
@@ -974,11 +1040,11 @@ static int clnp_print (const u_int8_t *pptr, u_int length)
 
         case    CLNP_PDU_ER: /* fall through */
         case   CLNP_PDU_ERP:
-            TCHECK(*pptr);
-            if (*(pptr) == NLPID_CLNP) {
-                printf("\n\t-----original packet-----\n\t");
+            ND_TCHECK_1(pptr);
+            if (EXTRACT_U_1(pptr) == NLPID_CLNP) {
+                ND_PRINT((ndo, "\n\t-----original packet-----\n\t"));
                 /* FIXME recursion protection */
-                clnp_print(pptr, length-clnp_header->length_indicator);
+                clnp_print(ndo, pptr, length - clnp_header->length_indicator);
                 break;
             }
 
@@ -989,15 +1055,15 @@ static int clnp_print (const u_int8_t *pptr, u_int length)
         default:
             /* dump the PDU specific data */
             if (length-(pptr-optr) > 0) {
-                printf("\n\t  undecoded non-header data, length %u",length-clnp_header->length_indicator);
-                print_unknown_data(gndo,pptr,"\n\t  ",length-(pptr-optr));
+                ND_PRINT((ndo, "\n\t  undecoded non-header data, length %u", length-clnp_header->length_indicator));
+                print_unknown_data(ndo, pptr, "\n\t  ", length - (pptr - optr));
             }
         }
 
         return (1);
 
  trunc:
-    fputs("[|clnp]", stdout);
+    ND_PRINT((ndo, "[|clnp]"));
     return (1);
 
 }
@@ -1015,35 +1081,33 @@ static const struct tok esis_pdu_values[] = {
 };
 
 struct esis_header_t {
-       u_int8_t nlpid;
-       u_int8_t length_indicator;
-       u_int8_t version;
-       u_int8_t reserved;
-       u_int8_t type;
-       u_int8_t holdtime[2];
-       u_int8_t cksum[2];
+       uint8_t nlpid;
+       uint8_t length_indicator;
+       uint8_t version;
+       uint8_t reserved;
+       uint8_t type;
+       uint8_t holdtime[2];
+       uint8_t cksum[2];
 };
 
 static void
-esis_print(const u_int8_t *pptr, u_int length)
+esis_print(netdissect_options *ndo,
+           const uint8_t *pptr, u_int length)
 {
-       const u_int8_t *optr;
+       const uint8_t *optr;
        u_int li,esis_pdu_type,source_address_length, source_address_number;
        const struct esis_header_t *esis_header;
 
-        if (!eflag)
-            printf("ES-IS");
+       if (!ndo->ndo_eflag)
+               ND_PRINT((ndo, "ES-IS"));
 
        if (length <= 2) {
-               if (qflag)
-                       printf("bad pkt!");
-               else
-                       printf("no header at all!");
+               ND_PRINT((ndo, ndo->ndo_qflag ? "bad pkt!" : "no header at all!"));
                return;
        }
 
        esis_header = (const struct esis_header_t *) pptr;
-        TCHECK(*esis_header);
+        ND_TCHECK(*esis_header);
         li = esis_header->length_indicator;
         optr = pptr;
 
@@ -1052,147 +1116,159 @@ esis_print(const u_int8_t *pptr, u_int length)
          */
 
         if (esis_header->nlpid != NLPID_ESIS) {
-            printf(" nlpid 0x%02x packet not supported", esis_header->nlpid);
+            ND_PRINT((ndo, " nlpid 0x%02x packet not supported", esis_header->nlpid));
             return;
         }
 
         if (esis_header->version != ESIS_VERSION) {
-            printf(" version %d packet not supported", esis_header->version);
+            ND_PRINT((ndo, " version %d packet not supported", esis_header->version));
             return;
         }
 
        if (li > length) {
-            printf(" length indicator(%d) > PDU size (%d)!", li, length);
+            ND_PRINT((ndo, " length indicator(%u) > PDU size (%u)!", li, length));
             return;
        }
 
        if (li < sizeof(struct esis_header_t) + 2) {
-            printf(" length indicator < min PDU size %d:", li);
-            while (--length != 0)
-                printf("%02X", *pptr++);
+            ND_PRINT((ndo, " length indicator %u < min PDU size:", li));
+            while (pptr < ndo->ndo_snapend) {
+                ND_PRINT((ndo, "%02X", EXTRACT_U_1(pptr)));
+                pptr++;
+            }
             return;
        }
 
         esis_pdu_type = esis_header->type & ESIS_PDU_TYPE_MASK;
 
-        if (vflag < 1) {
-            printf("%s%s, length %u",
-                   eflag ? "" : ", ",
+        if (ndo->ndo_vflag < 1) {
+            ND_PRINT((ndo, "%s%s, length %u",
+                   ndo->ndo_eflag ? "" : ", ",
                    tok2str(esis_pdu_values,"unknown type (%u)",esis_pdu_type),
-                   length);
+                   length));
             return;
         } else
-            printf("%slength %u\n\t%s (%u)",
-                   eflag ? "" : ", ",
+            ND_PRINT((ndo, "%slength %u\n\t%s (%u)",
+                   ndo->ndo_eflag ? "" : ", ",
                    length,
                    tok2str(esis_pdu_values,"unknown type: %u", esis_pdu_type),
-                   esis_pdu_type);
+                   esis_pdu_type));
 
-        printf(", v: %u%s", esis_header->version, esis_header->version == ESIS_VERSION ? "" : "unsupported" );
-        printf(", checksum: 0x%04x", EXTRACT_16BITS(esis_header->cksum));
+        ND_PRINT((ndo, ", v: %u%s", esis_header->version, esis_header->version == ESIS_VERSION ? "" : "unsupported" ));
+        ND_PRINT((ndo, ", checksum: 0x%04x", EXTRACT_BE_U_2(esis_header->cksum)));
 
-        osi_print_cksum(pptr, EXTRACT_16BITS(esis_header->cksum), 7, li);
+        osi_print_cksum(ndo, pptr, EXTRACT_BE_U_2(esis_header->cksum), 7,
+                        li);
 
-        printf(", holding time: %us, length indicator: %u",EXTRACT_16BITS(esis_header->holdtime),li);
+        ND_PRINT((ndo, ", holding time: %us, length indicator: %u",
+                  EXTRACT_BE_U_2(esis_header->holdtime), li));
 
-        if (vflag > 1)
-            print_unknown_data(gndo,optr,"\n\t",sizeof(struct esis_header_t));
+        if (ndo->ndo_vflag > 1)
+            print_unknown_data(ndo, optr, "\n\t", sizeof(struct esis_header_t));
 
        pptr += sizeof(struct esis_header_t);
        li -= sizeof(struct esis_header_t);
 
        switch (esis_pdu_type) {
        case ESIS_PDU_REDIRECT: {
-               const u_int8_t *dst, *snpa, *neta;
+               const uint8_t *dst, *snpa, *neta;
                u_int dstl, snpal, netal;
 
-               TCHECK(*pptr);
+               ND_TCHECK_1(pptr);
                if (li < 1) {
-                       printf(", bad redirect/li");
+                       ND_PRINT((ndo, ", bad redirect/li"));
                        return;
                }
-               dstl = *pptr;
+               dstl = EXTRACT_U_1(pptr);
                pptr++;
                li--;
-               TCHECK2(*pptr, dstl);
+               ND_TCHECK_LEN(pptr, dstl);
                if (li < dstl) {
-                       printf(", bad redirect/li");
+                       ND_PRINT((ndo, ", bad redirect/li"));
                        return;
                }
                dst = pptr;
                pptr += dstl;
                 li -= dstl;
-               printf("\n\t  %s", isonsap_string(dst,dstl));
+               ND_PRINT((ndo, "\n\t  %s", isonsap_string(ndo, dst, dstl)));
 
-               TCHECK(*pptr);
+               ND_TCHECK_1(pptr);
                if (li < 1) {
-                       printf(", bad redirect/li");
+                       ND_PRINT((ndo, ", bad redirect/li"));
                        return;
                }
-               snpal = *pptr;
+               snpal = EXTRACT_U_1(pptr);
                pptr++;
                li--;
-               TCHECK2(*pptr, snpal);
+               ND_TCHECK_LEN(pptr, snpal);
                if (li < snpal) {
-                       printf(", bad redirect/li");
+                       ND_PRINT((ndo, ", bad redirect/li"));
                        return;
                }
                snpa = pptr;
                pptr += snpal;
                 li -= snpal;
-               TCHECK(*pptr);
+               ND_TCHECK_1(pptr);
                if (li < 1) {
-                       printf(", bad redirect/li");
+                       ND_PRINT((ndo, ", bad redirect/li"));
                        return;
                }
-               netal = *pptr;
+               netal = EXTRACT_U_1(pptr);
                pptr++;
-               TCHECK2(*pptr, netal);
+               ND_TCHECK_LEN(pptr, netal);
                if (li < netal) {
-                       printf(", bad redirect/li");
+                       ND_PRINT((ndo, ", bad redirect/li"));
                        return;
                }
                neta = pptr;
                pptr += netal;
                 li -= netal;
 
-               if (netal == 0)
-                       printf("\n\t  %s", etheraddr_string(snpa));
+               if (snpal == 6)
+                       ND_PRINT((ndo, "\n\t  SNPA (length: %u): %s",
+                              snpal,
+                              etheraddr_string(ndo, snpa)));
                else
-                       printf("\n\t  %s", isonsap_string(neta,netal));
+                       ND_PRINT((ndo, "\n\t  SNPA (length: %u): %s",
+                              snpal,
+                              linkaddr_string(ndo, snpa, LINKADDR_OTHER, snpal)));
+               if (netal != 0)
+                       ND_PRINT((ndo, "\n\t  NET (length: %u) %s",
+                              netal,
+                              isonsap_string(ndo, neta, netal)));
                break;
        }
 
        case ESIS_PDU_ESH:
-            TCHECK(*pptr);
+            ND_TCHECK_1(pptr);
             if (li < 1) {
-                printf(", bad esh/li");
+                ND_PRINT((ndo, ", bad esh/li"));
                 return;
             }
-            source_address_number = *pptr;
+            source_address_number = EXTRACT_U_1(pptr);
             pptr++;
             li--;
 
-            printf("\n\t  Number of Source Addresses: %u", source_address_number);
+            ND_PRINT((ndo, "\n\t  Number of Source Addresses: %u", source_address_number));
 
             while (source_address_number > 0) {
-                TCHECK(*pptr);
+                ND_TCHECK_1(pptr);
                if (li < 1) {
-                    printf(", bad esh/li");
+                    ND_PRINT((ndo, ", bad esh/li"));
                    return;
                }
-                source_address_length = *pptr;
+                source_address_length = EXTRACT_U_1(pptr);
                 pptr++;
                li--;
 
-                TCHECK2(*pptr, source_address_length);
+                ND_TCHECK_LEN(pptr, source_address_length);
                if (li < source_address_length) {
-                    printf(", bad esh/li");
+                    ND_PRINT((ndo, ", bad esh/li"));
                    return;
                }
-                printf("\n\t  NET (length: %u): %s",
+                ND_PRINT((ndo, "\n\t  NET (length: %u): %s",
                        source_address_length,
-                       isonsap_string(pptr,source_address_length));
+                       isonsap_string(ndo, pptr, source_address_length)));
                 pptr += source_address_length;
                 li -= source_address_length;
                 source_address_number--;
@@ -1201,78 +1277,79 @@ esis_print(const u_int8_t *pptr, u_int length)
             break;
 
        case ESIS_PDU_ISH: {
-            TCHECK(*pptr);
+            ND_TCHECK_1(pptr);
             if (li < 1) {
-                printf(", bad ish/li");
+                ND_PRINT((ndo, ", bad ish/li"));
                 return;
             }
-            source_address_length = *pptr;
+            source_address_length = EXTRACT_U_1(pptr);
             pptr++;
             li--;
-            TCHECK2(*pptr, source_address_length);
+            ND_TCHECK_LEN(pptr, source_address_length);
             if (li < source_address_length) {
-                printf(", bad ish/li");
+                ND_PRINT((ndo, ", bad ish/li"));
                 return;
             }
-            printf("\n\t  NET (length: %u): %s", source_address_length, isonsap_string(pptr, source_address_length));
+            ND_PRINT((ndo, "\n\t  NET (length: %u): %s", source_address_length, isonsap_string(ndo, pptr, source_address_length)));
             pptr += source_address_length;
             li -= source_address_length;
             break;
        }
 
        default:
-            if (vflag <= 1) {
-                   if (pptr < snapend)
-                            print_unknown_data(gndo,pptr,"\n\t  ",snapend-pptr);
-            }
-            return;
+               if (ndo->ndo_vflag <= 1) {
+                       if (pptr < ndo->ndo_snapend)
+                               print_unknown_data(ndo, pptr, "\n\t  ", ndo->ndo_snapend - pptr);
+               }
+               return;
        }
 
         /* now walk the options */
         while (li != 0) {
             u_int op, opli;
-            const u_int8_t *tptr;
+            const uint8_t *tptr;
 
             if (li < 2) {
-                printf(", bad opts/li");
+                ND_PRINT((ndo, ", bad opts/li"));
                 return;
             }
-            TCHECK2(*pptr, 2);
-            op = *pptr++;
-            opli = *pptr++;
+            ND_TCHECK_2(pptr);
+            op = EXTRACT_U_1(pptr);
+            opli = EXTRACT_U_1(pptr + 1);
+            pptr += 2;
             li -= 2;
             if (opli > li) {
-                printf(", opt (%d) too long", op);
+                ND_PRINT((ndo, ", opt (%d) too long", op));
                 return;
             }
             li -= opli;
             tptr = pptr;
 
-            printf("\n\t  %s Option #%u, length %u, value: ",
+            ND_PRINT((ndo, "\n\t  %s Option #%u, length %u, value: ",
                    tok2str(esis_option_values,"Unknown",op),
                    op,
-                   opli);
+                   opli));
 
             switch (op) {
 
             case ESIS_OPTION_ES_CONF_TIME:
                 if (opli == 2) {
-                    TCHECK2(*pptr, 2);
-                    printf("%us", EXTRACT_16BITS(tptr));
+                    ND_TCHECK_2(pptr);
+                    ND_PRINT((ndo, "%us", EXTRACT_BE_U_2(tptr)));
                 } else
-                    printf("(bad length)");
+                    ND_PRINT((ndo, "(bad length)"));
                 break;
 
             case ESIS_OPTION_PROTOCOLS:
                 while (opli>0) {
-                    TCHECK(*pptr);
-                    printf("%s (0x%02x)",
+                    ND_TCHECK_1(tptr);
+                    ND_PRINT((ndo, "%s (0x%02x)",
                            tok2str(nlpid_values,
                                    "unknown",
-                                   *tptr),
-                           *tptr);
+                                   EXTRACT_U_1(tptr)),
+                           EXTRACT_U_1(tptr)));
                     if (opli>1) /* further NPLIDs ? - put comma */
-                        printf(", ");
+                        ND_PRINT((ndo, ", "));
                     tptr++;
                     opli--;
                 }
@@ -1290,249 +1367,270 @@ esis_print(const u_int8_t *pptr, u_int length)
             case ESIS_OPTION_SNPA_MASK:
 
             default:
-                print_unknown_data(gndo,tptr,"\n\t  ",opli);
+                print_unknown_data(ndo, tptr, "\n\t  ", opli);
                 break;
             }
-            if (vflag > 1)
-                print_unknown_data(gndo,pptr,"\n\t  ",opli);
+            if (ndo->ndo_vflag > 1)
+                print_unknown_data(ndo, pptr, "\n\t  ", opli);
             pptr += opli;
         }
 trunc:
-       return;
+        ND_PRINT((ndo, "[|esis]"));
 }
 
-
 static void
-isis_print_mcid (const struct isis_spb_mcid *mcid)
+isis_print_mcid(netdissect_options *ndo,
+                const struct isis_spb_mcid *mcid)
 {
   int i;
 
-  printf( "ID: %d, Name: ", mcid->format_id);
+  ND_TCHECK(*mcid);
+  ND_PRINT((ndo,  "ID: %d, Name: ", mcid->format_id));
 
-  for(i=0; i<32; i++)
-  {
-    printf("%c", mcid->name[i]);
-    if(mcid->name[i] == '\0')
-        break;
-  }
+  if (fn_printzp(ndo, mcid->name, 32, ndo->ndo_snapend))
+    goto trunc;
 
-  printf("\n\t              Lvl: %d",
-          EXTRACT_16BITS(mcid->revision_lvl));
+  ND_PRINT((ndo, "\n\t              Lvl: %d", EXTRACT_BE_U_2(mcid->revision_lvl)));
 
-  printf( ", Digest: ");
+  ND_PRINT((ndo,  ", Digest: "));
 
   for(i=0;i<16;i++)
-    printf("%.2x ",mcid->digest[i]);
+    ND_PRINT((ndo, "%.2x ", mcid->digest[i]));
+
+trunc:
+  ND_PRINT((ndo, "%s", tstr));
 }
 
 static int
-isis_print_mt_port_cap_subtlv (const u_int8_t *tptr, int len)
+isis_print_mt_port_cap_subtlv(netdissect_options *ndo,
+                              const uint8_t *tptr, int len)
 {
   int stlv_type, stlv_len;
   const struct isis_subtlv_spb_mcid *subtlv_spb_mcid;
   int i;
 
-  while (len > 0)
+  while (len > 2)
   {
-    stlv_type = *(tptr++);
-    stlv_len  = *(tptr++);
+    ND_TCHECK_2(tptr);
+    stlv_type = EXTRACT_U_1(tptr);
+    stlv_len  = EXTRACT_U_1(tptr + 1);
 
     /* first lets see if we know the subTLVs name*/
-    printf("\n\t       %s subTLV #%u, length: %u",
+    ND_PRINT((ndo, "\n\t       %s subTLV #%u, length: %u",
                tok2str(isis_mt_port_cap_subtlv_values, "unknown", stlv_type),
                stlv_type,
-               stlv_len);
+               stlv_len));
 
+    tptr = tptr + 2;
     /*len -= TLV_TYPE_LEN_OFFSET;*/
-    len = len -2;
+    len = len - 2;
+
+    /* Make sure the subTLV fits within the space left */
+    if (len < stlv_len)
+      goto trunc;
+    /* Make sure the entire subTLV is in the captured data */
+    ND_TCHECK_LEN(tptr, stlv_len);
 
     switch (stlv_type)
     {
       case ISIS_SUBTLV_SPB_MCID:
       {
-        if (!TTEST2(*(tptr), ISIS_SUBTLV_SPB_MCID_MIN_LEN))
-          goto trunctlv;
+       if (stlv_len < ISIS_SUBTLV_SPB_MCID_MIN_LEN)
+         goto trunc;
 
-        subtlv_spb_mcid = (struct isis_subtlv_spb_mcid *)tptr;
+        subtlv_spb_mcid = (const struct isis_subtlv_spb_mcid *)tptr;
 
-        printf( "\n\t         MCID: ");
-        isis_print_mcid (&(subtlv_spb_mcid->mcid));
+        ND_PRINT((ndo,  "\n\t         MCID: "));
+        isis_print_mcid(ndo, &(subtlv_spb_mcid->mcid));
 
           /*tptr += SPB_MCID_MIN_LEN;
             len -= SPB_MCID_MIN_LEN; */
 
-        printf( "\n\t         AUX-MCID: ");
-        isis_print_mcid (&(subtlv_spb_mcid->aux_mcid));
+        ND_PRINT((ndo,  "\n\t         AUX-MCID: "));
+        isis_print_mcid(ndo, &(subtlv_spb_mcid->aux_mcid));
 
           /*tptr += SPB_MCID_MIN_LEN;
             len -= SPB_MCID_MIN_LEN; */
-        tptr = tptr + sizeof(struct isis_subtlv_spb_mcid);
-        len = len - sizeof(struct isis_subtlv_spb_mcid);
+        tptr = tptr + ISIS_SUBTLV_SPB_MCID_MIN_LEN;
+        len = len - ISIS_SUBTLV_SPB_MCID_MIN_LEN;
+        stlv_len = stlv_len - ISIS_SUBTLV_SPB_MCID_MIN_LEN;
 
         break;
       }
 
       case ISIS_SUBTLV_SPB_DIGEST:
       {
-        if (!TTEST2(*(tptr), ISIS_SUBTLV_SPB_DIGEST_MIN_LEN))
-          goto trunctlv;
+        if (stlv_len < ISIS_SUBTLV_SPB_DIGEST_MIN_LEN)
+          goto trunc;
 
-        printf ("\n\t        RES: %d V: %d A: %d D: %d",
-                        (*(tptr) >> 5), (((*tptr)>> 4) & 0x01),
-                        ((*(tptr) >> 2) & 0x03), ((*tptr) & 0x03));
+        ND_PRINT((ndo, "\n\t        RES: %d V: %d A: %d D: %d",
+                        (EXTRACT_U_1(tptr) >> 5),
+                        ((EXTRACT_U_1(tptr) >> 4) & 0x01),
+                        ((EXTRACT_U_1(tptr) >> 2) & 0x03),
+                        (EXTRACT_U_1(tptr) & 0x03)));
 
         tptr++;
 
-        printf( "\n\t         Digest: ");
+        ND_PRINT((ndo,  "\n\t         Digest: "));
 
         for(i=1;i<=8; i++)
         {
-            printf("%08x ", EXTRACT_32BITS(tptr));
+            ND_PRINT((ndo, "%08x ", EXTRACT_BE_U_4(tptr)));
             if (i%4 == 0 && i != 8)
-              printf("\n\t                 ");
+              ND_PRINT((ndo, "\n\t                 "));
             tptr = tptr + 4;
         }
 
         len = len - ISIS_SUBTLV_SPB_DIGEST_MIN_LEN;
+        stlv_len = stlv_len - ISIS_SUBTLV_SPB_DIGEST_MIN_LEN;
 
         break;
       }
 
       case ISIS_SUBTLV_SPB_BVID:
       {
-        if (!TTEST2(*(tptr), stlv_len))
-          goto trunctlv;
-
-        while (len)
+        while (stlv_len >= ISIS_SUBTLV_SPB_BVID_MIN_LEN)
         {
-          if (!TTEST2(*(tptr), ISIS_SUBTLV_SPB_BVID_MIN_LEN))
-            goto trunctlv;
-
-          printf("\n\t           ECT: %08x",
-                      EXTRACT_32BITS(tptr));
+          ND_PRINT((ndo, "\n\t           ECT: %08x",
+                      EXTRACT_BE_U_4(tptr)));
 
           tptr = tptr+4;
 
-          printf(" BVID: %d, U:%01x M:%01x ",
-                     (EXTRACT_16BITS (tptr) >> 4) ,
-                     (EXTRACT_16BITS (tptr) >> 3) & 0x01,
-                     (EXTRACT_16BITS (tptr) >> 2) & 0x01);
+          ND_PRINT((ndo, " BVID: %d, U:%01x M:%01x ",
+                     (EXTRACT_BE_U_2(tptr) >> 4) ,
+                     (EXTRACT_BE_U_2(tptr) >> 3) & 0x01,
+                     (EXTRACT_BE_U_2(tptr) >> 2) & 0x01));
 
           tptr = tptr + 2;
           len = len - ISIS_SUBTLV_SPB_BVID_MIN_LEN;
+          stlv_len = stlv_len - ISIS_SUBTLV_SPB_BVID_MIN_LEN;
         }
 
         break;
       }
 
       default:
-          break;
+        break;
     }
+    tptr += stlv_len;
+    len -= stlv_len;
   }
 
   return 0;
 
-  trunctlv:
-    printf("\n\t\t packet exceeded snapshot");
+  trunc:
+    ND_PRINT((ndo, "\n\t\t"));
+    ND_PRINT((ndo, "%s", tstr));
     return(1);
 }
 
 static int
-isis_print_mt_capability_subtlv (const u_int8_t *tptr, int len)
+isis_print_mt_capability_subtlv(netdissect_options *ndo,
+                                const uint8_t *tptr, int len)
 {
   int stlv_type, stlv_len, tmp;
 
-  while (len > 0)
+  while (len > 2)
   {
-    stlv_type = *(tptr++);
-    stlv_len  = *(tptr++);
+    ND_TCHECK_2(tptr);
+    stlv_type = EXTRACT_U_1(tptr);
+    stlv_len  = EXTRACT_U_1(tptr + 1);
+    tptr = tptr + 2;
+    len = len - 2;
 
     /* first lets see if we know the subTLVs name*/
-    printf("\n\t      %s subTLV #%u, length: %u",
+    ND_PRINT((ndo, "\n\t      %s subTLV #%u, length: %u",
                tok2str(isis_mt_capability_subtlv_values, "unknown", stlv_type),
                stlv_type,
-               stlv_len);
+               stlv_len));
 
-    len = len - 2;
+    /* Make sure the subTLV fits within the space left */
+    if (len < stlv_len)
+      goto trunc;
+    /* Make sure the entire subTLV is in the captured data */
+    ND_TCHECK_LEN(tptr, stlv_len);
 
     switch (stlv_type)
     {
       case ISIS_SUBTLV_SPB_INSTANCE:
+          if (stlv_len < ISIS_SUBTLV_SPB_INSTANCE_MIN_LEN)
+            goto trunc;
 
-          if (!TTEST2(*(tptr), ISIS_SUBTLV_SPB_INSTANCE_MIN_LEN))
-            goto trunctlv;
-
-          printf("\n\t        CIST Root-ID: %08x", EXTRACT_32BITS(tptr));
+          ND_PRINT((ndo, "\n\t        CIST Root-ID: %08x", EXTRACT_BE_U_4(tptr)));
           tptr = tptr+4;
-          printf(" %08x", EXTRACT_32BITS(tptr));
+          ND_PRINT((ndo, " %08x", EXTRACT_BE_U_4(tptr)));
           tptr = tptr+4;
-          printf(", Path Cost: %08x", EXTRACT_32BITS(tptr));
+          ND_PRINT((ndo, ", Path Cost: %08x", EXTRACT_BE_U_4(tptr)));
           tptr = tptr+4;
-          printf(", Prio: %d", EXTRACT_16BITS(tptr));
+          ND_PRINT((ndo, ", Prio: %d", EXTRACT_BE_U_2(tptr)));
           tptr = tptr + 2;
-          printf("\n\t        RES: %d",
-                    EXTRACT_16BITS(tptr) >> 5);
-          printf(", V: %d",
-                    (EXTRACT_16BITS(tptr) >> 4) & 0x0001);
-          printf(", SPSource-ID: %d",
-                    (EXTRACT_32BITS(tptr) & 0x000fffff));
+          ND_PRINT((ndo, "\n\t        RES: %d",
+                    EXTRACT_BE_U_2(tptr) >> 5));
+          ND_PRINT((ndo, ", V: %d",
+                    (EXTRACT_BE_U_2(tptr) >> 4) & 0x0001));
+          ND_PRINT((ndo, ", SPSource-ID: %d",
+                    (EXTRACT_BE_U_4(tptr) & 0x000fffff)));
           tptr = tptr+4;
-          printf(", No of Trees: %x", *(tptr));
+          ND_PRINT((ndo, ", No of Trees: %x", EXTRACT_U_1(tptr)));
 
-          tmp = *(tptr++);
+          tmp = EXTRACT_U_1(tptr);
+          tptr++;
 
           len = len - ISIS_SUBTLV_SPB_INSTANCE_MIN_LEN;
+          stlv_len = stlv_len - ISIS_SUBTLV_SPB_INSTANCE_MIN_LEN;
 
           while (tmp)
           {
-            if (!TTEST2(*(tptr), ISIS_SUBTLV_SPB_INSTANCE_VLAN_TUPLE_LEN))
-              goto trunctlv;
+            if (stlv_len < ISIS_SUBTLV_SPB_INSTANCE_VLAN_TUPLE_LEN)
+              goto trunc;
 
-            printf ("\n\t         U:%d, M:%d, A:%d, RES:%d",
-                      *(tptr) >> 7, (*(tptr) >> 6) & 0x01,
-                      (*(tptr) >> 5) & 0x01, (*(tptr) & 0x1f));
+            ND_PRINT((ndo, "\n\t         U:%d, M:%d, A:%d, RES:%d",
+                      EXTRACT_U_1(tptr) >> 7,
+                      (EXTRACT_U_1(tptr) >> 6) & 0x01,
+                      (EXTRACT_U_1(tptr) >> 5) & 0x01,
+                      (EXTRACT_U_1(tptr) & 0x1f)));
 
             tptr++;
 
-            printf (", ECT: %08x", EXTRACT_32BITS(tptr));
+            ND_PRINT((ndo, ", ECT: %08x", EXTRACT_BE_U_4(tptr)));
 
             tptr = tptr + 4;
 
-            printf (", BVID: %d, SPVID: %d",
-                      (EXTRACT_24BITS(tptr) >> 12) & 0x000fff,
-                      EXTRACT_24BITS(tptr) & 0x000fff);
+            ND_PRINT((ndo, ", BVID: %d, SPVID: %d",
+                      (EXTRACT_BE_U_3(tptr) >> 12) & 0x000fff,
+                      EXTRACT_BE_U_3(tptr) & 0x000fff));
 
             tptr = tptr + 3;
             len = len - ISIS_SUBTLV_SPB_INSTANCE_VLAN_TUPLE_LEN;
+            stlv_len = stlv_len - ISIS_SUBTLV_SPB_INSTANCE_VLAN_TUPLE_LEN;
             tmp--;
           }
 
           break;
 
       case ISIS_SUBTLV_SPBM_SI:
+          if (stlv_len < 8)
+            goto trunc;
 
-          if (!TTEST2(*(tptr), 6))
-            goto trunctlv;
-
-          printf("\n\t        BMAC: %08x", EXTRACT_32BITS(tptr));
+          ND_PRINT((ndo, "\n\t        BMAC: %08x", EXTRACT_BE_U_4(tptr)));
           tptr = tptr+4;
-          printf("%04x", EXTRACT_16BITS(tptr));
+          ND_PRINT((ndo, "%04x", EXTRACT_BE_U_2(tptr)));
           tptr = tptr+2;
 
-          printf (", RES: %d, VID: %d", EXTRACT_16BITS(tptr) >> 12,
-                    (EXTRACT_16BITS(tptr)) & 0x0fff);
+          ND_PRINT((ndo, ", RES: %d, VID: %d", EXTRACT_BE_U_2(tptr) >> 12,
+                    (EXTRACT_BE_U_2(tptr)) & 0x0fff));
 
           tptr = tptr+2;
           len = len - 8;
           stlv_len = stlv_len - 8;
 
-          while (stlv_len)
-          {
-            printf("\n\t        T: %d, R: %d, RES: %d, ISID: %d",
-                    (EXTRACT_32BITS(tptr) >> 31),
-                    (EXTRACT_32BITS(tptr) >> 30) & 0x01,
-                    (EXTRACT_32BITS(tptr) >> 24) & 0x03f,
-                    (EXTRACT_32BITS(tptr)) & 0x0ffffff);
+          while (stlv_len >= 4) {
+            ND_TCHECK_4(tptr);
+            ND_PRINT((ndo, "\n\t        T: %d, R: %d, RES: %d, ISID: %d",
+                    (EXTRACT_BE_U_4(tptr) >> 31),
+                    (EXTRACT_BE_U_4(tptr) >> 30) & 0x01,
+                    (EXTRACT_BE_U_4(tptr) >> 24) & 0x03f,
+                    (EXTRACT_BE_U_4(tptr)) & 0x0ffffff));
 
             tptr = tptr + 4;
             len = len - 4;
@@ -1544,63 +1642,73 @@ isis_print_mt_capability_subtlv (const u_int8_t *tptr, int len)
       default:
         break;
     }
+    tptr += stlv_len;
+    len -= stlv_len;
   }
   return 0;
 
-  trunctlv:
-    printf("\n\t\t packet exceeded snapshot");
+  trunc:
+    ND_PRINT((ndo, "\n\t\t"));
+    ND_PRINT((ndo, "%s", tstr));
     return(1);
 }
 
-
 /* shared routine for printing system, node and lsp-ids */
 static char *
-isis_print_id(const u_int8_t *cp, int id_len)
+isis_print_id(const uint8_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++);
+    int sysid_len;
+
+    sysid_len = SYSTEM_ID_LEN;
+    if (sysid_len > id_len)
+        sysid_len = id_len;
+    for (i = 1; i <= sysid_len; i++) {
+        snprintf(pos, sizeof(id) - (pos - id), "%02x", EXTRACT_U_1(cp));
+       cp++;
        pos += strlen(pos);
        if (i == 2 || i == 4)
            *pos++ = '.';
        }
     if (id_len >= NODE_ID_LEN) {
-        snprintf(pos, sizeof(id) - (pos - id), ".%02x", *cp++);
+        snprintf(pos, sizeof(id) - (pos - id), ".%02x", EXTRACT_U_1(cp));
+       cp++;
        pos += strlen(pos);
     }
     if (id_len == LSP_ID_LEN)
-        snprintf(pos, sizeof(id) - (pos - id), "-%02x", *cp);
+        snprintf(pos, sizeof(id) - (pos - id), "-%02x", EXTRACT_U_1(cp));
     return (id);
 }
 
 /* print the 4-byte metric block which is common found in the old-style TLVs */
 static int
-isis_print_metric_block (const struct isis_metric_block *isis_metric_block)
+isis_print_metric_block(netdissect_options *ndo,
+                        const struct isis_metric_block *isis_metric_block)
 {
-    printf(", Default Metric: %d, %s",
+    ND_PRINT((ndo, ", 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");
+           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",
+        ND_PRINT((ndo, "\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");
+               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",
+        ND_PRINT((ndo, "\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");
+               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",
+        ND_PRINT((ndo, "\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");
+               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)
+isis_print_tlv_ip_reach(netdissect_options *ndo,
+                        const uint8_t *cp, const char *ident, int length)
 {
        int prefix_len;
        const struct isis_tlv_ip_reach *tlv_ip_reach;
@@ -1609,50 +1717,50 @@ isis_print_tlv_ip_reach (const u_int8_t *cp, const char *ident, int length)
 
        while (length > 0) {
                if ((size_t)length < sizeof(*tlv_ip_reach)) {
-                       printf("short IPv4 Reachability (%d vs %lu)",
+                       ND_PRINT((ndo, "short IPv4 Reachability (%d vs %lu)",
                                length,
-                               (unsigned long)sizeof(*tlv_ip_reach));
+                               (unsigned long)sizeof(*tlv_ip_reach)));
                        return (0);
                }
 
-               if (!TTEST(*tlv_ip_reach))
+               if (!ND_TTEST(*tlv_ip_reach))
                    return (0);
 
-               prefix_len = mask2plen(EXTRACT_32BITS(tlv_ip_reach->mask));
+               prefix_len = mask2plen(EXTRACT_BE_U_4(tlv_ip_reach->mask));
 
                if (prefix_len == -1)
-                       printf("%sIPv4 prefix: %s mask %s",
+                       ND_PRINT((ndo, "%sIPv4 prefix: %s mask %s",
                                ident,
-                              ipaddr_string((tlv_ip_reach->prefix)),
-                              ipaddr_string((tlv_ip_reach->mask)));
+                              ipaddr_string(ndo, (tlv_ip_reach->prefix)),
+                              ipaddr_string(ndo, (tlv_ip_reach->mask))));
                else
-                       printf("%sIPv4 prefix: %15s/%u",
+                       ND_PRINT((ndo, "%sIPv4 prefix: %15s/%u",
                                ident,
-                              ipaddr_string((tlv_ip_reach->prefix)),
-                              prefix_len);
+                              ipaddr_string(ndo, (tlv_ip_reach->prefix)),
+                              prefix_len));
 
-               printf(", Distribution: %s, Metric: %u, %s",
+               ND_PRINT((ndo, ", 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");
+                       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",
+                    ND_PRINT((ndo, "%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");
+                           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",
+                    ND_PRINT((ndo, "%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");
+                           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",
+                    ND_PRINT((ndo, "%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");
+                           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++;
@@ -1666,50 +1774,47 @@ isis_print_tlv_ip_reach (const u_int8_t *cp, const char *ident, int length)
  */
 
 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);
+isis_print_ip_reach_subtlv(netdissect_options *ndo,
+                           const uint8_t *tptr, int subt, int subl,
+                           const char *ident)
+{
+    /* first lets see if we know the subTLVs name*/
+    ND_PRINT((ndo, "%s%s subTLV #%u, length: %u",
+              ident, tok2str(isis_ext_ip_reach_subtlv_values, "unknown", subt),
+              subt, subl));
 
-       if (!TTEST2(*tptr,subl))
-           goto trunctlv;
+    ND_TCHECK_LEN(tptr, subl);
 
     switch(subt) {
     case ISIS_SUBTLV_EXTD_IP_REACH_MGMT_PREFIX_COLOR: /* fall through */
     case ISIS_SUBTLV_EXTD_IP_REACH_ADMIN_TAG32:
         while (subl >= 4) {
-           printf(", 0x%08x (=%u)",
-                  EXTRACT_32BITS(tptr),
-                  EXTRACT_32BITS(tptr));
+           ND_PRINT((ndo, ", 0x%08x (=%u)",
+                  EXTRACT_BE_U_4(tptr),
+                  EXTRACT_BE_U_4(tptr)));
            tptr+=4;
            subl-=4;
        }
        break;
     case ISIS_SUBTLV_EXTD_IP_REACH_ADMIN_TAG64:
         while (subl >= 8) {
-           printf(", 0x%08x%08x",
-                  EXTRACT_32BITS(tptr),
-                  EXTRACT_32BITS(tptr+4));
+           ND_PRINT((ndo, ", 0x%08x%08x",
+                  EXTRACT_BE_U_4(tptr),
+                  EXTRACT_BE_U_4(tptr + 4)));
            tptr+=8;
            subl-=8;
        }
        break;
     default:
-       if(!print_unknown_data(gndo,tptr,"\n\t\t    ",
-                              subl))
+       if (!print_unknown_data(ndo, tptr, "\n\t\t    ", subl))
          return(0);
        break;
     }
     return(1);
 
-trunctlv:
-    printf("%spacket exceeded snapshot",ident);
+trunc:
+    ND_PRINT((ndo, "%s", ident));
+    ND_PRINT((ndo, "%s", tstr));
     return(0);
 }
 
@@ -1719,121 +1824,121 @@ trunctlv:
  */
 
 static int
-isis_print_is_reach_subtlv (const u_int8_t *tptr,u_int subt,u_int subl,const char *ident) {
-
+isis_print_is_reach_subtlv(netdissect_options *ndo,
+                           const uint8_t *tptr, u_int subt, u_int subl,
+                           const char *ident)
+{
         u_int te_class,priority_level,gmpls_switch_cap;
         union { /* int to float conversion buffer for several subTLVs */
             float f;
-            u_int32_t i;
+            uint32_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);
+       ND_PRINT((ndo, "%s%s subTLV #%u, length: %u",
+                 ident, tok2str(isis_ext_is_reach_subtlv_values, "unknown", subt),
+                 subt, subl));
 
-       if (!TTEST2(*tptr,subl))
-           goto trunctlv;
+       ND_TCHECK_LEN(tptr, subl);
 
         switch(subt) {
         case ISIS_SUBTLV_EXT_IS_REACH_ADMIN_GROUP:
         case ISIS_SUBTLV_EXT_IS_REACH_LINK_LOCAL_REMOTE_ID:
         case ISIS_SUBTLV_EXT_IS_REACH_LINK_REMOTE_ID:
            if (subl >= 4) {
-             printf(", 0x%08x", EXTRACT_32BITS(tptr));
+             ND_PRINT((ndo, ", 0x%08x", EXTRACT_BE_U_4(tptr)));
              if (subl == 8) /* rfc4205 */
-               printf(", 0x%08x", EXTRACT_32BITS(tptr+4));
+               ND_PRINT((ndo, ", 0x%08x", EXTRACT_BE_U_4(tptr + 4)));
            }
            break;
         case ISIS_SUBTLV_EXT_IS_REACH_IPV4_INTF_ADDR:
         case ISIS_SUBTLV_EXT_IS_REACH_IPV4_NEIGHBOR_ADDR:
             if (subl >= sizeof(struct in_addr))
-              printf(", %s", ipaddr_string(tptr));
+              ND_PRINT((ndo, ", %s", ipaddr_string(ndo, tptr)));
             break;
         case ISIS_SUBTLV_EXT_IS_REACH_MAX_LINK_BW :
        case ISIS_SUBTLV_EXT_IS_REACH_RESERVABLE_BW:
             if (subl >= 4) {
-              bw.i = EXTRACT_32BITS(tptr);
-              printf(", %.3f Mbps", bw.f*8/1000000 );
+              bw.i = EXTRACT_BE_U_4(tptr);
+              ND_PRINT((ndo, ", %.3f Mbps", bw.f * 8 / 1000000));
             }
             break;
         case ISIS_SUBTLV_EXT_IS_REACH_UNRESERVED_BW :
             if (subl >= 32) {
               for (te_class = 0; te_class < 8; te_class++) {
-                bw.i = EXTRACT_32BITS(tptr);
-                printf("%s  TE-Class %u: %.3f Mbps",
+                bw.i = EXTRACT_BE_U_4(tptr);
+                ND_PRINT((ndo, "%s  TE-Class %u: %.3f Mbps",
                        ident,
                        te_class,
-                       bw.f*8/1000000 );
+                       bw.f * 8 / 1000000));
                tptr+=4;
              }
             }
             break;
         case ISIS_SUBTLV_EXT_IS_REACH_BW_CONSTRAINTS: /* fall through */
         case ISIS_SUBTLV_EXT_IS_REACH_BW_CONSTRAINTS_OLD:
-            printf("%sBandwidth Constraints Model ID: %s (%u)",
+            if (subl == 0)
+                break;
+            ND_PRINT((ndo, "%sBandwidth Constraints Model ID: %s (%u)",
                    ident,
-                   tok2str(diffserv_te_bc_values, "unknown", *tptr),
-                   *tptr);
+                   tok2str(diffserv_te_bc_values, "unknown", EXTRACT_U_1(tptr)),
+                   EXTRACT_U_1(tptr)));
             tptr++;
             /* decode BCs until the subTLV ends */
             for (te_class = 0; te_class < (subl-1)/4; te_class++) {
-                bw.i = EXTRACT_32BITS(tptr);
-                printf("%s  Bandwidth constraint CT%u: %.3f Mbps",
+                bw.i = EXTRACT_BE_U_4(tptr);
+                ND_PRINT((ndo, "%s  Bandwidth constraint CT%u: %.3f Mbps",
                        ident,
                        te_class,
-                       bw.f*8/1000000 );
+                       bw.f * 8 / 1000000));
                tptr+=4;
             }
             break;
         case ISIS_SUBTLV_EXT_IS_REACH_TE_METRIC:
             if (subl >= 3)
-              printf(", %u", EXTRACT_24BITS(tptr));
+              ND_PRINT((ndo, ", %u", EXTRACT_BE_U_3(tptr)));
             break;
         case ISIS_SUBTLV_EXT_IS_REACH_LINK_ATTRIBUTE:
             if (subl == 2) {
-               printf(", [ %s ] (0x%04x)",
+               ND_PRINT((ndo, ", [ %s ] (0x%04x)",
                       bittok2str(isis_subtlv_link_attribute_values,
                                  "Unknown",
-                                 EXTRACT_16BITS(tptr)),
-                      EXTRACT_16BITS(tptr));
+                                 EXTRACT_BE_U_2(tptr)),
+                      EXTRACT_BE_U_2(tptr)));
             }
             break;
         case ISIS_SUBTLV_EXT_IS_REACH_LINK_PROTECTION_TYPE:
             if (subl >= 2) {
-              printf(", %s, Priority %u",
-                  bittok2str(gmpls_link_prot_values, "none", *tptr),
-                   *(tptr+1));
+              ND_PRINT((ndo, ", %s, Priority %u",
+                  bittok2str(gmpls_link_prot_values, "none", EXTRACT_U_1(tptr)),
+                  EXTRACT_U_1(tptr + 1)));
             }
             break;
         case ISIS_SUBTLV_SPB_METRIC:
             if (subl >= 6) {
-              printf (", LM: %u", EXTRACT_24BITS(tptr));
+              ND_PRINT((ndo, ", LM: %u", EXTRACT_BE_U_3(tptr)));
               tptr=tptr+3;
-              printf (", P: %u", *(tptr));
-              printf (", P-ID: %u", EXTRACT_16BITS(++tptr));
+              ND_PRINT((ndo, ", P: %u", EXTRACT_U_1(tptr)));
+              tptr++;
+              ND_PRINT((ndo, ", P-ID: %u", EXTRACT_BE_U_2(tptr)));
             }
             break;
         case ISIS_SUBTLV_EXT_IS_REACH_INTF_SW_CAP_DESCR:
             if (subl >= 36) {
-              gmpls_switch_cap = *tptr;
-              printf("%s  Interface Switching Capability:%s",
+              gmpls_switch_cap = EXTRACT_U_1(tptr);
+              ND_PRINT((ndo, "%s  Interface Switching Capability:%s",
                    ident,
-                   tok2str(gmpls_switch_cap_values, "Unknown", gmpls_switch_cap));
-              printf(", LSP Encoding: %s",
-                   tok2str(gmpls_encoding_values, "Unknown", *(tptr+1)));
+                   tok2str(gmpls_switch_cap_values, "Unknown", gmpls_switch_cap)));
+              ND_PRINT((ndo, ", LSP Encoding: %s",
+                   tok2str(gmpls_encoding_values, "Unknown", EXTRACT_U_1((tptr + 1)))));
              tptr+=4;
-              printf("%s  Max LSP Bandwidth:",ident);
+              ND_PRINT((ndo, "%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",
+                bw.i = EXTRACT_BE_U_4(tptr);
+                ND_PRINT((ndo, "%s    priority level %d: %.3f Mbps",
                        ident,
                        priority_level,
-                       bw.f*8/1000000 );
+                       bw.f * 8 / 1000000));
                tptr+=4;
               }
               subl-=36;
@@ -1842,81 +1947,84 @@ isis_print_is_reach_subtlv (const u_int8_t *tptr,u_int subt,u_int subl,const cha
               case GMPLS_PSC2:
               case GMPLS_PSC3:
               case GMPLS_PSC4:
-                bw.i = EXTRACT_32BITS(tptr);
-                printf("%s  Min LSP Bandwidth: %.3f Mbps", ident, bw.f*8/1000000);
-                printf("%s  Interface MTU: %u", ident, EXTRACT_16BITS(tptr+4));
+                if (subl < 6)
+                    break;
+                bw.i = EXTRACT_BE_U_4(tptr);
+                ND_PRINT((ndo, "%s  Min LSP Bandwidth: %.3f Mbps", ident, bw.f * 8 / 1000000));
+                ND_PRINT((ndo, "%s  Interface MTU: %u", ident, EXTRACT_BE_U_2(tptr + 4)));
                 break;
               case GMPLS_TSC:
-                bw.i = EXTRACT_32BITS(tptr);
-                printf("%s  Min LSP Bandwidth: %.3f Mbps", ident, bw.f*8/1000000);
-                printf("%s  Indication %s", ident,
-                       tok2str(gmpls_switch_cap_tsc_indication_values, "Unknown (%u)", *(tptr+4)));
+                if (subl < 8)
+                    break;
+                bw.i = EXTRACT_BE_U_4(tptr);
+                ND_PRINT((ndo, "%s  Min LSP Bandwidth: %.3f Mbps", ident, bw.f * 8 / 1000000));
+                ND_PRINT((ndo, "%s  Indication %s", ident,
+                       tok2str(gmpls_switch_cap_tsc_indication_values, "Unknown (%u)", EXTRACT_U_1((tptr + 4)))));
                 break;
               default:
                 /* 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(gndo,tptr,"\n\t\t    ",
-                                         subl))
+                  if (!print_unknown_data(ndo, tptr, "\n\t\t    ", subl))
                     return(0);
                 }
               }
             }
             break;
         default:
-            if(!print_unknown_data(gndo,tptr,"\n\t\t    ",
-                                  subl))
+            if (!print_unknown_data(ndo, tptr, "\n\t\t    ", subl))
                 return(0);
             break;
         }
         return(1);
 
-trunctlv:
-    printf("%spacket exceeded snapshot",ident);
+trunc:
     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_type) {
-
+isis_print_ext_is_reach(netdissect_options *ndo,
+                        const uint8_t *tptr, const char *ident, int tlv_type)
+{
     char ident_buffer[20];
     int subtlv_type,subtlv_len,subtlv_sum_len;
     int proc_bytes = 0; /* how many bytes did we process ? */
 
-    if (!TTEST2(*tptr, NODE_ID_LEN))
+    if (!ND_TTEST_LEN(tptr, NODE_ID_LEN))
         return(0);
 
-    printf("%sIS Neighbor: %s", ident, isis_print_id(tptr, NODE_ID_LEN));
-    tptr+=(NODE_ID_LEN);
+    ND_PRINT((ndo, "%sIS Neighbor: %s", ident, isis_print_id(tptr, NODE_ID_LEN)));
+    tptr+=NODE_ID_LEN;
 
     if (tlv_type != ISIS_TLV_IS_ALIAS_ID) { /* the Alias TLV Metric field is implicit 0 */
-        if (!TTEST2(*tptr, 3))    /* and is therefore skipped */
+        if (!ND_TTEST_3(tptr))    /* and is therefore skipped */
            return(0);
-       printf(", Metric: %d",EXTRACT_24BITS(tptr));
+       ND_PRINT((ndo, ", Metric: %d", EXTRACT_BE_U_3(tptr)));
        tptr+=3;
     }
 
-    if (!TTEST2(*tptr, 1))
+    if (!ND_TTEST_1(tptr))
         return(0);
-    subtlv_sum_len=*(tptr++); /* read out subTLV length */
+    subtlv_sum_len=EXTRACT_U_1(tptr); /* read out subTLV length */
+    tptr++;
     proc_bytes=NODE_ID_LEN+3+1;
-    printf(", %ssub-TLVs present",subtlv_sum_len ? "" : "no ");
+    ND_PRINT((ndo, ", %ssub-TLVs present",subtlv_sum_len ? "" : "no "));
     if (subtlv_sum_len) {
-        printf(" (%u)",subtlv_sum_len);
+        ND_PRINT((ndo, " (%u)", subtlv_sum_len));
         while (subtlv_sum_len>0) {
-            if (!TTEST2(*tptr,2))
+            if (!ND_TTEST_2(tptr))
                 return(0);
-            subtlv_type=*(tptr++);
-            subtlv_len=*(tptr++);
-            /* prepend the ident string */
+            subtlv_type=EXTRACT_U_1(tptr);
+            subtlv_len=EXTRACT_U_1(tptr + 1);
+            tptr+=2;
+            /* prepend the indent string */
             snprintf(ident_buffer, sizeof(ident_buffer), "%s  ",ident);
-            if(!isis_print_is_reach_subtlv(tptr,subtlv_type,subtlv_len,ident_buffer))
+            if (!isis_print_is_reach_subtlv(ndo, tptr, subtlv_type, subtlv_len, ident_buffer))
                 return(0);
             tptr+=subtlv_len;
             subtlv_sum_len-=(subtlv_len+2);
@@ -1932,20 +2040,21 @@ isis_print_ext_is_reach (const u_int8_t *tptr,const char *ident, int tlv_type) {
  */
 
 static int
-isis_print_mtid (const u_int8_t *tptr,const char *ident) {
-
-    if (!TTEST2(*tptr, 2))
+isis_print_mtid(netdissect_options *ndo,
+                const uint8_t *tptr, const char *ident)
+{
+    if (!ND_TTEST_2(tptr))
         return(0);
 
-    printf("%s%s",
+    ND_PRINT((ndo, "%s%s",
            ident,
            tok2str(isis_mt_values,
                    "Reserved for IETF Consensus",
-                   ISIS_MASK_MTID(EXTRACT_16BITS(tptr))));
+                   ISIS_MASK_MTID(EXTRACT_BE_U_2(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))));
+    ND_PRINT((ndo, " Topology (0x%03x), Flags: [%s]",
+           ISIS_MASK_MTID(EXTRACT_BE_U_2(tptr)),
+           bittok2str(isis_mt_flag_values, "none",ISIS_MASK_MTFLAGS(EXTRACT_BE_U_2(tptr)))));
 
     return(2);
 }
@@ -1958,54 +2067,51 @@ isis_print_mtid (const u_int8_t *tptr,const char *ident) {
  */
 
 static int
-isis_print_extd_ip_reach (const u_int8_t *tptr, const char *ident, u_int16_t afi) {
-
+isis_print_extd_ip_reach(netdissect_options *ndo,
+                         const uint8_t *tptr, const char *ident, uint16_t afi)
+{
     char ident_buffer[20];
-#ifdef INET6
-    u_int8_t prefix[sizeof(struct in6_addr)]; /* shared copy buffer for IPv4 and IPv6 prefixes */
-#else
-    u_int8_t prefix[sizeof(struct in_addr)]; /* shared copy buffer for IPv4 prefixes */
-#endif
+    uint8_t prefix[sizeof(struct in6_addr)]; /* 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))
+    if (!ND_TTEST_4(tptr))
         return (0);
-    metric = EXTRACT_32BITS(tptr);
+    metric = EXTRACT_BE_U_4(tptr);
     processed=4;
     tptr+=4;
 
     if (afi == AF_INET) {
-        if (!TTEST2(*tptr, 1)) /* fetch status byte */
+        if (!ND_TTEST_1(tptr)) /* fetch status byte */
             return (0);
-        status_byte=*(tptr++);
+        status_byte=EXTRACT_U_1(tptr);
+        tptr++;
         bit_length = status_byte&0x3f;
         if (bit_length > 32) {
-            printf("%sIPv4 prefix: bad bit length %u",
+            ND_PRINT((ndo, "%sIPv4 prefix: bad bit length %u",
                    ident,
-                   bit_length);
+                   bit_length));
             return (0);
         }
         processed++;
-#ifdef INET6
     } else if (afi == AF_INET6) {
-        if (!TTEST2(*tptr, 1)) /* fetch status & prefix_len byte */
+        if (!ND_TTEST_2(tptr)) /* fetch status & prefix_len byte */
             return (0);
-        status_byte=*(tptr++);
-        bit_length=*(tptr++);
+        status_byte=EXTRACT_U_1(tptr);
+        bit_length=EXTRACT_U_1(tptr + 1);
         if (bit_length > 128) {
-            printf("%sIPv6 prefix: bad bit length %u",
+            ND_PRINT((ndo, "%sIPv6 prefix: bad bit length %u",
                    ident,
-                   bit_length);
+                   bit_length));
             return (0);
         }
+        tptr+=2;
         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))
+    if (!ND_TTEST_LEN(tptr, byte_length))
         return (0);
     memset(prefix, 0, sizeof prefix);   /* clear the copy buffer */
     memcpy(prefix,tptr,byte_length);    /* copy as much as is stored in the TLV */
@@ -2013,54 +2119,50 @@ isis_print_extd_ip_reach (const u_int8_t *tptr, const char *ident, u_int16_t afi
     processed+=byte_length;
 
     if (afi == AF_INET)
-        printf("%sIPv4 prefix: %15s/%u",
+        ND_PRINT((ndo, "%sIPv4 prefix: %15s/%u",
                ident,
-               ipaddr_string(prefix),
-               bit_length);
-#ifdef INET6
-    if (afi == AF_INET6)
-        printf("%sIPv6 prefix: %s/%u",
+               ipaddr_string(ndo, prefix),
+               bit_length));
+    else if (afi == AF_INET6)
+        ND_PRINT((ndo, "%sIPv6 prefix: %s/%u",
                ident,
-               ip6addr_string(prefix),
-               bit_length);
-#endif
+               ip6addr_string(ndo, prefix),
+               bit_length));
 
-    printf(", Distribution: %s, Metric: %u",
+    ND_PRINT((ndo, ", Distribution: %s, Metric: %u",
            ISIS_MASK_TLV_EXTD_IP_UPDOWN(status_byte) ? "down" : "up",
-           metric);
+           metric));
 
     if (afi == AF_INET && ISIS_MASK_TLV_EXTD_IP_SUBTLV(status_byte))
-        printf(", sub-TLVs present");
-#ifdef INET6
-    if (afi == AF_INET6)
-        printf(", %s%s",
+        ND_PRINT((ndo, ", sub-TLVs present"));
+    else if (afi == AF_INET6)
+        ND_PRINT((ndo, ", %s%s",
                ISIS_MASK_TLV_EXTD_IP6_IE(status_byte) ? "External" : "Internal",
-               ISIS_MASK_TLV_EXTD_IP6_SUBTLV(status_byte) ? ", sub-TLVs present" : "");
-#endif
+               ISIS_MASK_TLV_EXTD_IP6_SUBTLV(status_byte) ? ", sub-TLVs present" : ""));
 
     if ((afi == AF_INET  && ISIS_MASK_TLV_EXTD_IP_SUBTLV(status_byte))
-#ifdef INET6
      || (afi == AF_INET6 && ISIS_MASK_TLV_EXTD_IP6_SUBTLV(status_byte))
-#endif
        ) {
         /* 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))
+        if (!ND_TTEST_1(tptr))
             return (0);
-        sublen=*(tptr++);
+        sublen=EXTRACT_U_1(tptr);
+        tptr++;
         processed+=sublen+1;
-        printf(" (%u)",sublen);   /* print out subTLV length */
+        ND_PRINT((ndo, " (%u)", sublen));   /* print out subTLV length */
 
         while (sublen>0) {
-            if (!TTEST2(*tptr,2))
+            if (!ND_TTEST_2(tptr))
                 return (0);
-            subtlvtype=*(tptr++);
-            subtlvlen=*(tptr++);
-            /* prepend the ident string */
+            subtlvtype=EXTRACT_U_1(tptr);
+            subtlvlen=EXTRACT_U_1(tptr + 1);
+            tptr+=2;
+            /* prepend the indent string */
             snprintf(ident_buffer, sizeof(ident_buffer), "%s  ",ident);
-            if(!isis_print_ip_reach_subtlv(tptr,subtlvtype,subtlvlen,ident_buffer))
+            if (!isis_print_ip_reach_subtlv(ndo, tptr, subtlvtype, subtlvlen, ident_buffer))
                 return(0);
             tptr+=subtlvlen;
             sublen-=(subtlvlen+2);
@@ -2069,18 +2171,34 @@ isis_print_extd_ip_reach (const u_int8_t *tptr, const char *ident, u_int16_t afi
     return (processed);
 }
 
+/*
+ * Clear checksum and lifetime prior to signature verification.
+ */
+static void
+isis_clear_checksum_lifetime(void *header)
+{
+    struct isis_lsp_header *header_lsp = (struct isis_lsp_header *) header;
+
+    header_lsp->checksum[0] = 0;
+    header_lsp->checksum[1] = 0;
+    header_lsp->remaining_lifetime[0] = 0;
+    header_lsp->remaining_lifetime[1] = 0;
+}
+
 /*
  * isis_print
  * Decode IS-IS packets.  Return 0 on error.
  */
 
-static int isis_print (const u_int8_t *p, u_int length)
+static int
+isis_print(netdissect_options *ndo,
+           const uint8_t *p, u_int length)
 {
     const struct isis_common_header *isis_header;
 
     const struct isis_iih_lan_header *header_iih_lan;
     const struct isis_iih_ptp_header *header_iih_ptp;
-    struct isis_lsp_header *header_lsp;
+    const struct isis_lsp_header *header_lsp;
     const struct isis_csnp_header *header_csnp;
     const struct isis_psnp_header *header_psnp;
 
@@ -2089,9 +2207,10 @@ static int isis_print (const u_int8_t *p, u_int length)
     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;
+    uint8_t pdu_type, max_area, id_length, tlv_type, tlv_len, tmp, alen, lan_alen, prefix_len;
+    uint8_t ext_is_len, ext_ip_len, mt_len;
+    uint8_t isis_subtlv_idrp;
+    const uint8_t *optr, *pptr, *tptr;
     u_short packet_len,pdu_len, key_id;
     u_int i,vendor_id;
     int sigcheck;
@@ -2101,34 +2220,46 @@ static int isis_print (const u_int8_t *p, u_int length)
                  need it for parsing the checksum TLV and authentication
                  TLV verification */
     isis_header = (const struct isis_common_header *)p;
-    TCHECK(*isis_header);
+    ND_TCHECK(*isis_header);
+    if (length < ISIS_COMMON_HEADER_SIZE)
+        goto trunc;
     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 = (struct isis_lsp_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;
 
-    if (!eflag)
-        printf("IS-IS");
+    if (!ndo->ndo_eflag)
+        ND_PRINT((ndo, "IS-IS"));
 
     /*
      * Sanity checking of the header.
      */
 
     if (isis_header->version != ISIS_VERSION) {
-       printf("version %d packet not supported", isis_header->version);
+       ND_PRINT((ndo, "version %d packet not supported", isis_header->version));
        return (0);
     }
 
     if ((isis_header->id_length != SYSTEM_ID_LEN) && (isis_header->id_length != 0)) {
-       printf("system ID length of %d is not supported",
-              isis_header->id_length);
+       ND_PRINT((ndo, "system ID length of %d is not supported",
+              isis_header->id_length));
        return (0);
     }
 
     if (isis_header->pdu_version != ISIS_VERSION) {
-       printf("version %d packet not supported", isis_header->pdu_version);
+       ND_PRINT((ndo, "version %d packet not supported", isis_header->pdu_version));
+       return (0);
+    }
+
+    if (length < isis_header->fixed_len) {
+       ND_PRINT((ndo, "fixed header length %u > packet length %u", isis_header->fixed_len, length));
+       return (0);
+    }
+
+    if (isis_header->fixed_len < ISIS_COMMON_HEADER_SIZE) {
+       ND_PRINT((ndo, "fixed header length %u < minimum header size %u", isis_header->fixed_len, (u_int)ISIS_COMMON_HEADER_SIZE));
        return (0);
     }
 
@@ -2138,7 +2269,7 @@ static int isis_print (const u_int8_t *p, u_int length)
        max_area = 3;    /* silly shit */
        break;
     case 255:
-       printf("bad packet -- 255 areas");
+       ND_PRINT((ndo, "bad packet -- 255 areas"));
        return (0);
     default:
        break;
@@ -2167,265 +2298,263 @@ static int isis_print (const u_int8_t *p, u_int length)
 
     /* toss any non 6-byte sys-ID len PDUs */
     if (id_length != 6 ) {
-       printf("bad packet -- illegal sys-ID length (%u)", id_length);
+       ND_PRINT((ndo, "bad packet -- illegal sys-ID length (%u)", id_length));
        return (0);
     }
 
     pdu_type=isis_header->pdu_type;
 
     /* in non-verbose mode print the basic PDU Type plus PDU specific brief information*/
-    if (vflag < 1) {
-        printf("%s%s",
-               eflag ? "" : ", ",
-               tok2str(isis_pdu_values,"unknown PDU-Type %u",pdu_type));
-
-       switch (pdu_type) {
-
-       case ISIS_PDU_L1_LAN_IIH:
-       case ISIS_PDU_L2_LAN_IIH:
-           printf(", src-id %s",
-                   isis_print_id(header_iih_lan->source_id,SYSTEM_ID_LEN));
-           printf(", lan-id %s, prio %u",
-                   isis_print_id(header_iih_lan->lan_id,NODE_ID_LEN),
-                   header_iih_lan->priority);
-           break;
-       case ISIS_PDU_PTP_IIH:
-           printf(", src-id %s", isis_print_id(header_iih_ptp->source_id,SYSTEM_ID_LEN));
-           break;
-       case ISIS_PDU_L1_LSP:
-       case ISIS_PDU_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 ISIS_PDU_L1_CSNP:
-       case ISIS_PDU_L2_CSNP:
-           printf(", src-id %s", isis_print_id(header_csnp->source_id,NODE_ID_LEN));
-           break;
-       case ISIS_PDU_L1_PSNP:
-       case ISIS_PDU_L2_PSNP:
-           printf(", src-id %s", isis_print_id(header_psnp->source_id,NODE_ID_LEN));
-           break;
-
-       }
-       printf(", length %u", length);
-
-        return(1);
-    }
-
-    /* ok they seem to want to know everything - lets fully decode it */
-    printf("%slength %u", eflag ? "" : ", ",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),
-           isis_header->fixed_len,
-           isis_header->version,
-           isis_header->pdu_version,
-          id_length,
-          isis_header->id_length,
-           max_area,
-           isis_header->max_area);
-
-    if (vflag > 1) {
-        if(!print_unknown_data(gndo,optr,"\n\t",8)) /* provide the _o_riginal pointer */
-            return(0);                         /* for optionally debugging the common header */
+    if (ndo->ndo_vflag == 0) {
+        ND_PRINT((ndo, "%s%s",
+               ndo->ndo_eflag ? "" : ", ",
+               tok2str(isis_pdu_values, "unknown PDU-Type %u", pdu_type)));
+    } else {
+        /* ok they seem to want to know everything - lets fully decode it */
+        ND_PRINT((ndo, "%slength %u", ndo->ndo_eflag ? "" : ", ", length));
+
+        ND_PRINT((ndo, "\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),
+               isis_header->fixed_len,
+               isis_header->version,
+               isis_header->pdu_version,
+               id_length,
+               isis_header->id_length,
+               max_area,
+               isis_header->max_area));
+
+        if (ndo->ndo_vflag > 1) {
+            if (!print_unknown_data(ndo, optr, "\n\t", 8)) /* provide the _o_riginal pointer */
+                return (0);                         /* for optionally debugging the common header */
+        }
     }
 
     switch (pdu_type) {
 
     case ISIS_PDU_L1_LAN_IIH:
     case ISIS_PDU_L2_LAN_IIH:
-       if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE)) {
-           printf(", bogus fixed header length %u should be %lu",
-                  isis_header->fixed_len, (unsigned long)ISIS_IIH_LAN_HEADER_SIZE);
-           return (0);
-       }
+        if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE)) {
+            ND_PRINT((ndo, ", bogus fixed header length %u should be %lu",
+                     isis_header->fixed_len, (unsigned long)(ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE)));
+            return (0);
+        }
+        ND_TCHECK(*header_iih_lan);
+        if (length < ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE)
+            goto trunc;
+        if (ndo->ndo_vflag == 0) {
+            ND_PRINT((ndo, ", src-id %s",
+                      isis_print_id(header_iih_lan->source_id, SYSTEM_ID_LEN)));
+            ND_PRINT((ndo, ", lan-id %s, prio %u",
+                      isis_print_id(header_iih_lan->lan_id,NODE_ID_LEN),
+                      header_iih_lan->priority));
+            ND_PRINT((ndo, ", length %u", length));
+            return (1);
+        }
+        pdu_len=EXTRACT_BE_U_2(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;
+        }
 
-       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;
-       }
+        ND_PRINT((ndo, "\n\t  source-id: %s,  holding time: %us, Flags: [%s]",
+                  isis_print_id(header_iih_lan->source_id,SYSTEM_ID_LEN),
+                  EXTRACT_BE_U_2(header_iih_lan->holding_time),
+                  tok2str(isis_iih_circuit_type_values,
+                          "unknown circuit type 0x%02x",
+                          header_iih_lan->circuit_type)));
 
-       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  lan-id:    %s, Priority: %u, PDU length: %u",
-               isis_print_id(header_iih_lan->lan_id, NODE_ID_LEN),
-               (header_iih_lan->priority) & ISIS_LAN_PRIORITY_MASK,
-               pdu_len);
-
-        if (vflag > 1) {
-            if(!print_unknown_data(gndo,pptr,"\n\t  ",ISIS_IIH_LAN_HEADER_SIZE))
-                return(0);
+        ND_PRINT((ndo, "\n\t  lan-id:    %s, Priority: %u, PDU length: %u",
+                  isis_print_id(header_iih_lan->lan_id, NODE_ID_LEN),
+                  (header_iih_lan->priority) & ISIS_LAN_PRIORITY_MASK,
+                  pdu_len));
+
+        if (ndo->ndo_vflag > 1) {
+            if (!print_unknown_data(ndo, 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;
+        packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE);
+        pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_LAN_HEADER_SIZE);
+        break;
 
     case ISIS_PDU_PTP_IIH:
-       if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE)) {
-           printf(", bogus fixed header length %u should be %lu",
-                  isis_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) {
+        if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE)) {
+            ND_PRINT((ndo, ", bogus fixed header length %u should be %lu",
+                      isis_header->fixed_len, (unsigned long)(ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE)));
+            return (0);
+        }
+        ND_TCHECK(*header_iih_ptp);
+        if (length < ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE)
+            goto trunc;
+        if (ndo->ndo_vflag == 0) {
+            ND_PRINT((ndo, ", src-id %s", isis_print_id(header_iih_ptp->source_id, SYSTEM_ID_LEN)));
+            ND_PRINT((ndo, ", length %u", length));
+            return (1);
+        }
+        pdu_len=EXTRACT_BE_U_2(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));
+        ND_PRINT((ndo, "\n\t  source-id: %s, holding time: %us, Flags: [%s]",
+                  isis_print_id(header_iih_ptp->source_id,SYSTEM_ID_LEN),
+                  EXTRACT_BE_U_2(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);
+        ND_PRINT((ndo, "\n\t  circuit-id: 0x%02x, PDU length: %u",
+                  header_iih_ptp->circuit_id,
+                  pdu_len));
 
-        if (vflag > 1) {
-            if(!print_unknown_data(gndo,pptr,"\n\t  ",ISIS_IIH_PTP_HEADER_SIZE))
-                return(0);
+        if (ndo->ndo_vflag > 1) {
+            if (!print_unknown_data(ndo, 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;
+        packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE);
+        pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_IIH_PTP_HEADER_SIZE);
+        break;
 
     case ISIS_PDU_L1_LSP:
     case ISIS_PDU_L2_LSP:
-       if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE)) {
-           printf(", bogus fixed header length %u should be %lu",
-                  isis_header->fixed_len, (unsigned long)ISIS_LSP_HEADER_SIZE);
-           return (0);
-       }
-
-       pdu_len=EXTRACT_16BITS(header_lsp->pdu_len);
-       if (packet_len>pdu_len) {
+        if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE)) {
+            ND_PRINT((ndo, ", bogus fixed header length %u should be %lu",
+                   isis_header->fixed_len, (unsigned long)ISIS_LSP_HEADER_SIZE));
+            return (0);
+        }
+        ND_TCHECK(*header_lsp);
+        if (length < ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE)
+            goto trunc;
+        if (ndo->ndo_vflag == 0) {
+            ND_PRINT((ndo, ", lsp-id %s, seq 0x%08x, lifetime %5us",
+                      isis_print_id(header_lsp->lsp_id, LSP_ID_LEN),
+                      EXTRACT_BE_U_4(header_lsp->sequence_number),
+                      EXTRACT_BE_U_2(header_lsp->remaining_lifetime)));
+            ND_PRINT((ndo, ", length %u", length));
+            return (1);
+        }
+        pdu_len=EXTRACT_BE_U_2(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\n\t  chksum: 0x%04x",
+        ND_PRINT((ndo, "\n\t  lsp-id: %s, seq: 0x%08x, lifetime: %5us\n\t  chksum: 0x%04x",
                isis_print_id(header_lsp->lsp_id, LSP_ID_LEN),
-               EXTRACT_32BITS(header_lsp->sequence_number),
-               EXTRACT_16BITS(header_lsp->remaining_lifetime),
-               EXTRACT_16BITS(header_lsp->checksum));
-
-
-        osi_print_cksum((u_int8_t *)header_lsp->lsp_id,
-                        EXTRACT_16BITS(header_lsp->checksum), 12, length-12);
-
-        /*
-         * Clear checksum and lifetime prior to signature verification.
-         */
-        header_lsp->checksum[0] = 0;
-        header_lsp->checksum[1] = 0;
-        header_lsp->remaining_lifetime[0] = 0;
-        header_lsp->remaining_lifetime[1] = 0;
+               EXTRACT_BE_U_4(header_lsp->sequence_number),
+               EXTRACT_BE_U_2(header_lsp->remaining_lifetime),
+               EXTRACT_BE_U_2(header_lsp->checksum)));
 
+        osi_print_cksum(ndo, (const uint8_t *)header_lsp->lsp_id,
+                        EXTRACT_BE_U_2(header_lsp->checksum),
+                        12, length-12);
 
-       printf(", PDU length: %u, Flags: [ %s",
+        ND_PRINT((ndo, ", PDU length: %u, Flags: [ %s",
                pdu_len,
-               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)));
+               ISIS_MASK_LSP_OL_BIT(header_lsp->typeblock) ? "Overload bit set, " : ""));
+
+        if (ISIS_MASK_LSP_ATT_BITS(header_lsp->typeblock)) {
+            ND_PRINT((ndo, "%s", ISIS_MASK_LSP_ATT_DEFAULT_BIT(header_lsp->typeblock) ? "default " : ""));
+            ND_PRINT((ndo, "%s", ISIS_MASK_LSP_ATT_DELAY_BIT(header_lsp->typeblock) ? "delay " : ""));
+            ND_PRINT((ndo, "%s", ISIS_MASK_LSP_ATT_EXPENSE_BIT(header_lsp->typeblock) ? "expense " : ""));
+            ND_PRINT((ndo, "%s", ISIS_MASK_LSP_ATT_ERROR_BIT(header_lsp->typeblock) ? "error " : ""));
+            ND_PRINT((ndo, "ATT bit set, "));
+        }
+        ND_PRINT((ndo, "%s", ISIS_MASK_LSP_PARTITION_BIT(header_lsp->typeblock) ? "P bit set, " : ""));
+        ND_PRINT((ndo, "%s ]", tok2str(isis_lsp_istype_values, "Unknown(0x%x)",
+                  ISIS_MASK_LSP_ISTYPE_BITS(header_lsp->typeblock))));
 
-        if (vflag > 1) {
-            if(!print_unknown_data(gndo,pptr,"\n\t  ",ISIS_LSP_HEADER_SIZE))
-                return(0);
+        if (ndo->ndo_vflag > 1) {
+            if (!print_unknown_data(ndo, 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;
+        packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE);
+        pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_LSP_HEADER_SIZE);
+        break;
 
     case ISIS_PDU_L1_CSNP:
     case ISIS_PDU_L2_CSNP:
-       if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE)) {
-           printf(", bogus fixed header length %u should be %lu",
-                  isis_header->fixed_len, (unsigned long)ISIS_CSNP_HEADER_SIZE);
-           return (0);
-       }
-
-       pdu_len=EXTRACT_16BITS(header_csnp->pdu_len);
-       if (packet_len>pdu_len) {
+        if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE)) {
+            ND_PRINT((ndo, ", bogus fixed header length %u should be %lu",
+                      isis_header->fixed_len, (unsigned long)(ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE)));
+            return (0);
+        }
+        ND_TCHECK(*header_csnp);
+        if (length < ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE)
+            goto trunc;
+        if (ndo->ndo_vflag == 0) {
+            ND_PRINT((ndo, ", src-id %s", isis_print_id(header_csnp->source_id, NODE_ID_LEN)));
+            ND_PRINT((ndo, ", length %u", length));
+            return (1);
+        }
+        pdu_len=EXTRACT_BE_U_2(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",
+        ND_PRINT((ndo, "\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(gndo,pptr,"\n\t  ",ISIS_CSNP_HEADER_SIZE))
-                return(0);
+               pdu_len));
+        ND_PRINT((ndo, "\n\t  start lsp-id: %s",
+               isis_print_id(header_csnp->start_lsp_id, LSP_ID_LEN)));
+        ND_PRINT((ndo, "\n\t  end lsp-id:   %s",
+               isis_print_id(header_csnp->end_lsp_id, LSP_ID_LEN)));
+
+        if (ndo->ndo_vflag > 1) {
+            if (!print_unknown_data(ndo, 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);
+        packet_len -= (ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE);
+        pptr = p + (ISIS_COMMON_HEADER_SIZE+ISIS_CSNP_HEADER_SIZE);
         break;
 
     case ISIS_PDU_L1_PSNP:
     case ISIS_PDU_L2_PSNP:
-       if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_PSNP_HEADER_SIZE)) {
-           printf("- bogus fixed header length %u should be %lu",
-                  isis_header->fixed_len, (unsigned long)ISIS_PSNP_HEADER_SIZE);
-           return (0);
-       }
-
-       pdu_len=EXTRACT_16BITS(header_psnp->pdu_len);
-       if (packet_len>pdu_len) {
+        if (isis_header->fixed_len != (ISIS_COMMON_HEADER_SIZE+ISIS_PSNP_HEADER_SIZE)) {
+            ND_PRINT((ndo, "- bogus fixed header length %u should be %lu",
+                   isis_header->fixed_len, (unsigned long)(ISIS_COMMON_HEADER_SIZE+ISIS_PSNP_HEADER_SIZE)));
+            return (0);
+        }
+        ND_TCHECK(*header_psnp);
+        if (length < ISIS_COMMON_HEADER_SIZE+ISIS_PSNP_HEADER_SIZE)
+            goto trunc;
+        if (ndo->ndo_vflag == 0) {
+            ND_PRINT((ndo, ", src-id %s", isis_print_id(header_psnp->source_id, NODE_ID_LEN)));
+            ND_PRINT((ndo, ", length %u", length));
+            return (1);
+        }
+        pdu_len=EXTRACT_BE_U_2(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",
+        ND_PRINT((ndo, "\n\t  source-id:    %s, PDU length: %u",
                isis_print_id(header_psnp->source_id, NODE_ID_LEN),
-               pdu_len);
+               pdu_len));
 
-        if (vflag > 1) {
-            if(!print_unknown_data(gndo,pptr,"\n\t  ",ISIS_PSNP_HEADER_SIZE))
-                return(0);
+        if (ndo->ndo_vflag > 1) {
+            if (!print_unknown_data(ndo, 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;
+        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(gndo,pptr,"\n\t  ",length))
-           return(0);
+        if (ndo->ndo_vflag == 0) {
+            ND_PRINT((ndo, ", length %u", length));
+            return (1);
+        }
+       (void)print_unknown_data(ndo, pptr, "\n\t  ", length);
        return (0);
     }
 
@@ -2433,79 +2562,74 @@ static int isis_print (const u_int8_t *p, u_int length)
      * 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++;
+    while (packet_len > 0) {
+       ND_TCHECK_2(pptr);
+       if (packet_len < 2)
+           goto trunc;
+       tlv_type = EXTRACT_U_1(pptr);
+       tlv_len = EXTRACT_U_1(pptr + 1);
+       pptr += 2;
+       packet_len -= 2;
         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",
+       ND_PRINT((ndo, "\n\t    %s TLV #%u, length: %u",
                tok2str(isis_tlv_values,
                        "unknown",
                        tlv_type),
                tlv_type,
-               tlv_len);
+               tlv_len));
 
-        if (tlv_len == 0) /* something is malformed */
+        if (tlv_len == 0) /* something is invalid */
            continue;
 
+       if (packet_len < tlv_len)
+           goto trunc;
+
         /* now check if we have a decoder otherwise do a hexdump at the end*/
        switch (tlv_type) {
        case ISIS_TLV_AREA_ADDR:
-           if (!TTEST2(*tptr, 1))
-               goto trunctlv;
-           alen = *tptr++;
+           ND_TCHECK_1(tptr);
+           alen = EXTRACT_U_1(tptr);
+           tptr++;
            while (tmp && alen < tmp) {
-               printf("\n\t      Area address (length: %u): %s",
+               ND_TCHECK_LEN(tptr, alen);
+               ND_PRINT((ndo, "\n\t      Area address (length: %u): %s",
                        alen,
-                       isonsap_string(tptr,alen));
+                       isonsap_string(ndo, 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++;
+               ND_TCHECK_1(tptr);
+               alen = EXTRACT_U_1(tptr);
+               tptr++;
            }
            break;
        case ISIS_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;
+           while (tmp >= MAC_ADDR_LEN) {
+                ND_TCHECK_LEN(tptr, MAC_ADDR_LEN);
+                ND_PRINT((ndo, "\n\t      SNPA: %s", isis_print_id(tptr, MAC_ADDR_LEN)));
+                tmp -= MAC_ADDR_LEN;
+                tptr += MAC_ADDR_LEN;
            }
            break;
 
         case ISIS_TLV_ISNEIGH_VARLEN:
-            if (!TTEST2(*tptr, 1) || tmp < 3) /* min. TLV length */
+            if (!ND_TTEST_1(tptr) || tmp < 3) /* min. TLV length */
                goto trunctlv;
-           lan_alen = *tptr++; /* LAN address length */
+           lan_alen = EXTRACT_U_1(tptr); /* LAN address length */
+           tptr++;
            if (lan_alen == 0) {
-                printf("\n\t      LAN address length 0 bytes (invalid)");
+                ND_PRINT((ndo, "\n\t      LAN address length 0 bytes (invalid)"));
                 break;
             }
             tmp --;
-            printf("\n\t      LAN address length %u bytes ",lan_alen);
+            ND_PRINT((ndo, "\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));
+                ND_TCHECK_LEN(tptr, lan_alen);
+                ND_PRINT((ndo, "\n\t\tIS Neighbor: %s", isis_print_id(tptr, lan_alen)));
                 tmp -= lan_alen;
                 tptr +=lan_alen;
             }
@@ -2515,13 +2639,13 @@ static int isis_print (const u_int8_t *p, u_int length)
            break;
 
         case ISIS_TLV_MT_IS_REACH:
-            mt_len = isis_print_mtid(tptr, "\n\t      ");
+            mt_len = isis_print_mtid(ndo, tptr, "\n\t      ");
             if (mt_len == 0) /* did something go wrong ? */
                 goto trunctlv;
             tptr+=mt_len;
             tmp-=mt_len;
             while (tmp >= 2+NODE_ID_LEN+3+1) {
-                ext_is_len = isis_print_ext_is_reach(tptr,"\n\t      ",tlv_type);
+                ext_is_len = isis_print_ext_is_reach(ndo, tptr, "\n\t      ", tlv_type);
                 if (ext_is_len == 0) /* did something go wrong ? */
                     goto trunctlv;
 
@@ -2532,7 +2656,7 @@ static int isis_print (const u_int8_t *p, u_int length)
 
         case ISIS_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);
+               ext_is_len = isis_print_ext_is_reach(ndo, tptr, "\n\t      ", tlv_type);
                if (ext_is_len == 0) /* did something go wrong ? */
                    goto trunctlv;
                tmp-=ext_is_len;
@@ -2542,7 +2666,7 @@ static int isis_print (const u_int8_t *p, u_int length)
 
         case ISIS_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);
+                ext_is_len = isis_print_ext_is_reach(ndo, tptr, "\n\t      ", tlv_type);
                 if (ext_is_len == 0) /* did something go wrong ? */
                     goto trunctlv;
                 tmp-=ext_is_len;
@@ -2550,19 +2674,18 @@ static int isis_print (const u_int8_t *p, u_int length)
             }
             break;
         case ISIS_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",
+           ND_TCHECK_1(tptr);  /* check if there is one byte left to read out the virtual flag */
+            ND_PRINT((ndo, "\n\t      %s",
                    tok2str(isis_is_reach_virtual_values,
                            "bogus virtual flag 0x%02x",
-                           *tptr++));
+                           EXTRACT_U_1(tptr))));
+           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);
+               ND_TCHECK(*tlv_is_reach);
+               ND_PRINT((ndo, "\n\t      IS Neighbor: %s",
+                      isis_print_id(tlv_is_reach->neighbor_nodeid, NODE_ID_LEN)));
+               isis_print_metric_block(ndo, &tlv_is_reach->isis_metric_block);
                tmp -= sizeof(struct isis_tlv_is_reach);
                tlv_is_reach++;
            }
@@ -2571,11 +2694,10 @@ static int isis_print (const u_int8_t *p, u_int length)
         case ISIS_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);
+               ND_TCHECK(*tlv_es_reach);
+               ND_PRINT((ndo, "\n\t      ES Neighbor: %s",
+                       isis_print_id(tlv_es_reach->neighbor_sysid, SYSTEM_ID_LEN)));
+               isis_print_metric_block(ndo, &tlv_es_reach->isis_metric_block);
                tmp -= sizeof(struct isis_tlv_es_reach);
                tlv_es_reach++;
            }
@@ -2584,13 +2706,13 @@ static int isis_print (const u_int8_t *p, u_int length)
             /* those two TLVs share the same format */
        case ISIS_TLV_INT_IP_REACH:
        case ISIS_TLV_EXT_IP_REACH:
-           if (!isis_print_tlv_ip_reach(pptr, "\n\t      ", tlv_len))
-               return (1);
-           break;
+               if (!isis_print_tlv_ip_reach(ndo, pptr, "\n\t      ", tlv_len))
+                       return (1);
+               break;
 
        case ISIS_TLV_EXTD_IP_REACH:
            while (tmp>0) {
-                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", AF_INET);
+                ext_ip_len = isis_print_extd_ip_reach(ndo, tptr, "\n\t      ", AF_INET);
                 if (ext_ip_len == 0) /* did something go wrong ? */
                     goto trunctlv;
                 tptr+=ext_ip_len;
@@ -2599,7 +2721,7 @@ static int isis_print (const u_int8_t *p, u_int length)
            break;
 
         case ISIS_TLV_MT_IP_REACH:
-            mt_len = isis_print_mtid(tptr, "\n\t      ");
+            mt_len = isis_print_mtid(ndo, tptr, "\n\t      ");
             if (mt_len == 0) { /* did something go wrong ? */
                 goto trunctlv;
             }
@@ -2607,7 +2729,7 @@ static int isis_print (const u_int8_t *p, u_int length)
             tmp-=mt_len;
 
             while (tmp>0) {
-                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", AF_INET);
+                ext_ip_len = isis_print_extd_ip_reach(ndo, tptr, "\n\t      ", AF_INET);
                 if (ext_ip_len == 0) /* did something go wrong ? */
                     goto trunctlv;
                 tptr+=ext_ip_len;
@@ -2615,10 +2737,9 @@ static int isis_print (const u_int8_t *p, u_int length)
            }
            break;
 
-#ifdef INET6
        case ISIS_TLV_IP6_REACH:
            while (tmp>0) {
-                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", AF_INET6);
+                ext_ip_len = isis_print_extd_ip_reach(ndo, tptr, "\n\t      ", AF_INET6);
                 if (ext_ip_len == 0) /* did something go wrong ? */
                     goto trunctlv;
                 tptr+=ext_ip_len;
@@ -2627,7 +2748,7 @@ static int isis_print (const u_int8_t *p, u_int length)
            break;
 
        case ISIS_TLV_MT_IP6_REACH:
-            mt_len = isis_print_mtid(tptr, "\n\t      ");
+            mt_len = isis_print_mtid(ndo, tptr, "\n\t      ");
             if (mt_len == 0) { /* did something go wrong ? */
                 goto trunctlv;
             }
@@ -2635,7 +2756,7 @@ static int isis_print (const u_int8_t *p, u_int length)
             tmp-=mt_len;
 
            while (tmp>0) {
-                ext_ip_len = isis_print_extd_ip_reach(tptr, "\n\t      ", AF_INET6);
+                ext_ip_len = isis_print_extd_ip_reach(ndo, tptr, "\n\t      ", AF_INET6);
                 if (ext_ip_len == 0) /* did something go wrong ? */
                     goto trunctlv;
                 tptr+=ext_ip_len;
@@ -2645,64 +2766,54 @@ static int isis_print (const u_int8_t *p, u_int length)
 
        case ISIS_TLV_IP6ADDR:
            while (tmp>=sizeof(struct in6_addr)) {
-               if (!TTEST2(*tptr, sizeof(struct in6_addr)))
-                   goto trunctlv;
+               ND_TCHECK_LEN(tptr, sizeof(struct in6_addr));
 
-                printf("\n\t      IPv6 interface address: %s",
-                      ip6addr_string(tptr));
+                ND_PRINT((ndo, "\n\t      IPv6 interface address: %s",
+                      ip6addr_string(ndo, tptr)));
 
                tptr += sizeof(struct in6_addr);
                tmp -= sizeof(struct in6_addr);
            }
            break;
-#endif
        case ISIS_TLV_AUTH:
-           if (!TTEST2(*tptr, 1))
-               goto trunctlv;
+           ND_TCHECK_1(tptr);
 
-            printf("\n\t      %s: ",
+            ND_PRINT((ndo, "\n\t      %s: ",
                    tok2str(isis_subtlv_auth_values,
                            "unknown Authentication type 0x%02x",
-                           *tptr));
+                           EXTRACT_U_1(tptr))));
 
-           switch (*tptr) {
+           switch (EXTRACT_U_1(tptr)) {
            case ISIS_SUBTLV_AUTH_SIMPLE:
-               for(i=1;i<tlv_len;i++) {
-                   if (!TTEST2(*(tptr+i), 1))
-                       goto trunctlv;
-                   printf("%c",*(tptr+i));
-               }
+               if (fn_printzp(ndo, tptr + 1, tlv_len - 1, ndo->ndo_snapend))
+                   goto trunctlv;
                break;
            case ISIS_SUBTLV_AUTH_MD5:
                for(i=1;i<tlv_len;i++) {
-                   if (!TTEST2(*(tptr+i), 1))
-                       goto trunctlv;
-                   printf("%02x",*(tptr+i));
+                   ND_TCHECK_1(tptr + i);
+                   ND_PRINT((ndo, "%02x", EXTRACT_U_1(tptr + i)));
                }
                if (tlv_len != ISIS_SUBTLV_AUTH_MD5_LEN+1)
-                    printf(", (malformed subTLV) ");
+                    ND_PRINT((ndo, ", (invalid subTLV) "));
 
-#ifdef HAVE_LIBCRYPTO
-                sigcheck = signature_verify(optr, length,
-                                            (unsigned char *)tptr + 1);
-#else
-                sigcheck = CANT_CHECK_SIGNATURE;
-#endif
-                printf(" (%s)", tok2str(signature_check_values, "Unknown", sigcheck));
+                sigcheck = signature_verify(ndo, optr, length, tptr + 1,
+                                            isis_clear_checksum_lifetime,
+                                            header_lsp);
+                ND_PRINT((ndo, " (%s)", tok2str(signature_check_values, "Unknown", sigcheck)));
 
                break;
             case ISIS_SUBTLV_AUTH_GENERIC:
-                key_id = EXTRACT_16BITS((tptr+1));
-                printf("%u, password: ", key_id);
-                for(i=1 + sizeof(u_int16_t);i<tlv_len;i++) {
-                    if (!TTEST2(*(tptr+i), 1))
-                        goto trunctlv;
-                    printf("%02x",*(tptr+i));
+               ND_TCHECK_2(tptr + 1);
+                key_id = EXTRACT_BE_U_2(tptr + 1);
+                ND_PRINT((ndo, "%u, password: ", key_id));
+                for(i=1 + sizeof(uint16_t);i<tlv_len;i++) {
+                    ND_TCHECK_1(tptr + i);
+                    ND_PRINT((ndo, "%02x", EXTRACT_U_1(tptr + i)));
                 }
                 break;
            case ISIS_SUBTLV_AUTH_PRIVATE:
            default:
-               if(!print_unknown_data(gndo,tptr+1,"\n\t\t  ",tlv_len-1))
+               if (!print_unknown_data(ndo, tptr + 1, "\n\t\t  ", tlv_len - 1))
                    return(0);
                break;
            }
@@ -2711,49 +2822,42 @@ static int isis_print (const u_int8_t *p, u_int length)
        case ISIS_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 (%u)",
-                      tok2str(isis_ptp_adjancey_values, "unknown", *tptr),
-                        *tptr);
+               ND_TCHECK_1(tptr);
+               ND_PRINT((ndo, "\n\t      Adjacency State: %s (%u)",
+                      tok2str(isis_ptp_adjancey_values, "unknown", EXTRACT_U_1(tptr)),
+                      EXTRACT_U_1(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));
+               ND_TCHECK(tlv_ptp_adj->extd_local_circuit_id);
+               ND_PRINT((ndo, "\n\t      Extended Local circuit-ID: 0x%08x",
+                      EXTRACT_BE_U_4(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 System-ID: %s",
-                      isis_print_id(tlv_ptp_adj->neighbor_sysid,SYSTEM_ID_LEN));
+               ND_TCHECK_LEN(tlv_ptp_adj->neighbor_sysid, SYSTEM_ID_LEN);
+               ND_PRINT((ndo, "\n\t      Neighbor System-ID: %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));
+               ND_TCHECK(tlv_ptp_adj->neighbor_extd_local_circuit_id);
+               ND_PRINT((ndo, "\n\t      Neighbor Extended Local circuit-ID: 0x%08x",
+                      EXTRACT_BE_U_4(tlv_ptp_adj->neighbor_extd_local_circuit_id)));
            }
            break;
 
        case ISIS_TLV_PROTOCOLS:
-           printf("\n\t      NLPID(s): ");
+           ND_PRINT((ndo, "\n\t      NLPID(s): "));
            while (tmp>0) {
-               if (!TTEST2(*(tptr), 1))
-                   goto trunctlv;
-               printf("%s (0x%02x)",
+               ND_TCHECK_1(tptr);
+               ND_PRINT((ndo, "%s (0x%02x)",
                        tok2str(nlpid_values,
                                "unknown",
-                               *tptr),
-                       *tptr);
+                               EXTRACT_U_1(tptr)),
+                       EXTRACT_U_1(tptr)));
                if (tmp>1) /* further NPLIDs ? - put comma */
-                   printf(", ");
+                   ND_PRINT((ndo, ", "));
                 tptr++;
                 tmp--;
            }
@@ -2761,102 +2865,90 @@ static int isis_print (const u_int8_t *p, u_int length)
 
     case ISIS_TLV_MT_PORT_CAP:
     {
-      if (!TTEST2(*(tptr), 2))
-        goto trunctlv;
+      ND_TCHECK_2(tptr);
 
-      printf("\n\t       RES: %d, MTID(s): %d",
-              (EXTRACT_16BITS (tptr) >> 12),
-              (EXTRACT_16BITS (tptr) & 0x0fff));
+      ND_PRINT((ndo, "\n\t       RES: %d, MTID(s): %d",
+              (EXTRACT_BE_U_2(tptr) >> 12),
+              (EXTRACT_BE_U_2(tptr) & 0x0fff)));
 
       tmp = tmp-2;
       tptr = tptr+2;
 
       if (tmp)
-        isis_print_mt_port_cap_subtlv (tptr, tmp);
+        isis_print_mt_port_cap_subtlv(ndo, tptr, tmp);
 
       break;
     }
 
     case ISIS_TLV_MT_CAPABILITY:
 
-      if (!TTEST2(*(tptr), 2))
-        goto trunctlv;
+      ND_TCHECK_2(tptr);
 
-      printf("\n\t      O: %d, RES: %d, MTID(s): %d",
-                (EXTRACT_16BITS(tptr) >> 15) & 0x01,
-                (EXTRACT_16BITS(tptr) >> 12) & 0x07,
-                EXTRACT_16BITS(tptr) & 0x0fff);
+      ND_PRINT((ndo, "\n\t      O: %d, RES: %d, MTID(s): %d",
+                (EXTRACT_BE_U_2(tptr) >> 15) & 0x01,
+                (EXTRACT_BE_U_2(tptr) >> 12) & 0x07,
+                EXTRACT_BE_U_2(tptr) & 0x0fff));
 
       tmp = tmp-2;
       tptr = tptr+2;
 
       if (tmp)
-        isis_print_mt_capability_subtlv (tptr, tmp);
+        isis_print_mt_capability_subtlv(ndo, tptr, tmp);
 
       break;
 
        case ISIS_TLV_TE_ROUTER_ID:
-           if (!TTEST2(*pptr, sizeof(struct in_addr)))
-               goto trunctlv;
-           printf("\n\t      Traffic Engineering Router ID: %s", ipaddr_string(pptr));
+           ND_TCHECK_LEN(pptr, sizeof(struct in_addr));
+           ND_PRINT((ndo, "\n\t      Traffic Engineering Router ID: %s", ipaddr_string(ndo, pptr)));
            break;
 
        case ISIS_TLV_IPADDR:
            while (tmp>=sizeof(struct in_addr)) {
-               if (!TTEST2(*tptr, sizeof(struct in_addr)))
-                   goto trunctlv;
-               printf("\n\t      IPv4 interface address: %s", ipaddr_string(tptr));
+               ND_TCHECK_LEN(tptr, sizeof(struct in_addr));
+               ND_PRINT((ndo, "\n\t      IPv4 interface address: %s", ipaddr_string(ndo, tptr)));
                tptr += sizeof(struct in_addr);
                tmp -= sizeof(struct in_addr);
            }
            break;
 
        case ISIS_TLV_HOSTNAME:
-           printf("\n\t      Hostname: ");
-           while (tmp>0) {
-               if (!TTEST2(*tptr, 1))
-                   goto trunctlv;
-               printf("%c",*tptr++);
-                tmp--;
-           }
+           ND_PRINT((ndo, "\n\t      Hostname: "));
+           if (fn_printzp(ndo, tptr, tmp, ndo->ndo_snapend))
+               goto trunctlv;
            break;
 
        case ISIS_TLV_SHARED_RISK_GROUP:
            if (tmp < NODE_ID_LEN)
                break;
-           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);
+           ND_TCHECK_LEN(tptr, NODE_ID_LEN);
+           ND_PRINT((ndo, "\n\t      IS Neighbor: %s", isis_print_id(tptr, NODE_ID_LEN)));
+           tptr+=NODE_ID_LEN;
+           tmp-=NODE_ID_LEN;
 
            if (tmp < 1)
                break;
-           if (!TTEST2(*tptr, 1))
-                goto trunctlv;
-           printf(", Flags: [%s]", ISIS_MASK_TLV_SHARED_RISK_GROUP(*tptr++) ? "numbered" : "unnumbered");
+           ND_TCHECK_1(tptr);
+           ND_PRINT((ndo, ", Flags: [%s]", ISIS_MASK_TLV_SHARED_RISK_GROUP(EXTRACT_U_1(tptr)) ? "numbered" : "unnumbered"));
+           tptr++;
            tmp--;
 
            if (tmp < sizeof(struct in_addr))
                break;
-           if (!TTEST2(*tptr,sizeof(struct in_addr)))
-                goto trunctlv;
-           printf("\n\t      IPv4 interface address: %s", ipaddr_string(tptr));
+           ND_TCHECK_LEN(tptr, sizeof(struct in_addr));
+           ND_PRINT((ndo, "\n\t      IPv4 interface address: %s", ipaddr_string(ndo, tptr)));
            tptr+=sizeof(struct in_addr);
            tmp-=sizeof(struct in_addr);
 
            if (tmp < sizeof(struct in_addr))
                break;
-           if (!TTEST2(*tptr,sizeof(struct in_addr)))
-                goto trunctlv;
-           printf("\n\t      IPv4 neighbor address: %s", ipaddr_string(tptr));
+           ND_TCHECK_LEN(tptr, sizeof(struct in_addr));
+           ND_PRINT((ndo, "\n\t      IPv4 neighbor address: %s", ipaddr_string(ndo, tptr)));
            tptr+=sizeof(struct in_addr);
            tmp-=sizeof(struct in_addr);
 
            while (tmp>=4) {
-                if (!TTEST2(*tptr, 4))
-                    goto trunctlv;
-                printf("\n\t      Link-ID: 0x%08x", EXTRACT_32BITS(tptr));
+                ND_TCHECK_4(tptr);
+                ND_PRINT((ndo, "\n\t      Link-ID: 0x%08x", EXTRACT_BE_U_4(tptr)));
                 tptr+=4;
                 tmp-=4;
            }
@@ -2865,19 +2957,15 @@ static int isis_print (const u_int8_t *p, u_int length)
        case ISIS_TLV_LSP:
            tlv_lsp = (const struct isis_tlv_lsp *)tptr;
            while(tmp>=sizeof(struct isis_tlv_lsp)) {
-               if (!TTEST((tlv_lsp->lsp_id)[LSP_ID_LEN-1]))
-                   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));
+               ND_TCHECK((tlv_lsp->lsp_id)[LSP_ID_LEN-1]);
+               ND_PRINT((ndo, "\n\t      lsp-id: %s",
+                       isis_print_id(tlv_lsp->lsp_id, LSP_ID_LEN)));
+               ND_TCHECK_LEN(tlv_lsp->sequence_number, 4);
+               ND_PRINT((ndo, ", seq: 0x%08x", EXTRACT_BE_U_4(tlv_lsp->sequence_number)));
+               ND_TCHECK_LEN(tlv_lsp->remaining_lifetime, 2);
+               ND_PRINT((ndo, ", lifetime: %5ds", EXTRACT_BE_U_2(tlv_lsp->remaining_lifetime)));
+               ND_TCHECK_LEN(tlv_lsp->checksum, 2);
+               ND_PRINT((ndo, ", chksum: 0x%04x", EXTRACT_BE_U_2(tlv_lsp->checksum)));
                tmp-=sizeof(struct isis_tlv_lsp);
                tlv_lsp++;
            }
@@ -2886,15 +2974,29 @@ static int isis_print (const u_int8_t *p, u_int length)
        case ISIS_TLV_CHECKSUM:
            if (tmp < ISIS_TLV_CHECKSUM_MINLEN)
                break;
-           if (!TTEST2(*tptr, ISIS_TLV_CHECKSUM_MINLEN))
-               goto trunctlv;
-           printf("\n\t      checksum: 0x%04x ", EXTRACT_16BITS(tptr));
+           ND_TCHECK_LEN(tptr, ISIS_TLV_CHECKSUM_MINLEN);
+           ND_PRINT((ndo, "\n\t      checksum: 0x%04x ", EXTRACT_BE_U_2(tptr)));
             /* do not attempt to verify the checksum if it is zero
              * most likely a HMAC-MD5 TLV is also present and
              * to avoid conflicts the checksum TLV is zeroed.
              * see rfc3358 for details
              */
-            osi_print_cksum(optr, EXTRACT_16BITS(tptr), tptr-optr, length);
+            osi_print_cksum(ndo, optr, EXTRACT_BE_U_2(tptr), tptr-optr,
+                            length);
+           break;
+
+       case ISIS_TLV_POI:
+           if (tlv_len >= SYSTEM_ID_LEN + 1) {
+               ND_TCHECK_LEN(tptr, SYSTEM_ID_LEN + 1);
+               ND_PRINT((ndo, "\n\t      Purge Originator System-ID: %s",
+                      isis_print_id(tptr + 1, SYSTEM_ID_LEN)));
+           }
+
+           if (tlv_len == 2 * SYSTEM_ID_LEN + 1) {
+               ND_TCHECK_LEN(tptr, 2 * SYSTEM_ID_LEN + 1);
+               ND_PRINT((ndo, "\n\t      Received from System-ID: %s",
+                      isis_print_id(tptr + SYSTEM_ID_LEN + 1, SYSTEM_ID_LEN)));
+           }
            break;
 
        case ISIS_TLV_MT_SUPPORTED:
@@ -2904,13 +3006,13 @@ static int isis_print (const u_int8_t *p, u_int length)
                /* 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      ");
+                    mt_len = isis_print_mtid(ndo, 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");
+                   ND_PRINT((ndo, "\n\t      invalid MT-ID"));
                    break;
                }
            }
@@ -2920,10 +3022,9 @@ static int isis_print (const u_int8_t *p, u_int length)
             /* first attempt to decode the flags */
             if (tmp < ISIS_TLV_RESTART_SIGNALING_FLAGLEN)
                 break;
-            if (!TTEST2(*tptr, ISIS_TLV_RESTART_SIGNALING_FLAGLEN))
-                goto trunctlv;
-            printf("\n\t      Flags [%s]",
-                   bittok2str(isis_restart_flag_values, "none", *tptr));
+            ND_TCHECK_LEN(tptr, ISIS_TLV_RESTART_SIGNALING_FLAGLEN);
+            ND_PRINT((ndo, "\n\t      Flags [%s]",
+                   bittok2str(isis_restart_flag_values, "none", EXTRACT_U_1(tptr))));
             tptr+=ISIS_TLV_RESTART_SIGNALING_FLAGLEN;
             tmp-=ISIS_TLV_RESTART_SIGNALING_FLAGLEN;
 
@@ -2933,40 +3034,38 @@ static int isis_print (const u_int8_t *p, u_int length)
 
             if (tmp < ISIS_TLV_RESTART_SIGNALING_HOLDTIMELEN)
                 break;
-            if (!TTEST2(*tptr, ISIS_TLV_RESTART_SIGNALING_HOLDTIMELEN))
-                goto trunctlv;
+            ND_TCHECK_LEN(tptr, ISIS_TLV_RESTART_SIGNALING_HOLDTIMELEN);
 
-            printf(", Remaining holding time %us", EXTRACT_16BITS(tptr));
+            ND_PRINT((ndo, ", Remaining holding time %us", EXTRACT_BE_U_2(tptr)));
             tptr+=ISIS_TLV_RESTART_SIGNALING_HOLDTIMELEN;
             tmp-=ISIS_TLV_RESTART_SIGNALING_HOLDTIMELEN;
 
             /* is there an additional sysid field present ?*/
             if (tmp == SYSTEM_ID_LEN) {
-                    if (!TTEST2(*tptr, SYSTEM_ID_LEN))
-                            goto trunctlv;
-                    printf(", for %s",isis_print_id(tptr,SYSTEM_ID_LEN));
+                    ND_TCHECK_LEN(tptr, SYSTEM_ID_LEN);
+                    ND_PRINT((ndo, ", for %s", isis_print_id(tptr,SYSTEM_ID_LEN)));
             }
            break;
 
         case ISIS_TLV_IDRP_INFO:
            if (tmp < ISIS_TLV_IDRP_INFO_MINLEN)
                break;
-            if (!TTEST2(*tptr, ISIS_TLV_IDRP_INFO_MINLEN))
-                goto trunctlv;
-            printf("\n\t      Inter-Domain Information Type: %s",
+            ND_TCHECK_LEN(tptr, ISIS_TLV_IDRP_INFO_MINLEN);
+            ND_PRINT((ndo, "\n\t      Inter-Domain Information Type: %s",
                    tok2str(isis_subtlv_idrp_values,
                            "Unknown (0x%02x)",
-                           *tptr));
-            switch (*tptr++) {
+                           EXTRACT_U_1(tptr))));
+            isis_subtlv_idrp = EXTRACT_U_1(tptr);
+            tptr++;
+            switch (isis_subtlv_idrp) {
             case ISIS_SUBTLV_IDRP_ASN:
-                if (!TTEST2(*tptr, 2)) /* fetch AS number */
-                    goto trunctlv;
-                printf("AS Number: %u",EXTRACT_16BITS(tptr));
+                ND_TCHECK_2(tptr); /* fetch AS number */
+                ND_PRINT((ndo, "AS Number: %u", EXTRACT_BE_U_2(tptr)));
                 break;
             case ISIS_SUBTLV_IDRP_LOCAL:
             case ISIS_SUBTLV_IDRP_RES:
             default:
-                if(!print_unknown_data(gndo,tptr,"\n\t      ",tlv_len-1))
+                if (!print_unknown_data(ndo, tptr, "\n\t      ", tlv_len - 1))
                     return(0);
                 break;
             }
@@ -2975,16 +3074,14 @@ static int isis_print (const u_int8_t *p, u_int length)
         case ISIS_TLV_LSP_BUFFERSIZE:
            if (tmp < ISIS_TLV_LSP_BUFFERSIZE_MINLEN)
                break;
-            if (!TTEST2(*tptr, ISIS_TLV_LSP_BUFFERSIZE_MINLEN))
-                goto trunctlv;
-            printf("\n\t      LSP Buffersize: %u",EXTRACT_16BITS(tptr));
+            ND_TCHECK_LEN(tptr, ISIS_TLV_LSP_BUFFERSIZE_MINLEN);
+            ND_PRINT((ndo, "\n\t      LSP Buffersize: %u", EXTRACT_BE_U_2(tptr)));
             break;
 
         case ISIS_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));
+                ND_TCHECK_LEN(tptr, SYSTEM_ID_LEN);
+                ND_PRINT((ndo, "\n\t      %s", isis_print_id(tptr, SYSTEM_ID_LEN)));
                 tptr+=SYSTEM_ID_LEN;
                 tmp-=SYSTEM_ID_LEN;
             }
@@ -2993,29 +3090,26 @@ static int isis_print (const u_int8_t *p, u_int length)
         case ISIS_TLV_PREFIX_NEIGH:
            if (tmp < sizeof(struct isis_metric_block))
                break;
-            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);
+            ND_TCHECK_LEN(tptr, sizeof(struct isis_metric_block));
+            ND_PRINT((ndo, "\n\t      Metric Block"));
+            isis_print_metric_block(ndo, (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*/
+                ND_TCHECK_1(tptr);
+                prefix_len=EXTRACT_U_1(tptr); /* read out prefix length in semioctets*/
+                tptr++;
                 if (prefix_len < 2) {
-                    printf("\n\t\tAddress: prefix length %u < 2", prefix_len);
+                    ND_PRINT((ndo, "\n\t\tAddress: prefix length %u < 2", prefix_len));
                     break;
                 }
                 tmp--;
                 if (tmp < prefix_len/2)
                     break;
-                if (!TTEST2(*tptr, prefix_len/2))
-                    goto trunctlv;
-                printf("\n\t\tAddress: %s/%u",
-                       isonsap_string(tptr,prefix_len/2),
-                       prefix_len*4);
+                ND_TCHECK_LEN(tptr, prefix_len / 2);
+                ND_PRINT((ndo, "\n\t\tAddress: %s/%u",
+                       isonsap_string(ndo, tptr, prefix_len / 2), prefix_len * 4));
                 tptr+=prefix_len/2;
                 tmp-=prefix_len/2;
             }
@@ -3024,24 +3118,22 @@ static int isis_print (const u_int8_t *p, u_int length)
         case ISIS_TLV_IIH_SEQNR:
            if (tmp < ISIS_TLV_IIH_SEQNR_MINLEN)
                break;
-            if (!TTEST2(*tptr, ISIS_TLV_IIH_SEQNR_MINLEN)) /* check if four bytes are on the wire */
-                goto trunctlv;
-            printf("\n\t      Sequence number: %u", EXTRACT_32BITS(tptr) );
+            ND_TCHECK_LEN(tptr, ISIS_TLV_IIH_SEQNR_MINLEN); /* check if four bytes are on the wire */
+            ND_PRINT((ndo, "\n\t      Sequence number: %u", EXTRACT_BE_U_4(tptr)));
             break;
 
         case ISIS_TLV_VENDOR_PRIVATE:
            if (tmp < ISIS_TLV_VENDOR_PRIVATE_MINLEN)
                break;
-            if (!TTEST2(*tptr, ISIS_TLV_VENDOR_PRIVATE_MINLEN)) /* check if enough byte for a full oui */
-                goto trunctlv;
-            vendor_id = EXTRACT_24BITS(tptr);
-            printf("\n\t      Vendor: %s (%u)",
-                   tok2str(oui_values,"Unknown",vendor_id),
-                   vendor_id);
+            ND_TCHECK_LEN(tptr, ISIS_TLV_VENDOR_PRIVATE_MINLEN); /* check if enough byte for a full oui */
+            vendor_id = EXTRACT_BE_U_3(tptr);
+            ND_PRINT((ndo, "\n\t      Vendor: %s (%u)",
+                   tok2str(oui_values, "Unknown", vendor_id),
+                   vendor_id));
             tptr+=3;
             tmp-=3;
             if (tmp > 0) /* hexdump the rest */
-                if(!print_unknown_data(gndo,tptr,"\n\t\t",tmp))
+                if (!print_unknown_data(ndo, tptr, "\n\t\t", tmp))
                     return(0);
             break;
             /*
@@ -3056,51 +3148,62 @@ static int isis_print (const u_int8_t *p, u_int length)
         case ISIS_TLV_NORTEL_PRIVATE2:
 
        default:
-            if (vflag <= 1) {
-                if(!print_unknown_data(gndo,pptr,"\n\t\t",tlv_len))
-                    return(0);
-            }
-           break;
+               if (ndo->ndo_vflag <= 1) {
+                       if (!print_unknown_data(ndo, pptr, "\n\t\t", tlv_len))
+                               return(0);
+               }
+               break;
        }
         /* do we want to see an additionally hexdump ? */
-        if (vflag> 1) {
-           if(!print_unknown_data(gndo,pptr,"\n\t      ",tlv_len))
-               return(0);
-        }
+       if (ndo->ndo_vflag> 1) {
+               if (!print_unknown_data(ndo, 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);
+       ND_PRINT((ndo, "\n\t      %u straggler bytes", packet_len));
     }
     return (1);
 
  trunc:
-    fputs("[|isis]", stdout);
+    ND_PRINT((ndo, "%s", tstr));
     return (1);
 
  trunctlv:
-    printf("\n\t\t packet exceeded snapshot");
+    ND_PRINT((ndo, "\n\t\t"));
+    ND_PRINT((ndo, "%s", tstr));
     return(1);
 }
 
 static void
-osi_print_cksum (const u_int8_t *pptr, u_int16_t checksum,
-                    u_int checksum_offset, u_int length)
+osi_print_cksum(netdissect_options *ndo, const uint8_t *pptr,
+               uint16_t checksum, int checksum_offset, u_int length)
 {
-        u_int16_t calculated_checksum;
+        uint16_t calculated_checksum;
 
-        /* do not attempt to verify the checksum if it is zero */
-        if (!checksum) {
-                printf("(unverified)");
+        /* do not attempt to verify the checksum if it is zero,
+         * if the offset is nonsense,
+         * or the base pointer is not sane
+         */
+        if (!checksum
+            || checksum_offset < 0
+            || !ND_TTEST_2(pptr + checksum_offset)
+            || (u_int)checksum_offset > length
+            || !ND_TTEST_LEN(pptr, length)) {
+                ND_PRINT((ndo, " (unverified)"));
         } else {
+#if 0
+                printf("\nosi_print_cksum: %p %u %u\n", pptr, checksum_offset, length);
+#endif
                 calculated_checksum = create_osi_cksum(pptr, checksum_offset, length);
                 if (checksum == calculated_checksum) {
-                        printf(" (correct)");
+                        ND_PRINT((ndo, " (correct)"));
                 } else {
-                        printf(" (incorrect should be 0x%04x)", calculated_checksum);
+                        ND_PRINT((ndo, " (incorrect should be 0x%04x)", calculated_checksum));
                 }
         }
 }