]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-isoclns.c
add boundary, infinite loop checks
[tcpdump] / print-isoclns.c
index c3eb44191f9f1b5af44968a61870485477c7d86e..90299860cfda077f77390ccda1c4bab8dcb7a0a1 100644 (file)
  * Original code by Matt Thomas, Digital Equipment Corporation
  *
  * Extensively modified by Hannes Gredler ([email protected]) for more
- * complete IS-IS support.
+ * complete IS-IS & CLNP support.
  */
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-isoclns.c,v 1.123 2004-10-18 12:34:36 hannes Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-isoclns.c,v 1.138 2005-04-26 07:14:07 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -57,14 +57,15 @@ static const char rcsid[] _U_ =
 #define SYSTEM_ID_LEN  ETHER_ADDR_LEN
 #define NODE_ID_LEN     SYSTEM_ID_LEN+1
 #define LSP_ID_LEN      SYSTEM_ID_LEN+2
-#define NSAP_MAX_LENGTH 20
 
 #define ISIS_VERSION   1
 #define ESIS_VERSION   1
+#define CLNP_VERSION   1
 
 #define ISIS_PDU_TYPE_MASK      0x1F
 #define ESIS_PDU_TYPE_MASK      0x1F
 #define CLNP_PDU_TYPE_MASK      0x1F
+#define CLNP_FLAG_MASK          0xE0
 #define ISIS_LAN_PRIORITY_MASK  0x7F
 
 #define ISIS_PDU_L1_LAN_IIH    15
@@ -198,6 +199,94 @@ static struct tok esis_option_values[] = {
     { 0, NULL }
 };
 
+#define CLNP_OPTION_DISCARD_REASON   193
+#define CLNP_OPTION_QOS_MAINTENANCE  195 /* iso8473 */
+#define CLNP_OPTION_PRIORITY         205 /* iso8473 */
+
+static struct tok clnp_option_values[] = {
+    { CLNP_OPTION_DISCARD_REASON,  "Discard Reason"},
+    { CLNP_OPTION_PRIORITY,        "Priority"},
+    { CLNP_OPTION_QOS_MAINTENANCE, "QoS Maintenance"},
+    { 0, NULL }
+};
+
+static struct tok clnp_option_rfd_class_values[] = {
+    { 0x0, "General"},
+    { 0x8, "Address"},
+    { 0x9, "Source Routeing"},
+    { 0xa, "Lifetime"},
+    { 0xb, "PDU Discarded"},
+    { 0xc, "Reassembly"},
+    { 0, NULL }
+};
+
+static struct tok clnp_option_rfd_general_values[] = {
+    { 0x0, "Reason not specified"},
+    { 0x1, "Protocol procedure error"},
+    { 0x2, "Incorrect checksum"},
+    { 0x3, "PDU discarded due to congestion"},
+    { 0x4, "Header syntax error (cannot be parsed)"},
+    { 0x5, "Segmentation needed but not permitted"},
+    { 0x6, "Incomplete PDU received"},
+    { 0x7, "Duplicate option"},
+    { 0, NULL }
+};
+
+static struct tok clnp_option_rfd_address_values[] = {
+    { 0x0, "Destination address unreachable"},
+    { 0x1, "Destination address unknown"},
+    { 0, NULL }
+};
+
+static struct tok clnp_option_rfd_source_routeing_values[] = {
+    { 0x0, "Unspecified source routeing error"},
+    { 0x1, "Syntax error in source routeing field"},
+    { 0x2, "Unknown address in source routeing field"},
+    { 0x3, "Path not acceptable"},
+    { 0, NULL }
+};
+
+static struct tok clnp_option_rfd_lifetime_values[] = {
+    { 0x0, "Lifetime expired while data unit in transit"},
+    { 0x1, "Lifetime expired during reassembly"},
+    { 0, NULL }
+};
+
+static struct tok clnp_option_rfd_pdu_discard_values[] = {
+    { 0x0, "Unsupported option not specified"},
+    { 0x1, "Unsupported protocol version"},
+    { 0x2, "Unsupported security option"},
+    { 0x3, "Unsupported source routeing option"},
+    { 0x4, "Unsupported recording of route option"},
+    { 0, NULL }
+};
+
+static struct tok clnp_option_rfd_reassembly_values[] = {
+    { 0x0, "Reassembly interference"},
+    { 0, NULL }
+};
+
+/* array of 16 error-classes */
+static struct tok *clnp_option_rfd_error_class[] = {
+    clnp_option_rfd_general_values,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    clnp_option_rfd_address_values,
+    clnp_option_rfd_source_routeing_values,
+    clnp_option_rfd_lifetime_values,
+    clnp_option_rfd_pdu_discard_values,
+    clnp_option_rfd_reassembly_values,
+    NULL,
+    NULL,
+    NULL
+};
+
+
 #define ISIS_SUBTLV_EXT_IS_REACH_ADMIN_GROUP           3 /* draft-ietf-isis-traffic-05 */
 #define ISIS_SUBTLV_EXT_IS_REACH_LINK_LOCAL_REMOTE_ID  4 /* draft-ietf-isis-gmpls-extensions */
 #define ISIS_SUBTLV_EXT_IS_REACH_LINK_REMOTE_ID        5 /* draft-ietf-isis-traffic-05 */
@@ -267,6 +356,17 @@ static struct tok isis_subtlv_idrp_values[] = {
     { 0, NULL}
 };
 
+#define CLNP_SEGMENT_PART  0x80
+#define CLNP_MORE_SEGMENTS 0x40
+#define CLNP_REQUEST_ER    0x20
+
+static struct tok clnp_flag_values[] = {
+    { CLNP_SEGMENT_PART, "Segmentation permitted"},
+    { CLNP_MORE_SEGMENTS, "more Segments"},
+    { CLNP_REQUEST_ER, "request Error Report"},
+    { 0, NULL}
+};
+
 #define ISIS_MASK_LSP_OL_BIT(x)            ((x)&0x4)
 #define ISIS_MASK_LSP_ISTYPE_BITS(x)       ((x)&0x3)
 #define ISIS_MASK_LSP_PARTITION_BIT(x)     ((x)&0x80)
@@ -446,35 +546,6 @@ struct isis_tlv_lsp {
     u_int8_t checksum[2];
 };
 
-static char *
-print_nsap(register const u_int8_t *pptr, register int nsap_length)
-{
-       int nsap_idx;
-       static char nsap_ascii_output[sizeof("xx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xx")];
-        char *junk_buf = nsap_ascii_output;
-
-        if (nsap_length < 1 || nsap_length > NSAP_MAX_LENGTH) {
-                snprintf(nsap_ascii_output, sizeof(nsap_ascii_output),
-                    "illegal length");
-                return (nsap_ascii_output);
-        }
-
-       for (nsap_idx = 0; nsap_idx < nsap_length; nsap_idx++) {
-               if (!TTEST2(*pptr, 1))
-                       return (0);
-               snprintf(junk_buf,
-                   sizeof(nsap_ascii_output) - (junk_buf - nsap_ascii_output),
-                   "%02x", *pptr++);
-               junk_buf += strlen(junk_buf);
-               if (((nsap_idx & 1) == 0) &&
-                     (nsap_idx + 1 < nsap_length)) {
-                       *junk_buf++ = '.';
-               }
-       }
-        *(junk_buf) = '\0';
-       return (nsap_ascii_output);
-}
-
 #define ISIS_COMMON_HEADER_SIZE (sizeof(struct isis_common_header))
 #define ISIS_IIH_LAN_HEADER_SIZE (sizeof(struct isis_iih_lan_header))
 #define ISIS_IIH_PTP_HEADER_SIZE (sizeof(struct isis_iih_ptp_header))
@@ -494,8 +565,8 @@ void isoclns_print(const u_int8_t *p, u_int length, u_int caplen)
         }
 
         if (eflag)
-            printf("nlpid %s (0x%02x), ",
-                   tok2str(nlpid_values,"Unknown NLPID (0x%02x)",*p),
+            printf("OSI NLPID %s (0x%02x): ",
+                   tok2str(nlpid_values,"Unknown",*p),
                    *p);
         
        switch (*p) {
@@ -515,11 +586,17 @@ void isoclns_print(const u_int8_t *p, u_int length, u_int caplen)
                break;
 
        case NLPID_NULLNS:
-               (void)printf(", length: %u", length);
+               (void)printf("%slength: %u",
+                            eflag ? "" : ", ",
+                             length);
                break;
 
+        case NLPID_Q933:
+                q933_print(p+1, length-1);
+                break;
+
         case NLPID_IP:
-                ip_print(p+1, length-1);
+               ip_print(gndo, p+1, length-1);
                 break;
 
 #ifdef INET6
@@ -528,8 +605,16 @@ void isoclns_print(const u_int8_t *p, u_int length, u_int caplen)
                 break;
 #endif
 
+        case NLPID_PPP:
+                ppp_print(p+1, length-1);
+                break;
+
        default:
-               (void)printf(", length: %u", length);
+                if (!eflag)
+                    printf("OSI NLPID 0x%02x unknown",*p);
+               (void)printf("%slength: %u",
+                            eflag ? "" : ", ",
+                             length);
                if (caplen > 1)
                         print_unknown_data(p,"\n\t",caplen);
                break;
@@ -561,6 +646,12 @@ struct clnp_header_t {
     u_int8_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];
+};
+
 /*
  * clnp_print
  * Decode CLNP packets.  Return 0 on error.
@@ -569,83 +660,177 @@ struct clnp_header_t {
 static int clnp_print (const u_int8_t *pptr, u_int length)
 {
        const u_int8_t *optr,*source_address,*dest_address;
-        u_int li,source_address_length,dest_address_length, clnp_pdu_type;
+        u_int li,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;
 
        clnp_header = (const struct clnp_header_t *) pptr;
+        TCHECK(*clnp_header);
+
         li = clnp_header->length_indicator;
         optr = pptr;
 
         if (!eflag)
-            printf("CLNP");
+            printf("CLNP");
 
         /*
          * Sanity checking of the header.
          */
 
-        /* FIXME */
+        if (clnp_header->version != CLNP_VERSION) {
+            printf("version %d packet not supported", clnp_header->version);
+            return (0);
+        }
+
+        /* FIXME further header sanity checking */
 
         clnp_pdu_type = clnp_header->type & CLNP_PDU_TYPE_MASK;
+        clnp_flags = clnp_header->type & CLNP_FLAG_MASK;
 
         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, length %u",
-                   print_nsap(source_address, source_address_length),
-                   print_nsap(dest_address, dest_address_length),
+            printf("%s%s > %s, %s, length %u",
+                   eflag ? "" : ", ",
+                   isonsap_string(source_address, source_address_length),
+                   isonsap_string(dest_address, dest_address_length),
+                   tok2str(clnp_pdu_values,"unknown (%u)",clnp_pdu_type),
                    length);
             return (1);
         }
-        printf("length %u", length);
-
-    printf("\n\t%s PDU, hlen: %u, v: %u, lifetime: %u.%us, 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));
+        printf("%slength %u",eflag ? "" : ", ",length);
+
+        printf("\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));
 
         /* do not attempt to verify the checksum if it is zero */
         if (EXTRACT_16BITS(clnp_header->cksum) == 0)
                 printf("(unverified)");
-            else printf("(%s)", osi_cksum(optr, li) ? "incorrect" : "correct");
+            else printf("(%s)", osi_cksum(optr, clnp_header->length_indicator) ? "incorrect" : "correct");
+
+        printf("\n\tFlags [%s]",
+               bittok2str(clnp_flag_values,"none",clnp_flags));
 
         printf("\n\tsource address (length %u): %s\n\tdest   address (length %u): %s",
                source_address_length,
-               print_nsap(source_address, source_address_length),
+               isonsap_string(source_address, source_address_length),
                dest_address_length,
-               print_nsap(dest_address, dest_address_length));
+               isonsap_string(dest_address,dest_address_length));
+
+        if (clnp_flags & CLNP_SEGMENT_PART) {
+               clnp_segment_header = (const struct clnp_segment_header_t *) pptr;
+                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);
+        }
 
-        /* dump the remaining header data */
-        print_unknown_data(pptr,"\n\t",clnp_header->length_indicator-(pptr-optr));
+        /* now walk the options */
+        while (li >= 2) {
+            u_int op, opli;
+            const u_int8_t *tptr;
+            
+            TCHECK2(*pptr, 2);
+            if (li < 2) {
+                printf(", bad opts/li");
+                return (0);
+            }
+            op = *pptr++;
+            opli = *pptr++;
+            li -= 2;
+            TCHECK2(*pptr, opli);
+            if (opli > li) {
+                printf(", opt (%d) too long", op);
+                return (0);
+            }
+            li -= opli;
+            tptr = pptr;
+            
+            printf("\n\t  %s Option #%u, length %u, value: ",
+                   tok2str(clnp_option_values,"Unknown",op),
+                   op,
+                   opli);
+
+            switch (op) {
+
+            case CLNP_OPTION_PRIORITY:
+                printf("%u", *tptr);
+                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)",
+                       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);
+                break;
+
+                /*
+                 * FIXME those are the defined Options that lack a decoder
+                 * you are welcome to contribute code ;-)
+                 */
+
+            default:
+                print_unknown_data(tptr,"\n\t  ",opli);
+                break;
+            }
+            if (vflag > 1)
+                print_unknown_data(pptr,"\n\t  ",opli);
+            pptr += opli;
+        }
 
         switch (clnp_pdu_type) {
 
-        case   CLNP_PDU_ER:
+        case    CLNP_PDU_ER: /* fall through */
+        case   CLNP_PDU_ERP:
+            TCHECK(*pptr);
+            if (*(pptr) == NLPID_CLNP) {
+                printf("\n\t-----original packet-----\n\t");
+                /* FIXME recursion protection */
+                clnp_print(pptr, length-clnp_header->length_indicator);
+                break;
+            } 
+
         case   CLNP_PDU_DT:
         case   CLNP_PDU_MD:
         case   CLNP_PDU_ERQ:
-        case   CLNP_PDU_ERP:
-
+            
         default:
             /* dump the PDU specific data */
-            print_unknown_data(optr+clnp_header->length_indicator,"\n\t  ",length-clnp_header->length_indicator);
-
+            if (length-(pptr-optr) > 0) {
+                printf("\n\t  undecoded non-header data, length %u",length-clnp_header->length_indicator);
+                print_unknown_data(pptr,"\n\t  ",length-(pptr-optr));
+            }
         }
 
         return (1);
+
+ trunc:
+    fputs("[|clnp]", stdout);
+    return (1);
+
 }
 
 
@@ -678,7 +863,7 @@ esis_print(const u_int8_t *pptr, u_int length)
        const struct esis_header_t *esis_header;
 
         if (!eflag)
-            printf("ES-IS");
+            printf("ES-IS");
 
        if (length <= 2) {
                if (qflag)
@@ -689,6 +874,7 @@ esis_print(const u_int8_t *pptr, u_int length)
        }
 
        esis_header = (const struct esis_header_t *) pptr;
+        TCHECK(*esis_header);
         li = esis_header->length_indicator;
         optr = pptr;
 
@@ -697,22 +883,22 @@ 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);
+            printf(" 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);
+            printf(" version %d packet not supported", esis_header->version);
             return;
         }
                 
        if (li > length) {
-            printf("length indicator(%d) > PDU size (%d)!", li, length);
+            printf(" length indicator(%d) > PDU size (%d)!", li, length);
             return;
        }
 
        if (li < sizeof(struct esis_header_t) + 2) {
-            printf("length indicator < min PDU size %d:", li);
+            printf(" length indicator < min PDU size %d:", li);
             while (--length != 0)
                 printf("%02X", *pptr++);
             return;
@@ -721,12 +907,14 @@ esis_print(const u_int8_t *pptr, u_int length)
         esis_pdu_type = esis_header->type & ESIS_PDU_TYPE_MASK;
 
         if (vflag < 1) {
-            printf("%s, length %u",
+            printf("%s%s, length %u",
+                   eflag ? "" : ", ",
                    tok2str(esis_pdu_values,"unknown type (%u)",esis_pdu_type),
                    length);
             return;
         } else
-            printf("length %u\n\t%s (%u)",
+            printf("%slength %u\n\t%s (%u)",
+                   eflag ? "" : ", ",
                    length,
                    tok2str(esis_pdu_values,"unknown type: %u", esis_pdu_type),
                    esis_pdu_type);
@@ -736,7 +924,8 @@ esis_print(const u_int8_t *pptr, u_int length)
         /* do not attempt to verify the checksum if it is zero */
         if (EXTRACT_16BITS(esis_header->cksum) == 0)
                 printf("(unverified)");
-            else printf("(%s)", osi_cksum(pptr, li) ? "incorrect" : "correct");
+        else
+                printf("(%s)", osi_cksum(pptr, li) ? "incorrect" : "correct");
 
         printf(", holding time: %us, length indicator: %u",EXTRACT_16BITS(esis_header->holdtime),li);
 
@@ -748,25 +937,72 @@ esis_print(const u_int8_t *pptr, u_int length)
 
        switch (esis_pdu_type) {
        case ESIS_PDU_REDIRECT: {
-               const u_int8_t *dst, *snpa, *tptr;
+               const u_int8_t *dst, *snpa, *neta;
+               u_int dstl, snpal, netal;
 
-               dst = pptr; pptr += *pptr + 1;
-               if (pptr > snapend)
+               TCHECK(*pptr);
+               if (li < 1) {
+                       printf(", bad redirect/li");
+                       return;
+               }
+               dstl = *pptr;
+               pptr++;
+               li--;
+               TCHECK2(*pptr, dstl);
+               if (li < dstl) {
+                       printf(", bad redirect/li");
+                       return;
+               }
+               dst = pptr;
+               pptr += dstl;
+                li -= dstl;
+               printf("\n\t  %s", isonsap_string(dst,dstl));
+
+               TCHECK(*pptr);
+               if (li < 1) {
+                       printf(", bad redirect/li");
+                       return;
+               }
+               snpal = *pptr;
+               pptr++;
+               li--;
+               TCHECK2(*pptr, snpal);
+               if (li < snpal) {
+                       printf(", bad redirect/li");
+                       return;
+               }
+               snpa = pptr;
+               pptr += snpal;
+                li -= snpal;
+               TCHECK(*pptr);
+               if (li < 1) {
+                       printf(", bad redirect/li");
                        return;
-               printf("\n\t  %s", isonsap_string(dst));
-               snpa = pptr; pptr += *pptr + 1;
-               tptr = pptr;   pptr += *pptr + 1;
-               if (pptr > snapend)
+               }
+               netal = *pptr;
+               pptr++;
+               TCHECK2(*pptr, netal);
+               if (li < netal) {
+                       printf(", bad redirect/li");
                        return;
+               }
+               neta = pptr;
+               pptr += netal;
+                li -= netal;
 
-               if (tptr[0] == 0)
-                       printf("\n\t  %s", etheraddr_string(&snpa[1]));
+               if (netal == 0)
+                       printf("\n\t  %s", etheraddr_string(snpa));
                else
-                       printf("\n\t  %s", isonsap_string(tptr));
+                       printf("\n\t  %s", isonsap_string(neta,netal));
                break;
        }
 
        case ESIS_PDU_ESH:
+            TCHECK(*pptr);
+            if (li < 1) {
+                printf(", bad esh/li");
+                return;
+            }
             source_address_number = *pptr;
             pptr++;
             li--;
@@ -774,23 +1010,47 @@ esis_print(const u_int8_t *pptr, u_int length)
             printf("\n\t  Number of Source Addresses: %u", source_address_number);
            
             while (source_address_number > 0) {
+                TCHECK(*pptr);
+               if (li < 1) {
+                    printf(", bad esh/li");
+                   return;
+               }
                 source_address_length = *pptr;
+                pptr++;
+               li--;
+
+                TCHECK2(*pptr, source_address_length);
+               if (li < source_address_length) {
+                    printf(", bad esh/li");
+                   return;
+               }
                 printf("\n\t  NET (length: %u): %s",
                        source_address_length,
-                       print_nsap(pptr+1, source_address_length));
-
-                pptr += source_address_length+1;
-                li -= source_address_length+1;
+                       isonsap_string(pptr,source_address_length));
+                pptr += source_address_length;
+                li -= source_address_length;
                 source_address_number--;
             }
 
             break;
 
        case ESIS_PDU_ISH: {
+            TCHECK(*pptr);
+            if (li < 1) {
+                printf(", bad ish/li");
+                return;
+            }
             source_address_length = *pptr;
-            printf("\n\t  NET (length: %u): %s", source_address_length, print_nsap(pptr+1, source_address_length));
-            pptr += source_address_length+1;
-            li -= source_address_length +1;
+            pptr++;
+            li--;
+            TCHECK2(*pptr, source_address_length);
+            if (li < source_address_length) {
+                printf(", bad ish/li");
+                return;
+            }
+            printf("\n\t  NET (length: %u): %s", source_address_length, isonsap_string(pptr, source_address_length));
+            pptr += source_address_length;
+            li -= source_address_length;
             break;
        }
 
@@ -807,8 +1067,7 @@ esis_print(const u_int8_t *pptr, u_int length)
             u_int op, opli;
             const u_int8_t *tptr;
             
-            if (snapend - pptr < 2)
-                return;
+            TCHECK2(*pptr, 2);
             if (li < 2) {
                 printf(", bad opts/li");
                 return;
@@ -823,9 +1082,6 @@ esis_print(const u_int8_t *pptr, u_int length)
             li -= opli;
             tptr = pptr;
             
-            if (snapend < pptr)
-                return;
-            
             printf("\n\t  %s Option #%u, length %u, value: ",
                    tok2str(esis_option_values,"Unknown",op),
                    op,
@@ -834,12 +1090,13 @@ esis_print(const u_int8_t *pptr, u_int length)
             switch (op) {
 
             case ESIS_OPTION_ES_CONF_TIME:
+                TCHECK2(*pptr, 2);
                 printf("%us", EXTRACT_16BITS(tptr));
                 break;
-                
 
             case ESIS_OPTION_PROTOCOLS:
                 while (opli>0) {
+                    TCHECK(*pptr);
                     printf("%s (0x%02x)",
                            tok2str(nlpid_values,
                                    "unknown",
@@ -871,6 +1128,8 @@ esis_print(const u_int8_t *pptr, u_int length)
                 print_unknown_data(pptr,"\n\t  ",opli);
             pptr += opli;
         }
+trunc:
+       return;
 }   
 
 /* shared routine for printing system, node and lsp-ids */
@@ -1373,7 +1632,7 @@ static int isis_print (const u_int8_t *p, u_int length)
     header_psnp = (const struct isis_psnp_header *)pptr;
 
     if (!eflag)
-        printf("IS-IS");
+        printf("IS-IS");
 
     /*
      * Sanity checking of the header.
@@ -1438,7 +1697,9 @@ static int isis_print (const u_int8_t *p, u_int length)
 
     /* in non-verbose mode print the basic PDU Type plus PDU specific brief information*/
     if (vflag < 1) {
-        printf("%s", tok2str(isis_pdu_values,"unknown PDU-Type %u",pdu_type));
+        printf("%s%s",
+               eflag ? "" : ", ",
+               tok2str(isis_pdu_values,"unknown PDU-Type %u",pdu_type));
 
        switch (pdu_type) {
 
@@ -1476,7 +1737,7 @@ static int isis_print (const u_int8_t *p, u_int length)
     }
 
     /* ok they seem to want to know everything - lets fully decode it */
-    printf(", length: %u",length);
+    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,
@@ -1718,6 +1979,9 @@ static int isis_print (const u_int8_t *p, u_int length)
                tlv_type,
                tlv_len);
 
+        if (tlv_len == 0) /* something is malformed */
+            break;
+
         /* now check if we have a decoder otherwise do a hexdump at the end*/
        switch (tlv_type) {
        case ISIS_TLV_AREA_ADDR:
@@ -1727,7 +1991,7 @@ static int isis_print (const u_int8_t *p, u_int length)
            while (tmp && alen < tmp) {
                printf("\n\t      Area address (length: %u): %s",
                        alen,
-                       print_nsap(tptr, alen));
+                       isonsap_string(tptr,alen));
                tptr += alen;
                tmp -= alen + 1;
                if (tmp==0) /* if this is the last area address do not attemt a boundary check */
@@ -1748,9 +2012,13 @@ static int isis_print (const u_int8_t *p, u_int length)
            break;
 
         case ISIS_TLV_ISNEIGH_VARLEN:
-            if (!TTEST2(*tptr, 1))
+            if (!TTEST2(*tptr, 1) || tmp < 3) /* min. TLV length */
                goto trunctlv;
-           lan_alen = *tptr++; /* LAN adress length */
+           lan_alen = *tptr++; /* LAN address length */
+           if (lan_alen == 0) {
+                printf("\n\t      LAN address length 0 bytes (invalid)");
+                break;
+            }
             tmp --;
             printf("\n\t      LAN address length %u bytes ",lan_alen);
            while (tmp >= lan_alen) {
@@ -2161,11 +2429,15 @@ static int isis_print (const u_int8_t *p, u_int length)
                 if (!TTEST2(*tptr, 1))
                     goto trunctlv;
                 prefix_len=*tptr++; /* read out prefix length in semioctets*/
+                if (prefix_len < 2) {
+                    printf("\n\t\tAddress: prefix length %u < 2", prefix_len);
+                    break;
+                }
                 tmp--;
                 if (!TTEST2(*tptr, prefix_len/2))
                     goto trunctlv;
                 printf("\n\t\tAddress: %s/%u",
-                       print_nsap(tptr,prefix_len/2),
+                       isonsap_string(tptr,prefix_len/2),
                        prefix_len*4);
                 tptr+=prefix_len/2;
                 tmp-=prefix_len/2;
@@ -2250,3 +2522,11 @@ osi_cksum(const u_int8_t *tptr, u_int len)
        }
        return (c0 | c1);
 }
+
+
+/*
+ * Local Variables:
+ * c-style: whitesmith
+ * c-basic-offset: 8
+ * End:
+ */