]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-cfm.c
CI: Add warning exemptions for Sun C (suncc-5.14) on Solaris 10
[tcpdump] / print-cfm.c
index 7f4360f0178901bac2d83bef18c32f6d0abcae00..84fd5d9406b5168288849628af354c2666e0dbfa 100644 (file)
  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE.
  *
- * Support for the IEEE Connectivity Fault Management Protocols as per 802.1ag.
- *
- * Original code by Hannes Gredler ([email protected])
+ * Original code by Hannes Gredler ([email protected])
  */
 
-#ifndef lint
-static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-cfm.c,v 1.1 2006-10-12 10:26:12 hannes Exp $";
-#endif
-
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+/* \summary: IEEE 802.1ag Connectivity Fault Management (CFM) protocols printer */
 
-#include <tcpdump-stdinc.h>
+#include <config.h>
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include "netdissect-stdinc.h"
 
-#include "interface.h"
+#include "netdissect.h"
 #include "extract.h"
-#include "ether.h"
 #include "addrtoname.h"
+#include "oui.h"
+#include "af.h"
+
 
 struct cfm_common_header_t {
-    u_int8_t mdlevel_version;
-    u_int8_t opcode;
-    u_int8_t flags;
-    u_int8_t first_tlv_offset;
+    nd_uint8_t mdlevel_version;
+    nd_uint8_t opcode;
+    nd_uint8_t flags;
+    nd_uint8_t first_tlv_offset;
 };
 
 #define        CFM_VERSION 0
-#define CFM_EXTRACT_VERSION(x) (((x)&0x1f))
+#define CFM_EXTRACT_VERSION(x) ((x)&0x1f)
 #define CFM_EXTRACT_MD_LEVEL(x) (((x)&0xe0)>>5)
 
 #define        CFM_OPCODE_CCM 1
@@ -55,7 +46,7 @@ struct cfm_common_header_t {
 #define        CFM_OPCODE_LTM 5
 
 static const struct tok cfm_opcode_values[] = {
-    { CFM_OPCODE_CCM, "Continouity Check Message"},
+    { CFM_OPCODE_CCM, "Continuity Check Message"},
     { CFM_OPCODE_LBR, "Loopback Reply"},
     { CFM_OPCODE_LBM, "Loopback Message"},
     { CFM_OPCODE_LTR, "Linktrace Reply"},
@@ -67,25 +58,22 @@ static const struct tok cfm_opcode_values[] = {
  * Message Formats.
  */
 struct cfm_ccm_t {
-    u_int8_t sequence[4];
-    u_int8_t ma_epi[2];
-    u_int8_t md_nameformat;
-    u_int8_t md_namelength;
-    u_int8_t md_name[46]; /* md name and short ma name */
-    u_int8_t reserved_itu[16];
-    u_int8_t reserved[6];
+    nd_uint32_t sequence;
+    nd_uint16_t ma_epi;
+    nd_byte     names[48];
+    nd_byte     itu_t_y_1731[16];
 };
 
 /*
  * Timer Bases for the CCM Interval field.
  * Expressed in units of seconds.
  */
-const float ccm_interval_base[8] = {0, 0.003333, 0.01, 0.1, 1, 10, 60, 600};
+static const float ccm_interval_base[8] = {0.0f, 0.003333f, 0.01f, 0.1f, 1.0f, 10.0f, 60.0f, 600.0f};
 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
 
 #define CFM_CCM_RDI_FLAG 0x80
-#define CFM_EXTRACT_CCM_INTERVAL(x) (((x)&0x07))
+#define CFM_EXTRACT_CCM_INTERVAL(x) ((x)&0x07)
 
 #define CFM_CCM_MD_FORMAT_8021 0
 #define CFM_CCM_MD_FORMAT_NONE 1
@@ -118,37 +106,42 @@ static const struct tok cfm_ma_nameformat_values[] = {
 };
 
 struct cfm_lbm_t {
-    u_int8_t transaction_id[4];
-    u_int8_t reserved[4];
+    nd_uint32_t transaction_id;
 };
 
 struct cfm_ltm_t {
-    u_int8_t transaction_id[4];
-    u_int8_t egress_id[8];
-    u_int8_t ttl;
-    u_int8_t original_mac[ETHER_ADDR_LEN];
-    u_int8_t target_mac[ETHER_ADDR_LEN];
-    u_int8_t reserved[3];
+    nd_uint32_t transaction_id;
+    nd_uint8_t  ttl;
+    nd_mac48 original_mac;
+    nd_mac48 target_mac;
+};
+
+static const struct tok cfm_ltm_flag_values[] = {
+    { 0x80, "Use Forwarding-DB only"},
+    { 0, NULL}
 };
 
 struct cfm_ltr_t {
-    u_int8_t transaction_id[4];
-    u_int8_t last_egress_id[8];
-    u_int8_t next_egress_id[8];
-    u_int8_t ttl;
-    u_int8_t replay_action;
-    u_int8_t reserved[6];
+    nd_uint32_t transaction_id;
+    nd_uint8_t  ttl;
+    nd_uint8_t  replay_action;
 };
 
-/*
- * TLVs
- */
+static const struct tok cfm_ltr_flag_values[] = {
+    { 0x80, "UseFDB Only"},
+    { 0x40, "FwdYes"},
+    { 0x20, "Terminal MEP"},
+    { 0, NULL}
+};
 
-struct cfm_tlv_header_t {
-    u_int8_t type;
-    u_int8_t length[2];
+static const struct tok cfm_ltr_replay_action_values[] = {
+    { 1, "Exact Match"},
+    { 2, "Filtering DB"},
+    { 3, "MIP CCM DB"},
+    { 0, NULL}
 };
 
+
 #define CFM_TLV_END 0
 #define CFM_TLV_SENDER_ID 1
 #define CFM_TLV_PORT_STATUS 2
@@ -170,15 +163,121 @@ static const struct tok cfm_tlv_values[] = {
     { 0, NULL}
 };
 
+/*
+ * TLVs
+ */
+
+struct cfm_tlv_header_t {
+    nd_uint8_t  type;
+    nd_uint16_t length;
+};
+
 /* FIXME define TLV formats */
 
-void
-cfm_print(register const u_char *pptr, register u_int length) {
+static const struct tok cfm_tlv_port_status_values[] = {
+    { 1, "Blocked"},
+    { 2, "Up"},
+    { 0, NULL}
+};
+
+static const struct tok cfm_tlv_interface_status_values[] = {
+    { 1, "Up"},
+    { 2, "Down"},
+    { 3, "Testing"},
+    { 5, "Dormant"},
+    { 6, "not present"},
+    { 7, "lower Layer down"},
+    { 0, NULL}
+};
 
+#define CFM_CHASSIS_ID_CHASSIS_COMPONENT 1
+#define CFM_CHASSIS_ID_INTERFACE_ALIAS 2
+#define CFM_CHASSIS_ID_PORT_COMPONENT 3
+#define CFM_CHASSIS_ID_MAC_ADDRESS 4
+#define CFM_CHASSIS_ID_NETWORK_ADDRESS 5
+#define CFM_CHASSIS_ID_INTERFACE_NAME 6
+#define CFM_CHASSIS_ID_LOCAL 7
+
+static const struct tok cfm_tlv_senderid_chassisid_values[] = {
+    { 0, "Reserved"},
+    { CFM_CHASSIS_ID_CHASSIS_COMPONENT, "Chassis component"},
+    { CFM_CHASSIS_ID_INTERFACE_ALIAS, "Interface alias"},
+    { CFM_CHASSIS_ID_PORT_COMPONENT, "Port component"},
+    { CFM_CHASSIS_ID_MAC_ADDRESS, "MAC address"},
+    { CFM_CHASSIS_ID_NETWORK_ADDRESS, "Network address"},
+    { CFM_CHASSIS_ID_INTERFACE_NAME, "Interface name"},
+    { CFM_CHASSIS_ID_LOCAL, "Locally assigned"},
+    { 0, NULL}
+};
+
+
+static int
+cfm_network_addr_print(netdissect_options *ndo,
+                       const u_char *tptr, const u_int length)
+{
+    u_int network_addr_type;
+    u_int hexdump =  FALSE;
+
+    /*
+     * Although AFIs are typically 2 octets wide,
+     * 802.1ab specifies that this field width
+     * is only one octet.
+     */
+    if (length < 1) {
+        ND_PRINT("\n\t  Network Address Type (invalid, no data");
+        return hexdump;
+    }
+    /* The calling function must make any due ND_TCHECK calls. */
+    network_addr_type = GET_U_1(tptr);
+    ND_PRINT("\n\t  Network Address Type %s (%u)",
+           tok2str(af_values, "Unknown", network_addr_type),
+           network_addr_type);
+
+    /*
+     * Resolve the passed in Address.
+     */
+    switch(network_addr_type) {
+    case AFNUM_IP:
+        if (length != 1 + 4) {
+            ND_PRINT("(invalid IPv4 address length %u)", length - 1);
+            hexdump = TRUE;
+            break;
+        }
+        ND_PRINT(", %s", GET_IPADDR_STRING(tptr + 1));
+        break;
+
+    case AFNUM_IP6:
+        if (length != 1 + 16) {
+            ND_PRINT("(invalid IPv6 address length %u)", length - 1);
+            hexdump = TRUE;
+            break;
+        }
+        ND_PRINT(", %s", GET_IP6ADDR_STRING(tptr + 1));
+        break;
+
+    default:
+        hexdump = TRUE;
+        break;
+    }
+
+    return hexdump;
+}
+
+void
+cfm_print(netdissect_options *ndo,
+          const u_char *pptr, u_int length)
+{
     const struct cfm_common_header_t *cfm_common_header;
+    uint8_t mdlevel_version, opcode, flags, first_tlv_offset;
     const struct cfm_tlv_header_t *cfm_tlv_header;
-    const u_int8_t *tptr, *tlv_tptr, *ma_name, *ma_nameformat, *ma_namelength;
-    u_int tlen, cfm_tlv_len, cfm_tlv_type, tlv_tlen, ccm_interval;
+    const uint8_t *tptr, *tlv_ptr;
+    const uint8_t *namesp;
+    u_int names_data_remaining;
+    uint8_t md_nameformat, md_namelength;
+    const uint8_t *md_name;
+    uint8_t ma_nameformat, ma_namelength;
+    const uint8_t *ma_name;
+    u_int hexdump, tlen, cfm_tlv_len, cfm_tlv_type, ccm_interval;
 
 
     union {
@@ -188,108 +287,170 @@ cfm_print(register const u_char *pptr, register u_int length) {
         const struct cfm_ltr_t *cfm_ltr;
     } msg_ptr;
 
+    ndo->ndo_protocol = "cfm";
     tptr=pptr;
     cfm_common_header = (const struct cfm_common_header_t *)pptr;
-    TCHECK(*cfm_common_header);
+    if (length < sizeof(*cfm_common_header))
+        goto tooshort;
+    ND_TCHECK_SIZE(cfm_common_header);
 
     /*
      * Sanity checking of the header.
      */
-    if (CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version) != CFM_VERSION) {
-       printf("CFMv%u not supported, length %u",
-               CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version), length);
+    mdlevel_version = GET_U_1(cfm_common_header->mdlevel_version);
+    if (CFM_EXTRACT_VERSION(mdlevel_version) != CFM_VERSION) {
+       ND_PRINT("CFMv%u not supported, length %u",
+               CFM_EXTRACT_VERSION(mdlevel_version), length);
        return;
     }
 
-    printf("CFMv%u %s, length %u",
-           CFM_EXTRACT_VERSION(cfm_common_header->mdlevel_version),
-           tok2str(cfm_opcode_values, "unknown (%u)", cfm_common_header->opcode),
+    opcode = GET_U_1(cfm_common_header->opcode);
+    ND_PRINT("CFMv%u %s, MD Level %u, length %u",
+           CFM_EXTRACT_VERSION(mdlevel_version),
+           tok2str(cfm_opcode_values, "unknown (%u)", opcode),
+           CFM_EXTRACT_MD_LEVEL(mdlevel_version),
            length);
 
     /*
-     * In non-verbose mode just lets print the opcode and bail.
+     * In non-verbose mode just print the opcode and md-level.
      */
-    if (vflag < 1) {
+    if (ndo->ndo_vflag < 1) {
         return;
     }
 
-    printf("\n\tMD Level %u, First TLV offset %u",
-           CFM_EXTRACT_MD_LEVEL(cfm_common_header->mdlevel_version),
-           cfm_common_header->first_tlv_offset);
+    flags = GET_U_1(cfm_common_header->flags);
+    first_tlv_offset = GET_U_1(cfm_common_header->first_tlv_offset);
+    ND_PRINT("\n\tFirst TLV offset %u", first_tlv_offset);
 
-    tptr += sizeof(const struct cfm_common_header_t);
+    tptr += sizeof(struct cfm_common_header_t);
     tlen = length - sizeof(struct cfm_common_header_t);
 
-    switch (cfm_common_header->opcode) {
+    /*
+     * Sanity check the first TLV offset.
+     */
+    if (first_tlv_offset > tlen) {
+        ND_PRINT(" (too large, must be <= %u)", tlen);
+        return;
+    }
+
+    switch (opcode) {
     case CFM_OPCODE_CCM:
         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;
+        if (first_tlv_offset < sizeof(*msg_ptr.cfm_ccm)) {
+            ND_PRINT(" (too small 1, must be >= %zu)",
+                     sizeof(*msg_ptr.cfm_ccm));
+            return;
+        }
+        if (tlen < sizeof(*msg_ptr.cfm_ccm))
+            goto tooshort;
+        ND_TCHECK_SIZE(msg_ptr.cfm_ccm);
 
-        ccm_interval = CFM_EXTRACT_CCM_INTERVAL(cfm_common_header->flags);
-        printf(", Flags [CCM Interval %u%s]",
+        ccm_interval = CFM_EXTRACT_CCM_INTERVAL(flags);
+        ND_PRINT(", Flags [CCM Interval %u%s]",
                ccm_interval,
-               cfm_common_header->flags & CFM_CCM_RDI_FLAG ?
+               flags & CFM_CCM_RDI_FLAG ?
                ", RDI" : "");
 
         /*
          * Resolve the CCM interval field.
          */
         if (ccm_interval) {
-            printf("\n\t  CCM Interval %.3fs"
+            ND_PRINT("\n\t  CCM Interval %.3fs"
                    ", min CCM Lifetime %.3fs, max CCM Lifetime %.3fs",
                    ccm_interval_base[ccm_interval],
                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MIN_MULTIPLIER,
                    ccm_interval_base[ccm_interval] * CCM_INTERVAL_MAX_MULTIPLIER);
         }
 
-        printf("\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
-               EXTRACT_32BITS(msg_ptr.cfm_ccm->sequence),
-               EXTRACT_16BITS(msg_ptr.cfm_ccm->ma_epi));
+        ND_PRINT("\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
+               GET_BE_U_4(msg_ptr.cfm_ccm->sequence),
+               GET_BE_U_2(msg_ptr.cfm_ccm->ma_epi));
 
+        namesp = msg_ptr.cfm_ccm->names;
+        names_data_remaining = sizeof(msg_ptr.cfm_ccm->names);
 
         /*
          * Resolve the MD fields.
          */
-        printf("\n\t  MD Name Format %s (%u), MD Name length %u",
-               tok2str(cfm_md_nameformat_values, "Unknown",
-                       msg_ptr.cfm_ccm->md_nameformat),
-               msg_ptr.cfm_ccm->md_nameformat,
-               msg_ptr.cfm_ccm->md_namelength);
-
-        if (msg_ptr.cfm_ccm->md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
-            printf("\n\t  MD Name: ");
-            switch (msg_ptr.cfm_ccm->md_nameformat) {
+        md_nameformat = GET_U_1(namesp);
+        namesp++;
+        names_data_remaining--;  /* We know this is != 0 */
+        if (md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
+            md_namelength = GET_U_1(namesp);
+            namesp++;
+            names_data_remaining--; /* We know this is !=0 */
+            ND_PRINT("\n\t  MD Name Format %s (%u), MD Name length %u",
+                   tok2str(cfm_md_nameformat_values, "Unknown",
+                           md_nameformat),
+                   md_nameformat,
+                   md_namelength);
+
+            /*
+             * -3 for the MA short name format and length and one byte
+             * of MA short name.
+             */
+            if (md_namelength > names_data_remaining - 3) {
+                ND_PRINT(" (too large, must be <= %u)", names_data_remaining - 2);
+                return;
+            }
+
+            md_name = namesp;
+            ND_PRINT("\n\t  MD Name: ");
+            switch (md_nameformat) {
             case CFM_CCM_MD_FORMAT_DNS:
             case CFM_CCM_MD_FORMAT_CHAR:
-                safeputs(msg_ptr.cfm_ccm->md_name, msg_ptr.cfm_ccm->md_namelength);
+                nd_printjnp(ndo, md_name, md_namelength);
+                break;
+
+            case CFM_CCM_MD_FORMAT_MAC:
+                if (md_namelength == MAC48_LEN) {
+                    ND_PRINT("\n\t  MAC %s", GET_MAC48_STRING(md_name));
+                } else {
+                    ND_PRINT("\n\t  MAC (length invalid)");
+                }
                 break;
 
                 /* FIXME add printers for those MD formats - hexdump for now */
             case CFM_CCM_MA_FORMAT_8021:
-            case CFM_CCM_MD_FORMAT_MAC:
             default:
-                print_unknown_data(msg_ptr.cfm_ccm->md_name, "\n\t    ",
-                                   msg_ptr.cfm_ccm->md_namelength);
+                print_unknown_data(ndo, md_name, "\n\t    ",
+                                   md_namelength);
             }
+            namesp += md_namelength;
+            names_data_remaining -= md_namelength;
+        } else {
+            ND_PRINT("\n\t  MD Name Format %s (%u)",
+                   tok2str(cfm_md_nameformat_values, "Unknown",
+                           md_nameformat),
+                   md_nameformat);
         }
 
 
         /*
          * Resolve the MA fields.
          */
-        ma_nameformat = msg_ptr.cfm_ccm->md_name + msg_ptr.cfm_ccm->md_namelength;
-        ma_namelength = msg_ptr.cfm_ccm->md_name + msg_ptr.cfm_ccm->md_namelength + 1;
-        ma_name = msg_ptr.cfm_ccm->md_name + msg_ptr.cfm_ccm->md_namelength + 2;
-
-        printf("\n\t  MA Name-Format %s (%u), MA name length %u",
+        ma_nameformat = GET_U_1(namesp);
+        namesp++;
+        names_data_remaining--; /* We know this is != 0 */
+        ma_namelength = GET_U_1(namesp);
+        namesp++;
+        names_data_remaining--; /* We know this is != 0 */
+        ND_PRINT("\n\t  MA Name-Format %s (%u), MA name length %u",
                tok2str(cfm_ma_nameformat_values, "Unknown",
-                       *ma_nameformat),
-               *ma_nameformat,
-               *ma_namelength);        
+                       ma_nameformat),
+               ma_nameformat,
+               ma_namelength);
 
-        printf("\n\t  MA Name: ");
-        switch (*ma_nameformat) {
+        if (ma_namelength > names_data_remaining) {
+            ND_PRINT(" (too large, must be <= %u)", names_data_remaining);
+            return;
+        }
+
+        ma_name = namesp;
+        ND_PRINT("\n\t  MA Name: ");
+        switch (ma_nameformat) {
         case CFM_CCM_MA_FORMAT_CHAR:
-            safeputs(ma_name, *ma_namelength);
+            nd_printjnp(ndo, ma_name, ma_namelength);
             break;
 
             /* FIXME add printers for those MA formats - hexdump for now */
@@ -298,8 +459,56 @@ cfm_print(register const u_char *pptr, register u_int length) {
         case CFM_CCM_MA_FORMAT_INT:
         case CFM_CCM_MA_FORMAT_VPN:
         default:
-            print_unknown_data(ma_name, "\n\t    ", *ma_namelength);
+            print_unknown_data(ndo, ma_name, "\n\t    ", ma_namelength);
+        }
+        break;
+
+    case CFM_OPCODE_LTM:
+        msg_ptr.cfm_ltm = (const struct cfm_ltm_t *)tptr;
+        if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltm)) {
+            ND_PRINT(" (too small 4, must be >= %zu)",
+                     sizeof(*msg_ptr.cfm_ltm));
+            return;
+        }
+        if (tlen < sizeof(*msg_ptr.cfm_ltm))
+            goto tooshort;
+        ND_TCHECK_SIZE(msg_ptr.cfm_ltm);
+
+        ND_PRINT(", Flags [%s]",
+               bittok2str(cfm_ltm_flag_values, "none", flags));
+
+        ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
+               GET_BE_U_4(msg_ptr.cfm_ltm->transaction_id),
+               GET_U_1(msg_ptr.cfm_ltm->ttl));
+
+        ND_PRINT("\n\t  Original-MAC %s, Target-MAC %s",
+               GET_MAC48_STRING(msg_ptr.cfm_ltm->original_mac),
+               GET_MAC48_STRING(msg_ptr.cfm_ltm->target_mac));
+        break;
+
+    case CFM_OPCODE_LTR:
+        msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;
+        if (first_tlv_offset < sizeof(*msg_ptr.cfm_ltr)) {
+            ND_PRINT(" (too small 5, must be >= %zu)",
+                     sizeof(*msg_ptr.cfm_ltr));
+            return;
         }
+        if (tlen < sizeof(*msg_ptr.cfm_ltr))
+            goto tooshort;
+        ND_TCHECK_SIZE(msg_ptr.cfm_ltr);
+
+        ND_PRINT(", Flags [%s]",
+               bittok2str(cfm_ltr_flag_values, "none", flags));
+
+        ND_PRINT("\n\t  Transaction-ID 0x%08x, ttl %u",
+               GET_BE_U_4(msg_ptr.cfm_ltr->transaction_id),
+               GET_U_1(msg_ptr.cfm_ltr->ttl));
+
+        ND_PRINT("\n\t  Replay-Action %s (%u)",
+               tok2str(cfm_ltr_replay_action_values,
+                       "Unknown",
+                       GET_U_1(msg_ptr.cfm_ltr->replay_action)),
+               GET_U_1(msg_ptr.cfm_ltr->replay_action));
         break;
 
         /*
@@ -308,82 +517,248 @@ cfm_print(register const u_char *pptr, register u_int length) {
          */
     case CFM_OPCODE_LBR:
     case CFM_OPCODE_LBM:
-    case CFM_OPCODE_LTR:
-    case CFM_OPCODE_LTM:
     default:
-        if (tlen > cfm_common_header->first_tlv_offset) {
-            print_unknown_data(tptr, "\n\t  ",
-                               tlen -  cfm_common_header->first_tlv_offset);
-        }
+        print_unknown_data(ndo, tptr, "\n\t  ",
+                           tlen -  first_tlv_offset);
         break;
     }
 
-    /*
-     * Sanity check for not walking off.
-     */
-    if (tlen <= cfm_common_header->first_tlv_offset) {
-        return;
-    }
-
-    tptr += cfm_common_header->first_tlv_offset;
-    tlen -= cfm_common_header->first_tlv_offset;
-    
-    while (tlen > 0) {
-        /* did we capture enough for fully decoding the object header ? */
-        TCHECK2(*tptr, sizeof(struct cfm_tlv_header_t));
+    tptr += first_tlv_offset;
+    tlen -= first_tlv_offset;
 
+    while (tlen != 0) {
         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
-        cfm_tlv_len=EXTRACT_16BITS(&cfm_tlv_header->length);
-        cfm_tlv_type=cfm_tlv_header->type;
 
-        if (cfm_tlv_len < sizeof(struct cfm_tlv_header_t) ||
-            cfm_tlv_len > tlen) {
-            print_unknown_data(tptr+sizeof(sizeof(struct cfm_tlv_header_t)),"\n\t    ",tlen);
+        /* Enough to read the tlv type ? */
+        cfm_tlv_type = GET_U_1(cfm_tlv_header->type);
+
+        ND_PRINT("\n\t%s TLV (0x%02x)",
+               tok2str(cfm_tlv_values, "Unknown", cfm_tlv_type),
+               cfm_tlv_type);
+
+        if (cfm_tlv_type == CFM_TLV_END) {
+            /* Length is "Not present if the Type field is 0." */
             return;
         }
 
-        printf("\n\t  %s TLV (0x%04x), length: %u",
-               tok2str(cfm_tlv_values,
-                       "Unknown",
-                       cfm_tlv_type),
-               cfm_tlv_type,
-               cfm_tlv_len);
+        /* do we have the full tlv header ? */
+        if (tlen < sizeof(struct cfm_tlv_header_t))
+            goto tooshort;
+        ND_TCHECK_LEN(tptr, sizeof(struct cfm_tlv_header_t));
+        cfm_tlv_len=GET_BE_U_2(cfm_tlv_header->length);
 
-        tlv_tptr=tptr+sizeof(struct cfm_tlv_header_t);
-        tlv_tlen=cfm_tlv_len-sizeof(struct cfm_tlv_header_t);
+        ND_PRINT(", length %u", cfm_tlv_len);
 
-        /* did we capture enough for fully decoding the object ? */
-        TCHECK2(*tptr, cfm_tlv_len);
+        tptr += sizeof(struct cfm_tlv_header_t);
+        tlen -= sizeof(struct cfm_tlv_header_t);
+        tlv_ptr = tptr;
+
+        /* do we have the full tlv ? */
+        if (tlen < cfm_tlv_len)
+            goto tooshort;
+        ND_TCHECK_LEN(tptr, cfm_tlv_len);
+        hexdump = FALSE;
 
         switch(cfm_tlv_type) {
+        case CFM_TLV_PORT_STATUS:
+            if (cfm_tlv_len < 1) {
+                ND_PRINT(" (too short, must be >= 1)");
+                return;
+            }
+            ND_PRINT(", Status: %s (%u)",
+                   tok2str(cfm_tlv_port_status_values, "Unknown", GET_U_1(tptr)),
+                   GET_U_1(tptr));
+            break;
+
+        case CFM_TLV_INTERFACE_STATUS:
+            if (cfm_tlv_len < 1) {
+                ND_PRINT(" (too short, must be >= 1)");
+                return;
+            }
+            ND_PRINT(", Status: %s (%u)",
+                   tok2str(cfm_tlv_interface_status_values, "Unknown", GET_U_1(tptr)),
+                   GET_U_1(tptr));
+            break;
+
+        case CFM_TLV_PRIVATE:
+            if (cfm_tlv_len < 4) {
+                ND_PRINT(" (too short, must be >= 4)");
+                return;
+            }
+            ND_PRINT(", Vendor: %s (%u), Sub-Type %u",
+                   tok2str(oui_values,"Unknown", GET_BE_U_3(tptr)),
+                   GET_BE_U_3(tptr),
+                   GET_U_1(tptr + 3));
+            hexdump = TRUE;
+            break;
+
+        case CFM_TLV_SENDER_ID:
+        {
+            u_int chassis_id_type, chassis_id_length;
+            u_int mgmt_addr_length;
+
+            if (cfm_tlv_len < 1) {
+                ND_PRINT(" (too short, must be >= 1)");
+                goto next_tlv;
+            }
+
+            /*
+             * Get the Chassis ID length and check it.
+             * IEEE 802.1Q-2014 Section 21.5.3.1
+             */
+            chassis_id_length = GET_U_1(tptr);
+            tptr++;
+            tlen--;
+            cfm_tlv_len--;
+
+            if (chassis_id_length) {
+                /*
+                 * IEEE 802.1Q-2014 Section 21.5.3.2: Chassis ID Subtype, references
+                 * IEEE 802.1AB-2005 Section 9.5.2.2, subsequently
+                 * IEEE 802.1AB-2016 Section 8.5.2.2: chassis ID subtype
+                 */
+                if (cfm_tlv_len < 1) {
+                    ND_PRINT("\n\t  (TLV too short)");
+                    goto next_tlv;
+                }
+                chassis_id_type = GET_U_1(tptr);
+                cfm_tlv_len--;
+                ND_PRINT("\n\t  Chassis-ID Type %s (%u), Chassis-ID length %u",
+                       tok2str(cfm_tlv_senderid_chassisid_values,
+                               "Unknown",
+                               chassis_id_type),
+                       chassis_id_type,
+                       chassis_id_length);
+
+                if (cfm_tlv_len < chassis_id_length) {
+                    ND_PRINT("\n\t  (TLV too short)");
+                    goto next_tlv;
+                }
+
+                /* IEEE 802.1Q-2014 Section 21.5.3.3: Chassis ID */
+                switch (chassis_id_type) {
+                case CFM_CHASSIS_ID_MAC_ADDRESS:
+                    if (chassis_id_length != MAC48_LEN) {
+                        ND_PRINT(" (invalid MAC address length)");
+                        hexdump = TRUE;
+                        break;
+                    }
+                    ND_PRINT("\n\t  MAC %s", GET_MAC48_STRING(tptr + 1));
+                    break;
+
+                case CFM_CHASSIS_ID_NETWORK_ADDRESS:
+                    hexdump |= cfm_network_addr_print(ndo, tptr + 1, chassis_id_length);
+                    break;
+
+                case CFM_CHASSIS_ID_INTERFACE_NAME: /* fall through */
+                case CFM_CHASSIS_ID_INTERFACE_ALIAS:
+                case CFM_CHASSIS_ID_LOCAL:
+                case CFM_CHASSIS_ID_CHASSIS_COMPONENT:
+                case CFM_CHASSIS_ID_PORT_COMPONENT:
+                    nd_printjnp(ndo, tptr + 1, chassis_id_length);
+                    break;
+
+                default:
+                    hexdump = TRUE;
+                    break;
+                }
+                cfm_tlv_len -= chassis_id_length;
+
+                tptr += 1 + chassis_id_length;
+                tlen -= 1 + chassis_id_length;
+            }
+
+            /*
+             * Check if there is a Management Address.
+             * IEEE 802.1Q-2014 Section 21.5.3.4: Management Address Domain Length
+             * This and all subsequent fields are not present if the TLV length
+             * allows only the above fields.
+             */
+            if (cfm_tlv_len == 0) {
+                /* No, there isn't; we're done. */
+                break;
+            }
+
+            /* Here mgmt_addr_length stands for the management domain length. */
+            mgmt_addr_length = GET_U_1(tptr);
+            tptr++;
+            tlen--;
+            cfm_tlv_len--;
+            ND_PRINT("\n\t  Management Address Domain Length %u", mgmt_addr_length);
+            if (mgmt_addr_length) {
+                /* IEEE 802.1Q-2014 Section 21.5.3.5: Management Address Domain */
+                if (cfm_tlv_len < mgmt_addr_length) {
+                    ND_PRINT("\n\t  (TLV too short)");
+                    goto next_tlv;
+                }
+                cfm_tlv_len -= mgmt_addr_length;
+                /*
+                 * XXX - this is an OID; print it as such.
+                 */
+                hex_print(ndo, "\n\t  Management Address Domain: ", tptr, mgmt_addr_length);
+                tptr += mgmt_addr_length;
+                tlen -= mgmt_addr_length;
+
+                /*
+                 * IEEE 802.1Q-2014 Section 21.5.3.6: Management Address Length
+                 * This field is present if Management Address Domain Length is not 0.
+                 */
+                if (cfm_tlv_len < 1) {
+                    ND_PRINT(" (Management Address Length is missing)");
+                    hexdump = TRUE;
+                    break;
+                }
+
+                /* Here mgmt_addr_length stands for the management address length. */
+                mgmt_addr_length = GET_U_1(tptr);
+                tptr++;
+                tlen--;
+                cfm_tlv_len--;
+                ND_PRINT("\n\t  Management Address Length %u", mgmt_addr_length);
+                if (mgmt_addr_length) {
+                    /* IEEE 802.1Q-2014 Section 21.5.3.7: Management Address */
+                    if (cfm_tlv_len < mgmt_addr_length) {
+                        ND_PRINT("\n\t  (TLV too short)");
+                        return;
+                    }
+                    cfm_tlv_len -= mgmt_addr_length;
+                    /*
+                     * XXX - this is a TransportDomain; print it as such.
+                     */
+                    hex_print(ndo, "\n\t  Management Address: ", tptr, mgmt_addr_length);
+                    tptr += mgmt_addr_length;
+                    tlen -= mgmt_addr_length;
+                }
+            }
+            break;
+        }
 
             /*
              * FIXME those are the defined TLVs that lack a decoder
              * you are welcome to contribute code ;-)
              */
 
-        case CFM_TLV_END:
-        case CFM_TLV_SENDER_ID:
-        case CFM_TLV_PORT_STATUS:
-        case CFM_TLV_INTERFACE_STATUS:
         case CFM_TLV_DATA:
         case CFM_TLV_REPLY_INGRESS:
         case CFM_TLV_REPLY_EGRESS:
-        case CFM_TLV_PRIVATE:
         default:
-            if (vflag <= 1)
-                print_unknown_data(tlv_tptr,"\n\t    ",tlv_tlen);
+            hexdump = TRUE;
             break;
         }
         /* do we want to see an additional hexdump ? */
-        if (vflag > 1)
-            print_unknown_data(tptr+sizeof(sizeof(struct cfm_tlv_header_t)),"\n\t    ",
-                               cfm_tlv_len-sizeof(struct cfm_tlv_header_t));
+        if (hexdump || ndo->ndo_vflag > 1)
+            print_unknown_data(ndo, tlv_ptr, "\n\t  ", cfm_tlv_len);
 
+next_tlv:
         tptr+=cfm_tlv_len;
         tlen-=cfm_tlv_len;
     }
     return;
+
+tooshort:
+    ND_PRINT("\n\t\t packet is too short");
+    return;
+
 trunc:
-    printf("\n\t\t packet exceeded snapshot");
+    nd_print_trunc(ndo);
 }