Use more the EXTRACT_U_1() macro (40/n)

[tcpdump] / print-cfm.c

diff --git a/print-cfm.c b/print-cfm.c
index a85eec09139ea45b1d2df9abfc5dd7af9ee7a2a8..2a2485e96d7d7f69fe1227a89ab31c0b583c2d0b 100644 (file)
--- a/print-cfm.c
+++ b/print-cfm.c
@@ -12,21 +12,20 @@
  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE.
  *
  * 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])

  */
 
  */
 

-#define NETDISSECT_REWORKED
+/* \summary: IEEE 802.1ag Connectivity Fault Management (CFM) protocols printer */
+

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 

-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>

 
 #include <stdio.h>
 
 
 #include <stdio.h>
 

-#include "interface.h"
+#include "netdissect.h"

 #include "extract.h"
 #include "ether.h"
 #include "addrtoname.h"
 #include "extract.h"
 #include "ether.h"
 #include "addrtoname.h"


@@ -51,7 +50,7 @@ struct cfm_common_header_t {
 #define        CFM_OPCODE_LTM 5
 
 static const struct tok cfm_opcode_values[] = {
 #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"},
     { CFM_OPCODE_LBR, "Loopback Reply"},
     { CFM_OPCODE_LBM, "Loopback Message"},
     { CFM_OPCODE_LTR, "Linktrace Reply"},


@@ -65,18 +64,15 @@ static const struct tok cfm_opcode_values[] = {
 struct cfm_ccm_t {
     uint8_t sequence[4];
     uint8_t ma_epi[2];
 struct cfm_ccm_t {
     uint8_t sequence[4];
     uint8_t ma_epi[2];

-    uint8_t md_nameformat;
-    uint8_t md_namelength;
-    uint8_t md_name[46]; /* md name and short ma name */
-    uint8_t reserved_itu[16];
-    uint8_t reserved[6];
+    uint8_t names[48];
+    uint8_t itu_t_y_1731[16];

 };
 
 /*
  * Timer Bases for the CCM Interval field.
  * Expressed in units of seconds.
  */
 };
 
 /*
  * 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, 0.003333, 0.01, 0.1, 1, 10, 60, 600};

 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
 
 #define CCM_INTERVAL_MIN_MULTIPLIER 3.25
 #define CCM_INTERVAL_MAX_MULTIPLIER 3.5
 


@@ -115,16 +111,13 @@ static const struct tok cfm_ma_nameformat_values[] = {
 
 struct cfm_lbm_t {
     uint8_t transaction_id[4];
 
 struct cfm_lbm_t {
     uint8_t transaction_id[4];

-    uint8_t reserved[4];

 };
 
 struct cfm_ltm_t {
     uint8_t transaction_id[4];
 };
 
 struct cfm_ltm_t {
     uint8_t transaction_id[4];

-    uint8_t egress_id[8];

     uint8_t ttl;
     uint8_t original_mac[ETHER_ADDR_LEN];
     uint8_t target_mac[ETHER_ADDR_LEN];
     uint8_t ttl;
     uint8_t original_mac[ETHER_ADDR_LEN];
     uint8_t target_mac[ETHER_ADDR_LEN];

-    uint8_t reserved[3];

 };
 
 static const struct tok cfm_ltm_flag_values[] = {
 };
 
 static const struct tok cfm_ltm_flag_values[] = {


@@ -134,11 +127,8 @@ static const struct tok cfm_ltm_flag_values[] = {
 
 struct cfm_ltr_t {
     uint8_t transaction_id[4];
 
 struct cfm_ltr_t {
     uint8_t transaction_id[4];

-    uint8_t last_egress_id[8];
-    uint8_t next_egress_id[8];

     uint8_t ttl;
     uint8_t replay_action;
     uint8_t ttl;
     uint8_t replay_action;

-    uint8_t reserved[6];

 };
 
 static const struct tok cfm_ltr_flag_values[] = {
 };
 
 static const struct tok cfm_ltr_flag_values[] = {


@@ -226,35 +216,48 @@ static const struct tok cfm_tlv_senderid_chassisid_values[] = {
 
 
 static int
 
 
 static int

-cfm_mgmt_addr_print(netdissect_options *ndo,
-                    register const u_char *tptr)
+cfm_network_addr_print(netdissect_options *ndo,
+                       register const u_char *tptr, const u_int length)

 {
 {

-    u_int mgmt_addr_type;
+    u_int network_addr_type;

     u_int hexdump =  FALSE;
 
     /*
     u_int hexdump =  FALSE;
 
     /*

-     * Altough AFIs are tpically 2 octects wide,
+     * Although AFIs are typically 2 octects wide,

      * 802.1ab specifies that this field width
      * 802.1ab specifies that this field width

-     * is only once octet
+     * is only one octet.

      */
      */

-    mgmt_addr_type = *tptr;
-    ND_PRINT((ndo, "\n\t  Management Address Type %s (%u)",
-           tok2str(af_values, "Unknown", mgmt_addr_type),
-           mgmt_addr_type));
+    if (length < 1) {
+        ND_PRINT((ndo, "\n\t  Network Address Type (invalid, no data"));
+        return hexdump;
+    }
+    /* The calling function must make any due ND_TCHECK calls. */
+    network_addr_type = EXTRACT_U_1(tptr);
+    ND_PRINT((ndo, "\n\t  Network Address Type %s (%u)",
+           tok2str(af_values, "Unknown", network_addr_type),
+           network_addr_type));

 
     /*
      * Resolve the passed in Address.
      */
 
     /*
      * Resolve the passed in Address.
      */

-    switch(mgmt_addr_type) {
+    switch(network_addr_type) {

     case AFNUM_INET:
     case AFNUM_INET:

+        if (length != 1 + 4) {
+            ND_PRINT((ndo, "(invalid IPv4 address length %u)", length - 1));
+            hexdump = TRUE;
+            break;
+        }

         ND_PRINT((ndo, ", %s", ipaddr_string(ndo, tptr + 1)));
         break;
 
         ND_PRINT((ndo, ", %s", ipaddr_string(ndo, tptr + 1)));
         break;
 

-#ifdef INET6

     case AFNUM_INET6:
     case AFNUM_INET6:

+        if (length != 1 + 16) {
+            ND_PRINT((ndo, "(invalid IPv6 address length %u)", length - 1));
+            hexdump = TRUE;
+            break;
+        }

         ND_PRINT((ndo, ", %s", ip6addr_string(ndo, tptr + 1)));
         break;
         ND_PRINT((ndo, ", %s", ip6addr_string(ndo, tptr + 1)));
         break;

-#endif

 
     default:
         hexdump = TRUE;
 
     default:
         hexdump = TRUE;


@@ -264,29 +267,19 @@ cfm_mgmt_addr_print(netdissect_options *ndo,
     return hexdump;
 }
 
     return hexdump;
 }
 

-/*
- * The egress-ID string is a 16-Bit string plus a MAC address.
- */
-static const char *
-cfm_egress_id_string(netdissect_options *ndo, register const u_char *tptr)
-{
-    static char egress_id_buffer[80];
-
-    snprintf(egress_id_buffer, sizeof(egress_id_buffer),
-             "MAC 0x%4x-%s",
-             EXTRACT_16BITS(tptr),
-             etheraddr_string(ndo, tptr+2));
-
-    return egress_id_buffer;
-}
-

 void
 cfm_print(netdissect_options *ndo,
           register const u_char *pptr, register u_int length)
 {
     const struct cfm_common_header_t *cfm_common_header;
     const struct cfm_tlv_header_t *cfm_tlv_header;
 void
 cfm_print(netdissect_options *ndo,
           register const u_char *pptr, register u_int length)
 {
     const struct cfm_common_header_t *cfm_common_header;
     const struct cfm_tlv_header_t *cfm_tlv_header;

-    const uint8_t *tptr, *tlv_ptr, *ma_name, *ma_nameformat, *ma_namelength;
+    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;
 
 
     u_int hexdump, tlen, cfm_tlv_len, cfm_tlv_type, ccm_interval;
 
 


@@ -299,6 +292,8 @@ cfm_print(netdissect_options *ndo,
 
     tptr=pptr;
     cfm_common_header = (const struct cfm_common_header_t *)pptr;
 
     tptr=pptr;
     cfm_common_header = (const struct cfm_common_header_t *)pptr;

+    if (length < sizeof(*cfm_common_header))
+        goto tooshort;

     ND_TCHECK(*cfm_common_header);
 
     /*
     ND_TCHECK(*cfm_common_header);
 
     /*


@@ -325,12 +320,28 @@ cfm_print(netdissect_options *ndo,
 
     ND_PRINT((ndo, "\n\tFirst TLV offset %u", cfm_common_header->first_tlv_offset));
 
 
     ND_PRINT((ndo, "\n\tFirst TLV offset %u", cfm_common_header->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);
 
     tlen = length - sizeof(struct cfm_common_header_t);
 

+    /*
+     * Sanity check the first TLV offset.
+     */
+    if (cfm_common_header->first_tlv_offset > tlen) {
+        ND_PRINT((ndo, " (too large, must be <= %u)", tlen));
+        return;
+    }
+

     switch (cfm_common_header->opcode) {
     case CFM_OPCODE_CCM:
         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;
     switch (cfm_common_header->opcode) {
     case CFM_OPCODE_CCM:
         msg_ptr.cfm_ccm = (const struct cfm_ccm_t *)tptr;

+        if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ccm)) {
+            ND_PRINT((ndo, " (too small 1, must be >= %lu)",
+                     (unsigned long) sizeof(*msg_ptr.cfm_ccm)));
+            return;
+        }
+        if (tlen < sizeof(*msg_ptr.cfm_ccm))
+            goto tooshort;
+        ND_TCHECK(*msg_ptr.cfm_ccm);

 
         ccm_interval = CFM_EXTRACT_CCM_INTERVAL(cfm_common_header->flags);
         ND_PRINT((ndo, ", Flags [CCM Interval %u%s]",
 
         ccm_interval = CFM_EXTRACT_CCM_INTERVAL(cfm_common_header->flags);
         ND_PRINT((ndo, ", Flags [CCM Interval %u%s]",


@@ -350,58 +361,95 @@ cfm_print(netdissect_options *ndo,
         }
 
         ND_PRINT((ndo, "\n\t  Sequence Number 0x%08x, MA-End-Point-ID 0x%04x",
         }
 
         ND_PRINT((ndo, "\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)));
+               EXTRACT_BE_U_4(msg_ptr.cfm_ccm->sequence),
+               EXTRACT_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.
          */
 
         /*
          * Resolve the MD fields.
          */

-        ND_PRINT((ndo, "\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));
+        md_nameformat = *namesp;
+        namesp++;
+        names_data_remaining--;  /* We know this is != 0 */
+        if (md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
+            md_namelength = *namesp;
+            namesp++;
+            names_data_remaining--; /* We know this is !=0 */
+            ND_PRINT((ndo, "\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((ndo, " (too large, must be <= %u)", names_data_remaining - 2));
+                return;
+            }

 
 

-        if (msg_ptr.cfm_ccm->md_nameformat != CFM_CCM_MD_FORMAT_NONE) {
+            md_name = namesp;

             ND_PRINT((ndo, "\n\t  MD Name: "));
             ND_PRINT((ndo, "\n\t  MD Name: "));

-            switch (msg_ptr.cfm_ccm->md_nameformat) {
+            switch (md_nameformat) {

             case CFM_CCM_MD_FORMAT_DNS:
             case CFM_CCM_MD_FORMAT_CHAR:
             case CFM_CCM_MD_FORMAT_DNS:
             case CFM_CCM_MD_FORMAT_CHAR:

-                safeputs(ndo, msg_ptr.cfm_ccm->md_name, msg_ptr.cfm_ccm->md_namelength);
+                safeputs(ndo, md_name, md_namelength);

                 break;
 
             case CFM_CCM_MD_FORMAT_MAC:
                 break;
 
             case CFM_CCM_MD_FORMAT_MAC:

-                ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo,
-                           msg_ptr.cfm_ccm->md_name)));
+                if (md_namelength == 6) {
+                    ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo,
+                               md_name)));
+                } else {
+                    ND_PRINT((ndo, "\n\t  MAC (length invalid)"));
+                }

                 break;
 
                 /* FIXME add printers for those MD formats - hexdump for now */
             case CFM_CCM_MA_FORMAT_8021:
             default:
                 break;
 
                 /* FIXME add printers for those MD formats - hexdump for now */
             case CFM_CCM_MA_FORMAT_8021:
             default:

-                print_unknown_data(ndo, 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((ndo, "\n\t  MD Name Format %s (%u)",
+                   tok2str(cfm_md_nameformat_values, "Unknown",
+                           md_nameformat),
+                   md_nameformat));

         }
 
 
         /*
          * Resolve the MA fields.
          */
         }
 
 
         /*
          * 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;
-
+        ma_nameformat = *namesp;
+        namesp++;
+        names_data_remaining--; /* We know this is != 0 */
+        ma_namelength = *namesp;
+        namesp++;
+        names_data_remaining--; /* We know this is != 0 */

         ND_PRINT((ndo, "\n\t  MA Name-Format %s (%u), MA name length %u",
                tok2str(cfm_ma_nameformat_values, "Unknown",
         ND_PRINT((ndo, "\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));

 
 

+        if (ma_namelength > names_data_remaining) {
+            ND_PRINT((ndo, " (too large, must be <= %u)", names_data_remaining));
+            return;
+        }
+
+        ma_name = namesp;

         ND_PRINT((ndo, "\n\t  MA Name: "));
         ND_PRINT((ndo, "\n\t  MA Name: "));

-        switch (*ma_nameformat) {
+        switch (ma_nameformat) {

         case CFM_CCM_MA_FORMAT_CHAR:
         case CFM_CCM_MA_FORMAT_CHAR:

-            safeputs(ndo, ma_name, *ma_namelength);
+            safeputs(ndo, ma_name, ma_namelength);

             break;
 
             /* FIXME add printers for those MA formats - hexdump for now */
             break;
 
             /* FIXME add printers for those MA formats - hexdump for now */


@@ -410,19 +458,26 @@ cfm_print(netdissect_options *ndo,
         case CFM_CCM_MA_FORMAT_INT:
         case CFM_CCM_MA_FORMAT_VPN:
         default:
         case CFM_CCM_MA_FORMAT_INT:
         case CFM_CCM_MA_FORMAT_VPN:
         default:

-            print_unknown_data(ndo, 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;
         }
         break;
 
     case CFM_OPCODE_LTM:
         msg_ptr.cfm_ltm = (const struct cfm_ltm_t *)tptr;

+        if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ltm)) {
+            ND_PRINT((ndo, " (too small 4, must be >= %lu)",
+                     (unsigned long) sizeof(*msg_ptr.cfm_ltm)));
+            return;
+        }
+        if (tlen < sizeof(*msg_ptr.cfm_ltm))
+            goto tooshort;
+        ND_TCHECK(*msg_ptr.cfm_ltm);

 
         ND_PRINT((ndo, ", Flags [%s]",
                bittok2str(cfm_ltm_flag_values, "none", cfm_common_header->flags)));
 
 
         ND_PRINT((ndo, ", Flags [%s]",
                bittok2str(cfm_ltm_flag_values, "none", cfm_common_header->flags)));
 

-        ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, Egress-ID %s, ttl %u",
-               EXTRACT_32BITS(msg_ptr.cfm_ltm->transaction_id),
-               cfm_egress_id_string(ndo, msg_ptr.cfm_ltm->egress_id),
+        ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, ttl %u",
+               EXTRACT_BE_U_4(msg_ptr.cfm_ltm->transaction_id),

                msg_ptr.cfm_ltm->ttl));
 
         ND_PRINT((ndo, "\n\t  Original-MAC %s, Target-MAC %s",
                msg_ptr.cfm_ltm->ttl));
 
         ND_PRINT((ndo, "\n\t  Original-MAC %s, Target-MAC %s",


@@ -432,16 +487,20 @@ cfm_print(netdissect_options *ndo,
 
     case CFM_OPCODE_LTR:
         msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;
 
     case CFM_OPCODE_LTR:
         msg_ptr.cfm_ltr = (const struct cfm_ltr_t *)tptr;

+        if (cfm_common_header->first_tlv_offset < sizeof(*msg_ptr.cfm_ltr)) {
+            ND_PRINT((ndo, " (too small 5, must be >= %lu)",
+                     (unsigned long) sizeof(*msg_ptr.cfm_ltr)));
+            return;
+        }
+        if (tlen < sizeof(*msg_ptr.cfm_ltr))
+            goto tooshort;
+        ND_TCHECK(*msg_ptr.cfm_ltr);

 
         ND_PRINT((ndo, ", Flags [%s]",
                bittok2str(cfm_ltr_flag_values, "none", cfm_common_header->flags)));
 
 
         ND_PRINT((ndo, ", Flags [%s]",
                bittok2str(cfm_ltr_flag_values, "none", cfm_common_header->flags)));
 

-        ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, Last-Egress-ID %s",
-               EXTRACT_32BITS(msg_ptr.cfm_ltr->transaction_id),
-               cfm_egress_id_string(ndo, msg_ptr.cfm_ltr->last_egress_id)));
-
-        ND_PRINT((ndo, "\n\t  Next-Egress-ID %s, ttl %u",
-               cfm_egress_id_string(ndo, msg_ptr.cfm_ltr->next_egress_id),
+        ND_PRINT((ndo, "\n\t  Transaction-ID 0x%08x, ttl %u",
+               EXTRACT_BE_U_4(msg_ptr.cfm_ltr->transaction_id),

                msg_ptr.cfm_ltr->ttl));
 
         ND_PRINT((ndo, "\n\t  Replay-Action %s (%u)",
                msg_ptr.cfm_ltr->ttl));
 
         ND_PRINT((ndo, "\n\t  Replay-Action %s (%u)",


@@ -458,20 +517,11 @@ cfm_print(netdissect_options *ndo,
     case CFM_OPCODE_LBR:
     case CFM_OPCODE_LBM:
     default:
     case CFM_OPCODE_LBR:
     case CFM_OPCODE_LBM:
     default:

-        if (tlen > cfm_common_header->first_tlv_offset) {
-            print_unknown_data(ndo, tptr, "\n\t  ",
-                               tlen -  cfm_common_header->first_tlv_offset);
-        }
+        print_unknown_data(ndo, tptr, "\n\t  ",
+                           tlen -  cfm_common_header->first_tlv_offset);

         break;
     }
 
         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;
 
     tptr += cfm_common_header->first_tlv_offset;
     tlen -= cfm_common_header->first_tlv_offset;
 


@@ -479,62 +529,66 @@ cfm_print(netdissect_options *ndo,
         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
 
         /* Enough to read the tlv type ? */
         cfm_tlv_header = (const struct cfm_tlv_header_t *)tptr;
 
         /* Enough to read the tlv type ? */

-        ND_TCHECK2(*tptr, 1);
+        ND_TCHECK_1(tptr);

         cfm_tlv_type=cfm_tlv_header->type;
 
         cfm_tlv_type=cfm_tlv_header->type;
 

-        if (cfm_tlv_type != CFM_TLV_END) {
-            /* did we capture enough for fully decoding the object header ? */
-            ND_TCHECK2(*tptr, sizeof(struct cfm_tlv_header_t));
-            cfm_tlv_len=EXTRACT_16BITS(&cfm_tlv_header->length);
-        } else {
-            cfm_tlv_len = 0;
-        }
-
-        ND_PRINT((ndo, "\n\t%s TLV (0x%02x), length %u",
+        ND_PRINT((ndo, "\n\t%s TLV (0x%02x)",

                tok2str(cfm_tlv_values, "Unknown", cfm_tlv_type),
                tok2str(cfm_tlv_values, "Unknown", cfm_tlv_type),

-               cfm_tlv_type,
-               cfm_tlv_len));
-
-        /* sanity check for not walking off and infinite loop check. */
-        if ((cfm_tlv_type != CFM_TLV_END) &&
-            ((cfm_tlv_len + sizeof(struct cfm_tlv_header_t) > tlen) ||
-             (!cfm_tlv_len))) {
-            print_unknown_data(ndo, tptr, "\n\t  ", tlen);
+               cfm_tlv_type));
+
+        if (cfm_tlv_type == CFM_TLV_END) {
+            /* Length is "Not present if the Type field is 0." */

             return;
         }
 
             return;
         }
 

+        /* do we have the full tlv header ? */
+        if (tlen < sizeof(struct cfm_tlv_header_t))
+            goto tooshort;
+        ND_TCHECK2(*tptr, sizeof(struct cfm_tlv_header_t));
+        cfm_tlv_len=EXTRACT_BE_U_2(&cfm_tlv_header->length);
+
+        ND_PRINT((ndo, ", length %u", cfm_tlv_len));
+

         tptr += sizeof(struct cfm_tlv_header_t);
         tlen -= sizeof(struct cfm_tlv_header_t);
         tlv_ptr = tptr;
 
         tptr += sizeof(struct cfm_tlv_header_t);
         tlen -= sizeof(struct cfm_tlv_header_t);
         tlv_ptr = tptr;
 

-        /* did we capture enough for fully decoding the object ? */
-        if (cfm_tlv_type != CFM_TLV_END) {
-            ND_TCHECK2(*tptr, cfm_tlv_len);
-        }
+        /* do we have the full tlv ? */
+        if (tlen < cfm_tlv_len)
+            goto tooshort;
+        ND_TCHECK2(*tptr, cfm_tlv_len);

         hexdump = FALSE;
 
         switch(cfm_tlv_type) {
         hexdump = FALSE;
 
         switch(cfm_tlv_type) {

-        case CFM_TLV_END:
-            /* we are done - bail out */
-            return;
-

         case CFM_TLV_PORT_STATUS:
         case CFM_TLV_PORT_STATUS:

+            if (cfm_tlv_len < 1) {
+                ND_PRINT((ndo, " (too short, must be >= 1)"));
+                return;
+            }

             ND_PRINT((ndo, ", Status: %s (%u)",
             ND_PRINT((ndo, ", Status: %s (%u)",

-                   tok2str(cfm_tlv_port_status_values, "Unknown", *tptr),
-                   *tptr));
+                   tok2str(cfm_tlv_port_status_values, "Unknown", EXTRACT_U_1(tptr)),
+                   EXTRACT_U_1(tptr)));

             break;
 
         case CFM_TLV_INTERFACE_STATUS:
             break;
 
         case CFM_TLV_INTERFACE_STATUS:

+            if (cfm_tlv_len < 1) {
+                ND_PRINT((ndo, " (too short, must be >= 1)"));
+                return;
+            }

             ND_PRINT((ndo, ", Status: %s (%u)",
             ND_PRINT((ndo, ", Status: %s (%u)",

-                   tok2str(cfm_tlv_interface_status_values, "Unknown", *tptr),
-                   *tptr));
+                   tok2str(cfm_tlv_interface_status_values, "Unknown", EXTRACT_U_1(tptr)),
+                   EXTRACT_U_1(tptr)));

             break;
 
         case CFM_TLV_PRIVATE:
             break;
 
         case CFM_TLV_PRIVATE:

+            if (cfm_tlv_len < 4) {
+                ND_PRINT((ndo, " (too short, must be >= 4)"));
+                return;
+            }

             ND_PRINT((ndo, ", Vendor: %s (%u), Sub-Type %u",
             ND_PRINT((ndo, ", Vendor: %s (%u), Sub-Type %u",

-                   tok2str(oui_values,"Unknown", EXTRACT_24BITS(tptr)),
-                   EXTRACT_24BITS(tptr),
-                   *(tptr + 3)));
+                   tok2str(oui_values,"Unknown", EXTRACT_BE_U_3(tptr)),
+                   EXTRACT_BE_U_3(tptr),
+                   EXTRACT_U_1(tptr + 3)));

             hexdump = TRUE;
             break;
 
             hexdump = TRUE;
             break;
 


@@ -543,20 +597,32 @@ cfm_print(netdissect_options *ndo,
             u_int chassis_id_type, chassis_id_length;
             u_int mgmt_addr_length;
 
             u_int chassis_id_type, chassis_id_length;
             u_int mgmt_addr_length;
 

-            /*
-             * Check if there is a Chassis-ID.
-             */
-            chassis_id_length = *tptr;
-            if (chassis_id_length > tlen) {
-                hexdump = TRUE;
-                break;
+            if (cfm_tlv_len < 1) {
+                ND_PRINT((ndo, " (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 = EXTRACT_U_1(tptr);

             tptr++;
             tlen--;
             tptr++;
             tlen--;

+            cfm_tlv_len--;

 
             if (chassis_id_length) {
 
             if (chassis_id_length) {

-                chassis_id_type = *tptr;
+                /*
+                 * 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((ndo, "\n\t  (TLV too short)"));
+                    goto next_tlv;
+                }
+                chassis_id_type = EXTRACT_U_1(tptr);
+                cfm_tlv_len--;

                 ND_PRINT((ndo, "\n\t  Chassis-ID Type %s (%u), Chassis-ID length %u",
                        tok2str(cfm_tlv_senderid_chassisid_values,
                                "Unknown",
                 ND_PRINT((ndo, "\n\t  Chassis-ID Type %s (%u), Chassis-ID length %u",
                        tok2str(cfm_tlv_senderid_chassisid_values,
                                "Unknown",


@@ -564,13 +630,24 @@ cfm_print(netdissect_options *ndo,
                        chassis_id_type,
                        chassis_id_length));
 
                        chassis_id_type,
                        chassis_id_length));
 

+                if (cfm_tlv_len < chassis_id_length) {
+                    ND_PRINT((ndo, "\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:
                 switch (chassis_id_type) {
                 case CFM_CHASSIS_ID_MAC_ADDRESS:

+                    if (chassis_id_length != ETHER_ADDR_LEN) {
+                        ND_PRINT((ndo, " (invalid MAC address length)"));
+                        hexdump = TRUE;
+                        break;
+                    }

                     ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo, tptr + 1)));
                     break;
 
                 case CFM_CHASSIS_ID_NETWORK_ADDRESS:
                     ND_PRINT((ndo, "\n\t  MAC %s", etheraddr_string(ndo, tptr + 1)));
                     break;
 
                 case CFM_CHASSIS_ID_NETWORK_ADDRESS:

-                    hexdump |= cfm_mgmt_addr_print(ndo, tptr);
+                    hexdump |= cfm_network_addr_print(ndo, tptr + 1, chassis_id_length);

                     break;
 
                 case CFM_CHASSIS_ID_INTERFACE_NAME: /* fall through */
                     break;
 
                 case CFM_CHASSIS_ID_INTERFACE_NAME: /* fall through */


@@ -585,32 +662,76 @@ cfm_print(netdissect_options *ndo,
                     hexdump = TRUE;
                     break;
                 }
                     hexdump = TRUE;
                     break;
                 }

-            }
+                cfm_tlv_len -= chassis_id_length;

 
 

-            tptr += chassis_id_length;
-            tlen -= chassis_id_length;
+                tptr += 1 + chassis_id_length;
+                tlen -= 1 + chassis_id_length;
+            }

 
             /*
              * Check if there is a Management Address.
 
             /*
              * 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.

              */
              */

-            mgmt_addr_length = *tptr;
-            if (mgmt_addr_length > tlen) {
-                hexdump = TRUE;
+            if (cfm_tlv_len == 0) {
+                /* No, there isn't; we're done. */

                 break;
             }
 
                 break;
             }
 

+            /* Here mgmt_addr_length stands for the management domain length. */
+            mgmt_addr_length = EXTRACT_U_1(tptr);

             tptr++;
             tlen--;
             tptr++;
             tlen--;

-
+            cfm_tlv_len--;
+            ND_PRINT((ndo, "\n\t  Management Address Domain Length %u", mgmt_addr_length));

             if (mgmt_addr_length) {
             if (mgmt_addr_length) {

-                hexdump |= cfm_mgmt_addr_print(ndo, tptr);
-            }
-
-            tptr += mgmt_addr_length;
-            tlen -= mgmt_addr_length;
+                /* IEEE 802.1Q-2014 Section 21.5.3.5: Management Address Domain */
+                if (cfm_tlv_len < mgmt_addr_length) {
+                    ND_PRINT((ndo, "\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((ndo, " (Management Address Length is missing)"));
+                    hexdump = TRUE;
+                    break;
+                }

 
 

+                /* Here mgmt_addr_length stands for the management address length. */
+                mgmt_addr_length = EXTRACT_U_1(tptr);
+                tptr++;
+                tlen--;
+                cfm_tlv_len--;
+                ND_PRINT((ndo, "\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((ndo, "\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;

         }
         }

-        break;

 
             /*
              * FIXME those are the defined TLVs that lack a decoder
 
             /*
              * FIXME those are the defined TLVs that lack a decoder


@@ -628,10 +749,16 @@ cfm_print(netdissect_options *ndo,
         if (hexdump || ndo->ndo_vflag > 1)
             print_unknown_data(ndo, tlv_ptr, "\n\t  ", cfm_tlv_len);
 
         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;
         tptr+=cfm_tlv_len;
         tlen-=cfm_tlv_len;
     }
     return;

+
+tooshort:
+    ND_PRINT((ndo, "\n\t\t packet is too short"));
+    return;
+

 trunc:
     ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
 }
 trunc:
     ND_PRINT((ndo, "\n\t\t packet exceeded snapshot"));
 }