Based on Guy's suggestion from the user mailing list, dissect Ethernet frames with a type/len field in the range of 1501-1535 as invalid, and add an expert info to make it that much easier to find such invalid frames.

Also did some whitespace cleanup, converting tabs to spaces since most of the file was spaced, not tabbed, and swapped the order that the lg and ig bits get added to the tree because I think it looks better reading bits left-to-right.

TODO: I'm not entirely sure what to do in capture_eth() if that invalid range is encountered, so for now I just added some #if 0'd code as a placeholder.

Ref: http://www.wireshark.org/lists/wireshark-users/201106/msg00127.html



git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@37832 f5534014-38df-0310-8fa8-9805f1628bb7

1 files changed, 348 insertions, 295 deletions

diff --git a/epan/dissectors/packet-eth.c b/epan/dissectors/packet-eth.c
index 19fa69c5b0..8eb737d4be 100644
--- a/epan/dissectors/packet-eth.c
+++ b/epan/dissectors/packet-eth.c
@@ -64,17 +64,20 @@ static int hf_eth_vlan_pri = -1;
 static int hf_eth_vlan_cfi = -1;
 static int hf_eth_vlan_id = -1;
 static int hf_eth_type = -1;
+static int hf_eth_invalid_lentype = -1;
 static int hf_eth_addr = -1;
-static int hf_eth_ig = -1;
 static int hf_eth_lg = -1;
+static int hf_eth_ig = -1;
 static int hf_eth_trailer = -1;
 
 static gint ett_ieee8023 = -1;
 static gint ett_ether2 = -1;
+static gint ett_ether = -1;
 static gint ett_addr = -1;
 static gint ett_tag = -1;
 
 static dissector_handle_t fw1_handle;
+static dissector_handle_t data_handle;
 static heur_dissector_list_t heur_subdissector_list;
 static heur_dissector_list_t eth_trailer_subdissector_list;
 
@@ -82,15 +85,15 @@ static int eth_tap = -1;
 
 /* From Table G-2 of IEEE standard 802.1D-2004 */
 static const value_string pri_vals[] = {
-	{ 1, "Background"                        },
-	{ 2, "Spare"                             },
-	{ 0, "Best Effort (default)"             },
-	{ 3, "Excellent Effort"                  },
-	{ 4, "Controlled Load"                   },
-	{ 5, "Video, < 100ms latency and jitter" },
-	{ 6, "Voice, < 10ms latency and jitter"  },
-	{ 7, "Network Control"                   },
-	{ 0, NULL                                }
+    { 1, "Background"                        },
+    { 2, "Spare"                             },
+    { 0, "Best Effort (default)"             },
+    { 3, "Excellent Effort"                  },
+    { 4, "Controlled Load"                   },
+    { 5, "Video, < 100ms latency and jitter" },
+    { 6, "Voice, < 10ms latency and jitter"  },
+    { 7, "Network Control"                   },
+    { 0, NULL                                }
 };
 
 static const value_string cfi_vals[] = {
@@ -99,36 +102,36 @@ static const value_string cfi_vals[] = {
   { 0, NULL            }
 };
 
-#define ETH_HEADER_SIZE	14
+#define ETH_HEADER_SIZE    14
 
 static const true_false_string ig_tfs = {
-	"Group address (multicast/broadcast)",
-	"Individual address (unicast)"
+    "Group address (multicast/broadcast)",
+    "Individual address (unicast)"
 };
 static const true_false_string lg_tfs = {
-	"Locally administered address (this is NOT the factory default)",
-	"Globally unique address (factory default)"
+    "Locally administered address (this is NOT the factory default)",
+    "Globally unique address (factory default)"
 };
 
 /* These are the Netware-ish names for the different Ethernet frame types.
-	EthernetII: The ethernet with a Type field instead of a length field
-	Ethernet802.2: An 802.3 header followed by an 802.2 header
-	Ethernet802.3: A raw 802.3 packet. IPX/SPX can be the only payload.
-			There's no 802.2 hdr in this.
-	EthernetSNAP: Basically 802.2, just with 802.2SNAP. For our purposes,
-		there's no difference between 802.2 and 802.2SNAP, since we just
-		pass it down to the LLC dissector. -- Gilbert
+    EthernetII: The ethernet with a Type field instead of a length field
+    Ethernet802.2: An 802.3 header followed by an 802.2 header
+    Ethernet802.3: A raw 802.3 packet. IPX/SPX can be the only payload.
+            There's no 802.2 hdr in this.
+    EthernetSNAP: Basically 802.2, just with 802.2SNAP. For our purposes,
+        there's no difference between 802.2 and 802.2SNAP, since we just
+        pass it down to the LLC dissector. -- Gilbert
 */
-#define ETHERNET_II 	0
-#define ETHERNET_802_2	1
-#define ETHERNET_802_3	2
-#define ETHERNET_SNAP	3
+#define ETHERNET_II     0
+#define ETHERNET_802_2  1
+#define ETHERNET_802_3  2
+#define ETHERNET_SNAP   3
 
 void
 capture_eth(const guchar *pd, int offset, int len, packet_counts *ld)
 {
-  guint16    etype, length;
-  int     ethhdr_type;	/* the type of ethernet frame */
+  guint16 etype, length;
+  int ethhdr_type;          /* the type of ethernet frame */
 
   if (!BYTES_ARE_IN_FRAME(offset, len, ETH_HEADER_SIZE)) {
     ld->other++;
@@ -144,7 +147,7 @@ capture_eth(const guchar *pd, int offset, int len, packet_counts *ld)
        01-00-0C-00-00 or 0C-00-0C-00-00 for ISL frames. */
     if ((pd[offset] == 0x01 || pd[offset] == 0x0C) && pd[offset+1] == 0x00
         && pd[offset+2] == 0x0C && pd[offset+3] == 0x00
-	&& pd[offset+4] == 0x00) {
+        && pd[offset+4] == 0x00) {
       capture_isl(pd, offset, len, ld);
       return;
     }
@@ -157,15 +160,24 @@ capture_eth(const guchar *pd, int offset, int len, packet_counts *ld)
    * 802.2 LLC header, or it might be a frame with an 802.2 LLC
    * header.
    *
-   * If the type/length field is > the maximum 802.3 length,
+   * If the type/length field is >= the minimum Ethernet II length,
    * this is an Ethernet II frame, and it's a type field.
    *
+   * If the type/length field is > maximum 802.3 length and < minimum
+   * Ethernet II length, then this is an invalid packet.
+   *
    * If the type/length field is zero (ETHERTYPE_UNK), this is
    * a frame used internally by the Cisco MDS switch to contain
    * Fibre Channel ("Vegas").  We treat that as an Ethernet II
    * frame; the dissector for those frames registers itself with
    * an ethernet type of ETHERTYPE_UNK.
    */
+#if 0 /* TODO */
+  if (etype > IEEE_802_3_MAX_LEN && etype < ETHERNET_II_MIN_LEN) {
+    return;
+  }
+#endif
+
   if (etype <= IEEE_802_3_MAX_LEN && etype != ETHERTYPE_UNK) {
     length = etype;
 
@@ -212,22 +224,22 @@ static gboolean check_is_802_2(tvbuff_t *tvb, int fcs_len);
 
 static void
 dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
-	int fcs_len)
+    int fcs_len)
 {
-  proto_item		*ti = NULL, *tag_item;
-  eth_hdr 		*ehdr;
-  gboolean		is_802_2;
-  proto_tree		*fh_tree = NULL;
-  const guint8		*src_addr, *dst_addr;
-  static eth_hdr 	ehdrs[4];
-  static int		ehdr_num=0;
-  proto_tree		*tree;
-  proto_item		*addr_item;
-  proto_tree		*addr_tree=NULL;
-  proto_tree            *tag_tree;
-  gint                  offset;
-  guint8                tag_pri;
-  guint16               tag_vlan_id;
+  proto_item        *ti = NULL, *tag_item;
+  eth_hdr           *ehdr;
+  gboolean          is_802_2;
+  proto_tree        *fh_tree = NULL;
+  const guint8      *src_addr, *dst_addr;
+  static eth_hdr    ehdrs[4];
+  static int        ehdr_num=0;
+  proto_tree        *tree;
+  proto_item        *addr_item;
+  proto_tree        *addr_tree=NULL;
+  proto_tree        *tag_tree;
+  gint              offset;
+  guint8            tag_pri;
+  guint16           tag_vlan_id;
 
   ehdr_num++;
   if(ehdr_num>=4){
@@ -240,13 +252,13 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
   col_set_str(pinfo->cinfo, COL_PROTOCOL, "Ethernet");
 
   src_addr=tvb_get_ptr(tvb, 6, 6);
-  SET_ADDRESS(&pinfo->dl_src,	AT_ETHER, 6, src_addr);
-  SET_ADDRESS(&pinfo->src,	AT_ETHER, 6, src_addr);
-  SET_ADDRESS(&ehdr->src, 	AT_ETHER, 6, src_addr);
+  SET_ADDRESS(&pinfo->dl_src, AT_ETHER, 6, src_addr);
+  SET_ADDRESS(&pinfo->src, AT_ETHER, 6, src_addr);
+  SET_ADDRESS(&ehdr->src, AT_ETHER, 6, src_addr);
   dst_addr=tvb_get_ptr(tvb, 0, 6);
-  SET_ADDRESS(&pinfo->dl_dst,	AT_ETHER, 6, dst_addr);
-  SET_ADDRESS(&pinfo->dst,	AT_ETHER, 6, dst_addr);
-  SET_ADDRESS(&ehdr->dst, 	AT_ETHER, 6, dst_addr);
+  SET_ADDRESS(&pinfo->dl_dst, AT_ETHER, 6, dst_addr);
+  SET_ADDRESS(&pinfo->dst, AT_ETHER, 6, dst_addr);
+  SET_ADDRESS(&ehdr->dst, AT_ETHER, 6, dst_addr);
 
   ehdr->type = tvb_get_ntohs(tvb, 12);
 
@@ -266,12 +278,12 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
        destination address field; fortunately, they can be recognized by
        checking the first 5 octets of the destination address, which are
        01-00-0C-00-00 for ISL frames. */
-    if (	(tvb_get_guint8(tvb, 0) == 0x01 ||
-		 tvb_get_guint8(tvb, 0) == 0x0C) &&
-		tvb_get_guint8(tvb, 1) == 0x00 &&
-		tvb_get_guint8(tvb, 2) == 0x0C &&
-		tvb_get_guint8(tvb, 3) == 0x00 &&
-		tvb_get_guint8(tvb, 4) == 0x00 ) {
+    if ((tvb_get_guint8(tvb, 0) == 0x01 ||
+      tvb_get_guint8(tvb, 0) == 0x0C) &&
+      tvb_get_guint8(tvb, 1) == 0x00 &&
+      tvb_get_guint8(tvb, 2) == 0x0C &&
+      tvb_get_guint8(tvb, 3) == 0x00 &&
+      tvb_get_guint8(tvb, 4) == 0x00) {
       dissect_isl(tvb, pinfo, parent_tree, fcs_len);
       return;
     }
@@ -284,24 +296,60 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
    * 802.2 LLC header, or it might be a frame with an 802.2 LLC
    * header.
    *
-   * If the type/length field is > the maximum 802.3 length,
+   * If the type/length field is >= the minimum Ethernet II length,
    * this is an Ethernet II frame, and it's a type field.
    *
+   * If the type/length field is > maximum 802.3 length and < minimum
+   * Ethernet II length, then this is an invalid packet.
+   *
    * If the type/length field is zero (ETHERTYPE_UNK), this is
    * a frame used internally by the Cisco MDS switch to contain
    * Fibre Channel ("Vegas").  We treat that as an Ethernet II
    * frame; the dissector for those frames registers itself with
    * an ethernet type of ETHERTYPE_UNK.
    */
+  if (ehdr->type > IEEE_802_3_MAX_LEN && ehdr->type < ETHERNET_II_MIN_LEN) {
+    tvbuff_t *next_tvb;
+
+    col_add_fstr(pinfo->cinfo, COL_INFO,
+        "Ethernet Unknown: Invalid length/type: 0x%04x (%d)",
+        ehdr->type, ehdr->type);
+    ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
+        "Ethernet Unknown, Src: %s (%s), Dst: %s (%s)",
+        get_ether_name(src_addr), ether_to_str(src_addr),
+        get_ether_name(dst_addr), ether_to_str(dst_addr));
+    fh_tree = proto_item_add_subtree(ti, ett_ether);
+    addr_item = proto_tree_add_ether(fh_tree, hf_eth_dst, tvb, 0, 6, dst_addr);
+    if (addr_item)
+        addr_tree = proto_item_add_subtree(addr_item, ett_addr);
+    proto_tree_add_ether(addr_tree, hf_eth_addr, tvb, 0, 6, dst_addr);
+    proto_tree_add_item(addr_tree, hf_eth_lg, tvb, 0, 3, FALSE);
+    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 0, 3, FALSE);
+
+    addr_item = proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src_addr);
+    if (addr_item)
+        addr_tree = proto_item_add_subtree(addr_item, ett_addr);
+    proto_tree_add_ether(addr_tree, hf_eth_addr, tvb, 6, 6, src_addr);
+    proto_tree_add_item(addr_tree, hf_eth_lg, tvb, 6, 3, FALSE);
+    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 6, 3, FALSE);
+
+    ti = proto_tree_add_item(fh_tree, hf_eth_invalid_lentype, tvb, 12, 2, FALSE);
+    expert_add_info_format(pinfo, ti, PI_PROTOCOL, PI_WARN,
+        "Invalid length/type: 0x%04x (%d)", ehdr->type, ehdr->type);
+    next_tvb = tvb_new_subset_remaining(tvb, 14);
+    call_dissector(data_handle, next_tvb, pinfo, parent_tree);
+    return;
+  }
+
   if (ehdr->type <= IEEE_802_3_MAX_LEN && ehdr->type != ETHERTYPE_UNK) {
 
     is_802_2 = check_is_802_2(tvb, fcs_len);
 
      col_add_fstr(pinfo->cinfo, COL_INFO, "IEEE 802.3 Ethernet %s",
-		(is_802_2 ? "" : "Raw "));
+        (is_802_2 ? "" : "Raw "));
     if (tree) {
       ti = proto_tree_add_protocol_format(tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
-		"IEEE 802.3 Ethernet %s", (is_802_2 ? "" : "Raw "));
+        "IEEE 802.3 Ethernet %s", (is_802_2 ? "" : "Raw "));
 
       fh_tree = proto_item_add_subtree(ti, ett_ieee8023);
     }
@@ -320,26 +368,26 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
         addr_tree = proto_item_add_subtree(addr_item, ett_addr);
     }
     proto_tree_add_ether(addr_tree, hf_eth_addr, tvb, 0, 6, dst_addr);
-    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 0, 3, FALSE);
     proto_tree_add_item(addr_tree, hf_eth_lg, tvb, 0, 3, FALSE);
+    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 0, 3, FALSE);
 
     addr_item=proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src_addr);
     if(addr_item){
         addr_tree = proto_item_add_subtree(addr_item, ett_addr);
     }
     proto_tree_add_ether(addr_tree, hf_eth_addr, tvb, 6, 6, src_addr);
-    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 6, 3, FALSE);
     proto_tree_add_item(addr_tree, hf_eth_lg, tvb, 6, 3, FALSE);
+    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 6, 3, FALSE);
 
-    dissect_802_3(ehdr->type, is_802_2, tvb, ETH_HEADER_SIZE, pinfo, parent_tree, fh_tree,
-		  hf_eth_len, hf_eth_trailer, fcs_len);
+    dissect_802_3(ehdr->type, is_802_2, tvb, ETH_HEADER_SIZE, pinfo,
+        parent_tree, fh_tree, hf_eth_len, hf_eth_trailer, fcs_len);
   } else {
     if (eth_interpret_as_fw1_monitor) {
-	if ((dst_addr[0] == 'i') || (dst_addr[0] == 'I') ||
-	    (dst_addr[0] == 'o') || (dst_addr[0] == 'O')) {
-	  call_dissector(fw1_handle, tvb, pinfo, parent_tree);
-	  return;
-	}
+        if ((dst_addr[0] == 'i') || (dst_addr[0] == 'I') ||
+            (dst_addr[0] == 'o') || (dst_addr[0] == 'O')) {
+            call_dissector(fw1_handle, tvb, pinfo, parent_tree);
+            return;
+        }
     }
 
     col_set_str(pinfo->cinfo, COL_INFO, "Ethernet II");
@@ -347,14 +395,15 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
       col_append_str(pinfo->cinfo, COL_INFO, " (VLAN tagged)");
 
     if (parent_tree) {
-      if (PTREE_DATA(parent_tree)->visible) {
-          ti = proto_tree_add_protocol_format(parent_tree, proto_eth, tvb, 0, ETH_HEADER_SIZE,
-		"Ethernet II%s, Src: %s (%s), Dst: %s (%s)",
-		(ehdr->type == ETHERTYPE_VLAN || ehdr->type == q_in_q_ethertype) ? " (VLAN tagged)" : "",
-		get_ether_name(src_addr), ether_to_str(src_addr), get_ether_name(dst_addr), ether_to_str(dst_addr));
+        if (PTREE_DATA(parent_tree)->visible) {
+            ti = proto_tree_add_protocol_format(parent_tree, proto_eth, tvb, 0,
+                ETH_HEADER_SIZE, "Ethernet II%s, Src: %s (%s), Dst: %s (%s)",
+                (ehdr->type == ETHERTYPE_VLAN || ehdr->type == q_in_q_ethertype) ? " (VLAN tagged)" : "",
+                get_ether_name(src_addr), ether_to_str(src_addr),
+                get_ether_name(dst_addr), ether_to_str(dst_addr));
       }
       else {
-	    ti = proto_tree_add_item(parent_tree, proto_eth, tvb, 0, ETH_HEADER_SIZE, FALSE);
+            ti = proto_tree_add_item(parent_tree, proto_eth, tvb, 0, ETH_HEADER_SIZE, FALSE);
       }
       fh_tree = proto_item_add_subtree(ti, ett_ether2);
     }
@@ -364,8 +413,8 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
         addr_tree = proto_item_add_subtree(addr_item, ett_addr);
     }
     proto_tree_add_ether(addr_tree, hf_eth_addr, tvb, 0, 6, dst_addr);
-    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 0, 3, FALSE);
     proto_tree_add_item(addr_tree, hf_eth_lg, tvb, 0, 3, FALSE);
+    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 0, 3, FALSE);
 
     addr_item=proto_tree_add_ether(fh_tree, hf_eth_src, tvb, 6, 6, src_addr);
     if(addr_item){
@@ -376,8 +425,8 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
         }
     }
     proto_tree_add_ether(addr_tree, hf_eth_addr, tvb, 6, 6, src_addr);
-    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 6, 3, FALSE);
     proto_tree_add_item(addr_tree, hf_eth_lg, tvb, 6, 3, FALSE);
+    proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 6, 3, FALSE);
 
     offset = 12;
     while(ehdr->type == ETHERTYPE_VLAN || ehdr->type == q_in_q_ethertype) {
@@ -385,7 +434,7 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
       tag_tree = proto_item_add_subtree(tag_item, ett_tag);
 
       proto_tree_add_item(tag_tree, hf_eth_vlan_tpid, tvb, offset, 2, FALSE);
-      offset += 2; 
+      offset += 2;
 
       proto_tree_add_item(tag_tree, hf_eth_vlan_pri, tvb, offset, 2, FALSE);
       tag_pri = tvb_get_guint8(tvb, offset) >> 5;
@@ -396,7 +445,7 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
       tag_vlan_id = tvb_get_ntohs(tvb, offset) & 0x0FFF;
 
       proto_item_append_text(tag_item, "VLAN=%u, Priority=%s", tag_vlan_id,
-			     val_to_str(tag_pri, pri_vals, "Unknown"));
+        val_to_str(tag_pri, pri_vals, "Unknown"));
 
       if(check_col(pinfo->cinfo, COL_8021Q_VLAN_ID))
         col_add_fstr(pinfo->cinfo, COL_8021Q_VLAN_ID, "%u", tag_vlan_id);
@@ -437,10 +486,10 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
 /* -------------- */
 static gboolean check_is_802_2(tvbuff_t *tvb, int fcs_len)
 {
-  volatile gboolean	is_802_2;
+  volatile gboolean is_802_2;
   volatile int length;
   gint captured_length, reported_length;
-  
+
   is_802_2 = TRUE;
 
     /* Is there an 802.2 layer? I can tell by looking at the first 2
@@ -450,63 +499,63 @@ static gboolean check_is_802_2(tvbuff_t *tvb, int fcs_len)
        layer inside the 802.3 layer */
 
   TRY {
-	if (tvb_get_ntohs(tvb, 14) == 0xffff) {
-	    is_802_2 = FALSE;
-	}
-	/* Is this a CCSDS payload instead of an 802.2 (LLC)?
-	   Check the conditions enabled by the user for CCSDS presence */
-	else if (ccsds_heuristic_length || ccsds_heuristic_version ||
-	         ccsds_heuristic_header || ccsds_heuristic_bit) {
-	  gboolean CCSDS_len = TRUE;
-	  gboolean CCSDS_ver = TRUE;
-	  gboolean CCSDS_head = TRUE;
-	  gboolean CCSDS_bit = TRUE;
-	  /* See if the reported payload size matches the
-	     size contained in the CCSDS header. */
-	  if (ccsds_heuristic_length) {
-	    /* The following technique to account for FCS
-	       is copied from packet-ieee8023.c dissect_802_3() */
-	    length = tvb_get_ntohs(tvb, 12);
-	    reported_length = tvb_reported_length_remaining(tvb, ETH_HEADER_SIZE);
-	    if (fcs_len > 0) {
-		  if (reported_length >= fcs_len)
-		    reported_length -= fcs_len;
-		}
-		/* Make sure the length in the 802.3 header doesn't go past the end of
-		   the payload. */
-		if (length > reported_length) {
-		  length = reported_length;
-		}
-		/* Only allow inspection of 'length' number of bytes. */
-		captured_length = tvb_length_remaining(tvb, ETH_HEADER_SIZE);
-		if (captured_length > length)
-		  captured_length = length;
-		  
-	    /* Check if payload is large enough to contain a CCSDS header */
-	    if (captured_length >= 6) {
-	      /* Compare length to packet length contained in CCSDS header. */
-	      if (length != 7 + tvb_get_ntohs(tvb, ETH_HEADER_SIZE + 4))
-	        CCSDS_len = FALSE;
-	    }
-	  }
-	  /* Check if CCSDS Version number (first 3 bits of payload) is zero */
-	  if ((ccsds_heuristic_version) && (tvb_get_bits8(tvb, 8*ETH_HEADER_SIZE, 3)!=0))
-	    CCSDS_ver = FALSE;
-	  /* Check if Secondary Header Flag (4th bit of payload) is set to one. */
-	  if ((ccsds_heuristic_header) && (tvb_get_bits8(tvb, 8*ETH_HEADER_SIZE + 4, 1)!=1))
-	    CCSDS_head = FALSE;
-	  /* Check if spare bit (1st bit of 7th word of payload) is zero. */
-	  if ((ccsds_heuristic_bit) && (tvb_get_bits8(tvb, 8*ETH_HEADER_SIZE + 16*6, 1)!=0))
-	    CCSDS_bit = FALSE;
-	  /* If all the conditions are true, don't interpret payload as an 802.2 (LLC).
-	   * Additional check in packet-802.3.c will distinguish between
-	   * IPX and CCSDS packets*/
-	  if (CCSDS_len && CCSDS_ver && CCSDS_head && CCSDS_bit)
-	    is_802_2 = FALSE;
-	}
+    if (tvb_get_ntohs(tvb, 14) == 0xffff) {
+        is_802_2 = FALSE;
+    }
+    /* Is this a CCSDS payload instead of an 802.2 (LLC)?
+       Check the conditions enabled by the user for CCSDS presence */
+    else if (ccsds_heuristic_length || ccsds_heuristic_version ||
+             ccsds_heuristic_header || ccsds_heuristic_bit) {
+      gboolean CCSDS_len = TRUE;
+      gboolean CCSDS_ver = TRUE;
+      gboolean CCSDS_head = TRUE;
+      gboolean CCSDS_bit = TRUE;
+      /* See if the reported payload size matches the
+         size contained in the CCSDS header. */
+      if (ccsds_heuristic_length) {
+        /* The following technique to account for FCS
+           is copied from packet-ieee8023.c dissect_802_3() */
+        length = tvb_get_ntohs(tvb, 12);
+        reported_length = tvb_reported_length_remaining(tvb, ETH_HEADER_SIZE);
+        if (fcs_len > 0) {
+          if (reported_length >= fcs_len)
+            reported_length -= fcs_len;
+        }
+        /* Make sure the length in the 802.3 header doesn't go past the end of
+           the payload. */
+        if (length > reported_length) {
+          length = reported_length;
+        }
+        /* Only allow inspection of 'length' number of bytes. */
+        captured_length = tvb_length_remaining(tvb, ETH_HEADER_SIZE);
+        if (captured_length > length)
+          captured_length = length;
+
+        /* Check if payload is large enough to contain a CCSDS header */
+        if (captured_length >= 6) {
+          /* Compare length to packet length contained in CCSDS header. */
+          if (length != 7 + tvb_get_ntohs(tvb, ETH_HEADER_SIZE + 4))
+            CCSDS_len = FALSE;
+        }
+      }
+      /* Check if CCSDS Version number (first 3 bits of payload) is zero */
+      if ((ccsds_heuristic_version) && (tvb_get_bits8(tvb, 8*ETH_HEADER_SIZE, 3)!=0))
+        CCSDS_ver = FALSE;
+      /* Check if Secondary Header Flag (4th bit of payload) is set to one. */
+      if ((ccsds_heuristic_header) && (tvb_get_bits8(tvb, 8*ETH_HEADER_SIZE + 4, 1)!=1))
+        CCSDS_head = FALSE;
+      /* Check if spare bit (1st bit of 7th word of payload) is zero. */
+      if ((ccsds_heuristic_bit) && (tvb_get_bits8(tvb, 8*ETH_HEADER_SIZE + 16*6, 1)!=0))
+        CCSDS_bit = FALSE;
+      /* If all the conditions are true, don't interpret payload as an 802.2 (LLC).
+       * Additional check in packet-802.3.c will distinguish between
+       * IPX and CCSDS packets*/
+      if (CCSDS_len && CCSDS_ver && CCSDS_head && CCSDS_bit)
+        is_802_2 = FALSE;
+    }
   }
   CATCH2(BoundsError, ReportedBoundsError) {
-	    ; /* do nothing */
+        ; /* do nothing */
 
   }
   ENDTRY;
@@ -523,8 +572,8 @@ static gboolean check_is_802_2(tvbuff_t *tvb, int fcs_len)
  * it does, maybe it doesn't"), we try to infer whether it has an FCS.
  */
 void
-add_ethernet_trailer(packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree, int trailer_id,
-		     tvbuff_t *tvb, tvbuff_t *trailer_tvb, int fcs_len)
+add_ethernet_trailer(packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
+    int trailer_id, tvbuff_t *tvb, tvbuff_t *trailer_tvb, int fcs_len)
 {
   /* If there're some bytes left over, show those bytes as a trailer.
 
@@ -537,7 +586,7 @@ add_ethernet_trailer(packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
     gboolean has_fcs = FALSE;
 
     if (dissector_try_heuristic(eth_trailer_subdissector_list, trailer_tvb,
-		pinfo, tree)) {
+        pinfo, tree)) {
       return;
     }
 
@@ -551,52 +600,51 @@ add_ethernet_trailer(packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
          enough space in the trailer for the FCS, we assume we
          have an FCS.
 
-	 "Big enough" means 64 bytes or more; any frame that big
-	 needs no trailer, as there's no need to pad an Ethernet
-	 packet past 60 bytes.
+         "Big enough" means 64 bytes or more; any frame that big
+         needs no trailer, as there's no need to pad an Ethernet
+         packet past 60 bytes.
 
-	 The trailer must be at least 4 bytes long to have enough
-	 space for an FCS. */
+         The trailer must be at least 4 bytes long to have enough
+         space for an FCS. */
 
       if (fcs_len == 4 || (tvb_reported_length(tvb) >= 64 &&
-			   trailer_reported_length >= 4)) {
-	/* Either we know we have an FCS, or we believe we have an FCS. */
-	if (trailer_length < trailer_reported_length) {
-	  /* The packet is claimed to have enough data for a 4-byte FCS,
-	     but we didn't capture all of the packet.
-	     Slice off the 4-byte FCS from the reported length, and
-	     trim the captured length so it's no more than the reported
-	     length; that will slice off what of the FCS, if any, is
-	     in the captured packet. */
-	  trailer_reported_length -= 4;
-	  if (trailer_length > trailer_reported_length)
-	    trailer_length = trailer_reported_length;
-	  has_fcs = TRUE;
-	} else {
-	  /* We captured all of the packet, including what appears to
-	     be a 4-byte FCS.  Slice it off. */
-	  trailer_length -= 4;
-	  trailer_reported_length -= 4;
-	  has_fcs = TRUE;
-	}
+        trailer_reported_length >= 4)) {
+        /* Either we know we have an FCS, or we believe we have an FCS. */
+        if (trailer_length < trailer_reported_length) {
+          /* The packet is claimed to have enough data for a 4-byte FCS,
+             but we didn't capture all of the packet.
+             Slice off the 4-byte FCS from the reported length, and
+             trim the captured length so it's no more than the reported
+             length; that will slice off what of the FCS, if any, is
+             in the captured packet. */
+          trailer_reported_length -= 4;
+          if (trailer_length > trailer_reported_length)
+            trailer_length = trailer_reported_length;
+          has_fcs = TRUE;
+        } else {
+          /* We captured all of the packet, including what appears to
+             be a 4-byte FCS.  Slice it off. */
+          trailer_length -= 4;
+          trailer_reported_length -= 4;
+          has_fcs = TRUE;
+        }
       }
     }
     if (trailer_length != 0) {
       tvb_ensure_bytes_exist(tvb, 0, trailer_length);
       proto_tree_add_item(fh_tree, trailer_id, trailer_tvb, 0,
-			  trailer_length, FALSE);
+        trailer_length, FALSE);
     }
     if (has_fcs) {
       guint32 sent_fcs = tvb_get_ntohl(trailer_tvb, trailer_length);
       guint32 fcs = crc32_802_tvb(tvb, tvb_length(tvb) - 4);
       if (fcs == sent_fcs) {
-	proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
-			    "Frame check sequence: 0x%08x [correct]",
-			    sent_fcs);
+        proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
+          "Frame check sequence: 0x%08x [correct]", sent_fcs);
       } else {
-	proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
-			    "Frame check sequence: 0x%08x [incorrect, should be 0x%08x]",
-			    sent_fcs, fcs);
+        proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
+          "Frame check sequence: 0x%08x [incorrect, should be 0x%08x]",
+          sent_fcs, fcs);
       }
       trailer_length += 4;
     }
@@ -632,159 +680,164 @@ dissect_eth_withfcs(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 void
 proto_register_eth(void)
 {
-	static hf_register_info hf[] = {
-
-		{ &hf_eth_dst,
-		{ "Destination",	"eth.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
-			"Destination Hardware Address", HFILL }},
-
-		{ &hf_eth_src,
-		{ "Source",		"eth.src", FT_ETHER, BASE_NONE, NULL, 0x0,
-			"Source Hardware Address", HFILL }},
-
-		{ &hf_eth_len,
-		{ "Length",		"eth.len", FT_UINT16, BASE_DEC, NULL, 0x0,
-			NULL, HFILL }},
-
-		/* registered here but handled in packet-ethertype.c */
-		{ &hf_eth_type,
-		{ "Type",		"eth.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
-			NULL, HFILL }},
-
-		{ &hf_eth_vlan_tpid,
-		{ "Identifier", "eth.vlan.tpid", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
-			"Tag Protocol Identifier (TPID)", HFILL }},
-
-		{ &hf_eth_vlan_pri,
-		{ "Priority", "eth.vlan.pri", FT_UINT16, BASE_DEC, VALS(pri_vals), 0xE000,
-			"Priority Code Point (PCP)", HFILL }},
-
-		{ &hf_eth_vlan_cfi,
-		{ "CFI", "eth.vlan.cfi", FT_UINT16, BASE_DEC, VALS(cfi_vals), 0x1000,
-			"Canonical Format Identifier", HFILL }},
-
-		{ &hf_eth_vlan_id,
-                  { "VLAN", "eth.vlan.id", FT_UINT16, BASE_DEC, NULL, 0x0FFF,
-			"VLAN Identifier (VID)", HFILL }},
-
-		{ &hf_eth_addr,
-		{ "Address", "eth.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
-			"Source or Destination Hardware Address", HFILL }},
-
-                { &hf_eth_trailer,
-		{ "Trailer", "eth.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
-			"Ethernet Trailer or Checksum", HFILL }},
-
-                { &hf_eth_ig,
-		{ "IG bit", "eth.ig", FT_BOOLEAN, 24,
-		  TFS(&ig_tfs), 0x010000,
-		  "Specifies if this is an individual (unicast) or group (broadcast/multicast) address", HFILL }},
-
-                { &hf_eth_lg,
-		{ "LG bit", "eth.lg", FT_BOOLEAN, 24,
-		  TFS(&lg_tfs), 0x020000,
-		  "Specifies if this is a locally administered or globally unique (IEEE assigned) address", HFILL }}
-
-	};
-	static gint *ett[] = {
-		&ett_ieee8023,
-		&ett_ether2,
-		&ett_addr,
-		&ett_tag
-	};
-	module_t *eth_module;
-
-	proto_eth = proto_register_protocol("Ethernet", "Ethernet", "eth");
-	proto_register_field_array(proto_eth, hf, array_length(hf));
-	proto_register_subtree_array(ett, array_length(ett));
-
-	/* subdissector code */
-	register_heur_dissector_list("eth", &heur_subdissector_list);
-	register_heur_dissector_list("eth.trailer", &eth_trailer_subdissector_list);
-
-	/* Register configuration preferences */
-	eth_module = prefs_register_protocol(proto_eth, NULL);
-
-	prefs_register_bool_preference(eth_module, "assume_fcs",
-	    "Assume packets have FCS",
-	    "Some Ethernet adapters and drivers include the FCS at the end of a packet, others do not.  "
-	    "The Ethernet dissector attempts to guess whether a captured packet has an FCS, "
-	    "but it cannot always guess correctly.",
-	    &eth_assume_fcs);
-
-	prefs_register_bool_preference(eth_module, "interpret_as_fw1_monitor",
+    static hf_register_info hf[] = {
+
+        { &hf_eth_dst,
+        { "Destination", "eth.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
+            "Destination Hardware Address", HFILL }},
+
+        { &hf_eth_src,
+        { "Source", "eth.src", FT_ETHER, BASE_NONE, NULL, 0x0,
+            "Source Hardware Address", HFILL }},
+
+        { &hf_eth_len,
+        { "Length", "eth.len", FT_UINT16, BASE_DEC, NULL, 0x0,
+            NULL, HFILL }},
+
+        /* registered here but handled in packet-ethertype.c */
+        { &hf_eth_type,
+        { "Type", "eth.type", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
+            NULL, HFILL }},
+
+        { &hf_eth_invalid_lentype,
+        { "Invalid length/type", "eth.invalid_lentype", FT_UINT16, BASE_HEX_DEC,
+            NULL, 0x0, NULL, HFILL }},
+
+        { &hf_eth_vlan_tpid,
+        { "Identifier", "eth.vlan.tpid", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
+            "Tag Protocol Identifier (TPID)", HFILL }},
+
+        { &hf_eth_vlan_pri,
+        { "Priority", "eth.vlan.pri", FT_UINT16, BASE_DEC, VALS(pri_vals), 0xE000,
+            "Priority Code Point (PCP)", HFILL }},
+
+        { &hf_eth_vlan_cfi,
+        { "CFI", "eth.vlan.cfi", FT_UINT16, BASE_DEC, VALS(cfi_vals), 0x1000,
+            "Canonical Format Identifier", HFILL }},
+
+        { &hf_eth_vlan_id,
+        { "VLAN", "eth.vlan.id", FT_UINT16, BASE_DEC, NULL, 0x0FFF,
+            "VLAN Identifier (VID)", HFILL }},
+
+        { &hf_eth_addr,
+        { "Address", "eth.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
+            "Source or Destination Hardware Address", HFILL }},
+
+        { &hf_eth_trailer,
+        { "Trailer", "eth.trailer", FT_BYTES, BASE_NONE, NULL, 0x0,
+            "Ethernet Trailer or Checksum", HFILL }},
+
+        { &hf_eth_lg,
+        { "LG bit", "eth.lg", FT_BOOLEAN, 24,
+            TFS(&lg_tfs), 0x020000,
+            "Specifies if this is a locally administered or globally unique (IEEE assigned) address", HFILL }},
+
+        { &hf_eth_ig,
+        { "IG bit", "eth.ig", FT_BOOLEAN, 24,
+            TFS(&ig_tfs), 0x010000,
+            "Specifies if this is an individual (unicast) or group (broadcast/multicast) address", HFILL }}
+    };
+    static gint *ett[] = {
+        &ett_ieee8023,
+        &ett_ether2,
+        &ett_ether,
+        &ett_addr,
+        &ett_tag
+    };
+    module_t *eth_module;
+
+    proto_eth = proto_register_protocol("Ethernet", "Ethernet", "eth");
+    proto_register_field_array(proto_eth, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+
+    /* subdissector code */
+    register_heur_dissector_list("eth", &heur_subdissector_list);
+    register_heur_dissector_list("eth.trailer", &eth_trailer_subdissector_list);
+
+    /* Register configuration preferences */
+    eth_module = prefs_register_protocol(proto_eth, NULL);
+
+    prefs_register_bool_preference(eth_module, "assume_fcs",
+            "Assume packets have FCS",
+            "Some Ethernet adapters and drivers include the FCS at the end of a packet, others do not.  "
+            "The Ethernet dissector attempts to guess whether a captured packet has an FCS, "
+            "but it cannot always guess correctly.",
+            &eth_assume_fcs);
+
+    prefs_register_bool_preference(eth_module, "interpret_as_fw1_monitor",
             "Attempt to interpret as FireWall-1 monitor file",
             "Whether packets should be interpreted as coming from CheckPoint FireWall-1 monitor file if they look as if they do",
             &eth_interpret_as_fw1_monitor);
 
-        prefs_register_uint_preference(eth_module, "qinq_ethertype",
-	    "802.1QinQ Ethertype (in hex)", "The (hexadecimal) Ethertype used to indicate "
-	    "802.1QinQ VLAN in VLAN tunneling.", 16, &q_in_q_ethertype);
-	
-        /* This preference is copied over from the old vlan dissector by the set_pref()
-         * function in epan/prefs.c.  We don't have it in this dissector because there could
-         * be multiple VLAN tags nested within the Ethernet header, so we wouldn't know which
-         * one to show. */
-        prefs_register_obsolete_preference(eth_module, "summary_in_tree");
-
-	prefs_register_static_text_preference(eth_module, "ccsds_heuristic",
+    prefs_register_uint_preference(eth_module, "qinq_ethertype",
+            "802.1QinQ Ethertype (in hex)", "The (hexadecimal) Ethertype used to indicate "
+            "802.1QinQ VLAN in VLAN tunneling.", 16, &q_in_q_ethertype);
+
+    /* This preference is copied over from the old vlan dissector by the set_pref()
+     * function in epan/prefs.c.  We don't have it in this dissector because there could
+     * be multiple VLAN tags nested within the Ethernet header, so we wouldn't know which
+     * one to show. */
+    prefs_register_obsolete_preference(eth_module, "summary_in_tree");
+
+    prefs_register_static_text_preference(eth_module, "ccsds_heuristic",
             "These are the conditions to match a payload against in order to determine if this\n"
             "is a CCSDS (Consultative Committee for Space Data Systems) packet within\n"
             "an 802.3 packet. A packet is considered as a possible CCSDS packet only if\n"
             "one or more of the conditions are checked.",
             "Describe the conditions that must be true for the CCSDS dissector to be called");
 
-	prefs_register_bool_preference(eth_module, "ccsds_heuristic_length",
+    prefs_register_bool_preference(eth_module, "ccsds_heuristic_length",
             "CCSDS Length in header matches payload size",
             "Set the condition that must be true for the CCSDS dissector to be called",
             &ccsds_heuristic_length);
 
-	prefs_register_bool_preference(eth_module, "ccsds_heuristic_version",
+    prefs_register_bool_preference(eth_module, "ccsds_heuristic_version",
             "CCSDS Version # is zero",
             "Set the condition that must be true for the CCSDS dissector to be called",
             &ccsds_heuristic_version);
 
-	prefs_register_bool_preference(eth_module, "ccsds_heuristic_header",
+    prefs_register_bool_preference(eth_module, "ccsds_heuristic_header",
             "CCSDS Secondary Header Flag is set",
             "Set the condition that must be true for the CCSDS dissector to be called",
             &ccsds_heuristic_header);
 
-	prefs_register_bool_preference(eth_module, "ccsds_heuristic_bit",
+    prefs_register_bool_preference(eth_module, "ccsds_heuristic_bit",
             "CCSDS Spare bit is cleared",
             "Set the condition that must be true for the CCSDS dissector to be called",
             &ccsds_heuristic_bit);
 
-	register_dissector("eth_withoutfcs", dissect_eth_withoutfcs, proto_eth);
-	register_dissector("eth_withfcs", dissect_eth_withfcs, proto_eth);
-	register_dissector("eth", dissect_eth_maybefcs, proto_eth);
-	eth_tap = register_tap("eth");
+    register_dissector("eth_withoutfcs", dissect_eth_withoutfcs, proto_eth);
+    register_dissector("eth_withfcs", dissect_eth_withfcs, proto_eth);
+    register_dissector("eth", dissect_eth_maybefcs, proto_eth);
+    eth_tap = register_tap("eth");
 }
 
 void
 proto_reg_handoff_eth(void)
 {
-	dissector_handle_t eth_maybefcs_handle, eth_withoutfcs_handle;
-
-	/*
-	 * Get a handle for the Firewall-1 dissector.
-	 */
-	fw1_handle = find_dissector("fw1");
-
-	eth_maybefcs_handle = find_dissector("eth");
-	dissector_add_uint("wtap_encap", WTAP_ENCAP_ETHERNET, eth_maybefcs_handle);
-
-	eth_withoutfcs_handle = find_dissector("eth_withoutfcs");
-	dissector_add_uint("ethertype", ETHERTYPE_ETHBRIDGE, eth_withoutfcs_handle);
-	dissector_add_uint("chdlctype", ETHERTYPE_ETHBRIDGE, eth_withoutfcs_handle);
-	dissector_add_uint("gre.proto", ETHERTYPE_ETHBRIDGE, eth_withoutfcs_handle);
-
-	dissector_add_uint("sll.ltype", LINUX_SLL_P_ETHERNET, eth_withoutfcs_handle);
-	dissector_add_uint("usb.bulk", IF_CLASS_CDC_DATA, eth_withoutfcs_handle);
-
-	/*
-	 * This is to handle the output for the Cisco CMTS "cable intercept"
-	 * command - it encapsulates Ethernet frames in UDP packets, but
-	 * the UDP port is user-defined.
-	 */
-	dissector_add_handle("udp.port", eth_withoutfcs_handle);
+    dissector_handle_t eth_maybefcs_handle, eth_withoutfcs_handle;
+
+    /* Get a handle for the Firewall-1 dissector. */
+    fw1_handle = find_dissector("fw1");
+
+    /* Get a handle for the generic data dissector. */
+    data_handle = find_dissector("data");
+
+    eth_maybefcs_handle = find_dissector("eth");
+    dissector_add_uint("wtap_encap", WTAP_ENCAP_ETHERNET, eth_maybefcs_handle);
+
+    eth_withoutfcs_handle = find_dissector("eth_withoutfcs");
+    dissector_add_uint("ethertype", ETHERTYPE_ETHBRIDGE, eth_withoutfcs_handle);
+    dissector_add_uint("chdlctype", ETHERTYPE_ETHBRIDGE, eth_withoutfcs_handle);
+    dissector_add_uint("gre.proto", ETHERTYPE_ETHBRIDGE, eth_withoutfcs_handle);
+
+    dissector_add_uint("sll.ltype", LINUX_SLL_P_ETHERNET, eth_withoutfcs_handle);
+    dissector_add_uint("usb.bulk", IF_CLASS_CDC_DATA, eth_withoutfcs_handle);
+
+    /*
+     * This is to handle the output for the Cisco CMTS "cable intercept"
+     * command - it encapsulates Ethernet frames in UDP packets, but
+     * the UDP port is user-defined.
+     */
+    dissector_add_handle("udp.port", eth_withoutfcs_handle);
 }