Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1260 insertions, 0 deletions

diff --git a/epan/dissectors/packet-docsis.c b/epan/dissectors/packet-docsis.c
new file mode 100644
index 00000000..3de7f8aa
--- /dev/null
+++ b/epan/dissectors/packet-docsis.c
@@ -0,0 +1,1260 @@
+/* packet-docsis.c
+ * Routines for docsis dissection
+ * Copyright 2002, Anand V. Narwani <anand[AT]narwani.org>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+
+/* This code is based on the DOCSIS 1.1 specification available at:
+ * http://www.cablelabs.com/wp-content/uploads/specdocs/CM-SP-RFIv1.1-C01-050907.pdf
+ *
+ * This code was updated to include DOCSIS 3.1 specification details available at:
+ * http://www.cablelabs.com/wp-content/uploads/specdocs/CM-SP-MULPIv3.1-I09-160602.pdf
+ *
+ * Updates are backward compatible with previous DOCSIS spcifications.
+ *
+ * DOCSIS Captures can be facilitated using the Cable Monitor Feature
+ * available on Cisco Cable Modem Termination Systems:
+ * https://www.cisco.com/c/en/us/td/docs/cable/cmts/config_guide/b_cmts_security_and_cable_monitoring_features/b_cmts_security_and_cable_monitoring_features_chapter_010.html
+ *
+ * This dissector depends on the presence of a DOCSIS enapsulation type.
+ * There is no simple way to distinguish DOCSIS Frames from Ethernet frames,
+ * since the frames are copied from the RF interface on the CMTS to
+ * a Fast Ethernet interface; thus a preference was needed to enable
+ * the DOCSIS encapsulation type.
+ *
+ * Libpcap 0.7 and later allow a link-layer header type to be specified for
+ * some interfaces on some platforms; for Ethernet interfaces, they allow
+ * DOCSIS to be specified.  If an Ethernet capture is done with a link-layer
+ * type of DOCSIS, the file will have a link-layer header type of DLT_DOCSIS;
+ * Wireshark will treat the frames in that capture as DOCSIS frames, even
+ * if the preference mentioned above isn't enabled.
+ */
+
+#include "config.h"
+
+#include <epan/etypes.h>
+#include <epan/expert.h>
+#include <epan/packet.h>
+#include <epan/prefs.h>
+#include <epan/reassemble.h>
+#include <epan/addr_resolv.h>
+#include <epan/exceptions.h>
+#include <epan/crc16-tvb.h>
+#include <epan/crc32-tvb.h>
+
+void proto_register_docsis(void);
+void proto_reg_handoff_docsis(void);
+
+/* Assume all packets have an FCS */
+static gboolean docsis_check_fcs = TRUE;
+static gboolean docsis_dissect_encrypted_frames = FALSE;
+
+#define DOCSIS_MIN_HEADER_LEN   6
+
+#define FCTYPE_PACKET   0x00
+#define FCTYPE_RESERVED 0x01
+#define FCTYPE_ISOLAT   0x02
+#define FCTYPE_MACSPC   0x03
+
+#define FCPARM_TIMING_HDR           0x00
+#define FCPARM_MAC_MGMT_HDR         0x01
+#define FCPARM_RQST_FRM             0x02
+#define FCPARM_FRAG_HDR             0x03
+#define FCPARM_QUEUE_DEPTH_REQ_FRM  0x04
+#define FCPARM_CONCAT_HDR           0x1C
+
+#define EXT_HDR_OFF     0x00
+#define EXT_HDR_ON      0x01
+
+#define FRAG_FCS_LEN    4
+#define FRAG_FIRST      0x20
+#define FRAG_MIDDLE     0x00
+#define FRAG_LAST       0x10
+
+#define EH_NULL_CONFIG      0
+#define EH_REQUEST          1
+#define EH_ACK_REQ          2
+#define EH_BP_UP            3
+#define EH_BP_DOWN          4
+#define EH_SFLOW_HDR_DOWN   5
+#define EH_SFLOW_HDR_UP     6
+#define EH_BP_UP2           7
+#define EH_DS_SERVICE       8
+#define EH_PATH_VERIFY      9
+#define EH_RESERVED_10      10
+#define EH_RESERVED_11      11
+#define EH_RESERVED_12      12
+#define EH_RESERVED_13      13
+#define EH_RESERVED_14      14
+#define EH_EXTENDED         15
+
+/* Initialize the protocol and registered fields */
+static int proto_docsis = -1;
+static int hf_docsis_fctype = -1;
+static int hf_docsis_machdr_fcparm = -1;
+static int hf_docsis_fcparm = -1;
+static int hf_docsis_exthdr = -1;
+static int hf_docsis_concat_cnt = -1;
+static int hf_docsis_macparm = -1;
+static int hf_docsis_ehdrlen = -1;
+static int hf_docsis_len = -1;
+static int hf_docsis_eh_type = -1;
+static int hf_docsis_eh_len = -1;
+static int hf_docsis_eh_val = -1;
+static int hf_docsis_ehx_type = -1;
+static int hf_docsis_ehx_len = -1;
+static int hf_docsis_frag_rsvd = -1;
+static int hf_docsis_frag_first = -1;
+static int hf_docsis_frag_last = -1;
+static int hf_docsis_frag_seq = -1;
+static int hf_docsis_sid = -1;
+static int hf_docsis_mini_slots = -1;
+static int hf_docsis_requested_size = -1;
+static int hf_docsis_hcs = -1;
+static int hf_docsis_hcs_status = -1;
+static int hf_docsis_bpi_en = -1;
+static int hf_docsis_toggle_bit = -1;
+static int hf_docsis_key_seq = -1;
+static int hf_docsis_ehdr_ver = -1;
+static int hf_docsis_said = -1;
+static int hf_docsis_ehdr_phsi = -1;
+static int hf_docsis_ehdr_qind = -1;
+static int hf_docsis_ehdr_grants = -1;
+static int hf_docsis_reserved = -1;
+static int hf_docsis_ehdr_ds_traffic_pri = -1;
+static int hf_docsis_ehdr_ds_seq_chg_cnt = -1;
+static int hf_docsis_ehdr_ds_dsid = -1;
+static int hf_docsis_ehdr_ds_pkt_seq_num = -1;
+static int hf_docsis_ehdr_bpup2_bpi_en = -1;
+static int hf_docsis_ehdr_bpup2_toggle_bit = -1;
+static int hf_docsis_ehdr_bpup2_key_seq = -1;
+static int hf_docsis_ehdr_bpup2_ver = -1;
+static int hf_docsis_ehdr_bpup2_sid = -1;
+static int hf_docsis_ehdr_pv_st_refpt = -1;
+static int hf_docsis_ehdr_pv_timestamp = -1;
+
+static int hf_docsis_fragments = -1;
+static int hf_docsis_fragment = -1;
+static int hf_docsis_fragment_overlap = -1;
+static int hf_docsis_fragment_overlap_conflict = -1;
+static int hf_docsis_fragment_multiple_tails = -1;
+static int hf_docsis_fragment_too_long_fragment = -1;
+static int hf_docsis_fragment_error = -1;
+static int hf_docsis_fragment_count = -1;
+static int hf_docsis_reassembled_in = -1;
+static int hf_docsis_reassembled_length = -1;
+static int hf_docsis_reassembled_data = -1;
+static int hf_docsis_frag_fcs = -1;
+static int hf_docsis_frag_fcs_status = -1;
+
+static int hf_docsis_dst = -1;
+static int hf_docsis_dst_resolved = -1;
+static int hf_docsis_src = -1;
+static int hf_docsis_src_resolved = -1;
+static int hf_docsis_lg = -1;
+static int hf_docsis_ig = -1;
+static int hf_docsis_encrypted_payload = -1;
+
+static dissector_handle_t docsis_handle;
+static dissector_handle_t eth_withoutfcs_handle;
+static dissector_handle_t docsis_mgmt_handle;
+#if 0
+static dissector_table_t docsis_dissector_table;
+#endif
+
+static expert_field ei_docsis_hcs_bad = EI_INIT;
+static expert_field ei_docsis_len = EI_INIT;
+static expert_field ei_docsis_frag_fcs_bad = EI_INIT;
+static expert_field ei_docsis_eh_len = EI_INIT;
+
+/* Initialize the subtree pointers */
+static gint ett_docsis = -1;
+static gint ett_ehdr = -1;
+static gint ett_docsis_fragments = -1;
+static gint ett_docsis_fragment = -1;
+static gint ett_addr = -1;
+
+static const value_string fctype_vals[] = {
+  {FCTYPE_PACKET,   "Packet PDU"},
+  {FCTYPE_RESERVED, "Reserved"},
+  {FCTYPE_ISOLAT,   "Isolation PDU"},
+  {FCTYPE_MACSPC,   "MAC Specific"},
+  {0, NULL}
+};
+
+static const value_string eh_type_vals[] = {
+  {0,                 "NULL Configuration Parameter"},
+  {EH_REQUEST,        "Request"},
+  {EH_ACK_REQ,        "Acknowledgement Requested"},
+  {EH_BP_UP,          "Upstream Privacy Element"},
+  {EH_BP_DOWN,        "Downstream  Privacy Element"},
+  {EH_SFLOW_HDR_UP,   "Service Flow EH; PHS Header Upstream"},
+  {EH_SFLOW_HDR_DOWN, "Service Flow EH; PHS Header Downstream"},
+  {EH_BP_UP2,         "Upstream Privacy with Multi Channel"},
+  {EH_DS_SERVICE,     "Downstream Service"},
+  {EH_PATH_VERIFY,    "Path Verify"},
+  {EH_RESERVED_10,    "Reserved"},
+  {EH_RESERVED_11,    "Reserved"},
+  {EH_RESERVED_12,    "Reserved"},
+  {EH_RESERVED_13,    "Reserved"},
+  {EH_RESERVED_14,    "Reserved"},
+  {EH_EXTENDED,       "Extended"},
+  {0, NULL}
+};
+
+static const value_string ms_fcparm_vals[] = {
+  {FCPARM_TIMING_HDR,           "Timing Header"},
+  {FCPARM_MAC_MGMT_HDR,         "MAC Management Message"},
+  {FCPARM_RQST_FRM,             "Request Frame"},
+  {FCPARM_FRAG_HDR,             "Fragmentation Header"},
+  {FCPARM_QUEUE_DEPTH_REQ_FRM,  "Queue Depth-based Request Frame"},
+  {FCPARM_CONCAT_HDR,           "Concatenation Header"},
+  {0, NULL}
+};
+
+static const value_string pkt_fcparm_vals[] = {
+  {0x00,           "PDU MAC"},
+  {0x01,           "DELAY/DUPLICATE/MULTICAST/BROADCAST"},
+  {0, NULL}
+};
+
+static const true_false_string exthdr_tfs = {
+  "Extended Header Present",
+  "Extended Header Absent"
+};
+
+
+static const value_string local_proto_checksum_vals[] = {
+  { PROTO_CHECKSUM_E_BAD,        "Bad"  },
+  { PROTO_CHECKSUM_E_GOOD,       "Good" },
+  { PROTO_CHECKSUM_E_UNVERIFIED, "Unverified" },
+  { PROTO_CHECKSUM_E_NOT_PRESENT, "Not present" },
+
+  { 0,        NULL }
+};
+
+static const true_false_string qind_tfs = {
+  "Rate overrun",
+  "Rate non-overrun"
+};
+
+static const true_false_string odd_even_tfs = {
+  "Odd Key",
+  "Even Key",
+};
+
+static const value_string unique_no_phs[] = {
+  { 0, "No PHS on current packet" },
+  { 0, NULL }
+};
+
+/* Fragmentation Flags / Sequence */
+static guint8 frag_flags;
+static guint8 frag_seq;
+static guint16 frag_sid;
+
+/*
+ * Defragmentation of DOCSIS
+ */
+static reassembly_table docsis_reassembly_table;
+
+
+static const fragment_items docsis_frag_items = {
+  &ett_docsis_fragment,
+  &ett_docsis_fragments,
+  &hf_docsis_fragments,
+  &hf_docsis_fragment,
+  &hf_docsis_fragment_overlap,
+  &hf_docsis_fragment_overlap_conflict,
+  &hf_docsis_fragment_multiple_tails,
+  &hf_docsis_fragment_too_long_fragment,
+  &hf_docsis_fragment_error,
+  &hf_docsis_fragment_count,
+  &hf_docsis_reassembled_in,
+  &hf_docsis_reassembled_length,
+  &hf_docsis_reassembled_data,
+  "DOCSIS fragments"
+};
+
+/* Dissection */
+/* Code to Dissect the extended header; TLV Formatted headers */
+static void
+dissect_ehdr (tvbuff_t * tvb, proto_tree * tree, packet_info * pinfo, gboolean *is_encrypted)
+{
+  proto_tree *ehdr_tree;
+  proto_item *eh_length_item;
+  gint ehdrlen;
+  int pos;
+  guint8 type;
+  guint8 len;
+
+  ehdrlen = tvb_get_guint8 (tvb, 1);
+  pos = 4;
+
+  ehdr_tree = proto_tree_add_subtree(tree, tvb, pos, ehdrlen, ett_ehdr, NULL, "Extended Header");
+
+  while (pos < ehdrlen + 4)
+  {
+    type = (tvb_get_guint8 (tvb, pos) & 0xF0);
+    len = (tvb_get_guint8 (tvb, pos) & 0x0F);
+    if ((((type >> 4) & 0x0F)== 6) && (len == 2))
+    {
+      proto_tree_add_uint_format_value(ehdr_tree, hf_docsis_eh_type, tvb, pos, 1, 0x60, "Unsolicited Grant Sync EHDR Sub-Element");
+    }
+    else
+    {
+      proto_tree_add_item (ehdr_tree, hf_docsis_eh_type, tvb, pos, 1, ENC_BIG_ENDIAN);
+    }
+
+    eh_length_item = proto_tree_add_item (ehdr_tree, hf_docsis_eh_len, tvb, pos, 1, ENC_BIG_ENDIAN);
+    pos++;
+
+    switch ((type >> 4) & 0x0F)
+    {
+      case EH_REQUEST:
+        /* Request: Minislots Requested */
+        if (len == 3)
+        {
+          proto_tree_add_item(ehdr_tree, hf_docsis_mini_slots, tvb, pos, 1, ENC_NA);
+          proto_tree_add_item(ehdr_tree, hf_docsis_sid, tvb, pos + 1, 2, ENC_BIG_ENDIAN);
+        }
+        else
+        {
+          expert_add_info(pinfo, eh_length_item, &ei_docsis_eh_len);
+          return;
+        }
+        break;
+      case EH_ACK_REQ:
+        /* Deprecated in DOCSIS 3.1 */
+        if (len == 2)
+        {
+          proto_tree_add_item(ehdr_tree, hf_docsis_sid, tvb, pos, 2, ENC_BIG_ENDIAN);
+        }
+        else
+        {
+          expert_add_info(pinfo, eh_length_item, &ei_docsis_eh_len);
+          return;
+        }
+        break;
+      case EH_BP_UP:
+        /* Upstream Privacy EH Element or Upstream Privacy with fragmentation */
+        proto_tree_add_item (ehdr_tree, hf_docsis_key_seq, tvb, pos, 1,
+                             ENC_BIG_ENDIAN);
+        proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_ver, tvb, pos, 1,
+                             ENC_BIG_ENDIAN);
+        proto_tree_add_item_ret_boolean (ehdr_tree, hf_docsis_bpi_en, tvb, pos + 1, 1,
+                             ENC_BIG_ENDIAN, is_encrypted);
+        proto_tree_add_item (ehdr_tree, hf_docsis_toggle_bit, tvb, pos + 1,
+                             1, ENC_BIG_ENDIAN);
+        proto_tree_add_item (ehdr_tree, hf_docsis_sid, tvb, pos + 1, 2,
+                             ENC_BIG_ENDIAN);
+        frag_sid = tvb_get_guint8 (tvb, pos+1) & 0xCFFF;
+        proto_tree_add_item (ehdr_tree, hf_docsis_mini_slots, tvb, pos + 3,
+                             1, ENC_BIG_ENDIAN);
+        if (pinfo->fragmented)
+        {
+          proto_tree_add_item (ehdr_tree, hf_docsis_frag_rsvd, tvb, pos+4,
+                               1, ENC_BIG_ENDIAN);
+          frag_flags = tvb_get_guint8 (tvb, pos+4) & 0x30;
+          proto_tree_add_item (ehdr_tree, hf_docsis_frag_first, tvb, pos+4,
+                               1, ENC_BIG_ENDIAN);
+          proto_tree_add_item (ehdr_tree, hf_docsis_frag_last, tvb, pos+4,
+                               1, ENC_BIG_ENDIAN);
+          frag_seq = tvb_get_guint8 (tvb, pos+4) & 0x0F;
+          proto_tree_add_item (ehdr_tree, hf_docsis_frag_seq, tvb, pos+4,
+                               1, ENC_BIG_ENDIAN);
+        }
+        break;
+      case EH_BP_DOWN:
+        /* Downstream Privacy EH Element */
+        proto_tree_add_item (ehdr_tree, hf_docsis_key_seq, tvb, pos, 1,
+                             ENC_BIG_ENDIAN);
+        proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_ver, tvb, pos, 1,
+                             ENC_BIG_ENDIAN);
+        proto_tree_add_item_ret_boolean (ehdr_tree, hf_docsis_bpi_en, tvb, pos + 1, 1,
+                             ENC_BIG_ENDIAN, is_encrypted);
+        proto_tree_add_item (ehdr_tree, hf_docsis_toggle_bit, tvb, pos + 1,
+                             1, ENC_BIG_ENDIAN);
+        proto_tree_add_item (ehdr_tree, hf_docsis_said, tvb, pos + 1, 2,
+                             ENC_BIG_ENDIAN);
+        proto_tree_add_item (ehdr_tree, hf_docsis_reserved, tvb, pos + 3, 1,
+                             ENC_BIG_ENDIAN);
+        break;
+      case EH_SFLOW_HDR_DOWN:
+        /* Deprecated in DOCSIS 3.1, was Downstream Service Flow EH Element in earlier revisions */
+      case EH_SFLOW_HDR_UP:
+        /* Deprecated in DOCSIS 3.1, was Upstream Service Flow EH Element in earlier revisions */
+        proto_tree_add_item(ehdr_tree, hf_docsis_ehdr_phsi, tvb, pos, 1, ENC_BIG_ENDIAN);
+
+        if (len == 2)
+        {
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_qind, tvb, pos+1, 1, ENC_BIG_ENDIAN);
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_grants, tvb, pos+1, 1, ENC_BIG_ENDIAN);
+        }
+        break;
+      case EH_BP_UP2:
+        /* Upstream Privacy EH Element, version 2, with no piggyback request */
+        proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_bpup2_key_seq, tvb, pos, 1,
+                             ENC_BIG_ENDIAN);
+        proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_bpup2_ver, tvb, pos, 1,
+                             ENC_BIG_ENDIAN);
+        proto_tree_add_item_ret_boolean (ehdr_tree, hf_docsis_ehdr_bpup2_bpi_en, tvb, pos + 1, 1,
+                             ENC_BIG_ENDIAN, is_encrypted);
+        proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_bpup2_toggle_bit, tvb, pos + 1,
+                             1, ENC_BIG_ENDIAN);
+        proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_bpup2_sid, tvb, pos + 1, 2,
+                             ENC_BIG_ENDIAN);
+        break;
+      case EH_DS_SERVICE:
+        /* Downstream Service EH Element */
+        proto_tree_add_item(ehdr_tree, hf_docsis_ehdr_ds_traffic_pri, tvb, pos, 1, ENC_BIG_ENDIAN);
+
+        if (len == 3)
+        {
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_ds_dsid, tvb, pos, 3, ENC_BIG_ENDIAN);
+        }
+
+        if (len == 5)
+        {
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_ds_seq_chg_cnt, tvb, pos, 1, ENC_BIG_ENDIAN);
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_ds_dsid, tvb, pos, 3, ENC_BIG_ENDIAN);
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_ds_pkt_seq_num, tvb, pos+3, 2, ENC_BIG_ENDIAN);
+        }
+        break;
+      case EH_PATH_VERIFY:
+        /* Path Verify EH Element */
+        if (len == 5)
+        {
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_pv_st_refpt, tvb, pos, 1, ENC_BIG_ENDIAN);
+          proto_tree_add_item (ehdr_tree, hf_docsis_ehdr_pv_timestamp, tvb, pos+1, 4, ENC_BIG_ENDIAN);
+        }
+        break;
+      case EH_EXTENDED:
+        /* Extended EH Element, ignore eh_len */
+        proto_tree_add_item(ehdr_tree, hf_docsis_ehx_type, tvb, pos, 1, ENC_NA);
+        pos++;
+        proto_tree_add_item(ehdr_tree, hf_docsis_ehx_len, tvb, pos, 1, ENC_NA);
+        len = tvb_get_guint8(tvb, pos);
+        pos++;
+        /* FALLTHROUGH */
+      default:
+        if (len > 0)
+          proto_tree_add_item (ehdr_tree, hf_docsis_eh_val, tvb, pos,
+                               len, ENC_NA);
+    }
+    pos += len;
+  }
+
+  return;
+}
+
+/* Code to Dissect the Header Check Sequence field */
+/* Return FALSE in case FCS validation is enabled, but FCS is incorrect */
+/* Return TRUE in all other cases */
+static gboolean
+dissect_hcs_field (tvbuff_t * tvb, packet_info * pinfo, proto_tree * docsis_tree, gint hdrlen)
+{
+  /* dissect the header check sequence */
+  if(docsis_check_fcs){
+    /* CRC-CCITT(16+12+5+1) */
+    guint16 fcs = g_ntohs(crc16_ccitt_tvb(tvb, (hdrlen - 2)));
+    proto_tree_add_checksum(docsis_tree, tvb, (hdrlen - 2), hf_docsis_hcs, hf_docsis_hcs_status, &ei_docsis_hcs_bad, pinfo, fcs, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+
+    return (tvb_get_ntohs(tvb, (hdrlen - 2)) == fcs) ? TRUE : FALSE;
+  }
+  else
+  {
+    proto_tree_add_checksum(docsis_tree, tvb, (hdrlen - 2), hf_docsis_hcs, hf_docsis_hcs_status, &ei_docsis_hcs_bad, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
+  }
+  return TRUE;
+}
+
+/* Code to Dissect the extended header length / MAC Param field and Length field */
+/* The length field may condain a SID, but this logic is not handled here */
+static void
+dissect_exthdr_length_field (tvbuff_t * tvb, packet_info * pinfo, proto_tree * docsis_tree,
+                             guint8 exthdr, guint16 mac_parm, guint16 len_sid, guint16 *payload_length, gboolean *is_encrypted)
+{
+  proto_item *length_item;
+  if (exthdr == EXT_HDR_ON)
+  {
+    /* Add in Extended Header Length */
+    proto_tree_add_item (docsis_tree, hf_docsis_ehdrlen, tvb, 1, 1,  ENC_BIG_ENDIAN);
+    length_item = proto_tree_add_item (docsis_tree, hf_docsis_len, tvb, 2, 2, ENC_BIG_ENDIAN);
+    /* Validate PDU length */
+    if ((len_sid - mac_parm) > *payload_length)
+    {
+      *payload_length = len_sid;
+      expert_add_info(pinfo, length_item, &ei_docsis_len);
+    }
+    /* Pass off to the Extended Header dissection */
+    dissect_ehdr (tvb, docsis_tree, pinfo, is_encrypted);
+  }
+  else
+  {
+    /* Add in MAC Parm field only */
+    proto_tree_add_item (docsis_tree, hf_docsis_macparm, tvb, 1, 1, ENC_BIG_ENDIAN);
+    length_item = proto_tree_add_item (docsis_tree, hf_docsis_len, tvb, 2, 2, ENC_BIG_ENDIAN);
+    /* Validate PDU length */
+    if (len_sid > *payload_length)
+    {
+      *payload_length = len_sid;
+      expert_add_info(pinfo, length_item, &ei_docsis_len);
+    }
+  }
+  return;
+}
+
+/* Code to Dissect Encrypted DOCSIS Frames */
+/* Print DST and SRC MACs and do not dissect the payload */
+/* Implementation inferred from packet-eth.c */
+static void
+dissect_encrypted_frame (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, const guint8 fctype, const guint8 fcparm)
+{
+  guint32           offset, frame_len;
+  const guint8      *src_addr, *dst_addr;
+  const char        *src_addr_name, *dst_addr_name;
+  proto_item        *addr_item;
+  proto_tree        *addr_tree=NULL;
+//  tvbuff_t          *next_tvb;
+
+  /* According to CM-SP-SEC-v3.1, PDU regions of the following
+   * frames must be encrypted when security is enabled:
+   * - Variable-length PDU MAC Frames;
+   * - Fragmentation MAC Frames;
+   * - Registration Request (REG-REQ-MP) MAC Management Message Frames;
+   * - Isolation PDU MAC Frames.
+   * There are also other corner cases when MAC Management frames might be encrypted
+   * (e.g. EH_TYPE=7 as described in CM-SP-MULPIv3.1-I15-180509 Table 17 and Table 20)
+   */
+  if (fctype == FCTYPE_MACSPC) {
+    if (fcparm == FCPARM_MAC_MGMT_HDR) {
+      col_append_str (pinfo->cinfo, COL_INFO, " (Encrypted MMM)");
+    } else if (fcparm == FCPARM_FRAG_HDR) {
+      col_append_str (pinfo->cinfo, COL_INFO, " (Encrypted Fragmentation MAC Frame)");
+    } else {
+      col_append_str (pinfo->cinfo, COL_INFO, " (Encrypted)");
+    }
+  } else {
+    col_append_str (pinfo->cinfo, COL_INFO, " (Encrypted)");
+  }
+
+  offset = 0;
+  frame_len = tvb_captured_length_remaining (tvb, offset);
+  switch (fctype)
+  {
+    case FCTYPE_PACKET:
+    case FCTYPE_ISOLAT:
+    case FCTYPE_MACSPC:
+      dst_addr = tvb_get_ptr(tvb, 0, 6);
+      dst_addr_name = get_ether_name(dst_addr);
+      src_addr = tvb_get_ptr(tvb, 6, 6);
+      src_addr_name = get_ether_name(src_addr);
+
+      addr_item = proto_tree_add_ether(tree, hf_docsis_dst, tvb, 0, 6, dst_addr);
+      addr_tree = proto_item_add_subtree(addr_item, ett_addr);
+      addr_item=proto_tree_add_string(addr_tree, hf_docsis_dst_resolved, tvb, 0, 6,
+          dst_addr_name);
+      proto_item_set_generated(addr_item);
+      proto_tree_add_item(addr_tree, hf_docsis_lg, tvb, 0, 3, ENC_BIG_ENDIAN);
+      proto_tree_add_item(addr_tree, hf_docsis_ig, tvb, 0, 3, ENC_BIG_ENDIAN);
+
+      addr_item = proto_tree_add_ether(tree, hf_docsis_src, tvb, 6, 6, src_addr);
+      addr_tree = proto_item_add_subtree(addr_item, ett_addr);
+      addr_item=proto_tree_add_string(addr_tree, hf_docsis_src_resolved, tvb, 6, 6,
+          src_addr_name);
+      proto_item_set_generated(addr_item);
+      proto_tree_add_item(addr_tree, hf_docsis_lg, tvb, 6, 3, ENC_BIG_ENDIAN);
+      proto_tree_add_item(addr_tree, hf_docsis_ig, tvb, 6, 3, ENC_BIG_ENDIAN);
+
+      offset += 12;
+      break;
+  }
+  proto_tree_add_item(tree, hf_docsis_encrypted_payload, tvb, offset, frame_len - offset, ENC_NA);
+
+  return;
+}
+
+/* Main DOCSIS Dissection Entry Point */
+/* Code to Dissect the DOCSIS Frames */
+static int
+dissect_docsis (tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree, void* data _U_)
+{
+  guint8 fc = 0;
+  guint8 fctype = 0;
+  guint8 fcparm = 0;
+  guint8 exthdr = 0;
+  guint16 mac_parm = 0;
+  guint8 hdrlen = DOCSIS_MIN_HEADER_LEN;
+  guint16 len_sid = 0;
+  tvbuff_t *next_tvb = NULL;
+  tvbuff_t *mgt_tvb = NULL;
+  gint pdulen = 0;
+  guint16 payload_length = 0;
+  /* guint16 framelen = 0; */
+  gboolean save_fragmented;
+  gboolean is_encrypted = FALSE;
+  gboolean fcs_correct;
+  proto_item *ti;
+  proto_tree *docsis_tree;
+
+  /* Extract Frame Control parts */
+  fc = tvb_get_guint8 (tvb, 0); /* Frame Control Byte */
+  fctype = (fc >> 6) & 0x03;    /* Frame Control Type:  2 MSB Bits */
+  fcparm = (fc >> 1) & 0x1F;    /* Frame Control Parameter: Next 5 Bits */
+  exthdr = (fc & 0x01);         /* Extended Header Bit: LSB */
+
+  /* Extract the MAC Parm; MAC Parm and SID offsets; change for a Queue Depth Request */
+  if (fcparm == FCPARM_QUEUE_DEPTH_REQ_FRM) {
+    mac_parm = tvb_get_ntohs (tvb, 1);
+    len_sid = tvb_get_ntohs (tvb, 3);
+    hdrlen = DOCSIS_MIN_HEADER_LEN + 1; // 7-byte header for this message type
+  } else {
+    mac_parm = tvb_get_guint8 (tvb, 1);
+    len_sid = tvb_get_ntohs (tvb, 2);
+  }
+
+  /* Set Header Length based on presence of Extended header */
+  if (exthdr == EXT_HDR_ON) {
+    hdrlen += mac_parm;
+  }
+
+  /* Captured Payload Length is based on the length of the header */
+  payload_length = tvb_reported_length_remaining (tvb, hdrlen);
+
+  /* If this is a Request Frame, then pdulen is 0 and framelen is 6 */
+  if ((fctype == FCTYPE_MACSPC) && (fcparm == FCPARM_RQST_FRM || fcparm == FCPARM_QUEUE_DEPTH_REQ_FRM))
+  {
+    pdulen = 0;
+    /*
+    if (fcparm == FCPARM_QUEUE_DEPTH_REQ_FRM)
+      framelen = DOCSIS_MIN_HEADER_LEN + 1;
+    else
+      framelen = DOCSIS_MIN_HEADER_LEN;
+    */
+  } else {
+    /* framelen = DOCSIS_MIN_HEADER_LEN + len_sid; */
+    pdulen = len_sid - (mac_parm + 2);
+  }
+
+  /* Make entries in Protocol column and Info column on summary display */
+  col_set_str (pinfo->cinfo, COL_PROTOCOL, "DOCSIS");
+
+  switch (fctype)
+  {
+    case FCTYPE_PACKET:
+      col_set_str (pinfo->cinfo, COL_INFO, "Packet PDU");
+      break;
+    case FCTYPE_RESERVED:
+      col_set_str (pinfo->cinfo, COL_INFO, "Reserved PDU");
+      break;
+    case FCTYPE_ISOLAT:
+      col_set_str (pinfo->cinfo, COL_INFO, "Isolation PDU");
+      break;
+    case FCTYPE_MACSPC:
+      if (fcparm == FCPARM_RQST_FRM)
+        col_add_fstr (pinfo->cinfo, COL_INFO,
+                      "Request Frame SID=%u Mini Slots=%u", len_sid,
+                      mac_parm);
+      else if (fcparm == FCPARM_QUEUE_DEPTH_REQ_FRM)
+        col_add_fstr (pinfo->cinfo, COL_INFO,
+                      "Request Frame SID=%u, Requested Size=%uxN bytes", len_sid,
+                      mac_parm);
+      else if (fcparm == FCPARM_FRAG_HDR)
+        col_set_str (pinfo->cinfo, COL_INFO, "Fragmented Frame");
+      else
+        col_set_str (pinfo->cinfo, COL_INFO, "MAC Specific");
+      break;
+  }  /* switch fctype */
+
+  ti = proto_tree_add_item(tree, proto_docsis, tvb, 0, hdrlen, ENC_NA);
+  docsis_tree = proto_item_add_subtree (ti, ett_docsis);
+
+  /* add an item to the subtree, see section 1.6 for more information */
+
+  /* Add in FC Byte fields */
+  proto_tree_add_item (docsis_tree, hf_docsis_fctype, tvb, 0, 1, ENC_BIG_ENDIAN);
+
+  switch (fctype)
+  {
+    case FCTYPE_PACKET:
+    {
+      proto_item_append_text (ti, " Packet PDU");
+      proto_tree_add_item (docsis_tree, hf_docsis_fcparm, tvb, 0, 1, ENC_BIG_ENDIAN);
+      proto_tree_add_item (docsis_tree, hf_docsis_exthdr, tvb, 0, 1, ENC_BIG_ENDIAN);
+      /* Dissect Length field for a PDU */
+      dissect_exthdr_length_field (tvb, pinfo, docsis_tree, exthdr, mac_parm, len_sid, &payload_length, &is_encrypted);
+      /* Dissect Header Check Sequence field for a PDU */
+      fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+      if (fcs_correct && pdulen > 0)
+      {
+        next_tvb =  tvb_new_subset_remaining(tvb, hdrlen);
+        if(is_encrypted && !docsis_dissect_encrypted_frames)
+          dissect_encrypted_frame (next_tvb, pinfo, docsis_tree, fctype, fcparm);
+        else
+          call_dissector (eth_withoutfcs_handle, next_tvb, pinfo, docsis_tree);
+      }
+      break;
+    }
+    case FCTYPE_RESERVED:
+    {
+      proto_item_append_text (ti, " Reserved PDU");
+      proto_tree_add_item (docsis_tree, hf_docsis_fcparm, tvb, 0, 1, ENC_BIG_ENDIAN);
+      proto_tree_add_item (docsis_tree, hf_docsis_exthdr, tvb, 0, 1, ENC_BIG_ENDIAN);
+      /* Dissect Length field for a PDU */
+      dissect_exthdr_length_field (tvb, pinfo, docsis_tree, exthdr, mac_parm, len_sid, &payload_length, &is_encrypted);
+      /* Dissect Header Check Sequence field for a PDU */
+      fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+      if (fcs_correct)
+      {
+        /* Don't do anything for a Reserved Frame */
+        next_tvb =  tvb_new_subset_remaining(tvb, hdrlen);
+        call_data_dissector(next_tvb, pinfo, tree);
+      }
+      break;
+    }
+    case FCTYPE_ISOLAT:
+    {
+      proto_item_append_text (ti, " Isolation PDU");
+      proto_tree_add_item (docsis_tree, hf_docsis_fcparm, tvb, 0, 1, ENC_BIG_ENDIAN);
+      proto_tree_add_item (docsis_tree, hf_docsis_exthdr, tvb, 0, 1, ENC_BIG_ENDIAN);
+      /* Dissect Length field for a PDU */
+      dissect_exthdr_length_field (tvb, pinfo, docsis_tree, exthdr, mac_parm, len_sid, &payload_length, &is_encrypted);
+      /* Dissect Header Check Sequence field for a PDU */
+      fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+      if (fcs_correct && pdulen > 0)
+      {
+        next_tvb =  tvb_new_subset_remaining(tvb, hdrlen);
+        if(is_encrypted && !docsis_dissect_encrypted_frames)
+          dissect_encrypted_frame (next_tvb, pinfo, docsis_tree, fctype, fcparm);
+        else
+          call_dissector (eth_withoutfcs_handle, next_tvb, pinfo, docsis_tree);
+      }
+      break;
+    }
+    case FCTYPE_MACSPC:
+    {
+      proto_item_append_text (ti, " MAC-Specific PDU");
+      proto_tree_add_item (docsis_tree, hf_docsis_machdr_fcparm, tvb, 0, 1, ENC_BIG_ENDIAN);
+      proto_tree_add_item (docsis_tree, hf_docsis_exthdr, tvb, 0, 1, ENC_BIG_ENDIAN);
+      switch(fcparm)
+      {
+        case FCPARM_TIMING_HDR:
+          // no break
+        case FCPARM_MAC_MGMT_HDR:
+        {
+          /* Dissect Length field for a PDU */
+          dissect_exthdr_length_field (tvb, pinfo, docsis_tree, exthdr, mac_parm, len_sid, &payload_length, &is_encrypted);
+          /* Dissect Header Check Sequence field for a PDU */
+          fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+          if (fcs_correct)
+          {
+            /* Pass off to the DOCSIS Management dissector/s */
+            mgt_tvb = tvb_new_subset_remaining(tvb, hdrlen);
+            if(is_encrypted && !docsis_dissect_encrypted_frames)
+              dissect_encrypted_frame (mgt_tvb, pinfo, docsis_tree, fctype, fcparm);
+            else
+              call_dissector (docsis_mgmt_handle, mgt_tvb, pinfo, docsis_tree);
+          }
+          break;
+        }
+        case FCPARM_RQST_FRM:
+        {
+          /* Decode for a Request Frame.  No extended header */
+          proto_tree_add_uint (docsis_tree, hf_docsis_mini_slots, tvb, 1, 1, mac_parm);
+          proto_tree_add_uint (docsis_tree, hf_docsis_sid, tvb, 2, 2, len_sid);
+          /* Dissect Header Check Sequence field for a PDU */
+          fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+          if (fcs_correct)
+          {
+            /* Don't do anything for a Request Frame, there is no data following it */
+          }
+          break;
+        }
+        case FCPARM_FRAG_HDR:
+        {
+          /* Check if this is a fragmentation header */
+          save_fragmented = pinfo->fragmented;
+          pinfo->fragmented = TRUE;
+
+          /* Dissect Length field for a PDU */
+          dissect_exthdr_length_field (tvb, pinfo, docsis_tree, exthdr, mac_parm, len_sid, &payload_length, &is_encrypted);
+          /* Dissect Header Check Sequence field for a PDU */
+          fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+          if (fcs_correct)
+          {
+            /* Grab the Fragment FCS */
+            guint32 sent_fcs = tvb_get_ntohl(tvb, (hdrlen + len_sid - 4));
+            guint32 fcs = crc32_802_tvb(tvb, tvb_captured_length(tvb) - 4);
+
+            /* Only defragment valid frames with a good FCS */
+            if (sent_fcs == fcs)
+            {
+              fragment_head *frag_msg = NULL;
+              frag_msg = fragment_add_seq_check(&docsis_reassembly_table,
+                                                tvb, hdrlen, pinfo,
+                                                frag_sid, NULL, /* ID for fragments belonging together */
+                                                frag_seq, /* Fragment Sequence Number */
+                                                (len_sid - 4), /* fragment length - to the end */
+                                                !(frag_flags & FRAG_LAST)); /* More fragments? */
+
+              next_tvb = process_reassembled_data(tvb, hdrlen, pinfo,
+                                                  "Reassembled Message", frag_msg, &docsis_frag_items,
+                                                  NULL, docsis_tree);
+
+              if (frag_flags == FRAG_LAST)
+                pinfo->fragmented = FALSE;
+              else
+                pinfo->fragmented = TRUE;
+
+              if (frag_msg) { /* Reassembled */
+                proto_item_append_text (ti, " (Message Reassembled)");
+              } else { /* Not last packet of reassembled Short Message */
+                proto_item_append_text (ti, " (Message fragment %u)", frag_seq);
+
+              }
+
+              if(next_tvb)
+              {
+                /* By default assume an Ethernet payload */
+              if(is_encrypted && !docsis_dissect_encrypted_frames)
+                dissect_encrypted_frame (next_tvb, pinfo, docsis_tree, fctype, fcparm);
+              else
+                call_dissector (eth_withoutfcs_handle, next_tvb, pinfo, docsis_tree);
+              } else {
+                /* Otherwise treat as Data */
+                tvbuff_t *payload_tvb = tvb_new_subset_length_caplen(tvb, hdrlen, (len_sid - 4), -1);
+                call_data_dissector(payload_tvb, pinfo, docsis_tree);
+              }
+            } else {
+              /* Report frames with a bad FCS */
+              expert_add_info(pinfo, ti, &ei_docsis_frag_fcs_bad);
+            }
+            /* Add the Fragment FCS to the end of the parent tree */
+            proto_tree_add_checksum(docsis_tree, tvb, (hdrlen + len_sid - 4), hf_docsis_frag_fcs, hf_docsis_frag_fcs_status, &ei_docsis_frag_fcs_bad, pinfo, fcs, ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
+
+            pinfo->fragmented = save_fragmented;
+          }
+          break;
+        }
+        case FCPARM_QUEUE_DEPTH_REQ_FRM:
+        {
+          /* Decode for a Queue-depth Based Request */
+          proto_tree_add_uint (docsis_tree, hf_docsis_requested_size, tvb, 1, 2, mac_parm);
+          proto_tree_add_uint (docsis_tree, hf_docsis_sid, tvb, 3, 2, len_sid);
+          /* Dissect Header Check Sequence field for a PDU */
+          fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+          if (fcs_correct)
+          {
+          /* No PDU Payload for this frame */
+          }
+          break;
+        }
+        case FCPARM_CONCAT_HDR:
+        {
+          /* Decode for a Concatenated Header; ONLY for DOCSIS versions < 3.1.  No Extended Header */
+          proto_item_append_text (ti, " (Concatenated Header)");
+          proto_tree_add_item (docsis_tree, hf_docsis_concat_cnt, tvb, 1, 1, ENC_BIG_ENDIAN);
+          proto_tree_add_item (docsis_tree, hf_docsis_len, tvb, 2, 2, ENC_BIG_ENDIAN);
+          /* Dissect Header Check Sequence field for a PDU */
+          fcs_correct = dissect_hcs_field (tvb, pinfo, docsis_tree, hdrlen);
+          if (fcs_correct)
+          {
+            // There used to be a section of code here that recursively
+            // called dissect_docsis. It has been removed. If you plan on
+            // adding concatenated PDU support back you should consider
+            // doing something like the following:
+            // dissect_docsis(...) {
+            //   while(we_have_pdus_remaining) {
+            //     int pdu_len = dissect_docsis_pdu(...)
+            //     if (pdu_len < 1) {
+            //       add_expert...
+            //       break;
+            //     }
+            //   }
+            // }
+            // Adding back this functionality using recursion might result
+            // in this dissector being disabled by default or removed entirely.
+          }
+          break;
+        }
+        default:
+            /* Unknown parameter, stop dissection */
+          break;
+      } /* switch fcparm */
+      break;
+    }
+  } /* switch fctype */
+
+  return tvb_captured_length(tvb);
+}
+
+/* Register the protocol with Wireshark */
+void
+proto_register_docsis (void)
+{
+  static hf_register_info hf[] = {
+    {&hf_docsis_fctype,
+     {"FCType", "docsis.fctype",
+      FT_UINT8, BASE_HEX, VALS (fctype_vals), 0xC0,
+      "Frame Control Type", HFILL}
+    },
+    {&hf_docsis_fcparm,
+     {"FCParm", "docsis.fcparm",
+      FT_UINT8, BASE_DEC, VALS (pkt_fcparm_vals), 0x3E,
+      "Parameter Field", HFILL}
+    },
+    {&hf_docsis_machdr_fcparm,
+     {"FCParm", "docsis.fcparm",
+      FT_UINT8, BASE_DEC, VALS (ms_fcparm_vals), 0x3E,
+      "Parameter Field", HFILL}
+    },
+    {&hf_docsis_exthdr,
+     {"EXTHDR", "docsis.exthdr",
+      FT_BOOLEAN, 8, TFS (&exthdr_tfs), 0x01,
+      "Extended Header Presence", HFILL}
+    },
+    {&hf_docsis_macparm,
+     {"MACParm", "docsis.macparm",
+      FT_UINT8, BASE_HEX, NULL, 0x0,
+      "MAC Parameter Field", HFILL}
+    },
+    {&hf_docsis_concat_cnt,
+     {"Number of Concatenated Frames", "docsis.concat_cnt",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdrlen,
+     {"Extended Header Length (bytes)", "docsis.ehdrlen",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_len,
+     {"Length of the MAC frame (bytes)", "docsis.len",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      "Length of the MAC frame, not counting the fixed-length MAC header", HFILL}
+    },
+    {&hf_docsis_eh_type,
+     {"Type", "docsis.ehdr.type",
+      FT_UINT8, BASE_DEC, VALS (eh_type_vals), 0xF0,
+      "TLV Type", HFILL}
+    },
+    {&hf_docsis_eh_len,
+     {"Length", "docsis.ehdr.len",
+      FT_UINT8, BASE_DEC, NULL, 0x0F,
+      "TLV Len", HFILL}
+    },
+    {&hf_docsis_eh_val,
+     {"Value", "docsis.ehdr.value",
+      FT_BYTES, BASE_NONE, NULL, 0x0,
+      "TLV Value", HFILL}
+    },
+    {&hf_docsis_ehx_type,
+     {"Extended Type", "docsis.ehdr.ehx_type",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      "TLV Type", HFILL}
+    },
+    {&hf_docsis_ehx_len,
+     {"Extended Length", "docsis.ehdr.ehx_len",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      "TLV Len", HFILL}
+    },
+    {&hf_docsis_frag_rsvd,
+     {"Reserved", "docsis.frag_rsvd",
+      FT_UINT8, BASE_DEC, NULL, 0xC0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_frag_first,
+     {"First Frame", "docsis.frag_first",
+      FT_BOOLEAN, 8, NULL, 0x20,
+      NULL, HFILL}
+    },
+    {&hf_docsis_frag_last,
+     {"Last Frame", "docsis.frag_last",
+      FT_BOOLEAN, 8, NULL, 0x10,
+      NULL, HFILL}
+    },
+    {&hf_docsis_frag_seq,
+     {"Fragmentation Sequence #", "docsis.frag_seq",
+      FT_UINT8, BASE_DEC, NULL, 0x0F,
+      "Fragmentation Sequence Number", HFILL}
+    },
+    {&hf_docsis_sid,
+     {"SID", "docsis.ehdr.sid",
+      FT_UINT16, BASE_DEC_HEX, NULL, 0x3FFF,
+      "Service Identifier", HFILL}
+    },
+    {&hf_docsis_said,
+     {"SAID", "docsis.ehdr.said",
+      FT_UINT16, BASE_DEC, NULL, 0x3FFF,
+      "Security Association Identifier", HFILL}
+    },
+    {&hf_docsis_reserved,
+     {"Reserved", "docsis.ehdr.rsvd",
+      FT_UINT8, BASE_HEX, NULL, 0x0,
+      "Reserved Byte", HFILL}
+    },
+    {&hf_docsis_mini_slots,
+     {"MiniSlots", "docsis.ehdr.minislots",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      "Mini Slots Requested", HFILL}
+    },
+    {&hf_docsis_requested_size,
+     {"Requested bytes in units of N bytes, N a parameter of the service flow for which this request is being made", "docsis.ehdr.reqsize",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_key_seq,
+     {"Key Sequence", "docsis.ehdr.keyseq",
+      FT_UINT8, BASE_DEC, NULL, 0xF0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_ver,
+     {"Version", "docsis.ehdr.ver",
+      FT_UINT8, BASE_DEC, NULL, 0x0F,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_phsi,
+     {"Payload Header Suppression Index", "docsis.ehdr.phsi",
+      FT_UINT8, BASE_DEC|BASE_SPECIAL_VALS, VALS(unique_no_phs), 0x0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_qind,
+     {"Queue Indicator", "docsis.ehdr.qind",
+      FT_BOOLEAN, 8, TFS(&qind_tfs), 0x80,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_grants,
+     {"Active Grants", "docsis.ehdr.act_grants",
+      FT_UINT8, BASE_DEC, NULL, 0x7F,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_bpup2_key_seq,
+     {"Key Sequence", "docsis.ehdr.bpup2_keyseq",
+      FT_UINT8, BASE_DEC, NULL, 0xF0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_bpup2_ver,
+     {"Version", "docsis.ehdr.bpup2_ver",
+      FT_UINT8, BASE_DEC, NULL, 0x0F,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_bpup2_bpi_en,
+     {"Encryption", "docsis.ehdr.bpup2_bpi_en",
+      FT_BOOLEAN, 8, TFS (&tfs_enabled_disabled), 0x80,
+      "BPI Enable", HFILL}
+    },
+    {&hf_docsis_ehdr_bpup2_toggle_bit,
+     {"Toggle", "docsis.ehdr.bpup2_toggle_bit",
+      FT_BOOLEAN, 8, TFS (&odd_even_tfs), 0x40,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_bpup2_sid,
+     {"SID", "docsis.ehdr.bpup2_sid",
+      FT_UINT16, BASE_DEC, NULL, 0x3FFF,
+      "Service Identifier", HFILL}
+    },
+    { &hf_docsis_ehdr_pv_st_refpt,
+     { "Start Reference Point", "docsis.ehdr.pv_start_ref",
+       FT_UINT8, BASE_DEC, NULL, 0x0,
+       NULL, HFILL}
+    },
+    { &hf_docsis_ehdr_pv_timestamp,
+     { "Timestamp", "docsis.ehdr.pv_timestamp",
+       FT_UINT32, BASE_DEC, NULL, 0x0,
+       NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_ds_traffic_pri,
+     {"DS Traffic Priority", "docsis.ehdr.ds_traffic_pri",
+      FT_UINT8, BASE_DEC, NULL, 0xE0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_ds_seq_chg_cnt,
+     {"DS Sequence Change Count", "docsis.ehdr.ds_seq_chg_cnt",
+      FT_UINT8, BASE_DEC, NULL, 0x10,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_ds_dsid,
+     {"DS DSID", "docsis.ehdr.ds_dsid",
+      FT_UINT32, BASE_DEC, NULL, 0x0FFFFF,
+      NULL, HFILL}
+    },
+    {&hf_docsis_ehdr_ds_pkt_seq_num,
+     {"DS Packet Sequence Number", "docsis.ehdr.ds_pkt_seq_num",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL}
+    },
+    {&hf_docsis_hcs,
+     {"Header check sequence", "docsis.hcs",
+      FT_UINT16, BASE_HEX, NULL, 0x0,
+      NULL, HFILL}
+    },
+    { &hf_docsis_hcs_status,
+     { "HCS Status", "docsis.hcs.status",
+       FT_UINT8, BASE_NONE, VALS(local_proto_checksum_vals), 0x0,
+       NULL, HFILL}
+    },
+    { &hf_docsis_bpi_en,
+     { "Encryption", "docsis.bpi_en",
+       FT_BOOLEAN, 8, TFS (&tfs_enabled_disabled), 0x80,
+       "BPI Enable", HFILL}
+    },
+    { &hf_docsis_toggle_bit,
+     { "Toggle", "docsis.toggle_bit",
+       FT_BOOLEAN, 8, TFS (&odd_even_tfs), 0x40,
+       NULL, HFILL}
+    },
+    { &hf_docsis_fragment_overlap,
+     { "Fragment overlap", "docsis.fragment.overlap",
+       FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+       "Fragment overlaps with other fragments", HFILL}
+    },
+    { &hf_docsis_fragment_overlap_conflict,
+     { "Conflicting data in fragment overlap", "docsis.fragment.overlap.conflict",
+       FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+       "Overlapping fragments contained conflicting data", HFILL}
+    },
+    { &hf_docsis_fragment_multiple_tails,
+     { "Multiple tail fragments found", "docsis.fragment.multipletails",
+       FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+       "Several tails were found when defragmenting the packet", HFILL}
+    },
+    { &hf_docsis_fragment_too_long_fragment,
+     { "Fragment too long", "docsis.fragment.toolongfragment",
+       FT_BOOLEAN, BASE_NONE, NULL, 0x0,
+       "Fragment contained data past end of packet", HFILL}
+    },
+    { &hf_docsis_fragment_error,
+     { "Defragmentation error", "docsis.fragment.error",
+       FT_FRAMENUM, BASE_NONE, NULL, 0x0,
+       "Defragmentation error due to illegal fragments", HFILL}
+    },
+    { &hf_docsis_fragment_count,
+     { "Fragment count", "docsis.fragment.count",
+       FT_UINT32, BASE_DEC, NULL, 0x0,
+       NULL, HFILL}
+    },
+    { &hf_docsis_fragment,
+     { "DOCSIS Fragment", "docsis.fragment",
+       FT_FRAMENUM, BASE_NONE, NULL, 0x0,
+       NULL, HFILL}
+    },
+    { &hf_docsis_fragments,
+     { "DOCSIS Fragments", "docsis.fragments",
+       FT_BYTES, BASE_NONE, NULL, 0x0,
+       NULL, HFILL}
+    },
+    { &hf_docsis_reassembled_in,
+     { "Reassembled DOCSIS in frame", "docsis.reassembled_in",
+       FT_FRAMENUM, BASE_NONE, NULL, 0x0,
+       "This DOCSIS packet is reassembled in this frame", HFILL}
+    },
+    { &hf_docsis_reassembled_length,
+     { "Reassembled DOCSIS length", "docsis.reassembled.length",
+       FT_UINT32, BASE_DEC, NULL, 0x0,
+       "The total length of the reassembled payload", HFILL}
+    },
+    { &hf_docsis_reassembled_data,
+     { "Reassembled DOCSIS data", "docsis.reassembled.data",
+       FT_BYTES, BASE_NONE, NULL, 0x0,
+       "The reassembled payload", HFILL}
+    },
+    { &hf_docsis_frag_fcs,
+     { "Fragment FCS", "docsis.frag.fcs",
+       FT_UINT32, BASE_HEX, NULL, 0x0,
+       NULL, HFILL}
+    },
+    { &hf_docsis_frag_fcs_status,
+     { "Fragment FCS Status", "docsis.frag.fcs.status",
+       FT_UINT8, BASE_NONE, VALS(local_proto_checksum_vals), 0x0,
+       NULL, HFILL}
+    },
+    { &hf_docsis_encrypted_payload,
+      { "Encrypted Payload", "docsis.encrypted_payload",
+        FT_BYTES, BASE_NONE, NULL, 0x0,
+        "Encrypted data", HFILL }
+    }
+  };
+
+  static ei_register_info ei[] = {
+      { &ei_docsis_hcs_bad, { "docsis.hcs_bad", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
+      { &ei_docsis_len, { "docsis.len.past_end", PI_MALFORMED, PI_ERROR, "Length field value goes past the end of the payload", EXPFILL }},
+      { &ei_docsis_frag_fcs_bad, { "docsis.frag.fcs_bad", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
+      { &ei_docsis_eh_len, { "docsis.ehdr.len.past_end", PI_MALFORMED, PI_ERROR, "Extended Header Length Invalid!", EXPFILL }}
+  };
+
+  static gint *ett[] = {
+      &ett_docsis,
+      &ett_ehdr,
+      &ett_docsis_fragment,
+      &ett_docsis_fragments,
+      &ett_addr
+  };
+
+  module_t *docsis_module;
+  expert_module_t* expert_docsis;
+
+  proto_docsis = proto_register_protocol ("DOCSIS", "DOCSIS", "docsis");
+  proto_register_field_array (proto_docsis, hf, array_length (hf));
+  proto_register_subtree_array (ett, array_length (ett));
+
+  /* register expert notifications */
+  expert_docsis = expert_register_protocol(proto_docsis);
+  expert_register_field_array(expert_docsis, ei, array_length(ei));
+
+  /* Register configuration preferences */
+  docsis_module = prefs_register_protocol(proto_docsis, NULL);
+  prefs_register_bool_preference(docsis_module, "check_fcs",
+                                 "Validate the DOCSIS checksum if possible",
+                                 "Whether or not to validate the Header Check Sequence",
+                                 &docsis_check_fcs);
+   prefs_register_bool_preference(docsis_module, "dissect_encrypted_frames",
+                                 "Ignore EH 'encrypted' bit",
+                                 "Whether or not to attempt to dissect encrypted DOCSIS payload",
+                                 &docsis_dissect_encrypted_frames);
+
+#if 0
+  docsis_dissector_table = register_dissector_table ("docsis",
+                                                     "DOCSIS Encapsulation Type", proto_docsis,
+                                                     FT_UINT8, BASE_DEC);
+#endif
+
+  docsis_handle = register_dissector ("docsis", dissect_docsis, proto_docsis);
+  reassembly_table_register(&docsis_reassembly_table,
+                        &addresses_reassembly_table_functions);
+}
+
+void
+proto_reg_handoff_docsis (void)
+{
+  dissector_add_uint ("wtap_encap", WTAP_ENCAP_DOCSIS, docsis_handle);
+
+  hf_docsis_dst = proto_registrar_get_id_byname ("eth.dst");
+  hf_docsis_dst_resolved = proto_registrar_get_id_byname ("eth.dst_resolved");
+  hf_docsis_src = proto_registrar_get_id_byname ("eth.src");
+  hf_docsis_src_resolved = proto_registrar_get_id_byname ("eth.src_resolved");
+  hf_docsis_lg = proto_registrar_get_id_byname ("eth.lg");
+  hf_docsis_ig = proto_registrar_get_id_byname ("eth.ig");
+
+  docsis_mgmt_handle = find_dissector ("docsis_mgmt");
+  eth_withoutfcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_docsis);
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local Variables:
+ * c-basic-offset: 2
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=2 tabstop=8 expandtab:
+ * :indentSize=2:tabSize=8:noTabs=true:
+ */