Adding upstream version 4.2.2.upstream/4.2.2

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

1 files changed, 817 insertions, 0 deletions

diff --git a/epan/dissectors/packet-meta.c b/epan/dissectors/packet-meta.c
new file mode 100644
index 00000000..0c7c3243
--- /dev/null
+++ b/epan/dissectors/packet-meta.c
@@ -0,0 +1,817 @@
+/* Routines for 'Metadata' disassembly
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+
+#include <epan/packet.h>
+#include <wiretap/wtap.h>
+#include <epan/expert.h>
+#include <epan/proto_data.h>
+#include "packet-sscop.h"
+#include "packet-gsm_a_common.h"
+
+void proto_register_meta(void);
+void proto_reg_handoff_meta(void);
+
+/* schemas */
+#define META_SCHEMA_PCAP        1
+#define META_SCHEMA_DXT         2
+
+/* protocols */
+#define META_PROTO_DXT_ETHERNET        1
+#define META_PROTO_DXT_ETHERNET_CRC   36
+#define META_PROTO_DXT_ATM            41
+#define META_PROTO_DXT_ERF_AAL5       49
+#define META_PROTO_DXT_M3UA           61
+#define META_PROTO_DXT_NBAP           69
+#define META_PROTO_DXT_ATM_AAL2       76
+#define META_PROTO_DXT_FP_HINT        82
+#define META_PROTO_DXT_HDLC          106
+#define META_PROTO_DXT_CONTAINER     127
+#define META_PROTO_DXT_FP_CAPTURE    193
+#define META_PROTO_DXT_UTRAN_CAPSULE 194
+
+/* data types */
+#define META_TYPE_NONE             0
+#define META_TYPE_BOOLEAN          1
+#define META_TYPE_UINT8            2
+#define META_TYPE_UINT16           3
+#define META_TYPE_UINT32           4
+#define META_TYPE_UINT64           5
+#define META_TYPE_STRING          16
+
+/* item ids */
+#define META_ID_NULL               0
+#define META_ID_DIRECTION          1
+#define META_ID_SIGNALING          2
+#define META_ID_INCOMPLETE         3
+#define META_ID_DECIPHERED         4
+#define META_ID_PAYLOADCUT         5
+#define META_ID_TIMESTAMP64        6
+#define META_ID_AAL5PROTO          7
+#define META_ID_PHYLINKID        256
+#define META_ID_LOCALDEVID       257
+#define META_ID_REMOTEDEVID      258
+#define META_ID_TAPGROUPID       259
+#define META_ID_IMSI            1024
+#define META_ID_IMEI            1025
+#define META_ID_CELL            1026
+#define META_ID_TLLI            1027
+#define META_ID_NSAPI           1028
+#define META_ID_APN             1029
+#define META_ID_RAT             1030
+#define META_ID_CALLING         1031
+#define META_ID_CALLED          1032
+
+enum meta_direction {
+    META_DIR_UP,
+    META_DIR_DOWN
+};
+
+static int proto_meta = -1;
+extern int proto_sscop;
+
+/* fields */
+static int hf_meta_schema = -1;
+static int hf_meta_hdrlen = -1;
+static int hf_meta_proto = -1;
+static int hf_meta_reserved = -1;
+static int hf_meta_item = -1;
+static int hf_meta_item_id = -1;
+static int hf_meta_item_type = -1;
+static int hf_meta_item_len = -1;
+static int hf_meta_item_data = -1;
+/* specific fields */
+static int hf_meta_item_direction = -1;
+static int hf_meta_item_ts = -1;
+static int hf_meta_item_phylinkid = -1;
+static int hf_meta_item_nsapi = -1;
+static int hf_meta_item_imsi_value = -1;
+static int hf_meta_item_imsi_digits = -1;
+static int hf_meta_item_imei_value = -1;
+static int hf_meta_item_imei_digits = -1;
+static int hf_meta_item_signaling = -1;
+static int hf_meta_item_incomplete = -1;
+static int hf_meta_item_deciphered = -1;
+static int hf_meta_item_apn = -1;
+static int hf_meta_item_rat = -1;
+static int hf_meta_item_aal5proto = -1;
+static int hf_meta_item_cell = -1;
+static int hf_meta_item_localdevid = -1;
+static int hf_meta_item_remotedevid = -1;
+static int hf_meta_item_tapgroupid = -1;
+static int hf_meta_item_tlli = -1;
+static int hf_meta_item_calling = -1;
+static int hf_meta_item_called = -1;
+
+/* subtrees */
+static gint ett_meta = -1;
+static gint ett_meta_item = -1;
+static gint ett_meta_cell = -1;
+static gint ett_meta_imsi = -1;
+static gint ett_meta_imei = -1;
+
+static expert_field ei_meta_malformed = EI_INIT;
+static expert_field ei_meta_invalid_header = EI_INIT;
+
+/* default handle */
+static dissector_handle_t data_handle;
+static dissector_handle_t atm_untrunc_handle;
+static dissector_handle_t sscf_nni_handle;
+static dissector_handle_t alcap_handle;
+static dissector_handle_t nbap_handle;
+static dissector_handle_t ethwithfcs_handle;
+static dissector_handle_t ethwithoutfcs_handle;
+static dissector_handle_t fphint_handle;
+static dissector_handle_t mtp2_handle;
+
+static dissector_table_t meta_dissector_table;
+
+static const value_string meta_schema_vals[] = {
+    { META_SCHEMA_PCAP,     "PCAP" },
+    { META_SCHEMA_DXT,      "DXT" },
+    { 0, NULL }
+};
+
+static const value_string meta_proto_vals[] = {
+    { META_PROTO_DXT_ETHERNET,      "Ethernet without FCS" },
+    { META_PROTO_DXT_ETHERNET_CRC,  "Ethernet with FCS" },
+    { META_PROTO_DXT_ATM,           "ATM" },
+    { META_PROTO_DXT_ERF_AAL5,      "ERF AAL5" },
+    /* XXX: META_PROTO_DXT_M3UA ? */
+    /* XXX: META_PROTO_DXT_NBAP ? */
+    { META_PROTO_DXT_ATM_AAL2,      "ATM AAL2" },
+    { META_PROTO_DXT_FP_HINT,       "FP Hint" },
+    { META_PROTO_DXT_HDLC,          "HDLC" },
+    { META_PROTO_DXT_CONTAINER,     "DXT CONTAINER" },
+    { META_PROTO_DXT_FP_CAPTURE,    "FP CAPTURE" },
+    { META_PROTO_DXT_UTRAN_CAPSULE, "UTRAN CAPSULE" },
+    { 0, NULL }
+};
+static value_string_ext meta_proto_vals_ext = VALUE_STRING_EXT_INIT(meta_proto_vals);
+
+static const value_string meta_type_vals[] = {
+    { META_TYPE_NONE,       "NONE" },
+    { META_TYPE_BOOLEAN,    "BOOLEAN" },
+    { META_TYPE_UINT8,      "UINT8" },
+    { META_TYPE_UINT16,     "UINT16" },
+    { META_TYPE_UINT32,     "UINT32" },
+    { META_TYPE_UINT64,     "UINT64" },
+    { META_TYPE_STRING,     "STRING" },
+    { 0, NULL }
+};
+
+/* TODO: this must be on a per-schema basis! */
+static const value_string meta_id_vals[] = {
+    { META_ID_NULL,         "NULL" },
+    { META_ID_DIRECTION,    "Direction" },
+    { META_ID_SIGNALING,    "Signaling" },
+    { META_ID_INCOMPLETE,   "Incomplete" },
+    { META_ID_DECIPHERED,   "Deciphered" },
+    { META_ID_PAYLOADCUT,   "Payload cutted" },
+    { META_ID_TIMESTAMP64,  "Timestamp" },
+    { META_ID_AAL5PROTO,    "AAL5 Protocol Type" },
+    { META_ID_PHYLINKID,    "Physical Link ID" },
+    { META_ID_LOCALDEVID,   "Local Device ID" },
+    { META_ID_REMOTEDEVID,  "Remote Device ID" },
+    { META_ID_TAPGROUPID,   "Tap Group ID" },
+    { META_ID_IMSI,         "IMSI" },
+    { META_ID_IMEI,         "IMEI" },
+    { META_ID_CELL,         "Mobile Cell" },
+    { META_ID_TLLI,         "TLLI" },
+    { META_ID_NSAPI,        "NSAPI" },
+    { META_ID_APN,          "APN" },
+    { META_ID_RAT,          "RAT" },
+    { META_ID_CALLING,      "Calling Station ID" },
+    { META_ID_CALLED,       "Called Station ID" },
+    { 0, NULL }
+};
+static value_string_ext meta_id_vals_ext = VALUE_STRING_EXT_INIT(meta_id_vals);
+
+#define META_AAL5PROTO_MTP3     2
+#define META_AAL5PROTO_NS       3
+#define META_AAL5PROTO_ALCAP    5
+#define META_AAL5PROTO_NBAP     6
+static const value_string meta_aal5proto_vals[] = {
+    { META_AAL5PROTO_MTP3,  "SSCOP MTP3" },
+    { META_AAL5PROTO_ALCAP, "SSCOP ALCAP" },
+    { META_AAL5PROTO_NBAP,  "SSCOP NBAP" },
+    { META_AAL5PROTO_NS,    "GPRS NS" },
+    { 0, NULL }
+};
+
+static const value_string meta_direction_vals[] = {
+    { 0,    "Up" },
+    { 1,    "Down" },
+    { 0,    NULL }
+};
+
+static guint16 skip_item(proto_tree *meta_tree, tvbuff_t *tvb, packet_info *pinfo _U_, guint16 offs)
+{
+    guint16     id;
+    guint8      type;
+    guint16     len, aligned_len, total_len;
+    proto_tree *item_tree;
+    proto_item *subti;
+
+    id          = tvb_get_letohs(tvb, offs); offs += 2;
+    type        = tvb_get_guint8(tvb, offs); offs++;
+    len         = tvb_get_guint8(tvb, offs); offs++;
+    aligned_len = (len + 3) & 0xfffc;
+    total_len   = aligned_len + 4; /* 4: id, type, len fields */
+
+    subti = proto_tree_add_item(meta_tree, hf_meta_item, tvb, offs - 4,
+        aligned_len + 4, ENC_NA);
+    item_tree = proto_item_add_subtree(subti, ett_meta_item);
+    proto_tree_add_uint(item_tree, hf_meta_item_id, tvb, offs - 4, 2, id);
+    proto_tree_add_uint(item_tree, hf_meta_item_type, tvb, offs - 2, 1, type);
+    proto_tree_add_uint(item_tree, hf_meta_item_len,
+        tvb, offs - 1, 1, len);
+    if (len > 0)
+        proto_tree_add_item(item_tree, hf_meta_item_data,
+            tvb, offs, len, ENC_NA);
+
+    return total_len;
+}
+
+/*
+* offs: current offset in tvb
+*/
+static guint16 evaluate_meta_item_pcap(proto_tree *meta_tree, tvbuff_t *tvb, packet_info *pinfo, guint16 offs)
+{
+    guint16     id;
+    guint8      type;
+    guint16     len, aligned_len, total_len;
+    proto_tree *item_tree;
+    proto_item *subti;
+    /* field values */
+    guint8      dir;
+    guint64     ts;
+
+    id          = tvb_get_letohs(tvb, offs); offs += 2;
+    type        = tvb_get_guint8(tvb, offs); offs++;
+    len         = tvb_get_guint8(tvb, offs); offs++;
+    aligned_len = (len + 3) & 0xfffc;
+    total_len   = aligned_len + 4; /* 4: id, type, len fields */
+
+    switch (id) {
+        case META_ID_DIRECTION:
+            dir = tvb_get_guint8(tvb, offs);
+            pinfo->p2p_dir = dir == META_DIR_UP ? P2P_DIR_RECV : P2P_DIR_SENT;
+            proto_tree_add_uint(meta_tree, hf_meta_item_direction, tvb, offs, 1, dir);
+            break;
+        case META_ID_TIMESTAMP64:
+            ts = tvb_get_letoh64(tvb, offs);
+            proto_tree_add_uint64(meta_tree, hf_meta_item_ts, tvb, offs, 8, ts);
+            break;
+        case META_ID_SIGNALING:
+            proto_tree_add_boolean(meta_tree, hf_meta_item_signaling, tvb,
+                offs, 0, 1);
+            break;
+        case META_ID_INCOMPLETE:
+            proto_tree_add_boolean(meta_tree, hf_meta_item_incomplete, tvb,
+                offs, 0, 1);
+            break;
+        default:
+            subti = proto_tree_add_item(meta_tree, hf_meta_item, tvb, offs - 4,
+                aligned_len + 4, ENC_NA);
+            item_tree = proto_item_add_subtree(subti, ett_meta_item);
+            proto_tree_add_uint(item_tree, hf_meta_item_id, tvb, offs - 4, 2, id);
+            proto_tree_add_uint(item_tree, hf_meta_item_type, tvb, offs - 2, 1, type);
+            proto_tree_add_uint(item_tree, hf_meta_item_len,
+                tvb, offs - 1, 1, len);
+            if (len > 0)
+                proto_tree_add_item(item_tree, hf_meta_item_data,
+                    tvb, offs, len, ENC_NA);
+    }
+    return total_len;
+}
+
+/*
+* offs: current offset in tvb
+*/
+static guint16 evaluate_meta_item_dxt(proto_tree *meta_tree, tvbuff_t *tvb, packet_info *pinfo, guint16 offs, struct atm_phdr *atm_info)
+{
+    guint16             id;
+    guint8              type;
+    guint16             len, aligned_len, total_len;
+    proto_tree         *item_tree;
+    proto_item         *subti;
+    /* field values */
+    guint8              dir, nsapi, rat, aal5proto;
+    guint16             phylinkid, localdevid, remotedevid, tapgroupid;
+    guint32             tlli;
+    guint64             ts, cell;
+    sscop_payload_info *p_sscop_info;
+    proto_item         *cell_item, *imsi_item, *imei_item;
+    proto_tree         *cell_tree, *imsi_tree, *imei_tree;
+
+    id          = tvb_get_letohs(tvb, offs); offs += 2;
+    type        = tvb_get_guint8(tvb, offs); offs++;
+    len         = tvb_get_guint8(tvb, offs); offs++;
+    aligned_len = (len + 3) & 0xfffc;
+    total_len   = aligned_len + 4; /* 4: id, type, len fields */
+
+    switch (id) {
+        case META_ID_DIRECTION:
+            dir = tvb_get_guint8(tvb, offs);
+            pinfo->p2p_dir = (dir == META_DIR_UP ? P2P_DIR_RECV : P2P_DIR_SENT);
+            proto_tree_add_uint(meta_tree, hf_meta_item_direction, tvb, offs, 1, dir);
+            break;
+        case META_ID_TIMESTAMP64:
+            ts = tvb_get_letoh64(tvb, offs);
+            proto_tree_add_uint64(meta_tree, hf_meta_item_ts, tvb, offs, 8, ts);
+            break;
+        case META_ID_PHYLINKID:
+            phylinkid = tvb_get_letohs(tvb, offs);
+            pinfo->link_number = phylinkid;
+            proto_tree_add_uint(meta_tree, hf_meta_item_phylinkid, tvb,
+                offs, 2, phylinkid);
+            break;
+        case META_ID_NSAPI:
+            nsapi = tvb_get_guint8(tvb, offs);
+            proto_tree_add_uint(meta_tree, hf_meta_item_nsapi, tvb,
+                offs, 1, nsapi);
+            break;
+        case META_ID_IMSI:
+            imsi_item = proto_tree_add_item(meta_tree, hf_meta_item_imsi_digits, tvb,
+                offs, 8, ENC_BCD_DIGITS_0_9);
+            imsi_tree = proto_item_add_subtree(imsi_item, ett_meta_imsi);
+            proto_tree_add_item(imsi_tree, hf_meta_item_imsi_value,
+                tvb, offs, 8, ENC_LITTLE_ENDIAN);
+            break;
+        case META_ID_IMEI:
+            imei_item = proto_tree_add_item(meta_tree, hf_meta_item_imei_digits, tvb,
+                offs, 8, ENC_BCD_DIGITS_0_9);
+            imei_tree = proto_item_add_subtree(imei_item, ett_meta_imei);
+            proto_tree_add_item(imei_tree, hf_meta_item_imei_value,
+                tvb, offs, 8, ENC_LITTLE_ENDIAN);
+            break;
+        case META_ID_APN:
+            proto_tree_add_item(meta_tree, hf_meta_item_apn, tvb,
+                offs, len, ENC_ASCII);
+            break;
+        case META_ID_RAT:
+            rat = tvb_get_guint8(tvb, offs);
+            proto_tree_add_uint(meta_tree, hf_meta_item_rat, tvb,
+                offs, 1, rat);
+            break;
+        case META_ID_CELL:
+            cell = tvb_get_ntoh64(tvb, offs);
+            cell_item = proto_tree_add_uint64_format(meta_tree, hf_meta_item_cell,
+                                                     tvb, offs, 8, cell, "Mobile Cell");
+            cell_tree = proto_item_add_subtree(cell_item, ett_meta_cell);
+            de_gmm_rai(tvb, cell_tree, pinfo, offs, 8, NULL, 0);
+            de_cell_id(tvb, cell_tree, pinfo, offs + 6, 2, NULL, 0);
+            break;
+        case META_ID_SIGNALING:
+            proto_tree_add_boolean(meta_tree, hf_meta_item_signaling, tvb,
+                                   offs, 0, 1);
+            break;
+        case META_ID_INCOMPLETE:
+            proto_tree_add_boolean(meta_tree, hf_meta_item_incomplete, tvb,
+                offs, 0, 1);
+            break;
+        case META_ID_DECIPHERED:
+            proto_tree_add_boolean(meta_tree, hf_meta_item_deciphered, tvb,
+                offs, 0, 1);
+            break;
+        case META_ID_AAL5PROTO:
+            aal5proto    = tvb_get_guint8(tvb, offs);
+            p_sscop_info = (sscop_payload_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_sscop, 0);
+            if (!p_sscop_info) {
+                p_sscop_info = wmem_new0(wmem_file_scope(), sscop_payload_info);
+                p_add_proto_data(wmem_file_scope(), pinfo, proto_sscop, 0, p_sscop_info);
+            }
+            switch (aal5proto) {
+                case META_AAL5PROTO_MTP3:
+                    p_sscop_info->subdissector = sscf_nni_handle;
+                    /* hint for ATM dissector that this frame contains SSCOP */
+                    memset(atm_info, 0, sizeof(*atm_info));
+                    atm_info->type = TRAF_SSCOP;
+                    break;
+                case META_AAL5PROTO_ALCAP:
+                    p_sscop_info->subdissector = alcap_handle;
+                    break;
+                case META_AAL5PROTO_NBAP:
+                    p_sscop_info->subdissector = nbap_handle;
+                    break;
+                case META_AAL5PROTO_NS:
+                    /* hint for ATM dissector that this frame contains GPRS NS */
+                    memset(atm_info, 0, sizeof(*atm_info));
+                    atm_info->type = TRAF_GPRS_NS;
+                    break;
+                /* TODO: check for additional protos on Iu 802 LLC/SNAP ... */
+                default:
+                    /* TODO: add warning */
+                    p_remove_proto_data(wmem_file_scope(), pinfo, proto_sscop, 0);
+            }
+            proto_tree_add_uint(meta_tree, hf_meta_item_aal5proto, tvb,
+                offs, 1, aal5proto);
+            break;
+        case META_ID_LOCALDEVID:
+            localdevid = tvb_get_letohs(tvb, offs);
+            proto_tree_add_uint(meta_tree, hf_meta_item_localdevid, tvb,
+                offs, 2, localdevid);
+            break;
+        case META_ID_REMOTEDEVID:
+            remotedevid = tvb_get_letohs(tvb, offs);
+            proto_tree_add_uint(meta_tree, hf_meta_item_remotedevid, tvb,
+                offs, 2, remotedevid);
+            break;
+        case META_ID_TAPGROUPID:
+            tapgroupid = tvb_get_letohs(tvb, offs);
+            proto_tree_add_uint(meta_tree, hf_meta_item_tapgroupid, tvb,
+                offs, 2, tapgroupid);
+            break;
+        case META_ID_TLLI:
+            tlli = tvb_get_letohs(tvb, offs);
+            proto_tree_add_uint(meta_tree, hf_meta_item_tlli, tvb,
+                offs, 4, tlli);
+            break;
+        case META_ID_CALLING:
+            proto_tree_add_item(meta_tree, hf_meta_item_calling, tvb,
+                offs, len, ENC_ASCII);
+            break;
+        case META_ID_CALLED:
+            proto_tree_add_item(meta_tree, hf_meta_item_called, tvb,
+                offs, len, ENC_ASCII);
+            break;
+        default:
+            subti = proto_tree_add_item(meta_tree, hf_meta_item, tvb, offs - 4,
+                aligned_len + 4, ENC_NA);
+            item_tree = proto_item_add_subtree(subti, ett_meta_item);
+            proto_tree_add_uint(item_tree, hf_meta_item_id, tvb, offs - 4, 2, id);
+            proto_tree_add_uint(item_tree, hf_meta_item_type, tvb, offs - 2, 1, type);
+            proto_tree_add_uint(item_tree, hf_meta_item_len,
+                tvb, offs - 1, 1, len);
+            if (len > 0)
+                proto_tree_add_item(item_tree, hf_meta_item_data,
+                    tvb, offs, len, ENC_NA);
+    }
+    return total_len;
+}
+
+/*
+ * offs: current offset within tvb
+ * header_length: length of meta header
+ */
+static gint32 evaluate_meta_items(guint16 schema, tvbuff_t *tvb, packet_info *pinfo,
+    proto_tree *meta_tree, guint16 offs, gint32 header_length,
+    struct atm_phdr *atm_info)
+{
+    gint16 item_len;
+    gint32 total_len = 0;
+
+    while (total_len < header_length) {
+        switch (schema) {
+            case META_SCHEMA_DXT:
+                item_len = evaluate_meta_item_dxt(meta_tree, tvb, pinfo, offs + total_len, atm_info);
+                break;
+            case META_SCHEMA_PCAP:
+                item_len = evaluate_meta_item_pcap(meta_tree, tvb, pinfo, offs + total_len);
+                break;
+            default:
+                item_len = skip_item(meta_tree, tvb, pinfo, offs + total_len);
+        }
+        if (item_len < 4) { /* 4 is the minimum length of an item: id + type + length field */
+            expert_add_info_format(pinfo, meta_tree, &ei_meta_malformed,
+                "Malformed Packet %s (wrong item encoding)", pinfo->current_proto);
+            return -1;
+        }
+        total_len += item_len;
+    }
+    return total_len;
+}
+
+static int
+dissect_meta(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
+{
+#define META_HEADER_SIZE 8
+    guint16             schema, proto, hdrlen, reserved;
+    gint32              item_len;
+    guint32             aal2_ext, atm_hdr;
+    proto_tree         *meta_tree      = NULL;
+    proto_item         *ti             = NULL;
+    tvbuff_t           *next_tvb       = NULL;
+    dissector_handle_t  next_dissector = data_handle;
+    void               *next_dissector_data = NULL;
+    struct atm_phdr     atm_info;
+
+    col_set_str(pinfo->cinfo, COL_PROTOCOL, "META");
+
+    schema   = tvb_get_letohs(tvb, 0);
+    hdrlen   = tvb_get_letohs(tvb, 2);
+    proto    = tvb_get_letohs(tvb, 4);
+    reserved = tvb_get_letohs(tvb, 6);
+
+    if (tree) {
+        ti = proto_tree_add_item(tree, proto_meta, tvb, 0, hdrlen + 4, ENC_NA);
+        meta_tree = proto_item_add_subtree(ti, ett_meta);
+        proto_tree_add_uint(meta_tree, hf_meta_schema, tvb, 0, 2, schema);
+        proto_tree_add_uint(meta_tree, hf_meta_hdrlen, tvb, 2, 2, hdrlen);
+        proto_tree_add_uint(meta_tree, hf_meta_proto, tvb, 4, 2, proto);
+        proto_tree_add_uint(meta_tree, hf_meta_reserved, tvb, 6, 2, reserved);
+    }
+    item_len = evaluate_meta_items(schema, tvb, pinfo, meta_tree, META_HEADER_SIZE, hdrlen, &atm_info);
+
+    if (item_len < 0) {
+        /* evaluate_meta_items signalled an error */
+        return META_HEADER_SIZE; /* stop parsing */
+    }
+
+    if (hdrlen != item_len) {
+        expert_add_info(pinfo, ti, &ei_meta_invalid_header);
+        return META_HEADER_SIZE;
+    }
+
+    /* find next subdissector based on the chosen schema */
+    switch (schema) {
+        case META_SCHEMA_PCAP:
+            /* TODO */
+            break;
+        case META_SCHEMA_DXT:
+            switch (proto) {
+                case META_PROTO_DXT_ETHERNET:
+                    next_dissector = ethwithoutfcs_handle;
+                    break;
+                case META_PROTO_DXT_ETHERNET_CRC:
+                    next_dissector = ethwithfcs_handle;
+                    break;
+                case META_PROTO_DXT_FP_HINT:
+                    next_dissector = fphint_handle;
+                    break;
+                case META_PROTO_DXT_ATM:
+                    memset(&atm_info, 0, sizeof atm_info);
+                    atm_info.aal  = AAL_OAMCELL;
+                    atm_info.type = TRAF_UNKNOWN;
+                    next_dissector = atm_untrunc_handle;
+                    next_dissector_data = &atm_info;
+                    break;
+                case META_PROTO_DXT_ATM_AAL2:
+                    aal2_ext = tvb_get_ntohl(tvb, item_len + META_HEADER_SIZE); item_len += 4;
+                    atm_hdr  = tvb_get_ntohl(tvb, item_len + META_HEADER_SIZE); item_len += 4;
+                    memset(&atm_info, 0, sizeof(atm_info));
+                    atm_info.aal = AAL_2;
+                    /* atm_info.flags = pinfo->p2p_dir; */
+                    atm_info.vpi  = ((atm_hdr & 0x0ff00000) >> 20);
+                    atm_info.vci  = ((atm_hdr & 0x000ffff0) >>  4);
+                    atm_info.aal2_cid = aal2_ext & 0x000000ff;
+                    atm_info.type = TRAF_UMTS_FP;
+                    next_dissector = atm_untrunc_handle;
+                    next_dissector_data = &atm_info;
+                    break;
+                case META_PROTO_DXT_ERF_AAL5:
+                    atm_hdr = tvb_get_ntohl(tvb, item_len + META_HEADER_SIZE); item_len += 4;
+                    atm_info.vpi = ((atm_hdr & 0x0ff00000) >> 20);
+                    atm_info.vci = ((atm_hdr & 0x000ffff0) >>  4);
+                    atm_info.aal = AAL_5;
+                    next_dissector = atm_untrunc_handle;
+                    next_dissector_data = &atm_info;
+                    break;
+                case META_PROTO_DXT_HDLC:
+                    next_dissector = mtp2_handle;
+                    next_tvb = tvb_new_subset_length_caplen(tvb, item_len + META_HEADER_SIZE,
+                        tvb_reported_length(tvb)-item_len-META_HEADER_SIZE-2, -1);
+                    break;
+                default:
+                    next_dissector =
+                        dissector_get_uint_handle(meta_dissector_table, proto);
+            }
+    }
+    if (!next_tvb)
+        next_tvb = tvb_new_subset_remaining(tvb, item_len + META_HEADER_SIZE);
+
+    call_dissector_with_data(next_dissector, next_tvb, pinfo, tree,
+                             next_dissector_data);
+    return tvb_captured_length(tvb);
+}
+
+void
+proto_register_meta(void)
+{
+    static hf_register_info hf[] = {
+        /* metadata header */
+        { &hf_meta_schema,
+          { "Schema", "meta.schema",
+            FT_UINT16, BASE_DEC, VALS(meta_schema_vals), 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_hdrlen,
+          { "Header Length", "meta.hdrlen",
+            FT_UINT16, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_proto,
+          { "Protocol", "meta.proto",
+            FT_UINT16, BASE_DEC | BASE_EXT_STRING, &meta_proto_vals_ext, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_reserved,
+          { "Reserved", "meta.reserved",
+            FT_UINT16, BASE_HEX, NULL, 0,
+            NULL, HFILL }
+        },
+
+        /* general meta item */
+        { &hf_meta_item,
+          { "Unknown Item", "meta.item",
+            FT_NONE, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_id,
+          { "Item ID", "meta.item.id",
+            FT_UINT16, BASE_HEX | BASE_EXT_STRING, &meta_id_vals_ext, 0x0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_type,
+          { "Item Type", "meta.item.type",
+            FT_UINT8, BASE_HEX, VALS(meta_type_vals), 0x0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_len,
+          { "Item Length", "meta.item.len",
+            FT_UINT8, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_data,
+          { "Item Data", "meta.item.data",
+            FT_BYTES, BASE_NONE, NULL, 0x0,
+            NULL, HFILL }
+        },
+
+        /* specific meta items */
+        { &hf_meta_item_direction,
+          { "Direction", "meta.direction",
+            FT_UINT8, BASE_DEC, VALS(meta_direction_vals), 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_ts,
+          { "Timestamp", "meta.timestamp",
+            FT_UINT64, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_phylinkid,
+          { "Physical Link ID", "meta.phylinkid",
+            FT_UINT16, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_nsapi,
+          { "NSAPI", "meta.nsapi",
+            FT_UINT8, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_imsi_digits,
+          { "IMSI digits", "meta.imsi_digits",
+            FT_STRING, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_imsi_value,
+          { "IMSI value", "meta.imsi_value",
+            FT_UINT64, BASE_HEX, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_imei_digits,
+          { "IMEI digits", "meta.imei_digits",
+            FT_STRING, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_imei_value,
+          { "IMEI value", "meta.imei_value",
+            FT_UINT64, BASE_HEX, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_signaling,
+          { "Signaling", "meta.signaling",
+            FT_BOOLEAN, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_incomplete,
+          { "Incomplete", "meta.incomplete",
+            FT_BOOLEAN, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_deciphered,
+          { "Deciphered", "meta.deciphered",
+            FT_BOOLEAN, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_apn,
+          { "APN", "meta.apn",
+            FT_STRINGZ, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_rat,
+          { "RAT", "meta.rat",
+            FT_UINT8, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_aal5proto,
+          { "AAL5 Protocol Type", "meta.aal5proto",
+            FT_UINT8, BASE_DEC, VALS(meta_aal5proto_vals), 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_cell,
+          { "Mobile Cell", "meta.cell",
+            FT_UINT64, BASE_HEX, NULL, 0,
+            NULL, HFILL }
+        },
+
+        { &hf_meta_item_localdevid,
+          { "Local Device ID", "meta.localdevid",
+            FT_UINT16, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_remotedevid,
+          { "Remote Device ID", "meta.remotedevid",
+            FT_UINT16, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_tapgroupid,
+          { "Tap Group ID", "meta.tapgroupid",
+            FT_UINT16, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_tlli,
+          { "TLLI", "meta.tlli",
+            FT_UINT32, BASE_DEC, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_calling,
+          { "Calling Station ID", "meta.calling",
+            FT_STRINGZ, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+        { &hf_meta_item_called,
+          { "Called Station ID", "meta.called",
+            FT_STRINGZ, BASE_NONE, NULL, 0,
+            NULL, HFILL }
+        },
+    };
+
+    static gint *ett[] = {
+        &ett_meta,
+        &ett_meta_item,
+        &ett_meta_cell,
+        &ett_meta_imsi,
+        &ett_meta_imei
+    };
+
+    static ei_register_info ei[] = {
+        { &ei_meta_malformed, { "meta.malformed", PI_MALFORMED, PI_ERROR, "Malformed data", EXPFILL }},
+        { &ei_meta_invalid_header, { "meta.invalid_header_length", PI_MALFORMED, PI_ERROR, "Invalid Header Length", EXPFILL }},
+    };
+
+    expert_module_t* expert_meta;
+
+    proto_meta = proto_register_protocol("Metadata", "META", "meta");
+    register_dissector("meta", dissect_meta, proto_meta);
+
+    proto_register_field_array(proto_meta, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+    expert_meta = expert_register_protocol(proto_meta);
+    expert_register_field_array(expert_meta, ei, array_length(ei));
+
+    meta_dissector_table = register_dissector_table("meta.proto",
+            "META protocol", proto_meta, FT_UINT16, BASE_DEC);
+}
+
+void
+proto_reg_handoff_meta(void)
+{
+#if 0   /* enable once WTAP_ENCAP_META exists */
+    dissector_handle_t meta_handle;
+
+    meta_handle          = find_dissector("meta");
+    dissector_add_uint("wtap_encap", WTAP_ENCAP_META, meta_handle);
+#endif
+    data_handle          = find_dissector("data");
+    alcap_handle         = find_dissector_add_dependency("alcap", proto_meta);
+    atm_untrunc_handle   = find_dissector_add_dependency("atm_untruncated", proto_meta);
+    nbap_handle          = find_dissector_add_dependency("nbap", proto_meta);
+    sscf_nni_handle      = find_dissector_add_dependency("sscf-nni", proto_meta);
+    ethwithfcs_handle    = find_dissector_add_dependency("eth_withfcs", proto_meta);
+    ethwithoutfcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_meta);
+    fphint_handle        = find_dissector_add_dependency("fp_hint", proto_meta);
+    mtp2_handle          = find_dissector_add_dependency("mtp2", proto_meta);
+}
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */