Fix some gcc 4.6 "set but not used [-Wunused-but-set-variable]" warnings;
[metze/wireshark/wip.git] / epan / dissectors / packet-pdcp-lte.c
index 9fc39b13d1ce22e0a664967fafe36a2b1ce1f928..310606be92c862019c76bc2309ce318a8209d3ce 100644 (file)
 
 
 /* TODO:
-   - Update to latest version of 36.323
    - Complete ROHC support for RTP and extend to other profiles (including ROHCv2)
-   - Support for decryption
+   - Support for deciphering
    - Verify MAC authentication bytes
-   - Call LTE RRC dissector for uncompressed, signalling payloads
 */
 
 
 /* Initialize the protocol and registered fields. */
 int proto_pdcp_lte = -1;
 
+extern int proto_rlc_lte;
+
 /* Configuration (info known outside of PDU) */
 static int hf_pdcp_lte_configuration = -1;
 static int hf_pdcp_lte_direction = -1;
+static int hf_pdcp_lte_ueid = -1;
+static int hf_pdcp_lte_channel_type = -1;
+static int hf_pdcp_lte_channel_id = -1;
 static int hf_pdcp_lte_rohc = -1;
 static int hf_pdcp_lte_rohc_compression = -1;
 static int hf_pdcp_lte_rohc_mode = -1;
@@ -167,11 +170,23 @@ static int hf_pdcp_lte_rohc_ip_id = -1;
 static int hf_pdcp_lte_rohc_udp_checksum = -1;
 static int hf_pdcp_lte_rohc_payload = -1;
 
+/* Sequence Analysis */
+static int hf_pdcp_lte_sequence_analysis = -1;
+static int hf_pdcp_lte_sequence_analysis_ok = -1;
+static int hf_pdcp_lte_sequence_analysis_previous_frame = -1;
+static int hf_pdcp_lte_sequence_analysis_expected_sn = -1;
+
+static int hf_pdcp_lte_sequence_analysis_repeated = -1;
+static int hf_pdcp_lte_sequence_analysis_skipped = -1;
+
+
+
 
 /* Protocol subtree. */
 static int ett_pdcp = -1;
 static int ett_pdcp_configuration = -1;
 static int ett_pdcp_packet = -1;
+static int ett_pdcp_lte_sequence_analysis = -1;
 static int ett_pdcp_rohc = -1;
 static int ett_pdcp_rohc_static_ipv4 = -1;
 static int ett_pdcp_rohc_static_udp = -1;
@@ -196,6 +211,13 @@ static const value_string pdcp_plane_vals[] = {
     { 0,   NULL }
 };
 
+static const value_string logical_channel_vals[] = {
+    { Channel_DCCH,  "DCCH"},
+    { Channel_BCCH,  "BCCH"},
+    { Channel_CCCH,  "CCCH"},
+    { Channel_PCCH,  "PCCH"},
+    { 0,             NULL}
+};
 
 static const value_string rohc_mode_vals[] = {
     { UNIDIRECTIONAL,            "Unidirectional" },
@@ -205,13 +227,26 @@ static const value_string rohc_mode_vals[] = {
 };
 
 
-/* TODO: add more */
+/* Values taken from:
+   http://www.iana.org/assignments/rohc-pro-ids/rohc-pro-ids.txt */
 static const value_string rohc_profile_vals[] = {
-    { 0,   "Uncompressed" },
-    { 1,   "RTP" },
-    { 2,   "UDP" },
-    { 3,   "ESP/IP" },
-    { 0,   NULL }
+         { 0x0000,   "ROHC uncompressed" },      /* [RFC5795] */
+         { 0x0001,   "ROHC RTP" },               /* [RFC3095] */
+         { 0x0101,   "ROHCv2 RTP" },             /* [RFC5225] */
+         { 0x0002,   "ROHC UDP" },               /* [RFC3095] */
+         { 0x0102,   "ROHCv2 UDP" },             /* [RFC5225] */
+         { 0x0003,   "ROHC ESP" },               /* [RFC3095] */
+         { 0x0103,   "ROHCv2 ESP" },             /* [RFC5225] */
+         { 0x0004,   "ROHC IP" },                /* [RFC3843] */
+         { 0x0104,   "ROHCv2 IP" },              /* [RFC5225] */
+         { 0x0005,   "ROHC LLA" },               /* [RFC4362] */
+         { 0x0105,   "ROHC LLA with R-mode" },   /* [RFC3408] */
+         { 0x0006,   "ROHC TCP" },               /* [RFC4996] */
+         { 0x0007,   "ROHC RTP/UDP-Lite" },      /* [RFC4019] */
+         { 0x0107,   "ROHCv2 RTP/UDP-Lite" },    /* [RFC5225] */
+         { 0x0008,   "ROHC UDP-Lite" },          /* [RFC4019] */
+         { 0x0108,   "ROHCv2 UDP-Lite" },        /* [RFC5225] */
+         { 0,   NULL }
 };
 
 static const value_string pdu_type_vals[] = {
@@ -257,15 +292,347 @@ static const value_string ip_protocol_vals[] = {
 };
 
 
-dissector_handle_t ip_handle = 0;
+static dissector_handle_t ip_handle;
 
 
 /* Preference variables */
 static gboolean global_pdcp_show_feedback_option_tag_length = FALSE;
 static gboolean global_pdcp_dissect_user_plane_as_ip = FALSE;
 static gboolean global_pdcp_dissect_signalling_plane_as_rrc = FALSE;
+static gboolean global_pdcp_check_sequence_numbers = FALSE;
 static gboolean global_pdcp_dissect_rohc = FALSE;
 
+
+/**************************************************/
+/* Sequence number analysis                       */
+
+/* Channel key */
+typedef struct
+{
+    guint16            ueId;
+    LogicalChannelType channelType;
+    guint16            channelId;
+    guint8             direction;
+} pdcp_channel_hash_key;
+
+/* Channel state */
+typedef struct
+{
+    guint16  previousSequenceNumber;
+    guint32  previousFrameNum;
+} pdcp_channel_status;
+
+/* The sequence analysis channel hash table.
+   Maps key -> status */
+static GHashTable *pdcp_sequence_analysis_channel_hash = NULL;
+
+/* Equal keys */
+static gint pdcp_channel_equal(gconstpointer v, gconstpointer v2)
+{
+    const pdcp_channel_hash_key* val1 = v;
+    const pdcp_channel_hash_key* val2 = v2;
+
+    /* All fields must match */
+    return (memcmp(val1, val2, sizeof(pdcp_channel_hash_key)) == 0);
+}
+
+/* Compute a hash value for a given key. */
+static guint pdcp_channel_hash_func(gconstpointer v)
+{
+    const pdcp_channel_hash_key* val1 = v;
+
+    /* TODO: use multipliers */
+    return val1->ueId + val1->channelType + val1->channelId + val1->direction;
+}
+
+/* Hash table functions for frame reports */
+
+/* TODO: copied from packet-rlc-lte.c.  extern, or add to lib? */
+/* Equal keys */
+static gint pdcp_frame_equal(gconstpointer v, gconstpointer v2)
+{
+    return (v == v2);
+}
+
+/* Compute a hash value for a given key. */
+static guint pdcp_frame_hash_func(gconstpointer v)
+{
+    return GPOINTER_TO_UINT(v);
+}
+
+
+/* Info to attach to frame when first read, recording what to show about sequence */
+typedef struct
+{
+    gboolean  sequenceExpectedCorrect;
+    guint16   sequenceExpected;
+    guint32   previousFrameNum;
+
+    guint16   firstSN;
+    guint16   lastSN;
+
+    enum { SN_OK, SN_Repeated, SN_MAC_Retx, SN_Retx, SN_Missing} state;
+} pdcp_sequence_report_in_frame;
+
+/* The sequence analysis frame report hash table instance itself   */
+static GHashTable *pdcp_lte_frame_sequence_analysis_report_hash = NULL;
+
+
+/* Add to the tree values associated with sequence analysis for this frame */
+static void addChannelSequenceInfo(pdcp_sequence_report_in_frame *p,
+                                   pdcp_lte_info *p_pdcp_lte_info,
+                                   guint16   sequenceNumber,
+                                   packet_info *pinfo, proto_tree *tree, tvbuff_t *tvb)
+{
+    proto_tree *seqnum_tree;
+    proto_item *seqnum_ti;
+    proto_item *ti;
+
+    /* Create subtree */
+    seqnum_ti = proto_tree_add_string_format(tree,
+                                             hf_pdcp_lte_sequence_analysis,
+                                             tvb, 0, 0,
+                                             "", "Sequence Analysis");
+    seqnum_tree = proto_item_add_subtree(seqnum_ti,
+                                         ett_pdcp_lte_sequence_analysis);
+    PROTO_ITEM_SET_GENERATED(seqnum_ti);
+
+
+    /* Previous channel frame */
+    if (p->previousFrameNum != 0) {
+        proto_tree_add_uint(seqnum_tree, hf_pdcp_lte_sequence_analysis_previous_frame,
+                            tvb, 0, 0, p->previousFrameNum);
+    }
+
+    /* Expected sequence number */
+    ti = proto_tree_add_uint(seqnum_tree, hf_pdcp_lte_sequence_analysis_expected_sn,
+                            tvb, 0, 0, p->sequenceExpected);
+    PROTO_ITEM_SET_GENERATED(ti);
+
+    /* Make sure we have recognised SN length */
+    switch (p_pdcp_lte_info->seqnum_length) {
+        case PDCP_SN_LENGTH_5_BITS:
+        case PDCP_SN_LENGTH_7_BITS:
+        case PDCP_SN_LENGTH_12_BITS:
+            break;
+        default:
+            DISSECTOR_ASSERT_NOT_REACHED();
+            break;
+    }
+
+    switch (p->state) {
+        case SN_OK:
+            ti = proto_tree_add_boolean(seqnum_tree, hf_pdcp_lte_sequence_analysis_ok,
+                                        tvb, 0, 0, TRUE);
+            PROTO_ITEM_SET_GENERATED(ti);
+            proto_item_append_text(seqnum_ti, " - OK");
+            break;
+
+        case SN_Missing:
+            ti = proto_tree_add_boolean(seqnum_tree, hf_pdcp_lte_sequence_analysis_ok,
+                                        tvb, 0, 0, FALSE);
+            PROTO_ITEM_SET_GENERATED(ti);
+            ti = proto_tree_add_boolean(seqnum_tree, hf_pdcp_lte_sequence_analysis_skipped,
+                                        tvb, 0, 0, TRUE);
+            PROTO_ITEM_SET_GENERATED(ti);
+            if (p->lastSN != p->firstSN) {
+                expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
+                                       "PDCP SNs (%u to %u) missing for %s on UE %u",
+                                       p->firstSN, p->lastSN,
+                                       val_to_str_const(p_pdcp_lte_info->direction, direction_vals, "Unknown"),
+                                       p_pdcp_lte_info->ueid);
+                proto_item_append_text(seqnum_ti, " - SNs missing (%u to %u)",
+                                       p->firstSN, p->lastSN);
+            }
+            else {
+                expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
+                                       "PDCP SN (%u) missing for %s on UE %u",
+                                       p->firstSN,
+                                       val_to_str_const(p_pdcp_lte_info->direction, direction_vals, "Unknown"),
+                                       p_pdcp_lte_info->ueid);
+                proto_item_append_text(seqnum_ti, " - SN missing (%u)",
+                                       p->firstSN);
+            }
+            break;
+
+        case SN_Repeated:
+            ti = proto_tree_add_boolean(seqnum_tree, hf_pdcp_lte_sequence_analysis_ok,
+                                        tvb, 0, 0, FALSE);
+            PROTO_ITEM_SET_GENERATED(ti);
+            ti = proto_tree_add_boolean(seqnum_tree, hf_pdcp_lte_sequence_analysis_repeated,
+                                        tvb, 0, 0, TRUE);
+            PROTO_ITEM_SET_GENERATED(ti);
+            expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
+                                   "PDCP SN (%u) repeated for %s for UE %u",
+                                   p->firstSN,
+                                   val_to_str_const(p_pdcp_lte_info->direction, direction_vals, "Unknown"),
+                                   p_pdcp_lte_info->ueid);
+            proto_item_append_text(seqnum_ti, "- SN %u Repeated",
+                                   p->firstSN);
+            break;
+
+        default:
+            /* Incorrect sequence number */
+            expert_add_info_format(pinfo, ti, PI_SEQUENCE, PI_WARN,
+                                   "Wrong Sequence Number for %s on UE %u - got %u, expected %u",
+                                   val_to_str_const(p_pdcp_lte_info->direction, direction_vals, "Unknown"),
+                                   p_pdcp_lte_info->ueid, sequenceNumber, p->sequenceExpected);
+            break;
+    }
+}
+
+
+/* Update the channel status and set report for this frame */
+static void checkChannelSequenceInfo(packet_info *pinfo, tvbuff_t *tvb,
+                                     pdcp_lte_info *p_pdcp_lte_info,
+                                     guint16 sequenceNumber,
+                                     proto_tree *tree)
+{
+    pdcp_channel_hash_key          channel_key;
+    pdcp_channel_hash_key          *p_channel_key;
+    pdcp_channel_status            *p_channel_status;
+    pdcp_sequence_report_in_frame  *p_report_in_frame = NULL;
+    gboolean               createdChannel = FALSE;
+    guint16                expectedSequenceNumber = 0;
+    guint16                snLimit = 0;
+
+    /* If find stat_report_in_frame already, use that and get out */
+    if (pinfo->fd->flags.visited) {
+        p_report_in_frame = (pdcp_sequence_report_in_frame*)g_hash_table_lookup(pdcp_lte_frame_sequence_analysis_report_hash,
+                                                                                &pinfo->fd->num);
+        if (p_report_in_frame != NULL) {
+            addChannelSequenceInfo(p_report_in_frame, p_pdcp_lte_info,
+                                   sequenceNumber,
+                                   pinfo, tree, tvb);
+            return;
+        }
+        else {
+            /* Give up - we must have tried already... */
+            return;
+        }
+    }
+
+
+    /**************************************************/
+    /* Create or find an entry for this channel state */
+    memset(&channel_key, 0, sizeof(channel_key));
+    channel_key.ueId = p_pdcp_lte_info->ueid;
+    channel_key.channelType = p_pdcp_lte_info->channelType;
+    channel_key.channelId = p_pdcp_lte_info->channelId;
+    channel_key.direction = p_pdcp_lte_info->direction;
+
+    /* Do the table lookup */
+    p_channel_status = (pdcp_channel_status*)g_hash_table_lookup(pdcp_sequence_analysis_channel_hash, &channel_key);
+
+    /* Create table entry if necessary */
+    if (p_channel_status == NULL) {
+        createdChannel = TRUE;
+
+        /* Allocate a new value and duplicate key contents */
+        p_channel_status = se_alloc0(sizeof(pdcp_channel_status));
+        p_channel_key = se_memdup(&channel_key, sizeof(pdcp_channel_hash_key));
+
+        /* Add entry */
+        g_hash_table_insert(pdcp_sequence_analysis_channel_hash, p_channel_key, p_channel_status);
+    }
+
+    /* Create space for frame state_report */
+    p_report_in_frame = se_alloc(sizeof(pdcp_sequence_report_in_frame));
+
+    switch (p_pdcp_lte_info->seqnum_length) {
+        case PDCP_SN_LENGTH_5_BITS:
+            snLimit = 32;
+            break;
+        case PDCP_SN_LENGTH_7_BITS:
+            snLimit = 128;
+            break;
+        case PDCP_SN_LENGTH_12_BITS:
+            snLimit = 4096;
+            break;
+        default:
+            DISSECTOR_ASSERT_NOT_REACHED();
+            break;
+    }
+
+    /* Work out expected sequence number */
+    if (!createdChannel) {
+        expectedSequenceNumber = (p_channel_status->previousSequenceNumber + 1) % snLimit;
+    }
+
+    /* Set report for this frame */
+    /* For PDCP, sequence number is always expectedSequence number */
+    p_report_in_frame->sequenceExpectedCorrect = (sequenceNumber == expectedSequenceNumber);
+
+    /* For wrong sequence number... */
+    if (!p_report_in_frame->sequenceExpectedCorrect) {
+
+        /* Frames are not missing if we get an earlier sequence number again */
+        if (((snLimit + expectedSequenceNumber - sequenceNumber) % snLimit) > 15) {
+            p_report_in_frame->state = SN_Missing;
+            p_report_in_frame->firstSN = expectedSequenceNumber;
+            p_report_in_frame->lastSN = (snLimit + sequenceNumber - 1) % snLimit;
+
+            p_report_in_frame->sequenceExpected = expectedSequenceNumber;
+            p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
+
+            /* Update channel status to remember *this* frame */
+            p_channel_status->previousFrameNum = pinfo->fd->num;
+            p_channel_status->previousSequenceNumber = sequenceNumber;
+        }
+        else {
+            /* An SN has been repeated */
+            p_report_in_frame->state = SN_Repeated;
+            p_report_in_frame->firstSN = sequenceNumber;
+
+            p_report_in_frame->sequenceExpected = expectedSequenceNumber;
+            p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
+        }
+    }
+    else {
+        /* SN was OK */
+        p_report_in_frame->state = SN_OK;
+        p_report_in_frame->sequenceExpected = expectedSequenceNumber;
+        p_report_in_frame->previousFrameNum = p_channel_status->previousFrameNum;
+
+        /* Update channel status to remember *this* frame */
+        p_channel_status->previousFrameNum = pinfo->fd->num;
+        p_channel_status->previousSequenceNumber = sequenceNumber;
+    }
+
+    /* Associate with this frame number */
+    g_hash_table_insert(pdcp_lte_frame_sequence_analysis_report_hash, &pinfo->fd->num, p_report_in_frame);
+
+    /* Add state report for this frame into tree */
+    addChannelSequenceInfo(p_report_in_frame, p_pdcp_lte_info, sequenceNumber,
+                           pinfo, tree, tvb);
+}
+
+
+/* Write the given formatted text to:
+   - the info column
+   - the top-level RLC PDU item */
+static void write_pdu_label_and_info(proto_item *pdu_ti,
+                                     packet_info *pinfo, const char *format, ...)
+{
+    #define MAX_INFO_BUFFER 256
+    static char info_buffer[MAX_INFO_BUFFER];
+
+    va_list ap;
+
+    va_start(ap, format);
+    g_vsnprintf(info_buffer, MAX_INFO_BUFFER, format, ap);
+    va_end(ap);
+
+    /* Add to indicated places */
+    col_append_str(pinfo->cinfo, COL_INFO, info_buffer);
+    proto_item_append_text(pdu_ti, "%s", info_buffer);
+}
+
+
+
+/***************************************************************/
+
+
 /* Dissect a Large-CID field.
    Return following offset */
 static int dissect_large_cid(proto_tree *tree,
@@ -380,7 +747,7 @@ static int dissect_pdcp_dynamic_chain(proto_tree *tree,
         proto_item *root_ti;
         int tree_start_offset = offset;
         guint8     rx;
-        guint8     contributing_csrcs;
+        /*guint8     contributing_csrcs;*/
         guint16    sequence_number;
         guint32    timestamp;
         guint8     tis=0, tss=0;
@@ -394,7 +761,7 @@ static int dissect_pdcp_dynamic_chain(proto_tree *tree,
         /* V | P | RX | CC */
         rx = tvb_get_guint8(tvb, offset) & 0x10;
         proto_tree_add_item(dynamic_rtp_tree, hf_pdcp_lte_rohc_dynamic_rtp_rx, tvb, offset, 1, FALSE);
-        contributing_csrcs = tvb_get_guint8(tvb, offset) & 0x0f;
+        /*contributing_csrcs = tvb_get_guint8(tvb, offset) & 0x0f;*/
         proto_tree_add_item(dynamic_rtp_tree, hf_pdcp_lte_rohc_dynamic_rtp_cc, tvb, offset, 1, FALSE);
         offset += 1;
 
@@ -464,11 +831,11 @@ static int dissect_pdcp_dynamic_chain(proto_tree *tree,
 
 
 
-static int dissect_pdcp_irdyn_packet(proto_tree *tree _U_,
+static int dissect_pdcp_irdyn_packet(proto_tree *tree,
                                      proto_item *root_item,
-                                     tvbuff_t *tvb _U_,
+                                     tvbuff_t *tvb,
                                      int offset,
-                                     struct pdcp_lte_info *p_pdcp_info _U_,
+                                     struct pdcp_lte_info *p_pdcp_info,
                                      packet_info *pinfo)
 {
     col_append_str(pinfo->cinfo, COL_INFO, " IRDYN");
@@ -661,8 +1028,8 @@ static int dissect_pdcp_feedback_feedback2(proto_tree *tree,
                                            tvbuff_t *tvb,
                                            int offset,
                                            int size,
-                                           struct pdcp_lte_info *p_pdcp_info _U_,
-                                           packet_info *pinfo _U_)
+                                           struct pdcp_lte_info *p_pdcp_info,
+                                           packet_info *pinfo)
 {
     proto_item *ti;
     guint8  ack_type;
@@ -847,7 +1214,7 @@ static int dissect_pdcp_r_0_packet(proto_tree *tree,
                                    proto_item *root_item,
                                    tvbuff_t *tvb,
                                    int offset,
-                                   struct pdcp_lte_info *p_pdcp_info _U_,
+                                   struct pdcp_lte_info *p_pdcp_info,
                                    packet_info *pinfo)
 {
     guint8 sn;
@@ -1241,6 +1608,25 @@ static void show_pdcp_config(packet_info *pinfo, tvbuff_t *tvb, proto_tree *tree
                              p_pdcp_info->plane);
     PROTO_ITEM_SET_GENERATED(ti);
 
+    /* UEId */
+    if (p_pdcp_info->ueid != 0) {
+        ti = proto_tree_add_uint(configuration_tree, hf_pdcp_lte_ueid, tvb, 0, 0,
+                                 p_pdcp_info->ueid);
+        PROTO_ITEM_SET_GENERATED(ti);
+    }
+
+    /* Channel type */
+    ti = proto_tree_add_uint(configuration_tree, hf_pdcp_lte_channel_type, tvb, 0, 0,
+                             p_pdcp_info->channelType);
+    PROTO_ITEM_SET_GENERATED(ti);
+    if (p_pdcp_info->channelId != 0) {
+        /* Channel type */
+        ti = proto_tree_add_uint(configuration_tree, hf_pdcp_lte_channel_id, tvb, 0, 0,
+                                 p_pdcp_info->channelId);
+        PROTO_ITEM_SET_GENERATED(ti);
+    }
+
+
     /* User-plane-specific fields */
     if (p_pdcp_info->plane == USER_PLANE) {
 
@@ -1365,7 +1751,6 @@ static dissector_handle_t lookup_rrc_dissector_handle(struct pdcp_lte_info  *p_p
 
 
 /* Forwad declarations */
-void proto_reg_handoff_pdcp_lte(void);
 static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
 
 /* Heuristic dissection */
@@ -1391,17 +1776,6 @@ static gboolean dissect_pdcp_lte_heur(tvbuff_t *tvb, packet_info *pinfo,
         return FALSE;
     }
 
-    /* If redissecting, use previous info struct (if available) */
-    p_pdcp_lte_info = p_get_proto_data(pinfo->fd, proto_pdcp_lte);
-    if (p_pdcp_lte_info == NULL) {
-        /* Allocate new info struct for this frame */
-        p_pdcp_lte_info = se_alloc0(sizeof(struct pdcp_lte_info));
-        infoAlreadySet = FALSE;
-    }
-    else {
-        infoAlreadySet = TRUE;
-    }
-
     /* Do this again on re-dissection to re-discover offset of actual PDU */
 
     /* Needs to be at least as long as:
@@ -1414,11 +1788,24 @@ static gboolean dissect_pdcp_lte_heur(tvbuff_t *tvb, packet_info *pinfo,
     }
 
     /* OK, compare with signature string */
-    if (tvb_strneql(tvb, offset, PDCP_LTE_START_STRING, (gint)strlen(PDCP_LTE_START_STRING)) != 0) {
+    if (tvb_strneql(tvb, offset, PDCP_LTE_START_STRING, strlen(PDCP_LTE_START_STRING)) != 0) {
         return FALSE;
     }
     offset += (gint)strlen(PDCP_LTE_START_STRING);
 
+
+    /* If redissecting, use previous info struct (if available) */
+    p_pdcp_lte_info = p_get_proto_data(pinfo->fd, proto_pdcp_lte);
+    if (p_pdcp_lte_info == NULL) {
+        /* Allocate new info struct for this frame */
+        p_pdcp_lte_info = se_alloc0(sizeof(struct pdcp_lte_info));
+        infoAlreadySet = FALSE;
+    }
+    else {
+        infoAlreadySet = TRUE;
+    }
+
+
     /* Read fixed fields */
     p_pdcp_lte_info->no_header_pdu = tvb_get_guint8(tvb, offset++);
     p_pdcp_lte_info->plane = tvb_get_guint8(tvb, offset++);
@@ -1556,6 +1943,10 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
     /* Handle PDCP header (if present) */
     if (!p_pdcp_info->no_header_pdu) {
 
+        /* TODO: shouldn't need to initialise this one!! */
+        guint16  seqnum = 0;
+        gboolean seqnum_set = FALSE;
+
         /*****************************/
         /* Signalling plane messages */
         if (p_pdcp_info->plane == SIGNALING_PLANE) {
@@ -1563,12 +1954,12 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
             guint32 data_length;
 
             /* 5-bit sequence number */
+            seqnum = tvb_get_guint8(tvb, offset) & 0x1f;
+            seqnum_set = TRUE;
             proto_tree_add_item(pdcp_tree, hf_pdcp_lte_seq_num_5, tvb, offset, 1, FALSE);
-            col_append_fstr(pinfo->cinfo, COL_INFO, " sn=%u ",
-                            tvb_get_guint8(tvb, offset) & 0x1f);
+            write_pdu_label_and_info(root_ti, pinfo, " sn=%-2u ", seqnum);
             offset++;
 
-
             /* RRC data is all but last 4 bytes.
                Call lte-rrc dissector (according to direction and channel type) */
             if (global_pdcp_dissect_signalling_plane_as_rrc) {
@@ -1605,13 +1996,11 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
             col_append_fstr(pinfo->cinfo, COL_INFO, " MAC=0x%08x (%u bytes data)",
                             mac, data_length);
 
-            return;
         }
         else if (p_pdcp_info->plane == USER_PLANE) {
 
             /**********************************/
             /* User-plane messages            */
-            guint16 seqnum;
             gboolean pdu_type = (tvb_get_guint8(tvb, offset) & 0x80) >> 7;
 
             /* Data/Control flag */
@@ -1624,6 +2013,7 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
                 /* Number of sequence number bits depends upon config */
                 if (p_pdcp_info->seqnum_length == PDCP_SN_LENGTH_7_BITS) {
                     seqnum = tvb_get_guint8(tvb, offset) & 0x7f;
+                    seqnum_set = TRUE;
                     proto_tree_add_item(pdcp_tree, hf_pdcp_lte_seq_num_7, tvb, offset, 1, FALSE);
                     offset++;
                 }
@@ -1644,6 +2034,7 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
 
                     /* 12-bit sequence number */
                     seqnum = tvb_get_ntohs(tvb, offset) & 0x0fff;
+                    seqnum_set = TRUE;
                     proto_tree_add_item(pdcp_tree, hf_pdcp_lte_seq_num_12, tvb, offset, 2, FALSE);
                     offset += 2;
                 }
@@ -1652,7 +2043,7 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
                     return;
                 }
 
-                col_append_fstr(pinfo->cinfo, COL_INFO, " sn=%u ", seqnum);
+                write_pdu_label_and_info(root_ti, pinfo, " (SN=%u)", seqnum);
             }
             else {
                 /*******************************/
@@ -1701,9 +2092,8 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
                             if (bitmap_ti != NULL) {
                                 proto_item_append_text(bitmap_ti, " (not-received=%u)", not_received);
                             }
-                            col_append_fstr(pinfo->cinfo, COL_INFO,
-                                           " Status Report (fms=%u) not-received=%u",
-                                           fms, not_received);
+                            write_pdu_label_and_info(root_ti, pinfo, " Status Report (fms=%u) not-received=%u",
+                                                    fms, not_received);
                         }
                         return;
 
@@ -1718,55 +2108,64 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
         }
         else {
             /* Invalid plane setting...! */
-            col_append_fstr(pinfo->cinfo, COL_INFO, " - INVALID PLANE (%u)",
-                            p_pdcp_info->plane);
+            write_pdu_label_and_info(root_ti, pinfo, " - INVALID PLANE (%u)",
+                                     p_pdcp_info->plane);
             return;
         }
+
+        /* For now, only do sequence analysis if RLC wasn't present in the frame */
+        /* This can be fixed once RLC does re-assembly... */
+        if (global_pdcp_check_sequence_numbers && seqnum_set &&
+             (p_get_proto_data(pinfo->fd, proto_rlc_lte) == NULL)) {
+
+            checkChannelSequenceInfo(pinfo, tvb, p_pdcp_info,
+                                     (guint16)seqnum, pdcp_tree);
+        }
+
     }
     else {
         /* Show that its a no-header PDU */
-        col_append_str(pinfo->cinfo, COL_INFO, " No-Header ");
+        write_pdu_label_and_info(root_ti, pinfo, " No-Header ");
     }
 
 
     /* If not compressed with ROHC, show as user-plane data */
     if (!p_pdcp_info->rohc_compression) {
-
-        if (global_pdcp_dissect_user_plane_as_ip && (ip_handle != 0)) {
-            tvbuff_t *payload_tvb = tvb_new_subset_remaining(tvb, offset);
-            call_dissector_only(ip_handle, payload_tvb, pinfo, pdcp_tree);
-        }
-        else {
-            if (tvb_length_remaining(tvb, offset) > 0) {
-                if (p_pdcp_info->plane == USER_PLANE) {
-                    proto_tree_add_item(pdcp_tree, hf_pdcp_lte_user_plane_data, tvb, offset, -1, FALSE);
+        if (tvb_length_remaining(tvb, offset) > 0) {
+            if (p_pdcp_info->plane == USER_PLANE) {
+                if (global_pdcp_dissect_user_plane_as_ip) {
+                    tvbuff_t *payload_tvb = tvb_new_subset_remaining(tvb, offset);
+                    call_dissector_only(ip_handle, payload_tvb, pinfo, pdcp_tree);
                 }
                 else {
-                    if (global_pdcp_dissect_signalling_plane_as_rrc) {
-                        /* Get appropriate dissector handle */
-                        dissector_handle_t rrc_handle = lookup_rrc_dissector_handle(p_pdcp_info);
-
-                        if (rrc_handle != 0) {
-                            /* Call RRC dissector if have one */
-                            tvbuff_t *payload_tvb = tvb_new_subset(tvb, offset,
-                                                                   tvb_length_remaining(tvb, offset),
-                                                                   tvb_length_remaining(tvb, offset));
-                            call_dissector_only(rrc_handle, payload_tvb, pinfo, pdcp_tree);
-                        }
-                        else {
-                             /* Just show data */
-                             proto_tree_add_item(pdcp_tree, hf_pdcp_lte_signalling_data, tvb, offset,
-                                                 tvb_length_remaining(tvb, offset), FALSE);
-                        }
+                    proto_tree_add_item(pdcp_tree, hf_pdcp_lte_user_plane_data, tvb, offset, -1, FALSE);
+                }
+            }
+            else {
+                if (global_pdcp_dissect_signalling_plane_as_rrc) {
+                    /* Get appropriate dissector handle */
+                    dissector_handle_t rrc_handle = lookup_rrc_dissector_handle(p_pdcp_info);
+
+                    if (rrc_handle != 0) {
+                        /* Call RRC dissector if have one */
+                        tvbuff_t *payload_tvb = tvb_new_subset(tvb, offset,
+                                                               tvb_length_remaining(tvb, offset),
+                                                               tvb_length_remaining(tvb, offset));
+                        call_dissector_only(rrc_handle, payload_tvb, pinfo, pdcp_tree);
                     }
                     else {
-                        proto_tree_add_item(pdcp_tree, hf_pdcp_lte_signalling_data, tvb, offset, -1, FALSE);
+                         /* Just show data */
+                         proto_tree_add_item(pdcp_tree, hf_pdcp_lte_signalling_data, tvb, offset,
+                                             tvb_length_remaining(tvb, offset), FALSE);
                     }
                 }
-
-                col_append_fstr(pinfo->cinfo, COL_INFO, "(%u bytes data)",
-                                tvb_length_remaining(tvb, offset));
+                else {
+                    proto_tree_add_item(pdcp_tree, hf_pdcp_lte_signalling_data, tvb, offset, -1, FALSE);
+                }
             }
+
+            write_pdu_label_and_info(root_ti, pinfo, "(%u bytes data)",
+                                     tvb_length_remaining(tvb, offset));
         }
         return;
     }
@@ -1890,14 +2289,12 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
                  /* UO-1 if !(ipv4 && rand) */
                  if (!((p_pdcp_info->rohc_ip_version == 4) &&
                       (!p_pdcp_info->rnd))) {
-                    offset = dissect_pdcp_uo_1_packet(rohc_tree, rohc_ti, tvb, offset, p_pdcp_info, pinfo);
-                    return;
-                 }
-                else {
+
+                    dissect_pdcp_uo_1_packet(rohc_tree, rohc_ti, tvb, offset, p_pdcp_info, pinfo);
+                 } else {
                     /* Whether its UO-1-ID or UO-1-TS depends upon T bit */
                     dissect_pdcp_uo_1_ts_or_id_packet(rohc_tree, rohc_ti, tvb, offset, p_pdcp_info, pinfo);
-                    return;
-                }
+                 }
 
                 return;
 
@@ -1911,7 +2308,7 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
         if (!((p_pdcp_info->rohc_ip_version == 4) &&
               (!p_pdcp_info->rnd))) {
 
-            offset = dissect_pdcp_uor_2_packet(rohc_tree, rohc_ti, tvb, offset, p_pdcp_info, pinfo);
+            dissect_pdcp_uor_2_packet(rohc_tree, rohc_ti, tvb, offset, p_pdcp_info, pinfo);
         }
         else {
             /* Whether its UOR-2-ID or UOR-2-TS depends upon T bit */
@@ -1949,6 +2346,27 @@ static void dissect_pdcp_lte(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree
     }
 }
 
+/* Initializes the hash table and the mem_chunk area each time a new
+ * file is loaded or re-loaded in wireshark */
+static void
+pdcp_lte_init_protocol(void)
+{
+    /* Destroy any existing hashes. */
+    if (pdcp_sequence_analysis_channel_hash) {
+        g_hash_table_destroy(pdcp_sequence_analysis_channel_hash);
+    }
+    if (pdcp_lte_frame_sequence_analysis_report_hash) {
+        g_hash_table_destroy(pdcp_lte_frame_sequence_analysis_report_hash);
+    }
+
+
+    /* Now create them over */
+    pdcp_sequence_analysis_channel_hash = g_hash_table_new(pdcp_channel_hash_func, pdcp_channel_equal);
+    pdcp_lte_frame_sequence_analysis_report_hash = g_hash_table_new(pdcp_frame_hash_func, pdcp_frame_equal);
+}
+
+
+
 void proto_register_pdcp(void)
 {
     static hf_register_info hf[] =
@@ -1990,6 +2408,24 @@ void proto_register_pdcp(void)
               "Direction of message", HFILL
             }
         },
+        { &hf_pdcp_lte_ueid,
+            { "UE",
+              "pdcp-lte.ueid", FT_UINT16, BASE_DEC, 0, 0x0,
+              "UE Identifier", HFILL
+            }
+        },
+        { &hf_pdcp_lte_channel_type,
+            { "Channel type",
+              "pdcp-lte.channel-type", FT_UINT8, BASE_DEC, VALS(logical_channel_vals), 0x0,
+              NULL, HFILL
+            }
+        },
+        { &hf_pdcp_lte_channel_id,
+            { "Channel Id",
+              "pdcp-lte.channel-id", FT_UINT8, BASE_DEC, 0, 0x0,
+              NULL, HFILL
+            }
+        },
         { &hf_pdcp_lte_rohc_profile,
             { "ROHC profile",
               "pdcp-lte.rohc.profile", FT_UINT8, BASE_DEC, VALS(rohc_profile_vals), 0x0,
@@ -2102,6 +2538,44 @@ void proto_register_pdcp(void)
             }
         },
 
+
+        { &hf_pdcp_lte_sequence_analysis,
+            { "Sequence Analysis",
+              "pdcp-lte.sequence-analysis", FT_STRING, BASE_NONE, 0, 0x0,
+              NULL, HFILL
+            }
+        },
+        { &hf_pdcp_lte_sequence_analysis_ok,
+            { "OK",
+              "pdcp-lte.sequence-analysis.ok", FT_BOOLEAN, BASE_NONE, 0, 0x0,
+              NULL, HFILL
+            }
+        },
+        { &hf_pdcp_lte_sequence_analysis_previous_frame,
+            { "Previous frame for channel",
+              "pdcp-lte.sequence-analysis.previous-frame", FT_FRAMENUM, BASE_NONE, 0, 0x0,
+              NULL, HFILL
+            }
+        },
+        { &hf_pdcp_lte_sequence_analysis_expected_sn,
+            { "Expected SN",
+              "pdcp-lte.sequence-analysis.expected-sn", FT_UINT16, BASE_DEC, 0, 0x0,
+              NULL, HFILL
+            }
+        },
+        { &hf_pdcp_lte_sequence_analysis_skipped,
+            { "Skipped frames",
+              "pdcp-lte.sequence-analysis.skipped-frames", FT_BOOLEAN, BASE_NONE, 0, 0x0,
+              NULL, HFILL
+            }
+        },
+        { &hf_pdcp_lte_sequence_analysis_repeated,
+            { "Repeated frame",
+              "pdcp-lte.sequence-analysis.repeated-frame", FT_BOOLEAN, BASE_NONE, 0, 0x0,
+              NULL, HFILL
+            }
+        },
+
         { &hf_pdcp_lte_rohc,
             { "ROHC Message",
               "pdcp-lte.rohc", FT_NONE, BASE_NONE, NULL, 0,
@@ -2516,6 +2990,7 @@ void proto_register_pdcp(void)
         &ett_pdcp,
         &ett_pdcp_configuration,
         &ett_pdcp_packet,
+        &ett_pdcp_lte_sequence_analysis,
         &ett_pdcp_rohc,
         &ett_pdcp_rohc_static_ipv4,
         &ett_pdcp_rohc_static_udp,
@@ -2550,6 +3025,12 @@ void proto_register_pdcp(void)
         "Show unciphered Signalling-Plane data as RRC",
         &global_pdcp_dissect_signalling_plane_as_rrc);
 
+    /* Check for missing sequence numbers */
+    prefs_register_bool_preference(pdcp_lte_module, "check_sequence_numbers",
+        "Do sequence number analysis",
+        "Do sequence number analysis",
+        &global_pdcp_check_sequence_numbers);
+
     /* Attempt to dissect ROHC headers */
     prefs_register_bool_preference(pdcp_lte_module, "dissect_rohc",
         "Attempt to decode ROHC data",
@@ -2566,17 +3047,15 @@ void proto_register_pdcp(void)
         "When enabled, use heuristic dissector to find PDCP-LTE frames sent with "
         "UDP framing",
         &global_pdcp_lte_heur);
+
+    register_init_routine(&pdcp_lte_init_protocol);
 }
 
 void proto_reg_handoff_pdcp_lte(void)
 {
-    static dissector_handle_t pdcp_lte_handle;
-    if (!pdcp_lte_handle) {
-        pdcp_lte_handle = find_dissector("pdcp-lte");
+    /* Add as a heuristic UDP dissector */
+    heur_dissector_add("udp", dissect_pdcp_lte_heur, proto_pdcp_lte);
 
-        /* Add as a heuristic UDP dissector */
-        heur_dissector_add("udp", dissect_pdcp_lte_heur, proto_pdcp_lte);
-    }
     ip_handle = find_dissector("ip");
 }