path: root/epan/dissectors/packet-umts_rlc.c

/* packet-umts_rlc.c
 * Routines for UMTS RLC (Radio Link Control) v9.3.0 disassembly
 * http://www.3gpp.org/ftp/Specs/archive/25_series/25.322/
 *
 * 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 <epan/conversation.h>
#include <epan/expert.h>
#include <epan/prefs.h>
#include <epan/proto_data.h>

#include <wiretap/wtap.h>

/*
 * Optional include, for KASUMI support,
 * see header file for more information.
 * */

#include "packet-umts_fp.h"
#include "packet-umts_rlc.h"
#include "packet-rrc.h"

/* TODO:
 * - distinguish between startpoints and endpoints?
 * - use sub_num in fragment identification?
 */

void proto_register_rlc(void);
void proto_reg_handoff_rlc(void);

int proto_umts_rlc = -1;

extern int proto_fp;

/* Preference to perform reassembly */
static gboolean global_rlc_perform_reassemby = TRUE;

/* Preference to expect RLC headers without payloads */
static gboolean global_rlc_headers_expected = FALSE;

/* Preference to expect ONLY ciphered data */
static gboolean global_rlc_ciphered = FALSE;

/* Preference to ignore ciphering state reported from RRC */
/* This is important for captures with deciphered traffic AND the original security RRC messages present*/
static gboolean global_ignore_rrc_ciphering_indication = FALSE;

/* Preference to try deciphering */
static gboolean global_rlc_try_decipher = FALSE;

#ifdef HAVE_UMTS_KASUMI
static const char *global_rlc_kasumi_key = NULL;
#endif

/* LI size preference */
#define RLC_LI_UPPERLAYER 255 /* LI-size comes from rlc_info struct rather than preference */
static gint global_rlc_li_size = RLC_LI_UPPERLAYER;

static const enum_val_t li_size_enumvals[] = {
    {"7 bits", "7 bits", RLC_LI_7BITS},
    {"15 bits", "15 bits", RLC_LI_15BITS},
    {"Let upper layers decide", "Let upper layers decide", RLC_LI_UPPERLAYER},
    {NULL, NULL, -1}};

/* fields */
static int hf_rlc_seq = -1;
static int hf_rlc_ext = -1;
static int hf_rlc_pad = -1;
static int hf_rlc_frags = -1;
static int hf_rlc_frag = -1;
static int hf_rlc_duplicate_of = -1;
static int hf_rlc_reassembled_in = -1;
static int hf_rlc_he = -1;
static int hf_rlc_dc = -1;
static int hf_rlc_p = -1;
static int hf_rlc_li = -1;
static int hf_rlc_li_value = -1;
static int hf_rlc_li_ext = -1;
static int hf_rlc_li_data = -1;
static int hf_rlc_data = -1;
static int hf_rlc_ciphered_data = -1;
static int hf_rlc_ciphered_lis_data = -1;
static int hf_rlc_ctrl_type = -1;
static int hf_rlc_r1 = -1;
static int hf_rlc_rsn = -1;
static int hf_rlc_hfni = -1;
static int hf_rlc_sufi = -1;
static int hf_rlc_sufi_type = -1;
static int hf_rlc_sufi_lsn = -1;
static int hf_rlc_sufi_wsn = -1;
static int hf_rlc_sufi_sn = -1;
static int hf_rlc_sufi_l = -1;
static int hf_rlc_sufi_fsn = -1;
static int hf_rlc_sufi_len = -1;
static int hf_rlc_sufi_bitmap = -1;
static int hf_rlc_sufi_cw = -1;
static int hf_rlc_sufi_n = -1;
static int hf_rlc_sufi_sn_ack = -1;
static int hf_rlc_sufi_sn_mrw = -1;
static int hf_rlc_sufi_poll_sn = -1;
static int hf_rlc_header_only = -1;
static int hf_rlc_channel = -1;
static int hf_rlc_channel_rbid = -1;
static int hf_rlc_channel_dir = -1;
static int hf_rlc_channel_ueid = -1;
static int hf_rlc_sequence_number = -1;
static int hf_rlc_length = -1;
static int hf_rlc_bitmap_string = -1;

/* subtrees */
static int ett_rlc = -1;
static int ett_rlc_frag = -1;
static int ett_rlc_fragments = -1;
static int ett_rlc_sdu = -1;
static int ett_rlc_sufi = -1;
static int ett_rlc_bitmap = -1;
static int ett_rlc_rlist = -1;
static int ett_rlc_channel = -1;

static expert_field ei_rlc_li_reserved = EI_INIT;
static expert_field ei_rlc_he = EI_INIT;
static expert_field ei_rlc_li_incorrect_mal = EI_INIT;
static expert_field ei_rlc_sufi_cw = EI_INIT;
static expert_field ei_rlc_kasumi_implementation_missing = EI_INIT;
static expert_field ei_rlc_reassembly_unknown_error = EI_INIT;
static expert_field ei_rlc_reassembly_lingering_endpoint = EI_INIT;
static expert_field ei_rlc_sufi_len = EI_INIT;
static expert_field ei_rlc_reassembly_fail_unfinished_sequence = EI_INIT;
static expert_field ei_rlc_reassembly_fail_flag_set = EI_INIT;
static expert_field ei_rlc_sufi_type = EI_INIT;
static expert_field ei_rlc_reserved_bits_not_zero = EI_INIT;
static expert_field ei_rlc_ctrl_type = EI_INIT;
static expert_field ei_rlc_li_incorrect_warn = EI_INIT;
static expert_field ei_rlc_li_too_many = EI_INIT;
static expert_field ei_rlc_header_only = EI_INIT;
static expert_field ei_rlc_ciphered_data = EI_INIT;
static expert_field ei_rlc_no_per_frame_data = EI_INIT;
static expert_field ei_rlc_incomplete_sequence = EI_INIT;
static expert_field ei_rlc_unknown_udp_framing_tag = EI_INIT;
static expert_field ei_rlc_missing_udp_framing_tag = EI_INIT;

static dissector_handle_t ip_handle;
static dissector_handle_t rrc_handle;
static dissector_handle_t bmc_handle;

enum rlc_channel_type {
    RLC_PCCH,
    RLC_BCCH,
    RLC_UL_CCCH,
    RLC_DL_CCCH,
    RLC_UL_DCCH,
    RLC_DL_DCCH,
    RLC_PS_DTCH,
    RLC_DL_CTCH,
    RLC_UNKNOWN_CH
};

static const value_string rlc_dir_vals[] = {
    { P2P_DIR_UL, "Uplink" },
    { P2P_DIR_DL, "Downlink" },
    { 0, NULL }
};

static const true_false_string rlc_header_only_val = {
    "RLC PDU header only", "RLC PDU header and body present"
};

static const true_false_string rlc_ext_val = {
    "Next field is Length Indicator and E Bit", "Next field is data, piggybacked STATUS PDU or padding"
};

static const true_false_string rlc_dc_val = {
    "Data", "Control"
};

static const true_false_string rlc_p_val = {
    "Request a status report", "Status report not requested"
};

static const value_string rlc_he_vals[] = {
    { 0, "The succeeding octet contains data" },
    { 1, "The succeeding octet contains a length indicator and E bit" },
    { 2, "The succeeding octet contains data and the last octet of the PDU is the last octet of an SDU" },
    { 0, NULL }
};

#define RLC_STATUS      0x0
#define RLC_RESET       0x1
#define RLC_RESET_ACK   0x2
static const value_string rlc_ctrl_vals[] = {
    { RLC_STATUS,       "Status" },
    { RLC_RESET,        "Reset" },
    { RLC_RESET_ACK,    "Reset Ack" },
    { 0, NULL }
};

#define RLC_SUFI_NOMORE     0x0
#define RLC_SUFI_WINDOW     0x1
#define RLC_SUFI_ACK        0x2
#define RLC_SUFI_LIST       0x3
#define RLC_SUFI_BITMAP     0x4
#define RLC_SUFI_RLIST      0x5
#define RLC_SUFI_MRW        0x6
#define RLC_SUFI_MRW_ACK    0x7
#define RLC_SUFI_POLL       0x8
static const value_string rlc_sufi_vals[] = {
    { RLC_SUFI_NOMORE,  "No more data" },
    { RLC_SUFI_WINDOW,  "Window size" },
    { RLC_SUFI_ACK,     "Acknowledgement" },
    { RLC_SUFI_LIST,    "List" },
    { RLC_SUFI_BITMAP,  "Bitmap" },
    { RLC_SUFI_RLIST,   "Relative list" },
    { RLC_SUFI_MRW,     "Move receiving window" },
    { RLC_SUFI_MRW_ACK, "Move receiving window acknowledgement" },
    { RLC_SUFI_POLL,    "Poll" },
    { 0, NULL }
};

/* reassembly related data */
static GHashTable *fragment_table    = NULL; /* table of not yet assembled fragments */
static GHashTable *endpoints = NULL; /* List of SDU-endpoints */
static GHashTable *reassembled_table = NULL; /* maps fragment -> complete sdu */
static GHashTable *sequence_table    = NULL; /* channel -> seq */
static GHashTable *duplicate_table = NULL; /* duplicates */

/* identify an RLC channel, using one of two options:
 *  - via Radio Bearer ID and unique UE ID
 *  - via Radio Bearer ID and (VPI/VCI/CID) + Link ID
 */
struct rlc_channel {
    guint32          ueid;
    guint16          vpi;
    guint16          vci;
    guint8           cid;
    guint16          link;  /* link number */
    guint8           rbid;  /* radio bearer ID */
    guint8           dir;   /* direction */
    enum rlc_li_size li_size;
    enum rlc_mode    mode;
};

/* used for duplicate detection */
struct rlc_seq {
    guint32  frame_num;
    nstime_t arrival;
    guint16  seq;
    guint16  oc;        /* overflow counter, this is not used? */
};

struct rlc_seqlist {
    struct rlc_channel ch;
    GList *list;
    /* We will store one seqlist per channel so this is a good place to indicate
     *  whether or not this channel's reassembly has failed or not. */
    guint fail_packet; /* Equal to packet where fail flag was set or 0 otherwise. */
};

/* fragment representation */
struct rlc_frag {
    guint32             frame_num;
    struct rlc_channel  ch;
    guint16             seq;  /* RLC sequence number */
    guint16             li;   /* LI within current RLC frame */
    guint16             len;  /* length of fragment data */
    guint8             *data; /* store fragment data here */

    struct rlc_frag *next; /* next fragment */
};

struct rlc_sdu {
    tvbuff_t        *tvb;     /* contains reassembled tvb */
    guint16          len;     /* total length of reassembled SDU */
    guint16          fragcnt; /* number of fragments within this SDU */
    guint8          *data;    /* reassembled data buffer */

    struct rlc_frag *reassembled_in;
    struct rlc_frag *frags;   /* pointer to list of fragments */
    struct rlc_frag *last;    /* pointer to last fragment */
};

struct rlc_li {
    guint16     li;   /* original li */
    guint16     len;  /* length of this data fragment */
    guint8      ext;  /* extension bit value */
    proto_tree *tree; /* subtree for this LI */
};

/*** KASUMI related variables and structs ***/
typedef struct umts_kat_key{    /*Stores 128-bits KASUMI key*/
    guint64 high;       /*64 MSB*/
    guint64 low;    /*64 LSB*/
}kasumi_key;


/*Counter used as input for confidentiality algorithm*/
static guint32 ps_counter[31][2] ;
static gboolean counter_init[31][2];
static guint32 max_counter = 0;
static GTree  * counter_map;    /*Saves the countervalues at first pass through, since they will be update*/

/* hashtable functions for fragment table
 * rlc_channel -> SDU
 */
static guint
rlc_channel_hash(gconstpointer key)
{
    const struct rlc_channel *ch = (const struct rlc_channel *)key;

    if (ch->ueid)
        return ch->ueid | ch->rbid | ch->mode;

    return (ch->vci << 16) | (ch->link << 16) | ch->vpi | ch->vci;
}

static gboolean
rlc_channel_equal(gconstpointer a, gconstpointer b)
{
    const struct rlc_channel *x = (const struct rlc_channel *)a, *y = (const struct rlc_channel *)b;

    if (x->ueid || y->ueid)
        return x->ueid == y->ueid &&
            x->rbid == y->rbid &&
            x->mode == y->mode &&
            x->dir == y->dir ? TRUE : FALSE;

    return x->vpi == y->vpi &&
        x->vci == y->vci &&
        x->cid == y->cid &&
        x->rbid == y->rbid &&
        x->mode == y->mode &&
        x->dir == y->dir &&
        x->link == y->link ? TRUE : FALSE;
}

static int
rlc_channel_assign(struct rlc_channel *ch, enum rlc_mode mode, packet_info *pinfo, struct atm_phdr *atm)
{
    rlc_info        *rlcinf;
    fp_info         *fpinf;

    fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);
    if (!fpinf || !rlcinf) return -1;

    if (rlcinf->ueid[fpinf->cur_tb]) {
        ch->ueid = rlcinf->ueid[fpinf->cur_tb];
        ch->vpi = ch->vci = ch->link = ch->cid = 0;
    } else {
        if (!atm) return -1;
        ch->ueid = 1;
        ch->vpi = atm->vpi;
        ch->vci = atm->vci;
        ch->cid = atm->aal2_cid;
        ch->link = pinfo->link_number;
    }
    ch->rbid = rlcinf->rbid[fpinf->cur_tb];
    ch->dir = pinfo->link_dir;
    ch->mode = mode;
    ch->li_size = rlcinf->li_size[fpinf->cur_tb];

    return 0;
}

static struct rlc_channel *
rlc_channel_create(enum rlc_mode mode, packet_info *pinfo, struct atm_phdr *atm)
{
    struct rlc_channel *ch;
    int rv;

    ch = (struct rlc_channel *)g_malloc0(sizeof(struct rlc_channel));
    rv = rlc_channel_assign(ch, mode, pinfo, atm);

    if (rv != 0) {
        /* channel assignment failed */
        g_free(ch);
        ch = NULL;
        REPORT_DISSECTOR_BUG("Failed to assign channel");
    }
    return ch;
}

static void
rlc_channel_delete(gpointer data)
{
    g_free(data);
}

/* hashtable functions for reassembled table
 * fragment -> SDU
 */
static guint
rlc_frag_hash(gconstpointer key)
{
    const struct rlc_frag *frag = (const struct rlc_frag *)key;
    return (frag->frame_num << 12) | frag->seq;
}

static gboolean
rlc_frag_equal(gconstpointer a, gconstpointer b)
{
    const struct rlc_frag *x = (const struct rlc_frag *)a;
    const struct rlc_frag *y = (const struct rlc_frag *)b;

    return rlc_channel_equal(&x->ch, &y->ch) &&
        x->seq == y->seq &&
        x->frame_num == y->frame_num &&
        x->li == y->li ? TRUE : FALSE;
}

static struct rlc_sdu *
rlc_sdu_create(void)
{
    struct rlc_sdu *sdu;

    sdu = (struct rlc_sdu *)wmem_alloc0(wmem_file_scope(), sizeof(struct rlc_sdu));
    return sdu;
}

static void
rlc_frag_delete(gpointer data)
{
    struct rlc_frag *frag = (struct rlc_frag *)data;

    if (frag->data) {
        g_free(frag->data);
        frag->data = NULL;
    }
}

static void
rlc_sdu_frags_delete(gpointer data)
{
    struct rlc_sdu  *sdu = (struct rlc_sdu *)data;
    struct rlc_frag *frag;

    frag = sdu->frags;
    while (frag) {
        if (frag->data) {
            g_free(frag->data);
        }
        frag->data = NULL;
        frag = frag->next;
    }
}

static int
rlc_frag_assign(struct rlc_frag *frag, enum rlc_mode mode, packet_info *pinfo,
        guint16 seq, guint16 li, struct atm_phdr *atm)
{
    frag->frame_num = pinfo->num;
    frag->seq       = seq;
    frag->li        = li;
    frag->len       = 0;
    frag->data      = NULL;
    rlc_channel_assign(&frag->ch, mode, pinfo, atm);

    return 0;
}

static int
rlc_frag_assign_data(struct rlc_frag *frag, tvbuff_t *tvb,
             guint16 offset, guint16 length)
{
    frag->len  = length;
    frag->data = (guint8 *)g_malloc(length);
    tvb_memcpy(tvb, frag->data, offset, length);
    return 0;
}

static struct rlc_frag *
rlc_frag_create(tvbuff_t *tvb, enum rlc_mode mode, packet_info *pinfo,
        guint16 offset, guint16 length, guint16 seq, guint16 li,
        struct atm_phdr *atm)
{
    struct rlc_frag *frag;

    frag = (struct rlc_frag *)wmem_alloc0(wmem_file_scope(), sizeof(struct rlc_frag));
    rlc_frag_assign(frag, mode, pinfo, seq, li, atm);
    rlc_frag_assign_data(frag, tvb, offset, length);

    return frag;
}

static int
rlc_cmp_seq(gconstpointer a, gconstpointer b)
{
    const struct rlc_seq *_a = (const struct rlc_seq *)a, *_b = (const struct rlc_seq *)b;

    return  _a->seq < _b->seq ? -1 :
            _a->seq > _b->seq ?  1 :
            0;
}

static int moduloCompare(guint16 a, guint16 b, guint16 modulus)
{
    int ret;
    a = a % modulus;
    b = b % modulus;

    if( a <= b ){
        ret = a - b;
    } else {
        ret = a - (b + modulus);
    }
    if( ret == (1 - modulus) ){
        ret = 1;
    }
    return ret;
}

static guint16 getChannelSNModulus(struct rlc_channel * ch_lookup)
{
    if( RLC_UM == ch_lookup->mode){ /*FIXME: This is a very heuristic way to determine SN bitwidth. */
        return 128;
    } else {
        return 4096;
    }
}

/* "Value destroy" function called each time an entry is removed
 *  from the sequence_table hash.
 * It frees the GList pointed to by the entry.
 */
static void
free_sequence_table_entry_data(gpointer data)
{
    struct rlc_seqlist *list = (struct rlc_seqlist *)data;
    if (list->list != NULL) {
        g_list_free(list->list);
        list->list = NULL;   /* for good measure */
    }
}

/** Utility functions used for various comparisons/cleanups in tree **/
static gint
rlc_simple_key_cmp(gconstpointer b_ptr, gconstpointer a_ptr, gpointer ignore _U_){
    if( GPOINTER_TO_INT(a_ptr) > GPOINTER_TO_INT(b_ptr) ){
        return  -1;
    }
    return GPOINTER_TO_INT(a_ptr) < GPOINTER_TO_INT(b_ptr);
}

static void
fragment_table_init(void)
{
    int i;
    fragment_table = g_hash_table_new_full(rlc_channel_hash, rlc_channel_equal, rlc_channel_delete, NULL);
    endpoints = g_hash_table_new_full(rlc_channel_hash, rlc_channel_equal, rlc_channel_delete, NULL);
    reassembled_table = g_hash_table_new_full(rlc_frag_hash, rlc_frag_equal,
        rlc_frag_delete, rlc_sdu_frags_delete);
    sequence_table = g_hash_table_new_full(rlc_channel_hash, rlc_channel_equal,
        NULL, free_sequence_table_entry_data);
    duplicate_table = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, NULL);

    /*Reset and or clear deciphering variables*/
    counter_map = g_tree_new_full(rlc_simple_key_cmp,NULL,NULL,rlc_channel_delete);
    for(i = 0; i< 31; i++ ){
        ps_counter[i][0] = 0;
        ps_counter[i][1] = 0;
        counter_init[i][0] = 0;
        counter_init[i][1] = 0;
    }
    max_counter = 0;
}

static void
fragment_table_cleanup(void)
{
    g_tree_destroy(counter_map);
    g_hash_table_destroy(fragment_table);
    g_hash_table_destroy(endpoints);
    g_hash_table_destroy(reassembled_table);
    g_hash_table_destroy(sequence_table);
    g_hash_table_destroy(duplicate_table);
}

/* add the list of fragments for this sdu to 'tree' */
static void
tree_add_fragment_list(struct rlc_sdu *sdu, tvbuff_t *tvb, proto_tree *tree)
{
    proto_item      *ti;
    proto_tree      *frag_tree;
    guint16          offset;
    struct rlc_frag *sdufrag;

    ti = proto_tree_add_item(tree, hf_rlc_frags, tvb, 0, -1, ENC_NA);
    frag_tree = proto_item_add_subtree(ti, ett_rlc_fragments);
    proto_item_append_text(ti, " (%u bytes, %u fragments): ",
        sdu->len, sdu->fragcnt);
    sdufrag = sdu->frags;
    offset = 0;
    while (sdufrag) {
        if (sdufrag->len > 0) {
            proto_tree_add_uint_format(frag_tree, hf_rlc_frag, tvb, offset,
                sdufrag->len, sdufrag->frame_num, "Frame: %u, payload: %u-%u (%u bytes) (Seq: %u)",
                sdufrag->frame_num, offset, offset + sdufrag->len - 1, sdufrag->len, sdufrag->seq);
        } else {
            proto_tree_add_uint_format(frag_tree, hf_rlc_frag, tvb, offset,
                sdufrag->len, sdufrag->frame_num, "Frame: %u, payload: none (0 bytes) (Seq: %u)",
                sdufrag->frame_num, sdufrag->seq);
        }
        offset += sdufrag->len;
        sdufrag = sdufrag->next;
    }
}

/* add the list of fragments for this sdu to 'tree' */
static void
tree_add_fragment_list_incomplete(struct rlc_sdu *sdu, tvbuff_t *tvb, proto_tree *tree)
{
    proto_item      *ti;
    proto_tree      *frag_tree;
    guint16          offset;
    struct rlc_frag *sdufrag;

    ti = proto_tree_add_item(tree, hf_rlc_frags, tvb, 0, 0, ENC_NA);
    frag_tree = proto_item_add_subtree(ti, ett_rlc_fragments);
    proto_item_append_text(ti, " (%u bytes, %u fragments): ",
        sdu->len, sdu->fragcnt);
    sdufrag = sdu->frags;
    offset = 0;
    while (sdufrag) {
        proto_tree_add_uint_format(frag_tree, hf_rlc_frag, tvb, 0,
            0, sdufrag->frame_num, "Frame: %u, payload %u-%u (%u bytes) (Seq: %u)",
            sdufrag->frame_num, offset, offset + sdufrag->len - 1, sdufrag->len, sdufrag->seq);
        offset += sdufrag->len;
        sdufrag = sdufrag->next;
    }
}

/* Add the same description to too the two given proto_items */
static void
add_description(proto_item *li_ti, proto_item *length_ti,
                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);

    proto_item_append_text(li_ti, " (%s)", info_buffer);
    proto_item_append_text(length_ti, " (%s)", info_buffer);
}

/* add information for an LI to 'tree' */
static proto_tree *
tree_add_li(enum rlc_mode mode, struct rlc_li *li, guint8 li_idx, guint32 hdr_offs,
        gboolean li_is_on_2_bytes, tvbuff_t *tvb, proto_tree *tree)
{
    proto_item *root_ti, *ti;
    proto_tree *li_tree;
    guint32     li_offs;
    guint64     length;

    if (!tree) return NULL;

    if (li_is_on_2_bytes) {
        li_offs = hdr_offs + li_idx*2;
        root_ti = proto_tree_add_item(tree, hf_rlc_li, tvb, li_offs, 2, ENC_NA);
        li_tree = proto_item_add_subtree(root_ti, ett_rlc_frag);
        ti = proto_tree_add_bits_ret_val(li_tree, hf_rlc_li_value, tvb, li_offs*8, 15, &length, ENC_BIG_ENDIAN);

        switch (li->li) {
            case 0x0000:
                add_description(root_ti, ti, "The previous RLC PDU was exactly filled with the last segment of an RLC SDU and there is no LI that indicates the end of the RLC SDU in the previous RLC PDU");
                break;
            case 0x7ffa:
                if (mode == RLC_UM) {
                    add_description(root_ti, ti, "The first data octet in this RLC PDU is the first octet of an RLC SDU and the second last octet in this RLC PDU is the last octet of the same RLC SDU. The remaining octet in the RLC PDU is ignored");
                } else {
                    add_description(root_ti, ti, "Reserved");
                }
                break;
            case 0x7ffb:
                add_description(root_ti, ti, "The second last octet in the previous RLC PDU is the last octet of an RLC SDU and there is no LI to indicate the end of SDU. The remaining octet in the previous RLC PDU is ignored");
                break;
            case 0x7ffc:
                if (mode == RLC_UM) {
                    add_description(root_ti, ti, "The first data octet in this RLC PDU is the first octet of an RLC SDU");
                } else {
                    add_description(root_ti, ti, "Reserved");
                }
                break;
            case 0x7ffd:
                if (mode == RLC_UM) {
                    add_description(root_ti, ti, "The first data octet in this RLC PDU is the first octet of an RLC SDU and the last octet in this RLC PDU is the last octet of the same RLC SDU");
                } else {
                    add_description(root_ti, ti, "Reserved");
                }
                break;
            case 0x7ffe:
                if (mode == RLC_UM) {
                    add_description(root_ti, ti, "The RLC PDU contains a segment of an SDU but neither the first octet nor the last octet of this SDU");
                } else {
                    add_description(root_ti, ti, "The rest of the RLC PDU includes a piggybacked STATUS PDU");
                }
                break;
            case 0x7fff:
                add_description(root_ti, ti, "The rest of the RLC PDU is padding");
                break;

            default:
                add_description(root_ti, ti, "length=%u", (guint16)length);
                break;
        }
        proto_tree_add_bits_item(li_tree, hf_rlc_li_ext, tvb, li_offs*8+15, 1, ENC_BIG_ENDIAN);
    } else {
        li_offs = hdr_offs + li_idx;
        root_ti = proto_tree_add_item(tree, hf_rlc_li, tvb, li_offs, 1, ENC_NA);
        li_tree = proto_item_add_subtree(root_ti, ett_rlc_frag);
        ti = proto_tree_add_bits_ret_val(li_tree, hf_rlc_li_value, tvb, li_offs*8, 7, &length, ENC_BIG_ENDIAN);
        switch (li->li) {
            case 0x00:
                add_description(root_ti, ti, "The previous RLC PDU was exactly filled with the last segment of an RLC SDU and there is no LI that indicates the end of the RLC SDU in the previous RLC PDU");
                break;
            case 0x7c:
                if (mode == RLC_UM) {
                    add_description(root_ti, ti, "The first data octet in this RLC PDU is the first octet of an RLC SDU");
                } else {
                    add_description(root_ti, ti, "Reserved");
                }
                break;
            case 0x7d:
                if (mode == RLC_UM) {
                    add_description(root_ti, ti, "The first data octet in this RLC PDU is the first octet of an RLC SDU and the last octet in this RLC PDU is the last octet of the same RLC SDU");
                } else {
                    add_description(root_ti, ti, "Reserved");
                }
                break;
            case 0x7e:
                if (mode == RLC_UM) {
                    add_description(root_ti, ti, "The RLC PDU contains a segment of an SDU but neither the first octet nor the last octet of this SDU");
                } else {
                    add_description(root_ti, ti, "The rest of the RLC PDU includes a piggybacked STATUS PDU");
                }
                break;
            case 0x7f:
                add_description(root_ti, ti, "The rest of the RLC PDU is padding");
                break;

            default:
                add_description(root_ti, ti, "length=%u", (guint16)length);
                break;
        }
        proto_tree_add_bits_item(li_tree, hf_rlc_li_ext, tvb, li_offs*8+7, 1, ENC_BIG_ENDIAN);
    }

    if (li->len > 0) {
        if (li->li > tvb_reported_length_remaining(tvb, hdr_offs)) return li_tree;
        if (li->len > li->li) return li_tree;
        ti = proto_tree_add_item(li_tree, hf_rlc_li_data, tvb, hdr_offs + li->li - li->len, li->len, ENC_NA);
        PROTO_ITEM_SET_HIDDEN(ti);
    }

    return li_tree;
}

/* add a fragment to an SDU */
static int
rlc_sdu_add_fragment(enum rlc_mode mode, struct rlc_sdu *sdu, struct rlc_frag *frag)
{
    struct rlc_frag *tmp;

    if (!sdu->frags) {
        /* insert as first element */
        sdu->frags = frag;
        sdu->last = frag;
        sdu->fragcnt++;
        sdu->len += frag->len;
        return 0;
    }
    switch (mode) {
        case RLC_UM:
            /* insert as last element */
            sdu->last->next = frag;
            frag->next = NULL;
            sdu->last = frag;
            sdu->len += frag->len;
            break;
        case RLC_AM:
            /* insert ordered */
            tmp = sdu->frags;

            /* If receiving exotic border line sequence, e.g. 4094, 4095, 0, 1 */
            if (frag->seq+2048 < tmp->seq) {
                while (tmp->next && frag->seq+2048 < tmp->seq)
                    tmp = tmp->next;
                if (tmp->next == NULL) {
                    tmp->next = frag;
                    sdu->last = frag;
                } else {
                    while (tmp->next && tmp->next->seq < frag->seq)
                        tmp = tmp->next;
                    frag->next = tmp->next;
                    tmp->next = frag;
                    if (frag->next == NULL) sdu->last = frag;
                }
            } else { /* Receiving ordinary sequence */
                if (frag->seq < tmp->seq) {
                    /* insert as first element */
                    frag->next = tmp;
                    sdu->frags = frag;
                } else {
                    while (tmp->next && tmp->next->seq < frag->seq)
                        tmp = tmp->next;
                    frag->next = tmp->next;
                    tmp->next = frag;
                    if (frag->next == NULL) sdu->last = frag;
                }
            }
            sdu->len += frag->len;
            break;
        default:
            return -2;
    }
    sdu->fragcnt++;
    return 0;
}

static void
reassemble_data(struct rlc_channel *ch, struct rlc_sdu *sdu, struct rlc_frag *frag)
{
    struct rlc_frag *temp;
    guint16          offs = 0;

    if (!sdu || !ch || !sdu->frags) return;

    if (sdu->data) return; /* already assembled */

    if (frag)
        sdu->reassembled_in = frag;
    else
        sdu->reassembled_in = sdu->last;

    sdu->data = (guint8 *)wmem_alloc(wmem_file_scope(), sdu->len);
    temp = sdu->frags;
    while (temp && ((offs + temp->len) <= sdu->len)) {
        memcpy(sdu->data + offs, temp->data, temp->len);
        g_free(temp->data);
        temp->data = NULL;
        /* mark this fragment in reassembled table */
        g_hash_table_insert(reassembled_table, temp, sdu);

        offs += temp->len;
        temp = temp->next;
    }
}

#define RLC_ADD_FRAGMENT_FAIL_PRINT 0
#define RLC_ADD_FRAGMENT_DEBUG_PRINT 0
#if RLC_ADD_FRAGMENT_DEBUG_PRINT
static void
printends(GList * list)
{
    if (list == NULL)
        return;
    g_print("-> length: %d\n[", g_list_length(list));
    while (list)
    {
        g_print("%d ", GPOINTER_TO_INT(list->data));
        list = list->next;
    }
    g_print("]\n");
}
#endif

static struct rlc_frag **
get_frags(packet_info * pinfo, struct rlc_channel * ch_lookup, struct atm_phdr *atm)
{
    gpointer value = NULL;
    struct rlc_frag ** frags = NULL;
    /* Look for already created frags table */
    if (g_hash_table_lookup_extended(fragment_table, ch_lookup, NULL, &value)) {
        frags = (struct rlc_frag **)value;
    } else if (pinfo != NULL) {
        struct rlc_channel *ch;
        ch = rlc_channel_create(ch_lookup->mode, pinfo, atm);
        frags = (struct rlc_frag **)wmem_alloc0(wmem_file_scope(), sizeof(struct rlc_frag *) * 4096);
        g_hash_table_insert(fragment_table, ch, frags);
    } else {
        return NULL;
    }
    return frags;
}
static struct rlc_seqlist *
get_endlist(packet_info * pinfo, struct rlc_channel * ch_lookup, struct atm_phdr *atm)
{
    gpointer value = NULL;
    struct rlc_seqlist * endlist = NULL;
    /* If there already exists a frag table for this channel use that one. */
    if (g_hash_table_lookup_extended(endpoints, ch_lookup, NULL, &value)) {
        endlist = (struct rlc_seqlist *)value;
    } else if (pinfo != NULL) { /* Else create a new one. */
        struct rlc_channel * ch;

        endlist = wmem_new(wmem_file_scope(), struct rlc_seqlist);
        ch = rlc_channel_create(ch_lookup->mode, pinfo, atm);
        endlist->fail_packet = 0;
        endlist->list = NULL;
        endlist->list = g_list_prepend(endlist->list, GINT_TO_POINTER(-1));
        g_hash_table_insert(endpoints, ch, endlist);
    } else {
        return NULL;
    }
    return endlist;
}

static void
reassemble_sequence(struct rlc_frag ** frags, struct rlc_seqlist * endlist,
                    struct rlc_channel * ch_lookup, guint16 start, guint16 end)
{
    GList * element = NULL;
    struct rlc_sdu * sdu = rlc_sdu_create();

    guint16 snmod = getChannelSNModulus(ch_lookup);

    /* Insert fragments into SDU. */
    for (; moduloCompare(start,end,snmod ) <= 0; start = (start+1)%snmod)
    {
        struct rlc_frag * tempfrag = NULL;
        tempfrag = frags[start]->next;
        frags[start]->next = NULL;
        rlc_sdu_add_fragment(ch_lookup->mode, sdu, frags[start]);
        frags[start] = tempfrag;
    }

    /* Remove first endpoint. */
    element = g_list_first(endlist->list);
    if (element) {
        endlist->list = g_list_remove_link(endlist->list, element);
        if (frags[end] != NULL) {
            if (endlist->list) {
                endlist->list->data = GINT_TO_POINTER((GPOINTER_TO_INT(endlist->list->data) - 1 + snmod) % snmod);
            }
        }
    }
    reassemble_data(ch_lookup, sdu, NULL);
}

/* Reset the specified channel's reassembly data, useful for when a sequence
 * resets on transport channel swap. */
void
rlc_reset_channel(enum rlc_mode mode, guint8 rbid, guint8 dir, guint32 ueid,
                  struct atm_phdr *atm)
{
    struct rlc_frag ** frags = NULL;
    struct rlc_seqlist * endlist = NULL;
    struct rlc_channel ch_lookup;
    guint i;

    ch_lookup.mode = mode;
    ch_lookup.rbid = rbid;
    ch_lookup.dir = dir;
    ch_lookup.ueid = ueid;
    frags = get_frags(NULL, &ch_lookup, atm);
    endlist = get_endlist(NULL, &ch_lookup, atm);
    DISSECTOR_ASSERT(frags && endlist);

    endlist->fail_packet = 0;
    g_list_free(endlist->list);
    endlist->list = NULL;

    for (i = 0; i < 4096; i++) {
        frags[i] = NULL;
    }
}

/* add a new fragment to an SDU
 * if length == 0, just finalize the specified SDU
 */
static struct rlc_frag *
add_fragment(enum rlc_mode mode, tvbuff_t *tvb, packet_info *pinfo,
         proto_tree *tree, guint16 offset, guint16 seq, guint16 num_li,
         guint16 len, gboolean final, struct atm_phdr *atm)
{
    struct rlc_channel  ch_lookup;
    struct rlc_frag     frag_lookup, *frag = NULL;
    gpointer            orig_key = NULL, value = NULL;
    struct rlc_sdu     *sdu = NULL;
    struct rlc_frag ** frags = NULL;
    struct rlc_seqlist * endlist = NULL;
    GList * element = NULL;
    int snmod;

    if (rlc_channel_assign(&ch_lookup, mode, pinfo, atm) == -1) {
        return NULL;
    }
    rlc_frag_assign(&frag_lookup, mode, pinfo, seq, num_li, atm);
    #if RLC_ADD_FRAGMENT_DEBUG_PRINT
        g_print("packet: %d, channel (%d %d %d) seq: %u, num_li: %u, offset: %u, \n", pinfo->num, ch_lookup.dir, ch_lookup.rbid, ch_lookup.ueid, seq, num_li, offset);
    #endif

    snmod = getChannelSNModulus(&ch_lookup);

    /* look for an already assembled SDU */
    if (g_hash_table_lookup_extended(reassembled_table, &frag_lookup, &orig_key, &value)) {
        /* this fragment is already reassembled somewhere */
        frag = (struct rlc_frag *)orig_key;
        sdu = (struct rlc_sdu *)value;
        if (tree) {
            /* mark the fragment, if reassembly happened somewhere else */
            if (frag->seq != sdu->reassembled_in->seq ||
                frag->li != sdu->reassembled_in->li)
                proto_tree_add_uint(tree, hf_rlc_reassembled_in, tvb, 0, 0,
                    sdu->reassembled_in->frame_num);
        }
        return frag;
    }

    frags = get_frags(pinfo, &ch_lookup, atm);
    endlist = get_endlist(pinfo, &ch_lookup, atm);

    /* If already done reassembly */
    if (pinfo->fd->flags.visited) {
        if (tree && len > 0) {
            if (endlist->list && endlist->list->next) {
                gint16 start = (GPOINTER_TO_INT(endlist->list->data) + 1) % snmod;
                gint16 end = GPOINTER_TO_INT(endlist->list->next->data);
                gint16 missing = start;
                gboolean wecanreasmmore = TRUE;

                for (; moduloCompare(missing,end,snmod ) <= 0; missing = (missing+1)%snmod)
                {
                    if (frags[missing] == NULL) {
                        wecanreasmmore = FALSE;
                        break;
                    }
                }

                if (wecanreasmmore) {
                    reassemble_sequence(frags, endlist, &ch_lookup, start, end);
                } else {
                    if (end >= 0 && end < snmod && frags[end]) {
                        proto_tree_add_expert_format(tree, pinfo, &ei_rlc_reassembly_fail_unfinished_sequence, tvb, 0, 0,
                                        "Did not perform reassembly because of unfinished sequence (%d->%d [packet %u]), could not find %d.", start, end, frags[end]->frame_num, missing);
                    } else {
                        proto_tree_add_expert_format(tree, pinfo, &ei_rlc_reassembly_fail_unfinished_sequence, tvb, 0, 0,
                                        "Did not perform reassembly because of unfinished sequence (%d->%d [could not determine packet]), could not find %d.", start, end, missing);
                    }
                }
            } else if (endlist->list) {
                if (endlist->fail_packet != 0 && endlist->fail_packet <= pinfo->num) {
                    proto_tree_add_expert_format(tree, pinfo, &ei_rlc_reassembly_fail_flag_set, tvb, 0, 0, "Did not perform reassembly because fail flag was set in packet %u.", endlist->fail_packet);
                } else {
                    gint16 end = GPOINTER_TO_INT(endlist->list->data);
                    if (end >= 0 && end < snmod && frags[end]) {
                        proto_tree_add_expert_format(tree, pinfo, &ei_rlc_reassembly_lingering_endpoint, tvb, 0, 0, "Did not perform reassembly because of unfinished sequence, found lingering endpoint (%d [packet %d]).", end, frags[end]->frame_num);
                    } else {
                        proto_tree_add_expert_format(tree, pinfo, &ei_rlc_reassembly_lingering_endpoint, tvb, 0, 0, "Did not perform reassembly because of unfinished sequence, found lingering endpoint (%d [could not determine packet]).", end);
                    }
                }
            } else {
                expert_add_info(pinfo, NULL, &ei_rlc_reassembly_unknown_error);
            }
        }
        return NULL; /* If already done reassembly and no SDU found, too bad */
    }

    if (endlist->fail_packet != 0) { /* don't continue after sh*t has hit the fan */
        return NULL;
    }

    frag = rlc_frag_create(tvb, mode, pinfo, offset, len, seq, num_li, atm);

    /* If frags[seq] is not NULL then we must have data from several PDUs in the
     * same RLC packet (using Length Indicators) or something has gone terribly
     * wrong. */
    if (frags[seq] != NULL) {
        if (num_li > 0) {
            struct rlc_frag * tempfrag = frags[seq];
            while (tempfrag->next != NULL)
                tempfrag = tempfrag->next;
            tempfrag->next = frag;
        } else { /* This should never happen */
            endlist->fail_packet = pinfo->num;
            return NULL;
        }
    } else {
        frags[seq] = frag;
    }

    /* It is also possible that frags[seq] is NULL even though we do have data
     * from several PDUs in the same RLC packet. This is if the reassembly is
     * not lagging behind at all because of perfectly ordered sequences. */
    if (endlist->list && num_li != 0) {
        gint16 first = GPOINTER_TO_INT(endlist->list->data);
        if (seq == first) {
            endlist->list->data = GINT_TO_POINTER(first-1);
        }
    }

    /* If this is an endpoint */
    if (final) {
        endlist->list = g_list_append(endlist->list, GINT_TO_POINTER((gint)seq));
    }

    #if RLC_ADD_FRAGMENT_DEBUG_PRINT
    printends(endlist->list);
    #endif

    /* Try to reassemble SDU. */
    if (endlist->list && endlist->list->next) {
        gint16 start = (GPOINTER_TO_INT(endlist->list->data) + 1) % snmod;
        gint16 end = GPOINTER_TO_INT(endlist->list->next->data);
        if (frags[end] == NULL) {
#if RLC_ADD_FRAGMENT_FAIL_PRINT
            proto_tree_add_debug_text(tree, "frag[end] is null, this is probably because end was a startpoint but because of some error ended up being treated as an endpoint, setting fail flag, start %d, end %d, packet %u\n", start, end, pinfo->num);
#endif
            endlist->fail_packet = pinfo->num;
            return NULL;
        }

        /* If our endpoint is a LI=0 with no data. */
        if (start == end && frags[start]->len == 0) {
            element = g_list_first(endlist->list);
            if (element) {
                endlist->list = g_list_remove_link(endlist->list, element);
            }
            frags[start] = frags[start]->next;

            /* If frags[start] is not NULL now, then that means that there was
             * another fragment with the same seq number because of LI. If we
             * don't decrease the endpoint by 1 then that fragment will be
             * skipped and all hell will break lose. */
            if (frags[start] != NULL) {
                endlist->list->data = GINT_TO_POINTER(start-1);
            }
            /* NOTE: frags[start] is wmem_alloc'ed and will remain until file closes, we would want to free it here maybe. */
            return NULL;
        }

        #if RLC_ADD_FRAGMENT_DEBUG_PRINT
        g_print("start: %d, end: %d\n",start, end);
        #endif

        for (;  moduloCompare(start,end,snmod ) < 0; start = (start+1)%snmod)
        {
            if (frags[start] == NULL) {
                if (MIN((start-seq+snmod)%snmod, (seq-start+snmod)%snmod) >= snmod/4) {
#if RLC_ADD_FRAGMENT_FAIL_PRINT
                    proto_tree_add_debug_text(tree,
"Packet %u. Setting fail flag because RLC fragment with sequence number %u was \
too far away from an unfinished sequence (%u->%u). The missing sequence number \
is %u. The most recently complete sequence ended in packet %u.", pinfo->num, seq, 0, end, start, 0);
#endif
                    endlist->fail_packet = pinfo->num; /* If it has gone too far, give up */
                    return NULL;
                }
                return frag;
            }
        }
        start = (GPOINTER_TO_INT(endlist->list->data) + 1) % snmod;
        reassemble_sequence(frags, endlist, &ch_lookup, start, end);
    } else if (endlist->list) {
        gint16 first = (GPOINTER_TO_INT(endlist->list->data) + 1) % snmod;
        /* If the distance between the oldest stored endpoint in endlist and
         * this endpoint is too large, set fail flag. */
        if (MIN((first-seq+snmod)%snmod, (seq-first+snmod)%snmod) >= snmod/4) {
#if RLC_ADD_FRAGMENT_FAIL_PRINT
            proto_tree_add_debug_text(tree,
"Packet %u. Setting fail flag because RLC fragment with sequence number %u was \
too far away from an unfinished sequence with start %u and without end.", pinfo->num, seq, first);
#endif
            endlist->fail_packet = pinfo->num; /* Give up if things have gone too far. */
            return NULL;
        }
    }

    return frag;
}

/* is_data is used to identify rlc data parts that are not identified by an LI, but are at the end of
 * the RLC frame
 * these can be valid reassembly points, but only if the LI of the *next* relevant RLC frame is
 * set to '0' (this is indicated in the reassembled SDU
 */
static tvbuff_t *
get_reassembled_data(enum rlc_mode mode, tvbuff_t *tvb, packet_info *pinfo,
             proto_tree *tree, guint16 seq, guint16 num_li,
             struct atm_phdr *atm)
{
    gpointer         orig_frag, orig_sdu;
    struct rlc_sdu  *sdu;
    struct rlc_frag  lookup, *frag;

    rlc_frag_assign(&lookup, mode, pinfo, seq, num_li, atm);

    if (!g_hash_table_lookup_extended(reassembled_table, &lookup,
        &orig_frag, &orig_sdu))
        return NULL;

    sdu = (struct rlc_sdu *)orig_sdu;
    if (!sdu || !sdu->data)
        return NULL;

    /* TODO */
#if 0
    if (!rlc_frag_equal(&lookup, sdu->reassembled_in)) return NULL;
#endif

    frag = sdu->frags;
    while (frag->next) {
        if (frag->next->seq - frag->seq > 1) {
            proto_tree_add_expert(tree, pinfo, &ei_rlc_incomplete_sequence, tvb, 0, 0);
            tree_add_fragment_list_incomplete(sdu, tvb, tree);
            return NULL;
        }
        frag = frag->next;
    }

    sdu->tvb = tvb_new_child_real_data(tvb, sdu->data, sdu->len, sdu->len);
    add_new_data_source(pinfo, sdu->tvb, "Reassembled RLC Message");

    /* reassembly happened here, so create the fragment list */
    if (tree && sdu->fragcnt > 1)
        tree_add_fragment_list(sdu, sdu->tvb, tree);

    return sdu->tvb;
}

#define RLC_RETRANSMISSION_TIMEOUT 5 /* in seconds */
static gboolean
rlc_is_duplicate(enum rlc_mode mode, packet_info *pinfo, guint16 seq,
         guint32 *original, struct atm_phdr *atm)
{
    GList              *element;
    struct rlc_seqlist  lookup, *list;
    struct rlc_seq      seq_item, *seq_new;
    guint16 snmod;
    nstime_t delta;
    gboolean is_duplicate,is_unseen;

    if (rlc_channel_assign(&lookup.ch, mode, pinfo, atm) == -1)
        return FALSE;
    list = (struct rlc_seqlist *)g_hash_table_lookup(sequence_table, &lookup.ch);
    if (!list) {
        /* we see this channel for the first time */
        list = (struct rlc_seqlist *)wmem_alloc0(wmem_file_scope(), sizeof(*list));
        rlc_channel_assign(&list->ch, mode, pinfo, atm);
        g_hash_table_insert(sequence_table, &list->ch, list);
    }
    seq_item.seq = seq;
    seq_item.frame_num = pinfo->num;

    /* When seq is 12 bit (in RLC protocol), it will wrap around after 4096. */
    /* Window size is at most 4095 so we remove packets further away than that */
    element = g_list_first(list->list);
    snmod = getChannelSNModulus(&lookup.ch);
    if (element) {
        seq_new = (struct rlc_seq *)element->data;
        /* Add SN modulus because %-operation for negative values in C is not equal to mathematical modulus */
        if (MIN((seq_new->seq-seq+snmod)%snmod, (seq-seq_new->seq+snmod)%snmod) >= snmod/4) {
            list->list = g_list_remove_link(list->list, element);
        }
    }

    is_duplicate = FALSE;
    is_unseen = TRUE;
    element = g_list_find_custom(list->list, &seq_item, rlc_cmp_seq);
    while(element) {
        /* Check if this is a different frame (by comparing frame numbers) which arrived less than */
        /* RLC_RETRANSMISSION_TIMEOUT seconds ago */
        seq_new = (struct rlc_seq *)element->data;
        if (seq_new->frame_num < seq_item.frame_num) {
            nstime_delta(&delta, &pinfo->abs_ts, &seq_new->arrival);
            if (delta.secs < RLC_RETRANSMISSION_TIMEOUT) {
                /* This is a duplicate. */
                if (original) {
                    /* Save the frame number where our sequence number was previously seen */
                    *original = seq_new->frame_num;
                }
                is_duplicate = TRUE;
            }
        }
        else if (seq_new->frame_num == seq_item.frame_num) {
            /* Check if our frame is already in the list and this is a secondary check.*/
            /* in this case raise a flag so the frame isn't entered more than once to the list */
            is_unseen = FALSE;
        }
        element = g_list_find_custom(element->next, &seq_item, rlc_cmp_seq);
    }
    if(is_unseen) {
        /* Add to list for the first time this frame is checked */
        seq_new = (struct rlc_seq *)wmem_alloc0(wmem_file_scope(), sizeof(struct rlc_seq));
        *seq_new = seq_item;
        seq_new->arrival = pinfo->abs_ts;
        list->list = g_list_append(list->list, seq_new); /* insert in order of arrival */
    }
    return is_duplicate;
}

static void
rlc_call_subdissector(enum rlc_channel_type channel, tvbuff_t *tvb,
              packet_info *pinfo, proto_tree *tree)
{
    enum rrc_message_type msgtype;
    switch (channel) {
        case RLC_UL_CCCH:
            msgtype = RRC_MESSAGE_TYPE_UL_CCCH;
            break;
        case RLC_DL_CCCH:
            msgtype = RRC_MESSAGE_TYPE_DL_CCCH;
            break;
        case RLC_DL_CTCH:
            msgtype = RRC_MESSAGE_TYPE_INVALID;
            call_dissector(bmc_handle, tvb, pinfo, tree);
            /* once the packet has been dissected, protect it from further changes using a 'fence' in the INFO column */
            col_append_str(pinfo->cinfo, COL_INFO," ");
            col_set_fence(pinfo->cinfo, COL_INFO);
            break;
        case RLC_UL_DCCH:
            msgtype = RRC_MESSAGE_TYPE_UL_DCCH;
            break;
        case RLC_DL_DCCH:
            msgtype = RRC_MESSAGE_TYPE_DL_DCCH;
            break;
        case RLC_PCCH:
            msgtype = RRC_MESSAGE_TYPE_PCCH;
            break;
        case RLC_BCCH:
            msgtype = RRC_MESSAGE_TYPE_BCCH_FACH;
            break;
        case RLC_PS_DTCH:
            msgtype = RRC_MESSAGE_TYPE_INVALID;
            /* assume transparent PDCP for now */
            call_dissector(ip_handle, tvb, pinfo, tree);
            /* once the packet has been dissected, protect it from further changes using a 'fence' in the INFO column */
            col_append_str(pinfo->cinfo, COL_INFO," ");
            col_set_fence(pinfo->cinfo, COL_INFO);
            break;
        default:
            return; /* stop dissecting */
    }
    if (msgtype != RRC_MESSAGE_TYPE_INVALID) {
        struct rrc_info *rrcinf;
        fp_info *fpinf;
        fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
        rrcinf = (rrc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_rrc, 0);
        if (!rrcinf) {
            rrcinf = (rrc_info *)wmem_alloc0(wmem_file_scope(), sizeof(struct rrc_info));
            p_add_proto_data(wmem_file_scope(), pinfo, proto_rrc, 0, rrcinf);
        }
        rrcinf->msgtype[fpinf->cur_tb] = msgtype;
        call_dissector(rrc_handle, tvb, pinfo, tree);
        /* once the packet has been dissected, protect it from further changes using a 'fence' in the INFO column */
        col_append_str(pinfo->cinfo, COL_INFO," ");
        col_set_fence(pinfo->cinfo, COL_INFO);
    }
}

static void
add_channel_info(packet_info * pinfo, proto_tree * tree, fp_info * fpinf, rlc_info * rlcinf)
{
    proto_item * item;
    proto_tree * channel_tree ;

    item = proto_tree_add_item(tree, hf_rlc_channel, NULL, 0, 0, ENC_NA);
    channel_tree = proto_item_add_subtree(item, ett_rlc_channel);
    proto_item_append_text(item, " (rbid: %u, dir: %s, uid: 0x%08x)", rlcinf->rbid[fpinf->cur_tb],
                           val_to_str_const(pinfo->link_dir, rlc_dir_vals, "Unknown"), rlcinf->ueid[fpinf->cur_tb]);
    PROTO_ITEM_SET_GENERATED(item);
    item = proto_tree_add_uint(channel_tree, hf_rlc_channel_rbid, NULL, 0, 0, rlcinf->rbid[fpinf->cur_tb]);
    PROTO_ITEM_SET_GENERATED(item);
    item = proto_tree_add_uint(channel_tree, hf_rlc_channel_dir, NULL, 0, 0, pinfo->link_dir);
    PROTO_ITEM_SET_GENERATED(item);
    item = proto_tree_add_uint(channel_tree, hf_rlc_channel_ueid, NULL, 0, 0, rlcinf->ueid[fpinf->cur_tb]);
    PROTO_ITEM_SET_GENERATED(item);

}

#ifdef HAVE_UMTS_KASUMI
static guint8 *
translate_hex_key(gchar * char_key){
    int i,j;
    guint8 * key_in;

    key_in = wmem_alloc0(wmem_packet_scope(), sizeof(guint8)*16);
    j= (int)(strlen(char_key)/2)-1;
    /*Translate "hex-string" into a byte aligned block */
    for(i = (int)strlen(char_key); i> 0; i-=2 ){
        key_in[j] =  ( (guint8)  (strtol( &char_key[i-2], NULL, 16 ) ));
        char_key[i-2] = '\0';
        j--;
    }
    return key_in;

}
#endif

/** @brief Deciphers a given tvb
 *
 * Note that the actual KASUMI implementation needs to be placed into
 * epan/crypt/kasumi.* by "end users" since due to patents the actual implementation
 * cannot be distributed openly at the moment.
 *
 * Refer to 3GPP TS 35.201 and 3GPP TS 35.202 for further information.
 *
 *  @param tvb The ciphered data.
 *  @param  pinfo Packet info.
 *  @param counter the COUNTER value input
 *  @param rbid the radiobear id
 *  @param dir Direction of the link
 *  @param header_size Size of the unciphered header
 *  @return tvb Returns a deciphered tvb
 */
static tvbuff_t *
#ifndef HAVE_UMTS_KASUMI
rlc_decipher_tvb(tvbuff_t *tvb _U_, packet_info *pinfo, guint32 counter _U_,
                 guint8 rbid _U_, gboolean dir _U_, guint8 header_size _U_) {
    /*Check if we have a KASUMI implementation*/
    expert_add_info(pinfo, NULL, &ei_rlc_kasumi_implementation_missing);
    return NULL;
#else
rlc_decipher_tvb(tvbuff_t *tvb, packet_info *pinfo, guint32 counter, guint8 rbid, gboolean dir, guint8 header_size) {
    guint8* out=NULL,*key_in = NULL;
    tvbuff_t *t;

    /*Fix the key into a byte block*/
    /*TODO: This should be done in a preferences callback function*/
    out = wmem_alloc0(wmem_packet_scope(), strlen(global_rlc_kasumi_key)+1);
    memcpy(out,global_rlc_kasumi_key,strlen(global_rlc_kasumi_key));    /*Copy from prefrence const pointer*/
    key_in = translate_hex_key(out);    /*Translation*/

    /*Location for decrypted data & original RLC header*/
    out = tvb_memdup(pinfo->pool, tvb, 0, tvb_captured_length(tvb));

    /*Call f8 confidentiality function, note that rbid is zero indexed*/
    f8( key_in, counter, rbid-1, dir, &out[header_size], (tvb_captured_length(tvb)-header_size)*8 );

    /*Create new tvb.*/
    t = tvb_new_real_data(out,tvb_captured_length(tvb), tvb_reported_length(tvb));
    add_new_data_source(pinfo, t, "Deciphered RLC");
    return t;
#endif /* HAVE_UMTS_KASUMI */
}

/** @brief Checks if an RLC packet is ciphered, according to information reported from the RRC layer
 *
 *  @param pinfo Packet info.
 *  @param fpinf FP info
 *  @param rlcinf RLC info
 *  @param seq Sequence number of the RLC packet
 *  @return gboolean Returns TRUE if the packet is ciphered and false otherwise
 */
static gboolean
is_ciphered_according_to_rrc(packet_info *pinfo, fp_info *fpinf, rlc_info *rlcinf ,guint16 seq) {
    gint16              cur_tb;
    guint32             ueid;
    rrc_ciphering_info *ciphering_info;
    guint8              rbid;
    guint8              direction;
    guint32             security_mode_frame_num;
    gint32              ciphering_begin_seq;

    if(global_ignore_rrc_ciphering_indication) {
        return FALSE;
    }

    cur_tb = fpinf->cur_tb;
    ueid = rlcinf->ueid[cur_tb];
    ciphering_info =  (rrc_ciphering_info *)g_tree_lookup(rrc_ciph_info_tree, GINT_TO_POINTER((gint)ueid));
    if(ciphering_info != NULL) {
        rbid = rlcinf->rbid[cur_tb];
        direction = fpinf->is_uplink ? P2P_DIR_UL : P2P_DIR_DL;
        security_mode_frame_num = ciphering_info->setup_frame[direction];
        ciphering_begin_seq = ciphering_info->seq_no[rbid][direction];
        /* Making sure the rrc security message's frame number makes sense */
        if( security_mode_frame_num > 0 && security_mode_frame_num <= pinfo->num) {
            /* Making sure the sequence number where ciphering starts makes sense */
            /* TODO: This check is incorrect if the sequence numbers wrap around */
            if(ciphering_begin_seq >= 0 && ciphering_begin_seq <= seq){
                return TRUE;
            }
        }
    }
    return FALSE;
}

/*
 * @param key is created with GINT_TO_POINTER
 * @param value is a pointer to a guint32
 * @param data is a pointer to a guint32
 */
static gboolean
iter_same(gpointer key, gpointer value, gpointer data) {
    /*If true we found the correct frame*/
    if ((guint32)GPOINTER_TO_INT(key) > *(guint32*)data){
        *((guint32*)data) = *((guint32*)value);
        return TRUE;
    }
    *((guint32*)data) = (guint32)GPOINTER_TO_INT(key);

    return TRUE;
}

/**
 * Used for looking up and old ciphering counter value in the counter_map tree.
 * @param key is created with GINT_TO_POINTER
 * @param value is pointer to an array of 2 guint32s
 * @param data is a pointer to an array of 3 guint32s
 */
static gboolean
rlc_find_old_counter(gpointer key, gpointer value, gpointer data) {

    /*If true we found the correct frame*/
    if( (guint32)GPOINTER_TO_INT(key) >= ((guint32 *)data)[0] ){
        return TRUE;
    }
    /*Overwrite the data since the previous one wasn't correct*/
    ((guint32*)data)[1] = ((guint32*)value)[0];
    ((guint32*)data)[2] = ((guint32*)value)[1];

    return FALSE;
}

static void
rlc_decipher(tvbuff_t *tvb, packet_info * pinfo, proto_tree * tree, fp_info * fpinf,
             rlc_info * rlcinf, guint16 seq, enum rlc_mode mode)
{
    rrc_ciphering_info *ciphering_info;
    guint8 indx, header_size, hfn_shift;
    gint16 pos;
    guint8 ext;
    int ciphered_data_hf;

    indx = fpinf->is_uplink ? P2P_DIR_UL : P2P_DIR_DL;
    pos = fpinf->cur_tb;
    if (mode ==RLC_UM) {
        header_size = 1;
        hfn_shift = 7;
    } else {
        header_size = 2;
        hfn_shift = 12;
    }

    /*Ciphering info singled in RRC by securitymodecommands */
    ciphering_info =  (rrc_ciphering_info *)g_tree_lookup(rrc_ciph_info_tree, GINT_TO_POINTER((gint)rlcinf->ueid[fpinf->cur_tb]));

    /*TODO: This doesn't really work for all packets..*/
    /*Check if we have ciphering info and that this frame is ciphered*/
    if(ciphering_info!=NULL && ( (ciphering_info->setup_frame[indx] > 0 && ciphering_info->setup_frame[indx] < pinfo->num && ciphering_info->seq_no[rlcinf->rbid[pos]][indx] == -1)  ||
                     (ciphering_info->setup_frame[indx] < pinfo->num && ciphering_info->seq_no[rlcinf->rbid[pos]][indx] >= 0  && ciphering_info->seq_no[rlcinf->rbid[pos]][indx] <= seq) )){

        tvbuff_t *t;

        /*Check if this counter has been initialized*/
        if(!counter_init[rlcinf->rbid[pos]][indx] ){
            guint32 frame_num = pinfo->num;

            /*Initializes counter*/
            counter_init[rlcinf->rbid[pos]][0] = TRUE;
            counter_init[rlcinf->rbid[pos]][1] = TRUE;
            /*Find appropriate start value*/
            g_tree_foreach(ciphering_info->start_ps, (GTraverseFunc)iter_same, &frame_num);

            /*Set COUNTER value accordingly as specified by 6.4.8 in 3GPP TS 33.102 */
            if(max_counter +2 > frame_num && ciphering_info->seq_no[rlcinf->rbid[pos]][indx] == -1){
                ps_counter[rlcinf->rbid[pos]][0] = (max_counter+2) << hfn_shift;
                ps_counter[rlcinf->rbid[pos]][1] = (max_counter+2) << hfn_shift;
            }else{
                ps_counter[rlcinf->rbid[pos]][0] = frame_num << hfn_shift;
                ps_counter[rlcinf->rbid[pos]][1] = frame_num << hfn_shift;
            }

            if(!tree){
                /*Preserve counter value for next dissection round*/
                guint32 * ciph;
                ciph = (guint32 *)g_malloc(sizeof(guint32)*2);
                ciph[0] = ps_counter[rlcinf->rbid[pos]][0];
                ciph[1] = ps_counter[rlcinf->rbid[pos]][1];
                g_tree_insert(counter_map, GINT_TO_POINTER((gint)pinfo->num), ciph);
            }

        }
        /*Update the maximal COUNTER value seen so far*/
        max_counter = MAX(max_counter,((ps_counter[rlcinf->rbid[pos]][indx]) | seq) >> hfn_shift);

    /*XXX: Since RBID in umts isn't configured properly..*/
        if(rlcinf->rbid[pos] == 9 ){
            if(tree){
                guint32 frame_num[3];
                /*Set frame num we will be "searching" around*/
                frame_num[0] = pinfo->num;
                /*Find the correct counter value*/
                g_tree_foreach(counter_map, (GTraverseFunc)rlc_find_old_counter, &frame_num[0]);
                t = rlc_decipher_tvb(tvb, pinfo, (frame_num[indx+1] | seq),16,!fpinf->is_uplink,header_size);
            }else{
                t = rlc_decipher_tvb(tvb, pinfo, ((ps_counter[rlcinf->rbid[pos]][indx]) | seq),16,!fpinf->is_uplink,header_size);
            }
        }else{
            if(tree){
                /*We need to find the original counter value for second dissection pass*/
                guint32 frame_num[3];
                frame_num[0] = pinfo->num;
                g_tree_foreach(counter_map, (GTraverseFunc)rlc_find_old_counter, &frame_num[0]);
                t = rlc_decipher_tvb(tvb, pinfo, (frame_num[indx+1] | seq),rlcinf->rbid[pos],!fpinf->is_uplink,header_size);
            }else
                t = rlc_decipher_tvb(tvb, pinfo, ((ps_counter[rlcinf->rbid[pos]][indx]) | seq),rlcinf->rbid[pos],!fpinf->is_uplink,header_size);
        }

        /*Update the hyperframe number*/
        if(seq == 4095){

            ps_counter[rlcinf->rbid[pos]][indx] += 1 << hfn_shift;

            if(!tree){/*Preserve counter for second packet analysis run*/
                guint32 * ciph;
                ciph = (guint32 *)g_malloc(sizeof(guint32)*2);
                ciph[0] = ps_counter[rlcinf->rbid[pos]][0];
                ciph[1] = ps_counter[rlcinf->rbid[pos]][1];
                g_tree_insert(counter_map, GINT_TO_POINTER((gint)pinfo->num+1), ciph);
            }
        }

        /*Unable to decipher the packet*/
        if(t == NULL){
            /* Choosing the right field text ("LIs & Data" or just "Data") based on extension bit / header extension */
            ext = tvb_get_guint8(tvb, header_size - 1) & 0x01;
            ciphered_data_hf = (ext == 1) ? hf_rlc_ciphered_lis_data : hf_rlc_ciphered_data;
            /* Adding ciphered payload field to tree */
            proto_tree_add_item(tree, ciphered_data_hf, tvb, header_size, -1, ENC_NA);
            proto_tree_add_expert(tree, pinfo, &ei_rlc_ciphered_data, tvb, header_size, -1);
            col_append_str(pinfo->cinfo, COL_INFO, "[Ciphered Data]");
            return;

        }else{
            col_append_str(pinfo->cinfo, COL_INFO, "[Deciphered Data]");

            /*TODO: Old tvb should be freed here?*/
        }
    }
}

static void
dissect_rlc_tm(enum rlc_channel_type channel, tvbuff_t *tvb, packet_info *pinfo,
           proto_tree *top_level, proto_tree *tree)
{
    fp_info       *fpinf;
    rlc_info      *rlcinf;

    fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);

    if (tree) {
        if (fpinf && rlcinf) {
            /* Add "channel" information, very useful for debugging. */
            add_channel_info(pinfo, tree, fpinf, rlcinf);
        }
        proto_tree_add_item(tree, hf_rlc_data, tvb, 0, -1, ENC_NA);
    }
    rlc_call_subdissector(channel, tvb, pinfo, top_level);
}


static void
rlc_um_reassemble(tvbuff_t *tvb, guint8 offs, packet_info *pinfo, proto_tree *tree,
          proto_tree *top_level, enum rlc_channel_type channel, guint16 seq,
          struct rlc_li *li, guint16 num_li, gboolean li_is_on_2_bytes,
          struct atm_phdr *atm)
{
    guint8    i;
    gboolean  dissected = FALSE;
    gint      length;
    tvbuff_t *next_tvb  = NULL;

    /* perform reassembly now */
    for (i = 0; i < num_li; i++) {
        if ((!li_is_on_2_bytes && (li[i].li == 0x7f)) || (li[i].li == 0x7fff)) {
            /* padding, must be last LI */
            if (tree) {
                proto_tree_add_item(tree, hf_rlc_pad, tvb, offs, tvb_captured_length_remaining(tvb, offs), ENC_NA);
            }
            offs += tvb_captured_length_remaining(tvb, offs);
        } else if ((!li_is_on_2_bytes && (li[i].li == 0x7c)) || (li[i].li == 0x7ffc)) {
            /* a new SDU starts here, mark this seq as the first PDU. */
            struct rlc_channel  ch_lookup;
            struct rlc_seqlist * endlist = NULL;
            if( -1 != rlc_channel_assign(&ch_lookup, RLC_UM, pinfo, atm ) ){
                endlist = get_endlist(pinfo, &ch_lookup, atm);
                endlist->list->data = GINT_TO_POINTER((gint)seq);
                endlist->fail_packet=0;
            }

        } else if (li[i].li == 0x7ffa) {
            /* the first data octet in this RLC PDU is the first octet of an RLC SDU
               and the second last octet in this RLC PDU is the last octet of the same RLC SDU */
            length = tvb_reported_length_remaining(tvb, offs);
            if (length > 1) {
                length--;
                if (tree && length) {
                    proto_tree_add_item(tree, hf_rlc_data, tvb, offs, length, ENC_NA);
                }
                if (global_rlc_perform_reassemby) {
                    add_fragment(RLC_UM, tvb, pinfo, li[i].tree, offs, seq, i, length, TRUE, atm);
                    next_tvb = get_reassembled_data(RLC_UM, tvb, pinfo, tree, seq, i, atm);
                }
                offs += length;
            }
            if (tree) {
                proto_tree_add_item(tree, hf_rlc_pad, tvb, offs, 1, ENC_NA);
            }
            offs += 1;
        } else {
            if (tree && li[i].len) {
                proto_tree_add_item(tree, hf_rlc_data, tvb, offs, li[i].len, ENC_NA);
            }
            if (global_rlc_perform_reassemby) {
                add_fragment(RLC_UM, tvb, pinfo, li[i].tree, offs, seq, i, li[i].len, TRUE, atm);
                next_tvb = get_reassembled_data(RLC_UM, tvb, pinfo, tree, seq, i, atm);
            }
        }
        if (next_tvb) {
            dissected = TRUE;
            rlc_call_subdissector(channel, next_tvb, pinfo, top_level);
            next_tvb = NULL;
        }
        offs += li[i].len;
    }

    /* is there data left? */
    if (tvb_reported_length_remaining(tvb, offs) > 0) {
        if (tree) {
            proto_tree_add_item(tree, hf_rlc_data, tvb, offs, -1, ENC_NA);
        }
        if (global_rlc_perform_reassemby) {
            /* add remaining data as fragment */
            add_fragment(RLC_UM, tvb, pinfo, tree, offs, seq, i, tvb_captured_length_remaining(tvb, offs), FALSE, atm);
            if (dissected == FALSE)
                col_set_str(pinfo->cinfo, COL_INFO, "[RLC UM Fragment]");
        }
    }
    if (dissected == FALSE)
        col_append_fstr(pinfo->cinfo, COL_INFO, "[RLC UM Fragment]  SN=%u", seq);
    else
        if (channel == RLC_UNKNOWN_CH)
            col_append_fstr(pinfo->cinfo, COL_INFO, "[RLC UM Data]  SN=%u", seq);
}

static gint16
rlc_decode_li(enum rlc_mode mode, tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
          struct rlc_li *li, guint8 max_li, gboolean li_on_2_bytes)
{
    guint32     hdr_len, offs = 0, li_offs;
    guint8      ext, num_li = 0;
    guint16     next_bytes, prev_li = 0;
    proto_item *malformed;
    guint16     total_len;

    switch (mode) {
        case RLC_AM:
            offs = 1;
            break;
        case RLC_UM:
            offs = 0;
            break;
        case RLC_TM:
            /* fall through */
        case RLC_UNKNOWN_MODE:
        default:
            return -1;
    }
    hdr_len = offs;
    /* calculate header length */
    ext = tvb_get_guint8(tvb, hdr_len++) & 0x01;
    while (ext) {
        next_bytes = li_on_2_bytes ? tvb_get_ntohs(tvb, hdr_len) : tvb_get_guint8(tvb, hdr_len);
        ext = next_bytes & 0x01;
        hdr_len += li_on_2_bytes ? 2 : 1;
    }
    total_len = tvb_captured_length_remaining(tvb, hdr_len);

    /* do actual evaluation of LIs */
    ext = tvb_get_guint8(tvb, offs++) & 0x01;
    li_offs = offs;
    while (ext) {
        if (li_on_2_bytes) {
            next_bytes = tvb_get_ntohs(tvb, offs);
            offs += 2;
        } else {
            next_bytes = tvb_get_guint8(tvb, offs++);
        }
        ext = next_bytes & 0x01;
        li[num_li].ext = ext;
        li[num_li].li = next_bytes >> 1;

        if (li_on_2_bytes) {
            switch (li[num_li].li) {
                case 0x0000: /* previous segment was the last one */
                case 0x7ffb: /* previous PDU contains last segment of SDU (minus last byte) */
                case 0x7ffe: /* contains piggybacked STATUS in AM or segment in UM */
                case 0x7fff: /* padding */
                    li[num_li].len = 0;
                    break;
                case 0x7ffa: /* contains exactly one SDU (minus last byte), UM only */
                case 0x7ffc: /* start of a new SDU, UM only */
                case 0x7ffd: /* contains exactly one SDU, UM only */
                    li[num_li].len = 0;
                    if (mode == RLC_UM) {
                        /* valid for UM */
                        break;
                    }
                    /*invalid for AM */
                    /* add malformed LI for investigation */
                    malformed = tree_add_li(mode, &li[num_li], num_li, li_offs, li_on_2_bytes, tvb, tree);
                    expert_add_info(pinfo, malformed, &ei_rlc_li_reserved);
                    return -1; /* just give up on this */
                default:
                    /* since the LI is an offset (from the end of the header), it
                    * may not be larger than the total remaining length and no
                    * LI may be smaller than its preceding one
                    */
                    if (((li[num_li].li > total_len) && !global_rlc_headers_expected)
                        || (li[num_li].li < prev_li)) {
                        /* add malformed LI for investigation */
                        li[num_li].len = 0;
                        malformed = tree_add_li(mode, &li[num_li], num_li, li_offs, li_on_2_bytes, tvb, tree);
                        expert_add_info(pinfo, malformed, &ei_rlc_li_incorrect_warn);
                        return -1; /* just give up on this */
                    }
                    li[num_li].len = li[num_li].li - prev_li;
                    prev_li = li[num_li].li;
            }
        } else {
            switch (li[num_li].li) {
                case 0x00: /* previous segment was the last one */
                case 0x7e: /* contains piggybacked STATUS in AM or segment in UM */
                case 0x7f: /* padding */
                    li[num_li].len = 0;
                    break;
                case 0x7c: /* start of a new SDU, UM only */
                case 0x7d: /* contains exactly one SDU, UM only */
                    li[num_li].len = 0;
                    if (mode == RLC_UM) {
                        /* valid for UM */
                        break;
                    }
                    /*invalid for AM */
                    /* add malformed LI for investigation */
                    malformed = tree_add_li(mode, &li[num_li], num_li, li_offs, li_on_2_bytes, tvb, tree);
                    expert_add_info(pinfo, malformed, &ei_rlc_li_reserved);
                    return -1; /* just give up on this */
                default:
                    /* since the LI is an offset (from the end of the header), it
                    * may not be larger than the total remaining length and no
                    * LI may be smaller than its preceding one
                    */
                    li[num_li].len = li[num_li].li - prev_li;
                    if (((li[num_li].li > total_len) && !global_rlc_headers_expected)
                        || (li[num_li].li < prev_li)) {
                        /* add malformed LI for investigation */
                        li[num_li].len = 0;
                        malformed = tree_add_li(mode, &li[num_li], num_li, li_offs, li_on_2_bytes, tvb, tree);
                        expert_add_info_format(pinfo, malformed, &ei_rlc_li_incorrect_mal, "Incorrect LI value 0x%x", li[num_li].li);
                        return -1; /* just give up on this */
                    }
                    prev_li = li[num_li].li;
            }
        }
        li[num_li].tree = tree_add_li(mode, &li[num_li], num_li, li_offs, li_on_2_bytes, tvb, tree);
        num_li++;

        if (num_li >= max_li) {
            /* OK, so this is not really a malformed packet, but for now,
            * we will treat it as such, so that it is marked in some way */
            expert_add_info(pinfo, li[num_li-1].tree, &ei_rlc_li_too_many);
            return -1;
        }
    }
    return num_li;
}

static void
dissect_rlc_um(enum rlc_channel_type channel, tvbuff_t *tvb, packet_info *pinfo,
           proto_tree *top_level, proto_tree *tree, struct atm_phdr *atm)
{
#define MAX_LI 16
    struct rlc_li  li[MAX_LI];
    fp_info       *fpinf;
    rlc_info      *rlcinf;
    guint32        orig_num;
    guint8         seq;
    guint8         ext;
    guint8         next_byte, offs = 0;
    gint16         cur_tb, num_li  = 0;
    gboolean       is_truncated, li_is_on_2_bytes;
    proto_item    *truncated_ti;
    gboolean       ciphered_according_to_rrc = FALSE;
    gboolean       ciphered_flag = FALSE;
    gboolean       deciphered_flag = FALSE;
    int            ciphered_data_hf;


    next_byte = tvb_get_guint8(tvb, offs++);
    seq = next_byte >> 1;

    fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);

    if (tree) {
        if (fpinf && rlcinf) {
            /* Add "channel" information, very useful for debugging. */
            add_channel_info(pinfo, tree, fpinf, rlcinf);
        }
        /* show sequence number and extension bit */
        proto_tree_add_bits_item(tree, hf_rlc_seq, tvb, 0, 7, ENC_BIG_ENDIAN);
        proto_tree_add_bits_item(tree, hf_rlc_ext, tvb, 7, 1, ENC_BIG_ENDIAN);
    }

    if (!fpinf || !rlcinf) {
        proto_tree_add_expert(tree, pinfo, &ei_rlc_no_per_frame_data, tvb, 0, -1);
        return;
    }

    cur_tb = fpinf->cur_tb;
    ciphered_according_to_rrc = is_ciphered_according_to_rrc(pinfo, fpinf, rlcinf, (guint16)seq);
    ciphered_flag = rlcinf->ciphered[cur_tb];
    deciphered_flag = rlcinf->deciphered[cur_tb];
    if (((ciphered_according_to_rrc || ciphered_flag) && !deciphered_flag) || global_rlc_ciphered) {
        if(global_rlc_try_decipher){
            rlc_decipher(tvb, pinfo, tree, fpinf, rlcinf, seq, RLC_UM);
        }else{
            /* Choosing the right field text ("LIs & Data" or just "Data") based on extension bit */
            ext = tvb_get_guint8(tvb, 0) & 0x01;
            ciphered_data_hf = (ext == 1) ? hf_rlc_ciphered_lis_data : hf_rlc_ciphered_data;
            /* Adding ciphered payload field to tree */
            proto_tree_add_item(tree, ciphered_data_hf, tvb, offs, -1, ENC_NA);
            proto_tree_add_expert(tree, pinfo, &ei_rlc_ciphered_data, tvb, offs, -1);
            col_append_str(pinfo->cinfo, COL_INFO, "[Ciphered Data]");
            return;
        }
    }

    if (global_rlc_li_size == RLC_LI_UPPERLAYER) {
        if (rlcinf->li_size[cur_tb] == RLC_LI_VARIABLE) {
            li_is_on_2_bytes = (tvb_reported_length(tvb) > 125) ? TRUE : FALSE;
        } else {
            li_is_on_2_bytes = (rlcinf->li_size[cur_tb] == RLC_LI_15BITS) ? TRUE : FALSE;
        }
    } else { /* Override rlcinf configuration with preference. */
        li_is_on_2_bytes = (global_rlc_li_size == RLC_LI_15BITS) ? TRUE : FALSE;
    }



    num_li = rlc_decode_li(RLC_UM, tvb, pinfo, tree, li, MAX_LI, li_is_on_2_bytes);
    if (num_li == -1) return; /* something went wrong */
    offs += ((li_is_on_2_bytes) ? 2 : 1) * num_li;

    if (global_rlc_headers_expected) {
        /* There might not be any data, if only header was logged */
        is_truncated = (tvb_captured_length_remaining(tvb, offs) == 0);
        truncated_ti = proto_tree_add_boolean(tree, hf_rlc_header_only, tvb, 0, 0,
                                              is_truncated);
        if (is_truncated) {
            PROTO_ITEM_SET_GENERATED(truncated_ti);
            expert_add_info(pinfo, truncated_ti, &ei_rlc_header_only);
            return;
        } else {
            PROTO_ITEM_SET_HIDDEN(truncated_ti);
        }
    }

    /* do not detect duplicates or reassemble, if prefiltering is done */
    if (pinfo->num == 0) return;
    /* check for duplicates */
    if (rlc_is_duplicate(RLC_UM, pinfo, seq, &orig_num, atm) == TRUE) {
        col_add_fstr(pinfo->cinfo, COL_INFO, "[RLC UM Fragment] [Duplicate]  SN=%u", seq);
        proto_tree_add_uint(tree, hf_rlc_duplicate_of, tvb, 0, 0, orig_num);
        return;
    }
    rlc_um_reassemble(tvb, offs, pinfo, tree, top_level, channel, seq, li, num_li, li_is_on_2_bytes, atm);
}

static void
dissect_rlc_status(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree, guint8 offset)
{
    guint8      sufi_type, bits;
    guint64     len, sn, wsn, lsn, l;
    guint16     value, previous_sn;
    gboolean    isErrorBurstInd;
    gint        bit_offset, previous_bit_offset;
    guint       i, j;
    proto_tree *sufi_tree, *bitmap_tree, *rlist_tree;
    proto_item *sufi_item, *ti;
    #define BUFF_SIZE 41
    gchar      *buff                     = NULL;
    guint8      cw[15];
    guint8      sufi_start_offset;
    gboolean    seen_last                = FALSE;
    guint16     number_of_bitmap_entries = 0;

    bit_offset = offset*8 + 4; /* first SUFI type is always 4 bit shifted */

    while (!seen_last && tvb_reported_length_remaining(tvb, bit_offset/8) > 0) {
        /* SUFI */
        sufi_type = tvb_get_bits8(tvb, bit_offset, 4);
        sufi_start_offset = bit_offset/8;
        sufi_item = proto_tree_add_item(tree, hf_rlc_sufi, tvb, sufi_start_offset, 0, ENC_NA);
        sufi_tree = proto_item_add_subtree(sufi_item, ett_rlc_sufi);
        proto_tree_add_bits_item(sufi_tree, hf_rlc_sufi_type, tvb, bit_offset, 4, ENC_BIG_ENDIAN);
        proto_item_append_text(sufi_item, " (%s)", val_to_str_const(sufi_type, rlc_sufi_vals, "Unknown"));
        bit_offset += 4;
        switch (sufi_type) {
            case RLC_SUFI_NOMORE:
                seen_last = TRUE;
                break;
            case RLC_SUFI_ACK:
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_lsn, tvb, bit_offset, 12, &lsn, ENC_BIG_ENDIAN);
                col_append_fstr(pinfo->cinfo, COL_INFO, " LSN=%u", (guint16)lsn);
                proto_item_append_text(sufi_item, " LSN=%u", (guint16)lsn);
                bit_offset += 12;
                seen_last = TRUE;
                break;
            case RLC_SUFI_WINDOW:
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_wsn, tvb, bit_offset, 12, &wsn, ENC_BIG_ENDIAN);
                col_append_fstr(pinfo->cinfo, COL_INFO, " WSN=%u", (guint16)wsn);
                bit_offset += 12;
                break;
            case RLC_SUFI_LIST:
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_len, tvb, bit_offset, 4, &len, ENC_BIG_ENDIAN);
                col_append_fstr(pinfo->cinfo, COL_INFO,  " LIST(%u) - ", (guint8)len);
                bit_offset += 4;
                if (len) {
                    while (len) {
                        ti = proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_sn, tvb, bit_offset, 12, &sn, ENC_BIG_ENDIAN);
                        proto_item_append_text(ti, " (AMD PDU not correctly received)");
                        bit_offset += 12;
                        ti = proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_l, tvb, bit_offset, 4, &l, ENC_BIG_ENDIAN);
                        if (l) {
                            proto_item_append_text(ti, " (all consecutive AMD PDUs up to SN %u not correctly received)",
                                                   (unsigned)(sn+l)&0xfff);
                            col_append_fstr(pinfo->cinfo, COL_INFO,  "%u-%u ", (guint16)sn, (unsigned)(sn+l)&0xfff);
                        }
                        else {
                            col_append_fstr(pinfo->cinfo, COL_INFO,  "%u ", (guint16)sn);
                        }
                        bit_offset += 4;
                        len--;
                    }
                } else {
                    expert_add_info(pinfo, tree, &ei_rlc_sufi_len);
                }
                break;
            case RLC_SUFI_BITMAP:
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_len, tvb, bit_offset, 4, &len, ENC_BIG_ENDIAN);
                bit_offset += 4;
                len++; /* bitmap is len + 1 */
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_fsn, tvb, bit_offset, 12, &sn, ENC_BIG_ENDIAN);
                bit_offset += 12;
                proto_tree_add_item(sufi_tree, hf_rlc_sufi_bitmap, tvb, bit_offset/8, (gint)len, ENC_NA);
                bitmap_tree = proto_tree_add_subtree(sufi_tree, tvb, bit_offset/8, (gint)len, ett_rlc_bitmap, &ti, "Decoded bitmap:");
                col_append_str(pinfo->cinfo, COL_INFO, " BITMAP=(");

                buff = (gchar *)wmem_alloc(wmem_packet_scope(), BUFF_SIZE);
                for (i=0; i<len; i++) {
                    bits = tvb_get_bits8(tvb, bit_offset, 8);
                    for (l=0, j=0; l<8; l++) {
                        if ((bits << l) & 0x80) {
                            j += g_snprintf(&buff[j], BUFF_SIZE-j, "%4u,", (unsigned)(sn+(8*i)+l)&0xfff);
                            col_append_fstr(pinfo->cinfo, COL_INFO, " %u", (unsigned)(sn+(8*i)+l)&0xfff);
                            number_of_bitmap_entries++;
                        } else {
                            j += g_snprintf(&buff[j], BUFF_SIZE-j, "    ,");
                        }
                    }
                    proto_tree_add_string_format(bitmap_tree, hf_rlc_bitmap_string, tvb, bit_offset/8, 1, buff, "%s", buff);
                    bit_offset += 8;
                }
                proto_item_append_text(ti, " (%u SNs)", number_of_bitmap_entries);
                col_append_str(pinfo->cinfo, COL_INFO, " )");
                break;
            case RLC_SUFI_RLIST:
                previous_bit_offset = bit_offset;
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_len, tvb, bit_offset, 4, &len, ENC_BIG_ENDIAN);
                bit_offset += 4;
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_fsn, tvb, bit_offset, 12, &sn, ENC_BIG_ENDIAN);
                bit_offset += 12;
                proto_item_append_text(sufi_item, " (%u codewords)", (guint16)len);

                for (i=0; i<len; i++) {
                    ti = proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_cw, tvb, bit_offset, 4, &l, ENC_BIG_ENDIAN);
                    if (l == 0x01) {
                        proto_item_append_text(ti, " (Error burst indication)");
                    }
                    bit_offset += 4;
                    cw[i] = (guint8)l;
                }
                if (len && (((cw[len-1] & 0x01) == 0) || (cw[len-1] == 0x01))) {
                    expert_add_info(pinfo, tree, &ei_rlc_sufi_cw);
                } else {
                    rlist_tree = proto_tree_add_subtree(sufi_tree, tvb, previous_bit_offset/8, (bit_offset-previous_bit_offset)/8, ett_rlc_rlist, NULL, "Decoded list:");
                    proto_tree_add_uint_format_value(rlist_tree, hf_rlc_sequence_number, tvb, (previous_bit_offset+4)/8, 12/8, (guint32)sn, "%u (AMD PDU not correctly received)", (unsigned)sn);
                    col_append_fstr(pinfo->cinfo, COL_INFO, " RLIST=(%u", (unsigned)sn);

                    for (i=0, isErrorBurstInd=FALSE, j=0, previous_sn=(guint16)sn, value=0; i<len; i++) {
                        if (cw[i] == 0x01) {
                            isErrorBurstInd = TRUE;
                        } else {
                            value |= (cw[i] >> 1) << j;
                            j += 3;
                            if (cw[i] & 0x01) {
                                if (isErrorBurstInd) {
                                    previous_sn = (previous_sn + value) & 0xfff;
                                    ti = proto_tree_add_uint(rlist_tree, hf_rlc_length, tvb, (previous_bit_offset+16+4*i)/8, 1, value);
                                    if (value) {
                                        proto_item_append_text(ti, "  (all consecutive AMD PDUs up to SN %u not correctly received)", previous_sn);
                                        col_append_fstr(pinfo->cinfo, COL_INFO, " ->%u", previous_sn);
                                    }
                                    isErrorBurstInd = FALSE;
                                } else {
                                    value = (value + previous_sn) & 0xfff;
                                    proto_tree_add_uint_format_value(rlist_tree, hf_rlc_sequence_number, tvb, (previous_bit_offset+16+4*i)/8, 1, value, "%u (AMD PDU not correctly received)",value);
                                    col_append_fstr(pinfo->cinfo, COL_INFO, " %u", value);
                                    previous_sn = value;
                                }
                                value = j = 0;
                            }
                        }
                    }
                    col_append_str(pinfo->cinfo, COL_INFO, ")");
                }
                break;
            case RLC_SUFI_MRW_ACK:
                col_append_str(pinfo->cinfo, COL_INFO, " MRW-ACK");
                proto_tree_add_bits_item(sufi_tree, hf_rlc_sufi_n, tvb, bit_offset, 4, ENC_BIG_ENDIAN);
                bit_offset += 4;
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_sn_ack, tvb, bit_offset, 12, &sn, ENC_BIG_ENDIAN);
                bit_offset += 12;
                col_append_fstr(pinfo->cinfo, COL_INFO, " SN=%u", (guint16)sn);
                break;
            case RLC_SUFI_MRW:
                col_append_str(pinfo->cinfo, COL_INFO, " MRW");
                proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_len, tvb, bit_offset, 4, &len, ENC_BIG_ENDIAN);
                bit_offset += 4;
                if (len) {
                    while (len) {
                        proto_tree_add_bits_ret_val(sufi_tree, hf_rlc_sufi_sn_mrw, tvb, bit_offset, 12, &sn, ENC_BIG_ENDIAN);
                        col_append_fstr(pinfo->cinfo, COL_INFO, " SN=%u", (guint16)sn);
                        bit_offset += 12;
                        len--;
                    }
                } else {
                    /* only one SN_MRW field is present */
                    ti = proto_tree_add_bits_item(sufi_tree, hf_rlc_sufi_sn_mrw, tvb, bit_offset, 12, ENC_BIG_ENDIAN);
                    proto_item_append_text(ti, " (RLC SDU to be discarded in the Receiver extends above the configured transmission window in the Sender)");
                    bit_offset += 12;
                }
                proto_tree_add_bits_item(sufi_tree, hf_rlc_sufi_n, tvb, bit_offset, 4, ENC_BIG_ENDIAN);
                bit_offset += 4;
                break;
            case RLC_SUFI_POLL:
                proto_tree_add_bits_item(sufi_tree, hf_rlc_sufi_poll_sn, tvb, bit_offset, 12, ENC_BIG_ENDIAN);
                bit_offset += 12;
                break;

            default:
                expert_add_info(pinfo, tree, &ei_rlc_sufi_type);
                return; /* invalid value, ignore the rest */
        }

        /* Set extent of SUFI root */
        proto_item_set_len(sufi_item, ((bit_offset+7)/8) - sufi_start_offset);
    }
}

static void
dissect_rlc_control(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    guint8      type, next_byte;
    proto_item *ti;
    guint64     r1;
    guint64     rsn, hfn;

    next_byte = tvb_get_guint8(tvb, 0);
    type = (next_byte >> 4) & 0x07;

    ti = proto_tree_add_bits_item(tree, hf_rlc_ctrl_type, tvb, 1, 3, ENC_BIG_ENDIAN);
    switch (type) {
        case RLC_STATUS:
            dissect_rlc_status(tvb, pinfo, tree, 0);
            break;
        case RLC_RESET:
        case RLC_RESET_ACK:
            col_append_str(pinfo->cinfo, COL_INFO, (type == RLC_RESET) ? " RESET" : " RESET-ACK");
            proto_tree_add_bits_ret_val(tree, hf_rlc_rsn, tvb, 4, 1, &rsn, ENC_BIG_ENDIAN);
            proto_tree_add_bits_ret_val(tree, hf_rlc_r1, tvb, 5, 3, &r1, ENC_BIG_ENDIAN);
            if (r1) {
                expert_add_info(pinfo, ti, &ei_rlc_reserved_bits_not_zero);
                return;
            }
            proto_tree_add_bits_ret_val(tree, hf_rlc_hfni, tvb, 8, 20, &hfn, ENC_BIG_ENDIAN);
            col_append_fstr(pinfo->cinfo, COL_INFO, " RSN=%u HFN=%u", (guint16)rsn, (guint32)hfn);
            break;
        default:
            expert_add_info_format(pinfo, ti, &ei_rlc_ctrl_type, "Invalid RLC AM control type %u", type);
            return; /* invalid */
    }
}

static void
rlc_am_reassemble(tvbuff_t *tvb, guint8 offs, packet_info *pinfo,
          proto_tree *tree, proto_tree *top_level,
          enum rlc_channel_type channel, guint16 seq, gboolean poll_set, struct rlc_li *li,
          guint16 num_li, gboolean final, gboolean li_is_on_2_bytes,
          struct atm_phdr *atm)
{
    guint8    i;
    gboolean  piggyback = FALSE, dissected = FALSE;
    tvbuff_t *next_tvb  = NULL;

    struct rlc_channel  ch_lookup;
    struct rlc_seqlist * endlist = NULL;
    if( 0 == seq ){ /* assuming that a new RRC Connection is established when 0==seq.  */
        if( -1 != rlc_channel_assign(&ch_lookup, RLC_AM, pinfo, atm ) ){
            endlist = get_endlist(pinfo, &ch_lookup, atm);
            endlist->list->data = GINT_TO_POINTER( -1);
        }
    }

    /* perform reassembly now */
    for (i = 0; i < num_li; i++) {
        if ((!li_is_on_2_bytes && (li[i].li == 0x7e)) || (li[i].li == 0x7ffe)) {
            /* piggybacked status */
            piggyback = TRUE;
        } else if ((!li_is_on_2_bytes && (li[i].li == 0x7f)) || (li[i].li == 0x7fff)) {
            /* padding, must be last LI */
            if (tvb_reported_length_remaining(tvb, offs) > 0) {
                if (tree) {
                    proto_tree_add_item(tree, hf_rlc_pad, tvb, offs, -1, ENC_NA);
                }
                if (i == 0) {
                    /* Insert empty RLC frag so RLC doesn't miss this seq number. */
                    add_fragment(RLC_AM, tvb, pinfo, li[i].tree, offs, seq, i, 0, TRUE, atm);
                }
            }
            offs += tvb_captured_length_remaining(tvb, offs);
        } else {
            if (tree) {
                proto_tree_add_item(tree, hf_rlc_data, tvb, offs, li[i].len, ENC_NA);
            }
            if (global_rlc_perform_reassemby) {
                add_fragment(RLC_AM, tvb, pinfo, li[i].tree, offs, seq, i, li[i].len, TRUE, atm);
                next_tvb = get_reassembled_data(RLC_AM, tvb, pinfo, tree, seq, i, atm);
            }
        }
        if (next_tvb) {
            dissected = TRUE;
            rlc_call_subdissector(channel, next_tvb, pinfo, top_level);
            next_tvb = NULL;
        }
        offs += li[i].len;
    }

    if (piggyback) {
        dissect_rlc_status(tvb, pinfo, tree, offs);
    } else {
        if (tvb_reported_length_remaining(tvb, offs) > 0) {
            /* we have remaining data, which we need to mark in the tree */
            if (tree) {
                proto_tree_add_item(tree, hf_rlc_data, tvb, offs, -1, ENC_NA);
            }
            if (global_rlc_perform_reassemby) {
                add_fragment(RLC_AM, tvb, pinfo, tree, offs, seq, i,
                    tvb_captured_length_remaining(tvb,offs), final, atm);
                if (final) {
                    next_tvb = get_reassembled_data(RLC_AM, tvb, pinfo, tree, seq, i, atm);
                }
            }
        }
        if (next_tvb) {
            dissected = TRUE;
            rlc_call_subdissector(channel, next_tvb, pinfo, top_level);
            next_tvb = NULL;
        }
    }
    if (dissected == FALSE)
        col_append_fstr(pinfo->cinfo, COL_INFO, "[RLC AM Fragment]  SN=%u %s",
                     seq, poll_set ? "(P)" : "");
    else
        if (channel == RLC_UNKNOWN_CH)
            col_append_fstr(pinfo->cinfo, COL_INFO, "[RLC AM Data]  SN=%u %s",
                         seq, poll_set ? "(P)" : "");
}

static void
dissect_rlc_am(enum rlc_channel_type channel, tvbuff_t *tvb, packet_info *pinfo,
           proto_tree *top_level, proto_tree *tree, struct atm_phdr *atm)
{
#define MAX_LI 16
    struct rlc_li  li[MAX_LI];
    fp_info       *fpinf;
    rlc_info      *rlcinf;
    guint8         ext, dc;
    guint8         next_byte, offs = 0;
    guint32        orig_num        = 0;
    gint16         num_li          = 0;
    gint16         cur_tb;
    guint16        seq;
    gboolean       is_truncated, li_is_on_2_bytes;
    proto_item    *truncated_ti, *ti;
    guint64        polling;
    gboolean       ciphered_according_to_rrc = FALSE;
    gboolean       ciphered_flag = FALSE;
    gboolean       deciphered_flag = FALSE;
    int            ciphered_data_hf;

    fpinf = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    rlcinf = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);

    next_byte = tvb_get_guint8(tvb, offs++);
    dc = next_byte >> 7;
    if (tree) {
        if (fpinf && rlcinf) {
            /* Add "channel" information, very useful for debugging. */
            add_channel_info(pinfo, tree, fpinf, rlcinf);
        }
        proto_tree_add_bits_item(tree, hf_rlc_dc, tvb, 0, 1, ENC_BIG_ENDIAN);
    }
    if (dc == 0) {
        col_set_str(pinfo->cinfo, COL_INFO, "[RLC Control Frame]");
        dissect_rlc_control(tvb, pinfo, tree);
        return;
    }

    seq = next_byte & 0x7f;
    seq <<= 5;
    next_byte = tvb_get_guint8(tvb, offs++);
    seq |= (next_byte >> 3);

    ext = next_byte & 0x03;
    /* show header fields */
    proto_tree_add_bits_item(tree, hf_rlc_seq, tvb, 1, 12, ENC_BIG_ENDIAN);
    proto_tree_add_bits_ret_val(tree, hf_rlc_p, tvb, 13, 1, &polling, ENC_BIG_ENDIAN);
    ti = proto_tree_add_bits_item(tree, hf_rlc_he, tvb, 14, 2, ENC_BIG_ENDIAN);

    /* header extension may only be 00, 01 or 10 */
    if (ext > 2) {
        expert_add_info(pinfo, ti, &ei_rlc_he);
        return;
    }

    if (!fpinf || !rlcinf) {
        proto_tree_add_expert(tree, pinfo, &ei_rlc_no_per_frame_data, tvb, 0, -1);
        return;
    }

    cur_tb = fpinf->cur_tb;
    /**
     * WARNING DECIPHERING IS HIGHLY EXPERIMENTAL!!!
     * */
    ciphered_according_to_rrc = is_ciphered_according_to_rrc(pinfo, fpinf, rlcinf, (guint16)seq);
    ciphered_flag = rlcinf->ciphered[cur_tb];
    deciphered_flag = rlcinf->deciphered[cur_tb];
    if (((ciphered_according_to_rrc || ciphered_flag) && !deciphered_flag) || global_rlc_ciphered) {
        if(global_rlc_try_decipher){
            rlc_decipher(tvb, pinfo, tree, fpinf, rlcinf, seq, RLC_AM);
        }else{
            /* Choosing the right field text ("LIs & Data" or just "Data") based on header extension field */
            ciphered_data_hf = (ext == 0x01) ? hf_rlc_ciphered_lis_data : hf_rlc_ciphered_data;
            /* Adding ciphered payload field to tree */
            proto_tree_add_item(tree, ciphered_data_hf, tvb, offs, -1, ENC_NA);
            proto_tree_add_expert(tree, pinfo, &ei_rlc_ciphered_data, tvb, offs, -1);
            col_append_str(pinfo->cinfo, COL_INFO, "[Ciphered Data]");
            return;
        }
    }

    if (global_rlc_li_size == RLC_LI_UPPERLAYER) {
        if (rlcinf->li_size[cur_tb] == RLC_LI_VARIABLE) {
            li_is_on_2_bytes = (tvb_reported_length(tvb) > 126) ? TRUE : FALSE;
        } else {
            li_is_on_2_bytes = (rlcinf->li_size[cur_tb] == RLC_LI_15BITS) ? TRUE : FALSE;
        }
    } else { /* Override rlcinf configuration with preference. */
        li_is_on_2_bytes = (global_rlc_li_size == RLC_LI_15BITS) ? TRUE : FALSE;
    }

    num_li = rlc_decode_li(RLC_AM, tvb, pinfo, tree, li, MAX_LI, li_is_on_2_bytes);
    if (num_li == -1) return; /* something went wrong */
    offs += ((li_is_on_2_bytes) ? 2 : 1) * num_li;
    if (global_rlc_headers_expected) {
        /* There might not be any data, if only header was logged */
        is_truncated = (tvb_captured_length_remaining(tvb, offs) == 0);
        truncated_ti = proto_tree_add_boolean(tree, hf_rlc_header_only, tvb, 0, 0,
                                              is_truncated);
        if (is_truncated) {
            PROTO_ITEM_SET_GENERATED(truncated_ti);
            expert_add_info(pinfo, truncated_ti, &ei_rlc_header_only);
            return;
        } else {
            PROTO_ITEM_SET_HIDDEN(truncated_ti);
        }
    }

    /* do not detect duplicates or reassemble, if prefiltering is done */
    if (pinfo->num == 0) return;
    /* check for duplicates, but not if already visited */
    if (pinfo->fd->flags.visited == FALSE && rlc_is_duplicate(RLC_AM, pinfo, seq, &orig_num, atm) == TRUE) {
        g_hash_table_insert(duplicate_table, GUINT_TO_POINTER(pinfo->num), GUINT_TO_POINTER(orig_num));
        return;
    } else if (pinfo->fd->flags.visited == TRUE && tree) {
        gpointer value = g_hash_table_lookup(duplicate_table, GUINT_TO_POINTER(pinfo->num));
        if (value != NULL) {
            col_add_fstr(pinfo->cinfo, COL_INFO, "[RLC AM Fragment] [Duplicate]  SN=%u %s", seq, (polling != 0) ? "(P)" : "");
            proto_tree_add_uint(tree, hf_rlc_duplicate_of, tvb, 0, 0, GPOINTER_TO_UINT(value));
            return;
        }
    }

    rlc_am_reassemble(tvb, offs, pinfo, tree, top_level, channel, seq, polling != 0,
                      li, num_li, ext == 2, li_is_on_2_bytes, atm);
}

/* dissect entry functions */
static int
dissect_rlc_pcch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
    proto_tree *subtree = NULL;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);

    /* PCCH is always RLC TM */
    if (tree) {
        proto_item *ti;
        ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
        subtree = proto_item_add_subtree(ti, ett_rlc);
        proto_item_append_text(ti, " TM (PCCH)");
    }
    dissect_rlc_tm(RLC_PCCH, tvb, pinfo, tree, subtree);
    return tvb_captured_length(tvb);
}

static int
dissect_rlc_bcch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
    fp_info    *fpi;
    proto_item *ti      = NULL;
    proto_tree *subtree = NULL;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);

    fpi = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    if (!fpi) return 0; /* dissection failure */

    if (tree) {
        ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
        subtree = proto_item_add_subtree(ti, ett_rlc);
    }
    proto_item_append_text(ti, " TM (BCCH)");
    dissect_rlc_tm(RLC_BCCH, tvb, pinfo, tree, subtree);
    return tvb_captured_length(tvb);
}

static int
dissect_rlc_ccch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
    fp_info    *fpi;
    proto_item *ti      = NULL;
    proto_tree *subtree = NULL;
    struct atm_phdr *atm = (struct atm_phdr *)data;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);

    fpi = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    if (!fpi) return 0; /* dissection failure */

    if (tree) {
        ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
        subtree = proto_item_add_subtree(ti, ett_rlc);
    }

    if (fpi->is_uplink) {
        /* UL CCCH is always RLC TM */
        proto_item_append_text(ti, " TM (CCCH)");
        dissect_rlc_tm(RLC_UL_CCCH, tvb, pinfo, tree, subtree);
    } else {
        /* DL CCCH is always UM */
        proto_item_append_text(ti, " UM (CCCH)");
        dissect_rlc_um(RLC_DL_CCCH, tvb, pinfo, tree, subtree, atm);
    }
    return tvb_captured_length(tvb);
}

static int
dissect_rlc_ctch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void  *data)
{
    fp_info    *fpi;
    proto_item *ti      = NULL;
    proto_tree *subtree = NULL;
    struct atm_phdr *atm = (struct atm_phdr *)data;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);

    fpi = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    if (!fpi) return 0; /* dissection failure */

    if (tree) {
        ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
        subtree = proto_item_add_subtree(ti, ett_rlc);
    }

    /* CTCH is always UM */
    proto_item_append_text(ti, " UM (CTCH)");
    dissect_rlc_um(RLC_DL_CTCH, tvb, pinfo, tree, subtree, atm);
    return tvb_captured_length(tvb);
}

static int
dissect_rlc_dcch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
    proto_item            *ti      = NULL;
    proto_tree            *subtree = NULL;
    fp_info               *fpi;
    rlc_info              *rlci;
    enum rlc_channel_type  channel;
    struct atm_phdr       *atm = (struct atm_phdr *)data;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);

    fpi = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    rlci = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);

    if (!fpi || !rlci){
        proto_tree_add_expert(tree, pinfo, &ei_rlc_no_per_frame_data, tvb, 0, -1);
        return 1;
    }

    if (tree) {
        ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
        subtree = proto_item_add_subtree(ti, ett_rlc);
    }

    channel = fpi->is_uplink ? RLC_UL_DCCH : RLC_DL_DCCH;

    switch (rlci->mode[fpi->cur_tb]) {
        case RLC_UM:
            proto_item_append_text(ti, " UM (DCCH)");
            dissect_rlc_um(channel, tvb, pinfo, tree, subtree, atm);
            break;
        case RLC_AM:
            proto_item_append_text(ti, " AM (DCCH)");
            dissect_rlc_am(channel, tvb, pinfo, tree, subtree, atm);
            break;
    }
    return tvb_captured_length(tvb);
}

static int
dissect_rlc_ps_dtch(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
    proto_item *ti      = NULL;
    proto_tree *subtree = NULL;
    fp_info    *fpi;
    rlc_info   *rlci;
    struct atm_phdr *atm = (struct atm_phdr *)data;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);

    fpi  = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    rlci = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);

    if (!fpi || !rlci) {
        proto_tree_add_expert(tree, pinfo, &ei_rlc_no_per_frame_data, tvb, 0, -1);
        return 1;
    }

    if (tree) {
        ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
        subtree = proto_item_add_subtree(ti, ett_rlc);
    }

    switch (rlci->mode[fpi->cur_tb]) {
        case RLC_UM:
            proto_item_append_text(ti, " UM (PS DTCH)");
            dissect_rlc_um(RLC_PS_DTCH, tvb, pinfo, tree, subtree, atm);
            break;
        case RLC_AM:
            proto_item_append_text(ti, " AM (PS DTCH)");
            dissect_rlc_am(RLC_PS_DTCH, tvb, pinfo, tree, subtree, atm);
            break;
        case RLC_TM:
            proto_item_append_text(ti, " TM (PS DTCH)");
            dissect_rlc_tm(RLC_PS_DTCH, tvb, pinfo, tree, subtree);
            break;
    }
    return tvb_captured_length(tvb);
}

static int
dissect_rlc_dch_unknown(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
    proto_item *ti      = NULL;
    proto_tree *subtree = NULL;
    fp_info    *fpi;
    rlc_info   *rlci;
    struct atm_phdr *atm = (struct atm_phdr *)data;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);

    fpi = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    rlci = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);

    if (!fpi || !rlci) return 0;

    if (tree) {
        ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
        subtree = proto_item_add_subtree(ti, ett_rlc);
    }

    switch (rlci->mode[fpi->cur_tb]) {
        case RLC_UM:
            proto_item_append_text(ti, " UM (Unknown)");
            dissect_rlc_um(RLC_UNKNOWN_CH, tvb, pinfo, tree, subtree, atm);
            break;
        case RLC_AM:
            proto_item_append_text(ti, " AM (Unknown)");
            dissect_rlc_am(RLC_UNKNOWN_CH, tvb, pinfo, tree, subtree, atm);
            break;
        case RLC_TM:
            proto_item_append_text(ti, " TM (Unknown)");
            dissect_rlc_tm(RLC_UNKNOWN_CH, tvb, pinfo, tree, subtree);
            break;
    }
    return tvb_captured_length(tvb);
}

static void
report_heur_error(proto_tree *tree, packet_info *pinfo, expert_field *eiindex,
                  tvbuff_t *tvb, gint start, gint length)
{
    proto_item *ti;
    proto_tree *subtree;

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
    col_clear(pinfo->cinfo, COL_INFO);
    ti = proto_tree_add_item(tree, proto_umts_rlc, tvb, 0, -1, ENC_NA);
    subtree = proto_item_add_subtree(ti, ett_rlc);
    proto_tree_add_expert(subtree, pinfo, eiindex, tvb, start, length);
}

/* Heuristic dissector looks for supported framing protocol (see wiki page)  */
static gboolean
dissect_rlc_heur(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
    gint        offset             = 0;
    fp_info    *fpi;
    rlc_info   *rlci;
    tvbuff_t   *rlc_tvb;
    guint8      tag                = 0;
    guint       channelType        = UMTS_CHANNEL_TYPE_UNSPECIFIED;
    gboolean    fpInfoAlreadySet   = FALSE;
    gboolean    rlcInfoAlreadySet  = FALSE;
    gboolean    channelTypePresent = FALSE;
    gboolean    rlcModePresent     = FALSE;
    proto_item *ti                 = NULL;
    proto_tree *subtree            = NULL;
    struct atm_phdr *atm           = (struct atm_phdr *)data;

    /* Do this again on re-dissection to re-discover offset of actual PDU */

    /* Needs to be at least as long as:
       - the signature string
       - conditional header bytes
       - tag for data
       - at least one byte of RLC PDU payload */
    if (tvb_captured_length_remaining(tvb, offset) < (gint)(strlen(RLC_START_STRING)+2+2)) {
        return FALSE;
    }

    /* OK, compare with signature string */
    if (tvb_strneql(tvb, offset, RLC_START_STRING, (gint)strlen(RLC_START_STRING)) != 0) {
        return FALSE;
    }
    offset += (gint)strlen(RLC_START_STRING);

    /* If redissecting, use previous info struct (if available) */
    fpi = (fp_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_fp, 0);
    if (fpi == NULL) {
        /* Allocate new info struct for this frame */
        fpi = (fp_info *)wmem_alloc0(wmem_file_scope(), sizeof(fp_info));
    } else {
        fpInfoAlreadySet = TRUE;
    }
    rlci = (rlc_info *)p_get_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0);
    if (rlci == NULL) {
        /* Allocate new info struct for this frame */
        rlci = (rlc_info *)wmem_alloc0(wmem_file_scope(), sizeof(rlc_info));
    } else {
        rlcInfoAlreadySet = TRUE;
    }

    /* Setting non-zero UE-ID for RLC reassembly to work, might be
     * overriden if the optional URNTI tag is present */
    rlci->ueid[fpi->cur_tb] = 1;

    /* Read conditional/optional fields */
    while (tag != RLC_PAYLOAD_TAG) {
        /* Process next tag */
        tag = tvb_get_guint8(tvb, offset++);
        switch (tag) {
            case RLC_CHANNEL_TYPE_TAG:
                channelType = tvb_get_guint8(tvb, offset);
                offset++;
                channelTypePresent = TRUE;
                break;
            case RLC_MODE_TAG:
                rlci->mode[fpi->cur_tb] = tvb_get_guint8(tvb, offset);
                offset++;
                rlcModePresent = TRUE;
                break;
            case RLC_DIRECTION_TAG:
                if (tvb_get_guint8(tvb, offset) == DIRECTION_UPLINK) {
                    fpi->is_uplink = TRUE;
                    pinfo->link_dir = P2P_DIR_UL;
                } else {
                    fpi->is_uplink = FALSE;
                    pinfo->link_dir = P2P_DIR_DL;
                }
                offset++;
                break;
            case RLC_URNTI_TAG:
                rlci->ueid[fpi->cur_tb] = tvb_get_ntohl(tvb, offset);
                offset += 4;
                break;
            case RLC_RADIO_BEARER_ID_TAG:
                rlci->rbid[fpi->cur_tb] = tvb_get_guint8(tvb, offset);
                offset++;
                break;
            case RLC_LI_SIZE_TAG:
                rlci->li_size[fpi->cur_tb] = (enum rlc_li_size) tvb_get_guint8(tvb, offset);
                offset++;
                break;
            case RLC_PAYLOAD_TAG:
                /* Have reached data, so get out of loop */
                continue;
            default:
                /* It must be a recognised tag */
                report_heur_error(tree, pinfo, &ei_rlc_unknown_udp_framing_tag, tvb, offset-1, 1);
                return TRUE;
        }
    }

    if ((channelTypePresent == FALSE) && (rlcModePresent == FALSE)) {
        /* Conditional fields are missing */
        report_heur_error(tree, pinfo, &ei_rlc_missing_udp_framing_tag, tvb, 0, offset);
        return TRUE;
    }

    /* Store info in packet if needed */
    if (!fpInfoAlreadySet) {
        p_add_proto_data(wmem_file_scope(), pinfo, proto_fp, 0, fpi);
    }
    if (!rlcInfoAlreadySet) {
        p_add_proto_data(wmem_file_scope(), pinfo, proto_umts_rlc, 0, rlci);
    }

    /**************************************/
    /* OK, now dissect as RLC             */

    /* Create tvb that starts at actual RLC PDU */
    rlc_tvb = tvb_new_subset_remaining(tvb, offset);
    switch (channelType) {
        case UMTS_CHANNEL_TYPE_UNSPECIFIED:
            /* Call relevant dissector according to RLC mode */
            col_set_str(pinfo->cinfo, COL_PROTOCOL, "RLC");
            col_clear(pinfo->cinfo, COL_INFO);

            if (tree) {
                ti = proto_tree_add_item(tree, proto_umts_rlc, rlc_tvb, 0, -1, ENC_NA);
                subtree = proto_item_add_subtree(ti, ett_rlc);
            }

            if (rlci->mode[fpi->cur_tb] == RLC_AM) {
                proto_item_append_text(ti, " AM");
                dissect_rlc_am(RLC_UNKNOWN_CH, rlc_tvb, pinfo, tree, subtree, atm);
            } else if (rlci->mode[fpi->cur_tb] == RLC_UM) {
                proto_item_append_text(ti, " UM");
                dissect_rlc_um(RLC_UNKNOWN_CH, rlc_tvb, pinfo, tree, subtree, atm);
            } else {
                proto_item_append_text(ti, " TM");
                dissect_rlc_tm(RLC_UNKNOWN_CH, rlc_tvb, pinfo, tree, subtree);
            }
            break;
        case UMTS_CHANNEL_TYPE_PCCH:
            dissect_rlc_pcch(rlc_tvb, pinfo, tree, data);
            break;
        case UMTS_CHANNEL_TYPE_CCCH:
            dissect_rlc_ccch(rlc_tvb, pinfo, tree, data);
            break;
        case UMTS_CHANNEL_TYPE_DCCH:
            dissect_rlc_dcch(rlc_tvb, pinfo, tree, data);
            break;
        case UMTS_CHANNEL_TYPE_PS_DTCH:
            dissect_rlc_ps_dtch(rlc_tvb, pinfo, tree, data);
            break;
        case UMTS_CHANNEL_TYPE_CTCH:
            dissect_rlc_ctch(rlc_tvb, pinfo, tree, data);
            break;
        case UMTS_CHANNEL_TYPE_BCCH:
            dissect_rlc_bcch(rlc_tvb, pinfo, tree, data);
            break;
        default:
            /* Unknown channel type */
            return FALSE;
    }

    return TRUE;
}

void
proto_register_rlc(void)
{
    module_t *rlc_module;
    expert_module_t* expert_rlc;
    static hf_register_info hf[] = {
        { &hf_rlc_dc,
          { "D/C Bit", "rlc.dc",
            FT_BOOLEAN, BASE_NONE, TFS(&rlc_dc_val), 0, NULL, HFILL }
        },
        { &hf_rlc_ctrl_type,
          { "Control PDU Type", "rlc.ctrl_pdu_type",
            FT_UINT8, BASE_DEC, VALS(rlc_ctrl_vals), 0, "PDU Type", HFILL }
        },
        { &hf_rlc_r1,
          { "Reserved 1", "rlc.r1",
            FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_rsn,
          { "Reset Sequence Number", "rlc.rsn",
            FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_hfni,
          { "Hyper Frame Number Indicator", "rlc.hfni",
            FT_UINT24, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_seq,
          { "Sequence Number", "rlc.seq",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_ext,
          { "Extension Bit", "rlc.ext",
            FT_BOOLEAN, BASE_NONE, TFS(&rlc_ext_val), 0, NULL, HFILL }
        },
        { &hf_rlc_he,
          { "Header Extension Type", "rlc.he",
            FT_UINT8, BASE_DEC, VALS(rlc_he_vals), 0, NULL, HFILL }
        },
        { &hf_rlc_p,
          { "Polling Bit", "rlc.p",
            FT_BOOLEAN, BASE_NONE, TFS(&rlc_p_val), 0, NULL, HFILL }
        },
        { &hf_rlc_pad,
          { "Padding", "rlc.padding",
            FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_frags,
          { "Reassembled Fragments", "rlc.fragments",
            FT_NONE, BASE_NONE, NULL, 0, "Fragments", HFILL }
        },
        { &hf_rlc_frag,
          { "RLC Fragment", "rlc.fragment",
            FT_FRAMENUM, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_duplicate_of,
          { "Duplicate of", "rlc.duplicate_of",
            FT_FRAMENUM, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_reassembled_in,
          { "Reassembled Message in frame", "rlc.reassembled_in",
            FT_FRAMENUM, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_data,
          { "Data", "rlc.data",
            FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_ciphered_data,
          { "Ciphered Data", "rlc.ciphered_data",
            FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_ciphered_lis_data,
          { "Ciphered LIs & Data", "rlc.ciphered_data",
            FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        /* LI information */
        { &hf_rlc_li,
          { "LI", "rlc.li",
            FT_NONE, BASE_NONE, NULL, 0, "Length Indicator", HFILL }
        },
        { &hf_rlc_li_value,
          { "LI value", "rlc.li.value",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_li_ext,
          { "LI extension bit", "rlc.li.ext",
            FT_BOOLEAN, BASE_NONE, TFS(&rlc_ext_val), 0, NULL, HFILL }
        },
        { &hf_rlc_li_data,
          { "LI Data", "rlc.li.data",
            FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        /* SUFI information */
        { &hf_rlc_sufi,
          { "SUFI", "rlc.sufi",
            FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_type,
          { "SUFI Type", "rlc.sufi.type",
            FT_UINT8, BASE_DEC, VALS(rlc_sufi_vals), 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_lsn,
          { "Last Sequence Number", "rlc.sufi.lsn",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_wsn,
          { "Window Size Number", "rlc.sufi.wsn",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_sn,
          { "Sequence Number", "rlc.sufi.sn",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_l,
          { "Length", "rlc.sufi.l",
            FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_len,
          { "Length", "rlc.sufi.len",
            FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_fsn,
          { "First Sequence Number", "rlc.sufi.fsn",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_bitmap,
          { "Bitmap", "rlc.sufi.bitmap",
            FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_cw,
          { "Codeword", "rlc.sufi.cw",
            FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_n,
          { "Nlength", "rlc.sufi.n",
            FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_sn_ack,
          { "SN ACK", "rlc.sufi.sn_ack",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_sn_mrw,
          { "SN MRW", "rlc.sufi.sn_mrw",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sufi_poll_sn,
          { "Poll SN", "rlc.sufi.poll_sn",
            FT_UINT16, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        /* Other information */
        { &hf_rlc_header_only,
          { "RLC PDU header only", "rlc.header_only",
            FT_BOOLEAN, BASE_NONE, TFS(&rlc_header_only_val), 0 ,NULL, HFILL }
        },
        { &hf_rlc_channel,
          { "Channel", "rlc.channel",
            FT_NONE, BASE_NONE, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_channel_rbid,
          { "Radio Bearer ID", "rlc.channel.rbid",
            FT_UINT8, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_channel_dir,
          { "Direction", "rlc.channel.dir",
            FT_UINT8, BASE_DEC, VALS(rlc_dir_vals), 0, NULL, HFILL }
        },
        { &hf_rlc_channel_ueid,
          { "User Equipment ID", "rlc.channel.ueid",
            FT_UINT32, BASE_HEX, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_sequence_number,
          { "Sequence Number", "rlc.sequence_number",
            FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_length,
          { "Length", "rlc.length",
            FT_UINT32, BASE_DEC, NULL, 0, NULL, HFILL }
        },
        { &hf_rlc_bitmap_string,
          { "Bitmap string", "rlc.bitmap_string",
            FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL }
        },
    };

    static gint *ett[] = {
        &ett_rlc,
        &ett_rlc_frag,
        &ett_rlc_fragments,
        &ett_rlc_sdu,
        &ett_rlc_sufi,
        &ett_rlc_bitmap,
        &ett_rlc_rlist,
        &ett_rlc_channel
    };
    static ei_register_info ei[] = {
        { &ei_rlc_reassembly_fail_unfinished_sequence, { "rlc.reassembly.fail.unfinished_sequence", PI_REASSEMBLE, PI_ERROR, "Did not perform reassembly because of previous unfinished sequence.", EXPFILL }},
        { &ei_rlc_reassembly_fail_flag_set, { "rlc.reassembly.fail.flag_set", PI_REASSEMBLE, PI_ERROR, "Did not perform reassembly because fail flag was set previously.", EXPFILL }},
        { &ei_rlc_reassembly_lingering_endpoint, { "rlc.lingering_endpoint", PI_REASSEMBLE, PI_ERROR, "Lingering endpoint.", EXPFILL }},
        { &ei_rlc_reassembly_unknown_error, { "rlc.reassembly.unknown_error", PI_REASSEMBLE, PI_ERROR, "Unknown error.", EXPFILL }},
        { &ei_rlc_kasumi_implementation_missing, { "rlc.kasumi_implementation_missing", PI_UNDECODED, PI_WARN, "Unable to decipher packet since KASUMI implementation is missing.", EXPFILL }},
        { &ei_rlc_li_reserved, { "rlc.li.reserved", PI_PROTOCOL, PI_WARN, "Uses reserved LI", EXPFILL }},
        { &ei_rlc_li_incorrect_warn, { "rlc.li.incorrect", PI_PROTOCOL, PI_WARN, "Incorrect LI value", EXPFILL }},
        { &ei_rlc_li_incorrect_mal, { "rlc.li.incorrect", PI_MALFORMED, PI_ERROR, "Incorrect LI value 0x%x", EXPFILL }},
        { &ei_rlc_li_too_many, { "rlc.li.too_many", PI_MALFORMED, PI_ERROR, "Too many LI entries", EXPFILL }},
        { &ei_rlc_header_only, { "rlc.header_only.expert", PI_SEQUENCE, PI_NOTE, "RLC PDU SDUs have been omitted", EXPFILL }},
        { &ei_rlc_sufi_len, { "rlc.sufi.len.invalid", PI_MALFORMED, PI_ERROR, "Invalid length", EXPFILL }},
        { &ei_rlc_sufi_cw, { "rlc.sufi.cw.invalid", PI_PROTOCOL, PI_WARN, "Invalid last codeword", EXPFILL }},
        { &ei_rlc_sufi_type, { "rlc.sufi.type.invalid", PI_PROTOCOL, PI_WARN, "Invalid SUFI type", EXPFILL }},
        { &ei_rlc_reserved_bits_not_zero, { "rlc.reserved_bits_not_zero", PI_PROTOCOL, PI_WARN, "reserved bits not zero", EXPFILL }},
        { &ei_rlc_ctrl_type, { "rlc.ctrl_pdu_type.invalid", PI_PROTOCOL, PI_WARN, "Invalid RLC AM control type", EXPFILL }},
        { &ei_rlc_he, { "rlc.he.invalid", PI_PROTOCOL, PI_WARN, "Incorrect HE value", EXPFILL }},
        { &ei_rlc_ciphered_data, { "rlc.ciphered_data", PI_UNDECODED, PI_WARN, "Cannot dissect RLC frame because it is ciphered", EXPFILL }},
        { &ei_rlc_no_per_frame_data, { "rlc.no_per_frame_data", PI_PROTOCOL, PI_WARN, "Can't dissect RLC frame because no per-frame info was attached!", EXPFILL }},
        { &ei_rlc_incomplete_sequence, { "rlc.incomplete_sequence", PI_MALFORMED, PI_ERROR, "Error: Incomplete sequence", EXPFILL }},
        { &ei_rlc_unknown_udp_framing_tag, { "rlc.unknown_udp_framing_tag", PI_UNDECODED, PI_WARN, "Unknown UDP framing tag, aborting dissection", EXPFILL }},
        { &ei_rlc_missing_udp_framing_tag, { "rlc.missing_udp_framing_tag", PI_UNDECODED, PI_WARN, "Missing UDP framing conditional tag, aborting dissection", EXPFILL }}
    };

    proto_umts_rlc = proto_register_protocol("Radio Link Control", "RLC", "rlc");
    register_dissector("rlc.bcch",        dissect_rlc_bcch,        proto_umts_rlc);
    register_dissector("rlc.pcch",        dissect_rlc_pcch,        proto_umts_rlc);
    register_dissector("rlc.ccch",        dissect_rlc_ccch,        proto_umts_rlc);
    register_dissector("rlc.ctch",        dissect_rlc_ctch,        proto_umts_rlc);
    register_dissector("rlc.dcch",        dissect_rlc_dcch,        proto_umts_rlc);
    register_dissector("rlc.ps_dtch",     dissect_rlc_ps_dtch,     proto_umts_rlc);
    register_dissector("rlc.dch_unknown", dissect_rlc_dch_unknown, proto_umts_rlc);

    proto_register_field_array(proto_umts_rlc, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
    expert_rlc = expert_register_protocol(proto_umts_rlc);
    expert_register_field_array(expert_rlc, ei, array_length(ei));

    /* Preferences */
    rlc_module = prefs_register_protocol(proto_umts_rlc, NULL);

    prefs_register_obsolete_preference(rlc_module, "heuristic_rlc_over_udp");

    prefs_register_bool_preference(rlc_module, "perform_reassembly",
        "Try to reassemble SDUs",
        "When enabled, try to reassemble SDUs from the various PDUs received",
        &global_rlc_perform_reassemby);

    prefs_register_bool_preference(rlc_module, "header_only_mode",
        "May see RLC headers only",
        "When enabled, if data is not present, don't report as an error, but instead "
        "add expert info to indicate that headers were omitted",
        &global_rlc_headers_expected);

    prefs_register_bool_preference(rlc_module, "ignore_rrc_cipher_indication",
        "Ignore ciphering indication from higher layers",
        "When enabled, RLC will ignore sequence numbers reported in 'Security Mode Command'/'Security Mode Complete' (RRC) messages when checking if frames are ciphered",
        &global_ignore_rrc_ciphering_indication);

    prefs_register_bool_preference(rlc_module, "ciphered_data",
        "All data is ciphered",
        "When enabled, RLC will assume all payloads in RLC frames are ciphered",
        &global_rlc_ciphered);

#ifdef HAVE_UMTS_KASUMI
    prefs_register_bool_preference(rlc_module, "try_decipher",
        "Try to decipher data",
        "When enabled, RLC will try to decipher data. (Experimental)",
        &global_rlc_try_decipher);

    prefs_register_string_preference(rlc_module, "kasumi_key",
        "KASUMI key", "Key for kasumi 32 characters long hex-string", &global_rlc_kasumi_key);
#else
    /* If Wireshark isn't compiled with KASUMI we still want to register the above preferences
     * We are doing so for two reasons:
     * 1. To inform the user about the disabled preferences (using static text preference)
     * 2. To prevent errors when Wireshark reads a preferences file which includes records for these preferences
     */
    prefs_register_static_text_preference(rlc_module, "try_decipher",
        "Data deciphering is disabled", "Wireshark was compiled without the KASUMI decryption algorithm");

    prefs_register_obsolete_preference(rlc_module, "kasumi_key");
#endif /* HAVE_UMTS_KASUMI */

    prefs_register_enum_preference(rlc_module, "li_size",
        "LI size",
        "LI size in bits, either 7 or 15 bit",
        &global_rlc_li_size, li_size_enumvals, FALSE);

    register_init_routine(fragment_table_init);
    register_cleanup_routine(fragment_table_cleanup);
}

void
proto_reg_handoff_rlc(void)
{
    rrc_handle = find_dissector_add_dependency("rrc", proto_umts_rlc);
    ip_handle  = find_dissector_add_dependency("ip", proto_umts_rlc);
    bmc_handle = find_dissector_add_dependency("bmc", proto_umts_rlc);
    /* Add as a heuristic UDP dissector */
    heur_dissector_add("udp", dissect_rlc_heur, "RLC over UDP", "rlc_udp", proto_umts_rlc, HEURISTIC_DISABLE);
}

/*
 * Editor modelines
 *
 * Local Variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * ex: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */