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

/* packet-icq.c
 * Routines for ICQ packet disassembly
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

/*
 * This file: by Kojak <kojak@bigwig.net>
 *
 * Decoding code ripped, reference to the original author at the
 * appropriate place with the code itself.
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/to_str.h>
#include <epan/expert.h>

void proto_register_icq(void);
void proto_reg_handoff_icq(void);

static dissector_handle_t icq_handle;

static int proto_icq = -1;
static int hf_icq_version = -1;
static int hf_icq_uin = -1;
static int hf_icq_client_cmd = -1;
static int hf_icq_server_cmd = -1;
static int hf_icq_sessionid = -1;
static int hf_icq_checkcode = -1;
static int hf_icq_type = -1;
static int hf_icq_msg_type = -1;
static int hf_icq_seqnum1 = -1;
static int hf_icq_seqnum2 = -1;
static int hf_icq_checkcode_key = -1;
static int hf_icq_group = -1;
static int hf_icq_ack_random = -1;
static int hf_icq_keep_alive_random = -1;
static int hf_icq_status = -1;
static int hf_icq_meta_user_subcmd = -1;
/* Generated from convert_proto_tree_add_text.pl */
static int hf_icq_rand_user_tcpversion = -1;
static int hf_icq_meta_user_x3 = -1;
static int hf_icq_user_online_realip = -1;
static int hf_icq_rand_user_realip = -1;
static int hf_icq_meta_user_hideip = -1;
static int hf_icq_user_online_port = -1;
static int hf_icq_user_online_ip = -1;
static int hf_icq_num_uin_pairs = -1;
static int hf_icq_x1 = -1;
static int hf_icq_meta_user_timezone = -1;
static int hf_icq_user_online_version = -1;
static int hf_icq_receiver_uin = -1;
static int hf_icq_text_code = -1;
static int hf_icq_login_reply_ip = -1;
static int hf_icq_rand_user_ip = -1;
static int hf_icq_multi_num_packets = -1;
static int hf_icq_number_of_uins = -1;
static int hf_icq_meta_user_length = -1;
static int hf_icq_text_code_length = -1;
static int hf_icq_login_password = -1;
static int hf_icq_meta_user_x2 = -1;
static int hf_icq_login_time = -1;
static int hf_icq_meta_user_countrycode = -1;
static int hf_icq_msg_length = -1;
static int hf_icq_meta_user_about = -1;
static int hf_icq_meta_user_webaware = -1;
static int hf_icq_rand_user_class = -1;
static int hf_icq_rand_user_port = -1;
static int hf_icq_meta_user_found_authorization = -1;
static int hf_icq_meta_user_info_authorization = -1;
static int hf_icq_no_parameters = -1;
static int hf_icq_login_port = -1;
static int hf_icq_meta_user_result = -1;
static int hf_icq_login_ip = -1;
static int hf_icq_msg_authorization = -1;
static int hf_icq_msg = -1;
static int hf_icq_nickname = -1;
static int hf_icq_first_name = -1;
static int hf_icq_last_name = -1;
static int hf_icq_email = -1;
static int hf_icq_nickname_uint_string = -1;
static int hf_icq_first_name_uint_string = -1;
static int hf_icq_last_name_uint_string = -1;
static int hf_icq_email_uint_string = -1;
static int hf_icq_primary_email = -1;
static int hf_icq_secondary_email = -1;
static int hf_icq_old_email = -1;
static int hf_icq_city = -1;
static int hf_icq_state = -1;
static int hf_icq_phone = -1;
static int hf_icq_fax = -1;
static int hf_icq_street = -1;
static int hf_icq_cellphone = -1;
static int hf_icq_zip = -1;
static int hf_icq_description = -1;
static int hf_icq_url = -1;
static int hf_icq_text = -1;
static int hf_icq_unknown = -1;
static int hf_icq_reason = -1;
static int hf_icq_msg_contact = -1;
static int hf_icq_recv_time = -1;

static gint ett_icq = -1;
static gint ett_icq_header = -1;
static gint ett_icq_body = -1;
static gint ett_icq_body_parts = -1;

static expert_field ei_icq_unknown_meta_subcmd = EI_INIT;
static expert_field ei_icq_unknown_command = EI_INIT;

/* This is not IANA registered */
#define UDP_PORT_ICQ    4000

#define ICQ5_SERVER 0
#define ICQ5_CLIENT 1

static void
dissect_icqv5Server(tvbuff_t *tvb, int offset, packet_info *pinfo,
                    proto_tree *tree, int pktsize);

/* Offsets of fields in the ICQ headers */
/* Can be 0x0002 or 0x0005 */
#define ICQ_VERSION     0x00
/* Is either one (server) or four (client) bytes long */
/* Client header offsets */
#define ICQ5_UNKNOWN        0x02
#define ICQ5_CL_UIN         0x06
#define ICQ5_CL_SESSIONID   0x0a
#define ICQ5_CL_CMD         0x0e
#define ICQ5_CL_SEQNUM1     0x10
#define ICQ5_CL_SEQNUM2     0x12
#define ICQ5_CL_CHECKCODE   0x14
#define ICQ5_CL_PARAM       0x18
#define ICQ5_CL_HDRSIZE     0x18

/* Server header offsets */
#define ICQ5_SRV_SESSIONID  0x03
#define ICQ5_SRV_CMD        0x07
#define ICQ5_SRV_SEQNUM1    0x09
#define ICQ5_SRV_SEQNUM2    0x0b
#define ICQ5_SRV_UIN        0x0d
#define ICQ5_SRV_CHECKCODE  0x11
#define ICQ5_SRV_PARAM      0x15
#define ICQ5_SRV_HDRSIZE    0x15

#define SRV_ACK               0x000a

#define SRV_SILENT_TOO_LONG   0x001e

#define SRV_GO_AWAY           0x0028

#define SRV_NEW_UIN           0x0046

/* LOGIN_REPLY is very scary. It has a lot of fields that are undocumented
 * Only the IP field makes sense */
#define SRV_LOGIN_REPLY       0x005a
#define SRV_LOGIN_REPLY_IP    0x000c

#define SRV_BAD_PASS          0x0064

#define SRV_USER_ONLINE       0x006e
#define SRV_USER_ONL_UIN      0x0000
#define SRV_USER_ONL_IP       0x0004
#define SRV_USER_ONL_PORT     0x0008
#define SRV_USER_ONL_REALIP   0x000c
#define SRV_USER_ONL_X1       0x0010
#define SRV_USER_ONL_STATUS   0x0013
#define SRV_USER_ONL_X2       0x0015

#define SRV_USER_OFFLINE      0x0078
#define SRV_USER_OFFLINE_UIN  0x0000

#define SRV_MULTI             0x0212
#define SRV_MULTI_NUM         0x0000

#define SRV_META_USER         0x03de
#define SRV_META_USER_SUBCMD  0x0000
#define SRV_META_USER_RESULT  0x0002
#define SRV_META_USER_DATA    0x0003

#define SRV_UPDATE_SUCCESS    0x01e0

#define SRV_UPDATE_FAIL       0x01ea

/*
 * ICQv5 SRV_META_USER subcommands
 */
#define META_EX_USER_FOUND    0x0190
#define META_USER_FOUND       0x019a
#define META_ABOUT            0x00e6
#define META_USER_INFO        0x00c8

#define SRV_RECV_MESSAGE      0x00dc
#define SRV_RECV_MSG_UIN      0x0000
#define SRV_RECV_MSG_YEAR     0x0004
#define SRV_RECV_MSG_MONTH    0x0006
#define SRV_RECV_MSG_DAY      0x0007
#define SRV_RECV_MSG_HOUR     0x0008
#define SRV_RECV_MSG_MINUTE   0x0009
#define SRV_RECV_MSG_MSG_TYPE 0x000a

#define SRV_RAND_USER         0x024e
#define SRV_RAND_USER_UIN     0x0000
#define SRV_RAND_USER_IP      0x0004
#define SRV_RAND_USER_PORT    0x0008
#define SRV_RAND_USER_REAL_IP 0x000c
#define SRV_RAND_USER_CLASS   0x0010
#define SRV_RAND_USER_X1      0x0011
#define SRV_RAND_USER_STATUS  0x0015
#define SRV_RAND_USER_TCP_VER 0x0019

/* This message has the same structure as cmd_send_msg */
#define SRV_SYS_DELIVERED_MESS  0x0104

static const value_string serverMetaSubCmdCode[] = {
    { META_USER_FOUND,    "META_USER_FOUND" },
    { META_EX_USER_FOUND, "META_EX_USER_FOUND"  },
    { META_ABOUT,         "META_ABOUT" },
    { META_USER_INFO,     "META_USER_INFO" },
    { 0, NULL }
};

static const value_string serverCmdCode[] = {
    { SRV_ACK,                "SRV_ACK" },
    { SRV_SILENT_TOO_LONG,    "SRV_SILENT_TOO_LONG" },
    { SRV_GO_AWAY,            "SRV_GO_AWAY" },
    { SRV_NEW_UIN,            "SRV_NEW_UIN" },
    { SRV_LOGIN_REPLY,        "SRV_LOGIN_REPLY" },
    { SRV_BAD_PASS,           "SRV_BAD_PASS" },
    { SRV_USER_ONLINE,        "SRV_USER_ONLINE" },
    { SRV_USER_OFFLINE,       "SRV_USER_OFFLINE" },
    { 130,                    "SRV_QUERY" },
    { 140,                    "SRV_USER_FOUND" },
    { 160,                    "SRV_END_OF_SEARCH" },
    { 180,                    "SRV_NEW_USER" },
    { 200,                    "SRV_UPDATE_EXT" },
    { SRV_RECV_MESSAGE,       "SRV_RECV_MESSAGE" },
    { 230,                    "SRV_END_OFFLINE_MESSAGES" },
    { 240,                    "SRV_NOT_CONNECTED" },
    { 250,                    "SRV_TRY_AGAIN" },
    { SRV_SYS_DELIVERED_MESS, "SRV_SYS_DELIVERED_MESS" },
    { 280,                    "SRV_INFO_REPLY" },
    { 290,                    "SRV_EXT_INFO_REPLY" },
    { 420,                    "SRV_STATUS_UPDATE" },
    { 450,                    "SRV_SYSTEM_MESSAGE" },
    { SRV_UPDATE_SUCCESS,     "SRV_UPDATE_SUCCESS" },
    { SRV_UPDATE_FAIL,        "SRV_UPDATE_FAIL" },
    { 500,                    "SRV_AUTH_UPDATE" },
    { SRV_MULTI,              "SRV_MULTI_PACKET" },
    { 540,                    "SRV_END_CONTACTLIST_STATUS" },
    { SRV_RAND_USER,          "SRV_RAND_USER" },
    { SRV_META_USER,          "SRV_META_USER" },
    { 0, NULL }
};

#define MSG_TEXT            0x0001
#define MSG_URL             0x0004
#define MSG_AUTH_REQ        0x0006
#define MSG_AUTH            0x0008
#define MSG_USER_ADDED      0x000c
#define MSG_EMAIL           0x000e
#define MSG_CONTACTS        0x0013

#define STATUS_ONLINE       0x00000000
#define STATUS_AWAY         0x00000001
#define STATUS_DND          0x00000013
#define STATUS_INVISIBLE    0x00000100
#define STATUS_OCCUPIED     0x00000010
#define STATUS_NA           0x00000004
#define STATUS_CHAT         0x00000020

/* Offsets for all packets measured from the start of the payload; i.e.
 * with the ICQ header removed
 */
#define CMD_ACK                  0x000a
#define CMD_ACK_RANDOM           0x0000

#define CMD_SEND_MSG             0x010E
#define CMD_SEND_MSG_RECV_UIN    0x0000
#define CMD_SEND_MSG_MSG_TYPE    0x0004
#define CMD_SEND_MSG_MSG_LEN     0x0006
#define CMD_SEND_MSG_MSG_TEXT    0x0008
/* The rest of the packet should be a null-term string */

#define CMD_LOGIN                0x03E8
#define CMD_LOGIN_TIME           0x0000
#define CMD_LOGIN_PORT           0x0004
#define CMD_LOGIN_PASSLEN        0x0008
#define CMD_LOGIN_PASSWD         0x000A
/* The password is variable length; so when we've decoded the passwd,
 * the structure starts counting at 0 again.
 */
#define CMD_LOGIN_IP             0x0004
#define CMD_LOGIN_STATUS         0x0009

#define CMD_CONTACT_LIST         0x0406
#define CMD_CONTACT_LIST_NUM     0x0000

#define CMD_USER_META            0x064a

#define CMD_REG_NEW_USER         0x03fc

#define CMD_ACK_MESSAGES         0x0442
#define CMD_ACK_MESSAGES_RANDOM  0x0000

#define CMD_KEEP_ALIVE           0x042e
#define CMD_KEEP_ALIVE_RANDOM    0x0000

#define CMD_SEND_TEXT_CODE       0x0438
#define CMD_SEND_TEXT_CODE_LEN   0x0000
#define CMD_SEND_TEXT_CODE_TEXT  0x0002

#define CMD_MSG_TO_NEW_USER      0x0456

#define CMD_QUERY_SERVERS        0x04ba

#define CMD_QUERY_ADDONS         0x04c4

#define CMD_STATUS_CHANGE        0x04d8
#define CMD_STATUS_CHANGE_STATUS 0x0000

#define CMD_ADD_TO_LIST          0x053c
#define CMD_ADD_TO_LIST_UIN      0x0000

#define CMD_RAND_SEARCH          0x056e
#define CMD_RAND_SEARCH_GROUP    0x0000

#define CMD_META_USER            0x064a

static const value_string msgTypeCode[] = {
    { MSG_TEXT,       "MSG_TEXT" },
    { MSG_URL,        "MSG_URL" },
    { MSG_AUTH_REQ,   "MSG_AUTH_REQ" },
    { MSG_AUTH,       "MSG_AUTH" },
    { MSG_USER_ADDED, "MSG_USER_ADDED" },
    { MSG_EMAIL,      "MSG_EMAIL" },
    { MSG_CONTACTS,   "MSG_CONTACTS" },
    { 0, NULL }
};

static const value_string statusCode[] = {
    { STATUS_ONLINE,    "ONLINE" },
    { STATUS_AWAY,      "AWAY" },
    { STATUS_DND,       "DND" },
    { STATUS_INVISIBLE, "INVISIBLE" },
    { STATUS_OCCUPIED,  "OCCUPIED" },
    { STATUS_NA,        "NA" },
    { STATUS_CHAT,      "Free for Chat" },
    { 0, NULL }
};

static const value_string clientCmdCode[] = {
    { CMD_ACK,             "CMD_ACK" },
    { CMD_SEND_MSG,        "CMD_SEND_MESSAGE" },
    { CMD_LOGIN,           "CMD_LOGIN" },
    { CMD_REG_NEW_USER,    "CMD_REG_NEW_USER" },
    { 1030,                "CMD_CONTACT_LIST" },
    { 1050,                "CMD_SEARCH_UIN" },
    { 1060,                "CMD_SEARCH_USER" },
    { 1070,                "CMD_KEEP_ALIVE" },
    { CMD_SEND_TEXT_CODE,  "CMD_SEND_TEXT_CODE" },
    { CMD_ACK_MESSAGES,    "CMD_ACK_MESSAGES" },
    { 1100,                "CMD_LOGIN_1" },
    { CMD_MSG_TO_NEW_USER, "CMD_MSG_TO_NEW_USER" },
    { 1120,                "CMD_INFO_REQ" },
    { 1130,                "CMD_EXT_INFO_REQ" },
    { 1180,                "CMD_CHANGE_PW" },
    { 1190,                "CMD_NEW_USER_INFO" },
    { 1200,                "CMD_UPDATE_EXT_INFO" },
    { CMD_QUERY_SERVERS,   "CMD_QUERY_SERVERS" },
    { CMD_QUERY_ADDONS,    "CMD_QUERY_ADDONS" },
    { CMD_STATUS_CHANGE,   "CMD_STATUS_CHANGE" },
    { 1260,                "CMD_NEW_USER_1" },
    { 1290,                "CMD_UPDATE_INFO" },
    { 1300,                "CMD_AUTH_UPDATE" },
    { 1310,                "CMD_KEEP_ALIVE2" },
    { 1320,                "CMD_LOGIN_2" },
    { CMD_ADD_TO_LIST,     "CMD_ADD_TO_LIST" },
    { 1380,                "CMD_RAND_SET" },
    { CMD_RAND_SEARCH,     "CMD_RAND_SEARCH" },
    { CMD_META_USER,       "CMD_META_USER" },
    { 1700,                "CMD_INVIS_LIST" },
    { 1710,                "CMD_VIS_LIST" },
    { 1720,                "CMD_UPDATE_LIST" },
    { 0, NULL }
};

#if 0
static const value_string group_vals[] = {
    { 1, "Name" },
    { 2, "General" },
    { 3, "Romance" },
    { 4, "Games" },
    { 5, "Students" },
    { 6, "20 Something" },
    { 7, "30 Something" },
    { 8, "40 Something" },
    { 9, "50 or worse" },
    { 10, "Man want women" },
    { 11, "Women want men" },
    { 0, NULL }
};
#endif

/*
 * All ICQv5 decryption code thanx to Sebastien Dault (daus01@gel.usherb.ca)
 */
static const guchar
table_v5 [] = {
    0x59, 0x60, 0x37, 0x6B, 0x65, 0x62, 0x46, 0x48, 0x53, 0x61, 0x4C, 0x59, 0x60, 0x57, 0x5B, 0x3D,
    0x5E, 0x34, 0x6D, 0x36, 0x50, 0x3F, 0x6F, 0x67, 0x53, 0x61, 0x4C, 0x59, 0x40, 0x47, 0x63, 0x39,
    0x50, 0x5F, 0x5F, 0x3F, 0x6F, 0x47, 0x43, 0x69, 0x48, 0x33, 0x31, 0x64, 0x35, 0x5A, 0x4A, 0x42,
    0x56, 0x40, 0x67, 0x53, 0x41, 0x07, 0x6C, 0x49, 0x58, 0x3B, 0x4D, 0x46, 0x68, 0x43, 0x69, 0x48,
    0x33, 0x31, 0x44, 0x65, 0x62, 0x46, 0x48, 0x53, 0x41, 0x07, 0x6C, 0x69, 0x48, 0x33, 0x51, 0x54,
    0x5D, 0x4E, 0x6C, 0x49, 0x38, 0x4B, 0x55, 0x4A, 0x62, 0x46, 0x48, 0x33, 0x51, 0x34, 0x6D, 0x36,
    0x50, 0x5F, 0x5F, 0x5F, 0x3F, 0x6F, 0x47, 0x63, 0x59, 0x40, 0x67, 0x33, 0x31, 0x64, 0x35, 0x5A,
    0x6A, 0x52, 0x6E, 0x3C, 0x51, 0x34, 0x6D, 0x36, 0x50, 0x5F, 0x5F, 0x3F, 0x4F, 0x37, 0x4B, 0x35,
    0x5A, 0x4A, 0x62, 0x66, 0x58, 0x3B, 0x4D, 0x66, 0x58, 0x5B, 0x5D, 0x4E, 0x6C, 0x49, 0x58, 0x3B,
    0x4D, 0x66, 0x58, 0x3B, 0x4D, 0x46, 0x48, 0x53, 0x61, 0x4C, 0x59, 0x40, 0x67, 0x33, 0x31, 0x64,
    0x55, 0x6A, 0x32, 0x3E, 0x44, 0x45, 0x52, 0x6E, 0x3C, 0x31, 0x64, 0x55, 0x6A, 0x52, 0x4E, 0x6C,
    0x69, 0x48, 0x53, 0x61, 0x4C, 0x39, 0x30, 0x6F, 0x47, 0x63, 0x59, 0x60, 0x57, 0x5B, 0x3D, 0x3E,
    0x64, 0x35, 0x3A, 0x3A, 0x5A, 0x6A, 0x52, 0x4E, 0x6C, 0x69, 0x48, 0x53, 0x61, 0x6C, 0x49, 0x58,
    0x3B, 0x4D, 0x46, 0x68, 0x63, 0x39, 0x50, 0x5F, 0x5F, 0x3F, 0x6F, 0x67, 0x53, 0x41, 0x25, 0x41,
    0x3C, 0x51, 0x54, 0x3D, 0x5E, 0x54, 0x5D, 0x4E, 0x4C, 0x39, 0x50, 0x5F, 0x5F, 0x5F, 0x3F, 0x6F,
    0x47, 0x43, 0x69, 0x48, 0x33, 0x51, 0x54, 0x5D, 0x6E, 0x3C, 0x31, 0x64, 0x35, 0x5A, 0x00, 0x00 };


static guint32
get_v5key(guint32 code, int len)
{
    guint32 a1, a2, a3, a4, a5;
    guint32 check, key;

    a1 = code & 0x0001f000;
    a2 = code & 0x07c007c0;
    a3 = code & 0x003e0001;
    a4 = code & 0xf8000000;
    a5 = code & 0x0000083e;

    a1 = a1 >> 0x0c;
    a2 = a2 >> 0x01;
    a3 = a3 << 0x0a;
    a4 = a4 >> 0x10;
    a5 = a5 << 0x0f;

    check = a5 + a1 + a2 + a3 + a4;
    key = len * 0x68656C6C;
    key += check;
    return key;
}

static void
decrypt_v5(guchar *bfr, guint32 size,guint32 key)
{
    guint32 i;
    guint32 k;

    for (i=ICQ5_CL_SESSIONID; i < size; i+=4 ) {
        k = key+table_v5[i&0xff];
        if ( i != 0x16 ) {
            bfr[i] ^= (guchar)(k & 0xff);
            bfr[i+1] ^= (guchar)((k & 0xff00)>>8);
        }
        if ( i != 0x12 ) {
            bfr[i+2] ^= (guchar)((k & 0xff0000)>>16);
            bfr[i+3] ^= (guchar)((k & 0xff000000)>>24);
        }
    }
}

static void
icqv5_decode_msgType(proto_tree *tree, tvbuff_t *tvb, int offset, int size,
             packet_info *pinfo)
{
    proto_item *msg_item;
    proto_tree *subtree;
    int left = size;
    guint16 msgType;
    gint sep_offset;
    int sz;            /* Size of the current element */
    unsigned int n;
    static int * const url_field_descr[] = {
         &hf_icq_description,
         &hf_icq_url,
    };
#define N_URL_FIELDS    (sizeof url_field_descr / sizeof url_field_descr[0])
    static int * const email_field_descr[] = {
         &hf_icq_nickname,
         &hf_icq_first_name,
         &hf_icq_last_name,
         &hf_icq_email,
         &hf_icq_unknown,
         &hf_icq_text,
    };
#define N_EMAIL_FIELDS  (sizeof email_field_descr / sizeof email_field_descr[0])
    static int * const auth_req_field_descr[] = {
         &hf_icq_nickname,
         &hf_icq_first_name,
         &hf_icq_last_name,
         &hf_icq_email,
         &hf_icq_unknown,
         &hf_icq_reason,
    };
#define N_AUTH_REQ_FIELDS   (sizeof auth_req_field_descr / sizeof auth_req_field_descr[0])
    static int * const user_added_field_descr[] = {
         &hf_icq_nickname,
         &hf_icq_first_name,
         &hf_icq_last_name,
         &hf_icq_email,
    };
#define N_USER_ADDED_FIELDS (sizeof user_added_field_descr / sizeof user_added_field_descr[0])

    msgType = tvb_get_letohs(tvb, offset);
    subtree = proto_tree_add_subtree_format(tree, tvb, offset, size, ett_icq_body_parts, NULL,
                 "%s Message", val_to_str_const(msgType, msgTypeCode, "Unknown"));

    msg_item = proto_tree_add_item(subtree, hf_icq_msg_type, tvb, offset, 2, ENC_LITTLE_ENDIAN);
    offset += 2;
    left -= 2;
    if (msgType != MSG_AUTH) {
        /*
         * XXX - does a MSG_AUTH message really have 3 bytes of information
         * rather than a length field?
         */
        proto_tree_add_item(subtree, hf_icq_msg_length, tvb, offset, 2, ENC_LITTLE_ENDIAN);
        offset += 2;
        left -= 2;
    }

    switch(msgType) {
    case 0xffff:           /* Field unknown */
    break;
    default:
        expert_add_info_format(pinfo, msg_item, &ei_icq_unknown_command,
                   "Unknown msgType: %u (0x%x)", msgType, msgType);
        break;
    case MSG_TEXT:
        proto_tree_add_item(subtree, hf_icq_msg, tvb, offset, left, ENC_ASCII);
        break;
    case MSG_URL:
        for (n = 0; n < N_URL_FIELDS; n++) {
            if (n != N_URL_FIELDS - 1) {
                sep_offset = tvb_find_guint8(tvb, offset, left, 0xfe);
                sz = sep_offset - offset + 1;
            } else {
                sz = left;
            }
            if (sz != 0) {
                proto_tree_add_item(subtree, *url_field_descr[n], tvb, offset, sz, ENC_ASCII|ENC_NA);
            } else {
                proto_tree_add_string_format_value(subtree, *url_field_descr[n], tvb, offset, 0,
                            "", "(empty)");
            }
            offset += sz;
            left -= sz;
        }
        break;
    case MSG_EMAIL:
    for (n = 0; n < N_EMAIL_FIELDS; n++) {
        if (n != N_EMAIL_FIELDS - 1) {
            sep_offset = tvb_find_guint8(tvb, offset, left, 0xfe);
            sz = sep_offset - offset + 1;
        } else {
            sz = left;
        }
        if (sz != 0) {
            proto_tree_add_item(subtree, *email_field_descr[n], tvb, offset, sz, ENC_ASCII|ENC_NA);
        } else {
            proto_tree_add_string_format_value(subtree, *email_field_descr[n], tvb, offset, 0,
                        "", "(empty)");
        }
        offset += sz;
        left -= sz;
    }
    break;

    case MSG_AUTH:
    {
        /* Three bytes, first is a char signifying success */
        unsigned char auth_suc;

        auth_suc = tvb_get_guint8(tvb, offset);
        proto_tree_add_uint_format_value(subtree, hf_icq_msg_authorization, tvb, offset, 1,
                    auth_suc, "(%u) %s",auth_suc,
                    (auth_suc==0)?"Denied":"Allowed");
        offset++;
        proto_tree_add_item(subtree, hf_icq_x1, tvb, offset, 2, ENC_LITTLE_ENDIAN);
        break;
    }
    case MSG_AUTH_REQ:
        for (n = 0; n < N_AUTH_REQ_FIELDS; n++) {
            if (n != N_AUTH_REQ_FIELDS - 1) {
                sep_offset = tvb_find_guint8(tvb, offset, left, 0xfe);
                sz = sep_offset - offset + 1;
            } else {
                sz = left;
            }
            if (sz != 0) {
                proto_tree_add_item(subtree, *auth_req_field_descr[n], tvb, offset, sz, ENC_ASCII|ENC_NA);
            } else {
                proto_tree_add_string_format_value(subtree, *auth_req_field_descr[n], tvb, offset, 0,
                        "", "(empty)");
            }
            offset += sz;
            left -= sz;
        }
        break;
    case MSG_USER_ADDED:
    for (n = 0; n < N_USER_ADDED_FIELDS; n++) {
        if (n != N_USER_ADDED_FIELDS - 1) {
            sep_offset = tvb_find_guint8(tvb, offset, left, 0xfe);
            sz = sep_offset - offset + 1;
        } else {
            sz = left;
        }
        if (sz != 0) {
            proto_tree_add_item(subtree, *user_added_field_descr[n], tvb, offset, sz, ENC_ASCII|ENC_NA);
        } else {
            proto_tree_add_string_format_value(subtree, *user_added_field_descr[n], tvb, offset, 0,
                        "", "(empty)");
        }
        offset += sz;
        left -= sz;
    }
    break;
    case MSG_CONTACTS:
    {
        gint sep_offset_prev;
        int sz_local = 0;            /* Size of the current element */
        int n_local = 0;             /* The nth element */
        gboolean last = FALSE;

        while (!last) {
            sep_offset = tvb_find_guint8(tvb, offset, left, 0xfe);
            if (sep_offset != -1) {
                sz_local = sep_offset - offset + 1;
            }
            else {
                sz_local = left;
                last = TRUE;
            }

            if (n_local == 0) {
                /* The first element is the number of Nick/UIN pairs follow */
                proto_tree_add_item(subtree, hf_icq_num_uin_pairs, tvb, offset, sz_local, ENC_ASCII);
                n_local++;
            } else if (!last) {
                int svsz = sz_local;
                char* contact;

                left -= sz_local;
                sep_offset_prev = sep_offset;
                sep_offset = tvb_find_guint8(tvb, sep_offset_prev, left, 0xfe);
                if (sep_offset != -1)
                    sz_local = sep_offset - offset + 1;
                else {
                    sz_local = left;
                    last = TRUE;
                }
                contact = tvb_get_string_enc(wmem_packet_scope(), tvb, sep_offset_prev + 1, sz_local, ENC_ASCII);
                proto_tree_add_string_format(subtree, hf_icq_msg_contact, tvb, offset, sz_local + svsz,
                            contact, "%s: %s",
                            tvb_get_string_enc(wmem_packet_scope(), tvb, offset, svsz, ENC_ASCII),
                            contact);
                n_local += 2;
            }

            left -= (sz_local+1);
            offset = sep_offset + 1;
        }
        break;
    }
    }
}

/*********************************
 *
 * Client commands
 *
 *********************************/
static void
icqv5_cmd_send_text_code(proto_tree *tree, /* Tree to put the data in */
             tvbuff_t *tvb,    /* Decrypted packet content */
             int offset)       /* Offset from the start of the packet to the content */
{
    proto_tree *subtree = tree;
    guint16 len;

    len = tvb_get_letohs(tvb, offset+CMD_SEND_TEXT_CODE_LEN);
    proto_tree_add_item(subtree, hf_icq_text_code_length, tvb, offset + CMD_SEND_TEXT_CODE_LEN, 2, ENC_LITTLE_ENDIAN);

    if (len>0) {
        proto_tree_add_item(subtree, hf_icq_text_code, tvb, offset + CMD_SEND_TEXT_CODE_TEXT, len, ENC_ASCII);
    }

    proto_tree_add_item(subtree, hf_icq_x1, tvb, offset + CMD_SEND_TEXT_CODE_TEXT + len, 2, ENC_LITTLE_ENDIAN);
}

static void
icqv5_cmd_send_msg(proto_tree *tree, tvbuff_t *tvb, int offset, int size,
           packet_info *pinfo)
{
    proto_tree_add_item(tree, hf_icq_receiver_uin, tvb, offset + CMD_SEND_MSG_RECV_UIN, 4, ENC_LITTLE_ENDIAN);
    size -= 4;

    icqv5_decode_msgType(tree, tvb, offset + CMD_SEND_MSG_MSG_TYPE,
                 size, pinfo);
}

static void
icqv5_cmd_login(proto_tree *tree, tvbuff_t *tvb, int offset)
{
    proto_tree *subtree = tree;
    time_t theTime;
    char *aTime;
    guint32 passwdLen;

    if (tree) {
        theTime = tvb_get_letohl(tvb, offset + CMD_LOGIN_TIME);
        aTime = abs_time_secs_to_str(wmem_packet_scope(), theTime, ABSOLUTE_TIME_LOCAL, TRUE);
        proto_tree_add_uint_format_value(subtree, hf_icq_login_time, tvb, offset + CMD_LOGIN_TIME, 4,
                    (guint32)theTime, "%u = %s", (guint32)theTime, aTime);
        proto_tree_add_item(subtree, hf_icq_login_port, tvb, offset + CMD_LOGIN_PORT, 4, ENC_LITTLE_ENDIAN);
        passwdLen = tvb_get_letohs(tvb, offset + CMD_LOGIN_PASSLEN);
        proto_tree_add_item(subtree, hf_icq_login_password, tvb, offset + CMD_LOGIN_PASSLEN, 2 + passwdLen, ENC_ASCII);
        proto_tree_add_item(subtree, hf_icq_login_ip, tvb, offset + CMD_LOGIN_PASSWD + passwdLen + CMD_LOGIN_IP, 4, ENC_BIG_ENDIAN);
        proto_tree_add_item(subtree, hf_icq_status, tvb, offset + CMD_LOGIN_PASSWD + passwdLen + CMD_LOGIN_STATUS, 4, ENC_LITTLE_ENDIAN);
    }
}

static void
icqv5_cmd_contact_list(proto_tree *tree, tvbuff_t *tvb, int offset)
{
    unsigned char num;
    int i;
    guint32 uin;

    if (tree) {
        num = tvb_get_guint8(tvb, offset + CMD_CONTACT_LIST_NUM);
        proto_tree_add_item(tree, hf_icq_number_of_uins, tvb, offset + CMD_CONTACT_LIST, 1, ENC_NA);
        /*
         * A sequence of num times UIN follows
         */
        offset += (CMD_CONTACT_LIST_NUM + 1);
        for (i = 0; i < num; i++) {
            uin = tvb_get_letohl(tvb, offset);
            proto_tree_add_uint_format(tree, hf_icq_uin, tvb, offset, 4,
                    uin, "UIN[%d]: %u", i, uin);
            offset += 4;
        }
    }
}

/**********************
 *
 * Server commands
 *
 **********************
 */
static void
icqv5_srv_user_online(proto_tree *tree,/* Tree to put the data in */
                tvbuff_t *tvb,   /* Tvbuff with packet */
                int offset)      /* Offset from the start of the packet to the content */
{
    proto_tree *subtree = tree;

    if (tree) {
        proto_tree_add_item(subtree, hf_icq_uin, tvb, offset + SRV_USER_ONL_UIN, 4, ENC_LITTLE_ENDIAN);
        proto_tree_add_item(subtree, hf_icq_user_online_ip, tvb, offset + SRV_USER_ONL_IP, 4, ENC_BIG_ENDIAN);
        proto_tree_add_item(subtree, hf_icq_user_online_port, tvb, offset + SRV_USER_ONL_PORT, 4, ENC_LITTLE_ENDIAN);
        proto_tree_add_item(subtree, hf_icq_user_online_realip, tvb, offset + SRV_USER_ONL_REALIP, 4, ENC_BIG_ENDIAN);
        proto_tree_add_item(subtree, hf_icq_status, tvb, offset + SRV_USER_ONL_STATUS, 2, ENC_LITTLE_ENDIAN);
        /*
         * Kojak: Hypothesis is that this field might be an encoding for the
         * version used by the UIN that changed. To test this, I included
         * this line to the code.
         */
        proto_tree_add_item(subtree, hf_icq_user_online_version, tvb, offset + SRV_USER_ONL_X2, 4, ENC_LITTLE_ENDIAN);
    }
}

static void
// NOLINTNEXTLINE(misc-no-recursion)
icqv5_srv_multi(proto_tree *tree, /* Tree to put the data in */
        tvbuff_t *tvb,    /* Packet content */
        int offset,       /* Offset from the start of the packet to the content */
        packet_info *pinfo)
{
    guint8 num;
    guint16 pktSz;
    int i;

    num = tvb_get_guint8(tvb, offset + SRV_MULTI_NUM);
    proto_tree_add_item(tree, hf_icq_multi_num_packets, tvb, offset + SRV_MULTI_NUM, 1, ENC_NA);
    /*
     * A sequence of num times ( pktsize, packetData) follows
     */
    offset += (SRV_MULTI_NUM + 1);
    for (i = 0; i < num; i++) {
        pktSz = tvb_get_letohs(tvb, offset);
        offset += 2;
        // We recurse here, but we'll run out of packet before we run out of stack.
        dissect_icqv5Server(tvb, offset, pinfo, tree, pktSz);
        offset += pktSz;
    }
}

static void
icqv5_srv_meta_user(proto_tree *tree, /* Tree to put the data in */
            tvbuff_t *tvb,    /* Tvbuff with packet */
            int offset,       /* Offset from the start of the packet to the content */
            int size _U_,         /* Number of chars left to do */
            packet_info *pinfo)
{
    proto_tree *sstree;
    proto_item *ti;
    guint16 subcmd;
    unsigned char result;

    subcmd = tvb_get_letohs(tvb, offset + SRV_META_USER_SUBCMD);
    ti = proto_tree_add_item(tree, hf_icq_meta_user_subcmd, tvb, offset + SRV_META_USER_SUBCMD, 2, ENC_LITTLE_ENDIAN);
    sstree = proto_item_add_subtree(ti, ett_icq_body_parts);
    result = tvb_get_guint8(tvb, offset + SRV_META_USER_RESULT);
    proto_tree_add_uint_format_value(sstree, hf_icq_meta_user_result, tvb, offset + SRV_META_USER_RESULT,
                result, 1, "%s", (result==0x0a)?"Success":"Failure");

    /* Skip the META_USER header */
    offset += 3;

    switch(subcmd) {
    case META_EX_USER_FOUND:
    {
        /* This is almost the same as META_USER_FOUND,
         * however, there's an extra length field
         */

        /* Read the length field */
        proto_tree_add_item(sstree, hf_icq_meta_user_length, tvb, offset, 2, ENC_LITTLE_ENDIAN);

        offset += 2;
    }
    /* FALLTHRU */
    case META_USER_FOUND:
    {
        /* The goto mentioned in this block should be local to this
         * block if C'd allow it.
         *
         * They are used to "implement" a poorman's exception handling
         */
        int len = 0;
        unsigned char auth;
        /*
         * Read UIN
         */
        proto_tree_add_item(sstree, hf_icq_uin, tvb, offset, 4, ENC_LITTLE_ENDIAN);
        offset+=4;

        proto_tree_add_item_ret_length(sstree, hf_icq_nickname_uint_string, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset += len;
        proto_tree_add_item_ret_length(sstree, hf_icq_first_name_uint_string, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset += len;
        proto_tree_add_item_ret_length(sstree, hf_icq_last_name_uint_string, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset += len;
        proto_tree_add_item_ret_length(sstree, hf_icq_email_uint_string, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset += len;

        /* Get the authorize setting */
        auth = tvb_get_guint8(tvb, offset);
        proto_tree_add_uint_format_value(sstree, hf_icq_meta_user_found_authorization, tvb, offset, 1,
                auth, "%s", (auth==0x01)?"Necessary":"Who needs it");
        offset++;
        /* Get x2 */
        proto_tree_add_item(sstree, hf_icq_meta_user_x2, tvb, offset, 2, ENC_LITTLE_ENDIAN);
        offset+=2;
        /* Get x3 */
        proto_tree_add_item(sstree, hf_icq_meta_user_x3, tvb, offset, 4, ENC_LITTLE_ENDIAN);
        break;
    }
    case META_ABOUT:
    {
        /* Get the about information */
        proto_tree_add_item(sstree, hf_icq_meta_user_about, tvb, offset,
                2, ENC_LITTLE_ENDIAN|ENC_ASCII);
        break;
    }
    case META_USER_INFO:
    {
        int len = 0;
#if 0
        /* Get the uin */
        proto_tree_add_item(sstree, hf_icq_uin, tvb, offset, 4, ENC_LITTLE_ENDIAN);
        offset+=4;
#endif

        /*
         * Get every field from the description
         */
        proto_tree_add_item_ret_length(sstree, hf_icq_nickname_uint_string, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_first_name_uint_string, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_last_name_uint_string, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_primary_email, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_secondary_email, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_old_email, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_city, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_state, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_phone, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_fax, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_street, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_cellphone, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;
        proto_tree_add_item_ret_length(sstree, hf_icq_zip, tvb, offset, 2, ENC_LITTLE_ENDIAN|ENC_ASCII, &len);
        offset+=len;

        /* Get country code */
        proto_tree_add_item(sstree, hf_icq_meta_user_countrycode, tvb, offset, 2, ENC_LITTLE_ENDIAN);
        offset+=2;
        /* Get the timezone setting */
        proto_tree_add_item(sstree, hf_icq_meta_user_timezone, tvb, offset, 1, ENC_NA);
        offset++;
        /* Get the authorize setting */
        proto_tree_add_item(sstree, hf_icq_meta_user_info_authorization, tvb, offset, 1, ENC_NA);
        offset++;
        /* Get the webaware setting */
        proto_tree_add_item(sstree, hf_icq_meta_user_webaware, tvb, offset, 1, ENC_NA);
        offset++;
        /* Get the authorize setting */
        proto_tree_add_item(sstree, hf_icq_meta_user_hideip, tvb, offset, 1, ENC_NA);
        break;
    }
    default:
        /* This information is already printed in the tree */
        expert_add_info_format(pinfo, ti, &ei_icq_unknown_meta_subcmd,
                   "Unknown Meta subcmd: 0x%x", subcmd);
        break;
    }
}

static void
icqv5_srv_recv_message(proto_tree *tree, /* Tree to put the data in */
                        tvbuff_t *tvb,    /* Packet content */
                        int offset,       /* Offset from the start of the packet to the content */
                        int size,         /* Number of chars left to do */
                        packet_info *pinfo)
{
    guint16 year;
    guint8 month;
    guint8 day;
    guint8 hour;
    guint8 minute;

    proto_tree_add_item(tree, hf_icq_uin, tvb, offset + SRV_RECV_MSG_UIN,
                4, ENC_LITTLE_ENDIAN);
    year = tvb_get_letohs(tvb, offset + SRV_RECV_MSG_YEAR);
    month = tvb_get_guint8(tvb, offset + SRV_RECV_MSG_MONTH);
    day = tvb_get_guint8(tvb, offset + SRV_RECV_MSG_DAY);
    hour = tvb_get_guint8(tvb, offset + SRV_RECV_MSG_HOUR);
    minute = tvb_get_guint8(tvb, offset + SRV_RECV_MSG_MINUTE);

    proto_tree_add_bytes_format_value(tree, hf_icq_recv_time, tvb, offset + SRV_RECV_MSG_YEAR,
                2 + 4, NULL, "%u-%u-%u %02u:%02u",
                day, month, year, hour, minute);
    icqv5_decode_msgType(tree, tvb, offset + SRV_RECV_MSG_MSG_TYPE,
                 size-10, pinfo);
}

static void
icqv5_srv_rand_user(proto_tree *tree,      /* Tree to put the data in */
            tvbuff_t *tvb,         /* Tvbuff with packet */
            int offset)            /* Offset from the start of the packet to the content */
{
    proto_tree *subtree = tree;
    guint8 commClass;

    if (tree) {
        /* guint32 UIN */
        proto_tree_add_item(subtree, hf_icq_uin, tvb, offset + SRV_RAND_USER_UIN,
                    4, ENC_LITTLE_ENDIAN);
        /* guint32 IP */
        proto_tree_add_item(subtree, hf_icq_rand_user_ip, tvb, offset + SRV_RAND_USER_IP, 4, ENC_BIG_ENDIAN);
        /* guint16 portNum */
        /* XXX - 16 bits, or 32 bits? */
        proto_tree_add_item(subtree, hf_icq_rand_user_port, tvb, offset + SRV_RAND_USER_PORT, 4, ENC_LITTLE_ENDIAN);
        /* guint32 realIP */
        proto_tree_add_item(subtree, hf_icq_rand_user_realip, tvb, offset + SRV_RAND_USER_REAL_IP, 4, ENC_BIG_ENDIAN);
        /* guint8 Communication Class */
        commClass = tvb_get_guint8(tvb, offset + SRV_RAND_USER_CLASS);
        proto_tree_add_uint_format_value(subtree, hf_icq_rand_user_class, tvb, offset + SRV_RAND_USER_CLASS,
                    1, commClass, "%s", (commClass!=4)?"User to User":"Through Server");
        /* guint32 status */
        /* XXX - 16 bits, or 32 bits? */
        proto_tree_add_item(subtree, hf_icq_status, tvb, offset + SRV_RAND_USER_STATUS, 4, ENC_LITTLE_ENDIAN);

        /* guint16 tcpVersion */
        proto_tree_add_item(subtree, hf_icq_rand_user_tcpversion, tvb, offset + SRV_RAND_USER_TCP_VER, 2, ENC_LITTLE_ENDIAN);
    }
}

/*
 * Dissect all the v5 client traffic. This is encrypted, so be careful.
 */
static void
dissect_icqv5Client(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    proto_tree *icq_header_tree, *icq_body_tree;
    proto_item *ti, *cmd_item;

    int pktsize;        /* The actual size of the ICQ content */
    int capturedsize;       /* The captured size of the ICQ content */
    guint32 rounded_size;
    guint32 code, key;
    guint16 cmd;
    guint8 *decr_pd;        /* Decrypted content */
    tvbuff_t *decr_tvb;

    pktsize = tvb_reported_length(tvb);
    capturedsize = tvb_captured_length(tvb);

    /* Get the encryption key */
    code = tvb_get_letohl(tvb, ICQ5_CL_CHECKCODE);
    key = get_v5key(code, pktsize);

    /*
     * Make a copy of the packet data, and decrypt it.
     * The decryption processes 4 bytes at a time, and starts at
     * an offset of ICQ5_CL_SESSIONID (which isn't a multiple of 4),
     * so we make sure that there are
     *
     *  (ICQ5_CL_SESSIONID + a multiple of 4)
     *
     * bytes in the buffer.
     */
    rounded_size = ((((capturedsize - ICQ5_CL_SESSIONID) + 3)/4)*4) + ICQ5_CL_SESSIONID;
    /* rounded_size might exceed the tvb bounds so we can't just use tvb_memdup here. */
    decr_pd = (guint8 *)wmem_alloc(pinfo->pool, rounded_size);
    tvb_memcpy(tvb, decr_pd, 0, capturedsize);
    decrypt_v5(decr_pd, rounded_size, key);

    /* Allocate a new tvbuff, referring to the decrypted data. */
    decr_tvb = tvb_new_child_real_data(tvb, decr_pd, capturedsize, pktsize);

    /* Add the decrypted data to the data source list. */
    add_new_data_source(pinfo, decr_tvb, "Decrypted");

    cmd = tvb_get_letohs(decr_tvb, ICQ5_CL_CMD);

    col_add_fstr(pinfo->cinfo, COL_INFO, "ICQv5 %s", val_to_str_const(cmd, clientCmdCode, "Unknown"));

    icq_header_tree = proto_tree_add_subtree(tree, tvb, 0, ICQ5_CL_HDRSIZE, ett_icq_header, NULL, "Header");

    ti = proto_tree_add_boolean(icq_header_tree, hf_icq_type, tvb, 0, 0, ICQ5_CLIENT);
    proto_item_set_generated(ti);

    proto_tree_add_item(icq_header_tree, hf_icq_version, tvb, ICQ_VERSION, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_uin, tvb, ICQ5_CL_UIN, 4, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_sessionid, decr_tvb, ICQ5_CL_SESSIONID, 4, ENC_LITTLE_ENDIAN);
    cmd_item = proto_tree_add_item(icq_header_tree, hf_icq_client_cmd, decr_tvb, ICQ5_CL_CMD, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_seqnum1, decr_tvb, ICQ5_CL_SEQNUM1, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_seqnum2, decr_tvb, ICQ5_CL_SEQNUM2, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_checkcode, tvb, ICQ5_CL_CHECKCODE, 4, ENC_LITTLE_ENDIAN);
    ti = proto_tree_add_uint(icq_header_tree, hf_icq_checkcode_key, tvb, ICQ5_CL_CHECKCODE, 4, key);
    proto_item_set_generated(ti);

    icq_body_tree = proto_tree_add_subtree(tree, decr_tvb, ICQ5_CL_HDRSIZE, pktsize - ICQ5_CL_HDRSIZE, ett_icq_body, NULL, "Body");

    switch(cmd) {
    case CMD_ACK:
        proto_tree_add_item(icq_body_tree, hf_icq_ack_random, decr_tvb, ICQ5_CL_HDRSIZE + CMD_ACK_RANDOM, 4, ENC_LITTLE_ENDIAN);
        break;
    case CMD_SEND_MSG:
    case CMD_MSG_TO_NEW_USER:
        icqv5_cmd_send_msg(icq_body_tree, decr_tvb, ICQ5_CL_HDRSIZE,
                   pktsize - ICQ5_CL_HDRSIZE, pinfo);
        break;
    case CMD_RAND_SEARCH:
        proto_tree_add_item(icq_body_tree, hf_icq_group, decr_tvb, ICQ5_CL_HDRSIZE + CMD_RAND_SEARCH_GROUP, 4, ENC_LITTLE_ENDIAN);
        break;
    case CMD_LOGIN:
        icqv5_cmd_login(icq_body_tree, decr_tvb, ICQ5_CL_HDRSIZE);
        break;
    case CMD_SEND_TEXT_CODE:
        icqv5_cmd_send_text_code(icq_body_tree, decr_tvb, ICQ5_CL_HDRSIZE);
        break;
    case CMD_STATUS_CHANGE:
        proto_tree_add_item(icq_body_tree, hf_icq_status, decr_tvb, ICQ5_CL_HDRSIZE + CMD_STATUS_CHANGE_STATUS, 4, ENC_LITTLE_ENDIAN);
        break;
    case CMD_ACK_MESSAGES:
        proto_tree_add_item(icq_body_tree, hf_icq_ack_random, decr_tvb, ICQ5_CL_HDRSIZE + CMD_ACK_MESSAGES_RANDOM, 4, ENC_LITTLE_ENDIAN);
        break;
    case CMD_KEEP_ALIVE:
        proto_tree_add_item(icq_body_tree, hf_icq_keep_alive_random, decr_tvb, ICQ5_CL_HDRSIZE + CMD_KEEP_ALIVE_RANDOM, 4, ENC_LITTLE_ENDIAN);
        break;
    case CMD_ADD_TO_LIST:
        proto_tree_add_item(icq_body_tree, hf_icq_uin, decr_tvb, ICQ5_CL_HDRSIZE + CMD_ADD_TO_LIST_UIN, 4, ENC_LITTLE_ENDIAN);
        break;
    case CMD_CONTACT_LIST:
        icqv5_cmd_contact_list(icq_body_tree, decr_tvb, ICQ5_CL_HDRSIZE);
        break;
    case CMD_META_USER:
    case CMD_REG_NEW_USER:
    case CMD_QUERY_SERVERS:
    case CMD_QUERY_ADDONS:
        proto_tree_add_item(icq_body_tree, hf_icq_no_parameters, tvb, ICQ5_CL_HDRSIZE, 0, ENC_NA);
        break;
    default:
        expert_add_info(pinfo, cmd_item, &ei_icq_unknown_command);
        break;
    }
}

static void
// NOLINTNEXTLINE(misc-no-recursion)
dissect_icqv5Server(tvbuff_t *tvb, int offset, packet_info *pinfo,
            proto_tree *tree, int pktsize)
{
    /* Server traffic is easy, not encrypted */
    proto_tree *icq_header_tree, *icq_body_tree;
    proto_item *ti, *cmd_item;

    guint16 cmd = tvb_get_letohs(tvb, offset + ICQ5_SRV_CMD);

    if (pktsize == -1) {
        col_add_fstr(pinfo->cinfo, COL_INFO, "ICQv5 %s", val_to_str_const(cmd, serverCmdCode, "Unknown"));
        pktsize = tvb_reported_length(tvb);
    }

    icq_header_tree = proto_tree_add_subtree(tree, tvb, offset, ICQ5_SRV_HDRSIZE, ett_icq_header, NULL, "Header");

    ti = proto_tree_add_boolean(icq_header_tree, hf_icq_type, tvb, 0, 0, ICQ5_SERVER);
    proto_item_set_generated(ti);

    proto_tree_add_item(icq_header_tree, hf_icq_version, tvb, offset + ICQ_VERSION, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_sessionid, tvb, offset + ICQ5_SRV_SESSIONID, 4, ENC_LITTLE_ENDIAN);
    cmd_item = proto_tree_add_item(icq_header_tree, hf_icq_server_cmd, tvb, offset + ICQ5_SRV_CMD, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_seqnum1, tvb, offset + ICQ5_SRV_SEQNUM1, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_seqnum2, tvb, offset + ICQ5_SRV_SEQNUM2, 2, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_uin, tvb, offset + ICQ5_SRV_UIN, 4, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(icq_header_tree, hf_icq_checkcode, tvb, offset + ICQ5_SRV_CHECKCODE, 4, ENC_LITTLE_ENDIAN);

    icq_body_tree = proto_tree_add_subtree(tree, tvb, ICQ5_CL_HDRSIZE, pktsize - ICQ5_SRV_HDRSIZE, ett_icq_body, NULL, "Body");

    switch (cmd) {
    case SRV_RAND_USER:
        icqv5_srv_rand_user(icq_body_tree, tvb, offset + ICQ5_SRV_HDRSIZE);
        break;
    case SRV_SYS_DELIVERED_MESS:
        /* The message structures are all the same. Why not run
         * the same routine? */
        icqv5_cmd_send_msg(icq_body_tree, tvb, offset + ICQ5_SRV_HDRSIZE,
                   pktsize - ICQ5_SRV_HDRSIZE, pinfo);
        break;
    case SRV_USER_ONLINE:
        icqv5_srv_user_online(icq_body_tree, tvb, offset + ICQ5_SRV_HDRSIZE);
        break;
    case SRV_USER_OFFLINE:
        proto_tree_add_item(icq_body_tree, hf_icq_uin, tvb, offset + ICQ5_SRV_HDRSIZE + SRV_USER_OFFLINE_UIN, 4, ENC_LITTLE_ENDIAN);
        break;
    case SRV_LOGIN_REPLY:
        proto_tree_add_item(tree, hf_icq_login_reply_ip, tvb, offset + ICQ5_SRV_HDRSIZE + SRV_LOGIN_REPLY_IP, 4, ENC_BIG_ENDIAN);
        break;
    case SRV_META_USER:
        icqv5_srv_meta_user(icq_body_tree, tvb, offset + ICQ5_SRV_HDRSIZE,
                pktsize - ICQ5_SRV_HDRSIZE, pinfo);
        break;
    case SRV_RECV_MESSAGE:
        icqv5_srv_recv_message(icq_body_tree, tvb, offset + ICQ5_SRV_HDRSIZE,
                   pktsize - ICQ5_SRV_HDRSIZE, pinfo);
        break;
    case SRV_MULTI:
        // We recurse here, but we'll run out of packet before we run out of stack.
        icqv5_srv_multi(icq_body_tree, tvb, offset + ICQ5_SRV_HDRSIZE, pinfo);
        break;
    case SRV_ACK:
    case SRV_SILENT_TOO_LONG:
    case SRV_GO_AWAY:
    case SRV_NEW_UIN:
    case SRV_BAD_PASS:
    case SRV_UPDATE_SUCCESS:
        proto_tree_add_item(icq_body_tree, hf_icq_no_parameters, tvb, offset + ICQ5_SRV_HDRSIZE, 0, ENC_NA);
        break;
    default:
        expert_add_info(pinfo, cmd_item, &ei_icq_unknown_command);
        break;
    }
}

static void dissect_icqv5(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    if (tvb_get_letohl(tvb, ICQ5_UNKNOWN) == 0) {
        dissect_icqv5Client(tvb, pinfo, tree);
    } else {
        dissect_icqv5Server(tvb, 0, pinfo, tree, -1);
    }
}

static int
dissect_icq(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
    int version;
    proto_item *ti;
    proto_tree *icq_tree;

    version = tvb_get_letohs(tvb, ICQ_VERSION);
    if (version < 2 || version > 5)
        return 0;   /* This is not a (recognized) ICQ packet */

    col_add_fstr(pinfo->cinfo, COL_PROTOCOL, "ICQv%d", version);
    col_add_fstr(pinfo->cinfo, COL_INFO, "ICQ Version %d protocol", version);

    ti = proto_tree_add_protocol_format(tree, proto_icq, tvb, 0, -1, "ICQv%d", version);
    icq_tree = proto_item_add_subtree(ti, ett_icq);

    if (version == 5)
    {
        dissect_icqv5(tvb, pinfo, icq_tree);
    }
    else
    {
        proto_tree_add_item(icq_tree, hf_icq_version, tvb, ICQ_VERSION, 2, ENC_LITTLE_ENDIAN);
    }

    return (tvb_captured_length(tvb));
}

/* registration with the filtering engine */
void
proto_register_icq(void)
{
    static hf_register_info hf[] = {
        { &hf_icq_version,
          {"Version", "icq.version", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_type,
          {"Client/Server", "icq.client", FT_BOOLEAN, BASE_NONE, TFS(&tfs_client_server), 0x0, NULL, HFILL }},
        { &hf_icq_msg_type,
          {"Type", "icq.msg_type", FT_UINT16, BASE_DEC, VALS(msgTypeCode), 0x0, NULL, HFILL }},
        { &hf_icq_uin,
          {"UIN", "icq.uin", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_sessionid,
          {"Session ID", "icq.sessionid", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_client_cmd,
          {"Client command", "icq.client_cmd", FT_UINT16, BASE_DEC, VALS(clientCmdCode), 0x0, NULL, HFILL }},
        { &hf_icq_server_cmd,
          {"Server command", "icq.server_cmd", FT_UINT16, BASE_DEC, VALS(serverCmdCode), 0x0, NULL, HFILL }},
        { &hf_icq_checkcode,
          {"Checkcode", "icq.checkcode", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_checkcode_key,
          {"Key", "icq.checkcode_key", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_seqnum1,
          {"Seq Number 1", "icq.seqnum1", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_seqnum2,
          {"Seq Number 2", "icq.seqnum2", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_group,
          {"Group", "icq.group", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_ack_random,
          {"Random", "icq.ack.random", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_keep_alive_random,
          {"Random", "icq.keep_alive.random", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_status,
          {"Client command", "icq.status", FT_UINT32, BASE_DEC, VALS(statusCode), 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_subcmd,
          {"Subcommand", "icq.meta_user.subcmd", FT_UINT16, BASE_DEC, VALS(serverMetaSubCmdCode), 0x0, NULL, HFILL }},
        /* Generated from convert_proto_tree_add_text.pl */
        { &hf_icq_msg_length, { "Length", "icq.msg_length", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_msg, { "Msg", "icq.msg", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_msg_authorization, { "Authorization", "icq.msg_authorization", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_x1, { "X1", "icq.x1", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_num_uin_pairs, { "Number of pairs", "icq.num_uin_pairs", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_text_code_length, { "Length", "icq.text_code_length", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_text_code, { "Text", "icq.text_code", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_receiver_uin, { "Receiver UIN", "icq.receiver_uin", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_login_time, { "Time", "icq.login.time", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_login_port, { "Port", "icq.login.port", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_login_password, { "Password", "icq.login.password", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_login_ip, { "IP", "icq.login.ip", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_number_of_uins, { "Number of uins", "icq.number_of_uins", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_user_online_ip, { "IP", "icq.user_online.ip", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_user_online_port, { "Port", "icq.user_online.port", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_user_online_realip, { "RealIP", "icq.user_online.realip", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_user_online_version, { "Version", "icq.user_online.version", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_multi_num_packets, { "Number of pkts", "icq.multi.num_packets", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_result, { "Result", "icq.meta_user.result", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_length, { "Length", "icq.meta_user.length", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_found_authorization, { "Authorization", "icq.meta_user.found_authorization", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_x2, { "x2", "icq.meta_user.x2", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_x3, { "x3", "icq.meta_user.x3", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_about, { "About", "icq.meta_user.about", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_countrycode, { "Countrycode", "icq.meta_user.countrycode", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_timezone, { "Timezone", "icq.meta_user.timezone", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_info_authorization, { "Authorization", "icq.meta_user.info_authorization", FT_BOOLEAN, 8, TFS(&tfs_yes_no), 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_webaware, { "Webaware", "icq.meta_user.webaware", FT_BOOLEAN, 8, TFS(&tfs_yes_no), 0x0, NULL, HFILL }},
        { &hf_icq_meta_user_hideip, { "HideIP", "icq.meta_user.hideip", FT_BOOLEAN, 8, TFS(&tfs_yes_no), 0x0, NULL, HFILL }},
        { &hf_icq_rand_user_ip, { "IP", "icq.rand_user.ip", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_rand_user_port, { "Port", "icq.rand_user.port", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_rand_user_realip, { "RealIP", "icq.rand_user.realip", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_rand_user_class, { "Class", "icq.rand_user.class", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_rand_user_tcpversion, { "TCPVersion", "icq.rand_user.tcpversion", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_no_parameters, { "No parameters", "icq.no_parameters", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_login_reply_ip, { "IP", "icq.login_reply.ip", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_nickname, { "Nickname", "icq.nickname", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_first_name, { "First name", "icq.first_name", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_last_name, { "Last name", "icq.last_name", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_email, { "Email", "icq.email", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_nickname_uint_string, { "Nickname", "icq.nickname", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_first_name_uint_string, { "First name", "icq.first_name", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_last_name_uint_string, { "Last name", "icq.last_name", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_email_uint_string, { "Email", "icq.email", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_primary_email, { "Primary email", "icq.primary_email", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_secondary_email, { "Secondary email", "icq.secondary_email", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_old_email, { "Old email", "icq.old_email", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_city, { "City", "icq.city", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_state, { "State", "icq.state", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_phone, { "Phone", "icq.phone", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_fax, { "Fax", "icq.fax", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_street, { "Street", "icq.street", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_cellphone, { "Cellphone", "icq.cellphone", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_zip, { "Zip", "icq.zip", FT_UINT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_description, { "Description", "icq.description", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_url, { "URL", "icq.url", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_text, { "Text", "icq.text", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_unknown, { "Unknown", "icq.unknown", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_reason, { "Reason", "icq.reason", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_msg_contact, { "Contact", "icq.msg_contact", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
        { &hf_icq_recv_time, { "Time", "icq.recv_time", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
    };

    static gint *ett[] = {
        &ett_icq,
        &ett_icq_header,
        &ett_icq_body,
        &ett_icq_body_parts,
    };
    static ei_register_info ei[] = {
        { &ei_icq_unknown_meta_subcmd, { "icq.unknown_meta_subcmd", PI_UNDECODED, PI_WARN, "Unknown meta subcmd", EXPFILL }},
        { &ei_icq_unknown_command, { "icq.unknown_command", PI_UNDECODED, PI_WARN, "Unknown command", EXPFILL }},
    };

    expert_module_t *expert_icq;

    proto_icq = proto_register_protocol("ICQ Protocol", "ICQ", "icq");
    proto_register_field_array(proto_icq, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
    expert_icq = expert_register_protocol(proto_icq);
    expert_register_field_array(expert_icq, ei, array_length(ei));

    icq_handle = register_dissector("icq", dissect_icq, proto_icq);
}

void
proto_reg_handoff_icq(void)
{
    dissector_add_uint_with_preference("udp.port", UDP_PORT_ICQ, icq_handle);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */