path: root/epan/dissectors/packet-skinny.c.in

/* Do not modify this file. Changes will be overwritten */
/* Generated Automatically                              */
/* packet-skinny.c                                      */

/* packet-skinny.c
 * Dissector for the Skinny Client Control Protocol
 *   (The "D-Channel"-Protocol for Cisco Systems' IP-Phones)
 *
 * Author: Diederik de Groot <ddegroot@user.sf.net>, Copyright 2014
 * Rewritten to support newer skinny protocolversions (V0-V22)
 * Based on previous versions/contributions:
 *  - Joerg Mayer <jmayer@loplof.de>, Copyright 2001
 *  - Paul E. Erkkila (pee@erkkila.org) - fleshed out the decode
 *    skeleton to report values for most message/message fields.
 *    Much help from Guy Harris on figuring out the wireshark api.
 *  - packet-aim.c by Ralf Hoelzer <ralf@well.com>, Copyright 2000
 *  - Wireshark - Network traffic analyzer,
 *    By Gerald Combs <gerald@wireshark.org>, Copyright 1998
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/* [[[cog
#
# Using Cog.py Inplace Code Generator
#
# Dependencies:
# - python
# - cog.py: http://nedbatchelder.com/code/cog/
# - python.xml
# - python.xml.sax
#
cog.out('/*\n')
cog.out(' * Generated Automatically Using (from wireshark base directory):\n')
cog.out(' *   cog.py -D xmlfile=tools/SkinnyProtocolOptimized.xml -d -c -o epan/dissectors/packet-skinny.c epan/dissectors/packet-skinny.c.in\n')
cog.out(' */\n')
]]]*/

/*[[[end]]]*/

/* c-basic-offset: 2; tab-width: 8; indent-tabs-mode: nil
 * vi: set shiftwidth=2 tabstop=8 expandtab:
 * :indentSize=2:tabSize=8:noTabs=true:
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/tap.h>
#include <epan/ptvcursor.h>

#include "packet-rtp.h"
#include "packet-tcp.h"
#include "packet-ssl.h"
#include "packet-skinny.h"

void proto_register_skinny(void);
void proto_reg_handoff_skinny(void);


#define TCP_PORT_SKINNY 2000
#define SSL_PORT_SKINNY 2443 /* IANA assigned to PowerClient Central Storage Facility */

#define BASIC_MSG_TYPE 0x00
#define V10_MSG_TYPE 0x0A
#define V11_MSG_TYPE 0x0B
#define V15_MSG_TYPE 0x0F
#define V16_MSG_TYPE 0x10
#define V17_MSG_TYPE 0x11
#define V18_MSG_TYPE 0x12
#define V19_MSG_TYPE 0x13
#define V20_MSG_TYPE 0x14
#define V21_MSG_TYPE 0x15
#define V22_MSG_TYPE 0x16

static const value_string header_version[] = {
  { BASIC_MSG_TYPE, "Basic" },
  { V10_MSG_TYPE,   "V10" },
  { V11_MSG_TYPE,   "V11" },
  { V15_MSG_TYPE,   "V15" },
  { V16_MSG_TYPE,   "V16" },
  { V17_MSG_TYPE,   "V17" },
  { V18_MSG_TYPE,   "V18" },
  { V19_MSG_TYPE,   "V19" },
  { V20_MSG_TYPE,   "V20" },
  { V21_MSG_TYPE,   "V21" },
  { V22_MSG_TYPE,   "V22" },
  { 0             , NULL }
};

/* Declare MessageId */
/* [[[cog
import sys
sys.path.append('tools/')

import parse_xml2skinny_dissector as xml2skinny
global skinny
global message_dissector_functions

message_dissector_functions = ''
skinny = xml2skinny.xml2obj(xmlfile)

cog.out('static const value_string  message_id[] = {\n')
for message in skinny.message:
    message_dissector_functions += '%s' %message.dissect()
    cog.out('  { %s, "%s" },\n' %(message.opcode, message.name.replace('Message','')))
cog.out('  {0     , NULL}\n')
cog.out('};\n')
cog.out('static value_string_ext message_id_ext = VALUE_STRING_EXT_INIT(message_id);\n')
]]]*/
/*[[[end]]]*/


/* Declare Enums and Defines */
/* [[[cog
for enum in skinny.enum:
    name = enum.name[0].upper() + enum.name[1:]
    if enum.define == "yes":
        for entries in enum.entries:
            for entry in sorted(entries.entry, key=lambda x: int(x['value'],0)):
                if entries.type is not None:
                    cog.out('#define {0:38} 0x{1:05x} /* {2} */\n' .format(entry.name.upper(), int(entry.value,0), entries.type))
                else:
                    cog.out('#define {0:38} 0x{1:05x}\n' .format(entry.name.upper(), int(entry.value,0)))
        cog.out('\n')
    cog.out('static const value_string %s[] = {\n' %(name))
    for entries in enum.entries:
        for entry in sorted(entries.entry, key=lambda x: int(x['value'],0)):
            if enum.define == "yes":
                cog.out('  { %s, "%s" },\n' %(entry.name.upper(), entry.text))
            else:
                cog.out('  { 0x%05x, "%s" },\n' %(int(entry.value,0), entry.text))
    cog.out('  { 0x00000, NULL }\n')
    cog.out('};\n')
    cog.out('static value_string_ext %s_ext = VALUE_STRING_EXT_INIT(%s);\n\n' %(name, name))
]]]*/
/*[[[end]]]*/

/* Staticly Declared Variables */
static int proto_skinny                 = -1;
static int hf_skinny_messageId          = -1;
static int hf_skinny_data_length        = -1;
static int hf_skinny_hdr_version        = -1;
static int hf_skinny_xmlData            = -1;
static int hf_skinny_ipv4or6            = -1;

/* [[[cog
for key in sorted(xml2skinny.fieldsArray.keys()):
    cog.out('static int hf_skinny_%s = -1;\n' %key)
]]]*/
/*[[[end]]]*/

static dissector_table_t media_type_dissector_table;

/* Initialize the subtree pointers */
static gint ett_skinny          = -1;
static gint ett_skinny_tree     = -1;

/* desegmentation of SCCP */
static gboolean skinny_desegment = TRUE;

/* tap register id */
static int skinny_tap = -1;

/* skinny protocol tap info */
#define MAX_SKINNY_MESSAGES_IN_PACKET 10
static skinny_info_t pi_arr[MAX_SKINNY_MESSAGES_IN_PACKET];
static int pi_current = 0;
static skinny_info_t *si;

dissector_handle_t skinny_handle;

/* Get the length of a single SCCP PDU */
static guint
get_skinny_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
{
  guint32 hdr_data_length;

  /* Get the length of the SCCP packet. */
  hdr_data_length = tvb_get_letohl(tvb, offset);

  /* That length doesn't include the length of the header itself. */
  return hdr_data_length + 8;
}

static void
dissect_skinny_xml(ptvcursor_t *cursor, int hfindex, packet_info *pinfo, guint32 length, guint32 maxlength)
{
  proto_item         *item       = NULL;
  proto_tree         *subtree    = NULL;
  dissector_handle_t handle      = NULL;
  proto_tree         *tree       = ptvcursor_tree(cursor);
  guint32            offset      = ptvcursor_current_offset(cursor);
  tvbuff_t           *tvb        = ptvcursor_tvbuff(cursor);
  tvbuff_t           *next_tvb;

  if (length == 0) {
    length = tvb_strnlen(tvb, offset, -1);
  }
  if (length >= maxlength) {
    length = maxlength;
  }

  ptvcursor_add_no_advance(cursor, hfindex, length, ENC_ASCII|ENC_NA);

  item = proto_tree_add_item(tree, hf_skinny_xmlData, tvb, offset, length, ENC_ASCII|ENC_NA);
  subtree = proto_item_add_subtree(item, 0);
  next_tvb = tvb_new_subset(tvb, offset, length, -1);
  handle = dissector_get_string_handle(media_type_dissector_table, "text/xml");
  if (handle != NULL) {
    call_dissector(handle, next_tvb, pinfo, subtree);
  }
  ptvcursor_advance(cursor, maxlength);
}

static void
dissect_skinny_ipv4or6(ptvcursor_t *cursor, int hfindex_ipv4, int hfindex_ipv6, packet_info *pinfo)
{
  address            src_addr;
  guint32            ipversion   = 0;
  guint32            offset      = ptvcursor_current_offset(cursor);
  tvbuff_t           *tvb        = ptvcursor_tvbuff(cursor);
  guint32            hdr_version = tvb_get_letohl(tvb, 4);
  gboolean           is_video    = FALSE;

  /* ProtocolVersion > 18 include and extra field to declare IPv4 (0) / IPv6 (1) */
  if (hdr_version >= V17_MSG_TYPE) {
    ipversion = tvb_get_letohl(tvb, offset);
    ptvcursor_add(cursor, hf_skinny_ipv4or6, 4, ENC_LITTLE_ENDIAN);
  }
  if (ipversion == IPADDRTYPE_IPV4) {
    guint32 ip_address;
    src_addr.type = AT_IPv4;
    src_addr.len = 4;
    src_addr.data = (guint8 *)&ip_address;
    ip_address = tvb_get_ipv4(tvb, offset);
    rtp_add_address(pinfo, &src_addr, tvb_get_letohl(tvb, offset), 0, "Skinny", pinfo->num, is_video, NULL);
    ptvcursor_add(cursor, hfindex_ipv4, 4, ENC_BIG_ENDIAN);
    if (hdr_version >= V17_MSG_TYPE) {
      /* skip over the extra room for ipv6 addresses */
      ptvcursor_advance(cursor, 12);
    }
  } else if (ipversion == IPADDRTYPE_IPV6 || ipversion == IPADDRTYPE_IPV4_V6) {
    struct e_in6_addr IPv6;
    src_addr.type = AT_IPv6;
    src_addr.len = 16;
    src_addr.data = (guint8 *)&IPv6;
    tvb_get_ipv6(tvb, offset, &IPv6);
    rtp_add_address(pinfo, &src_addr, tvb_get_letohl(tvb, offset), 0, "Skinny", pinfo->num, is_video, NULL);
    ptvcursor_add(cursor, hfindex_ipv6, 16, ENC_NA);
  } else {
    /* Invalid : skip over ipv6 space completely */
    ptvcursor_advance(cursor, 16);
  }
}

/**
 * Parse a displayLabel string and check if it is using any embedded labels, if so lookup the label and add a user readable translation to the item_tree
 */
static void
dissect_skinny_displayLabel(ptvcursor_t *cursor, int hfindex, gint length)
{
  proto_item    *item             = NULL;
  proto_tree    *tree             = ptvcursor_tree(cursor);
  guint32       offset            = ptvcursor_current_offset(cursor);
  tvbuff_t      *tvb              = ptvcursor_tvbuff(cursor);
  wmem_strbuf_t *wmem_new         = NULL;
  gchar         *disp_string      = NULL;
  const gchar   *replacestr       = NULL;
  gboolean      show_replaced_str = FALSE;
  gint          x                 = 0;

  if (length == 0) {
    length = tvb_strnlen(tvb, offset, -1);
    if (length == -1) {
      /* did not find end of string */
      length = tvb_captured_length_remaining(tvb, offset);
    }
  }

  item = proto_tree_add_item(tree, hfindex, tvb, offset, length, ENC_ASCII | ENC_NA);

  wmem_new = wmem_strbuf_sized_new(wmem_packet_scope(), length + 1, 0);
  disp_string = (gchar*) wmem_alloc(wmem_packet_scope(), length + 1);
  disp_string[length] = '\0';
  tvb_memcpy(tvb, (void*)disp_string, offset, length);

  for (x = 0; x < length && disp_string[x] != '\0'; x++) {
    replacestr = NULL;
    if (x + 1 < length) {
      if (disp_string[x] == '\36') {
        replacestr = try_val_to_str_ext(disp_string[x + 1], &DisplayLabels_36_ext);
      } else if (disp_string[x] == '\200') {
        replacestr = try_val_to_str_ext(disp_string[x + 1], &DisplayLabels_200_ext);
      }
    }
    if (replacestr) {
      x++;        /* swallow replaced characters */
      wmem_strbuf_append(wmem_new, replacestr);
      show_replaced_str = TRUE;
    } else {
      wmem_strbuf_append_c(wmem_new, disp_string[x]);
    }
  }
  if (show_replaced_str) {
    proto_item_append_text(item, " => \"%s\"" , wmem_strbuf_get_str(wmem_new));
  }
  ptvcursor_advance(cursor, length);
}

/*** Messages Handlers ***/

/* [[[cog
cog.out(message_dissector_functions)
]]]*/
/*[[[end]]]*/

/* Messages Handler Array */
/* [[[cog
cog.out('typedef void (*message_handler) (ptvcursor_t * cursor, packet_info *pinfo);\n')
cog.out('static const struct opcode2handler {\n')
cog.out('  guint16 opcode;\n');
cog.out('  message_handler handler;\n');
cog.out('  const char *name;\n');
cog.out('} skinny_opcode2handler[] = {\n')
for message in skinny.message:
    cog.out('  {%-6s, %-47s, "%s"},\n' %(message.opcode, message.gen_handler(), message.name))
cog.out('};\n')
]]]*/
/*[[[end]]]*/

/* Dissect a single SCCP PDU */
static int dissect_skinny_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
  guint    offset   = 0;
  /*gboolean is_video = FALSE;*/    /* FIX ME: need to indicate video or not */
  ptvcursor_t* cursor;

  /* Header fields */
  guint32  hdr_data_length;
  guint32  hdr_version;
  guint32  data_messageid;
  guint16  i;

  /* Set up structures we will need to add the protocol subtree and manage it */
  proto_tree *skinny_tree = NULL;
  proto_item *ti = NULL;

  /* Initialization */
  /*
  hdr_data_length = tvb_get_letohl(tvb, offset);
  hdr_version     = tvb_get_letohl(tvb, offset+4);
  data_messageid  = tvb_get_letohl(tvb, offset+8);
  */
  hdr_data_length = tvb_get_letohl(tvb, 0);
  hdr_version     = tvb_get_letohl(tvb, 4);
  data_messageid  = tvb_get_letohl(tvb, 8);

  /* Initialise stat info for passing to tap */
  pi_current++;
  if (pi_current == MAX_SKINNY_MESSAGES_IN_PACKET)
  {
    /* Overwrite info in first struct if run out of space... */
    pi_current = 0;
  }
  si = &pi_arr[pi_current];
  si->messId = data_messageid;
  si->messageName = val_to_str_ext(data_messageid, &message_id_ext, "0x%08X (Unknown)");
  si->callId = 0;
  si->lineId = 0;
  si->passThruId = 0;
  si->callState = 0;
  g_free(si->callingParty);
  si->callingParty = NULL;
  g_free(si->calledParty);
  si->calledParty = NULL;
  si->openreceiveStatus = 0;
  si->startmediatransmisionStatus = 0;

  /* In the interest of speed, if "tree" is NULL, don't do any work not
   * necessary to generate protocol tree items.
   */
  if (tree) {
    ti = proto_tree_add_item(tree, proto_skinny, tvb, offset, hdr_data_length+8, ENC_NA);
    skinny_tree = proto_item_add_subtree(ti, ett_skinny);
    proto_tree_add_uint(skinny_tree, hf_skinny_data_length, tvb, offset, 4, hdr_data_length);
    proto_tree_add_uint(skinny_tree, hf_skinny_hdr_version, tvb, offset+4, 4, hdr_version);
  }

  col_add_fstr(pinfo->cinfo, COL_INFO,"%s ", si->messageName);
  col_set_fence(pinfo->cinfo, COL_INFO);

  /*offset += 8;*/
  /*cursor = ptvcursor_new(skinny_tree, tvb, offset);*/

  proto_tree_add_uint(skinny_tree, hf_skinny_messageId, tvb,offset+8, 4, data_messageid );
  /*ptvcursor_add(cursor, hf_skinny_messageId, 4, data_messageid);*/

  offset += 12;
  cursor = ptvcursor_new(skinny_tree, tvb, offset);

  for (i = 0; i < sizeof(skinny_opcode2handler)/sizeof(struct opcode2handler) ; i++) {
    if (skinny_opcode2handler[i].opcode == data_messageid && skinny_opcode2handler[i].handler) {
      skinny_opcode2handler[i].handler(cursor, pinfo);
    }
  }
  ptvcursor_free(cursor);

  tap_queue_packet(skinny_tap, pinfo, si);
  return tvb_captured_length(tvb);
}

/* Code to actually dissect the packets */
static int
dissect_skinny(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
  /* The general structure of a packet: {IP-Header|TCP-Header|n*SKINNY}
   * SKINNY-Packet: {Header(Size, Reserved)|Data(MessageID, Message-Data)}
   */
  /* Header fields */
  guint32 hdr_data_length;
  guint32 hdr_version;

  /* check, if this is really an SKINNY packet, they start with a length + 0 */

  if (tvb_captured_length(tvb) < 8)
  {
    return 0;
  }
  /* get relevant header information */
  hdr_data_length = tvb_get_letohl(tvb, 0);
  hdr_version     = tvb_get_letohl(tvb, 4);

  /*  data_size       = MIN(8+hdr_data_length, tvb_length(tvb)) - 0xC; */

  if (
      (hdr_data_length < 4) ||
      ((hdr_version != BASIC_MSG_TYPE) &&
       (hdr_version != V10_MSG_TYPE) &&
       (hdr_version != V11_MSG_TYPE) &&
       (hdr_version != V15_MSG_TYPE) &&
       (hdr_version != V16_MSG_TYPE) &&
       (hdr_version != V17_MSG_TYPE) &&
       (hdr_version != V18_MSG_TYPE) &&
       (hdr_version != V19_MSG_TYPE) &&
       (hdr_version != V20_MSG_TYPE) &&
       (hdr_version != V21_MSG_TYPE) &&
       (hdr_version != V22_MSG_TYPE))
     )
  {
      /* Not an SKINNY packet, just happened to use the same port */
      return 0;
  }

  /* Make entries in Protocol column and Info column on summary display */
  col_set_str(pinfo->cinfo, COL_PROTOCOL, "SKINNY");

  col_set_str(pinfo->cinfo, COL_INFO, "Skinny Client Control Protocol");

  tcp_dissect_pdus(tvb, pinfo, tree, skinny_desegment, 4, get_skinny_pdu_len, dissect_skinny_pdu, data);

  return tvb_captured_length(tvb);
}

/* Register the protocol with Wireshark */
void
proto_register_skinny(void)
{
  /* Setup list of header fields */
  static hf_register_info hf[] = {
    { &hf_skinny_data_length,
      {
        "Data length", "skinny.data_length", FT_UINT32, BASE_DEC, NULL, 0x0,
        "Number of bytes in the data portion.", HFILL }},
    { &hf_skinny_hdr_version,
      {
        "Header version", "skinny.hdr_version", FT_UINT32, BASE_HEX, VALS(header_version), 0x0,
        NULL, HFILL }},
    { &hf_skinny_messageId,
      {
        "Message ID", "skinny.messageId", FT_UINT32, BASE_DEC|BASE_EXT_STRING, &message_id_ext, 0x0,
        NULL, HFILL }},
    { &hf_skinny_xmlData,
      {
        "XML data", "skinny.xmlData", FT_STRING, BASE_NONE, NULL, 0x0,
        NULL,  HFILL }},
    { &hf_skinny_ipv4or6,
      {
        "IPv4or6", "skinny.ipv4or6", FT_UINT32, BASE_DEC|BASE_EXT_STRING, &IpAddrType_ext, 0x0,
        NULL, HFILL }},
    /* [[[cog
    for valuestr in sorted(xml2skinny.fieldsArray.values()):
      cog.out('%s' %valuestr)
    ]]]*/
    /*[[[end]]]*/
  };

  /* Setup protocol subtree array */
  static gint *ett[] = {
    &ett_skinny,
    &ett_skinny_tree,
  };

  module_t *skinny_module;

  /* Register the protocol name and description */
  proto_skinny = proto_register_protocol("Skinny Client Control Protocol",
                                         "SKINNY", "skinny");

  /* Required function calls to register the header fields and subtrees used */
  proto_register_field_array(proto_skinny, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));

  skinny_module = prefs_register_protocol(proto_skinny, NULL);
  prefs_register_bool_preference(skinny_module, "desegment",
    "Reassemble SCCP messages spanning multiple TCP segments",
    "Whether the SCCP dissector should reassemble messages spanning multiple TCP segments."
    " To use this option, you must also enable"
    " \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
    &skinny_desegment);

  skinny_handle = register_dissector("skinny", dissect_skinny, proto_skinny);

  skinny_tap = register_tap("skinny");
}

void
proto_reg_handoff_skinny(void)
{
  /* Skinny content type and internet media type used by other dissectors are the same */
  media_type_dissector_table = find_dissector_table("media_type");
  dissector_add_uint("tcp.port", TCP_PORT_SKINNY, skinny_handle);
  ssl_dissector_add(SSL_PORT_SKINNY, skinny_handle);
}

/*
 * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 2
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=2 tabstop=8 expandtab:
 * :indentSize=2:tabSize=8:noTabs=true:
 */