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packet-pres-template.c

/* packet-pres.c
 * Routine to dissect ISO 8823 OSI Presentation Protocol packets
 * Based on the dissector by 
 * Yuriy Sidelnikov <YSidelnikov@hotmail.com>
 *
 * $Id: packet-pres-template.c 27719 2009-03-13 22:21:22Z stig $
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <glib.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/conversation.h>
#include <epan/emem.h>
#include <epan/expert.h>
#include <epan/uat.h>

#include <stdio.h>
#include <string.h>

#include <epan/asn1.h>
#include <epan/oids.h>
#include "packet-ber.h"
#include "packet-ses.h"
#include "packet-pres.h"
#include "packet-rtse.h"


#define PNAME  "ISO 8823 OSI Presentation Protocol"
#define PSNAME "PRES"
#define PFNAME "pres"

/* Initialize the protocol and registered fields */
int proto_pres = -1;

/*   type of session envelop */
static struct SESSION_DATA_STRUCTURE* session = NULL;

/*      pointers for acse dissector  */
proto_tree *global_tree  = NULL;
packet_info *global_pinfo = NULL;

static const char *abstract_syntax_name_oid;
static guint32 presentation_context_identifier;

/* to keep track of presentation context identifiers and protocol-oids */
typedef struct _pres_ctx_oid_t {
      guint32 ctx_id;
      char *oid;
      guint32 index;
} pres_ctx_oid_t;
static GHashTable *pres_ctx_oid_table = NULL;

typedef struct _pres_user_t {
   guint ctx_id;
   char *oid;
} pres_user_t;

static pres_user_t *pres_users;
static guint num_pres_users;

static int hf_pres_CP_type = -1;
static int hf_pres_CPA_PPDU = -1;
static int hf_pres_Abort_type = -1;
static int hf_pres_CPR_PPDU = -1;
static int hf_pres_Typed_data_type = -1;

#include "packet-pres-hf.c"

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

#include "packet-pres-ett.c"

UAT_DEC_CB_DEF(pres_users, ctx_id, pres_user_t)
UAT_CSTRING_CB_DEF(pres_users, oid, pres_user_t)

static guint
pres_ctx_oid_hash(gconstpointer k)
{
      pres_ctx_oid_t *pco=(pres_ctx_oid_t *)k;
      return pco->ctx_id;
}

static gint
pres_ctx_oid_equal(gconstpointer k1, gconstpointer k2)
{
      pres_ctx_oid_t *pco1=(pres_ctx_oid_t *)k1;
      pres_ctx_oid_t *pco2=(pres_ctx_oid_t *)k2;
      return (pco1->ctx_id==pco2->ctx_id && pco1->index==pco2->index);
}

static void
pres_init(void)
{
      if( pres_ctx_oid_table ){
            g_hash_table_destroy(pres_ctx_oid_table);
            pres_ctx_oid_table = NULL;
      }
      pres_ctx_oid_table = g_hash_table_new(pres_ctx_oid_hash,
                  pres_ctx_oid_equal);

}

static void
register_ctx_id_and_oid(packet_info *pinfo _U_, guint32 idx, const char *oid)
{
      pres_ctx_oid_t *pco, *tmppco;
      conversation_t *conversation;

      if(!oid){
            /* we did not get any oid name, malformed packet? */
            return;
      }

      pco=se_alloc(sizeof(pres_ctx_oid_t));
      pco->ctx_id=idx;
      pco->oid=se_strdup(oid);
      conversation=find_conversation (pinfo->fd->num, &pinfo->src, &pinfo->dst, 
                  pinfo->ptype, pinfo->srcport, pinfo->destport, 0);
      if (conversation) {
            pco->index = conversation->index;
      } else {
            pco->index = 0;
      }

      /* if this ctx already exists, remove the old one first */
      tmppco=(pres_ctx_oid_t *)g_hash_table_lookup(pres_ctx_oid_table, pco);
      if(tmppco){
            g_hash_table_remove(pres_ctx_oid_table, tmppco);

      }
      g_hash_table_insert(pres_ctx_oid_table, pco, pco);
}

char *
find_oid_by_pres_ctx_id(packet_info *pinfo _U_, guint32 idx)
{
      pres_ctx_oid_t pco, *tmppco;
      conversation_t *conversation;

      pco.ctx_id=idx;
      conversation=find_conversation (pinfo->fd->num, &pinfo->src, &pinfo->dst, 
                  pinfo->ptype, pinfo->srcport, pinfo->destport, 0);
      if (conversation) {
            pco.index = conversation->index;
      } else {
            pco.index = 0;
      }

      tmppco=(pres_ctx_oid_t *)g_hash_table_lookup(pres_ctx_oid_table, &pco);
      if(tmppco){
            return tmppco->oid;
      }
      return NULL;
}

static void *
pres_copy_cb(void *dest, const void *orig, unsigned len _U_)
{
      pres_user_t *u = dest;
      const pres_user_t *o = orig;

      u->ctx_id = o->ctx_id;
      u->oid = g_strdup(o->oid);

      return dest;
}

static void
pres_free_cb(void *r)
{
      pres_user_t *u = r;

      g_free(u->oid);
}

static gboolean
pres_try_users_table(guint32 ctx_id, tvbuff_t *tvb, int offset, packet_info *pinfo)
{
      tvbuff_t *next_tvb;
      guint i;
   
      for (i = 0; i < num_pres_users; i++) {
            pres_user_t *u = &(pres_users[i]);

            if (u->ctx_id == ctx_id) {
                  /* Register oid so other dissectors can find this connection */
                  register_ctx_id_and_oid(pinfo, u->ctx_id, u->oid);
                  next_tvb = tvb_new_subset(tvb, offset, -1, -1);
                  call_ber_oid_callback(u->oid, next_tvb, offset, pinfo, global_tree);
                  return TRUE;
            }
      }

      return FALSE;
}


#include "packet-pres-fn.c"


/*
 * Dissect an PPDU.
 */
static int
dissect_ppdu(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
{
      proto_item *ti;
      proto_tree *pres_tree = NULL;
      guint s_type;
      asn1_ctx_t asn1_ctx;
      asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);

      /* do we have spdu type from the session dissector?  */
      if( !pinfo->private_data ){
            if(tree){
                  proto_tree_add_text(tree, tvb, offset, -1,
                        "Internal error:can't get spdu type from session dissector.");
                  return  FALSE;
            }
      }else{
            session  = ( (struct SESSION_DATA_STRUCTURE*)(pinfo->private_data) );
            if(session->spdu_type == 0 ){
                  if(tree){
                        proto_tree_add_text(tree, tvb, offset, -1,
                              "Internal error:wrong spdu type %x from session dissector.",session->spdu_type);
                        return  FALSE;
                  }
            }
      }
      /* get type of tag */
      s_type = tvb_get_guint8(tvb, offset);
      /*  set up type of Ppdu */
      if (check_col(pinfo->cinfo, COL_INFO))
            col_add_str(pinfo->cinfo, COL_INFO,
                      val_to_str(session->spdu_type, ses_vals, "Unknown Ppdu type (0x%02x)"));
      if (tree){
            ti = proto_tree_add_item(tree, proto_pres, tvb, offset, -1, FALSE);
            pres_tree = proto_item_add_subtree(ti, ett_pres);
      }

      switch(session->spdu_type){
            case SES_CONNECTION_REQUEST:
                  offset = dissect_pres_CP_type(FALSE, tvb, offset, &asn1_ctx, pres_tree, hf_pres_CP_type);
                  break;
            case SES_CONNECTION_ACCEPT:
                  offset = dissect_pres_CPA_PPDU(FALSE, tvb, offset, &asn1_ctx, pres_tree, hf_pres_CPA_PPDU);
                  break;
            case SES_ABORT:
            case SES_ABORT_ACCEPT:
                  offset = dissect_pres_Abort_type(FALSE, tvb, offset, &asn1_ctx, pres_tree, hf_pres_Abort_type);
                  break;
            case SES_DATA_TRANSFER:
                  offset = dissect_pres_CPC_type(FALSE, tvb, offset, &asn1_ctx, pres_tree, hf_pres_user_data);
                  break;
            case SES_TYPED_DATA:
                  offset = dissect_pres_Typed_data_type(FALSE, tvb, offset, &asn1_ctx, pres_tree, hf_pres_Typed_data_type);
                  break;
            case SES_RESYNCHRONIZE:
                  offset = dissect_pres_RS_PPDU(FALSE, tvb, offset, &asn1_ctx, pres_tree, -1);
                  break;
            case SES_RESYNCHRONIZE_ACK:
                  offset = dissect_pres_RSA_PPDU(FALSE, tvb, offset, &asn1_ctx, pres_tree, -1);
                  break;
            case SES_REFUSE:
                  offset = dissect_pres_CPR_PPDU(FALSE, tvb, offset, &asn1_ctx, pres_tree, hf_pres_CPR_PPDU);
                  break;
            default:
                  offset = dissect_pres_CPC_type(FALSE, tvb, offset, &asn1_ctx, pres_tree, hf_pres_user_data);
                  break;
      }

      return offset;
}

void
dissect_pres(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
{
      int offset = 0, old_offset;

      /* first, try to check length   */
      /* do we have at least 4 bytes  */
      if (!tvb_bytes_exist(tvb, 0, 4)){
            session = ((struct SESSION_DATA_STRUCTURE*)(pinfo->private_data));
            if (session && session->spdu_type != SES_MAJOR_SYNC_POINT) {
                  proto_tree_add_text(parent_tree, tvb, offset, 
                                  tvb_reported_length_remaining(tvb,offset),"User data");
                  return;  /* no, it isn't a presentation PDU */
            }
      }

      /*  we can't make any additional checking here   */
      /*  postpone it before dissector will have more information */

      if (check_col(pinfo->cinfo, COL_PROTOCOL))
            col_set_str(pinfo->cinfo, COL_PROTOCOL, "PRES");
      if (check_col(pinfo->cinfo, COL_INFO))
            col_clear(pinfo->cinfo, COL_INFO);
      /* save pointers for calling the acse dissector  */
      global_tree = parent_tree;
      global_pinfo = pinfo;

      if (session && session->spdu_type == SES_MAJOR_SYNC_POINT) {
            /* This is a reassembly initiated in packet-ses */
            char *oid = find_oid_by_pres_ctx_id (pinfo, session->pres_ctx_id);
            if (oid) {
                  call_ber_oid_callback (oid, tvb, offset, pinfo, parent_tree);
            } else {
                  proto_tree_add_text(parent_tree, tvb, offset, 
                                  tvb_reported_length_remaining(tvb,offset),"User data");
            }
            return;
         }
            
      while (tvb_reported_length_remaining(tvb, offset) > 0){
            old_offset = offset;
            offset = dissect_ppdu(tvb, offset, pinfo, parent_tree);
            if(offset <= old_offset){
                  proto_tree_add_text(parent_tree, tvb, offset, -1,"Invalid offset");
                  THROW(ReportedBoundsError);
            }
      }
}


/*--- proto_register_pres -------------------------------------------*/
void proto_register_pres(void) {

  /* List of fields */
  static hf_register_info hf[] = {
    { &hf_pres_CP_type,
      { "CP-type", "pres.cptype",
        FT_NONE, BASE_NONE, NULL, 0,
        "", HFILL }},
    { &hf_pres_CPA_PPDU,
      { "CPA-PPDU", "pres.cpapdu",
        FT_NONE, BASE_NONE, NULL, 0,
        "", HFILL }},
    { &hf_pres_Abort_type,
      { "Abort type", "pres.aborttype",
        FT_UINT32, BASE_DEC, VALS(pres_Abort_type_vals), 0,
        "", HFILL }},
    { &hf_pres_CPR_PPDU,
      { "CPR-PPDU", "pres.cprtype",
        FT_UINT32, BASE_DEC, VALS(pres_CPR_PPDU_vals), 0,
        "", HFILL }},
    { &hf_pres_Typed_data_type,
      { "Typed data type", "pres.Typed_data_type",
        FT_UINT32, BASE_DEC, VALS(pres_Typed_data_type_vals), 0,
        "", HFILL }},


#include "packet-pres-hfarr.c"
  };

  /* List of subtrees */
  static gint *ett[] = {
            &ett_pres,
#include "packet-pres-ettarr.c"
  };
  
  static uat_field_t users_flds[] = {
    UAT_FLD_DEC(pres_users,ctx_id,"Context Id","Presentation Context Identifier"),
    UAT_FLD_CSTRING(pres_users,oid,"Syntax Name OID","Abstract Syntax Name (Object Identifier)"),
    UAT_END_FIELDS
  };

  uat_t* users_uat = uat_new("PRES Users Context List",
                             sizeof(pres_user_t),
                             "pres_context_list",
                             TRUE,
                             (void**) &pres_users,
                             &num_pres_users,
                             UAT_CAT_PORTS,
                             "ChPresContextList",
                             pres_copy_cb,
                             NULL,
                             pres_free_cb,
                             users_flds);
  
  static module_t *pres_module;
  
  /* Register protocol */
  proto_pres = proto_register_protocol(PNAME, PSNAME, PFNAME);
  register_dissector("pres", dissect_pres, proto_pres);
  /* Register fields and subtrees */
  proto_register_field_array(proto_pres, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));
  register_init_routine(pres_init);

  pres_module = prefs_register_protocol(proto_pres, NULL);

  prefs_register_uat_preference(pres_module, "users_table", "Users Context List",
                                "A table that enumerates user protocols to be used against"
                                " specific presentation context identifiers",
                                users_uat);
}


/*--- proto_reg_handoff_pres ---------------------------------------*/
void proto_reg_handoff_pres(void) {

/*    register_ber_oid_dissector("0.4.0.0.1.1.1.1", dissect_pres, proto_pres, 
        "itu-t(0) identified-organization(4) etsi(0) mobileDomain(0) gsm-Network(1) abstractSyntax(1) pres(1) version1(1)"); */

}

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