src/libimcv/plugins/imc_scanner/imc_scanner.c

   1 /*
   2  * Copyright (C) 2011-2012 Andreas Steffen
   3  * HSR Hochschule fuer Technik Rapperswil
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation; either version 2 of the License, or (at your
   8  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * for more details.
  14  */
  15
  16 #include "imc_scanner_state.h"
  17
  18 #include <imc/imc_agent.h>
  19 #include <imc/imc_msg.h>
  20 #include <ietf/ietf_attr.h>
  21 #include <ietf/ietf_attr_attr_request.h>
  22 #include <ietf/ietf_attr_port_filter.h>
  23 #include <ietf/ietf_attr_remediation_instr.h>
  24
  25 #include <tncif_pa_subtypes.h>
  26
  27 #include <pen/pen.h>
  28 #include <utils/lexparser.h>
  29 #include <utils/debug.h>
  30
  31 #include <stdio.h>
  32
  33 /* IMC definitions */
  34
  35 static const char imc_name[] = "Scanner";
  36
  37 static pen_type_t msg_types[] = {
  38         { PEN_IETF, PA_SUBTYPE_IETF_VPN }
  39 };
  40
  41 static imc_agent_t *imc_scanner;
  42
  43 /**
  44  * see section 3.8.1 of TCG TNC IF-IMC Specification 1.3
  45  */
  46 TNC_Result TNC_IMC_Initialize(TNC_IMCID imc_id,
  47                                                           TNC_Version min_version,
  48                                                           TNC_Version max_version,
  49                                                           TNC_Version *actual_version)
  50 {
  51         if (imc_scanner)
  52         {
  53                 DBG1(DBG_IMC, "IMC \"%s\" has already been initialized", imc_name);
  54                 return TNC_RESULT_ALREADY_INITIALIZED;
  55         }
  56         imc_scanner = imc_agent_create(imc_name, msg_types, countof(msg_types),
  57                                                                    imc_id, actual_version);
  58         if (!imc_scanner)
  59         {
  60                 return TNC_RESULT_FATAL;
  61         }
  62         if (min_version > TNC_IFIMC_VERSION_1 || max_version < TNC_IFIMC_VERSION_1)
  63         {
  64                 DBG1(DBG_IMC, "no common IF-IMC version");
  65                 return TNC_RESULT_NO_COMMON_VERSION;
  66         }
  67         return TNC_RESULT_SUCCESS;
  68 }
  69
  70 /**
  71  * see section 3.8.2 of TCG TNC IF-IMC Specification 1.3
  72  */
  73 TNC_Result TNC_IMC_NotifyConnectionChange(TNC_IMCID imc_id,
  74                                                                                   TNC_ConnectionID connection_id,
  75                                                                                   TNC_ConnectionState new_state)
  76 {
  77         imc_state_t *state;
  78
  79         if (!imc_scanner)
  80         {
  81                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
  82                 return TNC_RESULT_NOT_INITIALIZED;
  83         }
  84         switch (new_state)
  85         {
  86                 case TNC_CONNECTION_STATE_CREATE:
  87                         state = imc_scanner_state_create(connection_id);
  88                         return imc_scanner->create_state(imc_scanner, state);
  89                 case TNC_CONNECTION_STATE_HANDSHAKE:
  90                         if (imc_scanner->change_state(imc_scanner, connection_id, new_state,
  91                                 &state) != TNC_RESULT_SUCCESS)
  92                         {
  93                                 return TNC_RESULT_FATAL;
  94                         }
  95                         state->set_result(state, imc_id,
  96                                                           TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
  97                         return TNC_RESULT_SUCCESS;
  98                 case TNC_CONNECTION_STATE_DELETE:
  99                         return imc_scanner->delete_state(imc_scanner, connection_id);
 100                 default:
 101                         return imc_scanner->change_state(imc_scanner, connection_id,
 102                                                                                          new_state, NULL);
 103         }
 104 }
 105
 106 /**
 107  * Determine all TCP and UDP server sockets listening on physical interfaces
 108  */
 109 static bool do_netstat(ietf_attr_port_filter_t *attr)
 110 {
 111         FILE *file;
 112         char buf[BUF_LEN];
 113         chunk_t line, token;
 114         int n = 0;
 115         bool success = FALSE;
 116         const char loopback_v4[] = "127.0.0.1";
 117         const char loopback_v6[] = "::1";
 118
 119         /* Open a pipe stream for reading the output of the netstat commmand */
 120         file = popen("/bin/netstat -n -l -p -4 -6 --inet", "r");
 121         if (!file)
 122         {
 123                 DBG1(DBG_IMC, "failed to run netstat command");
 124                 return FALSE;
 125         }
 126
 127         /* Read the output a line at a time */
 128         while (fgets(buf, sizeof(buf), file))
 129         {
 130                 u_char *pos;
 131                 u_int8_t new_protocol, protocol;
 132                 u_int16_t new_port, port;
 133                 int i;
 134                 enumerator_t *enumerator;
 135                 bool allowed, found = FALSE;
 136
 137                 DBG2(DBG_IMC, "%.*s", (int)(strlen(buf)-1), buf);
 138
 139                 if (n++ < 2)
 140                 {
 141                         /* skip the first two header lines */
 142                         continue;
 143                 }
 144                 line = chunk_create(buf, strlen(buf));
 145
 146                 /* Extract the IP protocol type */
 147                 if (!extract_token(&token, ' ', &line))
 148                 {
 149                         DBG1(DBG_IMC, "protocol field in netstat output not found");
 150                         goto end;
 151                 }
 152                 if (match("tcp", &token) || match("tcp6", &token))
 153                 {
 154                         new_protocol = IPPROTO_TCP;
 155                 }
 156                 else if (match("udp", &token) || match("udp6", &token))
 157                 {
 158                         new_protocol = IPPROTO_UDP;
 159                 }
 160                 else
 161                 {
 162                         DBG1(DBG_IMC, "skipped unknown IP protocol in netstat output");
 163                         continue;
 164                 }
 165
 166                 /* Skip the Recv-Q and Send-Q fields */
 167                 for (i = 0; i < 3; i++)
 168                 {
 169                         if (!eat_whitespace(&line) || !extract_token(&token, ' ', &line))
 170                         {
 171                                 token = chunk_empty;
 172                                 break;
 173                         }
 174                 }
 175                 if (token.len == 0)
 176                 {
 177                         DBG1(DBG_IMC, "local address field in netstat output not found");
 178                         goto end;
 179                 }
 180
 181                 /* Find the local port appended to the local address */
 182                 pos = token.ptr + token.len;
 183                 while (*--pos != ':' && --token.len);
 184                 if (*pos != ':')
 185                 {
 186                         DBG1(DBG_IMC, "local port field in netstat output not found");
 187                         goto end;
 188                 }
 189                 token.len--;
 190
 191                 /* ignore ports of IPv4 and IPv6 loopback interfaces */
 192                 if ((token.len == strlen(loopback_v4) &&
 193                                 memeq(loopback_v4, token.ptr, token.len)) ||
 194                         (token.len == strlen(loopback_v6) &&
 195                                 memeq(loopback_v6, token.ptr, token.len)))
 196                 {
 197                         continue;
 198                 }
 199
 200                 /* convert the port string to an integer */
 201                 new_port = atoi(pos+1);
 202
 203                 /* check if the there is already a port entry */
 204                 enumerator = attr->create_port_enumerator(attr);
 205                 while (enumerator->enumerate(enumerator, &allowed, &protocol, &port))
 206                 {
 207                         if (new_port == port && new_protocol == protocol)
 208                         {
 209                                 found = TRUE;
 210                         }
 211                 }
 212                 enumerator->destroy(enumerator);
 213
 214                 /* Skip the duplicate port entry */
 215                 if (found)
 216                 {
 217                         continue;
 218                 }
 219
 220                 /* Add new port entry */
 221                 attr->add_port(attr, FALSE, new_protocol, new_port);
 222         }
 223
 224         /* Successfully completed the parsing of the netstat output */
 225         success = TRUE;
 226
 227 end:
 228         /* Close the pipe stream */
 229         pclose(file);
 230         return success;
 231 }
 232
 233 /**
 234  * Add IETF Port Filter attribute to the send queue
 235  */
 236 static TNC_Result add_port_filter(imc_msg_t *msg)
 237 {
 238         pa_tnc_attr_t *attr;
 239         ietf_attr_port_filter_t *attr_port_filter;
 240
 241         attr = ietf_attr_port_filter_create();
 242         attr->set_noskip_flag(attr, TRUE);
 243         attr_port_filter = (ietf_attr_port_filter_t*)attr;
 244         if (!do_netstat(attr_port_filter))
 245         {
 246                 attr->destroy(attr);
 247                 return TNC_RESULT_FATAL;
 248         }
 249         msg->add_attribute(msg, attr);
 250
 251         return TNC_RESULT_SUCCESS;
 252 }
 253
 254 /**
 255  * see section 3.8.3 of TCG TNC IF-IMC Specification 1.3
 256  */
 257 TNC_Result TNC_IMC_BeginHandshake(TNC_IMCID imc_id,
 258                                                                   TNC_ConnectionID connection_id)
 259 {
 260         imc_state_t *state;
 261         imc_msg_t *out_msg;
 262         TNC_Result result = TNC_RESULT_SUCCESS;
 263
 264         if (!imc_scanner)
 265         {
 266                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 267                 return TNC_RESULT_NOT_INITIALIZED;
 268         }
 269         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 270         {
 271                 return TNC_RESULT_FATAL;
 272         }
 273         if (lib->settings->get_bool(lib->settings,
 274                                                                 "libimcv.plugins.imc-scanner.send_ports", TRUE))
 275         {
 276                 out_msg = imc_msg_create(imc_scanner, state, connection_id, imc_id,
 277                                                                  TNC_IMVID_ANY, msg_types[0]);
 278                 result = add_port_filter(out_msg);
 279                 if (result == TNC_RESULT_SUCCESS)
 280                 {
 281                         /* send PA-TNC message with the excl flag not set */
 282                         result = out_msg->send(out_msg, FALSE);
 283                 }
 284                 out_msg->destroy(out_msg);
 285         }
 286
 287         return result;
 288 }
 289
 290 static TNC_Result receive_message(imc_msg_t *in_msg)
 291 {
 292         imc_msg_t *out_msg;
 293         enumerator_t *enumerator;
 294         pa_tnc_attr_t *attr;
 295         pen_type_t attr_type;
 296         TNC_Result result = TNC_RESULT_SUCCESS;
 297         bool fatal_error = FALSE;
 298
 299         /* parse received PA-TNC message and handle local and remote errors */
 300         result = in_msg->receive(in_msg, &fatal_error);
 301         if (result != TNC_RESULT_SUCCESS)
 302         {
 303                 return result;
 304         }
 305         out_msg = imc_msg_create_as_reply(in_msg);
 306
 307         /* analyze PA-TNC attributes */
 308         enumerator = in_msg->create_attribute_enumerator(in_msg);
 309         while (enumerator->enumerate(enumerator, &attr))
 310         {
 311                 attr_type = attr->get_type(attr);
 312
 313                 if (attr_type.vendor_id != PEN_IETF)
 314                 {
 315                         continue;
 316                 }
 317                 if (attr_type.type == IETF_ATTR_ATTRIBUTE_REQUEST)
 318                 {
 319                         ietf_attr_attr_request_t *attr_cast;
 320                         pen_type_t *entry;
 321                         enumerator_t *e;
 322
 323                         attr_cast = (ietf_attr_attr_request_t*)attr;
 324
 325                         e = attr_cast->create_enumerator(attr_cast);
 326                         while (e->enumerate(e, &entry))
 327                         {
 328                                 if (entry->vendor_id != PEN_IETF)
 329                                 {
 330                                         continue;
 331                                 }
 332                                 switch (entry->type)
 333                                 {
 334                                         case IETF_ATTR_PORT_FILTER:
 335                                                 result = add_port_filter(out_msg);
 336                                                 break;
 337                                         default:
 338                                                 break;
 339                                 }
 340                         }
 341                         e->destroy(e);
 342                 }
 343                 else if (attr_type.type == IETF_ATTR_REMEDIATION_INSTRUCTIONS)
 344                 {
 345                         ietf_attr_remediation_instr_t *attr_cast;
 346                         pen_type_t parameters_type;
 347                         chunk_t parameters, string, lang_code;
 348
 349                         attr_cast = (ietf_attr_remediation_instr_t*)attr;
 350                         parameters_type = attr_cast->get_parameters_type(attr_cast);
 351                         parameters = attr_cast->get_parameters(attr_cast);
 352
 353                         if (parameters_type.vendor_id == PEN_IETF)
 354                         {
 355                                 switch (parameters_type.type)
 356                                 {
 357                                         case IETF_REMEDIATION_PARAMETERS_URI:
 358                                                 DBG1(DBG_IMC, "remediation uri: '%.*s'",
 359                                                                            parameters.len, parameters.ptr);
 360                                                 break;
 361                                         case IETF_REMEDIATION_PARAMETERS_STRING:
 362                                                 string = attr_cast->get_string(attr_cast, &lang_code);
 363                                                 DBG1(DBG_IMC, "remediation string: '%.*s' [%.*s]",
 364                                                                            string.len, string.ptr,
 365                                                                            lang_code.len, lang_code.ptr);
 366                                                 break;
 367                                         default:
 368                                                 DBG1(DBG_IMC, "remediation parameters %B", &parameters);
 369                                 }
 370                         }
 371                         else
 372                         {
 373                                 DBG1(DBG_IMC, "remediation parameters %B", &parameters);
 374                         }
 375                 }
 376         }
 377         enumerator->destroy(enumerator);
 378
 379         if (fatal_error)
 380         {
 381                 result = TNC_RESULT_FATAL;
 382         }
 383         else if (result == TNC_RESULT_SUCCESS)
 384         {
 385                 result = out_msg->send(out_msg, TRUE);
 386         }
 387         out_msg->destroy(out_msg);
 388
 389         return result;
 390 }
 391
 392 /**
 393  * see section 3.8.4 of TCG TNC IF-IMC Specification 1.3
 394
 395  */
 396 TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 397                                                                   TNC_ConnectionID connection_id,
 398                                                                   TNC_BufferReference msg,
 399                                                                   TNC_UInt32 msg_len,
 400                                                                   TNC_MessageType msg_type)
 401 {
 402         imc_state_t *state;
 403         imc_msg_t *in_msg;
 404         TNC_Result result;
 405
 406         if (!imc_scanner)
 407         {
 408                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 409                 return TNC_RESULT_NOT_INITIALIZED;
 410         }
 411         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 412         {
 413                 return TNC_RESULT_FATAL;
 414         }
 415
 416         in_msg = imc_msg_create_from_data(imc_scanner, state, connection_id,
 417                                                                           msg_type, chunk_create(msg, msg_len));
 418         result = receive_message(in_msg);
 419         in_msg->destroy(in_msg);
 420
 421         return result;
 422 }
 423
 424 /**
 425  * see section 3.8.6 of TCG TNC IF-IMV Specification 1.3
 426  */
 427 TNC_Result TNC_IMC_ReceiveMessageLong(TNC_IMCID imc_id,
 428                                                                           TNC_ConnectionID connection_id,
 429                                                                           TNC_UInt32 msg_flags,
 430                                                                           TNC_BufferReference msg,
 431                                                                           TNC_UInt32 msg_len,
 432                                                                           TNC_VendorID msg_vid,
 433                                                                           TNC_MessageSubtype msg_subtype,
 434                                                                           TNC_UInt32 src_imv_id,
 435                                                                           TNC_UInt32 dst_imc_id)
 436 {
 437         imc_state_t *state;
 438         imc_msg_t *in_msg;
 439         TNC_Result result;
 440
 441         if (!imc_scanner)
 442         {
 443                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 444                 return TNC_RESULT_NOT_INITIALIZED;
 445         }
 446         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 447         {
 448                 return TNC_RESULT_FATAL;
 449         }
 450         in_msg = imc_msg_create_from_long_data(imc_scanner, state, connection_id,
 451                                                                 src_imv_id, dst_imc_id, msg_vid, msg_subtype,
 452                                                                 chunk_create(msg, msg_len));
 453         result = receive_message(in_msg);
 454         in_msg->destroy(in_msg);
 455
 456         return result;
 457 }
 458
 459 /**
 460  * see section 3.8.7 of TCG TNC IF-IMC Specification 1.3
 461  */
 462 TNC_Result TNC_IMC_BatchEnding(TNC_IMCID imc_id,
 463                                                            TNC_ConnectionID connection_id)
 464 {
 465         if (!imc_scanner)
 466         {
 467                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 468                 return TNC_RESULT_NOT_INITIALIZED;
 469         }
 470         return TNC_RESULT_SUCCESS;
 471 }
 472
 473 /**
 474  * see section 3.8.8 of TCG TNC IF-IMC Specification 1.3
 475  */
 476 TNC_Result TNC_IMC_Terminate(TNC_IMCID imc_id)
 477 {
 478         if (!imc_scanner)
 479         {
 480                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 481                 return TNC_RESULT_NOT_INITIALIZED;
 482         }
 483         imc_scanner->destroy(imc_scanner);
 484         imc_scanner = NULL;
 485
 486         return TNC_RESULT_SUCCESS;
 487 }
 488
 489 /**
 490  * see section 4.2.8.1 of TCG TNC IF-IMC Specification 1.3
 491  */
 492 TNC_Result TNC_IMC_ProvideBindFunction(TNC_IMCID imc_id,
 493                                                                            TNC_TNCC_BindFunctionPointer bind_function)
 494 {
 495         if (!imc_scanner)
 496         {
 497                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 498                 return TNC_RESULT_NOT_INITIALIZED;
 499         }
 500         return imc_scanner->bind_functions(imc_scanner, bind_function);
 501 }