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