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 system_v4[]   = "127.0.1.1";
 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                    and the internal system IPv4 address */
 193                 if ((token.len == strlen(system_v4) &&
 194                                 memeq(system_v4, token.ptr, token.len)) ||
 195                         (token.len == strlen(loopback_v4) &&
 196                                 memeq(loopback_v4, token.ptr, token.len)) ||
 197                         (token.len == strlen(loopback_v6) &&
 198                                 memeq(loopback_v6, token.ptr, token.len)))
 199                 {
 200                         continue;
 201                 }
 202
 203                 /* convert the port string to an integer */
 204                 new_port = atoi(pos+1);
 205
 206                 /* check if the there is already a port entry */
 207                 enumerator = attr->create_port_enumerator(attr);
 208                 while (enumerator->enumerate(enumerator, &allowed, &protocol, &port))
 209                 {
 210                         if (new_port == port && new_protocol == protocol)
 211                         {
 212                                 found = TRUE;
 213                         }
 214                 }
 215                 enumerator->destroy(enumerator);
 216
 217                 /* Skip the duplicate port entry */
 218                 if (found)
 219                 {
 220                         continue;
 221                 }
 222
 223                 /* Add new port entry */
 224                 attr->add_port(attr, FALSE, new_protocol, new_port);
 225         }
 226
 227         /* Successfully completed the parsing of the netstat output */
 228         success = TRUE;
 229
 230 end:
 231         /* Close the pipe stream */
 232         pclose(file);
 233         return success;
 234 }
 235
 236 /**
 237  * Add IETF Port Filter attribute to the send queue
 238  */
 239 static TNC_Result add_port_filter(imc_msg_t *msg)
 240 {
 241         pa_tnc_attr_t *attr;
 242         ietf_attr_port_filter_t *attr_port_filter;
 243
 244         attr = ietf_attr_port_filter_create();
 245         attr->set_noskip_flag(attr, TRUE);
 246         attr_port_filter = (ietf_attr_port_filter_t*)attr;
 247         if (!do_netstat(attr_port_filter))
 248         {
 249                 attr->destroy(attr);
 250                 return TNC_RESULT_FATAL;
 251         }
 252         msg->add_attribute(msg, attr);
 253
 254         return TNC_RESULT_SUCCESS;
 255 }
 256
 257 /**
 258  * see section 3.8.3 of TCG TNC IF-IMC Specification 1.3
 259  */
 260 TNC_Result TNC_IMC_BeginHandshake(TNC_IMCID imc_id,
 261                                                                   TNC_ConnectionID connection_id)
 262 {
 263         imc_state_t *state;
 264         imc_msg_t *out_msg;
 265         TNC_Result result = TNC_RESULT_SUCCESS;
 266
 267         if (!imc_scanner)
 268         {
 269                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 270                 return TNC_RESULT_NOT_INITIALIZED;
 271         }
 272         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 273         {
 274                 return TNC_RESULT_FATAL;
 275         }
 276         if (lib->settings->get_bool(lib->settings,
 277                                                                 "libimcv.plugins.imc-scanner.push_info", TRUE))
 278         {
 279                 out_msg = imc_msg_create(imc_scanner, state, connection_id, imc_id,
 280                                                                  TNC_IMVID_ANY, msg_types[0]);
 281                 result = add_port_filter(out_msg);
 282                 if (result == TNC_RESULT_SUCCESS)
 283                 {
 284                         /* send PA-TNC message with the excl flag not set */
 285                         result = out_msg->send(out_msg, FALSE);
 286                 }
 287                 out_msg->destroy(out_msg);
 288         }
 289
 290         return result;
 291 }
 292
 293 static TNC_Result receive_message(imc_msg_t *in_msg)
 294 {
 295         imc_msg_t *out_msg;
 296         enumerator_t *enumerator;
 297         pa_tnc_attr_t *attr;
 298         pen_type_t attr_type;
 299         TNC_Result result = TNC_RESULT_SUCCESS;
 300         bool fatal_error = FALSE;
 301
 302         /* parse received PA-TNC message and handle local and remote errors */
 303         result = in_msg->receive(in_msg, &fatal_error);
 304         if (result != TNC_RESULT_SUCCESS)
 305         {
 306                 return result;
 307         }
 308         out_msg = imc_msg_create_as_reply(in_msg);
 309
 310         /* analyze PA-TNC attributes */
 311         enumerator = in_msg->create_attribute_enumerator(in_msg);
 312         while (enumerator->enumerate(enumerator, &attr))
 313         {
 314                 attr_type = attr->get_type(attr);
 315
 316                 if (attr_type.vendor_id != PEN_IETF)
 317                 {
 318                         continue;
 319                 }
 320                 if (attr_type.type == IETF_ATTR_ATTRIBUTE_REQUEST)
 321                 {
 322                         ietf_attr_attr_request_t *attr_cast;
 323                         pen_type_t *entry;
 324                         enumerator_t *e;
 325
 326                         attr_cast = (ietf_attr_attr_request_t*)attr;
 327
 328                         e = attr_cast->create_enumerator(attr_cast);
 329                         while (e->enumerate(e, &entry))
 330                         {
 331                                 if (entry->vendor_id != PEN_IETF)
 332                                 {
 333                                         continue;
 334                                 }
 335                                 switch (entry->type)
 336                                 {
 337                                         case IETF_ATTR_PORT_FILTER:
 338                                                 result = add_port_filter(out_msg);
 339                                                 break;
 340                                         default:
 341                                                 break;
 342                                 }
 343                         }
 344                         e->destroy(e);
 345                 }
 346         }
 347         enumerator->destroy(enumerator);
 348
 349         if (fatal_error)
 350         {
 351                 result = TNC_RESULT_FATAL;
 352         }
 353         else if (result == TNC_RESULT_SUCCESS)
 354         {
 355                 result = out_msg->send(out_msg, TRUE);
 356         }
 357         out_msg->destroy(out_msg);
 358
 359         return result;
 360 }
 361
 362 /**
 363  * see section 3.8.4 of TCG TNC IF-IMC Specification 1.3
 364
 365  */
 366 TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 367                                                                   TNC_ConnectionID connection_id,
 368                                                                   TNC_BufferReference msg,
 369                                                                   TNC_UInt32 msg_len,
 370                                                                   TNC_MessageType msg_type)
 371 {
 372         imc_state_t *state;
 373         imc_msg_t *in_msg;
 374         TNC_Result result;
 375
 376         if (!imc_scanner)
 377         {
 378                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 379                 return TNC_RESULT_NOT_INITIALIZED;
 380         }
 381         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 382         {
 383                 return TNC_RESULT_FATAL;
 384         }
 385
 386         in_msg = imc_msg_create_from_data(imc_scanner, state, connection_id,
 387                                                                           msg_type, chunk_create(msg, msg_len));
 388         result = receive_message(in_msg);
 389         in_msg->destroy(in_msg);
 390
 391         return result;
 392 }
 393
 394 /**
 395  * see section 3.8.6 of TCG TNC IF-IMV Specification 1.3
 396  */
 397 TNC_Result TNC_IMC_ReceiveMessageLong(TNC_IMCID imc_id,
 398                                                                           TNC_ConnectionID connection_id,
 399                                                                           TNC_UInt32 msg_flags,
 400                                                                           TNC_BufferReference msg,
 401                                                                           TNC_UInt32 msg_len,
 402                                                                           TNC_VendorID msg_vid,
 403                                                                           TNC_MessageSubtype msg_subtype,
 404                                                                           TNC_UInt32 src_imv_id,
 405                                                                           TNC_UInt32 dst_imc_id)
 406 {
 407         imc_state_t *state;
 408         imc_msg_t *in_msg;
 409         TNC_Result result;
 410
 411         if (!imc_scanner)
 412         {
 413                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 414                 return TNC_RESULT_NOT_INITIALIZED;
 415         }
 416         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 417         {
 418                 return TNC_RESULT_FATAL;
 419         }
 420         in_msg = imc_msg_create_from_long_data(imc_scanner, state, connection_id,
 421                                                                 src_imv_id, dst_imc_id, msg_vid, msg_subtype,
 422                                                                 chunk_create(msg, msg_len));
 423         result = receive_message(in_msg);
 424         in_msg->destroy(in_msg);
 425
 426         return result;
 427 }
 428
 429 /**
 430  * see section 3.8.7 of TCG TNC IF-IMC Specification 1.3
 431  */
 432 TNC_Result TNC_IMC_BatchEnding(TNC_IMCID imc_id,
 433                                                            TNC_ConnectionID connection_id)
 434 {
 435         if (!imc_scanner)
 436         {
 437                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 438                 return TNC_RESULT_NOT_INITIALIZED;
 439         }
 440         return TNC_RESULT_SUCCESS;
 441 }
 442
 443 /**
 444  * see section 3.8.8 of TCG TNC IF-IMC Specification 1.3
 445  */
 446 TNC_Result TNC_IMC_Terminate(TNC_IMCID imc_id)
 447 {
 448         if (!imc_scanner)
 449         {
 450                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 451                 return TNC_RESULT_NOT_INITIALIZED;
 452         }
 453         imc_scanner->destroy(imc_scanner);
 454         imc_scanner = NULL;
 455
 456         return TNC_RESULT_SUCCESS;
 457 }
 458
 459 /**
 460  * see section 4.2.8.1 of TCG TNC IF-IMC Specification 1.3
 461  */
 462 TNC_Result TNC_IMC_ProvideBindFunction(TNC_IMCID imc_id,
 463                                                                            TNC_TNCC_BindFunctionPointer bind_function)
 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 imc_scanner->bind_functions(imc_scanner, bind_function);
 471 }