src/libimcv/plugins/imc_scanner/imc_scanner.c

   1 /*
   2  * Copyright (C) 2011-2015 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_FIREWALL }
  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_DELETE:
  89                         return imc_scanner->delete_state(imc_scanner, connection_id);
  90                 default:
  91                         return imc_scanner->change_state(imc_scanner, connection_id,
  92                                                                                          new_state, NULL);
  93         }
  94 }
  95
  96 /**
  97  * Determine all TCP and UDP server sockets listening on physical interfaces
  98  */
  99 static bool do_netstat(ietf_attr_port_filter_t *attr)
 100 {
 101         FILE *file;
 102         char buf[BUF_LEN];
 103         chunk_t line, token;
 104         int n = 0;
 105         bool success = FALSE;
 106         const char system_v4[]   = "127.0.1.1";
 107         const char loopback_v4[] = "127.0.0.1";
 108         const char loopback_v6[] = "::1";
 109
 110         /* Open a pipe stream for reading the output of the netstat command */
 111         file = popen("/bin/netstat -n -l -p -4 -6 --inet", "r");
 112         if (!file)
 113         {
 114                 DBG1(DBG_IMC, "failed to run netstat command");
 115                 return FALSE;
 116         }
 117
 118         /* Read the output a line at a time */
 119         while (fgets(buf, sizeof(buf), file))
 120         {
 121                 u_char *pos;
 122                 uint8_t new_protocol, protocol;
 123                 uint16_t new_port, port;
 124                 int i;
 125                 enumerator_t *enumerator;
 126                 bool allowed, found = FALSE;
 127
 128                 DBG2(DBG_IMC, "%.*s", (int)(strlen(buf)-1), buf);
 129
 130                 if (n++ < 2)
 131                 {
 132                         /* skip the first two header lines */
 133                         continue;
 134                 }
 135                 line = chunk_create(buf, strlen(buf));
 136
 137                 /* Extract the IP protocol type */
 138                 if (!extract_token(&token, ' ', &line))
 139                 {
 140                         DBG1(DBG_IMC, "protocol field in netstat output not found");
 141                         goto end;
 142                 }
 143                 if (match("tcp", &token) || match("tcp6", &token))
 144                 {
 145                         new_protocol = IPPROTO_TCP;
 146                 }
 147                 else if (match("udp", &token) || match("udp6", &token))
 148                 {
 149                         new_protocol = IPPROTO_UDP;
 150                 }
 151                 else
 152                 {
 153                         DBG1(DBG_IMC, "skipped unknown IP protocol in netstat output");
 154                         continue;
 155                 }
 156
 157                 /* Skip the Recv-Q and Send-Q fields */
 158                 for (i = 0; i < 3; i++)
 159                 {
 160                         if (!eat_whitespace(&line) || !extract_token(&token, ' ', &line))
 161                         {
 162                                 token = chunk_empty;
 163                                 break;
 164                         }
 165                 }
 166                 if (token.len == 0)
 167                 {
 168                         DBG1(DBG_IMC, "local address field in netstat output not found");
 169                         goto end;
 170                 }
 171
 172                 /* Find the local port appended to the local address */
 173                 pos = token.ptr + token.len;
 174                 while (*--pos != ':' && --token.len);
 175                 if (*pos != ':')
 176                 {
 177                         DBG1(DBG_IMC, "local port field in netstat output not found");
 178                         goto end;
 179                 }
 180                 token.len--;
 181
 182                 /* ignore ports of IPv4 and IPv6 loopback interfaces
 183                    and the internal system IPv4 address */
 184                 if ((token.len == strlen(system_v4) &&
 185                                 memeq(system_v4, token.ptr, token.len)) ||
 186                         (token.len == strlen(loopback_v4) &&
 187                                 memeq(loopback_v4, token.ptr, token.len)) ||
 188                         (token.len == strlen(loopback_v6) &&
 189                                 memeq(loopback_v6, token.ptr, token.len)))
 190                 {
 191                         continue;
 192                 }
 193
 194                 /* convert the port string to an integer */
 195                 new_port = atoi(pos+1);
 196
 197                 /* check if the there is already a port entry */
 198                 enumerator = attr->create_port_enumerator(attr);
 199                 while (enumerator->enumerate(enumerator, &allowed, &protocol, &port))
 200                 {
 201                         if (new_port == port && new_protocol == protocol)
 202                         {
 203                                 found = TRUE;
 204                         }
 205                 }
 206                 enumerator->destroy(enumerator);
 207
 208                 /* Skip the duplicate port entry */
 209                 if (found)
 210                 {
 211                         continue;
 212                 }
 213
 214                 /* Add new port entry */
 215                 attr->add_port(attr, FALSE, new_protocol, new_port);
 216         }
 217
 218         /* Successfully completed the parsing of the netstat output */
 219         success = TRUE;
 220
 221 end:
 222         /* Close the pipe stream */
 223         pclose(file);
 224         return success;
 225 }
 226
 227 /**
 228  * Add IETF Port Filter attribute to the send queue
 229  */
 230 static TNC_Result add_port_filter(imc_msg_t *msg)
 231 {
 232         pa_tnc_attr_t *attr;
 233         ietf_attr_port_filter_t *attr_port_filter;
 234
 235         attr = ietf_attr_port_filter_create(pen_type_create(PEN_IETF,
 236                                                                                 IETF_ATTR_PORT_FILTER));
 237         attr->set_noskip_flag(attr, TRUE);
 238         attr_port_filter = (ietf_attr_port_filter_t*)attr;
 239         if (!do_netstat(attr_port_filter))
 240         {
 241                 attr->destroy(attr);
 242                 return TNC_RESULT_FATAL;
 243         }
 244         msg->add_attribute(msg, attr);
 245
 246         return TNC_RESULT_SUCCESS;
 247 }
 248
 249 /**
 250  * see section 3.8.3 of TCG TNC IF-IMC Specification 1.3
 251  */
 252 TNC_Result TNC_IMC_BeginHandshake(TNC_IMCID imc_id,
 253                                                                   TNC_ConnectionID connection_id)
 254 {
 255         imc_state_t *state;
 256         imc_msg_t *out_msg;
 257         TNC_Result result = TNC_RESULT_SUCCESS;
 258
 259         if (!imc_scanner)
 260         {
 261                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 262                 return TNC_RESULT_NOT_INITIALIZED;
 263         }
 264         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 265         {
 266                 return TNC_RESULT_FATAL;
 267         }
 268         if (lib->settings->get_bool(lib->settings,
 269                                                         "%s.plugins.imc-scanner.push_info", TRUE, lib->ns))
 270         {
 271                 out_msg = imc_msg_create(imc_scanner, state, connection_id, imc_id,
 272                                                                  TNC_IMVID_ANY, msg_types[0]);
 273                 result = add_port_filter(out_msg);
 274                 if (result == TNC_RESULT_SUCCESS)
 275                 {
 276                         /* send PA-TNC message with the excl flag not set */
 277                         result = out_msg->send(out_msg, FALSE);
 278                 }
 279                 out_msg->destroy(out_msg);
 280         }
 281
 282         return result;
 283 }
 284
 285 static TNC_Result receive_message(imc_msg_t *in_msg)
 286 {
 287         imc_msg_t *out_msg;
 288         enumerator_t *enumerator;
 289         pa_tnc_attr_t *attr;
 290         pen_type_t attr_type;
 291         TNC_Result result = TNC_RESULT_SUCCESS;
 292         bool fatal_error = FALSE;
 293
 294         /* generate an outgoing PA-TNC message - we might need it */
 295         out_msg = imc_msg_create_as_reply(in_msg);
 296
 297         /* parse received PA-TNC message and handle local and remote errors */
 298         result = in_msg->receive(in_msg, out_msg, &fatal_error);
 299         if (result != TNC_RESULT_SUCCESS)
 300         {
 301                 out_msg->destroy(out_msg);
 302                 return result;
 303         }
 304
 305         /* analyze PA-TNC attributes */
 306         enumerator = in_msg->create_attribute_enumerator(in_msg);
 307         while (enumerator->enumerate(enumerator, &attr))
 308         {
 309                 attr_type = attr->get_type(attr);
 310
 311                 if (attr_type.vendor_id != PEN_IETF)
 312                 {
 313                         continue;
 314                 }
 315                 if (attr_type.type == IETF_ATTR_ATTRIBUTE_REQUEST)
 316                 {
 317                         ietf_attr_attr_request_t *attr_cast;
 318                         pen_type_t *entry;
 319                         enumerator_t *e;
 320
 321                         attr_cast = (ietf_attr_attr_request_t*)attr;
 322
 323                         e = attr_cast->create_enumerator(attr_cast);
 324                         while (e->enumerate(e, &entry))
 325                         {
 326                                 if (entry->vendor_id != PEN_IETF)
 327                                 {
 328                                         continue;
 329                                 }
 330                                 switch (entry->type)
 331                                 {
 332                                         case IETF_ATTR_PORT_FILTER:
 333                                                 result = add_port_filter(out_msg);
 334                                                 break;
 335                                         default:
 336                                                 break;
 337                                 }
 338                         }
 339                         e->destroy(e);
 340                 }
 341         }
 342         enumerator->destroy(enumerator);
 343
 344         if (fatal_error)
 345         {
 346                 result = TNC_RESULT_FATAL;
 347         }
 348         else if (result == TNC_RESULT_SUCCESS)
 349         {
 350                 /* send PA-TNC message with the EXCL flag set */
 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 }