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 <pa_tnc/pa_tnc_msg.h>
  20 #include <ietf/ietf_attr.h>
  21 #include <ietf/ietf_attr_pa_tnc_error.h>
  22 #include <ietf/ietf_attr_port_filter.h>
  23 #include <ietf/ietf_attr_assess_result.h>
  24
  25 #include <tncif_pa_subtypes.h>
  26
  27 #include <pen/pen.h>
  28 #include <utils/lexparser.h>
  29 #include <debug.h>
  30
  31 #include <stdio.h>
  32
  33 /* IMC definitions */
  34
  35 static const char imc_name[] = "Scanner";
  36
  37 #define IMC_VENDOR_ID   PEN_ITA
  38 #define IMC_SUBTYPE             PA_SUBTYPE_ITA_SCANNER
  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, IMC_VENDOR_ID, IMC_SUBTYPE,
  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, BUF_LEN-1, 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", 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 static TNC_Result send_message(TNC_ConnectionID connection_id)
 233 {
 234         linked_list_t *attr_list;
 235         pa_tnc_attr_t *attr;
 236         ietf_attr_port_filter_t *attr_port_filter;
 237         TNC_Result result;
 238
 239         attr = ietf_attr_port_filter_create();
 240         attr->set_noskip_flag(attr, TRUE);
 241         attr_port_filter = (ietf_attr_port_filter_t*)attr;
 242         if (!do_netstat(attr_port_filter))
 243         {
 244                 attr->destroy(attr);
 245                 return TNC_RESULT_FATAL;
 246         }
 247         attr_list = linked_list_create();
 248         attr_list->insert_last(attr_list, attr);
 249         result = imc_scanner->send_message(imc_scanner, connection_id, FALSE, 0,
 250                                                                            TNC_IMVID_ANY, attr_list);
 251         attr_list->destroy(attr_list);
 252
 253         return result;
 254 }
 255
 256 /**
 257  * see section 3.8.3 of TCG TNC IF-IMC Specification 1.3
 258  */
 259 TNC_Result TNC_IMC_BeginHandshake(TNC_IMCID imc_id,
 260                                                                   TNC_ConnectionID connection_id)
 261 {
 262         if (!imc_scanner)
 263         {
 264                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 265                 return TNC_RESULT_NOT_INITIALIZED;
 266         }
 267         return send_message(connection_id);
 268 }
 269
 270 static TNC_Result receive_message(TNC_IMCID imc_id,
 271                                                                   TNC_ConnectionID connection_id,
 272                                                                   TNC_UInt32 msg_flags,
 273                                                                   chunk_t msg,
 274                                                                   TNC_VendorID msg_vid,
 275                                                                   TNC_MessageSubtype msg_subtype,
 276                                                                   TNC_UInt32 src_imv_id,
 277                                                                   TNC_UInt32 dst_imc_id)
 278 {
 279         pa_tnc_msg_t *pa_tnc_msg;
 280         pa_tnc_attr_t *attr;
 281         pen_type_t attr_type;
 282         imc_state_t *state;
 283         enumerator_t *enumerator;
 284         TNC_Result result;
 285         TNC_UInt32 target_imc_id;
 286         bool fatal_error;
 287
 288         if (!imc_scanner)
 289         {
 290                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 291                 return TNC_RESULT_NOT_INITIALIZED;
 292         }
 293
 294         /* get current IMC state */
 295         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 296         {
 297                 return TNC_RESULT_FATAL;
 298         }
 299
 300         /* parse received PA-TNC message and automatically handle any errors */
 301         result = imc_scanner->receive_message(imc_scanner, state, msg, msg_vid,
 302                                                         msg_subtype, src_imv_id, dst_imc_id, &pa_tnc_msg);
 303
 304         /* no parsed PA-TNC attributes available if an error occurred */
 305         if (!pa_tnc_msg)
 306         {
 307                 return result;
 308         }
 309         target_imc_id = (dst_imc_id == TNC_IMCID_ANY) ? imc_id : dst_imc_id;
 310
 311         /* preprocess any IETF standard error attributes */
 312         fatal_error = pa_tnc_msg->process_ietf_std_errors(pa_tnc_msg);
 313
 314         /* analyze PA-TNC attributes */
 315         enumerator = pa_tnc_msg->create_attribute_enumerator(pa_tnc_msg);
 316         while (enumerator->enumerate(enumerator, &attr))
 317         {
 318                 attr_type = attr->get_type(attr);
 319
 320                 if (attr_type.vendor_id == PEN_IETF &&
 321                         attr_type.type == IETF_ATTR_ASSESSMENT_RESULT)
 322                 {
 323                         ietf_attr_assess_result_t *ietf_attr;
 324
 325                         ietf_attr = (ietf_attr_assess_result_t*)attr;
 326                         state->set_result(state, target_imc_id,
 327                                                           ietf_attr->get_result(ietf_attr));
 328                 }
 329         }
 330         enumerator->destroy(enumerator);
 331         pa_tnc_msg->destroy(pa_tnc_msg);
 332
 333         if (fatal_error)
 334         {
 335                 return TNC_RESULT_FATAL;
 336         }
 337
 338         /* if no assessment result is known then repeat the measurement */
 339         return state->get_result(state, target_imc_id, NULL) ?
 340                    TNC_RESULT_SUCCESS : send_message(connection_id);
 341 }
 342
 343 /**
 344  * see section 3.8.4 of TCG TNC IF-IMC Specification 1.3
 345
 346  */
 347 TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 348                                                                   TNC_ConnectionID connection_id,
 349                                                                   TNC_BufferReference msg,
 350                                                                   TNC_UInt32 msg_len,
 351                                                                   TNC_MessageType msg_type)
 352 {
 353         TNC_VendorID msg_vid;
 354         TNC_MessageSubtype msg_subtype;
 355
 356         msg_vid = msg_type >> 8;
 357         msg_subtype = msg_type & TNC_SUBTYPE_ANY;
 358
 359         return receive_message(imc_id, connection_id, 0, chunk_create(msg, msg_len),
 360                                                    msg_vid,     msg_subtype, 0, TNC_IMCID_ANY);
 361 }
 362
 363 /**
 364  * see section 3.8.6 of TCG TNC IF-IMV Specification 1.3
 365  */
 366 TNC_Result TNC_IMC_ReceiveMessageLong(TNC_IMCID imc_id,
 367                                                                           TNC_ConnectionID connection_id,
 368                                                                           TNC_UInt32 msg_flags,
 369                                                                           TNC_BufferReference msg,
 370                                                                           TNC_UInt32 msg_len,
 371                                                                           TNC_VendorID msg_vid,
 372                                                                           TNC_MessageSubtype msg_subtype,
 373                                                                           TNC_UInt32 src_imv_id,
 374                                                                           TNC_UInt32 dst_imc_id)
 375 {
 376         return receive_message(imc_id, connection_id, msg_flags,
 377                                                    chunk_create(msg, msg_len), msg_vid, msg_subtype,
 378                                                    src_imv_id, dst_imc_id);
 379 }
 380
 381 /**
 382  * see section 3.8.7 of TCG TNC IF-IMC Specification 1.3
 383  */
 384 TNC_Result TNC_IMC_BatchEnding(TNC_IMCID imc_id,
 385                                                            TNC_ConnectionID connection_id)
 386 {
 387         if (!imc_scanner)
 388         {
 389                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 390                 return TNC_RESULT_NOT_INITIALIZED;
 391         }
 392         return TNC_RESULT_SUCCESS;
 393 }
 394
 395 /**
 396  * see section 3.8.8 of TCG TNC IF-IMC Specification 1.3
 397  */
 398 TNC_Result TNC_IMC_Terminate(TNC_IMCID imc_id)
 399 {
 400         if (!imc_scanner)
 401         {
 402                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 403                 return TNC_RESULT_NOT_INITIALIZED;
 404         }
 405         imc_scanner->destroy(imc_scanner);
 406         imc_scanner = NULL;
 407
 408         return TNC_RESULT_SUCCESS;
 409 }
 410
 411 /**
 412  * see section 4.2.8.1 of TCG TNC IF-IMC Specification 1.3
 413  */
 414 TNC_Result TNC_IMC_ProvideBindFunction(TNC_IMCID imc_id,
 415                                                                            TNC_TNCC_BindFunctionPointer bind_function)
 416 {
 417         if (!imc_scanner)
 418         {
 419                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 420                 return TNC_RESULT_NOT_INITIALIZED;
 421         }
 422         return imc_scanner->bind_functions(imc_scanner, bind_function);
 423 }