src/libimcv/plugins/imv_scanner/imv_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 "imv_scanner_state.h"
  17
  18 #include <imv/imv_agent.h>
  19 #include <imv/imv_msg.h>
  20 #include <ietf/ietf_attr.h>
  21 #include <ietf/ietf_attr_attr_request.h>
  22 #include <ietf/ietf_attr_pa_tnc_error.h>
  23 #include <ietf/ietf_attr_port_filter.h>
  24
  25 #include <tncif_names.h>
  26 #include <tncif_pa_subtypes.h>
  27
  28 #include <pen/pen.h>
  29 #include <collections/linked_list.h>
  30 #include <utils/lexparser.h>
  31 #include <utils/debug.h>
  32
  33 /* IMV definitions */
  34
  35 static const char imv_name[] = "Scanner";
  36
  37 static pen_type_t msg_types[] = {
  38         { PEN_IETF, PA_SUBTYPE_IETF_VPN }
  39 };
  40
  41 static imv_agent_t *imv_scanner;
  42
  43 typedef struct port_range_t port_range_t;
  44
  45 struct port_range_t {
  46         u_int16_t start, stop;
  47 };
  48
  49
  50 /**
  51  * Default port policy
  52  *
  53  * TRUE:  all server ports on the TNC client must be closed
  54  * FALSE: any server port on the TNC client is allowed to be open
  55  */
  56 static bool closed_port_policy = TRUE;
  57
  58 /**
  59  * List of TCP and UDP port ranges
  60  *
  61  * TRUE:  server ports on the TNC client that are allowed to be open
  62  * FALSE: server ports on the TNC client that must be closed
  63  */
  64 static linked_list_t *tcp_ports, *udp_ports;
  65
  66 /**
  67  * Get a TCP or UDP port list from strongswan.conf
  68  */
  69 static linked_list_t* get_port_list(char *label)
  70 {
  71         char key[40], *value;
  72         linked_list_t *list;
  73         chunk_t port_list, port_item, port_start;
  74         port_range_t *port_range;
  75
  76         list = linked_list_create();
  77
  78         snprintf(key, sizeof(key), "libimcv.plugins.imv-scanner.%s_ports", label);
  79         value = lib->settings->get_str(lib->settings, key, NULL);
  80         if (!value)
  81         {
  82                 DBG1(DBG_IMV, "%s not defined", key);
  83                 return list;
  84         }
  85         port_list = chunk_create(value, strlen(value));
  86         DBG2(DBG_IMV, "list of %s ports that %s:", label,
  87                  closed_port_policy ? "are allowed to be open" : "must be closed");
  88
  89         while (eat_whitespace(&port_list))
  90         {
  91                 if (!extract_token(&port_item, ' ', &port_list))
  92                 {
  93                         /* reached last port item */
  94                         port_item = port_list;
  95                         port_list = chunk_empty;
  96                 }
  97                 port_range = malloc_thing(port_range_t);
  98                 port_range->start = atoi(port_item.ptr);
  99
 100                 if (extract_token(&port_start, '-', &port_item) && port_item.len)
 101                 {
 102                         port_range->stop = atoi(port_item.ptr);
 103                 }
 104                 else
 105                 {
 106                         port_range->stop = port_range->start;
 107                 }
 108                 DBG2(DBG_IMV, "%5u - %5u", port_range->start, port_range->stop);
 109                 list->insert_last(list, port_range);
 110         }
 111
 112         return list;
 113 }
 114
 115
 116 /*
 117  * see section 3.8.1 of TCG TNC IF-IMV Specification 1.3
 118  */
 119 TNC_Result TNC_IMV_Initialize(TNC_IMVID imv_id,
 120                                                           TNC_Version min_version,
 121                                                           TNC_Version max_version,
 122                                                           TNC_Version *actual_version)
 123 {
 124         if (imv_scanner)
 125         {
 126                 DBG1(DBG_IMV, "IMV \"%s\" has already been initialized", imv_name);
 127                 return TNC_RESULT_ALREADY_INITIALIZED;
 128         }
 129         imv_scanner = imv_agent_create(imv_name, msg_types, countof(msg_types),
 130                                                                    imv_id, actual_version);
 131         if (!imv_scanner)
 132         {
 133                 return TNC_RESULT_FATAL;
 134         }
 135         if (min_version > TNC_IFIMV_VERSION_1 || max_version < TNC_IFIMV_VERSION_1)
 136         {
 137                 DBG1(DBG_IMV, "no common IF-IMV version");
 138                 return TNC_RESULT_NO_COMMON_VERSION;
 139         }
 140
 141         /* set the default port policy to closed (TRUE) or open (FALSE) */
 142         closed_port_policy = lib->settings->get_bool(lib->settings,
 143                                                 "libimcv.plugins.imv-scanner.closed_port_policy", TRUE);
 144         DBG2(DBG_IMV, "default port policy is %s ports",
 145                                                 closed_port_policy ? "closed" : "open");
 146
 147         /* get the list of open|closed ports */
 148         tcp_ports = get_port_list("tcp");
 149         udp_ports = get_port_list("udp");
 150
 151         return TNC_RESULT_SUCCESS;
 152 }
 153
 154 /**
 155  * see section 3.8.2 of TCG TNC IF-IMV Specification 1.3
 156  */
 157 TNC_Result TNC_IMV_NotifyConnectionChange(TNC_IMVID imv_id,
 158                                                                                   TNC_ConnectionID connection_id,
 159                                                                                   TNC_ConnectionState new_state)
 160 {
 161         imv_state_t *state;
 162
 163         if (!imv_scanner)
 164         {
 165                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 166                 return TNC_RESULT_NOT_INITIALIZED;
 167         }
 168         switch (new_state)
 169         {
 170                 case TNC_CONNECTION_STATE_CREATE:
 171                         state = imv_scanner_state_create(connection_id);
 172                         return imv_scanner->create_state(imv_scanner, state);
 173                 case TNC_CONNECTION_STATE_DELETE:
 174                         return imv_scanner->delete_state(imv_scanner, connection_id);
 175                 default:
 176                         return imv_scanner->change_state(imv_scanner, connection_id,
 177                                                                                          new_state, NULL);
 178         }
 179 }
 180
 181 static TNC_Result receive_message(imv_state_t *state, imv_msg_t *in_msg)
 182 {
 183         imv_msg_t *out_msg;
 184         enumerator_t *enumerator;
 185         pa_tnc_attr_t *attr;
 186         pen_type_t type;
 187         TNC_Result result;
 188         bool fatal_error = FALSE;
 189
 190         /* parse received PA-TNC message and handle local and remote errors */
 191         result = in_msg->receive(in_msg, &fatal_error);
 192         if (result != TNC_RESULT_SUCCESS)
 193         {
 194                 return result;
 195         }
 196
 197         /* analyze PA-TNC attributes */
 198         enumerator = in_msg->create_attribute_enumerator(in_msg);
 199         while (enumerator->enumerate(enumerator, &attr))
 200         {
 201                 type = attr->get_type(attr);
 202
 203                 if (type.vendor_id == PEN_IETF && type.type == IETF_ATTR_PORT_FILTER)
 204                 {
 205                         imv_scanner_state_t *imv_scanner_state;
 206                         ietf_attr_port_filter_t *attr_port_filter;
 207                         enumerator_t *enumerator;
 208                         u_int8_t protocol;
 209                         u_int16_t port;
 210                         bool blocked, compliant = TRUE;
 211
 212
 213                         imv_scanner_state = (imv_scanner_state_t*)state;
 214                         attr_port_filter = (ietf_attr_port_filter_t*)attr;
 215                         enumerator = attr_port_filter->create_port_enumerator(attr_port_filter);
 216                         while (enumerator->enumerate(enumerator, &blocked, &protocol, &port))
 217                         {
 218                                 enumerator_t *e;
 219                                 port_range_t *port_range;
 220                                 bool passed, found = FALSE;
 221                                 char buf[20];
 222
 223                                 if (blocked)
 224                                 {
 225                                         /* ignore closed ports */
 226                                         continue;
 227                                 }
 228
 229                                 e = (protocol == IPPROTO_TCP) ?
 230                                                         tcp_ports->create_enumerator(tcp_ports) :
 231                                                         udp_ports->create_enumerator(udp_ports);
 232                                 while (e->enumerate(e, &port_range))
 233                                 {
 234                                         if (port >= port_range->start && port <= port_range->stop)
 235                                         {
 236                                                 found = TRUE;
 237                                                 break;
 238                                         }
 239                                 }
 240                                 e->destroy(e);
 241
 242                                 passed = (closed_port_policy == found);
 243                                 DBG2(DBG_IMV, "%s port %5u %s: %s",
 244                                         (protocol == IPPROTO_TCP) ? "tcp" : "udp", port,
 245                                          blocked ? "closed" : "open", passed ? "ok" : "fatal");
 246                                 if (!passed)
 247                                 {
 248                                         compliant = FALSE;
 249                                         snprintf(buf, sizeof(buf), "%s/%u",
 250                                                         (protocol == IPPROTO_TCP) ? "tcp" : "udp", port);
 251                                         imv_scanner_state->add_violating_port(imv_scanner_state,
 252                                                                                                                   strdup(buf));
 253                                 }
 254                         }
 255                         enumerator->destroy(enumerator);
 256
 257                         if (compliant)
 258                         {
 259                                 state->set_recommendation(state,
 260                                                                 TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
 261                                                                 TNC_IMV_EVALUATION_RESULT_COMPLIANT);
 262                         }
 263                         else
 264                         {
 265                                 state->set_recommendation(state,
 266                                                                 TNC_IMV_ACTION_RECOMMENDATION_NO_ACCESS,
 267                                                                 TNC_IMV_EVALUATION_RESULT_NONCOMPLIANT_MAJOR);
 268                         }
 269                 }
 270         }
 271         enumerator->destroy(enumerator);
 272
 273         if (fatal_error)
 274         {
 275                 state->set_recommendation(state,
 276                                                                 TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION,
 277                                                                 TNC_IMV_EVALUATION_RESULT_ERROR);
 278         }
 279
 280         out_msg = imv_msg_create_as_reply(in_msg);
 281         result = out_msg->send_assessment(out_msg);
 282         out_msg->destroy(out_msg);
 283         if (result != TNC_RESULT_SUCCESS)
 284         {
 285                 return result;
 286         }
 287         return imv_scanner->provide_recommendation(imv_scanner, state);
 288  }
 289
 290 /**
 291  * see section 3.8.4 of TCG TNC IF-IMV Specification 1.3
 292  */
 293 TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
 294                                                                   TNC_ConnectionID connection_id,
 295                                                                   TNC_BufferReference msg,
 296                                                                   TNC_UInt32 msg_len,
 297                                                                   TNC_MessageType msg_type)
 298 {
 299         imv_state_t *state;
 300         imv_msg_t *in_msg;
 301         TNC_Result result;
 302
 303         if (!imv_scanner)
 304         {
 305                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 306                 return TNC_RESULT_NOT_INITIALIZED;
 307         }
 308         if (!imv_scanner->get_state(imv_scanner, connection_id, &state))
 309         {
 310                 return TNC_RESULT_FATAL;
 311         }
 312
 313         in_msg = imv_msg_create_from_data(imv_scanner, state, connection_id, msg_type,
 314                                                                           chunk_create(msg, msg_len));
 315         result = receive_message(state, in_msg);
 316         in_msg->destroy(in_msg);
 317
 318         return result;
 319 }
 320
 321 /**
 322  * see section 3.8.6 of TCG TNC IF-IMV Specification 1.3
 323  */
 324 TNC_Result TNC_IMV_ReceiveMessageLong(TNC_IMVID imv_id,
 325                                                                           TNC_ConnectionID connection_id,
 326                                                                           TNC_UInt32 msg_flags,
 327                                                                           TNC_BufferReference msg,
 328                                                                           TNC_UInt32 msg_len,
 329                                                                           TNC_VendorID msg_vid,
 330                                                                           TNC_MessageSubtype msg_subtype,
 331                                                                           TNC_UInt32 src_imc_id,
 332                                                                           TNC_UInt32 dst_imv_id)
 333 {
 334         imv_state_t *state;
 335         imv_msg_t *in_msg;
 336         TNC_Result result;
 337
 338         if (!imv_scanner)
 339         {
 340                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 341                 return TNC_RESULT_NOT_INITIALIZED;
 342         }
 343         if (!imv_scanner->get_state(imv_scanner, connection_id, &state))
 344         {
 345                 return TNC_RESULT_FATAL;
 346         }
 347         in_msg = imv_msg_create_from_long_data(imv_scanner, state, connection_id,
 348                                                                 src_imc_id, dst_imv_id, msg_vid, msg_subtype,
 349                                                                 chunk_create(msg, msg_len));
 350         result =receive_message(state, in_msg);
 351         in_msg->destroy(in_msg);
 352
 353         return result;
 354 }
 355
 356 /**
 357  * see section 3.8.7 of TCG TNC IF-IMV Specification 1.3
 358  */
 359 TNC_Result TNC_IMV_SolicitRecommendation(TNC_IMVID imv_id,
 360                                                                                  TNC_ConnectionID connection_id)
 361 {
 362         imv_state_t *state;
 363
 364         if (!imv_scanner)
 365         {
 366                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 367                 return TNC_RESULT_NOT_INITIALIZED;
 368         }
 369         if (!imv_scanner->get_state(imv_scanner, connection_id, &state))
 370         {
 371                 return TNC_RESULT_FATAL;
 372         }
 373         return imv_scanner->provide_recommendation(imv_scanner, state);
 374 }
 375
 376 /**
 377  * see section 3.8.8 of TCG TNC IF-IMV Specification 1.3
 378  */
 379 TNC_Result TNC_IMV_BatchEnding(TNC_IMVID imv_id,
 380                                                            TNC_ConnectionID connection_id)
 381 {
 382         imv_state_t *state;
 383         imv_msg_t *out_msg;
 384         pa_tnc_attr_t *attr;
 385         TNC_IMV_Action_Recommendation rec;
 386         TNC_IMV_Evaluation_Result eval;
 387         TNC_Result result = TNC_RESULT_SUCCESS;
 388
 389         if (!imv_scanner)
 390         {
 391                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 392                 return TNC_RESULT_NOT_INITIALIZED;
 393         }
 394         if (!imv_scanner->get_state(imv_scanner, connection_id, &state))
 395         {
 396                 return TNC_RESULT_FATAL;
 397         }
 398         state->get_recommendation(state, &rec, &eval);
 399         if (rec == TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION)
 400         {
 401                 out_msg = imv_msg_create(imv_scanner, state, connection_id, imv_id,
 402                                                                  TNC_IMCID_ANY, msg_types[0]);
 403                 attr = ietf_attr_attr_request_create(PEN_IETF, IETF_ATTR_PORT_FILTER);
 404                 out_msg->add_attribute(out_msg, attr);
 405
 406                 /* send PA-TNC message with excl flag not set */
 407                 result = out_msg->send(out_msg, FALSE);
 408                 out_msg->destroy(out_msg);
 409
 410         }
 411         return result;
 412 }
 413
 414 /**
 415  * see section 3.8.9 of TCG TNC IF-IMV Specification 1.3
 416  */
 417 TNC_Result TNC_IMV_Terminate(TNC_IMVID imv_id)
 418 {
 419         if (!imv_scanner)
 420         {
 421                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 422                 return TNC_RESULT_NOT_INITIALIZED;
 423         }
 424         tcp_ports->destroy_function(tcp_ports, free);
 425         udp_ports->destroy_function(udp_ports, free);
 426         imv_scanner->destroy(imv_scanner);
 427         imv_scanner = NULL;
 428
 429         return TNC_RESULT_SUCCESS;
 430 }
 431
 432 /**
 433  * see section 4.2.8.1 of TCG TNC IF-IMV Specification 1.3
 434  */
 435 TNC_Result TNC_IMV_ProvideBindFunction(TNC_IMVID imv_id,
 436                                                                            TNC_TNCS_BindFunctionPointer bind_function)
 437 {
 438         if (!imv_scanner)
 439         {
 440                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 441                 return TNC_RESULT_NOT_INITIALIZED;
 442         }
 443         return imv_scanner->bind_functions(imv_scanner, bind_function);
 444 }