src/libimcv/plugins/imv_scanner/imv_scanner.c

   1 /*
   2  * Copyright (C) 2011 Andreas Steffen, HSR Hochschule fuer Technik Rapperswil
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by the
   6  * Free Software Foundation; either version 2 of the License, or (at your
   7  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * for more details.
  13  */
  14
  15 #include "imv_scanner_state.h"
  16
  17 #include <imv/imv_agent.h>
  18 #include <pa_tnc/pa_tnc_msg.h>
  19 #include <ietf/ietf_attr.h>
  20 #include <ietf/ietf_attr_pa_tnc_error.h>
  21 #include <ietf/ietf_attr_port_filter.h>
  22
  23 #include <tncif_names.h>
  24 #include <tncif_pa_subtypes.h>
  25
  26 #include <pen/pen.h>
  27 #include <utils/linked_list.h>
  28 #include <utils/lexparser.h>
  29 #include <debug.h>
  30
  31 /* IMV definitions */
  32
  33 static const char imv_name[] = "Scanner";
  34
  35 #define IMV_VENDOR_ID   PEN_ITA
  36 #define IMV_SUBTYPE             PA_SUBTYPE_ITA_SCANNER
  37
  38 static imv_agent_t *imv_scanner;
  39
  40 typedef struct port_range_t port_range_t;
  41
  42 struct port_range_t {
  43         u_int16_t start, stop;
  44 };
  45
  46
  47 /**
  48  * Default port policy
  49  *
  50  * TRUE:  all server ports on the TNC client must be closed
  51  * FALSE: any server port on the TNC client is allowed to be open
  52  */
  53 static bool closed_port_policy = TRUE;
  54
  55 /**
  56  * List of TCP and UDP port ranges
  57  *
  58  * TRUE:  server ports on the TNC client that are allowed to be open
  59  * FALSE: server ports on the TNC client that must be closed
  60  */
  61 static linked_list_t *tcp_ports, *udp_ports;
  62
  63 /**
  64  * Get a TCP or UDP port list from strongswan.conf
  65  */
  66 static linked_list_t* get_port_list(char *label)
  67 {
  68         char key[40], *value;
  69         linked_list_t *list;
  70         chunk_t port_list, port_item, port_stop;
  71         port_range_t *port_range;
  72
  73         list = linked_list_create();
  74
  75         snprintf(key, sizeof(key), "libimcv.plugins.imv-scanner.%s_ports", label);
  76         value = lib->settings->get_str(lib->settings, key, NULL);
  77         if (!value)
  78         {
  79                 DBG1(DBG_IMV, "%s not defined", key);
  80                 return list;
  81         }
  82         port_list = chunk_create(value, strlen(value));
  83         DBG2(DBG_IMV, "list of %s ports that %s:", label,
  84                  closed_port_policy ? "are allowed to be open" : "must be closed");
  85
  86         while (eat_whitespace(&port_list))
  87         {
  88                 if (!extract_token(&port_item, ' ', &port_list))
  89                 {
  90                         /* reached last port item */
  91                         port_item = port_list;
  92                         port_list = chunk_empty;
  93                 }
  94                 port_range = malloc_thing(port_range_t);
  95                 port_range->start = atoi(port_item.ptr);;
  96
  97                 if (extract_token(&port_stop, '-', &port_item))
  98                 {
  99                         port_range->stop = atoi(port_stop.ptr);
 100                 }
 101                 else
 102                 {
 103                         port_range->stop = port_range->start;
 104                 }
 105                 DBG2(DBG_IMV, "%5u - %5u", port_range->start, port_range->stop);
 106                 list->insert_last(list, port_range);
 107         }
 108
 109         return list;
 110 }
 111
 112
 113 /*
 114  * see section 3.7.1 of TCG TNC IF-IMV Specification 1.2
 115  */
 116 TNC_Result TNC_IMV_Initialize(TNC_IMVID imv_id,
 117                                                           TNC_Version min_version,
 118                                                           TNC_Version max_version,
 119                                                           TNC_Version *actual_version)
 120 {
 121         if (imv_scanner)
 122         {
 123                 DBG1(DBG_IMV, "IMV \"%s\" has already been initialized", imv_name);
 124                 return TNC_RESULT_ALREADY_INITIALIZED;
 125         }
 126         imv_scanner = imv_agent_create(imv_name, IMV_VENDOR_ID, IMV_SUBTYPE,
 127                                                                 imv_id, actual_version);
 128         if (!imv_scanner)
 129         {
 130                 return TNC_RESULT_FATAL;
 131         }
 132         if (min_version > TNC_IFIMV_VERSION_1 || max_version < TNC_IFIMV_VERSION_1)
 133         {
 134                 DBG1(DBG_IMV, "no common IF-IMV version");
 135                 return TNC_RESULT_NO_COMMON_VERSION;
 136         }
 137
 138         /* set the default port policy to closed (TRUE) or open (FALSE) */
 139         closed_port_policy = lib->settings->get_bool(lib->settings,
 140                                                 "libimcv.plugins.imv-scanner.closed_port_policy", TRUE);
 141         DBG2(DBG_IMV, "default port policy is %s ports",
 142                                                 closed_port_policy ? "closed" : "open");
 143
 144         /* get the list of open|closed ports */
 145         tcp_ports = get_port_list("tcp");
 146         udp_ports = get_port_list("udp");
 147
 148         return TNC_RESULT_SUCCESS;
 149 }
 150
 151 /**
 152  * see section 3.7.2 of TCG TNC IF-IMV Specification 1.2
 153  */
 154 TNC_Result TNC_IMV_NotifyConnectionChange(TNC_IMVID imv_id,
 155                                                                                   TNC_ConnectionID connection_id,
 156                                                                                   TNC_ConnectionState new_state)
 157 {
 158         imv_state_t *state;
 159
 160         if (!imv_scanner)
 161         {
 162                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 163                 return TNC_RESULT_NOT_INITIALIZED;
 164         }
 165         switch (new_state)
 166         {
 167                 case TNC_CONNECTION_STATE_CREATE:
 168                         state = imv_scanner_state_create(connection_id);
 169                         return imv_scanner->create_state(imv_scanner, state);
 170                 case TNC_CONNECTION_STATE_DELETE:
 171                         return imv_scanner->delete_state(imv_scanner, connection_id);
 172                 default:
 173                         return imv_scanner->change_state(imv_scanner, connection_id,
 174                                                                                          new_state, NULL);
 175         }
 176 }
 177
 178 /**
 179  * see section 3.7.3 of TCG TNC IF-IMV Specification 1.2
 180  */
 181 TNC_Result TNC_IMV_ReceiveMessage(TNC_IMVID imv_id,
 182                                                                   TNC_ConnectionID connection_id,
 183                                                                   TNC_BufferReference msg,
 184                                                                   TNC_UInt32 msg_len,
 185                                                                   TNC_MessageType msg_type)
 186 {
 187         pa_tnc_msg_t *pa_tnc_msg;
 188         pa_tnc_attr_t *attr;
 189         imv_state_t *state;
 190         enumerator_t *enumerator;
 191         TNC_Result result;
 192         bool fatal_error = FALSE;
 193
 194         if (!imv_scanner)
 195         {
 196                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 197                 return TNC_RESULT_NOT_INITIALIZED;
 198         }
 199
 200         /* get current IMV state */
 201         if (!imv_scanner->get_state(imv_scanner, connection_id, &state))
 202         {
 203                 return TNC_RESULT_FATAL;
 204         }
 205
 206         /* parse received PA-TNC message and automatically handle any errors */
 207         result = imv_scanner->receive_message(imv_scanner, connection_id,
 208                                                                            chunk_create(msg, msg_len), msg_type,
 209                                                                            &pa_tnc_msg);
 210
 211         /* no parsed PA-TNC attributes available if an error occurred */
 212         if (!pa_tnc_msg)
 213         {
 214                 return result;
 215         }
 216
 217         /* analyze PA-TNC attributes */
 218         enumerator = pa_tnc_msg->create_attribute_enumerator(pa_tnc_msg);
 219         while (enumerator->enumerate(enumerator, &attr))
 220         {
 221                 if (attr->get_vendor_id(attr) != PEN_IETF)
 222                 {
 223                         continue;
 224                 }
 225
 226                 if (attr->get_type(attr) == IETF_ATTR_PA_TNC_ERROR)
 227                 {
 228                         ietf_attr_pa_tnc_error_t *error_attr;
 229                         pa_tnc_error_code_t error_code;
 230                         chunk_t msg_info, attr_info;
 231
 232                         error_attr = (ietf_attr_pa_tnc_error_t*)attr;
 233                         error_code = error_attr->get_error_code(error_attr);
 234                         msg_info = error_attr->get_msg_info(error_attr);
 235                         DBG1(DBG_IMV, "received PA-TNC error '%N' concerning message %#B",
 236                                  pa_tnc_error_code_names, error_code, &msg_info);
 237
 238                         switch (error_code)
 239                         {
 240                                 case PA_ERROR_ATTR_TYPE_NOT_SUPPORTED:
 241                                         attr_info = error_attr->get_attr_info(error_attr);
 242                                         DBG1(DBG_IMV, "  unsupported attribute %#B", &attr_info);
 243                                         break;
 244                                 default:
 245                                         break;
 246                         }
 247                         fatal_error = TRUE;
 248                 }
 249                 else if (attr->get_type(attr) == IETF_ATTR_PORT_FILTER)
 250                 {
 251                         ietf_attr_port_filter_t *attr_port_filter;
 252                         enumerator_t *enumerator;
 253                         u_int8_t protocol;
 254                         u_int16_t port;
 255                         char buf[BUF_LEN], *pos = buf;
 256                         size_t len = BUF_LEN;
 257                         bool blocked, compliant = TRUE;
 258
 259                         attr_port_filter = (ietf_attr_port_filter_t*)attr;
 260                         enumerator = attr_port_filter->create_port_enumerator(attr_port_filter);
 261                         while (enumerator->enumerate(enumerator, &blocked, &protocol, &port))
 262                         {
 263                                 enumerator_t *e;
 264                                 port_range_t *port_range;
 265                                 bool passed, found = FALSE;
 266                                 int written = 0;
 267
 268                                 if (blocked)
 269                                 {
 270                                         /* ignore closed ports */
 271                                         continue;
 272                                 }
 273
 274                                 e = (protocol == IPPROTO_TCP) ?
 275                                                         tcp_ports->create_enumerator(tcp_ports) :
 276                                                         udp_ports->create_enumerator(udp_ports);
 277                                 while (e->enumerate(e, &port_range))
 278                                 {
 279                                         if (port >= port_range->start && port <= port_range->stop)
 280                                         {
 281                                                 found = TRUE;
 282                                                 break;
 283                                         }
 284                                 }
 285                                 e->destroy(e);
 286
 287                                 passed = (closed_port_policy == found);
 288                                 DBG2(DBG_IMV, "%s port %5u %s: %s",
 289                                         (protocol == IPPROTO_TCP) ? "tcp" : "udp", port,
 290                                          blocked ? "closed" : "open", passed ? "ok" : "fatal");
 291                                 if (!passed)
 292                                 {
 293                                         compliant = FALSE;
 294                                         written = snprintf(pos, len, " %s/%u",
 295                                                                           (protocol == IPPROTO_TCP) ? "tcp" : "udp",
 296                                                                            port);
 297                                         if (written < 0 || written >= len)
 298                                         {
 299                                                 break;
 300                                         }
 301                                         pos += written;
 302                                         len -= written;
 303                                 }
 304                         }
 305                         enumerator->destroy(enumerator);
 306
 307                         if (compliant)
 308                         {
 309                                 state->set_recommendation(state,
 310                                                                 TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
 311                                                                 TNC_IMV_EVALUATION_RESULT_COMPLIANT);
 312                         }
 313                         else
 314                         {
 315                                 imv_scanner_state_t *imv_scanner_state;
 316
 317                                 imv_scanner_state = (imv_scanner_state_t*)state;
 318                                 imv_scanner_state->set_violating_ports(imv_scanner_state, buf);
 319                                 state->set_recommendation(state,
 320                                                                 TNC_IMV_ACTION_RECOMMENDATION_NO_ACCESS,
 321                                                                 TNC_IMV_EVALUATION_RESULT_NONCOMPLIANT_MAJOR);
 322                         }
 323                 }
 324         }
 325         enumerator->destroy(enumerator);
 326         pa_tnc_msg->destroy(pa_tnc_msg);
 327
 328         if (fatal_error)
 329         {
 330                 state->set_recommendation(state,
 331                                                                 TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION,
 332                                                                 TNC_IMV_EVALUATION_RESULT_ERROR);
 333                 return imv_scanner->provide_recommendation(imv_scanner, connection_id);
 334         }
 335
 336         return imv_scanner->provide_recommendation(imv_scanner, connection_id);
 337 }
 338
 339 /**
 340  * see section 3.7.4 of TCG TNC IF-IMV Specification 1.2
 341  */
 342 TNC_Result TNC_IMV_SolicitRecommendation(TNC_IMVID imv_id,
 343                                                                                  TNC_ConnectionID connection_id)
 344 {
 345         if (!imv_scanner)
 346         {
 347                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 348                 return TNC_RESULT_NOT_INITIALIZED;
 349         }
 350         return imv_scanner->provide_recommendation(imv_scanner, connection_id);
 351 }
 352
 353 /**
 354  * see section 3.7.5 of TCG TNC IF-IMV Specification 1.2
 355  */
 356 TNC_Result TNC_IMV_BatchEnding(TNC_IMVID imv_id,
 357                                                            TNC_ConnectionID connection_id)
 358 {
 359         if (!imv_scanner)
 360         {
 361                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 362                 return TNC_RESULT_NOT_INITIALIZED;
 363         }
 364         return TNC_RESULT_SUCCESS;
 365 }
 366
 367 /**
 368  * see section 3.7.6 of TCG TNC IF-IMV Specification 1.2
 369  */
 370 TNC_Result TNC_IMV_Terminate(TNC_IMVID imv_id)
 371 {
 372         if (!imv_scanner)
 373         {
 374                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 375                 return TNC_RESULT_NOT_INITIALIZED;
 376         }
 377         tcp_ports->destroy_function(tcp_ports, free);
 378         udp_ports->destroy_function(udp_ports, free);
 379         imv_scanner->destroy(imv_scanner);
 380         imv_scanner = NULL;
 381
 382         return TNC_RESULT_SUCCESS;
 383 }
 384
 385 /**
 386  * see section 4.2.8.1 of TCG TNC IF-IMV Specification 1.2
 387  */
 388 TNC_Result TNC_IMV_ProvideBindFunction(TNC_IMVID imv_id,
 389                                                                            TNC_TNCS_BindFunctionPointer bind_function)
 390 {
 391         if (!imv_scanner)
 392         {
 393                 DBG1(DBG_IMV, "IMV \"%s\" has not been initialized", imv_name);
 394                 return TNC_RESULT_NOT_INITIALIZED;
 395         }
 396         return imv_scanner->bind_functions(imv_scanner, bind_function);
 397 }