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 <pa_tnc/pa_tnc_msg.h>
  21 #include <ietf/ietf_attr.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 <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_ITA, PA_SUBTYPE_ITA_SCANNER }
  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, 1, imc_id, actual_version);
  56         if (!imc_scanner)
  57         {
  58                 return TNC_RESULT_FATAL;
  59         }
  60         if (min_version > TNC_IFIMC_VERSION_1 || max_version < TNC_IFIMC_VERSION_1)
  61         {
  62                 DBG1(DBG_IMC, "no common IF-IMC version");
  63                 return TNC_RESULT_NO_COMMON_VERSION;
  64         }
  65         return TNC_RESULT_SUCCESS;
  66 }
  67
  68 /**
  69  * see section 3.8.2 of TCG TNC IF-IMC Specification 1.3
  70  */
  71 TNC_Result TNC_IMC_NotifyConnectionChange(TNC_IMCID imc_id,
  72                                                                                   TNC_ConnectionID connection_id,
  73                                                                                   TNC_ConnectionState new_state)
  74 {
  75         imc_state_t *state;
  76
  77         if (!imc_scanner)
  78         {
  79                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
  80                 return TNC_RESULT_NOT_INITIALIZED;
  81         }
  82         switch (new_state)
  83         {
  84                 case TNC_CONNECTION_STATE_CREATE:
  85                         state = imc_scanner_state_create(connection_id);
  86                         return imc_scanner->create_state(imc_scanner, state);
  87                 case TNC_CONNECTION_STATE_HANDSHAKE:
  88                         if (imc_scanner->change_state(imc_scanner, connection_id, new_state,
  89                                 &state) != TNC_RESULT_SUCCESS)
  90                         {
  91                                 return TNC_RESULT_FATAL;
  92                         }
  93                         state->set_result(state, imc_id,
  94                                                           TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
  95                         return TNC_RESULT_SUCCESS;
  96                 case TNC_CONNECTION_STATE_DELETE:
  97                         return imc_scanner->delete_state(imc_scanner, connection_id);
  98                 default:
  99                         return imc_scanner->change_state(imc_scanner, connection_id,
 100                                                                                          new_state, NULL);
 101         }
 102 }
 103
 104 /**
 105  * Determine all TCP and UDP server sockets listening on physical interfaces
 106  */
 107 static bool do_netstat(ietf_attr_port_filter_t *attr)
 108 {
 109         FILE *file;
 110         char buf[BUF_LEN];
 111         chunk_t line, token;
 112         int n = 0;
 113         bool success = FALSE;
 114         const char loopback_v4[] = "127.0.0.1";
 115         const char loopback_v6[] = "::1";
 116
 117         /* Open a pipe stream for reading the output of the netstat commmand */
 118         file = popen("/bin/netstat -n -l -p -4 -6 --inet", "r");
 119         if (!file)
 120         {
 121                 DBG1(DBG_IMC, "Failed to run netstat command");
 122                 return FALSE;
 123         }
 124
 125         /* Read the output a line at a time */
 126         while (fgets(buf, BUF_LEN-1, file))
 127         {
 128                 u_char *pos;
 129                 u_int8_t new_protocol, protocol;
 130                 u_int16_t new_port, port;
 131                 int i;
 132                 enumerator_t *enumerator;
 133                 bool allowed, found = FALSE;
 134
 135                 DBG2(DBG_IMC, "%.*s", (int)(strlen(buf)-1), buf);
 136
 137                 if (n++ < 2)
 138                 {
 139                         /* skip the first two header lines */
 140                         continue;
 141                 }
 142                 line = chunk_create(buf, strlen(buf));
 143
 144                 /* Extract the IP protocol type */
 145                 if (!extract_token(&token, ' ', &line))
 146                 {
 147                         DBG1(DBG_IMC, "Protocol field in netstat output not found");
 148                         goto end;
 149                 }
 150                 if (match("tcp", &token) || match("tcp6", &token))
 151                 {
 152                         new_protocol = IPPROTO_TCP;
 153                 }
 154                 else if (match("udp", &token) || match("udp6", &token))
 155                 {
 156                         new_protocol = IPPROTO_UDP;
 157                 }
 158                 else
 159                 {
 160                         DBG1(DBG_IMC, "Skipped unknown IP protocol in netstat output");
 161                         continue;
 162                 }
 163
 164                 /* Skip the Recv-Q and Send-Q fields */
 165                 for (i = 0; i < 3; i++)
 166                 {
 167                         if (!eat_whitespace(&line) || !extract_token(&token, ' ', &line))
 168                         {
 169                                 token = chunk_empty;
 170                                 break;
 171                         }
 172                 }
 173                 if (token.len == 0)
 174                 {
 175                         DBG1(DBG_IMC, "Local Address field in netstat output not found");
 176                         goto end;
 177                 }
 178
 179                 /* Find the local port appended to the local address */
 180                 pos = token.ptr + token.len;
 181                 while (*--pos != ':' && --token.len);
 182                 if (*pos != ':')
 183                 {
 184                         DBG1(DBG_IMC, "Local port field in netstat output not found");
 185                         goto end;
 186                 }
 187                 token.len--;
 188
 189                 /* ignore ports of IPv4 and IPv6 loopback interfaces */
 190                 if ((token.len == strlen(loopback_v4) &&
 191                                 memeq(loopback_v4, token.ptr, token.len)) ||
 192                         (token.len == strlen(loopback_v6) &&
 193                                 memeq(loopback_v6, token.ptr, token.len)))
 194                 {
 195                         continue;
 196                 }
 197
 198                 /* convert the port string to an integer */
 199                 new_port = atoi(pos+1);
 200
 201                 /* check if the there is already a port entry */
 202                 enumerator = attr->create_port_enumerator(attr);
 203                 while (enumerator->enumerate(enumerator, &allowed, &protocol, &port))
 204                 {
 205                         if (new_port == port && new_protocol == protocol)
 206                         {
 207                                 found = TRUE;
 208                         }
 209                 }
 210                 enumerator->destroy(enumerator);
 211
 212                 /* Skip the duplicate port entry */
 213                 if (found)
 214                 {
 215                         continue;
 216                 }
 217
 218                 /* Add new port entry */
 219                 attr->add_port(attr, FALSE, new_protocol, new_port);
 220         }
 221
 222         /* Successfully completed the parsing of the netstat output */
 223         success = TRUE;
 224
 225 end:
 226         /* Close the pipe stream */
 227         pclose(file);
 228         return success;
 229 }
 230
 231 static TNC_Result send_message(imc_msg_t *out_msg)
 232 {
 233         pa_tnc_attr_t *attr;
 234         ietf_attr_port_filter_t *attr_port_filter;
 235
 236         attr = ietf_attr_port_filter_create();
 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         out_msg->add_attribute(out_msg, attr);
 245
 246         /* send PA-TNC message with the excl flag not set */
 247         return out_msg->send(out_msg, FALSE);
 248 }
 249
 250 /**
 251  * see section 3.8.3 of TCG TNC IF-IMC Specification 1.3
 252  */
 253 TNC_Result TNC_IMC_BeginHandshake(TNC_IMCID imc_id,
 254                                                                   TNC_ConnectionID connection_id)
 255 {
 256         imc_state_t *state;
 257         imc_msg_t *out_msg;
 258         TNC_Result result;
 259
 260         if (!imc_scanner)
 261         {
 262                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 263                 return TNC_RESULT_NOT_INITIALIZED;
 264         }
 265         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 266         {
 267                 return TNC_RESULT_FATAL;
 268         }
 269         out_msg = imc_msg_create(imc_scanner, state, connection_id, imc_id,
 270                                                          TNC_IMVID_ANY, msg_types[0]);
 271         result = send_message(out_msg);
 272         out_msg->destroy(out_msg);
 273
 274         return result;
 275 }
 276
 277 static TNC_Result receive_message(imc_msg_t *in_msg)
 278 {
 279         TNC_Result result;
 280         bool fatal_error = FALSE;
 281
 282         /* parse received PA-TNC message and handle local and remote errors */
 283         result = in_msg->receive(in_msg, &fatal_error);
 284         if (result != TNC_RESULT_SUCCESS)
 285         {
 286                 return result;
 287         }
 288         return fatal_error ? TNC_RESULT_FATAL : TNC_RESULT_SUCCESS;
 289 }
 290
 291 /**
 292  * see section 3.8.4 of TCG TNC IF-IMC Specification 1.3
 293
 294  */
 295 TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 296                                                                   TNC_ConnectionID connection_id,
 297                                                                   TNC_BufferReference msg,
 298                                                                   TNC_UInt32 msg_len,
 299                                                                   TNC_MessageType msg_type)
 300 {
 301         imc_state_t *state;
 302         imc_msg_t *in_msg;
 303         TNC_Result result;
 304
 305         if (!imc_scanner)
 306         {
 307                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 308                 return TNC_RESULT_NOT_INITIALIZED;
 309         }
 310         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 311         {
 312                 return TNC_RESULT_FATAL;
 313         }
 314
 315         in_msg = imc_msg_create_from_data(imc_scanner, state, connection_id,
 316                                                                           msg_type, chunk_create(msg, msg_len));
 317         result = receive_message(in_msg);
 318         in_msg->destroy(in_msg);
 319
 320         return result;
 321 }
 322
 323 /**
 324  * see section 3.8.6 of TCG TNC IF-IMV Specification 1.3
 325  */
 326 TNC_Result TNC_IMC_ReceiveMessageLong(TNC_IMCID imc_id,
 327                                                                           TNC_ConnectionID connection_id,
 328                                                                           TNC_UInt32 msg_flags,
 329                                                                           TNC_BufferReference msg,
 330                                                                           TNC_UInt32 msg_len,
 331                                                                           TNC_VendorID msg_vid,
 332                                                                           TNC_MessageSubtype msg_subtype,
 333                                                                           TNC_UInt32 src_imv_id,
 334                                                                           TNC_UInt32 dst_imc_id)
 335 {
 336         imc_state_t *state;
 337         imc_msg_t *in_msg;
 338         TNC_Result result;
 339
 340         if (!imc_scanner)
 341         {
 342                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 343                 return TNC_RESULT_NOT_INITIALIZED;
 344         }
 345         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 346         {
 347                 return TNC_RESULT_FATAL;
 348         }
 349         in_msg = imc_msg_create_from_long_data(imc_scanner, state, connection_id,
 350                                                                 src_imv_id, dst_imc_id, msg_vid, msg_subtype,
 351                                                                 chunk_create(msg, msg_len));
 352         result =receive_message(in_msg);
 353         in_msg->destroy(in_msg);
 354
 355         return result;
 356 }
 357
 358 /**
 359  * see section 3.8.7 of TCG TNC IF-IMC Specification 1.3
 360  */
 361 TNC_Result TNC_IMC_BatchEnding(TNC_IMCID imc_id,
 362                                                            TNC_ConnectionID connection_id)
 363 {
 364         if (!imc_scanner)
 365         {
 366                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 367                 return TNC_RESULT_NOT_INITIALIZED;
 368         }
 369         return TNC_RESULT_SUCCESS;
 370 }
 371
 372 /**
 373  * see section 3.8.8 of TCG TNC IF-IMC Specification 1.3
 374  */
 375 TNC_Result TNC_IMC_Terminate(TNC_IMCID imc_id)
 376 {
 377         if (!imc_scanner)
 378         {
 379                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 380                 return TNC_RESULT_NOT_INITIALIZED;
 381         }
 382         imc_scanner->destroy(imc_scanner);
 383         imc_scanner = NULL;
 384
 385         return TNC_RESULT_SUCCESS;
 386 }
 387
 388 /**
 389  * see section 4.2.8.1 of TCG TNC IF-IMC Specification 1.3
 390  */
 391 TNC_Result TNC_IMC_ProvideBindFunction(TNC_IMCID imc_id,
 392                                                                            TNC_TNCC_BindFunctionPointer bind_function)
 393 {
 394         if (!imc_scanner)
 395         {
 396                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 397                 return TNC_RESULT_NOT_INITIALIZED;
 398         }
 399         return imc_scanner->bind_functions(imc_scanner, bind_function);
 400 }