src/libimcv/plugins/imc_scanner/imc_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 "imc_scanner_state.h"
  16
  17 #include <imc/imc_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/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 #define IMC_VENDOR_ID   PEN_ITA
  37 #define IMC_SUBTYPE             PA_SUBTYPE_ITA_SCANNER
  38
  39 static imc_agent_t *imc_scanner;
  40
  41 /**
  42  * see section 3.8.1 of TCG TNC IF-IMC Specification 1.3
  43  */
  44 TNC_Result TNC_IMC_Initialize(TNC_IMCID imc_id,
  45                                                           TNC_Version min_version,
  46                                                           TNC_Version max_version,
  47                                                           TNC_Version *actual_version)
  48 {
  49         if (imc_scanner)
  50         {
  51                 DBG1(DBG_IMC, "IMC \"%s\" has already been initialized", imc_name);
  52                 return TNC_RESULT_ALREADY_INITIALIZED;
  53         }
  54         imc_scanner = imc_agent_create(imc_name, IMC_VENDOR_ID, IMC_SUBTYPE,
  55                                                                 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_DELETE:
  88                         return imc_scanner->delete_state(imc_scanner, connection_id);
  89                 default:
  90                         return imc_scanner->change_state(imc_scanner, connection_id,
  91                                                                                          new_state, NULL);
  92         }
  93 }
  94
  95 /**
  96  * Determine all TCP and UDP server sockets listening on physical interfaces
  97  */
  98 static bool do_netstat(ietf_attr_port_filter_t *attr)
  99 {
 100         FILE *file;
 101         char buf[BUF_LEN];
 102         chunk_t line, token;
 103         int n = 0;
 104         bool success = FALSE;
 105         const char loopback_v4[] = "127.0.0.1";
 106         const char loopback_v6[] = "::1";
 107
 108         /* Open a pipe stream for reading the output of the netstat commmand */
 109         file = popen("/bin/netstat -n -l -p -4 -6 --inet", "r");
 110         if (!file)
 111         {
 112                 DBG1(DBG_IMC, "Failed to run netstat command");
 113                 return FALSE;
 114         }
 115
 116         /* Read the output a line at a time */
 117         while (fgets(buf, BUF_LEN-1, file))
 118         {
 119                 u_char *pos;
 120                 u_int8_t new_protocol, protocol;
 121                 u_int16_t new_port, port;
 122                 int i;
 123                 enumerator_t *enumerator;
 124                 bool allowed, found = FALSE;
 125
 126                 DBG2(DBG_IMC, "%.*s", strlen(buf)-1, buf);
 127
 128                 if (n++ < 2)
 129                 {
 130                         /* skip the first two header lines */
 131                         continue;
 132                 }
 133                 line = chunk_create(buf, strlen(buf));
 134
 135                 /* Extract the IP protocol type */
 136                 if (!extract_token(&token, ' ', &line))
 137                 {
 138                         DBG1(DBG_IMC, "Protocol field in netstat output not found");
 139                         goto end;
 140                 }
 141                 if (match("tcp", &token) || match("tcp6", &token))
 142                 {
 143                         new_protocol = IPPROTO_TCP;
 144                 }
 145                 else if (match("udp", &token) || match("udp6", &token))
 146                 {
 147                         new_protocol = IPPROTO_UDP;
 148                 }
 149                 else
 150                 {
 151                         DBG1(DBG_IMC, "Skipped unknown IP protocol in netstat output");
 152                         continue;
 153                 }
 154
 155                 /* Skip the Recv-Q and Send-Q fields */
 156                 for (i = 0; i < 3; i++)
 157                 {
 158                         if (!eat_whitespace(&line) || !extract_token(&token, ' ', &line))
 159                         {
 160                                 token = chunk_empty;
 161                                 break;
 162                         }
 163                 }
 164                 if (token.len == 0)
 165                 {
 166                         DBG1(DBG_IMC, "Local Address field in netstat output not found");
 167                         goto end;
 168                 }
 169
 170                 /* Find the local port appended to the local address */
 171                 pos = token.ptr + token.len;
 172                 while (*--pos != ':' && --token.len);
 173                 if (*pos != ':')
 174                 {
 175                         DBG1(DBG_IMC, "Local port field in netstat output not found");
 176                         goto end;
 177                 }
 178                 token.len--;
 179
 180                 /* ignore ports of IPv4 and IPv6 loopback interfaces */
 181                 if ((token.len == strlen(loopback_v4) &&
 182                                 memeq(loopback_v4, token.ptr, token.len)) ||
 183                         (token.len == strlen(loopback_v6) &&
 184                                 memeq(loopback_v6, token.ptr, token.len)))
 185                 {
 186                         continue;
 187                 }
 188
 189                 /* convert the port string to an integer */
 190                 new_port = atoi(pos+1);
 191
 192                 /* check if the there is already a port entry */
 193                 enumerator = attr->create_port_enumerator(attr);
 194                 while (enumerator->enumerate(enumerator, &allowed, &protocol, &port))
 195                 {
 196                         if (new_port == port && new_protocol == protocol)
 197                         {
 198                                 found = TRUE;
 199                         }
 200                 }
 201                 enumerator->destroy(enumerator);
 202
 203                 /* Skip the duplicate port entry */
 204                 if (found)
 205                 {
 206                         continue;
 207                 }
 208
 209                 /* Add new port entry */
 210                 attr->add_port(attr, FALSE, new_protocol, new_port);
 211         }
 212
 213         /* Successfully completed the parsing of the netstat output */
 214         success = TRUE;
 215
 216 end:
 217         /* Close the pipe stream */
 218         pclose(file);
 219         return success;
 220 }
 221
 222 static TNC_Result send_message(TNC_ConnectionID connection_id)
 223 {
 224         linked_list_t *attr_list;
 225         pa_tnc_attr_t *attr;
 226         ietf_attr_port_filter_t *attr_port_filter;
 227         TNC_Result result;
 228
 229         attr = ietf_attr_port_filter_create();
 230         attr->set_noskip_flag(attr, TRUE);
 231         attr_port_filter = (ietf_attr_port_filter_t*)attr;
 232         if (!do_netstat(attr_port_filter))
 233         {
 234                 attr->destroy(attr);
 235                 return TNC_RESULT_FATAL;
 236         }
 237         attr_list = linked_list_create();
 238         attr_list->insert_last(attr_list, attr);
 239         result = imc_scanner->send_message(imc_scanner, connection_id, FALSE, 0,
 240                                                                            TNC_IMVID_ANY, attr_list);
 241         attr_list->destroy(attr_list);
 242
 243         return result;
 244 }
 245
 246 /**
 247  * see section 3.8.3 of TCG TNC IF-IMC Specification 1.3
 248  */
 249 TNC_Result TNC_IMC_BeginHandshake(TNC_IMCID imc_id,
 250                                                                   TNC_ConnectionID connection_id)
 251 {
 252         if (!imc_scanner)
 253         {
 254                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 255                 return TNC_RESULT_NOT_INITIALIZED;
 256         }
 257         return send_message(connection_id);
 258 }
 259
 260 static TNC_Result receive_message(TNC_IMCID imc_id,
 261                                                                   TNC_ConnectionID connection_id,
 262                                                                   TNC_UInt32 msg_flags,
 263                                                                   chunk_t msg,
 264                                                                   TNC_VendorID msg_vid,
 265                                                                   TNC_MessageSubtype msg_subtype,
 266                                                                   TNC_UInt32 src_imv_id,
 267                                                                   TNC_UInt32 dst_imc_id)
 268 {
 269         pa_tnc_msg_t *pa_tnc_msg;
 270         imc_state_t *state;
 271         TNC_Result result;
 272         bool fatal_error;
 273
 274         if (!imc_scanner)
 275         {
 276                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 277                 return TNC_RESULT_NOT_INITIALIZED;
 278         }
 279
 280         /* get current IMC state */
 281         if (!imc_scanner->get_state(imc_scanner, connection_id, &state))
 282         {
 283                 return TNC_RESULT_FATAL;
 284         }
 285
 286         /* parse received PA-TNC message and automatically handle any errors */
 287         result = imc_scanner->receive_message(imc_scanner, state, msg, msg_vid,
 288                                                         msg_subtype, src_imv_id, dst_imc_id, &pa_tnc_msg);
 289
 290         /* no parsed PA-TNC attributes available if an error occurred */
 291         if (!pa_tnc_msg)
 292         {
 293                 return result;
 294         }
 295
 296         /* preprocess any IETF standard error attributes */
 297         fatal_error = pa_tnc_msg->process_ietf_std_errors(pa_tnc_msg);
 298         pa_tnc_msg->destroy(pa_tnc_msg);
 299
 300         /* if no error occurred then always return the same response */
 301         return fatal_error ? TNC_RESULT_FATAL : send_message(connection_id);
 302 }
 303
 304 /**
 305  * see section 3.8.4 of TCG TNC IF-IMC Specification 1.3
 306  */
 307 TNC_Result TNC_IMC_ReceiveMessage(TNC_IMCID imc_id,
 308                                                                   TNC_ConnectionID connection_id,
 309                                                                   TNC_BufferReference msg,
 310                                                                   TNC_UInt32 msg_len,
 311                                                                   TNC_MessageType msg_type)
 312 {
 313         TNC_VendorID msg_vid;
 314         TNC_MessageSubtype msg_subtype;
 315
 316         msg_vid = msg_type >> 8;
 317         msg_subtype = msg_type & TNC_SUBTYPE_ANY;
 318
 319         return receive_message(imc_id, connection_id, 0, chunk_create(msg, msg_len),
 320                                                    msg_vid,     msg_subtype, 0, TNC_IMCID_ANY);
 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         return receive_message(imc_id, connection_id, msg_flags,
 337                                                    chunk_create(msg, msg_len), msg_vid, msg_subtype,
 338                                                    src_imv_id, dst_imc_id);
 339 }
 340
 341 /**
 342  * see section 3.8.7 of TCG TNC IF-IMC Specification 1.3
 343  */
 344 TNC_Result TNC_IMC_BatchEnding(TNC_IMCID imc_id,
 345                                                            TNC_ConnectionID connection_id)
 346 {
 347         if (!imc_scanner)
 348         {
 349                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 350                 return TNC_RESULT_NOT_INITIALIZED;
 351         }
 352         return TNC_RESULT_SUCCESS;
 353 }
 354
 355 /**
 356  * see section 3.8.8 of TCG TNC IF-IMC Specification 1.3
 357  */
 358 TNC_Result TNC_IMC_Terminate(TNC_IMCID imc_id)
 359 {
 360         if (!imc_scanner)
 361         {
 362                 DBG1(DBG_IMC, "IMC \"%s\" has not been initialized", imc_name);
 363                 return TNC_RESULT_NOT_INITIALIZED;
 364         }
 365         imc_scanner->destroy(imc_scanner);
 366         imc_scanner = NULL;
 367
 368         return TNC_RESULT_SUCCESS;
 369 }
 370
 371 /**
 372  * see section 4.2.8.1 of TCG TNC IF-IMC Specification 1.3
 373  */
 374 TNC_Result TNC_IMC_ProvideBindFunction(TNC_IMCID imc_id,
 375                                                                            TNC_TNCC_BindFunctionPointer bind_function)
 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         return imc_scanner->bind_functions(imc_scanner, bind_function);
 383 }