Added add_segment() method to IETF attributes
[strongswan.git] / src / libimcv / plugins / imv_scanner / imv_scanner_agent.c
1 /*
2 * Copyright (C) 2013-2014 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_agent.h"
17 #include "imv_scanner_state.h"
18
19 #include <imcv.h>
20 #include <imv/imv_agent.h>
21 #include <imv/imv_msg.h>
22 #include <ietf/ietf_attr.h>
23 #include <ietf/ietf_attr_attr_request.h>
24 #include <ietf/ietf_attr_pa_tnc_error.h>
25 #include <ietf/ietf_attr_port_filter.h>
26
27 #include <tncif_names.h>
28 #include <tncif_pa_subtypes.h>
29
30 #include <pen/pen.h>
31 #include <utils/debug.h>
32 #include <utils/lexparser.h>
33
34 typedef struct private_imv_scanner_agent_t private_imv_scanner_agent_t;
35
36 /* Subscribed PA-TNC message subtypes */
37 static pen_type_t msg_types[] = {
38 { PEN_IETF, PA_SUBTYPE_IETF_VPN }
39 };
40
41 /**
42 * Private data of an imv_scanner_agent_t object.
43 */
44 struct private_imv_scanner_agent_t {
45
46 /**
47 * Public members of imv_scanner_agent_t
48 */
49 imv_agent_if_t public;
50
51 /**
52 * IMV agent responsible for generic functions
53 */
54 imv_agent_t *agent;
55
56 };
57
58 METHOD(imv_agent_if_t, bind_functions, TNC_Result,
59 private_imv_scanner_agent_t *this, TNC_TNCS_BindFunctionPointer bind_function)
60 {
61 return this->agent->bind_functions(this->agent, bind_function);
62 }
63
64 METHOD(imv_agent_if_t, notify_connection_change, TNC_Result,
65 private_imv_scanner_agent_t *this, TNC_ConnectionID id,
66 TNC_ConnectionState new_state)
67 {
68 imv_state_t *state;
69
70 switch (new_state)
71 {
72 case TNC_CONNECTION_STATE_CREATE:
73 state = imv_scanner_state_create(id);
74 return this->agent->create_state(this->agent, state);
75 case TNC_CONNECTION_STATE_DELETE:
76 return this->agent->delete_state(this->agent, id);
77 default:
78 return this->agent->change_state(this->agent, id, new_state, NULL);
79 }
80 }
81
82 /**
83 * Process a received message
84 */
85 static TNC_Result receive_msg(private_imv_scanner_agent_t *this,
86 imv_state_t *state, imv_msg_t *in_msg)
87 {
88 imv_msg_t *out_msg;
89 imv_scanner_state_t *scanner_state;
90 enumerator_t *enumerator;
91 pa_tnc_attr_t *attr;
92 pen_type_t type;
93 TNC_Result result;
94 ietf_attr_port_filter_t *port_filter_attr;
95 bool fatal_error = FALSE;
96
97 /* generate an outgoing PA-TNC message - we might need it */
98 out_msg = imv_msg_create_as_reply(in_msg);
99
100 /* parse received PA-TNC message and handle local and remote errors */
101 result = in_msg->receive(in_msg, out_msg, &fatal_error);
102 if (result != TNC_RESULT_SUCCESS)
103 {
104 out_msg->destroy(out_msg);
105 return result;
106 }
107
108 /* analyze PA-TNC attributes */
109 enumerator = in_msg->create_attribute_enumerator(in_msg);
110 while (enumerator->enumerate(enumerator, &attr))
111 {
112 type = attr->get_type(attr);
113
114 if (type.vendor_id == PEN_IETF && type.type == IETF_ATTR_PORT_FILTER)
115 {
116 scanner_state = (imv_scanner_state_t*)state;
117 port_filter_attr = (ietf_attr_port_filter_t*)attr->get_ref(attr);
118 scanner_state->set_port_filter_attr(scanner_state, port_filter_attr);
119 }
120 }
121 enumerator->destroy(enumerator);
122
123 if (fatal_error)
124 {
125 state->set_recommendation(state,
126 TNC_IMV_ACTION_RECOMMENDATION_NO_RECOMMENDATION,
127 TNC_IMV_EVALUATION_RESULT_ERROR);
128 result = out_msg->send_assessment(out_msg);
129 if (result == TNC_RESULT_SUCCESS)
130 {
131 result = this->agent->provide_recommendation(this->agent, state);
132 }
133 }
134 else
135 {
136 /* send PA-TNC message with the EXCL flag set */
137 result = out_msg->send(out_msg, TRUE);
138 }
139 out_msg->destroy(out_msg);
140
141 return result;
142 }
143
144 METHOD(imv_agent_if_t, receive_message, TNC_Result,
145 private_imv_scanner_agent_t *this, TNC_ConnectionID id,
146 TNC_MessageType msg_type, chunk_t msg)
147 {
148 imv_state_t *state;
149 imv_msg_t *in_msg;
150 TNC_Result result;
151
152 if (!this->agent->get_state(this->agent, id, &state))
153 {
154 return TNC_RESULT_FATAL;
155 }
156 in_msg = imv_msg_create_from_data(this->agent, state, id, msg_type, msg);
157 result = receive_msg(this, state, in_msg);
158 in_msg->destroy(in_msg);
159
160 return result;
161 }
162
163 METHOD(imv_agent_if_t, receive_message_long, TNC_Result,
164 private_imv_scanner_agent_t *this, TNC_ConnectionID id,
165 TNC_UInt32 src_imc_id, TNC_UInt32 dst_imv_id,
166 TNC_VendorID msg_vid, TNC_MessageSubtype msg_subtype, chunk_t msg)
167 {
168 imv_state_t *state;
169 imv_msg_t *in_msg;
170 TNC_Result result;
171
172 if (!this->agent->get_state(this->agent, id, &state))
173 {
174 return TNC_RESULT_FATAL;
175 }
176 in_msg = imv_msg_create_from_long_data(this->agent, state, id,
177 src_imc_id, dst_imv_id, msg_vid, msg_subtype, msg);
178 result = receive_msg(this, state, in_msg);
179 in_msg->destroy(in_msg);
180
181 return result;
182
183 }
184
185 typedef struct port_range_t port_range_t;
186
187 struct port_range_t {
188 u_int16_t start, stop;
189 };
190
191 /**
192 * Parse a TCP or UDP port list from an argument string
193 */
194 static linked_list_t* get_port_list(u_int8_t protocol_family,
195 bool closed_port_policy, char *arg_str)
196 {
197 chunk_t port_list, port_item, port_start;
198 port_range_t *port_range;
199 linked_list_t *list;
200
201 list = linked_list_create();
202
203 port_list = chunk_from_str(arg_str);
204 DBG2(DBG_IMV, "list of %s ports that %s:",
205 (protocol_family == IPPROTO_TCP) ? "tcp" : "udp",
206 closed_port_policy ? "are allowed to be open" : "must be closed");
207
208 while (eat_whitespace(&port_list))
209 {
210 if (!extract_token(&port_item, ' ', &port_list))
211 {
212 /* reached last port item */
213 port_item = port_list;
214 port_list = chunk_empty;
215 }
216 port_range = malloc_thing(port_range_t);
217 port_range->start = atoi(port_item.ptr);
218
219 if (extract_token(&port_start, '-', &port_item) && port_item.len)
220 {
221 port_range->stop = atoi(port_item.ptr);
222 }
223 else
224 {
225 port_range->stop = port_range->start;
226 }
227 DBG2(DBG_IMV, "%5u - %5u", port_range->start, port_range->stop);
228 list->insert_last(list, port_range);
229 }
230
231 return list;
232 }
233
234 METHOD(imv_agent_if_t, batch_ending, TNC_Result,
235 private_imv_scanner_agent_t *this, TNC_ConnectionID id)
236 {
237 imv_msg_t *out_msg;
238 imv_state_t *state;
239 imv_session_t *session;
240 imv_workitem_t *workitem;
241 imv_scanner_state_t *scanner_state;
242 imv_scanner_handshake_state_t handshake_state;
243 pa_tnc_attr_t *attr;
244 ietf_attr_port_filter_t *port_filter_attr;
245 TNC_IMVID imv_id;
246 TNC_Result result = TNC_RESULT_SUCCESS;
247 bool no_workitems = TRUE;
248 enumerator_t *enumerator;
249
250 if (!this->agent->get_state(this->agent, id, &state))
251 {
252 return TNC_RESULT_FATAL;
253 }
254 scanner_state = (imv_scanner_state_t*)state;
255 handshake_state = scanner_state->get_handshake_state(scanner_state);
256 port_filter_attr = scanner_state->get_port_filter_attr(scanner_state);
257 session = state->get_session(state);
258 imv_id = this->agent->get_id(this->agent);
259
260 if (handshake_state == IMV_SCANNER_STATE_END)
261 {
262 return TNC_RESULT_SUCCESS;
263 }
264
265 /* create an empty out message - we might need it */
266 out_msg = imv_msg_create(this->agent, state, id, imv_id, TNC_IMCID_ANY,
267 msg_types[0]);
268
269 if (!imcv_db)
270 {
271 DBG2(DBG_IMV, "no workitems available - no evaluation possible");
272 state->set_recommendation(state,
273 TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
274 TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
275 result = out_msg->send_assessment(out_msg);
276 out_msg->destroy(out_msg);
277 scanner_state->set_handshake_state(scanner_state, IMV_SCANNER_STATE_END);
278
279 if (result != TNC_RESULT_SUCCESS)
280 {
281 return result;
282 }
283 return this->agent->provide_recommendation(this->agent, state);
284 }
285
286 if (handshake_state == IMV_SCANNER_STATE_INIT &&
287 session->get_policy_started(session))
288 {
289 enumerator = session->create_workitem_enumerator(session);
290 if (enumerator)
291 {
292 while (enumerator->enumerate(enumerator, &workitem))
293 {
294 if (workitem->get_imv_id(workitem) != TNC_IMVID_ANY)
295 {
296 continue;
297 }
298
299 switch (workitem->get_type(workitem))
300 {
301 case IMV_WORKITEM_TCP_PORT_OPEN:
302 case IMV_WORKITEM_TCP_PORT_BLOCK:
303 case IMV_WORKITEM_UDP_PORT_OPEN:
304 case IMV_WORKITEM_UDP_PORT_BLOCK:
305 if (!port_filter_attr &&
306 handshake_state != IMV_SCANNER_STATE_ATTR_REQ)
307 {
308 attr = ietf_attr_attr_request_create(PEN_IETF,
309 IETF_ATTR_PORT_FILTER);
310 out_msg->add_attribute(out_msg, attr);
311 handshake_state = IMV_SCANNER_STATE_ATTR_REQ;
312 }
313 break;
314 default:
315 continue;
316 }
317 workitem->set_imv_id(workitem, imv_id);
318 no_workitems = FALSE;
319 }
320 enumerator->destroy(enumerator);
321
322 if (no_workitems)
323 {
324 DBG2(DBG_IMV, "IMV %d has no workitems - "
325 "no evaluation requested", imv_id);
326 state->set_recommendation(state,
327 TNC_IMV_ACTION_RECOMMENDATION_ALLOW,
328 TNC_IMV_EVALUATION_RESULT_DONT_KNOW);
329 }
330 handshake_state = IMV_SCANNER_STATE_WORKITEMS;
331 scanner_state->set_handshake_state(scanner_state, handshake_state);
332 }
333 }
334
335 if (handshake_state == IMV_SCANNER_STATE_WORKITEMS && port_filter_attr)
336 {
337 TNC_IMV_Evaluation_Result eval;
338 TNC_IMV_Action_Recommendation rec;
339 u_int8_t protocol_family, protocol;
340 u_int16_t port;
341 bool closed_port_policy, blocked, first;
342 char result_str[BUF_LEN], *pos, *protocol_str;
343 size_t len;
344 int written;
345 linked_list_t *port_list;
346 enumerator_t *e1, *e2;
347
348 enumerator = session->create_workitem_enumerator(session);
349 while (enumerator->enumerate(enumerator, &workitem))
350 {
351 if (workitem->get_imv_id(workitem) != imv_id)
352 {
353 continue;
354 }
355 eval = TNC_IMV_EVALUATION_RESULT_COMPLIANT;
356
357 switch (workitem->get_type(workitem))
358 {
359 case IMV_WORKITEM_TCP_PORT_OPEN:
360 protocol_family = IPPROTO_TCP;
361 closed_port_policy = TRUE;
362 break;
363 case IMV_WORKITEM_TCP_PORT_BLOCK:
364 protocol_family = IPPROTO_TCP;
365 closed_port_policy = FALSE;
366 break;
367 case IMV_WORKITEM_UDP_PORT_OPEN:
368 protocol_family = IPPROTO_UDP;
369 closed_port_policy = TRUE;
370 break;
371 case IMV_WORKITEM_UDP_PORT_BLOCK:
372 protocol_family = IPPROTO_UDP;
373 closed_port_policy = FALSE;
374 break;
375 default:
376 continue;
377 }
378 port_list = get_port_list(protocol_family, closed_port_policy,
379 workitem->get_arg_str(workitem));
380 protocol_str = (protocol_family == IPPROTO_TCP) ? "tcp" : "udp";
381 result_str[0] = '\0';
382 pos = result_str;
383 len = BUF_LEN;
384 first = TRUE;
385
386 e1 = port_filter_attr->create_port_enumerator(port_filter_attr);
387 while (e1->enumerate(e1, &blocked, &protocol, &port))
388 {
389 port_range_t *port_range;
390 bool passed, found = FALSE;
391 char buf[20];
392
393 if (blocked || protocol != protocol_family)
394 {
395 /* ignore closed ports or non-matching protocols */
396 continue;
397 }
398
399 e2 = port_list->create_enumerator(port_list);
400 while (e2->enumerate(e2, &port_range))
401 {
402 if (port >= port_range->start && port <= port_range->stop)
403 {
404 found = TRUE;
405 break;
406 }
407 }
408 e2->destroy(e2);
409
410 passed = (closed_port_policy == found);
411 DBG2(DBG_IMV, "%s port %5u open: %s", protocol_str, port,
412 passed ? "ok" : "fatal");
413 if (!passed)
414 {
415 eval = TNC_IMV_EVALUATION_RESULT_NONCOMPLIANT_MINOR;
416 snprintf(buf, sizeof(buf), "%s/%u", protocol_str, port);
417 scanner_state->add_violating_port(scanner_state, strdup(buf));
418 if (first)
419 {
420 written = snprintf(pos, len, "violating %s ports:",
421 protocol_str);
422 if (written > 0 && written < len)
423 {
424 pos += written;
425 len -= written;
426 }
427 first = FALSE;
428 }
429 written = snprintf(pos, len, " %u", port);
430 if (written < 0 || written >= len)
431 {
432 pos += len - 1;
433 *pos = '\0';
434 }
435 else
436 {
437 pos += written;
438 len -= written;
439 }
440 }
441 }
442 e1->destroy(e1);
443
444 if (first)
445 {
446 snprintf(pos, len, "no violating %s ports", protocol_str);
447 }
448 port_list->destroy(port_list);
449
450 session->remove_workitem(session, enumerator);
451 rec = workitem->set_result(workitem, result_str, eval);
452 state->update_recommendation(state, rec, eval);
453 imcv_db->finalize_workitem(imcv_db, workitem);
454 workitem->destroy(workitem);
455 }
456 enumerator->destroy(enumerator);
457 }
458
459 /* finalized all workitems ? */
460 if (handshake_state == IMV_SCANNER_STATE_WORKITEMS &&
461 session->get_workitem_count(session, imv_id) == 0)
462 {
463 result = out_msg->send_assessment(out_msg);
464 out_msg->destroy(out_msg);
465 scanner_state->set_handshake_state(scanner_state, IMV_SCANNER_STATE_END);
466
467 if (result != TNC_RESULT_SUCCESS)
468 {
469 return result;
470 }
471 return this->agent->provide_recommendation(this->agent, state);
472 }
473
474 /* send non-empty PA-TNC message with excl flag not set */
475 if (out_msg->get_attribute_count(out_msg))
476 {
477 result = out_msg->send(out_msg, FALSE);
478 }
479 out_msg->destroy(out_msg);
480
481 return result;
482 }
483
484 METHOD(imv_agent_if_t, solicit_recommendation, TNC_Result,
485 private_imv_scanner_agent_t *this, TNC_ConnectionID id)
486 {
487 imv_state_t *state;
488
489 if (!this->agent->get_state(this->agent, id, &state))
490 {
491 return TNC_RESULT_FATAL;
492 }
493 return this->agent->provide_recommendation(this->agent, state);
494 }
495
496 METHOD(imv_agent_if_t, destroy, void,
497 private_imv_scanner_agent_t *this)
498 {
499 this->agent->destroy(this->agent);
500 free(this);
501 }
502
503 /**
504 * Described in header.
505 */
506 imv_agent_if_t *imv_scanner_agent_create(const char *name, TNC_IMVID id,
507 TNC_Version *actual_version)
508 {
509 private_imv_scanner_agent_t *this;
510 imv_agent_t *agent;
511
512 agent = imv_agent_create(name, msg_types, countof(msg_types), id,
513 actual_version);
514 if (!agent)
515 {
516 return NULL;
517 }
518
519 INIT(this,
520 .public = {
521 .bind_functions = _bind_functions,
522 .notify_connection_change = _notify_connection_change,
523 .receive_message = _receive_message,
524 .receive_message_long = _receive_message_long,
525 .batch_ending = _batch_ending,
526 .solicit_recommendation = _solicit_recommendation,
527 .destroy = _destroy,
528 },
529 .agent = agent,
530 );
531
532 return &this->public;
533 }
534