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