Removed redundant '=>' when logging binary data in parser and generator.
[strongswan.git] / src / libcharon / encoding / parser.c
1 /*
2 * Copyright (C) 2005-2009 Martin Willi
3 * Copyright (C) 2005 Jan Hutter
4 * Hochschule fuer Technik Rapperswil
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 */
16
17 #include <stdlib.h>
18 #include <arpa/inet.h>
19 #include <string.h>
20
21 #include "parser.h"
22
23 #include <library.h>
24 #include <daemon.h>
25 #include <utils/linked_list.h>
26 #include <encoding/payloads/encodings.h>
27 #include <encoding/payloads/payload.h>
28 #include <encoding/payloads/sa_payload.h>
29 #include <encoding/payloads/proposal_substructure.h>
30 #include <encoding/payloads/transform_substructure.h>
31 #include <encoding/payloads/transform_attribute.h>
32 #include <encoding/payloads/ke_payload.h>
33 #include <encoding/payloads/nonce_payload.h>
34 #include <encoding/payloads/id_payload.h>
35 #include <encoding/payloads/notify_payload.h>
36 #include <encoding/payloads/encryption_payload.h>
37 #include <encoding/payloads/auth_payload.h>
38 #include <encoding/payloads/cert_payload.h>
39 #include <encoding/payloads/certreq_payload.h>
40 #include <encoding/payloads/ts_payload.h>
41 #include <encoding/payloads/delete_payload.h>
42 #include <encoding/payloads/vendor_id_payload.h>
43 #include <encoding/payloads/cp_payload.h>
44 #include <encoding/payloads/configuration_attribute.h>
45 #include <encoding/payloads/eap_payload.h>
46 #include <encoding/payloads/unknown_payload.h>
47
48
49 typedef struct private_parser_t private_parser_t;
50
51 /**
52 * Private data stored in a context.
53 *
54 * Contains pointers and counters to store current state.
55 */
56 struct private_parser_t {
57 /**
58 * Public members, see parser_t.
59 */
60 parser_t public;
61
62 /**
63 * Current bit for reading in input data.
64 */
65 u_int8_t bit_pos;
66
67 /**
68 * Current byte for reading in input data.
69 */
70 u_int8_t *byte_pos;
71
72 /**
73 * Input data to parse.
74 */
75 u_int8_t *input;
76
77 /**
78 * Roof of input, used for length-checking.
79 */
80 u_int8_t *input_roof;
81
82 /**
83 * Set of encoding rules for this parsing session.
84 */
85 encoding_rule_t *rules;
86 };
87
88 /**
89 * Log invalid length error
90 */
91 static bool short_input(private_parser_t *this, int number)
92 {
93 DBG1(DBG_ENC, " not enough input to parse rule %d %N",
94 number, encoding_type_names, this->rules[number].type);
95 return FALSE;
96 }
97
98 /**
99 * Log unaligned rules
100 */
101 static bool bad_bitpos(private_parser_t *this, int number)
102 {
103 DBG1(DBG_ENC, " found rule %d %N on bitpos %d",
104 number, encoding_type_names, this->rules[number].type, this->bit_pos);
105 return FALSE;
106 }
107
108 /**
109 * Parse a 4-Bit unsigned integer from the current parsing position.
110 */
111 static bool parse_uint4(private_parser_t *this, int rule_number,
112 u_int8_t *output_pos)
113 {
114 if (this->byte_pos + sizeof(u_int8_t) > this->input_roof)
115 {
116 return short_input(this, rule_number);
117 }
118 switch (this->bit_pos)
119 {
120 case 0:
121 if (output_pos)
122 {
123 *output_pos = *(this->byte_pos) >> 4;
124 }
125 this->bit_pos = 4;
126 break;
127 case 4:
128 if (output_pos)
129 {
130 *output_pos = *(this->byte_pos) & 0x0F;
131 }
132 this->bit_pos = 0;
133 this->byte_pos++;
134 break;
135 default:
136 return bad_bitpos(this, rule_number);
137 }
138 if (output_pos)
139 {
140 DBG3(DBG_ENC, " => %d", *output_pos);
141 }
142 return TRUE;
143 }
144
145 /**
146 * Parse a 8-Bit unsigned integer from the current parsing position.
147 */
148 static bool parse_uint8(private_parser_t *this, int rule_number,
149 u_int8_t *output_pos)
150 {
151 if (this->byte_pos + sizeof(u_int8_t) > this->input_roof)
152 {
153 return short_input(this, rule_number);
154 }
155 if (this->bit_pos)
156 {
157 return bad_bitpos(this, rule_number);
158 }
159 if (output_pos)
160 {
161 *output_pos = *(this->byte_pos);
162 DBG3(DBG_ENC, " => %d", *output_pos);
163 }
164 this->byte_pos++;
165 return TRUE;
166 }
167
168 /**
169 * Parse a 15-Bit unsigned integer from the current parsing position.
170 */
171 static bool parse_uint15(private_parser_t *this, int rule_number,
172 u_int16_t *output_pos)
173 {
174 if (this->byte_pos + sizeof(u_int16_t) > this->input_roof)
175 {
176 return short_input(this, rule_number);
177 }
178 if (this->bit_pos != 1)
179 {
180 return bad_bitpos(this, rule_number);
181 }
182 if (output_pos)
183 {
184 memcpy(output_pos, this->byte_pos, sizeof(u_int16_t));
185 *output_pos = ntohs(*output_pos) & ~0x8000;
186 DBG3(DBG_ENC, " => %d", *output_pos);
187 }
188 this->byte_pos += sizeof(u_int16_t);
189 this->bit_pos = 0;
190 return TRUE;
191 }
192
193 /**
194 * Parse a 16-Bit unsigned integer from the current parsing position.
195 */
196 static bool parse_uint16(private_parser_t *this, int rule_number,
197 u_int16_t *output_pos)
198 {
199 if (this->byte_pos + sizeof(u_int16_t) > this->input_roof)
200 {
201 return short_input(this, rule_number);
202 }
203 if (this->bit_pos)
204 {
205 return bad_bitpos(this, rule_number);
206 }
207 if (output_pos)
208 {
209 memcpy(output_pos, this->byte_pos, sizeof(u_int16_t));
210 *output_pos = ntohs(*output_pos);
211 DBG3(DBG_ENC, " => %d", *output_pos);
212 }
213 this->byte_pos += sizeof(u_int16_t);
214 return TRUE;
215 }
216 /**
217 * Parse a 32-Bit unsigned integer from the current parsing position.
218 */
219 static bool parse_uint32(private_parser_t *this, int rule_number,
220 u_int32_t *output_pos)
221 {
222 if (this->byte_pos + sizeof(u_int32_t) > this->input_roof)
223 {
224 return short_input(this, rule_number);
225 }
226 if (this->bit_pos)
227 {
228 return bad_bitpos(this, rule_number);
229 }
230 if (output_pos)
231 {
232 memcpy(output_pos, this->byte_pos, sizeof(u_int32_t));
233 *output_pos = ntohl(*output_pos);
234 DBG3(DBG_ENC, " => %d", *output_pos);
235 }
236 this->byte_pos += sizeof(u_int32_t);
237 return TRUE;
238 }
239
240 /**
241 * Parse a given amount of bytes and writes them to a specific location
242 */
243 static bool parse_bytes(private_parser_t *this, int rule_number,
244 u_int8_t *output_pos, int bytes)
245 {
246 if (this->byte_pos + bytes > this->input_roof)
247 {
248 return short_input(this, rule_number);
249 }
250 if (this->bit_pos)
251 {
252 return bad_bitpos(this, rule_number);
253 }
254 if (output_pos)
255 {
256 memcpy(output_pos, this->byte_pos, bytes);
257 DBG3(DBG_ENC, " %b", output_pos, bytes);
258 }
259 this->byte_pos += bytes;
260 return TRUE;
261 }
262
263 /**
264 * Parse a single Bit from the current parsing position
265 */
266 static bool parse_bit(private_parser_t *this, int rule_number,
267 bool *output_pos)
268 {
269 if (this->byte_pos + sizeof(u_int8_t) > this->input_roof)
270 {
271 return short_input(this, rule_number);
272 }
273 if (output_pos)
274 {
275 u_int8_t mask;
276 mask = 0x01 << (7 - this->bit_pos);
277 *output_pos = *this->byte_pos & mask;
278
279 if (*output_pos)
280 { /* set to a "clean", comparable true */
281 *output_pos = TRUE;
282 }
283 DBG3(DBG_ENC, " => %d", *output_pos);
284 }
285 this->bit_pos = (this->bit_pos + 1) % 8;
286 if (this->bit_pos == 0)
287 {
288 this->byte_pos++;
289 }
290 return TRUE;
291 }
292
293 /**
294 * Parse substructures in a list.
295 */
296 static bool parse_list(private_parser_t *this, int rule_number,
297 linked_list_t **output_pos, payload_type_t payload_type, int length)
298 {
299 linked_list_t *list = *output_pos;
300
301 if (length < 0)
302 {
303 return short_input(this, rule_number);
304 }
305 if (this->bit_pos)
306 {
307 return bad_bitpos(this, rule_number);
308 }
309 while (length > 0)
310 {
311 u_int8_t *pos_before = this->byte_pos;
312 payload_t *payload;
313
314 DBG2(DBG_ENC, " %d bytes left, parsing recursively %N",
315 length, payload_type_names, payload_type);
316
317 if (this->public.parse_payload(&this->public, payload_type,
318 &payload) != SUCCESS)
319 {
320 DBG1(DBG_ENC, " parsing of a %N substructure failed",
321 payload_type_names, payload_type);
322 return FALSE;
323 }
324 list->insert_last(list, payload);
325 length -= this->byte_pos - pos_before;
326 }
327 if (length != 0)
328 { /* must yield exactly to zero */
329 DBG1(DBG_ENC, " length of %N substructure list invalid",
330 payload_type_names, payload_type);
331 return FALSE;
332 }
333 *output_pos = list;
334 return TRUE;
335 }
336
337 /**
338 * Parse data from current parsing position in a chunk.
339 */
340 static bool parse_chunk(private_parser_t *this, int rule_number,
341 chunk_t *output_pos, int length)
342 {
343 if (this->byte_pos + length > this->input_roof)
344 {
345 return short_input(this, rule_number);
346 }
347 if (this->bit_pos)
348 {
349 return bad_bitpos(this, rule_number);
350 }
351 if (output_pos)
352 {
353 *output_pos = chunk_alloc(length);
354 memcpy(output_pos->ptr, this->byte_pos, length);
355 DBG3(DBG_ENC, " %b", output_pos->ptr, length);
356 }
357 this->byte_pos += length;
358 return TRUE;
359 }
360
361 METHOD(parser_t, parse_payload, status_t,
362 private_parser_t *this, payload_type_t payload_type, payload_t **payload)
363 {
364 payload_t *pld;
365 void *output;
366 int payload_length = 0, spi_size = 0, attribute_length = 0, header_length;
367 u_int16_t ts_type = 0;
368 bool attribute_format = FALSE;
369 int rule_number, rule_count;
370 encoding_rule_t *rule;
371
372 /* create instance of the payload to parse */
373 pld = payload_create(payload_type);
374
375 DBG2(DBG_ENC, "parsing %N payload, %d bytes left",
376 payload_type_names, payload_type, this->input_roof - this->byte_pos);
377
378 DBG3(DBG_ENC, "parsing payload from %b",
379 this->byte_pos, this->input_roof - this->byte_pos);
380
381 /* base pointer for output, avoids casting in every rule */
382 output = pld;
383 /* parse the payload with its own rulse */
384 rule_count = pld->get_encoding_rules(pld, &this->rules);
385 for (rule_number = 0; rule_number < rule_count; rule_number++)
386 {
387 /* update header length for each rule, as it is dynamic (SPIs) */
388 header_length = pld->get_header_length(pld);
389
390 rule = &(this->rules[rule_number]);
391 DBG2(DBG_ENC, " parsing rule %d %N",
392 rule_number, encoding_type_names, rule->type);
393 switch ((int)rule->type)
394 {
395 case U_INT_4:
396 {
397 if (!parse_uint4(this, rule_number, output + rule->offset))
398 {
399 pld->destroy(pld);
400 return PARSE_ERROR;
401 }
402 break;
403 }
404 case U_INT_8:
405 case RESERVED_BYTE:
406 {
407 if (!parse_uint8(this, rule_number, output + rule->offset))
408 {
409 pld->destroy(pld);
410 return PARSE_ERROR;
411 }
412 break;
413 }
414 case U_INT_16:
415 {
416 if (!parse_uint16(this, rule_number, output + rule->offset))
417 {
418 pld->destroy(pld);
419 return PARSE_ERROR;
420 }
421 break;
422 }
423 case U_INT_32:
424 case HEADER_LENGTH:
425 {
426 if (!parse_uint32(this, rule_number, output + rule->offset))
427 {
428 pld->destroy(pld);
429 return PARSE_ERROR;
430 }
431 break;
432 }
433 case IKE_SPI:
434 {
435 if (!parse_bytes(this, rule_number, output + rule->offset, 8))
436 {
437 pld->destroy(pld);
438 return PARSE_ERROR;
439 }
440 break;
441 }
442 case RESERVED_BIT:
443 case FLAG:
444 {
445 if (!parse_bit(this, rule_number, output + rule->offset))
446 {
447 pld->destroy(pld);
448 return PARSE_ERROR;
449 }
450 break;
451 }
452 case PAYLOAD_LENGTH:
453 {
454 if (!parse_uint16(this, rule_number, output + rule->offset))
455 {
456 pld->destroy(pld);
457 return PARSE_ERROR;
458 }
459 /* parsed u_int16 should be aligned */
460 payload_length = *(u_int16_t*)(output + rule->offset);
461 /* all payloads must have at least 4 bytes header */
462 if (payload_length < 4)
463 {
464 pld->destroy(pld);
465 return PARSE_ERROR;
466 }
467 break;
468 }
469 case SPI_SIZE:
470 {
471 if (!parse_uint8(this, rule_number, output + rule->offset))
472 {
473 pld->destroy(pld);
474 return PARSE_ERROR;
475 }
476 spi_size = *(u_int8_t*)(output + rule->offset);
477 break;
478 }
479 case SPI:
480 {
481 if (!parse_chunk(this, rule_number, output + rule->offset,
482 spi_size))
483 {
484 pld->destroy(pld);
485 return PARSE_ERROR;
486 }
487 break;
488 }
489 case PAYLOAD_LIST + PROPOSAL_SUBSTRUCTURE:
490 case PAYLOAD_LIST + PROPOSAL_SUBSTRUCTURE_V1:
491 case PAYLOAD_LIST + TRANSFORM_SUBSTRUCTURE:
492 case PAYLOAD_LIST + TRANSFORM_SUBSTRUCTURE_V1:
493 case PAYLOAD_LIST + TRANSFORM_ATTRIBUTE:
494 case PAYLOAD_LIST + TRANSFORM_ATTRIBUTE_V1:
495 case PAYLOAD_LIST + CONFIGURATION_ATTRIBUTE:
496 case PAYLOAD_LIST + TRAFFIC_SELECTOR_SUBSTRUCTURE:
497 {
498 if (payload_length < header_length ||
499 !parse_list(this, rule_number, output + rule->offset,
500 rule->type - PAYLOAD_LIST,
501 payload_length - header_length))
502 {
503 pld->destroy(pld);
504 return PARSE_ERROR;
505 }
506 break;
507 }
508 case CHUNK_DATA:
509 {
510 if (payload_length < header_length ||
511 !parse_chunk(this, rule_number, output + rule->offset,
512 payload_length - header_length))
513 {
514 pld->destroy(pld);
515 return PARSE_ERROR;
516 }
517 break;
518 }
519 case ENCRYPTED_DATA:
520 {
521 if (!parse_chunk(this, rule_number, output + rule->offset,
522 this->input_roof - this->byte_pos))
523 {
524 pld->destroy(pld);
525 return PARSE_ERROR;
526 }
527 break;
528 }
529 case ATTRIBUTE_FORMAT:
530 {
531 if (!parse_bit(this, rule_number, output + rule->offset))
532 {
533 pld->destroy(pld);
534 return PARSE_ERROR;
535 }
536 attribute_format = *(bool*)(output + rule->offset);
537 break;
538 }
539 case ATTRIBUTE_TYPE:
540 {
541 if (!parse_uint15(this, rule_number, output + rule->offset))
542 {
543 pld->destroy(pld);
544 return PARSE_ERROR;
545 }
546 break;
547 }
548 case CONFIGURATION_ATTRIBUTE_LENGTH:
549 {
550 if (!parse_uint16(this, rule_number, output + rule->offset))
551 {
552 pld->destroy(pld);
553 return PARSE_ERROR;
554 }
555 attribute_length = *(u_int16_t*)(output + rule->offset);
556 break;
557 }
558 case ATTRIBUTE_LENGTH_OR_VALUE:
559 {
560 if (!parse_uint16(this, rule_number, output + rule->offset))
561 {
562 pld->destroy(pld);
563 return PARSE_ERROR;
564 }
565 attribute_length = *(u_int16_t*)(output + rule->offset);
566 break;
567 }
568 case ATTRIBUTE_VALUE:
569 {
570 if (attribute_format == FALSE &&
571 !parse_chunk(this, rule_number, output + rule->offset,
572 attribute_length))
573 {
574 pld->destroy(pld);
575 return PARSE_ERROR;
576 }
577 break;
578 }
579 case TS_TYPE:
580 {
581 if (!parse_uint8(this, rule_number, output + rule->offset))
582 {
583 pld->destroy(pld);
584 return PARSE_ERROR;
585 }
586 ts_type = *(u_int8_t*)(output + rule->offset);
587 break;
588 }
589 case ADDRESS:
590 {
591 int address_length = (ts_type == TS_IPV4_ADDR_RANGE) ? 4 : 16;
592
593 if (!parse_chunk(this, rule_number, output + rule->offset,
594 address_length))
595 {
596 pld->destroy(pld);
597 return PARSE_ERROR;
598 }
599 break;
600 }
601 default:
602 {
603 DBG1(DBG_ENC, " no rule to parse rule %d %N",
604 rule_number, encoding_type_names, rule->type);
605 pld->destroy(pld);
606 return PARSE_ERROR;
607 }
608 }
609 /* process next rulue */
610 rule++;
611 }
612
613 *payload = pld;
614 DBG2(DBG_ENC, "parsing %N payload finished",
615 payload_type_names, payload_type);
616 return SUCCESS;
617 }
618
619 METHOD(parser_t, get_remaining_byte_count, int,
620 private_parser_t *this)
621 {
622 return this->input_roof - this->byte_pos;
623 }
624
625 METHOD(parser_t, reset_context, void,
626 private_parser_t *this)
627 {
628 this->byte_pos = this->input;
629 this->bit_pos = 0;
630 }
631
632 METHOD(parser_t, destroy, void,
633 private_parser_t *this)
634 {
635 free(this);
636 }
637
638 /*
639 * Described in header.
640 */
641 parser_t *parser_create(chunk_t data)
642 {
643 private_parser_t *this;
644
645 INIT(this,
646 .public = {
647 .parse_payload = _parse_payload,
648 .reset_context = _reset_context,
649 .get_remaining_byte_count = _get_remaining_byte_count,
650 .destroy = _destroy,
651 },
652 .input = data.ptr,
653 .byte_pos = data.ptr,
654 .input_roof = data.ptr + data.len,
655 );
656
657 return &this->public;
658 }
659