- Fix the stupid mess we created when making this from the cmake branch
[reactos.git] / lib / drivers / lwip / src / core / snmp / asn1_enc.c
1 /**
2 * @file
3 * Abstract Syntax Notation One (ISO 8824, 8825) encoding
4 *
5 * @todo not optimised (yet), favor correctness over speed, favor speed over size
6 */
7
8 /*
9 * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without modification,
13 * are permitted provided that the following conditions are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright notice,
16 * this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright notice,
18 * this list of conditions and the following disclaimer in the documentation
19 * and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
24 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
26 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
28 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
31 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
32 * OF SUCH DAMAGE.
33 *
34 * Author: Christiaan Simons <christiaan.simons@axon.tv>
35 */
36
37 #include "lwip/opt.h"
38
39 #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
40
41 #include "lwip/snmp_asn1.h"
42
43 /**
44 * Returns octet count for length.
45 *
46 * @param length
47 * @param octets_needed points to the return value
48 */
49 void
50 snmp_asn1_enc_length_cnt(u16_t length, u8_t *octets_needed)
51 {
52 if (length < 0x80U)
53 {
54 *octets_needed = 1;
55 }
56 else if (length < 0x100U)
57 {
58 *octets_needed = 2;
59 }
60 else
61 {
62 *octets_needed = 3;
63 }
64 }
65
66 /**
67 * Returns octet count for an u32_t.
68 *
69 * @param value
70 * @param octets_needed points to the return value
71 *
72 * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
73 * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
74 * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
75 */
76 void
77 snmp_asn1_enc_u32t_cnt(u32_t value, u16_t *octets_needed)
78 {
79 if (value < 0x80UL)
80 {
81 *octets_needed = 1;
82 }
83 else if (value < 0x8000UL)
84 {
85 *octets_needed = 2;
86 }
87 else if (value < 0x800000UL)
88 {
89 *octets_needed = 3;
90 }
91 else if (value < 0x80000000UL)
92 {
93 *octets_needed = 4;
94 }
95 else
96 {
97 *octets_needed = 5;
98 }
99 }
100
101 /**
102 * Returns octet count for an s32_t.
103 *
104 * @param value
105 * @param octets_needed points to the return value
106 *
107 * @note ASN coded integers are _always_ signed.
108 */
109 void
110 snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed)
111 {
112 if (value < 0)
113 {
114 value = ~value;
115 }
116 if (value < 0x80L)
117 {
118 *octets_needed = 1;
119 }
120 else if (value < 0x8000L)
121 {
122 *octets_needed = 2;
123 }
124 else if (value < 0x800000L)
125 {
126 *octets_needed = 3;
127 }
128 else
129 {
130 *octets_needed = 4;
131 }
132 }
133
134 /**
135 * Returns octet count for an object identifier.
136 *
137 * @param ident_len object identifier array length
138 * @param ident points to object identifier array
139 * @param octets_needed points to the return value
140 */
141 void
142 snmp_asn1_enc_oid_cnt(u8_t ident_len, s32_t *ident, u16_t *octets_needed)
143 {
144 s32_t sub_id;
145 u8_t cnt;
146
147 cnt = 0;
148 if (ident_len > 1)
149 {
150 /* compressed prefix in one octet */
151 cnt++;
152 ident_len -= 2;
153 ident += 2;
154 }
155 while(ident_len > 0)
156 {
157 ident_len--;
158 sub_id = *ident;
159
160 sub_id >>= 7;
161 cnt++;
162 while(sub_id > 0)
163 {
164 sub_id >>= 7;
165 cnt++;
166 }
167 ident++;
168 }
169 *octets_needed = cnt;
170 }
171
172 /**
173 * Encodes ASN type field into a pbuf chained ASN1 msg.
174 *
175 * @param p points to output pbuf to encode value into
176 * @param ofs points to the offset within the pbuf chain
177 * @param type input ASN1 type
178 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
179 */
180 err_t
181 snmp_asn1_enc_type(struct pbuf *p, u16_t ofs, u8_t type)
182 {
183 u16_t plen, base;
184 u8_t *msg_ptr;
185
186 plen = 0;
187 while (p != NULL)
188 {
189 base = plen;
190 plen += p->len;
191 if (ofs < plen)
192 {
193 msg_ptr = (u8_t*)p->payload;
194 msg_ptr += ofs - base;
195 *msg_ptr = type;
196 return ERR_OK;
197 }
198 p = p->next;
199 }
200 /* p == NULL, ofs >= plen */
201 return ERR_ARG;
202 }
203
204 /**
205 * Encodes host order length field into a pbuf chained ASN1 msg.
206 *
207 * @param p points to output pbuf to encode length into
208 * @param ofs points to the offset within the pbuf chain
209 * @param length is the host order length to be encoded
210 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
211 */
212 err_t
213 snmp_asn1_enc_length(struct pbuf *p, u16_t ofs, u16_t length)
214 {
215 u16_t plen, base;
216 u8_t *msg_ptr;
217
218 plen = 0;
219 while (p != NULL)
220 {
221 base = plen;
222 plen += p->len;
223 if (ofs < plen)
224 {
225 msg_ptr = (u8_t*)p->payload;
226 msg_ptr += ofs - base;
227
228 if (length < 0x80)
229 {
230 *msg_ptr = (u8_t)length;
231 return ERR_OK;
232 }
233 else if (length < 0x100)
234 {
235 *msg_ptr = 0x81;
236 ofs += 1;
237 if (ofs >= plen)
238 {
239 /* next octet in next pbuf */
240 p = p->next;
241 if (p == NULL) { return ERR_ARG; }
242 msg_ptr = (u8_t*)p->payload;
243 }
244 else
245 {
246 /* next octet in same pbuf */
247 msg_ptr++;
248 }
249 *msg_ptr = (u8_t)length;
250 return ERR_OK;
251 }
252 else
253 {
254 u8_t i;
255
256 /* length >= 0x100 && length <= 0xFFFF */
257 *msg_ptr = 0x82;
258 i = 2;
259 while (i > 0)
260 {
261 i--;
262 ofs += 1;
263 if (ofs >= plen)
264 {
265 /* next octet in next pbuf */
266 p = p->next;
267 if (p == NULL) { return ERR_ARG; }
268 msg_ptr = (u8_t*)p->payload;
269 plen += p->len;
270 }
271 else
272 {
273 /* next octet in same pbuf */
274 msg_ptr++;
275 }
276 if (i == 0)
277 {
278 /* least significant length octet */
279 *msg_ptr = (u8_t)length;
280 }
281 else
282 {
283 /* most significant length octet */
284 *msg_ptr = (u8_t)(length >> 8);
285 }
286 }
287 return ERR_OK;
288 }
289 }
290 p = p->next;
291 }
292 /* p == NULL, ofs >= plen */
293 return ERR_ARG;
294 }
295
296 /**
297 * Encodes u32_t (counter, gauge, timeticks) into a pbuf chained ASN1 msg.
298 *
299 * @param p points to output pbuf to encode value into
300 * @param ofs points to the offset within the pbuf chain
301 * @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt())
302 * @param value is the host order u32_t value to be encoded
303 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
304 *
305 * @see snmp_asn1_enc_u32t_cnt()
306 */
307 err_t
308 snmp_asn1_enc_u32t(struct pbuf *p, u16_t ofs, u16_t octets_needed, u32_t value)
309 {
310 u16_t plen, base;
311 u8_t *msg_ptr;
312
313 plen = 0;
314 while (p != NULL)
315 {
316 base = plen;
317 plen += p->len;
318 if (ofs < plen)
319 {
320 msg_ptr = (u8_t*)p->payload;
321 msg_ptr += ofs - base;
322
323 if (octets_needed == 5)
324 {
325 /* not enough bits in 'value' add leading 0x00 */
326 octets_needed--;
327 *msg_ptr = 0x00;
328 ofs += 1;
329 if (ofs >= plen)
330 {
331 /* next octet in next pbuf */
332 p = p->next;
333 if (p == NULL) { return ERR_ARG; }
334 msg_ptr = (u8_t*)p->payload;
335 plen += p->len;
336 }
337 else
338 {
339 /* next octet in same pbuf */
340 msg_ptr++;
341 }
342 }
343 while (octets_needed > 1)
344 {
345 octets_needed--;
346 *msg_ptr = (u8_t)(value >> (octets_needed << 3));
347 ofs += 1;
348 if (ofs >= plen)
349 {
350 /* next octet in next pbuf */
351 p = p->next;
352 if (p == NULL) { return ERR_ARG; }
353 msg_ptr = (u8_t*)p->payload;
354 plen += p->len;
355 }
356 else
357 {
358 /* next octet in same pbuf */
359 msg_ptr++;
360 }
361 }
362 /* (only) one least significant octet */
363 *msg_ptr = (u8_t)value;
364 return ERR_OK;
365 }
366 p = p->next;
367 }
368 /* p == NULL, ofs >= plen */
369 return ERR_ARG;
370 }
371
372 /**
373 * Encodes s32_t integer into a pbuf chained ASN1 msg.
374 *
375 * @param p points to output pbuf to encode value into
376 * @param ofs points to the offset within the pbuf chain
377 * @param octets_needed encoding length (from snmp_asn1_enc_s32t_cnt())
378 * @param value is the host order s32_t value to be encoded
379 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
380 *
381 * @see snmp_asn1_enc_s32t_cnt()
382 */
383 err_t
384 snmp_asn1_enc_s32t(struct pbuf *p, u16_t ofs, u16_t octets_needed, s32_t value)
385 {
386 u16_t plen, base;
387 u8_t *msg_ptr;
388
389 plen = 0;
390 while (p != NULL)
391 {
392 base = plen;
393 plen += p->len;
394 if (ofs < plen)
395 {
396 msg_ptr = (u8_t*)p->payload;
397 msg_ptr += ofs - base;
398
399 while (octets_needed > 1)
400 {
401 octets_needed--;
402 *msg_ptr = (u8_t)(value >> (octets_needed << 3));
403 ofs += 1;
404 if (ofs >= plen)
405 {
406 /* next octet in next pbuf */
407 p = p->next;
408 if (p == NULL) { return ERR_ARG; }
409 msg_ptr = (u8_t*)p->payload;
410 plen += p->len;
411 }
412 else
413 {
414 /* next octet in same pbuf */
415 msg_ptr++;
416 }
417 }
418 /* (only) one least significant octet */
419 *msg_ptr = (u8_t)value;
420 return ERR_OK;
421 }
422 p = p->next;
423 }
424 /* p == NULL, ofs >= plen */
425 return ERR_ARG;
426 }
427
428 /**
429 * Encodes object identifier into a pbuf chained ASN1 msg.
430 *
431 * @param p points to output pbuf to encode oid into
432 * @param ofs points to the offset within the pbuf chain
433 * @param ident_len object identifier array length
434 * @param ident points to object identifier array
435 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
436 */
437 err_t
438 snmp_asn1_enc_oid(struct pbuf *p, u16_t ofs, u8_t ident_len, s32_t *ident)
439 {
440 u16_t plen, base;
441 u8_t *msg_ptr;
442
443 plen = 0;
444 while (p != NULL)
445 {
446 base = plen;
447 plen += p->len;
448 if (ofs < plen)
449 {
450 msg_ptr = (u8_t*)p->payload;
451 msg_ptr += ofs - base;
452
453 if (ident_len > 1)
454 {
455 if ((ident[0] == 1) && (ident[1] == 3))
456 {
457 /* compressed (most common) prefix .iso.org */
458 *msg_ptr = 0x2b;
459 }
460 else
461 {
462 /* calculate prefix */
463 *msg_ptr = (u8_t)((ident[0] * 40) + ident[1]);
464 }
465 ofs += 1;
466 if (ofs >= plen)
467 {
468 /* next octet in next pbuf */
469 p = p->next;
470 if (p == NULL) { return ERR_ARG; }
471 msg_ptr = (u8_t*)p->payload;
472 plen += p->len;
473 }
474 else
475 {
476 /* next octet in same pbuf */
477 msg_ptr++;
478 }
479 ident_len -= 2;
480 ident += 2;
481 }
482 else
483 {
484 /* @bug: allow empty varbinds for symmetry (we must decode them for getnext), allow partial compression?? */
485 /* ident_len <= 1, at least we need zeroDotZero (0.0) (ident_len == 2) */
486 return ERR_ARG;
487 }
488 while (ident_len > 0)
489 {
490 s32_t sub_id;
491 u8_t shift, tail;
492
493 ident_len--;
494 sub_id = *ident;
495 tail = 0;
496 shift = 28;
497 while(shift > 0)
498 {
499 u8_t code;
500
501 code = (u8_t)(sub_id >> shift);
502 if ((code != 0) || (tail != 0))
503 {
504 tail = 1;
505 *msg_ptr = code | 0x80;
506 ofs += 1;
507 if (ofs >= plen)
508 {
509 /* next octet in next pbuf */
510 p = p->next;
511 if (p == NULL) { return ERR_ARG; }
512 msg_ptr = (u8_t*)p->payload;
513 plen += p->len;
514 }
515 else
516 {
517 /* next octet in same pbuf */
518 msg_ptr++;
519 }
520 }
521 shift -= 7;
522 }
523 *msg_ptr = (u8_t)sub_id & 0x7F;
524 if (ident_len > 0)
525 {
526 ofs += 1;
527 if (ofs >= plen)
528 {
529 /* next octet in next pbuf */
530 p = p->next;
531 if (p == NULL) { return ERR_ARG; }
532 msg_ptr = (u8_t*)p->payload;
533 plen += p->len;
534 }
535 else
536 {
537 /* next octet in same pbuf */
538 msg_ptr++;
539 }
540 }
541 /* proceed to next sub-identifier */
542 ident++;
543 }
544 return ERR_OK;
545 }
546 p = p->next;
547 }
548 /* p == NULL, ofs >= plen */
549 return ERR_ARG;
550 }
551
552 /**
553 * Encodes raw data (octet string, opaque) into a pbuf chained ASN1 msg.
554 *
555 * @param p points to output pbuf to encode raw data into
556 * @param ofs points to the offset within the pbuf chain
557 * @param raw_len raw data length
558 * @param raw points raw data
559 * @return ERR_OK if successfull, ERR_ARG if we can't (or won't) encode
560 */
561 err_t
562 snmp_asn1_enc_raw(struct pbuf *p, u16_t ofs, u16_t raw_len, u8_t *raw)
563 {
564 u16_t plen, base;
565 u8_t *msg_ptr;
566
567 plen = 0;
568 while (p != NULL)
569 {
570 base = plen;
571 plen += p->len;
572 if (ofs < plen)
573 {
574 msg_ptr = (u8_t*)p->payload;
575 msg_ptr += ofs - base;
576
577 while (raw_len > 1)
578 {
579 /* copy raw_len - 1 octets */
580 raw_len--;
581 *msg_ptr = *raw;
582 raw++;
583 ofs += 1;
584 if (ofs >= plen)
585 {
586 /* next octet in next pbuf */
587 p = p->next;
588 if (p == NULL) { return ERR_ARG; }
589 msg_ptr = (u8_t*)p->payload;
590 plen += p->len;
591 }
592 else
593 {
594 /* next octet in same pbuf */
595 msg_ptr++;
596 }
597 }
598 if (raw_len > 0)
599 {
600 /* copy last or single octet */
601 *msg_ptr = *raw;
602 }
603 return ERR_OK;
604 }
605 p = p->next;
606 }
607 /* p == NULL, ofs >= plen */
608 return ERR_ARG;
609 }
610
611 #endif /* LWIP_SNMP */