1/*
2   FastLZ - lightning-fast lossless compression library
3
4   Copyright (C) 2007 Ariya Hidayat (ariya@kde.org)
5   Copyright (C) 2006 Ariya Hidayat (ariya@kde.org)
6   Copyright (C) 2005 Ariya Hidayat (ariya@kde.org)
7
8   Permission is hereby granted, free of charge, to any person obtaining a copy
9   of this software and associated documentation files (the "Software"), to deal
10   in the Software without restriction, including without limitation the rights
11   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12   copies of the Software, and to permit persons to whom the Software is
13   furnished to do so, subject to the following conditions:
14
15   The above copyright notice and this permission notice shall be included in
16   all copies or substantial portions of the Software.
17
18   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24   THE SOFTWARE.
25   */
26#include <sys/cdefs.h>
27#include "osdep.h"
28#include "cudbg.h"
29#include "cudbg_lib_common.h"
30#include "fastlz.h"
31
32static unsigned char sixpack_magic[8] = {137, '6', 'P', 'K', 13, 10, 26, 10};
33
34#define CUDBG_BLOCK_SIZE      (63*1024)
35#define CUDBG_CHUNK_BUF_LEN   16
36#define CUDBG_MIN_COMPR_LEN   32	/*min data length for applying compression*/
37
38/* for Adler-32 checksum algorithm, see RFC 1950 Section 8.2 */
39
40#define ADLER32_BASE 65521
41
42static inline unsigned long update_adler32(unsigned long checksum,
43					   const void *buf, int len)
44{
45	const unsigned char *ptr = (const unsigned char *)buf;
46	unsigned long s1 = checksum & 0xffff;
47	unsigned long s2 = (checksum >> 16) & 0xffff;
48
49	while (len > 0) {
50		unsigned k = len < 5552 ? len : 5552;
51		len -= k;
52
53		while (k >= 8) {
54			s1 += *ptr++; s2 += s1;
55			s1 += *ptr++; s2 += s1;
56			s1 += *ptr++; s2 += s1;
57			s1 += *ptr++; s2 += s1;
58			s1 += *ptr++; s2 += s1;
59			s1 += *ptr++; s2 += s1;
60			s1 += *ptr++; s2 += s1;
61			s1 += *ptr++; s2 += s1;
62			k -= 8;
63		}
64
65		while (k-- > 0) {
66			s1 += *ptr++; s2 += s1;
67		}
68		s1 = s1 % ADLER32_BASE;
69		s2 = s2 % ADLER32_BASE;
70	}
71	return (s2 << 16) + s1;
72}
73
74int write_magic(struct cudbg_buffer *_out_buff)
75{
76	int rc;
77
78	rc = write_to_buf(_out_buff->data, _out_buff->size, &_out_buff->offset,
79			  sixpack_magic, 8);
80
81	return rc;
82}
83
84int write_to_buf(void *out_buf, u32 out_buf_size, u32 *offset, void *in_buf,
85		 u32 in_buf_size)
86{
87	int rc = 0;
88
89	if (*offset >= out_buf_size) {
90		rc = CUDBG_STATUS_OUTBUFF_OVERFLOW;
91		goto err;
92	}
93
94	memcpy((char *)out_buf + *offset, in_buf, in_buf_size);
95	*offset = *offset + in_buf_size;
96
97err:
98	return rc;
99}
100
101int read_from_buf(void *in_buf, u32 in_buf_size, u32 *offset, void *out_buf,
102		  u32 out_buf_size)
103{
104	if (in_buf_size - *offset < out_buf_size)
105		return 0;
106
107	memcpy((char *)out_buf, (char *)in_buf + *offset, out_buf_size);
108	*offset =  *offset + out_buf_size;
109	return out_buf_size;
110}
111
112int write_chunk_header(struct cudbg_buffer *_outbuf, int id, int options,
113		       unsigned long size, unsigned long checksum,
114		       unsigned long extra)
115{
116	unsigned char buffer[CUDBG_CHUNK_BUF_LEN];
117	int rc = 0;
118
119	buffer[0] = id & 255;
120	buffer[1] = (unsigned char)(id >> 8);
121	buffer[2] = options & 255;
122	buffer[3] = (unsigned char)(options >> 8);
123	buffer[4] = size & 255;
124	buffer[5] = (size >> 8) & 255;
125	buffer[6] = (size >> 16) & 255;
126	buffer[7] = (size >> 24) & 255;
127	buffer[8] = checksum & 255;
128	buffer[9] = (checksum >> 8) & 255;
129	buffer[10] = (checksum >> 16) & 255;
130	buffer[11] = (checksum >> 24) & 255;
131	buffer[12] = extra & 255;
132	buffer[13] = (extra >> 8) & 255;
133	buffer[14] = (extra >> 16) & 255;
134	buffer[15] = (extra >> 24) & 255;
135
136	rc = write_to_buf(_outbuf->data, _outbuf->size, &_outbuf->offset,
137			  buffer, 16);
138
139	return rc;
140}
141
142int write_compression_hdr(struct cudbg_buffer *pin_buff,
143			  struct cudbg_buffer *pout_buff)
144{
145	struct cudbg_buffer tmp_buffer;
146	unsigned long fsize = pin_buff->size;
147	unsigned char *buffer;
148	unsigned long checksum;
149	int rc;
150	char *shown_name = "abc";
151
152	/* Always release inner scratch buffer, before releasing outer. */
153	rc = get_scratch_buff(pout_buff, 10, &tmp_buffer);
154
155	if (rc)
156		goto err;
157
158	buffer = (unsigned char *)tmp_buffer.data;
159
160	rc = write_magic(pout_buff);
161
162	if (rc)
163		goto err1;
164
165	/* chunk for File Entry */
166	buffer[0] = fsize & 255;
167	buffer[1] = (fsize >> 8) & 255;
168	buffer[2] = (fsize >> 16) & 255;
169	buffer[3] = (fsize >> 24) & 255;
170	buffer[4] = 0;
171	buffer[5] = 0;
172	buffer[6] = 0;
173	buffer[7] = 0;
174	buffer[8] = (strlen(shown_name)+1) & 255;
175	buffer[9] = (unsigned char)((strlen(shown_name)+1) >> 8);
176	checksum = 1L;
177	checksum = update_adler32(checksum, buffer, 10);
178	checksum = update_adler32(checksum, shown_name,
179				  (int)strlen(shown_name)+1);
180
181	rc = write_chunk_header(pout_buff, 1, 0,
182				10+(unsigned long)strlen(shown_name)+1,
183				checksum, 0);
184
185	if (rc)
186		goto err1;
187
188	rc = write_to_buf(pout_buff->data, pout_buff->size,
189			  &(pout_buff->offset), buffer, 10);
190
191	if (rc)
192		goto err1;
193
194	rc = write_to_buf(pout_buff->data, pout_buff->size,
195			   &(pout_buff->offset), shown_name,
196			   (u32)strlen(shown_name)+1);
197
198	if (rc)
199		goto err1;
200
201err1:
202	release_scratch_buff(&tmp_buffer, pout_buff);
203err:
204	return rc;
205}
206
207int compress_buff(struct cudbg_buffer *pin_buff, struct cudbg_buffer *pout_buff)
208{
209	struct cudbg_buffer tmp_buffer;
210	struct cudbg_hdr *cudbg_hdr;
211	unsigned long checksum;
212	unsigned char *result;
213	unsigned int bytes_read;
214	int chunk_size, level = 2, rc = 0;
215	int compress_method = 1;
216
217	bytes_read = pin_buff->size;
218	rc = get_scratch_buff(pout_buff, CUDBG_BLOCK_SIZE, &tmp_buffer);
219
220	if (rc)
221		goto err;
222
223	result = (unsigned char *)tmp_buffer.data;
224
225	if (bytes_read < 32)
226		compress_method = 0;
227
228	cudbg_hdr = (struct cudbg_hdr *)  pout_buff->data;
229
230	switch (compress_method) {
231	case 1:
232		chunk_size = fastlz_compress_level(level, pin_buff->data,
233						   bytes_read, result);
234
235		checksum = update_adler32(1L, result, chunk_size);
236
237		if ((chunk_size > 62000) && (cudbg_hdr->reserved[7] < (u32)
238		    chunk_size))   /* 64512 */
239			cudbg_hdr->reserved[7] = (u32) chunk_size;
240
241		rc = write_chunk_header(pout_buff, 17, 1, chunk_size, checksum,
242					bytes_read);
243
244		if (rc)
245			goto err_put_buff;
246
247		rc = write_to_buf(pout_buff->data, pout_buff->size,
248				  &pout_buff->offset, result, chunk_size);
249
250		if (rc)
251			goto err_put_buff;
252
253		break;
254
255		/* uncompressed, also fallback method */
256	case 0:
257	default:
258		checksum = update_adler32(1L, pin_buff->data, bytes_read);
259
260		rc = write_chunk_header(pout_buff, 17, 0, bytes_read, checksum,
261					bytes_read);
262
263		if (rc)
264			goto err_put_buff;
265
266		rc = write_to_buf(pout_buff->data, pout_buff->size,
267				  &pout_buff->offset, pin_buff->data,
268				  bytes_read);
269		if (rc)
270			goto err_put_buff;
271
272		break;
273	}
274
275err_put_buff:
276	release_scratch_buff(&tmp_buffer, pout_buff);
277err:
278	return rc;
279}
280
281/* return non-zero if magic sequence is detected */
282/* warning: reset the read pointer to the beginning of the file */
283int detect_magic(struct cudbg_buffer *_c_buff)
284{
285	unsigned char buffer[8];
286	size_t bytes_read;
287	int c;
288
289	bytes_read = read_from_buf(_c_buff->data, _c_buff->size,
290				   &_c_buff->offset, buffer, 8);
291
292	if (bytes_read < 8)
293		return 0;
294
295	for (c = 0; c < 8; c++)
296		if (buffer[c] != sixpack_magic[c])
297			return 0;
298
299	return -1;
300}
301
302static inline unsigned long readU16(const unsigned char *ptr)
303{
304	return ptr[0]+(ptr[1]<<8);
305}
306
307static inline unsigned long readU32(const unsigned char *ptr)
308{
309	return ptr[0]+(ptr[1]<<8)+(ptr[2]<<16)+(ptr[3]<<24);
310}
311
312int read_chunk_header(struct cudbg_buffer *pc_buff, int *pid, int *poptions,
313		      unsigned long *psize, unsigned long *pchecksum,
314		      unsigned long *pextra)
315{
316	unsigned char buffer[CUDBG_CHUNK_BUF_LEN];
317	int byte_r = read_from_buf(pc_buff->data, pc_buff->size,
318				   &pc_buff->offset, buffer, 16);
319	if (byte_r == 0)
320		return 0;
321
322	*pid = readU16(buffer) & 0xffff;
323	*poptions = readU16(buffer+2) & 0xffff;
324	*psize = readU32(buffer+4) & 0xffffffff;
325	*pchecksum = readU32(buffer+8) & 0xffffffff;
326	*pextra = readU32(buffer+12) & 0xffffffff;
327	return 0;
328}
329
330int validate_buffer(struct cudbg_buffer *compressed_buffer)
331{
332	if (!detect_magic(compressed_buffer))
333		return CUDBG_STATUS_INVALID_BUFF;
334
335	return 0;
336}
337
338int decompress_buffer(struct cudbg_buffer *pc_buff,
339		      struct cudbg_buffer *pd_buff)
340{
341	struct cudbg_buffer tmp_compressed_buffer;
342	struct cudbg_buffer tmp_decompressed_buffer;
343	unsigned char *compressed_buffer;
344	unsigned char *decompressed_buffer;
345	unsigned char buffer[CUDBG_MIN_COMPR_LEN];
346	unsigned long chunk_size;
347	unsigned long chunk_checksum;
348	unsigned long chunk_extra;
349	unsigned long checksum;
350	unsigned long r;
351	unsigned long remaining;
352	unsigned long bytes_read;
353	u32 decompressed_size = 0;
354	int chunk_id, chunk_options, rc;
355
356	if (pd_buff->size < 2 * CUDBG_BLOCK_SIZE)
357		return CUDBG_STATUS_SMALL_BUFF;
358
359	rc = get_scratch_buff(pd_buff, CUDBG_BLOCK_SIZE,
360			      &tmp_compressed_buffer);
361
362	if (rc)
363		goto err_cbuff;
364
365	rc = get_scratch_buff(pd_buff, CUDBG_BLOCK_SIZE,
366			      &tmp_decompressed_buffer);
367	if (rc)
368		goto err_dcbuff;
369
370	compressed_buffer = (unsigned char *)tmp_compressed_buffer.data;
371	decompressed_buffer = (unsigned char *)tmp_decompressed_buffer.data;
372
373	/* main loop */
374
375	for (;;) {
376		if (pc_buff->offset > pc_buff->size)
377			break;
378
379		rc =  read_chunk_header(pc_buff, &chunk_id, &chunk_options,
380					&chunk_size, &chunk_checksum,
381					&chunk_extra);
382		if (rc != 0)
383			break;
384
385		/* skip 8+16 */
386		if ((chunk_id == 1) && (chunk_size > 10) &&
387		    (chunk_size < CUDBG_BLOCK_SIZE)) {
388
389			bytes_read = read_from_buf(pc_buff->data, pc_buff->size,
390						   &pc_buff->offset, buffer,
391						   chunk_size);
392
393			if (bytes_read == 0)
394				return 0;
395
396			checksum = update_adler32(1L, buffer, chunk_size);
397			if (checksum != chunk_checksum)
398				return CUDBG_STATUS_CHKSUM_MISSMATCH;
399
400			decompressed_size = (u32)readU32(buffer);
401
402			if (pd_buff->size < decompressed_size) {
403
404				pd_buff->size = 2 * CUDBG_BLOCK_SIZE +
405						decompressed_size;
406				pc_buff->offset -= chunk_size + 16;
407				return CUDBG_STATUS_SMALL_BUFF;
408			}
409		}
410
411		if (chunk_size > CUDBG_BLOCK_SIZE) {
412			/* Release old allocated memory */
413			release_scratch_buff(&tmp_decompressed_buffer, pd_buff);
414			release_scratch_buff(&tmp_compressed_buffer, pd_buff);
415
416			/* allocate new memory with chunk_size size */
417			rc = get_scratch_buff(pd_buff, chunk_size,
418					      &tmp_compressed_buffer);
419			if (rc)
420				goto err_cbuff;
421
422			rc = get_scratch_buff(pd_buff, chunk_size,
423					      &tmp_decompressed_buffer);
424			if (rc)
425				goto err_dcbuff;
426
427			compressed_buffer = (unsigned char *)tmp_compressed_buffer.data;
428			decompressed_buffer = (unsigned char *)tmp_decompressed_buffer.data;
429		}
430
431		if ((chunk_id == 17) && decompressed_size) {
432			/* uncompressed */
433			switch (chunk_options) {
434				/* stored, simply copy to output */
435			case 0:
436				remaining = chunk_size;
437				checksum = 1L;
438				for (;;) {
439					/* Write a function for this */
440					r = (CUDBG_BLOCK_SIZE < remaining) ?
441					    CUDBG_BLOCK_SIZE : remaining;
442					bytes_read =
443					read_from_buf(pc_buff->data,
444						      pc_buff->size,
445						      &pc_buff->offset, buffer,
446						      r);
447
448					if (bytes_read == 0)
449						return 0;
450
451					write_to_buf(pd_buff->data,
452						     pd_buff->size,
453						     &pd_buff->offset, buffer,
454						     bytes_read);
455					checksum = update_adler32(checksum,
456								  buffer,
457								  bytes_read);
458					remaining -= bytes_read;
459
460					/* verify everything is written
461					 * correctly */
462					if (checksum != chunk_checksum)
463						return
464						CUDBG_STATUS_CHKSUM_MISSMATCH;
465				}
466
467				break;
468
469				/* compressed using FastLZ */
470			case 1:
471				bytes_read = read_from_buf(pc_buff->data,
472							   pc_buff->size,
473							   &pc_buff->offset,
474							   compressed_buffer,
475							   chunk_size);
476
477				if (bytes_read == 0)
478					return 0;
479
480				checksum = update_adler32(1L, compressed_buffer,
481							  chunk_size);
482
483				/* verify that the chunk data is correct */
484				if (checksum != chunk_checksum) {
485					return CUDBG_STATUS_CHKSUM_MISSMATCH;
486				} else {
487					/* decompress and verify */
488					remaining =
489					fastlz_decompress(compressed_buffer,
490							  chunk_size,
491							  decompressed_buffer,
492							  chunk_extra);
493
494					if (remaining != chunk_extra) {
495						rc =
496						CUDBG_STATUS_DECOMPRESS_FAIL;
497						goto err;
498					} else {
499						write_to_buf(pd_buff->data,
500							     pd_buff->size,
501							     &pd_buff->offset,
502							     decompressed_buffer,
503							     chunk_extra);
504					}
505				}
506				break;
507
508			default:
509				break;
510			}
511
512		}
513
514	}
515
516err:
517	release_scratch_buff(&tmp_decompressed_buffer, pd_buff);
518err_dcbuff:
519	release_scratch_buff(&tmp_compressed_buffer, pd_buff);
520
521err_cbuff:
522	return rc;
523}
524
525