[people/ms/u-boot.git] / lib / lzo / lzo1x_decompress.c

/*
 *  LZO1X Decompressor from MiniLZO
 *
 *  Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
 *
 *  The full LZO package can be found at:
 *  http://www.oberhumer.com/opensource/lzo/
 *
 *  Changed for kernel use by:
 *  Nitin Gupta <nitingupta910@gmail.com>
 *  Richard Purdie <rpurdie@openedhand.com>
 */

#include <common.h>
#include <linux/lzo.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include "lzodefs.h"

#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x))
#define HAVE_OP(x, op_end, op) ((size_t)(op_end - op) < (x))
#define HAVE_LB(m_pos, out, op) (m_pos < out || m_pos >= op)

#define COPY4(dst, src)	\
		put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst))

static const unsigned char lzop_magic[] = {
	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a
};

#define HEADER_HAS_FILTER	0x00000800L

static inline const unsigned char *parse_header(const unsigned char *src)
{
	u16 version;
	int i;

	/* read magic: 9 first bytes */
	for (i = 0; i < ARRAY_SIZE(lzop_magic); i++) {
		if (*src++ != lzop_magic[i])
			return NULL;
	}
	/* get version (2bytes), skip library version (2),
	 * 'need to be extracted' version (2) and
	 * method (1) */
	version = get_unaligned_be16(src);
	src += 7;
	if (version >= 0x0940)
		src++;
	if (get_unaligned_be32(src) & HEADER_HAS_FILTER)
		src += 4; /* filter info */

	/* skip flags, mode and mtime_low */
	src += 12;
	if (version >= 0x0940)
		src += 4;	/* skip mtime_high */

	i = *src++;
	/* don't care about the file name, and skip checksum */
	src += i + 4;

	return src;
}

int lzop_decompress(const unsigned char *src, size_t src_len,
		    unsigned char *dst, size_t *dst_len)
{
	unsigned char *start = dst;
	const unsigned char *send = src + src_len;
	u32 slen, dlen;
	size_t tmp;
	int r;

	src = parse_header(src);
	if (!src)
		return LZO_E_ERROR;

	while (src < send) {
		/* read uncompressed block size */
		dlen = get_unaligned_be32(src);
		src += 4;

		/* exit if last block */
		if (dlen == 0) {
			*dst_len = dst - start;
			return LZO_E_OK;
		}

		/* read compressed block size, and skip block checksum info */
		slen = get_unaligned_be32(src);
		src += 8;

		if (slen <= 0 || slen > dlen)
			return LZO_E_ERROR;

		/* decompress */
		tmp = dlen;
		r = lzo1x_decompress_safe((u8 *) src, slen, dst, &tmp);

		if (r != LZO_E_OK)
			return r;

		if (dlen != tmp)
			return LZO_E_ERROR;

		src += slen;
		dst += dlen;
	}

	return LZO_E_INPUT_OVERRUN;
}

int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
			unsigned char *out, size_t *out_len)
{
	const unsigned char * const ip_end = in + in_len;
	unsigned char * const op_end = out + *out_len;
	const unsigned char *ip = in, *m_pos;
	unsigned char *op = out;
	size_t t;

	*out_len = 0;

	if (*ip > 17) {
		t = *ip++ - 17;
		if (t < 4)
			goto match_next;
		if (HAVE_OP(t, op_end, op))
			goto output_overrun;
		if (HAVE_IP(t + 1, ip_end, ip))
			goto input_overrun;
		do {
			*op++ = *ip++;
		} while (--t > 0);
		goto first_literal_run;
	}

	while ((ip < ip_end)) {
		t = *ip++;
		if (t >= 16)
			goto match;
		if (t == 0) {
			if (HAVE_IP(1, ip_end, ip))
				goto input_overrun;
			while (*ip == 0) {
				t += 255;
				ip++;
				if (HAVE_IP(1, ip_end, ip))
					goto input_overrun;
			}
			t += 15 + *ip++;
		}
		if (HAVE_OP(t + 3, op_end, op))
			goto output_overrun;
		if (HAVE_IP(t + 4, ip_end, ip))
			goto input_overrun;

		COPY4(op, ip);
		op += 4;
		ip += 4;
		if (--t > 0) {
			if (t >= 4) {
				do {
					COPY4(op, ip);
					op += 4;
					ip += 4;
					t -= 4;
				} while (t >= 4);
				if (t > 0) {
					do {
						*op++ = *ip++;
					} while (--t > 0);
				}
			} else {
				do {
					*op++ = *ip++;
				} while (--t > 0);
			}
		}

first_literal_run:
		t = *ip++;
		if (t >= 16)
			goto match;
		m_pos = op - (1 + M2_MAX_OFFSET);
		m_pos -= t >> 2;
		m_pos -= *ip++ << 2;

		if (HAVE_LB(m_pos, out, op))
			goto lookbehind_overrun;

		if (HAVE_OP(3, op_end, op))
			goto output_overrun;
		*op++ = *m_pos++;
		*op++ = *m_pos++;
		*op++ = *m_pos;

		goto match_done;

		do {
match:
			if (t >= 64) {
				m_pos = op - 1;
				m_pos -= (t >> 2) & 7;
				m_pos -= *ip++ << 3;
				t = (t >> 5) - 1;
				if (HAVE_LB(m_pos, out, op))
					goto lookbehind_overrun;
				if (HAVE_OP(t + 3 - 1, op_end, op))
					goto output_overrun;
				goto copy_match;
			} else if (t >= 32) {
				t &= 31;
				if (t == 0) {
					if (HAVE_IP(1, ip_end, ip))
						goto input_overrun;
					while (*ip == 0) {
						t += 255;
						ip++;
						if (HAVE_IP(1, ip_end, ip))
							goto input_overrun;
					}
					t += 31 + *ip++;
				}
				m_pos = op - 1;
				m_pos -= get_unaligned_le16(ip) >> 2;
				ip += 2;
			} else if (t >= 16) {
				m_pos = op;
				m_pos -= (t & 8) << 11;

				t &= 7;
				if (t == 0) {
					if (HAVE_IP(1, ip_end, ip))
						goto input_overrun;
					while (*ip == 0) {
						t += 255;
						ip++;
						if (HAVE_IP(1, ip_end, ip))
							goto input_overrun;
					}
					t += 7 + *ip++;
				}
				m_pos -= get_unaligned_le16(ip) >> 2;
				ip += 2;
				if (m_pos == op)
					goto eof_found;
				m_pos -= 0x4000;
			} else {
				m_pos = op - 1;
				m_pos -= t >> 2;
				m_pos -= *ip++ << 2;

				if (HAVE_LB(m_pos, out, op))
					goto lookbehind_overrun;
				if (HAVE_OP(2, op_end, op))
					goto output_overrun;

				*op++ = *m_pos++;
				*op++ = *m_pos;
				goto match_done;
			}

			if (HAVE_LB(m_pos, out, op))
				goto lookbehind_overrun;
			if (HAVE_OP(t + 3 - 1, op_end, op))
				goto output_overrun;

			if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) {
				COPY4(op, m_pos);
				op += 4;
				m_pos += 4;
				t -= 4 - (3 - 1);
				do {
					COPY4(op, m_pos);
					op += 4;
					m_pos += 4;
					t -= 4;
				} while (t >= 4);
				if (t > 0)
					do {
						*op++ = *m_pos++;
					} while (--t > 0);
			} else {
copy_match:
				*op++ = *m_pos++;
				*op++ = *m_pos++;
				do {
					*op++ = *m_pos++;
				} while (--t > 0);
			}
match_done:
			t = ip[-2] & 3;
			if (t == 0)
				break;
match_next:
			if (HAVE_OP(t, op_end, op))
				goto output_overrun;
			if (HAVE_IP(t + 1, ip_end, ip))
				goto input_overrun;

			*op++ = *ip++;
			if (t > 1) {
				*op++ = *ip++;
				if (t > 2)
					*op++ = *ip++;
			}

			t = *ip++;
		} while (ip < ip_end);
	}

	*out_len = op - out;
	return LZO_E_EOF_NOT_FOUND;

eof_found:
	*out_len = op - out;
	return (ip == ip_end ? LZO_E_OK :
		(ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
input_overrun:
	*out_len = op - out;
	return LZO_E_INPUT_OVERRUN;

output_overrun:
	*out_len = op - out;
	return LZO_E_OUTPUT_OVERRUN;

lookbehind_overrun:
	*out_len = op - out;
	return LZO_E_LOOKBEHIND_OVERRUN;
}
Commit	Line	Data
b1b4e89a SR	1	/*
	2	* LZO1X Decompressor from MiniLZO
	3	*
	4	* Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
	5	*
	6	* The full LZO package can be found at:
	7	* http://www.oberhumer.com/opensource/lzo/
	8	*
	9	* Changed for kernel use by:
	10	* Nitin Gupta <nitingupta910@gmail.com>
	11	* Richard Purdie <rpurdie@openedhand.com>
	12	*/
	13
	14	#include <common.h>
	15	#include <linux/lzo.h>
	16	#include <asm/byteorder.h>
	17	#include <asm/unaligned.h>
	18	#include "lzodefs.h"
	19
	20	#define HAVE_IP(x, ip_end, ip) ((size_t)(ip_end - ip) < (x))
	21	#define HAVE_OP(x, op_end, op) ((size_t)(op_end - op) < (x))
	22	#define HAVE_LB(m_pos, out, op) (m_pos < out \|\| m_pos >= op)
	23
	24	#define COPY4(dst, src) \
	25	put_unaligned(get_unaligned((const u32 )(src)), (u32 )(dst))
	26
20dde48b PK	27	static const unsigned char lzop_magic[] = {
	28	0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a
	29	};
	30
	31	#define HEADER_HAS_FILTER 0x00000800L
	32
	33	static inline const unsigned char parse_header(const unsigned char src)
	34	{
20dde48b PK	35	u16 version;
	36	int i;
	37
	38	/* read magic: 9 first bytes */
	39	for (i = 0; i < ARRAY_SIZE(lzop_magic); i++) {
	40	if (*src++ != lzop_magic[i])
	41	return NULL;
	42	}
	43	/* get version (2bytes), skip library version (2),
	44	* 'need to be extracted' version (2) and
	45	* method (1) */
	46	version = get_unaligned_be16(src);
	47	src += 7;
	48	if (version >= 0x0940)
7b8ffea2	49	src++;
20dde48b PK	50	if (get_unaligned_be32(src) & HEADER_HAS_FILTER)
	51	src += 4; /* filter info */
	52
	53	/* skip flags, mode and mtime_low */
	54	src += 12;
	55	if (version >= 0x0940)
	56	src += 4; /* skip mtime_high */
	57
	58	i = *src++;
	59	/* don't care about the file name, and skip checksum */
	60	src += i + 4;
	61
	62	return src;
	63	}
	64
	65	int lzop_decompress(const unsigned char *src, size_t src_len,
	66	unsigned char dst, size_t dst_len)
	67	{
	68	unsigned char *start = dst;
	69	const unsigned char *send = src + src_len;
	70	u32 slen, dlen;
	71	size_t tmp;
	72	int r;
	73
	74	src = parse_header(src);
	75	if (!src)
	76	return LZO_E_ERROR;
	77
	78	while (src < send) {
	79	/* read uncompressed block size */
	80	dlen = get_unaligned_be32(src);
	81	src += 4;
	82
	83	/* exit if last block */
	84	if (dlen == 0) {
	85	*dst_len = dst - start;
	86	return LZO_E_OK;
	87	}
	88
	89	/* read compressed block size, and skip block checksum info */
	90	slen = get_unaligned_be32(src);
	91	src += 8;
	92
	93	if (slen <= 0 \|\| slen > dlen)
	94	return LZO_E_ERROR;
	95
	96	/* decompress */
	97	tmp = dlen;
	98	r = lzo1x_decompress_safe((u8 *) src, slen, dst, &tmp);
	99
	100	if (r != LZO_E_OK)
	101	return r;
	102
	103	if (dlen != tmp)
	104	return LZO_E_ERROR;
	105
	106	src += slen;
	107	dst += dlen;
	108	}
	109
	110	return LZO_E_INPUT_OVERRUN;
	111	}
	112
b1b4e89a SR	113	int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
	114	unsigned char out, size_t out_len)
	115	{
	116	const unsigned char * const ip_end = in + in_len;
	117	unsigned char * const op_end = out + *out_len;
	118	const unsigned char ip = in, m_pos;
	119	unsigned char *op = out;
	120	size_t t;
	121
	122	*out_len = 0;
	123
	124	if (*ip > 17) {
	125	t = *ip++ - 17;
	126	if (t < 4)
	127	goto match_next;
	128	if (HAVE_OP(t, op_end, op))
	129	goto output_overrun;
	130	if (HAVE_IP(t + 1, ip_end, ip))
	131	goto input_overrun;
	132	do {
	133	op++ = ip++;
	134	} while (--t > 0);
	135	goto first_literal_run;
	136	}
	137
	138	while ((ip < ip_end)) {
	139	t = *ip++;
	140	if (t >= 16)
	141	goto match;
	142	if (t == 0) {
	143	if (HAVE_IP(1, ip_end, ip))
	144	goto input_overrun;
	145	while (*ip == 0) {
	146	t += 255;
	147	ip++;
	148	if (HAVE_IP(1, ip_end, ip))
	149	goto input_overrun;
	150	}
	151	t += 15 + *ip++;
	152	}
	153	if (HAVE_OP(t + 3, op_end, op))
	154	goto output_overrun;
	155	if (HAVE_IP(t + 4, ip_end, ip))
	156	goto input_overrun;
	157
	158	COPY4(op, ip);
	159	op += 4;
	160	ip += 4;
	161	if (--t > 0) {
	162	if (t >= 4) {
	163	do {
	164	COPY4(op, ip);
	165	op += 4;
	166	ip += 4;
	167	t -= 4;
	168	} while (t >= 4);
	169	if (t > 0) {
	170	do {
	171	op++ = ip++;
	172	} while (--t > 0);
	173	}
	174	} else {
	175	do {
	176	op++ = ip++;
177	} while (--t > 0);
178	}
179	}
180
181	first_literal_run:
182	t = *ip++;
183	if (t >= 16)
184	goto match;
185	m_pos = op - (1 + M2_MAX_OFFSET);
186	m_pos -= t >> 2;
187	m_pos -= *ip++ << 2;
188
189	if (HAVE_LB(m_pos, out, op))
190	goto lookbehind_overrun;
191
192	if (HAVE_OP(3, op_end, op))
193	goto output_overrun;
194	op++ = m_pos++;
195	op++ = m_pos++;
196	op++ = m_pos;
197
198	goto match_done;
199
200	do {
201	match:
202	if (t >= 64) {
203	m_pos = op - 1;
204	m_pos -= (t >> 2) & 7;
205	m_pos -= *ip++ << 3;
206	t = (t >> 5) - 1;
207	if (HAVE_LB(m_pos, out, op))
208	goto lookbehind_overrun;
209	if (HAVE_OP(t + 3 - 1, op_end, op))
210	goto output_overrun;
211	goto copy_match;
212	} else if (t >= 32) {
213	t &= 31;
214	if (t == 0) {
215	if (HAVE_IP(1, ip_end, ip))
216	goto input_overrun;
217	while (*ip == 0) {
218	t += 255;
219	ip++;
220	if (HAVE_IP(1, ip_end, ip))
221	goto input_overrun;
222	}
223	t += 31 + *ip++;
224	}
225	m_pos = op - 1;
226	m_pos -= get_unaligned_le16(ip) >> 2;
227	ip += 2;
228	} else if (t >= 16) {
229	m_pos = op;
230	m_pos -= (t & 8) << 11;
231
232	t &= 7;
233	if (t == 0) {
234	if (HAVE_IP(1, ip_end, ip))
235	goto input_overrun;
236	while (*ip == 0) {
237	t += 255;
238	ip++;
239	if (HAVE_IP(1, ip_end, ip))
240	goto input_overrun;
241	}
242	t += 7 + *ip++;
243	}
244	m_pos -= get_unaligned_le16(ip) >> 2;
245	ip += 2;
246	if (m_pos == op)
247	goto eof_found;
248	m_pos -= 0x4000;
249	} else {
250	m_pos = op - 1;
251	m_pos -= t >> 2;
252	m_pos -= *ip++ << 2;
253
254	if (HAVE_LB(m_pos, out, op))
255	goto lookbehind_overrun;
256	if (HAVE_OP(2, op_end, op))
257	goto output_overrun;
258
259	op++ = m_pos++;
260	op++ = m_pos;
261	goto match_done;
262	}
263
264	if (HAVE_LB(m_pos, out, op))
265	goto lookbehind_overrun;
266	if (HAVE_OP(t + 3 - 1, op_end, op))
267	goto output_overrun;
268
269	if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) {
270	COPY4(op, m_pos);
271	op += 4;
272	m_pos += 4;
273	t -= 4 - (3 - 1);
274	do {
275	COPY4(op, m_pos);
276	op += 4;
277	m_pos += 4;
278	t -= 4;
279	} while (t >= 4);
280	if (t > 0)
281	do {
282	op++ = m_pos++;
283	} while (--t > 0);
284	} else {
285	copy_match:
286	op++ = m_pos++;
287	op++ = m_pos++;
288	do {
289	op++ = m_pos++;
290	} while (--t > 0);
291	}
292	match_done:
293	t = ip[-2] & 3;
294	if (t == 0)
295	break;
296	match_next:
297	if (HAVE_OP(t, op_end, op))
298	goto output_overrun;
299	if (HAVE_IP(t + 1, ip_end, ip))
300	goto input_overrun;
301
302	op++ = ip++;
303	if (t > 1) {
304	op++ = ip++;
305	if (t > 2)
306	op++ = ip++;
307	}
308
309	t = *ip++;
310	} while (ip < ip_end);
311	}
312
313	*out_len = op - out;
314	return LZO_E_EOF_NOT_FOUND;
315
316	eof_found:
317	*out_len = op - out;
318	return (ip == ip_end ? LZO_E_OK :
319	(ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
320	input_overrun:
321	*out_len = op - out;
322	return LZO_E_INPUT_OVERRUN;
323
324	output_overrun:
325	*out_len = op - out;
326	return LZO_E_OUTPUT_OVERRUN;
327
328	lookbehind_overrun:
329	*out_len = op - out;
330	return LZO_E_LOOKBEHIND_OVERRUN;
331	}