[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, remaining;
	int r;

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

	remaining = *dst_len;
	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;

		/* abort if buffer ran out of room */
		if (dlen > remaining)
			return LZO_E_OUTPUT_OVERRUN;

		/* When the input data is not compressed at all,
		 * lzo1x_decompress_safe will fail, so call memcpy()
		 * instead */
		if (dlen == slen) {
			memcpy(dst, src, slen);
		} else {
			/* decompress */
			tmp = dlen;
			r = lzo1x_decompress_safe((u8 *)src, slen, dst, &tmp);

			if (r != LZO_E_OK) {
				*dst_len = dst - start;
				return r;
			}

			if (dlen != tmp)
				return LZO_E_ERROR;
		}

		src += slen;
		dst += dlen;
		remaining -= 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;
ff9d2efd	71	size_t tmp, remaining;
20dde48b PK	72	int r;
	73
	74	src = parse_header(src);
	75	if (!src)
	76	return LZO_E_ERROR;
	77
ff9d2efd	78	remaining = *dst_len;
20dde48b PK	79	while (src < send) {
	80	/* read uncompressed block size */
	81	dlen = get_unaligned_be32(src);
	82	src += 4;
	83
	84	/* exit if last block */
	85	if (dlen == 0) {
	86	*dst_len = dst - start;
	87	return LZO_E_OK;
	88	}
	89
	90	/* read compressed block size, and skip block checksum info */
	91	slen = get_unaligned_be32(src);
	92	src += 8;
	93
	94	if (slen <= 0 \|\| slen > dlen)
	95	return LZO_E_ERROR;
	96
ff9d2efd KC	97	/* abort if buffer ran out of room */
	98	if (dlen > remaining)
	99	return LZO_E_OUTPUT_OVERRUN;
	100
a2cfc8d5 JL	101	/* When the input data is not compressed at all,
	102	* lzo1x_decompress_safe will fail, so call memcpy()
	103	* instead */
	104	if (dlen == slen) {
	105	memcpy(dst, src, slen);
	106	} else {
	107	/* decompress */
	108	tmp = dlen;
	109	r = lzo1x_decompress_safe((u8 *)src, slen, dst, &tmp);
	110
	111	if (r != LZO_E_OK) {
	112	*dst_len = dst - start;
	113	return r;
	114	}
	115
	116	if (dlen != tmp)
	117	return LZO_E_ERROR;
670c0179	118	}
20dde48b	119
20dde48b PK	120	src += slen;
20dde48b PK	121	dst += dlen;
ff9d2efd	122	remaining -= dlen;
20dde48b PK	123	}
	124
	125	return LZO_E_INPUT_OVERRUN;
	126	}
	127
b1b4e89a SR	128	int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
	129	unsigned char out, size_t out_len)
	130	{
	131	const unsigned char * const ip_end = in + in_len;
	132	unsigned char * const op_end = out + *out_len;
	133	const unsigned char ip = in, m_pos;
	134	unsigned char *op = out;
	135	size_t t;
	136
	137	*out_len = 0;
	138
	139	if (*ip > 17) {
	140	t = *ip++ - 17;
	141	if (t < 4)
	142	goto match_next;
	143	if (HAVE_OP(t, op_end, op))
	144	goto output_overrun;
	145	if (HAVE_IP(t + 1, ip_end, ip))
	146	goto input_overrun;
	147	do {
	148	op++ = ip++;
	149	} while (--t > 0);
	150	goto first_literal_run;
	151	}
	152
	153	while ((ip < ip_end)) {
	154	t = *ip++;
	155	if (t >= 16)
	156	goto match;
	157	if (t == 0) {
	158	if (HAVE_IP(1, ip_end, ip))
	159	goto input_overrun;
	160	while (*ip == 0) {
	161	t += 255;
	162	ip++;
	163	if (HAVE_IP(1, ip_end, ip))
	164	goto input_overrun;
	165	}
	166	t += 15 + *ip++;
	167	}
	168	if (HAVE_OP(t + 3, op_end, op))
	169	goto output_overrun;
	170	if (HAVE_IP(t + 4, ip_end, ip))
	171	goto input_overrun;
	172
	173	COPY4(op, ip);
	174	op += 4;
	175	ip += 4;
	176	if (--t > 0) {
	177	if (t >= 4) {
	178	do {
	179	COPY4(op, ip);
	180	op += 4;
	181	ip += 4;
	182	t -= 4;
	183	} while (t >= 4);
	184	if (t > 0) {
	185	do {
	186	op++ = ip++;
	187	} while (--t > 0);
	188	}
	189	} else {
	190	do {
	191	op++ = ip++;
192	} while (--t > 0);
193	}
194	}
195
196	first_literal_run:
197	t = *ip++;
198	if (t >= 16)
199	goto match;
200	m_pos = op - (1 + M2_MAX_OFFSET);
201	m_pos -= t >> 2;
202	m_pos -= *ip++ << 2;
203
204	if (HAVE_LB(m_pos, out, op))
205	goto lookbehind_overrun;
206
207	if (HAVE_OP(3, op_end, op))
208	goto output_overrun;
209	op++ = m_pos++;
210	op++ = m_pos++;
211	op++ = m_pos;
212
213	goto match_done;
214
215	do {
216	match:
217	if (t >= 64) {
218	m_pos = op - 1;
219	m_pos -= (t >> 2) & 7;
220	m_pos -= *ip++ << 3;
221	t = (t >> 5) - 1;
222	if (HAVE_LB(m_pos, out, op))
223	goto lookbehind_overrun;
224	if (HAVE_OP(t + 3 - 1, op_end, op))
225	goto output_overrun;
226	goto copy_match;
227	} else if (t >= 32) {
228	t &= 31;
229	if (t == 0) {
230	if (HAVE_IP(1, ip_end, ip))
231	goto input_overrun;
232	while (*ip == 0) {
233	t += 255;
234	ip++;
235	if (HAVE_IP(1, ip_end, ip))
236	goto input_overrun;
237	}
238	t += 31 + *ip++;
239	}
240	m_pos = op - 1;
241	m_pos -= get_unaligned_le16(ip) >> 2;
242	ip += 2;
243	} else if (t >= 16) {
244	m_pos = op;
245	m_pos -= (t & 8) << 11;
246
247	t &= 7;
248	if (t == 0) {
249	if (HAVE_IP(1, ip_end, ip))
250	goto input_overrun;
251	while (*ip == 0) {
252	t += 255;
253	ip++;
254	if (HAVE_IP(1, ip_end, ip))
255	goto input_overrun;
256	}
257	t += 7 + *ip++;
258	}
259	m_pos -= get_unaligned_le16(ip) >> 2;
260	ip += 2;
261	if (m_pos == op)
262	goto eof_found;
263	m_pos -= 0x4000;
264	} else {
265	m_pos = op - 1;
266	m_pos -= t >> 2;
267	m_pos -= *ip++ << 2;
268
269	if (HAVE_LB(m_pos, out, op))
270	goto lookbehind_overrun;
271	if (HAVE_OP(2, op_end, op))
272	goto output_overrun;
273
274	op++ = m_pos++;
275	op++ = m_pos;
276	goto match_done;
277	}
278
279	if (HAVE_LB(m_pos, out, op))
280	goto lookbehind_overrun;
281	if (HAVE_OP(t + 3 - 1, op_end, op))
282	goto output_overrun;
283
284	if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) {
285	COPY4(op, m_pos);
286	op += 4;
287	m_pos += 4;
288	t -= 4 - (3 - 1);
289	do {
290	COPY4(op, m_pos);
291	op += 4;
292	m_pos += 4;
293	t -= 4;
294	} while (t >= 4);
295	if (t > 0)
296	do {
297	op++ = m_pos++;
298	} while (--t > 0);
299	} else {
300	copy_match:
301	op++ = m_pos++;
302	op++ = m_pos++;
303	do {
304	op++ = m_pos++;
305	} while (--t > 0);
306	}
307	match_done:
308	t = ip[-2] & 3;
309	if (t == 0)
310	break;
311	match_next:
312	if (HAVE_OP(t, op_end, op))
313	goto output_overrun;
314	if (HAVE_IP(t + 1, ip_end, ip))
315	goto input_overrun;
316
317	op++ = ip++;
318	if (t > 1) {
319	op++ = ip++;
320	if (t > 2)
321	op++ = ip++;
322	}
323
324	t = *ip++;
325	} while (ip < ip_end);
326	}
327
328	*out_len = op - out;
329	return LZO_E_EOF_NOT_FOUND;
330
331	eof_found:
332	*out_len = op - out;
333	return (ip == ip_end ? LZO_E_OK :
334	(ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
335	input_overrun:
336	*out_len = op - out;
337	return LZO_E_INPUT_OVERRUN;
338
339	output_overrun:
340	*out_len = op - out;
341	return LZO_E_OUTPUT_OVERRUN;
342
343	lookbehind_overrun:
344	*out_len = op - out;
345	return LZO_E_LOOKBEHIND_OVERRUN;
346	}