[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)
{
	u8 level = 0;
	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)
		level = *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	{
	35	u8 level = 0;
	36	u16 version;
	37	int i;
	38
	39	/* read magic: 9 first bytes */
	40	for (i = 0; i < ARRAY_SIZE(lzop_magic); i++) {
	41	if (*src++ != lzop_magic[i])
	42	return NULL;
	43	}
	44	/* get version (2bytes), skip library version (2),
	45	* 'need to be extracted' version (2) and
	46	* method (1) */
	47	version = get_unaligned_be16(src);
	48	src += 7;
	49	if (version >= 0x0940)
	50	level = *src++;
	51	if (get_unaligned_be32(src) & HEADER_HAS_FILTER)
	52	src += 4; /* filter info */
	53
	54	/* skip flags, mode and mtime_low */
	55	src += 12;
	56	if (version >= 0x0940)
	57	src += 4; /* skip mtime_high */
	58
	59	i = *src++;
	60	/* don't care about the file name, and skip checksum */
	61	src += i + 4;
	62
	63	return src;
	64	}
	65
	66	int lzop_decompress(const unsigned char *src, size_t src_len,
	67	unsigned char dst, size_t dst_len)
	68	{
	69	unsigned char *start = dst;
	70	const unsigned char *send = src + src_len;
	71	u32 slen, dlen;
	72	size_t tmp;
	73	int r;
	74
	75	src = parse_header(src);
	76	if (!src)
	77	return LZO_E_ERROR;
	78
	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
97	/* decompress */
98	tmp = dlen;
99	r = lzo1x_decompress_safe((u8 *) src, slen, dst, &tmp);
100
101	if (r != LZO_E_OK)
102	return r;
103
104	if (dlen != tmp)
105	return LZO_E_ERROR;
106
107	src += slen;
108	dst += dlen;
109	}
110
111	return LZO_E_INPUT_OVERRUN;
112	}
113
b1b4e89a SR	114	int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
	115	unsigned char out, size_t out_len)
	116	{
	117	const unsigned char * const ip_end = in + in_len;
	118	unsigned char * const op_end = out + *out_len;
	119	const unsigned char ip = in, m_pos;
	120	unsigned char *op = out;
	121	size_t t;
	122
	123	*out_len = 0;
	124
	125	if (*ip > 17) {
	126	t = *ip++ - 17;
	127	if (t < 4)
	128	goto match_next;
	129	if (HAVE_OP(t, op_end, op))
	130	goto output_overrun;
	131	if (HAVE_IP(t + 1, ip_end, ip))
	132	goto input_overrun;
	133	do {
	134	op++ = ip++;
	135	} while (--t > 0);
	136	goto first_literal_run;
	137	}
	138
	139	while ((ip < ip_end)) {
	140	t = *ip++;
	141	if (t >= 16)
	142	goto match;
	143	if (t == 0) {
	144	if (HAVE_IP(1, ip_end, ip))
	145	goto input_overrun;
	146	while (*ip == 0) {
	147	t += 255;
	148	ip++;
	149	if (HAVE_IP(1, ip_end, ip))
	150	goto input_overrun;
	151	}
	152	t += 15 + *ip++;
	153	}
	154	if (HAVE_OP(t + 3, op_end, op))
	155	goto output_overrun;
	156	if (HAVE_IP(t + 4, ip_end, ip))
	157	goto input_overrun;
	158
	159	COPY4(op, ip);
	160	op += 4;
	161	ip += 4;
	162	if (--t > 0) {
	163	if (t >= 4) {
	164	do {
	165	COPY4(op, ip);
	166	op += 4;
	167	ip += 4;
	168	t -= 4;
	169	} while (t >= 4);
	170	if (t > 0) {
	171	do {
	172	op++ = ip++;
	173	} while (--t > 0);
	174	}
	175	} else {
	176	do {
	177	op++ = ip++;
178	} while (--t > 0);
179	}
180	}
181
182	first_literal_run:
183	t = *ip++;
184	if (t >= 16)
185	goto match;
186	m_pos = op - (1 + M2_MAX_OFFSET);
187	m_pos -= t >> 2;
188	m_pos -= *ip++ << 2;
189
190	if (HAVE_LB(m_pos, out, op))
191	goto lookbehind_overrun;
192
193	if (HAVE_OP(3, op_end, op))
194	goto output_overrun;
195	op++ = m_pos++;
196	op++ = m_pos++;
197	op++ = m_pos;
198
199	goto match_done;
200
201	do {
202	match:
203	if (t >= 64) {
204	m_pos = op - 1;
205	m_pos -= (t >> 2) & 7;
206	m_pos -= *ip++ << 3;
207	t = (t >> 5) - 1;
208	if (HAVE_LB(m_pos, out, op))
209	goto lookbehind_overrun;
210	if (HAVE_OP(t + 3 - 1, op_end, op))
211	goto output_overrun;
212	goto copy_match;
213	} else if (t >= 32) {
214	t &= 31;
215	if (t == 0) {
216	if (HAVE_IP(1, ip_end, ip))
217	goto input_overrun;
218	while (*ip == 0) {
219	t += 255;
220	ip++;
221	if (HAVE_IP(1, ip_end, ip))
222	goto input_overrun;
223	}
224	t += 31 + *ip++;
225	}
226	m_pos = op - 1;
227	m_pos -= get_unaligned_le16(ip) >> 2;
228	ip += 2;
229	} else if (t >= 16) {
230	m_pos = op;
231	m_pos -= (t & 8) << 11;
232
233	t &= 7;
234	if (t == 0) {
235	if (HAVE_IP(1, ip_end, ip))
236	goto input_overrun;
237	while (*ip == 0) {
238	t += 255;
239	ip++;
240	if (HAVE_IP(1, ip_end, ip))
241	goto input_overrun;
242	}
243	t += 7 + *ip++;
244	}
245	m_pos -= get_unaligned_le16(ip) >> 2;
246	ip += 2;
247	if (m_pos == op)
248	goto eof_found;
249	m_pos -= 0x4000;
250	} else {
251	m_pos = op - 1;
252	m_pos -= t >> 2;
253	m_pos -= *ip++ << 2;
254
255	if (HAVE_LB(m_pos, out, op))
256	goto lookbehind_overrun;
257	if (HAVE_OP(2, op_end, op))
258	goto output_overrun;
259
260	op++ = m_pos++;
261	op++ = m_pos;
262	goto match_done;
263	}
264
265	if (HAVE_LB(m_pos, out, op))
266	goto lookbehind_overrun;
267	if (HAVE_OP(t + 3 - 1, op_end, op))
268	goto output_overrun;
269
270	if (t >= 2 * 4 - (3 - 1) && (op - m_pos) >= 4) {
271	COPY4(op, m_pos);
272	op += 4;
273	m_pos += 4;
274	t -= 4 - (3 - 1);
275	do {
276	COPY4(op, m_pos);
277	op += 4;
278	m_pos += 4;
279	t -= 4;
280	} while (t >= 4);
281	if (t > 0)
282	do {
283	op++ = m_pos++;
284	} while (--t > 0);
285	} else {
286	copy_match:
287	op++ = m_pos++;
288	op++ = m_pos++;
289	do {
290	op++ = m_pos++;
291	} while (--t > 0);
292	}
293	match_done:
294	t = ip[-2] & 3;
295	if (t == 0)
296	break;
297	match_next:
298	if (HAVE_OP(t, op_end, op))
299	goto output_overrun;
300	if (HAVE_IP(t + 1, ip_end, ip))
301	goto input_overrun;
302
303	op++ = ip++;
304	if (t > 1) {
305	op++ = ip++;
306	if (t > 2)
307	op++ = ip++;
308	}
309
310	t = *ip++;
311	} while (ip < ip_end);
312	}
313
314	*out_len = op - out;
315	return LZO_E_EOF_NOT_FOUND;
316
317	eof_found:
318	*out_len = op - out;
319	return (ip == ip_end ? LZO_E_OK :
320	(ip < ip_end ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));
321	input_overrun:
322	*out_len = op - out;
323	return LZO_E_INPUT_OVERRUN;
324
325	output_overrun:
326	*out_len = op - out;
327	return LZO_E_OUTPUT_OVERRUN;
328
329	lookbehind_overrun:
330	*out_len = op - out;
331	return LZO_E_LOOKBEHIND_OVERRUN;
332	}