[mirror_ubuntu-bionic-kernel.git] / lib / zlib_inflate / inflate.c

/* inflate.c -- zlib interface to inflate modules
 * Copyright (C) 1995-1998 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h 
 */

#include <linux/zutil.h>
#include "infblock.h"
#include "infutil.h"

int zlib_inflate_workspacesize(void)
{
  return sizeof(struct inflate_workspace);
}


int zlib_inflateReset(
	z_streamp z
)
{
  if (z == NULL || z->state == NULL || z->workspace == NULL)
    return Z_STREAM_ERROR;
  z->total_in = z->total_out = 0;
  z->msg = NULL;
  z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
  zlib_inflate_blocks_reset(z->state->blocks, z, NULL);
  return Z_OK;
}


int zlib_inflateEnd(
	z_streamp z
)
{
  if (z == NULL || z->state == NULL || z->workspace == NULL)
    return Z_STREAM_ERROR;
  if (z->state->blocks != NULL)
    zlib_inflate_blocks_free(z->state->blocks, z);
  z->state = NULL;
  return Z_OK;
}


int zlib_inflateInit2_(
	z_streamp z,
	int w,
	const char *version,
	int stream_size
)
{
  if (version == NULL || version[0] != ZLIB_VERSION[0] ||
      stream_size != sizeof(z_stream) || z->workspace == NULL)
      return Z_VERSION_ERROR;

  /* initialize state */
  z->msg = NULL;
  z->state = &WS(z)->internal_state;
  z->state->blocks = NULL;

  /* handle undocumented nowrap option (no zlib header or check) */
  z->state->nowrap = 0;
  if (w < 0)
  {
    w = - w;
    z->state->nowrap = 1;
  }

  /* set window size */
  if (w < 8 || w > 15)
  {
    zlib_inflateEnd(z);
    return Z_STREAM_ERROR;
  }
  z->state->wbits = (uInt)w;

  /* create inflate_blocks state */
  if ((z->state->blocks =
      zlib_inflate_blocks_new(z, z->state->nowrap ? NULL : zlib_adler32, (uInt)1 << w))
      == NULL)
  {
    zlib_inflateEnd(z);
    return Z_MEM_ERROR;
  }

  /* reset state */
  zlib_inflateReset(z);
  return Z_OK;
}


/*
 * At the end of a Deflate-compressed PPP packet, we expect to have seen
 * a `stored' block type value but not the (zero) length bytes.
 */
static int zlib_inflate_packet_flush(inflate_blocks_statef *s)
{
    if (s->mode != LENS)
	return Z_DATA_ERROR;
    s->mode = TYPE;
    return Z_OK;
}


int zlib_inflateInit_(
	z_streamp z,
	const char *version,
	int stream_size
)
{
  return zlib_inflateInit2_(z, DEF_WBITS, version, stream_size);
}

#undef NEEDBYTE
#undef NEXTBYTE
#define NEEDBYTE {if(z->avail_in==0)goto empty;r=trv;}
#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)

int zlib_inflate(
	z_streamp z,
	int f
)
{
  int r, trv;
  uInt b;

  if (z == NULL || z->state == NULL || z->next_in == NULL)
    return Z_STREAM_ERROR;
  trv = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
  r = Z_BUF_ERROR;
  while (1) switch (z->state->mode)
  {
    case METHOD:
      NEEDBYTE
      if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
      {
        z->state->mode = I_BAD;
        z->msg = (char*)"unknown compression method";
        z->state->sub.marker = 5;       /* can't try inflateSync */
        break;
      }
      if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
      {
        z->state->mode = I_BAD;
        z->msg = (char*)"invalid window size";
        z->state->sub.marker = 5;       /* can't try inflateSync */
        break;
      }
      z->state->mode = FLAG;
    case FLAG:
      NEEDBYTE
      b = NEXTBYTE;
      if (((z->state->sub.method << 8) + b) % 31)
      {
        z->state->mode = I_BAD;
        z->msg = (char*)"incorrect header check";
        z->state->sub.marker = 5;       /* can't try inflateSync */
        break;
      }
      if (!(b & PRESET_DICT))
      {
        z->state->mode = BLOCKS;
        break;
      }
      z->state->mode = DICT4;
    case DICT4:
      NEEDBYTE
      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
      z->state->mode = DICT3;
    case DICT3:
      NEEDBYTE
      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
      z->state->mode = DICT2;
    case DICT2:
      NEEDBYTE
      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
      z->state->mode = DICT1;
    case DICT1:
      NEEDBYTE
      z->state->sub.check.need += (uLong)NEXTBYTE;
      z->adler = z->state->sub.check.need;
      z->state->mode = DICT0;
      return Z_NEED_DICT;
    case DICT0:
      z->state->mode = I_BAD;
      z->msg = (char*)"need dictionary";
      z->state->sub.marker = 0;       /* can try inflateSync */
      return Z_STREAM_ERROR;
    case BLOCKS:
      r = zlib_inflate_blocks(z->state->blocks, z, r);
      if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
	  r = zlib_inflate_packet_flush(z->state->blocks);
      if (r == Z_DATA_ERROR)
      {
        z->state->mode = I_BAD;
        z->state->sub.marker = 0;       /* can try inflateSync */
        break;
      }
      if (r == Z_OK)
        r = trv;
      if (r != Z_STREAM_END)
        return r;
      r = trv;
      zlib_inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
      if (z->state->nowrap)
      {
        z->state->mode = I_DONE;
        break;
      }
      z->state->mode = CHECK4;
    case CHECK4:
      NEEDBYTE
      z->state->sub.check.need = (uLong)NEXTBYTE << 24;
      z->state->mode = CHECK3;
    case CHECK3:
      NEEDBYTE
      z->state->sub.check.need += (uLong)NEXTBYTE << 16;
      z->state->mode = CHECK2;
    case CHECK2:
      NEEDBYTE
      z->state->sub.check.need += (uLong)NEXTBYTE << 8;
      z->state->mode = CHECK1;
    case CHECK1:
      NEEDBYTE
      z->state->sub.check.need += (uLong)NEXTBYTE;

      if (z->state->sub.check.was != z->state->sub.check.need)
      {
        z->state->mode = I_BAD;
        z->msg = (char*)"incorrect data check";
        z->state->sub.marker = 5;       /* can't try inflateSync */
        break;
      }
      z->state->mode = I_DONE;
    case I_DONE:
      return Z_STREAM_END;
    case I_BAD:
      return Z_DATA_ERROR;
    default:
      return Z_STREAM_ERROR;
  }
 empty:
  if (f != Z_PACKET_FLUSH)
    return r;
  z->state->mode = I_BAD;
  z->msg = (char *)"need more for packet flush";
  z->state->sub.marker = 0;       /* can try inflateSync */
  return Z_DATA_ERROR;
}
Commit	Line	Data
1da177e4 LT	1	/* inflate.c -- zlib interface to inflate modules
	2	* Copyright (C) 1995-1998 Mark Adler
	3	* For conditions of distribution and use, see copyright notice in zlib.h
	4	*/
	5
1da177e4 LT	6	#include <linux/zutil.h>
	7	#include "infblock.h"
	8	#include "infutil.h"
	9
	10	int zlib_inflate_workspacesize(void)
	11	{
	12	return sizeof(struct inflate_workspace);
	13	}
	14
	15
	16	int zlib_inflateReset(
	17	z_streamp z
	18	)
	19	{
	20	if (z == NULL \|\| z->state == NULL \|\| z->workspace == NULL)
	21	return Z_STREAM_ERROR;
	22	z->total_in = z->total_out = 0;
	23	z->msg = NULL;
	24	z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
	25	zlib_inflate_blocks_reset(z->state->blocks, z, NULL);
	26	return Z_OK;
	27	}
	28
	29
	30	int zlib_inflateEnd(
	31	z_streamp z
	32	)
	33	{
	34	if (z == NULL \|\| z->state == NULL \|\| z->workspace == NULL)
	35	return Z_STREAM_ERROR;
	36	if (z->state->blocks != NULL)
	37	zlib_inflate_blocks_free(z->state->blocks, z);
	38	z->state = NULL;
	39	return Z_OK;
	40	}
	41
	42
	43	int zlib_inflateInit2_(
	44	z_streamp z,
	45	int w,
	46	const char *version,
	47	int stream_size
	48	)
	49	{
	50	if (version == NULL \|\| version[0] != ZLIB_VERSION[0] \|\|
	51	stream_size != sizeof(z_stream) \|\| z->workspace == NULL)
	52	return Z_VERSION_ERROR;
	53
	54	/* initialize state */
	55	z->msg = NULL;
	56	z->state = &WS(z)->internal_state;
	57	z->state->blocks = NULL;
	58
	59	/* handle undocumented nowrap option (no zlib header or check) */
	60	z->state->nowrap = 0;
	61	if (w < 0)
	62	{
	63	w = - w;
	64	z->state->nowrap = 1;
	65	}
	66
	67	/* set window size */
	68	if (w < 8 \|\| w > 15)
	69	{
70	zlib_inflateEnd(z);
71	return Z_STREAM_ERROR;
72	}
73	z->state->wbits = (uInt)w;
74
75	/* create inflate_blocks state */
76	if ((z->state->blocks =
77	zlib_inflate_blocks_new(z, z->state->nowrap ? NULL : zlib_adler32, (uInt)1 << w))
78	== NULL)
79	{
80	zlib_inflateEnd(z);
81	return Z_MEM_ERROR;
82	}
83
84	/* reset state */
85	zlib_inflateReset(z);
86	return Z_OK;
87	}
88
89
90	/*
91	* At the end of a Deflate-compressed PPP packet, we expect to have seen
92	* a `stored' block type value but not the (zero) length bytes.
93	*/
94	static int zlib_inflate_packet_flush(inflate_blocks_statef *s)
95	{
96	if (s->mode != LENS)
97	return Z_DATA_ERROR;
98	s->mode = TYPE;
99	return Z_OK;
100	}
101
102
103	int zlib_inflateInit_(
104	z_streamp z,
105	const char *version,
106	int stream_size
107	)
108	{
109	return zlib_inflateInit2_(z, DEF_WBITS, version, stream_size);
110	}
111
112	#undef NEEDBYTE
113	#undef NEXTBYTE
114	#define NEEDBYTE {if(z->avail_in==0)goto empty;r=trv;}
115	#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
116
117	int zlib_inflate(
118	z_streamp z,
119	int f
120	)
121	{
122	int r, trv;
123	uInt b;
124
125	if (z == NULL \|\| z->state == NULL \|\| z->next_in == NULL)
126	return Z_STREAM_ERROR;
127	trv = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
128	r = Z_BUF_ERROR;
129	while (1) switch (z->state->mode)
130	{
131	case METHOD:
132	NEEDBYTE
133	if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
134	{
135	z->state->mode = I_BAD;
136	z->msg = (char*)"unknown compression method";
137	z->state->sub.marker = 5; /* can't try inflateSync */
138	break;
139	}
140	if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
141	{
142	z->state->mode = I_BAD;
143	z->msg = (char*)"invalid window size";
144	z->state->sub.marker = 5; /* can't try inflateSync */
145	break;
146	}
147	z->state->mode = FLAG;
148	case FLAG:
149	NEEDBYTE
150	b = NEXTBYTE;
151	if (((z->state->sub.method << 8) + b) % 31)
152	{
153	z->state->mode = I_BAD;
154	z->msg = (char*)"incorrect header check";
155	z->state->sub.marker = 5; /* can't try inflateSync */
156	break;
157	}
158	if (!(b & PRESET_DICT))
159	{
160	z->state->mode = BLOCKS;
161	break;
162	}
163	z->state->mode = DICT4;
164	case DICT4:
165	NEEDBYTE
166	z->state->sub.check.need = (uLong)NEXTBYTE << 24;
167	z->state->mode = DICT3;
168	case DICT3:
169	NEEDBYTE
170	z->state->sub.check.need += (uLong)NEXTBYTE << 16;
171	z->state->mode = DICT2;
172	case DICT2:
173	NEEDBYTE
174	z->state->sub.check.need += (uLong)NEXTBYTE << 8;
175	z->state->mode = DICT1;
176	case DICT1:
177	NEEDBYTE
178	z->state->sub.check.need += (uLong)NEXTBYTE;
179	z->adler = z->state->sub.check.need;
180	z->state->mode = DICT0;
181	return Z_NEED_DICT;
182	case DICT0:
183	z->state->mode = I_BAD;
184	z->msg = (char*)"need dictionary";
185	z->state->sub.marker = 0; /* can try inflateSync */
186	return Z_STREAM_ERROR;
187	case BLOCKS:
188	r = zlib_inflate_blocks(z->state->blocks, z, r);
189	if (f == Z_PACKET_FLUSH && z->avail_in == 0 && z->avail_out != 0)
190	r = zlib_inflate_packet_flush(z->state->blocks);
191	if (r == Z_DATA_ERROR)
192	{
193	z->state->mode = I_BAD;
194	z->state->sub.marker = 0; /* can try inflateSync */
195	break;
196	}
197	if (r == Z_OK)
198	r = trv;
199	if (r != Z_STREAM_END)
200	return r;
201	r = trv;
202	zlib_inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
203	if (z->state->nowrap)
204	{
205	z->state->mode = I_DONE;
206	break;
207	}
208	z->state->mode = CHECK4;
209	case CHECK4:
210	NEEDBYTE
211	z->state->sub.check.need = (uLong)NEXTBYTE << 24;
212	z->state->mode = CHECK3;
213	case CHECK3:
214	NEEDBYTE
215	z->state->sub.check.need += (uLong)NEXTBYTE << 16;
216	z->state->mode = CHECK2;
217	case CHECK2:
218	NEEDBYTE
219	z->state->sub.check.need += (uLong)NEXTBYTE << 8;
220	z->state->mode = CHECK1;
221	case CHECK1:
222	NEEDBYTE
223	z->state->sub.check.need += (uLong)NEXTBYTE;
224
225	if (z->state->sub.check.was != z->state->sub.check.need)
226	{
227	z->state->mode = I_BAD;
228	z->msg = (char*)"incorrect data check";
229	z->state->sub.marker = 5; /* can't try inflateSync */
230	break;
231	}
232	z->state->mode = I_DONE;
233	case I_DONE:
234	return Z_STREAM_END;
235	case I_BAD:
236	return Z_DATA_ERROR;
237	default:
238	return Z_STREAM_ERROR;
239	}
240	empty:
241	if (f != Z_PACKET_FLUSH)
242	return r;
243	z->state->mode = I_BAD;
244	z->msg = (char *)"need more for packet flush";
245	z->state->sub.marker = 0; /* can try inflateSync */
246	return Z_DATA_ERROR;
247	}