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-rw-r--r--libpng/inflate.c366
1 files changed, 366 insertions, 0 deletions
diff --git a/libpng/inflate.c b/libpng/inflate.c
new file mode 100644
index 0000000..32e9b8d
--- /dev/null
+++ b/libpng/inflate.c
@@ -0,0 +1,366 @@
+/* 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 "zutil.h"
+#include "infblock.h"
+
+struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
+
+typedef enum {
+ METHOD, /* waiting for method byte */
+ FLAG, /* waiting for flag byte */
+ DICT4, /* four dictionary check bytes to go */
+ DICT3, /* three dictionary check bytes to go */
+ DICT2, /* two dictionary check bytes to go */
+ DICT1, /* one dictionary check byte to go */
+ DICT0, /* waiting for inflateSetDictionary */
+ BLOCKS, /* decompressing blocks */
+ CHECK4, /* four check bytes to go */
+ CHECK3, /* three check bytes to go */
+ CHECK2, /* two check bytes to go */
+ CHECK1, /* one check byte to go */
+ DONE, /* finished check, done */
+ BAD} /* got an error--stay here */
+inflate_mode;
+
+/* inflate private state */
+struct internal_state {
+
+ /* mode */
+ inflate_mode mode; /* current inflate mode */
+
+ /* mode dependent information */
+ union {
+ uInt method; /* if FLAGS, method byte */
+ struct {
+ uLong was; /* computed check value */
+ uLong need; /* stream check value */
+ } check; /* if CHECK, check values to compare */
+ uInt marker; /* if BAD, inflateSync's marker bytes count */
+ } sub; /* submode */
+
+ /* mode independent information */
+ int nowrap; /* flag for no wrapper */
+ uInt wbits; /* log2(window size) (8..15, defaults to 15) */
+ inflate_blocks_statef
+ *blocks; /* current inflate_blocks state */
+
+};
+
+
+int ZEXPORT inflateReset(z)
+z_streamp z;
+{
+ if (z == Z_NULL || z->state == Z_NULL)
+ return Z_STREAM_ERROR;
+ z->total_in = z->total_out = 0;
+ z->msg = Z_NULL;
+ z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
+ inflate_blocks_reset(z->state->blocks, z, Z_NULL);
+ Tracev((stderr, "inflate: reset\n"));
+ return Z_OK;
+}
+
+
+int ZEXPORT inflateEnd(z)
+z_streamp z;
+{
+ if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
+ return Z_STREAM_ERROR;
+ if (z->state->blocks != Z_NULL)
+ inflate_blocks_free(z->state->blocks, z);
+ ZFREE(z, z->state);
+ z->state = Z_NULL;
+ Tracev((stderr, "inflate: end\n"));
+ return Z_OK;
+}
+
+
+int ZEXPORT inflateInit2_(z, w, version, stream_size)
+z_streamp z;
+int w;
+const char *version;
+int stream_size;
+{
+ if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+ stream_size != sizeof(z_stream))
+ return Z_VERSION_ERROR;
+
+ /* initialize state */
+ if (z == Z_NULL)
+ return Z_STREAM_ERROR;
+ z->msg = Z_NULL;
+ if (z->zalloc == Z_NULL)
+ {
+ z->zalloc = zcalloc;
+ z->opaque = (voidpf)0;
+ }
+ if (z->zfree == Z_NULL) z->zfree = zcfree;
+ if ((z->state = (struct internal_state FAR *)
+ ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
+ return Z_MEM_ERROR;
+ z->state->blocks = Z_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)
+ {
+ inflateEnd(z);
+ return Z_STREAM_ERROR;
+ }
+ z->state->wbits = (uInt)w;
+
+ /* create inflate_blocks state */
+ if ((z->state->blocks =
+ inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
+ == Z_NULL)
+ {
+ inflateEnd(z);
+ return Z_MEM_ERROR;
+ }
+ Tracev((stderr, "inflate: allocated\n"));
+
+ /* reset state */
+ inflateReset(z);
+ return Z_OK;
+}
+
+
+int ZEXPORT inflateInit_(z, version, stream_size)
+z_streamp z;
+const char *version;
+int stream_size;
+{
+ return inflateInit2_(z, DEF_WBITS, version, stream_size);
+}
+
+
+#define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
+#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
+
+int ZEXPORT inflate(z, f)
+z_streamp z;
+int f;
+{
+ int r;
+ uInt b;
+
+ if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
+ return Z_STREAM_ERROR;
+ f = 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 = 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 = 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 = BAD;
+ z->msg = (char*)"incorrect header check";
+ z->state->sub.marker = 5; /* can't try inflateSync */
+ break;
+ }
+ Tracev((stderr, "inflate: zlib header ok\n"));
+ 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 = BAD;
+ z->msg = (char*)"need dictionary";
+ z->state->sub.marker = 0; /* can try inflateSync */
+ return Z_STREAM_ERROR;
+ case BLOCKS:
+ r = inflate_blocks(z->state->blocks, z, r);
+ if (r == Z_DATA_ERROR)
+ {
+ z->state->mode = BAD;
+ z->state->sub.marker = 0; /* can try inflateSync */
+ break;
+ }
+ if (r == Z_OK)
+ r = f;
+ if (r != Z_STREAM_END)
+ return r;
+ r = f;
+ inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
+ if (z->state->nowrap)
+ {
+ z->state->mode = 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 = BAD;
+ z->msg = (char*)"incorrect data check";
+ z->state->sub.marker = 5; /* can't try inflateSync */
+ break;
+ }
+ Tracev((stderr, "inflate: zlib check ok\n"));
+ z->state->mode = DONE;
+ case DONE:
+ return Z_STREAM_END;
+ case BAD:
+ return Z_DATA_ERROR;
+ default:
+ return Z_STREAM_ERROR;
+ }
+#ifdef NEED_DUMMY_RETURN
+ return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
+#endif
+}
+
+
+int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
+z_streamp z;
+const Bytef *dictionary;
+uInt dictLength;
+{
+ uInt length = dictLength;
+
+ if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
+ return Z_STREAM_ERROR;
+
+ if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
+ z->adler = 1L;
+
+ if (length >= ((uInt)1<<z->state->wbits))
+ {
+ length = (1<<z->state->wbits)-1;
+ dictionary += dictLength - length;
+ }
+ inflate_set_dictionary(z->state->blocks, dictionary, length);
+ z->state->mode = BLOCKS;
+ return Z_OK;
+}
+
+
+int ZEXPORT inflateSync(z)
+z_streamp z;
+{
+ uInt n; /* number of bytes to look at */
+ Bytef *p; /* pointer to bytes */
+ uInt m; /* number of marker bytes found in a row */
+ uLong r, w; /* temporaries to save total_in and total_out */
+
+ /* set up */
+ if (z == Z_NULL || z->state == Z_NULL)
+ return Z_STREAM_ERROR;
+ if (z->state->mode != BAD)
+ {
+ z->state->mode = BAD;
+ z->state->sub.marker = 0;
+ }
+ if ((n = z->avail_in) == 0)
+ return Z_BUF_ERROR;
+ p = z->next_in;
+ m = z->state->sub.marker;
+
+ /* search */
+ while (n && m < 4)
+ {
+ static const Byte mark[4] = {0, 0, 0xff, 0xff};
+ if (*p == mark[m])
+ m++;
+ else if (*p)
+ m = 0;
+ else
+ m = 4 - m;
+ p++, n--;
+ }
+
+ /* restore */
+ z->total_in += p - z->next_in;
+ z->next_in = p;
+ z->avail_in = n;
+ z->state->sub.marker = m;
+
+ /* return no joy or set up to restart on a new block */
+ if (m != 4)
+ return Z_DATA_ERROR;
+ r = z->total_in; w = z->total_out;
+ inflateReset(z);
+ z->total_in = r; z->total_out = w;
+ z->state->mode = BLOCKS;
+ return Z_OK;
+}
+
+
+/* Returns true if inflate is currently at the end of a block generated
+ * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+ * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
+ * but removes the length bytes of the resulting empty stored block. When
+ * decompressing, PPP checks that at the end of input packet, inflate is
+ * waiting for these length bytes.
+ */
+int ZEXPORT inflateSyncPoint(z)
+z_streamp z;
+{
+ if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
+ return Z_STREAM_ERROR;
+ return inflate_blocks_sync_point(z->state->blocks);
+}
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