archival/libarchive/decompress_unzip.c -> decompress_gunzip.c. no code changes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 1256 insertions, 0 deletions

diff --git a/archival/libarchive/decompress_gunzip.c b/archival/libarchive/decompress_gunzip.c
new file mode 100644
index 0000000..50873e3
--- /dev/null
+++ b/archival/libarchive/decompress_gunzip.c
@@ -0,0 +1,1256 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * gunzip implementation for busybox
+ *
+ * Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
+ *
+ * Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
+ * based on gzip sources
+ *
+ * Adjusted further by Erik Andersen <andersen@codepoet.org> to support
+ * files as well as stdin/stdout, and to generally behave itself wrt
+ * command line handling.
+ *
+ * General cleanup to better adhere to the style guide and make use of standard
+ * busybox functions by Glenn McGrath
+ *
+ * read_gz interface + associated hacking by Laurence Anderson
+ *
+ * Fixed huft_build() so decoding end-of-block code does not grab more bits
+ * than necessary (this is required by unzip applet), added inflate_cleanup()
+ * to free leaked bytebuffer memory (used in unzip.c), and some minor style
+ * guide cleanups by Ed Clark
+ *
+ * gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
+ * Copyright (C) 1992-1993 Jean-loup Gailly
+ * The unzip code was written and put in the public domain by Mark Adler.
+ * Portions of the lzw code are derived from the public domain 'compress'
+ * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
+ * Ken Turkowski, Dave Mack and Peter Jannesen.
+ *
+ * See the file algorithm.doc for the compression algorithms and file formats.
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+#include <setjmp.h>
+#include "libbb.h"
+#include "bb_archive.h"
+
+typedef struct huft_t {
+	unsigned char e;	/* number of extra bits or operation */
+	unsigned char b;	/* number of bits in this code or subcode */
+	union {
+		unsigned short n;	/* literal, length base, or distance base */
+		struct huft_t *t;	/* pointer to next level of table */
+	} v;
+} huft_t;
+
+enum {
+	/* gunzip_window size--must be a power of two, and
+	 * at least 32K for zip's deflate method */
+	GUNZIP_WSIZE = 0x8000,
+	/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
+	BMAX = 16,	/* maximum bit length of any code (16 for explode) */
+	N_MAX = 288,	/* maximum number of codes in any set */
+};
+
+
+/* This is somewhat complex-looking arrangement, but it allows
+ * to place decompressor state either in bss or in
+ * malloc'ed space simply by changing #defines below.
+ * Sizes on i386:
+ * text    data     bss     dec     hex
+ * 5256       0     108    5364    14f4 - bss
+ * 4915       0       0    4915    1333 - malloc
+ */
+#define STATE_IN_BSS 0
+#define STATE_IN_MALLOC 1
+
+
+typedef struct state_t {
+	off_t gunzip_bytes_out; /* number of output bytes */
+	uint32_t gunzip_crc;
+
+	int gunzip_src_fd;
+	unsigned gunzip_outbuf_count; /* bytes in output buffer */
+
+	unsigned char *gunzip_window;
+
+	uint32_t *gunzip_crc_table;
+
+	/* bitbuffer */
+	unsigned gunzip_bb; /* bit buffer */
+	unsigned char gunzip_bk; /* bits in bit buffer */
+
+	/* input (compressed) data */
+	unsigned char *bytebuffer;      /* buffer itself */
+	off_t to_read;			/* compressed bytes to read (unzip only, -1 for gunzip) */
+//	unsigned bytebuffer_max;        /* buffer size */
+	unsigned bytebuffer_offset;     /* buffer position */
+	unsigned bytebuffer_size;       /* how much data is there (size <= max) */
+
+	/* private data of inflate_codes() */
+	unsigned inflate_codes_ml; /* masks for bl and bd bits */
+	unsigned inflate_codes_md; /* masks for bl and bd bits */
+	unsigned inflate_codes_bb; /* bit buffer */
+	unsigned inflate_codes_k; /* number of bits in bit buffer */
+	unsigned inflate_codes_w; /* current gunzip_window position */
+	huft_t *inflate_codes_tl;
+	huft_t *inflate_codes_td;
+	unsigned inflate_codes_bl;
+	unsigned inflate_codes_bd;
+	unsigned inflate_codes_nn; /* length and index for copy */
+	unsigned inflate_codes_dd;
+
+	smallint resume_copy;
+
+	/* private data of inflate_get_next_window() */
+	smallint method; /* method == -1 for stored, -2 for codes */
+	smallint need_another_block;
+	smallint end_reached;
+
+	/* private data of inflate_stored() */
+	unsigned inflate_stored_n;
+	unsigned inflate_stored_b;
+	unsigned inflate_stored_k;
+	unsigned inflate_stored_w;
+
+	const char *error_msg;
+	jmp_buf error_jmp;
+} state_t;
+#define gunzip_bytes_out    (S()gunzip_bytes_out   )
+#define gunzip_crc          (S()gunzip_crc         )
+#define gunzip_src_fd       (S()gunzip_src_fd      )
+#define gunzip_outbuf_count (S()gunzip_outbuf_count)
+#define gunzip_window       (S()gunzip_window      )
+#define gunzip_crc_table    (S()gunzip_crc_table   )
+#define gunzip_bb           (S()gunzip_bb          )
+#define gunzip_bk           (S()gunzip_bk          )
+#define to_read             (S()to_read            )
+// #define bytebuffer_max   (S()bytebuffer_max     )
+// Both gunzip and unzip can use constant buffer size now (16k):
+#define bytebuffer_max      0x4000
+#define bytebuffer          (S()bytebuffer         )
+#define bytebuffer_offset   (S()bytebuffer_offset  )
+#define bytebuffer_size     (S()bytebuffer_size    )
+#define inflate_codes_ml    (S()inflate_codes_ml   )
+#define inflate_codes_md    (S()inflate_codes_md   )
+#define inflate_codes_bb    (S()inflate_codes_bb   )
+#define inflate_codes_k     (S()inflate_codes_k    )
+#define inflate_codes_w     (S()inflate_codes_w    )
+#define inflate_codes_tl    (S()inflate_codes_tl   )
+#define inflate_codes_td    (S()inflate_codes_td   )
+#define inflate_codes_bl    (S()inflate_codes_bl   )
+#define inflate_codes_bd    (S()inflate_codes_bd   )
+#define inflate_codes_nn    (S()inflate_codes_nn   )
+#define inflate_codes_dd    (S()inflate_codes_dd   )
+#define resume_copy         (S()resume_copy        )
+#define method              (S()method             )
+#define need_another_block  (S()need_another_block )
+#define end_reached         (S()end_reached        )
+#define inflate_stored_n    (S()inflate_stored_n   )
+#define inflate_stored_b    (S()inflate_stored_b   )
+#define inflate_stored_k    (S()inflate_stored_k   )
+#define inflate_stored_w    (S()inflate_stored_w   )
+#define error_msg           (S()error_msg          )
+#define error_jmp           (S()error_jmp          )
+
+/* This is a generic part */
+#if STATE_IN_BSS /* Use global data segment */
+#define DECLARE_STATE /*nothing*/
+#define ALLOC_STATE /*nothing*/
+#define DEALLOC_STATE ((void)0)
+#define S() state.
+#define PASS_STATE /*nothing*/
+#define PASS_STATE_ONLY /*nothing*/
+#define STATE_PARAM /*nothing*/
+#define STATE_PARAM_ONLY void
+static state_t state;
+#endif
+
+#if STATE_IN_MALLOC /* Use malloc space */
+#define DECLARE_STATE state_t *state
+#define ALLOC_STATE (state = xzalloc(sizeof(*state)))
+#define DEALLOC_STATE free(state)
+#define S() state->
+#define PASS_STATE state,
+#define PASS_STATE_ONLY state
+#define STATE_PARAM state_t *state,
+#define STATE_PARAM_ONLY state_t *state
+#endif
+
+
+static const uint16_t mask_bits[] ALIGN2 = {
+	0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+	0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
+};
+
+/* Copy lengths for literal codes 257..285 */
+static const uint16_t cplens[] ALIGN2 = {
+	3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
+	67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
+};
+
+/* note: see note #13 above about the 258 in this list. */
+/* Extra bits for literal codes 257..285 */
+static const uint8_t cplext[] ALIGN1 = {
+	0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5,
+	5, 5, 5, 0, 99, 99
+}; /* 99 == invalid */
+
+/* Copy offsets for distance codes 0..29 */
+static const uint16_t cpdist[] ALIGN2 = {
+	1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
+	769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
+};
+
+/* Extra bits for distance codes */
+static const uint8_t cpdext[] ALIGN1 = {
+	0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
+	11, 11, 12, 12, 13, 13
+};
+
+/* Tables for deflate from PKZIP's appnote.txt. */
+/* Order of the bit length code lengths */
+static const uint8_t border[] ALIGN1 = {
+	16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
+};
+
+
+/*
+ * Free the malloc'ed tables built by huft_build(), which makes a linked
+ * list of the tables it made, with the links in a dummy first entry of
+ * each table.
+ * t: table to free
+ */
+static void huft_free(huft_t *p)
+{
+	huft_t *q;
+
+	/* Go through linked list, freeing from the malloced (t[-1]) address. */
+	while (p) {
+		q = (--p)->v.t;
+		free(p);
+		p = q;
+	}
+}
+
+static void huft_free_all(STATE_PARAM_ONLY)
+{
+	huft_free(inflate_codes_tl);
+	huft_free(inflate_codes_td);
+	inflate_codes_tl = NULL;
+	inflate_codes_td = NULL;
+}
+
+static void abort_unzip(STATE_PARAM_ONLY) NORETURN;
+static void abort_unzip(STATE_PARAM_ONLY)
+{
+	huft_free_all(PASS_STATE_ONLY);
+	longjmp(error_jmp, 1);
+}
+
+static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current, const unsigned required)
+{
+	while (*current < required) {
+		if (bytebuffer_offset >= bytebuffer_size) {
+			unsigned sz = bytebuffer_max - 4;
+			if (to_read >= 0 && to_read < sz) /* unzip only */
+				sz = to_read;
+			/* Leave the first 4 bytes empty so we can always unwind the bitbuffer
+			 * to the front of the bytebuffer */
+			bytebuffer_size = safe_read(gunzip_src_fd, &bytebuffer[4], sz);
+			if ((int)bytebuffer_size < 1) {
+				error_msg = "unexpected end of file";
+				abort_unzip(PASS_STATE_ONLY);
+			}
+			if (to_read >= 0) /* unzip only */
+				to_read -= bytebuffer_size;
+			bytebuffer_size += 4;
+			bytebuffer_offset = 4;
+		}
+		bitbuffer |= ((unsigned) bytebuffer[bytebuffer_offset]) << *current;
+		bytebuffer_offset++;
+		*current += 8;
+	}
+	return bitbuffer;
+}
+
+
+/* Given a list of code lengths and a maximum table size, make a set of
+ * tables to decode that set of codes.  Return zero on success, one if
+ * the given code set is incomplete (the tables are still built in this
+ * case), two if the input is invalid (all zero length codes or an
+ * oversubscribed set of lengths) - in this case stores NULL in *t.
+ *
+ * b:	code lengths in bits (all assumed <= BMAX)
+ * n:	number of codes (assumed <= N_MAX)
+ * s:	number of simple-valued codes (0..s-1)
+ * d:	list of base values for non-simple codes
+ * e:	list of extra bits for non-simple codes
+ * t:	result: starting table
+ * m:	maximum lookup bits, returns actual
+ */
+static int huft_build(const unsigned *b, const unsigned n,
+			   const unsigned s, const unsigned short *d,
+			   const unsigned char *e, huft_t **t, unsigned *m)
+{
+	unsigned a;             /* counter for codes of length k */
+	unsigned c[BMAX + 1];   /* bit length count table */
+	unsigned eob_len;       /* length of end-of-block code (value 256) */
+	unsigned f;             /* i repeats in table every f entries */
+	int g;                  /* maximum code length */
+	int htl;                /* table level */
+	unsigned i;             /* counter, current code */
+	unsigned j;             /* counter */
+	int k;                  /* number of bits in current code */
+	unsigned *p;            /* pointer into c[], b[], or v[] */
+	huft_t *q;              /* points to current table */
+	huft_t r;               /* table entry for structure assignment */
+	huft_t *u[BMAX];        /* table stack */
+	unsigned v[N_MAX];      /* values in order of bit length */
+	int ws[BMAX + 1];       /* bits decoded stack */
+	int w;                  /* bits decoded */
+	unsigned x[BMAX + 1];   /* bit offsets, then code stack */
+	unsigned *xp;           /* pointer into x */
+	int y;                  /* number of dummy codes added */
+	unsigned z;             /* number of entries in current table */
+
+	/* Length of EOB code, if any */
+	eob_len = n > 256 ? b[256] : BMAX;
+
+	*t = NULL;
+
+	/* Generate counts for each bit length */
+	memset(c, 0, sizeof(c));
+	p = (unsigned *) b; /* cast allows us to reuse p for pointing to b */
+	i = n;
+	do {
+		c[*p]++; /* assume all entries <= BMAX */
+		p++;     /* can't combine with above line (Solaris bug) */
+	} while (--i);
+	if (c[0] == n) {  /* null input - all zero length codes */
+		*m = 0;
+		return 2;
+	}
+
+	/* Find minimum and maximum length, bound *m by those */
+	for (j = 1; (c[j] == 0) && (j <= BMAX); j++)
+		continue;
+	k = j; /* minimum code length */
+	for (i = BMAX; (c[i] == 0) && i; i--)
+		continue;
+	g = i; /* maximum code length */
+	*m = (*m < j) ? j : ((*m > i) ? i : *m);
+
+	/* Adjust last length count to fill out codes, if needed */
+	for (y = 1 << j; j < i; j++, y <<= 1) {
+		y -= c[j];
+		if (y < 0)
+			return 2; /* bad input: more codes than bits */
+	}
+	y -= c[i];
+	if (y < 0)
+		return 2;
+	c[i] += y;
+
+	/* Generate starting offsets into the value table for each length */
+	x[1] = j = 0;
+	p = c + 1;
+	xp = x + 2;
+	while (--i) { /* note that i == g from above */
+		j += *p++;
+		*xp++ = j;
+	}
+
+	/* Make a table of values in order of bit lengths */
+	p = (unsigned *) b;
+	i = 0;
+	do {
+		j = *p++;
+		if (j != 0) {
+			v[x[j]++] = i;
+		}
+	} while (++i < n);
+
+	/* Generate the Huffman codes and for each, make the table entries */
+	x[0] = i = 0;   /* first Huffman code is zero */
+	p = v;          /* grab values in bit order */
+	htl = -1;       /* no tables yet--level -1 */
+	w = ws[0] = 0;  /* bits decoded */
+	u[0] = NULL;    /* just to keep compilers happy */
+	q = NULL;       /* ditto */
+	z = 0;          /* ditto */
+
+	/* go through the bit lengths (k already is bits in shortest code) */
+	for (; k <= g; k++) {
+		a = c[k];
+		while (a--) {
+			/* here i is the Huffman code of length k bits for value *p */
+			/* make tables up to required level */
+			while (k > ws[htl + 1]) {
+				w = ws[++htl];
+
+				/* compute minimum size table less than or equal to *m bits */
+				z = g - w;
+				z = z > *m ? *m : z; /* upper limit on table size */
+				j = k - w;
+				f = 1 << j;
+				if (f > a + 1) { /* try a k-w bit table */
+					/* too few codes for k-w bit table */
+					f -= a + 1; /* deduct codes from patterns left */
+					xp = c + k;
+					while (++j < z) { /* try smaller tables up to z bits */
+						f <<= 1;
+						if (f <= *++xp) {
+							break; /* enough codes to use up j bits */
+						}
+						f -= *xp; /* else deduct codes from patterns */
+					}
+				}
+				j = (w + j > eob_len && w < eob_len) ? eob_len - w : j;	/* make EOB code end at table */
+				z = 1 << j;	/* table entries for j-bit table */
+				ws[htl+1] = w + j;	/* set bits decoded in stack */
+
+				/* allocate and link in new table */
+				q = xzalloc((z + 1) * sizeof(huft_t));
+				*t = q + 1;	/* link to list for huft_free() */
+				t = &(q->v.t);
+				u[htl] = ++q;	/* table starts after link */
+
+				/* connect to last table, if there is one */
+				if (htl) {
+					x[htl] = i; /* save pattern for backing up */
+					r.b = (unsigned char) (w - ws[htl - 1]); /* bits to dump before this table */
+					r.e = (unsigned char) (16 + j); /* bits in this table */
+					r.v.t = q; /* pointer to this table */
+					j = (i & ((1 << w) - 1)) >> ws[htl - 1];
+					u[htl - 1][j] = r; /* connect to last table */
+				}
+			}
+
+			/* set up table entry in r */
+			r.b = (unsigned char) (k - w);
+			if (p >= v + n) {
+				r.e = 99; /* out of values--invalid code */
+			} else if (*p < s) {
+				r.e = (unsigned char) (*p < 256 ? 16 : 15);	/* 256 is EOB code */
+				r.v.n = (unsigned short) (*p++); /* simple code is just the value */
+			} else {
+				r.e = (unsigned char) e[*p - s]; /* non-simple--look up in lists */
+				r.v.n = d[*p++ - s];
+			}
+
+			/* fill code-like entries with r */
+			f = 1 << (k - w);
+			for (j = i >> w; j < z; j += f) {
+				q[j] = r;
+			}
+
+			/* backwards increment the k-bit code i */
+			for (j = 1 << (k - 1); i & j; j >>= 1) {
+				i ^= j;
+			}
+			i ^= j;
+
+			/* backup over finished tables */
+			while ((i & ((1 << w) - 1)) != x[htl]) {
+				w = ws[--htl];
+			}
+		}
+	}
+
+	/* return actual size of base table */
+	*m = ws[1];
+
+	/* Return 1 if we were given an incomplete table */
+	return y != 0 && g != 1;
+}
+
+
+/*
+ * inflate (decompress) the codes in a deflated (compressed) block.
+ * Return an error code or zero if it all goes ok.
+ *
+ * tl, td: literal/length and distance decoder tables
+ * bl, bd: number of bits decoded by tl[] and td[]
+ */
+/* called once from inflate_block */
+
+/* map formerly local static variables to globals */
+#define ml inflate_codes_ml
+#define md inflate_codes_md
+#define bb inflate_codes_bb
+#define k  inflate_codes_k
+#define w  inflate_codes_w
+#define tl inflate_codes_tl
+#define td inflate_codes_td
+#define bl inflate_codes_bl
+#define bd inflate_codes_bd
+#define nn inflate_codes_nn
+#define dd inflate_codes_dd
+static void inflate_codes_setup(STATE_PARAM unsigned my_bl, unsigned my_bd)
+{
+	bl = my_bl;
+	bd = my_bd;
+	/* make local copies of globals */
+	bb = gunzip_bb;			/* initialize bit buffer */
+	k = gunzip_bk;
+	w = gunzip_outbuf_count;	/* initialize gunzip_window position */
+	/* inflate the coded data */
+	ml = mask_bits[bl];		/* precompute masks for speed */
+	md = mask_bits[bd];
+}
+/* called once from inflate_get_next_window */
+static NOINLINE int inflate_codes(STATE_PARAM_ONLY)
+{
+	unsigned e;	/* table entry flag/number of extra bits */
+	huft_t *t;	/* pointer to table entry */
+
+	if (resume_copy)
+		goto do_copy;
+
+	while (1) {			/* do until end of block */
+		bb = fill_bitbuffer(PASS_STATE bb, &k, bl);
+		t = tl + ((unsigned) bb & ml);
+		e = t->e;
+		if (e > 16)
+			do {
+				if (e == 99)
+					abort_unzip(PASS_STATE_ONLY);;
+				bb >>= t->b;
+				k -= t->b;
+				e -= 16;
+				bb = fill_bitbuffer(PASS_STATE bb, &k, e);
+				t = t->v.t + ((unsigned) bb & mask_bits[e]);
+				e = t->e;
+			} while (e > 16);
+		bb >>= t->b;
+		k -= t->b;
+		if (e == 16) {	/* then it's a literal */
+			gunzip_window[w++] = (unsigned char) t->v.n;
+			if (w == GUNZIP_WSIZE) {
+				gunzip_outbuf_count = w;
+				//flush_gunzip_window();
+				w = 0;
+				return 1; // We have a block to read
+			}
+		} else {		/* it's an EOB or a length */
+			/* exit if end of block */
+			if (e == 15) {
+				break;
+			}
+
+			/* get length of block to copy */
+			bb = fill_bitbuffer(PASS_STATE bb, &k, e);
+			nn = t->v.n + ((unsigned) bb & mask_bits[e]);
+			bb >>= e;
+			k -= e;
+
+			/* decode distance of block to copy */
+			bb = fill_bitbuffer(PASS_STATE bb, &k, bd);
+			t = td + ((unsigned) bb & md);
+			e = t->e;
+			if (e > 16)
+				do {
+					if (e == 99)
+						abort_unzip(PASS_STATE_ONLY);
+					bb >>= t->b;
+					k -= t->b;
+					e -= 16;
+					bb = fill_bitbuffer(PASS_STATE bb, &k, e);
+					t = t->v.t + ((unsigned) bb & mask_bits[e]);
+					e = t->e;
+				} while (e > 16);
+			bb >>= t->b;
+			k -= t->b;
+			bb = fill_bitbuffer(PASS_STATE bb, &k, e);
+			dd = w - t->v.n - ((unsigned) bb & mask_bits[e]);
+			bb >>= e;
+			k -= e;
+
+			/* do the copy */
+ do_copy:
+			do {
+				/* Was: nn -= (e = (e = GUNZIP_WSIZE - ((dd &= GUNZIP_WSIZE - 1) > w ? dd : w)) > nn ? nn : e); */
+				/* Who wrote THAT?? rewritten as: */
+				unsigned delta;
+
+				dd &= GUNZIP_WSIZE - 1;
+				e = GUNZIP_WSIZE - (dd > w ? dd : w);
+				delta = w > dd ? w - dd : dd - w;
+				if (e > nn) e = nn;
+				nn -= e;
+
+				/* copy to new buffer to prevent possible overwrite */
+				if (delta >= e) {
+					memcpy(gunzip_window + w, gunzip_window + dd, e);
+					w += e;
+					dd += e;
+				} else {
+					/* do it slow to avoid memcpy() overlap */
+					/* !NOMEMCPY */
+					do {
+						gunzip_window[w++] = gunzip_window[dd++];
+					} while (--e);
+				}
+				if (w == GUNZIP_WSIZE) {
+					gunzip_outbuf_count = w;
+					resume_copy = (nn != 0);
+					//flush_gunzip_window();
+					w = 0;
+					return 1;
+				}
+			} while (nn);
+			resume_copy = 0;
+		}
+	}
+
+	/* restore the globals from the locals */
+	gunzip_outbuf_count = w;	/* restore global gunzip_window pointer */
+	gunzip_bb = bb;			/* restore global bit buffer */
+	gunzip_bk = k;
+
+	/* normally just after call to inflate_codes, but save code by putting it here */
+	/* free the decoding tables (tl and td), return */
+	huft_free_all(PASS_STATE_ONLY);
+
+	/* done */
+	return 0;
+}
+#undef ml
+#undef md
+#undef bb
+#undef k
+#undef w
+#undef tl
+#undef td
+#undef bl
+#undef bd
+#undef nn
+#undef dd
+
+
+/* called once from inflate_block */
+static void inflate_stored_setup(STATE_PARAM int my_n, int my_b, int my_k)
+{
+	inflate_stored_n = my_n;
+	inflate_stored_b = my_b;
+	inflate_stored_k = my_k;
+	/* initialize gunzip_window position */
+	inflate_stored_w = gunzip_outbuf_count;
+}
+/* called once from inflate_get_next_window */
+static int inflate_stored(STATE_PARAM_ONLY)
+{
+	/* read and output the compressed data */
+	while (inflate_stored_n--) {
+		inflate_stored_b = fill_bitbuffer(PASS_STATE inflate_stored_b, &inflate_stored_k, 8);
+		gunzip_window[inflate_stored_w++] = (unsigned char) inflate_stored_b;
+		if (inflate_stored_w == GUNZIP_WSIZE) {
+			gunzip_outbuf_count = inflate_stored_w;
+			//flush_gunzip_window();
+			inflate_stored_w = 0;
+			inflate_stored_b >>= 8;
+			inflate_stored_k -= 8;
+			return 1; /* We have a block */
+		}
+		inflate_stored_b >>= 8;
+		inflate_stored_k -= 8;
+	}
+
+	/* restore the globals from the locals */
+	gunzip_outbuf_count = inflate_stored_w;		/* restore global gunzip_window pointer */
+	gunzip_bb = inflate_stored_b;	/* restore global bit buffer */
+	gunzip_bk = inflate_stored_k;
+	return 0; /* Finished */
+}
+
+
+/*
+ * decompress an inflated block
+ * e: last block flag
+ *
+ * GLOBAL VARIABLES: bb, kk,
+ */
+/* Return values: -1 = inflate_stored, -2 = inflate_codes */
+/* One callsite in inflate_get_next_window */
+static int inflate_block(STATE_PARAM smallint *e)
+{
+	unsigned ll[286 + 30];  /* literal/length and distance code lengths */
+	unsigned t;     /* block type */
+	unsigned b;     /* bit buffer */
+	unsigned k;     /* number of bits in bit buffer */
+
+	/* make local bit buffer */
+
+	b = gunzip_bb;
+	k = gunzip_bk;
+
+	/* read in last block bit */
+	b = fill_bitbuffer(PASS_STATE b, &k, 1);
+	*e = b & 1;
+	b >>= 1;
+	k -= 1;
+
+	/* read in block type */
+	b = fill_bitbuffer(PASS_STATE b, &k, 2);
+	t = (unsigned) b & 3;
+	b >>= 2;
+	k -= 2;
+
+	/* restore the global bit buffer */
+	gunzip_bb = b;
+	gunzip_bk = k;
+
+	/* Do we see block type 1 often? Yes!
+	 * TODO: fix performance problem (see below) */
+	//bb_error_msg("blktype %d", t);
+
+	/* inflate that block type */
+	switch (t) {
+	case 0: /* Inflate stored */
+	{
+		unsigned n;	/* number of bytes in block */
+		unsigned b_stored;	/* bit buffer */
+		unsigned k_stored;	/* number of bits in bit buffer */
+
+		/* make local copies of globals */
+		b_stored = gunzip_bb;	/* initialize bit buffer */
+		k_stored = gunzip_bk;
+
+		/* go to byte boundary */
+		n = k_stored & 7;
+		b_stored >>= n;
+		k_stored -= n;
+
+		/* get the length and its complement */
+		b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
+		n = ((unsigned) b_stored & 0xffff);
+		b_stored >>= 16;
+		k_stored -= 16;
+
+		b_stored = fill_bitbuffer(PASS_STATE b_stored, &k_stored, 16);
+		if (n != (unsigned) ((~b_stored) & 0xffff)) {
+			abort_unzip(PASS_STATE_ONLY);	/* error in compressed data */
+		}
+		b_stored >>= 16;
+		k_stored -= 16;
+
+		inflate_stored_setup(PASS_STATE n, b_stored, k_stored);
+
+		return -1;
+	}
+	case 1:
+	/* Inflate fixed
+	 * decompress an inflated type 1 (fixed Huffman codes) block. We should
+	 * either replace this with a custom decoder, or at least precompute the
+	 * Huffman tables. TODO */
+	{
+		int i;                  /* temporary variable */
+		unsigned bl;            /* lookup bits for tl */
+		unsigned bd;            /* lookup bits for td */
+		/* gcc 4.2.1 is too dumb to reuse stackspace. Moved up... */
+		//unsigned ll[288];     /* length list for huft_build */
+
+		/* set up literal table */
+		for (i = 0; i < 144; i++)
+			ll[i] = 8;
+		for (; i < 256; i++)
+			ll[i] = 9;
+		for (; i < 280; i++)
+			ll[i] = 7;
+		for (; i < 288; i++) /* make a complete, but wrong code set */
+			ll[i] = 8;
+		bl = 7;
+		huft_build(ll, 288, 257, cplens, cplext, &inflate_codes_tl, &bl);
+		/* huft_build() never return nonzero - we use known data */
+
+		/* set up distance table */
+		for (i = 0; i < 30; i++) /* make an incomplete code set */
+			ll[i] = 5;
+		bd = 5;
+		huft_build(ll, 30, 0, cpdist, cpdext, &inflate_codes_td, &bd);
+
+		/* set up data for inflate_codes() */
+		inflate_codes_setup(PASS_STATE bl, bd);
+
+		/* huft_free code moved into inflate_codes */
+
+		return -2;
+	}
+	case 2: /* Inflate dynamic */
+	{
+		enum { dbits = 6 };     /* bits in base distance lookup table */
+		enum { lbits = 9 };     /* bits in base literal/length lookup table */
+
+		huft_t *td;             /* distance code table */
+		unsigned i;             /* temporary variables */
+		unsigned j;
+		unsigned l;             /* last length */
+		unsigned m;             /* mask for bit lengths table */
+		unsigned n;             /* number of lengths to get */
+		unsigned bl;            /* lookup bits for tl */
+		unsigned bd;            /* lookup bits for td */
+		unsigned nb;            /* number of bit length codes */
+		unsigned nl;            /* number of literal/length codes */
+		unsigned nd;            /* number of distance codes */
+
+		//unsigned ll[286 + 30];/* literal/length and distance code lengths */
+		unsigned b_dynamic;     /* bit buffer */
+		unsigned k_dynamic;     /* number of bits in bit buffer */
+
+		/* make local bit buffer */
+		b_dynamic = gunzip_bb;
+		k_dynamic = gunzip_bk;
+
+		/* read in table lengths */
+		b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 5);
+		nl = 257 + ((unsigned) b_dynamic & 0x1f);	/* number of literal/length codes */
+
+		b_dynamic >>= 5;
+		k_dynamic -= 5;
+		b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 5);
+		nd = 1 + ((unsigned) b_dynamic & 0x1f);	/* number of distance codes */
+
+		b_dynamic >>= 5;
+		k_dynamic -= 5;
+		b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 4);
+		nb = 4 + ((unsigned) b_dynamic & 0xf);	/* number of bit length codes */
+
+		b_dynamic >>= 4;
+		k_dynamic -= 4;
+		if (nl > 286 || nd > 30)
+			abort_unzip(PASS_STATE_ONLY);	/* bad lengths */
+
+		/* read in bit-length-code lengths */
+		for (j = 0; j < nb; j++) {
+			b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
+			ll[border[j]] = (unsigned) b_dynamic & 7;
+			b_dynamic >>= 3;
+			k_dynamic -= 3;
+		}
+		for (; j < 19; j++)
+			ll[border[j]] = 0;
+
+		/* build decoding table for trees - single level, 7 bit lookup */
+		bl = 7;
+		i = huft_build(ll, 19, 19, NULL, NULL, &inflate_codes_tl, &bl);
+		if (i != 0) {
+			abort_unzip(PASS_STATE_ONLY); //return i;	/* incomplete code set */
+		}
+
+		/* read in literal and distance code lengths */
+		n = nl + nd;
+		m = mask_bits[bl];
+		i = l = 0;
+		while ((unsigned) i < n) {
+			b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, (unsigned)bl);
+			td = inflate_codes_tl + ((unsigned) b_dynamic & m);
+			j = td->b;
+			b_dynamic >>= j;
+			k_dynamic -= j;
+			j = td->v.n;
+			if (j < 16) {	/* length of code in bits (0..15) */
+				ll[i++] = l = j;	/* save last length in l */
+			} else if (j == 16) {	/* repeat last length 3 to 6 times */
+				b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 2);
+				j = 3 + ((unsigned) b_dynamic & 3);
+				b_dynamic >>= 2;
+				k_dynamic -= 2;
+				if ((unsigned) i + j > n) {
+					abort_unzip(PASS_STATE_ONLY); //return 1;
+				}
+				while (j--) {
+					ll[i++] = l;
+				}
+			} else if (j == 17) {	/* 3 to 10 zero length codes */
+				b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 3);
+				j = 3 + ((unsigned) b_dynamic & 7);
+				b_dynamic >>= 3;
+				k_dynamic -= 3;
+				if ((unsigned) i + j > n) {
+					abort_unzip(PASS_STATE_ONLY); //return 1;
+				}
+				while (j--) {
+					ll[i++] = 0;
+				}
+				l = 0;
+			} else {	/* j == 18: 11 to 138 zero length codes */
+				b_dynamic = fill_bitbuffer(PASS_STATE b_dynamic, &k_dynamic, 7);
+				j = 11 + ((unsigned) b_dynamic & 0x7f);
+				b_dynamic >>= 7;
+				k_dynamic -= 7;
+				if ((unsigned) i + j > n) {
+					abort_unzip(PASS_STATE_ONLY); //return 1;
+				}
+				while (j--) {
+					ll[i++] = 0;
+				}
+				l = 0;
+			}
+		}
+
+		/* free decoding table for trees */
+		huft_free(inflate_codes_tl);
+
+		/* restore the global bit buffer */
+		gunzip_bb = b_dynamic;
+		gunzip_bk = k_dynamic;
+
+		/* build the decoding tables for literal/length and distance codes */
+		bl = lbits;
+
+		i = huft_build(ll, nl, 257, cplens, cplext, &inflate_codes_tl, &bl);
+		if (i != 0)
+			abort_unzip(PASS_STATE_ONLY);
+		bd = dbits;
+		i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &inflate_codes_td, &bd);
+		if (i != 0)
+			abort_unzip(PASS_STATE_ONLY);
+
+		/* set up data for inflate_codes() */
+		inflate_codes_setup(PASS_STATE bl, bd);
+
+		/* huft_free code moved into inflate_codes */
+
+		return -2;
+	}
+	default:
+		abort_unzip(PASS_STATE_ONLY);
+	}
+}
+
+/* Two callsites, both in inflate_get_next_window */
+static void calculate_gunzip_crc(STATE_PARAM_ONLY)
+{
+	gunzip_crc = crc32_block_endian0(gunzip_crc, gunzip_window, gunzip_outbuf_count, gunzip_crc_table);
+	gunzip_bytes_out += gunzip_outbuf_count;
+}
+
+/* One callsite in inflate_unzip_internal */
+static int inflate_get_next_window(STATE_PARAM_ONLY)
+{
+	gunzip_outbuf_count = 0;
+
+	while (1) {
+		int ret;
+
+		if (need_another_block) {
+			if (end_reached) {
+				calculate_gunzip_crc(PASS_STATE_ONLY);
+				end_reached = 0;
+				/* NB: need_another_block is still set */
+				return 0; /* Last block */
+			}
+			method = inflate_block(PASS_STATE &end_reached);
+			need_another_block = 0;
+		}
+
+		switch (method) {
+		case -1:
+			ret = inflate_stored(PASS_STATE_ONLY);
+			break;
+		case -2:
+			ret = inflate_codes(PASS_STATE_ONLY);
+			break;
+		default: /* cannot happen */
+			abort_unzip(PASS_STATE_ONLY);
+		}
+
+		if (ret == 1) {
+			calculate_gunzip_crc(PASS_STATE_ONLY);
+			return 1; /* more data left */
+		}
+		need_another_block = 1; /* end of that block */
+	}
+	/* Doesnt get here */
+}
+
+
+/* Called from unpack_gz_stream() and inflate_unzip() */
+static IF_DESKTOP(long long) int
+inflate_unzip_internal(STATE_PARAM int in, int out)
+{
+	IF_DESKTOP(long long) int n = 0;
+	ssize_t nwrote;
+
+	/* Allocate all global buffers (for DYN_ALLOC option) */
+	gunzip_window = xmalloc(GUNZIP_WSIZE);
+	gunzip_outbuf_count = 0;
+	gunzip_bytes_out = 0;
+	gunzip_src_fd = in;
+
+	/* (re) initialize state */
+	method = -1;
+	need_another_block = 1;
+	resume_copy = 0;
+	gunzip_bk = 0;
+	gunzip_bb = 0;
+
+	/* Create the crc table */
+	gunzip_crc_table = crc32_filltable(NULL, 0);
+	gunzip_crc = ~0;
+
+	error_msg = "corrupted data";
+	if (setjmp(error_jmp)) {
+		/* Error from deep inside zip machinery */
+		n = -1;
+		goto ret;
+	}
+
+	while (1) {
+		int r = inflate_get_next_window(PASS_STATE_ONLY);
+		nwrote = full_write(out, gunzip_window, gunzip_outbuf_count);
+		if (nwrote != (ssize_t)gunzip_outbuf_count) {
+			bb_perror_msg("write");
+			n = -1;
+			goto ret;
+		}
+		IF_DESKTOP(n += nwrote;)
+		if (r == 0) break;
+	}
+
+	/* Store unused bytes in a global buffer so calling applets can access it */
+	if (gunzip_bk >= 8) {
+		/* Undo too much lookahead. The next read will be byte aligned
+		 * so we can discard unused bits in the last meaningful byte. */
+		bytebuffer_offset--;
+		bytebuffer[bytebuffer_offset] = gunzip_bb & 0xff;
+		gunzip_bb >>= 8;
+		gunzip_bk -= 8;
+	}
+ ret:
+	/* Cleanup */
+	free(gunzip_window);
+	free(gunzip_crc_table);
+	return n;
+}
+
+
+/* External entry points */
+
+/* For unzip */
+
+IF_DESKTOP(long long) int FAST_FUNC
+inflate_unzip(inflate_unzip_result *res, off_t compr_size, int in, int out)
+{
+	IF_DESKTOP(long long) int n;
+	DECLARE_STATE;
+
+	ALLOC_STATE;
+
+	to_read = compr_size;
+//	bytebuffer_max = 0x8000;
+	bytebuffer_offset = 4;
+	bytebuffer = xmalloc(bytebuffer_max);
+	n = inflate_unzip_internal(PASS_STATE in, out);
+	free(bytebuffer);
+
+	res->crc = gunzip_crc;
+	res->bytes_out = gunzip_bytes_out;
+	DEALLOC_STATE;
+	return n;
+}
+
+
+/* For gunzip */
+
+/* helpers first */
+
+/* Top up the input buffer with at least n bytes. */
+static int top_up(STATE_PARAM unsigned n)
+{
+	int count = bytebuffer_size - bytebuffer_offset;
+
+	if (count < (int)n) {
+		memmove(bytebuffer, &bytebuffer[bytebuffer_offset], count);
+		bytebuffer_offset = 0;
+		bytebuffer_size = full_read(gunzip_src_fd, &bytebuffer[count], bytebuffer_max - count);
+		if ((int)bytebuffer_size < 0) {
+			bb_error_msg(bb_msg_read_error);
+			return 0;
+		}
+		bytebuffer_size += count;
+		if (bytebuffer_size < n)
+			return 0;
+	}
+	return 1;
+}
+
+static uint16_t buffer_read_le_u16(STATE_PARAM_ONLY)
+{
+	uint16_t res;
+#if BB_LITTLE_ENDIAN
+	move_from_unaligned16(res, &bytebuffer[bytebuffer_offset]);
+#else
+	res = bytebuffer[bytebuffer_offset];
+	res |= bytebuffer[bytebuffer_offset + 1] << 8;
+#endif
+	bytebuffer_offset += 2;
+	return res;
+}
+
+static uint32_t buffer_read_le_u32(STATE_PARAM_ONLY)
+{
+	uint32_t res;
+#if BB_LITTLE_ENDIAN
+	move_from_unaligned32(res, &bytebuffer[bytebuffer_offset]);
+#else
+	res = bytebuffer[bytebuffer_offset];
+	res |= bytebuffer[bytebuffer_offset + 1] << 8;
+	res |= bytebuffer[bytebuffer_offset + 2] << 16;
+	res |= bytebuffer[bytebuffer_offset + 3] << 24;
+#endif
+	bytebuffer_offset += 4;
+	return res;
+}
+
+static int check_header_gzip(STATE_PARAM unpack_info_t *info)
+{
+	union {
+		unsigned char raw[8];
+		struct {
+			uint8_t gz_method;
+			uint8_t flags;
+			uint32_t mtime;
+			uint8_t xtra_flags_UNUSED;
+			uint8_t os_flags_UNUSED;
+		} PACKED formatted;
+	} header;
+	struct BUG_header {
+		char BUG_header[sizeof(header) == 8 ? 1 : -1];
+	};
+
+	/*
+	 * Rewind bytebuffer. We use the beginning because the header has 8
+	 * bytes, leaving enough for unwinding afterwards.
+	 */
+	bytebuffer_size -= bytebuffer_offset;
+	memmove(bytebuffer, &bytebuffer[bytebuffer_offset], bytebuffer_size);
+	bytebuffer_offset = 0;
+
+	if (!top_up(PASS_STATE 8))
+		return 0;
+	memcpy(header.raw, &bytebuffer[bytebuffer_offset], 8);
+	bytebuffer_offset += 8;
+
+	/* Check the compression method */
+	if (header.formatted.gz_method != 8) {
+		return 0;
+	}
+
+	if (header.formatted.flags & 0x04) {
+		/* bit 2 set: extra field present */
+		unsigned extra_short;
+
+		if (!top_up(PASS_STATE 2))
+			return 0;
+		extra_short = buffer_read_le_u16(PASS_STATE_ONLY);
+		if (!top_up(PASS_STATE extra_short))
+			return 0;
+		/* Ignore extra field */
+		bytebuffer_offset += extra_short;
+	}
+
+	/* Discard original name and file comment if any */
+	/* bit 3 set: original file name present */
+	/* bit 4 set: file comment present */
+	if (header.formatted.flags & 0x18) {
+		while (1) {
+			do {
+				if (!top_up(PASS_STATE 1))
+					return 0;
+			} while (bytebuffer[bytebuffer_offset++] != 0);
+			if ((header.formatted.flags & 0x18) != 0x18)
+				break;
+			header.formatted.flags &= ~0x18;
+		}
+	}
+
+	if (info)
+		info->mtime = SWAP_LE32(header.formatted.mtime);
+
+	/* Read the header checksum */
+	if (header.formatted.flags & 0x02) {
+		if (!top_up(PASS_STATE 2))
+			return 0;
+		bytebuffer_offset += 2;
+	}
+	return 1;
+}
+
+IF_DESKTOP(long long) int FAST_FUNC
+unpack_gz_stream_with_info(int src_fd, int dst_fd, unpack_info_t *info)
+{
+	uint32_t v32;
+	IF_DESKTOP(long long) int total, n;
+	DECLARE_STATE;
+
+	total = 0;
+
+	ALLOC_STATE;
+	to_read = -1;
+//	bytebuffer_max = 0x8000;
+	bytebuffer = xmalloc(bytebuffer_max);
+	gunzip_src_fd = src_fd;
+
+ again:
+	if (!check_header_gzip(PASS_STATE info)) {
+		bb_error_msg("corrupted data");
+		total = -1;
+		goto ret;
+	}
+
+	n = inflate_unzip_internal(PASS_STATE src_fd, dst_fd);
+	if (n < 0) {
+		total = -1;
+		goto ret;
+	}
+	total += n;
+
+	if (!top_up(PASS_STATE 8)) {
+		bb_error_msg("corrupted data");
+		total = -1;
+		goto ret;
+	}
+
+	/* Validate decompression - crc */
+	v32 = buffer_read_le_u32(PASS_STATE_ONLY);
+	if ((~gunzip_crc) != v32) {
+		bb_error_msg("crc error");
+		total = -1;
+		goto ret;
+	}
+
+	/* Validate decompression - size */
+	v32 = buffer_read_le_u32(PASS_STATE_ONLY);
+	if ((uint32_t)gunzip_bytes_out != v32) {
+		bb_error_msg("incorrect length");
+		total = -1;
+	}
+
+	if (!top_up(PASS_STATE 2))
+		goto ret; /* EOF */
+
+	if (bytebuffer[bytebuffer_offset] == 0x1f
+	 && bytebuffer[bytebuffer_offset + 1] == 0x8b
+	) {
+		bytebuffer_offset += 2;
+		goto again;
+	}
+	/* GNU gzip says: */
+	/*bb_error_msg("decompression OK, trailing garbage ignored");*/
+
+ ret:
+	free(bytebuffer);
+	DEALLOC_STATE;
+	return total;
+}
+
+IF_DESKTOP(long long) int FAST_FUNC
+unpack_gz_stream(int in, int out)
+{
+	return unpack_gz_stream_with_info(in, out, NULL);
+}