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Diffstat (limited to 'archival/libarchive/decompress_gunzip.c')
| -rw-r--r-- | archival/libarchive/decompress_gunzip.c | 1256 |
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); +} |