| /* 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 <bug1@iinet.net.au> |
| * |
| * 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 tarball for details. |
| */ |
| |
| #include "libbb.h" |
| #include <sys/wait.h> |
| #include <signal.h> |
| #include "unarchive.h" |
| |
| typedef struct huft_s { |
| 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_s *t; /* pointer to next level of table */ |
| } v; |
| } huft_t; |
| |
| static int gunzip_src_fd; |
| unsigned int gunzip_bytes_out; /* number of output bytes */ |
| static unsigned int gunzip_outbuf_count; /* bytes in output buffer */ |
| |
| /* gunzip_window size--must be a power of two, and |
| * at least 32K for zip's deflate method */ |
| enum { gunzip_wsize = 0x8000 }; |
| static unsigned char *gunzip_window; |
| |
| static uint32_t *gunzip_crc_table; |
| uint32_t gunzip_crc; |
| |
| /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */ |
| #define BMAX 16 /* maximum bit length of any code (16 for explode) */ |
| #define N_MAX 288 /* maximum number of codes in any set */ |
| |
| /* bitbuffer */ |
| static unsigned int gunzip_bb; /* bit buffer */ |
| static unsigned char gunzip_bk; /* bits in bit buffer */ |
| |
| /* These control the size of the bytebuffer */ |
| static unsigned int bytebuffer_max = 0x8000; |
| static unsigned char *bytebuffer = NULL; |
| static unsigned int bytebuffer_offset = 0; |
| static unsigned int bytebuffer_size = 0; |
| |
| static const unsigned short mask_bits[] = { |
| 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 unsigned short cplens[] = { |
| 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 unsigned char cplext[] = { |
| 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 unsigned short cpdist[] = { |
| 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 unsigned char cpdext[] = { |
| 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 unsigned char border[] = { |
| 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 |
| }; |
| |
| static unsigned int fill_bitbuffer(unsigned int bitbuffer, unsigned int *current, const unsigned int required) |
| { |
| while (*current < required) { |
| if (bytebuffer_offset >= bytebuffer_size) { |
| /* Leave the first 4 bytes empty so we can always unwind the bitbuffer |
| * to the front of the bytebuffer, leave 4 bytes free at end of tail |
| * so we can easily top up buffer in check_trailer_gzip() */ |
| if (!(bytebuffer_size = bb_xread(gunzip_src_fd, &bytebuffer[4], bytebuffer_max - 8))) { |
| bb_error_msg_and_die("unexpected end of file"); |
| } |
| bytebuffer_size += 4; |
| bytebuffer_offset = 4; |
| } |
| bitbuffer |= ((unsigned int) bytebuffer[bytebuffer_offset]) << *current; |
| bytebuffer_offset++; |
| *current += 8; |
| } |
| return(bitbuffer); |
| } |
| |
| /* |
| * 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 int huft_free(huft_t * t) |
| { |
| huft_t *p; |
| huft_t *q; |
| |
| /* Go through linked list, freeing from the malloced (t[-1]) address. */ |
| p = t; |
| while (p != (huft_t *) NULL) { |
| q = (--p)->v.t; |
| free((char *) p); |
| p = q; |
| } |
| return 0; |
| } |
| |
| /* 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), and three if not enough memory. |
| * |
| * 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(unsigned int *b, const unsigned int n, |
| const unsigned int s, const unsigned short *d, |
| const unsigned char *e, huft_t ** t, unsigned int *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; |
| |
| /* Generate counts for each bit length */ |
| memset((void *)c, 0, sizeof(c)); |
| p = 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 */ |
| *t = (huft_t *) NULL; |
| *m = 0; |
| return 2; |
| } |
| |
| /* Find minimum and maximum length, bound *m by those */ |
| for (j = 1; (c[j] == 0) && (j <= BMAX); j++); |
| k = j; /* minimum code length */ |
| for (i = BMAX; (c[i] == 0) && i; i--); |
| 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) { |
| if ((y -= c[j]) < 0) { |
| return 2; /* bad input: more codes than bits */ |
| } |
| } |
| if ((y -= c[i]) < 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 */ |
| *xp++ = (j += *p++); |
| } |
| |
| /* Make a table of values in order of bit lengths */ |
| p = b; |
| i = 0; |
| do { |
| if ((j = *p++) != 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] = (huft_t *) NULL; /* just to keep compilers happy */ |
| q = (huft_t *) 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 = (z = g - w) > *m ? *m : z; /* upper limit on table size */ |
| if ((f = 1 << (j = k - w)) > 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 */ |
| if ((f <<= 1) <= *++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 = (huft_t *) 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 true (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[] |
| */ |
| static int inflate_codes(huft_t * my_tl, huft_t * my_td, const unsigned int my_bl, const unsigned int my_bd, int setup) |
| { |
| static unsigned int e; /* table entry flag/number of extra bits */ |
| static unsigned int n, d; /* length and index for copy */ |
| static unsigned int w; /* current gunzip_window position */ |
| static huft_t *t; /* pointer to table entry */ |
| static unsigned int ml, md; /* masks for bl and bd bits */ |
| static unsigned int b; /* bit buffer */ |
| static unsigned int k; /* number of bits in bit buffer */ |
| static huft_t *tl, *td; |
| static unsigned int bl, bd; |
| static int resumeCopy = 0; |
| |
| if (setup) { // 1st time we are called, copy in variables |
| tl = my_tl; |
| td = my_td; |
| bl = my_bl; |
| bd = my_bd; |
| /* make local copies of globals */ |
| b = 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]; |
| return 0; // Don't actually do anything the first time |
| } |
| |
| if (resumeCopy) goto do_copy; |
| |
| while (1) { /* do until end of block */ |
| b = fill_bitbuffer(b, &k, bl); |
| if ((e = (t = tl + ((unsigned) b & ml))->e) > 16) |
| do { |
| if (e == 99) { |
| bb_error_msg_and_die("inflate_codes error 1"); |
| } |
| b >>= t->b; |
| k -= t->b; |
| e -= 16; |
| b = fill_bitbuffer(b, &k, e); |
| } while ((e = |
| (t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16); |
| b >>= 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 */ |
| b = fill_bitbuffer(b, &k, e); |
| n = t->v.n + ((unsigned) b & mask_bits[e]); |
| b >>= e; |
| k -= e; |
| |
| /* decode distance of block to copy */ |
| b = fill_bitbuffer(b, &k, bd); |
| if ((e = (t = td + ((unsigned) b & md))->e) > 16) |
| do { |
| if (e == 99) |
| bb_error_msg_and_die("inflate_codes error 2"); |
| b >>= t->b; |
| k -= t->b; |
| e -= 16; |
| b = fill_bitbuffer(b, &k, e); |
| } while ((e = |
| (t = |
| t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16); |
| b >>= t->b; |
| k -= t->b; |
| b = fill_bitbuffer(b, &k, e); |
| d = w - t->v.n - ((unsigned) b & mask_bits[e]); |
| b >>= e; |
| k -= e; |
| |
| /* do the copy */ |
| do_copy: do { |
| n -= (e = |
| (e = |
| gunzip_wsize - ((d &= gunzip_wsize - 1) > w ? d : w)) > n ? n : e); |
| /* copy to new buffer to prevent possible overwrite */ |
| if (w - d >= e) { /* (this test assumes unsigned comparison) */ |
| memcpy(gunzip_window + w, gunzip_window + d, e); |
| w += e; |
| d += e; |
| } else { |
| /* do it slow to avoid memcpy() overlap */ |
| /* !NOMEMCPY */ |
| do { |
| gunzip_window[w++] = gunzip_window[d++]; |
| } while (--e); |
| } |
| if (w == gunzip_wsize) { |
| gunzip_outbuf_count = (w); |
| if (n) resumeCopy = 1; |
| else resumeCopy = 0; |
| //flush_gunzip_window(); |
| w = 0; |
| return 1; |
| } |
| } while (n); |
| resumeCopy = 0; |
| } |
| } |
| |
| /* restore the globals from the locals */ |
| gunzip_outbuf_count = w; /* restore global gunzip_window pointer */ |
| gunzip_bb = b; /* 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, return */ |
| huft_free(tl); |
| huft_free(td); |
| |
| /* done */ |
| return 0; |
| } |
| |
| static int inflate_stored(int my_n, int my_b_stored, int my_k_stored, int setup) |
| { |
| static unsigned int n, b_stored, k_stored, w; |
| if (setup) { |
| n = my_n; |
| b_stored = my_b_stored; |
| k_stored = my_k_stored; |
| w = gunzip_outbuf_count; /* initialize gunzip_window position */ |
| return 0; // Don't do anything first time |
| } |
| |
| /* read and output the compressed data */ |
| while (n--) { |
| b_stored = fill_bitbuffer(b_stored, &k_stored, 8); |
| gunzip_window[w++] = (unsigned char) b_stored; |
| if (w == gunzip_wsize) { |
| gunzip_outbuf_count = (w); |
| //flush_gunzip_window(); |
| w = 0; |
| b_stored >>= 8; |
| k_stored -= 8; |
| return 1; // We have a block |
| } |
| b_stored >>= 8; |
| k_stored -= 8; |
| } |
| |
| /* restore the globals from the locals */ |
| gunzip_outbuf_count = w; /* restore global gunzip_window pointer */ |
| gunzip_bb = b_stored; /* restore global bit buffer */ |
| gunzip_bk = k_stored; |
| return 0; // Finished |
| } |
| |
| /* |
| * decompress an inflated block |
| * e: last block flag |
| * |
| * GLOBAL VARIABLES: bb, kk, |
| */ |
| // Return values: -1 = inflate_stored, -2 = inflate_codes |
| static int inflate_block(int *e) |
| { |
| unsigned t; /* block type */ |
| register unsigned int b; /* bit buffer */ |
| unsigned int 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(b, &k, 1); |
| *e = (int) b & 1; |
| b >>= 1; |
| k -= 1; |
| |
| /* read in block type */ |
| b = fill_bitbuffer(b, &k, 2); |
| t = (unsigned) b & 3; |
| b >>= 2; |
| k -= 2; |
| |
| /* restore the global bit buffer */ |
| gunzip_bb = b; |
| gunzip_bk = k; |
| |
| /* inflate that block type */ |
| switch (t) { |
| case 0: /* Inflate stored */ |
| { |
| unsigned int n; /* number of bytes in block */ |
| unsigned int b_stored; /* bit buffer */ |
| unsigned int 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(b_stored, &k_stored, 16); |
| n = ((unsigned) b_stored & 0xffff); |
| b_stored >>= 16; |
| k_stored -= 16; |
| |
| b_stored = fill_bitbuffer(b_stored, &k_stored, 16); |
| if (n != (unsigned) ((~b_stored) & 0xffff)) { |
| return 1; /* error in compressed data */ |
| } |
| b_stored >>= 16; |
| k_stored -= 16; |
| |
| inflate_stored(n, b_stored, k_stored, 1); // Setup inflate_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. |
| */ |
| { |
| int i; /* temporary variable */ |
| huft_t *tl; /* literal/length code table */ |
| huft_t *td; /* distance code table */ |
| unsigned int bl; /* lookup bits for tl */ |
| unsigned int bd; /* lookup bits for td */ |
| unsigned int l[288]; /* length list for huft_build */ |
| |
| /* set up literal table */ |
| for (i = 0; i < 144; i++) { |
| l[i] = 8; |
| } |
| for (; i < 256; i++) { |
| l[i] = 9; |
| } |
| for (; i < 280; i++) { |
| l[i] = 7; |
| } |
| for (; i < 288; i++) { /* make a complete, but wrong code set */ |
| l[i] = 8; |
| } |
| bl = 7; |
| if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) { |
| return i; |
| } |
| |
| /* set up distance table */ |
| for (i = 0; i < 30; i++) { /* make an incomplete code set */ |
| l[i] = 5; |
| } |
| bd = 5; |
| if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) { |
| huft_free(tl); |
| return i; |
| } |
| |
| /* decompress until an end-of-block code */ |
| inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes |
| |
| /* huft_free code moved into inflate_codes */ |
| |
| return -2; |
| } |
| case 2: /* Inflate dynamic */ |
| { |
| const int dbits = 6; /* bits in base distance lookup table */ |
| const int lbits = 9; /* bits in base literal/length lookup table */ |
| |
| huft_t *tl; /* literal/length code table */ |
| huft_t *td; /* distance code table */ |
| unsigned int i; /* temporary variables */ |
| unsigned int j; |
| unsigned int l; /* last length */ |
| unsigned int m; /* mask for bit lengths table */ |
| unsigned int n; /* number of lengths to get */ |
| unsigned int bl; /* lookup bits for tl */ |
| unsigned int bd; /* lookup bits for td */ |
| unsigned int nb; /* number of bit length codes */ |
| unsigned int nl; /* number of literal/length codes */ |
| unsigned int nd; /* number of distance codes */ |
| |
| unsigned int ll[286 + 30]; /* literal/length and distance code lengths */ |
| unsigned int b_dynamic; /* bit buffer */ |
| unsigned int 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(b_dynamic, &k_dynamic, 5); |
| nl = 257 + ((unsigned int) b_dynamic & 0x1f); /* number of literal/length codes */ |
| |
| b_dynamic >>= 5; |
| k_dynamic -= 5; |
| b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5); |
| nd = 1 + ((unsigned int) b_dynamic & 0x1f); /* number of distance codes */ |
| |
| b_dynamic >>= 5; |
| k_dynamic -= 5; |
| b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 4); |
| nb = 4 + ((unsigned int) b_dynamic & 0xf); /* number of bit length codes */ |
| |
| b_dynamic >>= 4; |
| k_dynamic -= 4; |
| if (nl > 286 || nd > 30) { |
| return 1; /* bad lengths */ |
| } |
| |
| /* read in bit-length-code lengths */ |
| for (j = 0; j < nb; j++) { |
| b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3); |
| ll[border[j]] = (unsigned int) 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, &tl, &bl); |
| if (i != 0) { |
| if (i == 1) { |
| huft_free(tl); |
| } |
| return i; /* incomplete code set */ |
| } |
| |
| /* read in literal and distance code lengths */ |
| n = nl + nd; |
| m = mask_bits[bl]; |
| i = l = 0; |
| while ((unsigned int) i < n) { |
| b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, (unsigned int)bl); |
| j = (td = tl + ((unsigned int) b_dynamic & m))->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(b_dynamic, &k_dynamic, 2); |
| j = 3 + ((unsigned int) b_dynamic & 3); |
| b_dynamic >>= 2; |
| k_dynamic -= 2; |
| if ((unsigned int) i + j > n) { |
| return 1; |
| } |
| while (j--) { |
| ll[i++] = l; |
| } |
| } else if (j == 17) { /* 3 to 10 zero length codes */ |
| b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3); |
| j = 3 + ((unsigned int) b_dynamic & 7); |
| b_dynamic >>= 3; |
| k_dynamic -= 3; |
| if ((unsigned int) i + j > n) { |
| return 1; |
| } |
| while (j--) { |
| ll[i++] = 0; |
| } |
| l = 0; |
| } else { /* j == 18: 11 to 138 zero length codes */ |
| b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 7); |
| j = 11 + ((unsigned int) b_dynamic & 0x7f); |
| b_dynamic >>= 7; |
| k_dynamic -= 7; |
| if ((unsigned int) i + j > n) { |
| return 1; |
| } |
| while (j--) { |
| ll[i++] = 0; |
| } |
| l = 0; |
| } |
| } |
| |
| /* free decoding table for trees */ |
| huft_free(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; |
| |
| if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) { |
| if (i == 1) { |
| bb_error_msg_and_die("Incomplete literal tree"); |
| huft_free(tl); |
| } |
| return i; /* incomplete code set */ |
| } |
| |
| bd = dbits; |
| if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) { |
| if (i == 1) { |
| bb_error_msg_and_die("incomplete distance tree"); |
| huft_free(td); |
| } |
| huft_free(tl); |
| return i; /* incomplete code set */ |
| } |
| |
| /* decompress until an end-of-block code */ |
| inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes |
| |
| /* huft_free code moved into inflate_codes */ |
| |
| return -2; |
| } |
| default: |
| /* bad block type */ |
| bb_error_msg_and_die("bad block type %d\n", t); |
| } |
| } |
| |
| static void calculate_gunzip_crc(void) |
| { |
| int n; |
| for (n = 0; n < gunzip_outbuf_count; n++) { |
| gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8); |
| } |
| gunzip_bytes_out += gunzip_outbuf_count; |
| } |
| |
| static int inflate_get_next_window(void) |
| { |
| static int method = -1; // Method == -1 for stored, -2 for codes |
| static int e = 0; |
| static int needAnotherBlock = 1; |
| |
| gunzip_outbuf_count = 0; |
| |
| while(1) { |
| int ret; |
| |
| if (needAnotherBlock) { |
| if(e) { |
| calculate_gunzip_crc(); |
| e = 0; |
| needAnotherBlock = 1; |
| return 0; |
| } // Last block |
| method = inflate_block(&e); |
| needAnotherBlock = 0; |
| } |
| |
| switch (method) { |
| case -1: ret = inflate_stored(0,0,0,0); |
| break; |
| case -2: ret = inflate_codes(0,0,0,0,0); |
| break; |
| default: bb_error_msg_and_die("inflate error %d", method); |
| } |
| |
| if (ret == 1) { |
| calculate_gunzip_crc(); |
| return 1; // More data left |
| } else needAnotherBlock = 1; // End of that block |
| } |
| /* Doesnt get here */ |
| } |
| |
| /* Initialise bytebuffer, be careful not to overfill the buffer */ |
| void inflate_init(unsigned int bufsize) |
| { |
| /* Set the bytebuffer size, default is same as gunzip_wsize */ |
| bytebuffer_max = bufsize + 8; |
| bytebuffer_offset = 4; |
| bytebuffer_size = 0; |
| } |
| |
| void inflate_cleanup(void) |
| { |
| free(bytebuffer); |
| } |
| |
| int inflate_unzip(int in, int out) |
| { |
| ssize_t nwrote; |
| typedef void (*sig_type) (int); |
| |
| /* 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; |
| |
| /* initialize gunzip_window, bit buffer */ |
| gunzip_bk = 0; |
| gunzip_bb = 0; |
| |
| /* Create the crc table */ |
| gunzip_crc_table = bb_crc32_filltable(0); |
| gunzip_crc = ~0; |
| |
| /* Allocate space for buffer */ |
| bytebuffer = xmalloc(bytebuffer_max); |
| |
| while(1) { |
| int ret = inflate_get_next_window(); |
| nwrote = bb_full_write(out, gunzip_window, gunzip_outbuf_count); |
| if (nwrote == -1) { |
| bb_perror_msg("write"); |
| return -1; |
| } |
| if (ret == 0) break; |
| } |
| |
| /* Cleanup */ |
| free(gunzip_window); |
| free(gunzip_crc_table); |
| |
| /* 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; |
| } |
| return 0; |
| } |
| |
| int inflate_gunzip(int in, int out) |
| { |
| uint32_t stored_crc = 0; |
| unsigned int count; |
| |
| inflate_unzip(in, out); |
| |
| /* top up the input buffer with the rest of the trailer */ |
| count = bytebuffer_size - bytebuffer_offset; |
| if (count < 8) { |
| bb_xread_all(in, &bytebuffer[bytebuffer_size], 8 - count); |
| bytebuffer_size += 8 - count; |
| } |
| for (count = 0; count != 4; count++) { |
| stored_crc |= (bytebuffer[bytebuffer_offset] << (count * 8)); |
| bytebuffer_offset++; |
| } |
| |
| /* Validate decompression - crc */ |
| if (stored_crc != (~gunzip_crc)) { |
| bb_error_msg("crc error"); |
| return -1; |
| } |
| |
| /* Validate decompression - size */ |
| if (gunzip_bytes_out != |
| (bytebuffer[bytebuffer_offset] | (bytebuffer[bytebuffer_offset+1] << 8) | |
| (bytebuffer[bytebuffer_offset+2] << 16) | (bytebuffer[bytebuffer_offset+3] << 24))) { |
| bb_error_msg("Incorrect length"); |
| return -1; |
| } |
| |
| return 0; |
| } |