/* 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 "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 (1 > (bytebuffer_size = safe_read(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 */ 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", 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); } USE_DESKTOP(long long) int inflate_unzip(int in, int out) { USE_DESKTOP(long long total = 0;) 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 = crc32_filltable(0); gunzip_crc = ~0; /* Allocate space for buffer */ bytebuffer = xmalloc(bytebuffer_max); while(1) { int ret = inflate_get_next_window(); nwrote = full_write(out, gunzip_window, gunzip_outbuf_count); if (nwrote == -1) { bb_perror_msg("write"); return -1; } USE_DESKTOP(total += nwrote;) 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 USE_DESKTOP(total) + 0; } USE_DESKTOP(long long) int inflate_gunzip(int in, int out) { uint32_t stored_crc = 0; unsigned int count; USE_DESKTOP(long long total = )inflate_unzip(in, out); USE_DESKTOP(if (total < 0) return total;) /* top up the input buffer with the rest of the trailer */ count = bytebuffer_size - bytebuffer_offset; if (count < 8) { xread(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 USE_DESKTOP(total) + 0; }