/* 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 * based on gzip sources * * Adjusted further by Erik Andersen 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 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * * 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 license_msg below and the file COPYING for the software license. * See the file algorithm.doc for the compression algorithms and file formats. */ #include #include #include #include #include #include #include #include "libbb.h" static FILE *in_file, *out_file; static unsigned char *window; static unsigned long *crc_table = NULL; static unsigned long crc; /* shift register contents */ /* * window size--must be a power of two, and * at least 32K for zip's deflate method */ static const int WSIZE = 0x8000; /* If BMAX needs to be larger than 16, then h and x[] should be ulg. */ static const int BMAX = 16; /* maximum bit length of any code (16 for explode) */ static const int N_MAX = 288; /* maximum number of codes in any set */ static long bytes_out; /* number of output bytes */ static unsigned long outcnt; /* bytes in output buffer */ static unsigned hufts; /* track memory usage */ static unsigned long bb; /* bit buffer */ static unsigned bk; /* bits in bit buffer */ 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 const unsigned short mask_bits[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff }; //static int error_number = 0; /* ======================================================================== * Signal and error handler. */ static void abort_gzip() { error_msg("gzip aborted\n"); _exit(-1); } static void make_crc_table() { unsigned long table_entry; /* crc shift register */ unsigned long poly = 0; /* polynomial exclusive-or pattern */ int i; /* counter for all possible eight bit values */ int k; /* byte being shifted into crc apparatus */ /* terms of polynomial defining this crc (except x^32): */ static int p[] = { 0, 1, 2, 4, 5, 7, 8, 10, 11, 12, 16, 22, 23, 26 }; /* initial shift register value */ crc = 0xffffffffL; crc_table = (unsigned long *)xmalloc(256 * sizeof(unsigned long)); /* Make exclusive-or pattern from polynomial (0xedb88320) */ for (i = 0; i < sizeof(p) / sizeof(int); i++) poly |= 1L << (31 - p[i]); /* Compute and print table of CRC's, five per line */ for (i = 0; i < 256; i++) { table_entry = i; /* The idea to initialize the register with the byte instead of * zero was stolen from Haruhiko Okumura's ar002 */ for (k = 8; k; k--) { table_entry = table_entry & 1 ? (table_entry >> 1) ^ poly : table_entry >> 1; } crc_table[i] = table_entry; } } /* =========================================================================== * Write the output window window[0..outcnt-1] and update crc and bytes_out. * (Used for the decompressed data only.) */ static void flush_window(void) { int n; if (outcnt == 0) return; for (n = 0; n < outcnt; n++) { crc = crc_table[((int)crc ^ (window[n])) & 0xff] ^ (crc >> 8); } if (fwrite(window, 1, outcnt, out_file) != outcnt) { /* * The Parent process may not be interested in all the data we have, * in which case it will rudely close its end of the pipe and * wait for us to exit. */ if (errno == EPIPE) _exit(EXIT_SUCCESS); error_msg("Couldnt write"); _exit(EXIT_FAILURE); } bytes_out += (unsigned long)outcnt; outcnt = 0; } /* * 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, *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 short *e, huft_t ** t, int *m) { unsigned a; /* counter for codes of length k */ unsigned c[BMAX + 1]; /* bit length count table */ unsigned f; /* i repeats in table every f entries */ int g; /* maximum code length */ int h; /* table level */ unsigned i; /* counter, current code */ unsigned j; /* counter */ int k; /* number of bits in current code */ int l; /* bits per table (returned in m) */ 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 w; /* bits before this table == (l * h) */ 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 */ /* 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 0; } /* Find minimum and maximum length, bound *m by those */ l = *m; for (j = 1; j <= BMAX; j++) if (c[j]) break; k = j; /* minimum code length */ if ((unsigned)l < j) l = j; for (i = BMAX; i; i--) if (c[i]) break; g = i; /* maximum code length */ if ((unsigned)l > i) l = i; *m = l; /* 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 */ h = -1; /* no tables yet--level -1 */ w = -l; /* bits decoded == (l * h) */ 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 > w + l) { h++; w += l; /* previous table always l bits */ /* compute minimum size table less than or equal to l bits */ z = (z = g - w) > (unsigned)l ? l : 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 */ } } z = 1 << j; /* table entries for j-bit table */ /* allocate and link in new table */ if ((q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t))) == NULL) { if (h) { huft_free(u[0]); } return 3; /* not enough memory */ } hufts += z + 1; /* track memory usage */ *t = q + 1; /* link to list for huft_free() */ *(t = &(q->v.t)) = NULL; u[h] = ++q; /* table starts after link */ /* connect to last table, if there is one */ if (h) { x[h] = i; /* save pattern for backing up */ r.b = (unsigned char)l; /* 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 >> (w - l); /* (get around Turbo C bug) */ u[h - 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 end-of-block code */ r.v.n = (unsigned short)(*p); /* simple code is just the value */ p++; /* one compiler does not like *p++ */ } 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[h]) { h--; /* don't need to update q */ w -= l; } } } /* 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 * tl, huft_t * td, int bl, int bd) { unsigned long e; /* table entry flag/number of extra bits */ unsigned long n, d; /* length and index for copy */ unsigned long w; /* current window position */ huft_t *t; /* pointer to table entry */ unsigned ml, md; /* masks for bl and bd bits */ unsigned long b; /* bit buffer */ unsigned k; /* number of bits in bit buffer */ /* make local copies of globals */ b = bb; /* initialize bit buffer */ k = bk; w = outcnt; /* initialize window position */ /* inflate the coded data */ ml = mask_bits[bl]; /* precompute masks for speed */ md = mask_bits[bd]; for (;;) { /* do until end of block */ while (k < (unsigned)bl) { b |= ((unsigned long)fgetc(in_file)) << k; k += 8; } if ((e = (t = tl + ((unsigned)b & ml))->e) > 16) do { if (e == 99) { return 1; } b >>= t->b; k -= t->b; e -= 16; while (k < e) { b |= ((unsigned long)fgetc(in_file)) << k; k += 8; } } 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 */ window[w++] = (unsigned char)t->v.n; if (w == WSIZE) { outcnt = (w), flush_window(); w = 0; } } else { /* it's an EOB or a length */ /* exit if end of block */ if (e == 15) { break; } /* get length of block to copy */ while (k < e) { b |= ((unsigned long)fgetc(in_file)) << k; k += 8; } n = t->v.n + ((unsigned)b & mask_bits[e]); b >>= e; k -= e; /* decode distance of block to copy */ while (k < (unsigned)bd) { b |= ((unsigned long)fgetc(in_file)) << k; k += 8; } if ((e = (t = td + ((unsigned)b & md))->e) > 16) do { if (e == 99) return 1; b >>= t->b; k -= t->b; e -= 16; while (k < e) { b |= ((unsigned long) fgetc(in_file)) << k; k += 8; } } while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16); b >>= t->b; k -= t->b; while (k < e) { b |= ((unsigned long)fgetc(in_file)) << k; k += 8; } d = w - t->v.n - ((unsigned)b & mask_bits[e]); b >>= e; k -= e; /* do the copy */ do { n -= (e = (e = WSIZE - ((d &= WSIZE - 1) > w ? d : w)) > n ? n : e); #if !defined(NOMEMCPY) && !defined(DEBUG) if (w - d >= e) { /* (this test assumes unsigned comparison) */ memcpy(window + w, window + d, e); w += e; d += e; } else /* do it slow to avoid memcpy() overlap */ #endif /* !NOMEMCPY */ do { window[w++] = window[d++]; } while (--e); if (w == WSIZE) { outcnt = (w), flush_window(); w = 0; } } while (n); } } /* restore the globals from the locals */ outcnt = w; /* restore global window pointer */ bb = b; /* restore global bit buffer */ bk = k; /* done */ return 0; } /* * decompress an inflated block * e: last block flag * * GLOBAL VARIABLES: bb, kk, */ static int inflate_block(int *e) { unsigned t; /* block type */ unsigned long b; /* bit buffer */ unsigned k; /* number of bits in bit buffer */ static unsigned short cplens[] = { /* Copy lengths for literal codes 257..285 */ 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. */ static unsigned short cplext[] = { /* Extra bits for literal codes 257..285 */ 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 */ static unsigned short cpdist[] = { /* Copy offsets for distance codes 0..29 */ 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 }; static unsigned short cpdext[] = { /* Extra bits for distance codes */ 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 }; /* make local bit buffer */ b = bb; k = bk; /* read in last block bit */ while (k < 1) { b |= ((unsigned long)fgetc(in_file)) << k; k += 8; } *e = (int)b & 1; b >>= 1; k -= 1; /* read in block type */ while (k < 2) { b |= ((unsigned long)fgetc(in_file)) << k; k += 8; } t = (unsigned)b & 3; b >>= 2; k -= 2; /* restore the global bit buffer */ bb = b; bk = k; /* inflate that block type */ switch (t) { case 0: /* Inflate stored */ { unsigned long n; /* number of bytes in block */ unsigned long w; /* current window position */ unsigned long b_stored; /* bit buffer */ unsigned long k_stored; /* number of bits in bit buffer */ /* make local copies of globals */ b_stored = bb; /* initialize bit buffer */ k_stored = bk; w = outcnt; /* initialize window position */ /* go to byte boundary */ n = k_stored & 7; b_stored >>= n; k_stored -= n; /* get the length and its complement */ while (k_stored < 16) { b_stored |= ((unsigned long)fgetc(in_file)) << k_stored; k_stored += 8; } n = ((unsigned)b_stored & 0xffff); b_stored >>= 16; k_stored -= 16; while (k_stored < 16) { b_stored |= ((unsigned long)fgetc(in_file)) << k_stored; k_stored += 8; } if (n != (unsigned)((~b_stored) & 0xffff)) { return 1; /* error in compressed data */ } b_stored >>= 16; k_stored -= 16; /* read and output the compressed data */ while (n--) { while (k_stored < 8) { b_stored |= ((unsigned long)fgetc(in_file)) << k_stored; k_stored += 8; } window[w++] = (unsigned char)b_stored; if (w == (unsigned long)WSIZE) { outcnt = (w), flush_window(); w = 0; } b_stored >>= 8; k_stored -= 8; } /* restore the globals from the locals */ outcnt = w; /* restore global window pointer */ bb = b_stored; /* restore global bit buffer */ bk = k_stored; return 0; } 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 */ int bl; /* lookup bits for tl */ 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 */ if (inflate_codes(tl, td, bl, bd)) { huft_free(tl); huft_free(td); return 1; } /* free the decoding tables, return */ huft_free(tl); huft_free(td); return 0; } case 2: /* Inflate dynamic */ { /* Tables for deflate from PKZIP's appnote.txt. */ static unsigned border[] = { /* Order of the bit length code lengths */ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; int dbits = 6; /* bits in base distance lookup table */ int lbits = 9; /* bits in base literal/length lookup table */ int i; /* temporary variables */ unsigned j; unsigned l; /* last length */ unsigned m; /* mask for bit lengths table */ unsigned n; /* number of lengths to get */ huft_t *tl; /* literal/length code table */ huft_t *td; /* distance code table */ int bl; /* lookup bits for tl */ int 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 long b_dynamic; /* bit buffer */ unsigned k_dynamic; /* number of bits in bit buffer */ /* make local bit buffer */ b_dynamic = bb; k_dynamic = bk; /* read in table lengths */ while (k_dynamic < 5) { b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic; k_dynamic += 8; } nl = 257 + ((unsigned)b_dynamic & 0x1f); /* number of literal/length codes */ b_dynamic >>= 5; k_dynamic -= 5; while (k_dynamic < 5) { b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic; k_dynamic += 8; } nd = 1 + ((unsigned)b_dynamic & 0x1f); /* number of distance codes */ b_dynamic >>= 5; k_dynamic -= 5; while (k_dynamic < 4) { b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic; k_dynamic += 8; } nb = 4 + ((unsigned)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++) { while (k_dynamic < 3) { b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic; k_dynamic += 8; } 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; if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 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)i < n) { while (k_dynamic < (unsigned)bl) { b_dynamic |= ((unsigned long)fgetc(in_file)) << k_dynamic; k_dynamic += 8; } j = (td = tl + ((unsigned)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 */ while (k_dynamic < 2) { b_dynamic |= ((unsigned long) fgetc(in_file)) << k_dynamic; k_dynamic += 8; } j = 3 + ((unsigned)b_dynamic & 3); b_dynamic >>= 2; k_dynamic -= 2; if ((unsigned)i + j > n) { return 1; } while (j--) { ll[i++] = l; } } else if (j == 17) { /* 3 to 10 zero length codes */ while (k_dynamic < 3) { b_dynamic |= ((unsigned long) fgetc(in_file)) << k_dynamic; k_dynamic += 8; } j = 3 + ((unsigned)b_dynamic & 7); b_dynamic >>= 3; k_dynamic -= 3; if ((unsigned)i + j > n) { return 1; } while (j--) { ll[i++] = 0; } l = 0; } else { /* j == 18: 11 to 138 zero length codes */ while (k_dynamic < 7) { b_dynamic |= ((unsigned long) fgetc(in_file)) << k_dynamic; k_dynamic += 8; } j = 11 + ((unsigned)b_dynamic & 0x7f); b_dynamic >>= 7; k_dynamic -= 7; if ((unsigned)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 */ bb = b_dynamic; 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) { error_msg("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) { error_msg("incomplete distance tree"); huft_free(td); } huft_free(tl); return i; /* incomplete code set */ } /* decompress until an end-of-block code */ if (inflate_codes(tl, td, bl, bd)) { huft_free(tl); huft_free(td); return 1; } /* free the decoding tables, return */ huft_free(tl); huft_free(td); return 0; } default: /* bad block type */ return 2; } } /* * decompress an inflated entry * * GLOBAL VARIABLES: outcnt, bk, bb, hufts, inptr */ static int inflate() { int e; /* last block flag */ int r; /* result code */ unsigned h = 0; /* maximum struct huft's malloc'ed */ /* initialize window, bit buffer */ outcnt = 0; bk = 0; bb = 0; /* decompress until the last block */ do { hufts = 0; if ((r = inflate_block(&e)) != 0) { return r; } if (hufts > h) { h = hufts; } } while (!e); /* Undo too much lookahead. The next read will be byte aligned so we * can discard unused bits in the last meaningful byte. */ while (bk >= 8) { bk -= 8; ungetc((bb << bk), in_file); } /* flush out window */ flush_window(); /* return success */ return 0; } /* =========================================================================== * Unzip in to out. This routine works on both gzip and pkzip files. * * IN assertions: the buffer inbuf contains already the beginning of * the compressed data, from offsets inptr to insize-1 included. * The magic header has already been checked. The output buffer is cleared. * in, out: input and output file descriptors */ extern int unzip(FILE * l_in_file, FILE * l_out_file) { const int extra_field = 0x04; /* bit 2 set: extra field present */ const int orig_name = 0x08; /* bit 3 set: original file name present */ const int comment = 0x10; /* bit 4 set: file comment present */ unsigned char buf[8]; /* extended local header */ unsigned char flags; /* compression flags */ char magic[2]; /* magic header */ int method; typedef void (*sig_type) (int); int exit_code = 0; /* program exit code */ int i; in_file = l_in_file; out_file = l_out_file; if (signal(SIGINT, SIG_IGN) != SIG_IGN) { (void)signal(SIGINT, (sig_type) abort_gzip); } #ifdef SIGTERM // if (signal(SIGTERM, SIG_IGN) != SIG_IGN) { // (void) signal(SIGTERM, (sig_type) abort_gzip); // } #endif #ifdef SIGHUP if (signal(SIGHUP, SIG_IGN) != SIG_IGN) { (void)signal(SIGHUP, (sig_type) abort_gzip); } #endif signal(SIGPIPE, SIG_IGN); /* Allocate all global buffers (for DYN_ALLOC option) */ window = xmalloc((size_t) (((2L * WSIZE) + 1L) * sizeof(unsigned char))); outcnt = 0; bytes_out = 0L; magic[0] = fgetc(in_file); magic[1] = fgetc(in_file); /* Magic header for gzip files, 1F 8B = \037\213 */ if (memcmp(magic, "\037\213", 2) != 0) { error_msg("Invalid gzip magic"); return EXIT_FAILURE; } method = (int)fgetc(in_file); if (method != 8) { error_msg("unknown method %d -- get newer version of gzip", method); exit_code = 1; return -1; } flags = (unsigned char)fgetc(in_file); /* Ignore time stamp(4), extra flags(1), OS type(1) */ for (i = 0; i < 6; i++) fgetc(in_file); if ((flags & extra_field) != 0) { size_t extra; extra = fgetc(in_file); extra += fgetc(in_file) << 8; for (i = 0; i < extra; i++) fgetc(in_file); } /* Discard original name if any */ if ((flags & orig_name) != 0) { while (fgetc(in_file) != 0) ; /* null */ } /* Discard file comment if any */ if ((flags & comment) != 0) { while (fgetc(in_file) != 0) ; /* null */ } if (method < 0) { return (exit_code); } make_crc_table(); /* Decompress */ if (method == 8) { int res = inflate(); if (res == 3) { perror_msg("inflate"); exit_code = 1; } else if (res != 0) { error_msg("invalid compressed data--format violated"); exit_code = 1; } } else { error_msg("internal error, invalid method"); exit_code = 1; } /* Get the crc and original length * crc32 (see algorithm.doc) * uncompressed input size modulo 2^32 */ fread(buf, 1, 8, in_file); /* Validate decompression - crc */ if (!exit_code && (unsigned int)((buf[0] | (buf[1] << 8)) | ((buf[2] | (buf[3] << 8)) << 16)) != (crc ^ 0xffffffffL)) { error_msg("invalid compressed data--crc error"); exit_code = 1; } /* Validate decompression - size */ if (!exit_code && ((buf[4] | (buf[5] << 8)) | ((buf[6] | (buf[7] << 8)) << 16)) != (unsigned long)bytes_out) { error_msg("invalid compressed data--length error"); exit_code = 1; } free(window); free(crc_table); window = NULL; crc_table = NULL; return exit_code; }