+++ /dev/null
-/* gun.c -- simple gunzip to give an example of the use of inflateBack()
- * Copyright (C) 2003, 2005, 2008, 2010, 2012 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
- Version 1.7 12 August 2012 Mark Adler */
-
-/* Version history:
- 1.0 16 Feb 2003 First version for testing of inflateBack()
- 1.1 21 Feb 2005 Decompress concatenated gzip streams
- Remove use of "this" variable (C++ keyword)
- Fix return value for in()
- Improve allocation failure checking
- Add typecasting for void * structures
- Add -h option for command version and usage
- Add a bunch of comments
- 1.2 20 Mar 2005 Add Unix compress (LZW) decompression
- Copy file attributes from input file to output file
- 1.3 12 Jun 2005 Add casts for error messages [Oberhumer]
- 1.4 8 Dec 2006 LZW decompression speed improvements
- 1.5 9 Feb 2008 Avoid warning in latest version of gcc
- 1.6 17 Jan 2010 Avoid signed/unsigned comparison warnings
- 1.7 12 Aug 2012 Update for z_const usage in zlib 1.2.8
- */
-
-/*
- gun [ -t ] [ name ... ]
-
- decompresses the data in the named gzip files. If no arguments are given,
- gun will decompress from stdin to stdout. The names must end in .gz, -gz,
- .z, -z, _z, or .Z. The uncompressed data will be written to a file name
- with the suffix stripped. On success, the original file is deleted. On
- failure, the output file is deleted. For most failures, the command will
- continue to process the remaining names on the command line. A memory
- allocation failure will abort the command. If -t is specified, then the
- listed files or stdin will be tested as gzip files for integrity (without
- checking for a proper suffix), no output will be written, and no files
- will be deleted.
-
- Like gzip, gun allows concatenated gzip streams and will decompress them,
- writing all of the uncompressed data to the output. Unlike gzip, gun allows
- an empty file on input, and will produce no error writing an empty output
- file.
-
- gun will also decompress files made by Unix compress, which uses LZW
- compression. These files are automatically detected by virtue of their
- magic header bytes. Since the end of Unix compress stream is marked by the
- end-of-file, they cannot be concantenated. If a Unix compress stream is
- encountered in an input file, it is the last stream in that file.
-
- Like gunzip and uncompress, the file attributes of the orignal compressed
- file are maintained in the final uncompressed file, to the extent that the
- user permissions allow it.
-
- On my Mac OS X PowerPC G4, gun is almost twice as fast as gunzip (version
- 1.2.4) is on the same file, when gun is linked with zlib 1.2.2. Also the
- LZW decompression provided by gun is about twice as fast as the standard
- Unix uncompress command.
- */
-
-/* external functions and related types and constants */
-#include <stdio.h> /* fprintf() */
-#include <stdlib.h> /* malloc(), free() */
-#include <string.h> /* strerror(), strcmp(), strlen(), memcpy() */
-#include <errno.h> /* errno */
-#include <fcntl.h> /* open() */
-#include <unistd.h> /* read(), write(), close(), chown(), unlink() */
-#include <sys/types.h>
-#include <sys/stat.h> /* stat(), chmod() */
-#include <utime.h> /* utime() */
-#include "zlib.h" /* inflateBackInit(), inflateBack(), */
- /* inflateBackEnd(), crc32() */
-
-/* function declaration */
-#define local static
-
-/* buffer constants */
-#define SIZE 32768U /* input and output buffer sizes */
-#define PIECE 16384 /* limits i/o chunks for 16-bit int case */
-
-/* structure for infback() to pass to input function in() -- it maintains the
- input file and a buffer of size SIZE */
-struct ind {
- int infile;
- unsigned char *inbuf;
-};
-
-/* Load input buffer, assumed to be empty, and return bytes loaded and a
- pointer to them. read() is called until the buffer is full, or until it
- returns end-of-file or error. Return 0 on error. */
-local unsigned in(void *in_desc, z_const unsigned char **buf)
-{
- int ret;
- unsigned len;
- unsigned char *next;
- struct ind *me = (struct ind *)in_desc;
-
- next = me->inbuf;
- *buf = next;
- len = 0;
- do {
- ret = PIECE;
- if ((unsigned)ret > SIZE - len)
- ret = (int)(SIZE - len);
- ret = (int)read(me->infile, next, ret);
- if (ret == -1) {
- len = 0;
- break;
- }
- next += ret;
- len += ret;
- } while (ret != 0 && len < SIZE);
- return len;
-}
-
-/* structure for infback() to pass to output function out() -- it maintains the
- output file, a running CRC-32 check on the output and the total number of
- bytes output, both for checking against the gzip trailer. (The length in
- the gzip trailer is stored modulo 2^32, so it's ok if a long is 32 bits and
- the output is greater than 4 GB.) */
-struct outd {
- int outfile;
- int check; /* true if checking crc and total */
- unsigned long crc;
- unsigned long total;
-};
-
-/* Write output buffer and update the CRC-32 and total bytes written. write()
- is called until all of the output is written or an error is encountered.
- On success out() returns 0. For a write failure, out() returns 1. If the
- output file descriptor is -1, then nothing is written.
- */
-local int out(void *out_desc, unsigned char *buf, unsigned len)
-{
- int ret;
- struct outd *me = (struct outd *)out_desc;
-
- if (me->check) {
- me->crc = crc32(me->crc, buf, len);
- me->total += len;
- }
- if (me->outfile != -1)
- do {
- ret = PIECE;
- if ((unsigned)ret > len)
- ret = (int)len;
- ret = (int)write(me->outfile, buf, ret);
- if (ret == -1)
- return 1;
- buf += ret;
- len -= ret;
- } while (len != 0);
- return 0;
-}
-
-/* next input byte macro for use inside lunpipe() and gunpipe() */
-#define NEXT() (have ? 0 : (have = in(indp, &next)), \
- last = have ? (have--, (int)(*next++)) : -1)
-
-/* memory for gunpipe() and lunpipe() --
- the first 256 entries of prefix[] and suffix[] are never used, could
- have offset the index, but it's faster to waste the memory */
-unsigned char inbuf[SIZE]; /* input buffer */
-unsigned char outbuf[SIZE]; /* output buffer */
-unsigned short prefix[65536]; /* index to LZW prefix string */
-unsigned char suffix[65536]; /* one-character LZW suffix */
-unsigned char match[65280 + 2]; /* buffer for reversed match or gzip
- 32K sliding window */
-
-/* throw out what's left in the current bits byte buffer (this is a vestigial
- aspect of the compressed data format derived from an implementation that
- made use of a special VAX machine instruction!) */
-#define FLUSHCODE() \
- do { \
- left = 0; \
- rem = 0; \
- if (chunk > have) { \
- chunk -= have; \
- have = 0; \
- if (NEXT() == -1) \
- break; \
- chunk--; \
- if (chunk > have) { \
- chunk = have = 0; \
- break; \
- } \
- } \
- have -= chunk; \
- next += chunk; \
- chunk = 0; \
- } while (0)
-
-/* Decompress a compress (LZW) file from indp to outfile. The compress magic
- header (two bytes) has already been read and verified. There are have bytes
- of buffered input at next. strm is used for passing error information back
- to gunpipe().
-
- lunpipe() will return Z_OK on success, Z_BUF_ERROR for an unexpected end of
- file, read error, or write error (a write error indicated by strm->next_in
- not equal to Z_NULL), or Z_DATA_ERROR for invalid input.
- */
-local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp,
- int outfile, z_stream *strm)
-{
- int last; /* last byte read by NEXT(), or -1 if EOF */
- unsigned chunk; /* bytes left in current chunk */
- int left; /* bits left in rem */
- unsigned rem; /* unused bits from input */
- int bits; /* current bits per code */
- unsigned code; /* code, table traversal index */
- unsigned mask; /* mask for current bits codes */
- int max; /* maximum bits per code for this stream */
- unsigned flags; /* compress flags, then block compress flag */
- unsigned end; /* last valid entry in prefix/suffix tables */
- unsigned temp; /* current code */
- unsigned prev; /* previous code */
- unsigned final; /* last character written for previous code */
- unsigned stack; /* next position for reversed string */
- unsigned outcnt; /* bytes in output buffer */
- struct outd outd; /* output structure */
- unsigned char *p;
-
- /* set up output */
- outd.outfile = outfile;
- outd.check = 0;
-
- /* process remainder of compress header -- a flags byte */
- flags = NEXT();
- if (last == -1)
- return Z_BUF_ERROR;
- if (flags & 0x60) {
- strm->msg = (char *)"unknown lzw flags set";
- return Z_DATA_ERROR;
- }
- max = flags & 0x1f;
- if (max < 9 || max > 16) {
- strm->msg = (char *)"lzw bits out of range";
- return Z_DATA_ERROR;
- }
- if (max == 9) /* 9 doesn't really mean 9 */
- max = 10;
- flags &= 0x80; /* true if block compress */
-
- /* clear table */
- bits = 9;
- mask = 0x1ff;
- end = flags ? 256 : 255;
-
- /* set up: get first 9-bit code, which is the first decompressed byte, but
- don't create a table entry until the next code */
- if (NEXT() == -1) /* no compressed data is ok */
- return Z_OK;
- final = prev = (unsigned)last; /* low 8 bits of code */
- if (NEXT() == -1) /* missing a bit */
- return Z_BUF_ERROR;
- if (last & 1) { /* code must be < 256 */
- strm->msg = (char *)"invalid lzw code";
- return Z_DATA_ERROR;
- }
- rem = (unsigned)last >> 1; /* remaining 7 bits */
- left = 7;
- chunk = bits - 2; /* 7 bytes left in this chunk */
- outbuf[0] = (unsigned char)final; /* write first decompressed byte */
- outcnt = 1;
-
- /* decode codes */
- stack = 0;
- for (;;) {
- /* if the table will be full after this, increment the code size */
- if (end >= mask && bits < max) {
- FLUSHCODE();
- bits++;
- mask <<= 1;
- mask++;
- }
-
- /* get a code of length bits */
- if (chunk == 0) /* decrement chunk modulo bits */
- chunk = bits;
- code = rem; /* low bits of code */
- if (NEXT() == -1) { /* EOF is end of compressed data */
- /* write remaining buffered output */
- if (outcnt && out(&outd, outbuf, outcnt)) {
- strm->next_in = outbuf; /* signal write error */
- return Z_BUF_ERROR;
- }
- return Z_OK;
- }
- code += (unsigned)last << left; /* middle (or high) bits of code */
- left += 8;
- chunk--;
- if (bits > left) { /* need more bits */
- if (NEXT() == -1) /* can't end in middle of code */
- return Z_BUF_ERROR;
- code += (unsigned)last << left; /* high bits of code */
- left += 8;
- chunk--;
- }
- code &= mask; /* mask to current code length */
- left -= bits; /* number of unused bits */
- rem = (unsigned)last >> (8 - left); /* unused bits from last byte */
-
- /* process clear code (256) */
- if (code == 256 && flags) {
- FLUSHCODE();
- bits = 9; /* initialize bits and mask */
- mask = 0x1ff;
- end = 255; /* empty table */
- continue; /* get next code */
- }
-
- /* special code to reuse last match */
- temp = code; /* save the current code */
- if (code > end) {
- /* Be picky on the allowed code here, and make sure that the code
- we drop through (prev) will be a valid index so that random
- input does not cause an exception. The code != end + 1 check is
- empirically derived, and not checked in the original uncompress
- code. If this ever causes a problem, that check could be safely
- removed. Leaving this check in greatly improves gun's ability
- to detect random or corrupted input after a compress header.
- In any case, the prev > end check must be retained. */
- if (code != end + 1 || prev > end) {
- strm->msg = (char *)"invalid lzw code";
- return Z_DATA_ERROR;
- }
- match[stack++] = (unsigned char)final;
- code = prev;
- }
-
- /* walk through linked list to generate output in reverse order */
- p = match + stack;
- while (code >= 256) {
- *p++ = suffix[code];
- code = prefix[code];
- }
- stack = p - match;
- match[stack++] = (unsigned char)code;
- final = code;
-
- /* link new table entry */
- if (end < mask) {
- end++;
- prefix[end] = (unsigned short)prev;
- suffix[end] = (unsigned char)final;
- }
-
- /* set previous code for next iteration */
- prev = temp;
-
- /* write output in forward order */
- while (stack > SIZE - outcnt) {
- while (outcnt < SIZE)
- outbuf[outcnt++] = match[--stack];
- if (out(&outd, outbuf, outcnt)) {
- strm->next_in = outbuf; /* signal write error */
- return Z_BUF_ERROR;
- }
- outcnt = 0;
- }
- p = match + stack;
- do {
- outbuf[outcnt++] = *--p;
- } while (p > match);
- stack = 0;
-
- /* loop for next code with final and prev as the last match, rem and
- left provide the first 0..7 bits of the next code, end is the last
- valid table entry */
- }
-}
-
-/* Decompress a gzip file from infile to outfile. strm is assumed to have been
- successfully initialized with inflateBackInit(). The input file may consist
- of a series of gzip streams, in which case all of them will be decompressed
- to the output file. If outfile is -1, then the gzip stream(s) integrity is
- checked and nothing is written.
-
- The return value is a zlib error code: Z_MEM_ERROR if out of memory,
- Z_DATA_ERROR if the header or the compressed data is invalid, or if the
- trailer CRC-32 check or length doesn't match, Z_BUF_ERROR if the input ends
- prematurely or a write error occurs, or Z_ERRNO if junk (not a another gzip
- stream) follows a valid gzip stream.
- */
-local int gunpipe(z_stream *strm, int infile, int outfile)
-{
- int ret, first, last;
- unsigned have, flags, len;
- z_const unsigned char *next = NULL;
- struct ind ind, *indp;
- struct outd outd;
-
- /* setup input buffer */
- ind.infile = infile;
- ind.inbuf = inbuf;
- indp = &ind;
-
- /* decompress concatenated gzip streams */
- have = 0; /* no input data read in yet */
- first = 1; /* looking for first gzip header */
- strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */
- for (;;) {
- /* look for the two magic header bytes for a gzip stream */
- if (NEXT() == -1) {
- ret = Z_OK;
- break; /* empty gzip stream is ok */
- }
- if (last != 31 || (NEXT() != 139 && last != 157)) {
- strm->msg = (char *)"incorrect header check";
- ret = first ? Z_DATA_ERROR : Z_ERRNO;
- break; /* not a gzip or compress header */
- }
- first = 0; /* next non-header is junk */
-
- /* process a compress (LZW) file -- can't be concatenated after this */
- if (last == 157) {
- ret = lunpipe(have, next, indp, outfile, strm);
- break;
- }
-
- /* process remainder of gzip header */
- ret = Z_BUF_ERROR;
- if (NEXT() != 8) { /* only deflate method allowed */
- if (last == -1) break;
- strm->msg = (char *)"unknown compression method";
- ret = Z_DATA_ERROR;
- break;
- }
- flags = NEXT(); /* header flags */
- NEXT(); /* discard mod time, xflgs, os */
- NEXT();
- NEXT();
- NEXT();
- NEXT();
- NEXT();
- if (last == -1) break;
- if (flags & 0xe0) {
- strm->msg = (char *)"unknown header flags set";
- ret = Z_DATA_ERROR;
- break;
- }
- if (flags & 4) { /* extra field */
- len = NEXT();
- len += (unsigned)(NEXT()) << 8;
- if (last == -1) break;
- while (len > have) {
- len -= have;
- have = 0;
- if (NEXT() == -1) break;
- len--;
- }
- if (last == -1) break;
- have -= len;
- next += len;
- }
- if (flags & 8) /* file name */
- while (NEXT() != 0 && last != -1)
- ;
- if (flags & 16) /* comment */
- while (NEXT() != 0 && last != -1)
- ;
- if (flags & 2) { /* header crc */
- NEXT();
- NEXT();
- }
- if (last == -1) break;
-
- /* set up output */
- outd.outfile = outfile;
- outd.check = 1;
- outd.crc = crc32(0L, Z_NULL, 0);
- outd.total = 0;
-
- /* decompress data to output */
- strm->next_in = next;
- strm->avail_in = have;
- ret = inflateBack(strm, in, indp, out, &outd);
- if (ret != Z_STREAM_END) break;
- next = strm->next_in;
- have = strm->avail_in;
- strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */
-
- /* check trailer */
- ret = Z_BUF_ERROR;
- if (NEXT() != (int)(outd.crc & 0xff) ||
- NEXT() != (int)((outd.crc >> 8) & 0xff) ||
- NEXT() != (int)((outd.crc >> 16) & 0xff) ||
- NEXT() != (int)((outd.crc >> 24) & 0xff)) {
- /* crc error */
- if (last != -1) {
- strm->msg = (char *)"incorrect data check";
- ret = Z_DATA_ERROR;
- }
- break;
- }
- if (NEXT() != (int)(outd.total & 0xff) ||
- NEXT() != (int)((outd.total >> 8) & 0xff) ||
- NEXT() != (int)((outd.total >> 16) & 0xff) ||
- NEXT() != (int)((outd.total >> 24) & 0xff)) {
- /* length error */
- if (last != -1) {
- strm->msg = (char *)"incorrect length check";
- ret = Z_DATA_ERROR;
- }
- break;
- }
-
- /* go back and look for another gzip stream */
- }
-
- /* clean up and return */
- return ret;
-}
-
-/* Copy file attributes, from -> to, as best we can. This is best effort, so
- no errors are reported. The mode bits, including suid, sgid, and the sticky
- bit are copied (if allowed), the owner's user id and group id are copied
- (again if allowed), and the access and modify times are copied. */
-local void copymeta(char *from, char *to)
-{
- struct stat was;
- struct utimbuf when;
-
- /* get all of from's Unix meta data, return if not a regular file */
- if (stat(from, &was) != 0 || (was.st_mode & S_IFMT) != S_IFREG)
- return;
-
- /* set to's mode bits, ignore errors */
- (void)chmod(to, was.st_mode & 07777);
-
- /* copy owner's user and group, ignore errors */
- (void)chown(to, was.st_uid, was.st_gid);
-
- /* copy access and modify times, ignore errors */
- when.actime = was.st_atime;
- when.modtime = was.st_mtime;
- (void)utime(to, &when);
-}
-
-/* Decompress the file inname to the file outnname, of if test is true, just
- decompress without writing and check the gzip trailer for integrity. If
- inname is NULL or an empty string, read from stdin. If outname is NULL or
- an empty string, write to stdout. strm is a pre-initialized inflateBack
- structure. When appropriate, copy the file attributes from inname to
- outname.
-
- gunzip() returns 1 if there is an out-of-memory error or an unexpected
- return code from gunpipe(). Otherwise it returns 0.
- */
-local int gunzip(z_stream *strm, char *inname, char *outname, int test)
-{
- int ret;
- int infile, outfile;
-
- /* open files */
- if (inname == NULL || *inname == 0) {
- inname = "-";
- infile = 0; /* stdin */
- }
- else {
- infile = open(inname, O_RDONLY, 0);
- if (infile == -1) {
- fprintf(stderr, "gun cannot open %s\n", inname);
- return 0;
- }
- }
- if (test)
- outfile = -1;
- else if (outname == NULL || *outname == 0) {
- outname = "-";
- outfile = 1; /* stdout */
- }
- else {
- outfile = open(outname, O_CREAT | O_TRUNC | O_WRONLY, 0666);
- if (outfile == -1) {
- close(infile);
- fprintf(stderr, "gun cannot create %s\n", outname);
- return 0;
- }
- }
- errno = 0;
-
- /* decompress */
- ret = gunpipe(strm, infile, outfile);
- if (outfile > 2) close(outfile);
- if (infile > 2) close(infile);
-
- /* interpret result */
- switch (ret) {
- case Z_OK:
- case Z_ERRNO:
- if (infile > 2 && outfile > 2) {
- copymeta(inname, outname); /* copy attributes */
- unlink(inname);
- }
- if (ret == Z_ERRNO)
- fprintf(stderr, "gun warning: trailing garbage ignored in %s\n",
- inname);
- break;
- case Z_DATA_ERROR:
- if (outfile > 2) unlink(outname);
- fprintf(stderr, "gun data error on %s: %s\n", inname, strm->msg);
- break;
- case Z_MEM_ERROR:
- if (outfile > 2) unlink(outname);
- fprintf(stderr, "gun out of memory error--aborting\n");
- return 1;
- case Z_BUF_ERROR:
- if (outfile > 2) unlink(outname);
- if (strm->next_in != Z_NULL) {
- fprintf(stderr, "gun write error on %s: %s\n",
- outname, strerror(errno));
- }
- else if (errno) {
- fprintf(stderr, "gun read error on %s: %s\n",
- inname, strerror(errno));
- }
- else {
- fprintf(stderr, "gun unexpected end of file on %s\n",
- inname);
- }
- break;
- default:
- if (outfile > 2) unlink(outname);
- fprintf(stderr, "gun internal error--aborting\n");
- return 1;
- }
- return 0;
-}
-
-/* Process the gun command line arguments. See the command syntax near the
- beginning of this source file. */
-int main(int argc, char **argv)
-{
- int ret, len, test;
- char *outname;
- unsigned char *window;
- z_stream strm;
-
- /* initialize inflateBack state for repeated use */
- window = match; /* reuse LZW match buffer */
- strm.zalloc = Z_NULL;
- strm.zfree = Z_NULL;
- strm.opaque = Z_NULL;
- ret = inflateBackInit(&strm, 15, window);
- if (ret != Z_OK) {
- fprintf(stderr, "gun out of memory error--aborting\n");
- return 1;
- }
-
- /* decompress each file to the same name with the suffix removed */
- argc--;
- argv++;
- test = 0;
- if (argc && strcmp(*argv, "-h") == 0) {
- fprintf(stderr, "gun 1.6 (17 Jan 2010)\n");
- fprintf(stderr, "Copyright (C) 2003-2010 Mark Adler\n");
- fprintf(stderr, "usage: gun [-t] [file1.gz [file2.Z ...]]\n");
- return 0;
- }
- if (argc && strcmp(*argv, "-t") == 0) {
- test = 1;
- argc--;
- argv++;
- }
- if (argc)
- do {
- if (test)
- outname = NULL;
- else {
- len = (int)strlen(*argv);
- if (strcmp(*argv + len - 3, ".gz") == 0 ||
- strcmp(*argv + len - 3, "-gz") == 0)
- len -= 3;
- else if (strcmp(*argv + len - 2, ".z") == 0 ||
- strcmp(*argv + len - 2, "-z") == 0 ||
- strcmp(*argv + len - 2, "_z") == 0 ||
- strcmp(*argv + len - 2, ".Z") == 0)
- len -= 2;
- else {
- fprintf(stderr, "gun error: no gz type on %s--skipping\n",
- *argv);
- continue;
- }
- outname = malloc(len + 1);
- if (outname == NULL) {
- fprintf(stderr, "gun out of memory error--aborting\n");
- ret = 1;
- break;
- }
- memcpy(outname, *argv, len);
- outname[len] = 0;
- }
- ret = gunzip(&strm, *argv, outname, test);
- if (outname != NULL) free(outname);
- if (ret) break;
- } while (argv++, --argc);
- else
- ret = gunzip(&strm, NULL, NULL, test);
-
- /* clean up */
- inflateBackEnd(&strm);
- return ret;
-}
projects / ossec-hids.git / blobdiff