/* zpipe.c: example of proper use of zlib's inflate() and deflate()
Not copyrighted -- provided to the public domain
Version 1.5 11 December 2005 Mark Adler
Version 2.0 03 June 2009 Rainer Gerhards */
/* RSYSLOG NOTE:
* This file is primarily been used as a testing aid for rsyslog. We do NOT
* properly maintain it and it has been brought to our attention that it may
* have some security issues. However, we prefer not to remove the file as it
* may turn out to be useful for further testing. All users are advised NOT
* to base any development on this version here, but rather look for the
* original zpipe.c by the authors mentioned above.
*
* This file is beeing distributed as part of rsyslog, but is just an
* add-on. Most importantly, rsyslog's copyright does not apply but
* rather the (non-) copyright stated above.
*/
/* Version history:
1.0 30 Oct 2004 First version
1.1 8 Nov 2004 Add void casting for unused return values
Use switch statement for inflate() return values
1.2 9 Nov 2004 Add assertions to document zlib guarantees
1.3 6 Apr 2005 Remove incorrect assertion in inf()
1.4 11 Dec 2005 Add hack to avoid MSDOS end-of-line conversions
Avoid some compiler warnings for input and output buffers
2.0 03 Jun 2009 Add hack to support multiple deflate records inside a single
file on inflate. This is needed in order to support reading
files created by rsyslog's zip output writer.
*/
#include "config.h"
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "zlib.h"
#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__)
# include <fcntl.h>
# include <io.h>
# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY)
#else
# define SET_BINARY_MODE(file)
#endif
#define CHUNK 16384
/* Compress from file source to file dest until EOF on source.
def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
allocated for processing, Z_STREAM_ERROR if an invalid compression
level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
version of the library linked do not match, or Z_ERRNO if there is
an error reading or writing the files. */
int def(FILE *source, FILE *dest, int level)
{
int ret, flush;
unsigned have;
z_stream strm;
unsigned char in[CHUNK];
unsigned char out[CHUNK];
/* allocate deflate state */
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
ret = deflateInit(&strm, level);
if (ret != Z_OK)
return ret;
/* compress until end of file */
do {
strm.avail_in = fread(in, 1, CHUNK, source);
if (ferror(source)) {
(void)deflateEnd(&strm);
return Z_ERRNO;
}
flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
strm.next_in = in;
/* run deflate() on input until output buffer not full, finish
compression if all of source has been read in */
do {
strm.avail_out = CHUNK;
strm.next_out = out;
ret = deflate(&strm, flush); /* no bad return value */
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
have = CHUNK - strm.avail_out;
if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
(void)deflateEnd(&strm);
return Z_ERRNO;
}
} while (strm.avail_out == 0);
assert(strm.avail_in == 0); /* all input will be used */
/* done when last data in file processed */
} while (flush != Z_FINISH);
assert(ret == Z_STREAM_END); /* stream will be complete */
/* clean up and return */
(void)deflateEnd(&strm);
return Z_OK;
}
/* initialize stream for deflating (we need this in case of
* multiple records.
* rgerhards, 2009-06-03
*/
int doInflateInit(z_stream *strm)
{
int ret;
/* allocate inflate state */
strm->zalloc = Z_NULL;
strm->zfree = Z_NULL;
strm->opaque = Z_NULL;
strm->avail_in = 0;
strm->next_in = Z_NULL;
ret = inflateInit(strm);
return ret;
}
/* Decompress from file source to file dest until stream ends or EOF.
inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
allocated for processing, Z_DATA_ERROR if the deflate data is
invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
the version of the library linked do not match, or Z_ERRNO if there
is an error reading or writing the files. */
int inf(FILE *source, FILE *dest)
{
int ret;
unsigned have;
z_stream strm;
unsigned char in[CHUNK];
int len;
unsigned char *next_in_save;
unsigned char out[CHUNK];
ret = doInflateInit(&strm);
if (ret != Z_OK)
return ret;
/* decompress until deflate stream ends or end of file */
do {
len = fread(in, 1, CHUNK, source);
if (ferror(source)) {
(void)inflateEnd(&strm);
return Z_ERRNO;
}
if (len == 0) {
break;
}
strm.avail_in = len;
strm.next_in = in;
/* run inflate() on input until output buffer not full */
strm.avail_out = CHUNK;
strm.next_out = out;
do {
/* fprintf(stderr, "---inner LOOP---, avail_in %d, avail_out %d Byte 0: %x, 1: %x\n", strm.avail_in, strm.avail_out, *strm.next_in, *(strm.next_in+1));*/
do {
ret = inflate(&strm, Z_NO_FLUSH);
assert(ret != Z_STREAM_ERROR); /* state not clobbered */
switch (ret) {
case Z_NEED_DICT:
ret = Z_DATA_ERROR; /* and fall through */
case Z_DATA_ERROR:
case Z_MEM_ERROR:
(void)inflateEnd(&strm);
return ret;
}
have = CHUNK - strm.avail_out;
if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
(void)inflateEnd(&strm);
return Z_ERRNO;
}
} while (strm.avail_out == 0);
/* handle the case that more than one deflate record is contained
* in a single file. -- rgerhards, 2009-06-03
*/
if(ret == Z_STREAM_END) {
len -= strm.total_in;
if(len > 0) {
next_in_save = strm.next_in;
(void)inflateEnd(&strm);
ret = doInflateInit(&strm);
if (ret != Z_OK)
return ret;
strm.avail_in = len;
strm.next_in = next_in_save;
strm.avail_out = CHUNK;
strm.next_out = out;
ret = Z_OK; /* continue outer loop */
}
}
} while (strm.avail_in > 0);
/* done when inflate() says it's done */
} while (ret != Z_STREAM_END);
/* clean up and return */
(void)inflateEnd(&strm);
return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}
/* report a zlib or i/o error */
void zerr(int ret)
{
fputs("zpipe: ", stdout);
switch (ret) {
case Z_ERRNO:
if (ferror(stdin))
fputs("error reading stdin\n", stdout);
if (ferror(stdout))
fputs("error writing stdout\n", stdout);
break;
case Z_STREAM_ERROR:
fputs("invalid compression level\n", stdout);
break;
case Z_DATA_ERROR:
fputs("invalid or incomplete deflate data\n", stdout);
break;
case Z_MEM_ERROR:
fputs("out of memory\n", stdout);
break;
case Z_VERSION_ERROR:
fputs("zlib version mismatch!\n", stdout);
}
}
/* compress or decompress from stdin to stdout */
int main(int argc, char **argv)
{
int ret;
/* avoid end-of-line conversions */
SET_BINARY_MODE(stdin);
SET_BINARY_MODE(stdout);
/* do compression if no arguments */
if (argc == 1) {
ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
if (ret != Z_OK)
zerr(ret);
return ret;
}
/* do decompression if -d specified */
else if (argc == 2 && strcmp(argv[1], "-d") == 0) {
ret = inf(stdin, stdout);
if (ret != Z_OK)
zerr(ret);
return ret;
}
/* otherwise, report usage */
else {
fputs("zpipe usage: zpipe [-d] < source > dest\n", stdout);
return 1;
}
}