blob: 819148d2b35b71642fe967741746059618156e9d [file] [log] [blame]
/* minigzip.c -- simulate gzip using the zlib compression library
* Copyright (C) 1995-2006, 2010, 2011, 2016 Jean-loup Gailly
* For conditions of distribution and use, see copyright notice in zlib.h
*/
/*
* minigzip is a minimal implementation of the gzip utility. This is
* only an example of using zlib and isn't meant to replace the
* full-featured gzip. No attempt is made to deal with file systems
* limiting names to 14 or 8+3 characters, etc... Error checking is
* very limited. So use minigzip only for testing; use gzip for the
* real thing.
*/
#include "zbuild.h"
#ifdef ZLIB_COMPAT
# include "zlib.h"
#else
# include "zlib-ng.h"
#endif
#include <stdio.h>
#include <assert.h>
#ifdef USE_MMAP
# include <sys/types.h>
# include <sys/mman.h>
# include <sys/stat.h>
#endif
#if 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
#if defined(_MSC_VER) && _MSC_VER < 1900
# define snprintf _snprintf
#endif
#if !defined(Z_HAVE_UNISTD_H) && !defined(_LARGEFILE64_SOURCE)
#ifndef _WIN32 /* unlink already in stdio.h for Win32 */
extern int unlink (const char *);
#endif
#endif
#ifndef GZ_SUFFIX
# define GZ_SUFFIX ".gz"
#endif
#define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1)
#define BUFLEN 16384 /* read buffer size */
#define BUFLENW (BUFLEN * 3) /* write buffer size */
#define MAX_NAME_LEN 1024
static const char *prog = "minigzip_fuzzer";
void error (const char *msg);
void gz_compress (FILE *in, gzFile out);
#ifdef USE_MMAP
int gz_compress_mmap (FILE *in, gzFile out);
#endif
void gz_uncompress (gzFile in, FILE *out);
void file_compress (char *file, char *mode);
void file_uncompress (char *file);
int main (int argc, char *argv[]);
/* ===========================================================================
* Display error message and exit
*/
void error(const char *msg) {
fprintf(stderr, "%s: %s\n", prog, msg);
exit(1);
}
/* ===========================================================================
* Compress input to output then close both files.
*/
void gz_compress(FILE *in, gzFile out) {
char buf[BUFLEN];
int len;
int err;
#ifdef USE_MMAP
/* Try first compressing with mmap. If mmap fails (minigzip used in a
* pipe), use the normal fread loop.
*/
if (gz_compress_mmap(in, out) == Z_OK) return;
#endif
/* Clear out the contents of buf before reading from the file to avoid
MemorySanitizer: use-of-uninitialized-value warnings. */
memset(buf, 0, sizeof(buf));
for (;;) {
len = (int)fread(buf, 1, sizeof(buf), in);
if (ferror(in)) {
perror("fread");
exit(1);
}
if (len == 0) break;
if (PREFIX(gzwrite)(out, buf, (unsigned)len) != len) error(PREFIX(gzerror)(out, &err));
}
fclose(in);
if (PREFIX(gzclose)(out) != Z_OK) error("failed gzclose");
}
#ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */
/* Try compressing the input file at once using mmap. Return Z_OK if
* if success, Z_ERRNO otherwise.
*/
int gz_compress_mmap(FILE *in, gzFile out) {
int len;
int err;
int ifd = fileno(in);
char *buf; /* mmap'ed buffer for the entire input file */
off_t buf_len; /* length of the input file */
struct stat sb;
/* Determine the size of the file, needed for mmap: */
if (fstat(ifd, &sb) < 0) return Z_ERRNO;
buf_len = sb.st_size;
if (buf_len <= 0) return Z_ERRNO;
/* Now do the actual mmap: */
buf = mmap((void *)0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0);
if (buf == (char *)(-1)) return Z_ERRNO;
/* Compress the whole file at once: */
len = PREFIX(gzwrite)(out, (char *)buf, (unsigned)buf_len);
if (len != (int)buf_len) error(PREFIX(gzerror)(out, &err));
munmap(buf, buf_len);
fclose(in);
if (PREFIX(gzclose)(out) != Z_OK) error("failed gzclose");
return Z_OK;
}
#endif /* USE_MMAP */
/* ===========================================================================
* Uncompress input to output then close both files.
*/
void gz_uncompress(gzFile in, FILE *out) {
char buf[BUFLENW];
int len;
int err;
for (;;) {
len = PREFIX(gzread)(in, buf, sizeof(buf));
if (len < 0) error (PREFIX(gzerror)(in, &err));
if (len == 0) break;
if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
error("failed fwrite");
}
}
if (fclose(out)) error("failed fclose");
if (PREFIX(gzclose)(in) != Z_OK) error("failed gzclose");
}
/* ===========================================================================
* Compress the given file: create a corresponding .gz file and remove the
* original.
*/
void file_compress(char *file, char *mode) {
char outfile[MAX_NAME_LEN];
FILE *in;
gzFile out;
if (strlen(file) + strlen(GZ_SUFFIX) >= sizeof(outfile)) {
fprintf(stderr, "%s: filename too long\n", prog);
exit(1);
}
snprintf(outfile, sizeof(outfile), "%s%s", file, GZ_SUFFIX);
in = fopen(file, "rb");
if (in == NULL) {
perror(file);
exit(1);
}
out = PREFIX(gzopen)(outfile, mode);
if (out == NULL) {
fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile);
exit(1);
}
gz_compress(in, out);
unlink(file);
}
/* ===========================================================================
* Uncompress the given file and remove the original.
*/
void file_uncompress(char *file) {
char buf[MAX_NAME_LEN];
char *infile, *outfile;
FILE *out;
gzFile in;
size_t len = strlen(file);
if (len + strlen(GZ_SUFFIX) >= sizeof(buf)) {
fprintf(stderr, "%s: filename too long\n", prog);
exit(1);
}
snprintf(buf, sizeof(buf), "%s", file);
if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) {
infile = file;
outfile = buf;
outfile[len-3] = '\0';
} else {
outfile = file;
infile = buf;
snprintf(buf + len, sizeof(buf) - len, "%s", GZ_SUFFIX);
}
in = PREFIX(gzopen)(infile, "rb");
if (in == NULL) {
fprintf(stderr, "%s: can't gzopen %s\n", prog, infile);
exit(1);
}
out = fopen(outfile, "wb");
if (out == NULL) {
perror(file);
exit(1);
}
gz_uncompress(in, out);
unlink(infile);
}
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t dataLen) {
char *inFileName = "minigzip_fuzzer.out";
char *outFileName = "minigzip_fuzzer.out.gz";
char outmode[20];
FILE *in;
char buf[BUFLEN];
uint32_t offset = 0;
/* Discard inputs larger than 1Mb. */
static size_t kMaxSize = 1024 * 1024;
if (dataLen < 1 || dataLen > kMaxSize)
return 0;
in = fopen(inFileName, "wb");
if (fwrite(data, 1, (unsigned)dataLen, in) != dataLen)
error("failed fwrite");
if (fclose(in))
error("failed fclose");
memset(outmode, 0, sizeof(outmode));
snprintf(outmode, sizeof(outmode), "%s", "wb");
/* Compression level: [0..9]. */
outmode[2] = '0' + (data[0] % 10);
switch (data[dataLen-1] % 6) {
default:
case 0:
outmode[3] = 0;
break;
case 1:
/* compress with Z_FILTERED */
outmode[3] = 'f';
break;
case 2:
/* compress with Z_HUFFMAN_ONLY */
outmode[3] = 'h';
break;
case 3:
/* compress with Z_RLE */
outmode[3] = 'R';
break;
case 4:
/* compress with Z_FIXED */
outmode[3] = 'F';
break;
case 5:
/* direct */
outmode[3] = 'T';
break;
}
file_compress(inFileName, outmode);
/* gzopen does not support reading in direct mode */
if (outmode[3] == 'T')
inFileName = outFileName;
else
file_uncompress(outFileName);
/* Check that the uncompressed file matches the input data. */
in = fopen(inFileName, "rb");
if (in == NULL) {
perror(inFileName);
exit(1);
}
memset(buf, 0, sizeof(buf));
for (;;) {
int len = (int)fread(buf, 1, sizeof(buf), in);
if (ferror(in)) {
perror("fread");
exit(1);
}
if (len == 0)
break;
assert(0 == memcmp(data + offset, buf, len));
offset += len;
}
if (fclose(in))
error("failed fclose");
/* This function must return 0. */
return 0;
}