390 lines
10 KiB
C
390 lines
10 KiB
C
/*
|
|
* Copyright (c) 1998 Michael Smith.
|
|
* Copyright (c) 2000 Maxim Sobolev
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#ifndef REGRESSION
|
|
#include "stand.h"
|
|
#else
|
|
#include <stdlib.h>
|
|
#include <sys/errno.h>
|
|
#include <sys/fcntl.h>
|
|
#include <sys/types.h>
|
|
#include <sys/unistd.h>
|
|
|
|
struct open_file {
|
|
int f_flags; /* see F_* below */
|
|
void *f_fsdata; /* file system specific data */
|
|
};
|
|
#define F_READ 0x0001 /* file opened for reading */
|
|
#define EOFFSET (ELAST+8) /* relative seek not supported */
|
|
static inline u_int min(u_int a, u_int b) { return(a < b ? a : b); }
|
|
#define panic(x, y) abort()
|
|
#endif
|
|
|
|
#include <sys/stat.h>
|
|
#include <string.h>
|
|
#include <bzlib.h>
|
|
|
|
#define BZ_BUFSIZE 2048 /* XXX larger? */
|
|
|
|
struct bz_file
|
|
{
|
|
int bzf_rawfd;
|
|
bz_stream bzf_bzstream;
|
|
char bzf_buf[BZ_BUFSIZE];
|
|
int bzf_endseen;
|
|
};
|
|
|
|
static int bzf_fill(struct bz_file *z);
|
|
static int bzf_open(const char *path, struct open_file *f);
|
|
static int bzf_close(struct open_file *f);
|
|
static int bzf_read(struct open_file *f, void *buf, size_t size, size_t *resid);
|
|
static off_t bzf_seek(struct open_file *f, off_t offset, int where);
|
|
static int bzf_stat(struct open_file *f, struct stat *sb);
|
|
|
|
#ifndef REGRESSION
|
|
struct fs_ops bzipfs_fsops = {
|
|
.fs_name = "bzip",
|
|
.fo_open = bzf_open,
|
|
.fo_close = bzf_close,
|
|
.fo_read = bzf_read,
|
|
.fo_write = null_write,
|
|
.fo_seek = bzf_seek,
|
|
.fo_stat = bzf_stat,
|
|
.fo_readdir = null_readdir,
|
|
};
|
|
#endif
|
|
|
|
static int
|
|
bzf_fill(struct bz_file *bzf)
|
|
{
|
|
int result;
|
|
int req;
|
|
|
|
req = BZ_BUFSIZE - bzf->bzf_bzstream.avail_in;
|
|
result = 0;
|
|
|
|
/* If we need more */
|
|
if (req > 0) {
|
|
/* move old data to bottom of buffer */
|
|
if (req < BZ_BUFSIZE)
|
|
bcopy(bzf->bzf_buf + req, bzf->bzf_buf, BZ_BUFSIZE - req);
|
|
|
|
/* read to fill buffer and update availibility data */
|
|
result = read(bzf->bzf_rawfd, bzf->bzf_buf + bzf->bzf_bzstream.avail_in, req);
|
|
bzf->bzf_bzstream.next_in = bzf->bzf_buf;
|
|
if (result >= 0)
|
|
bzf->bzf_bzstream.avail_in += result;
|
|
}
|
|
return(result);
|
|
}
|
|
|
|
/*
|
|
* Adapted from get_byte/check_header in libz
|
|
*
|
|
* Returns 0 if the header is OK, nonzero if not.
|
|
*/
|
|
static int
|
|
get_byte(struct bz_file *bzf)
|
|
{
|
|
if ((bzf->bzf_bzstream.avail_in == 0) && (bzf_fill(bzf) == -1))
|
|
return(-1);
|
|
bzf->bzf_bzstream.avail_in--;
|
|
return(*(bzf->bzf_bzstream.next_in)++);
|
|
}
|
|
|
|
static int bz_magic[3] = {'B', 'Z', 'h'}; /* bzip2 magic header */
|
|
|
|
static int
|
|
check_header(struct bz_file *bzf)
|
|
{
|
|
unsigned int len;
|
|
int c;
|
|
|
|
/* Check the bzip2 magic header */
|
|
for (len = 0; len < 3; len++) {
|
|
c = get_byte(bzf);
|
|
if (c != bz_magic[len]) {
|
|
return(1);
|
|
}
|
|
}
|
|
/* Check that the block size is valid */
|
|
c = get_byte(bzf);
|
|
if (c < '1' || c > '9')
|
|
return(1);
|
|
|
|
/* Put back bytes that we've took from the input stream */
|
|
bzf->bzf_bzstream.next_in -= 4;
|
|
bzf->bzf_bzstream.avail_in += 4;
|
|
|
|
return(0);
|
|
}
|
|
|
|
static int
|
|
bzf_open(const char *fname, struct open_file *f)
|
|
{
|
|
static char *bzfname;
|
|
int rawfd;
|
|
struct bz_file *bzf;
|
|
char *cp;
|
|
int error;
|
|
struct stat sb;
|
|
|
|
/* Have to be in "just read it" mode */
|
|
if (f->f_flags != F_READ)
|
|
return(EPERM);
|
|
|
|
/* If the name already ends in .gz or .bz2, ignore it */
|
|
if ((cp = strrchr(fname, '.')) && (!strcmp(cp, ".gz")
|
|
|| !strcmp(cp, ".bz2") || !strcmp(cp, ".split")))
|
|
return(ENOENT);
|
|
|
|
/* Construct new name */
|
|
bzfname = malloc(strlen(fname) + 5);
|
|
if (bzfname == NULL)
|
|
return(ENOMEM);
|
|
sprintf(bzfname, "%s.bz2", fname);
|
|
|
|
/* Try to open the compressed datafile */
|
|
rawfd = open(bzfname, O_RDONLY);
|
|
free(bzfname);
|
|
if (rawfd == -1)
|
|
return(ENOENT);
|
|
|
|
if (fstat(rawfd, &sb) < 0) {
|
|
printf("bzf_open: stat failed\n");
|
|
close(rawfd);
|
|
return(ENOENT);
|
|
}
|
|
if (!S_ISREG(sb.st_mode)) {
|
|
printf("bzf_open: not a file\n");
|
|
close(rawfd);
|
|
return(EISDIR); /* best guess */
|
|
}
|
|
|
|
/* Allocate a bz_file structure, populate it */
|
|
bzf = malloc(sizeof(struct bz_file));
|
|
if (bzf == NULL)
|
|
return(ENOMEM);
|
|
bzero(bzf, sizeof(struct bz_file));
|
|
bzf->bzf_rawfd = rawfd;
|
|
|
|
/* Verify that the file is bzipped */
|
|
if (check_header(bzf)) {
|
|
close(bzf->bzf_rawfd);
|
|
free(bzf);
|
|
return(EFTYPE);
|
|
}
|
|
|
|
/* Initialise the inflation engine */
|
|
if ((error = BZ2_bzDecompressInit(&(bzf->bzf_bzstream), 0, 1)) != BZ_OK) {
|
|
printf("bzf_open: BZ2_bzDecompressInit returned %d\n", error);
|
|
close(bzf->bzf_rawfd);
|
|
free(bzf);
|
|
return(EIO);
|
|
}
|
|
|
|
/* Looks OK, we'll take it */
|
|
f->f_fsdata = bzf;
|
|
return(0);
|
|
}
|
|
|
|
static int
|
|
bzf_close(struct open_file *f)
|
|
{
|
|
struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
|
|
|
|
BZ2_bzDecompressEnd(&(bzf->bzf_bzstream));
|
|
close(bzf->bzf_rawfd);
|
|
free(bzf);
|
|
return(0);
|
|
}
|
|
|
|
static int
|
|
bzf_read(struct open_file *f, void *buf, size_t size, size_t *resid)
|
|
{
|
|
struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
|
|
int error;
|
|
|
|
bzf->bzf_bzstream.next_out = buf; /* where and how much */
|
|
bzf->bzf_bzstream.avail_out = size;
|
|
|
|
while (bzf->bzf_bzstream.avail_out && bzf->bzf_endseen == 0) {
|
|
if ((bzf->bzf_bzstream.avail_in == 0) && (bzf_fill(bzf) == -1)) {
|
|
printf("bzf_read: fill error\n");
|
|
return(EIO);
|
|
}
|
|
if (bzf->bzf_bzstream.avail_in == 0) { /* oops, unexpected EOF */
|
|
printf("bzf_read: unexpected EOF\n");
|
|
if (bzf->bzf_bzstream.avail_out == size)
|
|
return(EIO);
|
|
break;
|
|
}
|
|
|
|
error = BZ2_bzDecompress(&bzf->bzf_bzstream); /* decompression pass */
|
|
if (error == BZ_STREAM_END) { /* EOF, all done */
|
|
bzf->bzf_endseen = 1;
|
|
break;
|
|
}
|
|
if (error != BZ_OK) { /* argh, decompression error */
|
|
printf("bzf_read: BZ2_bzDecompress returned %d\n", error);
|
|
return(EIO);
|
|
}
|
|
}
|
|
if (resid != NULL)
|
|
*resid = bzf->bzf_bzstream.avail_out;
|
|
return(0);
|
|
}
|
|
|
|
static int
|
|
bzf_rewind(struct open_file *f)
|
|
{
|
|
struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
|
|
struct bz_file *bzf_tmp;
|
|
|
|
/*
|
|
* Since bzip2 does not have an equivalent inflateReset function a crude
|
|
* one needs to be provided. The functions all called in such a way that
|
|
* at any time an error occurs a roll back can be done (effectively making
|
|
* this rewind 'atomic', either the reset occurs successfully or not at all,
|
|
* with no 'undefined' state happening).
|
|
*/
|
|
|
|
/* Allocate a bz_file structure, populate it */
|
|
bzf_tmp = malloc(sizeof(struct bz_file));
|
|
if (bzf_tmp == NULL)
|
|
return(-1);
|
|
bzero(bzf_tmp, sizeof(struct bz_file));
|
|
bzf_tmp->bzf_rawfd = bzf->bzf_rawfd;
|
|
|
|
/* Initialise the inflation engine */
|
|
if (BZ2_bzDecompressInit(&(bzf_tmp->bzf_bzstream), 0, 1) != BZ_OK) {
|
|
free(bzf_tmp);
|
|
return(-1);
|
|
}
|
|
|
|
/* Seek back to the beginning of the file */
|
|
if (lseek(bzf->bzf_rawfd, 0, SEEK_SET) == -1) {
|
|
BZ2_bzDecompressEnd(&(bzf_tmp->bzf_bzstream));
|
|
free(bzf_tmp);
|
|
return(-1);
|
|
}
|
|
|
|
/* Free old bz_file data */
|
|
BZ2_bzDecompressEnd(&(bzf->bzf_bzstream));
|
|
free(bzf);
|
|
|
|
/* Use the new bz_file data */
|
|
f->f_fsdata = bzf_tmp;
|
|
|
|
return(0);
|
|
}
|
|
|
|
static off_t
|
|
bzf_seek(struct open_file *f, off_t offset, int where)
|
|
{
|
|
struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
|
|
off_t target;
|
|
char discard[16];
|
|
|
|
switch (where) {
|
|
case SEEK_SET:
|
|
target = offset;
|
|
break;
|
|
case SEEK_CUR:
|
|
target = offset + bzf->bzf_bzstream.total_out_lo32;
|
|
break;
|
|
default:
|
|
errno = EINVAL;
|
|
return(-1);
|
|
}
|
|
|
|
/* Can we get there from here? */
|
|
if (target < bzf->bzf_bzstream.total_out_lo32 && bzf_rewind(f) != 0) {
|
|
errno = EOFFSET;
|
|
return -1;
|
|
}
|
|
|
|
/* if bzf_rewind was called then bzf has changed */
|
|
bzf = (struct bz_file *)f->f_fsdata;
|
|
|
|
/* skip forwards if required */
|
|
while (target > bzf->bzf_bzstream.total_out_lo32) {
|
|
errno = bzf_read(f, discard, min(sizeof(discard),
|
|
target - bzf->bzf_bzstream.total_out_lo32), NULL);
|
|
if (errno)
|
|
return(-1);
|
|
/* Break out of loop if end of file has been reached. */
|
|
if (bzf->bzf_endseen)
|
|
break;
|
|
}
|
|
/* This is where we are (be honest if we overshot) */
|
|
return(bzf->bzf_bzstream.total_out_lo32);
|
|
}
|
|
|
|
static int
|
|
bzf_stat(struct open_file *f, struct stat *sb)
|
|
{
|
|
struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
|
|
int result;
|
|
|
|
/* stat as normal, but indicate that size is unknown */
|
|
if ((result = fstat(bzf->bzf_rawfd, sb)) == 0)
|
|
sb->st_size = -1;
|
|
return(result);
|
|
}
|
|
|
|
void
|
|
bz_internal_error(int errorcode)
|
|
{
|
|
panic("bzipfs: critical error %d in bzip2 library occurred", errorcode);
|
|
}
|
|
|
|
#ifdef REGRESSION
|
|
/* Small test case, open and decompress test.bz2 */
|
|
int main()
|
|
{
|
|
struct open_file f;
|
|
char buf[1024];
|
|
size_t resid;
|
|
int err;
|
|
|
|
memset(&f, '\0', sizeof(f));
|
|
f.f_flags = F_READ;
|
|
err = bzf_open("test", &f);
|
|
if (err != 0)
|
|
exit(1);
|
|
do {
|
|
err = bzf_read(&f, buf, sizeof(buf), &resid);
|
|
} while (err == 0 && resid != sizeof(buf));
|
|
|
|
if (err != 0)
|
|
exit(2);
|
|
exit(0);
|
|
}
|
|
#endif
|