freebsd-dev/lib/libstand/gzipfs.c
Mike Smith 95b50c2be3 Replace the old and extremely icky Mach/NetBSD allocator with a similarly
compact and much better one donated by Matt Dillon.  Implement a simple
sbrk() which uses the existing setheap() api.

Remove the custom allocator from the UFS code.  It wasn't working quite
right, and it shouldn't be needed with the new allocator.

Fix a serious problem with changing the value of already-existent
environment variables.  Don't attempt to modify the supposedly-const
argument to putenv()

Fix an off-by-one sizing error in the zipfs code detected by the new
allocator.

Submitted by:	zmalloc from Matt Dillon <dillon@backplane.com>
1998-09-26 01:42:40 +00:00

319 lines
8.2 KiB
C

/*
* Copyright (c) 1998 Michael Smith.
* 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.
*
* $Id: zipfs.c,v 1.2 1998/09/18 22:58:01 msmith Exp $
*
*/
#include "stand.h"
#include <sys/stat.h>
#include <string.h>
#include <zlib.h>
#define Z_BUFSIZE 2048 /* XXX larger? */
struct z_file
{
int zf_rawfd;
z_stream zf_zstream;
char zf_buf[Z_BUFSIZE];
};
static int zf_fill(struct z_file *z);
static int zf_open(const char *path, struct open_file *f);
static int zf_close(struct open_file *f);
static int zf_read(struct open_file *f, void *buf, size_t size, size_t *resid);
static off_t zf_seek(struct open_file *f, off_t offset, int where);
static int zf_stat(struct open_file *f, struct stat *sb);
struct fs_ops zipfs_fsops = {
"zip",
zf_open,
zf_close,
zf_read,
null_write,
zf_seek,
zf_stat
};
#if 0
void *
calloc(int items, size_t size)
{
return(malloc(items * size));
}
#endif
static int
zf_fill(struct z_file *zf)
{
int result;
int req;
req = Z_BUFSIZE - zf->zf_zstream.avail_in;
result = 0;
/* If we need more */
if (req > 0) {
/* move old data to bottom of buffer */
if (req < Z_BUFSIZE)
bcopy(zf->zf_buf + req, zf->zf_buf, Z_BUFSIZE - req);
/* read to fill buffer and update availibility data */
result = read(zf->zf_rawfd, zf->zf_buf + zf->zf_zstream.avail_in, req);
zf->zf_zstream.next_in = zf->zf_buf;
if (result >= 0)
zf->zf_zstream.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 z_file *zf)
{
if ((zf->zf_zstream.avail_in == 0) && (zf_fill(zf) == -1))
return(-1);
zf->zf_zstream.avail_in--;
return(*(zf->zf_zstream.next_in)++);
}
static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
/* gzip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
#define COMMENT 0x10 /* bit 4 set: file comment present */
#define RESERVED 0xE0 /* bits 5..7: reserved */
static int
check_header(struct z_file *zf)
{
int method; /* method byte */
int flags; /* flags byte */
uInt len;
int c;
/* Check the gzip magic header */
for (len = 0; len < 2; len++) {
c = get_byte(zf);
if (c != gz_magic[len]) {
return(1);
}
}
method = get_byte(zf);
flags = get_byte(zf);
if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
return(1);
}
/* Discard time, xflags and OS code: */
for (len = 0; len < 6; len++) (void)get_byte(zf);
if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
len = (uInt)get_byte(zf);
len += ((uInt)get_byte(zf))<<8;
/* len is garbage if EOF but the loop below will quit anyway */
while (len-- != 0 && get_byte(zf) != -1) ;
}
if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
while ((c = get_byte(zf)) != 0 && c != -1) ;
}
if ((flags & COMMENT) != 0) { /* skip the .gz file comment */
while ((c = get_byte(zf)) != 0 && c != -1) ;
}
if ((flags & HEAD_CRC) != 0) { /* skip the header crc */
for (len = 0; len < 2; len++) c = get_byte(zf);
}
/* if there's data left, we're in business */
return((c == -1) ? 1 : 0);
}
static int
zf_open(const char *fname, struct open_file *f)
{
static char *zfname;
int rawfd;
struct z_file *zf;
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, ignore it */
if ((cp = strrchr(fname, '.')) && !strcmp(cp, ".gz"))
return(ENOENT);
/* Construct new name */
zfname = malloc(strlen(fname) + 4);
sprintf(zfname, "%s.gz", fname);
/* Try to open the compressed datafile */
rawfd = open(zfname, O_RDONLY);
free(zfname);
if (rawfd == -1)
return(ENOENT);
if (fstat(rawfd, &sb) < 0) {
printf("zf_open: stat failed\n");
close(rawfd);
return(ENOENT);
}
if (!S_ISREG(sb.st_mode)) {
printf("zf_open: not a file\n");
close(rawfd);
return(EISDIR); /* best guess */
}
/* Allocate a z_file structure, populate it */
zf = malloc(sizeof(struct z_file));
bzero(zf, sizeof(struct z_file));
zf->zf_rawfd = rawfd;
/* Verify that the file is gzipped (XXX why do this afterwards?) */
if (check_header(zf)) {
close(zf->zf_rawfd);
inflateEnd(&(zf->zf_zstream));
free(zf);
return(EFTYPE);
}
/* Initialise the inflation engine */
if ((error = inflateInit2(&(zf->zf_zstream), -15)) != Z_OK) {
printf("zf_open: inflateInit returned %d : %s\n", error, zf->zf_zstream.msg);
close(zf->zf_rawfd);
free(zf);
return(EIO);
}
/* Looks OK, we'll take it */
f->f_fsdata = zf;
return(0);
}
static int
zf_close(struct open_file *f)
{
struct z_file *zf = (struct z_file *)f->f_fsdata;
inflateEnd(&(zf->zf_zstream));
close(zf->zf_rawfd);
free(zf);
return(0);
}
static int
zf_read(struct open_file *f, void *buf, size_t size, size_t *resid)
{
struct z_file *zf = (struct z_file *)f->f_fsdata;
int error;
zf->zf_zstream.next_out = buf; /* where and how much */
zf->zf_zstream.avail_out = size;
while (zf->zf_zstream.avail_out) {
if ((zf->zf_zstream.avail_in == 0) && (zf_fill(zf) == -1)) {
printf("zf_read: fill error\n");
return(-1);
}
if (zf->zf_zstream.avail_in == 0) { /* oops, unexpected EOF */
printf("zf_read: unexpected EOF\n");
break;
}
error = inflate(&zf->zf_zstream, Z_SYNC_FLUSH); /* decompression pass */
if (error == Z_STREAM_END) { /* EOF, all done */
break;
}
if (error != Z_OK) { /* argh, decompression error */
printf("inflate: %s\n", zf->zf_zstream.msg);
errno = EIO;
return(-1);
}
}
if (resid != NULL)
*resid = zf->zf_zstream.avail_out;
return(0);
}
static off_t
zf_seek(struct open_file *f, off_t offset, int where)
{
struct z_file *zf = (struct z_file *)f->f_fsdata;
off_t target;
char discard[16];
switch (where) {
case SEEK_SET:
target = offset;
break;
case SEEK_CUR:
target = offset + zf->zf_zstream.total_out;
break;
default:
target = -1;
}
/* Can we get there from here? */
if (target < zf->zf_zstream.total_out) {
errno = EOFFSET;
return -1;
}
/* skip forwards if required */
while (target > zf->zf_zstream.total_out) {
if (zf_read(f, discard, min(sizeof(discard), target - zf->zf_zstream.total_out), NULL) == -1)
return(-1);
}
/* This is where we are (be honest if we overshot) */
return (zf->zf_zstream.total_out);
}
static int
zf_stat(struct open_file *f, struct stat *sb)
{
struct z_file *zf = (struct z_file *)f->f_fsdata;
int result;
/* stat as normal, but indicate that size is unknown */
if ((result = fstat(zf->zf_rawfd, sb)) == 0)
sb->st_size = -1;
return(result);
}