2 * Copyright (c) 1998 Michael Smith.
3 * Copyright (c) 2000 Maxim Sobolev
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
35 #include <sys/errno.h>
36 #include <sys/fcntl.h>
37 #include <sys/types.h>
38 #include <sys/unistd.h>
41 int f_flags; /* see F_* below */
42 void *f_fsdata; /* file system specific data */
44 #define F_READ 0x0001 /* file opened for reading */
45 #define EOFFSET (ELAST+8) /* relative seek not supported */
46 static inline u_int min(u_int a, u_int b) { return(a < b ? a : b); }
47 #define panic(x, y) abort()
54 #define BZ_BUFSIZE 2048 /* XXX larger? */
59 bz_stream bzf_bzstream;
60 char bzf_buf[BZ_BUFSIZE];
64 static int bzf_fill(struct bz_file *z);
65 static int bzf_open(const char *path, struct open_file *f);
66 static int bzf_close(struct open_file *f);
67 static int bzf_read(struct open_file *f, void *buf, size_t size, size_t *resid);
68 static off_t bzf_seek(struct open_file *f, off_t offset, int where);
69 static int bzf_stat(struct open_file *f, struct stat *sb);
72 struct fs_ops bzipfs_fsops = {
85 bzf_fill(struct bz_file *bzf)
90 req = BZ_BUFSIZE - bzf->bzf_bzstream.avail_in;
95 /* move old data to bottom of buffer */
97 bcopy(bzf->bzf_buf + req, bzf->bzf_buf, BZ_BUFSIZE - req);
99 /* read to fill buffer and update availibility data */
100 result = read(bzf->bzf_rawfd, bzf->bzf_buf + bzf->bzf_bzstream.avail_in, req);
101 bzf->bzf_bzstream.next_in = bzf->bzf_buf;
103 bzf->bzf_bzstream.avail_in += result;
109 * Adapted from get_byte/check_header in libz
111 * Returns 0 if the header is OK, nonzero if not.
114 get_byte(struct bz_file *bzf)
116 if ((bzf->bzf_bzstream.avail_in == 0) && (bzf_fill(bzf) == -1))
118 bzf->bzf_bzstream.avail_in--;
119 return(*(bzf->bzf_bzstream.next_in)++);
122 static int bz_magic[3] = {'B', 'Z', 'h'}; /* bzip2 magic header */
125 check_header(struct bz_file *bzf)
130 /* Check the bzip2 magic header */
131 for (len = 0; len < 3; len++) {
133 if (c != bz_magic[len]) {
137 /* Check that the block size is valid */
139 if (c < '1' || c > '9')
142 /* Put back bytes that we've took from the input stream */
143 bzf->bzf_bzstream.next_in -= 4;
144 bzf->bzf_bzstream.avail_in += 4;
150 bzf_open(const char *fname, struct open_file *f)
152 static char *bzfname;
159 /* Have to be in "just read it" mode */
160 if (f->f_flags != F_READ)
163 /* If the name already ends in .gz or .bz2, ignore it */
164 if ((cp = strrchr(fname, '.')) && (!strcmp(cp, ".gz")
165 || !strcmp(cp, ".bz2") || !strcmp(cp, ".split")))
168 /* Construct new name */
169 bzfname = malloc(strlen(fname) + 5);
172 sprintf(bzfname, "%s.bz2", fname);
174 /* Try to open the compressed datafile */
175 rawfd = open(bzfname, O_RDONLY);
180 if (fstat(rawfd, &sb) < 0) {
181 printf("bzf_open: stat failed\n");
185 if (!S_ISREG(sb.st_mode)) {
186 printf("bzf_open: not a file\n");
188 return(EISDIR); /* best guess */
191 /* Allocate a bz_file structure, populate it */
192 bzf = malloc(sizeof(struct bz_file));
195 bzero(bzf, sizeof(struct bz_file));
196 bzf->bzf_rawfd = rawfd;
198 /* Verify that the file is bzipped */
199 if (check_header(bzf)) {
200 close(bzf->bzf_rawfd);
205 /* Initialise the inflation engine */
206 if ((error = BZ2_bzDecompressInit(&(bzf->bzf_bzstream), 0, 1)) != BZ_OK) {
207 printf("bzf_open: BZ2_bzDecompressInit returned %d\n", error);
208 close(bzf->bzf_rawfd);
213 /* Looks OK, we'll take it */
219 bzf_close(struct open_file *f)
221 struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
223 BZ2_bzDecompressEnd(&(bzf->bzf_bzstream));
224 close(bzf->bzf_rawfd);
230 bzf_read(struct open_file *f, void *buf, size_t size, size_t *resid)
232 struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
235 bzf->bzf_bzstream.next_out = buf; /* where and how much */
236 bzf->bzf_bzstream.avail_out = size;
238 while (bzf->bzf_bzstream.avail_out && bzf->bzf_endseen == 0) {
239 if ((bzf->bzf_bzstream.avail_in == 0) && (bzf_fill(bzf) == -1)) {
240 printf("bzf_read: fill error\n");
243 if (bzf->bzf_bzstream.avail_in == 0) { /* oops, unexpected EOF */
244 printf("bzf_read: unexpected EOF\n");
245 if (bzf->bzf_bzstream.avail_out == size)
250 error = BZ2_bzDecompress(&bzf->bzf_bzstream); /* decompression pass */
251 if (error == BZ_STREAM_END) { /* EOF, all done */
252 bzf->bzf_endseen = 1;
255 if (error != BZ_OK) { /* argh, decompression error */
256 printf("bzf_read: BZ2_bzDecompress returned %d\n", error);
261 *resid = bzf->bzf_bzstream.avail_out;
266 bzf_rewind(struct open_file *f)
268 struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
269 struct bz_file *bzf_tmp;
272 * Since bzip2 does not have an equivalent inflateReset function a crude
273 * one needs to be provided. The functions all called in such a way that
274 * at any time an error occurs a roll back can be done (effectively making
275 * this rewind 'atomic', either the reset occurs successfully or not at all,
276 * with no 'undefined' state happening).
279 /* Allocate a bz_file structure, populate it */
280 bzf_tmp = malloc(sizeof(struct bz_file));
283 bzero(bzf_tmp, sizeof(struct bz_file));
284 bzf_tmp->bzf_rawfd = bzf->bzf_rawfd;
286 /* Initialise the inflation engine */
287 if (BZ2_bzDecompressInit(&(bzf_tmp->bzf_bzstream), 0, 1) != BZ_OK) {
292 /* Seek back to the beginning of the file */
293 if (lseek(bzf->bzf_rawfd, 0, SEEK_SET) == -1) {
294 BZ2_bzDecompressEnd(&(bzf_tmp->bzf_bzstream));
299 /* Free old bz_file data */
300 BZ2_bzDecompressEnd(&(bzf->bzf_bzstream));
303 /* Use the new bz_file data */
304 f->f_fsdata = bzf_tmp;
310 bzf_seek(struct open_file *f, off_t offset, int where)
312 struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
321 target = offset + bzf->bzf_bzstream.total_out_lo32;
330 /* Can we get there from here? */
331 if (target < bzf->bzf_bzstream.total_out_lo32 && bzf_rewind(f) != 0) {
336 /* if bzf_rewind was called then bzf has changed */
337 bzf = (struct bz_file *)f->f_fsdata;
339 /* skip forwards if required */
340 while (target > bzf->bzf_bzstream.total_out_lo32) {
341 errno = bzf_read(f, discard, min(sizeof(discard),
342 target - bzf->bzf_bzstream.total_out_lo32), NULL);
346 /* This is where we are (be honest if we overshot) */
347 return(bzf->bzf_bzstream.total_out_lo32);
351 bzf_stat(struct open_file *f, struct stat *sb)
353 struct bz_file *bzf = (struct bz_file *)f->f_fsdata;
356 /* stat as normal, but indicate that size is unknown */
357 if ((result = fstat(bzf->bzf_rawfd, sb)) == 0)
363 bz_internal_error(int errorcode)
365 panic("bzipfs: critical error %d in bzip2 library occured\n", errorcode);
369 /* Small test case, open and decompress test.bz2 */
377 memset(&f, '\0', sizeof(f));
379 err = bzf_open("test", &f);
383 err = bzf_read(&f, buf, sizeof(buf), &resid);
384 } while (err == 0 && resid != sizeof(buf));