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-rw-r--r--lib/libstand/bzipfs.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/lib/libstand/bzipfs.c b/lib/libstand/bzipfs.c
new file mode 100644
index 000000000000..c0a8d9bec71c
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+++ b/lib/libstand/bzipfs.c
@@ -0,0 +1,297 @@
+/*
+ * 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>
+__FBSDID("$FreeBSD$");
+
+#include "stand.h"
+
+#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];
+};
+
+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);
+
+struct fs_ops bzipfs_fsops = {
+ "bzip",
+ bzf_open,
+ bzf_close,
+ bzf_read,
+ null_write,
+ bzf_seek,
+ bzf_stat,
+ null_readdir
+};
+
+#if 0
+void *
+calloc(int items, size_t size)
+{
+ return(malloc(items * size));
+}
+#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);
+ 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));
+ bzero(bzf, sizeof(struct bz_file));
+ bzf->bzf_rawfd = rawfd;
+
+ /* Verify that the file is bzipped (XXX why do this afterwards?) */
+ if (check_header(bzf)) {
+ close(bzf->bzf_rawfd);
+ BZ2_bzDecompressEnd(&(bzf->bzf_bzstream));
+ 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) {
+ if ((bzf->bzf_bzstream.avail_in == 0) && (bzf_fill(bzf) == -1)) {
+ printf("bzf_read: fill error\n");
+ return(-1);
+ }
+ if (bzf->bzf_bzstream.avail_in == 0) { /* oops, unexpected EOF */
+ printf("bzf_read: unexpected EOF\n");
+ break;
+ }
+
+ error = BZ2_bzDecompress(&bzf->bzf_bzstream); /* decompression pass */
+ if (error == BZ_STREAM_END) { /* EOF, all done */
+ break;
+ }
+ if (error != BZ_OK) { /* argh, decompression error */
+ printf("bzf_read: BZ2_bzDecompress returned %d\n", error);
+ errno = EIO;
+ return(-1);
+ }
+ }
+ if (resid != NULL)
+ *resid = bzf->bzf_bzstream.avail_out;
+ 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:
+ target = -1;
+ }
+
+ /* Can we get there from here? */
+ if (target < bzf->bzf_bzstream.total_out_lo32) {
+ errno = EOFFSET;
+ return -1;
+ }
+
+ /* skip forwards if required */
+ while (target > bzf->bzf_bzstream.total_out_lo32) {
+ if (bzf_read(f, discard, min(sizeof(discard), target - bzf->bzf_bzstream.total_out_lo32), NULL) == -1)
+ return(-1);
+ }
+ /* 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 occured\n", errorcode);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 23:34:02 +0000