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/*
* Copyright © 2007 Alistair Crooks. 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.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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/types.h>
#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <fuse.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
enum {
BigEndian = 4321,
LittleEndian = 1234
};
static struct stat dbst; /* stat info of database file */
static BTREEINFO bt; /* btree information */
static int verbose; /* how chatty are we? */
static DB *db; /* data base operations struct */
/* perform the stat operation */
/* if this is the root, then just synthesise the data */
/* otherwise, retrieve the data, and be sure to fill in the size */
/* we use the mtime of the database file for each of the records */
static int
dbfs_getattr(const char *path, struct stat *st)
{
int res = 0;
DBT k;
DBT v;
(void) memset(st, 0x0, sizeof(*st));
if (strcmp(path, "/") == 0) {
st->st_mode = S_IFDIR | 0755;
st->st_nlink = 2;
} else {
k.size = strlen(k.data = __UNCONST(path + 1));
if ((*db->seq)(db, &k, &v, R_CURSOR) != 0) {
return -ENOENT;
}
st->st_mode = S_IFREG | 0444;
st->st_nlink = 1;
st->st_size = v.size;
st->st_mtime = dbst.st_mtime;
st->st_atime = dbst.st_atime;
st->st_ctime = dbst.st_ctime;
st->st_uid = dbst.st_uid;
st->st_gid = dbst.st_gid;
}
return res;
}
/* readdir operation */
/* run through the database file, returning records by key */
static int
dbfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
off_t offset, struct fuse_file_info * fi)
{
static int ret;
static DBT k;
int flag;
DBT v;
(void) fi;
if (offset == 0) {
(void) memset(&k, 0x0, sizeof(k));
(void) filler(buf, ".", NULL, 0);
(void) filler(buf, "..", NULL, 0);
flag = R_FIRST;
ret = 0;
} else {
flag = R_CURSOR;
}
if (ret != 0) {
return 0;
}
for ( ; (ret = (*db->seq)(db, &k, &v, flag)) == 0 ; flag = R_NEXT) {
if (filler(buf, k.data, NULL, 0) != 0) {
return 0;
}
}
return 0;
}
/* open the file in the file system */
/* use seq method to get the record - get doesn't seem to work */
static int
dbfs_open(const char *path, struct fuse_file_info * fi)
{
DBT k;
DBT v;
k.size = strlen(k.data = __UNCONST(path));
if ((*db->get)(db, &k, &v, 0) != 0) {
return -ENOENT;
}
if ((fi->flags & 3) != O_RDONLY) {
return -EACCES;
}
return 0;
}
/* read the file's contents in the file system */
/* use seq method to get the record - get doesn't seem to work */
static int
dbfs_read(const char *path, char *buf, size_t size, off_t offset,
struct fuse_file_info * fi)
{
size_t len;
DBT k;
DBT v;
(void) fi;
k.size = strlen(k.data = __UNCONST(path + 1));
if ((*db->seq)(db, &k, &v, R_CURSOR) != 0) {
return -ENOENT;
}
len = v.size;
if (offset < len) {
if (offset + size > len) {
size = len - offset;
}
(void) memcpy(buf, (char *) v.data + offset, size);
buf[size - 1] = '\n';
} else {
size = 0;
}
return size;
}
/* fill in the statvfs struct */
static int
dbfs_statfs(const char *path, struct statvfs *st)
{
(void) memset(st, 0x0, sizeof(*st));
st->f_blocks = dbst.st_size / dbst.st_blksize;
st->f_bsize = st->f_frsize = st->f_iosize = dbst.st_blksize;
st->f_owner = dbst.st_uid;
st->f_files = 1;
return 0;
}
/* operations struct */
static struct fuse_operations dbfs_oper = {
.getattr = dbfs_getattr,
.readdir = dbfs_readdir,
.open = dbfs_open,
.read = dbfs_read,
.statfs = dbfs_statfs
};
int
main(int argc, char **argv)
{
int i;
while ((i = getopt(argc, argv, "v")) != -1) {
switch(i) {
case 'v':
verbose = 1;
break;
}
}
if (stat(argv[optind], &dbst) != 0) {
err(EXIT_FAILURE, "can't stat `%s'", argv[optind]);
}
bt.lorder = LittleEndian;
if ((db = dbopen(argv[optind], O_RDONLY, 0666, DB_BTREE, &bt)) == NULL) {
bt.lorder = BigEndian;
db = dbopen(argv[optind], O_RDONLY, 0666, DB_BTREE, &bt);
if (verbose) {
printf("Database not little endian - trying big endian now\n");
}
}
if (db == NULL) {
err(EXIT_FAILURE, "can't open db `%s'", argv[optind]);
}
return fuse_main(argc, argv, &dbfs_oper);
}
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