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/*
* Copyright (c) 2007 Vreixo Formoso
*
* This file is part of the libisofs project; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* or later as published by the Free Software Foundation.
* See COPYING file for details.
*/
#include "libisofs.h"
#include "util.h"
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
/**
* Private data for File IsoDataSource
*/
struct file_data_src
{
char *path;
int fd;
};
/**
* Increments the reference counting of the given IsoDataSource.
*/
void iso_data_source_ref(IsoDataSource *src)
{
src->refcount++;
}
/**
* Decrements the reference counting of the given IsoDataSource, freeing it
* if refcount reach 0.
*/
void iso_data_source_unref(IsoDataSource *src)
{
if (--src->refcount == 0) {
src->free_data(src);
free(src);
}
}
static
int ds_open(IsoDataSource *src)
{
int fd;
struct file_data_src *data;
if (src == NULL || src->data == NULL) {
return ISO_NULL_POINTER;
}
data = (struct file_data_src*) src->data;
if (data->fd != -1) {
return ISO_FILE_ALREADY_OPENED;
}
fd = open(data->path, O_RDONLY);
if (fd == -1) {
return ISO_FILE_ERROR;
}
data->fd = fd;
return ISO_SUCCESS;
}
static
int ds_close(IsoDataSource *src)
{
int ret;
struct file_data_src *data;
if (src == NULL || src->data == NULL) {
return ISO_NULL_POINTER;
}
data = (struct file_data_src*) src->data;
if (data->fd == -1) {
return ISO_FILE_NOT_OPENED;
}
/* close can fail if fd is not valid, but that should never happen */
ret = close(data->fd);
/* in any case we mark file as closed */
data->fd = -1;
return ret == 0 ? ISO_SUCCESS : ISO_FILE_ERROR;
}
static int ds_read_block(IsoDataSource *src, uint32_t lba, uint8_t *buffer)
{
struct file_data_src *data;
if (src == NULL || src->data == NULL || buffer == NULL) {
return ISO_NULL_POINTER;
}
data = (struct file_data_src*) src->data;
if (data->fd == -1) {
return ISO_FILE_NOT_OPENED;
}
/* goes to requested block */
if (lseek(data->fd, (off_t)lba * (off_t)2048, SEEK_SET) == (off_t) -1) {
return ISO_FILE_SEEK_ERROR;
}
/* TODO #00008 : guard against partial reads. */
if (read(data->fd, buffer, 2048) != 2048) {
return ISO_FILE_READ_ERROR;
}
return ISO_SUCCESS;
}
static
void ds_free_data(IsoDataSource *src)
{
struct file_data_src *data;
data = (struct file_data_src*)src->data;
/* close the file if needed */
if (data->fd != -1) {
close(data->fd);
}
free(data->path);
free(data);
}
/**
* Create a new IsoDataSource from a local file. This is suitable for
* accessing regular .iso images, or to acces drives via its block device
* and standard POSIX I/O calls.
*
* @param path
* The path of the file
* @param src
* Will be filled with the pointer to the newly created data source.
* @return
* 1 on success, < 0 on error.
*/
int iso_data_source_new_from_file(const char *path, IsoDataSource **src)
{
int ret;
struct file_data_src *data;
IsoDataSource *ds;
if (path == NULL || src == NULL) {
return ISO_NULL_POINTER;
}
/* ensure we have read access to the file */
ret = iso_eaccess(path);
if (ret < 0) {
return ret;
}
data = malloc(sizeof(struct file_data_src));
if (data == NULL) {
return ISO_OUT_OF_MEM;
}
ds = malloc(sizeof(IsoDataSource));
if (ds == NULL) {
free(data);
return ISO_OUT_OF_MEM;
}
/* fill data fields */
data->path = strdup(path);
if (data->path == NULL) {
free(data);
free(ds);
return ISO_OUT_OF_MEM;
}
data->fd = -1;
ds->version = 0;
ds->refcount = 1;
ds->data = data;
ds->open = ds_open;
ds->close = ds_close;
ds->read_block = ds_read_block;
ds->free_data = ds_free_data;
*src = ds;
return ISO_SUCCESS;
}