libfprint/examples/storage.c

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/*
* Trivial storage driver for example programs
*
* Copyright (C) 2019 Benjamin Berg <bberg@redhat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <glib.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <libfprint/fprint.h>
#define STORAGE_FILE "test-storage.variant"
static char *
get_print_data_descriptor (struct fp_print_data *data, struct fp_dev *dev, enum fp_finger finger)
{
gint drv_id;
gint devtype;
if (data) {
drv_id = fp_print_data_get_driver_id (data);
devtype = fp_print_data_get_devtype (data);
} else {
drv_id = fp_driver_get_driver_id(fp_dev_get_driver (dev));
devtype = fp_dev_get_devtype (dev);
}
return g_strdup_printf("%x/%08x/%x",
drv_id,
devtype,
finger);
}
static GVariantDict*
load_data(void)
{
GVariantDict *res;
GVariant *var;
gchar *contents = NULL;
gssize length = 0;
if (!g_file_get_contents (STORAGE_FILE, &contents, &length, NULL)) {
g_warning ("Error loading storage, assuming it is empty");
return g_variant_dict_new(NULL);
}
var = g_variant_new_from_data (G_VARIANT_TYPE_VARDICT, contents, length, FALSE, NULL, NULL);
res = g_variant_dict_new(var);
g_variant_unref(var);
return res;
}
static int
save_data(GVariant *data)
{
const gchar *contents = NULL;
gsize length;
length = g_variant_get_size(data);
contents = (gchar*) g_variant_get_data (data);
if (!g_file_set_contents (STORAGE_FILE, contents, length, NULL)) {
g_warning ("Error saving storage,!");
return -1;
}
g_variant_ref_sink(data);
g_variant_unref(data);
return 0;
}
int
print_data_save(struct fp_print_data *fp_data, enum fp_finger finger)
{
gchar *descr = get_print_data_descriptor (fp_data, NULL, finger);
GVariantDict *dict;
GVariant *val;
guchar *data;
gsize size;
int res;
dict = load_data();
size = fp_print_data_get_data(fp_data, &data);
val = g_variant_new_fixed_array (G_VARIANT_TYPE("y"), data, size, 1);
g_variant_dict_insert_value (dict, descr, val);
res = save_data(g_variant_dict_end(dict));
g_variant_dict_unref(dict);
return res;
}
struct fp_print_data*
print_data_load(struct fp_dev *dev, enum fp_finger finger)
{
gchar *descr = get_print_data_descriptor (NULL, dev, finger);
GVariantDict *dict;
guchar *stored_data;
gsize stored_len;
GVariant *val;
struct fp_print_data *res = NULL;
dict = load_data();
val = g_variant_dict_lookup_value (dict, descr, G_VARIANT_TYPE ("ay"));
if (val) {
stored_data = (guchar*) g_variant_get_fixed_array (val, &stored_len, 1);
res = fp_print_data_from_data(stored_data, stored_len);
g_variant_unref(val);
}
g_variant_dict_unref(dict);
g_free(descr);
return res;
}