/*      $NetBSD: config.c,v 1.6 2020/06/07 00:54:22 thorpej Exp $       */

/*-
 * Copyright (c) 2006 Itronix Inc.
 * 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 Itronix Inc. may not be used to endorse
 *    or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``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 ITRONIX INC. 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>
__RCSID("$NetBSD: config.c,v 1.6 2020/06/07 00:54:22 thorpej Exp $");

#include <sys/time.h>
#include <prop/proplib.h>
#include <bluetooth.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>

#include "bthcid.h"

static const char *key_file = "/var/db/bthcid.keys";
static const char *new_key_file = "/var/db/bthcid.keys.new";

static prop_dictionary_t
load_keys(void)
{
        prop_dictionary_t dict;
        char *xml;
        off_t len;
        int fd;

        fd = open(key_file, O_RDONLY, 0);
        if (fd < 0)
                return NULL;

        len = lseek(fd, 0, SEEK_END);
        if (len == 0) {
                close(fd);
                return NULL;
        }

        xml = malloc(len);
        if (xml == NULL) {
                close(fd);
                return NULL;
        }

        (void)lseek(fd, 0, SEEK_SET);
        if (read(fd, xml, len) != len) {
                free(xml);
                close(fd);
                return NULL;
        }

        dict = prop_dictionary_internalize(xml);
        free(xml);
        close(fd);
        return dict;
}

/*
 * Look up key in keys file. We store a dictionary for each
 * remote address, and inside that we have a data object for
 * each local address containing the key.
 */
uint8_t *
lookup_key(bdaddr_t *laddr, bdaddr_t *raddr)
{
        static uint8_t key[HCI_KEY_SIZE];
        prop_dictionary_t cfg;
        prop_object_t obj;

        cfg = load_keys();
        if (cfg == NULL)
                return NULL;

        obj = prop_dictionary_get(cfg, bt_ntoa(laddr, NULL));
        if (obj == NULL || prop_object_type(obj) != PROP_TYPE_DICTIONARY) {
                prop_object_release(cfg);
                return NULL;
        }

        obj = prop_dictionary_get(obj, bt_ntoa(raddr, NULL));
        if (obj == NULL || prop_object_type(obj) != PROP_TYPE_DATA
            || prop_data_size(obj) != sizeof(key)) {
                prop_object_release(cfg);
                return NULL;
        }

        memcpy(key, prop_data_value(obj), sizeof(key));
        prop_object_release(cfg);
        return key;
}

void
save_key(bdaddr_t *laddr, bdaddr_t *raddr, uint8_t *key)
{
        prop_dictionary_t cfg, dev;
        prop_data_t dat;
        char *xml;
        int fd;
        size_t len;

        cfg = load_keys();
        if (cfg == NULL) {
                cfg = prop_dictionary_create();
                if (cfg == NULL) {
                        syslog(LOG_ERR, "prop_dictionary_create() failed: %m");
                        return;
                }
        }

        dev = prop_dictionary_get(cfg, bt_ntoa(laddr, NULL));
        if (dev == NULL) {
                dev = prop_dictionary_create();
                if (dev == NULL) {
                        syslog(LOG_ERR, "prop_dictionary_create() failed: %m");
                        prop_object_release(cfg);
                        return;
                }

                if (!prop_dictionary_set(cfg, bt_ntoa(laddr, NULL), dev)) {
                        syslog(LOG_ERR, "prop_dictionary_set() failed: %m");
                        prop_object_release(dev);
                        prop_object_release(cfg);
                        return;
                }

                prop_object_release(dev);
        }

        dat = prop_data_create_nocopy(key, HCI_KEY_SIZE);
        if (dat == NULL) {
                syslog(LOG_ERR, "Cannot create data object: %m");
                prop_object_release(cfg);
                return;
        }

        if (!prop_dictionary_set(dev, bt_ntoa(raddr, NULL), dat)) {
                syslog(LOG_ERR, "prop_dictionary_set() failed: %m");
                prop_object_release(dat);
                prop_object_release(cfg);
                return;
        }

        prop_object_release(dat);

        xml = prop_dictionary_externalize(cfg);
        if (xml == NULL) {
                syslog(LOG_ERR, "prop_dictionary_externalize() failed: %m");
                prop_object_release(cfg);
                return;
        }

        prop_object_release(cfg);

        fd = open(new_key_file, O_WRONLY|O_TRUNC|O_CREAT|O_EXLOCK, 0600);
        if (fd < 0) {
                syslog(LOG_ERR, "Cannot open new keyfile %s: %m", key_file);
                free(xml);
                return;
        }

        len = strlen(xml);
        if ((size_t)write(fd, xml, len) != len) {
                syslog(LOG_ERR, "Write of keyfile failed: %m");
                free(xml);
                close(fd);
                unlink(new_key_file);
                return;
        }

        free(xml);
        close(fd);

        if (rename(new_key_file, key_file) < 0) {
                syslog(LOG_ERR, "rename(%s, %s) failed: %m",
                        new_key_file, key_file);

                unlink(new_key_file);
        }
}