root/libcwiid/bluetooth.c

/* Copyright (C) 2007 L. Donnie Smith <donnie.smith@gatech.edu>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include <stdlib.h>
#include <string.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include "cwiid_internal.h"

/* When filtering wiimotes, in order to avoid having to store the
 * remote names before the blue_dev array is malloced (because we don't
 * yet know how many wiimotes there are, we'll assume there are no more
 * than dev_count, and realloc to the actual number afterwards, since
 * reallocing to a smaller chunk should be fast. */
#define BT_MAX_INQUIRY 256
/* timeout in 2 second units */
int cwiid_get_bdinfo_array(int dev_id, unsigned int timeout, int max_bdinfo,
                           struct cwiid_bdinfo **bdinfo, uint8_t flags)
{
        inquiry_info *dev_list = NULL;
        int max_inquiry;
        int dev_count;
        int sock = -1;
        int bdinfo_count;
        int i, j;
        int err = 0;
        int ret;

        /* NULLify for the benefit of error handling */
        *bdinfo = NULL;

        /* If not given (=-1), get the first available Bluetooth interface */
        if (dev_id == -1) {
                if ((dev_id = hci_get_route(NULL)) == -1) {
                        cwiid_err(NULL, "No Bluetooth interface found");
                        return -1;
                }
        }

        /* Get Bluetooth Device List */
        if ((flags & BT_NO_WIIMOTE_FILTER) && (max_bdinfo != -1)) {
                max_inquiry = max_bdinfo;
        }
        else {
                max_inquiry = BT_MAX_INQUIRY;
        }
        if ((dev_count = hci_inquiry(dev_id, timeout, max_inquiry, NULL,
                                     &dev_list, IREQ_CACHE_FLUSH)) == -1) {
                cwiid_err(NULL, "Bluetooth device inquiry error");
                err = 1;
                goto CODA;
        }

        if (dev_count == 0) {
                bdinfo_count = 0;
                goto CODA;
        }

        /* Open connection to Bluetooth Interface */
        if ((sock = hci_open_dev(dev_id)) == -1) {
                cwiid_err(NULL, "Bluetooth interface open error");
                err = 1;
                goto CODA;
        }

        /* Allocate info list */
        if (max_bdinfo == -1) {
                max_bdinfo = dev_count;
        }
        if ((*bdinfo = malloc(max_bdinfo * sizeof **bdinfo)) == NULL) {
                cwiid_err(NULL, "Memory allocation error (bdinfo array)");
                err = 1;
                goto CODA;
        }

        /* Copy dev_list to bdinfo */
        for (bdinfo_count=i=0; (i < dev_count) && (bdinfo_count < max_bdinfo);
             i++) {
                /* Filter by class */
                if (!(flags & BT_NO_WIIMOTE_FILTER) &&
                  ((dev_list[i].dev_class[0] != WIIMOTE_CLASS_0) ||
                   (dev_list[i].dev_class[1] != WIIMOTE_CLASS_1) ||
                   (dev_list[i].dev_class[2] != WIIMOTE_CLASS_2))) {
                        continue;
                }

                /* timeout (10000) in milliseconds */
                if (hci_read_remote_name(sock, &dev_list[i].bdaddr, BT_NAME_LEN,
                                         (*bdinfo)[bdinfo_count].name, 10000)) {
                        cwiid_err(NULL, "Bluetooth name read error");
                        err = 1;
                        goto CODA;
                }

                /* Filter by name */
                if (!(flags & BT_NO_WIIMOTE_FILTER) &&
                  strncmp((*bdinfo)[bdinfo_count].name, WIIMOTE_NAME, BT_NAME_LEN) &&
                  strncmp((*bdinfo)[bdinfo_count].name, WIIBALANCE_NAME, BT_NAME_LEN)) {
                        continue;
                }

                /* Passed filter, add to bdinfo */
                bacpy(&(*bdinfo)[bdinfo_count].bdaddr, &dev_list[i].bdaddr);
                for (j=0; j<3; j++) {
                        (*bdinfo)[bdinfo_count].btclass[j] =
                                    dev_list[i].dev_class[j];
                }
                bdinfo_count++;
        }

        if (bdinfo_count == 0) {
                free(*bdinfo);
        }
        else if (bdinfo_count < max_bdinfo) {
                if ((*bdinfo = realloc(*bdinfo, bdinfo_count * sizeof **bdinfo))
                  == NULL) {
                        cwiid_err(NULL, "Memory reallocation error (bdinfo array)");
                        err = 1;
                        goto CODA;
                }
        }

CODA:
        if (dev_list) free(dev_list);
        if (sock != -1) hci_close_dev(sock);
        if (err) {
                if (*bdinfo) free(*bdinfo);
                ret = -1;
        }
        else {
                ret = bdinfo_count;
        }
        return ret;
}

int cwiid_find_wiimote(bdaddr_t *bdaddr, int timeout)
{
        struct cwiid_bdinfo *bdinfo;
        int bdinfo_count;

        if (timeout == -1) {
                while ((bdinfo_count = cwiid_get_bdinfo_array(-1, 2, 1, &bdinfo, 0))
                       == 0);
                if (bdinfo_count == -1) {
                        return -1;
                }
        }
        else {
                bdinfo_count = cwiid_get_bdinfo_array(-1, timeout, 1, &bdinfo, 0);
                if (bdinfo_count == -1) {
                        return -1;
                }
                else if (bdinfo_count == 0) {
                        cwiid_err(NULL, "No wiimotes found");
                        return -1;
                }
        }

        bacpy(bdaddr, &bdinfo[0].bdaddr);
        free(bdinfo);
        return 0;
}