/*      $NetBSD: client.c,v 1.7 2012/10/14 08:31:35 plunky Exp $        */

/*-
 * Copyright (c) 2008-2009 Iain Hibbert
 * 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.
 *
 * 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/cdefs.h>
__RCSID("$NetBSD: client.c,v 1.7 2012/10/14 08:31:35 plunky Exp $");

#include <bluetooth.h>
#include <errno.h>
#include <sdp.h>
#include <unistd.h>

#include "btpand.h"
#include "bnep.h"

__dead static void client_down(channel_t *);
static void client_query(void);

void
client_init(void)
{
        struct sockaddr_bt sa;
        channel_t *chan;
        socklen_t len;
        int fd, n;
        uint16_t mru, mtu;

        if (bdaddr_any(&remote_bdaddr))
                return;

        if (service_type)
                client_query();

        fd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
        if (fd == -1) {
                log_err("Could not open L2CAP socket: %m");
                exit(EXIT_FAILURE);
        }

        memset(&sa, 0, sizeof(sa));
        sa.bt_family = AF_BLUETOOTH;
        sa.bt_len = sizeof(sa);
        bdaddr_copy(&sa.bt_bdaddr, &local_bdaddr);
        if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
                log_err("Could not bind client socket: %m");
                exit(EXIT_FAILURE);
        }

        if (setsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_LM,
            &l2cap_mode, sizeof(l2cap_mode)) == -1) {
                log_err("Could not set link mode (0x%4.4x): %m", l2cap_mode);
                exit(EXIT_FAILURE);
        }

        mru = BNEP_MTU_MIN;
        if (setsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_IMTU,
            &mru, sizeof(mru)) == -1) {
                log_err("Could not set L2CAP IMTU (%d): %m", mru);
                exit(EXIT_FAILURE);
        }

        log_info("Opening connection to service 0x%4.4x at %s",
            service_class, bt_ntoa(&remote_bdaddr, NULL));

        sa.bt_psm = l2cap_psm;
        bdaddr_copy(&sa.bt_bdaddr, &remote_bdaddr);
        if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
                log_err("Could not connect: %m");
                exit(EXIT_FAILURE);
        }

        len = sizeof(mru);
        if (getsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_IMTU, &mru, &len) == -1) {
                log_err("Could not get IMTU: %m");
                exit(EXIT_FAILURE);
        }
        if (mru < BNEP_MTU_MIN) {
                log_err("L2CAP IMTU too small (%d)", mru);
                exit(EXIT_FAILURE);
        }

        len = sizeof(n);
        if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &n, &len) == -1) {
                log_err("Could not read SO_RCVBUF");
                exit(EXIT_FAILURE);
        }
        if (n < 10 * mru) {
                n = 10 * mru;
                if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &n, sizeof(n)) == -1)
                        log_info("Could not increase SO_RCVBUF (to %d)", n);
        }

        len = sizeof(mtu);
        if (getsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_OMTU, &mtu, &len) == -1) {
                log_err("Could not get L2CAP OMTU: %m");
                exit(EXIT_FAILURE);
        }
        if (mtu < BNEP_MTU_MIN) {
                log_err("L2CAP OMTU too small (%d)", mtu);
                exit(EXIT_FAILURE);
        }

        len = sizeof(n);
        if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &n, &len) == -1) {
                log_err("Could not get socket send buffer size: %m");
                close(fd);
                return;
        }
        if (n < (mtu * 2)) {
                n = mtu * 2;
                if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &n, sizeof(n)) == -1) {
                        log_err("Could not set socket send buffer size (%d): %m", n);
                        close(fd);
                        return;
                }
        }
        n = mtu;
        if (setsockopt(fd, SOL_SOCKET, SO_SNDLOWAT, &n, sizeof(n)) == -1) {
                log_err("Could not set socket low water mark (%d): %m", n);
                close(fd);
                return;
        }

        chan = channel_alloc();
        if (chan == NULL)
                exit(EXIT_FAILURE);

        chan->send = bnep_send;
        chan->recv = bnep_recv;
        chan->down = client_down;
        chan->mru = mru;
        chan->mtu = mtu;
        b2eaddr(chan->raddr, &remote_bdaddr);
        b2eaddr(chan->laddr, &local_bdaddr);
        chan->state = CHANNEL_WAIT_CONNECT_RSP;
        channel_timeout(chan, 10);
        if (!channel_open(chan, fd))
                exit(EXIT_FAILURE);

        bnep_send_control(chan, BNEP_SETUP_CONNECTION_REQUEST,
            2, service_class, SDP_SERVICE_CLASS_PANU);
}

static void
client_down(channel_t *chan)
{

        log_err("Client connection shut down, exiting");
        exit(EXIT_FAILURE);
}

static void
client_query(void)
{
        uint8_t buf[12];        /* enough for SSP and AIL both */
        sdp_session_t ss;
        sdp_data_t ssp, ail, rsp, rec, value, pdl, seq;
        uintmax_t psm;
        uint16_t attr;
        bool rv;

        ss = sdp_open(&local_bdaddr, &remote_bdaddr);
        if (ss == NULL) {
                log_err("%s: %m", service_type);
                exit(EXIT_FAILURE);
        }

        log_info("Searching for %s service at %s",
            service_type, bt_ntoa(&remote_bdaddr, NULL));

        seq.next = buf;
        seq.end = buf + sizeof(buf);

        /*
         * build ServiceSearchPattern (9 bytes)
         *
         *      uuid16  "service_class"
         *      uuid16  L2CAP
         *      uuid16  BNEP
         */
        ssp.next = seq.next;
        sdp_put_uuid16(&seq, service_class);
        sdp_put_uuid16(&seq, SDP_UUID_PROTOCOL_L2CAP);
        sdp_put_uuid16(&seq, SDP_UUID_PROTOCOL_BNEP);
        ssp.end = seq.next;

        /*
         * build AttributeIDList (3 bytes)
         *
         *      uint16  ProtocolDescriptorList
         */
        ail.next = seq.next;
        sdp_put_uint16(&seq, SDP_ATTR_PROTOCOL_DESCRIPTOR_LIST);
        ail.end = seq.next;

        rv = sdp_service_search_attribute(ss, &ssp, &ail, &rsp);
        if (!rv) {
                log_err("%s: %m", service_type);
                exit(EXIT_FAILURE);
        }

        /*
         * we expect the response to contain a list of records
         * containing a ProtocolDescriptorList. Find the first
         * one containing L2CAP and BNEP protocols and extract
         * the PSM.
         */
        rv = false;
        while (!rv && sdp_get_seq(&rsp, &rec)) {
                if (!sdp_get_attr(&rec, &attr, &value)
                    || attr != SDP_ATTR_PROTOCOL_DESCRIPTOR_LIST)
                        continue;

                sdp_get_alt(&value, &value);    /* drop any alt header */
                while (!rv && sdp_get_seq(&value, &pdl)) {
                        if (sdp_get_seq(&pdl, &seq)
                            && sdp_match_uuid16(&seq, SDP_UUID_PROTOCOL_L2CAP)
                            && sdp_get_uint(&seq, &psm)
                            && sdp_get_seq(&pdl, &seq)
                            && sdp_match_uuid16(&seq, SDP_UUID_PROTOCOL_BNEP))
                                rv = true;
                }
        }

        sdp_close(ss);

        if (!rv) {
                log_err("%s query failed", service_type);
                exit(EXIT_FAILURE);
        }

        l2cap_psm = (uint16_t)psm;
        log_info("Found PSM %u for service %s", l2cap_psm, service_type);
}