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      1 /*	$NetBSD: client.c,v 1.7 2012/10/14 08:31:35 plunky Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2008-2009 Iain Hibbert
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __RCSID("$NetBSD: client.c,v 1.7 2012/10/14 08:31:35 plunky Exp $");
     30 
     31 #include <bluetooth.h>
     32 #include <errno.h>
     33 #include <sdp.h>
     34 #include <unistd.h>
     35 
     36 #include "btpand.h"
     37 #include "bnep.h"
     38 
     39 __dead static void client_down(channel_t *);
     40 static void client_query(void);
     41 
     42 void
     43 client_init(void)
     44 {
     45 	struct sockaddr_bt sa;
     46 	channel_t *chan;
     47 	socklen_t len;
     48 	int fd, n;
     49 	uint16_t mru, mtu;
     50 
     51 	if (bdaddr_any(&remote_bdaddr))
     52 		return;
     53 
     54 	if (service_type)
     55 		client_query();
     56 
     57 	fd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_L2CAP);
     58 	if (fd == -1) {
     59 		log_err("Could not open L2CAP socket: %m");
     60 		exit(EXIT_FAILURE);
     61 	}
     62 
     63 	memset(&sa, 0, sizeof(sa));
     64 	sa.bt_family = AF_BLUETOOTH;
     65 	sa.bt_len = sizeof(sa);
     66 	bdaddr_copy(&sa.bt_bdaddr, &local_bdaddr);
     67 	if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
     68 		log_err("Could not bind client socket: %m");
     69 		exit(EXIT_FAILURE);
     70 	}
     71 
     72 	if (setsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_LM,
     73 	    &l2cap_mode, sizeof(l2cap_mode)) == -1) {
     74 		log_err("Could not set link mode (0x%4.4x): %m", l2cap_mode);
     75 		exit(EXIT_FAILURE);
     76 	}
     77 
     78 	mru = BNEP_MTU_MIN;
     79 	if (setsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_IMTU,
     80 	    &mru, sizeof(mru)) == -1) {
     81 		log_err("Could not set L2CAP IMTU (%d): %m", mru);
     82 		exit(EXIT_FAILURE);
     83 	}
     84 
     85 	log_info("Opening connection to service 0x%4.4x at %s",
     86 	    service_class, bt_ntoa(&remote_bdaddr, NULL));
     87 
     88 	sa.bt_psm = l2cap_psm;
     89 	bdaddr_copy(&sa.bt_bdaddr, &remote_bdaddr);
     90 	if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
     91 		log_err("Could not connect: %m");
     92 		exit(EXIT_FAILURE);
     93 	}
     94 
     95 	len = sizeof(mru);
     96 	if (getsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_IMTU, &mru, &len) == -1) {
     97 		log_err("Could not get IMTU: %m");
     98 		exit(EXIT_FAILURE);
     99 	}
    100 	if (mru < BNEP_MTU_MIN) {
    101 		log_err("L2CAP IMTU too small (%d)", mru);
    102 		exit(EXIT_FAILURE);
    103 	}
    104 
    105 	len = sizeof(n);
    106 	if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &n, &len) == -1) {
    107 		log_err("Could not read SO_RCVBUF");
    108 		exit(EXIT_FAILURE);
    109 	}
    110 	if (n < 10 * mru) {
    111 		n = 10 * mru;
    112 		if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &n, sizeof(n)) == -1)
    113 			log_info("Could not increase SO_RCVBUF (to %d)", n);
    114 	}
    115 
    116 	len = sizeof(mtu);
    117 	if (getsockopt(fd, BTPROTO_L2CAP, SO_L2CAP_OMTU, &mtu, &len) == -1) {
    118 		log_err("Could not get L2CAP OMTU: %m");
    119 		exit(EXIT_FAILURE);
    120 	}
    121 	if (mtu < BNEP_MTU_MIN) {
    122 		log_err("L2CAP OMTU too small (%d)", mtu);
    123 		exit(EXIT_FAILURE);
    124 	}
    125 
    126 	len = sizeof(n);
    127 	if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &n, &len) == -1) {
    128 		log_err("Could not get socket send buffer size: %m");
    129 		close(fd);
    130 		return;
    131 	}
    132 	if (n < (mtu * 2)) {
    133 		n = mtu * 2;
    134 		if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &n, sizeof(n)) == -1) {
    135 			log_err("Could not set socket send buffer size (%d): %m", n);
    136 			close(fd);
    137 			return;
    138 		}
    139 	}
    140 	n = mtu;
    141 	if (setsockopt(fd, SOL_SOCKET, SO_SNDLOWAT, &n, sizeof(n)) == -1) {
    142 		log_err("Could not set socket low water mark (%d): %m", n);
    143 		close(fd);
    144 		return;
    145 	}
    146 
    147 	chan = channel_alloc();
    148 	if (chan == NULL)
    149 		exit(EXIT_FAILURE);
    150 
    151 	chan->send = bnep_send;
    152 	chan->recv = bnep_recv;
    153 	chan->down = client_down;
    154 	chan->mru = mru;
    155 	chan->mtu = mtu;
    156 	b2eaddr(chan->raddr, &remote_bdaddr);
    157 	b2eaddr(chan->laddr, &local_bdaddr);
    158 	chan->state = CHANNEL_WAIT_CONNECT_RSP;
    159 	channel_timeout(chan, 10);
    160 	if (!channel_open(chan, fd))
    161 		exit(EXIT_FAILURE);
    162 
    163 	bnep_send_control(chan, BNEP_SETUP_CONNECTION_REQUEST,
    164 	    2, service_class, SDP_SERVICE_CLASS_PANU);
    165 }
    166 
    167 static void
    168 client_down(channel_t *chan)
    169 {
    170 
    171 	log_err("Client connection shut down, exiting");
    172 	exit(EXIT_FAILURE);
    173 }
    174 
    175 static void
    176 client_query(void)
    177 {
    178 	uint8_t buf[12];	/* enough for SSP and AIL both */
    179 	sdp_session_t ss;
    180 	sdp_data_t ssp, ail, rsp, rec, value, pdl, seq;
    181 	uintmax_t psm;
    182 	uint16_t attr;
    183 	bool rv;
    184 
    185 	ss = sdp_open(&local_bdaddr, &remote_bdaddr);
    186 	if (ss == NULL) {
    187 		log_err("%s: %m", service_type);
    188 		exit(EXIT_FAILURE);
    189 	}
    190 
    191 	log_info("Searching for %s service at %s",
    192 	    service_type, bt_ntoa(&remote_bdaddr, NULL));
    193 
    194 	seq.next = buf;
    195 	seq.end = buf + sizeof(buf);
    196 
    197 	/*
    198 	 * build ServiceSearchPattern (9 bytes)
    199 	 *
    200 	 *	uuid16	"service_class"
    201 	 *	uuid16	L2CAP
    202 	 *	uuid16	BNEP
    203 	 */
    204 	ssp.next = seq.next;
    205 	sdp_put_uuid16(&seq, service_class);
    206 	sdp_put_uuid16(&seq, SDP_UUID_PROTOCOL_L2CAP);
    207 	sdp_put_uuid16(&seq, SDP_UUID_PROTOCOL_BNEP);
    208 	ssp.end = seq.next;
    209 
    210 	/*
    211 	 * build AttributeIDList (3 bytes)
    212 	 *
    213 	 *	uint16	ProtocolDescriptorList
    214 	 */
    215 	ail.next = seq.next;
    216 	sdp_put_uint16(&seq, SDP_ATTR_PROTOCOL_DESCRIPTOR_LIST);
    217 	ail.end = seq.next;
    218 
    219 	rv = sdp_service_search_attribute(ss, &ssp, &ail, &rsp);
    220 	if (!rv) {
    221 		log_err("%s: %m", service_type);
    222 		exit(EXIT_FAILURE);
    223 	}
    224 
    225 	/*
    226 	 * we expect the response to contain a list of records
    227 	 * containing a ProtocolDescriptorList. Find the first
    228 	 * one containing L2CAP and BNEP protocols and extract
    229 	 * the PSM.
    230 	 */
    231 	rv = false;
    232 	while (!rv && sdp_get_seq(&rsp, &rec)) {
    233 		if (!sdp_get_attr(&rec, &attr, &value)
    234 		    || attr != SDP_ATTR_PROTOCOL_DESCRIPTOR_LIST)
    235 			continue;
    236 
    237 		sdp_get_alt(&value, &value);	/* drop any alt header */
    238 		while (!rv && sdp_get_seq(&value, &pdl)) {
    239 			if (sdp_get_seq(&pdl, &seq)
    240 			    && sdp_match_uuid16(&seq, SDP_UUID_PROTOCOL_L2CAP)
    241 			    && sdp_get_uint(&seq, &psm)
    242 			    && sdp_get_seq(&pdl, &seq)
    243 			    && sdp_match_uuid16(&seq, SDP_UUID_PROTOCOL_BNEP))
    244 				rv = true;
    245 		}
    246 	}
    247 
    248 	sdp_close(ss);
    249 
    250 	if (!rv) {
    251 		log_err("%s query failed", service_type);
    252 		exit(EXIT_FAILURE);
    253 	}
    254 
    255 	l2cap_psm = (uint16_t)psm;
    256 	log_info("Found PSM %u for service %s", l2cap_psm, service_type);
    257 }
    258