Home | History | Annotate | Line # | Download | only in bthcid
      1 /*	$NetBSD: client.c,v 1.6 2024/09/07 13:57:25 mlelstv Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2006 Itronix Inc.
      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  * 3. The name of Itronix Inc. may not be used to endorse
     16  *    or promote products derived from this software without specific
     17  *    prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY
     23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     26  * ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 __RCSID("$NetBSD: client.c,v 1.6 2024/09/07 13:57:25 mlelstv Exp $");
     34 
     35 #include <sys/ioctl.h>
     36 #include <sys/queue.h>
     37 #include <sys/time.h>
     38 #include <sys/stat.h>
     39 #include <sys/un.h>
     40 #include <bluetooth.h>
     41 #include <errno.h>
     42 #include <event.h>
     43 #include <fcntl.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 #include <syslog.h>
     47 #include <unistd.h>
     48 
     49 #include "bthcid.h"
     50 
     51 /*
     52  * A client is anybody who connects to our control socket to
     53  * receive PIN requests.
     54  */
     55 struct client {
     56 	struct event		ev;
     57 	int			fd;		/* client descriptor */
     58 	LIST_ENTRY(client)	next;
     59 };
     60 
     61 /*
     62  * PIN cache items are made when we have sent a client pin
     63  * request. The event is used to expire the item.
     64  */
     65 struct item {
     66 	struct event	 ev;
     67 	bdaddr_t	 laddr;			/* local device BDADDR */
     68 	bdaddr_t	 raddr;			/* remote device BDADDR */
     69 	uint8_t		 pin[HCI_PIN_SIZE];	/* PIN */
     70 	int		 hci;			/* HCI socket */
     71 	LIST_ENTRY(item) next;
     72 };
     73 
     74 static struct event		control_ev;
     75 
     76 static LIST_HEAD(,client)	client_list;
     77 static LIST_HEAD(,item)		item_list;
     78 
     79 static void process_control	(int, short, void *);
     80 static void process_client	(int, short, void *);
     81 static void process_item	(int, short, void *);
     82 
     83 #define PIN_REQUEST_TIMEOUT	30	/* Request is valid */
     84 #define PIN_TIMEOUT		300	/* PIN is valid */
     85 
     86 int
     87 init_control(const char *name, mode_t mode)
     88 {
     89 	struct sockaddr_un	un;
     90 	int			ctl;
     91 
     92 	LIST_INIT(&client_list);
     93 	LIST_INIT(&item_list);
     94 
     95 	if (name == NULL)
     96 		return 0;
     97 
     98 	if (unlink(name) < 0 && errno != ENOENT)
     99 		return -1;
    100 
    101 	ctl = socket(PF_LOCAL, SOCK_STREAM, 0);
    102 	if (ctl < 0)
    103 		return -1;
    104 
    105 	memset(&un, 0, sizeof(un));
    106 	un.sun_len = sizeof(un);
    107 	un.sun_family = AF_LOCAL;
    108 	strlcpy(un.sun_path, name, sizeof(un.sun_path));
    109 	if (bind(ctl, (struct sockaddr *)&un, sizeof(un)) < 0) {
    110 		close(ctl);
    111 		return -1;
    112 	}
    113 
    114 	if (chmod(name, mode) < 0) {
    115 		close(ctl);
    116 		unlink(name);
    117 		return -1;
    118 	}
    119 
    120 	if (listen(ctl, 10) < 0) {
    121 		close(ctl);
    122 		unlink(name);
    123 		return -1;
    124 	}
    125 
    126 	event_set(&control_ev, ctl, EV_READ | EV_PERSIST, process_control, NULL);
    127 	if (event_add(&control_ev, NULL) < 0) {
    128 		close(ctl);
    129 		unlink(name);
    130 		return -1;
    131 	}
    132 
    133 	return 0;
    134 }
    135 
    136 /* Process control socket event */
    137 static void
    138 process_control(int sock, short ev, void *arg)
    139 {
    140 	struct sockaddr_un	un;
    141 	socklen_t		n;
    142 	int			fd;
    143 	struct client		*cl;
    144 
    145 	n = sizeof(un);
    146 	fd = accept(sock, (struct sockaddr *)&un, &n);
    147 	if (fd < 0) {
    148 		syslog(LOG_ERR, "Could not accept PIN client connection");
    149 		return;
    150 	}
    151 
    152 	n = 1;
    153 	if (ioctl(fd, FIONBIO, &n) < 0) {
    154 		syslog(LOG_ERR, "Could not set non blocking IO for client");
    155 		close(fd);
    156 		return;
    157 	}
    158 
    159 	cl = malloc(sizeof(struct client));
    160 	if (cl == NULL) {
    161 		syslog(LOG_ERR, "Could not malloc client");
    162 		close(fd);
    163 		return;
    164 	}
    165 
    166 	memset(cl, 0, sizeof(struct client));
    167 	cl->fd = fd;
    168 
    169 	event_set(&cl->ev, fd, EV_READ | EV_PERSIST, process_client, cl);
    170 	if (event_add(&cl->ev, NULL) < 0) {
    171 		syslog(LOG_ERR, "Could not add client event");
    172 		free(cl);
    173 		close(fd);
    174 		return;
    175 	}
    176 
    177 	syslog(LOG_DEBUG, "New Client");
    178 	LIST_INSERT_HEAD(&client_list, cl, next);
    179 }
    180 
    181 /* Process client response packet */
    182 static void
    183 process_client(int sock, short ev, void *arg)
    184 {
    185 	bthcid_pin_response_t	 rp;
    186 	struct timeval		 tv;
    187 	struct sockaddr_bt	 sa;
    188 	struct client		*cl = arg;
    189 	struct item		*item;
    190 	int			 n;
    191 
    192 	n = recv(sock, &rp, sizeof(rp), 0);
    193 	if (n != sizeof(rp)) {
    194 		if (n != 0)
    195 			syslog(LOG_ERR, "Bad Client");
    196 
    197 		close(sock);
    198 		LIST_REMOVE(cl, next);
    199 		free(cl);
    200 
    201 		syslog(LOG_DEBUG, "Client Closed");
    202 		return;
    203 	}
    204 
    205 	syslog(LOG_DEBUG, "Received PIN for %s", bt_ntoa(&rp.raddr, NULL));
    206 
    207 	LIST_FOREACH(item, &item_list, next) {
    208 		if (bdaddr_same(&rp.laddr, &item->laddr) == 0
    209 		    || bdaddr_same(&rp.raddr, &item->raddr) == 0)
    210 			continue;
    211 
    212 		evtimer_del(&item->ev);
    213 		if (item->hci != -1) {
    214 			memset(&sa, 0, sizeof(sa));
    215 			sa.bt_len = sizeof(sa);
    216 			sa.bt_family = AF_BLUETOOTH;
    217 			bdaddr_copy(&sa.bt_bdaddr, &item->laddr);
    218 
    219 			send_pin_code_reply(item->hci, &sa, &item->raddr, rp.pin);
    220 			LIST_REMOVE(item, next);
    221 			free(item);
    222 			return;
    223 		}
    224 		goto newpin;
    225 	}
    226 
    227 	item = malloc(sizeof(struct item));
    228 	if (item == NULL) {
    229 		syslog(LOG_ERR, "Item allocation failed");
    230 		return;
    231 	}
    232 
    233 	memset(item, 0, sizeof(struct item));
    234 	bdaddr_copy(&item->laddr, &rp.laddr);
    235 	bdaddr_copy(&item->raddr, &rp.raddr);
    236 	evtimer_set(&item->ev, process_item, item);
    237 	LIST_INSERT_HEAD(&item_list, item, next);
    238 
    239 newpin:
    240 	syslog(LOG_DEBUG, "Caching PIN for %s", bt_ntoa(&rp.raddr, NULL));
    241 
    242 	memcpy(item->pin, rp.pin, HCI_PIN_SIZE);
    243 	item->hci = -1;
    244 
    245 	tv.tv_sec = PIN_TIMEOUT;
    246 	tv.tv_usec = 0;
    247 
    248 	if (evtimer_add(&item->ev, &tv) < 0) {
    249 		syslog(LOG_ERR, "Cannot add event timer for item");
    250 		LIST_REMOVE(item, next);
    251 		free(item);
    252 	}
    253 }
    254 
    255 /* Send PIN request to client */
    256 int
    257 send_client_request(bdaddr_t *laddr, bdaddr_t *raddr, int hci)
    258 {
    259 	bthcid_pin_request_t	 cp;
    260 	struct client		*cl;
    261 	struct item		*item;
    262 	int			 n = 0;
    263 	struct timeval		 tv;
    264 
    265 	memset(&cp, 0, sizeof(cp));
    266 	bdaddr_copy(&cp.laddr, laddr);
    267 	bdaddr_copy(&cp.raddr, raddr);
    268 	cp.time = PIN_REQUEST_TIMEOUT;
    269 
    270 	LIST_FOREACH(cl, &client_list, next) {
    271 		if (send(cl->fd, &cp, sizeof(cp), MSG_NOSIGNAL) != sizeof(cp))
    272 			syslog(LOG_ERR, "send PIN request failed");
    273 		else
    274 			n++;
    275 	}
    276 
    277 	if (n == 0)
    278 		return 0;
    279 
    280 	syslog(LOG_DEBUG, "Sent PIN requests to %d client%s.",
    281 				n, (n == 1 ? "" : "s"));
    282 
    283 	item = malloc(sizeof(struct item));
    284 	if (item == NULL) {
    285 		syslog(LOG_ERR, "Cannot allocate PIN request item");
    286 		return 0;
    287 	}
    288 
    289 	memset(item, 0, sizeof(struct item));
    290 	bdaddr_copy(&item->laddr, laddr);
    291 	bdaddr_copy(&item->raddr, raddr);
    292 	item->hci = hci;
    293 	evtimer_set(&item->ev, process_item, item);
    294 
    295 	tv.tv_sec = cp.time;
    296 	tv.tv_usec = 0;
    297 
    298 	if (evtimer_add(&item->ev, &tv) < 0) {
    299 		syslog(LOG_ERR, "Cannot add request timer");
    300 		free(item);
    301 		return 0;
    302 	}
    303 
    304 	LIST_INSERT_HEAD(&item_list, item, next);
    305 	return 1;
    306 }
    307 
    308 /* Process item event (by expiring it) */
    309 static void
    310 process_item(int fd, short ev, void *arg)
    311 {
    312 	struct item *item = arg;
    313 
    314 	syslog(LOG_DEBUG, "PIN for %s expired", bt_ntoa(&item->raddr, NULL));
    315 	LIST_REMOVE(item, next);
    316 	evtimer_del(&item->ev);
    317 	free(item);
    318 }
    319 
    320 /* lookup PIN in item cache */
    321 uint8_t *
    322 lookup_pin(bdaddr_t *laddr, bdaddr_t *raddr)
    323 {
    324 	static uint8_t pin[HCI_PIN_SIZE];
    325 	struct item *item;
    326 
    327 	LIST_FOREACH(item, &item_list, next) {
    328 		if (bdaddr_same(raddr, &item->raddr) == 0)
    329 			continue;
    330 
    331 		if (bdaddr_same(laddr, &item->laddr) == 0
    332 		    && bdaddr_any(&item->laddr) == 0)
    333 			continue;
    334 
    335 		if (item->hci >= 0)
    336 			break;
    337 
    338 		syslog(LOG_DEBUG, "Matched PIN from cache");
    339 		memcpy(pin, item->pin, sizeof(pin));
    340 
    341 		LIST_REMOVE(item, next);
    342 		evtimer_del(&item->ev);
    343 		free(item);
    344 
    345 		return pin;
    346 	}
    347 
    348 	return NULL;
    349 }
    350