1 /* $NetBSD: hci.c,v 1.4 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 * Copyright (c) 2001-2002 Maksim Yevmenkin <m_evmenkin@yahoo.com>
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 * notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 * notice, this list of conditions and the following disclaimer in the
42 * documentation and/or other materials provided with the distribution.
43 *
44 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
45 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
48 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
49 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
50 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
52 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
53 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54 * SUCH DAMAGE.
55 */
56
57 #include <sys/cdefs.h>
58 __RCSID("$NetBSD: hci.c,v 1.4 2024/09/07 13:57:25 mlelstv Exp $");
59
60 #include <sys/ioctl.h>
61 #include <sys/time.h>
62 #include <bluetooth.h>
63 #include <errno.h>
64 #include <event.h>
65 #include <string.h>
66 #include <syslog.h>
67 #include <unistd.h>
68
69 #include "bthcid.h"
70
71 static struct event hci_ev;
72
73 static void process_hci
74 (int, short, void *);
75
76 static int process_pin_code_request_event
77 (int, struct sockaddr_bt *, bdaddr_t *);
78 static int process_link_key_request_event
79 (int, struct sockaddr_bt *, bdaddr_t *);
80 static int process_link_key_notification_event
81 (int, struct sockaddr_bt *, hci_link_key_notification_ep *);
82
83 static int send_link_key_reply
84 (int, struct sockaddr_bt *, bdaddr_t *, uint8_t *);
85 static int send_hci_cmd
86 (int, struct sockaddr_bt *, uint16_t, size_t, void *);
87
88 static char dev_name[HCI_DEVNAME_SIZE];
89
90 /* Initialise HCI Events */
91 int
init_hci(const char * device)92 init_hci(const char *device)
93 {
94 struct bt_devfilter filter;
95 int hci;
96
97 hci = bt_devopen(device, 0);
98 if (hci < 0)
99 return -1;
100
101 memset(&filter, 0, sizeof(filter));
102 bt_devfilter_pkt_set(&filter, HCI_EVENT_PKT);
103 bt_devfilter_evt_set(&filter, HCI_EVENT_PIN_CODE_REQ);
104 bt_devfilter_evt_set(&filter, HCI_EVENT_LINK_KEY_REQ);
105 bt_devfilter_evt_set(&filter, HCI_EVENT_LINK_KEY_NOTIFICATION);
106 if (bt_devfilter(hci, &filter, NULL) < 0) {
107 close(hci);
108 return -1;
109 }
110
111 event_set(&hci_ev, hci, EV_READ | EV_PERSIST, process_hci, NULL);
112 if (event_add(&hci_ev, NULL) < 0) {
113 close(hci);
114 return -1;
115 }
116
117 return 0;
118 }
119
120 /* Process an HCI event */
121 static void
process_hci(int sock,short ev,void * arg)122 process_hci(int sock, short ev, void *arg)
123 {
124 char buffer[HCI_EVENT_PKT_SIZE];
125 hci_event_hdr_t *event = (hci_event_hdr_t *)buffer;
126 struct sockaddr_bt addr;
127 int n;
128 socklen_t size;
129
130 size = sizeof(addr);
131 n = recvfrom(sock, buffer, sizeof(buffer), 0,
132 (struct sockaddr *) &addr, &size);
133 if (n < 0) {
134 syslog(LOG_ERR, "Could not receive from HCI socket: %m");
135 return;
136 }
137
138 if (event->type != HCI_EVENT_PKT) {
139 syslog(LOG_ERR, "Received unexpected HCI packet, "
140 "type=%#x", event->type);
141
142 return;
143 }
144
145 if (!bt_devname(dev_name, &addr.bt_bdaddr))
146 strlcpy(dev_name, "unknown", sizeof(dev_name));
147
148 switch (event->event) {
149 case HCI_EVENT_PIN_CODE_REQ:
150 process_pin_code_request_event(sock, &addr,
151 (bdaddr_t *)(event + 1));
152 break;
153
154 case HCI_EVENT_LINK_KEY_REQ:
155 process_link_key_request_event(sock, &addr,
156 (bdaddr_t *)(event + 1));
157 break;
158
159 case HCI_EVENT_LINK_KEY_NOTIFICATION:
160 process_link_key_notification_event(sock, &addr,
161 (hci_link_key_notification_ep *)(event + 1));
162 break;
163
164 default:
165 syslog(LOG_ERR, "Received unexpected HCI event, "
166 "event=%#x", event->event);
167 break;
168 }
169
170 return;
171 }
172
173 /* Process PIN_Code_Request event */
174 static int
process_pin_code_request_event(int sock,struct sockaddr_bt * addr,bdaddr_t * bdaddr)175 process_pin_code_request_event(int sock, struct sockaddr_bt *addr,
176 bdaddr_t *bdaddr)
177 {
178 uint8_t *pin;
179
180 syslog(LOG_DEBUG, "Got PIN_Code_Request event from %s, "
181 "remote bdaddr %s",
182 dev_name,
183 bt_ntoa(bdaddr, NULL));
184
185 pin = lookup_pin(&addr->bt_bdaddr, bdaddr);
186 if (pin != NULL)
187 return send_pin_code_reply(sock, addr, bdaddr, pin);
188
189 if (send_client_request(&addr->bt_bdaddr, bdaddr, sock) == 0)
190 return send_pin_code_reply(sock, addr, bdaddr, NULL);
191
192 return 0;
193 }
194
195 /* Process Link_Key_Request event */
196 static int
process_link_key_request_event(int sock,struct sockaddr_bt * addr,bdaddr_t * bdaddr)197 process_link_key_request_event(int sock, struct sockaddr_bt *addr,
198 bdaddr_t *bdaddr)
199 {
200 uint8_t *key;
201
202 syslog(LOG_DEBUG,
203 "Got Link_Key_Request event from %s, remote bdaddr %s",
204 dev_name, bt_ntoa(bdaddr, NULL));
205
206 key = lookup_key(&addr->bt_bdaddr, bdaddr);
207
208 if (key != NULL) {
209 syslog(LOG_DEBUG, "Found Key, remote bdaddr %s",
210 bt_ntoa(bdaddr, NULL));
211
212 return send_link_key_reply(sock, addr, bdaddr, key);
213 }
214
215 syslog(LOG_DEBUG, "Could not find link key for remote bdaddr %s",
216 bt_ntoa(bdaddr, NULL));
217
218 return send_link_key_reply(sock, addr, bdaddr, NULL);
219 }
220
221 /* Send PIN_Code_[Negative]_Reply */
222 int
send_pin_code_reply(int sock,struct sockaddr_bt * addr,bdaddr_t * bdaddr,uint8_t * pin)223 send_pin_code_reply(int sock, struct sockaddr_bt *addr,
224 bdaddr_t *bdaddr, uint8_t *pin)
225 {
226 int n;
227
228 if (pin != NULL) {
229 hci_pin_code_rep_cp cp;
230
231 syslog(LOG_DEBUG, "Sending PIN_Code_Reply to %s "
232 "for remote bdaddr %s",
233 dev_name,
234 bt_ntoa(bdaddr, NULL));
235
236 bdaddr_copy(&cp.bdaddr, bdaddr);
237 memcpy(cp.pin, pin, HCI_PIN_SIZE);
238
239 n = HCI_PIN_SIZE;
240 while (n > 0 && pin[n - 1] == 0)
241 n--;
242 cp.pin_size = n;
243
244 n = send_hci_cmd(sock, addr,
245 HCI_CMD_PIN_CODE_REP, sizeof(cp), &cp);
246
247 } else {
248 syslog(LOG_DEBUG, "Sending PIN_Code_Negative_Reply to %s "
249 "for remote bdaddr %s",
250 dev_name,
251 bt_ntoa(bdaddr, NULL));
252
253 n = send_hci_cmd(sock, addr, HCI_CMD_PIN_CODE_NEG_REP,
254 sizeof(bdaddr_t), bdaddr);
255 }
256
257 if (n < 0) {
258 syslog(LOG_ERR, "Could not send PIN code reply to %s "
259 "for remote bdaddr %s: %m",
260 dev_name,
261 bt_ntoa(bdaddr, NULL));
262
263 return -1;
264 }
265
266 return 0;
267 }
268
269 /* Send Link_Key_[Negative]_Reply */
270 static int
send_link_key_reply(int sock,struct sockaddr_bt * addr,bdaddr_t * bdaddr,uint8_t * key)271 send_link_key_reply(int sock, struct sockaddr_bt *addr,
272 bdaddr_t *bdaddr, uint8_t *key)
273 {
274 int n;
275
276 if (key != NULL) {
277 hci_link_key_rep_cp cp;
278
279 bdaddr_copy(&cp.bdaddr, bdaddr);
280 memcpy(&cp.key, key, sizeof(cp.key));
281
282 syslog(LOG_DEBUG, "Sending Link_Key_Reply to %s "
283 "for remote bdaddr %s",
284 dev_name, bt_ntoa(bdaddr, NULL));
285
286 n = send_hci_cmd(sock, addr, HCI_CMD_LINK_KEY_REP, sizeof(cp), &cp);
287 } else {
288 hci_link_key_neg_rep_cp cp;
289
290 bdaddr_copy(&cp.bdaddr, bdaddr);
291
292 syslog(LOG_DEBUG, "Sending Link_Key_Negative_Reply to %s "
293 "for remote bdaddr %s",
294 dev_name, bt_ntoa(bdaddr, NULL));
295
296 n = send_hci_cmd(sock, addr, HCI_CMD_LINK_KEY_NEG_REP, sizeof(cp), &cp);
297 }
298
299 if (n < 0) {
300 syslog(LOG_ERR, "Could not send link key reply to %s "
301 "for remote bdaddr %s: %m",
302 dev_name, bt_ntoa(bdaddr, NULL));
303 return -1;
304 }
305
306 return 0;
307 }
308
309 /* Process Link_Key_Notification event */
310 static int
process_link_key_notification_event(int sock,struct sockaddr_bt * addr,hci_link_key_notification_ep * ep)311 process_link_key_notification_event(int sock, struct sockaddr_bt *addr,
312 hci_link_key_notification_ep *ep)
313 {
314
315 syslog(LOG_DEBUG, "Got Link_Key_Notification event from %s, "
316 "remote bdaddr %s",
317 dev_name,
318 bt_ntoa(&ep->bdaddr, NULL));
319
320 save_key(&addr->bt_bdaddr, &ep->bdaddr, ep->key);
321 return 0;
322 }
323
324 /* Send HCI Command Packet to socket */
325 static int
send_hci_cmd(int sock,struct sockaddr_bt * sa,uint16_t opcode,size_t len,void * buf)326 send_hci_cmd(int sock, struct sockaddr_bt *sa, uint16_t opcode, size_t len, void *buf)
327 {
328 char msg[HCI_CMD_PKT_SIZE];
329 hci_cmd_hdr_t *h = (hci_cmd_hdr_t *)msg;
330
331 h->type = HCI_CMD_PKT;
332 h->opcode = htole16(opcode);
333 h->length = len;
334
335 if (len > 0)
336 memcpy(msg + sizeof(hci_cmd_hdr_t), buf, len);
337
338 return sendto(sock, msg, sizeof(hci_cmd_hdr_t) + len, MSG_NOSIGNAL,
339 (struct sockaddr *)sa, sizeof(*sa));
340 }
341