xref: /freebsd/usr.sbin/bluetooth/rfcomm_pppd/rfcomm_pppd.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*
2  * rfcomm_pppd.c
3  */
4 
5 /*-
6  * Copyright (c) 2001-2008 Maksim Yevmenkin <m_evmenkin@yahoo.com>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $Id: rfcomm_pppd.c,v 1.5 2003/09/07 18:32:11 max Exp $
31  * $FreeBSD$
32  */
33 
34 #include <bluetooth.h>
35 #include <ctype.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <sdp.h>
40 #include <signal.h>
41 #include <stdarg.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <syslog.h>
46 #include <unistd.h>
47 
48 #define RFCOMM_PPPD	"rfcomm_pppd"
49 
50 int		rfcomm_channel_lookup	(bdaddr_t const *local,
51 					 bdaddr_t const *remote,
52 					 int service, int *channel, int *error);
53 
54 static void	exec_ppp	(int s, char *unit, char *label);
55 static void	sighandler	(int s);
56 static void	usage		(void);
57 
58 static int	done;
59 
60 /* Main */
61 int
62 main(int argc, char *argv[])
63 {
64 	struct sockaddr_rfcomm   sock_addr;
65 	char			*label = NULL, *unit = NULL, *ep = NULL;
66 	bdaddr_t		 addr;
67 	int			 s, channel, detach, server, service,
68 				 regdun, regsp;
69 	pid_t			 pid;
70 
71 	memcpy(&addr, NG_HCI_BDADDR_ANY, sizeof(addr));
72 	channel = 0;
73 	detach = 1;
74 	server = 0;
75 	service = 0;
76 	regdun = 0;
77 	regsp = 0;
78 
79 	/* Parse command line arguments */
80 	while ((s = getopt(argc, argv, "a:cC:dDhl:sSu:")) != -1) {
81 		switch (s) {
82 		case 'a': /* BDADDR */
83 			if (!bt_aton(optarg, &addr)) {
84 				struct hostent	*he = NULL;
85 
86 				if ((he = bt_gethostbyname(optarg)) == NULL)
87 					errx(1, "%s: %s", optarg, hstrerror(h_errno));
88 
89 				memcpy(&addr, he->h_addr, sizeof(addr));
90 			}
91 			break;
92 
93 		case 'c': /* client */
94 			server = 0;
95 			break;
96 
97 		case 'C': /* RFCOMM channel */
98 			channel = strtoul(optarg, &ep, 10);
99 			if (*ep != '\0') {
100 				channel = 0;
101 				switch (tolower(optarg[0])) {
102 				case 'd': /* DialUp Networking */
103 					service = SDP_SERVICE_CLASS_DIALUP_NETWORKING;
104 					break;
105 
106 				case 'l': /* LAN Access Using PPP */
107 					service = SDP_SERVICE_CLASS_LAN_ACCESS_USING_PPP;
108 					break;
109 				}
110 			}
111 			break;
112 
113 		case 'd': /* do not detach */
114 			detach = 0;
115 			break;
116 
117 		case 'D': /* Register DUN service as well as LAN service */
118 			regdun = 1;
119 			break;
120 
121 		case 'l': /* PPP label */
122 			label = optarg;
123 			break;
124 
125 		case 's': /* server */
126 			server = 1;
127 			break;
128 
129 		case 'S': /* Register SP service as well as LAN service */
130 			regsp = 1;
131 			break;
132 
133 		case 'u': /* PPP -unit option */
134 			strtoul(optarg, &ep, 10);
135 			if (*ep != '\0')
136 				usage();
137 				/* NOT REACHED */
138 
139 			unit = optarg;
140 			break;
141 
142 		case 'h':
143 		default:
144 			usage();
145 			/* NOT REACHED */
146 		}
147 	}
148 
149 	/* Check if we got everything we wanted */
150 	if (label == NULL)
151                 errx(1, "Must specify PPP label");
152 
153 	if (!server) {
154 		if (memcmp(&addr, NG_HCI_BDADDR_ANY, sizeof(addr)) == 0)
155                 	errx(1, "Must specify server BD_ADDR");
156 
157 		/* Check channel, if was not set then obtain it via SDP */
158 		if (channel == 0 && service != 0)
159 			if (rfcomm_channel_lookup(NULL, &addr, service,
160 							&channel, &s) != 0)
161 				errc(1, s, "Could not obtain RFCOMM channel");
162 	}
163 
164         if (channel <= 0 || channel > 30)
165                 errx(1, "Invalid RFCOMM channel number %d", channel);
166 
167 	openlog(RFCOMM_PPPD, LOG_PID | LOG_PERROR | LOG_NDELAY, LOG_USER);
168 
169 	if (detach) {
170 		pid = fork();
171 		if (pid == (pid_t) -1) {
172 			syslog(LOG_ERR, "Could not fork(). %s (%d)",
173 				strerror(errno), errno);
174 			exit(1);
175 		}
176 
177 		if (pid != 0)
178 			exit(0);
179 
180 		if (daemon(0, 0) < 0) {
181 			syslog(LOG_ERR, "Could not daemon(0, 0). %s (%d)",
182 				strerror(errno), errno);
183 			exit(1);
184 		}
185 	}
186 
187 	s = socket(PF_BLUETOOTH, SOCK_STREAM, BLUETOOTH_PROTO_RFCOMM);
188 	if (s < 0) {
189 		syslog(LOG_ERR, "Could not create socket. %s (%d)",
190 			strerror(errno), errno);
191 		exit(1);
192 	}
193 
194 	if (server) {
195 		struct sigaction	 sa;
196 		void			*ss = NULL;
197 		sdp_lan_profile_t	 lan;
198 
199 		/* Install signal handler */
200 		memset(&sa, 0, sizeof(sa));
201 		sa.sa_handler = sighandler;
202 
203 		if (sigaction(SIGTERM, &sa, NULL) < 0) {
204 			syslog(LOG_ERR, "Could not sigaction(SIGTERM). %s (%d)",
205 				strerror(errno), errno);
206 			exit(1);
207 		}
208 
209 		if (sigaction(SIGHUP, &sa, NULL) < 0) {
210 			syslog(LOG_ERR, "Could not sigaction(SIGHUP). %s (%d)",
211 				strerror(errno), errno);
212 			exit(1);
213 		}
214 
215 		if (sigaction(SIGINT, &sa, NULL) < 0) {
216 			syslog(LOG_ERR, "Could not sigaction(SIGINT). %s (%d)",
217 				strerror(errno), errno);
218 			exit(1);
219 		}
220 
221 		sa.sa_handler = SIG_IGN;
222 		sa.sa_flags = SA_NOCLDWAIT;
223 
224 		if (sigaction(SIGCHLD, &sa, NULL) < 0) {
225 			syslog(LOG_ERR, "Could not sigaction(SIGCHLD). %s (%d)",
226 				strerror(errno), errno);
227 			exit(1);
228 		}
229 
230 		/* bind socket and listen for incoming connections */
231 		sock_addr.rfcomm_len = sizeof(sock_addr);
232 		sock_addr.rfcomm_family = AF_BLUETOOTH;
233 		memcpy(&sock_addr.rfcomm_bdaddr, &addr,
234 			sizeof(sock_addr.rfcomm_bdaddr));
235 		sock_addr.rfcomm_channel = channel;
236 
237 		if (bind(s, (struct sockaddr *) &sock_addr,
238 				sizeof(sock_addr)) < 0) {
239 			syslog(LOG_ERR, "Could not bind socket. %s (%d)",
240 				strerror(errno), errno);
241 			exit(1);
242 		}
243 
244 		if (listen(s, 10) < 0) {
245 			syslog(LOG_ERR, "Could not listen on socket. %s (%d)",
246 				strerror(errno), errno);
247 			exit(1);
248 		}
249 
250 		ss = sdp_open_local(NULL);
251 		if (ss == NULL) {
252 			syslog(LOG_ERR, "Unable to create local SDP session");
253 			exit(1);
254 		}
255 
256 		if (sdp_error(ss) != 0) {
257 			syslog(LOG_ERR, "Unable to open local SDP session. " \
258 				"%s (%d)", strerror(sdp_error(ss)),
259 				sdp_error(ss));
260 			exit(1);
261 		}
262 
263 		memset(&lan, 0, sizeof(lan));
264 		lan.server_channel = channel;
265 
266 		if (sdp_register_service(ss,
267 				SDP_SERVICE_CLASS_LAN_ACCESS_USING_PPP,
268 				&addr, (void *) &lan, sizeof(lan), NULL) != 0) {
269 			syslog(LOG_ERR, "Unable to register LAN service with " \
270 				"local SDP daemon. %s (%d)",
271 				strerror(sdp_error(ss)), sdp_error(ss));
272 			exit(1);
273 		}
274 
275 		/*
276 		 * Register DUN (Dial-Up Networking) service on the same
277 		 * RFCOMM channel if requested. There is really no good reason
278 		 * to not to support this. AT-command exchange can be faked
279 		 * with chat script in ppp.conf
280 		 */
281 
282 		if (regdun) {
283 			sdp_dun_profile_t	dun;
284 
285 			memset(&dun, 0, sizeof(dun));
286 			dun.server_channel = channel;
287 
288 			if (sdp_register_service(ss,
289 					SDP_SERVICE_CLASS_DIALUP_NETWORKING,
290 					&addr, (void *) &dun, sizeof(dun),
291 					NULL) != 0) {
292 				syslog(LOG_ERR, "Unable to register DUN " \
293 					"service with local SDP daemon. " \
294 					"%s (%d)", strerror(sdp_error(ss)),
295 					sdp_error(ss));
296 				exit(1);
297 			}
298 		}
299 
300 		/*
301 		 * Register SP (Serial Port) service on the same RFCOMM channel
302 		 * if requested. It appears that some cell phones are using so
303 		 * called "callback mechanism". In this scenario user is trying
304 		 * to connect his cell phone to the Internet, and, user's host
305 		 * computer is acting as the gateway server. It seems that it
306 		 * is not possible to tell the phone to just connect and start
307 		 * using the LAN service. Instead the user's host computer must
308 		 * "jump start" the phone by connecting to the phone's SP
309 		 * service. What happens next is the phone kills the existing
310 		 * connection and opens another connection back to the user's
311 		 * host computer. The phone really wants to use LAN service,
312 		 * but for whatever reason it looks for SP service on the
313 		 * user's host computer. This brain damaged behavior was
314 		 * reported for Nokia 6600 and Sony/Ericsson P900. Both phones
315 		 * are Symbian-based phones. Perhaps this is a Symbian problem?
316 		 */
317 
318 		if (regsp) {
319 			sdp_sp_profile_t	sp;
320 
321 			memset(&sp, 0, sizeof(sp));
322 			sp.server_channel = channel;
323 
324 			if (sdp_register_service(ss,
325 					SDP_SERVICE_CLASS_SERIAL_PORT,
326 					&addr, (void *) &sp, sizeof(sp),
327 					NULL) != 0) {
328 				syslog(LOG_ERR, "Unable to register SP " \
329 					"service with local SDP daemon. " \
330 					"%s (%d)", strerror(sdp_error(ss)),
331 					sdp_error(ss));
332 				exit(1);
333 			}
334 		}
335 
336 		for (done = 0; !done; ) {
337 			socklen_t	len = sizeof(sock_addr);
338 			int		s1 = accept(s, (struct sockaddr *) &sock_addr, &len);
339 
340 			if (s1 < 0) {
341 				syslog(LOG_ERR, "Could not accept connection " \
342 					"on socket. %s (%d)", strerror(errno),
343 					errno);
344 				exit(1);
345 			}
346 
347 			pid = fork();
348 			if (pid == (pid_t) -1) {
349 				syslog(LOG_ERR, "Could not fork(). %s (%d)",
350 					strerror(errno), errno);
351 				exit(1);
352 			}
353 
354 			if (pid == 0) {
355 				sdp_close(ss);
356 				close(s);
357 
358 				/* Reset signal handler */
359 				memset(&sa, 0, sizeof(sa));
360 				sa.sa_handler = SIG_DFL;
361 
362 				sigaction(SIGTERM, &sa, NULL);
363 				sigaction(SIGHUP, &sa, NULL);
364 				sigaction(SIGINT, &sa, NULL);
365 				sigaction(SIGCHLD, &sa, NULL);
366 
367 				/* Become daemon */
368 				daemon(0, 0);
369 
370 				/*
371 				 * XXX Make sure user does not shoot himself
372 				 * in the foot. Do not pass unit option to the
373 				 * PPP when operating in the server mode.
374 				 */
375 
376 				exec_ppp(s1, NULL, label);
377 			} else
378 				close(s1);
379 		}
380 	} else {
381 		sock_addr.rfcomm_len = sizeof(sock_addr);
382 		sock_addr.rfcomm_family = AF_BLUETOOTH;
383 		memcpy(&sock_addr.rfcomm_bdaddr, NG_HCI_BDADDR_ANY,
384 			sizeof(sock_addr.rfcomm_bdaddr));
385 		sock_addr.rfcomm_channel = 0;
386 
387 		if (bind(s, (struct sockaddr *) &sock_addr,
388 				sizeof(sock_addr)) < 0) {
389 			syslog(LOG_ERR, "Could not bind socket. %s (%d)",
390 				strerror(errno), errno);
391 			exit(1);
392 		}
393 
394 		memcpy(&sock_addr.rfcomm_bdaddr, &addr,
395 			sizeof(sock_addr.rfcomm_bdaddr));
396 		sock_addr.rfcomm_channel = channel;
397 
398 		if (connect(s, (struct sockaddr *) &sock_addr,
399 				sizeof(sock_addr)) < 0) {
400 			syslog(LOG_ERR, "Could not connect socket. %s (%d)",
401 				strerror(errno), errno);
402 			exit(1);
403 		}
404 
405 		exec_ppp(s, unit, label);
406 	}
407 
408 	exit(0);
409 } /* main */
410 
411 /*
412  * Redirects stdin/stdout to s, stderr to /dev/null and exec
413  * 'ppp -direct -quiet [-unit N] label'. Never returns.
414  */
415 
416 static void
417 exec_ppp(int s, char *unit, char *label)
418 {
419 	char	 ppp[] = "/usr/sbin/ppp";
420 	char	*ppp_args[] = { ppp,  "-direct", "-quiet",
421 				NULL, NULL,      NULL,     NULL };
422 
423 	close(0);
424 	if (dup(s) < 0) {
425 		syslog(LOG_ERR, "Could not dup(0). %s (%d)",
426 			strerror(errno), errno);
427 		exit(1);
428 	}
429 
430 	close(1);
431 	if (dup(s) < 0) {
432 		syslog(LOG_ERR, "Could not dup(1). %s (%d)",
433 			strerror(errno), errno);
434 		exit(1);
435 	}
436 
437 	close(2);
438 	open("/dev/null", O_RDWR);
439 
440 	if (unit != NULL) {
441 		ppp_args[3] = "-unit";
442 		ppp_args[4] = unit;
443 		ppp_args[5] = label;
444 	} else
445 		ppp_args[3] = label;
446 
447 	if (execv(ppp, ppp_args) < 0) {
448 		syslog(LOG_ERR, "Could not exec(%s -direct -quiet%s%s %s). " \
449 			"%s (%d)", ppp, (unit != NULL)? " -unit " : "",
450 			(unit != NULL)? unit : "", label,
451 			strerror(errno), errno);
452 		exit(1);
453 	}
454 } /* run_ppp */
455 
456 /* Signal handler */
457 static void
458 sighandler(int s)
459 {
460 	done = 1;
461 } /* sighandler */
462 
463 /* Display usage and exit */
464 static void
465 usage(void)
466 {
467 	fprintf(stdout,
468 "Usage: %s options\n" \
469 "Where options are:\n" \
470 "\t-a address   Address to listen on or connect to (required for client)\n" \
471 "\t-c           Act as a clinet (default)\n" \
472 "\t-C channel   RFCOMM channel to listen on or connect to (required)\n" \
473 "\t-d           Run in foreground\n" \
474 "\t-D           Register Dial-Up Networking service (server mode only)\n" \
475 "\t-l label     Use PPP label (required)\n" \
476 "\t-s           Act as a server\n" \
477 "\t-S           Register Serial Port service (server mode only)\n" \
478 "\t-u N         Tell PPP to operate on /dev/tunN (client mode only)\n" \
479 "\t-h           Display this message\n", RFCOMM_PPPD);
480 
481 	exit(255);
482 } /* usage */
483 
484