1 /*
2 * rfcomm_pppd.c
3 */
4
5 /*-
6 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
7 *
8 * Copyright (c) 2001-2008 Maksim Yevmenkin <[email protected]>
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $Id: rfcomm_pppd.c,v 1.5 2003/09/07 18:32:11 max Exp $
33 * $FreeBSD$
34 */
35 #define L2CAP_SOCKET_CHECKED
36 #include <bluetooth.h>
37 #include <ctype.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <sdp.h>
42 #include <signal.h>
43 #include <stdarg.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <syslog.h>
48 #include <unistd.h>
49
50 #define RFCOMM_PPPD "rfcomm_pppd"
51
52 int rfcomm_channel_lookup (bdaddr_t const *local,
53 bdaddr_t const *remote,
54 int service, int *channel, int *error);
55
56 static void exec_ppp (int s, char *unit, char *label);
57 static void sighandler (int s);
58 static void usage (void);
59
60 static int done;
61
62 /* Main */
63 int
main(int argc,char * argv[])64 main(int argc, char *argv[])
65 {
66 struct sockaddr_rfcomm sock_addr;
67 char *label = NULL, *unit = NULL, *ep = NULL;
68 bdaddr_t addr;
69 int s, channel, detach, server, service,
70 regdun, regsp;
71 pid_t pid;
72
73 memcpy(&addr, NG_HCI_BDADDR_ANY, sizeof(addr));
74 channel = 0;
75 detach = 1;
76 server = 0;
77 service = 0;
78 regdun = 0;
79 regsp = 0;
80
81 /* Parse command line arguments */
82 while ((s = getopt(argc, argv, "a:cC:dDhl:sSu:")) != -1) {
83 switch (s) {
84 case 'a': /* BDADDR */
85 if (!bt_aton(optarg, &addr)) {
86 struct hostent *he = NULL;
87
88 if ((he = bt_gethostbyname(optarg)) == NULL)
89 errx(1, "%s: %s", optarg, hstrerror(h_errno));
90
91 memcpy(&addr, he->h_addr, sizeof(addr));
92 }
93 break;
94
95 case 'c': /* client */
96 server = 0;
97 break;
98
99 case 'C': /* RFCOMM channel */
100 channel = strtoul(optarg, &ep, 10);
101 if (*ep != '\0') {
102 channel = 0;
103 switch (tolower(optarg[0])) {
104 case 'd': /* DialUp Networking */
105 service = SDP_SERVICE_CLASS_DIALUP_NETWORKING;
106 break;
107
108 case 'l': /* LAN Access Using PPP */
109 service = SDP_SERVICE_CLASS_LAN_ACCESS_USING_PPP;
110 break;
111 }
112 }
113 break;
114
115 case 'd': /* do not detach */
116 detach = 0;
117 break;
118
119 case 'D': /* Register DUN service as well as LAN service */
120 regdun = 1;
121 break;
122
123 case 'l': /* PPP label */
124 label = optarg;
125 break;
126
127 case 's': /* server */
128 server = 1;
129 break;
130
131 case 'S': /* Register SP service as well as LAN service */
132 regsp = 1;
133 break;
134
135 case 'u': /* PPP -unit option */
136 strtoul(optarg, &ep, 10);
137 if (*ep != '\0')
138 usage();
139 /* NOT REACHED */
140
141 unit = optarg;
142 break;
143
144 case 'h':
145 default:
146 usage();
147 /* NOT REACHED */
148 }
149 }
150
151 /* Check if we got everything we wanted */
152 if (label == NULL)
153 errx(1, "Must specify PPP label");
154
155 if (!server) {
156 if (memcmp(&addr, NG_HCI_BDADDR_ANY, sizeof(addr)) == 0)
157 errx(1, "Must specify server BD_ADDR");
158
159 /* Check channel, if was not set then obtain it via SDP */
160 if (channel == 0 && service != 0)
161 if (rfcomm_channel_lookup(NULL, &addr, service,
162 &channel, &s) != 0)
163 errc(1, s, "Could not obtain RFCOMM channel");
164 }
165
166 if (channel <= 0 || channel > 30)
167 errx(1, "Invalid RFCOMM channel number %d", channel);
168
169 openlog(RFCOMM_PPPD, LOG_PID | LOG_PERROR | LOG_NDELAY, LOG_USER);
170
171 if (detach && daemon(0, 0) < 0) {
172 syslog(LOG_ERR, "Could not daemon(0, 0). %s (%d)",
173 strerror(errno), errno);
174 exit(1);
175 }
176
177 s = socket(PF_BLUETOOTH, SOCK_STREAM, BLUETOOTH_PROTO_RFCOMM);
178 if (s < 0) {
179 syslog(LOG_ERR, "Could not create socket. %s (%d)",
180 strerror(errno), errno);
181 exit(1);
182 }
183
184 if (server) {
185 struct sigaction sa;
186 void *ss = NULL;
187 sdp_lan_profile_t lan;
188
189 /* Install signal handler */
190 memset(&sa, 0, sizeof(sa));
191 sa.sa_handler = sighandler;
192
193 if (sigaction(SIGTERM, &sa, NULL) < 0) {
194 syslog(LOG_ERR, "Could not sigaction(SIGTERM). %s (%d)",
195 strerror(errno), errno);
196 exit(1);
197 }
198
199 if (sigaction(SIGHUP, &sa, NULL) < 0) {
200 syslog(LOG_ERR, "Could not sigaction(SIGHUP). %s (%d)",
201 strerror(errno), errno);
202 exit(1);
203 }
204
205 if (sigaction(SIGINT, &sa, NULL) < 0) {
206 syslog(LOG_ERR, "Could not sigaction(SIGINT). %s (%d)",
207 strerror(errno), errno);
208 exit(1);
209 }
210
211 sa.sa_handler = SIG_IGN;
212 sa.sa_flags = SA_NOCLDWAIT;
213
214 if (sigaction(SIGCHLD, &sa, NULL) < 0) {
215 syslog(LOG_ERR, "Could not sigaction(SIGCHLD). %s (%d)",
216 strerror(errno), errno);
217 exit(1);
218 }
219
220 /* bind socket and listen for incoming connections */
221 sock_addr.rfcomm_len = sizeof(sock_addr);
222 sock_addr.rfcomm_family = AF_BLUETOOTH;
223 memcpy(&sock_addr.rfcomm_bdaddr, &addr,
224 sizeof(sock_addr.rfcomm_bdaddr));
225 sock_addr.rfcomm_channel = channel;
226
227 if (bind(s, (struct sockaddr *) &sock_addr,
228 sizeof(sock_addr)) < 0) {
229 syslog(LOG_ERR, "Could not bind socket. %s (%d)",
230 strerror(errno), errno);
231 exit(1);
232 }
233
234 if (listen(s, 10) < 0) {
235 syslog(LOG_ERR, "Could not listen on socket. %s (%d)",
236 strerror(errno), errno);
237 exit(1);
238 }
239
240 ss = sdp_open_local(NULL);
241 if (ss == NULL) {
242 syslog(LOG_ERR, "Unable to create local SDP session");
243 exit(1);
244 }
245
246 if (sdp_error(ss) != 0) {
247 syslog(LOG_ERR, "Unable to open local SDP session. " \
248 "%s (%d)", strerror(sdp_error(ss)),
249 sdp_error(ss));
250 exit(1);
251 }
252
253 memset(&lan, 0, sizeof(lan));
254 lan.server_channel = channel;
255
256 if (sdp_register_service(ss,
257 SDP_SERVICE_CLASS_LAN_ACCESS_USING_PPP,
258 &addr, (void *) &lan, sizeof(lan), NULL) != 0) {
259 syslog(LOG_ERR, "Unable to register LAN service with " \
260 "local SDP daemon. %s (%d)",
261 strerror(sdp_error(ss)), sdp_error(ss));
262 exit(1);
263 }
264
265 /*
266 * Register DUN (Dial-Up Networking) service on the same
267 * RFCOMM channel if requested. There is really no good reason
268 * to not to support this. AT-command exchange can be faked
269 * with chat script in ppp.conf
270 */
271
272 if (regdun) {
273 sdp_dun_profile_t dun;
274
275 memset(&dun, 0, sizeof(dun));
276 dun.server_channel = channel;
277
278 if (sdp_register_service(ss,
279 SDP_SERVICE_CLASS_DIALUP_NETWORKING,
280 &addr, (void *) &dun, sizeof(dun),
281 NULL) != 0) {
282 syslog(LOG_ERR, "Unable to register DUN " \
283 "service with local SDP daemon. " \
284 "%s (%d)", strerror(sdp_error(ss)),
285 sdp_error(ss));
286 exit(1);
287 }
288 }
289
290 /*
291 * Register SP (Serial Port) service on the same RFCOMM channel
292 * if requested. It appears that some cell phones are using so
293 * called "callback mechanism". In this scenario user is trying
294 * to connect his cell phone to the Internet, and, user's host
295 * computer is acting as the gateway server. It seems that it
296 * is not possible to tell the phone to just connect and start
297 * using the LAN service. Instead the user's host computer must
298 * "jump start" the phone by connecting to the phone's SP
299 * service. What happens next is the phone kills the existing
300 * connection and opens another connection back to the user's
301 * host computer. The phone really wants to use LAN service,
302 * but for whatever reason it looks for SP service on the
303 * user's host computer. This brain damaged behavior was
304 * reported for Nokia 6600 and Sony/Ericsson P900. Both phones
305 * are Symbian-based phones. Perhaps this is a Symbian problem?
306 */
307
308 if (regsp) {
309 sdp_sp_profile_t sp;
310
311 memset(&sp, 0, sizeof(sp));
312 sp.server_channel = channel;
313
314 if (sdp_register_service(ss,
315 SDP_SERVICE_CLASS_SERIAL_PORT,
316 &addr, (void *) &sp, sizeof(sp),
317 NULL) != 0) {
318 syslog(LOG_ERR, "Unable to register SP " \
319 "service with local SDP daemon. " \
320 "%s (%d)", strerror(sdp_error(ss)),
321 sdp_error(ss));
322 exit(1);
323 }
324 }
325
326 for (done = 0; !done; ) {
327 socklen_t len = sizeof(sock_addr);
328 int s1 = accept(s, (struct sockaddr *) &sock_addr, &len);
329
330 if (s1 < 0) {
331 syslog(LOG_ERR, "Could not accept connection " \
332 "on socket. %s (%d)", strerror(errno),
333 errno);
334 exit(1);
335 }
336
337 pid = fork();
338 if (pid == (pid_t) -1) {
339 syslog(LOG_ERR, "Could not fork(). %s (%d)",
340 strerror(errno), errno);
341 exit(1);
342 }
343
344 if (pid == 0) {
345 sdp_close(ss);
346 close(s);
347
348 /* Reset signal handler */
349 memset(&sa, 0, sizeof(sa));
350 sa.sa_handler = SIG_DFL;
351
352 sigaction(SIGTERM, &sa, NULL);
353 sigaction(SIGHUP, &sa, NULL);
354 sigaction(SIGINT, &sa, NULL);
355 sigaction(SIGCHLD, &sa, NULL);
356
357 /* Become daemon */
358 daemon(0, 0);
359
360 /*
361 * XXX Make sure user does not shoot himself
362 * in the foot. Do not pass unit option to the
363 * PPP when operating in the server mode.
364 */
365
366 exec_ppp(s1, NULL, label);
367 } else
368 close(s1);
369 }
370 } else {
371 sock_addr.rfcomm_len = sizeof(sock_addr);
372 sock_addr.rfcomm_family = AF_BLUETOOTH;
373 memcpy(&sock_addr.rfcomm_bdaddr, NG_HCI_BDADDR_ANY,
374 sizeof(sock_addr.rfcomm_bdaddr));
375 sock_addr.rfcomm_channel = 0;
376
377 if (bind(s, (struct sockaddr *) &sock_addr,
378 sizeof(sock_addr)) < 0) {
379 syslog(LOG_ERR, "Could not bind socket. %s (%d)",
380 strerror(errno), errno);
381 exit(1);
382 }
383
384 memcpy(&sock_addr.rfcomm_bdaddr, &addr,
385 sizeof(sock_addr.rfcomm_bdaddr));
386 sock_addr.rfcomm_channel = channel;
387
388 if (connect(s, (struct sockaddr *) &sock_addr,
389 sizeof(sock_addr)) < 0) {
390 syslog(LOG_ERR, "Could not connect socket. %s (%d)",
391 strerror(errno), errno);
392 exit(1);
393 }
394
395 exec_ppp(s, unit, label);
396 }
397
398 exit(0);
399 } /* main */
400
401 /*
402 * Redirects stdin/stdout to s, stderr to /dev/null and exec
403 * 'ppp -direct -quiet [-unit N] label'. Never returns.
404 */
405
406 static void
exec_ppp(int s,char * unit,char * label)407 exec_ppp(int s, char *unit, char *label)
408 {
409 char ppp[] = "/usr/sbin/ppp";
410 char *ppp_args[] = { ppp, "-direct", "-quiet",
411 NULL, NULL, NULL, NULL };
412
413 close(0);
414 if (dup(s) < 0) {
415 syslog(LOG_ERR, "Could not dup(0). %s (%d)",
416 strerror(errno), errno);
417 exit(1);
418 }
419
420 close(1);
421 if (dup(s) < 0) {
422 syslog(LOG_ERR, "Could not dup(1). %s (%d)",
423 strerror(errno), errno);
424 exit(1);
425 }
426
427 close(2);
428 open("/dev/null", O_RDWR);
429
430 if (unit != NULL) {
431 ppp_args[3] = "-unit";
432 ppp_args[4] = unit;
433 ppp_args[5] = label;
434 } else
435 ppp_args[3] = label;
436
437 if (execv(ppp, ppp_args) < 0) {
438 syslog(LOG_ERR, "Could not exec(%s -direct -quiet%s%s %s). " \
439 "%s (%d)", ppp, (unit != NULL)? " -unit " : "",
440 (unit != NULL)? unit : "", label,
441 strerror(errno), errno);
442 exit(1);
443 }
444 } /* run_ppp */
445
446 /* Signal handler */
447 static void
sighandler(int s)448 sighandler(int s)
449 {
450 done = 1;
451 } /* sighandler */
452
453 /* Display usage and exit */
454 static void
usage(void)455 usage(void)
456 {
457 fprintf(stdout,
458 "Usage: %s options\n" \
459 "Where options are:\n" \
460 "\t-a address Address to listen on or connect to (required for client)\n" \
461 "\t-c Act as a clinet (default)\n" \
462 "\t-C channel RFCOMM channel to listen on or connect to (required)\n" \
463 "\t-d Run in foreground\n" \
464 "\t-D Register Dial-Up Networking service (server mode only)\n" \
465 "\t-l label Use PPP label (required)\n" \
466 "\t-s Act as a server\n" \
467 "\t-S Register Serial Port service (server mode only)\n" \
468 "\t-u N Tell PPP to operate on /dev/tunN (client mode only)\n" \
469 "\t-h Display this message\n", RFCOMM_PPPD);
470
471 exit(255);
472 } /* usage */
473
474