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