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1 /*
2  *
3  *  BlueZ - Bluetooth protocol stack for Linux
4  *
5  *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
6  *  Copyright (C) 2002-2010  Marcel Holtmann <marcel@holtmann.org>
7  *
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; either version 2 of the License, or
12  *  (at your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful,
15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  *  GNU General Public License for more details.
18  *
19  *  You should have received a copy of the GNU General Public License
20  *  along with this program; if not, write to the Free Software
21  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
22  *
23  */
24 
25 #ifdef HAVE_CONFIG_H
26 #include <config.h>
27 #endif
28 
29 #include <stdio.h>
30 #include <errno.h>
31 #include <ctype.h>
32 #include <fcntl.h>
33 #include <unistd.h>
34 #include <stdlib.h>
35 #include <syslog.h>
36 #include <dirent.h>
37 
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <sys/wait.h>
41 #include <sys/param.h>
42 #include <sys/ioctl.h>
43 #include <sys/socket.h>
44 
45 #include <netinet/in.h>
46 
47 #include <bluetooth/bluetooth.h>
48 #include <bluetooth/rfcomm.h>
49 
50 #include "dund.h"
51 #include "lib.h"
52 
53 #define PROC_BASE  "/proc"
54 
for_each_port(int (* func)(struct rfcomm_dev_info *,unsigned long),unsigned long arg)55 static int for_each_port(int (*func)(struct rfcomm_dev_info *, unsigned long), unsigned long arg)
56 {
57 	struct rfcomm_dev_list_req *dl;
58 	struct rfcomm_dev_info *di;
59 	long r = 0;
60 	int  sk, i;
61 
62 	sk = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_RFCOMM);
63 	if (sk < 0 ) {
64 		perror("Can't open RFCOMM control socket");
65 		exit(1);
66 	}
67 
68 	dl = malloc(sizeof(*dl) + RFCOMM_MAX_DEV * sizeof(*di));
69 	if (!dl) {
70 		perror("Can't allocate request memory");
71 		close(sk);
72 		exit(1);
73 	}
74 
75 	dl->dev_num = RFCOMM_MAX_DEV;
76 	di = dl->dev_info;
77 
78 	if (ioctl(sk, RFCOMMGETDEVLIST, (void *) dl) < 0) {
79 		perror("Can't get device list");
80 		exit(1);
81 	}
82 
83 	for (i = 0; i < dl->dev_num; i++) {
84 		r = func(di + i, arg);
85 		if (r) break;
86 	}
87 
88 	close(sk);
89 	free(dl);
90 	return r;
91 }
92 
uses_rfcomm(char * path,char * dev)93 static int uses_rfcomm(char *path, char *dev)
94 {
95 	struct dirent *de;
96 	DIR   *dir;
97 
98 	dir = opendir(path);
99 	if (!dir)
100 		return 0;
101 
102 	if (chdir(path) < 0)
103 		return 0;
104 
105 	while ((de = readdir(dir)) != NULL) {
106 		char link[PATH_MAX + 1];
107 		int  len = readlink(de->d_name, link, sizeof(link));
108 		if (len > 0) {
109 			link[len] = 0;
110 			if (strstr(link, dev)) {
111 				closedir(dir);
112 				return 1;
113 			}
114 		}
115 	}
116 
117 	closedir(dir);
118 
119 	return 0;
120 }
121 
find_pppd(int id,pid_t * pid)122 static int find_pppd(int id, pid_t *pid)
123 {
124 	struct dirent *de;
125 	char  path[PATH_MAX + 1];
126 	char  dev[10];
127 	int   empty = 1;
128 	DIR   *dir;
129 
130 	dir = opendir(PROC_BASE);
131 	if (!dir) {
132 		perror(PROC_BASE);
133 		return -1;
134 	}
135 
136 	sprintf(dev, "rfcomm%d", id);
137 
138 	*pid = 0;
139 	while ((de = readdir(dir)) != NULL) {
140 		empty = 0;
141 		if (isdigit(de->d_name[0])) {
142 			sprintf(path, "%s/%s/fd", PROC_BASE, de->d_name);
143 			if (uses_rfcomm(path, dev)) {
144 				*pid = atoi(de->d_name);
145 				break;
146 			}
147 		}
148 	}
149 	closedir(dir);
150 
151 	if (empty)
152 		fprintf(stderr, "%s is empty (not mounted ?)\n", PROC_BASE);
153 
154 	return *pid != 0;
155 }
156 
dun_exec(char * tty,char * prog,char ** args)157 static int dun_exec(char *tty, char *prog, char **args)
158 {
159 	int pid = fork();
160 	int fd;
161 
162 	switch (pid) {
163 	case -1:
164 		return -1;
165 
166 	case 0:
167 		break;
168 
169 	default:
170 		return pid;
171 	}
172 
173 	setsid();
174 
175 	/* Close all FDs */
176 	for (fd = 3; fd < 20; fd++)
177 		close(fd);
178 
179 	execvp(prog, args);
180 
181 	syslog(LOG_ERR, "Error while executing %s", prog);
182 
183 	exit(1);
184 }
185 
dun_create_tty(int sk,char * tty,int size)186 static int dun_create_tty(int sk, char *tty, int size)
187 {
188 	struct sockaddr_rc sa;
189 	struct stat st;
190 	socklen_t alen;
191 	int id, try = 30;
192 
193 	struct rfcomm_dev_req req = {
194 		flags:   (1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP),
195 		dev_id:  -1
196 	};
197 
198 	alen = sizeof(sa);
199 	if (getpeername(sk, (struct sockaddr *) &sa, &alen) < 0)
200 		return -1;
201 	bacpy(&req.dst, &sa.rc_bdaddr);
202 
203 	alen = sizeof(sa);
204 	if (getsockname(sk, (struct sockaddr *) &sa, &alen) < 0)
205 		return -1;
206 	bacpy(&req.src, &sa.rc_bdaddr);
207 	req.channel = sa.rc_channel;
208 
209 	id = ioctl(sk, RFCOMMCREATEDEV, &req);
210 	if (id < 0)
211 		return id;
212 
213 	snprintf(tty, size, "/dev/rfcomm%d", id);
214 	while (stat(tty, &st) < 0) {
215 		snprintf(tty, size, "/dev/bluetooth/rfcomm/%d", id);
216 		if (stat(tty, &st) < 0) {
217 			snprintf(tty, size, "/dev/rfcomm%d", id);
218 			if (try--) {
219 				usleep(100 * 1000);
220 				continue;
221 			}
222 
223 			memset(&req, 0, sizeof(req));
224 			req.dev_id = id;
225 			ioctl(sk, RFCOMMRELEASEDEV, &req);
226 
227 			return -1;
228 		}
229 	}
230 
231 	return id;
232 }
233 
dun_init(void)234 int dun_init(void)
235 {
236 	return 0;
237 }
238 
dun_cleanup(void)239 int dun_cleanup(void)
240 {
241 	return 0;
242 }
243 
show_conn(struct rfcomm_dev_info * di,unsigned long arg)244 static int show_conn(struct rfcomm_dev_info *di, unsigned long arg)
245 {
246 	pid_t pid;
247 
248 	if (di->state == BT_CONNECTED &&
249 		(di->flags & (1<<RFCOMM_REUSE_DLC)) &&
250 		(di->flags & (1<<RFCOMM_TTY_ATTACHED)) &&
251 		(di->flags & (1<<RFCOMM_RELEASE_ONHUP))) {
252 
253 		if (find_pppd(di->id, &pid)) {
254 			char dst[18];
255 			ba2str(&di->dst, dst);
256 
257 			printf("rfcomm%d: %s channel %d pppd pid %d\n",
258 					di->id, dst, di->channel, pid);
259 		}
260 	}
261 	return 0;
262 }
263 
kill_conn(struct rfcomm_dev_info * di,unsigned long arg)264 static int kill_conn(struct rfcomm_dev_info *di, unsigned long arg)
265 {
266 	bdaddr_t *dst = (bdaddr_t *) arg;
267 	pid_t pid;
268 
269 	if (di->state == BT_CONNECTED &&
270 		(di->flags & (1<<RFCOMM_REUSE_DLC)) &&
271 		(di->flags & (1<<RFCOMM_TTY_ATTACHED)) &&
272 		(di->flags & (1<<RFCOMM_RELEASE_ONHUP))) {
273 
274 		if (dst && bacmp(&di->dst, dst))
275 			return 0;
276 
277 		if (find_pppd(di->id, &pid)) {
278 			if (kill(pid, SIGINT) < 0)
279 				perror("Kill");
280 
281 			if (!dst)
282 				return 0;
283 			return 1;
284 		}
285 	}
286 	return 0;
287 }
288 
dun_show_connections(void)289 int dun_show_connections(void)
290 {
291 	for_each_port(show_conn, 0);
292 	return 0;
293 }
294 
dun_kill_connection(uint8_t * dst)295 int dun_kill_connection(uint8_t *dst)
296 {
297 	for_each_port(kill_conn, (unsigned long) dst);
298 	return 0;
299 }
300 
dun_kill_all_connections(void)301 int dun_kill_all_connections(void)
302 {
303 	for_each_port(kill_conn, 0);
304 	return 0;
305 }
306 
dun_open_connection(int sk,char * pppd,char ** args,int wait)307 int dun_open_connection(int sk, char *pppd, char **args, int wait)
308 {
309 	char tty[100];
310 	int  pid;
311 
312 	if (dun_create_tty(sk, tty, sizeof(tty) - 1) < 0) {
313 		syslog(LOG_ERR, "RFCOMM TTY creation failed. %s(%d)", strerror(errno), errno);
314 		return -1;
315 	}
316 
317 	args[0] = "pppd";
318 	args[1] = tty;
319 	args[2] = "nodetach";
320 
321 	pid = dun_exec(tty, pppd, args);
322 	if (pid < 0) {
323 		syslog(LOG_ERR, "Exec failed. %s(%d)", strerror(errno), errno);
324 		return -1;
325 	}
326 
327 	if (wait) {
328 		int status;
329 		waitpid(pid, &status, 0);
330 		/* FIXME: Check for waitpid errors */
331 	}
332 
333 	return 0;
334 }
335