1 /*
2 * Copyright (c) 2006 Paolo Abeni (Italy)
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Bluetooth sniffing API implementation for Linux platform
31 * By Paolo Abeni <paolo.abeni@email.it>
32 *
33 */
34
35 #ifdef HAVE_CONFIG_H
36 #include <config.h>
37 #endif
38
39 #include "pcap-int.h"
40 #include "pcap-bt-linux.h"
41 #include "pcap/bluetooth.h"
42
43 #include <errno.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 #include <fcntl.h>
47 #include <string.h>
48 #include <sys/ioctl.h>
49 #include <sys/socket.h>
50 #include <arpa/inet.h>
51
52 #include <bluetooth/bluetooth.h>
53 #include <bluetooth/hci.h>
54
55 #define BT_IFACE "bluetooth"
56 #define BT_CTRL_SIZE 128
57
58 /* forward declaration */
59 static int bt_activate(pcap_t *);
60 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
61 static int bt_inject_linux(pcap_t *, const void *, int);
62 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
63 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
64
65 /*
66 * Private data for capturing on Linux Bluetooth devices.
67 */
68 struct pcap_bt {
69 int dev_id; /* device ID of device we're bound to */
70 };
71
72 int
bt_findalldevs(pcap_if_list_t * devlistp,char * err_str)73 bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)
74 {
75 struct hci_dev_list_req *dev_list;
76 struct hci_dev_req *dev_req;
77 int sock;
78 unsigned i;
79 int ret = 0;
80
81 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
82 if (sock < 0)
83 {
84 /* if bluetooth is not supported this is not fatal*/
85 if (errno == EAFNOSUPPORT)
86 return 0;
87 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
88 errno, "Can't open raw Bluetooth socket");
89 return -1;
90 }
91
92 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
93 if (!dev_list)
94 {
95 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
96 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
97 ret = -1;
98 goto done;
99 }
100
101 dev_list->dev_num = HCI_MAX_DEV;
102
103 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
104 {
105 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
106 errno, "Can't get Bluetooth device list via ioctl");
107 ret = -1;
108 goto free;
109 }
110
111 dev_req = dev_list->dev_req;
112 for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
113 char dev_name[20], dev_descr[40];
114
115 snprintf(dev_name, sizeof(dev_name), BT_IFACE"%u", dev_req->dev_id);
116 snprintf(dev_descr, sizeof(dev_descr), "Bluetooth adapter number %u", i);
117
118 /*
119 * Bluetooth is a wireless technology.
120 * XXX - if there's the notion of associating with a
121 * network, and we can determine whether the interface
122 * is associated with a network, check that and set
123 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED
124 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
125 */
126 if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str) == NULL)
127 {
128 ret = -1;
129 break;
130 }
131 }
132
133 free:
134 free(dev_list);
135
136 done:
137 close(sock);
138 return ret;
139 }
140
141 pcap_t *
bt_create(const char * device,char * ebuf,int * is_ours)142 bt_create(const char *device, char *ebuf, int *is_ours)
143 {
144 const char *cp;
145 char *cpend;
146 long devnum;
147 pcap_t *p;
148
149 /* Does this look like a Bluetooth device? */
150 cp = strrchr(device, '/');
151 if (cp == NULL)
152 cp = device;
153 /* Does it begin with BT_IFACE? */
154 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
155 /* Nope, doesn't begin with BT_IFACE */
156 *is_ours = 0;
157 return NULL;
158 }
159 /* Yes - is BT_IFACE followed by a number? */
160 cp += sizeof BT_IFACE - 1;
161 devnum = strtol(cp, &cpend, 10);
162 if (cpend == cp || *cpend != '\0') {
163 /* Not followed by a number. */
164 *is_ours = 0;
165 return NULL;
166 }
167 if (devnum < 0) {
168 /* Followed by a non-valid number. */
169 *is_ours = 0;
170 return NULL;
171 }
172
173 /* OK, it's probably ours. */
174 *is_ours = 1;
175
176 p = PCAP_CREATE_COMMON(ebuf, struct pcap_bt);
177 if (p == NULL)
178 return (NULL);
179
180 p->activate_op = bt_activate;
181 return (p);
182 }
183
184 static int
bt_activate(pcap_t * handle)185 bt_activate(pcap_t* handle)
186 {
187 struct pcap_bt *handlep = handle->priv;
188 struct sockaddr_hci addr;
189 int opt;
190 int dev_id;
191 struct hci_filter flt;
192 int err = PCAP_ERROR;
193
194 /* get bt interface id */
195 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)
196 {
197 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
198 "Can't get Bluetooth device index from %s",
199 handle->opt.device);
200 return PCAP_ERROR;
201 }
202
203 /*
204 * Turn a negative snapshot value (invalid), a snapshot value of
205 * 0 (unspecified), or a value bigger than the normal maximum
206 * value, into the maximum allowed value.
207 *
208 * If some application really *needs* a bigger snapshot
209 * length, we should just increase MAXIMUM_SNAPLEN.
210 */
211 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
212 handle->snapshot = MAXIMUM_SNAPLEN;
213
214 /* Initialize some components of the pcap structure. */
215 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
216 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
217
218 handle->read_op = bt_read_linux;
219 handle->inject_op = bt_inject_linux;
220 handle->setfilter_op = install_bpf_program; /* no kernel filtering */
221 handle->setdirection_op = bt_setdirection_linux;
222 handle->set_datalink_op = NULL; /* can't change data link type */
223 handle->getnonblock_op = pcap_getnonblock_fd;
224 handle->setnonblock_op = pcap_setnonblock_fd;
225 handle->stats_op = bt_stats_linux;
226 handlep->dev_id = dev_id;
227
228 /* Create HCI socket */
229 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
230 if (handle->fd < 0) {
231 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
232 errno, "Can't create raw socket");
233 return PCAP_ERROR;
234 }
235
236 handle->buffer = malloc(handle->bufsize);
237 if (!handle->buffer) {
238 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
239 errno, "Can't allocate dump buffer");
240 goto close_fail;
241 }
242
243 opt = 1;
244 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
245 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
246 errno, "Can't enable data direction info");
247 goto close_fail;
248 }
249
250 opt = 1;
251 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
252 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
253 errno, "Can't enable time stamp");
254 goto close_fail;
255 }
256
257 /* Setup filter, do not call hci function to avoid dependence on
258 * external libs */
259 memset(&flt, 0, sizeof(flt));
260 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
261 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
262 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
263 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
264 errno, "Can't set filter");
265 goto close_fail;
266 }
267
268
269 /* Bind socket to the HCI device */
270 addr.hci_family = AF_BLUETOOTH;
271 addr.hci_dev = handlep->dev_id;
272 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
273 addr.hci_channel = HCI_CHANNEL_RAW;
274 #endif
275 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
276 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
277 errno, "Can't attach to device %d", handlep->dev_id);
278 goto close_fail;
279 }
280
281 if (handle->opt.rfmon) {
282 /*
283 * Monitor mode doesn't apply to Bluetooth devices.
284 */
285 err = PCAP_ERROR_RFMON_NOTSUP;
286 goto close_fail;
287 }
288
289 if (handle->opt.buffer_size != 0) {
290 /*
291 * Set the socket buffer size to the specified value.
292 */
293 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
294 &handle->opt.buffer_size,
295 sizeof(handle->opt.buffer_size)) == -1) {
296 pcap_fmt_errmsg_for_errno(handle->errbuf,
297 errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");
298 goto close_fail;
299 }
300 }
301
302 handle->selectable_fd = handle->fd;
303 return 0;
304
305 close_fail:
306 pcap_cleanup_live_common(handle);
307 return err;
308 }
309
310 static int
bt_read_linux(pcap_t * handle,int max_packets _U_,pcap_handler callback,u_char * user)311 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
312 {
313 struct cmsghdr *cmsg;
314 struct msghdr msg;
315 struct iovec iv;
316 ssize_t ret;
317 struct pcap_pkthdr pkth;
318 pcap_bluetooth_h4_header* bthdr;
319 u_char *pktd;
320 int in = 0;
321
322 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;
323 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
324 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
325 iv.iov_len = handle->snapshot;
326
327 memset(&msg, 0, sizeof(msg));
328 msg.msg_iov = &iv;
329 msg.msg_iovlen = 1;
330 msg.msg_control = handle->buffer;
331 msg.msg_controllen = BT_CTRL_SIZE;
332
333 /* ignore interrupt system call error */
334 do {
335 ret = recvmsg(handle->fd, &msg, 0);
336 if (handle->break_loop)
337 {
338 handle->break_loop = 0;
339 return -2;
340 }
341 } while ((ret == -1) && (errno == EINTR));
342
343 if (ret < 0) {
344 if (errno == EAGAIN || errno == EWOULDBLOCK) {
345 /* Nonblocking mode, no data */
346 return 0;
347 }
348 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
349 errno, "Can't receive packet");
350 return -1;
351 }
352
353 pkth.caplen = (bpf_u_int32)ret;
354
355 /* get direction and timestamp*/
356 cmsg = CMSG_FIRSTHDR(&msg);
357 while (cmsg) {
358 switch (cmsg->cmsg_type) {
359 case HCI_CMSG_DIR:
360 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
361 break;
362 case HCI_CMSG_TSTAMP:
363 memcpy(&pkth.ts, CMSG_DATA(cmsg),
364 sizeof pkth.ts);
365 break;
366 }
367 cmsg = CMSG_NXTHDR(&msg, cmsg);
368 }
369 switch (handle->direction) {
370
371 case PCAP_D_IN:
372 if (!in)
373 return 0;
374 break;
375
376 case PCAP_D_OUT:
377 if (in)
378 return 0;
379 break;
380
381 default:
382 break;
383 }
384
385 bthdr->direction = htonl(in != 0);
386 pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
387 pkth.len = pkth.caplen;
388 if (handle->fcode.bf_insns == NULL ||
389 pcap_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
390 callback(user, &pkth, pktd);
391 return 1;
392 }
393 return 0; /* didn't pass filter */
394 }
395
396 static int
bt_inject_linux(pcap_t * handle,const void * buf _U_,int size _U_)397 bt_inject_linux(pcap_t *handle, const void *buf _U_, int size _U_)
398 {
399 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
400 "Packet injection is not supported on Bluetooth devices");
401 return (-1);
402 }
403
404
405 static int
bt_stats_linux(pcap_t * handle,struct pcap_stat * stats)406 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
407 {
408 struct pcap_bt *handlep = handle->priv;
409 int ret;
410 struct hci_dev_info dev_info;
411 struct hci_dev_stats * s = &dev_info.stat;
412 dev_info.dev_id = handlep->dev_id;
413
414 /* ignore eintr */
415 do {
416 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
417 } while ((ret == -1) && (errno == EINTR));
418
419 if (ret < 0) {
420 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
421 errno, "Can't get stats via ioctl");
422 return (-1);
423
424 }
425
426 /* we receive both rx and tx frames, so comulate all stats */
427 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
428 s->acl_tx +s->sco_tx;
429 stats->ps_drop = s->err_rx + s->err_tx;
430 stats->ps_ifdrop = 0;
431 return 0;
432 }
433
434 static int
bt_setdirection_linux(pcap_t * p,pcap_direction_t d)435 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
436 {
437 /*
438 * It's guaranteed, at this point, that d is a valid
439 * direction value.
440 */
441 p->direction = d;
442 return 0;
443 }
444