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 #include <config.h>
36
37 #include "pcap-int.h"
38 #include "pcap-bt-linux.h"
39 #include "pcap/bluetooth.h"
40 #include "diag-control.h"
41
42 #include <errno.h>
43 #include <stdlib.h>
44 #include <unistd.h>
45 #include <fcntl.h>
46 #include <string.h>
47 #include <sys/ioctl.h>
48 #include <sys/socket.h>
49 #include <arpa/inet.h>
50
51 #include <bluetooth/bluetooth.h>
52 #include <bluetooth/hci.h>
53
54 #define BT_IFACE "bluetooth"
55 #define BT_CTRL_SIZE 128
56
57 /* forward declaration */
58 static int bt_activate(pcap_t *);
59 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
60 static int bt_inject_linux(pcap_t *, const void *, int);
61 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
62 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
63
64 /*
65 * Private data for capturing on Linux Bluetooth devices.
66 */
67 struct pcap_bt {
68 int dev_id; /* device ID of device we're bound to */
69 };
70
71 int
bt_findalldevs(pcap_if_list_t * devlistp,char * err_str)72 bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)
73 {
74 struct hci_dev_list_req *dev_list;
75 struct hci_dev_req *dev_req;
76 int sock;
77 unsigned i;
78 int ret = 0;
79
80 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
81 if (sock < 0)
82 {
83 /* if bluetooth is not supported this is not fatal*/
84 if (errno == EAFNOSUPPORT)
85 return 0;
86 pcapint_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
87 errno, "Can't open raw Bluetooth socket");
88 return PCAP_ERROR;
89 }
90
91 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
92 if (!dev_list)
93 {
94 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
95 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
96 ret = PCAP_ERROR;
97 goto done;
98 }
99
100 /*
101 * Zero the complete header, which is larger than dev_num because of tail
102 * padding, to silence Valgrind, which overshoots validating that dev_num
103 * has been set.
104 * https://github.com/the-tcpdump-group/libpcap/issues/1083
105 * https://bugs.kde.org/show_bug.cgi?id=448464
106 */
107 memset(dev_list, 0, sizeof(*dev_list));
108 dev_list->dev_num = HCI_MAX_DEV;
109
110 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
111 {
112 pcapint_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
113 errno, "Can't get Bluetooth device list via ioctl");
114 ret = PCAP_ERROR;
115 goto free;
116 }
117
118 dev_req = dev_list->dev_req;
119 for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
120 char dev_name[20], dev_descr[40];
121
122 snprintf(dev_name, sizeof(dev_name), BT_IFACE"%u", dev_req->dev_id);
123 snprintf(dev_descr, sizeof(dev_descr), "Bluetooth adapter number %u", i);
124
125 /*
126 * Bluetooth is a wireless technology.
127 * XXX - if there's the notion of associating with a
128 * network, and we can determine whether the interface
129 * is associated with a network, check that and set
130 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED
131 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
132 */
133 if (pcapint_add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str) == NULL)
134 {
135 ret = PCAP_ERROR;
136 break;
137 }
138 }
139
140 free:
141 free(dev_list);
142
143 done:
144 close(sock);
145 return ret;
146 }
147
148 pcap_t *
bt_create(const char * device,char * ebuf,int * is_ours)149 bt_create(const char *device, char *ebuf, int *is_ours)
150 {
151 const char *cp;
152 char *cpend;
153 long devnum;
154 pcap_t *p;
155
156 /* Does this look like a Bluetooth device? */
157 cp = strrchr(device, '/');
158 if (cp == NULL)
159 cp = device;
160 /* Does it begin with BT_IFACE? */
161 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
162 /* Nope, doesn't begin with BT_IFACE */
163 *is_ours = 0;
164 return NULL;
165 }
166 /* Yes - is BT_IFACE followed by a number? */
167 cp += sizeof BT_IFACE - 1;
168 devnum = strtol(cp, &cpend, 10);
169 if (cpend == cp || *cpend != '\0') {
170 /* Not followed by a number. */
171 *is_ours = 0;
172 return NULL;
173 }
174 if (devnum < 0) {
175 /* Followed by a non-valid number. */
176 *is_ours = 0;
177 return NULL;
178 }
179
180 /* OK, it's probably ours. */
181 *is_ours = 1;
182
183 p = PCAP_CREATE_COMMON(ebuf, struct pcap_bt);
184 if (p == NULL)
185 return (NULL);
186
187 p->activate_op = bt_activate;
188 return (p);
189 }
190
191 static int
bt_activate(pcap_t * handle)192 bt_activate(pcap_t* handle)
193 {
194 struct pcap_bt *handlep = handle->priv;
195 struct sockaddr_hci addr;
196 int opt;
197 int dev_id;
198 struct hci_filter flt;
199 int err = PCAP_ERROR;
200
201 /* get bt interface id */
202 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)
203 {
204 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
205 "Can't get Bluetooth device index from %s",
206 handle->opt.device);
207 return PCAP_ERROR;
208 }
209
210 /*
211 * Turn a negative snapshot value (invalid), a snapshot value of
212 * 0 (unspecified), or a value bigger than the normal maximum
213 * value, into the maximum allowed value.
214 *
215 * If some application really *needs* a bigger snapshot
216 * length, we should just increase MAXIMUM_SNAPLEN.
217 */
218 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
219 handle->snapshot = MAXIMUM_SNAPLEN;
220
221 /* Initialize some components of the pcap structure. */
222 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
223 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
224
225 handle->read_op = bt_read_linux;
226 handle->inject_op = bt_inject_linux;
227 handle->setfilter_op = pcapint_install_bpf_program; /* no kernel filtering */
228 handle->setdirection_op = bt_setdirection_linux;
229 handle->set_datalink_op = NULL; /* can't change data link type */
230 handle->getnonblock_op = pcapint_getnonblock_fd;
231 handle->setnonblock_op = pcapint_setnonblock_fd;
232 handle->stats_op = bt_stats_linux;
233 handlep->dev_id = dev_id;
234
235 /* Create HCI socket */
236 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
237 if (handle->fd < 0) {
238 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
239 errno, "Can't create raw socket");
240 return PCAP_ERROR;
241 }
242
243 handle->buffer = malloc(handle->bufsize);
244 if (!handle->buffer) {
245 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
246 errno, "Can't allocate dump buffer");
247 goto close_fail;
248 }
249
250 opt = 1;
251 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
252 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
253 errno, "Can't enable data direction info");
254 goto close_fail;
255 }
256
257 opt = 1;
258 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
259 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
260 errno, "Can't enable time stamp");
261 goto close_fail;
262 }
263
264 /* Setup filter, do not call hci function to avoid dependence on
265 * external libs */
266 memset(&flt, 0, sizeof(flt));
267 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
268 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
269 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
270 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
271 errno, "Can't set filter");
272 goto close_fail;
273 }
274
275
276 /* Bind socket to the HCI device */
277 addr.hci_family = AF_BLUETOOTH;
278 addr.hci_dev = handlep->dev_id;
279 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
280 addr.hci_channel = HCI_CHANNEL_RAW;
281 #endif
282 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
283 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
284 errno, "Can't attach to device %d", handlep->dev_id);
285 goto close_fail;
286 }
287
288 if (handle->opt.rfmon) {
289 /*
290 * Monitor mode doesn't apply to Bluetooth devices.
291 */
292 err = PCAP_ERROR_RFMON_NOTSUP;
293 goto close_fail;
294 }
295
296 if (handle->opt.buffer_size != 0) {
297 /*
298 * Set the socket buffer size to the specified value.
299 */
300 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
301 &handle->opt.buffer_size,
302 sizeof(handle->opt.buffer_size)) == -1) {
303 pcapint_fmt_errmsg_for_errno(handle->errbuf,
304 errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");
305 goto close_fail;
306 }
307 }
308
309 handle->selectable_fd = handle->fd;
310 return 0;
311
312 close_fail:
313 pcapint_cleanup_live_common(handle);
314 return err;
315 }
316
317 static int
bt_read_linux(pcap_t * handle,int max_packets _U_,pcap_handler callback,u_char * user)318 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
319 {
320 struct cmsghdr *cmsg;
321 struct msghdr msg;
322 struct iovec iv;
323 ssize_t ret;
324 struct pcap_pkthdr pkth;
325 pcap_bluetooth_h4_header* bthdr;
326 u_char *pktd;
327 int in = 0;
328
329 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;
330 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
331 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
332 iv.iov_len = handle->snapshot;
333
334 memset(&msg, 0, sizeof(msg));
335 msg.msg_iov = &iv;
336 msg.msg_iovlen = 1;
337 msg.msg_control = handle->buffer;
338 msg.msg_controllen = BT_CTRL_SIZE;
339
340 /* ignore interrupt system call error */
341 do {
342 if (handle->break_loop)
343 {
344 handle->break_loop = 0;
345 return PCAP_ERROR_BREAK;
346 }
347 ret = recvmsg(handle->fd, &msg, 0);
348 } while ((ret == -1) && (errno == EINTR));
349
350 if (ret < 0) {
351 if (errno == EAGAIN || errno == EWOULDBLOCK) {
352 /* Nonblocking mode, no data */
353 return 0;
354 }
355 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
356 errno, "Can't receive packet");
357 return PCAP_ERROR;
358 }
359
360 pkth.caplen = (bpf_u_int32)ret;
361
362 /* get direction and timestamp*/
363 cmsg = CMSG_FIRSTHDR(&msg);
364 while (cmsg) {
365 switch (cmsg->cmsg_type) {
366 case HCI_CMSG_DIR:
367 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
368 break;
369 case HCI_CMSG_TSTAMP:
370 memcpy(&pkth.ts, CMSG_DATA(cmsg),
371 sizeof pkth.ts);
372 break;
373 }
374 // for musl libc CMSG_NXTHDR()
375 DIAG_OFF_SIGN_COMPARE
376 cmsg = CMSG_NXTHDR(&msg, cmsg);
377 DIAG_ON_SIGN_COMPARE
378 }
379 switch (handle->direction) {
380
381 case PCAP_D_IN:
382 if (!in)
383 return 0;
384 break;
385
386 case PCAP_D_OUT:
387 if (in)
388 return 0;
389 break;
390
391 default:
392 break;
393 }
394
395 bthdr->direction = htonl(in != 0);
396 pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
397 pkth.len = pkth.caplen;
398 if (handle->fcode.bf_insns == NULL ||
399 pcapint_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
400 callback(user, &pkth, pktd);
401 return 1;
402 }
403 return 0; /* didn't pass filter */
404 }
405
406 static int
bt_inject_linux(pcap_t * handle,const void * buf _U_,int size _U_)407 bt_inject_linux(pcap_t *handle, const void *buf _U_, int size _U_)
408 {
409 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
410 "Packet injection is not supported on Bluetooth devices");
411 return (-1);
412 }
413
414
415 static int
bt_stats_linux(pcap_t * handle,struct pcap_stat * stats)416 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
417 {
418 struct pcap_bt *handlep = handle->priv;
419 int ret;
420 struct hci_dev_info dev_info;
421 struct hci_dev_stats * s = &dev_info.stat;
422 dev_info.dev_id = handlep->dev_id;
423
424 /* ignore eintr */
425 do {
426 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
427 } while ((ret == -1) && (errno == EINTR));
428
429 if (ret < 0) {
430 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
431 errno, "Can't get stats via ioctl");
432 return (-1);
433
434 }
435
436 /* we receive both rx and tx frames, so cumulate all stats */
437 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
438 s->acl_tx +s->sco_tx;
439 stats->ps_drop = s->err_rx + s->err_tx;
440 stats->ps_ifdrop = 0;
441 return 0;
442 }
443
444 static int
bt_setdirection_linux(pcap_t * p,pcap_direction_t d)445 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
446 {
447 /*
448 * It's guaranteed, at this point, that d is a valid
449 * direction value.
450 */
451 p->direction = d;
452 return 0;
453 }
454