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 *, size_t);
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 i, sock;
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 this is not fatal*/
84 if (errno == EAFNOSUPPORT)
85 return 0;
86 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
87 errno, "Can't open raw Bluetooth socket");
88 return -1;
89 }
90
91 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
92 if (!dev_list)
93 {
94 pcap_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 = -1;
97 goto done;
98 }
99
100 dev_list->dev_num = HCI_MAX_DEV;
101
102 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
103 {
104 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
105 errno, "Can't get Bluetooth device list via ioctl");
106 ret = -1;
107 goto free;
108 }
109
110 dev_req = dev_list->dev_req;
111 for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
112 char dev_name[20], dev_descr[30];
113
114 pcap_snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
115 pcap_snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
116
117 /*
118 * Bluetooth is a wireless technology.
119 * XXX - if there's the notion of associating with a
120 * network, and we can determine whether the interface
121 * is associated with a network, check that and set
122 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED
123 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
124 */
125 if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str) == NULL)
126 {
127 ret = -1;
128 break;
129 }
130 }
131
132 free:
133 free(dev_list);
134
135 done:
136 close(sock);
137 return ret;
138 }
139
140 pcap_t *
bt_create(const char * device,char * ebuf,int * is_ours)141 bt_create(const char *device, char *ebuf, int *is_ours)
142 {
143 const char *cp;
144 char *cpend;
145 long devnum;
146 pcap_t *p;
147
148 /* Does this look like a Bluetooth device? */
149 cp = strrchr(device, '/');
150 if (cp == NULL)
151 cp = device;
152 /* Does it begin with BT_IFACE? */
153 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
154 /* Nope, doesn't begin with BT_IFACE */
155 *is_ours = 0;
156 return NULL;
157 }
158 /* Yes - is BT_IFACE followed by a number? */
159 cp += sizeof BT_IFACE - 1;
160 devnum = strtol(cp, &cpend, 10);
161 if (cpend == cp || *cpend != '\0') {
162 /* Not followed by a number. */
163 *is_ours = 0;
164 return NULL;
165 }
166 if (devnum < 0) {
167 /* Followed by a non-valid number. */
168 *is_ours = 0;
169 return NULL;
170 }
171
172 /* OK, it's probably ours. */
173 *is_ours = 1;
174
175 p = pcap_create_common(ebuf, sizeof (struct pcap_bt));
176 if (p == NULL)
177 return (NULL);
178
179 p->activate_op = bt_activate;
180 return (p);
181 }
182
183 static int
bt_activate(pcap_t * handle)184 bt_activate(pcap_t* handle)
185 {
186 struct pcap_bt *handlep = handle->priv;
187 struct sockaddr_hci addr;
188 int opt;
189 int dev_id;
190 struct hci_filter flt;
191 int err = PCAP_ERROR;
192
193 /* get bt interface id */
194 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)
195 {
196 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
197 "Can't get Bluetooth device index from %s",
198 handle->opt.device);
199 return PCAP_ERROR;
200 }
201
202 /*
203 * Turn a negative snapshot value (invalid), a snapshot value of
204 * 0 (unspecified), or a value bigger than the normal maximum
205 * value, into the maximum allowed value.
206 *
207 * If some application really *needs* a bigger snapshot
208 * length, we should just increase MAXIMUM_SNAPLEN.
209 */
210 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
211 handle->snapshot = MAXIMUM_SNAPLEN;
212
213 /* Initialize some components of the pcap structure. */
214 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
215 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
216
217 handle->read_op = bt_read_linux;
218 handle->inject_op = bt_inject_linux;
219 handle->setfilter_op = install_bpf_program; /* no kernel filtering */
220 handle->setdirection_op = bt_setdirection_linux;
221 handle->set_datalink_op = NULL; /* can't change data link type */
222 handle->getnonblock_op = pcap_getnonblock_fd;
223 handle->setnonblock_op = pcap_setnonblock_fd;
224 handle->stats_op = bt_stats_linux;
225 handlep->dev_id = dev_id;
226
227 /* Create HCI socket */
228 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
229 if (handle->fd < 0) {
230 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
231 errno, "Can't create raw socket");
232 return PCAP_ERROR;
233 }
234
235 handle->buffer = malloc(handle->bufsize);
236 if (!handle->buffer) {
237 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
238 errno, "Can't allocate dump buffer");
239 goto close_fail;
240 }
241
242 opt = 1;
243 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
244 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
245 errno, "Can't enable data direction info");
246 goto close_fail;
247 }
248
249 opt = 1;
250 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
251 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
252 errno, "Can't enable time stamp");
253 goto close_fail;
254 }
255
256 /* Setup filter, do not call hci function to avoid dependence on
257 * external libs */
258 memset(&flt, 0, sizeof(flt));
259 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
260 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
261 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
262 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
263 errno, "Can't set filter");
264 goto close_fail;
265 }
266
267
268 /* Bind socket to the HCI device */
269 addr.hci_family = AF_BLUETOOTH;
270 addr.hci_dev = handlep->dev_id;
271 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
272 addr.hci_channel = HCI_CHANNEL_RAW;
273 #endif
274 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
275 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
276 errno, "Can't attach to device %d", handlep->dev_id);
277 goto close_fail;
278 }
279
280 if (handle->opt.rfmon) {
281 /*
282 * Monitor mode doesn't apply to Bluetooth devices.
283 */
284 err = PCAP_ERROR_RFMON_NOTSUP;
285 goto close_fail;
286 }
287
288 if (handle->opt.buffer_size != 0) {
289 /*
290 * Set the socket buffer size to the specified value.
291 */
292 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
293 &handle->opt.buffer_size,
294 sizeof(handle->opt.buffer_size)) == -1) {
295 pcap_fmt_errmsg_for_errno(handle->errbuf,
296 errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");
297 goto close_fail;
298 }
299 }
300
301 handle->selectable_fd = handle->fd;
302 return 0;
303
304 close_fail:
305 pcap_cleanup_live_common(handle);
306 return err;
307 }
308
309 static int
bt_read_linux(pcap_t * handle,int max_packets _U_,pcap_handler callback,u_char * user)310 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
311 {
312 struct cmsghdr *cmsg;
313 struct msghdr msg;
314 struct iovec iv;
315 ssize_t ret;
316 struct pcap_pkthdr pkth;
317 pcap_bluetooth_h4_header* bthdr;
318 u_char *pktd;
319 int in = 0;
320
321 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;
322 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
323 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
324 iv.iov_len = handle->snapshot;
325
326 memset(&msg, 0, sizeof(msg));
327 msg.msg_iov = &iv;
328 msg.msg_iovlen = 1;
329 msg.msg_control = handle->buffer;
330 msg.msg_controllen = BT_CTRL_SIZE;
331
332 /* ignore interrupt system call error */
333 do {
334 ret = recvmsg(handle->fd, &msg, 0);
335 if (handle->break_loop)
336 {
337 handle->break_loop = 0;
338 return -2;
339 }
340 } while ((ret == -1) && (errno == EINTR));
341
342 if (ret < 0) {
343 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
344 errno, "Can't receive packet");
345 return -1;
346 }
347
348 pkth.caplen = ret;
349
350 /* get direction and timestamp*/
351 cmsg = CMSG_FIRSTHDR(&msg);
352 while (cmsg) {
353 switch (cmsg->cmsg_type) {
354 case HCI_CMSG_DIR:
355 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
356 break;
357 case HCI_CMSG_TSTAMP:
358 memcpy(&pkth.ts, CMSG_DATA(cmsg),
359 sizeof pkth.ts);
360 break;
361 }
362 cmsg = CMSG_NXTHDR(&msg, cmsg);
363 }
364 if ((in && (handle->direction == PCAP_D_OUT)) ||
365 ((!in) && (handle->direction == PCAP_D_IN)))
366 return 0;
367
368 bthdr->direction = htonl(in != 0);
369 pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
370 pkth.len = pkth.caplen;
371 if (handle->fcode.bf_insns == NULL ||
372 bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
373 callback(user, &pkth, pktd);
374 return 1;
375 }
376 return 0; /* didn't pass filter */
377 }
378
379 static int
bt_inject_linux(pcap_t * handle,const void * buf _U_,size_t size _U_)380 bt_inject_linux(pcap_t *handle, const void *buf _U_, size_t size _U_)
381 {
382 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
383 "bluetooth devices");
384 return (-1);
385 }
386
387
388 static int
bt_stats_linux(pcap_t * handle,struct pcap_stat * stats)389 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
390 {
391 struct pcap_bt *handlep = handle->priv;
392 int ret;
393 struct hci_dev_info dev_info;
394 struct hci_dev_stats * s = &dev_info.stat;
395 dev_info.dev_id = handlep->dev_id;
396
397 /* ignore eintr */
398 do {
399 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
400 } while ((ret == -1) && (errno == EINTR));
401
402 if (ret < 0) {
403 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
404 errno, "Can't get stats via ioctl");
405 return (-1);
406
407 }
408
409 /* we receive both rx and tx frames, so comulate all stats */
410 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
411 s->acl_tx +s->sco_tx;
412 stats->ps_drop = s->err_rx + s->err_tx;
413 stats->ps_ifdrop = 0;
414 return 0;
415 }
416
417 static int
bt_setdirection_linux(pcap_t * p,pcap_direction_t d)418 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
419 {
420 p->direction = d;
421 return 0;
422 }
423