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 #ifdef NEED_STRERROR_H
44 #include "strerror.h"
45 #endif
46
47 #include <errno.h>
48 #include <stdlib.h>
49 #include <unistd.h>
50 #include <fcntl.h>
51 #include <string.h>
52 #include <sys/ioctl.h>
53 #include <sys/socket.h>
54 #include <arpa/inet.h>
55
56 #include <bluetooth/bluetooth.h>
57 #include <bluetooth/hci.h>
58
59 #define BT_IFACE "bluetooth"
60 #define BT_CTRL_SIZE 128
61
62 /* forward declaration */
63 static int bt_activate(pcap_t *);
64 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
65 static int bt_inject_linux(pcap_t *, const void *, size_t);
66 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
67 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
68
69 /*
70 * Private data for capturing on Linux Bluetooth devices.
71 */
72 struct pcap_bt {
73 int dev_id; /* device ID of device we're bound to */
74 };
75
76 int
bt_findalldevs(pcap_if_t ** alldevsp,char * err_str)77 bt_findalldevs(pcap_if_t **alldevsp, char *err_str)
78 {
79 struct hci_dev_list_req *dev_list;
80 struct hci_dev_req *dev_req;
81 int i, sock;
82 int ret = 0;
83
84 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
85 if (sock < 0)
86 {
87 /* if bluetooth is not supported this this is not fatal*/
88 if (errno == EAFNOSUPPORT)
89 return 0;
90 snprintf(err_str, PCAP_ERRBUF_SIZE,
91 "Can't open raw Bluetooth socket: %s", strerror(errno));
92 return -1;
93 }
94
95 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
96 if (!dev_list)
97 {
98 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
99 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
100 ret = -1;
101 goto done;
102 }
103
104 dev_list->dev_num = HCI_MAX_DEV;
105
106 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
107 {
108 snprintf(err_str, PCAP_ERRBUF_SIZE,
109 "Can't get Bluetooth device list via ioctl: %s",
110 strerror(errno));
111 ret = -1;
112 goto free;
113 }
114
115 dev_req = dev_list->dev_req;
116 for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
117 char dev_name[20], dev_descr[30];
118
119 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
120 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
121
122 if (pcap_add_if(alldevsp, dev_name, 0,
123 dev_descr, err_str) < 0)
124 {
125 ret = -1;
126 break;
127 }
128
129 }
130
131 free:
132 free(dev_list);
133
134 done:
135 close(sock);
136 return ret;
137 }
138
139 pcap_t *
bt_create(const char * device,char * ebuf,int * is_ours)140 bt_create(const char *device, char *ebuf, int *is_ours)
141 {
142 const char *cp;
143 char *cpend;
144 long devnum;
145 pcap_t *p;
146
147 /* Does this look like a Bluetooth device? */
148 cp = strrchr(device, '/');
149 if (cp == NULL)
150 cp = device;
151 /* Does it begin with BT_IFACE? */
152 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
153 /* Nope, doesn't begin with BT_IFACE */
154 *is_ours = 0;
155 return NULL;
156 }
157 /* Yes - is BT_IFACE followed by a number? */
158 cp += sizeof BT_IFACE - 1;
159 devnum = strtol(cp, &cpend, 10);
160 if (cpend == cp || *cpend != '\0') {
161 /* Not followed by a number. */
162 *is_ours = 0;
163 return NULL;
164 }
165 if (devnum < 0) {
166 /* Followed by a non-valid number. */
167 *is_ours = 0;
168 return NULL;
169 }
170
171 /* OK, it's probably ours. */
172 *is_ours = 1;
173
174 p = pcap_create_common(device, ebuf, sizeof (struct pcap_bt));
175 if (p == NULL)
176 return (NULL);
177
178 p->activate_op = bt_activate;
179 return (p);
180 }
181
182 static int
bt_activate(pcap_t * handle)183 bt_activate(pcap_t* handle)
184 {
185 struct pcap_bt *handlep = handle->priv;
186 struct sockaddr_hci addr;
187 int opt;
188 int dev_id;
189 struct hci_filter flt;
190 int err = PCAP_ERROR;
191
192 /* get bt interface id */
193 if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1)
194 {
195 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
196 "Can't get Bluetooth device index from %s",
197 handle->opt.source);
198 return PCAP_ERROR;
199 }
200
201 /* Initialize some components of the pcap structure. */
202 handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header);
203 handle->offset = BT_CTRL_SIZE;
204 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
205
206 handle->read_op = bt_read_linux;
207 handle->inject_op = bt_inject_linux;
208 handle->setfilter_op = install_bpf_program; /* no kernel filtering */
209 handle->setdirection_op = bt_setdirection_linux;
210 handle->set_datalink_op = NULL; /* can't change data link type */
211 handle->getnonblock_op = pcap_getnonblock_fd;
212 handle->setnonblock_op = pcap_setnonblock_fd;
213 handle->stats_op = bt_stats_linux;
214 handlep->dev_id = dev_id;
215
216 /* Create HCI socket */
217 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
218 if (handle->fd < 0) {
219 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
220 "Can't create raw socket: %s", strerror(errno));
221 return PCAP_ERROR;
222 }
223
224 handle->buffer = malloc(handle->bufsize);
225 if (!handle->buffer) {
226 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
227 pcap_strerror(errno));
228 goto close_fail;
229 }
230
231 opt = 1;
232 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
233 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
234 "Can't enable data direction info: %s", strerror(errno));
235 goto close_fail;
236 }
237
238 opt = 1;
239 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
240 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
241 "Can't enable time stamp: %s", strerror(errno));
242 goto close_fail;
243 }
244
245 /* Setup filter, do not call hci function to avoid dependence on
246 * external libs */
247 memset(&flt, 0, sizeof(flt));
248 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
249 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
250 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
251 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
252 "Can't set filter: %s", strerror(errno));
253 goto close_fail;
254 }
255
256
257 /* Bind socket to the HCI device */
258 addr.hci_family = AF_BLUETOOTH;
259 addr.hci_dev = handlep->dev_id;
260 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
261 addr.hci_channel = HCI_CHANNEL_RAW;
262 #endif
263 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
264 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
265 "Can't attach to device %d: %s", handlep->dev_id,
266 strerror(errno));
267 goto close_fail;
268 }
269
270 if (handle->opt.rfmon) {
271 /*
272 * Monitor mode doesn't apply to Bluetooth devices.
273 */
274 err = PCAP_ERROR_RFMON_NOTSUP;
275 goto close_fail;
276 }
277
278 if (handle->opt.buffer_size != 0) {
279 /*
280 * Set the socket buffer size to the specified value.
281 */
282 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
283 &handle->opt.buffer_size,
284 sizeof(handle->opt.buffer_size)) == -1) {
285 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
286 "SO_RCVBUF: %s", pcap_strerror(errno));
287 goto close_fail;
288 }
289 }
290
291 handle->selectable_fd = handle->fd;
292 return 0;
293
294 close_fail:
295 pcap_cleanup_live_common(handle);
296 return err;
297 }
298
299 static int
bt_read_linux(pcap_t * handle,int max_packets,pcap_handler callback,u_char * user)300 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
301 {
302 struct cmsghdr *cmsg;
303 struct msghdr msg;
304 struct iovec iv;
305 ssize_t ret;
306 struct pcap_pkthdr pkth;
307 pcap_bluetooth_h4_header* bthdr;
308
309 bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset];
310 iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)];
311 iv.iov_len = handle->snapshot;
312
313 memset(&msg, 0, sizeof(msg));
314 msg.msg_iov = &iv;
315 msg.msg_iovlen = 1;
316 msg.msg_control = handle->buffer;
317 msg.msg_controllen = handle->offset;
318
319 /* ignore interrupt system call error */
320 do {
321 ret = recvmsg(handle->fd, &msg, 0);
322 if (handle->break_loop)
323 {
324 handle->break_loop = 0;
325 return -2;
326 }
327 } while ((ret == -1) && (errno == EINTR));
328
329 if (ret < 0) {
330 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
331 "Can't receive packet: %s", strerror(errno));
332 return -1;
333 }
334
335 pkth.caplen = ret;
336
337 /* get direction and timestamp*/
338 cmsg = CMSG_FIRSTHDR(&msg);
339 int in=0;
340 while (cmsg) {
341 switch (cmsg->cmsg_type) {
342 case HCI_CMSG_DIR:
343 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
344 break;
345 case HCI_CMSG_TSTAMP:
346 memcpy(&pkth.ts, CMSG_DATA(cmsg),
347 sizeof pkth.ts);
348 break;
349 }
350 cmsg = CMSG_NXTHDR(&msg, cmsg);
351 }
352 if ((in && (handle->direction == PCAP_D_OUT)) ||
353 ((!in) && (handle->direction == PCAP_D_IN)))
354 return 0;
355
356 bthdr->direction = htonl(in != 0);
357 pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
358 pkth.len = pkth.caplen;
359 if (handle->fcode.bf_insns == NULL ||
360 bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset],
361 pkth.len, pkth.caplen)) {
362 callback(user, &pkth, &handle->buffer[handle->offset]);
363 return 1;
364 }
365 return 0; /* didn't pass filter */
366 }
367
368 static int
bt_inject_linux(pcap_t * handle,const void * buf,size_t size)369 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
370 {
371 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
372 "bluetooth devices");
373 return (-1);
374 }
375
376
377 static int
bt_stats_linux(pcap_t * handle,struct pcap_stat * stats)378 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
379 {
380 struct pcap_bt *handlep = handle->priv;
381 int ret;
382 struct hci_dev_info dev_info;
383 struct hci_dev_stats * s = &dev_info.stat;
384 dev_info.dev_id = handlep->dev_id;
385
386 /* ignore eintr */
387 do {
388 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
389 } while ((ret == -1) && (errno == EINTR));
390
391 if (ret < 0) {
392 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
393 "Can't get stats via ioctl: %s", strerror(errno));
394 return (-1);
395
396 }
397
398 /* we receive both rx and tx frames, so comulate all stats */
399 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
400 s->acl_tx +s->sco_tx;
401 stats->ps_drop = s->err_rx + s->err_tx;
402 stats->ps_ifdrop = 0;
403 return 0;
404 }
405
406 static int
bt_setdirection_linux(pcap_t * p,pcap_direction_t d)407 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
408 {
409 p->direction = d;
410 return 0;
411 }
412