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#ifndef lint
35static const char rcsid[] _U_ =
36    "@(#) $Header: /tcpdump/master/libpcap/pcap-bt-linux.c,v 1.15 2008-07-01 07:05:54 guy Exp $ (LBL)";
37#endif
38
39#ifdef HAVE_CONFIG_H
40#include "config.h"
41#endif
42
43#include "pcap-int.h"
44#include "pcap-bt-linux.h"
45#include "pcap/bluetooth.h"
46
47#ifdef NEED_STRERROR_H
48#include "strerror.h"
49#endif
50
51#include <errno.h>
52#include <stdlib.h>
53#include <unistd.h>
54#include <fcntl.h>
55#include <string.h>
56#include <sys/ioctl.h>
57#include <sys/socket.h>
58#include <arpa/inet.h>
59
60#include <bluetooth/bluetooth.h>
61#include <bluetooth/hci.h>
62
63#define BT_IFACE "bluetooth"
64#define BT_CTRL_SIZE 128
65
66/* forward declaration */
67static int bt_activate(pcap_t *);
68static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
69static int bt_inject_linux(pcap_t *, const void *, size_t);
70static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
71static int bt_stats_linux(pcap_t *, struct pcap_stat *);
72
73int
74bt_findalldevs(pcap_if_t **alldevsp, char *err_str)
75{
76	pcap_if_t *found_dev = *alldevsp;
77	struct hci_dev_list_req *dev_list;
78	struct hci_dev_req *dev_req;
79	int i, sock;
80	int ret = 0;
81
82	sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
83	if (sock < 0)
84	{
85		/* if bluetooth is not supported this this is not fatal*/
86		if (errno == EAFNOSUPPORT)
87			return 0;
88		snprintf(err_str, PCAP_ERRBUF_SIZE,
89		    "Can't open raw Bluetooth socket: %s", strerror(errno));
90		return -1;
91	}
92
93	dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
94	if (!dev_list)
95	{
96		snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
97			HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
98		ret = -1;
99		goto done;
100	}
101
102	dev_list->dev_num = HCI_MAX_DEV;
103
104	if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
105	{
106		snprintf(err_str, PCAP_ERRBUF_SIZE,
107		    "Can't get Bluetooth device list via ioctl: %s",
108		    strerror(errno));
109		ret = -1;
110		goto free;
111	}
112
113	dev_req = dev_list->dev_req;
114	for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
115		char dev_name[20], dev_descr[30];
116
117		snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
118		snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
119
120		if (pcap_add_if(&found_dev, dev_name, 0,
121		       dev_descr, err_str) < 0)
122		{
123			ret = -1;
124			break;
125		}
126
127	}
128
129free:
130	free(dev_list);
131
132done:
133	close(sock);
134	return ret;
135}
136
137pcap_t *
138bt_create(const char *device, char *ebuf, int *is_ours)
139{
140	const char *cp;
141	char *cpend;
142	long devnum;
143	pcap_t *p;
144
145	/* Does this look like a Bluetooth device? */
146	cp = strrchr(device, '/');
147	if (cp == NULL)
148		cp = device;
149	/* Does it begin with BT_IFACE? */
150	if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
151		/* Nope, doesn't begin with BT_IFACE */
152		*is_ours = 0;
153		return NULL;
154	}
155	/* Yes - is BT_IFACE followed by a number? */
156	cp += sizeof BT_IFACE - 1;
157	devnum = strtol(cp, &cpend, 10);
158	if (cpend == cp || *cpend != '\0') {
159		/* Not followed by a number. */
160		*is_ours = 0;
161		return NULL;
162	}
163	if (devnum < 0) {
164		/* Followed by a non-valid number. */
165		*is_ours = 0;
166		return NULL;
167	}
168
169	/* OK, it's probably ours. */
170	*is_ours = 1;
171
172	p = pcap_create_common(device, ebuf);
173	if (p == NULL)
174		return (NULL);
175
176	p->activate_op = bt_activate;
177	return (p);
178}
179
180static int
181bt_activate(pcap_t* handle)
182{
183	struct sockaddr_hci addr;
184	int opt;
185	int		dev_id;
186	struct hci_filter	flt;
187	int err = PCAP_ERROR;
188
189	/* get bt interface id */
190	if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1)
191	{
192		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
193			"Can't get Bluetooth device index from %s",
194			 handle->opt.source);
195		return PCAP_ERROR;
196	}
197
198	/* Initialize some components of the pcap structure. */
199	handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header);
200	handle->offset = BT_CTRL_SIZE;
201	handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
202
203	handle->read_op = bt_read_linux;
204	handle->inject_op = bt_inject_linux;
205	handle->setfilter_op = install_bpf_program; /* no kernel filtering */
206	handle->setdirection_op = bt_setdirection_linux;
207	handle->set_datalink_op = NULL;	/* can't change data link type */
208	handle->getnonblock_op = pcap_getnonblock_fd;
209	handle->setnonblock_op = pcap_setnonblock_fd;
210	handle->stats_op = bt_stats_linux;
211	handle->md.ifindex = dev_id;
212
213	/* Create HCI socket */
214	handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
215	if (handle->fd < 0) {
216		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
217		    "Can't create raw socket: %s", strerror(errno));
218		return PCAP_ERROR;
219	}
220
221	handle->buffer = malloc(handle->bufsize);
222	if (!handle->buffer) {
223		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
224			pcap_strerror(errno));
225		goto close_fail;
226	}
227
228	opt = 1;
229	if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
230		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
231		    "Can't enable data direction info: %s", strerror(errno));
232		goto close_fail;
233	}
234
235	opt = 1;
236	if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
237		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
238		    "Can't enable time stamp: %s", strerror(errno));
239		goto close_fail;
240	}
241
242	/* Setup filter, do not call hci function to avoid dependence on
243	 * external libs	*/
244	memset(&flt, 0, sizeof(flt));
245	memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
246	memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
247	if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
248		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
249		    "Can't set filter: %s", strerror(errno));
250		goto close_fail;
251	}
252
253
254	/* Bind socket to the HCI device */
255	addr.hci_family = AF_BLUETOOTH;
256	addr.hci_dev = handle->md.ifindex;
257#ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
258	addr.hci_channel = HCI_CHANNEL_RAW;
259#endif
260	if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
261		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
262		    "Can't attach to device %d: %s", handle->md.ifindex,
263		    strerror(errno));
264		goto close_fail;
265	}
266
267	if (handle->opt.rfmon) {
268		/*
269		 * Monitor mode doesn't apply to Bluetooth devices.
270		 */
271		err = PCAP_ERROR_RFMON_NOTSUP;
272		goto close_fail;
273	}
274
275	if (handle->opt.buffer_size != 0) {
276		/*
277		 * Set the socket buffer size to the specified value.
278		 */
279		if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
280		    &handle->opt.buffer_size,
281		    sizeof(handle->opt.buffer_size)) == -1) {
282			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
283				 "SO_RCVBUF: %s", pcap_strerror(errno));
284			goto close_fail;
285		}
286	}
287
288	handle->selectable_fd = handle->fd;
289	return 0;
290
291close_fail:
292	pcap_cleanup_live_common(handle);
293	return err;
294}
295
296static int
297bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
298{
299	struct cmsghdr *cmsg;
300	struct msghdr msg;
301	struct iovec  iv;
302	ssize_t ret;
303	struct pcap_pkthdr pkth;
304	pcap_bluetooth_h4_header* bthdr;
305
306	bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset];
307	iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)];
308	iv.iov_len  = handle->snapshot;
309
310	memset(&msg, 0, sizeof(msg));
311	msg.msg_iov = &iv;
312	msg.msg_iovlen = 1;
313	msg.msg_control = handle->buffer;
314	msg.msg_controllen = handle->offset;
315
316	/* ignore interrupt system call error */
317	do {
318		ret = recvmsg(handle->fd, &msg, 0);
319		if (handle->break_loop)
320		{
321			handle->break_loop = 0;
322			return -2;
323		}
324	} while ((ret == -1) && (errno == EINTR));
325
326	if (ret < 0) {
327		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
328		    "Can't receive packet: %s", strerror(errno));
329		return -1;
330	}
331
332	pkth.caplen = ret;
333
334	/* get direction and timestamp*/
335	cmsg = CMSG_FIRSTHDR(&msg);
336	int in=0;
337	while (cmsg) {
338		switch (cmsg->cmsg_type) {
339			case HCI_CMSG_DIR:
340				memcpy(&in, CMSG_DATA(cmsg), sizeof in);
341				break;
342                      	case HCI_CMSG_TSTAMP:
343                      		memcpy(&pkth.ts, CMSG_DATA(cmsg),
344                      		    sizeof pkth.ts);
345				break;
346		}
347		cmsg = CMSG_NXTHDR(&msg, cmsg);
348	}
349	if ((in && (handle->direction == PCAP_D_OUT)) ||
350				((!in) && (handle->direction == PCAP_D_IN)))
351		return 0;
352
353	bthdr->direction = htonl(in != 0);
354	pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
355	pkth.len = pkth.caplen;
356	if (handle->fcode.bf_insns == NULL ||
357	    bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset],
358	      pkth.len, pkth.caplen)) {
359		callback(user, &pkth, &handle->buffer[handle->offset]);
360		return 1;
361	}
362	return 0;	/* didn't pass filter */
363}
364
365static int
366bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
367{
368	snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
369    		"bluetooth devices");
370	return (-1);
371}
372
373
374static int
375bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
376{
377	int ret;
378	struct hci_dev_info dev_info;
379	struct hci_dev_stats * s = &dev_info.stat;
380	dev_info.dev_id = handle->md.ifindex;
381
382	/* ignore eintr */
383	do {
384		ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
385	} while ((ret == -1) && (errno == EINTR));
386
387	if (ret < 0) {
388		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
389		    "Can't get stats via ioctl: %s", strerror(errno));
390		return (-1);
391
392	}
393
394	/* we receive both rx and tx frames, so comulate all stats */
395	stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
396		s->acl_tx +s->sco_tx;
397	stats->ps_drop = s->err_rx + s->err_tx;
398	stats->ps_ifdrop = 0;
399	return 0;
400}
401
402static int
403bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
404{
405	p->direction = d;
406	return 0;
407}
408