/*

 * Copyright (c) 2006 Paolo Abeni (Italy)

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 * notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 * notice, this list of conditions and the following disclaimer in the

 * documentation and/or other materials provided with the distribution.

 * 3. The name of the author may not be used to endorse or promote

 * products derived from this software without specific prior written

 * permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * Bluetooth sniffing API implementation for Linux platform

 * By Paolo Abeni <paolo.abeni@email.it>

 *

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include "pcap-int.h"

#include "pcap-bt-linux.h"

#include "pcap/bluetooth.h"

#include <errno.h>

#include <stdlib.h>

#include <unistd.h>

#include <fcntl.h>

#include <string.h>

#include <sys/ioctl.h>

#include <sys/socket.h>

#include <arpa/inet.h>

#include <bluetooth/bluetooth.h>

#include <bluetooth/hci.h>

#define BT_IFACE "bluetooth"

#define BT_CTRL_SIZE 128

/* forward declaration */

static int bt_activate(pcap_t *);

static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);

static int bt_inject_linux(pcap_t *, const void *, size_t);

static int bt_setdirection_linux(pcap_t *, pcap_direction_t);

static int bt_stats_linux(pcap_t *, struct pcap_stat *);

/*

 * Private data for capturing on Linux Bluetooth devices.

 */

struct pcap_bt {

	int dev_id;		/* device ID of device we're bound to */

};

int

bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)

{

	struct hci_dev_list_req *dev_list;

	struct hci_dev_req *dev_req;

	int sock;

	unsigned i;

	int ret = 0;

	sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);

	if (sock < 0)

	{

		/* if bluetooth is not supported this is not fatal*/

		if (errno == EAFNOSUPPORT)

			return 0;

		pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,

		    errno, "Can't open raw Bluetooth socket");

		return -1;

	}

	dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));

	if (!dev_list)

	{

		pcap_snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",

			HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));

		ret = -1;

		goto done;

	}

	dev_list->dev_num = HCI_MAX_DEV;

	if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)

	{

		pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,

		    errno, "Can't get Bluetooth device list via ioctl");

		ret = -1;

		goto free;

	}

	dev_req = dev_list->dev_req;

	for (i = 0; i < dev_list->dev_num; i++, dev_req++) {

		char dev_name[20], dev_descr[40];

		pcap_snprintf(dev_name, sizeof(dev_name), BT_IFACE"%u", dev_req->dev_id);

		pcap_snprintf(dev_descr, sizeof(dev_descr), "Bluetooth adapter number %u", i);

		/*

		 * Bluetooth is a wireless technology.

		 * XXX - if there's the notion of associating with a

		 * network, and we can determine whether the interface

		 * is associated with a network, check that and set

		 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED

		 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.

		 */

		if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str)  == NULL)

		{

			ret = -1;

			break;

		}

	}

free:

	free(dev_list);

done:

	close(sock);

	return ret;

}

pcap_t *

bt_create(const char *device, char *ebuf, int *is_ours)

{

	const char *cp;

	char *cpend;

	long devnum;

	pcap_t *p;

	/* Does this look like a Bluetooth device? */

	cp = strrchr(device, '/');

	if (cp == NULL)

		cp = device;

	/* Does it begin with BT_IFACE? */

	if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {

		/* Nope, doesn't begin with BT_IFACE */

		*is_ours = 0;

		return NULL;

	}

	/* Yes - is BT_IFACE followed by a number? */

	cp += sizeof BT_IFACE - 1;

	devnum = strtol(cp, &cpend, 10);

	if (cpend == cp || *cpend != '\0') {

		/* Not followed by a number. */

		*is_ours = 0;

		return NULL;

	}

	if (devnum < 0) {

		/* Followed by a non-valid number. */

		*is_ours = 0;

		return NULL;

	}

	/* OK, it's probably ours. */

	*is_ours = 1;

	p = pcap_create_common(ebuf, sizeof (struct pcap_bt));

	if (p == NULL)

		return (NULL);

	p->activate_op = bt_activate;

	return (p);

}

static int

bt_activate(pcap_t* handle)

{

	struct pcap_bt *handlep = handle->priv;

	struct sockaddr_hci addr;

	int opt;

	int		dev_id;

	struct hci_filter	flt;

	int err = PCAP_ERROR;

	/* get bt interface id */

	if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)

	{

		pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,

			"Can't get Bluetooth device index from %s",

			 handle->opt.device);

		return PCAP_ERROR;

	}

	/*

	 * Turn a negative snapshot value (invalid), a snapshot value of

	 * 0 (unspecified), or a value bigger than the normal maximum

	 * value, into the maximum allowed value.

	 *

	 * If some application really *needs* a bigger snapshot

	 * length, we should just increase MAXIMUM_SNAPLEN.

	 */

	if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)

		handle->snapshot = MAXIMUM_SNAPLEN;

	/* Initialize some components of the pcap structure. */

	handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;

	handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;

	handle->read_op = bt_read_linux;

	handle->inject_op = bt_inject_linux;

	handle->setfilter_op = install_bpf_program; /* no kernel filtering */

	handle->setdirection_op = bt_setdirection_linux;

	handle->set_datalink_op = NULL;	/* can't change data link type */

	handle->getnonblock_op = pcap_getnonblock_fd;

	handle->setnonblock_op = pcap_setnonblock_fd;

	handle->stats_op = bt_stats_linux;

	handlep->dev_id = dev_id;

	/* Create HCI socket */

	handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);

	if (handle->fd < 0) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't create raw socket");

		return PCAP_ERROR;

	}

	handle->buffer = malloc(handle->bufsize);

	if (!handle->buffer) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't allocate dump buffer");

		goto close_fail;

	}

	opt = 1;

	if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't enable data direction info");

		goto close_fail;

	}

	opt = 1;

	if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't enable time stamp");

		goto close_fail;

	}

	/* Setup filter, do not call hci function to avoid dependence on

	 * external libs	*/

	memset(&flt, 0, sizeof(flt));

	memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));

	memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));

	if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't set filter");

		goto close_fail;

	}

	/* Bind socket to the HCI device */

	addr.hci_family = AF_BLUETOOTH;

	addr.hci_dev = handlep->dev_id;

#ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL

	addr.hci_channel = HCI_CHANNEL_RAW;

#endif

	if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't attach to device %d", handlep->dev_id);

		goto close_fail;

	}

	if (handle->opt.rfmon) {

		/*

		 * Monitor mode doesn't apply to Bluetooth devices.

		 */

		err = PCAP_ERROR_RFMON_NOTSUP;

		goto close_fail;

	}

	if (handle->opt.buffer_size != 0) {

		/*

		 * Set the socket buffer size to the specified value.

		 */

		if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,

		    &handle->opt.buffer_size,

		    sizeof(handle->opt.buffer_size)) == -1) {

			pcap_fmt_errmsg_for_errno(handle->errbuf,

			    errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");

			goto close_fail;

		}

	}

	handle->selectable_fd = handle->fd;

	return 0;

close_fail:

	pcap_cleanup_live_common(handle);

	return err;

}

static int

bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)

{

	struct cmsghdr *cmsg;

	struct msghdr msg;

	struct iovec  iv;

	ssize_t ret;

	struct pcap_pkthdr pkth;

	pcap_bluetooth_h4_header* bthdr;

	u_char *pktd;

	int in = 0;

	pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;

	bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;

	iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);

	iv.iov_len  = handle->snapshot;

	memset(&msg, 0, sizeof(msg));

	msg.msg_iov = &iv;

	msg.msg_iovlen = 1;

	msg.msg_control = handle->buffer;

	msg.msg_controllen = BT_CTRL_SIZE;

	/* ignore interrupt system call error */

	do {

		ret = recvmsg(handle->fd, &msg, 0);

		if (handle->break_loop)

		{

			handle->break_loop = 0;

			return -2;

		}

	} while ((ret == -1) && (errno == EINTR));

	if (ret < 0) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't receive packet");

		return -1;

	}

	pkth.caplen = ret;

	/* get direction and timestamp*/

	cmsg = CMSG_FIRSTHDR(&msg;;

	while (cmsg) {

		switch (cmsg->cmsg_type) {

			case HCI_CMSG_DIR:

				memcpy(&in, CMSG_DATA(cmsg), sizeof in);

				break;

                      	case HCI_CMSG_TSTAMP:

                      		memcpy(&pkth.ts, CMSG_DATA(cmsg),

                      		    sizeof pkth.ts);

				break;

		}

		cmsg = CMSG_NXTHDR(&msg, cmsg);

	}

	if ((in && (handle->direction == PCAP_D_OUT)) ||

				((!in) && (handle->direction == PCAP_D_IN)))

		return 0;

	bthdr->direction = htonl(in != 0);

	pkth.caplen+=sizeof(pcap_bluetooth_h4_header);

	pkth.len = pkth.caplen;

	if (handle->fcode.bf_insns == NULL ||

	    bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {

		callback(user, &pkth, pktd);

		return 1;

	}

	return 0;	/* didn't pass filter */

}

static int

bt_inject_linux(pcap_t *handle, const void *buf _U_, size_t size _U_)

{

	pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,

	    "Packet injection is not supported on Bluetooth devices");

	return (-1);

}

static int

bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)

{

	struct pcap_bt *handlep = handle->priv;

	int ret;

	struct hci_dev_info dev_info;

	struct hci_dev_stats * s = &dev_info.stat;

	dev_info.dev_id = handlep->dev_id;

	/* ignore eintr */

	do {

		ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);

	} while ((ret == -1) && (errno == EINTR));

	if (ret < 0) {

		pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "Can't get stats via ioctl");

		return (-1);

	}

	/* we receive both rx and tx frames, so comulate all stats */

	stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +

		s->acl_tx +s->sco_tx;

	stats->ps_drop = s->err_rx + s->err_tx;

	stats->ps_ifdrop = 0;

	return 0;

}

static int

bt_setdirection_linux(pcap_t *p, pcap_direction_t d)

{

	p->direction = d;

	return 0;

}