/*
   * 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 i, sock;
  	int ret = 0;
  
  	sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
  	if (sock < 0)
  	{
  		/* if bluetooth is not supported this 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[30];
  
  		pcap_snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
  		pcap_snprintf(dev_descr, 30, "Bluetooth adapter number %d", 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, "inject 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;
  }