nexmon – Rev 1
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/*
* 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"
#ifdef NEED_STRERROR_H
#include "strerror.h"
#endif
#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_t **alldevsp, 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;
snprintf(err_str, PCAP_ERRBUF_SIZE,
"Can't open raw Bluetooth socket: %s", strerror(errno));
return -1;
}
dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
if (!dev_list)
{
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)
{
snprintf(err_str, PCAP_ERRBUF_SIZE,
"Can't get Bluetooth device list via ioctl: %s",
strerror(errno));
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];
snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
if (pcap_add_if(alldevsp, dev_name, 0,
dev_descr, err_str) < 0)
{
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(device, 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.source, BT_IFACE"%d", &dev_id) != 1)
{
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't get Bluetooth device index from %s",
handle->opt.source);
return PCAP_ERROR;
}
/* Initialize some components of the pcap structure. */
handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header);
handle->offset = BT_CTRL_SIZE;
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) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't create raw socket: %s", strerror(errno));
return PCAP_ERROR;
}
handle->buffer = malloc(handle->bufsize);
if (!handle->buffer) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
pcap_strerror(errno));
goto close_fail;
}
opt = 1;
if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't enable data direction info: %s", strerror(errno));
goto close_fail;
}
opt = 1;
if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't enable time stamp: %s", strerror(errno));
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) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't set filter: %s", strerror(errno));
goto close_fail;
}
/* Bind socket to the HCI device */
addr.hci_family = AF_BLUETOOTH;
addr.hci_dev = handlep->dev_id;
#ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
addr.hci_channel = HCI_CHANNEL_RAW;
#endif
if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't attach to device %d: %s", handlep->dev_id,
strerror(errno));
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) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"SO_RCVBUF: %s", pcap_strerror(errno));
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, 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;
bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset];
iv.iov_base = &handle->buffer[handle->offset+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 = handle->offset;
/* 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) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't receive packet: %s", strerror(errno));
return -1;
}
pkth.caplen = ret;
/* get direction and timestamp*/
cmsg = CMSG_FIRSTHDR(&msg);
int in=0;
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, &handle->buffer[handle->offset],
pkth.len, pkth.caplen)) {
callback(user, &pkth, &handle->buffer[handle->offset]);
return 1;
}
return 0; /* didn't pass filter */
}
static int
bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
{
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) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"Can't get stats via ioctl: %s", strerror(errno));
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;
}