The Tcpdump Group git mirrors - libpcap/blob - pcap-bt-linux.c

   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. Neither the name of the Politecnico di Torino, CACE Technologies
  15  * nor the names of its contributors may be used to endorse or promote
  16  * products derived from this software without specific prior written
  17  * permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * Bluetooth sniffing API implementation for Linux platform
  32  * By Paolo Abeni <paolo.abeni@email.it>
  33  *
  34  */
  35 #ifndef lint
  36 static const char rcsid[] _U_ =
  37     "@(#) $Header: /tcpdump/master/libpcap/pcap-bt-linux.c,v 1.7 2007-04-01 21:43:55 guy Exp $ (LBL)";
  38 #endif
  39
  40 #ifdef HAVE_CONFIG_H
  41 #include "config.h"
  42 #endif
  43
  44 #include "pcap-int.h"
  45 #include "pcap-bt-linux.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
  59 #include <bluetooth/bluetooth.h>
  60 #include <bluetooth/hci.h>
  61
  62 #define BT_IFACE "bluetooth"
  63 #define BT_CTRL_SIZE 128
  64
  65 /* forward declaration */
  66 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  67 static int bt_inject_linux(pcap_t *, const void *, size_t);
  68 static int bt_setfilter_linux(pcap_t *, struct bpf_program *);
  69 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  70 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  71 static void bt_close_linux(pcap_t *);
  72
  73 int
  74 bt_platform_finddevs(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, "Can't open raw Bluetooth socket %d:%s",
  89                         errno, 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 %d 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, "Can't get Bluetooth device list via ioctl %d:%s",
 107                         errno, strerror(errno));
 108                 ret = -1;
 109                 goto free;
 110         }
 111
 112         dev_req = dev_list->dev_req;
 113         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 114                 char dev_name[20], dev_descr[30];
 115
 116                 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 117                 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 118
 119                 if (pcap_add_if(&found_dev, dev_name, 0,
 120                        dev_descr, err_str) < 0)
 121                 {
 122                         ret = -1;
 123                         break;
 124                 }
 125
 126         }
 127
 128 free:
 129         free(dev_list);
 130
 131 done:
 132         close(sock);
 133         return ret;
 134 }
 135
 136 pcap_t*
 137 bt_open_live(const char* bus, int snaplen, int promisc , int to_ms, char* errmsg)
 138 {
 139         struct sockaddr_hci addr;
 140         int opt;
 141         pcap_t          *handle;
 142         int             dev_id;
 143         struct hci_filter       flt;
 144
 145         /* get bt interface id */
 146         if (sscanf(bus, BT_IFACE"%d", &dev_id) != 1)
 147         {
 148                 snprintf(errmsg, PCAP_ERRBUF_SIZE,
 149                         "Can't get usb bus index from %s", bus);
 150                 return NULL;
 151         }
 152
 153         /* Allocate a handle for this session. */
 154         handle = malloc(sizeof(*handle));
 155         if (handle == NULL) {
 156                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "malloc: %s",
 157                         pcap_strerror(errno));
 158                 return NULL;
 159         }
 160
 161         /* Initialize some components of the pcap structure. */
 162         memset(handle, 0, sizeof(*handle));
 163         handle->snapshot        = snaplen;
 164         handle->md.timeout      = to_ms;
 165         handle->bufsize = snaplen+BT_CTRL_SIZE;
 166         handle->offset = BT_CTRL_SIZE;
 167         handle->linktype = DLT_BLUETOOTH_HCI_H4;
 168
 169         handle->read_op = bt_read_linux;
 170         handle->inject_op = bt_inject_linux;
 171         handle->setfilter_op = bt_setfilter_linux;
 172         handle->setdirection_op = bt_setdirection_linux;
 173         handle->set_datalink_op = NULL; /* can't change data link type */
 174         handle->getnonblock_op = pcap_getnonblock_fd;
 175         handle->setnonblock_op = pcap_setnonblock_fd;
 176         handle->stats_op = bt_stats_linux;
 177         handle->close_op = bt_close_linux;
 178         handle->md.ifindex = dev_id;
 179
 180         /* Create HCI socket */
 181         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 182         if (handle->fd < 0) {
 183                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s",
 184                         errno, strerror(errno));
 185                 free(handle);
 186                 return NULL;
 187         }
 188
 189         handle->buffer = malloc(snaplen+BT_CTRL_SIZE);
 190         if (!handle->buffer) {
 191                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 192                         pcap_strerror(errno));
 193                 pcap_close(handle);
 194                 return NULL;
 195         }
 196
 197         opt = 1;
 198         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 199                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't enable data direction info %d:%s",
 200                         errno, strerror(errno));
 201                 pcap_close(handle);
 202                 return NULL;
 203         }
 204
 205         opt = 1;
 206         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 207                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't enable time stamp %d:%s",
 208                         errno, strerror(errno));
 209                 pcap_close(handle);
 210                 return NULL;
 211         }
 212
 213         /* Setup filter, do not call hci function to avoid dependence on
 214          * external libs        */
 215         memset(&flt, 0, sizeof(flt));
 216         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 217         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 218         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 219                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't set filter %d:%s",
 220                         errno, strerror(errno));
 221                 pcap_close(handle);
 222                 return NULL;
 223         }
 224
 225
 226         /* Bind socket to the HCI device */
 227         addr.hci_family = AF_BLUETOOTH;
 228         addr.hci_dev = handle->md.ifindex;
 229         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 230                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s",
 231                         handle->md.ifindex, errno, strerror(errno));
 232                 pcap_close(handle);
 233                 return NULL;
 234         }
 235         handle->selectable_fd = handle->fd;
 236
 237         return handle;
 238 }
 239
 240 static int
 241 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 242 {
 243         struct cmsghdr *cmsg;
 244         struct msghdr msg;
 245         struct iovec  iv;
 246         struct pcap_pkthdr pkth;
 247
 248         iv.iov_base = &handle->buffer[handle->offset];
 249         iv.iov_len  = handle->snapshot;
 250
 251         memset(&msg, 0, sizeof(msg));
 252         msg.msg_iov = &iv;
 253         msg.msg_iovlen = 1;
 254         msg.msg_control = handle->buffer;
 255         msg.msg_controllen = handle->offset;
 256
 257         /* ignore interrupt system call error */
 258         do {
 259                 pkth.caplen = recvmsg(handle->fd, &msg, 0);
 260                 if (handle->break_loop)
 261                 {
 262                         handle->break_loop = 0;
 263                         return -2;
 264                 }
 265         } while ((pkth.caplen == -1) && (errno == EINTR));
 266
 267
 268         if (pkth.caplen < 0) {
 269                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s",
 270                         errno, strerror(errno));
 271                 return -1;
 272         }
 273
 274         /* get direction and timestamp*/
 275         cmsg = CMSG_FIRSTHDR(&msg);
 276         while (cmsg) {
 277                 int in;
 278                 switch (cmsg->cmsg_type) {
 279                         case HCI_CMSG_DIR:
 280                                 in = *((int *) CMSG_DATA(cmsg));
 281                                 break;
 282                         case HCI_CMSG_TSTAMP:
 283                                 pkth.ts = *((struct timeval *) CMSG_DATA(cmsg));
 284                                 break;
 285                 }
 286                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 287         }
 288         pkth.len = pkth.caplen;
 289         callback(user, &pkth, iv.iov_base);
 290         return 1;
 291 }
 292
 293 static int
 294 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 295 {
 296         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 297                 "bluetooth devices");
 298         return (-1);
 299 }
 300
 301
 302 static void
 303 bt_close_linux(pcap_t* handle)
 304 {
 305         close(handle->fd);
 306         free(handle->buffer);
 307 }
 308
 309
 310 static int
 311 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 312 {
 313         int ret;
 314         struct hci_dev_info dev_info;
 315         struct hci_dev_stats * s = &dev_info.stat;
 316         dev_info.dev_id = handle->md.ifindex;
 317
 318         /* ingnore eintr */
 319         do {
 320                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 321         } while ((ret == -1) && (errno == EINTR));
 322
 323         if (ret < 0) {
 324                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can get stats"
 325                         " via ioctl %d:%s", errno, strerror(errno));
 326                 return (-1);
 327
 328         }
 329
 330         /* we receive both rx and tx frames, so comulate all stats */
 331         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 332                 s->acl_tx +s->sco_tx;
 333         stats->ps_drop = s->err_rx + s->err_tx;
 334         stats->ps_ifdrop = 0;
 335         return 0;
 336 }
 337
 338 static int
 339 bt_setfilter_linux(pcap_t *p, struct bpf_program *fp)
 340 {
 341         return 0;
 342 }
 343
 344
 345 static int
 346 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 347 {
 348         p->direction = d;
 349         return 0;
 350 }