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. 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
  35 static 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 */
  67 static int bt_activate(pcap_t *);
  68 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  69 static int bt_inject_linux(pcap_t *, const void *, size_t);
  70 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  71 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  72
  73 int
  74 bt_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
 129 free:
 130         free(dev_list);
 131
 132 done:
 133         close(sock);
 134         return ret;
 135 }
 136
 137 pcap_t *
 138 bt_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
 180 static int
 181 bt_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
 291 close_fail:
 292         pcap_cleanup_live_common(handle);
 293         return err;
 294 }
 295
 296 static int
 297 bt_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
 365 static int
 366 bt_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
 374 static int
 375 bt_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
 402 static int
 403 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 404 {
 405         p->direction = d;
 406         return 0;
 407 }