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
  35 #ifdef HAVE_CONFIG_H
  36 #include <config.h>
  37 #endif
  38
  39 #include "pcap-int.h"
  40 #include "pcap-bt-linux.h"
  41 #include "pcap/bluetooth.h"
  42
  43 #include <errno.h>
  44 #include <stdlib.h>
  45 #include <unistd.h>
  46 #include <fcntl.h>
  47 #include <string.h>
  48 #include <sys/ioctl.h>
  49 #include <sys/socket.h>
  50 #include <arpa/inet.h>
  51
  52 #include <bluetooth/bluetooth.h>
  53 #include <bluetooth/hci.h>
  54
  55 #define BT_IFACE "bluetooth"
  56 #define BT_CTRL_SIZE 128
  57
  58 /* forward declaration */
  59 static int bt_activate(pcap_t *);
  60 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  61 static int bt_inject_linux(pcap_t *, const void *, size_t);
  62 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  63 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  64
  65 /*
  66  * Private data for capturing on Linux Bluetooth devices.
  67  */
  68 struct pcap_bt {
  69         int dev_id;             /* device ID of device we're bound to */
  70 };
  71
  72 int
  73 bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)
  74 {
  75         struct hci_dev_list_req *dev_list;
  76         struct hci_dev_req *dev_req;
  77         int i, sock;
  78         int ret = 0;
  79
  80         sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
  81         if (sock < 0)
  82         {
  83                 /* if bluetooth is not supported this this is not fatal*/
  84                 if (errno == EAFNOSUPPORT)
  85                         return 0;
  86                 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
  87                     errno, "Can't open raw Bluetooth socket");
  88                 return -1;
  89         }
  90
  91         dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  92         if (!dev_list)
  93         {
  94                 pcap_snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
  95                         HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  96                 ret = -1;
  97                 goto done;
  98         }
  99
 100         dev_list->dev_num = HCI_MAX_DEV;
 101
 102         if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
 103         {
 104                 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
 105                     errno, "Can't get Bluetooth device list via ioctl");
 106                 ret = -1;
 107                 goto free;
 108         }
 109
 110         dev_req = dev_list->dev_req;
 111         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 112                 char dev_name[20], dev_descr[30];
 113
 114                 pcap_snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 115                 pcap_snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 116
 117                 if (add_dev(devlistp, dev_name, 0, dev_descr, err_str) == NULL)
 118                 {
 119                         ret = -1;
 120                         break;
 121                 }
 122
 123         }
 124
 125 free:
 126         free(dev_list);
 127
 128 done:
 129         close(sock);
 130         return ret;
 131 }
 132
 133 pcap_t *
 134 bt_create(const char *device, char *ebuf, int *is_ours)
 135 {
 136         const char *cp;
 137         char *cpend;
 138         long devnum;
 139         pcap_t *p;
 140
 141         /* Does this look like a Bluetooth device? */
 142         cp = strrchr(device, '/');
 143         if (cp == NULL)
 144                 cp = device;
 145         /* Does it begin with BT_IFACE? */
 146         if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
 147                 /* Nope, doesn't begin with BT_IFACE */
 148                 *is_ours = 0;
 149                 return NULL;
 150         }
 151         /* Yes - is BT_IFACE followed by a number? */
 152         cp += sizeof BT_IFACE - 1;
 153         devnum = strtol(cp, &cpend, 10);
 154         if (cpend == cp || *cpend != '\0') {
 155                 /* Not followed by a number. */
 156                 *is_ours = 0;
 157                 return NULL;
 158         }
 159         if (devnum < 0) {
 160                 /* Followed by a non-valid number. */
 161                 *is_ours = 0;
 162                 return NULL;
 163         }
 164
 165         /* OK, it's probably ours. */
 166         *is_ours = 1;
 167
 168         p = pcap_create_common(ebuf, sizeof (struct pcap_bt));
 169         if (p == NULL)
 170                 return (NULL);
 171
 172         p->activate_op = bt_activate;
 173         return (p);
 174 }
 175
 176 static int
 177 bt_activate(pcap_t* handle)
 178 {
 179         struct pcap_bt *handlep = handle->priv;
 180         struct sockaddr_hci addr;
 181         int opt;
 182         int             dev_id;
 183         struct hci_filter       flt;
 184         int err = PCAP_ERROR;
 185
 186         /* get bt interface id */
 187         if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)
 188         {
 189                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 190                         "Can't get Bluetooth device index from %s",
 191                          handle->opt.device);
 192                 return PCAP_ERROR;
 193         }
 194
 195         /*
 196          * Turn a negative snapshot value (invalid), a snapshot value of
 197          * 0 (unspecified), or a value bigger than the normal maximum
 198          * value, into the maximum allowed value.
 199          *
 200          * If some application really *needs* a bigger snapshot
 201          * length, we should just increase MAXIMUM_SNAPLEN.
 202          */
 203         if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
 204                 handle->snapshot = MAXIMUM_SNAPLEN;
 205
 206         /* Initialize some components of the pcap structure. */
 207         handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
 208         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 209
 210         handle->read_op = bt_read_linux;
 211         handle->inject_op = bt_inject_linux;
 212         handle->setfilter_op = install_bpf_program; /* no kernel filtering */
 213         handle->setdirection_op = bt_setdirection_linux;
 214         handle->set_datalink_op = NULL; /* can't change data link type */
 215         handle->getnonblock_op = pcap_getnonblock_fd;
 216         handle->setnonblock_op = pcap_setnonblock_fd;
 217         handle->stats_op = bt_stats_linux;
 218         handlep->dev_id = dev_id;
 219
 220         /* Create HCI socket */
 221         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 222         if (handle->fd < 0) {
 223                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 224                     errno, "Can't create raw socket");
 225                 return PCAP_ERROR;
 226         }
 227
 228         handle->buffer = malloc(handle->bufsize);
 229         if (!handle->buffer) {
 230                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 231                     errno, "Can't allocate dump buffer");
 232                 goto close_fail;
 233         }
 234
 235         opt = 1;
 236         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 237                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 238                     errno, "Can't enable data direction info");
 239                 goto close_fail;
 240         }
 241
 242         opt = 1;
 243         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 244                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 245                     errno, "Can't enable time stamp");
 246                 goto close_fail;
 247         }
 248
 249         /* Setup filter, do not call hci function to avoid dependence on
 250          * external libs        */
 251         memset(&flt, 0, sizeof(flt));
 252         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 253         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 254         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 255                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 256                     errno, "Can't set filter");
 257                 goto close_fail;
 258         }
 259
 260
 261         /* Bind socket to the HCI device */
 262         addr.hci_family = AF_BLUETOOTH;
 263         addr.hci_dev = handlep->dev_id;
 264 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
 265         addr.hci_channel = HCI_CHANNEL_RAW;
 266 #endif
 267         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 268                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 269                     errno, "Can't attach to device %d", handlep->dev_id);
 270                 goto close_fail;
 271         }
 272
 273         if (handle->opt.rfmon) {
 274                 /*
 275                  * Monitor mode doesn't apply to Bluetooth devices.
 276                  */
 277                 err = PCAP_ERROR_RFMON_NOTSUP;
 278                 goto close_fail;
 279         }
 280
 281         if (handle->opt.buffer_size != 0) {
 282                 /*
 283                  * Set the socket buffer size to the specified value.
 284                  */
 285                 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
 286                     &handle->opt.buffer_size,
 287                     sizeof(handle->opt.buffer_size)) == -1) {
 288                         pcap_fmt_errmsg_for_errno(handle->errbuf,
 289                             errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");
 290                         goto close_fail;
 291                 }
 292         }
 293
 294         handle->selectable_fd = handle->fd;
 295         return 0;
 296
 297 close_fail:
 298         pcap_cleanup_live_common(handle);
 299         return err;
 300 }
 301
 302 static int
 303 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 304 {
 305         struct cmsghdr *cmsg;
 306         struct msghdr msg;
 307         struct iovec  iv;
 308         ssize_t ret;
 309         struct pcap_pkthdr pkth;
 310         pcap_bluetooth_h4_header* bthdr;
 311         u_char *pktd;
 312         int in = 0;
 313
 314         pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;
 315         bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
 316         iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
 317         iv.iov_len  = handle->snapshot;
 318
 319         memset(&msg, 0, sizeof(msg));
 320         msg.msg_iov = &iv;
 321         msg.msg_iovlen = 1;
 322         msg.msg_control = handle->buffer;
 323         msg.msg_controllen = BT_CTRL_SIZE;
 324
 325         /* ignore interrupt system call error */
 326         do {
 327                 ret = recvmsg(handle->fd, &msg, 0);
 328                 if (handle->break_loop)
 329                 {
 330                         handle->break_loop = 0;
 331                         return -2;
 332                 }
 333         } while ((ret == -1) && (errno == EINTR));
 334
 335         if (ret < 0) {
 336                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 337                     errno, "Can't receive packet");
 338                 return -1;
 339         }
 340
 341         pkth.caplen = ret;
 342
 343         /* get direction and timestamp*/
 344         cmsg = CMSG_FIRSTHDR(&msg);
 345         while (cmsg) {
 346                 switch (cmsg->cmsg_type) {
 347                         case HCI_CMSG_DIR:
 348                                 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
 349                                 break;
 350                         case HCI_CMSG_TSTAMP:
 351                                 memcpy(&pkth.ts, CMSG_DATA(cmsg),
 352                                     sizeof pkth.ts);
 353                                 break;
 354                 }
 355                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 356         }
 357         if ((in && (handle->direction == PCAP_D_OUT)) ||
 358                                 ((!in) && (handle->direction == PCAP_D_IN)))
 359                 return 0;
 360
 361         bthdr->direction = htonl(in != 0);
 362         pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
 363         pkth.len = pkth.caplen;
 364         if (handle->fcode.bf_insns == NULL ||
 365             bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
 366                 callback(user, &pkth, pktd);
 367                 return 1;
 368         }
 369         return 0;       /* didn't pass filter */
 370 }
 371
 372 static int
 373 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 374 {
 375         pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 376                 "bluetooth devices");
 377         return (-1);
 378 }
 379
 380
 381 static int
 382 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 383 {
 384         struct pcap_bt *handlep = handle->priv;
 385         int ret;
 386         struct hci_dev_info dev_info;
 387         struct hci_dev_stats * s = &dev_info.stat;
 388         dev_info.dev_id = handlep->dev_id;
 389
 390         /* ignore eintr */
 391         do {
 392                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 393         } while ((ret == -1) && (errno == EINTR));
 394
 395         if (ret < 0) {
 396                 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 397                     errno, "Can't get stats via ioctl");
 398                 return (-1);
 399
 400         }
 401
 402         /* we receive both rx and tx frames, so comulate all stats */
 403         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 404                 s->acl_tx +s->sco_tx;
 405         stats->ps_drop = s->err_rx + s->err_tx;
 406         stats->ps_ifdrop = 0;
 407         return 0;
 408 }
 409
 410 static int
 411 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 412 {
 413         p->direction = d;
 414         return 0;
 415 }