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 /*
  74  * Private data for capturing on Linux Bluetooth devices.
  75  */
  76 struct pcap_bt {
  77         int dev_id;             /* device ID of device we're bound to */
  78 };
  79
  80 int
  81 bt_findalldevs(pcap_if_t **alldevsp, char *err_str)
  82 {
  83         pcap_if_t *found_dev = *alldevsp;
  84         struct hci_dev_list_req *dev_list;
  85         struct hci_dev_req *dev_req;
  86         int i, sock;
  87         int ret = 0;
  88
  89         sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
  90         if (sock < 0)
  91         {
  92                 /* if bluetooth is not supported this this is not fatal*/
  93                 if (errno == EAFNOSUPPORT)
  94                         return 0;
  95                 snprintf(err_str, PCAP_ERRBUF_SIZE,
  96                     "Can't open raw Bluetooth socket: %s", strerror(errno));
  97                 return -1;
  98         }
  99
 100         dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
 101         if (!dev_list)
 102         {
 103                 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
 104                         HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
 105                 ret = -1;
 106                 goto done;
 107         }
 108
 109         dev_list->dev_num = HCI_MAX_DEV;
 110
 111         if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
 112         {
 113                 snprintf(err_str, PCAP_ERRBUF_SIZE,
 114                     "Can't get Bluetooth device list via ioctl: %s",
 115                     strerror(errno));
 116                 ret = -1;
 117                 goto free;
 118         }
 119
 120         dev_req = dev_list->dev_req;
 121         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 122                 char dev_name[20], dev_descr[30];
 123
 124                 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 125                 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 126
 127                 if (pcap_add_if(&found_dev, dev_name, 0,
 128                        dev_descr, err_str) < 0)
 129                 {
 130                         ret = -1;
 131                         break;
 132                 }
 133
 134         }
 135
 136 free:
 137         free(dev_list);
 138
 139 done:
 140         close(sock);
 141         return ret;
 142 }
 143
 144 pcap_t *
 145 bt_create(const char *device, char *ebuf, int *is_ours)
 146 {
 147         const char *cp;
 148         char *cpend;
 149         long devnum;
 150         pcap_t *p;
 151
 152         /* Does this look like a Bluetooth device? */
 153         cp = strrchr(device, '/');
 154         if (cp == NULL)
 155                 cp = device;
 156         /* Does it begin with BT_IFACE? */
 157         if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
 158                 /* Nope, doesn't begin with BT_IFACE */
 159                 *is_ours = 0;
 160                 return NULL;
 161         }
 162         /* Yes - is BT_IFACE followed by a number? */
 163         cp += sizeof BT_IFACE - 1;
 164         devnum = strtol(cp, &cpend, 10);
 165         if (cpend == cp || *cpend != '\0') {
 166                 /* Not followed by a number. */
 167                 *is_ours = 0;
 168                 return NULL;
 169         }
 170         if (devnum < 0) {
 171                 /* Followed by a non-valid number. */
 172                 *is_ours = 0;
 173                 return NULL;
 174         }
 175
 176         /* OK, it's probably ours. */
 177         *is_ours = 1;
 178
 179         p = pcap_create_common(device, ebuf, sizeof (struct pcap_bt));
 180         if (p == NULL)
 181                 return (NULL);
 182
 183         p->activate_op = bt_activate;
 184         return (p);
 185 }
 186
 187 static int
 188 bt_activate(pcap_t* handle)
 189 {
 190         struct pcap_bt *handlep = handle->priv;
 191         struct sockaddr_hci addr;
 192         int opt;
 193         int             dev_id;
 194         struct hci_filter       flt;
 195         int err = PCAP_ERROR;
 196
 197         /* get bt interface id */
 198         if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1)
 199         {
 200                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 201                         "Can't get Bluetooth device index from %s",
 202                          handle->opt.source);
 203                 return PCAP_ERROR;
 204         }
 205
 206         /* Initialize some components of the pcap structure. */
 207         handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header);
 208         handle->offset = BT_CTRL_SIZE;
 209         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 210
 211         handle->read_op = bt_read_linux;
 212         handle->inject_op = bt_inject_linux;
 213         handle->setfilter_op = install_bpf_program; /* no kernel filtering */
 214         handle->setdirection_op = bt_setdirection_linux;
 215         handle->set_datalink_op = NULL; /* can't change data link type */
 216         handle->getnonblock_op = pcap_getnonblock_fd;
 217         handle->setnonblock_op = pcap_setnonblock_fd;
 218         handle->stats_op = bt_stats_linux;
 219         handlep->dev_id = dev_id;
 220
 221         /* Create HCI socket */
 222         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 223         if (handle->fd < 0) {
 224                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 225                     "Can't create raw socket: %s", strerror(errno));
 226                 return PCAP_ERROR;
 227         }
 228
 229         handle->buffer = malloc(handle->bufsize);
 230         if (!handle->buffer) {
 231                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 232                         pcap_strerror(errno));
 233                 goto close_fail;
 234         }
 235
 236         opt = 1;
 237         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 238                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 239                     "Can't enable data direction info: %s", strerror(errno));
 240                 goto close_fail;
 241         }
 242
 243         opt = 1;
 244         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 245                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 246                     "Can't enable time stamp: %s", strerror(errno));
 247                 goto close_fail;
 248         }
 249
 250         /* Setup filter, do not call hci function to avoid dependence on
 251          * external libs        */
 252         memset(&flt, 0, sizeof(flt));
 253         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 254         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 255         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 256                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 257                     "Can't set filter: %s", strerror(errno));
 258                 goto close_fail;
 259         }
 260
 261
 262         /* Bind socket to the HCI device */
 263         addr.hci_family = AF_BLUETOOTH;
 264         addr.hci_dev = handlep->dev_id;
 265 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
 266         addr.hci_channel = HCI_CHANNEL_RAW;
 267 #endif
 268         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 269                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 270                     "Can't attach to device %d: %s", handlep->dev_id,
 271                     strerror(errno));
 272                 goto close_fail;
 273         }
 274
 275         if (handle->opt.rfmon) {
 276                 /*
 277                  * Monitor mode doesn't apply to Bluetooth devices.
 278                  */
 279                 err = PCAP_ERROR_RFMON_NOTSUP;
 280                 goto close_fail;
 281         }
 282
 283         if (handle->opt.buffer_size != 0) {
 284                 /*
 285                  * Set the socket buffer size to the specified value.
 286                  */
 287                 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
 288                     &handle->opt.buffer_size,
 289                     sizeof(handle->opt.buffer_size)) == -1) {
 290                         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 291                                  "SO_RCVBUF: %s", pcap_strerror(errno));
 292                         goto close_fail;
 293                 }
 294         }
 295
 296         handle->selectable_fd = handle->fd;
 297         return 0;
 298
 299 close_fail:
 300         pcap_cleanup_live_common(handle);
 301         return err;
 302 }
 303
 304 static int
 305 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 306 {
 307         struct cmsghdr *cmsg;
 308         struct msghdr msg;
 309         struct iovec  iv;
 310         ssize_t ret;
 311         struct pcap_pkthdr pkth;
 312         pcap_bluetooth_h4_header* bthdr;
 313
 314         bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset];
 315         iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)];
 316         iv.iov_len  = handle->snapshot;
 317
 318         memset(&msg, 0, sizeof(msg));
 319         msg.msg_iov = &iv;
 320         msg.msg_iovlen = 1;
 321         msg.msg_control = handle->buffer;
 322         msg.msg_controllen = handle->offset;
 323
 324         /* ignore interrupt system call error */
 325         do {
 326                 ret = recvmsg(handle->fd, &msg, 0);
 327                 if (handle->break_loop)
 328                 {
 329                         handle->break_loop = 0;
 330                         return -2;
 331                 }
 332         } while ((ret == -1) && (errno == EINTR));
 333
 334         if (ret < 0) {
 335                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 336                     "Can't receive packet: %s", strerror(errno));
 337                 return -1;
 338         }
 339
 340         pkth.caplen = ret;
 341
 342         /* get direction and timestamp*/
 343         cmsg = CMSG_FIRSTHDR(&msg);
 344         int in=0;
 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, &handle->buffer[handle->offset],
 366               pkth.len, pkth.caplen)) {
 367                 callback(user, &pkth, &handle->buffer[handle->offset]);
 368                 return 1;
 369         }
 370         return 0;       /* didn't pass filter */
 371 }
 372
 373 static int
 374 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 375 {
 376         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 377                 "bluetooth devices");
 378         return (-1);
 379 }
 380
 381
 382 static int
 383 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 384 {
 385         struct pcap_bt *handlep = handle->priv;
 386         int ret;
 387         struct hci_dev_info dev_info;
 388         struct hci_dev_stats * s = &dev_info.stat;
 389         dev_info.dev_id = handlep->dev_id;
 390
 391         /* ignore eintr */
 392         do {
 393                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 394         } while ((ret == -1) && (errno == EINTR));
 395
 396         if (ret < 0) {
 397                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 398                     "Can't get stats via ioctl: %s", strerror(errno));
 399                 return (-1);
 400
 401         }
 402
 403         /* we receive both rx and tx frames, so comulate all stats */
 404         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 405                 s->acl_tx +s->sco_tx;
 406         stats->ps_drop = s->err_rx + s->err_tx;
 407         stats->ps_ifdrop = 0;
 408         return 0;
 409 }
 410
 411 static int
 412 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 413 {
 414         p->direction = d;
 415         return 0;
 416 }