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