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         /*
 201          * Turn a negative snapshot value (invalid), a snapshot value of
 202          * 0 (unspecified), or a value bigger than the normal maximum
 203          * value, into the maximum allowed value.
 204          *
 205          * If some application really *needs* a bigger snapshot
 206          * length, we should just increase MAXIMUM_SNAPLEN.
 207          */
 208         if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
 209                 handle->snapshot = MAXIMUM_SNAPLEN;
 210
 211         /* Initialize some components of the pcap structure. */
 212         handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
 213         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 214
 215         handle->read_op = bt_read_linux;
 216         handle->inject_op = bt_inject_linux;
 217         handle->setfilter_op = install_bpf_program; /* no kernel filtering */
 218         handle->setdirection_op = bt_setdirection_linux;
 219         handle->set_datalink_op = NULL; /* can't change data link type */
 220         handle->getnonblock_op = pcap_getnonblock_fd;
 221         handle->setnonblock_op = pcap_setnonblock_fd;
 222         handle->stats_op = bt_stats_linux;
 223         handlep->dev_id = dev_id;
 224
 225         /* Create HCI socket */
 226         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 227         if (handle->fd < 0) {
 228                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 229                     "Can't create raw socket: %s", strerror(errno));
 230                 return PCAP_ERROR;
 231         }
 232
 233         handle->buffer = malloc(handle->bufsize);
 234         if (!handle->buffer) {
 235                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 236                         pcap_strerror(errno));
 237                 goto close_fail;
 238         }
 239
 240         opt = 1;
 241         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 242                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 243                     "Can't enable data direction info: %s", strerror(errno));
 244                 goto close_fail;
 245         }
 246
 247         opt = 1;
 248         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 249                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 250                     "Can't enable time stamp: %s", strerror(errno));
 251                 goto close_fail;
 252         }
 253
 254         /* Setup filter, do not call hci function to avoid dependence on
 255          * external libs        */
 256         memset(&flt, 0, sizeof(flt));
 257         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 258         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 259         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 260                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 261                     "Can't set filter: %s", strerror(errno));
 262                 goto close_fail;
 263         }
 264
 265
 266         /* Bind socket to the HCI device */
 267         addr.hci_family = AF_BLUETOOTH;
 268         addr.hci_dev = handlep->dev_id;
 269 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
 270         addr.hci_channel = HCI_CHANNEL_RAW;
 271 #endif
 272         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 273                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 274                     "Can't attach to device %d: %s", handlep->dev_id,
 275                     strerror(errno));
 276                 goto close_fail;
 277         }
 278
 279         if (handle->opt.rfmon) {
 280                 /*
 281                  * Monitor mode doesn't apply to Bluetooth devices.
 282                  */
 283                 err = PCAP_ERROR_RFMON_NOTSUP;
 284                 goto close_fail;
 285         }
 286
 287         if (handle->opt.buffer_size != 0) {
 288                 /*
 289                  * Set the socket buffer size to the specified value.
 290                  */
 291                 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
 292                     &handle->opt.buffer_size,
 293                     sizeof(handle->opt.buffer_size)) == -1) {
 294                         pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 295                                  "SO_RCVBUF: %s", pcap_strerror(errno));
 296                         goto close_fail;
 297                 }
 298         }
 299
 300         handle->selectable_fd = handle->fd;
 301         return 0;
 302
 303 close_fail:
 304         pcap_cleanup_live_common(handle);
 305         return err;
 306 }
 307
 308 static int
 309 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 310 {
 311         struct cmsghdr *cmsg;
 312         struct msghdr msg;
 313         struct iovec  iv;
 314         ssize_t ret;
 315         struct pcap_pkthdr pkth;
 316         pcap_bluetooth_h4_header* bthdr;
 317         u_char *pktd;
 318         int in = 0;
 319
 320         pktd = (u_char *)handle->buffer + BT_CTRL_SIZE;
 321         bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
 322         iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
 323         iv.iov_len  = handle->snapshot;
 324
 325         memset(&msg, 0, sizeof(msg));
 326         msg.msg_iov = &iv;
 327         msg.msg_iovlen = 1;
 328         msg.msg_control = handle->buffer;
 329         msg.msg_controllen = BT_CTRL_SIZE;
 330
 331         /* ignore interrupt system call error */
 332         do {
 333                 ret = recvmsg(handle->fd, &msg, 0);
 334                 if (handle->break_loop)
 335                 {
 336                         handle->break_loop = 0;
 337                         return -2;
 338                 }
 339         } while ((ret == -1) && (errno == EINTR));
 340
 341         if (ret < 0) {
 342                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 343                     "Can't receive packet: %s", strerror(errno));
 344                 return -1;
 345         }
 346
 347         pkth.caplen = ret;
 348
 349         /* get direction and timestamp*/
 350         cmsg = CMSG_FIRSTHDR(&msg);
 351         while (cmsg) {
 352                 switch (cmsg->cmsg_type) {
 353                         case HCI_CMSG_DIR:
 354                                 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
 355                                 break;
 356                         case HCI_CMSG_TSTAMP:
 357                                 memcpy(&pkth.ts, CMSG_DATA(cmsg),
 358                                     sizeof pkth.ts);
 359                                 break;
 360                 }
 361                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 362         }
 363         if ((in && (handle->direction == PCAP_D_OUT)) ||
 364                                 ((!in) && (handle->direction == PCAP_D_IN)))
 365                 return 0;
 366
 367         bthdr->direction = htonl(in != 0);
 368         pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
 369         pkth.len = pkth.caplen;
 370         if (handle->fcode.bf_insns == NULL ||
 371             bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
 372                 callback(user, &pkth, pktd);
 373                 return 1;
 374         }
 375         return 0;       /* didn't pass filter */
 376 }
 377
 378 static int
 379 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 380 {
 381         pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 382                 "bluetooth devices");
 383         return (-1);
 384 }
 385
 386
 387 static int
 388 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 389 {
 390         struct pcap_bt *handlep = handle->priv;
 391         int ret;
 392         struct hci_dev_info dev_info;
 393         struct hci_dev_stats * s = &dev_info.stat;
 394         dev_info.dev_id = handlep->dev_id;
 395
 396         /* ignore eintr */
 397         do {
 398                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 399         } while ((ret == -1) && (errno == EINTR));
 400
 401         if (ret < 0) {
 402                 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 403                     "Can't get stats via ioctl: %s", strerror(errno));
 404                 return (-1);
 405
 406         }
 407
 408         /* we receive both rx and tx frames, so comulate all stats */
 409         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 410                 s->acl_tx +s->sco_tx;
 411         stats->ps_drop = s->err_rx + s->err_tx;
 412         stats->ps_ifdrop = 0;
 413         return 0;
 414 }
 415
 416 static int
 417 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 418 {
 419         p->direction = d;
 420         return 0;
 421 }