contrib/libpcap/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_t **alldevsp, 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                 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                 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                 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                 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 120                 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 121
 122                 if (pcap_add_if(alldevsp, dev_name, 0,
 123                        dev_descr, err_str) < 0)
 124                 {
 125                         ret = -1;
 126                         break;
 127                 }
 128
 129         }
 130
 131 free:
 132         free(dev_list);
 133
 134 done:
 135         close(sock);
 136         return ret;
 137 }
 138
 139 pcap_t *
 140 bt_create(const char *device, char *ebuf, int *is_ours)
 141 {
 142         const char *cp;
 143         char *cpend;
 144         long devnum;
 145         pcap_t *p;
 146
 147         /* Does this look like a Bluetooth device? */
 148         cp = strrchr(device, '/');
 149         if (cp == NULL)
 150                 cp = device;
 151         /* Does it begin with BT_IFACE? */
 152         if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
 153                 /* Nope, doesn't begin with BT_IFACE */
 154                 *is_ours = 0;
 155                 return NULL;
 156         }
 157         /* Yes - is BT_IFACE followed by a number? */
 158         cp += sizeof BT_IFACE - 1;
 159         devnum = strtol(cp, &cpend, 10);
 160         if (cpend == cp || *cpend != '\0') {
 161                 /* Not followed by a number. */
 162                 *is_ours = 0;
 163                 return NULL;
 164         }
 165         if (devnum < 0) {
 166                 /* Followed by a non-valid number. */
 167                 *is_ours = 0;
 168                 return NULL;
 169         }
 170
 171         /* OK, it's probably ours. */
 172         *is_ours = 1;
 173
 174         p = pcap_create_common(device, ebuf, sizeof (struct pcap_bt));
 175         if (p == NULL)
 176                 return (NULL);
 177
 178         p->activate_op = bt_activate;
 179         return (p);
 180 }
 181
 182 static int
 183 bt_activate(pcap_t* handle)
 184 {
 185         struct pcap_bt *handlep = handle->priv;
 186         struct sockaddr_hci addr;
 187         int opt;
 188         int             dev_id;
 189         struct hci_filter       flt;
 190         int err = PCAP_ERROR;
 191
 192         /* get bt interface id */
 193         if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1)
 194         {
 195                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 196                         "Can't get Bluetooth device index from %s",
 197                          handle->opt.source);
 198                 return PCAP_ERROR;
 199         }
 200
 201         /* Initialize some components of the pcap structure. */
 202         handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header);
 203         handle->offset = BT_CTRL_SIZE;
 204         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 205
 206         handle->read_op = bt_read_linux;
 207         handle->inject_op = bt_inject_linux;
 208         handle->setfilter_op = install_bpf_program; /* no kernel filtering */
 209         handle->setdirection_op = bt_setdirection_linux;
 210         handle->set_datalink_op = NULL; /* can't change data link type */
 211         handle->getnonblock_op = pcap_getnonblock_fd;
 212         handle->setnonblock_op = pcap_setnonblock_fd;
 213         handle->stats_op = bt_stats_linux;
 214         handlep->dev_id = dev_id;
 215
 216         /* Create HCI socket */
 217         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 218         if (handle->fd < 0) {
 219                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 220                     "Can't create raw socket: %s", strerror(errno));
 221                 return PCAP_ERROR;
 222         }
 223
 224         handle->buffer = malloc(handle->bufsize);
 225         if (!handle->buffer) {
 226                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 227                         pcap_strerror(errno));
 228                 goto close_fail;
 229         }
 230
 231         opt = 1;
 232         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 233                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 234                     "Can't enable data direction info: %s", strerror(errno));
 235                 goto close_fail;
 236         }
 237
 238         opt = 1;
 239         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 240                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 241                     "Can't enable time stamp: %s", strerror(errno));
 242                 goto close_fail;
 243         }
 244
 245         /* Setup filter, do not call hci function to avoid dependence on
 246          * external libs        */
 247         memset(&flt, 0, sizeof(flt));
 248         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 249         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 250         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 251                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 252                     "Can't set filter: %s", strerror(errno));
 253                 goto close_fail;
 254         }
 255
 256
 257         /* Bind socket to the HCI device */
 258         addr.hci_family = AF_BLUETOOTH;
 259         addr.hci_dev = handlep->dev_id;
 260 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
 261         addr.hci_channel = HCI_CHANNEL_RAW;
 262 #endif
 263         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 264                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 265                     "Can't attach to device %d: %s", handlep->dev_id,
 266                     strerror(errno));
 267                 goto close_fail;
 268         }
 269
 270         if (handle->opt.rfmon) {
 271                 /*
 272                  * Monitor mode doesn't apply to Bluetooth devices.
 273                  */
 274                 err = PCAP_ERROR_RFMON_NOTSUP;
 275                 goto close_fail;
 276         }
 277
 278         if (handle->opt.buffer_size != 0) {
 279                 /*
 280                  * Set the socket buffer size to the specified value.
 281                  */
 282                 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
 283                     &handle->opt.buffer_size,
 284                     sizeof(handle->opt.buffer_size)) == -1) {
 285                         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 286                                  "SO_RCVBUF: %s", pcap_strerror(errno));
 287                         goto close_fail;
 288                 }
 289         }
 290
 291         handle->selectable_fd = handle->fd;
 292         return 0;
 293
 294 close_fail:
 295         pcap_cleanup_live_common(handle);
 296         return err;
 297 }
 298
 299 static int
 300 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 301 {
 302         struct cmsghdr *cmsg;
 303         struct msghdr msg;
 304         struct iovec  iv;
 305         ssize_t ret;
 306         struct pcap_pkthdr pkth;
 307         pcap_bluetooth_h4_header* bthdr;
 308
 309         bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset];
 310         iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)];
 311         iv.iov_len  = handle->snapshot;
 312
 313         memset(&msg, 0, sizeof(msg));
 314         msg.msg_iov = &iv;
 315         msg.msg_iovlen = 1;
 316         msg.msg_control = handle->buffer;
 317         msg.msg_controllen = handle->offset;
 318
 319         /* ignore interrupt system call error */
 320         do {
 321                 ret = recvmsg(handle->fd, &msg, 0);
 322                 if (handle->break_loop)
 323                 {
 324                         handle->break_loop = 0;
 325                         return -2;
 326                 }
 327         } while ((ret == -1) && (errno == EINTR));
 328
 329         if (ret < 0) {
 330                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 331                     "Can't receive packet: %s", strerror(errno));
 332                 return -1;
 333         }
 334
 335         pkth.caplen = ret;
 336
 337         /* get direction and timestamp*/
 338         cmsg = CMSG_FIRSTHDR(&msg);
 339         int in=0;
 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, &handle->buffer[handle->offset],
 361               pkth.len, pkth.caplen)) {
 362                 callback(user, &pkth, &handle->buffer[handle->offset]);
 363                 return 1;
 364         }
 365         return 0;       /* didn't pass filter */
 366 }
 367
 368 static int
 369 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 370 {
 371         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 372                 "bluetooth devices");
 373         return (-1);
 374 }
 375
 376
 377 static int
 378 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 379 {
 380         struct pcap_bt *handlep = handle->priv;
 381         int ret;
 382         struct hci_dev_info dev_info;
 383         struct hci_dev_stats * s = &dev_info.stat;
 384         dev_info.dev_id = handlep->dev_id;
 385
 386         /* ignore eintr */
 387         do {
 388                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 389         } while ((ret == -1) && (errno == EINTR));
 390
 391         if (ret < 0) {
 392                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 393                     "Can't get stats via ioctl: %s", strerror(errno));
 394                 return (-1);
 395
 396         }
 397
 398         /* we receive both rx and tx frames, so comulate all stats */
 399         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 400                 s->acl_tx +s->sco_tx;
 401         stats->ps_drop = s->err_rx + s->err_tx;
 402         stats->ps_ifdrop = 0;
 403         return 0;
 404 }
 405
 406 static int
 407 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 408 {
 409         p->direction = d;
 410         return 0;
 411 }