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. Neither the name of the Politecnico di Torino, CACE Technologies
  15  * nor the names of its contributors may be used to endorse or promote
  16  * products derived from this software without specific prior written
  17  * permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  *
  31  * Bluetooth sniffing API implementation for Linux platform
  32  * By Paolo Abeni <paolo.abeni@email.com>
  33  *
  34  */
  35
  36 #ifdef HAVE_CONFIG_H
  37 #include "config.h"
  38 #endif
  39
  40 #include "pcap-int.h"
  41 #include "pcap-bt-linux.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
  55 #include <bluetooth/bluetooth.h>
  56 #include <bluetooth/hci.h>
  57
  58 #define BT_IFACE "bluetooth"
  59 #define BT_CTRL_SIZE 128
  60
  61 /* forward declaration */
  62 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  63 static int bt_inject_linux(pcap_t *, const void *, size_t);
  64 static int bt_setfilter_linux(pcap_t *, struct bpf_program *);
  65 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  66 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  67 static void bt_close_linux(pcap_t *);
  68
  69 int
  70 bt_platform_finddevs(pcap_if_t **alldevsp, char *err_str)
  71 {
  72         pcap_if_t *found_dev = *alldevsp;
  73         struct hci_dev_list_req *dev_list;
  74         struct hci_dev_req *dev_req;
  75         int i, sock;
  76         int ret = 0;
  77
  78         sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
  79         if (sock < 0)
  80         {
  81                 snprintf(err_str, PCAP_ERRBUF_SIZE, "can't open raw by socket %d:%s",
  82                         errno, strerror(errno));
  83                 return -1;
  84         }
  85
  86         dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  87         if (!dev_list)
  88         {
  89                 snprintf(err_str, PCAP_ERRBUF_SIZE, "can't allocate %d bytes for dev cache",
  90                         HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  91                 ret = -1;
  92                 goto done;
  93         }
  94
  95         dev_list->dev_num = HCI_MAX_DEV;
  96
  97         if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
  98         {
  99                 snprintf(err_str, PCAP_ERRBUF_SIZE, "can't get dev list via ioctl %d:%s",
 100                         errno, strerror(errno));
 101                 ret = -1;
 102                 goto free;
 103         }
 104
 105         dev_req = dev_list->dev_req;
 106         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 107                 char dev_name[20], dev_descr[30];
 108
 109                 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 110                 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 111
 112                 if (pcap_add_if(&found_dev, dev_name, 0,
 113                        dev_descr, err_str) < 0)
 114                 {
 115                         ret = -1;
 116                         break;
 117                 }
 118
 119         }
 120
 121 free:
 122         free(dev_list);
 123
 124 done:
 125         close(sock);
 126         return ret;
 127 }
 128
 129 pcap_t*
 130 bt_open_live(const char* bus, int snaplen, int promisc , int to_ms, char* errmsg)
 131 {
 132         struct sockaddr_hci addr;
 133         int opt;
 134         pcap_t          *handle;
 135         int             dev_id;
 136         struct hci_filter       flt;
 137
 138         /* get bt interface id */
 139         if (sscanf(bus, BT_IFACE"%d", &dev_id) != 1)
 140         {
 141                 snprintf(errmsg, PCAP_ERRBUF_SIZE,
 142                         "Can't get usb bus index from %s", bus);
 143                 return NULL;
 144         }
 145
 146         /* Allocate a handle for this session. */
 147         handle = malloc(sizeof(*handle));
 148         if (handle == NULL) {
 149                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "malloc: %s",
 150                         pcap_strerror(errno));
 151                 return NULL;
 152         }
 153
 154         /* Initialize some components of the pcap structure. */
 155         memset(handle, 0, sizeof(*handle));
 156         handle->snapshot        = snaplen;
 157         handle->md.timeout      = to_ms;
 158         handle->bufsize = snaplen+BT_CTRL_SIZE;
 159         handle->offset = BT_CTRL_SIZE;
 160         handle->linktype = DLT_BLUETOOTH_HCI_H4;
 161
 162         handle->read_op = bt_read_linux;
 163         handle->inject_op = bt_inject_linux;
 164         handle->setfilter_op = bt_setfilter_linux;
 165         handle->setdirection_op = bt_setdirection_linux;
 166         handle->set_datalink_op = NULL; /* can't change data link type */
 167         handle->getnonblock_op = pcap_getnonblock_fd;
 168         handle->setnonblock_op = pcap_setnonblock_fd;
 169         handle->stats_op = bt_stats_linux;
 170         handle->close_op = bt_close_linux;
 171         handle->md.ifindex = dev_id;
 172
 173         /* Create HCI socket */
 174         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 175         if (handle->fd < 0) {
 176                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s",
 177                         errno, strerror(errno));
 178                 free(handle);
 179                 return NULL;
 180         }
 181
 182         handle->buffer = malloc(snaplen+BT_CTRL_SIZE);
 183         if (!handle->buffer) {
 184                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 185                         pcap_strerror(errno));
 186                 pcap_close(handle);
 187                 return NULL;
 188         }
 189
 190         opt = 1;
 191         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 192                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't enable data direction info %d:%s",
 193                         errno, strerror(errno));
 194                 pcap_close(handle);
 195                 return NULL;
 196         }
 197
 198         opt = 1;
 199         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 200                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't enable time stamp %d:%s",
 201                         errno, strerror(errno));
 202                 pcap_close(handle);
 203                 return NULL;
 204         }
 205
 206         /* Setup filter, do not call hci function to avoid dependence on
 207          * external libs        */
 208         memset(&flt, 0, sizeof(flt));
 209         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 210         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 211         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 212                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't set filter %d:%s",
 213                         errno, strerror(errno));
 214                 pcap_close(handle);
 215                 return NULL;
 216         }
 217
 218
 219         /* Bind socket to the HCI device */
 220         addr.hci_family = AF_BLUETOOTH;
 221         addr.hci_dev = handle->md.ifindex;
 222         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 223                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s",
 224                         handle->md.ifindex, errno, strerror(errno));
 225                 pcap_close(handle);
 226                 return NULL;
 227         }
 228         handle->selectable_fd = handle->fd;
 229
 230         return handle;
 231 }
 232
 233 static int
 234 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 235 {
 236         struct cmsghdr *cmsg;
 237         struct msghdr msg;
 238         struct iovec  iv;
 239         struct pcap_pkthdr pkth;
 240
 241         iv.iov_base = &handle->buffer[handle->offset];
 242         iv.iov_len  = handle->snapshot;
 243
 244         memset(&msg, 0, sizeof(msg));
 245         msg.msg_iov = &iv;
 246         msg.msg_iovlen = 1;
 247         msg.msg_control = handle->buffer;
 248         msg.msg_controllen = handle->offset;
 249
 250         /* ignore interrupt system call error */
 251         do {
 252                 pkth.caplen = recvmsg(handle->fd, &msg, 0);
 253                 if (handle->break_loop)
 254                 {
 255                         handle->break_loop = 0;
 256                         return -2;
 257                 }
 258         } while ((pkth.caplen == -1) && (errno == EINTR));
 259
 260
 261         if (pkth.caplen < 0) {
 262                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s",
 263                         handle->md.ifindex, errno, strerror(errno));
 264                 return -1;
 265         }
 266
 267         /* get direction and timestamp*/
 268         cmsg = CMSG_FIRSTHDR(&msg);
 269         while (cmsg) {
 270                 int in;
 271                 switch (cmsg->cmsg_type) {
 272                         case HCI_CMSG_DIR:
 273                                 in = *((int *) CMSG_DATA(cmsg));
 274                                 break;
 275                         case HCI_CMSG_TSTAMP:
 276                                 pkth.ts = *((struct timeval *) CMSG_DATA(cmsg));
 277                                 break;
 278                 }
 279                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 280         }
 281         pkth.len = pkth.caplen;
 282         callback(user, &pkth, iv.iov_base);
 283         return 1;
 284 }
 285
 286 static int
 287 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 288 {
 289         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 290                 "bluetooth devices");
 291         return (-1);
 292 }
 293
 294
 295 static void
 296 bt_close_linux(pcap_t* handle)
 297 {
 298         close(handle->fd);
 299         free(handle->buffer);
 300 }
 301
 302
 303 static int
 304 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 305 {
 306         int ret;
 307         struct hci_dev_info dev_info;
 308         struct hci_dev_stats * s = &dev_info.stat;
 309         dev_info.dev_id = handle->md.ifindex;
 310
 311         /* ingnore eintr */
 312         do {
 313                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 314         } while ((ret == -1) && (errno == EINTR));
 315
 316         if (ret < 0) {
 317                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can get stats"
 318                         " via ioctl %d:%s", errno, strerror(errno));
 319                 return (-1);
 320
 321         }
 322
 323         /* we receive both rx and tx frames, so comulate all stats */
 324         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 325                 s->acl_tx +s->sco_tx;
 326         stats->ps_drop = s->err_rx + s->err_tx;
 327         stats->ps_ifdrop = 0;
 328         return 0;
 329 }
 330
 331 static int
 332 bt_setfilter_linux(pcap_t *p, struct bpf_program *fp)
 333 {
 334         return 0;
 335 }
 336
 337
 338 static int
 339 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 340 {
 341         p->direction = d;
 342         return 0;
 343 }