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.it>
  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                 /* if bluetooth is not supported this this is not fatal*/
  82                 if (errno == EAFNOSUPPORT)
  83                         return 0;
  84                 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't open raw Bluetooth socket %d:%s",
  85                         errno, strerror(errno));
  86                 return -1;
  87         }
  88
  89         dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  90         if (!dev_list)
  91         {
  92                 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %d bytes for Bluetooth device list",
  93                         HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  94                 ret = -1;
  95                 goto done;
  96         }
  97
  98         dev_list->dev_num = HCI_MAX_DEV;
  99
 100         if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
 101         {
 102                 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't get Bluetooth device list via ioctl %d:%s",
 103                         errno, strerror(errno));
 104                 ret = -1;
 105                 goto free;
 106         }
 107
 108         dev_req = dev_list->dev_req;
 109         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 110                 char dev_name[20], dev_descr[30];
 111
 112                 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 113                 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 114
 115                 if (pcap_add_if(&found_dev, dev_name, 0,
 116                        dev_descr, err_str) < 0)
 117                 {
 118                         ret = -1;
 119                         break;
 120                 }
 121
 122         }
 123
 124 free:
 125         free(dev_list);
 126
 127 done:
 128         close(sock);
 129         return ret;
 130 }
 131
 132 pcap_t*
 133 bt_open_live(const char* bus, int snaplen, int promisc , int to_ms, char* errmsg)
 134 {
 135         struct sockaddr_hci addr;
 136         int opt;
 137         pcap_t          *handle;
 138         int             dev_id;
 139         struct hci_filter       flt;
 140
 141         /* get bt interface id */
 142         if (sscanf(bus, BT_IFACE"%d", &dev_id) != 1)
 143         {
 144                 snprintf(errmsg, PCAP_ERRBUF_SIZE,
 145                         "Can't get usb bus index from %s", bus);
 146                 return NULL;
 147         }
 148
 149         /* Allocate a handle for this session. */
 150         handle = malloc(sizeof(*handle));
 151         if (handle == NULL) {
 152                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "malloc: %s",
 153                         pcap_strerror(errno));
 154                 return NULL;
 155         }
 156
 157         /* Initialize some components of the pcap structure. */
 158         memset(handle, 0, sizeof(*handle));
 159         handle->snapshot        = snaplen;
 160         handle->md.timeout      = to_ms;
 161         handle->bufsize = snaplen+BT_CTRL_SIZE;
 162         handle->offset = BT_CTRL_SIZE;
 163         handle->linktype = DLT_BLUETOOTH_HCI_H4;
 164
 165         handle->read_op = bt_read_linux;
 166         handle->inject_op = bt_inject_linux;
 167         handle->setfilter_op = bt_setfilter_linux;
 168         handle->setdirection_op = bt_setdirection_linux;
 169         handle->set_datalink_op = NULL; /* can't change data link type */
 170         handle->getnonblock_op = pcap_getnonblock_fd;
 171         handle->setnonblock_op = pcap_setnonblock_fd;
 172         handle->stats_op = bt_stats_linux;
 173         handle->close_op = bt_close_linux;
 174         handle->md.ifindex = dev_id;
 175
 176         /* Create HCI socket */
 177         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 178         if (handle->fd < 0) {
 179                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s",
 180                         errno, strerror(errno));
 181                 free(handle);
 182                 return NULL;
 183         }
 184
 185         handle->buffer = malloc(snaplen+BT_CTRL_SIZE);
 186         if (!handle->buffer) {
 187                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 188                         pcap_strerror(errno));
 189                 pcap_close(handle);
 190                 return NULL;
 191         }
 192
 193         opt = 1;
 194         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 195                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't enable data direction info %d:%s",
 196                         errno, strerror(errno));
 197                 pcap_close(handle);
 198                 return NULL;
 199         }
 200
 201         opt = 1;
 202         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 203                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't enable time stamp %d:%s",
 204                         errno, strerror(errno));
 205                 pcap_close(handle);
 206                 return NULL;
 207         }
 208
 209         /* Setup filter, do not call hci function to avoid dependence on
 210          * external libs        */
 211         memset(&flt, 0, sizeof(flt));
 212         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 213         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 214         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 215                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't set filter %d:%s",
 216                         errno, strerror(errno));
 217                 pcap_close(handle);
 218                 return NULL;
 219         }
 220
 221
 222         /* Bind socket to the HCI device */
 223         addr.hci_family = AF_BLUETOOTH;
 224         addr.hci_dev = handle->md.ifindex;
 225         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 226                 snprintf(errmsg, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s",
 227                         handle->md.ifindex, errno, strerror(errno));
 228                 pcap_close(handle);
 229                 return NULL;
 230         }
 231         handle->selectable_fd = handle->fd;
 232
 233         return handle;
 234 }
 235
 236 static int
 237 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 238 {
 239         struct cmsghdr *cmsg;
 240         struct msghdr msg;
 241         struct iovec  iv;
 242         struct pcap_pkthdr pkth;
 243
 244         iv.iov_base = &handle->buffer[handle->offset];
 245         iv.iov_len  = handle->snapshot;
 246
 247         memset(&msg, 0, sizeof(msg));
 248         msg.msg_iov = &iv;
 249         msg.msg_iovlen = 1;
 250         msg.msg_control = handle->buffer;
 251         msg.msg_controllen = handle->offset;
 252
 253         /* ignore interrupt system call error */
 254         do {
 255                 pkth.caplen = recvmsg(handle->fd, &msg, 0);
 256                 if (handle->break_loop)
 257                 {
 258                         handle->break_loop = 0;
 259                         return -2;
 260                 }
 261         } while ((pkth.caplen == -1) && (errno == EINTR));
 262
 263
 264         if (pkth.caplen < 0) {
 265                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s",
 266                         handle->md.ifindex, errno, strerror(errno));
 267                 return -1;
 268         }
 269
 270         /* get direction and timestamp*/
 271         cmsg = CMSG_FIRSTHDR(&msg);
 272         while (cmsg) {
 273                 int in;
 274                 switch (cmsg->cmsg_type) {
 275                         case HCI_CMSG_DIR:
 276                                 in = *((int *) CMSG_DATA(cmsg));
 277                                 break;
 278                         case HCI_CMSG_TSTAMP:
 279                                 pkth.ts = *((struct timeval *) CMSG_DATA(cmsg));
 280                                 break;
 281                 }
 282                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 283         }
 284         pkth.len = pkth.caplen;
 285         callback(user, &pkth, iv.iov_base);
 286         return 1;
 287 }
 288
 289 static int
 290 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 291 {
 292         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 293                 "bluetooth devices");
 294         return (-1);
 295 }
 296
 297
 298 static void
 299 bt_close_linux(pcap_t* handle)
 300 {
 301         close(handle->fd);
 302         free(handle->buffer);
 303 }
 304
 305
 306 static int
 307 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 308 {
 309         int ret;
 310         struct hci_dev_info dev_info;
 311         struct hci_dev_stats * s = &dev_info.stat;
 312         dev_info.dev_id = handle->md.ifindex;
 313
 314         /* ingnore eintr */
 315         do {
 316                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 317         } while ((ret == -1) && (errno == EINTR));
 318
 319         if (ret < 0) {
 320                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can get stats"
 321                         " via ioctl %d:%s", errno, strerror(errno));
 322                 return (-1);
 323
 324         }
 325
 326         /* we receive both rx and tx frames, so comulate all stats */
 327         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 328                 s->acl_tx +s->sco_tx;
 329         stats->ps_drop = s->err_rx + s->err_tx;
 330         stats->ps_ifdrop = 0;
 331         return 0;
 332 }
 333
 334 static int
 335 bt_setfilter_linux(pcap_t *p, struct bpf_program *fp)
 336 {
 337         return 0;
 338 }
 339
 340
 341 static int
 342 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 343 {
 344         p->direction = d;
 345         return 0;
 346 }