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 #ifndef lint
  35 static const char rcsid[] _U_ =
  36     "@(#) $Header: /tcpdump/master/libpcap/pcap-bt-linux.c,v 1.9.2.2 2008-04-04 19:39:05 guy Exp $ (LBL)";
  37 #endif
  38
  39 #ifdef HAVE_CONFIG_H
  40 #include "config.h"
  41 #endif
  42
  43 #include "pcap-int.h"
  44 #include "pcap-bt-linux.h"
  45 #include "pcap/bluetooth.h"
  46
  47 #ifdef NEED_STRERROR_H
  48 #include "strerror.h"
  49 #endif
  50
  51 #include <errno.h>
  52 #include <stdlib.h>
  53 #include <unistd.h>
  54 #include <fcntl.h>
  55 #include <string.h>
  56 #include <sys/ioctl.h>
  57 #include <sys/socket.h>
  58 #include <arpa/inet.h>
  59
  60 #include <bluetooth/bluetooth.h>
  61 #include <bluetooth/hci.h>
  62
  63 #define BT_IFACE "bluetooth"
  64 #define BT_CTRL_SIZE 128
  65
  66 /* forward declaration */
  67 static int bt_activate(pcap_t *);
  68 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  69 static int bt_inject_linux(pcap_t *, const void *, size_t);
  70 static int bt_setfilter_linux(pcap_t *, struct bpf_program *);
  71 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  72 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  73 static void bt_close_linux(pcap_t *);
  74
  75 int
  76 bt_platform_finddevs(pcap_if_t **alldevsp, char *err_str)
  77 {
  78         pcap_if_t *found_dev = *alldevsp;
  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, "Can't open raw Bluetooth socket %d:%s",
  91                         errno, 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, "Can't get Bluetooth device list via ioctl %d:%s",
 109                         errno, strerror(errno));
 110                 ret = -1;
 111                 goto free;
 112         }
 113
 114         dev_req = dev_list->dev_req;
 115         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 116                 char dev_name[20], dev_descr[30];
 117
 118                 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
 119                 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
 120
 121                 if (pcap_add_if(&found_dev, dev_name, 0,
 122                        dev_descr, err_str) < 0)
 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)
 140 {
 141         pcap_t *p;
 142
 143         p = pcap_create_common(device, ebuf);
 144         if (p == NULL)
 145                 return (NULL);
 146
 147         p->activate_op = bt_activate;
 148         return (p);
 149 }
 150
 151 static int
 152 bt_activate(pcap_t* handle)
 153 {
 154         struct sockaddr_hci addr;
 155         int opt;
 156         int             dev_id;
 157         struct hci_filter       flt;
 158
 159         /* get bt interface id */
 160         if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1)
 161         {
 162                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 163                         "Can't get Bluetooth device index from %s",
 164                          handle->opt.source);
 165                 return -1;
 166         }
 167
 168         /* Initialize some components of the pcap structure. */
 169         handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header);
 170         handle->offset = BT_CTRL_SIZE;
 171         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 172
 173         handle->read_op = bt_read_linux;
 174         handle->inject_op = bt_inject_linux;
 175         handle->setfilter_op = bt_setfilter_linux;
 176         handle->setdirection_op = bt_setdirection_linux;
 177         handle->set_datalink_op = NULL; /* can't change data link type */
 178         handle->getnonblock_op = pcap_getnonblock_fd;
 179         handle->setnonblock_op = pcap_setnonblock_fd;
 180         handle->stats_op = bt_stats_linux;
 181         handle->close_op = bt_close_linux;
 182         handle->md.ifindex = dev_id;
 183
 184         /* Create HCI socket */
 185         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 186         if (handle->fd < 0) {
 187                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't create raw socket %d:%s",
 188                         errno, strerror(errno));
 189                 return -1;
 190         }
 191
 192         handle->buffer = malloc(handle->bufsize);
 193         if (!handle->buffer) {
 194                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 195                         pcap_strerror(errno));
 196                 goto close_fail;
 197         }
 198
 199         opt = 1;
 200         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 201                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't enable data direction info %d:%s",
 202                         errno, strerror(errno));
 203                 goto close_fail;
 204         }
 205
 206         opt = 1;
 207         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 208                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't enable time stamp %d:%s",
 209                         errno, strerror(errno));
 210                 goto close_fail;
 211         }
 212
 213         /* Setup filter, do not call hci function to avoid dependence on
 214          * external libs        */
 215         memset(&flt, 0, sizeof(flt));
 216         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 217         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 218         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 219                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't set filter %d:%s",
 220                         errno, strerror(errno));
 221                 goto close_fail;
 222         }
 223
 224
 225         /* Bind socket to the HCI device */
 226         addr.hci_family = AF_BLUETOOTH;
 227         addr.hci_dev = handle->md.ifindex;
 228         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 229                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't attach to device %d %d:%s",
 230                         handle->md.ifindex, errno, strerror(errno));
 231                 goto close_fail;
 232         }
 233         handle->selectable_fd = handle->fd;
 234         return 0;
 235
 236 close_fail:
 237         close(handle->fd);
 238         return -1;
 239 }
 240
 241 static int
 242 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
 243 {
 244         struct cmsghdr *cmsg;
 245         struct msghdr msg;
 246         struct iovec  iv;
 247         struct pcap_pkthdr pkth;
 248         pcap_bluetooth_h4_header* bthdr;
 249
 250         bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset];
 251         iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)];
 252         iv.iov_len  = handle->snapshot;
 253
 254         memset(&msg, 0, sizeof(msg));
 255         msg.msg_iov = &iv;
 256         msg.msg_iovlen = 1;
 257         msg.msg_control = handle->buffer;
 258         msg.msg_controllen = handle->offset;
 259
 260         /* ignore interrupt system call error */
 261         do {
 262                 pkth.caplen = recvmsg(handle->fd, &msg, 0);
 263                 if (handle->break_loop)
 264                 {
 265                         handle->break_loop = 0;
 266                         return -2;
 267                 }
 268         } while ((pkth.caplen == -1) && (errno == EINTR));
 269
 270
 271         if (pkth.caplen < 0) {
 272                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't receive packet %d:%s",
 273                         errno, strerror(errno));
 274                 return -1;
 275         }
 276
 277         /* get direction and timestamp*/
 278         cmsg = CMSG_FIRSTHDR(&msg);
 279         int in=0;
 280         while (cmsg) {
 281                 switch (cmsg->cmsg_type) {
 282                         case HCI_CMSG_DIR:
 283                                 in = *((int *) CMSG_DATA(cmsg));
 284                                 break;
 285                         case HCI_CMSG_TSTAMP:
 286                                 pkth.ts = *((struct timeval *) CMSG_DATA(cmsg));
 287                                 break;
 288                 }
 289                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 290         }
 291         if ((in && (handle->direction == PCAP_D_OUT)) ||
 292                                 ((!in) && (handle->direction == PCAP_D_IN)))
 293                 return 0;
 294
 295         bthdr->direction = htonl(in != 0);
 296         pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
 297         pkth.len = pkth.caplen;
 298         callback(user, &pkth, &handle->buffer[handle->offset]);
 299         return 1;
 300 }
 301
 302 static int
 303 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
 304 {
 305         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
 306                 "bluetooth devices");
 307         return (-1);
 308 }
 309
 310
 311 static void
 312 bt_close_linux(pcap_t* handle)
 313 {
 314         close(handle->fd);
 315         free(handle->buffer);
 316 }
 317
 318
 319 static int
 320 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 321 {
 322         int ret;
 323         struct hci_dev_info dev_info;
 324         struct hci_dev_stats * s = &dev_info.stat;
 325         dev_info.dev_id = handle->md.ifindex;
 326
 327         /* ingnore eintr */
 328         do {
 329                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 330         } while ((ret == -1) && (errno == EINTR));
 331
 332         if (ret < 0) {
 333                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "can get stats"
 334                         " via ioctl %d:%s", errno, strerror(errno));
 335                 return (-1);
 336
 337         }
 338
 339         /* we receive both rx and tx frames, so comulate all stats */
 340         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 341                 s->acl_tx +s->sco_tx;
 342         stats->ps_drop = s->err_rx + s->err_tx;
 343         stats->ps_ifdrop = 0;
 344         return 0;
 345 }
 346
 347 static int
 348 bt_setfilter_linux(pcap_t *p, struct bpf_program *fp)
 349 {
 350         return 0;
 351 }
 352
 353
 354 static int
 355 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 356 {
 357         p->direction = d;
 358         return 0;
 359 }