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 #include <config.h>
  36
  37 #include "pcap-int.h"
  38 #include "pcap-bt-linux.h"
  39 #include "pcap/bluetooth.h"
  40 #include "diag-control.h"
  41
  42 #include <errno.h>
  43 #include <stdlib.h>
  44 #include <unistd.h>
  45 #include <fcntl.h>
  46 #include <string.h>
  47 #include <sys/ioctl.h>
  48 #include <sys/socket.h>
  49 #include <arpa/inet.h>
  50
  51 #include <bluetooth/bluetooth.h>
  52 #include <bluetooth/hci.h>
  53
  54 #define BT_IFACE "bluetooth"
  55 #define BT_CTRL_SIZE 128
  56
  57 /* forward declaration */
  58 static int bt_activate(pcap_t *);
  59 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
  60 static int bt_inject_linux(pcap_t *, const void *, int);
  61 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
  62 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
  63
  64 /*
  65  * Private data for capturing on Linux Bluetooth devices.
  66  */
  67 struct pcap_bt {
  68         int dev_id;             /* device ID of device we're bound to */
  69 };
  70
  71 int
  72 bt_findalldevs(pcap_if_list_t *devlistp, char *err_str)
  73 {
  74         struct hci_dev_list_req *dev_list;
  75         struct hci_dev_req *dev_req;
  76         int sock;
  77         unsigned i;
  78         int ret = 0;
  79
  80         sock  = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
  81         if (sock < 0)
  82         {
  83                 /* if bluetooth is not supported this is not fatal*/
  84                 if (errno == EAFNOSUPPORT)
  85                         return 0;
  86                 pcapint_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
  87                     errno, "Can't open raw Bluetooth socket");
  88                 return PCAP_ERROR;
  89         }
  90
  91         dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  92         if (!dev_list)
  93         {
  94                 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
  95                         HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
  96                 ret = PCAP_ERROR;
  97                 goto done;
  98         }
  99
 100         /*
 101          * Zero the complete header, which is larger than dev_num because of tail
 102          * padding, to silence Valgrind, which overshoots validating that dev_num
 103          * has been set.
 104          * https://github.com/the-tcpdump-group/libpcap/issues/1083
 105          * https://bugs.kde.org/show_bug.cgi?id=448464
 106          */
 107         memset(dev_list, 0, sizeof(*dev_list));
 108         dev_list->dev_num = HCI_MAX_DEV;
 109
 110         if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
 111         {
 112                 pcapint_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE,
 113                     errno, "Can't get Bluetooth device list via ioctl");
 114                 ret = PCAP_ERROR;
 115                 goto free;
 116         }
 117
 118         dev_req = dev_list->dev_req;
 119         for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
 120                 char dev_name[20], dev_descr[40];
 121
 122                 snprintf(dev_name, sizeof(dev_name), BT_IFACE"%u", dev_req->dev_id);
 123                 snprintf(dev_descr, sizeof(dev_descr), "Bluetooth adapter number %u", i);
 124
 125                 /*
 126                  * Bluetooth is a wireless technology.
 127                  * XXX - if there's the notion of associating with a
 128                  * network, and we can determine whether the interface
 129                  * is associated with a network, check that and set
 130                  * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED
 131                  * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
 132                  */
 133                 if (pcapint_add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str)  == NULL)
 134                 {
 135                         ret = PCAP_ERROR;
 136                         break;
 137                 }
 138         }
 139
 140 free:
 141         free(dev_list);
 142
 143 done:
 144         close(sock);
 145         return ret;
 146 }
 147
 148 pcap_t *
 149 bt_create(const char *device, char *ebuf, int *is_ours)
 150 {
 151         const char *cp;
 152         char *cpend;
 153         long devnum;
 154         pcap_t *p;
 155
 156         /* Does this look like a Bluetooth device? */
 157         cp = device;
 158         /* Does it begin with BT_IFACE? */
 159         if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
 160                 /* Nope, doesn't begin with BT_IFACE */
 161                 *is_ours = 0;
 162                 return NULL;
 163         }
 164         /* Yes - is BT_IFACE followed by a number? */
 165         cp += sizeof BT_IFACE - 1;
 166         devnum = strtol(cp, &cpend, 10);
 167         if (cpend == cp || *cpend != '\0') {
 168                 /* Not followed by a number. */
 169                 *is_ours = 0;
 170                 return NULL;
 171         }
 172         if (devnum < 0) {
 173                 /* Followed by a non-valid number. */
 174                 *is_ours = 0;
 175                 return NULL;
 176         }
 177
 178         /* OK, it's probably ours. */
 179         *is_ours = 1;
 180
 181         p = PCAP_CREATE_COMMON(ebuf, struct pcap_bt);
 182         if (p == NULL)
 183                 return (NULL);
 184
 185         p->activate_op = bt_activate;
 186         return (p);
 187 }
 188
 189 static int
 190 bt_activate(pcap_t* handle)
 191 {
 192         struct pcap_bt *handlep = handle->priv;
 193         struct sockaddr_hci addr;
 194         int opt;
 195         int             dev_id;
 196         struct hci_filter       flt;
 197         int err = PCAP_ERROR;
 198
 199         /* get bt interface id */
 200         if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1)
 201         {
 202                 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 203                         "Can't get Bluetooth device index from %s",
 204                          handle->opt.device);
 205                 return PCAP_ERROR;
 206         }
 207
 208         /*
 209          * Turn a negative snapshot value (invalid), a snapshot value of
 210          * 0 (unspecified), or a value bigger than the normal maximum
 211          * value, into the maximum allowed value.
 212          *
 213          * If some application really *needs* a bigger snapshot
 214          * length, we should just increase MAXIMUM_SNAPLEN.
 215          */
 216         if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
 217                 handle->snapshot = MAXIMUM_SNAPLEN;
 218
 219         /* Initialize some components of the pcap structure. */
 220         handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot;
 221         handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
 222
 223         handle->read_op = bt_read_linux;
 224         handle->inject_op = bt_inject_linux;
 225         handle->setfilter_op = pcapint_install_bpf_program; /* no kernel filtering */
 226         handle->setdirection_op = bt_setdirection_linux;
 227         handle->set_datalink_op = NULL; /* can't change data link type */
 228         handle->getnonblock_op = pcapint_getnonblock_fd;
 229         handle->setnonblock_op = pcapint_setnonblock_fd;
 230         handle->stats_op = bt_stats_linux;
 231         handlep->dev_id = dev_id;
 232
 233         /* Create HCI socket */
 234         handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 235         if (handle->fd < 0) {
 236                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 237                     errno, "Can't create raw socket");
 238                 return PCAP_ERROR;
 239         }
 240
 241         handle->buffer = malloc(handle->bufsize);
 242         if (!handle->buffer) {
 243                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 244                     errno, "Can't allocate dump buffer");
 245                 goto close_fail;
 246         }
 247
 248         opt = 1;
 249         if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
 250                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 251                     errno, "Can't enable data direction info");
 252                 goto close_fail;
 253         }
 254
 255         opt = 1;
 256         if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
 257                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 258                     errno, "Can't enable time stamp");
 259                 goto close_fail;
 260         }
 261
 262         /* Setup filter, do not call hci function to avoid dependence on
 263          * external libs        */
 264         memset(&flt, 0, sizeof(flt));
 265         memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
 266         memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
 267         if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
 268                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 269                     errno, "Can't set filter");
 270                 goto close_fail;
 271         }
 272
 273
 274         /* Bind socket to the HCI device */
 275         addr.hci_family = AF_BLUETOOTH;
 276         addr.hci_dev = handlep->dev_id;
 277 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL
 278         addr.hci_channel = HCI_CHANNEL_RAW;
 279 #endif
 280         if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 281                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 282                     errno, "Can't attach to device %d", handlep->dev_id);
 283                 goto close_fail;
 284         }
 285
 286         if (handle->opt.rfmon) {
 287                 /*
 288                  * Monitor mode doesn't apply to Bluetooth devices.
 289                  */
 290                 err = PCAP_ERROR_RFMON_NOTSUP;
 291                 goto close_fail;
 292         }
 293
 294         if (handle->opt.buffer_size != 0) {
 295                 /*
 296                  * Set the socket buffer size to the specified value.
 297                  */
 298                 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
 299                     &handle->opt.buffer_size,
 300                     sizeof(handle->opt.buffer_size)) == -1) {
 301                         pcapint_fmt_errmsg_for_errno(handle->errbuf,
 302                             errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF");
 303                         goto close_fail;
 304                 }
 305         }
 306
 307         handle->selectable_fd = handle->fd;
 308         return 0;
 309
 310 close_fail:
 311         pcapint_cleanup_live_common(handle);
 312         return err;
 313 }
 314
 315 static int
 316 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
 317 {
 318         struct cmsghdr *cmsg;
 319         struct msghdr msg;
 320         struct iovec  iv;
 321         ssize_t ret;
 322         struct pcap_pkthdr pkth;
 323         pcap_bluetooth_h4_header* bthdr;
 324         u_char *pktd;
 325         int in = 0;
 326
 327         pktd = handle->buffer + BT_CTRL_SIZE;
 328         bthdr = (pcap_bluetooth_h4_header*)(void *)pktd;
 329         iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header);
 330         iv.iov_len  = handle->snapshot;
 331
 332         memset(&msg, 0, sizeof(msg));
 333         msg.msg_iov = &iv;
 334         msg.msg_iovlen = 1;
 335         msg.msg_control = handle->buffer;
 336         msg.msg_controllen = BT_CTRL_SIZE;
 337
 338         /* ignore interrupt system call error */
 339         do {
 340                 if (handle->break_loop)
 341                 {
 342                         handle->break_loop = 0;
 343                         return PCAP_ERROR_BREAK;
 344                 }
 345                 ret = recvmsg(handle->fd, &msg, 0);
 346         } while ((ret == -1) && (errno == EINTR));
 347
 348         if (ret < 0) {
 349                 if (errno == EAGAIN || errno == EWOULDBLOCK) {
 350                         /* Nonblocking mode, no data */
 351                         return 0;
 352                 }
 353                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 354                     errno, "Can't receive packet");
 355                 return PCAP_ERROR;
 356         }
 357
 358         pkth.caplen = (bpf_u_int32)ret;
 359
 360         /* get direction and timestamp*/
 361         cmsg = CMSG_FIRSTHDR(&msg);
 362         while (cmsg) {
 363                 switch (cmsg->cmsg_type) {
 364                         case HCI_CMSG_DIR:
 365                                 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
 366                                 break;
 367                         case HCI_CMSG_TSTAMP:
 368                                 memcpy(&pkth.ts, CMSG_DATA(cmsg),
 369                                         sizeof pkth.ts);
 370                                 break;
 371                 }
 372                 // for musl libc CMSG_NXTHDR()
 373 DIAG_OFF_SIGN_COMPARE
 374                 cmsg = CMSG_NXTHDR(&msg, cmsg);
 375 DIAG_ON_SIGN_COMPARE
 376         }
 377         switch (handle->direction) {
 378
 379         case PCAP_D_IN:
 380                 if (!in)
 381                         return 0;
 382                 break;
 383
 384         case PCAP_D_OUT:
 385                 if (in)
 386                         return 0;
 387                 break;
 388
 389         default:
 390                 break;
 391         }
 392
 393         bthdr->direction = htonl(in != 0);
 394         pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
 395         pkth.len = pkth.caplen;
 396         if (handle->fcode.bf_insns == NULL ||
 397             pcapint_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
 398                 callback(user, &pkth, pktd);
 399                 return 1;
 400         }
 401         return 0;       /* didn't pass filter */
 402 }
 403
 404 static int
 405 bt_inject_linux(pcap_t *handle, const void *buf _U_, int size _U_)
 406 {
 407         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 408             "Packet injection is not supported on Bluetooth devices");
 409         return (-1);
 410 }
 411
 412
 413 static int
 414 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
 415 {
 416         struct pcap_bt *handlep = handle->priv;
 417         int ret;
 418         struct hci_dev_info dev_info;
 419         struct hci_dev_stats * s = &dev_info.stat;
 420         dev_info.dev_id = handlep->dev_id;
 421
 422         /* ignore eintr */
 423         do {
 424                 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
 425         } while ((ret == -1) && (errno == EINTR));
 426
 427         if (ret < 0) {
 428                 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
 429                     errno, "Can't get stats via ioctl");
 430                 return (-1);
 431
 432         }
 433
 434         /* we receive both rx and tx frames, so cumulate all stats */
 435         stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
 436                 s->acl_tx +s->sco_tx;
 437         stats->ps_drop = s->err_rx + s->err_tx;
 438         stats->ps_ifdrop = 0;
 439         return 0;
 440 }
 441
 442 static int
 443 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
 444 {
 445         /*
 446          * It's guaranteed, at this point, that d is a valid
 447          * direction value.
 448          */
 449         p->direction = d;
 450         return 0;
 451 }