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 #include <errno.h> 44 #include <stdlib.h> 45 #include <unistd.h> 46 #include <fcntl.h> 47 #include <string.h> 48 #include <sys/ioctl.h> 49 #include <sys/socket.h> 50 #include <arpa/inet.h> 51 52 #include <bluetooth/bluetooth.h> 53 #include <bluetooth/hci.h> 54 55 #define BT_IFACE "bluetooth" 56 #define BT_CTRL_SIZE 128 57 58 /* forward declaration */ 59 static int bt_activate(pcap_t *); 60 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *); 61 static int bt_inject_linux(pcap_t *, const void *, int); 62 static int bt_setdirection_linux(pcap_t *, pcap_direction_t); 63 static int bt_stats_linux(pcap_t *, struct pcap_stat *); 64 65 /* 66 * Private data for capturing on Linux Bluetooth devices. 67 */ 68 struct pcap_bt { 69 int dev_id; /* device ID of device we're bound to */ 70 }; 71 72 int 73 bt_findalldevs(pcap_if_list_t *devlistp, char *err_str) 74 { 75 struct hci_dev_list_req *dev_list; 76 struct hci_dev_req *dev_req; 77 int sock; 78 unsigned i; 79 int ret = 0; 80 81 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 82 if (sock < 0) 83 { 84 /* if bluetooth is not supported this is not fatal*/ 85 if (errno == EAFNOSUPPORT) 86 return 0; 87 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE, 88 errno, "Can't open raw Bluetooth socket"); 89 return -1; 90 } 91 92 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 93 if (!dev_list) 94 { 95 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list", 96 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 97 ret = -1; 98 goto done; 99 } 100 101 /* 102 * Zero the complete header, which is larger than dev_num because of tail 103 * padding, to silence Valgrind, which overshoots validating that dev_num 104 * has been set. 105 * https://github.com/the-tcpdump-group/libpcap/issues/1083 106 * https://bugs.kde.org/show_bug.cgi?id=448464 107 */ 108 memset(dev_list, 0, sizeof(*dev_list)); 109 dev_list->dev_num = HCI_MAX_DEV; 110 111 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0) 112 { 113 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE, 114 errno, "Can't get Bluetooth device list via ioctl"); 115 ret = -1; 116 goto free; 117 } 118 119 dev_req = dev_list->dev_req; 120 for (i = 0; i < dev_list->dev_num; i++, dev_req++) { 121 char dev_name[20], dev_descr[40]; 122 123 snprintf(dev_name, sizeof(dev_name), BT_IFACE"%u", dev_req->dev_id); 124 snprintf(dev_descr, sizeof(dev_descr), "Bluetooth adapter number %u", i); 125 126 /* 127 * Bluetooth is a wireless technology. 128 * XXX - if there's the notion of associating with a 129 * network, and we can determine whether the interface 130 * is associated with a network, check that and set 131 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED 132 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED. 133 */ 134 if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str) == NULL) 135 { 136 ret = -1; 137 break; 138 } 139 } 140 141 free: 142 free(dev_list); 143 144 done: 145 close(sock); 146 return ret; 147 } 148 149 pcap_t * 150 bt_create(const char *device, char *ebuf, int *is_ours) 151 { 152 const char *cp; 153 char *cpend; 154 long devnum; 155 pcap_t *p; 156 157 /* Does this look like a Bluetooth device? */ 158 cp = strrchr(device, '/'); 159 if (cp == NULL) 160 cp = device; 161 /* Does it begin with BT_IFACE? */ 162 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) { 163 /* Nope, doesn't begin with BT_IFACE */ 164 *is_ours = 0; 165 return NULL; 166 } 167 /* Yes - is BT_IFACE followed by a number? */ 168 cp += sizeof BT_IFACE - 1; 169 devnum = strtol(cp, &cpend, 10); 170 if (cpend == cp || *cpend != '\0') { 171 /* Not followed by a number. */ 172 *is_ours = 0; 173 return NULL; 174 } 175 if (devnum < 0) { 176 /* Followed by a non-valid number. */ 177 *is_ours = 0; 178 return NULL; 179 } 180 181 /* OK, it's probably ours. */ 182 *is_ours = 1; 183 184 p = PCAP_CREATE_COMMON(ebuf, struct pcap_bt); 185 if (p == NULL) 186 return (NULL); 187 188 p->activate_op = bt_activate; 189 return (p); 190 } 191 192 static int 193 bt_activate(pcap_t* handle) 194 { 195 struct pcap_bt *handlep = handle->priv; 196 struct sockaddr_hci addr; 197 int opt; 198 int dev_id; 199 struct hci_filter flt; 200 int err = PCAP_ERROR; 201 202 /* get bt interface id */ 203 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1) 204 { 205 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 206 "Can't get Bluetooth device index from %s", 207 handle->opt.device); 208 return PCAP_ERROR; 209 } 210 211 /* 212 * Turn a negative snapshot value (invalid), a snapshot value of 213 * 0 (unspecified), or a value bigger than the normal maximum 214 * value, into the maximum allowed value. 215 * 216 * If some application really *needs* a bigger snapshot 217 * length, we should just increase MAXIMUM_SNAPLEN. 218 */ 219 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN) 220 handle->snapshot = MAXIMUM_SNAPLEN; 221 222 /* Initialize some components of the pcap structure. */ 223 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot; 224 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 225 226 handle->read_op = bt_read_linux; 227 handle->inject_op = bt_inject_linux; 228 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 229 handle->setdirection_op = bt_setdirection_linux; 230 handle->set_datalink_op = NULL; /* can't change data link type */ 231 handle->getnonblock_op = pcap_getnonblock_fd; 232 handle->setnonblock_op = pcap_setnonblock_fd; 233 handle->stats_op = bt_stats_linux; 234 handlep->dev_id = dev_id; 235 236 /* Create HCI socket */ 237 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 238 if (handle->fd < 0) { 239 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 240 errno, "Can't create raw socket"); 241 return PCAP_ERROR; 242 } 243 244 handle->buffer = malloc(handle->bufsize); 245 if (!handle->buffer) { 246 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 247 errno, "Can't allocate dump buffer"); 248 goto close_fail; 249 } 250 251 opt = 1; 252 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 253 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 254 errno, "Can't enable data direction info"); 255 goto close_fail; 256 } 257 258 opt = 1; 259 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 260 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 261 errno, "Can't enable time stamp"); 262 goto close_fail; 263 } 264 265 /* Setup filter, do not call hci function to avoid dependence on 266 * external libs */ 267 memset(&flt, 0, sizeof(flt)); 268 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 269 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 270 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 271 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 272 errno, "Can't set filter"); 273 goto close_fail; 274 } 275 276 277 /* Bind socket to the HCI device */ 278 addr.hci_family = AF_BLUETOOTH; 279 addr.hci_dev = handlep->dev_id; 280 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL 281 addr.hci_channel = HCI_CHANNEL_RAW; 282 #endif 283 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 284 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 285 errno, "Can't attach to device %d", handlep->dev_id); 286 goto close_fail; 287 } 288 289 if (handle->opt.rfmon) { 290 /* 291 * Monitor mode doesn't apply to Bluetooth devices. 292 */ 293 err = PCAP_ERROR_RFMON_NOTSUP; 294 goto close_fail; 295 } 296 297 if (handle->opt.buffer_size != 0) { 298 /* 299 * Set the socket buffer size to the specified value. 300 */ 301 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 302 &handle->opt.buffer_size, 303 sizeof(handle->opt.buffer_size)) == -1) { 304 pcap_fmt_errmsg_for_errno(handle->errbuf, 305 errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF"); 306 goto close_fail; 307 } 308 } 309 310 handle->selectable_fd = handle->fd; 311 return 0; 312 313 close_fail: 314 pcap_cleanup_live_common(handle); 315 return err; 316 } 317 318 static int 319 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 320 { 321 struct cmsghdr *cmsg; 322 struct msghdr msg; 323 struct iovec iv; 324 ssize_t ret; 325 struct pcap_pkthdr pkth; 326 pcap_bluetooth_h4_header* bthdr; 327 u_char *pktd; 328 int in = 0; 329 330 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE; 331 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd; 332 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header); 333 iv.iov_len = handle->snapshot; 334 335 memset(&msg, 0, sizeof(msg)); 336 msg.msg_iov = &iv; 337 msg.msg_iovlen = 1; 338 msg.msg_control = handle->buffer; 339 msg.msg_controllen = BT_CTRL_SIZE; 340 341 /* ignore interrupt system call error */ 342 do { 343 ret = recvmsg(handle->fd, &msg, 0); 344 if (handle->break_loop) 345 { 346 handle->break_loop = 0; 347 return -2; 348 } 349 } while ((ret == -1) && (errno == EINTR)); 350 351 if (ret < 0) { 352 if (errno == EAGAIN || errno == EWOULDBLOCK) { 353 /* Nonblocking mode, no data */ 354 return 0; 355 } 356 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 357 errno, "Can't receive packet"); 358 return -1; 359 } 360 361 pkth.caplen = (bpf_u_int32)ret; 362 363 /* get direction and timestamp*/ 364 cmsg = CMSG_FIRSTHDR(&msg); 365 while (cmsg) { 366 switch (cmsg->cmsg_type) { 367 case HCI_CMSG_DIR: 368 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 369 break; 370 case HCI_CMSG_TSTAMP: 371 memcpy(&pkth.ts, CMSG_DATA(cmsg), 372 sizeof pkth.ts); 373 break; 374 } 375 cmsg = CMSG_NXTHDR(&msg, cmsg); 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 pcap_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 pcap_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 comulate 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 } 452