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 = strrchr(device, '/'); 158 if (cp == NULL) 159 cp = device; 160 /* Does it begin with BT_IFACE? */ 161 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) { 162 /* Nope, doesn't begin with BT_IFACE */ 163 *is_ours = 0; 164 return NULL; 165 } 166 /* Yes - is BT_IFACE followed by a number? */ 167 cp += sizeof BT_IFACE - 1; 168 devnum = strtol(cp, &cpend, 10); 169 if (cpend == cp || *cpend != '\0') { 170 /* Not followed by a number. */ 171 *is_ours = 0; 172 return NULL; 173 } 174 if (devnum < 0) { 175 /* Followed by a non-valid number. */ 176 *is_ours = 0; 177 return NULL; 178 } 179 180 /* OK, it's probably ours. */ 181 *is_ours = 1; 182 183 p = PCAP_CREATE_COMMON(ebuf, struct pcap_bt); 184 if (p == NULL) 185 return (NULL); 186 187 p->activate_op = bt_activate; 188 return (p); 189 } 190 191 static int 192 bt_activate(pcap_t* handle) 193 { 194 struct pcap_bt *handlep = handle->priv; 195 struct sockaddr_hci addr; 196 int opt; 197 int dev_id; 198 struct hci_filter flt; 199 int err = PCAP_ERROR; 200 201 /* get bt interface id */ 202 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1) 203 { 204 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 205 "Can't get Bluetooth device index from %s", 206 handle->opt.device); 207 return PCAP_ERROR; 208 } 209 210 /* 211 * Turn a negative snapshot value (invalid), a snapshot value of 212 * 0 (unspecified), or a value bigger than the normal maximum 213 * value, into the maximum allowed value. 214 * 215 * If some application really *needs* a bigger snapshot 216 * length, we should just increase MAXIMUM_SNAPLEN. 217 */ 218 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN) 219 handle->snapshot = MAXIMUM_SNAPLEN; 220 221 /* Initialize some components of the pcap structure. */ 222 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot; 223 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 224 225 handle->read_op = bt_read_linux; 226 handle->inject_op = bt_inject_linux; 227 handle->setfilter_op = pcapint_install_bpf_program; /* no kernel filtering */ 228 handle->setdirection_op = bt_setdirection_linux; 229 handle->set_datalink_op = NULL; /* can't change data link type */ 230 handle->getnonblock_op = pcapint_getnonblock_fd; 231 handle->setnonblock_op = pcapint_setnonblock_fd; 232 handle->stats_op = bt_stats_linux; 233 handlep->dev_id = dev_id; 234 235 /* Create HCI socket */ 236 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 237 if (handle->fd < 0) { 238 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 239 errno, "Can't create raw socket"); 240 return PCAP_ERROR; 241 } 242 243 handle->buffer = malloc(handle->bufsize); 244 if (!handle->buffer) { 245 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 246 errno, "Can't allocate dump buffer"); 247 goto close_fail; 248 } 249 250 opt = 1; 251 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 252 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 253 errno, "Can't enable data direction info"); 254 goto close_fail; 255 } 256 257 opt = 1; 258 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 259 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 260 errno, "Can't enable time stamp"); 261 goto close_fail; 262 } 263 264 /* Setup filter, do not call hci function to avoid dependence on 265 * external libs */ 266 memset(&flt, 0, sizeof(flt)); 267 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 268 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 269 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 270 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 271 errno, "Can't set filter"); 272 goto close_fail; 273 } 274 275 276 /* Bind socket to the HCI device */ 277 addr.hci_family = AF_BLUETOOTH; 278 addr.hci_dev = handlep->dev_id; 279 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL 280 addr.hci_channel = HCI_CHANNEL_RAW; 281 #endif 282 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 283 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 284 errno, "Can't attach to device %d", handlep->dev_id); 285 goto close_fail; 286 } 287 288 if (handle->opt.rfmon) { 289 /* 290 * Monitor mode doesn't apply to Bluetooth devices. 291 */ 292 err = PCAP_ERROR_RFMON_NOTSUP; 293 goto close_fail; 294 } 295 296 if (handle->opt.buffer_size != 0) { 297 /* 298 * Set the socket buffer size to the specified value. 299 */ 300 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 301 &handle->opt.buffer_size, 302 sizeof(handle->opt.buffer_size)) == -1) { 303 pcapint_fmt_errmsg_for_errno(handle->errbuf, 304 errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF"); 305 goto close_fail; 306 } 307 } 308 309 handle->selectable_fd = handle->fd; 310 return 0; 311 312 close_fail: 313 pcapint_cleanup_live_common(handle); 314 return err; 315 } 316 317 static int 318 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 319 { 320 struct cmsghdr *cmsg; 321 struct msghdr msg; 322 struct iovec iv; 323 ssize_t ret; 324 struct pcap_pkthdr pkth; 325 pcap_bluetooth_h4_header* bthdr; 326 u_char *pktd; 327 int in = 0; 328 329 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE; 330 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd; 331 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header); 332 iv.iov_len = handle->snapshot; 333 334 memset(&msg, 0, sizeof(msg)); 335 msg.msg_iov = &iv; 336 msg.msg_iovlen = 1; 337 msg.msg_control = handle->buffer; 338 msg.msg_controllen = BT_CTRL_SIZE; 339 340 /* ignore interrupt system call error */ 341 do { 342 if (handle->break_loop) 343 { 344 handle->break_loop = 0; 345 return PCAP_ERROR_BREAK; 346 } 347 ret = recvmsg(handle->fd, &msg, 0); 348 } while ((ret == -1) && (errno == EINTR)); 349 350 if (ret < 0) { 351 if (errno == EAGAIN || errno == EWOULDBLOCK) { 352 /* Nonblocking mode, no data */ 353 return 0; 354 } 355 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 356 errno, "Can't receive packet"); 357 return PCAP_ERROR; 358 } 359 360 pkth.caplen = (bpf_u_int32)ret; 361 362 /* get direction and timestamp*/ 363 cmsg = CMSG_FIRSTHDR(&msg); 364 while (cmsg) { 365 switch (cmsg->cmsg_type) { 366 case HCI_CMSG_DIR: 367 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 368 break; 369 case HCI_CMSG_TSTAMP: 370 memcpy(&pkth.ts, CMSG_DATA(cmsg), 371 sizeof pkth.ts); 372 break; 373 } 374 // for musl libc CMSG_NXTHDR() 375 DIAG_OFF_SIGN_COMPARE 376 cmsg = CMSG_NXTHDR(&msg, cmsg); 377 DIAG_ON_SIGN_COMPARE 378 } 379 switch (handle->direction) { 380 381 case PCAP_D_IN: 382 if (!in) 383 return 0; 384 break; 385 386 case PCAP_D_OUT: 387 if (in) 388 return 0; 389 break; 390 391 default: 392 break; 393 } 394 395 bthdr->direction = htonl(in != 0); 396 pkth.caplen+=sizeof(pcap_bluetooth_h4_header); 397 pkth.len = pkth.caplen; 398 if (handle->fcode.bf_insns == NULL || 399 pcapint_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) { 400 callback(user, &pkth, pktd); 401 return 1; 402 } 403 return 0; /* didn't pass filter */ 404 } 405 406 static int 407 bt_inject_linux(pcap_t *handle, const void *buf _U_, int size _U_) 408 { 409 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 410 "Packet injection is not supported on Bluetooth devices"); 411 return (-1); 412 } 413 414 415 static int 416 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats) 417 { 418 struct pcap_bt *handlep = handle->priv; 419 int ret; 420 struct hci_dev_info dev_info; 421 struct hci_dev_stats * s = &dev_info.stat; 422 dev_info.dev_id = handlep->dev_id; 423 424 /* ignore eintr */ 425 do { 426 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info); 427 } while ((ret == -1) && (errno == EINTR)); 428 429 if (ret < 0) { 430 pcapint_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 431 errno, "Can't get stats via ioctl"); 432 return (-1); 433 434 } 435 436 /* we receive both rx and tx frames, so cumulate all stats */ 437 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx + 438 s->acl_tx +s->sco_tx; 439 stats->ps_drop = s->err_rx + s->err_tx; 440 stats->ps_ifdrop = 0; 441 return 0; 442 } 443 444 static int 445 bt_setdirection_linux(pcap_t *p, pcap_direction_t d) 446 { 447 /* 448 * It's guaranteed, at this point, that d is a valid 449 * direction value. 450 */ 451 p->direction = d; 452 return 0; 453 } 454