1 /* $NetBSD: pcap-bt-linux.c,v 1.3 2015/03/31 21:39:42 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2006 Paolo Abeni (Italy) 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote 17 * products derived from this software without specific prior written 18 * permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 * 32 * Bluetooth sniffing API implementation for Linux platform 33 * By Paolo Abeni <paolo.abeni@email.it> 34 * 35 */ 36 #include <sys/cdefs.h> 37 __RCSID("$NetBSD: pcap-bt-linux.c,v 1.3 2015/03/31 21:39:42 christos Exp $"); 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_setdirection_linux(pcap_t *, pcap_direction_t); 71 static int bt_stats_linux(pcap_t *, struct pcap_stat *); 72 73 /* 74 * Private data for capturing on Linux Bluetooth devices. 75 */ 76 struct pcap_bt { 77 int dev_id; /* device ID of device we're bound to */ 78 }; 79 80 int 81 bt_findalldevs(pcap_if_t **alldevsp, char *err_str) 82 { 83 struct hci_dev_list_req *dev_list; 84 struct hci_dev_req *dev_req; 85 int i, sock; 86 int ret = 0; 87 88 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 89 if (sock < 0) 90 { 91 /* if bluetooth is not supported this this is not fatal*/ 92 if (errno == EAFNOSUPPORT) 93 return 0; 94 snprintf(err_str, PCAP_ERRBUF_SIZE, 95 "Can't open raw Bluetooth socket: %s", strerror(errno)); 96 return -1; 97 } 98 99 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 100 if (!dev_list) 101 { 102 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list", 103 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 104 ret = -1; 105 goto done; 106 } 107 108 dev_list->dev_num = HCI_MAX_DEV; 109 110 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0) 111 { 112 snprintf(err_str, PCAP_ERRBUF_SIZE, 113 "Can't get Bluetooth device list via ioctl: %s", 114 strerror(errno)); 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[30]; 122 123 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id); 124 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i); 125 126 if (pcap_add_if(alldevsp, dev_name, 0, 127 dev_descr, err_str) < 0) 128 { 129 ret = -1; 130 break; 131 } 132 133 } 134 135 free: 136 free(dev_list); 137 138 done: 139 close(sock); 140 return ret; 141 } 142 143 pcap_t * 144 bt_create(const char *device, char *ebuf, int *is_ours) 145 { 146 const char *cp; 147 char *cpend; 148 long devnum; 149 pcap_t *p; 150 151 /* Does this look like a Bluetooth device? */ 152 cp = strrchr(device, '/'); 153 if (cp == NULL) 154 cp = device; 155 /* Does it begin with BT_IFACE? */ 156 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) { 157 /* Nope, doesn't begin with BT_IFACE */ 158 *is_ours = 0; 159 return NULL; 160 } 161 /* Yes - is BT_IFACE followed by a number? */ 162 cp += sizeof BT_IFACE - 1; 163 devnum = strtol(cp, &cpend, 10); 164 if (cpend == cp || *cpend != '\0') { 165 /* Not followed by a number. */ 166 *is_ours = 0; 167 return NULL; 168 } 169 if (devnum < 0) { 170 /* Followed by a non-valid number. */ 171 *is_ours = 0; 172 return NULL; 173 } 174 175 /* OK, it's probably ours. */ 176 *is_ours = 1; 177 178 p = pcap_create_common(device, ebuf, sizeof (struct pcap_bt)); 179 if (p == NULL) 180 return (NULL); 181 182 p->activate_op = bt_activate; 183 return (p); 184 } 185 186 static int 187 bt_activate(pcap_t* handle) 188 { 189 struct pcap_bt *handlep = handle->priv; 190 struct sockaddr_hci addr; 191 int opt; 192 int dev_id; 193 struct hci_filter flt; 194 int err = PCAP_ERROR; 195 196 /* get bt interface id */ 197 if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1) 198 { 199 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 200 "Can't get Bluetooth device index from %s", 201 handle->opt.source); 202 return PCAP_ERROR; 203 } 204 205 /* Initialize some components of the pcap structure. */ 206 handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header); 207 handle->offset = BT_CTRL_SIZE; 208 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 209 210 handle->read_op = bt_read_linux; 211 handle->inject_op = bt_inject_linux; 212 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 213 handle->setdirection_op = bt_setdirection_linux; 214 handle->set_datalink_op = NULL; /* can't change data link type */ 215 handle->getnonblock_op = pcap_getnonblock_fd; 216 handle->setnonblock_op = pcap_setnonblock_fd; 217 handle->stats_op = bt_stats_linux; 218 handlep->dev_id = dev_id; 219 220 /* Create HCI socket */ 221 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 222 if (handle->fd < 0) { 223 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 224 "Can't create raw socket: %s", strerror(errno)); 225 return PCAP_ERROR; 226 } 227 228 handle->buffer = malloc(handle->bufsize); 229 if (!handle->buffer) { 230 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", 231 pcap_strerror(errno)); 232 goto close_fail; 233 } 234 235 opt = 1; 236 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 237 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 238 "Can't enable data direction info: %s", strerror(errno)); 239 goto close_fail; 240 } 241 242 opt = 1; 243 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 244 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 245 "Can't enable time stamp: %s", strerror(errno)); 246 goto close_fail; 247 } 248 249 /* Setup filter, do not call hci function to avoid dependence on 250 * external libs */ 251 memset(&flt, 0, sizeof(flt)); 252 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 253 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 254 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 255 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 256 "Can't set filter: %s", strerror(errno)); 257 goto close_fail; 258 } 259 260 261 /* Bind socket to the HCI device */ 262 addr.hci_family = AF_BLUETOOTH; 263 addr.hci_dev = handlep->dev_id; 264 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL 265 addr.hci_channel = HCI_CHANNEL_RAW; 266 #endif 267 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 268 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 269 "Can't attach to device %d: %s", handlep->dev_id, 270 strerror(errno)); 271 goto close_fail; 272 } 273 274 if (handle->opt.rfmon) { 275 /* 276 * Monitor mode doesn't apply to Bluetooth devices. 277 */ 278 err = PCAP_ERROR_RFMON_NOTSUP; 279 goto close_fail; 280 } 281 282 if (handle->opt.buffer_size != 0) { 283 /* 284 * Set the socket buffer size to the specified value. 285 */ 286 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 287 &handle->opt.buffer_size, 288 sizeof(handle->opt.buffer_size)) == -1) { 289 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 290 "SO_RCVBUF: %s", pcap_strerror(errno)); 291 goto close_fail; 292 } 293 } 294 295 handle->selectable_fd = handle->fd; 296 return 0; 297 298 close_fail: 299 pcap_cleanup_live_common(handle); 300 return err; 301 } 302 303 static int 304 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 305 { 306 struct cmsghdr *cmsg; 307 struct msghdr msg; 308 struct iovec iv; 309 ssize_t ret; 310 struct pcap_pkthdr pkth; 311 pcap_bluetooth_h4_header* bthdr; 312 313 bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset]; 314 iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)]; 315 iv.iov_len = handle->snapshot; 316 317 memset(&msg, 0, sizeof(msg)); 318 msg.msg_iov = &iv; 319 msg.msg_iovlen = 1; 320 msg.msg_control = handle->buffer; 321 msg.msg_controllen = handle->offset; 322 323 /* ignore interrupt system call error */ 324 do { 325 ret = recvmsg(handle->fd, &msg, 0); 326 if (handle->break_loop) 327 { 328 handle->break_loop = 0; 329 return -2; 330 } 331 } while ((ret == -1) && (errno == EINTR)); 332 333 if (ret < 0) { 334 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 335 "Can't receive packet: %s", strerror(errno)); 336 return -1; 337 } 338 339 pkth.caplen = ret; 340 341 /* get direction and timestamp*/ 342 cmsg = CMSG_FIRSTHDR(&msg); 343 int in=0; 344 while (cmsg) { 345 switch (cmsg->cmsg_type) { 346 case HCI_CMSG_DIR: 347 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 348 break; 349 case HCI_CMSG_TSTAMP: 350 memcpy(&pkth.ts, CMSG_DATA(cmsg), 351 sizeof pkth.ts); 352 break; 353 } 354 cmsg = CMSG_NXTHDR(&msg, cmsg); 355 } 356 if ((in && (handle->direction == PCAP_D_OUT)) || 357 ((!in) && (handle->direction == PCAP_D_IN))) 358 return 0; 359 360 bthdr->direction = htonl(in != 0); 361 pkth.caplen+=sizeof(pcap_bluetooth_h4_header); 362 pkth.len = pkth.caplen; 363 if (handle->fcode.bf_insns == NULL || 364 bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset], 365 pkth.len, pkth.caplen)) { 366 callback(user, &pkth, &handle->buffer[handle->offset]); 367 return 1; 368 } 369 return 0; /* didn't pass filter */ 370 } 371 372 static int 373 bt_inject_linux(pcap_t *handle, const void *buf, size_t size) 374 { 375 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " 376 "bluetooth devices"); 377 return (-1); 378 } 379 380 381 static int 382 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats) 383 { 384 struct pcap_bt *handlep = handle->priv; 385 int ret; 386 struct hci_dev_info dev_info; 387 struct hci_dev_stats * s = &dev_info.stat; 388 dev_info.dev_id = handlep->dev_id; 389 390 /* ignore eintr */ 391 do { 392 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info); 393 } while ((ret == -1) && (errno == EINTR)); 394 395 if (ret < 0) { 396 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 397 "Can't get stats via ioctl: %s", strerror(errno)); 398 return (-1); 399 400 } 401 402 /* we receive both rx and tx frames, so comulate all stats */ 403 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx + 404 s->acl_tx +s->sco_tx; 405 stats->ps_drop = s->err_rx + s->err_tx; 406 stats->ps_ifdrop = 0; 407 return 0; 408 } 409 410 static int 411 bt_setdirection_linux(pcap_t *p, pcap_direction_t d) 412 { 413 p->direction = d; 414 return 0; 415 } 416