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 #ifdef NEED_STRERROR_H 44 #include "strerror.h" 45 #endif 46 47 #include <errno.h> 48 #include <stdlib.h> 49 #include <unistd.h> 50 #include <fcntl.h> 51 #include <string.h> 52 #include <sys/ioctl.h> 53 #include <sys/socket.h> 54 #include <arpa/inet.h> 55 56 #include <bluetooth/bluetooth.h> 57 #include <bluetooth/hci.h> 58 59 #define BT_IFACE "bluetooth" 60 #define BT_CTRL_SIZE 128 61 62 /* forward declaration */ 63 static int bt_activate(pcap_t *); 64 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *); 65 static int bt_inject_linux(pcap_t *, const void *, size_t); 66 static int bt_setdirection_linux(pcap_t *, pcap_direction_t); 67 static int bt_stats_linux(pcap_t *, struct pcap_stat *); 68 69 /* 70 * Private data for capturing on Linux Bluetooth devices. 71 */ 72 struct pcap_bt { 73 int dev_id; /* device ID of device we're bound to */ 74 }; 75 76 int 77 bt_findalldevs(pcap_if_t **alldevsp, char *err_str) 78 { 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 pcap_snprintf(err_str, PCAP_ERRBUF_SIZE, 91 "Can't open raw Bluetooth socket: %s", 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 pcap_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 pcap_snprintf(err_str, PCAP_ERRBUF_SIZE, 109 "Can't get Bluetooth device list via ioctl: %s", 110 strerror(errno)); 111 ret = -1; 112 goto free; 113 } 114 115 dev_req = dev_list->dev_req; 116 for (i = 0; i < dev_list->dev_num; i++, dev_req++) { 117 char dev_name[20], dev_descr[30]; 118 119 pcap_snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id); 120 pcap_snprintf(dev_descr, 30, "Bluetooth adapter number %d", i); 121 122 if (pcap_add_if(alldevsp, dev_name, 0, 123 dev_descr, err_str) < 0) 124 { 125 ret = -1; 126 break; 127 } 128 129 } 130 131 free: 132 free(dev_list); 133 134 done: 135 close(sock); 136 return ret; 137 } 138 139 pcap_t * 140 bt_create(const char *device, char *ebuf, int *is_ours) 141 { 142 const char *cp; 143 char *cpend; 144 long devnum; 145 pcap_t *p; 146 147 /* Does this look like a Bluetooth device? */ 148 cp = strrchr(device, '/'); 149 if (cp == NULL) 150 cp = device; 151 /* Does it begin with BT_IFACE? */ 152 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) { 153 /* Nope, doesn't begin with BT_IFACE */ 154 *is_ours = 0; 155 return NULL; 156 } 157 /* Yes - is BT_IFACE followed by a number? */ 158 cp += sizeof BT_IFACE - 1; 159 devnum = strtol(cp, &cpend, 10); 160 if (cpend == cp || *cpend != '\0') { 161 /* Not followed by a number. */ 162 *is_ours = 0; 163 return NULL; 164 } 165 if (devnum < 0) { 166 /* Followed by a non-valid number. */ 167 *is_ours = 0; 168 return NULL; 169 } 170 171 /* OK, it's probably ours. */ 172 *is_ours = 1; 173 174 p = pcap_create_common(ebuf, sizeof (struct pcap_bt)); 175 if (p == NULL) 176 return (NULL); 177 178 p->activate_op = bt_activate; 179 return (p); 180 } 181 182 static int 183 bt_activate(pcap_t* handle) 184 { 185 struct pcap_bt *handlep = handle->priv; 186 struct sockaddr_hci addr; 187 int opt; 188 int dev_id; 189 struct hci_filter flt; 190 int err = PCAP_ERROR; 191 192 /* get bt interface id */ 193 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1) 194 { 195 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 196 "Can't get Bluetooth device index from %s", 197 handle->opt.device); 198 return PCAP_ERROR; 199 } 200 201 /* Initialize some components of the pcap structure. */ 202 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot; 203 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 204 205 handle->read_op = bt_read_linux; 206 handle->inject_op = bt_inject_linux; 207 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 208 handle->setdirection_op = bt_setdirection_linux; 209 handle->set_datalink_op = NULL; /* can't change data link type */ 210 handle->getnonblock_op = pcap_getnonblock_fd; 211 handle->setnonblock_op = pcap_setnonblock_fd; 212 handle->stats_op = bt_stats_linux; 213 handlep->dev_id = dev_id; 214 215 /* Create HCI socket */ 216 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 217 if (handle->fd < 0) { 218 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 219 "Can't create raw socket: %s", strerror(errno)); 220 return PCAP_ERROR; 221 } 222 223 handle->buffer = malloc(handle->bufsize); 224 if (!handle->buffer) { 225 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", 226 pcap_strerror(errno)); 227 goto close_fail; 228 } 229 230 opt = 1; 231 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 232 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 233 "Can't enable data direction info: %s", strerror(errno)); 234 goto close_fail; 235 } 236 237 opt = 1; 238 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 239 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 240 "Can't enable time stamp: %s", strerror(errno)); 241 goto close_fail; 242 } 243 244 /* Setup filter, do not call hci function to avoid dependence on 245 * external libs */ 246 memset(&flt, 0, sizeof(flt)); 247 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 248 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 249 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 250 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 251 "Can't set filter: %s", strerror(errno)); 252 goto close_fail; 253 } 254 255 256 /* Bind socket to the HCI device */ 257 addr.hci_family = AF_BLUETOOTH; 258 addr.hci_dev = handlep->dev_id; 259 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL 260 addr.hci_channel = HCI_CHANNEL_RAW; 261 #endif 262 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 263 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 264 "Can't attach to device %d: %s", handlep->dev_id, 265 strerror(errno)); 266 goto close_fail; 267 } 268 269 if (handle->opt.rfmon) { 270 /* 271 * Monitor mode doesn't apply to Bluetooth devices. 272 */ 273 err = PCAP_ERROR_RFMON_NOTSUP; 274 goto close_fail; 275 } 276 277 if (handle->opt.buffer_size != 0) { 278 /* 279 * Set the socket buffer size to the specified value. 280 */ 281 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 282 &handle->opt.buffer_size, 283 sizeof(handle->opt.buffer_size)) == -1) { 284 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 285 "SO_RCVBUF: %s", pcap_strerror(errno)); 286 goto close_fail; 287 } 288 } 289 290 handle->selectable_fd = handle->fd; 291 return 0; 292 293 close_fail: 294 pcap_cleanup_live_common(handle); 295 return err; 296 } 297 298 static int 299 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 300 { 301 struct cmsghdr *cmsg; 302 struct msghdr msg; 303 struct iovec iv; 304 ssize_t ret; 305 struct pcap_pkthdr pkth; 306 pcap_bluetooth_h4_header* bthdr; 307 u_char *pktd; 308 int in = 0; 309 310 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE; 311 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd; 312 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header); 313 iv.iov_len = handle->snapshot; 314 315 memset(&msg, 0, sizeof(msg)); 316 msg.msg_iov = &iv; 317 msg.msg_iovlen = 1; 318 msg.msg_control = handle->buffer; 319 msg.msg_controllen = BT_CTRL_SIZE; 320 321 /* ignore interrupt system call error */ 322 do { 323 ret = recvmsg(handle->fd, &msg, 0); 324 if (handle->break_loop) 325 { 326 handle->break_loop = 0; 327 return -2; 328 } 329 } while ((ret == -1) && (errno == EINTR)); 330 331 if (ret < 0) { 332 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 333 "Can't receive packet: %s", strerror(errno)); 334 return -1; 335 } 336 337 pkth.caplen = ret; 338 339 /* get direction and timestamp*/ 340 cmsg = CMSG_FIRSTHDR(&msg); 341 while (cmsg) { 342 switch (cmsg->cmsg_type) { 343 case HCI_CMSG_DIR: 344 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 345 break; 346 case HCI_CMSG_TSTAMP: 347 memcpy(&pkth.ts, CMSG_DATA(cmsg), 348 sizeof pkth.ts); 349 break; 350 } 351 cmsg = CMSG_NXTHDR(&msg, cmsg); 352 } 353 if ((in && (handle->direction == PCAP_D_OUT)) || 354 ((!in) && (handle->direction == PCAP_D_IN))) 355 return 0; 356 357 bthdr->direction = htonl(in != 0); 358 pkth.caplen+=sizeof(pcap_bluetooth_h4_header); 359 pkth.len = pkth.caplen; 360 if (handle->fcode.bf_insns == NULL || 361 bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) { 362 callback(user, &pkth, pktd); 363 return 1; 364 } 365 return 0; /* didn't pass filter */ 366 } 367 368 static int 369 bt_inject_linux(pcap_t *handle, const void *buf, size_t size) 370 { 371 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " 372 "bluetooth devices"); 373 return (-1); 374 } 375 376 377 static int 378 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats) 379 { 380 struct pcap_bt *handlep = handle->priv; 381 int ret; 382 struct hci_dev_info dev_info; 383 struct hci_dev_stats * s = &dev_info.stat; 384 dev_info.dev_id = handlep->dev_id; 385 386 /* ignore eintr */ 387 do { 388 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info); 389 } while ((ret == -1) && (errno == EINTR)); 390 391 if (ret < 0) { 392 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 393 "Can't get stats via ioctl: %s", strerror(errno)); 394 return (-1); 395 396 } 397 398 /* we receive both rx and tx frames, so comulate all stats */ 399 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx + 400 s->acl_tx +s->sco_tx; 401 stats->ps_drop = s->err_rx + s->err_tx; 402 stats->ps_ifdrop = 0; 403 return 0; 404 } 405 406 static int 407 bt_setdirection_linux(pcap_t *p, pcap_direction_t d) 408 { 409 p->direction = d; 410 return 0; 411 } 412