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 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 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 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 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id); 120 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(device, 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.source, BT_IFACE"%d", &dev_id) != 1) 194 { 195 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 196 "Can't get Bluetooth device index from %s", 197 handle->opt.source); 198 return PCAP_ERROR; 199 } 200 201 /* Initialize some components of the pcap structure. */ 202 handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header); 203 handle->offset = BT_CTRL_SIZE; 204 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 205 206 handle->read_op = bt_read_linux; 207 handle->inject_op = bt_inject_linux; 208 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 209 handle->setdirection_op = bt_setdirection_linux; 210 handle->set_datalink_op = NULL; /* can't change data link type */ 211 handle->getnonblock_op = pcap_getnonblock_fd; 212 handle->setnonblock_op = pcap_setnonblock_fd; 213 handle->stats_op = bt_stats_linux; 214 handlep->dev_id = dev_id; 215 216 /* Create HCI socket */ 217 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 218 if (handle->fd < 0) { 219 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 220 "Can't create raw socket: %s", strerror(errno)); 221 return PCAP_ERROR; 222 } 223 224 handle->buffer = malloc(handle->bufsize); 225 if (!handle->buffer) { 226 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", 227 pcap_strerror(errno)); 228 goto close_fail; 229 } 230 231 opt = 1; 232 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 233 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 234 "Can't enable data direction info: %s", strerror(errno)); 235 goto close_fail; 236 } 237 238 opt = 1; 239 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 240 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 241 "Can't enable time stamp: %s", strerror(errno)); 242 goto close_fail; 243 } 244 245 /* Setup filter, do not call hci function to avoid dependence on 246 * external libs */ 247 memset(&flt, 0, sizeof(flt)); 248 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 249 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 250 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 251 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 252 "Can't set filter: %s", strerror(errno)); 253 goto close_fail; 254 } 255 256 257 /* Bind socket to the HCI device */ 258 addr.hci_family = AF_BLUETOOTH; 259 addr.hci_dev = handlep->dev_id; 260 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL 261 addr.hci_channel = HCI_CHANNEL_RAW; 262 #endif 263 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 264 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 265 "Can't attach to device %d: %s", handlep->dev_id, 266 strerror(errno)); 267 goto close_fail; 268 } 269 270 if (handle->opt.rfmon) { 271 /* 272 * Monitor mode doesn't apply to Bluetooth devices. 273 */ 274 err = PCAP_ERROR_RFMON_NOTSUP; 275 goto close_fail; 276 } 277 278 if (handle->opt.buffer_size != 0) { 279 /* 280 * Set the socket buffer size to the specified value. 281 */ 282 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 283 &handle->opt.buffer_size, 284 sizeof(handle->opt.buffer_size)) == -1) { 285 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 286 "SO_RCVBUF: %s", pcap_strerror(errno)); 287 goto close_fail; 288 } 289 } 290 291 handle->selectable_fd = handle->fd; 292 return 0; 293 294 close_fail: 295 pcap_cleanup_live_common(handle); 296 return err; 297 } 298 299 static int 300 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 301 { 302 struct cmsghdr *cmsg; 303 struct msghdr msg; 304 struct iovec iv; 305 ssize_t ret; 306 struct pcap_pkthdr pkth; 307 pcap_bluetooth_h4_header* bthdr; 308 309 bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset]; 310 iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)]; 311 iv.iov_len = handle->snapshot; 312 313 memset(&msg, 0, sizeof(msg)); 314 msg.msg_iov = &iv; 315 msg.msg_iovlen = 1; 316 msg.msg_control = handle->buffer; 317 msg.msg_controllen = handle->offset; 318 319 /* ignore interrupt system call error */ 320 do { 321 ret = recvmsg(handle->fd, &msg, 0); 322 if (handle->break_loop) 323 { 324 handle->break_loop = 0; 325 return -2; 326 } 327 } while ((ret == -1) && (errno == EINTR)); 328 329 if (ret < 0) { 330 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 331 "Can't receive packet: %s", strerror(errno)); 332 return -1; 333 } 334 335 pkth.caplen = ret; 336 337 /* get direction and timestamp*/ 338 cmsg = CMSG_FIRSTHDR(&msg); 339 int in=0; 340 while (cmsg) { 341 switch (cmsg->cmsg_type) { 342 case HCI_CMSG_DIR: 343 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 344 break; 345 case HCI_CMSG_TSTAMP: 346 memcpy(&pkth.ts, CMSG_DATA(cmsg), 347 sizeof pkth.ts); 348 break; 349 } 350 cmsg = CMSG_NXTHDR(&msg, cmsg); 351 } 352 if ((in && (handle->direction == PCAP_D_OUT)) || 353 ((!in) && (handle->direction == PCAP_D_IN))) 354 return 0; 355 356 bthdr->direction = htonl(in != 0); 357 pkth.caplen+=sizeof(pcap_bluetooth_h4_header); 358 pkth.len = pkth.caplen; 359 if (handle->fcode.bf_insns == NULL || 360 bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset], 361 pkth.len, pkth.caplen)) { 362 callback(user, &pkth, &handle->buffer[handle->offset]); 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 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 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