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 *, size_t); 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 i, sock; 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 this is not fatal*/ 84 if (errno == EAFNOSUPPORT) 85 return 0; 86 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE, 87 errno, "Can't open raw Bluetooth socket"); 88 return -1; 89 } 90 91 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 92 if (!dev_list) 93 { 94 pcap_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 = -1; 97 goto done; 98 } 99 100 dev_list->dev_num = HCI_MAX_DEV; 101 102 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0) 103 { 104 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE, 105 errno, "Can't get Bluetooth device list via ioctl"); 106 ret = -1; 107 goto free; 108 } 109 110 dev_req = dev_list->dev_req; 111 for (i = 0; i < dev_list->dev_num; i++, dev_req++) { 112 char dev_name[20], dev_descr[30]; 113 114 pcap_snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id); 115 pcap_snprintf(dev_descr, 30, "Bluetooth adapter number %d", i); 116 117 /* 118 * Bluetooth is a wireless technology. 119 * XXX - if there's the notion of associating with a 120 * network, and we can determine whether the interface 121 * is associated with a network, check that and set 122 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED 123 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED. 124 */ 125 if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str) == NULL) 126 { 127 ret = -1; 128 break; 129 } 130 } 131 132 free: 133 free(dev_list); 134 135 done: 136 close(sock); 137 return ret; 138 } 139 140 pcap_t * 141 bt_create(const char *device, char *ebuf, int *is_ours) 142 { 143 const char *cp; 144 char *cpend; 145 long devnum; 146 pcap_t *p; 147 148 /* Does this look like a Bluetooth device? */ 149 cp = strrchr(device, '/'); 150 if (cp == NULL) 151 cp = device; 152 /* Does it begin with BT_IFACE? */ 153 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) { 154 /* Nope, doesn't begin with BT_IFACE */ 155 *is_ours = 0; 156 return NULL; 157 } 158 /* Yes - is BT_IFACE followed by a number? */ 159 cp += sizeof BT_IFACE - 1; 160 devnum = strtol(cp, &cpend, 10); 161 if (cpend == cp || *cpend != '\0') { 162 /* Not followed by a number. */ 163 *is_ours = 0; 164 return NULL; 165 } 166 if (devnum < 0) { 167 /* Followed by a non-valid number. */ 168 *is_ours = 0; 169 return NULL; 170 } 171 172 /* OK, it's probably ours. */ 173 *is_ours = 1; 174 175 p = pcap_create_common(ebuf, sizeof (struct pcap_bt)); 176 if (p == NULL) 177 return (NULL); 178 179 p->activate_op = bt_activate; 180 return (p); 181 } 182 183 static int 184 bt_activate(pcap_t* handle) 185 { 186 struct pcap_bt *handlep = handle->priv; 187 struct sockaddr_hci addr; 188 int opt; 189 int dev_id; 190 struct hci_filter flt; 191 int err = PCAP_ERROR; 192 193 /* get bt interface id */ 194 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1) 195 { 196 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 197 "Can't get Bluetooth device index from %s", 198 handle->opt.device); 199 return PCAP_ERROR; 200 } 201 202 /* 203 * Turn a negative snapshot value (invalid), a snapshot value of 204 * 0 (unspecified), or a value bigger than the normal maximum 205 * value, into the maximum allowed value. 206 * 207 * If some application really *needs* a bigger snapshot 208 * length, we should just increase MAXIMUM_SNAPLEN. 209 */ 210 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN) 211 handle->snapshot = MAXIMUM_SNAPLEN; 212 213 /* Initialize some components of the pcap structure. */ 214 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot; 215 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 216 217 handle->read_op = bt_read_linux; 218 handle->inject_op = bt_inject_linux; 219 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 220 handle->setdirection_op = bt_setdirection_linux; 221 handle->set_datalink_op = NULL; /* can't change data link type */ 222 handle->getnonblock_op = pcap_getnonblock_fd; 223 handle->setnonblock_op = pcap_setnonblock_fd; 224 handle->stats_op = bt_stats_linux; 225 handlep->dev_id = dev_id; 226 227 /* Create HCI socket */ 228 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 229 if (handle->fd < 0) { 230 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 231 errno, "Can't create raw socket"); 232 return PCAP_ERROR; 233 } 234 235 handle->buffer = malloc(handle->bufsize); 236 if (!handle->buffer) { 237 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 238 errno, "Can't allocate dump buffer"); 239 goto close_fail; 240 } 241 242 opt = 1; 243 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 244 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 245 errno, "Can't enable data direction info"); 246 goto close_fail; 247 } 248 249 opt = 1; 250 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 251 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 252 errno, "Can't enable time stamp"); 253 goto close_fail; 254 } 255 256 /* Setup filter, do not call hci function to avoid dependence on 257 * external libs */ 258 memset(&flt, 0, sizeof(flt)); 259 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 260 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 261 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 262 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 263 errno, "Can't set filter"); 264 goto close_fail; 265 } 266 267 268 /* Bind socket to the HCI device */ 269 addr.hci_family = AF_BLUETOOTH; 270 addr.hci_dev = handlep->dev_id; 271 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL 272 addr.hci_channel = HCI_CHANNEL_RAW; 273 #endif 274 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 275 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 276 errno, "Can't attach to device %d", handlep->dev_id); 277 goto close_fail; 278 } 279 280 if (handle->opt.rfmon) { 281 /* 282 * Monitor mode doesn't apply to Bluetooth devices. 283 */ 284 err = PCAP_ERROR_RFMON_NOTSUP; 285 goto close_fail; 286 } 287 288 if (handle->opt.buffer_size != 0) { 289 /* 290 * Set the socket buffer size to the specified value. 291 */ 292 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 293 &handle->opt.buffer_size, 294 sizeof(handle->opt.buffer_size)) == -1) { 295 pcap_fmt_errmsg_for_errno(handle->errbuf, 296 errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF"); 297 goto close_fail; 298 } 299 } 300 301 handle->selectable_fd = handle->fd; 302 return 0; 303 304 close_fail: 305 pcap_cleanup_live_common(handle); 306 return err; 307 } 308 309 static int 310 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 311 { 312 struct cmsghdr *cmsg; 313 struct msghdr msg; 314 struct iovec iv; 315 ssize_t ret; 316 struct pcap_pkthdr pkth; 317 pcap_bluetooth_h4_header* bthdr; 318 u_char *pktd; 319 int in = 0; 320 321 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE; 322 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd; 323 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header); 324 iv.iov_len = handle->snapshot; 325 326 memset(&msg, 0, sizeof(msg)); 327 msg.msg_iov = &iv; 328 msg.msg_iovlen = 1; 329 msg.msg_control = handle->buffer; 330 msg.msg_controllen = BT_CTRL_SIZE; 331 332 /* ignore interrupt system call error */ 333 do { 334 ret = recvmsg(handle->fd, &msg, 0); 335 if (handle->break_loop) 336 { 337 handle->break_loop = 0; 338 return -2; 339 } 340 } while ((ret == -1) && (errno == EINTR)); 341 342 if (ret < 0) { 343 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 344 errno, "Can't receive packet"); 345 return -1; 346 } 347 348 pkth.caplen = ret; 349 350 /* get direction and timestamp*/ 351 cmsg = CMSG_FIRSTHDR(&msg); 352 while (cmsg) { 353 switch (cmsg->cmsg_type) { 354 case HCI_CMSG_DIR: 355 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 356 break; 357 case HCI_CMSG_TSTAMP: 358 memcpy(&pkth.ts, CMSG_DATA(cmsg), 359 sizeof pkth.ts); 360 break; 361 } 362 cmsg = CMSG_NXTHDR(&msg, cmsg); 363 } 364 if ((in && (handle->direction == PCAP_D_OUT)) || 365 ((!in) && (handle->direction == PCAP_D_IN))) 366 return 0; 367 368 bthdr->direction = htonl(in != 0); 369 pkth.caplen+=sizeof(pcap_bluetooth_h4_header); 370 pkth.len = pkth.caplen; 371 if (handle->fcode.bf_insns == NULL || 372 bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) { 373 callback(user, &pkth, pktd); 374 return 1; 375 } 376 return 0; /* didn't pass filter */ 377 } 378 379 static int 380 bt_inject_linux(pcap_t *handle, const void *buf _U_, size_t size _U_) 381 { 382 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " 383 "bluetooth devices"); 384 return (-1); 385 } 386 387 388 static int 389 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats) 390 { 391 struct pcap_bt *handlep = handle->priv; 392 int ret; 393 struct hci_dev_info dev_info; 394 struct hci_dev_stats * s = &dev_info.stat; 395 dev_info.dev_id = handlep->dev_id; 396 397 /* ignore eintr */ 398 do { 399 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info); 400 } while ((ret == -1) && (errno == EINTR)); 401 402 if (ret < 0) { 403 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 404 errno, "Can't get stats via ioctl"); 405 return (-1); 406 407 } 408 409 /* we receive both rx and tx frames, so comulate all stats */ 410 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx + 411 s->acl_tx +s->sco_tx; 412 stats->ps_drop = s->err_rx + s->err_tx; 413 stats->ps_ifdrop = 0; 414 return 0; 415 } 416 417 static int 418 bt_setdirection_linux(pcap_t *p, pcap_direction_t d) 419 { 420 p->direction = d; 421 return 0; 422 } 423