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 sock; 78 unsigned i; 79 int ret = 0; 80 81 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 82 if (sock < 0) 83 { 84 /* if bluetooth is not supported this is not fatal*/ 85 if (errno == EAFNOSUPPORT) 86 return 0; 87 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE, 88 errno, "Can't open raw Bluetooth socket"); 89 return -1; 90 } 91 92 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 93 if (!dev_list) 94 { 95 pcap_snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list", 96 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 97 ret = -1; 98 goto done; 99 } 100 101 dev_list->dev_num = HCI_MAX_DEV; 102 103 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0) 104 { 105 pcap_fmt_errmsg_for_errno(err_str, PCAP_ERRBUF_SIZE, 106 errno, "Can't get Bluetooth device list via ioctl"); 107 ret = -1; 108 goto free; 109 } 110 111 dev_req = dev_list->dev_req; 112 for (i = 0; i < dev_list->dev_num; i++, dev_req++) { 113 char dev_name[20], dev_descr[40]; 114 115 pcap_snprintf(dev_name, sizeof(dev_name), BT_IFACE"%u", dev_req->dev_id); 116 pcap_snprintf(dev_descr, sizeof(dev_descr), "Bluetooth adapter number %u", i); 117 118 /* 119 * Bluetooth is a wireless technology. 120 * XXX - if there's the notion of associating with a 121 * network, and we can determine whether the interface 122 * is associated with a network, check that and set 123 * the status to PCAP_IF_CONNECTION_STATUS_CONNECTED 124 * or PCAP_IF_CONNECTION_STATUS_DISCONNECTED. 125 */ 126 if (add_dev(devlistp, dev_name, PCAP_IF_WIRELESS, dev_descr, err_str) == NULL) 127 { 128 ret = -1; 129 break; 130 } 131 } 132 133 free: 134 free(dev_list); 135 136 done: 137 close(sock); 138 return ret; 139 } 140 141 pcap_t * 142 bt_create(const char *device, char *ebuf, int *is_ours) 143 { 144 const char *cp; 145 char *cpend; 146 long devnum; 147 pcap_t *p; 148 149 /* Does this look like a Bluetooth device? */ 150 cp = strrchr(device, '/'); 151 if (cp == NULL) 152 cp = device; 153 /* Does it begin with BT_IFACE? */ 154 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) { 155 /* Nope, doesn't begin with BT_IFACE */ 156 *is_ours = 0; 157 return NULL; 158 } 159 /* Yes - is BT_IFACE followed by a number? */ 160 cp += sizeof BT_IFACE - 1; 161 devnum = strtol(cp, &cpend, 10); 162 if (cpend == cp || *cpend != '\0') { 163 /* Not followed by a number. */ 164 *is_ours = 0; 165 return NULL; 166 } 167 if (devnum < 0) { 168 /* Followed by a non-valid number. */ 169 *is_ours = 0; 170 return NULL; 171 } 172 173 /* OK, it's probably ours. */ 174 *is_ours = 1; 175 176 p = pcap_create_common(ebuf, sizeof (struct pcap_bt)); 177 if (p == NULL) 178 return (NULL); 179 180 p->activate_op = bt_activate; 181 return (p); 182 } 183 184 static int 185 bt_activate(pcap_t* handle) 186 { 187 struct pcap_bt *handlep = handle->priv; 188 struct sockaddr_hci addr; 189 int opt; 190 int dev_id; 191 struct hci_filter flt; 192 int err = PCAP_ERROR; 193 194 /* get bt interface id */ 195 if (sscanf(handle->opt.device, BT_IFACE"%d", &dev_id) != 1) 196 { 197 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 198 "Can't get Bluetooth device index from %s", 199 handle->opt.device); 200 return PCAP_ERROR; 201 } 202 203 /* 204 * Turn a negative snapshot value (invalid), a snapshot value of 205 * 0 (unspecified), or a value bigger than the normal maximum 206 * value, into the maximum allowed value. 207 * 208 * If some application really *needs* a bigger snapshot 209 * length, we should just increase MAXIMUM_SNAPLEN. 210 */ 211 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN) 212 handle->snapshot = MAXIMUM_SNAPLEN; 213 214 /* Initialize some components of the pcap structure. */ 215 handle->bufsize = BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header)+handle->snapshot; 216 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 217 218 handle->read_op = bt_read_linux; 219 handle->inject_op = bt_inject_linux; 220 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 221 handle->setdirection_op = bt_setdirection_linux; 222 handle->set_datalink_op = NULL; /* can't change data link type */ 223 handle->getnonblock_op = pcap_getnonblock_fd; 224 handle->setnonblock_op = pcap_setnonblock_fd; 225 handle->stats_op = bt_stats_linux; 226 handlep->dev_id = dev_id; 227 228 /* Create HCI socket */ 229 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 230 if (handle->fd < 0) { 231 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 232 errno, "Can't create raw socket"); 233 return PCAP_ERROR; 234 } 235 236 handle->buffer = malloc(handle->bufsize); 237 if (!handle->buffer) { 238 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 239 errno, "Can't allocate dump buffer"); 240 goto close_fail; 241 } 242 243 opt = 1; 244 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 245 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 246 errno, "Can't enable data direction info"); 247 goto close_fail; 248 } 249 250 opt = 1; 251 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 252 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 253 errno, "Can't enable time stamp"); 254 goto close_fail; 255 } 256 257 /* Setup filter, do not call hci function to avoid dependence on 258 * external libs */ 259 memset(&flt, 0, sizeof(flt)); 260 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 261 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 262 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 263 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 264 errno, "Can't set filter"); 265 goto close_fail; 266 } 267 268 269 /* Bind socket to the HCI device */ 270 addr.hci_family = AF_BLUETOOTH; 271 addr.hci_dev = handlep->dev_id; 272 #ifdef HAVE_STRUCT_SOCKADDR_HCI_HCI_CHANNEL 273 addr.hci_channel = HCI_CHANNEL_RAW; 274 #endif 275 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 276 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 277 errno, "Can't attach to device %d", handlep->dev_id); 278 goto close_fail; 279 } 280 281 if (handle->opt.rfmon) { 282 /* 283 * Monitor mode doesn't apply to Bluetooth devices. 284 */ 285 err = PCAP_ERROR_RFMON_NOTSUP; 286 goto close_fail; 287 } 288 289 if (handle->opt.buffer_size != 0) { 290 /* 291 * Set the socket buffer size to the specified value. 292 */ 293 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 294 &handle->opt.buffer_size, 295 sizeof(handle->opt.buffer_size)) == -1) { 296 pcap_fmt_errmsg_for_errno(handle->errbuf, 297 errno, PCAP_ERRBUF_SIZE, "SO_RCVBUF"); 298 goto close_fail; 299 } 300 } 301 302 handle->selectable_fd = handle->fd; 303 return 0; 304 305 close_fail: 306 pcap_cleanup_live_common(handle); 307 return err; 308 } 309 310 static int 311 bt_read_linux(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 312 { 313 struct cmsghdr *cmsg; 314 struct msghdr msg; 315 struct iovec iv; 316 ssize_t ret; 317 struct pcap_pkthdr pkth; 318 pcap_bluetooth_h4_header* bthdr; 319 u_char *pktd; 320 int in = 0; 321 322 pktd = (u_char *)handle->buffer + BT_CTRL_SIZE; 323 bthdr = (pcap_bluetooth_h4_header*)(void *)pktd; 324 iv.iov_base = pktd + sizeof(pcap_bluetooth_h4_header); 325 iv.iov_len = handle->snapshot; 326 327 memset(&msg, 0, sizeof(msg)); 328 msg.msg_iov = &iv; 329 msg.msg_iovlen = 1; 330 msg.msg_control = handle->buffer; 331 msg.msg_controllen = BT_CTRL_SIZE; 332 333 /* ignore interrupt system call error */ 334 do { 335 ret = recvmsg(handle->fd, &msg, 0); 336 if (handle->break_loop) 337 { 338 handle->break_loop = 0; 339 return -2; 340 } 341 } while ((ret == -1) && (errno == EINTR)); 342 343 if (ret < 0) { 344 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 345 errno, "Can't receive packet"); 346 return -1; 347 } 348 349 pkth.caplen = ret; 350 351 /* get direction and timestamp*/ 352 cmsg = CMSG_FIRSTHDR(&msg); 353 while (cmsg) { 354 switch (cmsg->cmsg_type) { 355 case HCI_CMSG_DIR: 356 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 357 break; 358 case HCI_CMSG_TSTAMP: 359 memcpy(&pkth.ts, CMSG_DATA(cmsg), 360 sizeof pkth.ts); 361 break; 362 } 363 cmsg = CMSG_NXTHDR(&msg, cmsg); 364 } 365 if ((in && (handle->direction == PCAP_D_OUT)) || 366 ((!in) && (handle->direction == PCAP_D_IN))) 367 return 0; 368 369 bthdr->direction = htonl(in != 0); 370 pkth.caplen+=sizeof(pcap_bluetooth_h4_header); 371 pkth.len = pkth.caplen; 372 if (handle->fcode.bf_insns == NULL || 373 bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) { 374 callback(user, &pkth, pktd); 375 return 1; 376 } 377 return 0; /* didn't pass filter */ 378 } 379 380 static int 381 bt_inject_linux(pcap_t *handle, const void *buf _U_, size_t size _U_) 382 { 383 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 384 "Packet injection is not supported on Bluetooth devices"); 385 return (-1); 386 } 387 388 389 static int 390 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats) 391 { 392 struct pcap_bt *handlep = handle->priv; 393 int ret; 394 struct hci_dev_info dev_info; 395 struct hci_dev_stats * s = &dev_info.stat; 396 dev_info.dev_id = handlep->dev_id; 397 398 /* ignore eintr */ 399 do { 400 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info); 401 } while ((ret == -1) && (errno == EINTR)); 402 403 if (ret < 0) { 404 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 405 errno, "Can't get stats via ioctl"); 406 return (-1); 407 408 } 409 410 /* we receive both rx and tx frames, so comulate all stats */ 411 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx + 412 s->acl_tx +s->sco_tx; 413 stats->ps_drop = s->err_rx + s->err_tx; 414 stats->ps_ifdrop = 0; 415 return 0; 416 } 417 418 static int 419 bt_setdirection_linux(pcap_t *p, pcap_direction_t d) 420 { 421 p->direction = d; 422 return 0; 423 } 424