1 /* $NetBSD: pcap-bt-linux.c,v 1.1.1.4 2013/12/31 16:57:28 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 #ifndef lint 37 static const char rcsid[] _U_ = 38 "@(#) Header: /tcpdump/master/libpcap/pcap-bt-linux.c,v 1.15 2008-07-01 07:05:54 guy Exp (LBL)"; 39 #endif 40 41 #ifdef HAVE_CONFIG_H 42 #include "config.h" 43 #endif 44 45 #include "pcap-int.h" 46 #include "pcap-bt-linux.h" 47 #include "pcap/bluetooth.h" 48 49 #ifdef NEED_STRERROR_H 50 #include "strerror.h" 51 #endif 52 53 #include <errno.h> 54 #include <stdlib.h> 55 #include <unistd.h> 56 #include <fcntl.h> 57 #include <string.h> 58 #include <sys/ioctl.h> 59 #include <sys/socket.h> 60 #include <arpa/inet.h> 61 62 #include <bluetooth/bluetooth.h> 63 #include <bluetooth/hci.h> 64 65 #define BT_IFACE "bluetooth" 66 #define BT_CTRL_SIZE 128 67 68 /* forward declaration */ 69 static int bt_activate(pcap_t *); 70 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *); 71 static int bt_inject_linux(pcap_t *, const void *, size_t); 72 static int bt_setdirection_linux(pcap_t *, pcap_direction_t); 73 static int bt_stats_linux(pcap_t *, struct pcap_stat *); 74 75 /* 76 * Private data for capturing on Linux Bluetooth devices. 77 */ 78 struct pcap_bt { 79 int dev_id; /* device ID of device we're bound to */ 80 }; 81 82 int 83 bt_findalldevs(pcap_if_t **alldevsp, char *err_str) 84 { 85 struct hci_dev_list_req *dev_list; 86 struct hci_dev_req *dev_req; 87 int i, sock; 88 int ret = 0; 89 90 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 91 if (sock < 0) 92 { 93 /* if bluetooth is not supported this this is not fatal*/ 94 if (errno == EAFNOSUPPORT) 95 return 0; 96 snprintf(err_str, PCAP_ERRBUF_SIZE, 97 "Can't open raw Bluetooth socket: %s", strerror(errno)); 98 return -1; 99 } 100 101 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 102 if (!dev_list) 103 { 104 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list", 105 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list)); 106 ret = -1; 107 goto done; 108 } 109 110 dev_list->dev_num = HCI_MAX_DEV; 111 112 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0) 113 { 114 snprintf(err_str, PCAP_ERRBUF_SIZE, 115 "Can't get Bluetooth device list via ioctl: %s", 116 strerror(errno)); 117 ret = -1; 118 goto free; 119 } 120 121 dev_req = dev_list->dev_req; 122 for (i = 0; i < dev_list->dev_num; i++, dev_req++) { 123 char dev_name[20], dev_descr[30]; 124 125 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id); 126 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i); 127 128 if (pcap_add_if(alldevsp, dev_name, 0, 129 dev_descr, err_str) < 0) 130 { 131 ret = -1; 132 break; 133 } 134 135 } 136 137 free: 138 free(dev_list); 139 140 done: 141 close(sock); 142 return ret; 143 } 144 145 pcap_t * 146 bt_create(const char *device, char *ebuf, int *is_ours) 147 { 148 const char *cp; 149 char *cpend; 150 long devnum; 151 pcap_t *p; 152 153 /* Does this look like a Bluetooth device? */ 154 cp = strrchr(device, '/'); 155 if (cp == NULL) 156 cp = device; 157 /* Does it begin with BT_IFACE? */ 158 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) { 159 /* Nope, doesn't begin with BT_IFACE */ 160 *is_ours = 0; 161 return NULL; 162 } 163 /* Yes - is BT_IFACE followed by a number? */ 164 cp += sizeof BT_IFACE - 1; 165 devnum = strtol(cp, &cpend, 10); 166 if (cpend == cp || *cpend != '\0') { 167 /* Not followed by a number. */ 168 *is_ours = 0; 169 return NULL; 170 } 171 if (devnum < 0) { 172 /* Followed by a non-valid number. */ 173 *is_ours = 0; 174 return NULL; 175 } 176 177 /* OK, it's probably ours. */ 178 *is_ours = 1; 179 180 p = pcap_create_common(device, ebuf, sizeof (struct pcap_bt)); 181 if (p == NULL) 182 return (NULL); 183 184 p->activate_op = bt_activate; 185 return (p); 186 } 187 188 static int 189 bt_activate(pcap_t* handle) 190 { 191 struct pcap_bt *handlep = handle->priv; 192 struct sockaddr_hci addr; 193 int opt; 194 int dev_id; 195 struct hci_filter flt; 196 int err = PCAP_ERROR; 197 198 /* get bt interface id */ 199 if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1) 200 { 201 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 202 "Can't get Bluetooth device index from %s", 203 handle->opt.source); 204 return PCAP_ERROR; 205 } 206 207 /* Initialize some components of the pcap structure. */ 208 handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header); 209 handle->offset = BT_CTRL_SIZE; 210 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR; 211 212 handle->read_op = bt_read_linux; 213 handle->inject_op = bt_inject_linux; 214 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 215 handle->setdirection_op = bt_setdirection_linux; 216 handle->set_datalink_op = NULL; /* can't change data link type */ 217 handle->getnonblock_op = pcap_getnonblock_fd; 218 handle->setnonblock_op = pcap_setnonblock_fd; 219 handle->stats_op = bt_stats_linux; 220 handlep->dev_id = dev_id; 221 222 /* Create HCI socket */ 223 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 224 if (handle->fd < 0) { 225 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 226 "Can't create raw socket: %s", strerror(errno)); 227 return PCAP_ERROR; 228 } 229 230 handle->buffer = malloc(handle->bufsize); 231 if (!handle->buffer) { 232 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", 233 pcap_strerror(errno)); 234 goto close_fail; 235 } 236 237 opt = 1; 238 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) { 239 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 240 "Can't enable data direction info: %s", strerror(errno)); 241 goto close_fail; 242 } 243 244 opt = 1; 245 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) { 246 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 247 "Can't enable time stamp: %s", strerror(errno)); 248 goto close_fail; 249 } 250 251 /* Setup filter, do not call hci function to avoid dependence on 252 * external libs */ 253 memset(&flt, 0, sizeof(flt)); 254 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask)); 255 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask)); 256 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) { 257 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 258 "Can't set filter: %s", strerror(errno)); 259 goto close_fail; 260 } 261 262 263 /* Bind socket to the HCI device */ 264 addr.hci_family = AF_BLUETOOTH; 265 addr.hci_dev = handlep->dev_id; 266 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL 267 addr.hci_channel = HCI_CHANNEL_RAW; 268 #endif 269 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 270 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 271 "Can't attach to device %d: %s", handlep->dev_id, 272 strerror(errno)); 273 goto close_fail; 274 } 275 276 if (handle->opt.rfmon) { 277 /* 278 * Monitor mode doesn't apply to Bluetooth devices. 279 */ 280 err = PCAP_ERROR_RFMON_NOTSUP; 281 goto close_fail; 282 } 283 284 if (handle->opt.buffer_size != 0) { 285 /* 286 * Set the socket buffer size to the specified value. 287 */ 288 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF, 289 &handle->opt.buffer_size, 290 sizeof(handle->opt.buffer_size)) == -1) { 291 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 292 "SO_RCVBUF: %s", pcap_strerror(errno)); 293 goto close_fail; 294 } 295 } 296 297 handle->selectable_fd = handle->fd; 298 return 0; 299 300 close_fail: 301 pcap_cleanup_live_common(handle); 302 return err; 303 } 304 305 static int 306 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user) 307 { 308 struct cmsghdr *cmsg; 309 struct msghdr msg; 310 struct iovec iv; 311 ssize_t ret; 312 struct pcap_pkthdr pkth; 313 pcap_bluetooth_h4_header* bthdr; 314 315 bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset]; 316 iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)]; 317 iv.iov_len = handle->snapshot; 318 319 memset(&msg, 0, sizeof(msg)); 320 msg.msg_iov = &iv; 321 msg.msg_iovlen = 1; 322 msg.msg_control = handle->buffer; 323 msg.msg_controllen = handle->offset; 324 325 /* ignore interrupt system call error */ 326 do { 327 ret = recvmsg(handle->fd, &msg, 0); 328 if (handle->break_loop) 329 { 330 handle->break_loop = 0; 331 return -2; 332 } 333 } while ((ret == -1) && (errno == EINTR)); 334 335 if (ret < 0) { 336 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 337 "Can't receive packet: %s", strerror(errno)); 338 return -1; 339 } 340 341 pkth.caplen = ret; 342 343 /* get direction and timestamp*/ 344 cmsg = CMSG_FIRSTHDR(&msg); 345 int in=0; 346 while (cmsg) { 347 switch (cmsg->cmsg_type) { 348 case HCI_CMSG_DIR: 349 memcpy(&in, CMSG_DATA(cmsg), sizeof in); 350 break; 351 case HCI_CMSG_TSTAMP: 352 memcpy(&pkth.ts, CMSG_DATA(cmsg), 353 sizeof pkth.ts); 354 break; 355 } 356 cmsg = CMSG_NXTHDR(&msg, cmsg); 357 } 358 if ((in && (handle->direction == PCAP_D_OUT)) || 359 ((!in) && (handle->direction == PCAP_D_IN))) 360 return 0; 361 362 bthdr->direction = htonl(in != 0); 363 pkth.caplen+=sizeof(pcap_bluetooth_h4_header); 364 pkth.len = pkth.caplen; 365 if (handle->fcode.bf_insns == NULL || 366 bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset], 367 pkth.len, pkth.caplen)) { 368 callback(user, &pkth, &handle->buffer[handle->offset]); 369 return 1; 370 } 371 return 0; /* didn't pass filter */ 372 } 373 374 static int 375 bt_inject_linux(pcap_t *handle, const void *buf, size_t size) 376 { 377 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on " 378 "bluetooth devices"); 379 return (-1); 380 } 381 382 383 static int 384 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats) 385 { 386 struct pcap_bt *handlep = handle->priv; 387 int ret; 388 struct hci_dev_info dev_info; 389 struct hci_dev_stats * s = &dev_info.stat; 390 dev_info.dev_id = handlep->dev_id; 391 392 /* ignore eintr */ 393 do { 394 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info); 395 } while ((ret == -1) && (errno == EINTR)); 396 397 if (ret < 0) { 398 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 399 "Can't get stats via ioctl: %s", strerror(errno)); 400 return (-1); 401 402 } 403 404 /* we receive both rx and tx frames, so comulate all stats */ 405 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx + 406 s->acl_tx +s->sco_tx; 407 stats->ps_drop = s->err_rx + s->err_tx; 408 stats->ps_ifdrop = 0; 409 return 0; 410 } 411 412 static int 413 bt_setdirection_linux(pcap_t *p, pcap_direction_t d) 414 { 415 p->direction = d; 416 return 0; 417 } 418