1 /* 2 * Copyright (c) 2014 Michal Labedzki for Tieto Corporation 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 */ 31 32 #ifdef HAVE_CONFIG_H 33 #include <config.h> 34 #endif 35 36 #include <errno.h> 37 #include <stdint.h> 38 #include <stdlib.h> 39 #include <string.h> 40 41 #include <bluetooth/bluetooth.h> 42 #include <bluetooth/hci.h> 43 44 #include "pcap/bluetooth.h" 45 #include "pcap-int.h" 46 47 #include "pcap-bt-monitor-linux.h" 48 49 #define BT_CONTROL_SIZE 32 50 #define INTERFACE_NAME "bluetooth-monitor" 51 52 /* 53 * Private data. 54 * Currently contains nothing. 55 */ 56 struct pcap_bt_monitor { 57 int dummy; 58 }; 59 60 /* 61 * Fields and alignment must match the declaration in the Linux kernel 3.4+. 62 * See struct hci_mon_hdr in include/net/bluetooth/hci_mon.h. 63 */ 64 struct hci_mon_hdr { 65 uint16_t opcode; 66 uint16_t index; 67 uint16_t len; 68 } __attribute__((packed)); 69 70 int 71 bt_monitor_findalldevs(pcap_if_list_t *devlistp, char *err_str) 72 { 73 int ret = 0; 74 75 /* 76 * Bluetooth is a wireless technology. 77 * 78 * This is a device to monitor all Bluetooth interfaces, so 79 * there's no notion of "connected" or "disconnected", any 80 * more than there's a notion of "connected" or "disconnected" 81 * for the "any" device. 82 */ 83 if (add_dev(devlistp, INTERFACE_NAME, 84 PCAP_IF_WIRELESS|PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE, 85 "Bluetooth Linux Monitor", err_str) == NULL) 86 { 87 ret = -1; 88 } 89 90 return ret; 91 } 92 93 static int 94 bt_monitor_read(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 95 { 96 struct cmsghdr *cmsg; 97 struct msghdr msg; 98 struct iovec iv[2]; 99 ssize_t ret; 100 struct pcap_pkthdr pkth; 101 pcap_bluetooth_linux_monitor_header *bthdr; 102 u_char *pktd; 103 struct hci_mon_hdr hdr; 104 105 pktd = (u_char *)handle->buffer + BT_CONTROL_SIZE; 106 bthdr = (pcap_bluetooth_linux_monitor_header*)(void *)pktd; 107 108 iv[0].iov_base = &hdr; 109 iv[0].iov_len = sizeof(hdr); 110 iv[1].iov_base = pktd + sizeof(pcap_bluetooth_linux_monitor_header); 111 iv[1].iov_len = handle->snapshot; 112 113 memset(&pkth.ts, 0, sizeof(pkth.ts)); 114 memset(&msg, 0, sizeof(msg)); 115 msg.msg_iov = iv; 116 msg.msg_iovlen = 2; 117 msg.msg_control = handle->buffer; 118 msg.msg_controllen = BT_CONTROL_SIZE; 119 120 do { 121 ret = recvmsg(handle->fd, &msg, 0); 122 if (handle->break_loop) 123 { 124 handle->break_loop = 0; 125 return -2; 126 } 127 } while ((ret == -1) && (errno == EINTR)); 128 129 if (ret < 0) { 130 if (errno == EAGAIN || errno == EWOULDBLOCK) { 131 /* Nonblocking mode, no data */ 132 return 0; 133 } 134 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 135 errno, "Can't receive packet"); 136 return -1; 137 } 138 139 pkth.caplen = (bpf_u_int32)(ret - sizeof(hdr) + sizeof(pcap_bluetooth_linux_monitor_header)); 140 pkth.len = pkth.caplen; 141 142 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { 143 if (cmsg->cmsg_level != SOL_SOCKET) continue; 144 145 if (cmsg->cmsg_type == SCM_TIMESTAMP) { 146 memcpy(&pkth.ts, CMSG_DATA(cmsg), sizeof(pkth.ts)); 147 } 148 } 149 150 bthdr->adapter_id = htons(hdr.index); 151 bthdr->opcode = htons(hdr.opcode); 152 153 if (handle->fcode.bf_insns == NULL || 154 pcap_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) { 155 callback(user, &pkth, pktd); 156 return 1; 157 } 158 return 0; /* didn't pass filter */ 159 } 160 161 static int 162 bt_monitor_inject(pcap_t *handle, const void *buf _U_, int size _U_) 163 { 164 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 165 "Packet injection is not supported yet on Bluetooth monitor devices"); 166 return -1; 167 } 168 169 static int 170 bt_monitor_stats(pcap_t *handle _U_, struct pcap_stat *stats) 171 { 172 stats->ps_recv = 0; 173 stats->ps_drop = 0; 174 stats->ps_ifdrop = 0; 175 176 return 0; 177 } 178 179 static int 180 bt_monitor_activate(pcap_t* handle) 181 { 182 struct sockaddr_hci addr; 183 int err = PCAP_ERROR; 184 int opt; 185 186 if (handle->opt.rfmon) { 187 /* monitor mode doesn't apply here */ 188 return PCAP_ERROR_RFMON_NOTSUP; 189 } 190 191 /* 192 * Turn a negative snapshot value (invalid), a snapshot value of 193 * 0 (unspecified), or a value bigger than the normal maximum 194 * value, into the maximum allowed value. 195 * 196 * If some application really *needs* a bigger snapshot 197 * length, we should just increase MAXIMUM_SNAPLEN. 198 */ 199 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN) 200 handle->snapshot = MAXIMUM_SNAPLEN; 201 202 handle->bufsize = BT_CONTROL_SIZE + sizeof(pcap_bluetooth_linux_monitor_header) + handle->snapshot; 203 handle->linktype = DLT_BLUETOOTH_LINUX_MONITOR; 204 205 handle->read_op = bt_monitor_read; 206 handle->inject_op = bt_monitor_inject; 207 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 208 handle->setdirection_op = NULL; /* Not implemented */ 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_monitor_stats; 213 214 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 215 if (handle->fd < 0) { 216 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 217 errno, "Can't create raw socket"); 218 return PCAP_ERROR; 219 } 220 221 handle->buffer = malloc(handle->bufsize); 222 if (!handle->buffer) { 223 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 224 errno, "Can't allocate dump buffer"); 225 goto close_fail; 226 } 227 228 /* Bind socket to the HCI device */ 229 addr.hci_family = AF_BLUETOOTH; 230 addr.hci_dev = HCI_DEV_NONE; 231 addr.hci_channel = HCI_CHANNEL_MONITOR; 232 233 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 234 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 235 errno, "Can't attach to interface"); 236 goto close_fail; 237 } 238 239 opt = 1; 240 if (setsockopt(handle->fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) { 241 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 242 errno, "Can't enable time stamp"); 243 goto close_fail; 244 } 245 246 handle->selectable_fd = handle->fd; 247 248 return 0; 249 250 close_fail: 251 pcap_cleanup_live_common(handle); 252 return err; 253 } 254 255 pcap_t * 256 bt_monitor_create(const char *device, char *ebuf, int *is_ours) 257 { 258 pcap_t *p; 259 const char *cp; 260 261 cp = strrchr(device, '/'); 262 if (cp == NULL) 263 cp = device; 264 265 if (strcmp(cp, INTERFACE_NAME) != 0) { 266 *is_ours = 0; 267 return NULL; 268 } 269 270 *is_ours = 1; 271 p = PCAP_CREATE_COMMON(ebuf, struct pcap_bt_monitor); 272 if (p == NULL) 273 return NULL; 274 275 p->activate_op = bt_monitor_activate; 276 277 return p; 278 } 279