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 * Fields and alignment must match the declaration in the Linux kernel 3.4+. 54 * See struct hci_mon_hdr in include/net/bluetooth/hci_mon.h. 55 */ 56 struct hci_mon_hdr { 57 uint16_t opcode; 58 uint16_t index; 59 uint16_t len; 60 } __attribute__((packed)); 61 62 int 63 bt_monitor_findalldevs(pcap_if_list_t *devlistp, char *err_str) 64 { 65 int ret = 0; 66 67 /* 68 * Bluetooth is a wireless technology. 69 * 70 * This is a device to monitor all Bluetooth interfaces, so 71 * there's no notion of "connected" or "disconnected", any 72 * more than there's a notion of "connected" or "disconnected" 73 * for the "any" device. 74 */ 75 if (add_dev(devlistp, INTERFACE_NAME, 76 PCAP_IF_WIRELESS|PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE, 77 "Bluetooth Linux Monitor", err_str) == NULL) 78 { 79 ret = -1; 80 } 81 82 return ret; 83 } 84 85 static int 86 bt_monitor_read(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 87 { 88 struct cmsghdr *cmsg; 89 struct msghdr msg; 90 struct iovec iv[2]; 91 ssize_t ret; 92 struct pcap_pkthdr pkth; 93 pcap_bluetooth_linux_monitor_header *bthdr; 94 u_char *pktd; 95 struct hci_mon_hdr hdr; 96 97 pktd = (u_char *)handle->buffer + BT_CONTROL_SIZE; 98 bthdr = (pcap_bluetooth_linux_monitor_header*)(void *)pktd; 99 100 iv[0].iov_base = &hdr; 101 iv[0].iov_len = sizeof(hdr); 102 iv[1].iov_base = pktd + sizeof(pcap_bluetooth_linux_monitor_header); 103 iv[1].iov_len = handle->snapshot; 104 105 memset(&pkth.ts, 0, sizeof(pkth.ts)); 106 memset(&msg, 0, sizeof(msg)); 107 msg.msg_iov = iv; 108 msg.msg_iovlen = 2; 109 msg.msg_control = handle->buffer; 110 msg.msg_controllen = BT_CONTROL_SIZE; 111 112 do { 113 ret = recvmsg(handle->fd, &msg, 0); 114 if (handle->break_loop) 115 { 116 handle->break_loop = 0; 117 return -2; 118 } 119 } while ((ret == -1) && (errno == EINTR)); 120 121 if (ret < 0) { 122 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 123 errno, "Can't receive packet"); 124 return -1; 125 } 126 127 pkth.caplen = ret - sizeof(hdr) + sizeof(pcap_bluetooth_linux_monitor_header); 128 pkth.len = pkth.caplen; 129 130 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { 131 if (cmsg->cmsg_level != SOL_SOCKET) continue; 132 133 if (cmsg->cmsg_type == SCM_TIMESTAMP) { 134 memcpy(&pkth.ts, CMSG_DATA(cmsg), sizeof(pkth.ts)); 135 } 136 } 137 138 bthdr->adapter_id = htons(hdr.index); 139 bthdr->opcode = htons(hdr.opcode); 140 141 if (handle->fcode.bf_insns == NULL || 142 bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) { 143 callback(user, &pkth, pktd); 144 return 1; 145 } 146 return 0; /* didn't pass filter */ 147 } 148 149 static int 150 bt_monitor_inject(pcap_t *handle, const void *buf _U_, size_t size _U_) 151 { 152 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported yet"); 153 return -1; 154 } 155 156 static int 157 bt_monitor_setdirection(pcap_t *p, pcap_direction_t d) 158 { 159 p->direction = d; 160 return 0; 161 } 162 163 static int 164 bt_monitor_stats(pcap_t *handle _U_, struct pcap_stat *stats) 165 { 166 stats->ps_recv = 0; 167 stats->ps_drop = 0; 168 stats->ps_ifdrop = 0; 169 170 return 0; 171 } 172 173 static int 174 bt_monitor_activate(pcap_t* handle) 175 { 176 struct sockaddr_hci addr; 177 int err = PCAP_ERROR; 178 int opt; 179 180 if (handle->opt.rfmon) { 181 /* monitor mode doesn't apply here */ 182 return PCAP_ERROR_RFMON_NOTSUP; 183 } 184 185 /* 186 * Turn a negative snapshot value (invalid), a snapshot value of 187 * 0 (unspecified), or a value bigger than the normal maximum 188 * value, into the maximum allowed value. 189 * 190 * If some application really *needs* a bigger snapshot 191 * length, we should just increase MAXIMUM_SNAPLEN. 192 */ 193 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN) 194 handle->snapshot = MAXIMUM_SNAPLEN; 195 196 handle->bufsize = BT_CONTROL_SIZE + sizeof(pcap_bluetooth_linux_monitor_header) + handle->snapshot; 197 handle->linktype = DLT_BLUETOOTH_LINUX_MONITOR; 198 199 handle->read_op = bt_monitor_read; 200 handle->inject_op = bt_monitor_inject; 201 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 202 handle->setdirection_op = bt_monitor_setdirection; 203 handle->set_datalink_op = NULL; /* can't change data link type */ 204 handle->getnonblock_op = pcap_getnonblock_fd; 205 handle->setnonblock_op = pcap_setnonblock_fd; 206 handle->stats_op = bt_monitor_stats; 207 208 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 209 if (handle->fd < 0) { 210 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 211 errno, "Can't create raw socket"); 212 return PCAP_ERROR; 213 } 214 215 handle->buffer = malloc(handle->bufsize); 216 if (!handle->buffer) { 217 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 218 errno, "Can't allocate dump buffer"); 219 goto close_fail; 220 } 221 222 /* Bind socket to the HCI device */ 223 addr.hci_family = AF_BLUETOOTH; 224 addr.hci_dev = HCI_DEV_NONE; 225 addr.hci_channel = HCI_CHANNEL_MONITOR; 226 227 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 228 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 229 errno, "Can't attach to interface"); 230 goto close_fail; 231 } 232 233 opt = 1; 234 if (setsockopt(handle->fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) { 235 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, 236 errno, "Can't enable time stamp"); 237 goto close_fail; 238 } 239 240 handle->selectable_fd = handle->fd; 241 242 return 0; 243 244 close_fail: 245 pcap_cleanup_live_common(handle); 246 return err; 247 } 248 249 pcap_t * 250 bt_monitor_create(const char *device, char *ebuf, int *is_ours) 251 { 252 pcap_t *p; 253 const char *cp; 254 255 cp = strrchr(device, '/'); 256 if (cp == NULL) 257 cp = device; 258 259 if (strcmp(cp, INTERFACE_NAME) != 0) { 260 *is_ours = 0; 261 return NULL; 262 } 263 264 *is_ours = 1; 265 p = pcap_create_common(ebuf, 0); 266 if (p == NULL) 267 return NULL; 268 269 p->activate_op = bt_monitor_activate; 270 271 return p; 272 } 273
