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