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 <stdlib.h> 38 #include <string.h> 39 40 #include <bluetooth/bluetooth.h> 41 #include <bluetooth/hci.h> 42 #include <bluetooth/mgmt.h> 43 44 #include "pcap/bluetooth.h" 45 #include "pcap-int.h" 46 47 #define BT_CONTROL_SIZE 32 48 #define INTERFACE_NAME "bluetooth-monitor" 49 50 int 51 bt_monitor_findalldevs(pcap_if_t **alldevsp, char *err_str) 52 { 53 int ret = 0; 54 55 if (pcap_add_if(alldevsp, INTERFACE_NAME, 0, 56 "Bluetooth Linux Monitor", err_str) < 0) 57 { 58 ret = -1; 59 } 60 61 return ret; 62 } 63 64 static int 65 bt_monitor_read(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 66 { 67 struct cmsghdr *cmsg; 68 struct msghdr msg; 69 struct iovec iv[2]; 70 ssize_t ret; 71 struct pcap_pkthdr pkth; 72 pcap_bluetooth_linux_monitor_header *bthdr; 73 struct mgmt_hdr hdr; 74 int in = 0; 75 76 bthdr = (pcap_bluetooth_linux_monitor_header*) &handle->buffer[handle->offset]; 77 78 iv[0].iov_base = &hdr; 79 iv[0].iov_len = MGMT_HDR_SIZE; 80 iv[1].iov_base = &handle->buffer[handle->offset + sizeof(pcap_bluetooth_linux_monitor_header)]; 81 iv[1].iov_len = handle->snapshot; 82 83 memset(&pkth.ts, 0, sizeof(pkth.ts)); 84 memset(&msg, 0, sizeof(msg)); 85 msg.msg_iov = iv; 86 msg.msg_iovlen = 2; 87 msg.msg_control = handle->buffer; 88 msg.msg_controllen = handle->offset; 89 90 do { 91 ret = recvmsg(handle->fd, &msg, 0); 92 if (handle->break_loop) 93 { 94 handle->break_loop = 0; 95 return -2; 96 } 97 } while ((ret == -1) && (errno == EINTR)); 98 99 if (ret < 0) { 100 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 101 "Can't receive packet: %s", strerror(errno)); 102 return -1; 103 } 104 105 pkth.caplen = ret - MGMT_HDR_SIZE + sizeof(pcap_bluetooth_linux_monitor_header); 106 pkth.len = pkth.caplen; 107 108 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { 109 if (cmsg->cmsg_level != SOL_SOCKET) continue; 110 111 if (cmsg->cmsg_type == SCM_TIMESTAMP) { 112 memcpy(&pkth.ts, CMSG_DATA(cmsg), sizeof(pkth.ts)); 113 } 114 } 115 116 bthdr->adapter_id = htons(hdr.index); 117 bthdr->opcode = htons(hdr.opcode); 118 119 if (handle->fcode.bf_insns == NULL || 120 bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset], 121 pkth.len, pkth.caplen)) { 122 callback(user, &pkth, &handle->buffer[handle->offset]); 123 return 1; 124 } 125 return 0; /* didn't pass filter */ 126 } 127 128 static int 129 bt_monitor_inject(pcap_t *handle, const void *buf _U_, size_t size _U_) 130 { 131 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported yet"); 132 return -1; 133 } 134 135 static int 136 bt_monitor_setdirection(pcap_t *p, pcap_direction_t d) 137 { 138 p->direction = d; 139 return 0; 140 } 141 142 static int 143 bt_monitor_stats(pcap_t *handle _U_, struct pcap_stat *stats) 144 { 145 stats->ps_recv = 0; 146 stats->ps_drop = 0; 147 stats->ps_ifdrop = 0; 148 149 return 0; 150 } 151 152 static int 153 bt_monitor_activate(pcap_t* handle) 154 { 155 struct sockaddr_hci addr; 156 int err = PCAP_ERROR; 157 int opt; 158 159 if (handle->opt.rfmon) { 160 /* monitor mode doesn't apply here */ 161 return PCAP_ERROR_RFMON_NOTSUP; 162 } 163 164 handle->bufsize = handle->snapshot + BT_CONTROL_SIZE + sizeof(pcap_bluetooth_linux_monitor_header); 165 handle->offset = BT_CONTROL_SIZE; 166 handle->linktype = DLT_BLUETOOTH_LINUX_MONITOR; 167 168 handle->read_op = bt_monitor_read; 169 handle->inject_op = bt_monitor_inject; 170 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 171 handle->setdirection_op = bt_monitor_setdirection; 172 handle->set_datalink_op = NULL; /* can't change data link type */ 173 handle->getnonblock_op = pcap_getnonblock_fd; 174 handle->setnonblock_op = pcap_setnonblock_fd; 175 handle->stats_op = bt_monitor_stats; 176 177 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 178 if (handle->fd < 0) { 179 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 180 "Can't create raw socket: %s", strerror(errno)); 181 return PCAP_ERROR; 182 } 183 184 handle->buffer = malloc(handle->bufsize); 185 if (!handle->buffer) { 186 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", 187 pcap_strerror(errno)); 188 goto close_fail; 189 } 190 191 /* Bind socket to the HCI device */ 192 addr.hci_family = AF_BLUETOOTH; 193 addr.hci_dev = HCI_DEV_NONE; 194 addr.hci_channel = HCI_CHANNEL_MONITOR; 195 196 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 197 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 198 "Can't attach to interface: %s", strerror(errno)); 199 goto close_fail; 200 } 201 202 opt = 1; 203 if (setsockopt(handle->fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) { 204 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 205 "Can't enable time stamp: %s", strerror(errno)); 206 goto close_fail; 207 } 208 209 handle->selectable_fd = handle->fd; 210 211 return 0; 212 213 close_fail: 214 pcap_cleanup_live_common(handle); 215 return err; 216 } 217 218 pcap_t * 219 bt_monitor_create(const char *device, char *ebuf, int *is_ours) 220 { 221 pcap_t *p; 222 const char *cp; 223 224 cp = strrchr(device, '/'); 225 if (cp == NULL) 226 cp = device; 227 228 if (strcmp(cp, INTERFACE_NAME) != 0) { 229 *is_ours = 0; 230 return NULL; 231 } 232 233 *is_ours = 1; 234 p = pcap_create_common(device, ebuf, 0); 235 if (p == NULL) 236 return NULL; 237 238 p->activate_op = bt_monitor_activate; 239 240 return p; 241 } 242