1 /* $NetBSD: pcap-bt-monitor-linux.c,v 1.4 2017/01/24 22:29:28 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2014 Michal Labedzki for Tieto Corporation 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 */ 33 34 #include <sys/cdefs.h> 35 __RCSID("$NetBSD: pcap-bt-monitor-linux.c,v 1.4 2017/01/24 22:29:28 christos Exp $"); 36 37 #ifdef HAVE_CONFIG_H 38 #include "config.h" 39 #endif 40 41 #include <errno.h> 42 #include <stdint.h> 43 #include <stdlib.h> 44 #include <string.h> 45 46 #include <bluetooth/bluetooth.h> 47 #include <bluetooth/hci.h> 48 49 #include "pcap/bluetooth.h" 50 #include "pcap-int.h" 51 52 #include "pcap-bt-monitor-linux.h" 53 54 #define BT_CONTROL_SIZE 32 55 #define INTERFACE_NAME "bluetooth-monitor" 56 57 /* 58 * Fields and alignment must match the declaration in the Linux kernel 3.4+. 59 * See struct hci_mon_hdr in include/net/bluetooth/hci_mon.h. 60 */ 61 struct hci_mon_hdr { 62 uint16_t opcode; 63 uint16_t index; 64 uint16_t len; 65 } __attribute__((packed)); 66 67 int 68 bt_monitor_findalldevs(pcap_if_t **alldevsp, char *err_str) 69 { 70 int ret = 0; 71 72 if (pcap_add_if(alldevsp, INTERFACE_NAME, 0, 73 "Bluetooth Linux Monitor", err_str) < 0) 74 { 75 ret = -1; 76 } 77 78 return ret; 79 } 80 81 static int 82 bt_monitor_read(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user) 83 { 84 struct cmsghdr *cmsg; 85 struct msghdr msg; 86 struct iovec iv[2]; 87 ssize_t ret; 88 struct pcap_pkthdr pkth; 89 pcap_bluetooth_linux_monitor_header *bthdr; 90 u_char *pktd; 91 struct hci_mon_hdr hdr; 92 93 pktd = (u_char *)handle->buffer + BT_CONTROL_SIZE; 94 bthdr = (pcap_bluetooth_linux_monitor_header*)(void *)pktd; 95 96 iv[0].iov_base = &hdr; 97 iv[0].iov_len = sizeof(hdr); 98 iv[1].iov_base = pktd + sizeof(pcap_bluetooth_linux_monitor_header); 99 iv[1].iov_len = handle->snapshot; 100 101 memset(&pkth.ts, 0, sizeof(pkth.ts)); 102 memset(&msg, 0, sizeof(msg)); 103 msg.msg_iov = iv; 104 msg.msg_iovlen = 2; 105 msg.msg_control = handle->buffer; 106 msg.msg_controllen = BT_CONTROL_SIZE; 107 108 do { 109 ret = recvmsg(handle->fd, &msg, 0); 110 if (handle->break_loop) 111 { 112 handle->break_loop = 0; 113 return -2; 114 } 115 } while ((ret == -1) && (errno == EINTR)); 116 117 if (ret < 0) { 118 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 119 "Can't receive packet: %s", strerror(errno)); 120 return -1; 121 } 122 123 pkth.caplen = ret - sizeof(hdr) + sizeof(pcap_bluetooth_linux_monitor_header); 124 pkth.len = pkth.caplen; 125 126 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { 127 if (cmsg->cmsg_level != SOL_SOCKET) continue; 128 129 if (cmsg->cmsg_type == SCM_TIMESTAMP) { 130 memcpy(&pkth.ts, CMSG_DATA(cmsg), sizeof(pkth.ts)); 131 } 132 } 133 134 bthdr->adapter_id = htons(hdr.index); 135 bthdr->opcode = htons(hdr.opcode); 136 137 if (handle->fcode.bf_insns == NULL || 138 bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) { 139 callback(user, &pkth, pktd); 140 return 1; 141 } 142 return 0; /* didn't pass filter */ 143 } 144 145 static int 146 bt_monitor_inject(pcap_t *handle, const void *buf _U_, size_t size _U_) 147 { 148 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported yet"); 149 return -1; 150 } 151 152 static int 153 bt_monitor_setdirection(pcap_t *p, pcap_direction_t d) 154 { 155 p->direction = d; 156 return 0; 157 } 158 159 static int 160 bt_monitor_stats(pcap_t *handle _U_, struct pcap_stat *stats) 161 { 162 stats->ps_recv = 0; 163 stats->ps_drop = 0; 164 stats->ps_ifdrop = 0; 165 166 return 0; 167 } 168 169 static int 170 bt_monitor_activate(pcap_t* handle) 171 { 172 struct sockaddr_hci addr; 173 int err = PCAP_ERROR; 174 int opt; 175 176 if (handle->opt.rfmon) { 177 /* monitor mode doesn't apply here */ 178 return PCAP_ERROR_RFMON_NOTSUP; 179 } 180 181 handle->bufsize = BT_CONTROL_SIZE + sizeof(pcap_bluetooth_linux_monitor_header) + handle->snapshot; 182 handle->linktype = DLT_BLUETOOTH_LINUX_MONITOR; 183 184 handle->read_op = bt_monitor_read; 185 handle->inject_op = bt_monitor_inject; 186 handle->setfilter_op = install_bpf_program; /* no kernel filtering */ 187 handle->setdirection_op = bt_monitor_setdirection; 188 handle->set_datalink_op = NULL; /* can't change data link type */ 189 handle->getnonblock_op = pcap_getnonblock_fd; 190 handle->setnonblock_op = pcap_setnonblock_fd; 191 handle->stats_op = bt_monitor_stats; 192 193 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); 194 if (handle->fd < 0) { 195 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 196 "Can't create raw socket: %s", strerror(errno)); 197 return PCAP_ERROR; 198 } 199 200 handle->buffer = malloc(handle->bufsize); 201 if (!handle->buffer) { 202 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s", 203 pcap_strerror(errno)); 204 goto close_fail; 205 } 206 207 /* Bind socket to the HCI device */ 208 addr.hci_family = AF_BLUETOOTH; 209 addr.hci_dev = HCI_DEV_NONE; 210 addr.hci_channel = HCI_CHANNEL_MONITOR; 211 212 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 213 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 214 "Can't attach to interface: %s", strerror(errno)); 215 goto close_fail; 216 } 217 218 opt = 1; 219 if (setsockopt(handle->fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) { 220 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, 221 "Can't enable time stamp: %s", strerror(errno)); 222 goto close_fail; 223 } 224 225 handle->selectable_fd = handle->fd; 226 227 return 0; 228 229 close_fail: 230 pcap_cleanup_live_common(handle); 231 return err; 232 } 233 234 pcap_t * 235 bt_monitor_create(const char *device, char *ebuf, int *is_ours) 236 { 237 pcap_t *p; 238 const char *cp; 239 240 cp = strrchr(device, '/'); 241 if (cp == NULL) 242 cp = device; 243 244 if (strcmp(cp, INTERFACE_NAME) != 0) { 245 *is_ours = 0; 246 return NULL; 247 } 248 249 *is_ours = 1; 250 p = pcap_create_common(ebuf, 0); 251 if (p == NULL) 252 return NULL; 253 254 p->activate_op = bt_monitor_activate; 255 256 return p; 257 } 258