The Tcpdump Group git mirrors - libpcap/blob - pcap-bt-monitor-linux.c

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