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 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
  37
  38 #include <errno.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41
  42 #include <bluetooth/bluetooth.h>
  43 #include <bluetooth/hci.h>
  44 #include <bluetooth/mgmt.h>
  45
  46 #include "pcap/bluetooth.h"
  47 #include "pcap-int.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     int in = 0;
  77
  78     bthdr = (pcap_bluetooth_linux_monitor_header*) &handle->buffer[handle->offset];
  79
  80     iv[0].iov_base = &hdr;
  81     iv[0].iov_len = MGMT_HDR_SIZE;
  82     iv[1].iov_base = &handle->buffer[handle->offset + sizeof(pcap_bluetooth_linux_monitor_header)];
  83     iv[1].iov_len = handle->snapshot;
  84
  85     memset(&pkth.ts, 0, sizeof(pkth.ts));
  86     memset(&msg, 0, sizeof(msg));
  87     msg.msg_iov = iv;
  88     msg.msg_iovlen = 2;
  89     msg.msg_control = handle->buffer;
  90     msg.msg_controllen = handle->offset;
  91
  92     do {
  93         ret = recvmsg(handle->fd, &msg, 0);
  94         if (handle->break_loop)
  95         {
  96             handle->break_loop = 0;
  97             return -2;
  98         }
  99     } while ((ret == -1) && (errno == EINTR));
 100
 101     if (ret < 0) {
 102         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 103             "Can't receive packet: %s", strerror(errno));
 104         return -1;
 105     }
 106
 107     pkth.caplen = ret - MGMT_HDR_SIZE + sizeof(pcap_bluetooth_linux_monitor_header);
 108     pkth.len = pkth.caplen;
 109
 110     for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
 111         if (cmsg->cmsg_level != SOL_SOCKET) continue;
 112
 113         if (cmsg->cmsg_type == SCM_TIMESTAMP) {
 114             memcpy(&pkth.ts, CMSG_DATA(cmsg), sizeof(pkth.ts));
 115         }
 116     }
 117
 118     bthdr->adapter_id = htons(hdr.index);
 119     bthdr->opcode = htons(hdr.opcode);
 120
 121     if (handle->fcode.bf_insns == NULL ||
 122         bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset],
 123           pkth.len, pkth.caplen)) {
 124         callback(user, &pkth, &handle->buffer[handle->offset]);
 125         return 1;
 126     }
 127     return 0;   /* didn't pass filter */
 128 }
 129
 130 static int
 131 bt_monitor_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)
 132 {
 133     snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported yet");
 134     return -1;
 135 }
 136
 137 static int
 138 bt_monitor_setdirection(pcap_t *p, pcap_direction_t d)
 139 {
 140     p->direction = d;
 141     return 0;
 142 }
 143
 144 static int
 145 bt_monitor_stats(pcap_t *handle _U_, struct pcap_stat *stats)
 146 {
 147     stats->ps_recv = 0;
 148     stats->ps_drop = 0;
 149     stats->ps_ifdrop = 0;
 150
 151     return 0;
 152 }
 153
 154 static int
 155 bt_monitor_activate(pcap_t* handle)
 156 {
 157     struct sockaddr_hci addr;
 158     int err = PCAP_ERROR;
 159     int opt;
 160
 161     if (handle->opt.rfmon) {
 162         /* monitor mode doesn't apply here */
 163         return PCAP_ERROR_RFMON_NOTSUP;
 164     }
 165
 166     handle->bufsize = handle->snapshot + BT_CONTROL_SIZE + sizeof(pcap_bluetooth_linux_monitor_header);
 167     handle->offset = BT_CONTROL_SIZE;
 168     handle->linktype = DLT_BLUETOOTH_LINUX_MONITOR;
 169
 170     handle->read_op = bt_monitor_read;
 171     handle->inject_op = bt_monitor_inject;
 172     handle->setfilter_op = install_bpf_program; /* no kernel filtering */
 173     handle->setdirection_op = bt_monitor_setdirection;
 174     handle->set_datalink_op = NULL; /* can't change data link type */
 175     handle->getnonblock_op = pcap_getnonblock_fd;
 176     handle->setnonblock_op = pcap_setnonblock_fd;
 177     handle->stats_op = bt_monitor_stats;
 178
 179     handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
 180     if (handle->fd < 0) {
 181         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 182             "Can't create raw socket: %s", strerror(errno));
 183         return PCAP_ERROR;
 184     }
 185
 186     handle->buffer = malloc(handle->bufsize);
 187     if (!handle->buffer) {
 188         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
 189             pcap_strerror(errno));
 190         goto close_fail;
 191     }
 192
 193     /* Bind socket to the HCI device */
 194     addr.hci_family = AF_BLUETOOTH;
 195     addr.hci_dev = HCI_DEV_NONE;
 196     addr.hci_channel = HCI_CHANNEL_MONITOR;
 197
 198     if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
 199         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 200             "Can't attach to interface: %s", strerror(errno));
 201         goto close_fail;
 202     }
 203
 204     opt = 1;
 205     if (setsockopt(handle->fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) {
 206         snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
 207             "Can't enable time stamp: %s", strerror(errno));
 208         goto close_fail;
 209     }
 210
 211     handle->selectable_fd = handle->fd;
 212
 213     return 0;
 214
 215 close_fail:
 216     pcap_cleanup_live_common(handle);
 217     return err;
 218 }
 219
 220 pcap_t *
 221 bt_monitor_create(const char *device, char *ebuf, int *is_ours)
 222 {
 223     pcap_t      *p;
 224     const char  *cp;
 225
 226     cp = strrchr(device, '/');
 227     if (cp == NULL)
 228         cp = device;
 229
 230     if (strcmp(cp, INTERFACE_NAME) != 0) {
 231         *is_ours = 0;
 232         return NULL;
 233     }
 234
 235     *is_ours = 1;
 236     p = pcap_create_common(device, ebuf, 0);
 237     if (p == NULL)
 238         return NULL;
 239
 240     p->activate_op = bt_monitor_activate;
 241
 242     return p;
 243 }
 244 #endif /* SOCKADDR_HCI_HAS_HCI_CHANNEL */