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 #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 }