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 <stdint.h>
38 #include <stdlib.h>
39 #include <string.h>
40
41 #include <bluetooth/bluetooth.h>
42 #include <bluetooth/hci.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 /*
53 * Fields and alignment must match the declaration in the Linux kernel 3.4+.
54 * See struct hci_mon_hdr in include/net/bluetooth/hci_mon.h.
55 */
56 struct hci_mon_hdr {
57 uint16_t opcode;
58 uint16_t index;
59 uint16_t len;
60 } __attribute__((packed));
61
62 int
bt_monitor_findalldevs(pcap_if_list_t * devlistp,char * err_str)63 bt_monitor_findalldevs(pcap_if_list_t *devlistp, char *err_str)
64 {
65 int ret = 0;
66
67 /*
68 * Bluetooth is a wireless technology.
69 *
70 * This is a device to monitor all Bluetooth interfaces, so
71 * there's no notion of "connected" or "disconnected", any
72 * more than there's a notion of "connected" or "disconnected"
73 * for the "any" device.
74 */
75 if (add_dev(devlistp, INTERFACE_NAME,
76 PCAP_IF_WIRELESS|PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
77 "Bluetooth Linux Monitor", err_str) == NULL)
78 {
79 ret = -1;
80 }
81
82 return ret;
83 }
84
85 static int
bt_monitor_read(pcap_t * handle,int max_packets _U_,pcap_handler callback,u_char * user)86 bt_monitor_read(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
87 {
88 struct cmsghdr *cmsg;
89 struct msghdr msg;
90 struct iovec iv[2];
91 ssize_t ret;
92 struct pcap_pkthdr pkth;
93 pcap_bluetooth_linux_monitor_header *bthdr;
94 u_char *pktd;
95 struct hci_mon_hdr hdr;
96
97 pktd = (u_char *)handle->buffer + BT_CONTROL_SIZE;
98 bthdr = (pcap_bluetooth_linux_monitor_header*)(void *)pktd;
99
100 iv[0].iov_base = &hdr;
101 iv[0].iov_len = sizeof(hdr);
102 iv[1].iov_base = pktd + sizeof(pcap_bluetooth_linux_monitor_header);
103 iv[1].iov_len = handle->snapshot;
104
105 memset(&pkth.ts, 0, sizeof(pkth.ts));
106 memset(&msg, 0, sizeof(msg));
107 msg.msg_iov = iv;
108 msg.msg_iovlen = 2;
109 msg.msg_control = handle->buffer;
110 msg.msg_controllen = BT_CONTROL_SIZE;
111
112 do {
113 ret = recvmsg(handle->fd, &msg, 0);
114 if (handle->break_loop)
115 {
116 handle->break_loop = 0;
117 return -2;
118 }
119 } while ((ret == -1) && (errno == EINTR));
120
121 if (ret < 0) {
122 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
123 errno, "Can't receive packet");
124 return -1;
125 }
126
127 pkth.caplen = ret - sizeof(hdr) + sizeof(pcap_bluetooth_linux_monitor_header);
128 pkth.len = pkth.caplen;
129
130 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
131 if (cmsg->cmsg_level != SOL_SOCKET) continue;
132
133 if (cmsg->cmsg_type == SCM_TIMESTAMP) {
134 memcpy(&pkth.ts, CMSG_DATA(cmsg), sizeof(pkth.ts));
135 }
136 }
137
138 bthdr->adapter_id = htons(hdr.index);
139 bthdr->opcode = htons(hdr.opcode);
140
141 if (handle->fcode.bf_insns == NULL ||
142 bpf_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
143 callback(user, &pkth, pktd);
144 return 1;
145 }
146 return 0; /* didn't pass filter */
147 }
148
149 static int
bt_monitor_inject(pcap_t * handle,const void * buf _U_,size_t size _U_)150 bt_monitor_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)
151 {
152 pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported yet");
153 return -1;
154 }
155
156 static int
bt_monitor_setdirection(pcap_t * p,pcap_direction_t d)157 bt_monitor_setdirection(pcap_t *p, pcap_direction_t d)
158 {
159 p->direction = d;
160 return 0;
161 }
162
163 static int
bt_monitor_stats(pcap_t * handle _U_,struct pcap_stat * stats)164 bt_monitor_stats(pcap_t *handle _U_, struct pcap_stat *stats)
165 {
166 stats->ps_recv = 0;
167 stats->ps_drop = 0;
168 stats->ps_ifdrop = 0;
169
170 return 0;
171 }
172
173 static int
bt_monitor_activate(pcap_t * handle)174 bt_monitor_activate(pcap_t* handle)
175 {
176 struct sockaddr_hci addr;
177 int err = PCAP_ERROR;
178 int opt;
179
180 if (handle->opt.rfmon) {
181 /* monitor mode doesn't apply here */
182 return PCAP_ERROR_RFMON_NOTSUP;
183 }
184
185 /*
186 * Turn a negative snapshot value (invalid), a snapshot value of
187 * 0 (unspecified), or a value bigger than the normal maximum
188 * value, into the maximum allowed value.
189 *
190 * If some application really *needs* a bigger snapshot
191 * length, we should just increase MAXIMUM_SNAPLEN.
192 */
193 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
194 handle->snapshot = MAXIMUM_SNAPLEN;
195
196 handle->bufsize = BT_CONTROL_SIZE + sizeof(pcap_bluetooth_linux_monitor_header) + handle->snapshot;
197 handle->linktype = DLT_BLUETOOTH_LINUX_MONITOR;
198
199 handle->read_op = bt_monitor_read;
200 handle->inject_op = bt_monitor_inject;
201 handle->setfilter_op = install_bpf_program; /* no kernel filtering */
202 handle->setdirection_op = bt_monitor_setdirection;
203 handle->set_datalink_op = NULL; /* can't change data link type */
204 handle->getnonblock_op = pcap_getnonblock_fd;
205 handle->setnonblock_op = pcap_setnonblock_fd;
206 handle->stats_op = bt_monitor_stats;
207
208 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
209 if (handle->fd < 0) {
210 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
211 errno, "Can't create raw socket");
212 return PCAP_ERROR;
213 }
214
215 handle->buffer = malloc(handle->bufsize);
216 if (!handle->buffer) {
217 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
218 errno, "Can't allocate dump buffer");
219 goto close_fail;
220 }
221
222 /* Bind socket to the HCI device */
223 addr.hci_family = AF_BLUETOOTH;
224 addr.hci_dev = HCI_DEV_NONE;
225 addr.hci_channel = HCI_CHANNEL_MONITOR;
226
227 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
228 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
229 errno, "Can't attach to interface");
230 goto close_fail;
231 }
232
233 opt = 1;
234 if (setsockopt(handle->fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) {
235 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
236 errno, "Can't enable time stamp");
237 goto close_fail;
238 }
239
240 handle->selectable_fd = handle->fd;
241
242 return 0;
243
244 close_fail:
245 pcap_cleanup_live_common(handle);
246 return err;
247 }
248
249 pcap_t *
bt_monitor_create(const char * device,char * ebuf,int * is_ours)250 bt_monitor_create(const char *device, char *ebuf, int *is_ours)
251 {
252 pcap_t *p;
253 const char *cp;
254
255 cp = strrchr(device, '/');
256 if (cp == NULL)
257 cp = device;
258
259 if (strcmp(cp, INTERFACE_NAME) != 0) {
260 *is_ours = 0;
261 return NULL;
262 }
263
264 *is_ours = 1;
265 p = pcap_create_common(ebuf, 0);
266 if (p == NULL)
267 return NULL;
268
269 p->activate_op = bt_monitor_activate;
270
271 return p;
272 }
273