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 * Private data.
54 * Currently contains nothing.
55 */
56 struct pcap_bt_monitor {
57 int dummy;
58 };
59
60 /*
61 * Fields and alignment must match the declaration in the Linux kernel 3.4+.
62 * See struct hci_mon_hdr in include/net/bluetooth/hci_mon.h.
63 */
64 struct hci_mon_hdr {
65 uint16_t opcode;
66 uint16_t index;
67 uint16_t len;
68 } __attribute__((packed));
69
70 int
bt_monitor_findalldevs(pcap_if_list_t * devlistp,char * err_str)71 bt_monitor_findalldevs(pcap_if_list_t *devlistp, char *err_str)
72 {
73 int ret = 0;
74
75 /*
76 * Bluetooth is a wireless technology.
77 *
78 * This is a device to monitor all Bluetooth interfaces, so
79 * there's no notion of "connected" or "disconnected", any
80 * more than there's a notion of "connected" or "disconnected"
81 * for the "any" device.
82 */
83 if (add_dev(devlistp, INTERFACE_NAME,
84 PCAP_IF_WIRELESS|PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
85 "Bluetooth Linux Monitor", err_str) == NULL)
86 {
87 ret = -1;
88 }
89
90 return ret;
91 }
92
93 static int
bt_monitor_read(pcap_t * handle,int max_packets _U_,pcap_handler callback,u_char * user)94 bt_monitor_read(pcap_t *handle, int max_packets _U_, pcap_handler callback, u_char *user)
95 {
96 struct cmsghdr *cmsg;
97 struct msghdr msg;
98 struct iovec iv[2];
99 ssize_t ret;
100 struct pcap_pkthdr pkth;
101 pcap_bluetooth_linux_monitor_header *bthdr;
102 u_char *pktd;
103 struct hci_mon_hdr hdr;
104
105 pktd = (u_char *)handle->buffer + BT_CONTROL_SIZE;
106 bthdr = (pcap_bluetooth_linux_monitor_header*)(void *)pktd;
107
108 iv[0].iov_base = &hdr;
109 iv[0].iov_len = sizeof(hdr);
110 iv[1].iov_base = pktd + sizeof(pcap_bluetooth_linux_monitor_header);
111 iv[1].iov_len = handle->snapshot;
112
113 memset(&pkth.ts, 0, sizeof(pkth.ts));
114 memset(&msg, 0, sizeof(msg));
115 msg.msg_iov = iv;
116 msg.msg_iovlen = 2;
117 msg.msg_control = handle->buffer;
118 msg.msg_controllen = BT_CONTROL_SIZE;
119
120 do {
121 ret = recvmsg(handle->fd, &msg, 0);
122 if (handle->break_loop)
123 {
124 handle->break_loop = 0;
125 return -2;
126 }
127 } while ((ret == -1) && (errno == EINTR));
128
129 if (ret < 0) {
130 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
131 errno, "Can't receive packet");
132 return -1;
133 }
134
135 pkth.caplen = (bpf_u_int32)(ret - sizeof(hdr) + sizeof(pcap_bluetooth_linux_monitor_header));
136 pkth.len = pkth.caplen;
137
138 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
139 if (cmsg->cmsg_level != SOL_SOCKET) continue;
140
141 if (cmsg->cmsg_type == SCM_TIMESTAMP) {
142 memcpy(&pkth.ts, CMSG_DATA(cmsg), sizeof(pkth.ts));
143 }
144 }
145
146 bthdr->adapter_id = htons(hdr.index);
147 bthdr->opcode = htons(hdr.opcode);
148
149 if (handle->fcode.bf_insns == NULL ||
150 pcap_filter(handle->fcode.bf_insns, pktd, pkth.len, pkth.caplen)) {
151 callback(user, &pkth, pktd);
152 return 1;
153 }
154 return 0; /* didn't pass filter */
155 }
156
157 static int
bt_monitor_inject(pcap_t * handle,const void * buf _U_,int size _U_)158 bt_monitor_inject(pcap_t *handle, const void *buf _U_, int size _U_)
159 {
160 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
161 "Packet injection is not supported yet on Bluetooth monitor devices");
162 return -1;
163 }
164
165 static int
bt_monitor_stats(pcap_t * handle _U_,struct pcap_stat * stats)166 bt_monitor_stats(pcap_t *handle _U_, struct pcap_stat *stats)
167 {
168 stats->ps_recv = 0;
169 stats->ps_drop = 0;
170 stats->ps_ifdrop = 0;
171
172 return 0;
173 }
174
175 static int
bt_monitor_activate(pcap_t * handle)176 bt_monitor_activate(pcap_t* handle)
177 {
178 struct sockaddr_hci addr;
179 int err = PCAP_ERROR;
180 int opt;
181
182 if (handle->opt.rfmon) {
183 /* monitor mode doesn't apply here */
184 return PCAP_ERROR_RFMON_NOTSUP;
185 }
186
187 /*
188 * Turn a negative snapshot value (invalid), a snapshot value of
189 * 0 (unspecified), or a value bigger than the normal maximum
190 * value, into the maximum allowed value.
191 *
192 * If some application really *needs* a bigger snapshot
193 * length, we should just increase MAXIMUM_SNAPLEN.
194 */
195 if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)
196 handle->snapshot = MAXIMUM_SNAPLEN;
197
198 handle->bufsize = BT_CONTROL_SIZE + sizeof(pcap_bluetooth_linux_monitor_header) + handle->snapshot;
199 handle->linktype = DLT_BLUETOOTH_LINUX_MONITOR;
200
201 handle->read_op = bt_monitor_read;
202 handle->inject_op = bt_monitor_inject;
203 handle->setfilter_op = install_bpf_program; /* no kernel filtering */
204 handle->setdirection_op = NULL; /* Not implemented */
205 handle->set_datalink_op = NULL; /* can't change data link type */
206 handle->getnonblock_op = pcap_getnonblock_fd;
207 handle->setnonblock_op = pcap_setnonblock_fd;
208 handle->stats_op = bt_monitor_stats;
209
210 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
211 if (handle->fd < 0) {
212 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
213 errno, "Can't create raw socket");
214 return PCAP_ERROR;
215 }
216
217 handle->buffer = malloc(handle->bufsize);
218 if (!handle->buffer) {
219 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
220 errno, "Can't allocate dump buffer");
221 goto close_fail;
222 }
223
224 /* Bind socket to the HCI device */
225 addr.hci_family = AF_BLUETOOTH;
226 addr.hci_dev = HCI_DEV_NONE;
227 addr.hci_channel = HCI_CHANNEL_MONITOR;
228
229 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
230 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
231 errno, "Can't attach to interface");
232 goto close_fail;
233 }
234
235 opt = 1;
236 if (setsockopt(handle->fd, SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) {
237 pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE,
238 errno, "Can't enable time stamp");
239 goto close_fail;
240 }
241
242 handle->selectable_fd = handle->fd;
243
244 return 0;
245
246 close_fail:
247 pcap_cleanup_live_common(handle);
248 return err;
249 }
250
251 pcap_t *
bt_monitor_create(const char * device,char * ebuf,int * is_ours)252 bt_monitor_create(const char *device, char *ebuf, int *is_ours)
253 {
254 pcap_t *p;
255 const char *cp;
256
257 cp = strrchr(device, '/');
258 if (cp == NULL)
259 cp = device;
260
261 if (strcmp(cp, INTERFACE_NAME) != 0) {
262 *is_ours = 0;
263 return NULL;
264 }
265
266 *is_ours = 1;
267 p = PCAP_CREATE_COMMON(ebuf, struct pcap_bt_monitor);
268 if (p == NULL)
269 return NULL;
270
271 p->activate_op = bt_monitor_activate;
272
273 return p;
274 }
275