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
bt_monitor_findalldevs(pcap_if_t ** alldevsp,char * err_str)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
bt_monitor_read(pcap_t * handle,int max_packets _U_,pcap_handler callback,u_char * user)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
bt_monitor_inject(pcap_t * handle,const void * buf _U_,size_t size _U_)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
bt_monitor_setdirection(pcap_t * p,pcap_direction_t d)137 bt_monitor_setdirection(pcap_t *p, pcap_direction_t d)
138 {
139 p->direction = d;
140 return 0;
141 }
142
143 static int
bt_monitor_stats(pcap_t * handle _U_,struct pcap_stat * stats)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
bt_monitor_activate(pcap_t * handle)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 *
bt_monitor_create(const char * device,char * ebuf,int * is_ours)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 }
243