1 /******************************************************************************
2 *
3 * Copyright (C) 2015 Google Inc.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 ******************************************************************************/
18
19 #include <mutex>
20
21 #include <base/logging.h>
22 #include <resolv.h>
23 #include <zlib.h>
24
25 #include "btif/include/btif_debug.h"
26 #include "btif/include/btif_debug_btsnoop.h"
27 #include "hci/include/btsnoop_mem.h"
28 #include "include/bt_target.h"
29 #include "osi/include/ringbuffer.h"
30 #include "osi/include/time.h"
31
32 #define REDUCE_HCI_TYPE_TO_SIGNIFICANT_BITS(type) ((type) >> 8)
33
34 // Total btsnoop memory log buffer size
35 #ifndef BTSNOOP_MEM_BUFFER_SIZE
36 static const size_t BTSNOOP_MEM_BUFFER_SIZE = (256 * 1024);
37 #endif
38
39 // Block size for copying buffers (for compression/encoding etc.)
40 static const size_t BLOCK_SIZE = 16384;
41
42 // Maximum line length in bugreport (should be multiple of 4 for base64 output)
43 static const uint8_t MAX_LINE_LENGTH = 128;
44
45 static std::mutex buffer_mutex;
46 static ringbuffer_t* buffer = NULL;
47 static uint64_t last_timestamp_ms = 0;
48
49 static size_t btsnoop_calculate_packet_length(uint16_t type,
50 const uint8_t* data,
51 size_t length);
52
btsnoop_cb(const uint16_t type,const uint8_t * data,const size_t length,const uint64_t timestamp_us)53 static void btsnoop_cb(const uint16_t type, const uint8_t* data,
54 const size_t length, const uint64_t timestamp_us) {
55 btsnooz_header_t header;
56
57 size_t included_length = btsnoop_calculate_packet_length(type, data, length);
58 if (included_length == 0) return;
59
60 std::lock_guard<std::mutex> lock(buffer_mutex);
61
62 // Make room in the ring buffer
63
64 while (ringbuffer_available(buffer) <
65 (included_length + sizeof(btsnooz_header_t))) {
66 ringbuffer_pop(buffer, (uint8_t*)&header, sizeof(btsnooz_header_t));
67 ringbuffer_delete(buffer, header.length - 1);
68 }
69
70 // Insert data
71 header.type = REDUCE_HCI_TYPE_TO_SIGNIFICANT_BITS(type);
72 header.length = included_length + 1; // +1 for type byte
73 header.packet_length = length + 1; // +1 for type byte.
74 header.delta_time_ms =
75 last_timestamp_ms ? timestamp_us - last_timestamp_ms : 0;
76 last_timestamp_ms = timestamp_us;
77
78 ringbuffer_insert(buffer, (uint8_t*)&header, sizeof(btsnooz_header_t));
79 ringbuffer_insert(buffer, data, included_length);
80 }
81
btsnoop_calculate_packet_length(uint16_t type,const uint8_t * data,size_t length)82 static size_t btsnoop_calculate_packet_length(uint16_t type,
83 const uint8_t* data,
84 size_t length) {
85 static const size_t HCI_ACL_HEADER_SIZE = 4;
86 static const size_t L2CAP_HEADER_SIZE = 4;
87 static const size_t L2CAP_CID_OFFSET = (HCI_ACL_HEADER_SIZE + 2);
88 static const uint16_t L2CAP_SIGNALING_CID = 0x0001;
89
90 // Maximum amount of ACL data to log.
91 // Enough for an RFCOMM frame up to the frame check;
92 // not enough for a HID report or audio data.
93 static const size_t MAX_HCI_ACL_LEN = 14;
94
95 // Calculate packet length to be included
96
97 switch (type) {
98 case BT_EVT_TO_LM_HCI_CMD:
99 return length;
100
101 case BT_EVT_TO_BTU_HCI_EVT:
102 return length;
103
104 case BT_EVT_TO_LM_HCI_ACL:
105 case BT_EVT_TO_BTU_HCI_ACL: {
106 size_t len_hci_acl = HCI_ACL_HEADER_SIZE + L2CAP_HEADER_SIZE;
107 // Check if we have enough data for an L2CAP header
108 if (length > len_hci_acl) {
109 uint16_t l2cap_cid =
110 data[L2CAP_CID_OFFSET] | (data[L2CAP_CID_OFFSET + 1] << 8);
111 if (l2cap_cid == L2CAP_SIGNALING_CID) {
112 // For the signaling CID, take the full packet.
113 // That way, the PSM setup is captured, allowing decoding of PSMs down
114 // the road.
115 return length;
116 } else {
117 // Otherwise, return as much as we reasonably can
118 len_hci_acl = MAX_HCI_ACL_LEN;
119 }
120 }
121 return len_hci_acl < length ? len_hci_acl : length;
122 }
123
124 case BT_EVT_TO_LM_HCI_SCO:
125 case BT_EVT_TO_BTU_HCI_SCO:
126 // We're not logging SCO packets at this time since they are not currently
127 // used.
128 // FALLTHROUGH
129 default:
130 return 0;
131 }
132 }
133
btsnoop_compress(ringbuffer_t * rb_dst,ringbuffer_t * rb_src)134 static bool btsnoop_compress(ringbuffer_t* rb_dst, ringbuffer_t* rb_src) {
135 CHECK(rb_dst != NULL);
136 CHECK(rb_src != NULL);
137
138 z_stream zs;
139 zs.zalloc = Z_NULL;
140 zs.zfree = Z_NULL;
141 zs.opaque = Z_NULL;
142
143 if (deflateInit(&zs, Z_DEFAULT_COMPRESSION) != Z_OK) return false;
144
145 bool rc = true;
146 uint8_t block_src[BLOCK_SIZE];
147 uint8_t block_dst[BLOCK_SIZE];
148
149 const size_t num_blocks =
150 (ringbuffer_size(rb_src) + BLOCK_SIZE - 1) / BLOCK_SIZE;
151 for (size_t i = 0; i < num_blocks; ++i) {
152 zs.avail_in =
153 ringbuffer_peek(rb_src, i * BLOCK_SIZE, block_src, BLOCK_SIZE);
154 zs.next_in = block_src;
155
156 do {
157 zs.avail_out = BLOCK_SIZE;
158 zs.next_out = block_dst;
159
160 int err = deflate(&zs, (i == num_blocks - 1) ? Z_FINISH : Z_NO_FLUSH);
161 if (err == Z_STREAM_ERROR) {
162 rc = false;
163 break;
164 }
165
166 const size_t length = BLOCK_SIZE - zs.avail_out;
167 ringbuffer_insert(rb_dst, block_dst, length);
168 } while (zs.avail_out == 0);
169 }
170
171 deflateEnd(&zs);
172 return rc;
173 }
174
btif_debug_btsnoop_init(void)175 void btif_debug_btsnoop_init(void) {
176 if (buffer == NULL) buffer = ringbuffer_init(BTSNOOP_MEM_BUFFER_SIZE);
177 btsnoop_mem_set_callback(btsnoop_cb);
178 }
179
btif_debug_btsnoop_dump(int fd)180 void btif_debug_btsnoop_dump(int fd) {
181 ringbuffer_t* ringbuffer = ringbuffer_init(BTSNOOP_MEM_BUFFER_SIZE);
182 if (ringbuffer == NULL) {
183 dprintf(fd, "%s Unable to allocate memory for compression", __func__);
184 return;
185 }
186
187 // Prepend preamble
188
189 btsnooz_preamble_t preamble;
190 preamble.version = BTSNOOZ_CURRENT_VERSION;
191 preamble.last_timestamp_ms = last_timestamp_ms;
192 ringbuffer_insert(ringbuffer, (uint8_t*)&preamble,
193 sizeof(btsnooz_preamble_t));
194
195 // Compress data
196
197 uint8_t b64_in[3] = {0};
198 char b64_out[5] = {0};
199
200 size_t line_length = 0;
201
202 bool rc;
203 {
204 std::lock_guard<std::mutex> lock(buffer_mutex);
205 dprintf(fd, "--- BEGIN:BTSNOOP_LOG_SUMMARY (%zu bytes in) ---\n",
206 ringbuffer_size(buffer));
207 rc = btsnoop_compress(ringbuffer, buffer);
208 }
209
210 if (rc == false) {
211 dprintf(fd, "%s Log compression failed", __func__);
212 goto error;
213 }
214
215 // Base64 encode & output
216
217 while (ringbuffer_size(ringbuffer) > 0) {
218 size_t read = ringbuffer_pop(ringbuffer, b64_in, 3);
219 if (line_length >= MAX_LINE_LENGTH) {
220 dprintf(fd, "\n");
221 line_length = 0;
222 }
223 line_length += b64_ntop(b64_in, read, b64_out, 5);
224 dprintf(fd, "%s", b64_out);
225 }
226
227 dprintf(fd, "\n--- END:BTSNOOP_LOG_SUMMARY ---\n");
228
229 error:
230 ringbuffer_free(ringbuffer);
231 }
232