1 /******************************************************************************
2 *
3 * Copyright (C) 2013 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 #define LOG_TAG "bt_snoop_net"
20
21 #include <assert.h>
22 #include <errno.h>
23 #include <netinet/in.h>
24 #include <pthread.h>
25 #include <stdbool.h>
26 #include <string.h>
27 #include <sys/prctl.h>
28 #include <sys/socket.h>
29 #include <sys/types.h>
30 #include <unistd.h>
31
32 #include "osi/include/log.h"
33 #include "osi/include/osi.h"
34
35 static void safe_close_(int *fd);
36 static void *listen_fn_(void *context);
37
38 static const char *LISTEN_THREAD_NAME_ = "btsnoop_net_listen";
39 static const int LOCALHOST_ = 0x7F000001;
40 static const int LISTEN_PORT_ = 8872;
41
42 static pthread_t listen_thread_;
43 static bool listen_thread_valid_ = false;
44 static pthread_mutex_t client_socket_lock_ = PTHREAD_MUTEX_INITIALIZER;
45 static int listen_socket_ = -1;
46 static int client_socket_ = -1;
47
btsnoop_net_open()48 void btsnoop_net_open() {
49 #if (!defined(BT_NET_DEBUG) || (BT_NET_DEBUG != TRUE))
50 return; // Disable using network sockets for security reasons
51 #endif
52
53 listen_thread_valid_ = (pthread_create(&listen_thread_, NULL, listen_fn_, NULL) == 0);
54 if (!listen_thread_valid_) {
55 LOG_ERROR(LOG_TAG, "%s pthread_create failed: %s", __func__, strerror(errno));
56 } else {
57 LOG_DEBUG(LOG_TAG, "initialized");
58 }
59 }
60
btsnoop_net_close()61 void btsnoop_net_close() {
62 #if (!defined(BT_NET_DEBUG) || (BT_NET_DEBUG != TRUE))
63 return; // Disable using network sockets for security reasons
64 #endif
65
66 if (listen_thread_valid_) {
67 shutdown(listen_socket_, SHUT_RDWR);
68 pthread_join(listen_thread_, NULL);
69 safe_close_(&client_socket_);
70 listen_thread_valid_ = false;
71 }
72 }
73
btsnoop_net_write(const void * data,size_t length)74 void btsnoop_net_write(const void *data, size_t length) {
75 #if (!defined(BT_NET_DEBUG) || (BT_NET_DEBUG != TRUE))
76 return; // Disable using network sockets for security reasons
77 #endif
78
79 pthread_mutex_lock(&client_socket_lock_);
80 if (client_socket_ != -1) {
81 ssize_t ret;
82 OSI_NO_INTR(ret = send(client_socket_, data, length, 0));
83
84 if (ret == -1 && errno == ECONNRESET) {
85 safe_close_(&client_socket_);
86 }
87 }
88 pthread_mutex_unlock(&client_socket_lock_);
89 }
90
listen_fn_(UNUSED_ATTR void * context)91 static void *listen_fn_(UNUSED_ATTR void *context) {
92
93 prctl(PR_SET_NAME, (unsigned long)LISTEN_THREAD_NAME_, 0, 0, 0);
94
95 listen_socket_ = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
96 if (listen_socket_ == -1) {
97 LOG_ERROR(LOG_TAG, "%s socket creation failed: %s", __func__, strerror(errno));
98 goto cleanup;
99 }
100
101 int enable = 1;
102 if (setsockopt(listen_socket_, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(enable)) == -1) {
103 LOG_ERROR(LOG_TAG, "%s unable to set SO_REUSEADDR: %s", __func__, strerror(errno));
104 goto cleanup;
105 }
106
107 struct sockaddr_in addr;
108 addr.sin_family = AF_INET;
109 addr.sin_addr.s_addr = htonl(LOCALHOST_);
110 addr.sin_port = htons(LISTEN_PORT_);
111 if (bind(listen_socket_, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
112 LOG_ERROR(LOG_TAG, "%s unable to bind listen socket: %s", __func__, strerror(errno));
113 goto cleanup;
114 }
115
116 if (listen(listen_socket_, 10) == -1) {
117 LOG_ERROR(LOG_TAG, "%s unable to listen: %s", __func__, strerror(errno));
118 goto cleanup;
119 }
120
121 for (;;) {
122 int client_socket;
123 OSI_NO_INTR(client_socket = accept(listen_socket_, NULL, NULL));
124 if (client_socket == -1) {
125 if (errno == EINVAL || errno == EBADF) {
126 break;
127 }
128 LOG_WARN(LOG_TAG, "%s error accepting socket: %s", __func__, strerror(errno));
129 continue;
130 }
131
132 /* When a new client connects, we have to send the btsnoop file header. This allows
133 a decoder to treat the session as a new, valid btsnoop file. */
134 pthread_mutex_lock(&client_socket_lock_);
135 safe_close_(&client_socket_);
136 client_socket_ = client_socket;
137
138 OSI_NO_INTR(send(client_socket_, "btsnoop\0\0\0\0\1\0\0\x3\xea", 16, 0));
139 pthread_mutex_unlock(&client_socket_lock_);
140 }
141
142 cleanup:
143 safe_close_(&listen_socket_);
144 return NULL;
145 }
146
safe_close_(int * fd)147 static void safe_close_(int *fd) {
148 assert(fd != NULL);
149 if (*fd != -1) {
150 close(*fd);
151 *fd = -1;
152 }
153 }
154