1 /*
2 * Copyright (c) 2024 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #ifdef OHOS_SOCKET_HOOK_ENABLE
17 #include <unistd.h>
18 #include <signal.h>
19 #include <stdlib.h>
20 #include <limits.h>
21 #include <dlfcn.h>
22 #include <errno.h>
23 #include <ctype.h>
24 #include <assert.h>
25 #include <string.h>
26 #include <stdio.h>
27 #include "musl_socket_preinit_common.h"
28 #include "musl_log.h"
29
30 static char *__socket_hook_shared_lib = "libfwmark_client.z.so";
31 static char *__socket_hook_function_prefix = "ohos_socket_hook";
32 void* shared_lib_func[LAST_FUNC];
33 long long __ohos_socket_hook_shared_library;
34 typedef bool (*init_func_type)(const struct SocketDispatchType*, bool*, const char*);
35 typedef void (*finalize_func_type)();
36 #define MAX_SYMBOL_SIZE 1000
37
init_socket_function(void * shared_library_handler,SocketSocketType * func)38 static bool init_socket_function(void* shared_library_handler, SocketSocketType* func)
39 {
40 char symbol[MAX_SYMBOL_SIZE];
41 (void)snprintf(symbol, sizeof(symbol), "%s_%s", __socket_hook_function_prefix, "socket");
42 *func = (SocketSocketType)(dlsym(shared_library_handler, symbol));
43 if (*func == NULL) {
44 return false;
45 }
46 return true;
47 }
48
clear_socket_function()49 static void clear_socket_function()
50 {
51 memset(shared_lib_func, 0, sizeof(shared_lib_func));
52 }
53
socket_finalize()54 static void socket_finalize()
55 {
56 ((finalize_func_type)shared_lib_func[FINALIZE_FUNC])();
57 __current_dispatch = 0;
58 __socket_hook_begin_flag = false;
59 // Don't dlclose because hidumper crash
60 }
61
finish_install_ohos_socket_hooks(const char * options)62 static bool finish_install_ohos_socket_hooks(const char* options)
63 {
64 init_func_type init_func = (init_func_type)(shared_lib_func[INITIALIZE_FUNC]);
65 if (!init_func(&__libc_socket_default_dispatch, NULL, options)) {
66 MUSL_LOGI("Netsys, init_func failed.");
67 clear_socket_function();
68 return false;
69 }
70
71 int ret_value = atexit(socket_finalize);
72 if (ret_value != 0) {
73 MUSL_LOGI("Netsys, set atexit failed.");
74 }
75 return true;
76 }
77
init_socket_hook_shared_library(void * shared_library_handle)78 static bool init_socket_hook_shared_library(void* shared_library_handle)
79 {
80 static const char* names[] = {
81 "initialize",
82 "finalize",
83 "get_hook_flag",
84 "set_hook_flag",
85 };
86
87 for (int i = 0; i < LAST_FUNC; i++) {
88 char symbol[MAX_SYMBOL_SIZE];
89 (void)snprintf(symbol, sizeof(symbol), "%s_%s", __socket_hook_function_prefix, names[i]);
90 shared_lib_func[i] = dlsym(shared_library_handle, symbol);
91 if (shared_lib_func[i] == NULL) {
92 clear_socket_function();
93 return false;
94 }
95 }
96
97 if (!init_socket_function(shared_library_handle, &(__musl_libc_socket_dispatch.socket))) {
98 MUSL_LOGI("Netsys, set socket function failed.");
99 clear_socket_function();
100 return false;
101 }
102
103 return true;
104 }
105
load_socket_hook_shared_library()106 static void* load_socket_hook_shared_library()
107 {
108 void* shared_library_handle = NULL;
109
110 shared_library_handle = dlopen(__socket_hook_shared_lib, RTLD_NOW | RTLD_LOCAL);
111
112 if (shared_library_handle == NULL) {
113 MUSL_LOGI("Netsys, Unable to open shared library %s: %s.\n", __socket_hook_shared_lib, dlerror());
114 return NULL;
115 }
116
117 if (!init_socket_hook_shared_library(shared_library_handle)) {
118 dlclose(shared_library_handle);
119 shared_library_handle = NULL;
120 }
121 return shared_library_handle;
122 }
123
install_ohos_socket_hook()124 static void install_ohos_socket_hook()
125 {
126 void* shared_library_handle = (void *)__ohos_socket_hook_shared_library;
127 if (shared_library_handle != NULL && shared_library_handle != (void*)-1) {
128 MUSL_LOGI("Netsys, ohos_socket_hook_shared_library has had.");
129 return;
130 }
131
132 __current_dispatch = 0;
133 shared_library_handle = load_socket_hook_shared_library();
134 if (shared_library_handle == NULL) {
135 MUSL_LOGI("Netsys, load_socket_hook_shared_library failed.");
136 return;
137 }
138 MUSL_LOGI("Netsys, load_socket_hook_shared_library success.");
139
140 if (finish_install_ohos_socket_hooks(NULL)) {
141 MUSL_LOGI("Netsys, finish_install_ohos_socket_hooks success.");
142 __ohos_socket_hook_shared_library = (long long)shared_library_handle;
143 __current_dispatch = (long long)(&__musl_libc_socket_dispatch);
144 } else {
145 MUSL_LOGI("Netsys, finish_install_ohos_socket_hooks failed.");
146 __ohos_socket_hook_shared_library = 0;
147 dlclose((void *)shared_library_handle);
148 }
149 }
150
init_ohos_socket_hook()151 static void init_ohos_socket_hook()
152 {
153 install_ohos_socket_hook();
154 }
155
__musl_socket_initialize()156 __attribute__((constructor())) static void __musl_socket_initialize()
157 {
158 bool begin_flag = __get_socket_hook_begin_flag();
159 MUSL_LOGI("Netsys, %d begin musl_socket_initialize, flag %d.\n", getpid(), begin_flag);
160 if (!begin_flag) {
161 __socket_hook_begin_flag = true;
162 init_ohos_socket_hook();
163 }
164 }
165 #endif
166