1 /*
2 * libjingle
3 * Copyright 2004--2010, Google Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "talk/base/latebindingsymboltable.h"
29
30 #ifdef LINUX
31 #include <dlfcn.h>
32 #endif
33
34 #include "talk/base/logging.h"
35
36 namespace talk_base {
37
GetDllError()38 inline static const char *GetDllError() {
39 #ifdef LINUX
40 char *err = dlerror();
41 if (err) {
42 return err;
43 } else {
44 return "No error";
45 }
46 #else
47 #error Not implemented
48 #endif
49 }
50
InternalLoadDll(const char dll_name[])51 DllHandle InternalLoadDll(const char dll_name[]) {
52 #ifdef LINUX
53 DllHandle handle = dlopen(dll_name, RTLD_NOW);
54 #else
55 #error Not implemented
56 #endif
57 if (handle == kInvalidDllHandle) {
58 LOG(LS_WARNING) << "Can't load " << dll_name << ": " << GetDllError();
59 }
60 return handle;
61 }
62
InternalUnloadDll(DllHandle handle)63 void InternalUnloadDll(DllHandle handle) {
64 #ifdef LINUX
65 if (dlclose(handle) != 0) {
66 LOG(LS_ERROR) << GetDllError();
67 }
68 #else
69 #error Not implemented
70 #endif
71 }
72
LoadSymbol(DllHandle handle,const char * symbol_name,void ** symbol)73 static bool LoadSymbol(DllHandle handle,
74 const char *symbol_name,
75 void **symbol) {
76 #ifdef LINUX
77 *symbol = dlsym(handle, symbol_name);
78 char *err = dlerror();
79 if (err) {
80 LOG(LS_ERROR) << "Error loading symbol " << symbol_name << ": " << err;
81 return false;
82 } else if (!*symbol) {
83 LOG(LS_ERROR) << "Symbol " << symbol_name << " is NULL";
84 return false;
85 }
86 return true;
87 #else
88 #error Not implemented
89 #endif
90 }
91
92 // This routine MUST assign SOME value for every symbol, even if that value is
93 // NULL, or else some symbols may be left with uninitialized data that the
94 // caller may later interpret as a valid address.
InternalLoadSymbols(DllHandle handle,int num_symbols,const char * const symbol_names[],void * symbols[])95 bool InternalLoadSymbols(DllHandle handle,
96 int num_symbols,
97 const char *const symbol_names[],
98 void *symbols[]) {
99 #ifdef LINUX
100 // Clear any old errors.
101 dlerror();
102 #endif
103 for (int i = 0; i < num_symbols; ++i) {
104 if (!LoadSymbol(handle, symbol_names[i], &symbols[i])) {
105 return false;
106 }
107 }
108 return true;
109 }
110
111 } // namespace talk_base
112