1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
/* +------------------------------------+
* | Inspire Internet Relay Chat Daemon |
* +------------------------------------+
*
* InspIRCd: (C) 2002-2009 InspIRCd Development Team
* See: http://www.inspircd.org/wiki/index.php/Credits
*
* This program is free but copyrighted software; see
* the file COPYING for details.
*
* ---------------------------------------------------
*/
#ifndef __DLL_H
#define __DLL_H
/** The DLLManager class is able to load a module file by filename,
* and locate its init_module symbol.
*/
class CoreExport DLLManager
{
protected:
/** The last error string, or NULL
*/
const char *err;
public:
/** This constructor loads the module using dlopen()
* @param ServerInstance The creator class of this object
* @param fname The filename to load. This should be within
* the modules dir.
*/
DLLManager(InspIRCd* ServerInstance, const char *fname);
virtual ~DLLManager();
/** Get a symbol using dynamic linking.
* @param v A function pointer, pointing at an init_module function
* @param sym_name The symbol name to find, usually "init_module"
* @return true if the symbol can be found, also the symbol will be put into v.
*/
bool GetSymbol(void **v, const char *sym_name);
/** Get the last error from dlopen() or dlsym().
* @return The last error string, or NULL if no error has occured.
*/
const char* LastError()
{
return err;
}
/** The module handle.
* This is OS dependent, on POSIX platforms it is a pointer to a function
* pointer (yes, really!) and on windows it is a library handle.
*/
void *h;
};
class CoreExport LoadModuleException : public CoreException
{
public:
/** This constructor can be used to specify an error message before throwing.
*/
LoadModuleException(const std::string &message)
: CoreException(message, "the core")
{
}
/** This destructor solves world hunger, cancels the world debt, and causes the world to end.
* Actually no, it does nothing. Never mind.
* @throws Nothing!
*/
virtual ~LoadModuleException() throw() {};
};
class CoreExport FindSymbolException : public CoreException
{
public:
/** This constructor can be used to specify an error message before throwing.
*/
FindSymbolException(const std::string &message)
: CoreException(message, "the core")
{
}
/** This destructor solves world hunger, cancels the world debt, and causes the world to end.
* Actually no, it does nothing. Never mind.
* @throws Nothing!
*/
virtual ~FindSymbolException() throw() {};
};
/** This is the highest-level class of the DLLFactory system used to load InspIRCd modules and commands.
* All the dirty mucking around with dl*() is done by DLLManager, all this does it put a pretty shell on
* it and make it nice to use to load modules and core commands. This class is quite specialised for these
* two uses and it may not be useful more generally -- use DLLManager directly for that.
*/
template <typename ReturnType> class CoreExport DLLFactory : public DLLManager
{
protected:
/** This typedef represents the init_* function within each module or command.
* The init_module function is the only exported extern "C" declaration
* in any module file. In a cmd_*.cpp file the equivilant is init_command
*/
typedef ReturnType * (initfunctype) (InspIRCd*);
/** Pointer to the init function.
*/
initfunctype* init_func;
/** Instance pointer to be passed to init_*() when it is called.
*/
InspIRCd* ServerInstance;
public:
/** Default constructor.
* This constructor passes its paramerers down through DLLFactoryBase and then DLLManager
* to load the module, then calls the factory function to retrieve a pointer to a ModuleFactory
* class. It is then down to the core to call the ModuleFactory::CreateModule() method and
* receive a Module* which it can insert into its module lists.
*/
DLLFactory(InspIRCd* Instance, const char *fname, const char *func_name)
: DLLManager(Instance, fname), init_func(NULL), ServerInstance(Instance)
{
const char* error = LastError();
if(!error)
{
if(!GetSymbol((void **)&init_func, func_name))
{
throw FindSymbolException("Missing " + std::string(func_name) + "() entrypoint!");
}
}
else
{
throw LoadModuleException(error);
}
}
/** Calls the 'init_module' C exported function within a module, which
* returns a pointer to a Module derived object.
*/
ReturnType* CallInit()
{
if(init_func)
{
return init_func(ServerInstance);
}
else
{
return NULL;
}
}
/** The destructor deletes the ModuleFactory pointer.
*/
~DLLFactory()
{
}
};
#endif
|
