1 | /* |
2 | * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include <stdio.h> |
11 | #include "internal/cryptlib.h" |
12 | #include "internal/dso.h" |
13 | #include "crypto/dso_conf.h" |
14 | #include "internal/refcount.h" |
15 | |
16 | /**********************************************************************/ |
17 | /* The low-level handle type used to refer to a loaded shared library */ |
18 | |
19 | struct dso_st { |
20 | DSO_METHOD *meth; |
21 | /* |
22 | * Standard dlopen uses a (void *). Win32 uses a HANDLE. VMS doesn't use |
23 | * anything but will need to cache the filename for use in the dso_bind |
24 | * handler. All in all, let each method control its own destiny. |
25 | * "Handles" and such go in a STACK. |
26 | */ |
27 | STACK_OF(void) *meth_data; |
28 | CRYPTO_REF_COUNT references; |
29 | int flags; |
30 | /* |
31 | * For use by applications etc ... use this for your bits'n'pieces, don't |
32 | * touch meth_data! |
33 | */ |
34 | CRYPTO_EX_DATA ex_data; |
35 | /* |
36 | * If this callback function pointer is set to non-NULL, then it will be |
37 | * used in DSO_load() in place of meth->dso_name_converter. NB: This |
38 | * should normally set using DSO_set_name_converter(). |
39 | */ |
40 | DSO_NAME_CONVERTER_FUNC name_converter; |
41 | /* |
42 | * If this callback function pointer is set to non-NULL, then it will be |
43 | * used in DSO_load() in place of meth->dso_merger. NB: This should |
44 | * normally set using DSO_set_merger(). |
45 | */ |
46 | DSO_MERGER_FUNC merger; |
47 | /* |
48 | * This is populated with (a copy of) the platform-independent filename |
49 | * used for this DSO. |
50 | */ |
51 | char *filename; |
52 | /* |
53 | * This is populated with (a copy of) the translated filename by which |
54 | * the DSO was actually loaded. It is NULL iff the DSO is not currently |
55 | * loaded. NB: This is here because the filename translation process may |
56 | * involve a callback being invoked more than once not only to convert to |
57 | * a platform-specific form, but also to try different filenames in the |
58 | * process of trying to perform a load. As such, this variable can be |
59 | * used to indicate (a) whether this DSO structure corresponds to a |
60 | * loaded library or not, and (b) the filename with which it was actually |
61 | * loaded. |
62 | */ |
63 | char *loaded_filename; |
64 | CRYPTO_RWLOCK *lock; |
65 | }; |
66 | |
67 | struct dso_meth_st { |
68 | const char *name; |
69 | /* |
70 | * Loads a shared library, NB: new DSO_METHODs must ensure that a |
71 | * successful load populates the loaded_filename field, and likewise a |
72 | * successful unload OPENSSL_frees and NULLs it out. |
73 | */ |
74 | int (*dso_load) (DSO *dso); |
75 | /* Unloads a shared library */ |
76 | int (*dso_unload) (DSO *dso); |
77 | /* |
78 | * Binds a function - assumes a return type of DSO_FUNC_TYPE. This should |
79 | * be cast to the real function prototype by the caller. Platforms that |
80 | * don't have compatible representations for different prototypes (this |
81 | * is possible within ANSI C) are highly unlikely to have shared |
82 | * libraries at all, let alone a DSO_METHOD implemented for them. |
83 | */ |
84 | DSO_FUNC_TYPE (*dso_bind_func) (DSO *dso, const char *symname); |
85 | /* |
86 | * The generic (yuck) "ctrl()" function. NB: Negative return values |
87 | * (rather than zero) indicate errors. |
88 | */ |
89 | long (*dso_ctrl) (DSO *dso, int cmd, long larg, void *parg); |
90 | /* |
91 | * The default DSO_METHOD-specific function for converting filenames to a |
92 | * canonical native form. |
93 | */ |
94 | DSO_NAME_CONVERTER_FUNC dso_name_converter; |
95 | /* |
96 | * The default DSO_METHOD-specific function for converting filenames to a |
97 | * canonical native form. |
98 | */ |
99 | DSO_MERGER_FUNC dso_merger; |
100 | /* [De]Initialisation handlers. */ |
101 | int (*init) (DSO *dso); |
102 | int (*finish) (DSO *dso); |
103 | /* Return pathname of the module containing location */ |
104 | int (*pathbyaddr) (void *addr, char *path, int sz); |
105 | /* Perform global symbol lookup, i.e. among *all* modules */ |
106 | void *(*globallookup) (const char *symname); |
107 | }; |
108 | |