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
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "secport.h"
#include "nspr.h"
#ifdef XP_UNIX
#include <unistd.h>
#define BL_MAXSYMLINKS 20
/*
* If 'link' is a symbolic link, this function follows the symbolic links
* and returns the pathname of the ultimate source of the symbolic links.
* If 'link' is not a symbolic link, this function returns NULL.
* The caller should call PR_Free to free the string returned by this
* function.
*/
static char* loader_GetOriginalPathname(const char* link)
{
char* resolved = NULL;
char* input = NULL;
PRUint32 iterations = 0;
PRInt32 len = 0, retlen = 0;
if (!link) {
PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
return NULL;
}
len = PR_MAX(1024, strlen(link) + 1);
resolved = PR_Malloc(len);
input = PR_Malloc(len);
if (!resolved || !input) {
if (resolved) {
PR_Free(resolved);
}
if (input) {
PR_Free(input);
}
return NULL;
}
strcpy(input, link);
while ( (iterations++ < BL_MAXSYMLINKS) &&
( (retlen = readlink(input, resolved, len - 1)) > 0) ) {
char* tmp = input;
resolved[retlen] = '\0'; /* NULL termination */
input = resolved;
resolved = tmp;
}
PR_Free(resolved);
if (iterations == 1 && retlen < 0) {
PR_Free(input);
input = NULL;
}
return input;
}
#endif /* XP_UNIX */
/*
* Load the library with the file name 'name' residing in the same
* directory as the reference library, whose pathname is 'referencePath'.
*/
static PRLibrary *
loader_LoadLibInReferenceDir(const char *referencePath, const char *name)
{
PRLibrary *dlh = NULL;
char *fullName = NULL;
char* c;
PRLibSpec libSpec;
/* Remove the trailing filename from referencePath and add the new one */
c = strrchr(referencePath, PR_GetDirectorySeparator());
if (c) {
size_t referencePathSize = 1 + c - referencePath;
fullName = (char*) PORT_Alloc(strlen(name) + referencePathSize + 1);
if (fullName) {
memcpy(fullName, referencePath, referencePathSize);
strcpy(fullName + referencePathSize, name);
#ifdef DEBUG_LOADER
PR_fprintf(PR_STDOUT, "\nAttempting to load fully-qualified %s\n",
fullName);
#endif
libSpec.type = PR_LibSpec_Pathname;
libSpec.value.pathname = fullName;
dlh = PR_LoadLibraryWithFlags(libSpec, PR_LD_NOW | PR_LD_LOCAL
#ifdef PR_LD_ALT_SEARCH_PATH
/* allow library's dependencies to be found in the same directory
* on Windows even if PATH is not set. Requires NSPR 4.8.1 . */
| PR_LD_ALT_SEARCH_PATH
#endif
);
PORT_Free(fullName);
}
}
return dlh;
}
/*
* Load a shared library called "newShLibName" in the same directory as
* a shared library that is already loaded, called existingShLibName.
* A pointer to a static function in that shared library,
* staticShLibFunc, is required.
*
* existingShLibName:
* The file name of the shared library that shall be used as the
* "reference library". The loader will attempt to load the requested
* library from the same directory as the reference library.
*
* staticShLibFunc:
* Pointer to a static function in the "reference library".
*
* newShLibName:
* The simple file name of the new shared library to be loaded.
*
* We use PR_GetLibraryFilePathname to get the pathname of the loaded
* shared lib that contains this function, and then do a
* PR_LoadLibraryWithFlags with an absolute pathname for the shared
* library to be loaded.
*
* On Windows, the "alternate search path" strategy is employed, if available.
* On Unix, if existingShLibName is a symbolic link, and no link exists for the
* new library, the original link will be resolved, and the new library loaded
* from the resolved location.
*
* If the new shared library is not found in the same location as the reference
* library, it will then be loaded from the normal system library path.
*
*/
PRLibrary *
PORT_LoadLibraryFromOrigin(const char* existingShLibName,
PRFuncPtr staticShLibFunc,
const char *newShLibName)
{
PRLibrary *lib = NULL;
char* fullPath = NULL;
PRLibSpec libSpec;
/* Get the pathname for existingShLibName, e.g. /usr/lib/libnss3.so
* PR_GetLibraryFilePathname works with either the base library name or a
* function pointer, depending on the platform.
* We require the address of a function in the "reference library",
* provided by the caller. To avoid getting the address of the stub/thunk
* of an exported function by accident, use the address of a static
* function rather than an exported function.
*/
fullPath = PR_GetLibraryFilePathname(existingShLibName,
staticShLibFunc);
if (fullPath) {
lib = loader_LoadLibInReferenceDir(fullPath, newShLibName);
#ifdef XP_UNIX
if (!lib) {
/*
* If fullPath is a symbolic link, resolve the symbolic
* link and try again.
*/
char* originalfullPath = loader_GetOriginalPathname(fullPath);
if (originalfullPath) {
PR_Free(fullPath);
fullPath = originalfullPath;
lib = loader_LoadLibInReferenceDir(fullPath, newShLibName);
}
}
#endif
PR_Free(fullPath);
}
if (!lib) {
#ifdef DEBUG_LOADER
PR_fprintf(PR_STDOUT, "\nAttempting to load %s\n", newShLibName);
#endif
libSpec.type = PR_LibSpec_Pathname;
libSpec.value.pathname = newShLibName;
lib = PR_LoadLibraryWithFlags(libSpec, PR_LD_NOW | PR_LD_LOCAL);
}
if (NULL == lib) {
#ifdef DEBUG_LOADER
PR_fprintf(PR_STDOUT, "\nLoading failed : %s.\n", newShLibName);
#endif
}
return lib;
}
|
