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/* 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
/*
* This file is meant to be included by other .c files.
* This file takes a "parameter", the scope which includes this
* code shall declare this variable:
* const char *NameOfThisSharedLib;
*
* NameOfThisSharedLib:
* 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.
*/
#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)
{
#ifdef __GLIBC__
char* tmp = realpath(link, NULL);
char* resolved;
if (!tmp)
return NULL;
resolved = PR_Malloc(strlen(tmp) + 1);
strcpy(resolved, tmp); /* This is necessary because PR_Free might not be using free() */
free(tmp);
return resolved;
#else
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
}
#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);
PORT_Free(fullName);
}
}
return dlh;
}
/*
* We use PR_GetLibraryFilePathname to get the pathname of the loaded
* shared lib that contains this function, and then do a PR_LoadLibrary
* with an absolute pathname for the softoken shared library.
*/
static PRLibrary*
loader_LoadLibrary(const char* nameToLoad)
{
PRLibrary* lib = NULL;
char* fullPath = NULL;
PRLibSpec libSpec;
/* Get the pathname for nameOfAlreadyLoadedLib, i.e. /usr/lib/libnss3.so
* PR_GetLibraryFilePathname works with either the base library name or a
* function pointer, depending on the platform. We can't query an exported
* symbol such as NSC_GetFunctionList, because on some platforms we can't
* find symbols in loaded implicit dependencies.
* But we can just get the address of this function !
*/
fullPath = PR_GetLibraryFilePathname(NameOfThisSharedLib,
(PRFuncPtr)&loader_LoadLibrary);
if (fullPath) {
lib = loader_LoadLibInReferenceDir(fullPath, nameToLoad);
#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, nameToLoad);
}
}
#endif
PR_Free(fullPath);
}
if (!lib) {
#ifdef DEBUG_LOADER
PR_fprintf(PR_STDOUT, "\nAttempting to load %s\n", nameToLoad);
#endif
libSpec.type = PR_LibSpec_Pathname;
libSpec.value.pathname = nameToLoad;
lib = PR_LoadLibraryWithFlags(libSpec, PR_LD_NOW | PR_LD_LOCAL);
}
if (NULL == lib) {
#ifdef DEBUG_LOADER
PR_fprintf(PR_STDOUT, "\nLoading failed : %s.\n", nameToLoad);
#endif
}
return lib;
}