The Tor Browser: comparison security/nss/lib/util/secload.c

--1:000000000000
+:c422a52d970f
+/* 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;
+}

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comparison: security/nss/lib/util/secload.c

security/nss/lib/util/secload.c