import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

security/nss/lib/freebl/genload.c

@@ -0,0 +1,167 @@
+/* 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/. */
+
+/*
+ * 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;
+}