1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/nss/lib/util/secload.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,182 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#include "secport.h"
1.9 +#include "nspr.h"
1.10 +
1.11 +#ifdef XP_UNIX
1.12 +#include <unistd.h>
1.13 +#define BL_MAXSYMLINKS 20
1.14 +
1.15 +/*
1.16 + * If 'link' is a symbolic link, this function follows the symbolic links
1.17 + * and returns the pathname of the ultimate source of the symbolic links.
1.18 + * If 'link' is not a symbolic link, this function returns NULL.
1.19 + * The caller should call PR_Free to free the string returned by this
1.20 + * function.
1.21 + */
1.22 +static char* loader_GetOriginalPathname(const char* link)
1.23 +{
1.24 + char* resolved = NULL;
1.25 + char* input = NULL;
1.26 + PRUint32 iterations = 0;
1.27 + PRInt32 len = 0, retlen = 0;
1.28 + if (!link) {
1.29 + PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
1.30 + return NULL;
1.31 + }
1.32 + len = PR_MAX(1024, strlen(link) + 1);
1.33 + resolved = PR_Malloc(len);
1.34 + input = PR_Malloc(len);
1.35 + if (!resolved || !input) {
1.36 + if (resolved) {
1.37 + PR_Free(resolved);
1.38 + }
1.39 + if (input) {
1.40 + PR_Free(input);
1.41 + }
1.42 + return NULL;
1.43 + }
1.44 + strcpy(input, link);
1.45 + while ( (iterations++ < BL_MAXSYMLINKS) &&
1.46 + ( (retlen = readlink(input, resolved, len - 1)) > 0) ) {
1.47 + char* tmp = input;
1.48 + resolved[retlen] = '\0'; /* NULL termination */
1.49 + input = resolved;
1.50 + resolved = tmp;
1.51 + }
1.52 + PR_Free(resolved);
1.53 + if (iterations == 1 && retlen < 0) {
1.54 + PR_Free(input);
1.55 + input = NULL;
1.56 + }
1.57 + return input;
1.58 +}
1.59 +#endif /* XP_UNIX */
1.60 +
1.61 +/*
1.62 + * Load the library with the file name 'name' residing in the same
1.63 + * directory as the reference library, whose pathname is 'referencePath'.
1.64 + */
1.65 +static PRLibrary *
1.66 +loader_LoadLibInReferenceDir(const char *referencePath, const char *name)
1.67 +{
1.68 + PRLibrary *dlh = NULL;
1.69 + char *fullName = NULL;
1.70 + char* c;
1.71 + PRLibSpec libSpec;
1.72 +
1.73 + /* Remove the trailing filename from referencePath and add the new one */
1.74 + c = strrchr(referencePath, PR_GetDirectorySeparator());
1.75 + if (c) {
1.76 + size_t referencePathSize = 1 + c - referencePath;
1.77 + fullName = (char*) PORT_Alloc(strlen(name) + referencePathSize + 1);
1.78 + if (fullName) {
1.79 + memcpy(fullName, referencePath, referencePathSize);
1.80 + strcpy(fullName + referencePathSize, name);
1.81 +#ifdef DEBUG_LOADER
1.82 + PR_fprintf(PR_STDOUT, "\nAttempting to load fully-qualified %s\n",
1.83 + fullName);
1.84 +#endif
1.85 + libSpec.type = PR_LibSpec_Pathname;
1.86 + libSpec.value.pathname = fullName;
1.87 + dlh = PR_LoadLibraryWithFlags(libSpec, PR_LD_NOW | PR_LD_LOCAL
1.88 +#ifdef PR_LD_ALT_SEARCH_PATH
1.89 + /* allow library's dependencies to be found in the same directory
1.90 + * on Windows even if PATH is not set. Requires NSPR 4.8.1 . */
1.91 + | PR_LD_ALT_SEARCH_PATH
1.92 +#endif
1.93 + );
1.94 + PORT_Free(fullName);
1.95 + }
1.96 + }
1.97 + return dlh;
1.98 +}
1.99 +
1.100 +/*
1.101 + * Load a shared library called "newShLibName" in the same directory as
1.102 + * a shared library that is already loaded, called existingShLibName.
1.103 + * A pointer to a static function in that shared library,
1.104 + * staticShLibFunc, is required.
1.105 + *
1.106 + * existingShLibName:
1.107 + * The file name of the shared library that shall be used as the
1.108 + * "reference library". The loader will attempt to load the requested
1.109 + * library from the same directory as the reference library.
1.110 + *
1.111 + * staticShLibFunc:
1.112 + * Pointer to a static function in the "reference library".
1.113 + *
1.114 + * newShLibName:
1.115 + * The simple file name of the new shared library to be loaded.
1.116 + *
1.117 + * We use PR_GetLibraryFilePathname to get the pathname of the loaded
1.118 + * shared lib that contains this function, and then do a
1.119 + * PR_LoadLibraryWithFlags with an absolute pathname for the shared
1.120 + * library to be loaded.
1.121 + *
1.122 + * On Windows, the "alternate search path" strategy is employed, if available.
1.123 + * On Unix, if existingShLibName is a symbolic link, and no link exists for the
1.124 + * new library, the original link will be resolved, and the new library loaded
1.125 + * from the resolved location.
1.126 + *
1.127 + * If the new shared library is not found in the same location as the reference
1.128 + * library, it will then be loaded from the normal system library path.
1.129 + *
1.130 + */
1.131 +
1.132 +PRLibrary *
1.133 +PORT_LoadLibraryFromOrigin(const char* existingShLibName,
1.134 + PRFuncPtr staticShLibFunc,
1.135 + const char *newShLibName)
1.136 +{
1.137 + PRLibrary *lib = NULL;
1.138 + char* fullPath = NULL;
1.139 + PRLibSpec libSpec;
1.140 +
1.141 + /* Get the pathname for existingShLibName, e.g. /usr/lib/libnss3.so
1.142 + * PR_GetLibraryFilePathname works with either the base library name or a
1.143 + * function pointer, depending on the platform.
1.144 + * We require the address of a function in the "reference library",
1.145 + * provided by the caller. To avoid getting the address of the stub/thunk
1.146 + * of an exported function by accident, use the address of a static
1.147 + * function rather than an exported function.
1.148 + */
1.149 + fullPath = PR_GetLibraryFilePathname(existingShLibName,
1.150 + staticShLibFunc);
1.151 +
1.152 + if (fullPath) {
1.153 + lib = loader_LoadLibInReferenceDir(fullPath, newShLibName);
1.154 +#ifdef XP_UNIX
1.155 + if (!lib) {
1.156 + /*
1.157 + * If fullPath is a symbolic link, resolve the symbolic
1.158 + * link and try again.
1.159 + */
1.160 + char* originalfullPath = loader_GetOriginalPathname(fullPath);
1.161 + if (originalfullPath) {
1.162 + PR_Free(fullPath);
1.163 + fullPath = originalfullPath;
1.164 + lib = loader_LoadLibInReferenceDir(fullPath, newShLibName);
1.165 + }
1.166 + }
1.167 +#endif
1.168 + PR_Free(fullPath);
1.169 + }
1.170 + if (!lib) {
1.171 +#ifdef DEBUG_LOADER
1.172 + PR_fprintf(PR_STDOUT, "\nAttempting to load %s\n", newShLibName);
1.173 +#endif
1.174 + libSpec.type = PR_LibSpec_Pathname;
1.175 + libSpec.value.pathname = newShLibName;
1.176 + lib = PR_LoadLibraryWithFlags(libSpec, PR_LD_NOW | PR_LD_LOCAL);
1.177 + }
1.178 + if (NULL == lib) {
1.179 +#ifdef DEBUG_LOADER
1.180 + PR_fprintf(PR_STDOUT, "\nLoading failed : %s.\n", newShLibName);
1.181 +#endif
1.182 + }
1.183 + return lib;
1.184 +}
1.185 +
