1 /*
  2  * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "cds/cds_globals.hpp"
 26 #include "cds/cdsConfig.hpp"
 27 #include "cds/dynamicArchive.hpp"
 28 #include "cds/filemap.hpp"
 29 #include "cds/heapShared.hpp"
 30 #include "classfile/classFileParser.hpp"
 31 #include "classfile/classLoader.inline.hpp"
 32 #include "classfile/classLoaderExt.hpp"
 33 #include "classfile/classLoaderData.inline.hpp"
 34 #include "classfile/classLoadInfo.hpp"
 35 #include "classfile/klassFactory.hpp"
 36 #include "classfile/modules.hpp"
 37 #include "classfile/systemDictionary.hpp"
 38 #include "classfile/vmSymbols.hpp"
 39 #include "gc/shared/collectedHeap.hpp"
 40 #include "logging/log.hpp"
 41 #include "memory/allocation.inline.hpp"
 42 #include "memory/resourceArea.hpp"
 43 #include "oops/instanceKlass.hpp"
 44 #include "oops/klass.inline.hpp"
 45 #include "oops/oop.inline.hpp"
 46 #include "oops/symbol.hpp"
 47 #include "runtime/arguments.hpp"
 48 #include "runtime/handles.inline.hpp"
 49 #include "runtime/java.hpp"
 50 #include "runtime/os.hpp"
 51 #include "utilities/checkedCast.hpp"
 52 #include "utilities/stringUtils.hpp"
 53 
 54 jshort ClassLoaderExt::_app_class_paths_start_index = ClassLoaderExt::max_classpath_index;
 55 jshort ClassLoaderExt::_app_module_paths_start_index = ClassLoaderExt::max_classpath_index;
 56 jshort ClassLoaderExt::_max_used_path_index = 0;
 57 int ClassLoaderExt::_num_module_paths = 0;
 58 bool ClassLoaderExt::_has_app_classes = false;
 59 bool ClassLoaderExt::_has_platform_classes = false;
 60 bool ClassLoaderExt::_has_non_jar_in_classpath = false;
 61 
 62 void ClassLoaderExt::append_boot_classpath(ClassPathEntry* new_entry) {
 63   if (CDSConfig::is_using_archive()) {
 64     warning("Sharing is only supported for boot loader classes because bootstrap classpath has been appended");
 65     FileMapInfo::current_info()->set_has_platform_or_app_classes(false);
 66     if (DynamicArchive::is_mapped()) {
 67       FileMapInfo::dynamic_info()->set_has_platform_or_app_classes(false);
 68     }
 69   }
 70   ClassLoader::add_to_boot_append_entries(new_entry);
 71 }
 72 
 73 void ClassLoaderExt::setup_app_search_path(JavaThread* current) {
 74   assert(CDSConfig::is_dumping_archive(), "sanity");
 75   int start_index = ClassLoader::num_boot_classpath_entries();
 76   _app_class_paths_start_index = checked_cast<jshort>(start_index);
 77   char* app_class_path = os::strdup_check_oom(Arguments::get_appclasspath(), mtClass);
 78 
 79   if (strcmp(app_class_path, ".") == 0) {
 80     // This doesn't make any sense, even for AppCDS, so let's skip it. We
 81     // don't want to throw an error here because -cp "." is usually assigned
 82     // by the launcher when classpath is not specified.
 83     trace_class_path("app loader class path (skipped)=", app_class_path);
 84   } else {
 85     trace_class_path("app loader class path=", app_class_path);
 86     ClassLoader::setup_app_search_path(current, app_class_path);
 87   }
 88 
 89   os::free(app_class_path);
 90 }
 91 
 92 int ClassLoaderExt::compare_module_names(const char** p1, const char** p2) {
 93   return strcmp(*p1, *p2);
 94 }
 95 
 96 void ClassLoaderExt::process_module_table(JavaThread* current, ModuleEntryTable* met) {
 97   ResourceMark rm(current);
 98   GrowableArray<const char*>* module_paths = new GrowableArray<const char*>(5);
 99 
100   class ModulePathsGatherer : public ModuleClosure {
101     JavaThread* _current;
102     GrowableArray<const char*>* _module_paths;
103    public:
104     ModulePathsGatherer(JavaThread* current, GrowableArray<const char*>* module_paths) :
105       _current(current), _module_paths(module_paths) {}
106     void do_module(ModuleEntry* m) {
107       char* uri = m->location()->as_C_string();
108       if (strncmp(uri, "file:", 5) == 0) {
109         char* path = ClassLoader::uri_to_path(uri);
110         extract_jar_files_from_path(path, _module_paths);
111       }
112     }
113   };
114 
115   ModulePathsGatherer gatherer(current, module_paths);
116   {
117     MutexLocker ml(Module_lock);
118     met->modules_do(&gatherer);
119   }
120 
121   // Sort the module paths before storing into CDS archive for simpler
122   // checking at runtime.
123   module_paths->sort(compare_module_names);
124 
125   for (int i = 0; i < module_paths->length(); i++) {
126     ClassLoader::setup_module_search_path(current, module_paths->at(i));
127   }
128 }
129 
130 void ClassLoaderExt::setup_module_paths(JavaThread* current) {
131   assert(CDSConfig::is_dumping_archive(), "sanity");
132   int start_index = ClassLoader::num_boot_classpath_entries() +
133                     ClassLoader::num_app_classpath_entries();
134   _app_module_paths_start_index = checked_cast<jshort>(start_index);
135   Handle system_class_loader (current, SystemDictionary::java_system_loader());
136   ModuleEntryTable* met = Modules::get_module_entry_table(system_class_loader);
137   process_module_table(current, met);
138 }
139 
140 bool ClassLoaderExt::has_jar_suffix(const char* filename) {
141   // In jdk.internal.module.ModulePath.readModule(), it checks for the ".jar" suffix.
142   // Performing the same check here.
143   const char* dot = strrchr(filename, '.');
144   if (dot != nullptr && strcmp(dot + 1, "jar") == 0) {
145     return true;
146   }
147   return false;
148 }
149 
150 void ClassLoaderExt::extract_jar_files_from_path(const char* path, GrowableArray<const char*>* module_paths) {
151   DIR* dirp = os::opendir(path);
152   if (dirp == nullptr && errno == ENOTDIR && has_jar_suffix(path)) {
153     module_paths->append(path);
154   } else {
155     if (dirp != nullptr) {
156       struct dirent* dentry;
157       while ((dentry = os::readdir(dirp)) != nullptr) {
158         const char* file_name = dentry->d_name;
159         if (has_jar_suffix(file_name)) {
160           size_t full_name_len = strlen(path) + strlen(file_name) + strlen(os::file_separator()) + 1;
161           char* full_name = NEW_RESOURCE_ARRAY(char, full_name_len);
162           int n = os::snprintf(full_name, full_name_len, "%s%s%s", path, os::file_separator(), file_name);
163           assert((size_t)n == full_name_len - 1, "Unexpected number of characters in string");
164           module_paths->append(full_name);
165         }
166       }
167       os::closedir(dirp);
168     }
169   }
170 }
171 
172 char* ClassLoaderExt::read_manifest(JavaThread* current, ClassPathEntry* entry,
173                                     jint *manifest_size, bool clean_text) {
174   const char* name = "META-INF/MANIFEST.MF";
175   char* manifest;
176   jint size;
177 
178   assert(entry->is_jar_file(), "must be");
179   manifest = (char*) ((ClassPathZipEntry*)entry )->open_entry(current, name, &size, true);
180 
181   if (manifest == nullptr) { // No Manifest
182     *manifest_size = 0;
183     return nullptr;
184   }
185 
186 
187   if (clean_text) {
188     // See http://docs.oracle.com/javase/6/docs/technotes/guides/jar/jar.html#JAR%20Manifest
189     // (1): replace all CR/LF and CR with LF
190     StringUtils::replace_no_expand(manifest, "\r\n", "\n");
191 
192     // (2) remove all new-line continuation (remove all "\n " substrings)
193     StringUtils::replace_no_expand(manifest, "\n ", "");
194   }
195 
196   *manifest_size = (jint)strlen(manifest);
197   return manifest;
198 }
199 
200 char* ClassLoaderExt::get_class_path_attr(const char* jar_path, char* manifest, jint manifest_size) {
201   const char* tag = "Class-Path: ";
202   const int tag_len = (int)strlen(tag);
203   char* found = nullptr;
204   char* line_start = manifest;
205   char* end = manifest + manifest_size;
206 
207   assert(*end == 0, "must be nul-terminated");
208 
209   while (line_start < end) {
210     char* line_end = strchr(line_start, '\n');
211     if (line_end == nullptr) {
212       // JAR spec require the manifest file to be terminated by a new line.
213       break;
214     }
215     if (strncmp(tag, line_start, tag_len) == 0) {
216       if (found != nullptr) {
217         // Same behavior as jdk/src/share/classes/java/util/jar/Attributes.java
218         // If duplicated entries are found, the last one is used.
219         log_warning(cds)("Warning: Duplicate name in Manifest: %s.\n"
220                       "Ensure that the manifest does not have duplicate entries, and\n"
221                       "that blank lines separate individual sections in both your\n"
222                       "manifest and in the META-INF/MANIFEST.MF entry in the jar file:\n%s\n", tag, jar_path);
223       }
224       found = line_start + tag_len;
225       assert(found <= line_end, "sanity");
226       *line_end = '\0';
227     }
228     line_start = line_end + 1;
229   }
230   return found;
231 }
232 
233 void ClassLoaderExt::process_jar_manifest(JavaThread* current, ClassPathEntry* entry) {
234   ResourceMark rm(current);
235   jint manifest_size;
236   char* manifest = read_manifest(current, entry, &manifest_size);
237 
238   if (manifest == nullptr) {
239     return;
240   }
241 
242   if (strstr(manifest, "Extension-List:") != nullptr) {
243     vm_exit_during_cds_dumping(err_msg("-Xshare:dump does not support Extension-List in JAR manifest: %s", entry->name()));
244   }
245 
246   if (strstr(manifest, "Multi-Release: true") != nullptr) {
247     entry->set_multi_release_jar();
248   }
249 
250   char* cp_attr = get_class_path_attr(entry->name(), manifest, manifest_size);
251 
252   if (cp_attr != nullptr && strlen(cp_attr) > 0) {
253     trace_class_path("found Class-Path: ", cp_attr);
254 
255     char sep = os::file_separator()[0];
256     const char* dir_name = entry->name();
257     const char* dir_tail = strrchr(dir_name, sep);
258 #ifdef _WINDOWS
259     // On Windows, we also support forward slash as the file separator when locating entries in the classpath entry.
260     const char* dir_tail2 = strrchr(dir_name, '/');
261     if (dir_tail == nullptr) {
262       dir_tail = dir_tail2;
263     } else if (dir_tail2 != nullptr && dir_tail2 > dir_tail) {
264       dir_tail = dir_tail2;
265     }
266 #endif
267     int dir_len;
268     if (dir_tail == nullptr) {
269       dir_len = 0;
270     } else {
271       dir_len = pointer_delta_as_int(dir_tail, dir_name) + 1;
272     }
273 
274     // Split the cp_attr by spaces, and add each file
275     char* file_start = cp_attr;
276     char* end = file_start + strlen(file_start);
277 
278     while (file_start < end) {
279       char* file_end = strchr(file_start, ' ');
280       if (file_end != nullptr) {
281         *file_end = 0;
282         file_end += 1;
283       } else {
284         file_end = end;
285       }
286 
287       size_t name_len = strlen(file_start);
288       if (name_len > 0) {
289         ResourceMark rm(current);
290         size_t libname_len = dir_len + name_len;
291         char* libname = NEW_RESOURCE_ARRAY(char, libname_len + 1);
292         int n = os::snprintf(libname, libname_len + 1, "%.*s%s", dir_len, dir_name, file_start);
293         assert((size_t)n == libname_len, "Unexpected number of characters in string");
294         if (ClassLoader::update_class_path_entry_list(current, libname, true, false, true /* from_class_path_attr */)) {
295           trace_class_path("library = ", libname);
296         } else {
297           trace_class_path("library (non-existent) = ", libname);
298           FileMapInfo::record_non_existent_class_path_entry(libname);
299         }
300       }
301 
302       file_start = file_end;
303     }
304   }
305   return;
306 }
307 
308 void ClassLoaderExt::setup_search_paths(JavaThread* current) {
309   ClassLoaderExt::setup_app_search_path(current);
310 }
311 
312 void ClassLoaderExt::record_result(const s2 classpath_index, InstanceKlass* result, bool redefined) {
313   assert(CDSConfig::is_dumping_archive(), "sanity");
314 
315   // We need to remember where the class comes from during dumping.
316   oop loader = result->class_loader();
317   s2 classloader_type = ClassLoader::BOOT_LOADER;
318   if (SystemDictionary::is_system_class_loader(loader)) {
319     classloader_type = ClassLoader::APP_LOADER;
320     ClassLoaderExt::set_has_app_classes();
321   } else if (SystemDictionary::is_platform_class_loader(loader)) {
322     classloader_type = ClassLoader::PLATFORM_LOADER;
323     ClassLoaderExt::set_has_platform_classes();
324   }
325   if (classpath_index > ClassLoaderExt::max_used_path_index()) {
326     ClassLoaderExt::set_max_used_path_index(classpath_index);
327   }
328   result->set_shared_classpath_index(classpath_index);
329   result->set_shared_class_loader_type(classloader_type);
330 #if INCLUDE_CDS_JAVA_HEAP
331   if (CDSConfig::is_dumping_heap() && AllowArchivingWithJavaAgent && classloader_type == ClassLoader::BOOT_LOADER &&
332       classpath_index < 0 && redefined) {
333     // When dumping the heap (which happens only during static dump), classes for the built-in
334     // loaders are always loaded from known locations (jimage, classpath or modulepath),
335     // so classpath_index should always be >= 0.
336     // The only exception is when a java agent is used during dump time (for testing
337     // purposes only). If a class is transformed by the agent, the CodeSource of
338     // this class may point to an unknown location. This may break heap object archiving,
339     // which requires all the boot classes to be from known locations. This is an
340     // uncommon scenario (even in test cases). Let's simply disable heap object archiving.
341     ResourceMark rm;
342     log_warning(cds)("CDS heap objects cannot be written because class %s maybe modified by ClassFileLoadHook.",
343                      result->external_name());
344     CDSConfig::disable_heap_dumping();
345   }
346 #endif // INCLUDE_CDS_JAVA_HEAP
347 }