/*

 * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "classfile/classLoader.hpp"

#include "classfile/sharedClassUtil.hpp"

#include "classfile/symbolTable.hpp"

#include "classfile/systemDictionaryShared.hpp"

#include "classfile/altHashing.hpp"

#include "memory/filemap.hpp"

#include "memory/metadataFactory.hpp"

#include "memory/oopFactory.hpp"

#include "oops/objArrayOop.hpp"

#include "runtime/arguments.hpp"

#include "runtime/java.hpp"

#include "runtime/os.hpp"

#include "runtime/vm_version.hpp"

#include "services/memTracker.hpp"

#include "utilities/defaultStream.hpp"

# include <sys/stat.h>

# include <errno.h>

#ifndef O_BINARY       // if defined (Win32) use binary files.

#define O_BINARY 0     // otherwise do nothing.

#endif

PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC

extern address JVM_FunctionAtStart();

extern address JVM_FunctionAtEnd();

// Complain and stop. All error conditions occurring during the writing of

// an archive file should stop the process.  Unrecoverable errors during

// the reading of the archive file should stop the process.

static void fail(const char *msg, va_list ap) {

  // This occurs very early during initialization: tty is not initialized.

  jio_fprintf(defaultStream::error_stream(),

              "An error has occurred while processing the"

              " shared archive file.\n");

  jio_vfprintf(defaultStream::error_stream(), msg, ap);

  jio_fprintf(defaultStream::error_stream(), "\n");

  // Do not change the text of the below message because some tests check for it.

  vm_exit_during_initialization("Unable to use shared archive.", NULL);

}

void FileMapInfo::fail_stop(const char *msg, ...) {

        va_list ap;

  va_start(ap, msg);

  fail(msg, ap);        // Never returns.

  va_end(ap);           // for completeness.

}

// Complain and continue.  Recoverable errors during the reading of the

// archive file may continue (with sharing disabled).

//

// If we continue, then disable shared spaces and close the file.

void FileMapInfo::fail_continue(const char *msg, ...) {

  va_list ap;

  va_start(ap, msg);

  MetaspaceShared::set_archive_loading_failed();

  if (PrintSharedArchiveAndExit && _validating_classpath_entry_table) {

    // If we are doing PrintSharedArchiveAndExit and some of the classpath entries

    // do not validate, we can still continue "limping" to validate the remaining

    // entries. No need to quit.

    tty->print("[");

    tty->vprint(msg, ap);

    tty->print_cr("]");

  } else {

    if (RequireSharedSpaces) {

      fail(msg, ap);

    } else {

      if (PrintSharedSpaces) {

        tty->print_cr("UseSharedSpaces: %s", msg);

      }

    }

  }

  va_end(ap);

}

// Fill in the fileMapInfo structure with data about this VM instance.

// This method copies the vm version info into header_version.  If the version is too

// long then a truncated version, which has a hash code appended to it, is copied.

//

// Using a template enables this method to verify that header_version is an array of

// length JVM_IDENT_MAX.  This ensures that the code that writes to the CDS file and

// the code that reads the CDS file will both use the same size buffer.  Hence, will

// use identical truncation.  This is necessary for matching of truncated versions.

template <int N> static void get_header_version(char (&header_version) [N]) {

  assert(N == JVM_IDENT_MAX, "Bad header_version size");

  const char *vm_version = VM_Version::internal_vm_info_string();

  const int version_len = (int)strlen(vm_version);

  if (version_len < (JVM_IDENT_MAX-1)) {

    strcpy(header_version, vm_version);

  } else {

    // Get the hash value.  Use a static seed because the hash needs to return the same

    // value over multiple jvm invocations.

    unsigned int hash = AltHashing::murmur3_32(8191, (const jbyte*)vm_version, version_len);

    // Truncate the ident, saving room for the 8 hex character hash value.

    strncpy(header_version, vm_version, JVM_IDENT_MAX-9);

    // Append the hash code as eight hex digits.

    sprintf(&header_version[JVM_IDENT_MAX-9], "%08x", hash);

    header_version[JVM_IDENT_MAX-1] = 0;  // Null terminate.

  }

}

FileMapInfo::FileMapInfo() {

  assert(_current_info == NULL, "must be singleton"); // not thread safe

  _current_info = this;

  memset(this, 0, sizeof(FileMapInfo));

  _file_offset = 0;

  _file_open = false;

  _header = SharedClassUtil::allocate_file_map_header();

  _header->_version = _invalid_version;

}

FileMapInfo::~FileMapInfo() {

  assert(_current_info == this, "must be singleton"); // not thread safe

  _current_info = NULL;

}

void FileMapInfo::populate_header(size_t alignment) {

  _header->populate(this, alignment);

}

size_t FileMapInfo::FileMapHeader::data_size() {

  return SharedClassUtil::file_map_header_size() - sizeof(FileMapInfo::FileMapHeaderBase);

}

void FileMapInfo::FileMapHeader::populate(FileMapInfo* mapinfo, size_t alignment) {

  _magic = 0xf00baba2;

  _version = _current_version;

  _alignment = alignment;

  _obj_alignment = ObjectAlignmentInBytes;

  _classpath_entry_table_size = mapinfo->_classpath_entry_table_size;

  _classpath_entry_table = mapinfo->_classpath_entry_table;

  _classpath_entry_size = mapinfo->_classpath_entry_size;

  // The following fields are for sanity checks for whether this archive

  // will function correctly with this JVM and the bootclasspath it's

  // invoked with.

  // JVM version string ... changes on each build.

  get_header_version(_jvm_ident);

}

void FileMapInfo::allocate_classpath_entry_table() {

  int bytes = 0;

  int count = 0;

  char* strptr = NULL;

  char* strptr_max = NULL;

  Thread* THREAD = Thread::current();

  ClassLoaderData* loader_data = ClassLoaderData::the_null_class_loader_data();

  size_t entry_size = SharedClassUtil::shared_class_path_entry_size();

  for (int pass=0; pass<2; pass++) {

    ClassPathEntry *cpe = ClassLoader::classpath_entry(0);

    for (int cur_entry = 0 ; cpe != NULL; cpe = cpe->next(), cur_entry++) {

      const char *name = cpe->name();

      int name_bytes = (int)(strlen(name) + 1);

      if (pass == 0) {

        count ++;

        bytes += (int)entry_size;

        bytes += name_bytes;

        if (TraceClassPaths || (TraceClassLoading && Verbose)) {

          tty->print_cr("[Add main shared path (%s) %s]", (cpe->is_jar_file() ? "jar" : "dir"), name);

        }

      } else {

        SharedClassPathEntry* ent = shared_classpath(cur_entry);

        if (cpe->is_jar_file()) {

          struct stat st;

          if (os::stat(name, &st) != 0) {

            // The file/dir must exist, or it would not have been added

            // into ClassLoader::classpath_entry().

            //

            // If we can't access a jar file in the boot path, then we can't

            // make assumptions about where classes get loaded from.

            FileMapInfo::fail_stop("Unable to open jar file %s.", name);

          }

          EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.

          SharedClassUtil::update_shared_classpath(cpe, ent, st.st_mtime, st.st_size, THREAD);

        } else {

          ent->_filesize  = -1;

          if (!os::dir_is_empty(name)) {

            ClassLoader::exit_with_path_failure("Cannot have non-empty directory in archived classpaths", name);

          }

        }

        ent->_name = strptr;

        if (strptr + name_bytes <= strptr_max) {

          strncpy(strptr, name, (size_t)name_bytes); // name_bytes includes trailing 0.

          strptr += name_bytes;

        } else {

          assert(0, "miscalculated buffer size");

        }

      }

    }

    if (pass == 0) {

      EXCEPTION_MARK; // The following call should never throw, but would exit VM on error.

      Array<u8>* arr = MetadataFactory::new_array<u8>(loader_data, (bytes + 7)/8, THREAD);

      strptr = (char*)(arr->data());

      strptr_max = strptr + bytes;

      SharedClassPathEntry* table = (SharedClassPathEntry*)strptr;

      strptr += entry_size * count;

      _classpath_entry_table_size = count;

      _classpath_entry_table = table;

      _classpath_entry_size = entry_size;

    }

  }

}

bool FileMapInfo::validate_classpath_entry_table() {

  _validating_classpath_entry_table = true;

  int count = _header->_classpath_entry_table_size;

  _classpath_entry_table = _header->_classpath_entry_table;

  _classpath_entry_size = _header->_classpath_entry_size;

  for (int i=0; i<count; i++) {

    SharedClassPathEntry* ent = shared_classpath(i);

    struct stat st;

    const char* name = ent->_name;

    bool ok = true;

    if (TraceClassPaths || (TraceClassLoading && Verbose)) {

      tty->print_cr("[Checking shared classpath entry: %s]", name);

    }

    if (os::stat(name, &st) != 0) {

      fail_continue("Required classpath entry does not exist: %s", name);

      ok = false;

    } else if (ent->is_dir()) {

      if (!os::dir_is_empty(name)) {

        fail_continue("directory is not empty: %s", name);

        ok = false;

      }

    } else {

      if (ent->_timestamp != st.st_mtime ||

          ent->_filesize != st.st_size) {

        ok = false;

        if (PrintSharedArchiveAndExit) {

          fail_continue(ent->_timestamp != st.st_mtime ?

                        "Timestamp mismatch" :

                        "File size mismatch");

        } else {

          fail_continue("A jar file is not the one used while building"

                        " the shared archive file: %s", name);

        }

      }

    }

    if (ok) {

      if (TraceClassPaths || (TraceClassLoading && Verbose)) {

        tty->print_cr("[ok]");

      }

    } else if (!PrintSharedArchiveAndExit) {

      _validating_classpath_entry_table = false;

      return false;

    }

  }

  _classpath_entry_table_size = _header->_classpath_entry_table_size;

  _validating_classpath_entry_table = false;

  return true;

}

// Read the FileMapInfo information from the file.

bool FileMapInfo::init_from_file(int fd) {

  size_t sz = _header->data_size();

  char* addr = _header->data();

  size_t n = os::read(fd, addr, (unsigned int)sz);

  if (n != sz) {

    fail_continue("Unable to read the file header.");

    return false;

  }

  if (_header->_version != current_version()) {

    fail_continue("The shared archive file has the wrong version.");

    return false;

  }

  _file_offset = (long)n;

  size_t info_size = _header->_paths_misc_info_size;

  _paths_misc_info = NEW_C_HEAP_ARRAY_RETURN_NULL(char, info_size, mtClass);

  if (_paths_misc_info == NULL) {

    fail_continue("Unable to read the file header.");

    return false;

  }

  n = os::read(fd, _paths_misc_info, (unsigned int)info_size);

  if (n != info_size) {

    fail_continue("Unable to read the shared path info header.");

    FREE_C_HEAP_ARRAY(char, _paths_misc_info);

    _paths_misc_info = NULL;

    return false;

  }

  size_t len = lseek(fd, 0, SEEK_END);

  struct FileMapInfo::FileMapHeader::space_info* si =

    &_header->_space[MetaspaceShared::mc];

  if (si->_file_offset >= len || len - si->_file_offset < si->_used) {

    fail_continue("The shared archive file has been truncated.");

    return false;

  }

  _file_offset += (long)n;

  return true;

}

// Read the FileMapInfo information from the file.

bool FileMapInfo::open_for_read() {

  _full_path = Arguments::GetSharedArchivePath();

  int fd = open(_full_path, O_RDONLY | O_BINARY, 0);

  if (fd < 0) {

    if (errno == ENOENT) {

      // Not locating the shared archive is ok.

      fail_continue("Specified shared archive not found.");

    } else {

      fail_continue("Failed to open shared archive file (%s).",

                    strerror(errno));

    }

    return false;

  }

  _fd = fd;

  _file_open = true;

  return true;

}

// Write the FileMapInfo information to the file.

void FileMapInfo::open_for_write() {

 _full_path = Arguments::GetSharedArchivePath();

  if (PrintSharedSpaces) {

    tty->print_cr("Dumping shared data to file: ");

    tty->print_cr("   %s", _full_path);

  }

#ifdef _WINDOWS  // On Windows, need WRITE permission to remove the file.

  chmod(_full_path, _S_IREAD | _S_IWRITE);

#endif

  // Use remove() to delete the existing file because, on Unix, this will

  // allow processes that have it open continued access to the file.

  remove(_full_path);

  int fd = open(_full_path, O_RDWR | O_CREAT | O_TRUNC | O_BINARY, 0444);

  if (fd < 0) {

    fail_stop("Unable to create shared archive file %s.", _full_path);

  }

  _fd = fd;

  _file_offset = 0;

  _file_open = true;

}

// Write the header to the file, seek to the next allocation boundary.

void FileMapInfo::write_header() {

  int info_size = ClassLoader::get_shared_paths_misc_info_size();

  _header->_paths_misc_info_size = info_size;

  align_file_position();

  size_t sz = _header->data_size();

  char* addr = _header->data();

  write_bytes(addr, (int)sz); // skip the C++ vtable

  write_bytes(ClassLoader::get_shared_paths_misc_info(), info_size);

  align_file_position();

}

// Dump shared spaces to file.

void FileMapInfo::write_space(int i, Metaspace* space, bool read_only) {

  align_file_position();

  size_t used = space->used_bytes_slow(Metaspace::NonClassType);

  size_t capacity = space->capacity_bytes_slow(Metaspace::NonClassType);

  struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[i];

  write_region(i, (char*)space->bottom(), used, capacity, read_only, false);

}

// Dump region to file.

void FileMapInfo::write_region(int region, char* base, size_t size,

                               size_t capacity, bool read_only,

                               bool allow_exec) {

  struct FileMapInfo::FileMapHeader::space_info* si = &_header->_space[region];

  if (_file_open) {

    guarantee(si->_file_offset == _file_offset, "file offset mismatch.");

    if (PrintSharedSpaces) {

      tty->print_cr("Shared file region %d: 0x%6x bytes, addr " INTPTR_FORMAT

                    " file offset 0x%6x", region, size, base, _file_offset);

    }

  } else {

    si->_file_offset = _file_offset;

  }

  si->_base = base;

  si->_used = size;

  si->_capacity = capacity;

  si->_read_only = read_only;

  si->_allow_exec = allow_exec;

  si->_crc = ClassLoader::crc32(0, base, (jint)size);

  write_bytes_aligned(base, (int)size);

}

// Dump bytes to file -- at the current file position.

void FileMapInfo::write_bytes(const void* buffer, int nbytes) {

  if (_file_open) {

    int n = ::write(_fd, buffer, nbytes);

    if (n != nbytes) {

      // It is dangerous to leave the corrupted shared archive file around,

      // close and remove the file. See bug 6372906.

      close();

      remove(_full_path);

      fail_stop("Unable to write to shared archive file.");

    }

  }

  _file_offset += nbytes;

}

// Align file position to an allocation unit boundary.

void FileMapInfo::align_file_position() {

  size_t new_file_offset = align_size_up(_file_offset,

                                         os::vm_allocation_granularity());

  if (new_file_offset != _file_offset) {

    _file_offset = new_file_offset;

    if (_file_open) {

      // Seek one byte back from the target and write a byte to insure

      // that the written file is the correct length.

      _file_offset -= 1;

      if (lseek(_fd, (long)_file_offset, SEEK_SET) < 0) {

        fail_stop("Unable to seek.");

      }

      char zero = 0;

      write_bytes(&zero, 1);

    }

  }

}

// Dump bytes to file -- at the current file position.

void FileMapInfo::write_bytes_aligned(const void* buffer, int nbytes) {

  align_file_position();

  write_bytes(buffer, nbytes);

  align_file_position();

}

// Close the shared archive file.  This does NOT unmap mapped regions.

void FileMapInfo::close() {

  if (_file_open) {

    if (::close(_fd) < 0) {

      fail_stop("Unable to close the shared archive file.");

    }

    _file_open = false;

    _fd = -1;

  }

}