/*

 * Copyright (C) 2009-2018 Tobias Brunner

 * Copyright (C) 2008 Martin Willi

 *

 * Copyright (C) secunet Security Networks AG

 *

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

 * under the terms of the GNU General Public License as published by the

 * Free Software Foundation; either version 2 of the License, or (at your

 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.

 *

 * This program 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

 * for more details.

 */

#include "library.h"

#include <stdlib.h>

#include <utils/debug.h>

#include <threading/thread.h>

#include <utils/identification.h>

#include <networking/host.h>

#include <collections/array.h>

#include <collections/hashtable.h>

#include <utils/backtrace.h>

#include <selectors/traffic_selector.h>

#include <crypto/proposal/proposal.h>

#define CHECKSUM_LIBRARY IPSEC_LIB_DIR"/libchecksum.so"

#ifndef STRONGSWAN_CONF

#define STRONGSWAN_CONF NULL

#endif

typedef struct private_library_t private_library_t;

/**

 * private data of library

 */

struct private_library_t {

  /**

   * public functions

   */

  library_t public;

  /**

   * Hashtable with registered objects (name => object)

   */

  hashtable_t *objects;

  /**

   * Integrity check failed?

   */

  bool init_failed;

#ifdef LEAK_DETECTIVE

  /**

   * Where to write leak detective output to

   */

  FILE *ld_out;

#endif

  /**

   * Number of times we have been initialized

   */

  refcount_t ref;

};

#define MAX_NAMESPACES 5

/**

 * Additional namespaces registered using __attribute__((constructor))

 */

static char *namespaces[MAX_NAMESPACES];

static int ns_count;

/**

 * Described in header

 */

void library_add_namespace(char *ns)

{

  if (ns_count < MAX_NAMESPACES - 1)

  {

    namespaces[ns_count] = ns;

    ns_count++;

  }

  else

  {

    fprintf(stderr, "failed to register additional namespace alias, please "

        "increase MAX_NAMESPACES");

  }

}

/**

 * Register plugins if built statically

 */

#ifdef STATIC_PLUGIN_CONSTRUCTORS

#include "plugin_constructors.c"

#endif

/**

 * library instance

 */

library_t *lib = NULL;

#ifdef LEAK_DETECTIVE

/**

 * Default leak report callback

 */

CALLBACK(report_leaks, void,

  private_library_t *this, int count, size_t bytes, backtrace_t *bt,

  bool detailed)

{

  fprintf(this->ld_out, "%zu bytes total, %d allocations, %zu bytes average:\n",

      bytes, count, bytes / count);

  bt->log(bt, this->ld_out, detailed);

}

/**

 * Default leak report summary callback

 */

CALLBACK(sum_leaks, void,

  private_library_t *this, int count, size_t bytes, int whitelisted)

{

  switch (count)

  {

    case 0:

      fprintf(this->ld_out, "No leaks detected");

      break;

    case 1:

      fprintf(this->ld_out, "One leak detected");

      break;

    default:

      fprintf(this->ld_out, "%d leaks detected, %zu bytes", count, bytes);

      break;

  }

  fprintf(this->ld_out, ", %d suppressed by whitelist\n", whitelisted);

}

#endif /* LEAK_DETECTIVE */

/**

 * Deinitialize library

 */

void library_deinit()

{

  private_library_t *this = (private_library_t*)lib;

  bool detailed;

  if (!this || !ref_put(&this->ref))

  { /* have more users */

    return;

  }

  detailed = lib->settings->get_bool(lib->settings,

                "%s.leak_detective.detailed", TRUE, lib->ns);

  /* make sure the cache is clear before unloading plugins */

  lib->credmgr->flush_cache(lib->credmgr, CERT_ANY);

  this->public.streams->destroy(this->public.streams);

  this->public.watcher->destroy(this->public.watcher);

  this->public.scheduler->destroy(this->public.scheduler);

  this->public.processor->destroy(this->public.processor);

  this->public.plugins->destroy(this->public.plugins);

  this->public.hosts->destroy(this->public.hosts);

  this->public.settings->destroy(this->public.settings);

  this->public.credmgr->destroy(this->public.credmgr);

  this->public.creds->destroy(this->public.creds);

  this->public.encoding->destroy(this->public.encoding);

  this->public.ocsp->destroy(this->public.ocsp);

  this->public.metadata->destroy(this->public.metadata);

  this->public.crypto->destroy(this->public.crypto);

  this->public.caps->destroy(this->public.caps);

  this->public.proposal->destroy(this->public.proposal);

  this->public.fetcher->destroy(this->public.fetcher);

  this->public.resolver->destroy(this->public.resolver);

  this->public.db->destroy(this->public.db);

  this->public.printf_hook->destroy(this->public.printf_hook);

  this->objects->destroy(this->objects);

  if (this->public.integrity)

  {

    this->public.integrity->destroy(this->public.integrity);

  }

  if (lib->leak_detective)

  {

    lib->leak_detective->report(lib->leak_detective, detailed);

    lib->leak_detective->destroy(lib->leak_detective);

    lib->leak_detective = NULL;

  }

#ifdef LEAK_DETECTIVE

  if (this->ld_out && this->ld_out != stderr)

  {

    fclose(this->ld_out);

  }

#endif /* LEAK_DETECTIVE */

  backtrace_deinit();

  arrays_deinit();

  utils_deinit();

  threads_deinit();

  free(this->public.conf);

  free((void*)this->public.ns);

  free(this);

  lib = NULL;

}

METHOD(library_t, get, void*,

  private_library_t *this, char *name)

{

  return this->objects->get(this->objects, name);

}

METHOD(library_t, set, bool,

  private_library_t *this, char *name, void *object)

{

  if (object)

  {

    if (this->objects->get(this->objects, name))

    {

      return FALSE;

    }

    this->objects->put(this->objects, name, object);

    return TRUE;

  }

  return this->objects->remove(this->objects, name) != NULL;

}

/**

 * Hashtable hash function

 */

static u_int hash(char *key)

{

  return chunk_hash(chunk_create(key, strlen(key)));

}

/**

 * Hashtable equals function

 */

static bool equals(char *a, char *b)

{

  return streq(a, b);

}

/**

 * Number of words we write and memwipe() in memwipe check

 */

#define MEMWIPE_WIPE_WORDS 16

#ifndef NO_CHECK_MEMWIPE

/**

 * Write magic to memory, and try to clear it with memwipe()

 */

__attribute__((noinline))

static void do_magic(int *magic, int **out)

{

  int buf[MEMWIPE_WIPE_WORDS], i;

  *out = buf;

  for (i = 0; i < countof(buf); i++)

  {

    buf[i] = *magic;

  }

  /* passing buf to dbg should make sure the compiler can't optimize out buf.

   * we use directly dbg(3), as DBG3() might be stripped with DEBUG_LEVEL. */

  dbg(DBG_LIB, 3, "memwipe() pre: %b", buf, sizeof(buf));

  memwipe(buf, sizeof(buf));

}

/**

 * Check if memwipe works as expected

 */

static bool check_memwipe()

{

  int magic = 0xCAFEBABE, *buf, i;

  do_magic(&magic, &buf);

  for (i = 0; i < MEMWIPE_WIPE_WORDS; i++)

  {

    if (buf[i] == magic)

    {

      DBG1(DBG_LIB, "memwipe() check failed: stackdir: %b",

         buf, MEMWIPE_WIPE_WORDS * sizeof(int));

      return FALSE;

    }

  }

  return TRUE;

}

#endif

/*

 * see header file

 */

bool library_init(char *settings, const char *namespace)

{

  private_library_t *this;

  printf_hook_t *pfh;

  int i;

  if (lib)

  { /* already initialized, increase refcount */

    this = (private_library_t*)lib;

    ref_get(&this->ref);

    return !this->init_failed;

  }

  chunk_hash_seed();

  INIT(this,

    .public = {

      .get = _get,

      .set = _set,

      .ns = strdup(namespace ?: "libstrongswan"),

      .conf = strdupnull(settings ?: (getenv("STRONGSWAN_CONF") ?: STRONGSWAN_CONF)),

    },

    .ref = 1,

  );

  lib = &this->public;

  threads_init();

  utils_init();

  arrays_init();

  backtrace_init();

#ifdef LEAK_DETECTIVE

  {

    FILE *out = NULL;

    char *log;

    log = getenv("LEAK_DETECTIVE_LOG");

    if (log)

    {

      out = fopen(log, "a");

    }

    this->ld_out = out ?: stderr;

  }

  lib->leak_detective = leak_detective_create();

  if (lib->leak_detective)

  {

    lib->leak_detective->set_report_cb(lib->leak_detective,

                       report_leaks, sum_leaks, this);

  }

#endif /* LEAK_DETECTIVE */

  pfh = printf_hook_create();

  this->public.printf_hook = pfh;

  pfh->add_handler(pfh, 'b', mem_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_INT,

           PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'B', chunk_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'H', host_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'N', enum_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_INT,

           PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'T', time_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_INT,

           PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'V', time_delta_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_POINTER,

           PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'Y', identification_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'R', traffic_selector_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);

  pfh->add_handler(pfh, 'P', proposal_printf_hook,

           PRINTF_HOOK_ARGTYPE_POINTER, PRINTF_HOOK_ARGTYPE_END);

  this->objects = hashtable_create((hashtable_hash_t)hash,

                   (hashtable_equals_t)equals, 4);

  this->public.settings = settings_create(NULL);

  if (!this->public.settings->load_files(this->public.settings,

                       this->public.conf, FALSE))

  {

    DBG1(DBG_LIB, "abort initialization due to invalid configuration");

    this->init_failed = TRUE;

  }

  /* add registered aliases */

  for (i = 0; i < ns_count; ++i)

  {

    lib->settings->add_fallback(lib->settings, lib->ns, namespaces[i]);

  }

  /* all namespace settings may fall back to libstrongswan */

  lib->settings->add_fallback(lib->settings, lib->ns, "libstrongswan");

  this->public.hosts = host_resolver_create();

  this->public.proposal = proposal_keywords_create();

  this->public.caps = capabilities_create();

  this->public.crypto = crypto_factory_create();

  this->public.creds = credential_factory_create();

  this->public.credmgr = credential_manager_create();

  this->public.encoding = cred_encoding_create();

  this->public.ocsp = ocsp_responders_create();

  this->public.metadata = metadata_factory_create();

  this->public.fetcher = fetcher_manager_create();

  this->public.resolver = resolver_manager_create();

  this->public.db = database_factory_create();

  this->public.processor = processor_create();

  this->public.scheduler = scheduler_create();

  this->public.watcher = watcher_create();

  this->public.streams = stream_manager_create();

  this->public.plugins = plugin_loader_create();

#ifndef NO_CHECK_MEMWIPE

  if (!check_memwipe())

  {

    return FALSE;

  }

#endif

  if (lib->settings->get_bool(lib->settings,

                "%s.integrity_test", FALSE, lib->ns))

  {

#ifdef INTEGRITY_TEST

    this->public.integrity = integrity_checker_create(CHECKSUM_LIBRARY);

    if (!lib->integrity->check(lib->integrity, "libstrongswan", library_init))

    {

      DBG1(DBG_LIB, "integrity check of libstrongswan failed");

      this->init_failed = TRUE;

    }

#else /* !INTEGRITY_TEST */

    DBG1(DBG_LIB, "integrity test enabled, but not supported");

    this->init_failed = TRUE;

#endif /* INTEGRITY_TEST */

  }

  diffie_hellman_init();

  return !this->init_failed;

}