/***************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

 * copies of the Software, and permit persons to whom the Software is

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

 ***************************************************************************/

#include "curl_setup.h"

#include "urldata.h"

#include "multiif.h"

#include "curl_threads.h"

#include "curl_share.h"

#include "vtls/vtls.h"

#include "vtls/vtls_scache.h"

#include "hsts.h"

#include "url.h"

static void share_destroy(struct Curl_share *share)

{

  if(!share)

    return;

  if(share->specifier & (1 << CURL_LOCK_DATA_CONNECT)) {

    Curl_cpool_destroy(&share->cpool);

  }

  Curl_dnscache_destroy(&share->dnscache);

#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)

  Curl_cookie_cleanup(share->cookies);

#endif

#ifndef CURL_DISABLE_HSTS

  Curl_hsts_cleanup(&share->hsts);

#endif

#ifdef USE_SSL

  if(share->ssl_scache) {

    Curl_ssl_scache_destroy(share->ssl_scache);

    share->ssl_scache = NULL;

  }

#endif

  Curl_psl_destroy(&share->psl);

  Curl_close(&share->admin);

#ifdef USE_MUTEX

  Curl_mutex_destroy(&share->lock);

#endif

  curlx_memzero(share, sizeof(*share));

  curlx_free(share);

}

CURLSH *curl_share_init(void)

{

  struct Curl_share *share = curlx_calloc(1, sizeof(struct Curl_share));

  if(share) {

    share->magic = CURL_GOOD_SHARE;

    share->specifier |= (1 << CURL_LOCK_DATA_SHARE);

#ifdef USE_MUTEX

    Curl_mutex_init(&share->lock);

#endif

    share->ref_count = 1;

    Curl_dnscache_init(&share->dnscache, 23);

    share->admin = curl_easy_init();

    if(!share->admin) {

      share_destroy(share);

      return NULL;

    }

    /* admin handles have mid 0 */

    share->admin->mid = 0;

    share->admin->state.internal = TRUE;

#ifdef DEBUGBUILD

    if(getenv("CURL_DEBUG"))

      share->admin->set.verbose = TRUE;

#endif

  }

  return share;

}

static uint32_t share_ref_inc(struct Curl_share *share)

{

  uint32_t n;

#ifdef USE_MUTEX

  Curl_mutex_acquire(&share->lock);

  n = ++(share->ref_count);

  share->has_been_shared = TRUE;

  Curl_mutex_release(&share->lock);

#else

  n = ++(share->ref_count);

  share->has_been_shared = TRUE;

#endif

  return n;

}

static uint32_t share_ref_dec(struct Curl_share *share)

{

  uint32_t n;

#ifdef USE_MUTEX

  Curl_mutex_acquire(&share->lock);

  DEBUGASSERT(share->ref_count);

  n = --(share->ref_count);

  Curl_mutex_release(&share->lock);

#else

  n = --(share->ref_count);

#endif

  return n;

}

static bool share_has_been_shared(struct Curl_share *share)

{

  bool was_shared;

#ifdef USE_MUTEX

  Curl_mutex_acquire(&share->lock);

  was_shared = share->has_been_shared;

  Curl_mutex_release(&share->lock);

#else

  was_shared = share->has_been_shared;

#endif

  return was_shared;

}

static bool share_lock_acquire(struct Curl_share *share,

                               struct Curl_easy *data)

{

  if(share->lockfunc && share->unlockfunc &&

     (data || share_has_been_shared(share))) {

    share->lockfunc(data, CURL_LOCK_DATA_SHARE, CURL_LOCK_ACCESS_SINGLE,

                    share->clientdata);

    return TRUE;

  }

  return FALSE;

}

static void share_lock_release(struct Curl_share *share,

                               struct Curl_easy *data,

                               bool locked)

{

  if(locked) {

    DEBUGASSERT(share->unlockfunc);

    if(share->unlockfunc)

      share->unlockfunc(data, CURL_LOCK_DATA_SHARE, share->clientdata);

  }

}

static bool share_in_use(struct Curl_share *share)

{

  bool in_use;

#ifdef USE_MUTEX

  Curl_mutex_acquire(&share->lock);

  in_use = (share->ref_count > 1);

  Curl_mutex_release(&share->lock);

#else

  bool locked = share_lock_acquire(share, NULL);

  in_use = (share->ref_count > 1);

  share_lock_release(share, NULL, locked);

#endif

  return in_use;

}

static void share_unlink(struct Curl_share **pshare,

                         struct Curl_easy *data,

                         bool locked)

{

  struct Curl_share *share = *pshare;

  uint32_t n;

  *pshare = NULL;

  n = share_ref_dec(share);

  if(locked)

    share_lock_release(share, data, locked);

  if(!n)  /* last reference gone */

    share_destroy(share);

}

#undef curl_share_setopt

CURLSHcode curl_share_setopt(CURLSH *sh, CURLSHoption option, ...)

{

  va_list param;

  int type;

  curl_lock_function lockfunc;

  curl_unlock_function unlockfunc;

  void *ptr;

  CURLSHcode res = CURLSHE_OK;

  struct Curl_share *share = sh;

  if(!GOOD_SHARE_HANDLE(share))

    return CURLSHE_INVALID;

  if(share_in_use(share)) {

    /* do not allow setting options while one or more handles are already

       using this share */

    return CURLSHE_IN_USE;

  }

  va_start(param, option);

  switch(option) {

  case CURLSHOPT_SHARE:

    /* this is a type this share will share */

    type = va_arg(param, int);

    switch(type) {

    case CURL_LOCK_DATA_DNS:

      break;

    case CURL_LOCK_DATA_COOKIE:

#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)

      if(!share->cookies) {

        share->cookies = Curl_cookie_init();

        if(!share->cookies)

          res = CURLSHE_NOMEM;

      }

#else /* CURL_DISABLE_HTTP || CURL_DISABLE_COOKIES */

      res = CURLSHE_NOT_BUILT_IN;

#endif

      break;

    case CURL_LOCK_DATA_HSTS:

#ifndef CURL_DISABLE_HSTS

      if(!share->hsts) {

        share->hsts = Curl_hsts_init();

        if(!share->hsts)

          res = CURLSHE_NOMEM;

      }

#else /* CURL_DISABLE_HSTS */

      res = CURLSHE_NOT_BUILT_IN;

#endif

      break;

    case CURL_LOCK_DATA_SSL_SESSION:

#ifdef USE_SSL

      if(!share->ssl_scache) {

        /* There is no way (yet) for the application to configure the

         * session cache size, shared between many transfers. As for curl

         * itself, a high session count will impact startup time. Also, the

         * scache is not optimized for several hundreds of peers.

         * Keep it at a reasonable level. */

        if(Curl_ssl_scache_create(25, 2, &share->ssl_scache))

          res = CURLSHE_NOMEM;

      }

#else

      res = CURLSHE_NOT_BUILT_IN;

#endif

      break;

    case CURL_LOCK_DATA_CONNECT:

      /* It is safe to set this option several times on a share. */

      if(!share->cpool.initialized) {

        Curl_cpool_init(&share->cpool, share->admin, share, 103);

      }

      break;

    case CURL_LOCK_DATA_PSL:

#ifndef USE_LIBPSL

      res = CURLSHE_NOT_BUILT_IN;

#endif

      break;

    default:

      res = CURLSHE_BAD_OPTION;

    }

    if(!res)

      share->specifier |= (unsigned int)(1 << type);

    break;

  case CURLSHOPT_UNSHARE:

    /* this is a type this share will no longer share */

    type = va_arg(param, int);

    switch(type) {

    case CURL_LOCK_DATA_DNS:

      break;

    case CURL_LOCK_DATA_COOKIE:

#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)

      if(share->cookies) {

        Curl_cookie_cleanup(share->cookies);

        share->cookies = NULL;

      }

#else /* CURL_DISABLE_HTTP || CURL_DISABLE_COOKIES */

      res = CURLSHE_NOT_BUILT_IN;

#endif

      break;

    case CURL_LOCK_DATA_HSTS:

#ifndef CURL_DISABLE_HSTS

      if(share->hsts) {

        Curl_hsts_cleanup(&share->hsts);

      }

#else /* CURL_DISABLE_HSTS */

      res = CURLSHE_NOT_BUILT_IN;

#endif

      break;

    case CURL_LOCK_DATA_SSL_SESSION:

#ifdef USE_SSL

      if(share->ssl_scache) {

        Curl_ssl_scache_destroy(share->ssl_scache);

        share->ssl_scache = NULL;

      }

#else

      res = CURLSHE_NOT_BUILT_IN;

#endif

      break;

    case CURL_LOCK_DATA_CONNECT:

      break;

    default:

      res = CURLSHE_BAD_OPTION;

      break;

    }

    if(!res)

      share->specifier &= ~(unsigned int)(1 << type);

    break;

  case CURLSHOPT_LOCKFUNC:

    lockfunc = va_arg(param, curl_lock_function);

    share->lockfunc = lockfunc;

    break;

  case CURLSHOPT_UNLOCKFUNC:

    unlockfunc = va_arg(param, curl_unlock_function);

    share->unlockfunc = unlockfunc;

    break;

  case CURLSHOPT_USERDATA:

    ptr = va_arg(param, void *);

    share->clientdata = ptr;

    break;

  default:

    res = CURLSHE_BAD_OPTION;

    break;

  }

  va_end(param);

  return res;

}

CURLSHcode curl_share_cleanup(CURLSH *sh)

{

  struct Curl_share *share = sh;

  bool locked;

  if(!GOOD_SHARE_HANDLE(share))

    return CURLSHE_INVALID;

  if(share_in_use(share))

    return CURLSHE_IN_USE;

  locked = share_lock_acquire(share, NULL);

  share_unlink(&share, NULL, locked);

  return CURLSHE_OK;

}

CURLSHcode Curl_share_lock(struct Curl_easy *data, curl_lock_data type,

                           curl_lock_access accesstype)

{

  struct Curl_share *share = data->share;

  if(!share)

    return CURLSHE_INVALID;

  if(share->specifier & (unsigned int)(1 << type)) {

    if(share->lockfunc) /* only call this if set! */

      share->lockfunc(data, type, accesstype, share->clientdata);

  }

  /* else if we do not share this, pretend successful lock */

  return CURLSHE_OK;

}

CURLSHcode Curl_share_unlock(struct Curl_easy *data, curl_lock_data type)

{

  struct Curl_share *share = data->share;

  if(!share)

    return CURLSHE_INVALID;

  if(share->specifier & (unsigned int)(1 << type)) {

    if(share->unlockfunc) /* only call this if set! */

      share->unlockfunc(data, type, share->clientdata);

  }

  return CURLSHE_OK;

}

CURLcode Curl_share_easy_unlink(struct Curl_easy *data)

{

  struct Curl_share *share = data->share;

  if(share) {

    bool locked = share_lock_acquire(share, data);

    /* If data has a connection from this share, detach it. */

    if(data->conn && (share->specifier & (1 << CURL_LOCK_DATA_CONNECT)))

      Curl_detach_connection(data);

#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)

    if(share->cookies == data->cookies)

      data->cookies = NULL;

#endif

#ifndef CURL_DISABLE_HSTS

    if(share->hsts == data->hsts)

      data->hsts = NULL;

#endif

#ifdef USE_LIBPSL

    if(&share->psl == data->psl)

      data->psl = data->multi ? &data->multi->psl : NULL;

#endif

    share_unlink(&data->share, data, locked);

  }

  return CURLE_OK;

}

CURLcode Curl_share_easy_link(struct Curl_easy *data,

                              struct Curl_share *share)

{

  if(data->share) {

    DEBUGASSERT(0);

    return CURLE_FAILED_INIT;

  }

  if(share) {

    bool locked = share_lock_acquire(share, data);

    share_ref_inc(share);

    data->share = share;

#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_COOKIES)

    if(share->cookies) {

      /* use shared cookie list, first free own one if any */

      Curl_cookie_cleanup(data->cookies);

      /* enable cookies since we now use a share that uses cookies! */

      data->cookies = share->cookies;

    }

#endif /* CURL_DISABLE_HTTP */

#ifndef CURL_DISABLE_HSTS

    if(share->hsts) {

      /* first free the private one if any */

      Curl_hsts_cleanup(&data->hsts);

      data->hsts = share->hsts;

    }

#endif

#ifdef USE_LIBPSL

    if(share->specifier & (1 << CURL_LOCK_DATA_PSL))

      data->psl = &share->psl;

#endif

    /* check for host cache not needed,

     * it will be done by curl_easy_perform */

    share_lock_release(share, data, locked);

  }

  return CURLE_OK;

}