/*-

 * SPDX-License-Identifier: BSD-3-Clause

 *

 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.

 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.

 * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * a) Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *

 * b) Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the distribution.

 *

 * c) Neither the name of Cisco Systems, Inc. nor the names of its

 *    contributors may be used to endorse or promote products derived

 *    from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

#if defined(__Userspace__)

#include <sys/types.h>

#if !defined(_WIN32)

#include <sys/wait.h>

#include <unistd.h>

#include <pthread.h>

#endif

#if defined(__native_client__)

#include <sys/select.h>

#endif

#include <stdlib.h>

#include <string.h>

#include <stdio.h>

#include <errno.h>

#include <user_atomic.h>

#include <netinet/sctp_sysctl.h>

#include <netinet/sctp_pcb.h>

#else

#include <netinet/sctp_os.h>

#include <netinet/sctp_callout.h>

#include <netinet/sctp_pcb.h>

#endif

#include <netinet/sctputil.h>

/*

 * Callout/Timer routines for OS that doesn't have them

 */

#if defined(__APPLE__) || defined(__Userspace__)

static uint32_t ticks = 0;

#else

extern int ticks;

#endif

uint32_t sctp_get_tick_count(void) {

  uint32_t ret;

  SCTP_TIMERQ_LOCK();

  ret = ticks;

  SCTP_TIMERQ_UNLOCK();

  return ret;

}

/*

 * SCTP_TIMERQ_LOCK protects:

 * - SCTP_BASE_INFO(callqueue)

 * - sctp_os_timer_next: next timer to check

 */

static sctp_os_timer_t *sctp_os_timer_next = NULL;

void

sctp_os_timer_init(sctp_os_timer_t *c)

{

  memset(c, 0, sizeof(*c));

}

int

sctp_os_timer_start(sctp_os_timer_t *c, uint32_t to_ticks, void (*ftn) (void *),

                    void *arg)

{

  int ret = 0;

  /* paranoia */

  if ((c == NULL) || (ftn == NULL))

    return (ret);

  SCTP_TIMERQ_LOCK();

  /* check to see if we're rescheduling a timer */

  if (c->c_flags & SCTP_CALLOUT_PENDING) {

    ret = 1;

    if (c == sctp_os_timer_next) {

      sctp_os_timer_next = TAILQ_NEXT(c, tqe);

    }

    TAILQ_REMOVE(&SCTP_BASE_INFO(callqueue), c, tqe);

    /*

     * part of the normal "stop a pending callout" process

     * is to clear the CALLOUT_ACTIVE and CALLOUT_PENDING

     * flags.  We don't bother since we are setting these

     * below and we still hold the lock.

     */

  }

  /*

   * We could unlock/splx here and lock/spl at the TAILQ_INSERT_TAIL,

   * but there's no point since doing this setup doesn't take much time.

   */

  if (to_ticks == 0)

    to_ticks = 1;

  c->c_arg = arg;

  c->c_flags = (SCTP_CALLOUT_ACTIVE | SCTP_CALLOUT_PENDING);

  c->c_func = ftn;

  c->c_time = ticks + to_ticks;

  TAILQ_INSERT_TAIL(&SCTP_BASE_INFO(callqueue), c, tqe);

  SCTP_TIMERQ_UNLOCK();

  return (ret);

}

int

sctp_os_timer_stop(sctp_os_timer_t *c)

{

  SCTP_TIMERQ_LOCK();

  /*

   * Don't attempt to delete a callout that's not on the queue.

   */

  if ((c->c_flags & SCTP_CALLOUT_PENDING) == 0) {

    c->c_flags &= ~SCTP_CALLOUT_ACTIVE;

    SCTP_TIMERQ_UNLOCK();

    return (0);

  }

  c->c_flags &= ~(SCTP_CALLOUT_ACTIVE | SCTP_CALLOUT_PENDING);

  if (c == sctp_os_timer_next) {

    sctp_os_timer_next = TAILQ_NEXT(c, tqe);

  }

  TAILQ_REMOVE(&SCTP_BASE_INFO(callqueue), c, tqe);

  SCTP_TIMERQ_UNLOCK();

  return (1);

}

void

sctp_handle_tick(uint32_t elapsed_ticks)

{

  sctp_os_timer_t *c;

  void (*c_func)(void *);

  void *c_arg;

  SCTP_TIMERQ_LOCK();

  /* update our tick count */

  ticks += elapsed_ticks;

  c = TAILQ_FIRST(&SCTP_BASE_INFO(callqueue));

  while (c) {

    if (SCTP_UINT32_GE(ticks, c->c_time)) {

      sctp_os_timer_next = TAILQ_NEXT(c, tqe);

      TAILQ_REMOVE(&SCTP_BASE_INFO(callqueue), c, tqe);

      c_func = c->c_func;

      c_arg = c->c_arg;

      c->c_flags &= ~SCTP_CALLOUT_PENDING;

      SCTP_TIMERQ_UNLOCK();

      c_func(c_arg);

      SCTP_TIMERQ_LOCK();

      c = sctp_os_timer_next;

    } else {

      c = TAILQ_NEXT(c, tqe);

    }

  }

  sctp_os_timer_next = NULL;

  SCTP_TIMERQ_UNLOCK();

}

#if defined(__APPLE__) && !defined(__Userspace__)

void

sctp_timeout(void *arg SCTP_UNUSED)

{

  sctp_handle_tick(SCTP_BASE_VAR(sctp_main_timer_ticks));

  sctp_start_main_timer();

}

#endif

#if defined(__Userspace__)

#define TIMEOUT_INTERVAL 10

void *

user_sctp_timer_iterate(void *arg)

{

  sctp_userspace_set_threadname("SCTP timer");

  for (;;) {

#if defined(_WIN32)

    Sleep(TIMEOUT_INTERVAL);

#else

    struct timespec amount, remaining;

    remaining.tv_sec = 0;

    remaining.tv_nsec = TIMEOUT_INTERVAL * 1000 * 1000;

    do {

      amount = remaining;

    } while (nanosleep(&amount, &remaining) == -1);

#endif

    if (atomic_cmpset_int(&SCTP_BASE_VAR(timer_thread_should_exit), 1, 1)) {

      break;

    }

    sctp_handle_tick(sctp_msecs_to_ticks(TIMEOUT_INTERVAL));

  }

  return (NULL);

}

void

sctp_start_timer_thread(void)

{

  /*

   * No need to do SCTP_TIMERQ_LOCK_INIT();

   * here, it is being done in sctp_pcb_init()

   */

  int rc;

  rc = sctp_userspace_thread_create(&SCTP_BASE_VAR(timer_thread), user_sctp_timer_iterate);

  if (rc) {

    SCTP_PRINTF("ERROR; return code from sctp_thread_create() is %d\n", rc);

  } else {

    SCTP_BASE_VAR(timer_thread_started) = 1;

  }

}

void

sctp_stop_timer_thread(void)

{

  atomic_cmpset_int(&SCTP_BASE_VAR(timer_thread_should_exit), 0, 1);

  if (SCTP_BASE_VAR(timer_thread_started)) {

#if defined(_WIN32)

    WaitForSingleObject(SCTP_BASE_VAR(timer_thread), INFINITE);

    CloseHandle(SCTP_BASE_VAR(timer_thread));

#else

    pthread_join(SCTP_BASE_VAR(timer_thread), NULL);

#endif

  }

}

#endif