gstreamer/ext/sctp/usrsctp/usrsctplib/netinet/sctp_callout.c
Tim-Philipp Müller f4538e24b6 sctp: import internal copy of usrsctp library
There are problems with global shared state and no API stability
guarantees, and we can't rely on distros shipping the fixes we
need. Both firefox and Chrome bundle their own copies too.

Imported from https://github.com/sctplab/usrsctp,
commit 547d3b46c64876c0336b9eef297fda58dbe1adaf
Date: Thu Jul 23 21:49:32 2020 +0200

Fixes https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/issues/870

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1465>
2020-08-14 01:32:45 +01:00

249 lines
6.4 KiB
C

/*-
* 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)) {
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