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sctp_callout.c (6568B)


      1 /*-
      2 * SPDX-License-Identifier: BSD-3-Clause
      3 *
      4 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
      5 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
      6 * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
      7 *
      8 * Redistribution and use in source and binary forms, with or without
      9 * modification, are permitted provided that the following conditions are met:
     10 *
     11 * a) Redistributions of source code must retain the above copyright notice,
     12 *    this list of conditions and the following disclaimer.
     13 *
     14 * b) Redistributions in binary form must reproduce the above copyright
     15 *    notice, this list of conditions and the following disclaimer in
     16 *    the documentation and/or other materials provided with the distribution.
     17 *
     18 * c) Neither the name of Cisco Systems, Inc. nor the names of its
     19 *    contributors may be used to endorse or promote products derived
     20 *    from this software without specific prior written permission.
     21 *
     22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     24 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
     26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
     32 * THE POSSIBILITY OF SUCH DAMAGE.
     33 */
     34 
     35 #if defined(__Userspace__)
     36 #include <sys/types.h>
     37 #if !defined(_WIN32)
     38 #include <sys/wait.h>
     39 #include <unistd.h>
     40 #include <pthread.h>
     41 #endif
     42 #if defined(__native_client__)
     43 #include <sys/select.h>
     44 #endif
     45 #include <stdlib.h>
     46 #include <string.h>
     47 #include <stdio.h>
     48 #include <errno.h>
     49 #include <user_atomic.h>
     50 #include <netinet/sctp_sysctl.h>
     51 #include <netinet/sctp_pcb.h>
     52 #else
     53 #include <netinet/sctp_os.h>
     54 #include <netinet/sctp_callout.h>
     55 #include <netinet/sctp_pcb.h>
     56 #endif
     57 #include <netinet/sctputil.h>
     58 
     59 /*
     60 * Callout/Timer routines for OS that doesn't have them
     61 */
     62 #if defined(__APPLE__) || defined(__Userspace__)
     63 static uint32_t ticks = 0;
     64 #else
     65 extern int ticks;
     66 #endif
     67 
     68 uint32_t sctp_get_tick_count(void) {
     69 uint32_t ret;
     70 
     71 SCTP_TIMERQ_LOCK();
     72 ret = ticks;
     73 SCTP_TIMERQ_UNLOCK();
     74 return ret;
     75 }
     76 
     77 /*
     78 * SCTP_TIMERQ_LOCK protects:
     79 * - SCTP_BASE_INFO(callqueue)
     80 * - sctp_os_timer_next: next timer to check
     81 */
     82 static sctp_os_timer_t *sctp_os_timer_next = NULL;
     83 
     84 void
     85 sctp_os_timer_init(sctp_os_timer_t *c)
     86 {
     87 memset(c, 0, sizeof(*c));
     88 }
     89 
     90 int
     91 sctp_os_timer_start(sctp_os_timer_t *c, uint32_t to_ticks, void (*ftn) (void *),
     92                    void *arg)
     93 {
     94 int ret = 0;
     95 
     96 /* paranoia */
     97 if ((c == NULL) || (ftn == NULL))
     98 	return (ret);
     99 
    100 SCTP_TIMERQ_LOCK();
    101 /* check to see if we're rescheduling a timer */
    102 if (c->c_flags & SCTP_CALLOUT_PENDING) {
    103 	ret = 1;
    104 	if (c == sctp_os_timer_next) {
    105 		sctp_os_timer_next = TAILQ_NEXT(c, tqe);
    106 	}
    107 	TAILQ_REMOVE(&SCTP_BASE_INFO(callqueue), c, tqe);
    108 	/*
    109 	 * part of the normal "stop a pending callout" process
    110 	 * is to clear the CALLOUT_ACTIVE and CALLOUT_PENDING
    111 	 * flags.  We don't bother since we are setting these
    112 	 * below and we still hold the lock.
    113 	 */
    114 }
    115 
    116 /*
    117  * We could unlock/splx here and lock/spl at the TAILQ_INSERT_TAIL,
    118  * but there's no point since doing this setup doesn't take much time.
    119  */
    120 if (to_ticks == 0)
    121 	to_ticks = 1;
    122 
    123 c->c_arg = arg;
    124 c->c_flags = (SCTP_CALLOUT_ACTIVE | SCTP_CALLOUT_PENDING);
    125 c->c_func = ftn;
    126 c->c_time = ticks + to_ticks;
    127 TAILQ_INSERT_TAIL(&SCTP_BASE_INFO(callqueue), c, tqe);
    128 SCTP_TIMERQ_UNLOCK();
    129 return (ret);
    130 }
    131 
    132 int
    133 sctp_os_timer_stop(sctp_os_timer_t *c)
    134 {
    135 SCTP_TIMERQ_LOCK();
    136 /*
    137  * Don't attempt to delete a callout that's not on the queue.
    138  */
    139 if ((c->c_flags & SCTP_CALLOUT_PENDING) == 0) {
    140 	c->c_flags &= ~SCTP_CALLOUT_ACTIVE;
    141 	SCTP_TIMERQ_UNLOCK();
    142 	return (0);
    143 }
    144 c->c_flags &= ~(SCTP_CALLOUT_ACTIVE | SCTP_CALLOUT_PENDING);
    145 if (c == sctp_os_timer_next) {
    146 	sctp_os_timer_next = TAILQ_NEXT(c, tqe);
    147 }
    148 TAILQ_REMOVE(&SCTP_BASE_INFO(callqueue), c, tqe);
    149 SCTP_TIMERQ_UNLOCK();
    150 return (1);
    151 }
    152 
    153 void
    154 sctp_handle_tick(uint32_t elapsed_ticks)
    155 {
    156 sctp_os_timer_t *c;
    157 void (*c_func)(void *);
    158 void *c_arg;
    159 
    160 SCTP_TIMERQ_LOCK();
    161 /* update our tick count */
    162 ticks += elapsed_ticks;
    163 c = TAILQ_FIRST(&SCTP_BASE_INFO(callqueue));
    164 while (c) {
    165 	if (SCTP_UINT32_GE(ticks, c->c_time)) {
    166 		sctp_os_timer_next = TAILQ_NEXT(c, tqe);
    167 		TAILQ_REMOVE(&SCTP_BASE_INFO(callqueue), c, tqe);
    168 		c_func = c->c_func;
    169 		c_arg = c->c_arg;
    170 		c->c_flags &= ~SCTP_CALLOUT_PENDING;
    171 		SCTP_TIMERQ_UNLOCK();
    172 		c_func(c_arg);
    173 		SCTP_TIMERQ_LOCK();
    174 		c = sctp_os_timer_next;
    175 	} else {
    176 		c = TAILQ_NEXT(c, tqe);
    177 	}
    178 }
    179 sctp_os_timer_next = NULL;
    180 SCTP_TIMERQ_UNLOCK();
    181 }
    182 
    183 #if defined(__APPLE__) && !defined(__Userspace__)
    184 void
    185 sctp_timeout(void *arg SCTP_UNUSED)
    186 {
    187 sctp_handle_tick(SCTP_BASE_VAR(sctp_main_timer_ticks));
    188 sctp_start_main_timer();
    189 }
    190 #endif
    191 
    192 #if defined(__Userspace__)
    193 #define TIMEOUT_INTERVAL 10
    194 
    195 void *
    196 user_sctp_timer_iterate(void *arg)
    197 {
    198 sctp_userspace_set_threadname("SCTP timer");
    199 for (;;) {
    200 #if defined(_WIN32)
    201 	Sleep(TIMEOUT_INTERVAL);
    202 #else
    203 	struct timespec amount, remaining;
    204 
    205 	remaining.tv_sec = 0;
    206 	remaining.tv_nsec = TIMEOUT_INTERVAL * 1000 * 1000;
    207 	do {
    208 		amount = remaining;
    209 	} while (nanosleep(&amount, &remaining) == -1);
    210 #endif
    211 	if (atomic_cmpset_int(&SCTP_BASE_VAR(timer_thread_should_exit), 1, 1)) {
    212 		break;
    213 	}
    214 	sctp_handle_tick(sctp_msecs_to_ticks(TIMEOUT_INTERVAL));
    215 }
    216 return (NULL);
    217 }
    218 
    219 void
    220 sctp_start_timer_thread(void)
    221 {
    222 /*
    223  * No need to do SCTP_TIMERQ_LOCK_INIT();
    224  * here, it is being done in sctp_pcb_init()
    225  */
    226 int rc;
    227 
    228 rc = sctp_userspace_thread_create(&SCTP_BASE_VAR(timer_thread), user_sctp_timer_iterate);
    229 if (rc) {
    230 	SCTP_PRINTF("ERROR; return code from sctp_thread_create() is %d\n", rc);
    231 } else {
    232 	SCTP_BASE_VAR(timer_thread_started) = 1;
    233 }
    234 }
    235 
    236 void
    237 sctp_stop_timer_thread(void)
    238 {
    239 atomic_cmpset_int(&SCTP_BASE_VAR(timer_thread_should_exit), 0, 1);
    240 if (SCTP_BASE_VAR(timer_thread_started)) {
    241 #if defined(_WIN32)
    242 	WaitForSingleObject(SCTP_BASE_VAR(timer_thread), INFINITE);
    243 	CloseHandle(SCTP_BASE_VAR(timer_thread));
    244 #else
    245 	pthread_join(SCTP_BASE_VAR(timer_thread), NULL);
    246 #endif
    247 }
    248 }
    249 #endif