net/sctp/stream_sched.c - third_party/linux - Git at Google

 /* SCTP kernel implementation
  * (C) Copyright Red Hat Inc. 2017
  *
  * This file is part of the SCTP kernel implementation
  *
  * These functions manipulate sctp stream queue/scheduling.
  *
  * This SCTP implementation 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, or (at your option)
  * any later version.
  *
  * This SCTP implementation 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.
  *
  * You should have received a copy of the GNU General Public License
  * along with GNU CC; see the file COPYING.  If not, see
  * <http://www.gnu.org/licenses/>.
  *
  * Please send any bug reports or fixes you make to the
  * email addresched(es):
  *    lksctp developers <linux-sctp@vger.kernel.org>
  *
  * Written or modified by:
  *    Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
  */

 #include <linux/list.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
 #include <net/sctp/stream_sched.h>

 /* First Come First Serve (a.k.a. FIFO)
  * RFC DRAFT ndata Section 3.1
  */
 static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid,
 			       __u16 value, gfp_t gfp)
 {
 	return 0;
 }

 static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid,
 			       __u16 *value)
 {
 	*value = 0;
 	return 0;
 }

 static int sctp_sched_fcfs_init(struct sctp_stream *stream)
 {
 	return 0;
 }

 static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
 				    gfp_t gfp)
 {
 	return 0;
 }

 static void sctp_sched_fcfs_free(struct sctp_stream *stream)
 {
 }

 static void sctp_sched_fcfs_enqueue(struct sctp_outq *q,
 				    struct sctp_datamsg *msg)
 {
 }

 static struct sctp_chunk *sctp_sched_fcfs_dequeue(struct sctp_outq *q)
 {
 	struct sctp_stream *stream = &q->asoc->stream;
 	struct sctp_chunk *ch = NULL;
 	struct list_head *entry;

 	if (list_empty(&q->out_chunk_list))
 		goto out;

 	if (stream->out_curr) {
 		ch = list_entry(stream->out_curr->ext->outq.next,
 				struct sctp_chunk, stream_list);
 	} else {
 		entry = q->out_chunk_list.next;
 		ch = list_entry(entry, struct sctp_chunk, list);
 	}

 	sctp_sched_dequeue_common(q, ch);

 out:
 	return ch;
 }

 static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q,
 					 struct sctp_chunk *chunk)
 {
 }

 static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream)
 {
 }

 static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream)
 {
 }

 static struct sctp_sched_ops sctp_sched_fcfs = {
 	.set = sctp_sched_fcfs_set,
 	.get = sctp_sched_fcfs_get,
 	.init = sctp_sched_fcfs_init,
 	.init_sid = sctp_sched_fcfs_init_sid,
 	.free = sctp_sched_fcfs_free,
 	.enqueue = sctp_sched_fcfs_enqueue,
 	.dequeue = sctp_sched_fcfs_dequeue,
 	.dequeue_done = sctp_sched_fcfs_dequeue_done,
 	.sched_all = sctp_sched_fcfs_sched_all,
 	.unsched_all = sctp_sched_fcfs_unsched_all,
 };

 static void sctp_sched_ops_fcfs_init(void)
 {
 	sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
 }

 /* API to other parts of the stack */

 static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];

 void sctp_sched_ops_register(enum sctp_sched_type sched,
 			     struct sctp_sched_ops *sched_ops)
 {
 	sctp_sched_ops[sched] = sched_ops;
 }

 void sctp_sched_ops_init(void)
 {
 	sctp_sched_ops_fcfs_init();
 	sctp_sched_ops_prio_init();
 	sctp_sched_ops_rr_init();
 }

 int sctp_sched_set_sched(struct sctp_association *asoc,
 			 enum sctp_sched_type sched)
 {
 	struct sctp_sched_ops *n = sctp_sched_ops[sched];
 	struct sctp_sched_ops *old = asoc->outqueue.sched;
 	struct sctp_datamsg *msg = NULL;
 	struct sctp_chunk *ch;
 	int i, ret = 0;

 	if (old == n)
 		return ret;

 	if (sched > SCTP_SS_MAX)
 		return -EINVAL;

 	if (old) {
 		old->free(&asoc->stream);

 		/* Give the next scheduler a clean slate. */
 		for (i = 0; i < asoc->stream.outcnt; i++) {
 			void *p = asoc->stream.out[i].ext;

 			if (!p)
 				continue;

 			p += offsetofend(struct sctp_stream_out_ext, outq);
 			memset(p, 0, sizeof(struct sctp_stream_out_ext) -
 				     offsetofend(struct sctp_stream_out_ext, outq));
 		}
 	}

 	asoc->outqueue.sched = n;
 	n->init(&asoc->stream);
 	for (i = 0; i < asoc->stream.outcnt; i++) {
 		if (!asoc->stream.out[i].ext)
 			continue;

 		ret = n->init_sid(&asoc->stream, i, GFP_KERNEL);
 		if (ret)
 			goto err;
 	}

 	/* We have to requeue all chunks already queued. */
 	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
 		if (ch->msg == msg)
 			continue;
 		msg = ch->msg;
 		n->enqueue(&asoc->outqueue, msg);
 	}

 	return ret;

 err:
 	n->free(&asoc->stream);
 	asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */

 	return ret;
 }

 int sctp_sched_get_sched(struct sctp_association *asoc)
 {
 	int i;

 	for (i = 0; i <= SCTP_SS_MAX; i++)
 		if (asoc->outqueue.sched == sctp_sched_ops[i])
 			return i;

 	return 0;
 }

 int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
 			 __u16 value, gfp_t gfp)
 {
 	if (sid >= asoc->stream.outcnt)
 		return -EINVAL;

 	if (!asoc->stream.out[sid].ext) {
 		int ret;

 		ret = sctp_stream_init_ext(&asoc->stream, sid);
 		if (ret)
 			return ret;
 	}

 	return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp);
 }

 int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
 			 __u16 *value)
 {
 	if (sid >= asoc->stream.outcnt)
 		return -EINVAL;

 	if (!asoc->stream.out[sid].ext)
 		return 0;

 	return asoc->outqueue.sched->get(&asoc->stream, sid, value);
 }

 void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch)
 {
 	if (!list_is_last(&ch->frag_list, &ch->msg->chunks) &&
 	    !q->asoc->intl_enable) {
 		struct sctp_stream_out *sout;
 		__u16 sid;

 		/* datamsg is not finish, so save it as current one,
 		 * in case application switch scheduler or a higher
 		 * priority stream comes in.
 		 */
 		sid = sctp_chunk_stream_no(ch);
 		sout = &q->asoc->stream.out[sid];
 		q->asoc->stream.out_curr = sout;
 		return;
 	}

 	q->asoc->stream.out_curr = NULL;
 	q->sched->dequeue_done(q, ch);
 }

 /* Auxiliary functions for the schedulers */
 void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch)
 {
 	list_del_init(&ch->list);
 	list_del_init(&ch->stream_list);
 	q->out_qlen -= ch->skb->len;
 }

 int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
 {
 	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);

 	INIT_LIST_HEAD(&stream->out[sid].ext->outq);
 	return sched->init_sid(stream, sid, gfp);
 }

 struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream)
 {
 	struct sctp_association *asoc;

 	asoc = container_of(stream, struct sctp_association, stream);

 	return asoc->outqueue.sched;
 }
	/* SCTP kernel implementation
	* (C) Copyright Red Hat Inc. 2017
	*
	* This file is part of the SCTP kernel implementation
	*
	* These functions manipulate sctp stream queue/scheduling.
	*
	* This SCTP implementation 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, or (at your option)
	* any later version.
	*
	* This SCTP implementation 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.
	*
	* You should have received a copy of the GNU General Public License
	* along with GNU CC; see the file COPYING. If not, see
	* <http://www.gnu.org/licenses/>.
	*
	* Please send any bug reports or fixes you make to the
	* email addresched(es):
	* lksctp developers <linux-sctp@vger.kernel.org>
	*
	* Written or modified by:
	* Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
	*/

	#include <linux/list.h>
	#include <net/sctp/sctp.h>
	#include <net/sctp/sm.h>
	#include <net/sctp/stream_sched.h>

	/* First Come First Serve (a.k.a. FIFO)
	* RFC DRAFT ndata Section 3.1
	*/
	static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid,
	__u16 value, gfp_t gfp)
	{
	return 0;
	}

	static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid,
	__u16 *value)
	{
	*value = 0;
	return 0;
	}

	static int sctp_sched_fcfs_init(struct sctp_stream *stream)
	{
	return 0;
	}

	static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
	gfp_t gfp)
	{
	return 0;
	}

	static void sctp_sched_fcfs_free(struct sctp_stream *stream)
	{
	}

	static void sctp_sched_fcfs_enqueue(struct sctp_outq *q,
	struct sctp_datamsg *msg)
	{
	}

	static struct sctp_chunk sctp_sched_fcfs_dequeue(struct sctp_outq q)
	{
	struct sctp_stream *stream = &q->asoc->stream;
	struct sctp_chunk *ch = NULL;
	struct list_head *entry;

	if (list_empty(&q->out_chunk_list))
	goto out;

	if (stream->out_curr) {
	ch = list_entry(stream->out_curr->ext->outq.next,
	struct sctp_chunk, stream_list);
	} else {
	entry = q->out_chunk_list.next;
	ch = list_entry(entry, struct sctp_chunk, list);
	}

	sctp_sched_dequeue_common(q, ch);

	out:
	return ch;
	}

	static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q,
	struct sctp_chunk *chunk)
	{
	}

	static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream)
	{
	}

	static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream)
	{
	}

	static struct sctp_sched_ops sctp_sched_fcfs = {
	.set = sctp_sched_fcfs_set,
	.get = sctp_sched_fcfs_get,
	.init = sctp_sched_fcfs_init,
	.init_sid = sctp_sched_fcfs_init_sid,
	.free = sctp_sched_fcfs_free,
	.enqueue = sctp_sched_fcfs_enqueue,
	.dequeue = sctp_sched_fcfs_dequeue,
	.dequeue_done = sctp_sched_fcfs_dequeue_done,
	.sched_all = sctp_sched_fcfs_sched_all,
	.unsched_all = sctp_sched_fcfs_unsched_all,
	};

	static void sctp_sched_ops_fcfs_init(void)
	{
	sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
	}

	/* API to other parts of the stack */

	static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];

	void sctp_sched_ops_register(enum sctp_sched_type sched,
	struct sctp_sched_ops *sched_ops)
	{
	sctp_sched_ops[sched] = sched_ops;
	}

	void sctp_sched_ops_init(void)
	{
	sctp_sched_ops_fcfs_init();
	sctp_sched_ops_prio_init();
	sctp_sched_ops_rr_init();
	}

	int sctp_sched_set_sched(struct sctp_association *asoc,
	enum sctp_sched_type sched)
	{
	struct sctp_sched_ops *n = sctp_sched_ops[sched];
	struct sctp_sched_ops *old = asoc->outqueue.sched;
	struct sctp_datamsg *msg = NULL;
	struct sctp_chunk *ch;
	int i, ret = 0;

	if (old == n)
	return ret;

	if (sched > SCTP_SS_MAX)
	return -EINVAL;

	if (old) {
	old->free(&asoc->stream);

	/* Give the next scheduler a clean slate. */
	for (i = 0; i < asoc->stream.outcnt; i++) {
	void *p = asoc->stream.out[i].ext;

	if (!p)
	continue;

	p += offsetofend(struct sctp_stream_out_ext, outq);
	memset(p, 0, sizeof(struct sctp_stream_out_ext) -
	offsetofend(struct sctp_stream_out_ext, outq));
	}
	}

	asoc->outqueue.sched = n;
	n->init(&asoc->stream);
	for (i = 0; i < asoc->stream.outcnt; i++) {
	if (!asoc->stream.out[i].ext)
	continue;

	ret = n->init_sid(&asoc->stream, i, GFP_KERNEL);
	if (ret)
	goto err;
	}

	/* We have to requeue all chunks already queued. */
	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
	if (ch->msg == msg)
	continue;
	msg = ch->msg;
	n->enqueue(&asoc->outqueue, msg);
	}

	return ret;

	err:
	n->free(&asoc->stream);
	asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */

	return ret;
	}

	int sctp_sched_get_sched(struct sctp_association *asoc)
	{
	int i;

	for (i = 0; i <= SCTP_SS_MAX; i++)
	if (asoc->outqueue.sched == sctp_sched_ops[i])
	return i;

	return 0;
	}

	int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
	__u16 value, gfp_t gfp)
	{
	if (sid >= asoc->stream.outcnt)
	return -EINVAL;

	if (!asoc->stream.out[sid].ext) {
	int ret;

	ret = sctp_stream_init_ext(&asoc->stream, sid);
	if (ret)
	return ret;
	}

	return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp);
	}

	int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
	__u16 *value)
	{
	if (sid >= asoc->stream.outcnt)
	return -EINVAL;

	if (!asoc->stream.out[sid].ext)
	return 0;

	return asoc->outqueue.sched->get(&asoc->stream, sid, value);
	}

	void sctp_sched_dequeue_done(struct sctp_outq q, struct sctp_chunk ch)
	{
	if (!list_is_last(&ch->frag_list, &ch->msg->chunks) &&
	!q->asoc->intl_enable) {
	struct sctp_stream_out *sout;
	__u16 sid;

	/* datamsg is not finish, so save it as current one,
	* in case application switch scheduler or a higher
	* priority stream comes in.
	*/
	sid = sctp_chunk_stream_no(ch);
	sout = &q->asoc->stream.out[sid];
	q->asoc->stream.out_curr = sout;
	return;
	}

	q->asoc->stream.out_curr = NULL;
	q->sched->dequeue_done(q, ch);
	}

	/* Auxiliary functions for the schedulers */
	void sctp_sched_dequeue_common(struct sctp_outq q, struct sctp_chunk ch)
	{
	list_del_init(&ch->list);
	list_del_init(&ch->stream_list);
	q->out_qlen -= ch->skb->len;
	}

	int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
	{
	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);

	INIT_LIST_HEAD(&stream->out[sid].ext->outq);
	return sched->init_sid(stream, sid, gfp);
	}

	struct sctp_sched_ops sctp_sched_ops_from_stream(struct sctp_stream stream)
	{
	struct sctp_association *asoc;

	asoc = container_of(stream, struct sctp_association, stream);

	return asoc->outqueue.sched;
	}