[linux-block.git] / net / sctp / stream_sched.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* 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.
 *
 * 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_sid(struct sctp_stream *stream, __u16 sid)
{
}

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_sid = sctp_sched_fcfs_free_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++) {
			struct sctp_stream_out_ext *ext = SCTP_SO(&asoc->stream, i)->ext;

			if (!ext)
				continue;
			memset_after(ext, 0, outq);
		}
	}

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

		ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC);
		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 (!SCTP_SO(&asoc->stream, 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 (!SCTP_SO(&asoc->stream, 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->peer.intl_capable) {
		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 = SCTP_SO(&q->asoc->stream, 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);
	struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext;

	INIT_LIST_HEAD(&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;
}
Commit	Line	Data
47505b8b	1	// SPDX-License-Identifier: GPL-2.0-or-later
5bbbbe32 MRL	2	/* SCTP kernel implementation
	3	* (C) Copyright Red Hat Inc. 2017
	4	*
	5	* This file is part of the SCTP kernel implementation
	6	*
	7	* These functions manipulate sctp stream queue/scheduling.
	8	*
5bbbbe32 MRL	9	* Please send any bug reports or fixes you make to the
	10	* email addresched(es):
	11	* lksctp developers <linux-sctp@vger.kernel.org>
	12	*
	13	* Written or modified by:
	14	* Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
	15	*/
	16
	17	#include <linux/list.h>
	18	#include <net/sctp/sctp.h>
	19	#include <net/sctp/sm.h>
	20	#include <net/sctp/stream_sched.h>
	21
	22	/* First Come First Serve (a.k.a. FIFO)
	23	* RFC DRAFT ndata Section 3.1
	24	*/
	25	static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid,
	26	__u16 value, gfp_t gfp)
	27	{
	28	return 0;
	29	}
	30
	31	static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid,
	32	__u16 *value)
	33	{
	34	*value = 0;
	35	return 0;
	36	}
	37
	38	static int sctp_sched_fcfs_init(struct sctp_stream *stream)
	39	{
	40	return 0;
	41	}
	42
	43	static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
	44	gfp_t gfp)
	45	{
	46	return 0;
	47	}
	48
9ed7bfc7 ZS	49	static void sctp_sched_fcfs_free_sid(struct sctp_stream *stream, __u16 sid)
	50	{
	51	}
	52
5bbbbe32 MRL	53	static void sctp_sched_fcfs_free(struct sctp_stream *stream)
	54	{
	55	}
	56
	57	static void sctp_sched_fcfs_enqueue(struct sctp_outq *q,
	58	struct sctp_datamsg *msg)
	59	{
	60	}
	61
	62	static struct sctp_chunk sctp_sched_fcfs_dequeue(struct sctp_outq q)
	63	{
	64	struct sctp_stream *stream = &q->asoc->stream;
	65	struct sctp_chunk *ch = NULL;
	66	struct list_head *entry;
	67
	68	if (list_empty(&q->out_chunk_list))
	69	goto out;
	70
	71	if (stream->out_curr) {
	72	ch = list_entry(stream->out_curr->ext->outq.next,
	73	struct sctp_chunk, stream_list);
	74	} else {
	75	entry = q->out_chunk_list.next;
	76	ch = list_entry(entry, struct sctp_chunk, list);
	77	}
	78
	79	sctp_sched_dequeue_common(q, ch);
	80
	81	out:
	82	return ch;
	83	}
	84
	85	static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q,
	86	struct sctp_chunk *chunk)
	87	{
	88	}
	89
	90	static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream)
	91	{
	92	}
	93
	94	static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream)
	95	{
	96	}
	97
	98	static struct sctp_sched_ops sctp_sched_fcfs = {
	99	.set = sctp_sched_fcfs_set,
	100	.get = sctp_sched_fcfs_get,
	101	.init = sctp_sched_fcfs_init,
	102	.init_sid = sctp_sched_fcfs_init_sid,
9ed7bfc7	103	.free_sid = sctp_sched_fcfs_free_sid,
5bbbbe32 MRL	104	.free = sctp_sched_fcfs_free,
	105	.enqueue = sctp_sched_fcfs_enqueue,
	106	.dequeue = sctp_sched_fcfs_dequeue,
	107	.dequeue_done = sctp_sched_fcfs_dequeue_done,
	108	.sched_all = sctp_sched_fcfs_sched_all,
	109	.unsched_all = sctp_sched_fcfs_unsched_all,
	110	};
	111
1ba896f6 XL	112	static void sctp_sched_ops_fcfs_init(void)
	113	{
	114	sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
	115	}
	116
5bbbbe32 MRL	117	/* API to other parts of the stack */
5bbbbe32 MRL	118
1ba896f6	119	static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];
637784ad	120
1ba896f6 XL	121	void sctp_sched_ops_register(enum sctp_sched_type sched,
	122	struct sctp_sched_ops *sched_ops)
	123	{
	124	sctp_sched_ops[sched] = sched_ops;
	125	}
	126
	127	void sctp_sched_ops_init(void)
	128	{
	129	sctp_sched_ops_fcfs_init();
	130	sctp_sched_ops_prio_init();
	131	sctp_sched_ops_rr_init();
	132	}
5bbbbe32 MRL	133
	134	int sctp_sched_set_sched(struct sctp_association *asoc,
	135	enum sctp_sched_type sched)
	136	{
	137	struct sctp_sched_ops *n = sctp_sched_ops[sched];
	138	struct sctp_sched_ops *old = asoc->outqueue.sched;
	139	struct sctp_datamsg *msg = NULL;
	140	struct sctp_chunk *ch;
	141	int i, ret = 0;
	142
	143	if (old == n)
	144	return ret;
	145
	146	if (sched > SCTP_SS_MAX)
	147	return -EINVAL;
	148
	149	if (old) {
	150	old->free(&asoc->stream);
	151
	152	/* Give the next scheduler a clean slate. */
	153	for (i = 0; i < asoc->stream.outcnt; i++) {
29849a48	154	struct sctp_stream_out_ext *ext = SCTP_SO(&asoc->stream, i)->ext;
5bbbbe32	155
29849a48	156	if (!ext)
5bbbbe32	157	continue;
29849a48	158	memset_after(ext, 0, outq);
5bbbbe32 MRL	159	}
	160	}
	161
	162	asoc->outqueue.sched = n;
	163	n->init(&asoc->stream);
	164	for (i = 0; i < asoc->stream.outcnt; i++) {
05364ca0	165	if (!SCTP_SO(&asoc->stream, i)->ext)
5bbbbe32 MRL	166	continue;
5bbbbe32 MRL	167
b89fc26f	168	ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC);
5bbbbe32 MRL	169	if (ret)
	170	goto err;
	171	}
	172
	173	/* We have to requeue all chunks already queued. */
	174	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
	175	if (ch->msg == msg)
	176	continue;
	177	msg = ch->msg;
	178	n->enqueue(&asoc->outqueue, msg);
	179	}
	180
	181	return ret;
	182
	183	err:
	184	n->free(&asoc->stream);
	185	asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */
	186
	187	return ret;
	188	}
	189
	190	int sctp_sched_get_sched(struct sctp_association *asoc)
	191	{
	192	int i;
	193
	194	for (i = 0; i <= SCTP_SS_MAX; i++)
	195	if (asoc->outqueue.sched == sctp_sched_ops[i])
	196	return i;
	197
	198	return 0;
	199	}
	200
	201	int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
	202	__u16 value, gfp_t gfp)
	203	{
	204	if (sid >= asoc->stream.outcnt)
	205	return -EINVAL;
	206
05364ca0	207	if (!SCTP_SO(&asoc->stream, sid)->ext) {
5bbbbe32 MRL	208	int ret;
	209
	210	ret = sctp_stream_init_ext(&asoc->stream, sid);
	211	if (ret)
	212	return ret;
	213	}
	214
	215	return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp);
	216	}
	217
	218	int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
	219	__u16 *value)
	220	{
	221	if (sid >= asoc->stream.outcnt)
	222	return -EINVAL;
	223
05364ca0	224	if (!SCTP_SO(&asoc->stream, sid)->ext)
5bbbbe32 MRL	225	return 0;
	226
	227	return asoc->outqueue.sched->get(&asoc->stream, sid, value);
	228	}
	229
	230	void sctp_sched_dequeue_done(struct sctp_outq q, struct sctp_chunk ch)
	231	{
ef4775e3	232	if (!list_is_last(&ch->frag_list, &ch->msg->chunks) &&
da1f6d4d	233	!q->asoc->peer.intl_capable) {
5bbbbe32 MRL	234	struct sctp_stream_out *sout;
	235	__u16 sid;
	236
	237	/* datamsg is not finish, so save it as current one,
	238	* in case application switch scheduler or a higher
	239	* priority stream comes in.
	240	*/
	241	sid = sctp_chunk_stream_no(ch);
05364ca0	242	sout = SCTP_SO(&q->asoc->stream, sid);
5bbbbe32 MRL	243	q->asoc->stream.out_curr = sout;
	244	return;
	245	}
	246
	247	q->asoc->stream.out_curr = NULL;
	248	q->sched->dequeue_done(q, ch);
	249	}
	250
	251	/* Auxiliary functions for the schedulers */
	252	void sctp_sched_dequeue_common(struct sctp_outq q, struct sctp_chunk ch)
	253	{
	254	list_del_init(&ch->list);
	255	list_del_init(&ch->stream_list);
	256	q->out_qlen -= ch->skb->len;
	257	}
	258
	259	int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
	260	{
	261	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
05364ca0	262	struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext;
5bbbbe32	263
05364ca0	264	INIT_LIST_HEAD(&ext->outq);
5bbbbe32 MRL	265	return sched->init_sid(stream, sid, gfp);
	266	}
	267
	268	struct sctp_sched_ops sctp_sched_ops_from_stream(struct sctp_stream stream)
	269	{
	270	struct sctp_association *asoc;
	271
	272	asoc = container_of(stream, struct sctp_association, stream);
	273
	274	return asoc->outqueue.sched;
	275	}