[linux-2.6-block.git] / net / sctp / stream_sched.c

/* 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 = SCTP_SO(&asoc->stream, 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 (!SCTP_SO(&asoc->stream, 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 (!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->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 = 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
5bbbbe32 MRL	1	/* SCTP kernel implementation
	2	* (C) Copyright Red Hat Inc. 2017
	3	*
	4	* This file is part of the SCTP kernel implementation
	5	*
	6	* These functions manipulate sctp stream queue/scheduling.
	7	*
	8	* This SCTP implementation is free software;
	9	* you can redistribute it and/or modify it under the terms of
	10	* the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2, or (at your option)
	12	* any later version.
	13	*
	14	* This SCTP implementation is distributed in the hope that it
	15	* will be useful, but WITHOUT ANY WARRANTY; without even the implied
	16	* ************************
	17	* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	18	* See the GNU General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with GNU CC; see the file COPYING. If not, see
	22	* <http://www.gnu.org/licenses/>.
	23	*
	24	* Please send any bug reports or fixes you make to the
	25	* email addresched(es):
	26	* lksctp developers <linux-sctp@vger.kernel.org>
	27	*
	28	* Written or modified by:
	29	* Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
	30	*/
	31
	32	#include <linux/list.h>
	33	#include <net/sctp/sctp.h>
	34	#include <net/sctp/sm.h>
	35	#include <net/sctp/stream_sched.h>
	36
	37	/* First Come First Serve (a.k.a. FIFO)
	38	* RFC DRAFT ndata Section 3.1
	39	*/
	40	static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid,
	41	__u16 value, gfp_t gfp)
	42	{
	43	return 0;
	44	}
	45
	46	static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid,
	47	__u16 *value)
	48	{
	49	*value = 0;
	50	return 0;
	51	}
	52
	53	static int sctp_sched_fcfs_init(struct sctp_stream *stream)
	54	{
	55	return 0;
	56	}
	57
	58	static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid,
	59	gfp_t gfp)
	60	{
	61	return 0;
	62	}
	63
	64	static void sctp_sched_fcfs_free(struct sctp_stream *stream)
65	{
66	}
67
68	static void sctp_sched_fcfs_enqueue(struct sctp_outq *q,
69	struct sctp_datamsg *msg)
70	{
71	}
72
73	static struct sctp_chunk sctp_sched_fcfs_dequeue(struct sctp_outq q)
74	{
75	struct sctp_stream *stream = &q->asoc->stream;
76	struct sctp_chunk *ch = NULL;
77	struct list_head *entry;
78
79	if (list_empty(&q->out_chunk_list))
80	goto out;
81
82	if (stream->out_curr) {
83	ch = list_entry(stream->out_curr->ext->outq.next,
84	struct sctp_chunk, stream_list);
85	} else {
86	entry = q->out_chunk_list.next;
87	ch = list_entry(entry, struct sctp_chunk, list);
88	}
89
90	sctp_sched_dequeue_common(q, ch);
91
92	out:
93	return ch;
94	}
95
96	static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q,
97	struct sctp_chunk *chunk)
98	{
99	}
100
101	static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream)
102	{
103	}
104
105	static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream)
106	{
107	}
108
109	static struct sctp_sched_ops sctp_sched_fcfs = {
110	.set = sctp_sched_fcfs_set,
111	.get = sctp_sched_fcfs_get,
112	.init = sctp_sched_fcfs_init,
113	.init_sid = sctp_sched_fcfs_init_sid,
114	.free = sctp_sched_fcfs_free,
115	.enqueue = sctp_sched_fcfs_enqueue,
116	.dequeue = sctp_sched_fcfs_dequeue,
117	.dequeue_done = sctp_sched_fcfs_dequeue_done,
118	.sched_all = sctp_sched_fcfs_sched_all,
119	.unsched_all = sctp_sched_fcfs_unsched_all,
120	};
121
1ba896f6 XL	122	static void sctp_sched_ops_fcfs_init(void)
	123	{
	124	sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs);
	125	}
	126
5bbbbe32 MRL	127	/* API to other parts of the stack */
5bbbbe32 MRL	128
1ba896f6	129	static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1];
637784ad	130
1ba896f6 XL	131	void sctp_sched_ops_register(enum sctp_sched_type sched,
	132	struct sctp_sched_ops *sched_ops)
	133	{
	134	sctp_sched_ops[sched] = sched_ops;
	135	}
	136
	137	void sctp_sched_ops_init(void)
	138	{
	139	sctp_sched_ops_fcfs_init();
	140	sctp_sched_ops_prio_init();
	141	sctp_sched_ops_rr_init();
	142	}
5bbbbe32 MRL	143
	144	int sctp_sched_set_sched(struct sctp_association *asoc,
	145	enum sctp_sched_type sched)
	146	{
	147	struct sctp_sched_ops *n = sctp_sched_ops[sched];
	148	struct sctp_sched_ops *old = asoc->outqueue.sched;
	149	struct sctp_datamsg *msg = NULL;
	150	struct sctp_chunk *ch;
	151	int i, ret = 0;
	152
	153	if (old == n)
	154	return ret;
	155
	156	if (sched > SCTP_SS_MAX)
	157	return -EINVAL;
	158
	159	if (old) {
	160	old->free(&asoc->stream);
	161
	162	/* Give the next scheduler a clean slate. */
	163	for (i = 0; i < asoc->stream.outcnt; i++) {
05364ca0	164	void *p = SCTP_SO(&asoc->stream, i)->ext;
5bbbbe32 MRL	165
	166	if (!p)
	167	continue;
	168
	169	p += offsetofend(struct sctp_stream_out_ext, outq);
	170	memset(p, 0, sizeof(struct sctp_stream_out_ext) -
	171	offsetofend(struct sctp_stream_out_ext, outq));
	172	}
	173	}
	174
	175	asoc->outqueue.sched = n;
	176	n->init(&asoc->stream);
	177	for (i = 0; i < asoc->stream.outcnt; i++) {
05364ca0	178	if (!SCTP_SO(&asoc->stream, i)->ext)
5bbbbe32 MRL	179	continue;
	180
	181	ret = n->init_sid(&asoc->stream, i, GFP_KERNEL);
	182	if (ret)
	183	goto err;
	184	}
	185
	186	/* We have to requeue all chunks already queued. */
	187	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
	188	if (ch->msg == msg)
	189	continue;
	190	msg = ch->msg;
	191	n->enqueue(&asoc->outqueue, msg);
	192	}
	193
	194	return ret;
	195
	196	err:
	197	n->free(&asoc->stream);
	198	asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */
	199
	200	return ret;
	201	}
	202
	203	int sctp_sched_get_sched(struct sctp_association *asoc)
	204	{
	205	int i;
	206
	207	for (i = 0; i <= SCTP_SS_MAX; i++)
	208	if (asoc->outqueue.sched == sctp_sched_ops[i])
	209	return i;
	210
	211	return 0;
	212	}
	213
	214	int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid,
	215	__u16 value, gfp_t gfp)
	216	{
	217	if (sid >= asoc->stream.outcnt)
	218	return -EINVAL;
	219
05364ca0	220	if (!SCTP_SO(&asoc->stream, sid)->ext) {
5bbbbe32 MRL	221	int ret;
	222
	223	ret = sctp_stream_init_ext(&asoc->stream, sid);
	224	if (ret)
	225	return ret;
	226	}
	227
	228	return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp);
	229	}
	230
	231	int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid,
	232	__u16 *value)
	233	{
	234	if (sid >= asoc->stream.outcnt)
	235	return -EINVAL;
	236
05364ca0	237	if (!SCTP_SO(&asoc->stream, sid)->ext)
5bbbbe32 MRL	238	return 0;
	239
	240	return asoc->outqueue.sched->get(&asoc->stream, sid, value);
	241	}
	242
	243	void sctp_sched_dequeue_done(struct sctp_outq q, struct sctp_chunk ch)
	244	{
ef4775e3 XL	245	if (!list_is_last(&ch->frag_list, &ch->msg->chunks) &&
ef4775e3 XL	246	!q->asoc->intl_enable) {
5bbbbe32 MRL	247	struct sctp_stream_out *sout;
	248	__u16 sid;
	249
	250	/* datamsg is not finish, so save it as current one,
	251	* in case application switch scheduler or a higher
	252	* priority stream comes in.
	253	*/
	254	sid = sctp_chunk_stream_no(ch);
05364ca0	255	sout = SCTP_SO(&q->asoc->stream, sid);
5bbbbe32 MRL	256	q->asoc->stream.out_curr = sout;
	257	return;
	258	}
	259
	260	q->asoc->stream.out_curr = NULL;
	261	q->sched->dequeue_done(q, ch);
	262	}
	263
	264	/* Auxiliary functions for the schedulers */
	265	void sctp_sched_dequeue_common(struct sctp_outq q, struct sctp_chunk ch)
	266	{
	267	list_del_init(&ch->list);
	268	list_del_init(&ch->stream_list);
	269	q->out_qlen -= ch->skb->len;
	270	}
	271
	272	int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp)
	273	{
	274	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
05364ca0	275	struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext;
5bbbbe32	276
05364ca0	277	INIT_LIST_HEAD(&ext->outq);
5bbbbe32 MRL	278	return sched->init_sid(stream, sid, gfp);
	279	}
	280
	281	struct sctp_sched_ops sctp_sched_ops_from_stream(struct sctp_stream stream)
	282	{
	283	struct sctp_association *asoc;
	284
	285	asoc = container_of(stream, struct sctp_association, stream);
	286
	287	return asoc->outqueue.sched;
	288	}