summaryrefslogtreecommitdiff
path: root/net/sctp/stream_sched.c
blob: 54afbe4fb087200404bdc9b43bd5b5b7088d7b6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
// 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_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,
	.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();
	sctp_sched_ops_fc_init();
	sctp_sched_ops_wfq_init();
}

static void sctp_sched_free_sched(struct sctp_stream *stream)
{
	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
	struct sctp_stream_out_ext *soute;
	int i;

	sched->unsched_all(stream);
	for (i = 0; i < stream->outcnt; i++) {
		soute = SCTP_SO(stream, i)->ext;
		if (!soute)
			continue;
		sched->free_sid(stream, i);
		/* Give the next scheduler a clean slate. */
		memset_after(soute, 0, outq);
	}
}

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

	if (sched > SCTP_SS_MAX)
		return -EINVAL;

	n = sctp_sched_ops[sched];
	if (old == n)
		return ret;

	if (old)
		sctp_sched_free_sched(&asoc->stream);

	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:
	sctp_sched_free_sched(&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;
}