summaryrefslogtreecommitdiff
path: root/net/sctp/stream_sched_rr.c
blob: cc444fe0d67c2df1cbc53e5a6f7bcb036a555d36 (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
// 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>

/* Priority handling
 * RFC DRAFT ndata section 3.2
 */
static void sctp_sched_rr_unsched_all(struct sctp_stream *stream);

static void sctp_sched_rr_next_stream(struct sctp_stream *stream)
{
	struct list_head *pos;

	pos = stream->rr_next->rr_list.next;
	if (pos == &stream->rr_list)
		pos = pos->next;
	stream->rr_next = list_entry(pos, struct sctp_stream_out_ext, rr_list);
}

static void sctp_sched_rr_unsched(struct sctp_stream *stream,
				  struct sctp_stream_out_ext *soute)
{
	if (stream->rr_next == soute)
		/* Try to move to the next stream */
		sctp_sched_rr_next_stream(stream);

	list_del_init(&soute->rr_list);

	/* If we have no other stream queued, clear next */
	if (list_empty(&stream->rr_list))
		stream->rr_next = NULL;
}

static void sctp_sched_rr_sched(struct sctp_stream *stream,
				struct sctp_stream_out_ext *soute)
{
	if (!list_empty(&soute->rr_list))
		/* Already scheduled. */
		return;

	/* Schedule the stream */
	list_add_tail(&soute->rr_list, &stream->rr_list);

	if (!stream->rr_next)
		stream->rr_next = soute;
}

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

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

static int sctp_sched_rr_init(struct sctp_stream *stream)
{
	INIT_LIST_HEAD(&stream->rr_list);
	stream->rr_next = NULL;

	return 0;
}

static int sctp_sched_rr_init_sid(struct sctp_stream *stream, __u16 sid,
				  gfp_t gfp)
{
	INIT_LIST_HEAD(&SCTP_SO(stream, sid)->ext->rr_list);

	return 0;
}

static void sctp_sched_rr_free_sid(struct sctp_stream *stream, __u16 sid)
{
}

static void sctp_sched_rr_free(struct sctp_stream *stream)
{
	sctp_sched_rr_unsched_all(stream);
}

static void sctp_sched_rr_enqueue(struct sctp_outq *q,
				  struct sctp_datamsg *msg)
{
	struct sctp_stream *stream;
	struct sctp_chunk *ch;
	__u16 sid;

	ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list);
	sid = sctp_chunk_stream_no(ch);
	stream = &q->asoc->stream;
	sctp_sched_rr_sched(stream, SCTP_SO(stream, sid)->ext);
}

static struct sctp_chunk *sctp_sched_rr_dequeue(struct sctp_outq *q)
{
	struct sctp_stream *stream = &q->asoc->stream;
	struct sctp_stream_out_ext *soute;
	struct sctp_chunk *ch = NULL;

	/* Bail out quickly if queue is empty */
	if (list_empty(&q->out_chunk_list))
		goto out;

	/* Find which chunk is next */
	if (stream->out_curr)
		soute = stream->out_curr->ext;
	else
		soute = stream->rr_next;
	ch = list_entry(soute->outq.next, struct sctp_chunk, stream_list);

	sctp_sched_dequeue_common(q, ch);

out:
	return ch;
}

static void sctp_sched_rr_dequeue_done(struct sctp_outq *q,
				       struct sctp_chunk *ch)
{
	struct sctp_stream_out_ext *soute;
	__u16 sid;

	/* Last chunk on that msg, move to the next stream */
	sid = sctp_chunk_stream_no(ch);
	soute = SCTP_SO(&q->asoc->stream, sid)->ext;

	sctp_sched_rr_next_stream(&q->asoc->stream);

	if (list_empty(&soute->outq))
		sctp_sched_rr_unsched(&q->asoc->stream, soute);
}

static void sctp_sched_rr_sched_all(struct sctp_stream *stream)
{
	struct sctp_association *asoc;
	struct sctp_stream_out_ext *soute;
	struct sctp_chunk *ch;

	asoc = container_of(stream, struct sctp_association, stream);
	list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) {
		__u16 sid;

		sid = sctp_chunk_stream_no(ch);
		soute = SCTP_SO(stream, sid)->ext;
		if (soute)
			sctp_sched_rr_sched(stream, soute);
	}
}

static void sctp_sched_rr_unsched_all(struct sctp_stream *stream)
{
	struct sctp_stream_out_ext *soute, *tmp;

	list_for_each_entry_safe(soute, tmp, &stream->rr_list, rr_list)
		sctp_sched_rr_unsched(stream, soute);
}

static struct sctp_sched_ops sctp_sched_rr = {
	.set = sctp_sched_rr_set,
	.get = sctp_sched_rr_get,
	.init = sctp_sched_rr_init,
	.init_sid = sctp_sched_rr_init_sid,
	.free_sid = sctp_sched_rr_free_sid,
	.free = sctp_sched_rr_free,
	.enqueue = sctp_sched_rr_enqueue,
	.dequeue = sctp_sched_rr_dequeue,
	.dequeue_done = sctp_sched_rr_dequeue_done,
	.sched_all = sctp_sched_rr_sched_all,
	.unsched_all = sctp_sched_rr_unsched_all,
};

void sctp_sched_ops_rr_init(void)
{
	sctp_sched_ops_register(SCTP_SS_RR, &sctp_sched_rr);
}