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1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* SCTP kernel implementation | |
3 | * (C) Copyright Red Hat Inc. 2022 | |
4 | * | |
5 | * This file is part of the SCTP kernel implementation | |
6 | * | |
7 | * These functions manipulate sctp stream queue/scheduling. | |
8 | * | |
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 | * Xin Long <lucien.xin@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 | ||
42d452e7 XL |
22 | /* Fair Capacity and Weighted Fair Queueing handling |
23 | * RFC 8260 section 3.5 and 3.6 | |
4821a076 XL |
24 | */ |
25 | static void sctp_sched_fc_unsched_all(struct sctp_stream *stream); | |
26 | ||
42d452e7 XL |
27 | static int sctp_sched_wfq_set(struct sctp_stream *stream, __u16 sid, |
28 | __u16 weight, gfp_t gfp) | |
29 | { | |
30 | struct sctp_stream_out_ext *soute = SCTP_SO(stream, sid)->ext; | |
31 | ||
32 | if (!weight) | |
33 | return -EINVAL; | |
34 | ||
35 | soute->fc_weight = weight; | |
36 | return 0; | |
37 | } | |
38 | ||
39 | static int sctp_sched_wfq_get(struct sctp_stream *stream, __u16 sid, | |
40 | __u16 *value) | |
41 | { | |
42 | struct sctp_stream_out_ext *soute = SCTP_SO(stream, sid)->ext; | |
43 | ||
44 | *value = soute->fc_weight; | |
45 | return 0; | |
46 | } | |
47 | ||
4821a076 XL |
48 | static int sctp_sched_fc_set(struct sctp_stream *stream, __u16 sid, |
49 | __u16 weight, gfp_t gfp) | |
50 | { | |
51 | return 0; | |
52 | } | |
53 | ||
54 | static int sctp_sched_fc_get(struct sctp_stream *stream, __u16 sid, | |
55 | __u16 *value) | |
56 | { | |
57 | return 0; | |
58 | } | |
59 | ||
60 | static int sctp_sched_fc_init(struct sctp_stream *stream) | |
61 | { | |
62 | INIT_LIST_HEAD(&stream->fc_list); | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
67 | static int sctp_sched_fc_init_sid(struct sctp_stream *stream, __u16 sid, | |
68 | gfp_t gfp) | |
69 | { | |
70 | struct sctp_stream_out_ext *soute = SCTP_SO(stream, sid)->ext; | |
71 | ||
72 | INIT_LIST_HEAD(&soute->fc_list); | |
73 | soute->fc_length = 0; | |
42d452e7 | 74 | soute->fc_weight = 1; |
4821a076 XL |
75 | |
76 | return 0; | |
77 | } | |
78 | ||
79 | static void sctp_sched_fc_free_sid(struct sctp_stream *stream, __u16 sid) | |
80 | { | |
81 | } | |
82 | ||
83 | static void sctp_sched_fc_sched(struct sctp_stream *stream, | |
84 | struct sctp_stream_out_ext *soute) | |
85 | { | |
86 | struct sctp_stream_out_ext *pos; | |
87 | ||
88 | if (!list_empty(&soute->fc_list)) | |
89 | return; | |
90 | ||
91 | list_for_each_entry(pos, &stream->fc_list, fc_list) | |
42d452e7 XL |
92 | if ((__u64)pos->fc_length * soute->fc_weight >= |
93 | (__u64)soute->fc_length * pos->fc_weight) | |
4821a076 XL |
94 | break; |
95 | list_add_tail(&soute->fc_list, &pos->fc_list); | |
96 | } | |
97 | ||
98 | static void sctp_sched_fc_enqueue(struct sctp_outq *q, | |
99 | struct sctp_datamsg *msg) | |
100 | { | |
101 | struct sctp_stream *stream; | |
102 | struct sctp_chunk *ch; | |
103 | __u16 sid; | |
104 | ||
105 | ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list); | |
106 | sid = sctp_chunk_stream_no(ch); | |
107 | stream = &q->asoc->stream; | |
108 | sctp_sched_fc_sched(stream, SCTP_SO(stream, sid)->ext); | |
109 | } | |
110 | ||
111 | static struct sctp_chunk *sctp_sched_fc_dequeue(struct sctp_outq *q) | |
112 | { | |
113 | struct sctp_stream *stream = &q->asoc->stream; | |
114 | struct sctp_stream_out_ext *soute; | |
115 | struct sctp_chunk *ch; | |
116 | ||
117 | /* Bail out quickly if queue is empty */ | |
118 | if (list_empty(&q->out_chunk_list)) | |
119 | return NULL; | |
120 | ||
121 | /* Find which chunk is next */ | |
122 | if (stream->out_curr) | |
123 | soute = stream->out_curr->ext; | |
124 | else | |
125 | soute = list_entry(stream->fc_list.next, struct sctp_stream_out_ext, fc_list); | |
126 | ch = list_entry(soute->outq.next, struct sctp_chunk, stream_list); | |
127 | ||
128 | sctp_sched_dequeue_common(q, ch); | |
129 | return ch; | |
130 | } | |
131 | ||
132 | static void sctp_sched_fc_dequeue_done(struct sctp_outq *q, | |
133 | struct sctp_chunk *ch) | |
134 | { | |
135 | struct sctp_stream *stream = &q->asoc->stream; | |
136 | struct sctp_stream_out_ext *soute, *pos; | |
137 | __u16 sid, i; | |
138 | ||
139 | sid = sctp_chunk_stream_no(ch); | |
140 | soute = SCTP_SO(stream, sid)->ext; | |
141 | /* reduce all fc_lengths by U32_MAX / 4 if the current fc_length overflows. */ | |
142 | if (soute->fc_length > U32_MAX - ch->skb->len) { | |
143 | for (i = 0; i < stream->outcnt; i++) { | |
144 | pos = SCTP_SO(stream, i)->ext; | |
145 | if (!pos) | |
146 | continue; | |
147 | if (pos->fc_length <= (U32_MAX >> 2)) { | |
148 | pos->fc_length = 0; | |
149 | continue; | |
150 | } | |
151 | pos->fc_length -= (U32_MAX >> 2); | |
152 | } | |
153 | } | |
154 | soute->fc_length += ch->skb->len; | |
155 | ||
156 | if (list_empty(&soute->outq)) { | |
157 | list_del_init(&soute->fc_list); | |
158 | return; | |
159 | } | |
160 | ||
161 | pos = soute; | |
162 | list_for_each_entry_continue(pos, &stream->fc_list, fc_list) | |
42d452e7 XL |
163 | if ((__u64)pos->fc_length * soute->fc_weight >= |
164 | (__u64)soute->fc_length * pos->fc_weight) | |
4821a076 XL |
165 | break; |
166 | list_move_tail(&soute->fc_list, &pos->fc_list); | |
167 | } | |
168 | ||
169 | static void sctp_sched_fc_sched_all(struct sctp_stream *stream) | |
170 | { | |
171 | struct sctp_association *asoc; | |
172 | struct sctp_chunk *ch; | |
173 | ||
174 | asoc = container_of(stream, struct sctp_association, stream); | |
175 | list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) { | |
176 | __u16 sid = sctp_chunk_stream_no(ch); | |
177 | ||
178 | if (SCTP_SO(stream, sid)->ext) | |
179 | sctp_sched_fc_sched(stream, SCTP_SO(stream, sid)->ext); | |
180 | } | |
181 | } | |
182 | ||
183 | static void sctp_sched_fc_unsched_all(struct sctp_stream *stream) | |
184 | { | |
185 | struct sctp_stream_out_ext *soute, *tmp; | |
186 | ||
187 | list_for_each_entry_safe(soute, tmp, &stream->fc_list, fc_list) | |
188 | list_del_init(&soute->fc_list); | |
189 | } | |
190 | ||
191 | static struct sctp_sched_ops sctp_sched_fc = { | |
192 | .set = sctp_sched_fc_set, | |
193 | .get = sctp_sched_fc_get, | |
194 | .init = sctp_sched_fc_init, | |
195 | .init_sid = sctp_sched_fc_init_sid, | |
196 | .free_sid = sctp_sched_fc_free_sid, | |
197 | .enqueue = sctp_sched_fc_enqueue, | |
198 | .dequeue = sctp_sched_fc_dequeue, | |
199 | .dequeue_done = sctp_sched_fc_dequeue_done, | |
200 | .sched_all = sctp_sched_fc_sched_all, | |
201 | .unsched_all = sctp_sched_fc_unsched_all, | |
202 | }; | |
203 | ||
204 | void sctp_sched_ops_fc_init(void) | |
205 | { | |
206 | sctp_sched_ops_register(SCTP_SS_FC, &sctp_sched_fc); | |
207 | } | |
42d452e7 XL |
208 | |
209 | static struct sctp_sched_ops sctp_sched_wfq = { | |
210 | .set = sctp_sched_wfq_set, | |
211 | .get = sctp_sched_wfq_get, | |
212 | .init = sctp_sched_fc_init, | |
213 | .init_sid = sctp_sched_fc_init_sid, | |
214 | .free_sid = sctp_sched_fc_free_sid, | |
215 | .enqueue = sctp_sched_fc_enqueue, | |
216 | .dequeue = sctp_sched_fc_dequeue, | |
217 | .dequeue_done = sctp_sched_fc_dequeue_done, | |
218 | .sched_all = sctp_sched_fc_sched_all, | |
219 | .unsched_all = sctp_sched_fc_unsched_all, | |
220 | }; | |
221 | ||
222 | void sctp_sched_ops_wfq_init(void) | |
223 | { | |
224 | sctp_sched_ops_register(SCTP_SS_WFQ, &sctp_sched_wfq); | |
225 | } |