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 | |
22 | /* Fair Capacity and Weighted Fair Queueing handling |
23 | * RFC 8260 section 3.5 and 3.6 |
24 | */ |
25 | static void sctp_sched_fc_unsched_all(struct sctp_stream *stream); |
26 | |
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 | |
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(list: &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(list: &soute->fc_list); |
73 | soute->fc_length = 0; |
74 | soute->fc_weight = 1; |
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(head: &soute->fc_list)) |
89 | return; |
90 | |
91 | list_for_each_entry(pos, &stream->fc_list, fc_list) |
92 | if ((__u64)pos->fc_length * soute->fc_weight >= |
93 | (__u64)soute->fc_length * pos->fc_weight) |
94 | break; |
95 | list_add_tail(new: &soute->fc_list, head: &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(head: &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(head: &soute->outq)) { |
157 | list_del_init(entry: &soute->fc_list); |
158 | return; |
159 | } |
160 | |
161 | pos = soute; |
162 | list_for_each_entry_continue(pos, &stream->fc_list, fc_list) |
163 | if ((__u64)pos->fc_length * soute->fc_weight >= |
164 | (__u64)soute->fc_length * pos->fc_weight) |
165 | break; |
166 | list_move_tail(list: &soute->fc_list, head: &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(entry: &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(sched: SCTP_SS_FC, sched_ops: &sctp_sched_fc); |
207 | } |
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(sched: SCTP_SS_WFQ, sched_ops: &sctp_sched_wfq); |
225 | } |
226 | |