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(&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; 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(&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(&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) 163 if ((__u64)pos->fc_length * soute->fc_weight >= 164 (__u64)soute->fc_length * pos->fc_weight) 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 } 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 } 226