1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright Red Hat Inc. 2017 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 * Marcelo Ricardo Leitner <marcelo.leitner@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 /* First Come First Serve (a.k.a. FIFO) 23 * RFC DRAFT ndata Section 3.1 24 */ 25 static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid, 26 __u16 value, gfp_t gfp) 27 { 28 return 0; 29 } 30 31 static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid, 32 __u16 *value) 33 { 34 *value = 0; 35 return 0; 36 } 37 38 static int sctp_sched_fcfs_init(struct sctp_stream *stream) 39 { 40 return 0; 41 } 42 43 static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid, 44 gfp_t gfp) 45 { 46 return 0; 47 } 48 49 static void sctp_sched_fcfs_free_sid(struct sctp_stream *stream, __u16 sid) 50 { 51 } 52 53 static void sctp_sched_fcfs_enqueue(struct sctp_outq *q, 54 struct sctp_datamsg *msg) 55 { 56 } 57 58 static struct sctp_chunk *sctp_sched_fcfs_dequeue(struct sctp_outq *q) 59 { 60 struct sctp_stream *stream = &q->asoc->stream; 61 struct sctp_chunk *ch = NULL; 62 struct list_head *entry; 63 64 if (list_empty(&q->out_chunk_list)) 65 goto out; 66 67 if (stream->out_curr) { 68 ch = list_entry(stream->out_curr->ext->outq.next, 69 struct sctp_chunk, stream_list); 70 } else { 71 entry = q->out_chunk_list.next; 72 ch = list_entry(entry, struct sctp_chunk, list); 73 } 74 75 sctp_sched_dequeue_common(q, ch); 76 77 out: 78 return ch; 79 } 80 81 static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q, 82 struct sctp_chunk *chunk) 83 { 84 } 85 86 static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream) 87 { 88 } 89 90 static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream) 91 { 92 } 93 94 static struct sctp_sched_ops sctp_sched_fcfs = { 95 .set = sctp_sched_fcfs_set, 96 .get = sctp_sched_fcfs_get, 97 .init = sctp_sched_fcfs_init, 98 .init_sid = sctp_sched_fcfs_init_sid, 99 .free_sid = sctp_sched_fcfs_free_sid, 100 .enqueue = sctp_sched_fcfs_enqueue, 101 .dequeue = sctp_sched_fcfs_dequeue, 102 .dequeue_done = sctp_sched_fcfs_dequeue_done, 103 .sched_all = sctp_sched_fcfs_sched_all, 104 .unsched_all = sctp_sched_fcfs_unsched_all, 105 }; 106 107 static void sctp_sched_ops_fcfs_init(void) 108 { 109 sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs); 110 } 111 112 /* API to other parts of the stack */ 113 114 static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1]; 115 116 void sctp_sched_ops_register(enum sctp_sched_type sched, 117 struct sctp_sched_ops *sched_ops) 118 { 119 sctp_sched_ops[sched] = sched_ops; 120 } 121 122 void sctp_sched_ops_init(void) 123 { 124 sctp_sched_ops_fcfs_init(); 125 sctp_sched_ops_prio_init(); 126 sctp_sched_ops_rr_init(); 127 } 128 129 static void sctp_sched_free_sched(struct sctp_stream *stream) 130 { 131 struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream); 132 struct sctp_stream_out_ext *soute; 133 int i; 134 135 sched->unsched_all(stream); 136 for (i = 0; i < stream->outcnt; i++) { 137 soute = SCTP_SO(stream, i)->ext; 138 if (!soute) 139 continue; 140 sched->free_sid(stream, i); 141 /* Give the next scheduler a clean slate. */ 142 memset_after(soute, 0, outq); 143 } 144 } 145 146 int sctp_sched_set_sched(struct sctp_association *asoc, 147 enum sctp_sched_type sched) 148 { 149 struct sctp_sched_ops *n = sctp_sched_ops[sched]; 150 struct sctp_sched_ops *old = asoc->outqueue.sched; 151 struct sctp_datamsg *msg = NULL; 152 struct sctp_chunk *ch; 153 int i, ret = 0; 154 155 if (old == n) 156 return ret; 157 158 if (sched > SCTP_SS_MAX) 159 return -EINVAL; 160 161 if (old) 162 sctp_sched_free_sched(&asoc->stream); 163 164 asoc->outqueue.sched = n; 165 n->init(&asoc->stream); 166 for (i = 0; i < asoc->stream.outcnt; i++) { 167 if (!SCTP_SO(&asoc->stream, i)->ext) 168 continue; 169 170 ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC); 171 if (ret) 172 goto err; 173 } 174 175 /* We have to requeue all chunks already queued. */ 176 list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) { 177 if (ch->msg == msg) 178 continue; 179 msg = ch->msg; 180 n->enqueue(&asoc->outqueue, msg); 181 } 182 183 return ret; 184 185 err: 186 sctp_sched_free_sched(&asoc->stream); 187 asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */ 188 189 return ret; 190 } 191 192 int sctp_sched_get_sched(struct sctp_association *asoc) 193 { 194 int i; 195 196 for (i = 0; i <= SCTP_SS_MAX; i++) 197 if (asoc->outqueue.sched == sctp_sched_ops[i]) 198 return i; 199 200 return 0; 201 } 202 203 int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid, 204 __u16 value, gfp_t gfp) 205 { 206 if (sid >= asoc->stream.outcnt) 207 return -EINVAL; 208 209 if (!SCTP_SO(&asoc->stream, sid)->ext) { 210 int ret; 211 212 ret = sctp_stream_init_ext(&asoc->stream, sid); 213 if (ret) 214 return ret; 215 } 216 217 return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp); 218 } 219 220 int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid, 221 __u16 *value) 222 { 223 if (sid >= asoc->stream.outcnt) 224 return -EINVAL; 225 226 if (!SCTP_SO(&asoc->stream, sid)->ext) 227 return 0; 228 229 return asoc->outqueue.sched->get(&asoc->stream, sid, value); 230 } 231 232 void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch) 233 { 234 if (!list_is_last(&ch->frag_list, &ch->msg->chunks) && 235 !q->asoc->peer.intl_capable) { 236 struct sctp_stream_out *sout; 237 __u16 sid; 238 239 /* datamsg is not finish, so save it as current one, 240 * in case application switch scheduler or a higher 241 * priority stream comes in. 242 */ 243 sid = sctp_chunk_stream_no(ch); 244 sout = SCTP_SO(&q->asoc->stream, sid); 245 q->asoc->stream.out_curr = sout; 246 return; 247 } 248 249 q->asoc->stream.out_curr = NULL; 250 q->sched->dequeue_done(q, ch); 251 } 252 253 /* Auxiliary functions for the schedulers */ 254 void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch) 255 { 256 list_del_init(&ch->list); 257 list_del_init(&ch->stream_list); 258 q->out_qlen -= ch->skb->len; 259 } 260 261 int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp) 262 { 263 struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream); 264 struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext; 265 266 INIT_LIST_HEAD(&ext->outq); 267 return sched->init_sid(stream, sid, gfp); 268 } 269 270 struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream) 271 { 272 struct sctp_association *asoc; 273 274 asoc = container_of(stream, struct sctp_association, stream); 275 276 return asoc->outqueue.sched; 277 } 278