1 /* SCTP kernel implementation 2 * (C) Copyright Red Hat Inc. 2017 3 * 4 * This file is part of the SCTP kernel implementation 5 * 6 * These functions manipulate sctp stream queue/scheduling. 7 * 8 * This SCTP implementation is free software; 9 * you can redistribute it and/or modify it under the terms of 10 * the GNU General Public License as published by 11 * the Free Software Foundation; either version 2, or (at your option) 12 * any later version. 13 * 14 * This SCTP implementation is distributed in the hope that it 15 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 16 * ************************ 17 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 18 * See the GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with GNU CC; see the file COPYING. If not, see 22 * <http://www.gnu.org/licenses/>. 23 * 24 * Please send any bug reports or fixes you make to the 25 * email addresched(es): 26 * lksctp developers <linux-sctp@vger.kernel.org> 27 * 28 * Written or modified by: 29 * Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> 30 */ 31 32 #include <linux/list.h> 33 #include <net/sctp/sctp.h> 34 #include <net/sctp/sm.h> 35 #include <net/sctp/stream_sched.h> 36 37 /* First Come First Serve (a.k.a. FIFO) 38 * RFC DRAFT ndata Section 3.1 39 */ 40 static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid, 41 __u16 value, gfp_t gfp) 42 { 43 return 0; 44 } 45 46 static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid, 47 __u16 *value) 48 { 49 *value = 0; 50 return 0; 51 } 52 53 static int sctp_sched_fcfs_init(struct sctp_stream *stream) 54 { 55 return 0; 56 } 57 58 static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid, 59 gfp_t gfp) 60 { 61 return 0; 62 } 63 64 static void sctp_sched_fcfs_free(struct sctp_stream *stream) 65 { 66 } 67 68 static void sctp_sched_fcfs_enqueue(struct sctp_outq *q, 69 struct sctp_datamsg *msg) 70 { 71 } 72 73 static struct sctp_chunk *sctp_sched_fcfs_dequeue(struct sctp_outq *q) 74 { 75 struct sctp_stream *stream = &q->asoc->stream; 76 struct sctp_chunk *ch = NULL; 77 struct list_head *entry; 78 79 if (list_empty(&q->out_chunk_list)) 80 goto out; 81 82 if (stream->out_curr) { 83 ch = list_entry(stream->out_curr->ext->outq.next, 84 struct sctp_chunk, stream_list); 85 } else { 86 entry = q->out_chunk_list.next; 87 ch = list_entry(entry, struct sctp_chunk, list); 88 } 89 90 sctp_sched_dequeue_common(q, ch); 91 92 out: 93 return ch; 94 } 95 96 static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q, 97 struct sctp_chunk *chunk) 98 { 99 } 100 101 static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream) 102 { 103 } 104 105 static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream) 106 { 107 } 108 109 static struct sctp_sched_ops sctp_sched_fcfs = { 110 .set = sctp_sched_fcfs_set, 111 .get = sctp_sched_fcfs_get, 112 .init = sctp_sched_fcfs_init, 113 .init_sid = sctp_sched_fcfs_init_sid, 114 .free = sctp_sched_fcfs_free, 115 .enqueue = sctp_sched_fcfs_enqueue, 116 .dequeue = sctp_sched_fcfs_dequeue, 117 .dequeue_done = sctp_sched_fcfs_dequeue_done, 118 .sched_all = sctp_sched_fcfs_sched_all, 119 .unsched_all = sctp_sched_fcfs_unsched_all, 120 }; 121 122 static void sctp_sched_ops_fcfs_init(void) 123 { 124 sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs); 125 } 126 127 /* API to other parts of the stack */ 128 129 static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1]; 130 131 void sctp_sched_ops_register(enum sctp_sched_type sched, 132 struct sctp_sched_ops *sched_ops) 133 { 134 sctp_sched_ops[sched] = sched_ops; 135 } 136 137 void sctp_sched_ops_init(void) 138 { 139 sctp_sched_ops_fcfs_init(); 140 sctp_sched_ops_prio_init(); 141 sctp_sched_ops_rr_init(); 142 } 143 144 int sctp_sched_set_sched(struct sctp_association *asoc, 145 enum sctp_sched_type sched) 146 { 147 struct sctp_sched_ops *n = sctp_sched_ops[sched]; 148 struct sctp_sched_ops *old = asoc->outqueue.sched; 149 struct sctp_datamsg *msg = NULL; 150 struct sctp_chunk *ch; 151 int i, ret = 0; 152 153 if (old == n) 154 return ret; 155 156 if (sched > SCTP_SS_MAX) 157 return -EINVAL; 158 159 if (old) { 160 old->free(&asoc->stream); 161 162 /* Give the next scheduler a clean slate. */ 163 for (i = 0; i < asoc->stream.outcnt; i++) { 164 void *p = SCTP_SO(&asoc->stream, i)->ext; 165 166 if (!p) 167 continue; 168 169 p += offsetofend(struct sctp_stream_out_ext, outq); 170 memset(p, 0, sizeof(struct sctp_stream_out_ext) - 171 offsetofend(struct sctp_stream_out_ext, outq)); 172 } 173 } 174 175 asoc->outqueue.sched = n; 176 n->init(&asoc->stream); 177 for (i = 0; i < asoc->stream.outcnt; i++) { 178 if (!SCTP_SO(&asoc->stream, i)->ext) 179 continue; 180 181 ret = n->init_sid(&asoc->stream, i, GFP_KERNEL); 182 if (ret) 183 goto err; 184 } 185 186 /* We have to requeue all chunks already queued. */ 187 list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) { 188 if (ch->msg == msg) 189 continue; 190 msg = ch->msg; 191 n->enqueue(&asoc->outqueue, msg); 192 } 193 194 return ret; 195 196 err: 197 n->free(&asoc->stream); 198 asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */ 199 200 return ret; 201 } 202 203 int sctp_sched_get_sched(struct sctp_association *asoc) 204 { 205 int i; 206 207 for (i = 0; i <= SCTP_SS_MAX; i++) 208 if (asoc->outqueue.sched == sctp_sched_ops[i]) 209 return i; 210 211 return 0; 212 } 213 214 int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid, 215 __u16 value, gfp_t gfp) 216 { 217 if (sid >= asoc->stream.outcnt) 218 return -EINVAL; 219 220 if (!SCTP_SO(&asoc->stream, sid)->ext) { 221 int ret; 222 223 ret = sctp_stream_init_ext(&asoc->stream, sid); 224 if (ret) 225 return ret; 226 } 227 228 return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp); 229 } 230 231 int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid, 232 __u16 *value) 233 { 234 if (sid >= asoc->stream.outcnt) 235 return -EINVAL; 236 237 if (!SCTP_SO(&asoc->stream, sid)->ext) 238 return 0; 239 240 return asoc->outqueue.sched->get(&asoc->stream, sid, value); 241 } 242 243 void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch) 244 { 245 if (!list_is_last(&ch->frag_list, &ch->msg->chunks) && 246 !q->asoc->intl_enable) { 247 struct sctp_stream_out *sout; 248 __u16 sid; 249 250 /* datamsg is not finish, so save it as current one, 251 * in case application switch scheduler or a higher 252 * priority stream comes in. 253 */ 254 sid = sctp_chunk_stream_no(ch); 255 sout = SCTP_SO(&q->asoc->stream, sid); 256 q->asoc->stream.out_curr = sout; 257 return; 258 } 259 260 q->asoc->stream.out_curr = NULL; 261 q->sched->dequeue_done(q, ch); 262 } 263 264 /* Auxiliary functions for the schedulers */ 265 void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch) 266 { 267 list_del_init(&ch->list); 268 list_del_init(&ch->stream_list); 269 q->out_qlen -= ch->skb->len; 270 } 271 272 int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp) 273 { 274 struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream); 275 struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext; 276 277 INIT_LIST_HEAD(&ext->outq); 278 return sched->init_sid(stream, sid, gfp); 279 } 280 281 struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream) 282 { 283 struct sctp_association *asoc; 284 285 asoc = container_of(stream, struct sctp_association, stream); 286 287 return asoc->outqueue.sched; 288 } 289