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