// SPDX-License-Identifier: GPL-2.0-or-later /* SCTP kernel implementation * (C) Copyright Red Hat Inc. 2017 * * This file is part of the SCTP kernel implementation * * These functions manipulate sctp stream queue/scheduling. * * Please send any bug reports or fixes you make to the * email addresched(es): * lksctp developers <linux-sctp@vger.kernel.org> * * Written or modified by: * Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> */ #include <linux/list.h> #include <net/sctp/sctp.h> #include <net/sctp/sm.h> #include <net/sctp/stream_sched.h> /* First Come First Serve (a.k.a. FIFO) * RFC DRAFT ndata Section 3.1 */ static int sctp_sched_fcfs_set(struct sctp_stream *stream, __u16 sid, __u16 value, gfp_t gfp) { return 0; } static int sctp_sched_fcfs_get(struct sctp_stream *stream, __u16 sid, __u16 *value) { *value = 0; return 0; } static int sctp_sched_fcfs_init(struct sctp_stream *stream) { return 0; } static int sctp_sched_fcfs_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp) { return 0; } static void sctp_sched_fcfs_free_sid(struct sctp_stream *stream, __u16 sid) { } static void sctp_sched_fcfs_enqueue(struct sctp_outq *q, struct sctp_datamsg *msg) { } static struct sctp_chunk *sctp_sched_fcfs_dequeue(struct sctp_outq *q) { struct sctp_stream *stream = &q->asoc->stream; struct sctp_chunk *ch = NULL; struct list_head *entry; if (list_empty(&q->out_chunk_list)) goto out; if (stream->out_curr) { ch = list_entry(stream->out_curr->ext->outq.next, struct sctp_chunk, stream_list); } else { entry = q->out_chunk_list.next; ch = list_entry(entry, struct sctp_chunk, list); } sctp_sched_dequeue_common(q, ch); out: return ch; } static void sctp_sched_fcfs_dequeue_done(struct sctp_outq *q, struct sctp_chunk *chunk) { } static void sctp_sched_fcfs_sched_all(struct sctp_stream *stream) { } static void sctp_sched_fcfs_unsched_all(struct sctp_stream *stream) { } static struct sctp_sched_ops sctp_sched_fcfs = { .set = sctp_sched_fcfs_set, .get = sctp_sched_fcfs_get, .init = sctp_sched_fcfs_init, .init_sid = sctp_sched_fcfs_init_sid, .free_sid = sctp_sched_fcfs_free_sid, .enqueue = sctp_sched_fcfs_enqueue, .dequeue = sctp_sched_fcfs_dequeue, .dequeue_done = sctp_sched_fcfs_dequeue_done, .sched_all = sctp_sched_fcfs_sched_all, .unsched_all = sctp_sched_fcfs_unsched_all, }; static void sctp_sched_ops_fcfs_init(void) { sctp_sched_ops_register(SCTP_SS_FCFS, &sctp_sched_fcfs); } /* API to other parts of the stack */ static struct sctp_sched_ops *sctp_sched_ops[SCTP_SS_MAX + 1]; void sctp_sched_ops_register(enum sctp_sched_type sched, struct sctp_sched_ops *sched_ops) { sctp_sched_ops[sched] = sched_ops; } void sctp_sched_ops_init(void) { sctp_sched_ops_fcfs_init(); sctp_sched_ops_prio_init(); sctp_sched_ops_rr_init(); } static void sctp_sched_free_sched(struct sctp_stream *stream) { struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream); struct sctp_stream_out_ext *soute; int i; sched->unsched_all(stream); for (i = 0; i < stream->outcnt; i++) { soute = SCTP_SO(stream, i)->ext; if (!soute) continue; sched->free_sid(stream, i); /* Give the next scheduler a clean slate. */ memset_after(soute, 0, outq); } } int sctp_sched_set_sched(struct sctp_association *asoc, enum sctp_sched_type sched) { struct sctp_sched_ops *n = sctp_sched_ops[sched]; struct sctp_sched_ops *old = asoc->outqueue.sched; struct sctp_datamsg *msg = NULL; struct sctp_chunk *ch; int i, ret = 0; if (old == n) return ret; if (sched > SCTP_SS_MAX) return -EINVAL; if (old) sctp_sched_free_sched(&asoc->stream); asoc->outqueue.sched = n; n->init(&asoc->stream); for (i = 0; i < asoc->stream.outcnt; i++) { if (!SCTP_SO(&asoc->stream, i)->ext) continue; ret = n->init_sid(&asoc->stream, i, GFP_ATOMIC); if (ret) goto err; } /* We have to requeue all chunks already queued. */ list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) { if (ch->msg == msg) continue; msg = ch->msg; n->enqueue(&asoc->outqueue, msg); } return ret; err: sctp_sched_free_sched(&asoc->stream); asoc->outqueue.sched = &sctp_sched_fcfs; /* Always safe */ return ret; } int sctp_sched_get_sched(struct sctp_association *asoc) { int i; for (i = 0; i <= SCTP_SS_MAX; i++) if (asoc->outqueue.sched == sctp_sched_ops[i]) return i; return 0; } int sctp_sched_set_value(struct sctp_association *asoc, __u16 sid, __u16 value, gfp_t gfp) { if (sid >= asoc->stream.outcnt) return -EINVAL; if (!SCTP_SO(&asoc->stream, sid)->ext) { int ret; ret = sctp_stream_init_ext(&asoc->stream, sid); if (ret) return ret; } return asoc->outqueue.sched->set(&asoc->stream, sid, value, gfp); } int sctp_sched_get_value(struct sctp_association *asoc, __u16 sid, __u16 *value) { if (sid >= asoc->stream.outcnt) return -EINVAL; if (!SCTP_SO(&asoc->stream, sid)->ext) return 0; return asoc->outqueue.sched->get(&asoc->stream, sid, value); } void sctp_sched_dequeue_done(struct sctp_outq *q, struct sctp_chunk *ch) { if (!list_is_last(&ch->frag_list, &ch->msg->chunks) && !q->asoc->peer.intl_capable) { struct sctp_stream_out *sout; __u16 sid; /* datamsg is not finish, so save it as current one, * in case application switch scheduler or a higher * priority stream comes in. */ sid = sctp_chunk_stream_no(ch); sout = SCTP_SO(&q->asoc->stream, sid); q->asoc->stream.out_curr = sout; return; } q->asoc->stream.out_curr = NULL; q->sched->dequeue_done(q, ch); } /* Auxiliary functions for the schedulers */ void sctp_sched_dequeue_common(struct sctp_outq *q, struct sctp_chunk *ch) { list_del_init(&ch->list); list_del_init(&ch->stream_list); q->out_qlen -= ch->skb->len; } int sctp_sched_init_sid(struct sctp_stream *stream, __u16 sid, gfp_t gfp) { struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream); struct sctp_stream_out_ext *ext = SCTP_SO(stream, sid)->ext; INIT_LIST_HEAD(&ext->outq); return sched->init_sid(stream, sid, gfp); } struct sctp_sched_ops *sctp_sched_ops_from_stream(struct sctp_stream *stream) { struct sctp_association *asoc; asoc = container_of(stream, struct sctp_association, stream); return asoc->outqueue.sched; }