diff options
Diffstat (limited to 'net/sctp/stream_sched_fc.c')
| -rw-r--r-- | net/sctp/stream_sched_fc.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/net/sctp/stream_sched_fc.c b/net/sctp/stream_sched_fc.c new file mode 100644 index 000000000000..b336c2f5486b --- /dev/null +++ b/net/sctp/stream_sched_fc.c @@ -0,0 +1,183 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* SCTP kernel implementation + * (C) Copyright Red Hat Inc. 2022 + * + * 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: + * Xin Long <lucien.xin@gmail.com> + */ + +#include <linux/list.h> +#include <net/sctp/sctp.h> +#include <net/sctp/sm.h> +#include <net/sctp/stream_sched.h> + +/* Fair Capacity handling + * RFC 8260 section 3.5 + */ +static void sctp_sched_fc_unsched_all(struct sctp_stream *stream); + +static int sctp_sched_fc_set(struct sctp_stream *stream, __u16 sid, + __u16 weight, gfp_t gfp) +{ + return 0; +} + +static int sctp_sched_fc_get(struct sctp_stream *stream, __u16 sid, + __u16 *value) +{ + return 0; +} + +static int sctp_sched_fc_init(struct sctp_stream *stream) +{ + INIT_LIST_HEAD(&stream->fc_list); + + return 0; +} + +static int sctp_sched_fc_init_sid(struct sctp_stream *stream, __u16 sid, + gfp_t gfp) +{ + struct sctp_stream_out_ext *soute = SCTP_SO(stream, sid)->ext; + + INIT_LIST_HEAD(&soute->fc_list); + soute->fc_length = 0; + + return 0; +} + +static void sctp_sched_fc_free_sid(struct sctp_stream *stream, __u16 sid) +{ +} + +static void sctp_sched_fc_sched(struct sctp_stream *stream, + struct sctp_stream_out_ext *soute) +{ + struct sctp_stream_out_ext *pos; + + if (!list_empty(&soute->fc_list)) + return; + + list_for_each_entry(pos, &stream->fc_list, fc_list) + if (pos->fc_length >= soute->fc_length) + break; + list_add_tail(&soute->fc_list, &pos->fc_list); +} + +static void sctp_sched_fc_enqueue(struct sctp_outq *q, + struct sctp_datamsg *msg) +{ + struct sctp_stream *stream; + struct sctp_chunk *ch; + __u16 sid; + + ch = list_first_entry(&msg->chunks, struct sctp_chunk, frag_list); + sid = sctp_chunk_stream_no(ch); + stream = &q->asoc->stream; + sctp_sched_fc_sched(stream, SCTP_SO(stream, sid)->ext); +} + +static struct sctp_chunk *sctp_sched_fc_dequeue(struct sctp_outq *q) +{ + struct sctp_stream *stream = &q->asoc->stream; + struct sctp_stream_out_ext *soute; + struct sctp_chunk *ch; + + /* Bail out quickly if queue is empty */ + if (list_empty(&q->out_chunk_list)) + return NULL; + + /* Find which chunk is next */ + if (stream->out_curr) + soute = stream->out_curr->ext; + else + soute = list_entry(stream->fc_list.next, struct sctp_stream_out_ext, fc_list); + ch = list_entry(soute->outq.next, struct sctp_chunk, stream_list); + + sctp_sched_dequeue_common(q, ch); + return ch; +} + +static void sctp_sched_fc_dequeue_done(struct sctp_outq *q, + struct sctp_chunk *ch) +{ + struct sctp_stream *stream = &q->asoc->stream; + struct sctp_stream_out_ext *soute, *pos; + __u16 sid, i; + + sid = sctp_chunk_stream_no(ch); + soute = SCTP_SO(stream, sid)->ext; + /* reduce all fc_lengths by U32_MAX / 4 if the current fc_length overflows. */ + if (soute->fc_length > U32_MAX - ch->skb->len) { + for (i = 0; i < stream->outcnt; i++) { + pos = SCTP_SO(stream, i)->ext; + if (!pos) + continue; + if (pos->fc_length <= (U32_MAX >> 2)) { + pos->fc_length = 0; + continue; + } + pos->fc_length -= (U32_MAX >> 2); + } + } + soute->fc_length += ch->skb->len; + + if (list_empty(&soute->outq)) { + list_del_init(&soute->fc_list); + return; + } + + pos = soute; + list_for_each_entry_continue(pos, &stream->fc_list, fc_list) + if (pos->fc_length >= soute->fc_length) + break; + list_move_tail(&soute->fc_list, &pos->fc_list); +} + +static void sctp_sched_fc_sched_all(struct sctp_stream *stream) +{ + struct sctp_association *asoc; + struct sctp_chunk *ch; + + asoc = container_of(stream, struct sctp_association, stream); + list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list) { + __u16 sid = sctp_chunk_stream_no(ch); + + if (SCTP_SO(stream, sid)->ext) + sctp_sched_fc_sched(stream, SCTP_SO(stream, sid)->ext); + } +} + +static void sctp_sched_fc_unsched_all(struct sctp_stream *stream) +{ + struct sctp_stream_out_ext *soute, *tmp; + + list_for_each_entry_safe(soute, tmp, &stream->fc_list, fc_list) + list_del_init(&soute->fc_list); +} + +static struct sctp_sched_ops sctp_sched_fc = { + .set = sctp_sched_fc_set, + .get = sctp_sched_fc_get, + .init = sctp_sched_fc_init, + .init_sid = sctp_sched_fc_init_sid, + .free_sid = sctp_sched_fc_free_sid, + .enqueue = sctp_sched_fc_enqueue, + .dequeue = sctp_sched_fc_dequeue, + .dequeue_done = sctp_sched_fc_dequeue_done, + .sched_all = sctp_sched_fc_sched_all, + .unsched_all = sctp_sched_fc_unsched_all, +}; + +void sctp_sched_ops_fc_init(void) +{ + sctp_sched_ops_register(SCTP_SS_FC, &sctp_sched_fc); +} |