// 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 <[email protected]>
*
* Written or modified by:
* Marcelo Ricardo Leitner <[email protected]>
*/
#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();
sctp_sched_ops_fc_init();
sctp_sched_ops_wfq_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 *old = asoc->outqueue.sched;
struct sctp_datamsg *msg = NULL;
struct sctp_sched_ops *n;
struct sctp_chunk *ch;
int i, ret = 0;
if (sched > SCTP_SS_MAX)
return -EINVAL;
n = sctp_sched_ops[sched];
if (old == n)
return ret;
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;
}
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