v4.19.13 snapshot.
diff --git a/net/sctp/stream_sched.c b/net/sctp/stream_sched.c
new file mode 100644
index 0000000..a6c04a9
--- /dev/null
+++ b/net/sctp/stream_sched.c
@@ -0,0 +1,288 @@
+/* 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.
+ *
+ * This SCTP implementation is free software;
+ * you can redistribute it and/or modify it under the terms of
+ * the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This SCTP implementation is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * ************************
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU CC; see the file COPYING. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * 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(struct sctp_stream *stream)
+{
+}
+
+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 = sctp_sched_fcfs_free,
+ .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();
+}
+
+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) {
+ old->free(&asoc->stream);
+
+ /* Give the next scheduler a clean slate. */
+ for (i = 0; i < asoc->stream.outcnt; i++) {
+ void *p = SCTP_SO(&asoc->stream, i)->ext;
+
+ if (!p)
+ continue;
+
+ p += offsetofend(struct sctp_stream_out_ext, outq);
+ memset(p, 0, sizeof(struct sctp_stream_out_ext) -
+ offsetofend(struct sctp_stream_out_ext, outq));
+ }
+ }
+
+ 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_KERNEL);
+ 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:
+ n->free(&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->intl_enable) {
+ 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;
+}