1 files changed, 270 insertions, 0 deletions

diff --git a/net/sctp/stream_sched.c b/net/sctp/stream_sched.c
new file mode 100644
index 000000000000..40a9a9de2b98
--- /dev/null
+++ b/net/sctp/stream_sched.c
@@ -0,0 +1,270 @@
+/* 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,
+};
+
+/* API to other parts of the stack */
+
+struct sctp_sched_ops *sctp_sched_ops[] = {
+        &sctp_sched_fcfs,
+};
+
+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 = asoc->stream.out[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 (!asoc->stream.out[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 (!asoc->stream.out[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 (!asoc->stream.out[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)) {
+                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 = &q->asoc->stream.out[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);
+
+        INIT_LIST_HEAD(&stream->out[sid].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;
+}