path: root/net/sctp/stream.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001 Intel Corp.
 *
 * This file is part of the SCTP kernel implementation
 *
 * This file contains sctp stream maniuplation primitives and helpers.
 *
 * Please send any bug reports or fixes you make to the
 * email address(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>

static void sctp_stream_shrink_out(struct sctp_stream *stream, __u16 outcnt)
{
	struct sctp_association *asoc;
	struct sctp_chunk *ch, *temp;
	struct sctp_outq *outq;

	asoc = container_of(stream, struct sctp_association, stream);
	outq = &asoc->outqueue;

	list_for_each_entry_safe(ch, temp, &outq->out_chunk_list, list) {
		__u16 sid = sctp_chunk_stream_no(ch);

		if (sid < outcnt)
			continue;

		sctp_sched_dequeue_common(outq, ch);
		/* No need to call dequeue_done here because
		 * the chunks are not scheduled by now.
		 */

		/* Mark as failed send. */
		sctp_chunk_fail(ch, (__force __u32)SCTP_ERROR_INV_STRM);
		if (asoc->peer.prsctp_capable &&
		    SCTP_PR_PRIO_ENABLED(ch->sinfo.sinfo_flags))
			asoc->sent_cnt_removable--;

		sctp_chunk_free(ch);
	}
}

/* Migrates chunks from stream queues to new stream queues if needed,
 * but not across associations. Also, removes those chunks to streams
 * higher than the new max.
 */
static void sctp_stream_outq_migrate(struct sctp_stream *stream,
				     struct sctp_stream *new, __u16 outcnt)
{
	int i;

	if (stream->outcnt > outcnt)
		sctp_stream_shrink_out(stream, outcnt);

	if (new) {
		/* Here we actually move the old ext stuff into the new
		 * buffer, because we want to keep it. Then
		 * sctp_stream_update will swap ->out pointers.
		 */
		for (i = 0; i < outcnt; i++) {
			kfree(SCTP_SO(new, i)->ext);
			SCTP_SO(new, i)->ext = SCTP_SO(stream, i)->ext;
			SCTP_SO(stream, i)->ext = NULL;
		}
	}

	for (i = outcnt; i < stream->outcnt; i++) {
		kfree(SCTP_SO(stream, i)->ext);
		SCTP_SO(stream, i)->ext = NULL;
	}
}

static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
				 gfp_t gfp)
{
	int ret;

	if (outcnt <= stream->outcnt)
		goto out;

	ret = genradix_prealloc(&stream->out, outcnt, gfp);
	if (ret)
		return ret;

out:
	stream->outcnt = outcnt;
	return 0;
}

static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt,
				gfp_t gfp)
{
	int ret;

	if (incnt <= stream->incnt)
		goto out;

	ret = genradix_prealloc(&stream->in, incnt, gfp);
	if (ret)
		return ret;

out:
	stream->incnt = incnt;
	return 0;
}

int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
		     gfp_t gfp)
{
	struct sctp_sched_ops *sched = sctp_sched_ops_from_stream(stream);
	int i, ret = 0;

	gfp |= __GFP_NOWARN;

	/* Initial stream->out size may be very big, so free it and alloc
	 * a new one with new outcnt to save memory if needed.
	 */
	if (outcnt == stream->outcnt)
		goto handle_in;

	/* Filter out chunks queued on streams that won't exist anymore */
	sched->unsched_all(stream);
	sctp_stream_outq_migrate(stream, NULL, outcnt);
	sched->sched_all(stream);

	ret = sctp_stream_alloc_out(stream, outcnt, gfp);
	if (ret)
		goto out_err;

	for (i = 0; i < stream->outcnt; i++)
		SCTP_SO(stream, i)->state = SCTP_STREAM_OPEN;

handle_in:
	sctp_stream_interleave_init(stream);
	if (!incnt)
		goto out;

	ret = sctp_stream_alloc_in(stream, incnt, gfp);
	if (ret)
		goto in_err;

	goto out;

in_err:
	sched->free(stream);
	genradix_free(&stream->in);
out_err:
	genradix_free(&stream->out);
	stream->outcnt = 0;
out:
	return ret;
}

int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid)
{
	struct sctp_stream_out_ext *soute;
	int ret;

	soute = kzalloc(sizeof(*soute), GFP_KERNEL);
	if (!soute)
		return -ENOMEM;
	SCTP_SO(stream, sid)->ext = soute;

	ret = sctp_sched_init_sid(stream, sid, GFP_KERNEL);
	if (ret) {
		kfree(SCTP_SO(