path: root/net/sctp/stream.c

/* 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
 *
 * These functions manipulate sctp tsn mapping array.
 *
 * 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 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>

/* 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)
{
	struct sctp_association *asoc;
	struct sctp_chunk *ch, *temp;
	struct sctp_outq *outq;
	int i;

	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);
	}

	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(new->out[i].ext);
			new->out[i].ext = stream->out[i].ext;
			stream->out[i].ext = NULL;
		}
	}

	for (i = outcnt; i < stream->outcnt; i++)
		kfree(stream->out[i].ext);
}

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

	out = kmalloc_array(outcnt, sizeof(*out), gfp);
	if (!out)
		return -ENOMEM;

	if (stream->out) {
		memcpy(out, stream->out, min(outcnt, stream->outcnt) *
					 sizeof(*out));
		kfree(stream->out);
	}

	if (outcnt > stream->outcnt)
		memset(out + stream->outcnt, 0,
		       (outcnt - stream->outcnt) * sizeof(*out));

	stream->out = out;

	return 0;
}

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

	in = kmalloc_array(incnt, sizeof(*stream->in), gfp);

	if (!in)
		return -ENOMEM;

	if (stream->in) {
		memcpy(in, stream->in, min(incnt, stream->incnt) *
				       sizeof(*in));
		kfree(stream->in);
	}

	if (incnt > stream->incnt)
		memset(in + stream->incnt, 0,
		       (incnt - stream->incnt) * sizeof(*in));

	stream->in = in;

	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 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;

	stream->outcnt = outcnt;
	for (i = 0; i < stream->outcnt