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
 *
 * This file contains sctp stream maniuplation primitives and helpers.
 *
 * 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>

static struct flex_array *fa_alloc(size_t elem_size, size_t elem_count,
				   gfp_t gfp)
{
	struct flex_array *result;
	int err;

	result = flex_array_alloc(elem_size, elem_count, gfp);
	if (result) {
		err = flex_array_prealloc(result, 0, elem_count, gfp);
		if (err) {
			flex_array_free(result);
			result = NULL;
		}
	}

	return result;
}

static void fa_free(struct flex_array *fa)
{
	if (fa)
		flex_array_free(fa);
}

static void fa_copy(struct flex_array *fa, struct flex_array *from,
		    size_t index, size_t count)
{
	void *elem;

	while (count--) {
		elem = flex_array_get(from, index);
		flex_array_put(fa, index, elem, 0);
		index++;
	}
}

static void fa_zero(struct flex_array *fa, size_t index, size_t count)
{
	void *elem;

	while (count--) {
		elem = flex_array_get(fa, index);
		memset(elem, 0, fa->element_size);
		index++;
	}
}

static size_t fa_index(struct flex_array *fa, void *elem, size_t count)
{
	size_t index = 0;

	while (count--) {
		if (elem == flex_array_get(fa, index))
			break;
		index++;
	}

	return index;
}

/* 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(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)
{
	struct flex_array *out;
	size_t elem_size = sizeof(struct sctp_stream_out);

	out = fa_alloc(