[net-next-2.6.git] / net / sctp / inqueue.c

/* SCTP kernel reference Implementation
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2002 International Business Machines, Corp.
 * 
 * This file is part of the SCTP kernel reference Implementation
 * 
 * These functions are the methods for accessing the SCTP inqueue.
 *
 * An SCTP inqueue is a queue into which you push SCTP packets
 * (which might be bundles or fragments of chunks) and out of which you
 * pop SCTP whole chunks.
 * 
 * The SCTP reference 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.
 * 
 * The SCTP reference 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, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.  
 * 
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 * 
 * Or submit a bug report through the following website:
 *    http://www.sf.net/projects/lksctp
 *
 * Written or modified by: 
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson <karl@athena.chicago.il.us>
 * 
 * Any bugs reported given to us we will try to fix... any fixes shared will
 * be incorporated into the next SCTP release.
 */

#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
#include <linux/interrupt.h>

/* Initialize an SCTP inqueue.  */
void sctp_inq_init(struct sctp_inq *queue)
{
	INIT_LIST_HEAD(&queue->in_chunk_list);
	queue->in_progress = NULL;

	/* Create a task for delivering data.  */
	INIT_WORK(&queue->immediate, NULL);

	queue->malloced = 0;
}

/* Release the memory associated with an SCTP inqueue.  */
void sctp_inq_free(struct sctp_inq *queue)
{
	struct sctp_chunk *chunk, *tmp;

	/* Empty the queue.  */
	list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) {
		list_del_init(&chunk->list);
		sctp_chunk_free(chunk);
	}

	/* If there is a packet which is currently being worked on,
	 * free it as well.
	 */
	if (queue->in_progress) {
		sctp_chunk_free(queue->in_progress);
		queue->in_progress = NULL;
	}

	if (queue->malloced) {
		/* Dump the master memory segment.  */
		kfree(queue);
	}
}

/* Put a new packet in an SCTP inqueue.
 * We assume that packet->sctp_hdr is set and in host byte order.
 */
void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
{
	/* Directly call the packet handling routine. */

	/* We are now calling this either from the soft interrupt
	 * or from the backlog processing.
	 * Eventually, we should clean up inqueue to not rely
	 * on the BH related data structures.
	 */
	list_add_tail(&chunk->list, &q->in_chunk_list);
	q->immediate.func(&q->immediate);
}

/* Extract a chunk from an SCTP inqueue.
 *
 * WARNING:  If you need to put the chunk on another queue, you need to
 * make a shallow copy (clone) of it.
 */
struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
{
	struct sctp_chunk *chunk;
	sctp_chunkhdr_t *ch = NULL;

	/* The assumption is that we are safe to process the chunks
	 * at this time.
	 */

	if ((chunk = queue->in_progress)) {
		/* There is a packet that we have been working on.
		 * Any post processing work to do before we move on?
		 */
		if (chunk->singleton ||
		    chunk->end_of_packet ||
		    chunk->pdiscard) {
			sctp_chunk_free(chunk);
			chunk = queue->in_progress = NULL;
		} else {
			/* Nothing to do. Next chunk in the packet, please. */
			ch = (sctp_chunkhdr_t *) chunk->chunk_end;

			/* Force chunk->skb->data to chunk->chunk_end.  */
			skb_pull(chunk->skb,
				 chunk->chunk_end - chunk->skb->data);
		}
	}

	/* Do we need to take the next packet out of the queue to process? */
	if (!chunk) {
		struct list_head *entry;

		/* Is the queue empty?  */
		if (list_empty(&queue->in_chunk_list))
			return NULL;

		entry = queue->in_chunk_list.next;
		chunk = queue->in_progress =
			list_entry(entry, struct sctp_chunk, list);
		list_del_init(entry);

		/* This is the first chunk in the packet.  */
		chunk->singleton = 1;
		ch = (sctp_chunkhdr_t *) chunk->skb->data;
		chunk->data_accepted = 0;
	}

        chunk->chunk_hdr = ch;
        chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
	/* In the unlikely case of an IP reassembly, the skb could be
	 * non-linear. If so, update chunk_end so that it doesn't go past
	 * the skb->tail.
	 */
	if (unlikely(skb_is_nonlinear(chunk->skb))) {
		if (chunk->chunk_end > chunk->skb->tail)
			chunk->chunk_end = chunk->skb->tail;
	}
	skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
	chunk->subh.v = NULL; /* Subheader is no longer valid.  */

	if (chunk->chunk_end < chunk->skb->tail) {
		/* This is not a singleton */
		chunk->singleton = 0;
	} else if (chunk->chunk_end > chunk->skb->tail) {
                /* RFC 2960, Section 6.10  Bundling
		 *
		 * Partial chunks MUST NOT be placed in an SCTP packet.
		 * If the receiver detects a partial chunk, it MUST drop
		 * the chunk.  
		 *
		 * Since the end of the chunk is past the end of our buffer
		 * (which contains the whole packet, we can freely discard
		 * the whole packet.
		 */
		sctp_chunk_free(chunk);
		chunk = queue->in_progress = NULL;

		return NULL;
	} else {
		/* We are at the end of the packet, so mark the chunk
		 * in case we need to send a SACK.
		 */
		chunk->end_of_packet = 1;
	}

	SCTP_DEBUG_PRINTK("+++sctp_inq_pop+++ chunk %p[%s],"
			  " length %d, skb->len %d\n",chunk,
			  sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
			  ntohs(chunk->chunk_hdr->length), chunk->skb->len);
	return chunk;
}

/* Set a top-half handler.
 *
 * Originally, we the top-half handler was scheduled as a BH.  We now
 * call the handler directly in sctp_inq_push() at a time that
 * we know we are lock safe.
 * The intent is that this routine will pull stuff out of the
 * inqueue and process it.
 */
void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
{
	INIT_WORK(&q->immediate, callback);
}
Commit	Line	Data
1da177e4 LT	1	/* SCTP kernel reference Implementation
	2	* Copyright (c) 1999-2000 Cisco, Inc.
	3	* Copyright (c) 1999-2001 Motorola, Inc.
	4	* Copyright (c) 2002 International Business Machines, Corp.
	5	*
	6	* This file is part of the SCTP kernel reference Implementation
	7	*
	8	* These functions are the methods for accessing the SCTP inqueue.
	9	*
	10	* An SCTP inqueue is a queue into which you push SCTP packets
	11	* (which might be bundles or fragments of chunks) and out of which you
	12	* pop SCTP whole chunks.
	13	*
	14	* The SCTP reference implementation is free software;
	15	* you can redistribute it and/or modify it under the terms of
	16	* the GNU General Public License as published by
	17	* the Free Software Foundation; either version 2, or (at your option)
	18	* any later version.
	19	*
	20	* The SCTP reference implementation is distributed in the hope that it
	21	* will be useful, but WITHOUT ANY WARRANTY; without even the implied
	22	* ************************
	23	* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	24	* See the GNU General Public License for more details.
	25	*
	26	* You should have received a copy of the GNU General Public License
	27	* along with GNU CC; see the file COPYING. If not, write to
	28	* the Free Software Foundation, 59 Temple Place - Suite 330,
	29	* Boston, MA 02111-1307, USA.
	30	*
	31	* Please send any bug reports or fixes you make to the
	32	* email address(es):
	33	* lksctp developers <lksctp-developers@lists.sourceforge.net>
	34	*
	35	* Or submit a bug report through the following website:
	36	* http://www.sf.net/projects/lksctp
	37	*
	38	* Written or modified by:
	39	* La Monte H.P. Yarroll <piggy@acm.org>
	40	* Karl Knutson <karl@athena.chicago.il.us>
	41	*
	42	* Any bugs reported given to us we will try to fix... any fixes shared will
	43	* be incorporated into the next SCTP release.
	44	*/
	45
	46	#include <net/sctp/sctp.h>
	47	#include <net/sctp/sm.h>
	48	#include <linux/interrupt.h>
	49
	50	/* Initialize an SCTP inqueue. */
	51	void sctp_inq_init(struct sctp_inq *queue)
	52	{
79af02c2	53	INIT_LIST_HEAD(&queue->in_chunk_list);
1da177e4 LT	54	queue->in_progress = NULL;
	55
	56	/* Create a task for delivering data. */
c4028958	57	INIT_WORK(&queue->immediate, NULL);
1da177e4 LT	58
	59	queue->malloced = 0;
	60	}
	61
	62	/* Release the memory associated with an SCTP inqueue. */
	63	void sctp_inq_free(struct sctp_inq *queue)
	64	{
79af02c2	65	struct sctp_chunk chunk, tmp;
1da177e4 LT	66
1da177e4 LT	67	/* Empty the queue. */
79af02c2 DM	68	list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) {
79af02c2 DM	69	list_del_init(&chunk->list);
1da177e4	70	sctp_chunk_free(chunk);
79af02c2	71	}
1da177e4 LT	72
	73	/* If there is a packet which is currently being worked on,
	74	* free it as well.
	75	*/
7a48f923	76	if (queue->in_progress) {
1da177e4	77	sctp_chunk_free(queue->in_progress);
7a48f923 SS	78	queue->in_progress = NULL;
7a48f923 SS	79	}
1da177e4 LT	80
	81	if (queue->malloced) {
	82	/* Dump the master memory segment. */
	83	kfree(queue);
	84	}
	85	}
	86
	87	/* Put a new packet in an SCTP inqueue.
	88	* We assume that packet->sctp_hdr is set and in host byte order.
	89	*/
ac0b0462	90	void sctp_inq_push(struct sctp_inq q, struct sctp_chunk chunk)
1da177e4 LT	91	{
	92	/* Directly call the packet handling routine. */
	93
	94	/* We are now calling this either from the soft interrupt
	95	* or from the backlog processing.
	96	* Eventually, we should clean up inqueue to not rely
	97	* on the BH related data structures.
	98	*/
ac0b0462	99	list_add_tail(&chunk->list, &q->in_chunk_list);
c4028958	100	q->immediate.func(&q->immediate);
1da177e4 LT	101	}
	102
	103	/* Extract a chunk from an SCTP inqueue.
	104	*
	105	* WARNING: If you need to put the chunk on another queue, you need to
	106	* make a shallow copy (clone) of it.
	107	*/
	108	struct sctp_chunk sctp_inq_pop(struct sctp_inq queue)
	109	{
	110	struct sctp_chunk *chunk;
	111	sctp_chunkhdr_t *ch = NULL;
	112
	113	/* The assumption is that we are safe to process the chunks
	114	* at this time.
	115	*/
	116
	117	if ((chunk = queue->in_progress)) {
	118	/* There is a packet that we have been working on.
	119	* Any post processing work to do before we move on?
	120	*/
	121	if (chunk->singleton \|\|
	122	chunk->end_of_packet \|\|
	123	chunk->pdiscard) {
	124	sctp_chunk_free(chunk);
	125	chunk = queue->in_progress = NULL;
	126	} else {
	127	/* Nothing to do. Next chunk in the packet, please. */
	128	ch = (sctp_chunkhdr_t *) chunk->chunk_end;
	129
	130	/* Force chunk->skb->data to chunk->chunk_end. */
	131	skb_pull(chunk->skb,
	132	chunk->chunk_end - chunk->skb->data);
	133	}
	134	}
	135
	136	/* Do we need to take the next packet out of the queue to process? */
	137	if (!chunk) {
79af02c2 DM	138	struct list_head *entry;
79af02c2 DM	139
1da177e4	140	/* Is the queue empty? */
79af02c2	141	if (list_empty(&queue->in_chunk_list))
1da177e4 LT	142	return NULL;
1da177e4 LT	143
79af02c2	144	entry = queue->in_chunk_list.next;
1da177e4	145	chunk = queue->in_progress =
79af02c2 DM	146	list_entry(entry, struct sctp_chunk, list);
79af02c2 DM	147	list_del_init(entry);
1da177e4 LT	148
	149	/* This is the first chunk in the packet. */
	150	chunk->singleton = 1;
	151	ch = (sctp_chunkhdr_t *) chunk->skb->data;
7c3ceb4f	152	chunk->data_accepted = 0;
1da177e4 LT	153	}
	154
	155	chunk->chunk_hdr = ch;
	156	chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
	157	/* In the unlikely case of an IP reassembly, the skb could be
	158	* non-linear. If so, update chunk_end so that it doesn't go past
	159	* the skb->tail.
	160	*/
	161	if (unlikely(skb_is_nonlinear(chunk->skb))) {
	162	if (chunk->chunk_end > chunk->skb->tail)
	163	chunk->chunk_end = chunk->skb->tail;
	164	}
	165	skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
	166	chunk->subh.v = NULL; /* Subheader is no longer valid. */
	167
	168	if (chunk->chunk_end < chunk->skb->tail) {
	169	/* This is not a singleton */
	170	chunk->singleton = 0;
	171	} else if (chunk->chunk_end > chunk->skb->tail) {
	172	/* RFC 2960, Section 6.10 Bundling
	173	*
	174	* Partial chunks MUST NOT be placed in an SCTP packet.
	175	* If the receiver detects a partial chunk, it MUST drop
	176	* the chunk.
	177	*
	178	* Since the end of the chunk is past the end of our buffer
	179	* (which contains the whole packet, we can freely discard
	180	* the whole packet.
	181	*/
	182	sctp_chunk_free(chunk);
	183	chunk = queue->in_progress = NULL;
	184
	185	return NULL;
	186	} else {
	187	/* We are at the end of the packet, so mark the chunk
	188	* in case we need to send a SACK.
	189	*/
	190	chunk->end_of_packet = 1;
	191	}
	192
	193	SCTP_DEBUG_PRINTK("+++sctp_inq_pop+++ chunk %p[%s],"
	194	" length %d, skb->len %d\n",chunk,
	195	sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
	196	ntohs(chunk->chunk_hdr->length), chunk->skb->len);
	197	return chunk;
	198	}
	199
	200	/* Set a top-half handler.
	201	*
	202	* Originally, we the top-half handler was scheduled as a BH. We now
	203	* call the handler directly in sctp_inq_push() at a time that
	204	* we know we are lock safe.
	205	* The intent is that this routine will pull stuff out of the
	206	* inqueue and process it.
	207	*/
c4028958	208	void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
1da177e4	209	{
c4028958	210	INIT_WORK(&q->immediate, callback);
1da177e4 LT	211	}
1da177e4 LT	212