[GitHub/mt8127/android_kernel_alcatel_ttab.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)
{
	skb_queue_head_init(&queue->in);
	queue->in_progress = NULL;

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

	queue->malloced = 0;
}

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

	/* Empty the queue.  */
	while ((chunk = (struct sctp_chunk *) skb_dequeue(&queue->in)) != NULL)
		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);

	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 *packet)
{
	/* 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.
	 */
	skb_queue_tail(&(q->in), (struct sk_buff *) packet);
	q->immediate.func(q->immediate.data);
}

/* 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) {
		/* Is the queue empty?  */
        	if (skb_queue_empty(&queue->in))
			return NULL;

		chunk = queue->in_progress =
			(struct sctp_chunk *) skb_dequeue(&queue->in);

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

        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,
				 void (*callback)(void *), void *arg)
{
	INIT_WORK(&q->immediate, callback, arg);
}
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	{
	53	skb_queue_head_init(&queue->in);
	54	queue->in_progress = NULL;
	55
	56	/* Create a task for delivering data. */
	57	INIT_WORK(&queue->immediate, NULL, NULL);
	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	{
65	struct sctp_chunk *chunk;
66
67	/* Empty the queue. */
68	while ((chunk = (struct sctp_chunk *) skb_dequeue(&queue->in)) != NULL)
69	sctp_chunk_free(chunk);
70
71	/* If there is a packet which is currently being worked on,
72	* free it as well.
73	*/
74	if (queue->in_progress)
75	sctp_chunk_free(queue->in_progress);
76
77	if (queue->malloced) {
78	/* Dump the master memory segment. */
79	kfree(queue);
80	}
81	}
82
83	/* Put a new packet in an SCTP inqueue.
84	* We assume that packet->sctp_hdr is set and in host byte order.
85	*/
86	void sctp_inq_push(struct sctp_inq q, struct sctp_chunk packet)
87	{
88	/* Directly call the packet handling routine. */
89
90	/* We are now calling this either from the soft interrupt
91	* or from the backlog processing.
92	* Eventually, we should clean up inqueue to not rely
93	* on the BH related data structures.
94	*/
95	skb_queue_tail(&(q->in), (struct sk_buff *) packet);
96	q->immediate.func(q->immediate.data);
97	}
98
99	/* Extract a chunk from an SCTP inqueue.
100	*
101	* WARNING: If you need to put the chunk on another queue, you need to
102	* make a shallow copy (clone) of it.
103	*/
104	struct sctp_chunk sctp_inq_pop(struct sctp_inq queue)
105	{
106	struct sctp_chunk *chunk;
107	sctp_chunkhdr_t *ch = NULL;
108
109	/* The assumption is that we are safe to process the chunks
110	* at this time.
111	*/
112
113	if ((chunk = queue->in_progress)) {
114	/* There is a packet that we have been working on.
115	* Any post processing work to do before we move on?
116	*/
117	if (chunk->singleton \|\|
118	chunk->end_of_packet \|\|
119	chunk->pdiscard) {
120	sctp_chunk_free(chunk);
121	chunk = queue->in_progress = NULL;
122	} else {
123	/* Nothing to do. Next chunk in the packet, please. */
124	ch = (sctp_chunkhdr_t *) chunk->chunk_end;
125
126	/* Force chunk->skb->data to chunk->chunk_end. */
127	skb_pull(chunk->skb,
128	chunk->chunk_end - chunk->skb->data);
129	}
130	}
131
132	/* Do we need to take the next packet out of the queue to process? */
133	if (!chunk) {
134	/* Is the queue empty? */
135	if (skb_queue_empty(&queue->in))
136	return NULL;
137
138	chunk = queue->in_progress =
139	(struct sctp_chunk *) skb_dequeue(&queue->in);
140
141	/* This is the first chunk in the packet. */
142	chunk->singleton = 1;
143	ch = (sctp_chunkhdr_t *) chunk->skb->data;
144	}
145
146	chunk->chunk_hdr = ch;
147	chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
148	/* In the unlikely case of an IP reassembly, the skb could be
149	* non-linear. If so, update chunk_end so that it doesn't go past
150	* the skb->tail.
151	*/
152	if (unlikely(skb_is_nonlinear(chunk->skb))) {
153	if (chunk->chunk_end > chunk->skb->tail)
154	chunk->chunk_end = chunk->skb->tail;
155	}
156	skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
157	chunk->subh.v = NULL; /* Subheader is no longer valid. */
158
159	if (chunk->chunk_end < chunk->skb->tail) {
160	/* This is not a singleton */
161	chunk->singleton = 0;
162	} else if (chunk->chunk_end > chunk->skb->tail) {
163	/* RFC 2960, Section 6.10 Bundling
164	*
165	* Partial chunks MUST NOT be placed in an SCTP packet.
166	* If the receiver detects a partial chunk, it MUST drop
167	* the chunk.
168	*
169	* Since the end of the chunk is past the end of our buffer
170	* (which contains the whole packet, we can freely discard
171	* the whole packet.
172	*/
173	sctp_chunk_free(chunk);
174	chunk = queue->in_progress = NULL;
175
176	return NULL;
177	} else {
178	/* We are at the end of the packet, so mark the chunk
179	* in case we need to send a SACK.
180	*/
181	chunk->end_of_packet = 1;
182	}
183
184	SCTP_DEBUG_PRINTK("+++sctp_inq_pop+++ chunk %p[%s],"
185	" length %d, skb->len %d\n",chunk,
186	sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
187	ntohs(chunk->chunk_hdr->length), chunk->skb->len);
188	return chunk;
189	}
190
191	/* Set a top-half handler.
192	*
193	* Originally, we the top-half handler was scheduled as a BH. We now
194	* call the handler directly in sctp_inq_push() at a time that
195	* we know we are lock safe.
196	* The intent is that this routine will pull stuff out of the
197	* inqueue and process it.
198	*/
199	void sctp_inq_set_th_handler(struct sctp_inq *q,
200	void (callback)(void ), void *arg)
201	{
202	INIT_WORK(&q->immediate, callback, arg);
203	}
204