patch-2.4.23 linux-2.4.23/net/sctp/inqueue.c

• Lines: 200
• Date: 2003-11-28 10:26:21.000000000 -0800
• Orig file: linux-2.4.22/net/sctp/inqueue.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.22/net/sctp/inqueue.c linux-2.4.23/net/sctp/inqueue.c
@@ -0,0 +1,199 @@
+/* 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_LIST_HEAD(&queue->immediate.list);
+	queue->immediate.sync = 0;
+	queue->immediate.routine = NULL;
+	queue->immediate.data = NULL;
+
+	queue->malloced = 0;
+}
+
+/* Create an initialized sctp_inq.  */
+struct sctp_inq *sctp_inq_new(void)
+{
+	struct sctp_inq *retval;
+
+	retval = t_new(struct sctp_inq, GFP_ATOMIC);
+	if (retval) {
+		sctp_inq_init(retval);
+		retval->malloced = 1;
+	}
+        return retval;
+}
+
+/* Release the memory associated with an SCTP inqueue.  */
+void sctp_inq_free(struct sctp_inq *queue)
+{
+	sctp_chunk_t *chunk;
+
+	/* Empty the queue.  */
+	while ((chunk = (sctp_chunk_t *) skb_dequeue(&queue->in)))
+		sctp_free_chunk(chunk);
+
+	/* If there is a packet which is currently being worked on,
+	 * free it as well.
+	 */
+	if (queue->in_progress)
+		sctp_free_chunk(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, sctp_chunk_t *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.routine(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.
+ */
+sctp_chunk_t *sctp_inq_pop(struct sctp_inq *queue)
+{
+	sctp_chunk_t *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_free_chunk(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 =
+			(sctp_chunk_t *) 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));
+	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 {
+		/* 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)
+{
+	q->immediate.routine = callback;
+	q->immediate.data = arg;
+}
+