1 files changed, 246 insertions, 0 deletions
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c
new file mode 100644
index 00000000..397296fb
--- /dev/null
+++ b/net/sctp/inqueue.c
@@ -0,0 +1,246 @@
+/* SCTP kernel 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 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.
+ *
+ * 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, 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+#include <linux/interrupt.h>
+#include <linux/slab.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. */
+	if (chunk->rcvr->dead) {
+		sctp_chunk_free(chunk);
+		return;
+	}
+
+	/* 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);
+}
+
+/* Peek at the next chunk on the inqeue. */
+struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue)
+{
+	struct sctp_chunk *chunk;
+	sctp_chunkhdr_t *ch = NULL;
+
+	chunk = queue->in_progress;
+	/* If there is no more chunks in this packet, say so */
+	if (chunk->singleton ||
+	    chunk->end_of_packet ||
+	    chunk->pdiscard)
+		    return NULL;
+
+	ch = (sctp_chunkhdr_t *)chunk->chunk_end;
+
+	return ch;
+}
+
+
+/* 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);
+
+			/* Verify that we have at least chunk headers
+			 * worth of buffer left.
+			 */
+			if (skb_headlen(chunk->skb) < sizeof(sctp_chunkhdr_t)) {
+				sctp_chunk_free(chunk);
+				chunk = queue->in_progress = NULL;
+			}
+		}
+	}
+
+	/* 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 > skb_tail_pointer(chunk->skb))
+			chunk->chunk_end = skb_tail_pointer(chunk->skb);
+	}
+	skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
+	chunk->subh.v = NULL; /* Subheader is no longer valid.  */
+
+	if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) {
+		/* This is not a singleton */
+		chunk->singleton = 0;
+	} else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
+		/* 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);
+}
+