--- /dev/null
+/* 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, 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:
+ * La Monte H.P. Yarroll <piggy@acm.org>
+ * Karl Knutson <karl@athena.chicago.il.us>
+ */
+
+#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);
+}
+
+/* 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;
+ }
+}
+
+/* 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);
+ if (chunk->asoc)
+ chunk->asoc->stats.ipackets++;
+ 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);
+ /* We are guaranteed to pull a SCTP header. */
+ }
+ }
+
+ /* 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 + sizeof(sctp_chunkhdr_t) <
+ skb_tail_pointer(chunk->skb)) {
+ /* This is not a singleton */
+ chunk->singleton = 0;
+ } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
+ /* Discard inside state machine. */
+ chunk->pdiscard = 1;
+ chunk->chunk_end = skb_tail_pointer(chunk->skb);
+ } 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;
+ }
+
+ pr_debug("+++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);
+}
Code Review / kvmfornfv.git / blobdiff