linux/net/sctp/inqueue.c
Jeff Kirsher 4b2f13a251 sctp: Fix FSF address in file headers
Several files refer to an old address for the Free Software Foundation
in the file header comment.  Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.

CC: Vlad Yasevich <vyasevich@gmail.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 12:37:56 -05:00

234 lines
6.6 KiB
C

/* 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);
/* 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;
}
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);
}