mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
![Daniel Borkmann](/assets/img/avatar_default.png)
We should get rid of all own SCTP debug printk macros and use the ones that the kernel offers anyway instead. This makes the code more readable and conform to the kernel code, and offers all the features of dynamic debbuging that pr_debug() et al has, such as only turning on/off portions of debug messages at runtime through debugfs. The runtime cost of having CONFIG_DYNAMIC_DEBUG enabled, but none of the debug statements printing, is negligible [1]. If kernel debugging is completly turned off, then these statements will also compile into "empty" functions. While we're at it, we also need to change the Kconfig option as it /now/ only refers to the ifdef'ed code portions in outqueue.c that enable further debugging/tracing of SCTP transaction fields. Also, since SCTP_ASSERT code was enabled with this Kconfig option and has now been removed, we transform those code parts into WARNs resp. where appropriate BUG_ONs so that those bugs can be more easily detected as probably not many people have SCTP debugging permanently turned on. To turn on all SCTP debugging, the following steps are needed: # mount -t debugfs none /sys/kernel/debug # echo -n 'module sctp +p' > /sys/kernel/debug/dynamic_debug/control This can be done more fine-grained on a per file, per line basis and others as described in [2]. [1] https://www.kernel.org/doc/ols/2009/ols2009-pages-39-46.pdf [2] Documentation/dynamic-debug-howto.txt Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
240 lines
6.9 KiB
C
240 lines
6.9 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, 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);
|
|
}
|
|
|
|
/* 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);
|
|
}
|