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Diffstat (limited to 'net/sctp/inqueue.c')
| -rw-r--r-- | net/sctp/inqueue.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c new file mode 100644 index 00000000000..cedf4351556 --- /dev/null +++ b/net/sctp/inqueue.c @@ -0,0 +1,204 @@ +/* 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_WORK(&queue->immediate, NULL, NULL); + + queue->malloced = 0; +} + +/* Release the memory associated with an SCTP inqueue. */ +void sctp_inq_free(struct sctp_inq *queue) +{ + struct sctp_chunk *chunk; + + /* Empty the queue. */ + while ((chunk = (struct sctp_chunk *) skb_dequeue(&queue->in)) != NULL) + 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); + + 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 *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.func(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. + */ +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); + } + } + + /* 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 = + (struct sctp_chunk *) 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)); + /* 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 > chunk->skb->tail) + chunk->chunk_end = chunk->skb->tail; + } + 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 if (chunk->chunk_end > chunk->skb->tail) { + /* 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, + void (*callback)(void *), void *arg) +{ + INIT_WORK(&q->immediate, callback, arg); +} + |