/* 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) { 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. */ /* 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); } /* 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) { 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 > 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, work_func_t callback) { INIT_WORK(&q->immediate, callback); }