diff options
Diffstat (limited to '')
-rw-r--r-- | net/sctp/inqueue.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c new file mode 100644 index 000000000..eb93ffe24 --- /dev/null +++ b/net/sctp/inqueue.c @@ -0,0 +1,252 @@ +/* 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; + struct sctp_chunkhdr *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 = (struct sctp_chunkhdr *)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; + struct sctp_chunkhdr *ch = NULL; + + /* The assumption is that we are safe to process the chunks + * at this time. + */ + + chunk = queue->in_progress; + if (chunk) { + /* 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) { + if (chunk->head_skb == chunk->skb) { + chunk->skb = skb_shinfo(chunk->skb)->frag_list; + goto new_skb; + } + if (chunk->skb->next) { + chunk->skb = chunk->skb->next; + goto new_skb; + } + + if (chunk->head_skb) + chunk->skb = chunk->head_skb; + sctp_chunk_free(chunk); + chunk = queue->in_progress = NULL; + } else { + /* Nothing to do. Next chunk in the packet, please. */ + ch = (struct sctp_chunkhdr *)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; + +next_chunk: + /* Is the queue empty? */ + entry = sctp_list_dequeue(&queue->in_chunk_list); + if (!entry) + return NULL; + + chunk = list_entry(entry, struct sctp_chunk, list); + + if (skb_is_gso(chunk->skb) && skb_is_gso_sctp(chunk->skb)) { + /* GSO-marked skbs but without frags, handle + * them normally + */ + if (skb_shinfo(chunk->skb)->frag_list) + chunk->head_skb = chunk->skb; + + /* skbs with "cover letter" */ + if (chunk->head_skb && chunk->skb->data_len == chunk->skb->len) + chunk->skb = skb_shinfo(chunk->skb)->frag_list; + + if (WARN_ON(!chunk->skb)) { + __SCTP_INC_STATS(dev_net(chunk->skb->dev), SCTP_MIB_IN_PKT_DISCARDS); + sctp_chunk_free(chunk); + goto next_chunk; + } + } + + if (chunk->asoc) + sock_rps_save_rxhash(chunk->asoc->base.sk, chunk->skb); + + queue->in_progress = chunk; + +new_skb: + /* This is the first chunk in the packet. */ + ch = (struct sctp_chunkhdr *)chunk->skb->data; + chunk->singleton = 1; + chunk->data_accepted = 0; + chunk->pdiscard = 0; + chunk->auth = 0; + chunk->has_asconf = 0; + chunk->end_of_packet = 0; + if (chunk->head_skb) { + struct sctp_input_cb + *cb = SCTP_INPUT_CB(chunk->skb), + *head_cb = SCTP_INPUT_CB(chunk->head_skb); + + cb->chunk = head_cb->chunk; + cb->af = head_cb->af; + } + } + + chunk->chunk_hdr = ch; + chunk->chunk_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length)); + skb_pull(chunk->skb, sizeof(*ch)); + chunk->subh.v = NULL; /* Subheader is no longer valid. */ + + if (chunk->chunk_end + sizeof(*ch) <= 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); +} |