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![Randy Dunlap](/assets/img/avatar_default.png)
Drop the repeated word "an". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: linux-sctp@vger.kernel.org Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
1136 lines
29 KiB
C
1136 lines
29 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* SCTP kernel implementation
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* (C) Copyright IBM Corp. 2001, 2004
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* Copyright (c) 1999-2000 Cisco, Inc.
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* Copyright (c) 1999-2001 Motorola, Inc.
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* Copyright (c) 2001 Intel Corp.
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* Copyright (c) 2001 Nokia, Inc.
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* Copyright (c) 2001 La Monte H.P. Yarroll
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*
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* This abstraction carries sctp events to the ULP (sockets).
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*
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* Please send any bug reports or fixes you make to the
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* email address(es):
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* lksctp developers <linux-sctp@vger.kernel.org>
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*
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* Written or modified by:
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* Jon Grimm <jgrimm@us.ibm.com>
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* La Monte H.P. Yarroll <piggy@acm.org>
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* Sridhar Samudrala <sri@us.ibm.com>
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*/
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include <net/busy_poll.h>
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#include <net/sctp/structs.h>
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#include <net/sctp/sctp.h>
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#include <net/sctp/sm.h>
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/* Forward declarations for internal helpers. */
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static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
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struct sctp_ulpevent *);
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static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *,
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struct sctp_ulpevent *);
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static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq);
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/* 1st Level Abstractions */
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/* Initialize a ULP queue from a block of memory. */
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struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq,
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struct sctp_association *asoc)
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{
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memset(ulpq, 0, sizeof(struct sctp_ulpq));
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ulpq->asoc = asoc;
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skb_queue_head_init(&ulpq->reasm);
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skb_queue_head_init(&ulpq->reasm_uo);
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skb_queue_head_init(&ulpq->lobby);
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ulpq->pd_mode = 0;
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return ulpq;
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}
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/* Flush the reassembly and ordering queues. */
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void sctp_ulpq_flush(struct sctp_ulpq *ulpq)
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{
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struct sk_buff *skb;
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struct sctp_ulpevent *event;
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while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) {
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event = sctp_skb2event(skb);
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sctp_ulpevent_free(event);
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}
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while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) {
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event = sctp_skb2event(skb);
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sctp_ulpevent_free(event);
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}
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while ((skb = __skb_dequeue(&ulpq->reasm_uo)) != NULL) {
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event = sctp_skb2event(skb);
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sctp_ulpevent_free(event);
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}
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}
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/* Dispose of a ulpqueue. */
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void sctp_ulpq_free(struct sctp_ulpq *ulpq)
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{
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sctp_ulpq_flush(ulpq);
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}
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/* Process an incoming DATA chunk. */
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int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
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gfp_t gfp)
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{
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struct sk_buff_head temp;
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struct sctp_ulpevent *event;
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int event_eor = 0;
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/* Create an event from the incoming chunk. */
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event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
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if (!event)
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return -ENOMEM;
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event->ssn = ntohs(chunk->subh.data_hdr->ssn);
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event->ppid = chunk->subh.data_hdr->ppid;
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/* Do reassembly if needed. */
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event = sctp_ulpq_reasm(ulpq, event);
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/* Do ordering if needed. */
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if (event) {
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/* Create a temporary list to collect chunks on. */
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skb_queue_head_init(&temp);
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__skb_queue_tail(&temp, sctp_event2skb(event));
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if (event->msg_flags & MSG_EOR)
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event = sctp_ulpq_order(ulpq, event);
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}
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/* Send event to the ULP. 'event' is the sctp_ulpevent for
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* very first SKB on the 'temp' list.
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*/
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if (event) {
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event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
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sctp_ulpq_tail_event(ulpq, &temp);
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}
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return event_eor;
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}
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/* Add a new event for propagation to the ULP. */
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/* Clear the partial delivery mode for this socket. Note: This
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* assumes that no association is currently in partial delivery mode.
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*/
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int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc)
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{
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struct sctp_sock *sp = sctp_sk(sk);
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if (atomic_dec_and_test(&sp->pd_mode)) {
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/* This means there are no other associations in PD, so
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* we can go ahead and clear out the lobby in one shot
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*/
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if (!skb_queue_empty(&sp->pd_lobby)) {
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skb_queue_splice_tail_init(&sp->pd_lobby,
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&sk->sk_receive_queue);
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return 1;
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}
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} else {
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/* There are other associations in PD, so we only need to
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* pull stuff out of the lobby that belongs to the
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* associations that is exiting PD (all of its notifications
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* are posted here).
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*/
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if (!skb_queue_empty(&sp->pd_lobby) && asoc) {
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struct sk_buff *skb, *tmp;
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struct sctp_ulpevent *event;
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sctp_skb_for_each(skb, &sp->pd_lobby, tmp) {
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event = sctp_skb2event(skb);
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if (event->asoc == asoc) {
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__skb_unlink(skb, &sp->pd_lobby);
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__skb_queue_tail(&sk->sk_receive_queue,
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skb);
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}
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}
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}
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}
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return 0;
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}
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/* Set the pd_mode on the socket and ulpq */
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static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq)
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{
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struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk);
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atomic_inc(&sp->pd_mode);
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ulpq->pd_mode = 1;
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}
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/* Clear the pd_mode and restart any pending messages waiting for delivery. */
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static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
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{
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ulpq->pd_mode = 0;
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sctp_ulpq_reasm_drain(ulpq);
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return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc);
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}
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int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sk_buff_head *skb_list)
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{
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struct sock *sk = ulpq->asoc->base.sk;
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struct sctp_sock *sp = sctp_sk(sk);
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struct sctp_ulpevent *event;
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struct sk_buff_head *queue;
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struct sk_buff *skb;
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int clear_pd = 0;
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skb = __skb_peek(skb_list);
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event = sctp_skb2event(skb);
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/* If the socket is just going to throw this away, do not
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* even try to deliver it.
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*/
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if (sk->sk_shutdown & RCV_SHUTDOWN &&
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(sk->sk_shutdown & SEND_SHUTDOWN ||
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!sctp_ulpevent_is_notification(event)))
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goto out_free;
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if (!sctp_ulpevent_is_notification(event)) {
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sk_mark_napi_id(sk, skb);
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sk_incoming_cpu_update(sk);
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}
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/* Check if the user wishes to receive this event. */
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if (!sctp_ulpevent_is_enabled(event, ulpq->asoc->subscribe))
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goto out_free;
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/* If we are in partial delivery mode, post to the lobby until
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* partial delivery is cleared, unless, of course _this_ is
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* the association the cause of the partial delivery.
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*/
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if (atomic_read(&sp->pd_mode) == 0) {
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queue = &sk->sk_receive_queue;
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} else {
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if (ulpq->pd_mode) {
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/* If the association is in partial delivery, we
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* need to finish delivering the partially processed
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* packet before passing any other data. This is
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* because we don't truly support stream interleaving.
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*/
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if ((event->msg_flags & MSG_NOTIFICATION) ||
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(SCTP_DATA_NOT_FRAG ==
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(event->msg_flags & SCTP_DATA_FRAG_MASK)))
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queue = &sp->pd_lobby;
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else {
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clear_pd = event->msg_flags & MSG_EOR;
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queue = &sk->sk_receive_queue;
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}
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} else {
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/*
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* If fragment interleave is enabled, we
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* can queue this to the receive queue instead
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* of the lobby.
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*/
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if (sp->frag_interleave)
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queue = &sk->sk_receive_queue;
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else
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queue = &sp->pd_lobby;
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}
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}
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skb_queue_splice_tail_init(skb_list, queue);
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/* Did we just complete partial delivery and need to get
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* rolling again? Move pending data to the receive
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* queue.
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*/
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if (clear_pd)
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sctp_ulpq_clear_pd(ulpq);
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if (queue == &sk->sk_receive_queue && !sp->data_ready_signalled) {
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if (!sock_owned_by_user(sk))
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sp->data_ready_signalled = 1;
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sk->sk_data_ready(sk);
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}
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return 1;
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out_free:
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if (skb_list)
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sctp_queue_purge_ulpevents(skb_list);
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else
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sctp_ulpevent_free(event);
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return 0;
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}
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/* 2nd Level Abstractions */
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/* Helper function to store chunks that need to be reassembled. */
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static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
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struct sctp_ulpevent *event)
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{
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struct sk_buff *pos;
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struct sctp_ulpevent *cevent;
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__u32 tsn, ctsn;
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tsn = event->tsn;
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/* See if it belongs at the end. */
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pos = skb_peek_tail(&ulpq->reasm);
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if (!pos) {
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__skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
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return;
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}
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/* Short circuit just dropping it at the end. */
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cevent = sctp_skb2event(pos);
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ctsn = cevent->tsn;
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if (TSN_lt(ctsn, tsn)) {
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__skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
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return;
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}
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/* Find the right place in this list. We store them by TSN. */
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skb_queue_walk(&ulpq->reasm, pos) {
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cevent = sctp_skb2event(pos);
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ctsn = cevent->tsn;
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if (TSN_lt(tsn, ctsn))
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break;
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}
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/* Insert before pos. */
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__skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
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}
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/* Helper function to return an event corresponding to the reassembled
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* datagram.
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* This routine creates a re-assembled skb given the first and last skb's
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* as stored in the reassembly queue. The skb's may be non-linear if the sctp
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* payload was fragmented on the way and ip had to reassemble them.
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* We add the rest of skb's to the first skb's fraglist.
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*/
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struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net,
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struct sk_buff_head *queue,
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struct sk_buff *f_frag,
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struct sk_buff *l_frag)
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{
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struct sk_buff *pos;
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struct sk_buff *new = NULL;
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struct sctp_ulpevent *event;
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struct sk_buff *pnext, *last;
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struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
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/* Store the pointer to the 2nd skb */
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if (f_frag == l_frag)
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pos = NULL;
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else
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pos = f_frag->next;
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/* Get the last skb in the f_frag's frag_list if present. */
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for (last = list; list; last = list, list = list->next)
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;
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/* Add the list of remaining fragments to the first fragments
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* frag_list.
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*/
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if (last)
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last->next = pos;
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else {
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if (skb_cloned(f_frag)) {
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/* This is a cloned skb, we can't just modify
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* the frag_list. We need a new skb to do that.
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* Instead of calling skb_unshare(), we'll do it
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* ourselves since we need to delay the free.
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*/
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new = skb_copy(f_frag, GFP_ATOMIC);
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if (!new)
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return NULL; /* try again later */
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sctp_skb_set_owner_r(new, f_frag->sk);
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skb_shinfo(new)->frag_list = pos;
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} else
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skb_shinfo(f_frag)->frag_list = pos;
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}
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/* Remove the first fragment from the reassembly queue. */
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__skb_unlink(f_frag, queue);
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/* if we did unshare, then free the old skb and re-assign */
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if (new) {
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kfree_skb(f_frag);
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f_frag = new;
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}
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while (pos) {
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pnext = pos->next;
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/* Update the len and data_len fields of the first fragment. */
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f_frag->len += pos->len;
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f_frag->data_len += pos->len;
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/* Remove the fragment from the reassembly queue. */
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__skb_unlink(pos, queue);
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/* Break if we have reached the last fragment. */
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if (pos == l_frag)
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break;
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pos->next = pnext;
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pos = pnext;
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}
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event = sctp_skb2event(f_frag);
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SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS);
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return event;
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}
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|
|
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/* Helper function to check if an incoming chunk has filled up the last
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* missing fragment in a SCTP datagram and return the corresponding event.
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*/
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static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
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{
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struct sk_buff *pos;
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struct sctp_ulpevent *cevent;
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struct sk_buff *first_frag = NULL;
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__u32 ctsn, next_tsn;
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struct sctp_ulpevent *retval = NULL;
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struct sk_buff *pd_first = NULL;
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struct sk_buff *pd_last = NULL;
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size_t pd_len = 0;
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struct sctp_association *asoc;
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u32 pd_point;
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|
|
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/* Initialized to 0 just to avoid compiler warning message. Will
|
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* never be used with this value. It is referenced only after it
|
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* is set when we find the first fragment of a message.
|
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*/
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next_tsn = 0;
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|
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/* The chunks are held in the reasm queue sorted by TSN.
|
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* Walk through the queue sequentially and look for a sequence of
|
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* fragmented chunks that complete a datagram.
|
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* 'first_frag' and next_tsn are reset when we find a chunk which
|
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* is the first fragment of a datagram. Once these 2 fields are set
|
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* we expect to find the remaining middle fragments and the last
|
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* fragment in order. If not, first_frag is reset to NULL and we
|
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* start the next pass when we find another first fragment.
|
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*
|
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* There is a potential to do partial delivery if user sets
|
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* SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here
|
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* to see if can do PD.
|
|
*/
|
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skb_queue_walk(&ulpq->reasm, pos) {
|
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cevent = sctp_skb2event(pos);
|
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ctsn = cevent->tsn;
|
|
|
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switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
|
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case SCTP_DATA_FIRST_FRAG:
|
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/* If this "FIRST_FRAG" is the first
|
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* element in the queue, then count it towards
|
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* possible PD.
|
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*/
|
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if (skb_queue_is_first(&ulpq->reasm, pos)) {
|
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pd_first = pos;
|
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pd_last = pos;
|
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pd_len = pos->len;
|
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} else {
|
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pd_first = NULL;
|
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pd_last = NULL;
|
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pd_len = 0;
|
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}
|
|
|
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first_frag = pos;
|
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next_tsn = ctsn + 1;
|
|
break;
|
|
|
|
case SCTP_DATA_MIDDLE_FRAG:
|
|
if ((first_frag) && (ctsn == next_tsn)) {
|
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next_tsn++;
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|
if (pd_first) {
|
|
pd_last = pos;
|
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pd_len += pos->len;
|
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}
|
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} else
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first_frag = NULL;
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break;
|
|
|
|
case SCTP_DATA_LAST_FRAG:
|
|
if (first_frag && (ctsn == next_tsn))
|
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goto found;
|
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else
|
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first_frag = NULL;
|
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break;
|
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}
|
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}
|
|
|
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asoc = ulpq->asoc;
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|
if (pd_first) {
|
|
/* Make sure we can enter partial deliver.
|
|
* We can trigger partial delivery only if framgent
|
|
* interleave is set, or the socket is not already
|
|
* in partial delivery.
|
|
*/
|
|
if (!sctp_sk(asoc->base.sk)->frag_interleave &&
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atomic_read(&sctp_sk(asoc->base.sk)->pd_mode))
|
|
goto done;
|
|
|
|
cevent = sctp_skb2event(pd_first);
|
|
pd_point = sctp_sk(asoc->base.sk)->pd_point;
|
|
if (pd_point && pd_point <= pd_len) {
|
|
retval = sctp_make_reassembled_event(asoc->base.net,
|
|
&ulpq->reasm,
|
|
pd_first, pd_last);
|
|
if (retval)
|
|
sctp_ulpq_set_pd(ulpq);
|
|
}
|
|
}
|
|
done:
|
|
return retval;
|
|
found:
|
|
retval = sctp_make_reassembled_event(ulpq->asoc->base.net,
|
|
&ulpq->reasm, first_frag, pos);
|
|
if (retval)
|
|
retval->msg_flags |= MSG_EOR;
|
|
goto done;
|
|
}
|
|
|
|
/* Retrieve the next set of fragments of a partial message. */
|
|
static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq)
|
|
{
|
|
struct sk_buff *pos, *last_frag, *first_frag;
|
|
struct sctp_ulpevent *cevent;
|
|
__u32 ctsn, next_tsn;
|
|
int is_last;
|
|
struct sctp_ulpevent *retval;
|
|
|
|
/* The chunks are held in the reasm queue sorted by TSN.
|
|
* Walk through the queue sequentially and look for the first
|
|
* sequence of fragmented chunks.
|
|
*/
|
|
|
|
if (skb_queue_empty(&ulpq->reasm))
|
|
return NULL;
|
|
|
|
last_frag = first_frag = NULL;
|
|
retval = NULL;
|
|
next_tsn = 0;
|
|
is_last = 0;
|
|
|
|
skb_queue_walk(&ulpq->reasm, pos) {
|
|
cevent = sctp_skb2event(pos);
|
|
ctsn = cevent->tsn;
|
|
|
|
switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
|
|
case SCTP_DATA_FIRST_FRAG:
|
|
if (!first_frag)
|
|
return NULL;
|
|
goto done;
|
|
case SCTP_DATA_MIDDLE_FRAG:
|
|
if (!first_frag) {
|
|
first_frag = pos;
|
|
next_tsn = ctsn + 1;
|
|
last_frag = pos;
|
|
} else if (next_tsn == ctsn) {
|
|
next_tsn++;
|
|
last_frag = pos;
|
|
} else
|
|
goto done;
|
|
break;
|
|
case SCTP_DATA_LAST_FRAG:
|
|
if (!first_frag)
|
|
first_frag = pos;
|
|
else if (ctsn != next_tsn)
|
|
goto done;
|
|
last_frag = pos;
|
|
is_last = 1;
|
|
goto done;
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/* We have the reassembled event. There is no need to look
|
|
* further.
|
|
*/
|
|
done:
|
|
retval = sctp_make_reassembled_event(ulpq->asoc->base.net, &ulpq->reasm,
|
|
first_frag, last_frag);
|
|
if (retval && is_last)
|
|
retval->msg_flags |= MSG_EOR;
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
/* Helper function to reassemble chunks. Hold chunks on the reasm queue that
|
|
* need reassembling.
|
|
*/
|
|
static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
|
|
struct sctp_ulpevent *event)
|
|
{
|
|
struct sctp_ulpevent *retval = NULL;
|
|
|
|
/* Check if this is part of a fragmented message. */
|
|
if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) {
|
|
event->msg_flags |= MSG_EOR;
|
|
return event;
|
|
}
|
|
|
|
sctp_ulpq_store_reasm(ulpq, event);
|
|
if (!ulpq->pd_mode)
|
|
retval = sctp_ulpq_retrieve_reassembled(ulpq);
|
|
else {
|
|
__u32 ctsn, ctsnap;
|
|
|
|
/* Do not even bother unless this is the next tsn to
|
|
* be delivered.
|
|
*/
|
|
ctsn = event->tsn;
|
|
ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map);
|
|
if (TSN_lte(ctsn, ctsnap))
|
|
retval = sctp_ulpq_retrieve_partial(ulpq);
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
/* Retrieve the first part (sequential fragments) for partial delivery. */
|
|
static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq)
|
|
{
|
|
struct sk_buff *pos, *last_frag, *first_frag;
|
|
struct sctp_ulpevent *cevent;
|
|
__u32 ctsn, next_tsn;
|
|
struct sctp_ulpevent *retval;
|
|
|
|
/* The chunks are held in the reasm queue sorted by TSN.
|
|
* Walk through the queue sequentially and look for a sequence of
|
|
* fragmented chunks that start a datagram.
|
|
*/
|
|
|
|
if (skb_queue_empty(&ulpq->reasm))
|
|
return NULL;
|
|
|
|
last_frag = first_frag = NULL;
|
|
retval = NULL;
|
|
next_tsn = 0;
|
|
|
|
skb_queue_walk(&ulpq->reasm, pos) {
|
|
cevent = sctp_skb2event(pos);
|
|
ctsn = cevent->tsn;
|
|
|
|
switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) {
|
|
case SCTP_DATA_FIRST_FRAG:
|
|
if (!first_frag) {
|
|
first_frag = pos;
|
|
next_tsn = ctsn + 1;
|
|
last_frag = pos;
|
|
} else
|
|
goto done;
|
|
break;
|
|
|
|
case SCTP_DATA_MIDDLE_FRAG:
|
|
if (!first_frag)
|
|
return NULL;
|
|
if (ctsn == next_tsn) {
|
|
next_tsn++;
|
|
last_frag = pos;
|
|
} else
|
|
goto done;
|
|
break;
|
|
|
|
case SCTP_DATA_LAST_FRAG:
|
|
if (!first_frag)
|
|
return NULL;
|
|
else
|
|
goto done;
|
|
break;
|
|
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/* We have the reassembled event. There is no need to look
|
|
* further.
|
|
*/
|
|
done:
|
|
retval = sctp_make_reassembled_event(ulpq->asoc->base.net, &ulpq->reasm,
|
|
first_frag, last_frag);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Flush out stale fragments from the reassembly queue when processing
|
|
* a Forward TSN.
|
|
*
|
|
* RFC 3758, Section 3.6
|
|
*
|
|
* After receiving and processing a FORWARD TSN, the data receiver MUST
|
|
* take cautions in updating its re-assembly queue. The receiver MUST
|
|
* remove any partially reassembled message, which is still missing one
|
|
* or more TSNs earlier than or equal to the new cumulative TSN point.
|
|
* In the event that the receiver has invoked the partial delivery API,
|
|
* a notification SHOULD also be generated to inform the upper layer API
|
|
* that the message being partially delivered will NOT be completed.
|
|
*/
|
|
void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn)
|
|
{
|
|
struct sk_buff *pos, *tmp;
|
|
struct sctp_ulpevent *event;
|
|
__u32 tsn;
|
|
|
|
if (skb_queue_empty(&ulpq->reasm))
|
|
return;
|
|
|
|
skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
|
|
event = sctp_skb2event(pos);
|
|
tsn = event->tsn;
|
|
|
|
/* Since the entire message must be abandoned by the
|
|
* sender (item A3 in Section 3.5, RFC 3758), we can
|
|
* free all fragments on the list that are less then
|
|
* or equal to ctsn_point
|
|
*/
|
|
if (TSN_lte(tsn, fwd_tsn)) {
|
|
__skb_unlink(pos, &ulpq->reasm);
|
|
sctp_ulpevent_free(event);
|
|
} else
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Drain the reassembly queue. If we just cleared parted delivery, it
|
|
* is possible that the reassembly queue will contain already reassembled
|
|
* messages. Retrieve any such messages and give them to the user.
|
|
*/
|
|
static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq)
|
|
{
|
|
struct sctp_ulpevent *event = NULL;
|
|
|
|
if (skb_queue_empty(&ulpq->reasm))
|
|
return;
|
|
|
|
while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) {
|
|
struct sk_buff_head temp;
|
|
|
|
skb_queue_head_init(&temp);
|
|
__skb_queue_tail(&temp, sctp_event2skb(event));
|
|
|
|
/* Do ordering if needed. */
|
|
if (event->msg_flags & MSG_EOR)
|
|
event = sctp_ulpq_order(ulpq, event);
|
|
|
|
/* Send event to the ULP. 'event' is the
|
|
* sctp_ulpevent for very first SKB on the temp' list.
|
|
*/
|
|
if (event)
|
|
sctp_ulpq_tail_event(ulpq, &temp);
|
|
}
|
|
}
|
|
|
|
|
|
/* Helper function to gather skbs that have possibly become
|
|
* ordered by an incoming chunk.
|
|
*/
|
|
static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq,
|
|
struct sctp_ulpevent *event)
|
|
{
|
|
struct sk_buff_head *event_list;
|
|
struct sk_buff *pos, *tmp;
|
|
struct sctp_ulpevent *cevent;
|
|
struct sctp_stream *stream;
|
|
__u16 sid, csid, cssn;
|
|
|
|
sid = event->stream;
|
|
stream = &ulpq->asoc->stream;
|
|
|
|
event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev;
|
|
|
|
/* We are holding the chunks by stream, by SSN. */
|
|
sctp_skb_for_each(pos, &ulpq->lobby, tmp) {
|
|
cevent = (struct sctp_ulpevent *) pos->cb;
|
|
csid = cevent->stream;
|
|
cssn = cevent->ssn;
|
|
|
|
/* Have we gone too far? */
|
|
if (csid > sid)
|
|
break;
|
|
|
|
/* Have we not gone far enough? */
|
|
if (csid < sid)
|
|
continue;
|
|
|
|
if (cssn != sctp_ssn_peek(stream, in, sid))
|
|
break;
|
|
|
|
/* Found it, so mark in the stream. */
|
|
sctp_ssn_next(stream, in, sid);
|
|
|
|
__skb_unlink(pos, &ulpq->lobby);
|
|
|
|
/* Attach all gathered skbs to the event. */
|
|
__skb_queue_tail(event_list, pos);
|
|
}
|
|
}
|
|
|
|
/* Helper function to store chunks needing ordering. */
|
|
static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq,
|
|
struct sctp_ulpevent *event)
|
|
{
|
|
struct sk_buff *pos;
|
|
struct sctp_ulpevent *cevent;
|
|
__u16 sid, csid;
|
|
__u16 ssn, cssn;
|
|
|
|
pos = skb_peek_tail(&ulpq->lobby);
|
|
if (!pos) {
|
|
__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
|
|
return;
|
|
}
|
|
|
|
sid = event->stream;
|
|
ssn = event->ssn;
|
|
|
|
cevent = (struct sctp_ulpevent *) pos->cb;
|
|
csid = cevent->stream;
|
|
cssn = cevent->ssn;
|
|
if (sid > csid) {
|
|
__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
|
|
return;
|
|
}
|
|
|
|
if ((sid == csid) && SSN_lt(cssn, ssn)) {
|
|
__skb_queue_tail(&ulpq->lobby, sctp_event2skb(event));
|
|
return;
|
|
}
|
|
|
|
/* Find the right place in this list. We store them by
|
|
* stream ID and then by SSN.
|
|
*/
|
|
skb_queue_walk(&ulpq->lobby, pos) {
|
|
cevent = (struct sctp_ulpevent *) pos->cb;
|
|
csid = cevent->stream;
|
|
cssn = cevent->ssn;
|
|
|
|
if (csid > sid)
|
|
break;
|
|
if (csid == sid && SSN_lt(ssn, cssn))
|
|
break;
|
|
}
|
|
|
|
|
|
/* Insert before pos. */
|
|
__skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event));
|
|
}
|
|
|
|
static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq,
|
|
struct sctp_ulpevent *event)
|
|
{
|
|
__u16 sid, ssn;
|
|
struct sctp_stream *stream;
|
|
|
|
/* Check if this message needs ordering. */
|
|
if (event->msg_flags & SCTP_DATA_UNORDERED)
|
|
return event;
|
|
|
|
/* Note: The stream ID must be verified before this routine. */
|
|
sid = event->stream;
|
|
ssn = event->ssn;
|
|
stream = &ulpq->asoc->stream;
|
|
|
|
/* Is this the expected SSN for this stream ID? */
|
|
if (ssn != sctp_ssn_peek(stream, in, sid)) {
|
|
/* We've received something out of order, so find where it
|
|
* needs to be placed. We order by stream and then by SSN.
|
|
*/
|
|
sctp_ulpq_store_ordered(ulpq, event);
|
|
return NULL;
|
|
}
|
|
|
|
/* Mark that the next chunk has been found. */
|
|
sctp_ssn_next(stream, in, sid);
|
|
|
|
/* Go find any other chunks that were waiting for
|
|
* ordering.
|
|
*/
|
|
sctp_ulpq_retrieve_ordered(ulpq, event);
|
|
|
|
return event;
|
|
}
|
|
|
|
/* Helper function to gather skbs that have possibly become
|
|
* ordered by forward tsn skipping their dependencies.
|
|
*/
|
|
static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid)
|
|
{
|
|
struct sk_buff *pos, *tmp;
|
|
struct sctp_ulpevent *cevent;
|
|
struct sctp_ulpevent *event;
|
|
struct sctp_stream *stream;
|
|
struct sk_buff_head temp;
|
|
struct sk_buff_head *lobby = &ulpq->lobby;
|
|
__u16 csid, cssn;
|
|
|
|
stream = &ulpq->asoc->stream;
|
|
|
|
/* We are holding the chunks by stream, by SSN. */
|
|
skb_queue_head_init(&temp);
|
|
event = NULL;
|
|
sctp_skb_for_each(pos, lobby, tmp) {
|
|
cevent = (struct sctp_ulpevent *) pos->cb;
|
|
csid = cevent->stream;
|
|
cssn = cevent->ssn;
|
|
|
|
/* Have we gone too far? */
|
|
if (csid > sid)
|
|
break;
|
|
|
|
/* Have we not gone far enough? */
|
|
if (csid < sid)
|
|
continue;
|
|
|
|
/* see if this ssn has been marked by skipping */
|
|
if (!SSN_lt(cssn, sctp_ssn_peek(stream, in, csid)))
|
|
break;
|
|
|
|
__skb_unlink(pos, lobby);
|
|
if (!event)
|
|
/* Create a temporary list to collect chunks on. */
|
|
event = sctp_skb2event(pos);
|
|
|
|
/* Attach all gathered skbs to the event. */
|
|
__skb_queue_tail(&temp, pos);
|
|
}
|
|
|
|
/* If we didn't reap any data, see if the next expected SSN
|
|
* is next on the queue and if so, use that.
|
|
*/
|
|
if (event == NULL && pos != (struct sk_buff *)lobby) {
|
|
cevent = (struct sctp_ulpevent *) pos->cb;
|
|
csid = cevent->stream;
|
|
cssn = cevent->ssn;
|
|
|
|
if (csid == sid && cssn == sctp_ssn_peek(stream, in, csid)) {
|
|
sctp_ssn_next(stream, in, csid);
|
|
__skb_unlink(pos, lobby);
|
|
__skb_queue_tail(&temp, pos);
|
|
event = sctp_skb2event(pos);
|
|
}
|
|
}
|
|
|
|
/* Send event to the ULP. 'event' is the sctp_ulpevent for
|
|
* very first SKB on the 'temp' list.
|
|
*/
|
|
if (event) {
|
|
/* see if we have more ordered that we can deliver */
|
|
sctp_ulpq_retrieve_ordered(ulpq, event);
|
|
sctp_ulpq_tail_event(ulpq, &temp);
|
|
}
|
|
}
|
|
|
|
/* Skip over an SSN. This is used during the processing of
|
|
* Forwared TSN chunk to skip over the abandoned ordered data
|
|
*/
|
|
void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn)
|
|
{
|
|
struct sctp_stream *stream;
|
|
|
|
/* Note: The stream ID must be verified before this routine. */
|
|
stream = &ulpq->asoc->stream;
|
|
|
|
/* Is this an old SSN? If so ignore. */
|
|
if (SSN_lt(ssn, sctp_ssn_peek(stream, in, sid)))
|
|
return;
|
|
|
|
/* Mark that we are no longer expecting this SSN or lower. */
|
|
sctp_ssn_skip(stream, in, sid, ssn);
|
|
|
|
/* Go find any other chunks that were waiting for
|
|
* ordering and deliver them if needed.
|
|
*/
|
|
sctp_ulpq_reap_ordered(ulpq, sid);
|
|
}
|
|
|
|
__u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, struct sk_buff_head *list,
|
|
__u16 needed)
|
|
{
|
|
__u16 freed = 0;
|
|
__u32 tsn, last_tsn;
|
|
struct sk_buff *skb, *flist, *last;
|
|
struct sctp_ulpevent *event;
|
|
struct sctp_tsnmap *tsnmap;
|
|
|
|
tsnmap = &ulpq->asoc->peer.tsn_map;
|
|
|
|
while ((skb = skb_peek_tail(list)) != NULL) {
|
|
event = sctp_skb2event(skb);
|
|
tsn = event->tsn;
|
|
|
|
/* Don't renege below the Cumulative TSN ACK Point. */
|
|
if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap)))
|
|
break;
|
|
|
|
/* Events in ordering queue may have multiple fragments
|
|
* corresponding to additional TSNs. Sum the total
|
|
* freed space; find the last TSN.
|
|
*/
|
|
freed += skb_headlen(skb);
|
|
flist = skb_shinfo(skb)->frag_list;
|
|
for (last = flist; flist; flist = flist->next) {
|
|
last = flist;
|
|
freed += skb_headlen(last);
|
|
}
|
|
if (last)
|
|
last_tsn = sctp_skb2event(last)->tsn;
|
|
else
|
|
last_tsn = tsn;
|
|
|
|
/* Unlink the event, then renege all applicable TSNs. */
|
|
__skb_unlink(skb, list);
|
|
sctp_ulpevent_free(event);
|
|
while (TSN_lte(tsn, last_tsn)) {
|
|
sctp_tsnmap_renege(tsnmap, tsn);
|
|
tsn++;
|
|
}
|
|
if (freed >= needed)
|
|
return freed;
|
|
}
|
|
|
|
return freed;
|
|
}
|
|
|
|
/* Renege 'needed' bytes from the ordering queue. */
|
|
static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed)
|
|
{
|
|
return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed);
|
|
}
|
|
|
|
/* Renege 'needed' bytes from the reassembly queue. */
|
|
static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed)
|
|
{
|
|
return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed);
|
|
}
|
|
|
|
/* Partial deliver the first message as there is pressure on rwnd. */
|
|
void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq,
|
|
gfp_t gfp)
|
|
{
|
|
struct sctp_ulpevent *event;
|
|
struct sctp_association *asoc;
|
|
struct sctp_sock *sp;
|
|
__u32 ctsn;
|
|
struct sk_buff *skb;
|
|
|
|
asoc = ulpq->asoc;
|
|
sp = sctp_sk(asoc->base.sk);
|
|
|
|
/* If the association is already in Partial Delivery mode
|
|
* we have nothing to do.
|
|
*/
|
|
if (ulpq->pd_mode)
|
|
return;
|
|
|
|
/* Data must be at or below the Cumulative TSN ACK Point to
|
|
* start partial delivery.
|
|
*/
|
|
skb = skb_peek(&asoc->ulpq.reasm);
|
|
if (skb != NULL) {
|
|
ctsn = sctp_skb2event(skb)->tsn;
|
|
if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)))
|
|
return;
|
|
}
|
|
|
|
/* If the user enabled fragment interleave socket option,
|
|
* multiple associations can enter partial delivery.
|
|
* Otherwise, we can only enter partial delivery if the
|
|
* socket is not in partial deliver mode.
|
|
*/
|
|
if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) {
|
|
/* Is partial delivery possible? */
|
|
event = sctp_ulpq_retrieve_first(ulpq);
|
|
/* Send event to the ULP. */
|
|
if (event) {
|
|
struct sk_buff_head temp;
|
|
|
|
skb_queue_head_init(&temp);
|
|
__skb_queue_tail(&temp, sctp_event2skb(event));
|
|
sctp_ulpq_tail_event(ulpq, &temp);
|
|
sctp_ulpq_set_pd(ulpq);
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Renege some packets to make room for an incoming chunk. */
|
|
void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
|
|
gfp_t gfp)
|
|
{
|
|
struct sctp_association *asoc = ulpq->asoc;
|
|
__u32 freed = 0;
|
|
__u16 needed;
|
|
|
|
needed = ntohs(chunk->chunk_hdr->length) -
|
|
sizeof(struct sctp_data_chunk);
|
|
|
|
if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) {
|
|
freed = sctp_ulpq_renege_order(ulpq, needed);
|
|
if (freed < needed)
|
|
freed += sctp_ulpq_renege_frags(ulpq, needed - freed);
|
|
}
|
|
/* If able to free enough room, accept this chunk. */
|
|
if (sk_rmem_schedule(asoc->base.sk, chunk->skb, needed) &&
|
|
freed >= needed) {
|
|
int retval = sctp_ulpq_tail_data(ulpq, chunk, gfp);
|
|
/*
|
|
* Enter partial delivery if chunk has not been
|
|
* delivered; otherwise, drain the reassembly queue.
|
|
*/
|
|
if (retval <= 0)
|
|
sctp_ulpq_partial_delivery(ulpq, gfp);
|
|
else if (retval == 1)
|
|
sctp_ulpq_reasm_drain(ulpq);
|
|
}
|
|
|
|
sk_mem_reclaim(asoc->base.sk);
|
|
}
|
|
|
|
|
|
|
|
/* Notify the application if an association is aborted and in
|
|
* partial delivery mode. Send up any pending received messages.
|
|
*/
|
|
void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp)
|
|
{
|
|
struct sctp_ulpevent *ev = NULL;
|
|
struct sctp_sock *sp;
|
|
struct sock *sk;
|
|
|
|
if (!ulpq->pd_mode)
|
|
return;
|
|
|
|
sk = ulpq->asoc->base.sk;
|
|
sp = sctp_sk(sk);
|
|
if (sctp_ulpevent_type_enabled(ulpq->asoc->subscribe,
|
|
SCTP_PARTIAL_DELIVERY_EVENT))
|
|
ev = sctp_ulpevent_make_pdapi(ulpq->asoc,
|
|
SCTP_PARTIAL_DELIVERY_ABORTED,
|
|
0, 0, 0, gfp);
|
|
if (ev)
|
|
__skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev));
|
|
|
|
/* If there is data waiting, send it up the socket now. */
|
|
if ((sctp_ulpq_clear_pd(ulpq) || ev) && !sp->data_ready_signalled) {
|
|
sp->data_ready_signalled = 1;
|
|
sk->sk_data_ready(sk);
|
|
}
|
|
}
|