v4.19.13 snapshot.
diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c
new file mode 100644
index 0000000..0b42710
--- /dev/null
+++ b/net/sctp/ulpqueue.c
@@ -0,0 +1,1153 @@
+/* SCTP kernel implementation
+ * (C) Copyright IBM Corp. 2001, 2004
+ * Copyright (c) 1999-2000 Cisco, Inc.
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001 Intel Corp.
+ * Copyright (c) 2001 Nokia, Inc.
+ * Copyright (c) 2001 La Monte H.P. Yarroll
+ *
+ * This abstraction carries sctp events to the ULP (sockets).
+ *
+ * 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:
+ * Jon Grimm <jgrimm@us.ibm.com>
+ * La Monte H.P. Yarroll <piggy@acm.org>
+ * Sridhar Samudrala <sri@us.ibm.com>
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/busy_poll.h>
+#include <net/sctp/structs.h>
+#include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
+
+/* Forward declarations for internal helpers. */
+static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *);
+static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *,
+ struct sctp_ulpevent *);
+static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq);
+
+/* 1st Level Abstractions */
+
+/* Initialize a ULP queue from a block of memory. */
+struct sctp_ulpq *sctp_ulpq_init(struct sctp_ulpq *ulpq,
+ struct sctp_association *asoc)
+{
+ memset(ulpq, 0, sizeof(struct sctp_ulpq));
+
+ ulpq->asoc = asoc;
+ skb_queue_head_init(&ulpq->reasm);
+ skb_queue_head_init(&ulpq->reasm_uo);
+ skb_queue_head_init(&ulpq->lobby);
+ ulpq->pd_mode = 0;
+
+ return ulpq;
+}
+
+
+/* Flush the reassembly and ordering queues. */
+void sctp_ulpq_flush(struct sctp_ulpq *ulpq)
+{
+ struct sk_buff *skb;
+ struct sctp_ulpevent *event;
+
+ while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) {
+ event = sctp_skb2event(skb);
+ sctp_ulpevent_free(event);
+ }
+
+ while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) {
+ event = sctp_skb2event(skb);
+ sctp_ulpevent_free(event);
+ }
+
+ while ((skb = __skb_dequeue(&ulpq->reasm_uo)) != NULL) {
+ event = sctp_skb2event(skb);
+ sctp_ulpevent_free(event);
+ }
+}
+
+/* Dispose of a ulpqueue. */
+void sctp_ulpq_free(struct sctp_ulpq *ulpq)
+{
+ sctp_ulpq_flush(ulpq);
+}
+
+/* Process an incoming DATA chunk. */
+int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
+ gfp_t gfp)
+{
+ struct sk_buff_head temp;
+ struct sctp_ulpevent *event;
+ int event_eor = 0;
+
+ /* Create an event from the incoming chunk. */
+ event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp);
+ if (!event)
+ return -ENOMEM;
+
+ event->ssn = ntohs(chunk->subh.data_hdr->ssn);
+ event->ppid = chunk->subh.data_hdr->ppid;
+
+ /* Do reassembly if needed. */
+ event = sctp_ulpq_reasm(ulpq, event);
+
+ /* Do ordering if needed. */
+ if ((event) && (event->msg_flags & MSG_EOR)) {
+ /* Create a temporary list to collect chunks on. */
+ skb_queue_head_init(&temp);
+ __skb_queue_tail(&temp, sctp_event2skb(event));
+
+ 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) {
+ event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0;
+ sctp_ulpq_tail_event(ulpq, event);
+ }
+
+ return event_eor;
+}
+
+/* Add a new event for propagation to the ULP. */
+/* Clear the partial delivery mode for this socket. Note: This
+ * assumes that no association is currently in partial delivery mode.
+ */
+int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc)
+{
+ struct sctp_sock *sp = sctp_sk(sk);
+
+ if (atomic_dec_and_test(&sp->pd_mode)) {
+ /* This means there are no other associations in PD, so
+ * we can go ahead and clear out the lobby in one shot
+ */
+ if (!skb_queue_empty(&sp->pd_lobby)) {
+ skb_queue_splice_tail_init(&sp->pd_lobby,
+ &sk->sk_receive_queue);
+ return 1;
+ }
+ } else {
+ /* There are other associations in PD, so we only need to
+ * pull stuff out of the lobby that belongs to the
+ * associations that is exiting PD (all of its notifications
+ * are posted here).
+ */
+ if (!skb_queue_empty(&sp->pd_lobby) && asoc) {
+ struct sk_buff *skb, *tmp;
+ struct sctp_ulpevent *event;
+
+ sctp_skb_for_each(skb, &sp->pd_lobby, tmp) {
+ event = sctp_skb2event(skb);
+ if (event->asoc == asoc) {
+ __skb_unlink(skb, &sp->pd_lobby);
+ __skb_queue_tail(&sk->sk_receive_queue,
+ skb);
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
+/* Set the pd_mode on the socket and ulpq */
+static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq)
+{
+ struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk);
+
+ atomic_inc(&sp->pd_mode);
+ ulpq->pd_mode = 1;
+}
+
+/* Clear the pd_mode and restart any pending messages waiting for delivery. */
+static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq)
+{
+ ulpq->pd_mode = 0;
+ sctp_ulpq_reasm_drain(ulpq);
+ return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc);
+}
+
+/* If the SKB of 'event' is on a list, it is the first such member
+ * of that list.
+ */
+int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event)
+{
+ struct sock *sk = ulpq->asoc->base.sk;
+ struct sctp_sock *sp = sctp_sk(sk);
+ struct sk_buff_head *queue, *skb_list;
+ struct sk_buff *skb = sctp_event2skb(event);
+ int clear_pd = 0;
+
+ skb_list = (struct sk_buff_head *) skb->prev;
+
+ /* If the socket is just going to throw this away, do not
+ * even try to deliver it.
+ */
+ if (sk->sk_shutdown & RCV_SHUTDOWN &&
+ (sk->sk_shutdown & SEND_SHUTDOWN ||
+ !sctp_ulpevent_is_notification(event)))
+ goto out_free;
+
+ if (!sctp_ulpevent_is_notification(event)) {
+ sk_mark_napi_id(sk, skb);
+ sk_incoming_cpu_update(sk);
+ }
+ /* Check if the user wishes to receive this event. */
+ if (!sctp_ulpevent_is_enabled(event, &sp->subscribe))
+ goto out_free;
+
+ /* If we are in partial delivery mode, post to the lobby until
+ * partial delivery is cleared, unless, of course _this_ is
+ * the association the cause of the partial delivery.
+ */
+
+ if (atomic_read(&sp->pd_mode) == 0) {
+ queue = &sk->sk_receive_queue;
+ } else {
+ if (ulpq->pd_mode) {
+ /* If the association is in partial delivery, we
+ * need to finish delivering the partially processed
+ * packet before passing any other data. This is
+ * because we don't truly support stream interleaving.
+ */
+ if ((event->msg_flags & MSG_NOTIFICATION) ||
+ (SCTP_DATA_NOT_FRAG ==
+ (event->msg_flags & SCTP_DATA_FRAG_MASK)))
+ queue = &sp->pd_lobby;
+ else {
+ clear_pd = event->msg_flags & MSG_EOR;
+ queue = &sk->sk_receive_queue;
+ }
+ } else {
+ /*
+ * If fragment interleave is enabled, we
+ * can queue this to the receive queue instead
+ * of the lobby.
+ */
+ if (sp->frag_interleave)
+ queue = &sk->sk_receive_queue;
+ else
+ queue = &sp->pd_lobby;
+ }
+ }
+
+ /* If we are harvesting multiple skbs they will be
+ * collected on a list.
+ */
+ if (skb_list)
+ skb_queue_splice_tail_init(skb_list, queue);
+ else
+ __skb_queue_tail(queue, skb);
+
+ /* Did we just complete partial delivery and need to get
+ * rolling again? Move pending data to the receive
+ * queue.
+ */
+ if (clear_pd)
+ sctp_ulpq_clear_pd(ulpq);
+
+ if (queue == &sk->sk_receive_queue && !sp->data_ready_signalled) {
+ if (!sock_owned_by_user(sk))
+ sp->data_ready_signalled = 1;
+ sk->sk_data_ready(sk);
+ }
+ return 1;
+
+out_free:
+ if (skb_list)
+ sctp_queue_purge_ulpevents(skb_list);
+ else
+ sctp_ulpevent_free(event);
+
+ return 0;
+}
+
+/* 2nd Level Abstractions */
+
+/* Helper function to store chunks that need to be reassembled. */
+static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq,
+ struct sctp_ulpevent *event)
+{
+ struct sk_buff *pos;
+ struct sctp_ulpevent *cevent;
+ __u32 tsn, ctsn;
+
+ tsn = event->tsn;
+
+ /* See if it belongs at the end. */
+ pos = skb_peek_tail(&ulpq->reasm);
+ if (!pos) {
+ __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
+ return;
+ }
+
+ /* Short circuit just dropping it at the end. */
+ cevent = sctp_skb2event(pos);
+ ctsn = cevent->tsn;
+ if (TSN_lt(ctsn, tsn)) {
+ __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event));
+ return;
+ }
+
+ /* Find the right place in this list. We store them by TSN. */
+ skb_queue_walk(&ulpq->reasm, pos) {
+ cevent = sctp_skb2event(pos);
+ ctsn = cevent->tsn;
+
+ if (TSN_lt(tsn, ctsn))
+ break;
+ }
+
+ /* Insert before pos. */
+ __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(event));
+
+}
+
+/* Helper function to return an event corresponding to the reassembled
+ * datagram.
+ * This routine creates a re-assembled skb given the first and last skb's
+ * as stored in the reassembly queue. The skb's may be non-linear if the sctp
+ * payload was fragmented on the way and ip had to reassemble them.
+ * We add the rest of skb's to the first skb's fraglist.
+ */
+struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net,
+ struct sk_buff_head *queue,
+ struct sk_buff *f_frag,
+ struct sk_buff *l_frag)
+{
+ struct sk_buff *pos;
+ struct sk_buff *new = NULL;
+ struct sctp_ulpevent *event;
+ struct sk_buff *pnext, *last;
+ struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
+
+ /* Store the pointer to the 2nd skb */
+ if (f_frag == l_frag)
+ pos = NULL;
+ else
+ pos = f_frag->next;
+
+ /* Get the last skb in the f_frag's frag_list if present. */
+ for (last = list; list; last = list, list = list->next)
+ ;
+
+ /* Add the list of remaining fragments to the first fragments
+ * frag_list.
+ */
+ if (last)
+ last->next = pos;
+ else {
+ if (skb_cloned(f_frag)) {
+ /* This is a cloned skb, we can't just modify
+ * the frag_list. We need a new skb to do that.
+ * Instead of calling skb_unshare(), we'll do it
+ * ourselves since we need to delay the free.
+ */
+ new = skb_copy(f_frag, GFP_ATOMIC);
+ if (!new)
+ return NULL; /* try again later */
+
+ sctp_skb_set_owner_r(new, f_frag->sk);
+
+ skb_shinfo(new)->frag_list = pos;
+ } else
+ skb_shinfo(f_frag)->frag_list = pos;
+ }
+
+ /* Remove the first fragment from the reassembly queue. */
+ __skb_unlink(f_frag, queue);
+
+ /* if we did unshare, then free the old skb and re-assign */
+ if (new) {
+ kfree_skb(f_frag);
+ f_frag = new;
+ }
+
+ while (pos) {
+
+ pnext = pos->next;
+
+ /* Update the len and data_len fields of the first fragment. */
+ f_frag->len += pos->len;
+ f_frag->data_len += pos->len;
+
+ /* Remove the fragment from the reassembly queue. */
+ __skb_unlink(pos, queue);
+
+ /* Break if we have reached the last fragment. */
+ if (pos == l_frag)
+ break;
+ pos->next = pnext;
+ pos = pnext;
+ }
+
+ event = sctp_skb2event(f_frag);
+ SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS);
+
+ return event;
+}
+
+
+/* Helper function to check if an incoming chunk has filled up the last
+ * missing fragment in a SCTP datagram and return the corresponding event.
+ */
+static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq)
+{
+ struct sk_buff *pos;
+ struct sctp_ulpevent *cevent;
+ struct sk_buff *first_frag = NULL;
+ __u32 ctsn, next_tsn;
+ struct sctp_ulpevent *retval = NULL;
+ struct sk_buff *pd_first = NULL;
+ struct sk_buff *pd_last = NULL;
+ size_t pd_len = 0;
+ struct sctp_association *asoc;
+ u32 pd_point;
+
+ /* Initialized to 0 just to avoid compiler warning message. Will
+ * never be used with this value. It is referenced only after it
+ * is set when we find the first fragment of a message.
+ */
+ next_tsn = 0;
+
+ /* 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 complete a datagram.
+ * 'first_frag' and next_tsn are reset when we find a chunk which
+ * is the first fragment of a datagram. Once these 2 fields are set
+ * we expect to find the remaining middle fragments and the last
+ * fragment in order. If not, first_frag is reset to NULL and we
+ * start the next pass when we find another first fragment.
+ *
+ * There is a potential to do partial delivery if user sets
+ * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here
+ * to see if can do PD.
+ */
+ 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 this "FIRST_FRAG" is the first
+ * element in the queue, then count it towards
+ * possible PD.
+ */
+ if (pos == ulpq->reasm.next) {
+ pd_first = pos;
+ pd_last = pos;
+ pd_len = pos->len;
+ } else {
+ pd_first = NULL;
+ pd_last = NULL;
+ pd_len = 0;
+ }
+
+ first_frag = pos;
+ next_tsn = ctsn + 1;
+ break;
+
+ case SCTP_DATA_MIDDLE_FRAG:
+ if ((first_frag) && (ctsn == next_tsn)) {
+ next_tsn++;
+ if (pd_first) {
+ pd_last = pos;
+ pd_len += pos->len;
+ }
+ } else
+ first_frag = NULL;
+ break;
+
+ case SCTP_DATA_LAST_FRAG:
+ if (first_frag && (ctsn == next_tsn))
+ goto found;
+ else
+ first_frag = NULL;
+ break;
+ }
+ }
+
+ asoc = ulpq->asoc;
+ 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 &&
+ 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(sock_net(asoc->base.sk),
+ &ulpq->reasm,
+ pd_first,
+ pd_last);
+ if (retval)
+ sctp_ulpq_set_pd(ulpq);
+ }
+ }
+done:
+ return retval;
+found:
+ retval = sctp_make_reassembled_event(sock_net(ulpq->asoc->base.sk),
+ &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(sock_net(ulpq->asoc->base.sk),
+ &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(sock_net(ulpq->asoc->base.sk),
+ &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;
+ struct sk_buff_head temp;
+
+ if (skb_queue_empty(&ulpq->reasm))
+ return;
+
+ while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) {
+ /* Do ordering if needed. */
+ if ((event) && (event->msg_flags & MSG_EOR)) {
+ skb_queue_head_init(&temp);
+ __skb_queue_tail(&temp, sctp_event2skb(event));
+
+ 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, event);
+ }
+}
+
+
+/* Helper function to gather skbs that have possibly become
+ * ordered by an 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, event);
+ }
+}
+
+/* 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) {
+ sctp_ulpq_tail_event(ulpq, event);
+ 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 (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 sock *sk;
+ struct sctp_sock *sp;
+
+ if (!ulpq->pd_mode)
+ return;
+
+ sk = ulpq->asoc->base.sk;
+ sp = sctp_sk(sk);
+ if (sctp_ulpevent_type_enabled(SCTP_PARTIAL_DELIVERY_EVENT,
+ &sctp_sk(sk)->subscribe))
+ 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);
+ }
+}