sctp: ABORT if receive, reassmbly, or reodering queue is not empty while closing...

commit cd4fcc704f30f2064ab30b5300d44d431e46db50 upstream.

Trigger user ABORT if application closes a socket which has data
queued on the socket receive queue or chunks waiting on the
reassembly or ordering queue as this would imply data being lost
which defeats the point of a graceful shutdown.

This behavior is already practiced in TCP.

We do not check the input queue because that would mean to parse
all chunks on it to look for unacknowledged data which seems too
much of an effort. Control chunks or duplicated chunks may also
be in the input queue and should not be stopping a graceful
shutdown.

Signed-off-by: Thomas Graf <tgraf@infradead.org>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/include/net/sctp/ulpevent.h b/include/net/sctp/ulpevent.h
index 7ea12e8e6676bb6175e57aae51943fb7db8f0868..b93b71917ffdd85469dd187741b504cbb603a5f4 100644 (file)
--- a/include/net/sctp/ulpevent.h
+++ b/include/net/sctp/ulpevent.h
@@ -80,7 +80,7 @@ static inline struct sctp_ulpevent *sctp_skb2event(struct sk_buff *skb)
 
 void sctp_ulpevent_free(struct sctp_ulpevent *);
 int sctp_ulpevent_is_notification(const struct sctp_ulpevent *);
-void sctp_queue_purge_ulpevents(struct sk_buff_head *list);
+unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list);
 
 struct sctp_ulpevent *sctp_ulpevent_make_assoc_change(
        const struct sctp_association *asoc,

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 22631c11a1965eceac06de5d431e30a62642f4cb..03daceb2d9a057aa4e69346b8b56fb799943100b 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1373,6 +1373,7 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
        struct sctp_endpoint *ep;
        struct sctp_association *asoc;
        struct list_head *pos, *temp;
+       unsigned int data_was_unread;
 
        SCTP_DEBUG_PRINTK("sctp_close(sk: 0x%p, timeout:%ld)\n", sk, timeout);
 
@@ -1382,6 +1383,10 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
 
        ep = sctp_sk(sk)->ep;
 
+       /* Clean up any skbs sitting on the receive queue.  */
+       data_was_unread = sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
+       data_was_unread += sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);
+
        /* Walk all associations on an endpoint.  */
        list_for_each_safe(pos, temp, &ep->asocs) {
                asoc = list_entry(pos, struct sctp_association, asocs);
@@ -1399,7 +1404,9 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
                        }
                }
 
-               if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
+               if (data_was_unread || !skb_queue_empty(&asoc->ulpq.lobby) ||
+                   !skb_queue_empty(&asoc->ulpq.reasm) ||
+                   (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime)) {
                        struct sctp_chunk *chunk;
 
                        chunk = sctp_make_abort_user(asoc, NULL, 0);
@@ -1409,10 +1416,6 @@ SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
                        sctp_primitive_SHUTDOWN(asoc, NULL);
        }
 
-       /* Clean up any skbs sitting on the receive queue.  */
-       sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
-       sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);
-
        /* On a TCP-style socket, block for at most linger_time if set. */
        if (sctp_style(sk, TCP) && timeout)
                sctp_wait_for_close(sk, timeout);

diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c
index aa72e89c3ee1685ad6d4096c76072daf80937f16..3b81c62f96831a490fa45919ee90ab70a754145b 100644 (file)
--- a/net/sctp/ulpevent.c
+++ b/net/sctp/ulpevent.c
@@ -1053,9 +1053,19 @@ void sctp_ulpevent_free(struct sctp_ulpevent *event)
 }
 
 /* Purge the skb lists holding ulpevents. */
-void sctp_queue_purge_ulpevents(struct sk_buff_head *list)
+unsigned int sctp_queue_purge_ulpevents(struct sk_buff_head *list)
 {
        struct sk_buff *skb;
-       while ((skb = skb_dequeue(list)) != NULL)
-               sctp_ulpevent_free(sctp_skb2event(skb));
+       unsigned int data_unread = 0;
+
+       while ((skb = skb_dequeue(list)) != NULL) {
+               struct sctp_ulpevent *event = sctp_skb2event(skb);
+
+               if (!sctp_ulpevent_is_notification(event))
+                       data_unread += skb->len;
+
+               sctp_ulpevent_free(event);
+       }
+
+       return data_unread;
 }