Merge tag 'powerpc-4.8-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...

[cascardo/linux.git] / net / sctp / output.c

diff --git a/net/sctp/output.c b/net/sctp/output.c
index 1f1682b..31b7bc3 100644 (file)
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -878,7 +878,7 @@ static sctp_xmit_t sctp_packet_will_fit(struct sctp_packet *packet,
                                        struct sctp_chunk *chunk,
                                        u16 chunk_len)
 {
-       size_t psize, pmtu;
+       size_t psize, pmtu, maxsize;
        sctp_xmit_t retval = SCTP_XMIT_OK;
 
        psize = packet->size;
@@ -906,6 +906,17 @@ static sctp_xmit_t sctp_packet_will_fit(struct sctp_packet *packet,
                        goto out;
                }
 
+               /* Similarly, if this chunk was built before a PMTU
+                * reduction, we have to fragment it at IP level now. So
+                * if the packet already contains something, we need to
+                * flush.
+                */
+               maxsize = pmtu - packet->overhead;
+               if (packet->auth)
+                       maxsize -= WORD_ROUND(packet->auth->skb->len);
+               if (chunk_len > maxsize)
+                       retval = SCTP_XMIT_PMTU_FULL;
+
                /* It is also okay to fragment if the chunk we are
                 * adding is a control chunk, but only if current packet
                 * is not a GSO one otherwise it causes fragmentation of