Only use the fallback mtu after 2 unsuccessful retransmissions if it is less
than the mtu we are already using
Reviewed-by: Tim Hudson <tjh@openssl.org>
diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index 5b3de08..308afff 100644
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c
@@ -475,13 +475,17 @@
int dtls1_check_timeout_num(SSL *s)
{
+ unsigned int mtu;
+
s->d1->timeout.num_alerts++;
/* Reduce MTU after 2 unsuccessful retransmissions */
if (s->d1->timeout.num_alerts > 2
&& !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
{
- s->d1->mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
+ mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
+ if(mtu < s->d1->mtu)
+ s->d1->mtu = mtu;
}
if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
