From: Matt Caswell <matt@openssl.org>
Date: Tue, 2 Dec 2014 11:16:35 +0000 (+0000)
Subject: Only use the fallback mtu after 2 unsuccessful retransmissions if it is less
X-Git-Tag: OpenSSL_1_0_1k~61
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=65796038742b02a71bcefd2f48cb434966bfdb9b;p=oweals%2Fopenssl.git

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>
(cherry picked from commit 047f21593eebbc617a410a208ded01e65ca11028)
---

diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index c66797d4fe..39058577e2 100644
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c
@@ -438,13 +438,17 @@ void dtls1_stop_timer(SSL *s)
 
 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)