From: Nikos Mavrogiannopoulos <nmav@redhat.com>
Date: Thu, 4 Sep 2014 12:23:44 +0000 (+0200)
Subject: Disallow zero fragments in DTLS for packets which have data.
X-Git-Tag: gnutls_3_4_0~989
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e7b3046c595099a615d1ae2bede643b0214b0f35;p=thirdparty%2Fgnutls.git

Disallow zero fragments in DTLS for packets which have data.

Reported by Manuel Pégourié-Gonnard.
---

diff --git a/lib/gnutls_dtls.c b/lib/gnutls_dtls.c
index 3b14322081..ab02721a8d 100644
--- a/lib/gnutls_dtls.c
+++ b/lib/gnutls_dtls.c
@@ -107,6 +107,14 @@ transmit_message(gnutls_session_t session,
 		else
 			frag_len = mtu;
 
+		/* we normally allow fragments of zero length, to allow
+		 * the packets which have zero size. On the others don't
+		 * send such fragments */
+		if (frag_len == 0 && data_size > 0) {
+			ret = 0;
+			break;
+		}
+
 		/* Fragment offset */
 		_gnutls_write_uint24(offset, &mtu_data[6]);