Turn off the DF bit.

diff --git a/src/lib/packet.c b/src/lib/packet.c
index 5eb1f19..952a85b 100644 (file)
--- a/src/lib/packet.c
+++ b/src/lib/packet.c
@@ -225,6 +225,30 @@ int fr_socket(fr_ipaddr_t *ipaddr, int port)
        }
 #endif /* HAVE_STRUCT_SOCKADDR_IN6 */
 
+       if (ipaddr->af == AF_INET) {
+               UNUSED int flag;
+               
+#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
+               /*
+                *      Disable PMTU discovery.  On Linux, this
+                *      also makes sure that the "don't fragment"
+                *      flag is zero.
+                */
+               flag = IP_PMTUDISC_DONT;
+               setsockopt(sock->fd, IPPROTO_IP, IP_MTU_DISCOVER,
+                          &action, sizeof(action));
+#endif
+
+#if defined(IP_DONTFRAG)
+               /*
+                *      Ensure that the "don't fragment" flag is zero.
+                */
+               flag = 0;
+               setsockopt(sock->fd, IPPROTO_IP, IP_DONTFRAG,
+                          &off, sizeof(off));
+#endif
+       }
+
        if (bind(sockfd, (struct sockaddr *) &salocal, salen) < 0) {
                close(sockfd);
                fr_strerror_printf("cannot bind socket: %s", strerror(errno));