Move don't fragment to a function and set it for connected UDP sockets too

diff --git a/src/lib/util/socket.c b/src/lib/util/socket.c
index fa072444e7f9e39587edfc2d08775b23eb9c9aa7..288312827cdcdf63d260b209a2cbb5ef3a1f07e9 100644 (file)
--- a/src/lib/util/socket.c
+++ b/src/lib/util/socket.c
@@ -166,6 +166,61 @@ static int socket_inaddr_any_v6only(UNUSED int sockfd, UNUSED fr_ipaddr_t const
 }
 #endif
 
+#if (defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)) || defined(IP_DONTFRAG)
+/** Set the don't fragment bit
+ *
+ * @param[in] sockfd   to set don't fragment bit for.
+ * @param[in] af       of the socket.
+ * @return
+ *     - 0 on success.
+ *     - -1 on failure.
+ */
+static int socket_dont_fragment(int sockfd, int af)
+{
+       /*
+        *      Set the "don't fragment" flag on UDP sockets.  Most
+        *      routers don't have good support for fragmented UDP
+        *      packets.
+        */
+       if (af == AF_INET) {
+               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;
+
+               if (setsockopt(sockfd, IPPROTO_IP, IP_MTU_DISCOVER, &flag, sizeof(flag)) < 0) {
+                       fr_strerror_printf("Failed disabling PMTU discovery: %s", fr_syserror(errno));
+                       return -1;
+               }
+#  endif
+
+#  if defined(IP_DONTFRAG)
+               /*
+                *      Ensure that the "don't fragment" flag is zero.
+                */
+               flag = 0;
+
+               if (setsockopt(sockfd, IPPROTO_IP, IP_DONTFRAG, &flag, sizeof(flag)) < 0) {
+                       fr_strerror_printf("Failed setting don't fragment flag: %s", fr_syserror(errno));
+                       return -1;
+               }
+#  endif
+       }
+
+       return 0;
+}
+#else
+static int socket_dont_fragment(UNUSED int sockfd, UNUSED int af)
+{
+       return 0;
+}
+#endif /* lots of things */
+
 /** Check the proto value is sane/supported
  *
  * @param[in] proto to check
@@ -340,14 +395,20 @@ int fr_socket_client_udp(fr_ipaddr_t const *src_ipaddr, fr_ipaddr_t const *dst_i
        sockfd = socket(dst_ipaddr->af, SOCK_DGRAM, 0);
        if (sockfd < 0) {
                fr_strerror_printf("Error creating UDP socket: %s", fr_syserror(errno));
-               return sockfd;
+               return -1;
        }
 
        if (async && (fr_nonblock(sockfd) < 0)) {
+       error:
                close(sockfd);
                return -1;
        }
 
+       /*
+        *      Ensure don't fragment bit is set
+        */
+       if (socket_dont_fragment(sockfd, src_ipaddr->af) < 0) goto error;
+
        /*
         *      Allow the caller to bind us to a specific source IP.
         */
@@ -649,45 +710,10 @@ int fr_socket_server_udp(fr_ipaddr_t const *src_ipaddr, uint16_t *src_port, char
         */
        if (socket_inaddr_any_v6only(sockfd, src_ipaddr) < 0) goto error;
 
-#if (defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)) || defined(IP_DONTFRAG)
        /*
-        *      Set the "don't fragment" flag on UDP sockets.  Most
-        *      routers don't have good support for fragmented UDP
-        *      packets.
+        *      Ensure don't fragment bit is set
         */
-       if (src_ipaddr->af == AF_INET) {
-               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;
-
-               if (setsockopt(sockfd, IPPROTO_IP, IP_MTU_DISCOVER, &flag, sizeof(flag)) < 0) {
-                       fr_strerror_printf("Failed disabling PMTU discovery: %s", fr_syserror(errno));
-                       close(sockfd);
-                       return -1;
-               }
-#  endif
-
-#  if defined(IP_DONTFRAG)
-               /*
-                *      Ensure that the "don't fragment" flag is zero.
-                */
-               flag = 0;
-
-               if (setsockopt(sockfd, IPPROTO_IP, IP_DONTFRAG, &flag, sizeof(flag)) < 0) {
-                       fr_strerror_printf("Failed setting don't fragment flag: %s", fr_syserror(errno));
-                       close(sockfd);
-                       return -1;
-               }
-#  endif
-       }
-#endif /* lots of things */
+       if (socket_dont_fragment(sockfd, src_ipaddr->af) < 0) goto error;
 
 #ifdef SO_TIMESTAMP
        {