rx: Normalize use of some MTU-discovery fields
[openafs.git] / src / rx / rx.c
index 6c71368..5079a8c 100644 (file)
@@ -2888,7 +2888,7 @@ rxi_SetPeerMtu(struct rx_peer *peer, afs_uint32 host, afs_uint32 port, int mtu)
        if (peer->ifMTU < OLD_MAX_PACKET_SIZE)
            peer->maxDgramPackets = 1;
        /* We no longer have valid peer packet information */
-       if (peer->maxPacketSize-RX_IPUDP_SIZE > peer->ifMTU)
+       if (peer->maxPacketSize + RX_HEADER_SIZE > peer->ifMTU)
            peer->maxPacketSize = 0;
         MUTEX_EXIT(&peer->peer_lock);
 
@@ -4396,12 +4396,12 @@ rxi_ReceiveAckPacket(struct rx_call *call, struct rx_packet *np,
         * but we are clearly receiving.
         */
        if (!peer->maxPacketSize)
-           peer->maxPacketSize = RX_MIN_PACKET_SIZE+RX_IPUDP_SIZE;
+           peer->maxPacketSize = RX_MIN_PACKET_SIZE - RX_HEADER_SIZE;
 
        if (pktsize > peer->maxPacketSize) {
            peer->maxPacketSize = pktsize;
-           if ((pktsize-RX_IPUDP_SIZE > peer->ifMTU)) {
-               peer->ifMTU=pktsize-RX_IPUDP_SIZE;
+           if ((pktsize + RX_HEADER_SIZE > peer->ifMTU)) {
+               peer->ifMTU = pktsize + RX_HEADER_SIZE;
                peer->natMTU = rxi_AdjustIfMTU(peer->ifMTU);
                rxi_ScheduleGrowMTUEvent(call, 1);
            }
@@ -5531,7 +5531,7 @@ rxi_SendAck(struct rx_call *call,
         */
        if (call->conn->peer->maxPacketSize &&
            (call->conn->peer->maxPacketSize < OLD_MAX_PACKET_SIZE
-            +RX_IPUDP_SIZE))
+            - RX_HEADER_SIZE))
            padbytes = call->conn->peer->maxPacketSize+16;
        else
            padbytes = call->conn->peer->maxMTU + 128;
@@ -6471,13 +6471,14 @@ mtuout:
         call->lastReceiveTime) {
        int oldMTU = conn->peer->ifMTU;
 
-       /* if we thought we could send more, perhaps things got worse */
-       if (conn->peer->maxPacketSize > conn->lastPacketSize)
-           /* maxpacketsize will be cleared in rxi_SetPeerMtu */
-           newmtu = MAX(conn->peer->maxPacketSize-RX_IPUDP_SIZE,
-                        conn->lastPacketSize-(128+RX_IPUDP_SIZE));
+       /* If we thought we could send more, perhaps things got worse.
+        * Shrink by 128 bytes and try again. */
+       if (conn->peer->maxPacketSize < conn->lastPacketSize)
+           /* maxPacketSize will be cleared in rxi_SetPeerMtu */
+           newmtu = MAX(conn->peer->maxPacketSize + RX_HEADER_SIZE,
+                        conn->lastPacketSize - 128 + RX_HEADER_SIZE);
        else
-           newmtu = conn->lastPacketSize-(128+RX_IPUDP_SIZE);
+           newmtu = conn->lastPacketSize - 128 + RX_HEADER_SIZE;
 
        /* minimum capped in SetPeerMtu */
        rxi_SetPeerMtu(conn->peer, 0, 0, newmtu);