rx: Avoid new server calls for big-seq DATA pkts

[openafs.git] / src / rx / rx.c

diff --git a/src/rx/rx.c b/src/rx/rx.c
index b008400..2296014 100644 (file)
--- a/src/rx/rx.c
+++ b/src/rx/rx.c
@@ -3294,6 +3294,36 @@ rxi_ReceiveServerCall(osi_socket socket, struct rx_packet *np,
     call = conn->call[channel];
 
     if (!call) {
+       if (np->header.type != RX_PACKET_TYPE_DATA) {
+           /*
+            * Clients must send DATA packets at some point to create a new
+            * call. If the first packet we saw for this call channel is
+            * something else, then either the DATA packets got lost/delayed,
+            * or we were restarted and this is an existing call from before we
+            * were restarted. In the latter case, some clients get confused if
+            * we respond to such requests, so just drop the packet to make
+            * things easier for them.
+            */
+           MUTEX_EXIT(&conn->conn_call_lock);
+           if (rx_stats_active)
+               rx_atomic_inc(&rx_stats.spuriousPacketsRead);
+           return NULL;
+       }
+
+       if (np->header.seq > rx_maxReceiveWindow) {
+           /*
+            * This is a DATA packet for further along in the call than is
+            * possible for a new call. This is probably from an existing call
+            * that was in the middle of running when we were restarted; ignore
+            * it to avoid confusing clients. (See above comment about non-DATA
+            * packets.)
+            */
+           MUTEX_EXIT(&conn->conn_call_lock);
+           if (rx_stats_active)
+               rx_atomic_inc(&rx_stats.spuriousPacketsRead);
+           return NULL;
+       }
+
        if (rxi_AbortIfServerBusy(socket, conn, np)) {
            MUTEX_EXIT(&conn->conn_call_lock);
            return NULL;