net: tftp: Avoid sending extra ack on completion

in tftpboot, if ack was already sent previously for this
packet, don't send again.

Fixes: cc6b87ecaa96 ("net: tftp: Add client support for RFC 7440")
Reported-by: Suneel Garapati <suneelglinux@gmail.com>
Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
Tested-by: Suneel Garapati <suneelglinux@gmail.com>
Tested-by: Oliver Graute <oliver.graute@kococonnector.com>

diff --git a/net/tftp.c b/net/tftp.c
index d8cb12120bbc52bab2360a62ba5eadf539acbbce..00ab7ca0b3c41f2e3e8d6683d06a6fafc8b452b3 100644 (file)
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -669,6 +669,12 @@ static void tftp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
                        break;
                }
 
+               if (len < tftp_block_size) {
+                       tftp_send();
+                       tftp_complete();
+                       break;
+               }
+
                /*
                 *      Acknowledge the block just received, which will prompt
                 *      the remote for the next one.
@@ -677,11 +683,6 @@ static void tftp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
                        tftp_send();
                        tftp_next_ack += tftp_windowsize;
                }
-
-               if (len < tftp_block_size) {
-                       tftp_send();
-                       tftp_complete();
-               }
                break;
 
        case TFTP_ERROR: