net/arp: account for ARP delay, avoid duplicate packets on timeout

eth_rx() in the main reception loop may trigger sending a packet which
is already timed out (or will immediately) upon reception of an ARP reply.
As long as the ARP reply is pending, the timeout handler of a packet
should be postponed.
Happens on TFTP with bad network (e.g. WLAN).

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

diff --git a/net/arp.c b/net/arp.c
index b1f12bf..824d2e9 100644 (file)
--- a/net/arp.c
+++ b/net/arp.c
@@ -96,12 +96,12 @@ void arp_request(void)
        arp_raw_request(net_ip, net_null_ethaddr, net_arp_wait_reply_ip);
 }
 
-void arp_timeout_check(void)
+int arp_timeout_check(void)
 {
        ulong t;
 
        if (!net_arp_wait_packet_ip.s_addr)
-               return;
+               return 0;
 
        t = get_timer(0);
 
@@ -118,6 +118,7 @@ void arp_timeout_check(void)
                        arp_request();
                }
        }
+       return 1;
 }
 
 void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)

diff --git a/net/arp.h b/net/arp.h
index 43c6296..a288d61 100644 (file)
--- a/net/arp.h
+++ b/net/arp.h
@@ -25,7 +25,7 @@ void arp_init(void);
 void arp_request(void);
 void arp_raw_request(struct in_addr source_ip, const uchar *targetEther,
        struct in_addr target_ip);
-void arp_timeout_check(void);
+int arp_timeout_check(void);
 void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len);
 
 #endif /* __ARP_H__ */

diff --git a/net/net.c b/net/net.c
index a115ce2..6f75e3c 100644 (file)
--- a/net/net.c
+++ b/net/net.c
@@ -569,7 +569,9 @@ restart:
                        goto done;
                }
 
-               arp_timeout_check();
+               if (arp_timeout_check() > 0) {
+                   time_start = get_timer(0);
+               }
 
                /*
                 *      Check for a timeout, and run the timeout handler