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>

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>
Stefan Brüns · Joe Hershberger · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent 943231119f
Showing 3 changed files with 7 additions and 4 deletions Side-by-side Diff
net/arp.c
net/arp.h
net/net.c
@@ -96,12 +96,12 @@
 	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 @@
 			arp_request();
 		}
 	}
+	return 1;
 }
  
 void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
@@ -25,7 +25,7 @@
 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__ */
@@ -569,7 +569,9 @@
 			goto done;
 		}
  
-		arp_timeout_check();
+		if (arp_timeout_check() > 0) {
+		    time_start = get_timer(0);
+		}
  
 		/*
 		 *	Check for a timeout, and run the timeout handler
...	...	@@ -96,12 +96,12 @@
96	96	arp_raw_request(net_ip, net_null_ethaddr, net_arp_wait_reply_ip);
97	97	}
98	98
99		-void arp_timeout_check(void)
	99	+int arp_timeout_check(void)
100	100	{
101	101	ulong t;
102	102
103	103	if (!net_arp_wait_packet_ip.s_addr)
104		- return;
	104	+ return 0;
105	105
106	106	t = get_timer(0);
107	107
...	...	@@ -118,6 +118,7 @@
118	118	arp_request();
119	119	}
120	120	}
	121	+ return 1;
121	122	}
122	123
123	124	void arp_receive(struct ethernet_hdr et, struct ip_udp_hdr ip, int len)
...	...	@@ -25,7 +25,7 @@
25	25	void arp_request(void);
26	26	void arp_raw_request(struct in_addr source_ip, const uchar *targetEther,
27	27	struct in_addr target_ip);
28		-void arp_timeout_check(void);
	28	+int arp_timeout_check(void);
29	29	void arp_receive(struct ethernet_hdr et, struct ip_udp_hdr ip, int len);
30	30
31	31	#endif /* __ARP_H__ */
...	...	@@ -569,7 +569,9 @@
569	569	goto done;
570	570	}
571	571
572		- arp_timeout_check();
	572	+ if (arp_timeout_check() > 0) {
	573	+ time_start = get_timer(0);
	574	+ }
573	575
574	576	/*
575	577	* Check for a timeout, and run the timeout handler