[PATCH] net: ping: reset stored IP once the command finishes

[Marek Szyprowski]

Hi Tom,

On 12.06.2020 18:04, Tom Rini wrote:
> On Wed, Mar 25, 2020 at 02:42:00PM +0100, Marek Szyprowski wrote:
>> Reset stored ping IP address before leaving the netloop to ensure that
>> the subsequent calls to the netloop, especially for the other protocols,
>> won't be interrupted by the received ICMP_ECHO_REPLY packet.
>>
>> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
>> ---
>>   net/ping.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/ping.c b/net/ping.c
>> index 633c942..d912e3d 100644
>> --- a/net/ping.c
>> +++ b/net/ping.c
>> @@ -63,6 +63,7 @@ static int ping_send(void)
>>   static void ping_timeout_handler(void)
>>   {
>>   	eth_halt();
>> +	net_ping_ip.s_addr = 0;
>>   	net_set_state(NETLOOP_FAIL);	/* we did not get the reply */
>>   }
>>   
>> @@ -84,8 +85,10 @@ void ping_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
>>   	switch (icmph->type) {
>>   	case ICMP_ECHO_REPLY:
>>   		src_ip = net_read_ip((void *)&ip->ip_src);
>> -		if (src_ip.s_addr == net_ping_ip.s_addr)
>> +		if (src_ip.s_addr == net_ping_ip.s_addr) {
>> +			net_ping_ip.s_addr = 0;
>>   			net_set_state(NETLOOP_SUCCESS);
>> +		}
>>   		return;
>>   	case ICMP_ECHO_REQUEST:
>>   		eth_hdr_size = net_update_ether(et, et->et_src, PROT_IP);
> This breaks a number of tests in test/dm/eth.c.  Can you please adjust
> the tests as well to not rely on the behavior you're fixing?  Thanks!

I've checked and it turned out that it is not possible to fix the 
net_retry test. It clearly shows that the net_retry feature relies on 
the fact that the state machine of the net related commands are 
preserved between the calls.

I wonder how to fix this without breaking the netretry feature. The only 
solution I see is to clear net_ping_ip at the beginning of the 
net_loop() if the protocol is not equal to PING. Quite ugly...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland