Packets not arriving

pcmattman · Post by **pcmattman** » Sat Apr 14, 2007 9:05 pm

I've finally been able to send IP packets from my OS without any problems. The sniffer I have setup detects them coming out.

The problem is, Windows still doesn't recognize them. Pinging my OS still times out, even though it is clear that the packet makes it to my PC.

Any ideas?

mystran · Post by **mystran** » Sat Apr 14, 2007 9:11 pm

Can you receive packets without promiscuous mode now?

pcmattman · Post by **pcmattman** » Sat Apr 14, 2007 9:19 pm

No... I still receive packets with promiscuous mode on. Without it it doesn't work.

I have forgotten the offsets from the io address of PAR0-PAR5 (which makes my life very difficult).

Edit: Code to get the physical address:

Code: Select all

	// useful variables
	int wordlen = 2;
	int i;
	uint8_t buffer[32];
	
	outportb(data->ioAddress + REMOTEBYTECOUNT0, 0x20);
	outportb(data->ioAddress + REMOTEBYTECOUNT1, 0x00);

	outportb(data->ioAddress + REMOTESTARTADDRESS0, 0x00);
	outportb(data->ioAddress + REMOTESTARTADDRESS1, 0x00);

	outportb(data->ioAddress + COMMAND, E8390_START | E8390_NODMA | E8390_PAGE0);

	for(i=0; i<32; i+=2)
	{
		buffer[i] = inportb(data->ioAddress + IOPORT);
		buffer[i+1] = inportb(data->ioAddress + IOPORT);

		if(buffer[i] != buffer[i+1])
			wordlen = 1;
	}

	if(wordlen == 2)
	{
		data->wordMode = 1;
		for(i=0; i<16; i++)
			data->saprom[i] = buffer[i*2];
		
		outportb(data->ioAddress + DATACONFIGURATION, 0x48 );
		return;
	}
	else
	{
		data->wordMode = 0;
	}

Without promiscuous mode, it just plain doesn't work...

mystran · Post by **mystran** » Sat Apr 14, 2007 9:34 pm

Our Wiki links to http://www.national.com/pf/DP/DP8390D.html for data.

Maybe it helps.

Anyway, my theory is that you either have the MAC wrong, or you are sending it in wrong order (either in network packets, or in ARP packets).

pcmattman · Post by **pcmattman** » Sat Apr 14, 2007 9:35 pm

Which order should it be?

ARP packets work, the handler just swaps the destination and source address fields.

Edit: the OS gets the correct MAC and sends it correctly (I looked at the ARP cache).

mystran · Post by **mystran** » Sat Apr 14, 2007 9:45 pm

Can you make me a new testing image? I wanna try if I manage to get some packets out of it and see if they look ok..

pcmattman · Post by **pcmattman** » Sat Apr 14, 2007 9:49 pm

Packets sent are OK... ATM it's receiving them. Disabling promiscuous mode basically stopped my OS from receiving any packets, apart from ARP requests because they are a broadcast.

How exactly am I meant to get a MAC address out of the PAR0-PAR5 registers? I tried it but it didn't work (I got 0:0:0:0:0:0).

Edit: I'd prefer to fix the receive problem first, then when I get around to sending data I can send you an image.

I believe that the problem is with my MAC address that I have retrieved - when Windows receives the ICMP packet and finds that it's come from the wrong address it gets confused.

Edit 2: This is the ethernet layer of sending, which isn't used for ARP packets:

Code: Select all

int sendPacketEthernet(struct ethernet_t *eth, packet_t *p)
{
	struct ethHeader_t *ethPkt;
	packet_t *pkt;
	
	pkt = packetAddHeader(sizeof(struct ethHeader_t), p);
	if(!pkt || !pkt->data)
	{
		return 0;
	}
	
	// the real length
	int packlen = pkt->len;
	
	ethPkt = (struct ethHeader_t *)pkt->data;
	int i = 0;
	/** at the moment the destination is hard-coded, so we don't have to keep an ARP cache **/
	ethPkt->dest[i++] = 0x00;
	ethPkt->dest[i++] = 0x0F;
	ethPkt->dest[i++] = 0xEA;
	ethPkt->dest[i++] = 0xA0;
	ethPkt->dest[i++] = 0x15;
	ethPkt->dest[i] = 0xAF;
	memcpy(ethPkt->src, eth->macAddr, 6);
	ethPkt->type = htons(ETHER_FRAME_IP);
		
	// send the packet
	eth->send(eth, pkt);

	return 1;	
}

It could be a problem here that causes the problem.

mystran · Post by **mystran** » Sat Apr 14, 2007 9:58 pm

Hehe, I know exactly as much as the datasheets say. I've never tried to program a ne2k driver (that's on TODO list ofcourse, but I've not started with that yet) so no idea.. well other than what the datasheets tell... which I don't feel like reading right now...

But I still offer to try to sniff packets sent by your current driver, to see if they can offer any insight into what is going on..

pcmattman · Post by **pcmattman** » Sat Apr 14, 2007 10:10 pm

Oh well, I'll just have to keep working at it

IMHO Windows is sending the packet, all well and good, then when it receives the reply it checks that the addresses and such match, in this case they probably don't...

The image is online now - ne2k_testing.img (CVS)... You just have to ping 192.168.1.109 and it should come up with the ARP request receive. Then nothing. If you want one which replies (ie. promiscuous mode) ask.

Edit: this is what the sniffer gets in promiscuous mode:

Code: Select all

14:22:52.504254 IP Matthew > 192.168.1.109: ICMP echo request, id 512, seq 257, length 40
14:22:52.516217 IP 192.168.1.109 > Matthew: ICMP echo reply, id 512, seq 257, length 40

Should work... but doesn't, raw packet display:

Code: Select all

14:24:18.004407 IP Matthew > 192.168.1.109: ICMP echo request, id 512, seq 1537, length 40
E..<I)....ml...n...m..E[....abcdefghijklmnopqrstuvwabcdefghi
14:24:18.010338 IP 192.168.1.109 > Matthew: ICMP echo reply, id 512, seq 1281, length 40
E..<[email protected]

Any ideas?

mystran · Post by **mystran** » Sat Apr 14, 2007 10:17 pm

Code: Select all

<07:27:11|root@wall:~># arp
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.1.109            ether   B0:C4:20:00:00:00   C                     eth1

Seems fine... let's see if I can dig something else out of the thing..

pcmattman · Post by **pcmattman** » Sat Apr 14, 2007 10:18 pm

mystran wrote:
Code: Select all
<07:27:11|root@wall:~># arp
Address                  HWtype  HWaddress           Flags Mask            Iface
192.168.1.109            ether   B0:C4:20:00:00:00   C                     eth1
Seems fine... let's see if I can dig something else out of the thing..

I told you that ARP requests work... try pinging it.

Edit: I decoded the raw packet for the ICMP ping, the MAC addresses are:

Code: Select all

Sent packet:
From: 00 0F EA A0 15 AF
To: 00 B0 C4 20 FF A1

Reply:
From: 00 B0 C4 20 FF A1
To: 00 0F EA A0 15 AF

Sounds right to me...

Edit 2: I dissected the raw packets and everything is right. I'm seriously stuck now. BTW, did I give you the promiscuous mode one, or the non-promiscuous mode one? And have you tried to ping it?

Edit 3: I'm uploading a promiscuous mode image so you have a point of comparison.

mystran · Post by **mystran** » Sat Apr 14, 2007 10:40 pm

Hmmh.. for ARP packets, the MAC it prints for the sender is indeed what it should be...

But the image you gave me doesn't seem to be able to receive anything... I'd need the promiscuous version.

Code: Select all


Sent packet:
From: 00 0F EA A0 15 AF
To: 00 B0 C4 20 FF A1

Reply:
From: 00 B0 C4 20 FF A1
To: 00 0F EA A0 15 AF

Hmh... how does that sound right to you?

B0:C0:20:00:00:00 is what Bochs defaults to... or have you changed your Bochs to use 00:B0:C4:20:FF:A1 instead?

hmmh..

pcmattman · Post by **pcmattman** » Sat Apr 14, 2007 11:01 pm

Yes, I changed the Bochs config to make the MAC 00:B0:C4:20:FF:A1.

The promiscuous version is in my CVS repositry. (or should be anyway).

mystran · Post by **mystran** » Sat Apr 14, 2007 11:15 pm

Should it print something when it receives a packet?

pcmattman · Post by **pcmattman** » Sun Apr 15, 2007 12:28 am

Depends. What type? If it's TCP or ICMP, it should print something (same as ARP).

Which image are you using?

Edit: I wrote to PAR0-PAR5 the proper MAC address. My OS now receives packets without promiscuous mode

. Now Windows still won't read them.