void send_ip_header( unsigned short totallen, const unsigned char * to, unsigned char proto )
{
/*
//This uses about 50 bytes less of flash, but 12 bytes more of ram. You can choose that tradeoff.
static unsigned char data[] = { 0x45, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 64, 0x00, 0x00, 0x00 };
data[2] = totallen >> 8;
data[3] = totallen & 0xFF;
data[9] = proto;
enc424j600_pushblob( data, 12 );
*/
enc424j600_push16( 0x4500 );
enc424j600_push16( totallen );
enc424j600_push16( 0x0000 ); //ID
enc424j600_push16( 0x4000 ); //Don't frgment, no fragment offset
enc424j600_push8( 64 ); // TTL
enc424j600_push8( proto ); // protocol
enc424j600_push16( 0 ); //Checksum
enc424j600_pushblob( MyIP, 4 );
enc424j600_pushblob( to, 4 );
}
int8_t RequestARP( uint8_t * ip )
{
uint8_t i;
for( i = 0; i < ARP_CLIENT_TABLE_SIZE; i++ )
{
if( memcmp( (char*)&ClientArpTable[i].ip, ip, 4 ) == 0 ) //XXX did I mess up my casting?
{
return i;
}
}
SwitchToBroadcast();
//No MAC Found. Send an ARP request.
enc424j600_finish_callback_now();
enc424j600_startsend( NetGetScratch() );
send_etherlink_header( 0x0806 );
enc424j600_push16( 0x0001 ); //Ethernet
enc424j600_push16( 0x0800 ); //Protocol (IP)
enc424j600_push16( 0x0604 ); //HW size, Proto size
enc424j600_push16( 0x0001 ); //Request
enc424j600_pushblob( MyMAC, 6 );
enc424j600_pushblob( MyIP, 4 );
enc424j600_push16( 0x0000 );
enc424j600_push16( 0x0000 );
enc424j600_push16( 0x0000 );
enc424j600_pushblob( ip, 4 );
enc424j600_endsend();
return -1;
}
void send_etherlink_header( unsigned short type )
{
enc424j600_pushblob( macfrom, 6 );
// The mac does this for us.
enc424j600_pushblob( MyMAC, 6 );
enc424j600_push16( type );
}
void DoPing( uint8_t pingslot )
{
unsigned short ppl;
uint16_t seqnum = ++ClientPingEntries[pingslot].last_send_seqnum;
uint16_t checksum = (seqnum + pingslot + 0x0800) ;
int8_t arpslot = RequestARP( ClientPingEntries[pingslot].ip );
if (arpslot < 0) {
return;
}
//must set macfrom to be the IP address of the target.
memcpy( macfrom, ClientArpTable[arpslot].mac, 6 );
enc424j600_startsend( NetGetScratch() );
send_etherlink_header( 0x0800 );
send_ip_header( 32, ClientPingEntries[pingslot].ip, 0x01 );
enc424j600_push16( 0x0800 ); //ping request + 0 for code
enc424j600_push16( ~checksum ); //Checksum
enc424j600_push16( pingslot ); //Idneitifer
enc424j600_push16( seqnum ); //Sequence number
enc424j600_push16( 0x0000 ); //Payload
enc424j600_push16( 0x0000 );
enc424j600_start_checksum( 8, 20 );
ppl = enc424j600_get_checksum();
enc424j600_alter_word( 18, ppl );
enc424j600_endsend();
}
//Mode = 1 for discover, Mode = 3 for request - if discover, dhcp_server should be 0.
void RequestNewIP( uint8_t mode, uint8_t * negotiating_ip, uint8_t * dhcp_server )
{
uint8_t oldip[4];
SwitchToBroadcast();
enc424j600_stopop();
enc424j600_startsend( NetGetScratch() );
send_etherlink_header( 0x0800 );
//Tricky - backup our IP - we want to spoof it to 0.0.0.0
memcpy( oldip, MyIP, 4 );
MyIP[0] = 0; MyIP[1] = 0; MyIP[2] = 0; MyIP[3] = 0;
send_ip_header( 0, "\xff\xff\xff\xff", 17 ); //UDP Packet to 255.255.255.255
memcpy( MyIP, oldip, 4 );
/*
enc424j600_push16( 68 ); //From bootpc
enc424j600_push16( 67 ); //To bootps
enc424j600_push16( 0 ); //length for later
enc424j600_push16( 0 ); //csum for later
//Payload of BOOTP packet.
// 1, //Bootp request
// 1, //Ethernet
enc424j600_push16( 0x0101 );
// 6, //MAC Length
// 0, //Hops
enc424j600_push16( 0x0600 );
*/
enc424j600_pushpgmblob( PSTR("\x00\x44\x00\x43\x00\x00\x00\x00\x01\x01\x06"), 12 ); //NOTE: Last digit is 0 on wire, not included in string.
enc424j600_pushblob( MyMAC, 4 );
enc424j600_push16( dhcp_clocking ); //seconds
enc424j600_pushzeroes( 10 ); //unicast, CLIADDR, YIADDR
if( dhcp_server )
enc424j600_pushblob( dhcp_server, 4 );
else
enc424j600_pushzeroes( 4 );
enc424j600_pushzeroes( 4 ); //GIADDR IP
enc424j600_pushblob( MyMAC, 6 ); //client mac
enc424j600_pushzeroes( 10 + 0x40 + 0x80 ); //padding + Server Host Name
enc424j600_push16( 0x6382 ); //DHCP Magic Cookie
enc424j600_push16( 0x5363 );
//Now we are on our DHCP portion
enc424j600_push8( 0x35 ); //DHCP Message Type
enc424j600_push16( 0x0100 | mode );
{
enc424j600_push16( 0x3204 ); //Requested IP address. (4 length)
enc424j600_pushblob( negotiating_ip, 4 );
}
if( dhcp_server ) //request
{
enc424j600_push16( 0x3604 );
enc424j600_pushblob( dhcp_server, 4 );
}
if( DHCPName )
{
uint8_t namelen = strlen( DHCPName );
enc424j600_push8( 0x0c ); //Name
enc424j600_push8( namelen );
enc424j600_pushblob( DHCPName, namelen );
}
enc424j600_push16( 0x3702 ); //Parameter request list
enc424j600_push16( 0x0103 ); //subnet mask, router
// enc424j600_push16( 0x2a06 ); //NTP server, DNS server (We don't use either NTP or DNS)
enc424j600_push8( 0xff ); //End option
enc424j600_pushzeroes( 32 ); //Padding
util_finish_udp_packet();
}
static void HandleICMP()
{
unsigned short id;
unsigned short seqnum;
unsigned char type;
unsigned short payloadsize = iptotallen - SIZEOFICMP;
unsigned short payload_from_start, payload_dest_start;
icmp_in++;
type = enc424j600_pop8();
enc424j600_pop8(); //code
enc424j600_pop16(); //Checksum
switch( type )
{
// Ping Response
case 0: {
uint16_t id;
id = enc424j600_pop16();
if( id < PING_RESPONSES_SIZE )
{
ClientPingEntries[id].last_recv_seqnum = enc424j600_pop16(); //Seqnum
}
enc424j600_stopop();
enc424j600_finish_callback_now();
break;
}
// Ping Request
case 8: {
//Tricky: We would ordinarily POPB to read out the payload, but we're using
//the DMA engine to copy that data.
// POPB( payload, payloadsize );
//Suspend reading for now (but don't allow over-writing of the data)
enc424j600_stopop();
payload_from_start = enc424j600_read_ctrl_reg16( EERXRDPTL );
enc424j600_startsend( NetGetScratch() );
send_etherlink_header( 0x0800 );
send_ip_header( iptotallen, ipsource, 0x01 );
enc424j600_push16( 0 ); //ping reply + code
enc424j600_push16( 0 ); //Checksum
// enc424j600_push16( id );
// enc424j600_push16( seqnum );
//Packet confiugred. Need to copy payload.
//Ordinarily, we'd enc424j600_pushblob for the payload, but we're currently using the DMA engine for our work here.
enc424j600_stopop();
payload_dest_start = enc424j600_read_ctrl_reg16( EEGPWRPTL );
//+4 = id + seqnum (we're DMAing that, too)
enc424j600_copy_memory( payload_dest_start, payload_from_start, payloadsize + 4, RX_BUFFER_START, RX_BUFFER_END-1 );
enc424j600_write_ctrl_reg16( EEGPWRPTL, payload_dest_start + payloadsize + 4 );
enc424j600_finish_callback_now();
//Calculate header and ICMP checksums
enc424j600_start_checksum( 8+6, 20 );
unsigned short ppl = enc424j600_get_checksum();
enc424j600_start_checksum( 28+6, payloadsize + 8 );
enc424j600_alter_word( 18+6, ppl );
ppl = enc424j600_get_checksum();
enc424j600_alter_word( 30+6, ppl );
enc424j600_endsend();
icmp_out++;
break;
}
}
}
static void HandleArp (void)
{
unsigned short i;
unsigned char sendermac_ip_and_targetmac[16];
// unsigned char senderip[10]; //Actually sender ip + target mac, put in one to shrink code.
unsigned short proto;
unsigned char opcode;
// unsigned char ipproto;
enc424j600_pop16(); //Hardware type
proto = enc424j600_pop16();
enc424j600_pop16(); //hwsize, protosize
opcode = enc424j600_pop16(); //XXX: This includes "code" as well, it seems.
switch( opcode )
{
// ARP Request
case 1: {
unsigned char match;
enc424j600_popblob( sendermac_ip_and_targetmac, 16 );
match = 1;
//sendhex2( 0xff );
//Target IP (check for copy)
for( i = 0; i < 4; i++ )
if( enc424j600_pop8() != MyIP[i] )
match = 0;
if( match == 0 )
return;
//We must send a response, so we termiante the packet now.
enc424j600_finish_callback_now();
enc424j600_startsend( NetGetScratch() );
send_etherlink_header( 0x0806 );
enc424j600_push16( 0x0001 ); //Ethernet
enc424j600_push16( proto ); //Protocol
enc424j600_push16( 0x0604 ); //HW size, Proto size
enc424j600_push16( 0x0002 ); //Reply
enc424j600_pushblob( MyMAC, 6 );
enc424j600_pushblob( MyIP, 4 );
enc424j600_pushblob( sendermac_ip_and_targetmac, 10 ); // do not send target mac.
enc424j600_endsend();
// Have a match!
break;
}
// ARP Reply
case 2: {
uint8_t sender_mac_and_ip_and_comp_mac[16];
enc424j600_popblob( sender_mac_and_ip_and_comp_mac, 16 );
enc424j600_finish_callback_now();
//First, make sure that we're the ones who are supposed to receive the ARP.
for( i = 0; i < 6; i++ )
{
if( sender_mac_and_ip_and_comp_mac[i+10] != MyMAC[i] )
break;
}
if( i != 6 )
break;
//We're the right recipent. Put it in the table.
memcpy( &ClientArpTable[ClientArpTablePointer], sender_mac_and_ip_and_comp_mac, 10 );
ClientArpTablePointer = (ClientArpTablePointer+1)%ARP_CLIENT_TABLE_SIZE;
break;
}
default: {
//???? don't know what to do.
return;
}
}
}
