tIPv4Header *hdr = (void*)buf;
int ret;
+ if( MAC_EQU(to, cMAC_ZERO) ) {
+ // No route to host
+ Log_Notice("IPv4", "No route to host %i.%i.%i.%i",
+ Address.B[0], Address.B[1], Address.B[2], Address.B[3]);
+ return 0;
+ }
+
// OUTPUT Firewall rule go here
- ret = IPTablesV4_TestChain("OUTPUT",
- (tIPv4*)Iface->Address, &Address,
+ ret = IPTables_TestChain("OUTPUT",
+ 4, (tIPv4*)Iface->Address, &Address,
Protocol, 0,
Length, Data);
- if(ret != 0) {
+ if(ret > 0) {
// Just drop it (with an error)
+ Log_Notice("IPv4", "Firewall dropped packet");
return 0;
}
hdr->HeaderChecksum = 0; // Will be set later
hdr->Source = *(tIPv4*)Iface->Address;
hdr->Destination = Address;
- hdr->HeaderChecksum = IPv4_Checksum(hdr, sizeof(tIPv4Header));
+ hdr->HeaderChecksum = htons(IPv4_Checksum(hdr, sizeof(tIPv4Header)));
Log_Log("IPv4", "Sending packet to %i.%i.%i.%i",
Address.B[0], Address.B[1], Address.B[2], Address.B[3]);
Uint8 *data;
int dataLength;
int ret;
-
+
if(Length < sizeof(tIPv4Header)) return;
#if 0
// Check Header checksum
{
Uint16 hdrVal, compVal;
- hdrVal = hdr->HeaderChecksum;
+ hdrVal = ntohs(hdr->HeaderChecksum);
hdr->HeaderChecksum = 0;
- compVal = IPv4_Checksum(hdr, hdr->HeaderLength);
+ compVal = IPv4_Checksum(hdr, hdr->HeaderLength * 4);
if(hdrVal != compVal) {
Log_Log("IPv4", "Header checksum fails (%04x != %04x)", hdrVal, compVal);
return ;
// Firewall rules
if( iface ) {
// Incoming Packets
- ret = IPTablesV4_TestChain("INPUT",
- &hdr->Source, &hdr->Destination,
+ ret = IPTables_TestChain("INPUT",
+ 4, &hdr->Source, &hdr->Destination,
hdr->Protocol, 0,
dataLength, data
);
}
else {
// Routed packets
- ret = IPTablesV4_TestChain("FORWARD",
- &hdr->Source, &hdr->Destination,
+ ret = IPTables_TestChain("FORWARD",
+ 4, &hdr->Source, &hdr->Destination,
hdr->Protocol, 0,
dataLength, data
);
case 1:
Log_Debug("IPv4", "Silently dropping packet");
return ;
+ case -1:
+ // Bad rule
+ break ;
// Unknown, silent drop
default:
+ Log_Warning("IPv4", "Unknown firewall rule");
return ;
}
// Routing
if(!iface)
{
+ tMacAddr to;
+ tRoute *rt;
+
Log_Debug("IPv4", "Route the packet");
+ // Drop the packet if the TTL is zero
+ if( hdr->TTL == 0 ) {
+ Log_Warning("IPv4", "TODO: Sent ICMP-Timeout when TTL exceeded");
+ return ;
+ }
+
+ hdr->TTL --;
+
+ rt = IPStack_FindRoute(4, NULL, &hdr->Destination); // Get the route (gets the interface)
+ to = ARP_Resolve4(rt->Interface, hdr->Destination); // Resolve address
+ if( MAC_EQU(to, cMAC_ZERO) )
+ return ;
+
+ // Send packet
+ Log_Log("IPv4", "Forwarding packet to %i.%i.%i.%i (via %i.%i.%i.%i)",
+ hdr->Destination.B[0], hdr->Destination.B[1],
+ hdr->Destination.B[2], hdr->Destination.B[3],
+ ((tIPv4*)rt->NextHop)->B[0], ((tIPv4*)rt->NextHop)->B[1],
+ ((tIPv4*)rt->NextHop)->B[2], ((tIPv4*)rt->NextHop)->B[3]);
+ Link_SendPacket(rt->Interface->Adapter, IPV4_ETHERNET_ID, to, Length, Buffer);
- // TODO: Parse Routing tables and determine where to send it
return ;
}
// Send it on
- if( gaIPv4_Callbacks[hdr->Protocol] )
- gaIPv4_Callbacks[hdr->Protocol]( iface, &hdr->Source, dataLength, data );
- else
+ if( !gaIPv4_Callbacks[hdr->Protocol] ) {
Log_Log("IPv4", "Unknown Protocol %i", hdr->Protocol);
+ return ;
+ }
+
+ gaIPv4_Callbacks[hdr->Protocol]( iface, &hdr->Source, dataLength, data );
}
/**
* \brief Convert a network prefix to a netmask
* \param FixedBits Netmask size (/n)
*
- * For example /24 will become 255.255.255.0
+ * For example /24 will become 255.255.255.0 (0xFFFFFF00)
*/
Uint32 IPv4_Netmask(int FixedBits)
{
*/
Uint16 IPv4_Checksum(const void *Buf, int Size)
{
- Uint16 sum = 0;
+ Uint32 sum = 0;
const Uint16 *arr = Buf;
int i;
for(i = 0; i < Size; i++ )
{
Uint16 val = ntohs(arr[i]);
- if((int)sum + val > 0xFFFF)
- sum ++; // Simulate 1's complement
sum += val;
}
- return ~sum ;
+
+ // Apply one's complement
+ while (sum >> 16)
+ sum = (sum & 0xFFFF) + (sum >> 16);
+
+ return ~sum;
}
/**