// === CODE ===
/**
- * \fn int IPv4_Initialise()
+ * \brief Initialise the IPv4 Code
*/
int IPv4_Initialise()
{
}
/**
- * \fn int IPv4_RegisterCallback( int ID, tIPCallback Callback )
* \brief Registers a callback
+ * \param ID 8-bit packet type ID
+ * \param Callback Callback function
*/
int IPv4_RegisterCallback(int ID, tIPCallback Callback)
{
* \param ID Some random ID number
* \param Length Data Length
* \param Data Packet Data
+ * \return Boolean Success
*/
int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int Length, const void *Data)
{
tMacAddr to = ARP_Resolve4(Iface, Address);
+ const tMacAddr zero = {{0,0,0,0,0,0}};
int bufSize = sizeof(tIPv4Header) + Length;
char buf[bufSize];
tIPv4Header *hdr = (void*)buf;
int ret;
- // TODO: OUTPUT Firewall rule go here
+ if( MAC_EQU(to, zero) ) {
+ return 0;
+ }
+
+ // OUTPUT Firewall rule go here
ret = IPTablesV4_TestChain("OUTPUT",
- &Iface->IP4.Address, &Address,
+ (tIPv4*)Iface->Address, &Address,
Protocol, 0,
Length, Data);
-
- if(ret != 0)
- {
- // Just drop it
+ if(ret != 0) {
+ // Just drop it (with an error)
return 0;
}
hdr->TTL = DEFAULT_TTL;
hdr->Protocol = Protocol;
hdr->HeaderChecksum = 0; // Will be set later
- hdr->Source = Iface->IP4.Address;
+ 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]);
//Log_Log("IPv4", "Version = %i", hdr->Version);
//Log_Log("IPv4", "HeaderLength = %i", hdr->HeaderLength);
//Log_Log("IPv4", "DiffServices = %i", hdr->DiffServices);
- Log_Log("IPv4", "TotalLength = %i", ntohs(hdr->TotalLength) );
+ Log_Debug("IPv4", "TotalLength = %i", ntohs(hdr->TotalLength) );
//Log_Log("IPv4", "Identifcation = %i", ntohs(hdr->Identifcation) );
//Log_Log("IPv4", "TTL = %i", hdr->TTL );
- Log_Log("IPv4", "Protocol = %i", hdr->Protocol );
+ Log_Debug("IPv4", "Protocol = %i", hdr->Protocol );
//Log_Log("IPv4", "HeaderChecksum = 0x%x", ntohs(hdr->HeaderChecksum) );
- Log_Log("IPv4", "Source = %i.%i.%i.%i",
+ Log_Debug("IPv4", "Source = %i.%i.%i.%i",
hdr->Source.B[0], hdr->Source.B[1], hdr->Source.B[2], hdr->Source.B[3] );
- Log_Log("IPv4", "Destination = %i.%i.%i.%i",
+ Log_Debug("IPv4", "Destination = %i.%i.%i.%i",
hdr->Destination.B[0], hdr->Destination.B[1],
hdr->Destination.B[2], hdr->Destination.B[3] );
#endif
}
// Check Header checksum
- //TODO
+ {
+ Uint16 hdrVal, compVal;
+ hdrVal = ntohs(hdr->HeaderChecksum);
+ hdr->HeaderChecksum = 0;
+ compVal = IPv4_Checksum(hdr, hdr->HeaderLength * 4);
+ if(hdrVal != compVal) {
+ Log_Log("IPv4", "Header checksum fails (%04x != %04x)", hdrVal, compVal);
+ return ;
+ }
+ hdr->HeaderChecksum = hdrVal;
+ }
// Check Packet length
if( ntohs(hdr->TotalLength) > Length) {
return;
}
-
// TODO: Handle packet fragmentation
+
// Get Data and Data Length
dataLength = ntohs(hdr->TotalLength) - sizeof(tIPv4Header);
data = &hdr->Options[0];
// Get Interface (allowing broadcasts)
iface = IPv4_GetInterface(Adapter, hdr->Destination, 1);
- // TODO: INPUT Firewall Rule
+ // Firewall rules
if( iface ) {
+ // Incoming Packets
ret = IPTablesV4_TestChain("INPUT",
&hdr->Source, &hdr->Destination,
hdr->Protocol, 0,
);
}
else {
+ // Routed packets
ret = IPTablesV4_TestChain("FORWARD",
&hdr->Source, &hdr->Destination,
hdr->Protocol, 0,
// 0 - Allow
case 0: break;
// 1 - Silent Drop
- case 1: return ;
+ case 1:
+ Log_Debug("IPv4", "Silently dropping packet");
+ return ;
// Unknown, silent drop
default:
return ;
// Routing
if(!iface)
{
- Log_Log("IPv4", "Route the packet");
+ //Log_Debug("IPv4", "Route the packet");
// TODO: Parse Routing tables and determine where to send it
// Send it on
if( gaIPv4_Callbacks[hdr->Protocol] )
- gaIPv4_Callbacks[hdr->Protocol] (iface, &hdr->Source, dataLength, data);
+ gaIPv4_Callbacks[hdr->Protocol]( iface, &hdr->Source, dataLength, data );
else
Log_Log("IPv4", "Unknown Protocol %i", hdr->Protocol);
}
/**
* \fn tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address)
* \brief Searches an adapter for a matching address
+ * \param Adapter Incoming Adapter
+ * \param Address Destination Address
+ * \param Broadcast Allow broadcast packets
*/
tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast)
{
{
if( iface->Adapter != Adapter ) continue;
if( iface->Type != 4 ) continue;
- if( IP4_EQU(Address, iface->IP4.Address) )
+ //Log_Debug("IPv4", "%x == %x?\n", addr, ntohl(((tIPv4*)iface->Address)->L));
+ if( IP4_EQU(Address, *(tIPv4*)iface->Address) )
return iface;
if( !Broadcast ) continue;
- this = ntohl( iface->IP4.Address.L );
+ this = ntohl( ((tIPv4*)iface->Address)->L );
// Check for broadcast
- netmask = IPv4_Netmask(iface->IP4.SubnetBits);
+ netmask = IPv4_Netmask(iface->SubnetBits);
if( (addr & netmask) == (this & netmask)
&& (addr & ~netmask) == (0xFFFFFFFF & ~netmask) )
/**
* \brief Convert a network prefix to a netmask
+ * \param FixedBits Netmask size (/n)
*
* For example /24 will become 255.255.255.0
*/
/**
* \brief Calculate the IPv4 Checksum
+ * \param Buf Input buffer
+ * \param Size Size of input
+ *
+ * One's complement sum of all 16-bit words (bitwise inverted)
*/
Uint16 IPv4_Checksum(const void *Buf, int Size)
{
- Uint16 sum = 0;
+ Uint32 sum = 0;
const Uint16 *arr = Buf;
int i;
Size = (Size + 1) >> 1; // 16-bit word count
for(i = 0; i < Size; i++ )
{
- if((int)sum + arr[i] > 0xFFFF)
- sum ++; // Simulate 1's complement
- sum += arr[i];
+ Uint16 val = ntohs(arr[i]);
+ sum += val;
}
- return ~sum ;
+
+ // Apply one's complement
+ while (sum >> 16)
+ sum = (sum & 0xFFFF) + (sum >> 16);
+
+ return ~sum;
}
/**
* \brief Sends an ICMP Echo and waits for a reply
+ * \param IFace Interface
+ * \param Addr Destination address
*/
-int IPv4_Ping(tInterface *Iface, tIPv4 Addr)
+int IPv4_Ping(tInterface *IFace, tIPv4 Addr)
{
- return ICMP_Ping(Iface, Addr);
+ return ICMP_Ping(IFace, Addr);
}