// === 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)
{
tIPv4Header *hdr = (void*)buf;
int ret;
- // TODO: OUTPUT Firewall rule go here
- ret = IPTablesV4_TestChain("OUTPUT",
- &Iface->IP4.Address, &Address,
+ 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 = IPTables_TestChain("OUTPUT",
+ 4, (tIPv4*)Iface->Address, &Address,
Protocol, 0,
Length, Data);
-
- if(ret != 0)
- {
- // Just drop it
+ if(ret > 0) {
+ // Just drop it (with an error)
+ Log_Notice("IPv4", "Firewall dropped packet");
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]);
Uint8 *data;
int dataLength;
int ret;
-
+
if(Length < sizeof(tIPv4Header)) return;
#if 0
//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 ) {
- ret = IPTablesV4_TestChain("INPUT",
- &hdr->Source, &hdr->Destination,
+ // Incoming Packets
+ ret = IPTables_TestChain("INPUT",
+ 4, &hdr->Source, &hdr->Destination,
hdr->Protocol, 0,
dataLength, data
);
}
else {
- ret = IPTablesV4_TestChain("FORWARD",
- &hdr->Source, &hdr->Destination,
+ // Routed packets
+ ret = IPTables_TestChain("FORWARD",
+ 4, &hdr->Source, &hdr->Destination,
hdr->Protocol, 0,
dataLength, data
);
// 0 - Allow
case 0: break;
// 1 - Silent Drop
- case 1: return ;
+ 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)
{
- Log_Log("IPv4", "Route the packet");
+ 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 );
}
/**
* \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) )
+ 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
+ * For example /24 will become 255.255.255.0 (0xFFFFFF00)
*/
Uint32 IPv4_Netmask(int FixedBits)
{
/**
* \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);
}
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