* Acess2 IP Stack
* - IPv4 Protcol Handling
*/
-#define DEBUG 1
+#define DEBUG 0
#include "ipstack.h"
#include "link.h"
#include "ipv4.h"
+#include "hwaddr_cache.h"
#include "firewall.h"
+// === CONSTANTS ===
#define DEFAULT_TTL 32
+#define IPV4_TRACE 1 // set to 1 to enable packet tracing
// === IMPORTS ===
extern tInterface *gIP_Interfaces;
extern void ICMP_Initialise();
extern int ICMP_Ping(tInterface *Interface, tIPv4 Addr);
-extern tMacAddr ARP_Resolve4(tInterface *Interface, tIPv4 Address);
// === PROTOTYPES ===
int IPv4_Initialise();
- int IPv4_RegisterCallback(int ID, tIPCallback Callback);
+// int IPv4_RegisterCallback(int ID, tIPRxCallback Callback, );
void IPv4_int_GetPacket(tAdapter *Interface, tMacAddr From, int Length, void *Buffer);
tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast);
Uint32 IPv4_Netmask(int FixedBits);
int IPv4_Ping(tInterface *Iface, tIPv4 Addr);
// === GLOBALS ===
-tIPCallback gaIPv4_Callbacks[256];
+struct {
+ tIPRxCallback* rx_cb;
+ tIPErrorCallback* err_cb;
+} gaIPv4_Callbacks[256];
// === CODE ===
/**
* \param ID 8-bit packet type ID
* \param Callback Callback function
*/
-int IPv4_RegisterCallback(int ID, tIPCallback Callback)
+int IPv4_RegisterCallback(int ID, tIPRxCallback *RxCallback, tIPErrorCallback *ErrCallback)
{
if( ID < 0 || ID > 255 ) return 0;
- if( gaIPv4_Callbacks[ID] ) return 0;
- gaIPv4_Callbacks[ID] = Callback;
+ if( gaIPv4_Callbacks[ID].rx_cb ) return 0;
+ gaIPv4_Callbacks[ID].rx_cb = RxCallback;
+ gaIPv4_Callbacks[ID].err_cb = ErrCallback;
return 1;
}
* \param Data Packet Data
* \return Boolean Success
*/
-int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int Length, const void *Data)
+int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, tIPStackBuffer *Buffer)
{
- tMacAddr to;
- int bufSize = sizeof(tIPv4Header) + Length;
- char buf[bufSize];
- tIPv4Header *hdr = (void*)buf;
- int ret;
+ tIPv4Header hdr;
+
+ int length = IPStack_Buffer_GetLength(Buffer);
- to = ARP_Resolve4(Iface, Address);
+ // --- Resolve destination MAC address
+ tMacAddr to = HWCache_Resolve(Iface, &Address);
if( MAC_EQU(to, cMAC_ZERO) ) {
// No route to host
Log_Notice("IPv4", "No route to host %i.%i.%i.%i",
return 0;
}
- // OUTPUT Firewall rule go here
- ret = IPTables_TestChain("OUTPUT",
+ // --- Handle OUTPUT firewall rules
+ // TODO: Update firewall rules for tIPStackBuffer
+ #if 0
+ int ret = IPTables_TestChain("OUTPUT",
4, (tIPv4*)Iface->Address, &Address,
Protocol, 0,
- Length, Data);
+ length, Data);
if(ret > 0) {
// Just drop it (with an error)
Log_Notice("IPv4", "Firewall dropped packet");
return 0;
}
+ #endif
+
+ // --- Initialise header
+ hdr.Version = 4;
+ hdr.HeaderLength = sizeof(tIPv4Header)/4;
+ hdr.DiffServices = 0; // TODO: Check
- memcpy(&hdr->Options[0], Data, Length);
- hdr->Version = 4;
- hdr->HeaderLength = sizeof(tIPv4Header)/4;
- hdr->DiffServices = 0; // TODO: Check
-
- hdr->Reserved = 0;
- hdr->DontFragment = 0;
- hdr->MoreFragments = 0;
- hdr->FragOffLow = 0;
- hdr->FragOffHi = 0;
-
- hdr->TotalLength = htons( bufSize );
- hdr->Identifcation = htons( ID ); // TODO: Check
- hdr->TTL = DEFAULT_TTL;
- hdr->Protocol = Protocol;
- hdr->HeaderChecksum = 0; // Will be set later
- hdr->Source = *(tIPv4*)Iface->Address;
- hdr->Destination = Address;
- hdr->HeaderChecksum = htons( IPv4_Checksum(hdr, sizeof(tIPv4Header)) );
+ hdr.Reserved = 0;
+ hdr.DontFragment = 0;
+ hdr.MoreFragments = 0;
+ hdr.FragOffLow = 0;
+ hdr.FragOffHi = 0;
+ hdr.TotalLength = htons( sizeof(tIPv4Header) + length );
+ hdr.Identifcation = htons( ID ); // TODO: Check
+ hdr.TTL = DEFAULT_TTL;
+ hdr.Protocol = Protocol;
+ hdr.HeaderChecksum = 0; // Will be set later
+ hdr.Source = *(tIPv4*)Iface->Address;
+ hdr.Destination = Address;
+
+ // Actually set checksum (zeroed above)
+ hdr.HeaderChecksum = htons( IPv4_Checksum(&hdr, sizeof(tIPv4Header)) );
+
+ IPStack_Buffer_AppendSubBuffer(Buffer, sizeof(tIPv4Header), 0, &hdr, NULL, NULL);
+
+ #if IPV4_TRACE
Log_Log("IPv4", "Sending packet to %i.%i.%i.%i",
Address.B[0], Address.B[1], Address.B[2], Address.B[3]);
- Link_SendPacket(Iface->Adapter, IPV4_ETHERNET_ID, to, bufSize, buf);
+ #endif
+ Link_SendPacket(Iface->Adapter, IPV4_ETHERNET_ID, to, Buffer);
return 1;
}
void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buffer)
{
tIPv4Header *hdr = Buffer;
- tInterface *iface;
Uint8 *data;
int dataLength;
int ret;
// TODO: Handle packet fragmentation
-
- Log_Debug("IPv4", " From %i.%i.%i.%i to %i.%i.%i.%i",
+ #if IPV4_TRACE
+ Log_Debug("IPv4", "Proto 0x%x From %i.%i.%i.%i to %i.%i.%i.%i",
+ hdr->Protocol,
hdr->Source.B[0], hdr->Source.B[1], hdr->Source.B[2], hdr->Source.B[3],
hdr->Destination.B[0], hdr->Destination.B[1], hdr->Destination.B[2], hdr->Destination.B[3]
);
+ #endif
// 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);
+ tInterface *iface = IPv4_GetInterface(Adapter, hdr->Destination, 1);
// Firewall rules
if( iface ) {
}
else {
// Routed packets
+ // Drop the packet if the TTL is zero
+ if( hdr->TTL == 0 ) {
+ Log_Warning("IPv4", "TODO: Send ICMP-Timeout when TTL exceeded");
+ return ;
+ }
+ hdr->TTL --;
+
ret = IPTables_TestChain("FORWARD",
4, &hdr->Source, &hdr->Destination,
hdr->Protocol, 0,
// 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: Send ICMP-Timeout when TTL exceeded");
- return ;
- }
-
- hdr->TTL --;
-
- rt = IPStack_FindRoute(4, NULL, &hdr->Destination); // Get the route (gets the interface)
- if( !rt || !rt->Interface )
- return ;
- 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);
-
-
+ //IPStack_RoutePacket(4, &hdr->Destination, Length, Buffer);
return ;
}
+
+ // Populate ARP cache from recieved packets
+ // - Should be safe
+ if( IPStack_CompareAddress(4, &hdr->Source, iface->Address, iface->SubnetBits) )
+ {
+ HWCache_Set(Adapter, 4, &hdr->Source, &From);
+ }
// Send it on
- if( !gaIPv4_Callbacks[hdr->Protocol] ) {
+ if( !gaIPv4_Callbacks[hdr->Protocol].rx_cb ) {
Log_Log("IPv4", "Unknown Protocol %i", hdr->Protocol);
return ;
}
- gaIPv4_Callbacks[hdr->Protocol]( iface, &hdr->Source, dataLength, data );
+ gaIPv4_Callbacks[hdr->Protocol].rx_cb( iface, &hdr->Source, dataLength, data );
+}
+
+/*
+ * Handles an error from the ICMPv4 code, 'Buf' contains part of an IPv4 packet
+ */
+void IPv4_HandleError(tInterface *Iface, tIPErrorMode Mode, size_t Length, const void *Buf)
+{
+ if(Length < sizeof(tIPv4Header)) return;
+ const tIPv4Header* hdr = Buf;
+ if(hdr->Version != 4) return;
+
+ // Get Data and Data Length
+ size_t dataLength = MIN(Length, ntohs(hdr->TotalLength)) - sizeof(tIPv4Header);
+ const void *data = &hdr->Options[0];
+
+ if( gaIPv4_Callbacks[hdr->Protocol].err_cb )
+ gaIPv4_Callbacks[hdr->Protocol].err_cb(Iface, Mode, &hdr->Source, dataLength, data);
}
/**
*/
tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast)
{
- tInterface *iface = NULL;
- Uint32 netmask;
- Uint32 addr, this;
+ tInterface *zero_iface = NULL;
ENTER("pAdapter xAddress bBroadcast", Adapter, Address, Broadcast);
- addr = ntohl( Address.L );
+ Uint32 addr = ntohl( Address.L );
LOG("addr = 0x%x", addr);
- for( iface = gIP_Interfaces; iface; iface = iface->Next)
+ for( tInterface *iface = gIP_Interfaces; iface; iface = iface->Next)
{
if( iface->Adapter != Adapter ) continue;
if( iface->Type != 4 ) continue;
LEAVE('p', iface);
return iface;
}
-
+
+ LOG("iface->Address = 0x%x", *(Uint32*)iface->Address);
+
+ if( *(Uint32*)iface->Address == 0 ) {
+ if( zero_iface ) {
+ Log_Notice("IPv4", "Multiple 0.0.0.0 interfaces on the same adapter, ignoring");
+ }
+ else {
+ zero_iface = iface;
+ LOG("Zero IF %p", iface);
+ }
+ continue ;
+ }
+
if( !Broadcast ) continue;
// Check for broadcast
- this = ntohl( ((tIPv4*)iface->Address)->L );
- netmask = IPv4_Netmask(iface->SubnetBits);
+ Uint32 this = ntohl( ((tIPv4*)iface->Address)->L );
+ Uint32 netmask = IPv4_Netmask(iface->SubnetBits);
LOG("iface addr = 0x%x, netmask = 0x%x (bits = %i)", this, netmask, iface->SubnetBits);
if( (addr & netmask) == (this & netmask) && (addr & ~netmask) == (0xFFFFFFFF & ~netmask) )
return iface;
}
}
+
+ // Special case for intefaces that are being DHCP configured
+ // - If the interface address is 0.0.0.0, then if there is no match for the
+ // destination the packet is treated as if it was addressed to 0.0.0.0
+ if( zero_iface && Broadcast )
+ {
+ LOG("Using 0.0.0.0 interface with magic!");
+ LEAVE('p', zero_iface);
+ return zero_iface;
+ }
+
LEAVE('n');
return NULL;
}
*/
Uint16 IPv4_Checksum(const void *Buf, size_t Length)
{
+ //Debug_HexDump("IPv4_Checksum", Buf, Length);
const Uint16 *words = Buf;
Uint32 sum = 0;
int i;