* Acess2 IP Stack
* - Address Resolution Protocol
*/
+#define DEBUG 0
#include "ipstack.h"
#include "arp.h"
#include "link.h"
#define ARP_CACHE_SIZE 64
+#define ARP_MAX_AGE (60*60*1000) // 1Hr
// === IMPORTS ===
extern tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast);
void ARP_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buffer);
// === GLOBALS ===
-struct sARP_Cache {
+struct sARP_Cache4 {
+ tIPv4 IP;
tMacAddr MAC;
- tIPv4 IP4;
- tIPv6 IP6;
Sint64 LastUpdate;
-} *gaARP_Cache;
- int giARP_CacheSpace;
+ Sint64 LastUsed;
+} *gaARP_Cache4;
+ int giARP_Cache4Space;
+tSpinlock glARP_Cache4;
+struct sARP_Cache6 {
+ tIPv6 IP;
+ tMacAddr MAC;
+ Sint64 LastUpdate;
+ Sint64 LastUsed;
+} *gaARP_Cache6;
+ int giARP_Cache6Space;
+tSpinlock glARP_Cache6;
+ int giARP_LastUpdateID = 0;
// === CODE ===
/**
*/
int ARP_Initialise()
{
- gaARP_Cache = malloc( ARP_CACHE_SIZE * sizeof(*gaARP_Cache) );
- memset( gaARP_Cache, 0, ARP_CACHE_SIZE * sizeof(*gaARP_Cache) );
- giARP_CacheSpace = ARP_CACHE_SIZE;
+ gaARP_Cache4 = malloc( ARP_CACHE_SIZE * sizeof(struct sARP_Cache4) );
+ memset( gaARP_Cache4, 0, ARP_CACHE_SIZE * sizeof(struct sARP_Cache4) );
+ giARP_Cache4Space = ARP_CACHE_SIZE;
+
+ gaARP_Cache6 = malloc( ARP_CACHE_SIZE * sizeof(struct sARP_Cache6) );
+ memset( gaARP_Cache6, 0, ARP_CACHE_SIZE * sizeof(struct sARP_Cache6) );
+ giARP_Cache6Space = ARP_CACHE_SIZE;
Link_RegisterType(0x0806, ARP_int_GetPacket);
return 1;
}
+/**
+ * \brief Resolves a MAC address from an IPv4 address
+ */
+tMacAddr ARP_Resolve4(tInterface *Interface, tIPv4 Address)
+{
+ int lastID;
+ int i;
+
+ ENTER("pInterface xAddress", Interface, Address);
+
+ LOCK( &glARP_Cache4 );
+ for( i = 0; i < giARP_Cache4Space; i++ )
+ {
+ if(gaARP_Cache4[i].IP.L != Address.L) continue;
+
+ // Check if the entry needs to be refreshed
+ if( now() - gaARP_Cache4[i].LastUpdate > ARP_MAX_AGE ) break;
+
+ RELEASE( &glARP_Cache4 );
+ LOG("Return %x:%x:%x:%x:%x:%x",
+ gaARP_Cache4[i].MAC.B[0], gaARP_Cache4[i].MAC.B[1],
+ gaARP_Cache4[i].MAC.B[2], gaARP_Cache4[i].MAC.B[3],
+ gaARP_Cache4[i].MAC.B[4], gaARP_Cache4[i].MAC.B[5]
+ );
+ LEAVE('-');
+ return gaARP_Cache4[i].MAC;
+ }
+ RELEASE( &glARP_Cache4 );
+
+ lastID = giARP_LastUpdateID;
+ ARP_int_Resolve4(Interface, Address);
+ for(;;)
+ {
+ while(lastID == giARP_LastUpdateID) Threads_Yield();
+ lastID = giARP_LastUpdateID;
+
+ LOCK( &glARP_Cache4 );
+ for( i = 0; i < giARP_Cache4Space; i++ )
+ {
+ if(gaARP_Cache4[i].IP.L != Address.L) continue;
+
+ RELEASE( &glARP_Cache4 );
+ return gaARP_Cache4[i].MAC;
+ }
+ RELEASE( &glARP_Cache4 );
+ }
+}
+
/**
* \fn int ARP_int_Resolve4(tInterface *Interface, tIPv4 Address)
* \brief Request the network to resolve an IPv4 Address
{
struct sArpRequest4 req;
+ Log("[ARP4 ] Asking for address %i.%i.%i.%i",
+ Address.B[0], Address.B[1], Address.B[2], Address.B[3]
+ );
req.HWType = htons(0x100); // Ethernet
req.Type = htons(0x0800);
req.HWSize = 6;
return 0;
}
+/**
+ * \brief Updates the ARP Cache entry for an IPv4 Address
+ */
+void ARP_UpdateCache4(tIPv4 SWAddr, tMacAddr HWAddr)
+{
+ int i;
+ int free = -1;
+ int oldest = 0;
+
+ // Find an entry for the IP address in the cache
+ LOCK(&glARP_Cache4);
+ for( i = giARP_Cache4Space; i--; )
+ {
+ if(gaARP_Cache4[oldest].LastUpdate > gaARP_Cache4[i].LastUpdate) {
+ oldest = i;
+ }
+ if( gaARP_Cache4[i].IP.L == SWAddr.L ) break;
+ if( gaARP_Cache4[i].LastUpdate == 0 && free == -1 ) free = i;
+ }
+ // If there was no match, we need to make one
+ if(i == -1) {
+ if(free != -1)
+ i = free;
+ else
+ i = oldest;
+ gaARP_Cache4[i].IP = SWAddr;
+ }
+
+ gaARP_Cache4[i].MAC = HWAddr;
+ gaARP_Cache4[i].LastUpdate = now();
+ RELEASE(&glARP_Cache4);
+}
+
+/**
+ * \brief Updates the ARP Cache entry for an IPv6 Address
+ */
+void ARP_UpdateCache6(tIPv6 SWAddr, tMacAddr HWAddr)
+{
+ int i;
+ int free = -1;
+ int oldest = 0;
+
+ // Find an entry for the MAC address in the cache
+ LOCK(&glARP_Cache6);
+ for( i = giARP_Cache6Space; i--; )
+ {
+ if(gaARP_Cache6[oldest].LastUpdate > gaARP_Cache6[i].LastUpdate) {
+ oldest = i;
+ }
+ if( MAC_EQU(gaARP_Cache6[i].MAC, HWAddr) ) break;
+ if( gaARP_Cache6[i].LastUpdate == 0 && free == -1 ) free = i;
+ }
+ // If there was no match, we need to make one
+ if(i == -1) {
+ if(free != -1)
+ i = free;
+ else
+ i = oldest;
+ gaARP_Cache6[i].MAC = HWAddr;
+ }
+
+ gaARP_Cache6[i].IP = SWAddr;
+ gaARP_Cache6[i].LastUpdate = now();
+ RELEASE(&glARP_Cache6);
+}
+
/**
* \fn void ARP_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buffer)
* \brief Called when an ARP packet is recieved
*/
void ARP_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buffer)
{
- int i, free = -1;
- int oldest = 0;
tArpRequest4 *req4 = Buffer;
tArpRequest6 *req6 = Buffer;
tInterface *iface;
iface = IPv4_GetInterface(Adapter, req4->DestIP, 0);
if( iface )
{
+ Log("[ARP ] Caching sender's IP Address");
+ ARP_UpdateCache4(req4->SourceIP, req4->SourceMac);
+
req4->DestIP = req4->SourceIP;
req4->DestMac = req4->SourceMac;
req4->SourceIP = iface->IP4.Address;
break;
- case 2: // Ooh! A response!
- // Find an entry for the MAC address in the cache
- for( i = giARP_CacheSpace; i--; )
- {
- if(gaARP_Cache[oldest].LastUpdate > gaARP_Cache[i].LastUpdate) {
- oldest = i;
- }
- if( MAC_EQU(gaARP_Cache[i].MAC, From) ) break;
- if( gaARP_Cache[i].LastUpdate == 0 && free==-1 ) free = i;
- }
- if(i + 1 == 0) {
- if(free != -1)
- i = free;
- else
- i = oldest;
- }
-
+ case 2: // Ooh! A response!
// Check what type of IP it is
switch( req4->SWSize )
{
case 4:
- gaARP_Cache[i].IP4 = req4->SourceIP;
+ ARP_UpdateCache4( req4->SourceIP, From );
break;
case 6:
if( Length < sizeof(tArpRequest6) ) {
Log("[ARP ] Recieved undersized packet (IPv6)");
return ;
}
- gaARP_Cache[i].IP6 = req6->SourceIP;
+ ARP_UpdateCache6( req6->SourceIP, From );
break;
default:
Log("[ARP ] Unknown Protocol Address size (%i)", req4->SWSize);
return ;
}
- gaARP_Cache[i].LastUpdate = now();
break;
}
}