3 * - IPv4 Protcol Handling
12 extern tInterface *gIP_Interfaces;
13 extern void ICMP_Initialise();
14 extern int ICMP_Ping(tInterface *Interface, tIPv4 Addr);
15 extern tMacAddr ARP_Resolve4(tInterface *Interface, tIPv4 Address);
18 int IPv4_Initialise();
19 int IPv4_RegisterCallback(int ID, tIPCallback Callback);
20 void IPv4_int_GetPacket(tAdapter *Interface, tMacAddr From, int Length, void *Buffer);
21 tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast);
22 Uint32 IPv4_Netmask(int FixedBits);
23 Uint16 IPv4_Checksum(void *Buf, int Size);
24 int IPv4_Ping(tInterface *Iface, tIPv4 Addr);
27 tIPCallback gaIPv4_Callbacks[256];
31 * \fn int IPv4_Initialise()
36 Link_RegisterType(IPV4_ETHERNET_ID, IPv4_int_GetPacket);
41 * \fn int IPv4_RegisterCallback( int ID, tIPCallback Callback )
42 * \brief Registers a callback
44 int IPv4_RegisterCallback(int ID, tIPCallback Callback)
46 if( ID < 0 || ID > 255 ) return 0;
47 if( gaIPv4_Callbacks[ID] ) return 0;
48 gaIPv4_Callbacks[ID] = Callback;
53 * \brief Creates and sends an IPv4 Packet
54 * \param Iface Interface
55 * \param Address Destination IP
56 * \param Protocol Protocol ID
57 * \param ID Some random ID number
58 * \param Length Data Length
59 * \param Data Packet Data
61 int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int Length, void *Data)
63 tMacAddr to = ARP_Resolve4(Iface, Address);
64 int bufSize = sizeof(tIPv4Header) + Length;
66 tIPv4Header *hdr = (void*)buf;
68 memcpy(&hdr->Options[0], Data, Length);
70 hdr->HeaderLength = sizeof(tIPv4Header)/4;
71 hdr->DiffServices = 0; // TODO: Check
74 hdr->DontFragment = 0;
75 hdr->MoreFragments = 0;
79 hdr->TotalLength = htons( bufSize );
80 hdr->Identifcation = htons( ID ); // TODO: Check
81 hdr->TTL = DEFAULT_TTL;
82 hdr->Protocol = Protocol;
83 hdr->HeaderChecksum = 0; // Will be set later
84 hdr->Source = Iface->IP4.Address;
85 hdr->Destination = Address;
86 hdr->HeaderChecksum = IPv4_Checksum(hdr, sizeof(tIPv4Header));
88 Log_Log("IPv4", "Sending packet to %i.%i.%i.%i",
89 Address.B[0], Address.B[1], Address.B[2], Address.B[3]);
90 Link_SendPacket(Iface->Adapter, IPV4_ETHERNET_ID, to, bufSize, buf);
95 * \fn void IPv4_int_GetPacket(tInterface *Adapter, tMacAddr From, int Length, void *Buffer)
96 * \brief Process an IPv4 Packet
98 void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buffer)
100 tIPv4Header *hdr = Buffer;
104 if(Length < sizeof(tIPv4Header)) return;
106 //Log_Log("IPv4", "Version = %i", hdr->Version);
107 //Log_Log("IPv4", "HeaderLength = %i", hdr->HeaderLength);
108 //Log_Log("IPv4", "DiffServices = %i", hdr->DiffServices);
109 Log_Log("IPv4", "TotalLength = %i", ntohs(hdr->TotalLength) );
110 //Log_Log("IPv4", "Identifcation = %i", ntohs(hdr->Identifcation) );
111 //Log_Log("IPv4", "TTL = %i", hdr->TTL );
112 Log_Log("IPv4", "Protocol = %i", hdr->Protocol );
113 //Log_Log("IPv4", "HeaderChecksum = 0x%x", ntohs(hdr->HeaderChecksum) );
114 Log_Log("IPv4", "Source = %i.%i.%i.%i",
115 hdr->Source.B[0], hdr->Source.B[1], hdr->Source.B[2], hdr->Source.B[3] );
116 Log_Log("IPv4", "Destination = %i.%i.%i.%i",
117 hdr->Destination.B[0], hdr->Destination.B[1],
118 hdr->Destination.B[2], hdr->Destination.B[3] );
120 // Check that the version IS IPv4
121 if(hdr->Version != 4) {
122 Log_Log("IPv4", "hdr->Version(%i) != 4", hdr->Version);
126 // Check Header checksum
129 // Check Packet length
130 if( ntohs(hdr->TotalLength) > Length) {
131 Log_Log("IPv4", "hdr->TotalLength(%i) > Length(%i)", ntohs(hdr->TotalLength), Length);
135 // Get Interface (allowing broadcasts)
136 iface = IPv4_GetInterface(Adapter, hdr->Destination, 1);
138 Log_Log("IPv4", "Ignoring Packet (Not for us)");
139 return; // Not for us? Well, let's ignore it
145 dataLength = ntohs(hdr->TotalLength) - sizeof(tIPv4Header);
146 data = &hdr->Options[0];
149 if( gaIPv4_Callbacks[hdr->Protocol] )
150 gaIPv4_Callbacks[hdr->Protocol] (iface, &hdr->Source, dataLength, data);
152 Log_Log("IPv4", "Unknown Protocol %i", hdr->Protocol);
156 * \fn tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address)
157 * \brief Searches an adapter for a matching address
159 tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast)
161 tInterface *iface = NULL;
165 addr = ntohl( Address.L );
167 for( iface = gIP_Interfaces; iface; iface = iface->Next)
169 if( iface->Adapter != Adapter ) continue;
170 if( iface->Type != 4 ) continue;
171 if( IP4_EQU(Address, iface->IP4.Address) )
174 if( !Broadcast ) continue;
176 this = ntohl( iface->IP4.Address.L );
178 // Check for broadcast
179 netmask = IPv4_Netmask(iface->IP4.SubnetBits);
181 //Log("netmask = 0x%08x", netmask);
182 //Log("addr = 0x%08x", addr);
183 //Log("this = 0x%08x", this);
184 //Log("%08x == %08x && %08x == %08x",
185 // (addr & netmask), (this & netmask),
186 // (addr & ~netmask), (0xFFFFFFFF & ~netmask)
188 if( (addr & netmask) == (this & netmask)
189 && (addr & ~netmask) == (0xFFFFFFFF & ~netmask) )
196 * \brief Convert a network prefix to a netmask
198 * For example /24 will become 255.255.255.0
200 Uint32 IPv4_Netmask(int FixedBits)
202 Uint32 ret = 0xFFFFFFFF;
203 ret >>= (32-FixedBits);
204 ret <<= (32-FixedBits);
205 // Returs a little endian netmask
210 * \brief Calculate the IPv4 Checksum
212 Uint16 IPv4_Checksum(void *Buf, int Size)
218 Log("IPv4_Checksum: (%p, %i)", Buf, Size);
220 Size = (Size + 1) >> 1;
221 for(i = 0; i < Size; i++ )
223 if((int)sum + arr[i] > 0xFFFF)
224 sum ++; // Simulate 1's complement
231 * \brief Sends an ICMP Echo and waits for a reply
233 int IPv4_Ping(tInterface *Iface, tIPv4 Addr)
235 return ICMP_Ping(Iface, Addr);