X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;ds=sidebyside;f=Modules%2FIPStack%2Fipv4.c;h=b6c70858d70409b4c1c299ff466ad4d8fd8ac236;hb=e6b37dbe81b4492796fd262f95fc94e06cb67966;hp=d57b124dd55aa09a16dab251bdeddc7a175a94fc;hpb=6c5a509b5e14e097ca537c539bc9babe3b8f0c4c;p=tpg%2Facess2.git diff --git a/Modules/IPStack/ipv4.c b/Modules/IPStack/ipv4.c index d57b124d..b6c70858 100644 --- a/Modules/IPStack/ipv4.c +++ b/Modules/IPStack/ipv4.c @@ -5,12 +5,24 @@ #include "ipstack.h" #include "link.h" #include "ipv4.h" +#include "firewall.h" + +#define DEFAULT_TTL 32 + +// === 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); 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); +Uint16 IPv4_Checksum(const void *Buf, int Size); + int IPv4_Ping(tInterface *Iface, tIPv4 Addr); // === GLOBALS === tIPCallback gaIPv4_Callbacks[256]; @@ -21,10 +33,78 @@ tIPCallback gaIPv4_Callbacks[256]; */ int IPv4_Initialise() { + ICMP_Initialise(); Link_RegisterType(IPV4_ETHERNET_ID, IPv4_int_GetPacket); return 1; } +/** + * \fn int IPv4_RegisterCallback( int ID, tIPCallback Callback ) + * \brief Registers a callback + */ +int IPv4_RegisterCallback(int ID, tIPCallback Callback) +{ + if( ID < 0 || ID > 255 ) return 0; + if( gaIPv4_Callbacks[ID] ) return 0; + gaIPv4_Callbacks[ID] = Callback; + return 1; +} + +/** + * \brief Creates and sends an IPv4 Packet + * \param Iface Interface + * \param Address Destination IP + * \param Protocol Protocol ID + * \param ID Some random ID number + * \param Length Data Length + * \param Data Packet Data + */ +int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int Length, const void *Data) +{ + tMacAddr to = ARP_Resolve4(Iface, Address); + int bufSize = sizeof(tIPv4Header) + Length; + char buf[bufSize]; + tIPv4Header *hdr = (void*)buf; + int ret; + + // TODO: OUTPUT Firewall rule go here + ret = IPTablesV4_TestChain("OUTPUT", + &Iface->IP4.Address, &Address, + Protocol, 0, + Length, Data); + + if(ret != 0) + { + // Just drop it + return 0; + } + + 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 = Iface->IP4.Address; + hdr->Destination = Address; + hdr->HeaderChecksum = 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]); + Link_SendPacket(Iface->Adapter, IPV4_ETHERNET_ID, to, bufSize, buf); + return 1; +} + /** * \fn void IPv4_int_GetPacket(tInterface *Adapter, tMacAddr From, int Length, void *Buffer) * \brief Process an IPv4 Packet @@ -33,31 +113,94 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff { tIPv4Header *hdr = Buffer; tInterface *iface; - char *data; + 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_Log("IPv4", "Identifcation = %i", ntohs(hdr->Identifcation) ); + //Log_Log("IPv4", "TTL = %i", hdr->TTL ); + Log_Log("IPv4", "Protocol = %i", hdr->Protocol ); + //Log_Log("IPv4", "HeaderChecksum = 0x%x", ntohs(hdr->HeaderChecksum) ); + Log_Log("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", + hdr->Destination.B[0], hdr->Destination.B[1], + hdr->Destination.B[2], hdr->Destination.B[3] ); + #endif + // Check that the version IS IPv4 - if(hdr->Version != 4) return; + if(hdr->Version != 4) { + Log_Log("IPv4", "hdr->Version(%i) != 4", hdr->Version); + return; + } // Check Header checksum //TODO // Check Packet length - if(hdr->TotalLength > Length) return; + if( ntohs(hdr->TotalLength) > Length) { + Log_Log("IPv4", "hdr->TotalLength(%i) > Length(%i)", ntohs(hdr->TotalLength), Length); + return; + } - // Get Interface (allowing broadcasts) - iface = IPv4_GetInterface(Adapter, hdr->Source, 1); - if(!iface) return; // Not for us? Well, let's ignore it - // Defragment - //TODO + // TODO: Handle packet fragmentation - dataLength = hdr->TotalLength - sizeof(tIPv4Header); + // 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 + if( iface ) { + ret = IPTablesV4_TestChain("INPUT", + &hdr->Source, &hdr->Destination, + hdr->Protocol, 0, + dataLength, data + ); + } + else { + ret = IPTablesV4_TestChain("FORWARD", + &hdr->Source, &hdr->Destination, + hdr->Protocol, 0, + dataLength, data + ); + } + switch(ret) + { + // 0 - Allow + case 0: break; + // 1 - Silent Drop + case 1: return ; + // Unknown, silent drop + default: + return ; + } + + // Routing + if(!iface) + { + Log_Log("IPv4", "Route the packet"); + + // TODO: Parse Routing tables and determine where to send it + + return ; + } + // Send it on - gaIPv4_Callbacks[hdr->Protocol] (iface, &hdr->Source, dataLength, data); + if( gaIPv4_Callbacks[hdr->Protocol] ) + gaIPv4_Callbacks[hdr->Protocol] (iface, &hdr->Source, dataLength, data); + else + Log_Log("IPv4", "Unknown Protocol %i", hdr->Protocol); } /** @@ -68,19 +211,26 @@ tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast) { tInterface *iface = NULL; Uint32 netmask; + Uint32 addr, this; - for( iface = Adapter->Interfaces; iface; iface = iface->Next) + addr = ntohl( Address.L ); + + for( iface = gIP_Interfaces; iface; iface = iface->Next) { + if( iface->Adapter != Adapter ) continue; if( iface->Type != 4 ) continue; if( IP4_EQU(Address, iface->IP4.Address) ) return iface; if( !Broadcast ) continue; + this = ntohl( iface->IP4.Address.L ); + // Check for broadcast netmask = IPv4_Netmask(iface->IP4.SubnetBits); - if( (Address.L & netmask) == (iface->IP4.Address.L & netmask) - && (Address.L & ~netmask) == (0xFFFFFFFF & ~netmask) ) + + if( (addr & netmask) == (this & netmask) + && (addr & ~netmask) == (0xFFFFFFFF & ~netmask) ) return iface; } return NULL; @@ -96,5 +246,33 @@ Uint32 IPv4_Netmask(int FixedBits) Uint32 ret = 0xFFFFFFFF; ret >>= (32-FixedBits); ret <<= (32-FixedBits); + // Returns a native endian netmask return ret; } + +/** + * \brief Calculate the IPv4 Checksum + */ +Uint16 IPv4_Checksum(const void *Buf, int Size) +{ + Uint16 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]; + } + return ~sum ; +} + +/** + * \brief Sends an ICMP Echo and waits for a reply + */ +int IPv4_Ping(tInterface *Iface, tIPv4 Addr) +{ + return ICMP_Ping(Iface, Addr); +}