X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Modules%2FIPStack%2Fipv4.c;h=e37085bf06fa10ce8405933d3ce9e44c31bb2517;hb=94ecc5441605ad5151e625457531e7f90470db31;hp=7e7c5854544ca254e77bd0103f560dbcbd31a7f0;hpb=0f48b41ce8edd3b6d549d641b35901e4b51a5132;p=tpg%2Facess2.git diff --git a/Modules/IPStack/ipv4.c b/Modules/IPStack/ipv4.c index 7e7c5854..e37085bf 100644 --- a/Modules/IPStack/ipv4.c +++ b/Modules/IPStack/ipv4.c @@ -5,11 +5,15 @@ #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 void UDP_Initialise(); +extern int ICMP_Ping(tInterface *Interface, tIPv4 Addr); +extern tMacAddr ARP_Resolve4(tInterface *Interface, tIPv4 Address); // === PROTOTYPES === int IPv4_Initialise(); @@ -17,25 +21,27 @@ extern void UDP_Initialise(); 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]; // === CODE === /** - * \fn int IPv4_Initialise() + * \brief Initialise the IPv4 Code */ int IPv4_Initialise() { ICMP_Initialise(); - UDP_Initialise(); Link_RegisterType(IPV4_ETHERNET_ID, IPv4_int_GetPacket); return 1; } /** - * \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) { @@ -45,6 +51,60 @@ int IPv4_RegisterCallback(int ID, tIPCallback 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 + * \return Boolean Success + */ +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; + + // OUTPUT Firewall rule go here + ret = IPTablesV4_TestChain("OUTPUT", + (tIPv4*)Iface->Address, &Address, + Protocol, 0, + Length, Data); + if(ret != 0) { + // Just drop it (with an error) + 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 = *(tIPv4*)Iface->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 @@ -55,57 +115,114 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff tInterface *iface; Uint8 *data; int dataLength; + int ret; + if(Length < sizeof(tIPv4Header)) return; - //Log("[IPv4 ] Version = %i", hdr->Version); - Log("[IPv4 ] HeaderLength = %i", hdr->HeaderLength); - Log("[IPv4 ] DiffServices = %i", hdr->DiffServices); - //Log("[IPv4 ] TotalLength = %i", ntohs(hdr->TotalLength) ); - //Log("[IPv4 ] Identifcation = %i", ntohs(hdr->Identifcation) ); - //Log("[IPv4 ] TTL = %i", hdr->TTL ); - Log("[IPv4 ] Protocol = %i", hdr->Protocol ); - //Log("[IPv4 ] HeaderChecksum = 0x%x", ntohs(hdr->HeaderChecksum) ); - Log("[IPv4 ] Source = %i.%i.%i.%i", + #if 0 + //Log_Log("IPv4", "Version = %i", hdr->Version); + //Log_Log("IPv4", "HeaderLength = %i", hdr->HeaderLength); + //Log_Log("IPv4", "DiffServices = %i", hdr->DiffServices); + Log_Debug("IPv4", "TotalLength = %i", ntohs(hdr->TotalLength) ); + //Log_Log("IPv4", "Identifcation = %i", ntohs(hdr->Identifcation) ); + //Log_Log("IPv4", "TTL = %i", hdr->TTL ); + Log_Debug("IPv4", "Protocol = %i", hdr->Protocol ); + //Log_Log("IPv4", "HeaderChecksum = 0x%x", ntohs(hdr->HeaderChecksum) ); + 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("[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 that the version IS IPv4 if(hdr->Version != 4) { - Log("[IPv4 ] hdr->Version(%i) != 4", hdr->Version); + Log_Log("IPv4", "hdr->Version(%i) != 4", hdr->Version); return; } // Check Header checksum - //TODO + { + Uint16 hdrVal, compVal; + hdrVal = hdr->HeaderChecksum; + hdr->HeaderChecksum = 0; + compVal = IPv4_Checksum(hdr, hdr->HeaderLength); + 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) { - Log("[IPv4 ] hdr->TotalLength(%i) > Length(%i)", hdr->TotalLength, Length); + Log_Log("IPv4", "hdr->TotalLength(%i) > Length(%i)", 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); - if(!iface) { - Log("[IPv4 ] Ignoring Packet (Not for us)"); - return; // Not for us? Well, let's ignore it - } - // Defragment - //TODO + // Firewall rules + if( iface ) { + // Incoming Packets + ret = IPTablesV4_TestChain("INPUT", + &hdr->Source, &hdr->Destination, + hdr->Protocol, 0, + dataLength, data + ); + } + else { + // Routed packets + 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: + Log_Debug("IPv4", "Silently dropping packet"); + return ; + // Unknown, silent drop + default: + return ; + } - dataLength = hdr->TotalLength - sizeof(tIPv4Header); - data = &hdr->Options[0]; + // Routing + if(!iface) + { + Log_Debug("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); } /** * \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) { @@ -119,23 +236,16 @@ 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); - //Log("netmask = 0x%08x", netmask); - //Log("addr = 0x%08x", addr); - //Log("this = 0x%08x", this); - //Log("%08x == %08x && %08x == %08x", - // (addr & netmask), (this & netmask), - // (addr & ~netmask), (0xFFFFFFFF & ~netmask) - // ); if( (addr & netmask) == (this & netmask) && (addr & ~netmask) == (0xFFFFFFFF & ~netmask) ) return iface; @@ -145,6 +255,7 @@ tInterface *IPv4_GetInterface(tAdapter *Adapter, tIPv4 Address, int Broadcast) /** * \brief Convert a network prefix to a netmask + * \param FixedBits Netmask size (/n) * * For example /24 will become 255.255.255.0 */ @@ -153,6 +264,39 @@ Uint32 IPv4_Netmask(int FixedBits) Uint32 ret = 0xFFFFFFFF; ret >>= (32-FixedBits); ret <<= (32-FixedBits); - // Returs a little endian netmask + // Returns a native endian netmask return ret; } + +/** + * \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; + 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 + * \param IFace Interface + * \param Addr Destination address + */ +int IPv4_Ping(tInterface *IFace, tIPv4 Addr) +{ + return ICMP_Ping(IFace, Addr); +}