X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Modules%2FIPStack%2Fipv4.c;h=6c387cc173e0e6b48a78854e335af096acaaa559;hb=f903bcea88df0cf2e12583ae74e35c4bfb6760bf;hp=933b90ba49b3bc0914e978f0743eb5cdf6cae662;hpb=35f03318dedb1b430175e8005b64896424a644ef;p=tpg%2Facess2.git diff --git a/Modules/IPStack/ipv4.c b/Modules/IPStack/ipv4.c index 933b90ba..6c387cc1 100644 --- a/Modules/IPStack/ipv4.c +++ b/Modules/IPStack/ipv4.c @@ -5,6 +5,7 @@ #include "ipstack.h" #include "link.h" #include "ipv4.h" +#include "firewall.h" #define DEFAULT_TTL 32 @@ -12,7 +13,6 @@ extern tInterface *gIP_Interfaces; extern void ICMP_Initialise(); extern int ICMP_Ping(tInterface *Interface, tIPv4 Addr); -extern void UDP_Initialise(); extern tMacAddr ARP_Resolve4(tInterface *Interface, tIPv4 Address); // === PROTOTYPES === @@ -21,7 +21,7 @@ extern tMacAddr ARP_Resolve4(tInterface *Interface, tIPv4 Address); 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(void *Buf, int Size); +Uint16 IPv4_Checksum(const void *Buf, int Size); int IPv4_Ping(tInterface *Iface, tIPv4 Addr); // === GLOBALS === @@ -29,19 +29,19 @@ 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) { @@ -53,28 +53,61 @@ int IPv4_RegisterCallback(int ID, tIPCallback Callback) /** * \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, void *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; + + if( MAC_EQU(to, cMAC_ZERO) ) { + // No route to host + Log_Notice("IPv4", "No route to host %i.%i.%i.%i", + Address.B[0], Address.B[1], Address.B[2], Address.B[3]); + return 0; + } + + // OUTPUT Firewall rule go here + ret = IPTables_TestChain("OUTPUT", + 4, (tIPv4*)Iface->Address, &Address, + Protocol, 0, + Length, Data); + if(ret > 0) { + // Just drop it (with an error) + Log_Notice("IPv4", "Firewall dropped packet"); + return 0; + } memcpy(&hdr->Options[0], Data, Length); hdr->Version = 4; - hdr->HeaderLength = htons( sizeof(tIPv4Header) ); + 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->Source = *(tIPv4*)Iface->Address; hdr->Destination = Address; - hdr->HeaderChecksum = htons( IPv4_Checksum(hdr, sizeof(tIPv4Header)) ); + hdr->HeaderChecksum = htons(IPv4_Checksum(hdr, sizeof(tIPv4Header))); - Log("[IPv4 ] Sending packet to %i.%i.%i.%i", + 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; @@ -90,57 +123,142 @@ 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 = ntohs(hdr->HeaderChecksum); + hdr->HeaderChecksum = 0; + compVal = IPv4_Checksum(hdr, hdr->HeaderLength * 4); + 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 = IPTables_TestChain("INPUT", + 4, &hdr->Source, &hdr->Destination, + hdr->Protocol, 0, + dataLength, data + ); + } + else { + // Routed packets + ret = IPTables_TestChain("FORWARD", + 4, &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 ; + case -1: + // Bad rule + break ; + // Unknown, silent drop + default: + Log_Warning("IPv4", "Unknown firewall rule"); + return ; + } - dataLength = hdr->TotalLength - sizeof(tIPv4Header); - data = &hdr->Options[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: Sent ICMP-Timeout when TTL exceeded"); + return ; + } + + hdr->TTL --; + + rt = IPStack_FindRoute(4, NULL, &hdr->Destination); // Get the route (gets the interface) + 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); + + + return ; + } // Send it on - gaIPv4_Callbacks[hdr->Protocol] (iface, &hdr->Source, dataLength, data); + if( !gaIPv4_Callbacks[hdr->Protocol] ) { + Log_Log("IPv4", "Unknown Protocol %i", hdr->Protocol); + return ; + } + + gaIPv4_Callbacks[hdr->Protocol]( iface, &hdr->Source, dataLength, data ); } /** * \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) { @@ -154,23 +272,16 @@ 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; @@ -180,41 +291,55 @@ 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 + * For example /24 will become 255.255.255.0 (0xFFFFFF00) */ 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(void *Buf, int Size) +Uint16 IPv4_Checksum(const void *Buf, int Size) { - Uint16 sum = 0; - Uint16 *arr = Buf; + Uint32 sum = 0; + const Uint16 *arr = Buf; int i; - Size = (Size + 1) >> 1; - for(i = 0; i < Size; i++ ) + // Sum all whole words + for(i = 0; i < Size/2; i++ ) { - if((int)sum + arr[i] > 0xFFFF) - sum ++; // Simulate 1's complement - sum += arr[i]; + Uint16 val = ntohs(arr[i]); + sum += val; } + // Add the tail word +// if( i*2 != Size ) +// sum += arr[i]&0xFF; + + // Apply one's complement + while (sum >> 16) + sum = (sum & 0xFFFF) + (sum >> 16); + 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) +int IPv4_Ping(tInterface *IFace, tIPv4 Addr) { - return ICMP_Ping(Iface, Addr); + return ICMP_Ping(IFace, Addr); }