X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;ds=sidebyside;f=Modules%2FIPStack%2Fipv4.c;h=b77581eb0939c80c5e737385b7d10af947d0651c;hb=7941d6b368acb0abc17e6a77ffaf7b4c306b67ab;hp=b6c70858d70409b4c1c299ff466ad4d8fd8ac236;hpb=3af08228012b1e79b7f47457f606911f3064dcbd;p=tpg%2Facess2.git diff --git a/Modules/IPStack/ipv4.c b/Modules/IPStack/ipv4.c index b6c70858..b77581eb 100644 --- a/Modules/IPStack/ipv4.c +++ b/Modules/IPStack/ipv4.c @@ -29,7 +29,7 @@ tIPCallback gaIPv4_Callbacks[256]; // === CODE === /** - * \fn int IPv4_Initialise() + * \brief Initialise the IPv4 Code */ int IPv4_Initialise() { @@ -39,8 +39,9 @@ int IPv4_Initialise() } /** - * \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) { @@ -58,6 +59,7 @@ int IPv4_RegisterCallback(int ID, tIPCallback Callback) * \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) { @@ -67,15 +69,21 @@ int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int tIPv4Header *hdr = (void*)buf; int ret; - // TODO: OUTPUT Firewall rule go here - ret = IPTablesV4_TestChain("OUTPUT", - &Iface->IP4.Address, &Address, + 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 + if(ret > 0) { + // Just drop it (with an error) + Log_Notice("IPv4", "Firewall dropped packet"); return 0; } @@ -95,9 +103,9 @@ int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int 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 = IPv4_Checksum(hdr, sizeof(tIPv4Header)); + hdr->HeaderChecksum = htons(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]); @@ -116,21 +124,21 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff 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_Debug("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_Debug("IPv4", "Protocol = %i", hdr->Protocol ); //Log_Log("IPv4", "HeaderChecksum = 0x%x", ntohs(hdr->HeaderChecksum) ); - Log_Log("IPv4", "Source = %i.%i.%i.%i", + 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_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 @@ -142,7 +150,17 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff } // 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) { @@ -150,9 +168,9 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff return; } - // TODO: Handle packet fragmentation + // Get Data and Data Length dataLength = ntohs(hdr->TotalLength) - sizeof(tIPv4Header); data = &hdr->Options[0]; @@ -160,17 +178,19 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff // Get Interface (allowing broadcasts) iface = IPv4_GetInterface(Adapter, hdr->Destination, 1); - // TODO: INPUT Firewall Rule + // Firewall rules if( iface ) { - ret = IPTablesV4_TestChain("INPUT", - &hdr->Source, &hdr->Destination, + // Incoming Packets + ret = IPTables_TestChain("INPUT", + 4, &hdr->Source, &hdr->Destination, hdr->Protocol, 0, dataLength, data ); } else { - ret = IPTablesV4_TestChain("FORWARD", - &hdr->Source, &hdr->Destination, + // Routed packets + ret = IPTables_TestChain("FORWARD", + 4, &hdr->Source, &hdr->Destination, hdr->Protocol, 0, dataLength, data ); @@ -180,32 +200,65 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff // 0 - Allow case 0: break; // 1 - Silent Drop - case 1: return ; + 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 ; } // Routing if(!iface) { - Log_Log("IPv4", "Route the packet"); + 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); - // TODO: Parse Routing tables and determine where to send it return ; } // Send it on - if( gaIPv4_Callbacks[hdr->Protocol] ) - gaIPv4_Callbacks[hdr->Protocol] (iface, &hdr->Source, dataLength, data); - else + 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) { @@ -219,15 +272,15 @@ 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); if( (addr & netmask) == (this & netmask) && (addr & ~netmask) == (0xFFFFFFFF & ~netmask) ) @@ -238,8 +291,9 @@ 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) { @@ -252,27 +306,37 @@ Uint32 IPv4_Netmask(int FixedBits) /** * \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; + Uint32 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]; + Uint16 val = ntohs(arr[i]); + sum += val; } - return ~sum ; + + // 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); }