X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Modules%2FIPStack%2Fipv4.c;h=d16cc97d0d6154a4c21e1320fde27de6a85d3050;hb=2c3ab58b961dea91fdfbf432a7fdf9593c6e7a8e;hp=31d6f027fe9cdd23a4b252626df43f4879fc392a;hpb=26e66aa0a682e2f1a5d9328b6037b5779310f8f3;p=tpg%2Facess2.git diff --git a/Modules/IPStack/ipv4.c b/Modules/IPStack/ipv4.c index 31d6f027..d16cc97d 100644 --- a/Modules/IPStack/ipv4.c +++ b/Modules/IPStack/ipv4.c @@ -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(const void *Buf, int Size); +Uint16 IPv4_Checksum(const void *Buf, size_t Length); int IPv4_Ping(tInterface *Iface, tIPv4 Addr); // === GLOBALS === @@ -69,13 +69,21 @@ int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int 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 = IPTablesV4_TestChain("OUTPUT", - (tIPv4*)Iface->Address, &Address, + ret = IPTables_TestChain("OUTPUT", + 4, (tIPv4*)Iface->Address, &Address, Protocol, 0, Length, Data); - if(ret != 0) { + if(ret > 0) { // Just drop it (with an error) + Log_Notice("IPv4", "Firewall dropped packet"); return 0; } @@ -97,7 +105,7 @@ int IPv4_SendPacket(tInterface *Iface, tIPv4 Address, int Protocol, int ID, int hdr->HeaderChecksum = 0; // Will be set later 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]); @@ -116,7 +124,7 @@ 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 @@ -144,9 +152,9 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff // Check Header checksum { Uint16 hdrVal, compVal; - hdrVal = hdr->HeaderChecksum; + hdrVal = ntohs(hdr->HeaderChecksum); hdr->HeaderChecksum = 0; - compVal = IPv4_Checksum(hdr, hdr->HeaderLength); + compVal = IPv4_Checksum(hdr, hdr->HeaderLength * 4); if(hdrVal != compVal) { Log_Log("IPv4", "Header checksum fails (%04x != %04x)", hdrVal, compVal); return ; @@ -173,16 +181,16 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff // Firewall rules if( iface ) { // Incoming Packets - ret = IPTablesV4_TestChain("INPUT", - &hdr->Source, &hdr->Destination, + ret = IPTables_TestChain("INPUT", + 4, &hdr->Source, &hdr->Destination, hdr->Protocol, 0, dataLength, data ); } else { // Routed packets - ret = IPTablesV4_TestChain("FORWARD", - &hdr->Source, &hdr->Destination, + ret = IPTables_TestChain("FORWARD", + 4, &hdr->Source, &hdr->Destination, hdr->Protocol, 0, dataLength, data ); @@ -195,26 +203,54 @@ void IPv4_int_GetPacket(tAdapter *Adapter, tMacAddr From, int Length, void *Buff 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) { + 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 ); } /** @@ -257,7 +293,7 @@ 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 + * For example /24 will become 255.255.255.0 (0xFFFFFF00) */ Uint32 IPv4_Netmask(int FixedBits) { @@ -275,21 +311,25 @@ Uint32 IPv4_Netmask(int FixedBits) * * One's complement sum of all 16-bit words (bitwise inverted) */ -Uint16 IPv4_Checksum(const void *Buf, int Size) +Uint16 IPv4_Checksum(const void *Buf, size_t Length) { - Uint16 sum = 0; - const Uint16 *arr = Buf; + const Uint16 *words = Buf; + Uint32 sum = 0; int i; - Size = (Size + 1) >> 1; // 16-bit word count - for(i = 0; i < Size; i++ ) + // Sum all whole words + for(i = 0; i < Length/2; i++ ) { - Uint16 val = ntohs(arr[i]); - if((int)sum + val > 0xFFFF) - sum ++; // Simulate 1's complement - sum += val; + sum += ntohs(words[i]); } - return ~sum ; + if( Length & 1 ) + sum += ntohs( words[i] & 0xFF ); + + // Apply one's complement + while (sum >> 16) + sum = (sum & 0xFFFF) + (sum >> 16); + + return ~sum; } /**