diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libui_sdl/LAN.cpp | 121 |
1 files changed, 105 insertions, 16 deletions
diff --git a/src/libui_sdl/LAN.cpp b/src/libui_sdl/LAN.cpp index c3f84ff..a8ff1f9 100644 --- a/src/libui_sdl/LAN.cpp +++ b/src/libui_sdl/LAN.cpp @@ -74,6 +74,7 @@ int NumAdapters = 0; void* PCapLib = NULL; pcap_t* PCapAdapter = NULL; +AdapterData* PCapAdapterData; u8 PCapPacketBuffer[2048]; int PCapPacketLen; @@ -249,13 +250,14 @@ bool Init() #endif // __WIN32__ // open pcap device - dev = (pcap_if_t*)Adapters[0].Internal; + PCapAdapterData = &Adapters[0]; for (int i = 0; i < NumAdapters; i++) { if (!strncmp(Adapters[i].DeviceName, Config::LANDevice, 128)) - dev = (pcap_if_t*)Adapters[i].Internal; + PCapAdapterData = &Adapters[i]; } + dev = (pcap_if_t*)PCapAdapterData->Internal; PCapAdapter = pcap_open_live(dev->name, 2048, PCAP_OPENFLAG_PROMISCUOUS, 1, errbuf); if (!PCapAdapter) { @@ -336,7 +338,8 @@ zarp=transid; printf("DHCP: frame type %d, transid %08X\n", type, transid); - if (type == 1) // discover + if (type == 1 || // discover + type == 3) // request { u8 resp[512]; u8* out = &resp[0]; @@ -359,7 +362,14 @@ zarp=transid; *out++ = 0x11; // protocol (UDP) *(u16*)out = 0; out += 2; // checksum *(u32*)out = htonl(serverip); out += 4; // source IP - *(u32*)out = htonl(0xFFFFFFFF); out += 4; // destination IP + if (type == 1) + { + *(u32*)out = htonl(0xFFFFFFFF); out += 4; // destination IP + } + else if (type == 3) + { + *(u32*)out = htonl(clientip); out += 4; // destination IP + } // UDP u8* udpheader = out; @@ -388,7 +398,7 @@ zarp=transid; // DHCP options *out++ = 53; *out++ = 1; - *out++ = 2; // DHCP type: offer + *out++ = (type==1) ? 2 : 5; // DHCP type: offer/ack *out++ = 1; *out++ = 4; *(u32*)out = htonl(0xFFFFFF00); out += 4; // subnet mask *out++ = 3; *out++ = 4; @@ -397,8 +407,22 @@ zarp=transid; *(u32*)out = htonl(442030); out += 4; // lease time *out++ = 54; *out++ = 4; *(u32*)out = htonl(serverip); out += 4; // DHCP server - *out++ = 6; *out++ = 4; - *(u32*)out = htonl(0x08080808); out += 4; // DNS (TODO!!) + + u8 numdns = 0; + for (int i = 0; i < 8; i++) + { + if (*(u32*)&PCapAdapterData->DNS[i][0] != 0) + numdns++; + } + *out++ = 6; *out++ = 4*numdns; + for (int i = 0; i < 8; i++) + { + u32 dnsip = *(u32*)&PCapAdapterData->DNS[i][0]; + if (dnsip != 0) + { + *(u32*)out = htonl(dnsip); out += 4; + } + } *out++ = 0xFF; memset(out, 0, 20); out += 20; @@ -454,22 +478,87 @@ zarp=transid; return false; } +bool HandleARPFrame(u8* data, int len) +{ + const u32 serverip = 0x0A404001; + const u32 clientip = 0x0A404010; + + u16 protocol = ntohs(*(u16*)&data[0x10]); + if (protocol != 0x0800) return false; + + u16 op = ntohs(*(u16*)&data[0x14]); + u32 targetip = ntohl(*(u32*)&data[0x26]); + + if (op == 1 && targetip == serverip) + { + // opcode 1=req 2=reply + // sender MAC + // sender IP + // target MAC + // target IP + + u8 resp[64]; + u8* out = &resp[0]; + + // ethernet + memcpy(out, &data[6], 6); out += 6; + *out++ = 0x00; *out++ = 0xAB; *out++ = 0x33; + *out++ = 0x28; *out++ = 0x99; *out++ = 0x44; + *(u16*)out = htons(0x0806); out += 2; + + // ARP + *(u16*)out = htons(0x0001); out += 2; // hardware type + *(u16*)out = htons(0x0800); out += 2; // protocol + *out++ = 6; // MAC address size + *out++ = 4; // IP address size + *(u16*)out = htons(0x0002); out += 2; // opcode + *out++ = 0x00; *out++ = 0xAB; *out++ = 0x33; + *out++ = 0x28; *out++ = 0x99; *out++ = 0x44; + *(u32*)out = htonl(targetip); out += 4; + memcpy(out, &data[0x16], 6+4); out += 6+4; + + u32 framelen = (u32)(out - &resp[0]); + + // TODO: if there is already a packet queued, this will overwrite it + // that being said, this will only happen during DHCP setup, so probably + // not a big deal + + PCapPacketLen = framelen; + memcpy(PCapPacketBuffer, resp, PCapPacketLen); + PCapRXNum = 1; + + // also broadcast them to the network + pcap_sendpacket(PCapAdapter, data, len); + pcap_sendpacket(PCapAdapter, resp, framelen); + + return true; + } + + return false; +} + bool HandlePacket(u8* data, int len) { - if (ntohs(*(u16*)&data[0xC]) != 0x0800) // IPv4 - return false; + u16 ethertype = ntohs(*(u16*)&data[0xC]); - u8 protocol = data[0x17]; - if (protocol == 0x11) // UDP + if (ethertype == 0x0800) // IPv4 { - u16 srcport = ntohs(*(u16*)&data[0x22]); - u16 dstport = ntohs(*(u16*)&data[0x24]); - if (srcport == 68 && dstport == 67) // DHCP + u8 protocol = data[0x17]; + if (protocol == 0x11) // UDP { - printf("LANMAGIC: DHCP packet\n"); - return HandleDHCPFrame(data, len); + u16 srcport = ntohs(*(u16*)&data[0x22]); + u16 dstport = ntohs(*(u16*)&data[0x24]); + if (srcport == 68 && dstport == 67) // DHCP + { + printf("LANMAGIC: DHCP packet\n"); + return HandleDHCPFrame(data, len); + } } } + else if (ethertype == 0x0806) // ARP + { + return HandleARPFrame(data, len); + } return false; } |