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3f82c7dcc1a85eba3326582246310636b930214c
melonDS/src/libui_sdl/LAN_Socket.cpp
Arisotura 3f82c7dcc1 make melonDS build again
2019-03-04 23:17:03 +01:00

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/*
Copyright 2016-2019 Arisotura
This file is part of melonDS.
melonDS is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option)
any later version.
melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with melonDS. If not, see http://www.gnu.org/licenses/.
*/
// indirect LAN interface, powered by BSD sockets.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "Wifi.h"
#include "LAN_Socket.h"
#include "../Config.h"
#ifdef __WIN32__
#include <winsock2.h>
#include <ws2tcpip.h>
#define socket_t SOCKET
#define sockaddr_t SOCKADDR
#else
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/select.h>
#include <sys/socket.h>
#define socket_t int
#define sockaddr_t struct sockaddr
#define closesocket close
#endif
#ifndef INVALID_SOCKET
#define INVALID_SOCKET (socket_t)-1
#endif
namespace LAN_Socket
{
u8 PacketBuffer[2048];
int PacketLen;
volatile int RXNum;
u16 IPv4ID;
// TODO: UDP sockets
// * use FIFO list
// * assign new socket when seeing new IP/port
typedef struct
{
u8 DestIP[4];
u16 DestPort;
// 0: unused
// 1: connected
u8 Status;
} TCPSocket;
TCPSocket TCPSocketList[16];
bool Init()
{
// TODO: how to deal with cases where an adapter is unplugged or changes config??
//if (PCapLib) return true;
//Lib = NULL;
PacketLen = 0;
RXNum = 0;
IPv4ID = 1;
memset(TCPSocketList, 0, sizeof(TCPSocketList));
return true;
}
void DeInit()
{
//
}
/*bool HandleIncomingIPFrame(u8* data, int len)
{
const u32 serverip = 0x0A404001;
const u32 clientip = 0x0A404010;
//if (memcmp(&data[0x1E], PCapAdapterData->IP_v4, 4))
// return false;
u8 protocol = data[0x17];
//memcpy(&data[6], &PCapAdapterData->DHCP_MAC[0], 6);
memcpy(&data[0], Wifi::GetMAC(), 6);
data[6] = 0x00; data[7] = 0xAB; data[8] = 0x33;
data[9] = 0x28; data[10] = 0x99; data[11] = 0x44;
*(u32*)&data[0x1E] = htonl(clientip);
u8* ipheader = &data[0xE];
u8* protoheader = &data[0x22];
// IP checksum
u32 tmp = 0;
*(u16*)&ipheader[10] = 0;
for (int i = 0; i < 20; i += 2)
tmp += ntohs(*(u16*)&ipheader[i]);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
*(u16*)&ipheader[10] = htons(tmp);
if (protocol == 0x11)
{
u32 udplen = ntohs(*(u16*)&protoheader[4]);
// UDP checksum
tmp = 0;
*(u16*)&protoheader[6] = 0;
tmp += ntohs(*(u16*)&ipheader[12]);
tmp += ntohs(*(u16*)&ipheader[14]);
tmp += ntohs(*(u16*)&ipheader[16]);
tmp += ntohs(*(u16*)&ipheader[18]);
tmp += ntohs(0x1100);
tmp += udplen;
for (u8* i = protoheader; i < &protoheader[udplen-1]; i += 2)
tmp += ntohs(*(u16*)i);
if (udplen & 1) tmp += (protoheader[udplen-1] << 8);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
if (tmp == 0) tmp = 0xFFFF;
*(u16*)&protoheader[6] = htons(tmp);
}
else if (protocol == 0x06)
{
u32 tcplen = ntohs(*(u16*)&ipheader[2]) - 0x14;
u16 srcport = ntohs(*(u16*)&protoheader[0]);
u16 dstport = ntohs(*(u16*)&protoheader[2]);
u16 flags = ntohs(*(u16*)&protoheader[12]);
// TODO: check if they send a FIN, I guess
int sockid = -1;
for (int i = 0; i < (sizeof(TCPSocketList)/sizeof(TCPSocket)); i++)
{
TCPSocket* sock = &TCPSocketList[i];
if (sock->Status == 1 && !memcmp(&sock->DestIP, &ipheader[12], 4) && sock->DestPort == srcport)
{
sockid = i;
break;
}
}
if (sockid == -1)
{
return true;
}
// TCP checksum
tmp = 0;
*(u16*)&protoheader[16] = 0;
tmp += ntohs(*(u16*)&ipheader[12]);
tmp += ntohs(*(u16*)&ipheader[14]);
tmp += ntohs(*(u16*)&ipheader[16]);
tmp += ntohs(*(u16*)&ipheader[18]);
tmp += ntohs(0x0600);
tmp += tcplen;
for (u8* i = protoheader; i < &protoheader[tcplen-1]; i += 2)
tmp += ntohs(*(u16*)i);
if (tcplen & 1) tmp += (protoheader[tcplen-1] << 8);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
*(u16*)&protoheader[16] = htons(tmp);
}
return false;
}*/
/*void RXCallback(u_char* blarg, const struct pcap_pkthdr* header, const u_char* data)
{
while (PCapRXNum > 0);
if (header->len > 2048-64) return;
PCapPacketLen = header->len;
memcpy(PCapPacketBuffer, data, PCapPacketLen);
PCapRXNum = 1;
if (!Config::DirectLAN)
{
u16 ethertype = ntohs(*(u16*)&data[0xC]);
if (ethertype == 0x0800) // IPv4
{
if (HandleIncomingIPFrame(PCapPacketBuffer, header->len))
PCapRXNum = 0;
}
}
}*/
bool HandleDHCPFrame(u8* data, int len)
{
const u32 serverip = 0x0A404001;
const u32 clientip = 0x0A404010;
u8 type = 0xFF;
u32 transid = *(u32*)&data[0x2E];
u8* options = &data[0x11A];
for (;;)
{
if (options >= &data[len]) break;
u8 opt = *options++;
if (opt == 255) break;
u8 len = *options++;
switch (opt)
{
case 53: // frame type
type = options[0];
break;
}
options += len;
}
if (type == 0xFF)
{
printf("DHCP: bad frame\n");
return false;
}
printf("DHCP: frame type %d, transid %08X\n", type, transid);
if (type == 1 || // discover
type == 3) // request
{
u8 resp[512];
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(0x0800); out += 2;
// IP
u8* ipheader = out;
*out++ = 0x45;
*out++ = 0x00;
*(u16*)out = 0; out += 2; // total length
*(u16*)out = htons(IPv4ID); out += 2; IPv4ID++;
*out++ = 0x00;
*out++ = 0x00;
*out++ = 0x80; // TTL
*out++ = 0x11; // protocol (UDP)
*(u16*)out = 0; out += 2; // checksum
*(u32*)out = htonl(serverip); out += 4; // source 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;
*(u16*)out = htons(67); out += 2; // source port
*(u16*)out = htons(68); out += 2; // destination port
*(u16*)out = 0; out += 2; // length
*(u16*)out = 0; out += 2; // checksum
// DHCP
u8* body = out;
*out++ = 0x02;
*out++ = 0x01;
*out++ = 0x06;
*out++ = 0x00;
*(u32*)out = transid; out += 4;
*(u16*)out = 0; out += 2; // seconds elapsed
*(u16*)out = 0; out += 2;
*(u32*)out = htonl(0x00000000); out += 4; // client IP
*(u32*)out = htonl(clientip); out += 4; // your IP
*(u32*)out = htonl(serverip); out += 4; // server IP
*(u32*)out = htonl(0x00000000); out += 4; // gateway IP
memcpy(out, &data[6], 6); out += 6;
memset(out, 0, 10); out += 10;
memset(out, 0, 192); out += 192;
*(u32*)out = 0x63538263; out += 4; // DHCP magic
// DHCP options
*out++ = 53; *out++ = 1;
*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;
*(u32*)out = htonl(serverip); out += 4; // router
*out++ = 51; *out++ = 4;
*(u32*)out = htonl(442030); out += 4; // lease time
*out++ = 54; *out++ = 4;
*(u32*)out = htonl(serverip); out += 4; // DHCP server
/*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 = dnsip; out += 4;
}
}*/
*out++ = 6; *out++ = 4;
*(u32*)out = htonl(0x08080808); out += 4; // DNS (hax)
*out++ = 0xFF;
memset(out, 0, 20); out += 20;
// lengths
u32 framelen = (u32)(out - &resp[0]);
if (framelen & 1) { *out++ = 0; framelen++; }
*(u16*)&ipheader[2] = htons(framelen - 0xE);
*(u16*)&udpheader[4] = htons(framelen - (0xE + 0x14));
// IP checksum
u32 tmp = 0;
for (int i = 0; i < 20; i += 2)
tmp += ntohs(*(u16*)&ipheader[i]);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
*(u16*)&ipheader[10] = htons(tmp);
// UDP checksum
// (note: normally not mandatory, but some older sgIP versions require it)
tmp = 0;
tmp += ntohs(*(u16*)&ipheader[12]);
tmp += ntohs(*(u16*)&ipheader[14]);
tmp += ntohs(*(u16*)&ipheader[16]);
tmp += ntohs(*(u16*)&ipheader[18]);
tmp += ntohs(0x1100);
tmp += (u32)(out - udpheader);
for (u8* i = udpheader; i < out; i += 2)
tmp += ntohs(*(u16*)i);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
if (tmp == 0) tmp = 0xFFFF;
*(u16*)&udpheader[6] = htons(tmp);
// 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
PacketLen = framelen;
memcpy(PacketBuffer, resp, PacketLen);
RXNum = 1;
return true;
}
return false;
}
bool HandleIPFrame(u8* data, int len)
{
const u32 serverip = 0x0A404001;
const u32 clientip = 0x0A404010;
u8 protocol = data[0x17];
// any kind of IPv4 frame that isn't DHCP
// we do NAT and forward it to the network
// like:
// melonRouter -> host
// destination MAC set to host MAC
// source MAC set to melonRouter MAC
//memcpy(&data[0], &PCapAdapterData->DHCP_MAC[0], 6);
//memcpy(&data[6], &PCapAdapterData->MAC[0], 6);
//*(u32*)&data[0x1A] = *(u32*)&PCapAdapterData->IP_v4[0];
u8* ipheader = &data[0xE];
u8* protoheader = &data[0x22];
// IP checksum
u32 tmp = 0;
*(u16*)&ipheader[10] = 0;
for (int i = 0; i < 20; i += 2)
tmp += ntohs(*(u16*)&ipheader[i]);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
*(u16*)&ipheader[10] = htons(tmp);
if (protocol == 0x11)
{
u32 udplen = ntohs(*(u16*)&protoheader[4]);
// UDP checksum
tmp = 0;
*(u16*)&protoheader[6] = 0;
tmp += ntohs(*(u16*)&ipheader[12]);
tmp += ntohs(*(u16*)&ipheader[14]);
tmp += ntohs(*(u16*)&ipheader[16]);
tmp += ntohs(*(u16*)&ipheader[18]);
tmp += ntohs(0x1100);
tmp += udplen;
for (u8* i = protoheader; i < &protoheader[udplen]; i += 2)
tmp += ntohs(*(u16*)i);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
if (tmp == 0) tmp = 0xFFFF;
*(u16*)&protoheader[6] = htons(tmp);
}
else if (protocol == 0x06)
{
u32 tcplen = ntohs(*(u16*)&ipheader[2]) - 0x14;
u16 srcport = ntohs(*(u16*)&protoheader[0]);
u16 dstport = ntohs(*(u16*)&protoheader[2]);
u16 flags = ntohs(*(u16*)&protoheader[12]);
if (flags & 0x002) // SYN
{
int sockid = -1;
for (int i = 0; i < (sizeof(TCPSocketList)/sizeof(TCPSocket)); i++)
{
TCPSocket* sock = &TCPSocketList[i];
if (sock->Status == 1 && !memcmp(&sock->DestIP, &ipheader[16], 4) && sock->DestPort == dstport)
{
printf("LANMAGIC: duplicate TCP socket\n");
sockid = i;
break;
}
}
if (sockid == -1)
{
for (int i = 0; i < (sizeof(TCPSocketList)/sizeof(TCPSocket)); i++)
{
TCPSocket* sock = &TCPSocketList[i];
if (sock->Status == 0)
{
sockid = i;
break;
}
}
}
if (sockid == -1)
{
printf("LANMAGIC: !! TCP SOCKET LIST FULL\n");
return true;
}
printf("LANMAGIC: opening TCP socket #%d to %d.%d.%d.%d:%d\n",
sockid,
ipheader[16], ipheader[17], ipheader[18], ipheader[19],
dstport);
// keep track of it
// (TODO: also keep track of source port?)
TCPSocket* sock = &TCPSocketList[sockid];
sock->Status = 1;
memcpy(sock->DestIP, &ipheader[16], 4);
sock->DestPort = dstport;
}
else
{
int sockid = -1;
for (int i = 0; i < (sizeof(TCPSocketList)/sizeof(TCPSocket)); i++)
{
TCPSocket* sock = &TCPSocketList[i];
if (sock->Status == 1 && !memcmp(&sock->DestIP, &ipheader[16], 4) && sock->DestPort == dstport)
{
sockid = i;
break;
}
}
if (sockid == -1)
{
printf("LANMAGIC: bad TCP packet\n");
return true;
}
if (flags & 0x001) // FIN
{
// TODO: cleverer termination?
// also timeout etc
TCPSocketList[sockid].Status = 0;
}
}
// TCP checksum
tmp = 0;
*(u16*)&protoheader[16] = 0;
tmp += ntohs(*(u16*)&ipheader[12]);
tmp += ntohs(*(u16*)&ipheader[14]);
tmp += ntohs(*(u16*)&ipheader[16]);
tmp += ntohs(*(u16*)&ipheader[18]);
tmp += ntohs(0x0600);
tmp += tcplen;
for (u8* i = protoheader; i < &protoheader[tcplen]; i += 2)
tmp += ntohs(*(u16*)i);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
if (tmp == 0) tmp = 0xFFFF;
*(u16*)&protoheader[16] = htons(tmp);
}
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]);
// TODO: handle ARP to the client
// this only handles ARP to the DHCP/router
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
PacketLen = framelen;
memcpy(PacketBuffer, resp, PacketLen);
RXNum = 1;
return true;
}
return false;
}
bool HandlePacket(u8* data, int len)
{
u16 ethertype = ntohs(*(u16*)&data[0xC]);
if (ethertype == 0x0800) // IPv4
{
u8 protocol = data[0x17];
if (protocol == 0x11) // UDP
{
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);
}
}
printf("LANMAGIC: IP packet\n");
return HandleIPFrame(data, len);
}
else if (ethertype == 0x0806) // ARP
{
printf("LANMAGIC: ARP packet\n");
return HandleARPFrame(data, len);
}
return false;
}
int SendPacket(u8* data, int len)
{
if (len > 2048)
{
printf("LAN_SendPacket: error: packet too long (%d)\n", len);
return 0;
}
// TODO: blarg
if (HandlePacket(data, len))
return len;
return len;
}
int RecvPacket(u8* data)
{
int ret = 0;
if (RXNum > 0)
{
memcpy(data, PacketBuffer, PacketLen);
ret = PacketLen;
RXNum = 0;
}
// TODO: check sockets
return ret;
}
}
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