Files
melonDS/src/frontend/qt_sdl/LAN_Socket.cpp
Nadia Holmquist Pedersen a2406e3c0e Vendored libslirp (#2045)
Add vendored libslirp into the repo with a shim to remove its dependency on glib.
2024-05-15 18:00:55 +02:00

544 lines
13 KiB
C++

/*
Copyright 2016-2023 melonDS team
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 "FIFO.h"
#include "Platform.h"
#include <libslirp.h>
#ifdef __WIN32__
#include <ws2tcpip.h>
#else
#include <sys/socket.h>
#include <netdb.h>
#include <poll.h>
#include <time.h>
#endif
using namespace melonDS;
namespace LAN_Socket
{
using Platform::Log;
using Platform::LogLevel;
const u32 kSubnet = 0x0A400000;
const u32 kServerIP = kSubnet | 0x01;
const u32 kDNSIP = kSubnet | 0x02;
const u32 kClientIP = kSubnet | 0x10;
const u8 kServerMAC[6] = {0x00, 0xAB, 0x33, 0x28, 0x99, 0x44};
FIFO<u32, (0x8000 >> 2)> RXBuffer;
u32 IPv4ID;
Slirp* Ctx = nullptr;
/*const int FDListMax = 64;
struct pollfd FDList[FDListMax];
int FDListSize;*/
#ifdef __WIN32__
#define poll WSAPoll
// https://stackoverflow.com/questions/5404277/porting-clock-gettime-to-windows
struct timespec { long tv_sec; long tv_nsec; };
#define CLOCK_MONOTONIC 1312
int clock_gettime(int, struct timespec *spec)
{
__int64 wintime;
GetSystemTimeAsFileTime((FILETIME*)&wintime);
wintime -=116444736000000000LL; //1jan1601 to 1jan1970
spec->tv_sec = wintime / 10000000LL; //seconds
spec->tv_nsec = wintime % 10000000LL * 100; //nano-seconds
return 0;
}
#endif // __WIN32__
void RXEnqueue(const void* buf, int len)
{
int alignedlen = (len + 3) & ~3;
int totallen = alignedlen + 4;
if (!RXBuffer.CanFit(totallen >> 2))
{
Log(LogLevel::Warn, "slirp: !! NOT ENOUGH SPACE IN RX BUFFER\n");
return;
}
u32 header = (alignedlen & 0xFFFF) | (len << 16);
RXBuffer.Write(header);
for (int i = 0; i < alignedlen; i += 4)
RXBuffer.Write(((u32*)buf)[i>>2]);
}
ssize_t SlirpCbSendPacket(const void* buf, size_t len, void* opaque)
{
if (len > 2048)
{
Log(LogLevel::Warn, "slirp: packet too big (%zu)\n", len);
return 0;
}
Log(LogLevel::Debug, "slirp: response packet of %zu bytes, type %04X\n", len, ntohs(((u16*)buf)[6]));
RXEnqueue(buf, len);
return len;
}
void SlirpCbGuestError(const char* msg, void* opaque)
{
Log(LogLevel::Error, "SLIRP: error: %s\n", msg);
}
int64_t SlirpCbClockGetNS(void* opaque)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ts.tv_sec * 1000000000LL + ts.tv_nsec;
}
void* SlirpCbTimerNew(SlirpTimerCb cb, void* cb_opaque, void* opaque)
{
return nullptr;
}
void SlirpCbTimerFree(void* timer, void* opaque)
{
}
void SlirpCbTimerMod(void* timer, int64_t expire_time, void* opaque)
{
}
void SlirpCbRegisterPollFD(int fd, void* opaque)
{
Log(LogLevel::Debug, "Slirp: register poll FD %d\n", fd);
/*if (FDListSize >= FDListMax)
{
printf("!! SLIRP FD LIST FULL\n");
return;
}
for (int i = 0; i < FDListSize; i++)
{
if (FDList[i].fd == fd) return;
}
FDList[FDListSize].fd = fd;
FDListSize++;*/
}
void SlirpCbUnregisterPollFD(int fd, void* opaque)
{
Log(LogLevel::Debug, "Slirp: unregister poll FD %d\n", fd);
/*if (FDListSize < 1)
{
printf("!! SLIRP FD LIST EMPTY\n");
return;
}
for (int i = 0; i < FDListSize; i++)
{
if (FDList[i].fd == fd)
{
FDListSize--;
FDList[i] = FDList[FDListSize];
}
}*/
}
void SlirpCbNotify(void* opaque)
{
Log(LogLevel::Debug, "Slirp: notify???\n");
}
SlirpCb cb =
{
.send_packet = SlirpCbSendPacket,
.guest_error = SlirpCbGuestError,
.clock_get_ns = SlirpCbClockGetNS,
.timer_new = SlirpCbTimerNew,
.timer_free = SlirpCbTimerFree,
.timer_mod = SlirpCbTimerMod,
.register_poll_fd = SlirpCbRegisterPollFD,
.unregister_poll_fd = SlirpCbUnregisterPollFD,
.notify = SlirpCbNotify
};
bool Init()
{
IPv4ID = 0;
//FDListSize = 0;
//memset(FDList, 0, sizeof(FDList));
SlirpConfig cfg;
memset(&cfg, 0, sizeof(cfg));
cfg.version = 1;
cfg.in_enabled = true;
*(u32*)&cfg.vnetwork = htonl(kSubnet);
*(u32*)&cfg.vnetmask = htonl(0xFFFFFF00);
*(u32*)&cfg.vhost = htonl(kServerIP);
cfg.vhostname = "melonServer";
*(u32*)&cfg.vdhcp_start = htonl(kClientIP);
*(u32*)&cfg.vnameserver = htonl(kDNSIP);
Ctx = slirp_new(&cfg, &cb, nullptr);
return true;
}
void DeInit()
{
if (Ctx)
{
slirp_cleanup(Ctx);
Ctx = nullptr;
}
}
void FinishUDPFrame(u8* data, int len)
{
u8* ipheader = &data[0xE];
u8* udpheader = &data[0x22];
// lengths
*(u16*)&ipheader[2] = htons(len - 0xE);
*(u16*)&udpheader[4] = htons(len - (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 += (len-0x22);
for (u8* i = udpheader; i < &udpheader[len-0x23]; i += 2)
tmp += ntohs(*(u16*)i);
if (len & 1)
tmp += ntohs((u_short)udpheader[len-0x23]);
while (tmp >> 16)
tmp = (tmp & 0xFFFF) + (tmp >> 16);
tmp ^= 0xFFFF;
if (tmp == 0) tmp = 0xFFFF;
*(u16*)&udpheader[6] = htons(tmp);
}
void HandleDNSFrame(u8* data, int len)
{
u8* ipheader = &data[0xE];
u8* udpheader = &data[0x22];
u8* dnsbody = &data[0x2A];
u32 srcip = ntohl(*(u32*)&ipheader[12]);
u16 srcport = ntohs(*(u16*)&udpheader[0]);
u16 id = ntohs(*(u16*)&dnsbody[0]);
u16 flags = ntohs(*(u16*)&dnsbody[2]);
u16 numquestions = ntohs(*(u16*)&dnsbody[4]);
u16 numanswers = ntohs(*(u16*)&dnsbody[6]);
u16 numauth = ntohs(*(u16*)&dnsbody[8]);
u16 numadd = ntohs(*(u16*)&dnsbody[10]);
Log(LogLevel::Debug, "DNS: ID=%04X, flags=%04X, Q=%d, A=%d, auth=%d, add=%d\n",
id, flags, numquestions, numanswers, numauth, numadd);
// for now we only take 'simple' DNS requests
if (flags & 0x8000) return;
if (numquestions != 1 || numanswers != 0) return;
u8 resp[1024];
u8* out = &resp[0];
// ethernet
memcpy(out, &data[6], 6); out += 6;
memcpy(out, kServerMAC, 6); out += 6;
*(u16*)out = htons(0x0800); out += 2;
// IP
u8* resp_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(kDNSIP); out += 4; // source IP
*(u32*)out = htonl(srcip); out += 4; // destination IP
// UDP
u8* resp_udpheader = out;
*(u16*)out = htons(53); out += 2; // source port
*(u16*)out = htons(srcport); out += 2; // destination port
*(u16*)out = 0; out += 2; // length
*(u16*)out = 0; out += 2; // checksum
// DNS
u8* resp_body = out;
*(u16*)out = htons(id); out += 2; // ID
*(u16*)out = htons(0x8000); out += 2; // flags
*(u16*)out = htons(numquestions); out += 2; // num questions
*(u16*)out = htons(numquestions); out += 2; // num answers
*(u16*)out = 0; out += 2; // num authority
*(u16*)out = 0; out += 2; // num additional
u32 curoffset = 12;
for (u16 i = 0; i < numquestions; i++)
{
if (curoffset >= (len-0x2A)) return;
u8 bitlength = 0;
while ((bitlength = dnsbody[curoffset++]) != 0)
curoffset += bitlength;
curoffset += 4;
}
u32 qlen = curoffset-12;
if (qlen > 512) return;
memcpy(out, &dnsbody[12], qlen); out += qlen;
curoffset = 12;
for (u16 i = 0; i < numquestions; i++)
{
// assemble the requested domain name
u8 bitlength = 0;
char domainname[256] = ""; int o = 0;
while ((bitlength = dnsbody[curoffset++]) != 0)
{
if ((o+bitlength) >= 255)
{
// welp. atleast try not to explode.
domainname[o++] = '\0';
break;
}
strncpy(&domainname[o], (const char *)&dnsbody[curoffset], bitlength);
o += bitlength;
curoffset += bitlength;
if (dnsbody[curoffset] != 0)
domainname[o++] = '.';
else
domainname[o++] = '\0';
}
u16 type = ntohs(*(u16*)&dnsbody[curoffset]);
u16 cls = ntohs(*(u16*)&dnsbody[curoffset+2]);
printf("- q%d: %04X %04X %s", i, type, cls, domainname);
// get answer
struct addrinfo dns_hint;
struct addrinfo* dns_res;
u32 addr_res;
memset(&dns_hint, 0, sizeof(dns_hint));
dns_hint.ai_family = AF_INET; // TODO: other address types (INET6, etc)
if (getaddrinfo(domainname, "0", &dns_hint, &dns_res) == 0)
{
struct addrinfo* p = dns_res;
while (p)
{
struct sockaddr_in* addr = (struct sockaddr_in*)p->ai_addr;
addr_res = *(u32*)&addr->sin_addr;
printf(" -> %d.%d.%d.%d",
addr_res & 0xFF, (addr_res >> 8) & 0xFF,
(addr_res >> 16) & 0xFF, addr_res >> 24);
break;
p = p->ai_next;
}
}
else
{
printf(" shat itself :(");
addr_res = 0;
}
printf("\n");
curoffset += 4;
// TODO: betterer support
// (under which conditions does the C00C marker work?)
*(u16*)out = htons(0xC00C); out += 2;
*(u16*)out = htons(type); out += 2;
*(u16*)out = htons(cls); out += 2;
*(u32*)out = htonl(3600); out += 4; // TTL (hardcoded for now)
*(u16*)out = htons(4); out += 2; // address length
*(u32*)out = addr_res; out += 4; // address
}
u32 framelen = (u32)(out - &resp[0]);
if (framelen & 1) { *out++ = 0; framelen++; }
FinishUDPFrame(resp, framelen);
RXEnqueue(resp, framelen);
}
int SendPacket(u8* data, int len)
{
if (!Ctx) return 0;
if (len > 2048)
{
Log(LogLevel::Error, "LAN_SendPacket: error: packet too long (%d)\n", len);
return 0;
}
u16 ethertype = ntohs(*(u16*)&data[0xC]);
if (ethertype == 0x800)
{
u8 protocol = data[0x17];
if (protocol == 0x11) // UDP
{
u16 dstport = ntohs(*(u16*)&data[0x24]);
if (dstport == 53 && htonl(*(u32*)&data[0x1E]) == kDNSIP) // DNS
{
HandleDNSFrame(data, len);
return len;
}
}
}
slirp_input(Ctx, data, len);
return len;
}
const int PollListMax = 64;
struct pollfd PollList[PollListMax];
int PollListSize;
int SlirpCbAddPoll(int fd, int events, void* opaque)
{
if (PollListSize >= PollListMax)
{
Log(LogLevel::Error, "slirp: POLL LIST FULL\n");
return -1;
}
int idx = PollListSize++;
//printf("Slirp: add poll: fd=%d, idx=%d, events=%08X\n", fd, idx, events);
u16 evt = 0;
if (events & SLIRP_POLL_IN) evt |= POLLIN;
if (events & SLIRP_POLL_OUT) evt |= POLLWRNORM;
#ifndef __WIN32__
// CHECKME
if (events & SLIRP_POLL_PRI) evt |= POLLPRI;
if (events & SLIRP_POLL_ERR) evt |= POLLERR;
if (events & SLIRP_POLL_HUP) evt |= POLLHUP;
#endif // !__WIN32__
PollList[idx].fd = fd;
PollList[idx].events = evt;
return idx;
}
int SlirpCbGetREvents(int idx, void* opaque)
{
if (idx < 0 || idx >= PollListSize)
return 0;
//printf("Slirp: get revents, idx=%d, res=%04X\n", idx, FDList[idx].revents);
u16 evt = PollList[idx].revents;
int ret = 0;
if (evt & POLLIN) ret |= SLIRP_POLL_IN;
if (evt & POLLWRNORM) ret |= SLIRP_POLL_OUT;
if (evt & POLLPRI) ret |= SLIRP_POLL_PRI;
if (evt & POLLERR) ret |= SLIRP_POLL_ERR;
if (evt & POLLHUP) ret |= SLIRP_POLL_HUP;
return ret;
}
int RecvPacket(u8* data)
{
if (!Ctx) return 0;
int ret = 0;
//if (PollListSize > 0)
{
u32 timeout = 0;
PollListSize = 0;
slirp_pollfds_fill(Ctx, &timeout, SlirpCbAddPoll, nullptr);
int res = poll(PollList, PollListSize, timeout);
slirp_pollfds_poll(Ctx, res<0, SlirpCbGetREvents, nullptr);
}
if (!RXBuffer.IsEmpty())
{
u32 header = RXBuffer.Read();
u32 len = header & 0xFFFF;
for (int i = 0; i < len; i += 4)
((u32*)data)[i>>2] = RXBuffer.Read();
ret = header >> 16;
}
return ret;
}
}