var IP = "127.0.0.1";
var PORT = 22023;
var SETEP = 0x741084; // InnerNetClient.SetEndpoint
var GETCONN = 0x722214; // AmongUsClient.GetConnectionData
var UDPSEND = 0xE8772C; // UdpConnection.Send

function lg(m) { console.log("[amng] " + m); }

function js(p) {
    if (p.isNull()) return "";
    var n = Memory.readS32(p.add(16));
    if (n <= 0 || n > 64) return "";
    return Memory.readUtf16String(p.add(20), n);
}

function redirect(sockaddr) {
    if (sockaddr.isNull()) return false;
    var fam = Memory.readU16(sockaddr);
    if (fam !== 2) return false; // AF_INET only
    var p = (Memory.readU8(sockaddr.add(2)) << 8) | Memory.readU8(sockaddr.add(3));
    if (p !== 22023 && p !== 22024) return false;
    // patch in place: ip + port
    Memory.writeU8(sockaddr.add(2), (PORT >> 8) & 255);
    Memory.writeU8(sockaddr.add(3), PORT & 255);
    var parts = IP.split(".");
    for (var i = 0; i < 4; i++) Memory.writeU8(sockaddr.add(4 + i), parseInt(parts[i]));
    return true;
}

function hookLibc() {
    var libc = Process.findModuleByName("libc.so");
    ["connect", "sendto", "sendmsg"].forEach(function(n) {
        var a = Module.findExportByName("libc.so", n);
        if (a === null) return;
        Interceptor.attach(a, {
            onEnter: function(ac) {
                if (n === "connect" && redirect(ac[1])) lg("redirect connect");
                if (n === "sendto" && redirect(ac[4])) lg("redirect sendto");
            }
        });
    });
    lg("libc hook done");
}

function hookIl2cpp(base) {
    var nw = Module.findExportByName("libil2cpp.so", "il2cpp_string_new");
    var setep = base.add(SETEP);
    Interceptor.attach(setep, {
        onEnter: function(ac) {
            var old = js(ac[1]);
            lg("SetEndpoint " + old + ":" + ac[2].toInt32());
            if (nw !== null) {
                var ns = Memory.readPointer(Memory.readPointer(nw));
                var f = new NativeFunction(nw, "pointer", ["pointer"]);
                var s = f(Memory.allocUtf8String(IP));
                this.context.x1 = s;
                this.context.x2 = ptr(PORT);
            }
        }
    });
    Interceptor.attach(base.add(GETCONN), {
        onLeave: function(rv) {
            lg("GetConnectionData ret=" + rv);
        }
    });
    Interceptor.attach(base.add(UDPSEND), {
        onEnter: function(ac) { lg("UdpConnection.Send"); }
    });
    lg("il2cpp hooks at " + base);
}

function boot() {
    lg("boot " + IP + ":" + PORT);
    hookLibc();
    var b = Module.findBaseAddress("libil2cpp.so");
    if (b !== null) {
        hookIl2cpp(b);
        return;
    }
    var t = setInterval(function() {
        var q = Module.findBaseAddress("libil2cpp.so");
        if (q !== null) { clearInterval(t); hookIl2cpp(q); }
    }, 500);
}

setImmediate(boot);