1 files changed, 46 insertions, 0 deletions
diff --git a/mcproto/handshake.ha b/mcproto/handshake.ha
new file mode 100644
index 0000000..8df5254
--- /dev/null
+++ b/mcproto/handshake.ha
@@ -0,0 +1,46 @@
+use trace;
+
+export def SB_HANDSHAKE: i32 = 0x00;
+
+export type Handshake = struct {
+	proto_ver: i32,
+	server_addr: str,
+	server_port: u16,
+	next_state: NextState,
+};
+
+export type NextState = enum i32 {
+	STATUS = 1,
+	LOGIN = 2,
+};
+
+export fn encode_handshake(out: *[]u8, pkt: *Handshake) void = {
+	encode_varint(out, pkt.proto_ver);
+	encode_string(out, pkt.server_addr);
+	encode_short(out, pkt.server_port);
+	encode_varint(out, pkt.next_state);
+};
+
+export fn decode_handshake(ctx: *Context) (Handshake | trace::failed) = {
+	const ctx_ = context(ctx, "protocol version");
+	const proto_ver = decode_varint(&ctx_)?;
+	const ctx_ = context(ctx, "server address");
+	const server_addr = decode_string(&ctx_, 255)?;
+	const ctx_ = context(ctx, "server port");
+	const server_port = decode_short(&ctx_)?;
+	const ctx_ = context(ctx, "next state");
+	const next_state = decode_varint(&ctx_)?: NextState;
+	if (next_state != NextState::STATUS
+			&& next_state != NextState::LOGIN) {
+		return error(&ctx_, "Invalid next state 0x{:02x}",
+			next_state: i32);
+	};
+	expect_end(ctx)?;
+
+	return Handshake {
+		proto_ver = proto_ver,
+		server_addr = server_addr,
+		server_port = server_port,
+		next_state = next_state,
+	};
+};