From 4c6f2c2547e1d97f12ebe708fac693a6183bbc45 Mon Sep 17 00:00:00 2001
From: german77 <juangerman-13@hotmail.com>
Date: Mon, 20 Sep 2021 16:57:55 -0500
Subject: input_common: Move touch and analog from button. Move udp protocol
---
src/input_common/helpers/udp_protocol.cpp | 78 +++++++++++++++++++++++++++++++
1 file changed, 78 insertions(+)
create mode 100644 src/input_common/helpers/udp_protocol.cpp
(limited to 'src/input_common/helpers/udp_protocol.cpp')
diff --git a/src/input_common/helpers/udp_protocol.cpp b/src/input_common/helpers/udp_protocol.cpp
new file mode 100644
index 0000000000..cdeab7e118
--- /dev/null
+++ b/src/input_common/helpers/udp_protocol.cpp
@@ -0,0 +1,78 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cstddef>
+#include <cstring>
+#include "common/logging/log.h"
+#include "input_common/helpers/udp_protocol.h"
+
+namespace InputCommon::CemuhookUDP {
+
+static constexpr std::size_t GetSizeOfResponseType(Type t) {
+ switch (t) {
+ case Type::Version:
+ return sizeof(Response::Version);
+ case Type::PortInfo:
+ return sizeof(Response::PortInfo);
+ case Type::PadData:
+ return sizeof(Response::PadData);
+ }
+ return 0;
+}
+
+namespace Response {
+
+/**
+ * Returns Type if the packet is valid, else none
+ *
+ * Note: Modifies the buffer to zero out the crc (since thats the easiest way to check without
+ * copying the buffer)
+ */
+std::optional<Type> Validate(u8* data, std::size_t size) {
+ if (size < sizeof(Header)) {
+ return std::nullopt;
+ }
+ Header header{};
+ std::memcpy(&header, data, sizeof(Header));
+ if (header.magic != SERVER_MAGIC) {
+ LOG_ERROR(Input, "UDP Packet has an unexpected magic value");
+ return std::nullopt;
+ }
+ if (header.protocol_version != PROTOCOL_VERSION) {
+ LOG_ERROR(Input, "UDP Packet protocol mismatch");
+ return std::nullopt;
+ }
+ if (header.type < Type::Version || header.type > Type::PadData) {
+ LOG_ERROR(Input, "UDP Packet is an unknown type");
+ return std::nullopt;
+ }
+
+ // Packet size must equal sizeof(Header) + sizeof(Data)
+ // and also verify that the packet info mentions the correct size. Since the spec includes the
+ // type of the packet as part of the data, we need to include it in size calculations here
+ // ie: payload_length == sizeof(T) + sizeof(Type)
+ const std::size_t data_len = GetSizeOfResponseType(header.type);
+ if (header.payload_length != data_len + sizeof(Type) || size < data_len + sizeof(Header)) {
+ LOG_ERROR(
+ Input,
+ "UDP Packet payload length doesn't match. Received: {} PayloadLength: {} Expected: {}",
+ size, header.payload_length, data_len + sizeof(Type));
+ return std::nullopt;
+ }
+
+ const u32 crc32 = header.crc;
+ boost::crc_32_type result;
+ // zero out the crc in the buffer and then run the crc against it
+ std::memset(&data[offsetof(Header, crc)], 0, sizeof(u32_le));
+
+ result.process_bytes(data, data_len + sizeof(Header));
+ if (crc32 != result.checksum()) {
+ LOG_ERROR(Input, "UDP Packet CRC check failed. Offset: {}", offsetof(Header, crc));
+ return std::nullopt;
+ }
+ return header.type;
+}
+} // namespace Response
+
+} // namespace InputCommon::CemuhookUDP
--
cgit v1.2.3-70-g09d2