Use std::span (backported) and std::byte to make our buffers safer

5 files changed, 42 insertions, 35 deletions

diff --git a/src/audio/include/audio_decoder.hpp b/src/audio/include/audio_decoder.hpp
index 4d2fd5f3..a32442da 100644
--- a/src/audio/include/audio_decoder.hpp
+++ b/src/audio/include/audio_decoder.hpp
@@ -1,8 +1,10 @@
 #pragma once
 
 #include <cstddef>
+#include <cstdint>
 
 #include "ff.h"
+#include "span.hpp"
 
 #include "audio_element.hpp"
 #include "codec.hpp"
@@ -23,8 +25,8 @@ class AudioDecoder : public IAudioElement {
 
   auto ProcessStreamInfo(StreamInfo& info)
       -> cpp::result<void, AudioProcessingError>;
-  auto ProcessChunk(uint8_t* data, std::size_t length)
-      -> cpp::result<size_t, AudioProcessingError>;
+  auto ProcessChunk(cpp::span<std::byte>& chunk)
+      -> cpp::result<std::size_t, AudioProcessingError>;
   auto ProcessIdle() -> cpp::result<void, AudioProcessingError>;
 
   AudioDecoder(const AudioDecoder&) = delete;
@@ -34,7 +36,8 @@ class AudioDecoder : public IAudioElement {
   std::unique_ptr<codecs::ICodec> current_codec_;
   std::optional<StreamInfo> stream_info_;
 
-  uint8_t* chunk_buffer_;
+  std::byte* raw_chunk_buffer_;
+  cpp::span<std::byte> chunk_buffer_;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/audio_element.hpp b/src/audio/include/audio_element.hpp
index 5b697784..06e47b35 100644
--- a/src/audio/include/audio_element.hpp
+++ b/src/audio/include/audio_element.hpp
@@ -1,7 +1,5 @@
 #pragma once
 
-#include <stdint.h>
-
 #include <cstdint>
 
 #include "freertos/FreeRTOS.h"
@@ -9,6 +7,7 @@
 #include "freertos/message_buffer.h"
 #include "freertos/portmacro.h"
 #include "result.hpp"
+#include "span.hpp"
 
 #include "stream_info.hpp"
 #include "types.hpp"
@@ -77,8 +76,8 @@ class IAudioElement {
    * bytes in this chunk that were actually used; leftover bytes will be
    * prepended to the next call.
    */
-  virtual auto ProcessChunk(uint8_t* data, std::size_t length)
-      -> cpp::result<size_t, AudioProcessingError> = 0;
+  virtual auto ProcessChunk(cpp::span<std::byte>& chunk)
+      -> cpp::result<std::size_t, AudioProcessingError> = 0;
 
   /*
    * Called when there has been no data received over the input buffer for some
diff --git a/src/audio/include/chunk.hpp b/src/audio/include/chunk.hpp
index 365c83d0..0cbe8d5c 100644
--- a/src/audio/include/chunk.hpp
+++ b/src/audio/include/chunk.hpp
@@ -12,6 +12,7 @@
 #include "freertos/portmacro.h"
 #include "freertos/queue.h"
 #include "result.hpp"
+#include "span.hpp"
 
 namespace audio {
 
@@ -37,9 +38,8 @@ enum ChunkWriteResult {
  * more input to read.
  */
 auto WriteChunksToStream(MessageBufferHandle_t* stream,
-                         uint8_t* working_buffer,
-                         size_t working_buffer_length,
-                         std::function<size_t(uint8_t*, size_t)> callback,
+                         cpp::span<std::byte> working_buffer,
+                         std::function<size_t(cpp::span<std::byte>)> callback,
                          TickType_t max_wait) -> ChunkWriteResult;
 
 enum ChunkReadResult {
@@ -64,7 +64,7 @@ class ChunkReader {
 
   auto Reset() -> void;
 
-  auto GetLastMessage() -> std::pair<uint8_t*, size_t>;
+  auto GetLastMessage() -> cpp::span<std::byte>;
 
   /*
    * Reads chunks of data from the given input stream, and invokes the given
@@ -79,12 +79,13 @@ class ChunkReader {
    * will place the message at the start of the working_buffer and then return.
    */
   auto ReadChunkFromStream(
-      std::function<std::optional<size_t>(uint8_t*, size_t)> callback,
+      std::function<std::optional<size_t>(cpp::span<std::byte>)> callback,
       TickType_t max_wait) -> ChunkReadResult;
 
  private:
   MessageBufferHandle_t* stream_;
-  uint8_t* working_buffer_;
+  std::byte* raw_working_buffer_;
+  cpp::span<std::byte> working_buffer_;
 
   std::size_t leftover_bytes_ = 0;
   std::size_t last_message_size_ = 0;
diff --git a/src/audio/include/fatfs_audio_input.hpp b/src/audio/include/fatfs_audio_input.hpp
index c54b32bd..3ca79457 100644
--- a/src/audio/include/fatfs_audio_input.hpp
+++ b/src/audio/include/fatfs_audio_input.hpp
@@ -8,6 +8,7 @@
 
 #include "freertos/message_buffer.h"
 #include "freertos/queue.h"
+#include "span.hpp"
 
 #include "audio_element.hpp"
 #include "storage.hpp"
@@ -21,28 +22,28 @@ class FatfsAudioInput : public IAudioElement {
 
   auto ProcessStreamInfo(StreamInfo& info)
       -> cpp::result<void, AudioProcessingError>;
-  auto ProcessChunk(uint8_t* data, std::size_t length)
-      -> cpp::result<size_t, AudioProcessingError>;
+  auto ProcessChunk(cpp::span<std::byte>& chunk)
+      -> cpp::result<std::size_t, AudioProcessingError> = 0;
   auto ProcessIdle() -> cpp::result<void, AudioProcessingError>;
 
-  auto SendChunk(uint8_t* buffer, size_t size) -> size_t;
+  auto SendChunk(cpp::span<std::byte> dest) -> size_t;
 
  private:
   auto GetRingBufferDistance() -> size_t;
 
   std::shared_ptr<drivers::SdStorage> storage_;
 
-  uint8_t* file_buffer_;
-  uint8_t* file_buffer_read_pos_;
-  uint8_t* pending_read_pos_;
-  uint8_t* file_buffer_write_pos_;
+  std::byte* raw_file_buffer_;
+  cpp::span<std::byte> file_buffer_;
+  cpp::span<std::byte>::iterator file_buffer_read_pos_;
+  cpp::span<std::byte>::iterator pending_read_pos_;
+  cpp::span<std::byte>::iterator file_buffer_write_pos_;
 
-  uint8_t* chunk_buffer_;
+  std::byte* raw_chunk_buffer_;
+  cpp::span<std::byte> chunk_buffer_;
 
   FIL current_file_;
-  bool is_file_open_ = false;
-
-  MessageBufferHandle_t input_buffer_;
+  bool is_file_open_;
 
   uint8_t* output_buffer_memory_;
   StaticMessageBuffer_t output_buffer_metadata_;
diff --git a/src/audio/include/stream_message.hpp b/src/audio/include/stream_message.hpp
index cbd7c733..043f9dc3 100644
--- a/src/audio/include/stream_message.hpp
+++ b/src/audio/include/stream_message.hpp
@@ -1,12 +1,12 @@
 #pragma once
 
-#include <stdint.h>
-
+#include <cstdint>
 #include <functional>
 #include <optional>
 
 #include "cbor.h"
 #include "result.hpp"
+#include "span.hpp"
 
 namespace audio {
 
@@ -20,14 +20,13 @@ enum MessageType {
 };
 
 template <typename Writer>
-auto WriteMessage(MessageType type,
-                  Writer&& writer,
-                  uint8_t* buffer,
-                  size_t length) -> cpp::result<size_t, CborError> {
+auto WriteMessage(MessageType type, Writer&& writer, cpp::span<std::byte> data)
+    -> cpp::result<size_t, CborError> {
   CborEncoder root;
   CborEncoder container;
+  uint8_t* cast_data = reinterpret_cast<uint8_t*>(data.data());
 
-  cbor_encoder_init(&root, buffer, length, kEncoderFlags);
+  cbor_encoder_init(&root, cast_data, data.size(), kEncoderFlags);
   cbor_encoder_create_array(&root, &container, 2);
   cbor_encode_uint(&container, type);
 
@@ -37,17 +36,18 @@ auto WriteMessage(MessageType type,
   }
 
   cbor_encoder_close_container(&root, &container);
-  return cbor_encoder_get_buffer_size(&root, buffer);
+  return cbor_encoder_get_buffer_size(&root, cast_data);
 }
 
 template <typename Result, typename Reader>
-auto ReadMessage(Reader&& reader, uint8_t* buffer, size_t length)
+auto ReadMessage(Reader&& reader, cpp::span<std::byte> data)
     -> cpp::result<Result, CborError> {
   CborParser parser;
   CborValue root;
   CborValue container;
 
-  cbor_parser_init(buffer, length, kDecoderFlags, &parser, &root);
+  cbor_parser_init(reinterpret_cast<uint8_t*>(data.data()), data.size(),
+                   kDecoderFlags, &parser, &root);
   cbor_value_enter_container(&root, &container);
   // Skip the type header
   cbor_value_advance_fixed(&container);
@@ -55,6 +55,9 @@ auto ReadMessage(Reader&& reader, uint8_t* buffer, size_t length)
   return std::invoke(reader, container);
 }
 
-auto ReadMessageType(uint8_t* buffer, size_t length) -> MessageType;
+auto WriteTypeOnlyMessage(MessageType type, cpp::span<std::byte> data)
+    -> cpp::result<size_t, CborError>;
+auto ReadMessageType(cpp::span<std::byte> msg) -> MessageType;
+auto GetAdditionalData(cpp::span<std::byte> msg) -> cpp::span<std::byte>;
 
 }  // namespace audio