feat(frame): Implemented frame class

Recieves a hex string, containing all frame data and stores it as
something more useful

1 files changed, 65 insertions, 0 deletions

diff --git a/src/frame.cpp b/src/frame.cpp
new file mode 100644
index 0000000..ab8a5f3
--- /dev/null
+++ b/src/frame.cpp
@@ -0,0 +1,65 @@
+#include "frame.h"
+
+unsigned char hex_byte_to_byte(unsigned char byte) {
+	if (byte >= 'a' && byte <= 'f') return byte - 'a' + 10;
+	if (byte >= 'A' && byte <= 'F') return byte - 'A' + 10;
+	if (byte >= '0' && byte <= '9') return byte - '0';
+	throw std::invalid_argument("Character isn't a hex value!");
+}
+
+unsigned char hex_value_to_byte(const unsigned char* hex) {
+	return (hex_byte_to_byte(hex[0]) << 4) | hex_byte_to_byte(hex[1]);
+}
+
+unsigned char next_hex_byte(const unsigned char*& iso_tp_frame) {
+	if (*iso_tp_frame == '\0')
+		throw "Bad";
+
+	char byte = hex_value_to_byte(iso_tp_frame);
+	iso_tp_frame += 2;
+	return byte;
+}
+
+// b0 b1 b2 b3 b4 b5 b6 b7
+// 02 10 C0 00 00 00 00 00
+void Frame::parse_frame_str(const unsigned char* iso_tp_frame) {
+	unsigned char byte0 = next_hex_byte(iso_tp_frame);
+
+	this->type = (FrameType)((byte0 & 0b11110000) >> 4);
+	this->size =              byte0 & 0b00001111;
+
+	switch (this->type) {
+		// Single frame
+		case SF: this->data_size = size;
+		         break;
+
+		// First frame
+		case FF: {
+		         	unsigned char byte1 = next_hex_byte(iso_tp_frame);
+		         	this->size = (this->size << 8) | byte1;
+		         	this->data_size = 6;
+		         }
+		         break;
+
+		// Consecutive frame
+		case CF: this->data_size = 7;
+		         break;
+
+		// Flow control frame (ignore)
+		case FC: this->data_size = 0;
+		         this->size = 0;
+		         break;
+	}
+
+	this->data = (unsigned char*)malloc(sizeof(unsigned char) * this->data_size);
+	for (int i = 0; i < this->data_size; ++i) {
+		this->data[i] = next_hex_byte(iso_tp_frame);
+	}
+}
+
+std::ostream& operator<<(std::ostream& os, const Frame& f) {
+	for (int i = 0; i < f.data_size; ++i) {
+		os << (unsigned)f.data[i];
+	}
+	return os;
+}