Handshake packet implementation

PROTOCOL

@@ -0,0 +1,45 @@
+--- DDTU PROTOCOL v1 ---
+
+- High level overview -
+
+- Node Modes -
+
+[Receive]
+Is for receiving information.
+
+[Send]
+Is for sending data to the receiving end.
+
+[Sync]
+Is for syncing one directory among 2 ends. (Make contents the same on both sides)
+
+[Daemon]
+Is used to create a longstanding sync daemon which syncs the directory with all incoming
+sync connections    
+
+
+All infomation|commands are sent via packets with specific structure
+
+- Packet bytes representation -
+
+First 16 bytes - the total packet length
+The next 1 byte - number that represents this packet's type (ID) where:
+1: HANDSHAKE PACKET
+2: HANDSHAKE ACCEPT
+3: CONNECTION SHUTDOWN PACKET
+4: TEXT PACKET
+5: FILEINFO PACKET
+6: FILEDATA PACKET
+
+Then the internal structure varies from one packet type to the other,
+but the content-types are encoded as follows:
+u8 - just 1 BE byte
+u128 - 16 BE bytes
+String - u128 representing the string length and then UTF-8 encoded character bytes
+[u8] - u128 as the length of a byte array, then the array itself
+bool - convert it to u8 where 0 == false, 1 == true
+
+- Packets -
+[Handshake]
+This is the first packet that must be sent by connecting node to waiting node.
+Its existence tells the receiving end that the  

TODO

@@ -1,4 +1,5 @@
 1. Write base foundation for sending and receiving information
 2. Wire it all together
 3. Make it encrypted
-4. Daemon
+4. Allow receiving node to connect as well
+5. Daemon

src/args/parser.rs

@@ -14,18 +14,11 @@ GNU Affero General Public License for more details.
 */
 
 use crate::util::error::Error;
+use crate::protocol::specs::RunMode;
 use std::path;
 
 #[derive(PartialEq, Eq, Debug)]
-pub enum RunMode {
-    SEND,
-    RECEIVE,
-    SYNC,
-    DAEMON,
-}
-
-#[derive(PartialEq, Eq, Debug)]
-pub enum Type {
+pub enum DataType {
     TEXT,
     FILE,
     DIR,
@@ -36,7 +29,7 @@ pub struct Args {
     pub help: bool,
     pub version: bool,
     pub mode: RunMode,
-    pub send_type: Type,
+    pub send_type: DataType,
     pub address_str: String,
     pub send_path: path::PathBuf,
     pub save_directory: path::PathBuf,
@@ -50,7 +43,7 @@ impl Args {
             help: false,
             version: false,
             mode: RunMode::DAEMON,
-            send_type: Type::TEXT,
+            send_type: DataType::TEXT,
             address_str: "".to_string(),
             send_path: path::PathBuf::new(),
             save_directory: path::PathBuf::new(),
@@ -61,6 +54,7 @@ impl Args {
 }
 
 pub fn parse(raw_args: &Vec<String>) -> Result<Args, Error> {
+
     let mut parsed_args: Args = Args::default();
 
     // parse arguments, ignoring the first argument
@@ -79,37 +73,37 @@ pub fn parse(raw_args: &Vec<String>) -> Result<Args, Error> {
         }
 
         "send" => {
-            if arg_amount < 4 {
+            if arg_amount < 5 {
                 // not enough arguments !
                 return Err(Error::new("not enough arguments for send mode"));
             }
 
             parsed_args.mode = RunMode::SEND;
 
-            // type
+            // DataType
             match raw_args[2].to_lowercase().as_str() {
                 "text" => {
-                    parsed_args.send_type = Type::TEXT;
+                    parsed_args.send_type = DataType::TEXT;
                     parsed_args.text_to_send = String::from(&raw_args[3]);
                 }
 
                 "file" => {
-                    parsed_args.send_type = Type::FILE;
+                    parsed_args.send_type = DataType::FILE;
                     parsed_args.send_path = std::path::Path::new(&raw_args[3]).to_path_buf();
                 }
 
                 "dir" => {
-                    parsed_args.send_type = Type::DIR;
+                    parsed_args.send_type = DataType::DIR;
                     parsed_args.send_path = std::path::Path::new(&raw_args[3]).to_path_buf();
                 }
 
                 _ => {
-                    return Err(Error::new(format!("invalid type {}", raw_args[2]).as_str()));
+                    return Err(Error::new(format!("invalid DataType {}", raw_args[2]).as_str()));
                 }
             }
 
             // src
-            if parsed_args.send_type == Type::FILE || parsed_args.send_type == Type::DIR {
+            if parsed_args.send_type == DataType::FILE || parsed_args.send_type == DataType::DIR {
                 // check if exists
                 match path::Path::new(raw_args[3].as_str()).exists() {
                     true => {
@@ -121,18 +115,15 @@ pub fn parse(raw_args: &Vec<String>) -> Result<Args, Error> {
                     }
                 }
             }
+
+            // addr
+            parsed_args.address_str = raw_args[4].to_string();
         }
 
         "recv" => {
-            if arg_amount < 3 {
-                // not enough arguments !
-                return Err(Error::new("not enough arguments for receiving mode"));
-            }
-
             parsed_args.mode = RunMode::RECEIVE;            
-            parsed_args.address_str = raw_args[2].to_string();
-            if arg_amount > 3 {
-                parsed_args.save_directory = path::Path::new(raw_args[3].as_str()).to_path_buf();
+            if arg_amount > 2 {
+                parsed_args.save_directory = path::Path::new(raw_args[2].as_str()).to_path_buf();
             }
         }
         

src/main.rs

@@ -18,8 +18,10 @@ mod protocol;
 mod args;
 mod crypt;
 mod fsys;
+mod nodes;
 
-use args::parser::{Args, RunMode};
+use protocol::specs::RunMode;
+use args::parser::Args;
 use std::net;
 use crate::protocol::specs::{Packet, PacketType};
 
@@ -34,10 +36,10 @@ ddtu [FLAG] [MODE] [MODE-specific arguments]
 [version]: ddtu version -> print version
 
 [MODE]
-[send]: ddtu send [TYPE] [SRC] -> prepare to send [SRC] of [TYPE] and wait for someone to receive
-[recv]: ddtu recv [SRC] [DEST](optional) -> receive anything from another ddtu instance running on [SRC], saving it at [DEST]
-[sync]: ddtu sync [DIR] [DEST] -> sync [DIRectory] contents with another ddtu instance on [DEST]  
-[daemon]: ddtu daemon -> start syncing daemon
+[send]: ddtu send [TYPE] [SRC] [ADDR] -> send [SRC] of [TYPE] to [ADDR]
+[recv]: ddtu recv [DIR](optional) -> wait for connection and receive anything from another ddtu instance, saving it to [DIR]
+[sync]: ddtu sync [DIR] [ADDR] -> sync [DIRectory] contents with another ddtu instance on [ADDR]  
+[daemon]: ddtu daemon -> start sync daemon
 
 [TYPE]
 [text]: ddtu send text \'text to send\' -> send text
@@ -93,11 +95,11 @@ fn main() {
 
             println!("connected to {}", args.address_str);
 
-            match protocol::specs::read_next_packet(&mut conn) {
+            match protocol::packets::read_next_packet(&mut conn) {
                 Ok(packet) => {
                     match packet.get_type() {
                         PacketType::TextData => {
-                            let mut text_packet = protocol::packets::TextPacket::empty();
+                            let mut text_packet = protocol::packets::Text::empty();
                             text_packet.from_bytes(packet.as_bytes());
                             println!("{}", text_packet.text);
                         }
@@ -144,8 +146,8 @@ fn main() {
             println!("{} has connected", addr);
 
             // send text
-            let textpacket = protocol::packets::TextPacket::new(&args.text_to_send);
-            match protocol::specs::send_packet(&mut conn, &textpacket) {
+            let Text = protocol::packets::Text::new(&args.text_to_send);
+            match protocol::packets::send_packet(&mut conn, &Text) {
                 Ok(()) => {}
                 Err(error) => {
                     println!("{}", error.text);

src/nodes/mod.rs

@@ -1 +1,2 @@
-pub mod node;
+pub mod recv_node;
+pub mod send_node;

src/nodes/node.rs

@@ -1,9 +0,0 @@
-pub struct Node {
-
-}
-
-impl Node {
-    pub fn new() -> Node {
-        return Node{};
-    }
-}

src/nodes/recv_node.rs

@@ -0,0 +1,106 @@
+/*
+ddtu - digital data transferring utility
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+*/
+
+use crate::util::error::Error;
+use crate::protocol::specs::PacketType;
+use crate::protocol::specs::Packet;
+use crate::protocol::packets;
+use crate::protocol;
+use std::path;
+use std::net;
+
+pub fn start(address_string: String, save_directory: path::PathBuf, verbose_output: bool) -> Option<Error> {
+    let listener: net::TcpListener;
+    match net::TcpListener::bind(address_string) {
+        Ok(l) => {
+            listener = l;
+        }
+        Err(error) => {
+            return Some(Error::new(format!("could not create TCP listener: {}", error).as_str()));
+        }
+    }
+
+
+    // wait for incoming connection from another ddtu instance,
+    // reject any connection that doesn't provide handshake information
+    let mut connection: net::TcpStream;
+    let mut address: net::SocketAddr;
+    let mut handshake: packets::Handshake = packets::Handshake::empty();
+    loop {
+        match listener.accept() {
+            Ok((c, a)) => {
+                connection = c;
+                address = a;
+            }
+            Err(error) => {
+                return Some(Error::new(format!("error accepting a new incoming connection: {}", error).as_str()));
+            }
+        }
+    
+        if verbose_output {
+            println!("Connection from {}", address);
+        }
+
+        // read the first packet
+        let incoming_packet: Box<dyn Packet>;
+        match protocol::packets::read_next_packet(&mut connection) {
+            Ok(packet) => {
+                incoming_packet = packet;
+            }
+
+            Err(_) => {
+                // not a valid packet; it's most probably not another instance
+                if verbose_output {
+                    println!("{} did not provide valid handshake packet. Dropping connection...", address);
+                }
+                connection.shutdown(net::Shutdown::Both);
+                continue;
+            }
+        }
+
+        match incoming_packet.get_type() {
+            PacketType::Handshake => {                        
+                match handshake.from_bytes(incoming_packet.as_bytes()) {
+                    Some(error) => {
+                        return Some(
+                            Error::new(
+                                format!("error constructing handshake from {}: {}", address, error.text).as_str()
+                            ));
+                    }
+                    None => {}
+                }
+
+                if verbose_output {
+                    println!("Handshake from {}", address);
+                }
+
+                // break out of loop
+                break;
+            }
+
+            _ => {
+                if verbose_output {
+                    println!("{} didn't send a handshake packet, but {:?} packet instead. Dropping connection...", address, incoming_packet.get_type());
+                }
+                connection.shutdown(net::Shutdown::Both);
+                continue;
+            }
+        }
+    }
+
+    // now read and process incoming packets; essentialy receiving something !
+
+    return None;
+}

src/nodes/send_node.rs

@@ -0,0 +1,21 @@
+/*
+ddtu - digital data transferring utility
+Copyright (C) 2022  Kasyanov Nikolay Alexeyevich (Unbewohnte)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+*/
+
+use std::net;
+use std::path;
+
+pub fn start(address: String, source: path::PathBuf) {
+
+}

src/protocol/packets.rs

@@ -13,45 +13,150 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.
 */
 
+use std::net;
+use std::io::Write;
+use std::io::Read;
+
 use crate::util::error::Error;
-use crate::util::buf_read::{read_u128_slice, read_utf8_string_slice};
+use crate::util::buf_read::{read_u128_slice_be, read_utf8_string_slice};
 use crate::protocol::specs::*;
 use crate::fsys::file::ChunkedFile;
 
 
-pub struct TextPacket {
+pub fn send_packet(conn: &mut net::TcpStream, packet: &dyn Packet) -> Result<(), Error> {
+    let mut payload: Vec<u8> = Vec::<u8>::new();
+
+    let packet_bytes: Vec<u8> = packet.as_bytes();
+    let packet_len: usize = packet_bytes.len();
+    
+    payload.extend_from_slice(&(packet_len as u128).to_be_bytes());
+    payload.extend_from_slice(&packet_bytes);
+
+    match conn.write_all(&payload) {
+        Ok(()) => {
+            return Ok(());
+        }
+
+        Err(error) => {
+            return Err(Error::new(format!("could not write packet to the connection: {}", error).as_str()))
+        }
+    }
+}
+
+pub fn read_next_packet(conn: &mut net::TcpStream) -> Result<Box<dyn Packet>, Error> {
+    let mut u128_buf: [u8; 16] = [0; 16];
+
+    match conn.read_exact(&mut u128_buf) {
+        Ok(()) => {}
+        Err(error) => {
+            return Err(Error::new(format!("error while reading initial length bytes: {}", error).as_str()));
+        }
+    }
+    let packet_len: u128 = u128::from_be_bytes(u128_buf);
+
+    let mut packet_bytes: Vec<u8> = vec!(0; packet_len as usize);
+    match conn.read_exact(&mut packet_bytes) {
+        Ok(()) => {}
+        Err(error) => {
+            return Err(Error::new(format!("error while reading packet contents: {}", error).as_str()));
+        }
+    }
+
+    if packet_bytes.len() < packet_len as usize {
+        return Err(
+            Error::new(
+                format!("read {} packet bytes instead of specified {}", packet_bytes.len(), packet_len).as_str())
+            );
+    }
+
+    let packet_type_byte: u8 = u8::from_be_bytes([packet_bytes[0]]);
+    match packet_type_byte {
+        CONNECTION_SHUTDOWN_PACKET_ID => {
+            return Ok(Box::new(ConnectionShutdown{}));
+        }
+
+        TEXT_PACKET_ID => {
+            let mut new_text_packet: Text = Text::empty();
+            let result = new_text_packet.from_bytes(packet_bytes);
+            match result {
+                Some(error) => {
+                    return Err(Error::new(format!("could not construct new text packet: {}", error.text).as_str()));
+                }
+
+                None => {
+                    return Ok(Box::new(new_text_packet));
+                }
+            }
+        }
+
+        FILEINFO_PACKET_ID => {
+            let mut new_fileinfo_packet: FileInfo = FileInfo::empty();
+            let result = new_fileinfo_packet.from_bytes(packet_bytes);
+            match result {
+                Some(error) => {
+                    return Err(Error::new(format!("could not construct new fileinfo packet: {}", error.text).as_str()));
+                }
+
+                None => {
+                    return Ok(Box::new(new_fileinfo_packet));
+                }
+            }
+        }
+
+        FILEDATA_PACKET_ID => {
+            let mut new_filedata_packet: FileData = FileData::empty();
+            let result = new_filedata_packet.from_bytes(packet_bytes);
+            match result {
+                Some(error) => {
+                    return Err(Error::new(format!("could not construct new filedata packet: {}", error.text).as_str()));
+                }
+
+                None => {
+                    return Ok(Box::new(new_filedata_packet));
+                }
+            }
+        }
+
+        _ => {
+            return Err(Error::new(format!("invalid packet type ID \"{}\"", packet_type_byte).as_str()));
+        }
+    }
+}
+
+
+pub struct Text {
     pub text: String,
 }
 
-impl TextPacket {
-    pub fn empty() -> TextPacket {
-        return TextPacket{
+impl Text {
+    pub fn empty() -> Text {
+        return Text{
             text: "".to_string(),
         };
     }
 
-    pub fn new(txt: &str) -> TextPacket {
-        return TextPacket {
+    pub fn new(txt: &str) -> Text {
+        return Text {
             text: txt.to_string(),
         }
     }
 }
 
-impl Packet for TextPacket {
+impl Packet for Text {
     fn get_type(&self) -> PacketType {
         return PacketType::TextData;
     } 
 
     fn as_bytes(&self) -> Vec<u8> {
-        let mut packet_as_bytes: Vec<u8> = Vec::<u8>::new();
+        let mut packet_bytes: Vec<u8> = Vec::<u8>::new();
 
-        packet_as_bytes.extend_from_slice(&TEXT_PACKET_ID.to_be_bytes());
+        packet_bytes.extend_from_slice(&TEXT_PACKET_ID.to_be_bytes());
 
         let text_length: u128 = self.text.len() as u128;
-        packet_as_bytes.extend_from_slice(&text_length.to_be_bytes());
-        packet_as_bytes.extend_from_slice(&self.text.as_bytes());
+        packet_bytes.extend_from_slice(&text_length.to_be_bytes());
+        packet_bytes.extend_from_slice(&self.text.as_bytes());
 
-        return packet_as_bytes;
+        return packet_bytes;
     }
 
     fn from_bytes(&mut self, packet_bytes: Vec<u8>) -> Option<Error> {
@@ -70,7 +175,7 @@ impl Packet for TextPacket {
         }
 
         // get text length
-        let text_length: u128 = read_u128_slice(&packet_bytes[1..17]);
+        let text_length: u128 = read_u128_slice_be(&packet_bytes[1..17]);
         
         if text_length as usize > packet_bytes[17..].len() {
             return Some(
@@ -92,16 +197,16 @@ impl Packet for TextPacket {
 }
 
 
-pub struct FileInfoPacket {
+pub struct FileInfo {
     pub file_id: u128,
     pub filename: String,
     pub filesize: u128,
     pub relative_path: String,
 }
 
-impl FileInfoPacket {
-    pub fn empty() -> FileInfoPacket {
-        return FileInfoPacket{
+impl FileInfo {
+    pub fn empty() -> FileInfo {
+        return FileInfo{
             file_id: 0,
             filename: String::new(),
             filesize: 0,
@@ -109,8 +214,8 @@ impl FileInfoPacket {
         };
     }
 
-    pub fn new(file: &ChunkedFile, file_id: u128, rel_path: String) -> Result<FileInfoPacket, Error> {
-        let mut new_fileinfo_packet: FileInfoPacket = FileInfoPacket::empty();
+    pub fn new(file: &ChunkedFile, file_id: u128, rel_path: String) -> Result<FileInfo, Error> {
+        let mut new_fileinfo_packet: FileInfo = FileInfo::empty();
         
         // id
         new_fileinfo_packet.file_id = file_id;
@@ -146,31 +251,33 @@ impl FileInfoPacket {
     }
 }
 
-impl Packet for FileInfoPacket {
+impl Packet for FileInfo {
     fn get_type(&self) -> PacketType {
         return PacketType::FileInfo;
     }
 
     fn as_bytes(&self) -> Vec<u8> {
-        let mut packet_as_bytes: Vec<u8> = Vec::<u8>::new();
+        let mut packet_bytes: Vec<u8> = Vec::<u8>::new();
+
+        packet_bytes.extend_from_slice(&FILEINFO_PACKET_ID.to_be_bytes());
         
         // file id
-        packet_as_bytes.extend_from_slice(&self.file_id.to_be_bytes());
+        packet_bytes.extend_from_slice(&self.file_id.to_be_bytes());
 
         // filename
         let filename_bytes_length: u128 = self.filename.len() as u128;
-        packet_as_bytes.extend_from_slice(&filename_bytes_length.to_be_bytes());
-        packet_as_bytes.extend_from_slice(&self.filename.as_bytes());
+        packet_bytes.extend_from_slice(&filename_bytes_length.to_be_bytes());
+        packet_bytes.extend_from_slice(&self.filename.as_bytes());
 
         // filesize
-        packet_as_bytes.extend_from_slice(&self.filesize.to_be_bytes());
+        packet_bytes.extend_from_slice(&self.filesize.to_be_bytes());
 
         // relative path
         let relative_path_bytes_length: u128 = self.relative_path.len() as u128;
-        packet_as_bytes.extend_from_slice(&relative_path_bytes_length.to_be_bytes());
-        packet_as_bytes.extend_from_slice(&self.relative_path.as_bytes());
+        packet_bytes.extend_from_slice(&relative_path_bytes_length.to_be_bytes());
+        packet_bytes.extend_from_slice(&self.relative_path.as_bytes());
 
-        return packet_as_bytes;
+        return packet_bytes;
     }
 
     fn from_bytes(&mut self, packet_bytes: Vec<u8>) -> Option<Error> {
@@ -181,17 +288,17 @@ impl Packet for FileInfoPacket {
         }
 
         // file id
-        self.file_id = read_u128_slice(&packet_bytes[0..16]);
+        self.file_id = read_u128_slice_be(&packet_bytes[0..16]);
 
         // get filename
-        let filename_length: u128 = read_u128_slice(&packet_bytes[16..32]);
+        let filename_length: u128 = read_u128_slice_be(&packet_bytes[16..32]);
         self.filename = read_utf8_string_slice(&packet_bytes[32..(filename_length+32) as usize]);
 
         // filesize
-        self.filesize = read_u128_slice(&packet_bytes[(filename_length+32) as usize..(filename_length+32+16) as usize]);
+        self.filesize = read_u128_slice_be(&packet_bytes[(filename_length+32) as usize..(filename_length+32+16) as usize]);
 
         // relative path
-        let rel_path_length: u128 = read_u128_slice(
+        let rel_path_length: u128 = read_u128_slice_be(
             &packet_bytes[(filename_length+32+16) as usize..(filename_length+32+16+16)as usize]
         );
         self.relative_path = read_utf8_string_slice(
@@ -203,15 +310,15 @@ impl Packet for FileInfoPacket {
 }
 
 
-pub struct FileDataPacket {
+pub struct FileData {
     pub file_id: u128,
     pub chunk_no: u128,
     pub chunk: [u8; CHUNK_SIZE],
 }
 
-impl FileDataPacket {
-    pub fn empty() -> FileDataPacket {
-        return FileDataPacket {
+impl FileData {
+    pub fn empty() -> FileData {
+        return FileData {
             file_id: 0,
             chunk_no: 0,
             chunk: [0; CHUNK_SIZE],
@@ -219,7 +326,7 @@ impl FileDataPacket {
     }
 }
 
-impl Packet for FileDataPacket {
+impl Packet for FileData {
     fn get_type(&self) -> PacketType {
         return PacketType::FileData;
     }
@@ -227,6 +334,8 @@ impl Packet for FileDataPacket {
     fn as_bytes(&self) -> Vec<u8> {
         let mut packet_bytes: Vec<u8> = Vec::<u8>::new();
         
+        packet_bytes.extend_from_slice(&FILEDATA_PACKET_ID.to_be_bytes());
+
         // file id
         packet_bytes.extend_from_slice(&self.file_id.to_be_bytes());
 
@@ -248,24 +357,24 @@ impl Packet for FileDataPacket {
         }
 
         // file id
-        self.file_id = read_u128_slice(&packet_bytes[0..16]);
+        self.file_id = read_u128_slice_be(&packet_bytes[0..16]);
         
         // chunk number
-        self.chunk_no = read_u128_slice(&packet_bytes[16..32]);
+        self.chunk_no = read_u128_slice_be(&packet_bytes[16..32]);
 
         // chunk bytes
-        let chunk_length = read_u128_slice(&packet_bytes[32..48]);
+        let chunk_length = read_u128_slice_be(&packet_bytes[32..48]);
         for i in 48..(48+chunk_length) as usize {
-            self.chunk[i-48] = packet_bytes[i];
+            self.chunk[i-48] = packet_bytes[i].to_be();
         } 
         
         return None;
     }
 }
 
-pub struct ConnectionShutdownPacket {}
+pub struct ConnectionShutdown {}
 
-impl Packet for ConnectionShutdownPacket {
+impl Packet for ConnectionShutdown {
     fn get_type(&self) -> PacketType {
         return PacketType::ConnectionShutdown;
     }
@@ -279,34 +388,64 @@ impl Packet for ConnectionShutdownPacket {
     }
 }
 
-pub struct HandshakePaket {
+pub struct Handshake {
     pub protocol_version: u8,
-    pub use_encryption: bool,
     pub encryption_type: u8,
     pub encryption_key: Vec<u8>,
 }
 
-impl HandshakePaket {
-    fn empty() -> HandshakePaket {
-        return HandshakePaket{
+impl Handshake {
+    pub fn empty() -> Handshake {
+        return Handshake{
             protocol_version: PROTOCOL_LATEST_VERSION,
-            use_encryption: false,
-            encryption_type: ECRYPTION_XOR,
+            encryption_type: ENCRYPTION_NO_ENCRYPTION,
             encryption_key: vec!(0, 0, 0, 0, 0, 0, 0, 0),
         };
     }
 }
 
-impl Packet for HandshakePaket {
+impl Packet for Handshake {
     fn get_type(&self) -> PacketType {
         return PacketType::Handshake;
     }
 
     fn as_bytes(&self) -> Vec<u8> {
-        return vec!(HANDSHAKE_PACKET_ID.to_be_bytes()[0]);
+        let mut packet_bytes: Vec<u8> = Vec::<u8>::new();
+
+        packet_bytes.extend_from_slice(&HANDSHAKE_PACKET_ID.to_be_bytes());
+        
+        // protocol version
+        packet_bytes.extend_from_slice(&PROTOCOL_LATEST_VERSION.to_be_bytes());
+
+        // encryption type
+        packet_bytes.extend_from_slice(&self.encryption_type.to_be_bytes());
+
+        // encryption key
+        packet_bytes.extend_from_slice(&(self.encryption_key.len() as u128).to_be_bytes());
+        packet_bytes.extend_from_slice(&self.encryption_key);
+
+        return packet_bytes;
     }
 
-    fn from_bytes(&mut self, _packet_bytes: Vec<u8>) -> Option<Error> {
+    fn from_bytes(&mut self, packet_bytes: Vec<u8>) -> Option<Error> {
+        if packet_bytes.len() < 1+1+1+16+1 {
+            return Some(
+                Error::new(format!("{} bytes is too small for a handshake packet to be valid", packet_bytes.len()).as_str())
+            );
+        }
+
+        // protocol version
+        self.protocol_version = packet_bytes[0].to_be();
+
+        // encryption type
+        self.encryption_type = packet_bytes[1].to_be();
+
+        // key
+        let key_len: u128 = read_u128_slice_be(&packet_bytes[1..17]);
+        for i in 17..(17+key_len) as usize {
+            self.encryption_key[i-17] = packet_bytes[i].to_be();
+        }
+
         return None;
     }
 }

src/protocol/specs.rs

@@ -13,36 +13,12 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.
 */
 
-/*
----PROTOCOL SPECs---
-
-- Packet bytes representation -
-
-First 16 bytes - the total packet length
-The next 1 byte - number that represents this packet's type (ID) where:
-1: HANDSHAKE PACKET
-2: CONNECTION SHUTDOWN PACKET
-3: TEXT PACKET
-4: FILEINFO PACKET
-5: FILEDATA PACKET
-
-Then the internal structure varies from one packet type to the other,
-but the content-types are encoded as follows:
-u8 - just 1 BE byte
-u128 - 16 BE bytes
-String - u128 representing the string length and then UTF-8 encoded character bytes
-[u8] - u128 as the length of a byte array, then the array itself
-*/
-
 use crate::util::error::Error;
 use crate::protocol::packets::*;
 
-use std::net;
-use std::io::Write;
-use std::io::Read;
-
 // Protocol versioning
-pub const PROTOCOL_LATEST_VERSION: u8 = 1;
+pub const PROTOCOL_VERSION_1: u8 = 1;
+pub const PROTOCOL_LATEST_VERSION: u8 = PROTOCOL_VERSION_1;
 
 // Packets' IDs
 pub const HANDSHAKE_PACKET_ID: u8 = 1;
@@ -55,9 +31,18 @@ pub const FILEDATA_PACKET_ID: u8 = 5;
 pub const CHUNK_SIZE: usize = 262_144; // 256 KB
 
 // Encryption types
+pub const ENCRYPTION_NO_ENCRYPTION: u8 = 0;
 pub const ECRYPTION_XOR: u8 = 1;
 
-#[derive(PartialEq, Eq)]
+#[derive(PartialEq, Eq, Debug)]
+pub enum RunMode {
+    SEND,
+    RECEIVE,
+    SYNC,
+    DAEMON,
+}
+
+#[derive(PartialEq, Eq, Debug)]
 pub enum PacketType {
     ConnectionShutdown,
     TextData,
@@ -70,105 +55,4 @@ pub trait Packet {
     fn get_type(&self) -> PacketType;
     fn as_bytes(&self) -> Vec<u8>;
     fn from_bytes(&mut self, packet_bytes: Vec<u8>) -> Option<Error>;
-}
-
-
-pub fn send_packet(conn: &mut net::TcpStream, packet: &dyn Packet) -> Result<(), Error> {
-    let mut payload: Vec<u8> = Vec::<u8>::new();
-
-    let packet_bytes: Vec<u8> = packet.as_bytes();
-    let packet_len: usize = packet_bytes.len();
-    
-    payload.extend_from_slice(&u128::to_be_bytes(packet_len as u128));
-    payload.extend_from_slice(&packet_bytes);
-
-    match conn.write_all(&payload) {
-        Ok(()) => {
-            return Ok(());
-        }
-
-        Err(error) => {
-            return Err(Error::new(format!("could not write packet to the connection: {}", error).as_str()))
-        }
-    }
-}
-
-pub fn read_next_packet(conn: &mut net::TcpStream) -> Result<Box<dyn Packet>, Error> {
-    let mut u128_buf: [u8; 16] = [0; 16];
-
-    match conn.read_exact(&mut u128_buf) {
-        Ok(()) => {}
-        Err(error) => {
-            return Err(Error::new(format!("error while reading initial length bytes: {}", error).as_str()));
-        }
-    }
-    let packet_len: u128 = u128::from_be_bytes(u128_buf);
-
-    let mut packet_bytes: Vec<u8> = vec!(0; packet_len as usize);
-    match conn.read_exact(&mut packet_bytes) {
-        Ok(()) => {}
-        Err(error) => {
-            return Err(Error::new(format!("error while reading packet contents: {}", error).as_str()));
-        }
-    }
-
-    if packet_bytes.len() < packet_len as usize {
-        return Err(
-            Error::new(
-                format!("read {} packet bytes instead of specified {}", packet_bytes.len(), packet_len).as_str())
-            );
-    }
-
-    let packet_type_byte: u8 = u8::from_be_bytes([packet_bytes[0]]);
-    match packet_type_byte {
-        CONNECTION_SHUTDOWN_PACKET_ID => {
-            return Ok(Box::new(ConnectionShutdownPacket{}));
-        }
-
-        TEXT_PACKET_ID => {
-            let mut new_text_packet: TextPacket = TextPacket::empty();
-            let result = new_text_packet.from_bytes(packet_bytes);
-            match result {
-                Some(error) => {
-                    return Err(Error::new(format!("could not construct new text packet: {}", error.text).as_str()));
-                }
-
-                None => {
-                    return Ok(Box::new(new_text_packet));
-                }
-            }
-        }
-
-        FILEINFO_PACKET_ID => {
-            let mut new_fileinfo_packet: FileInfoPacket = FileInfoPacket::empty();
-            let result = new_fileinfo_packet.from_bytes(packet_bytes);
-            match result {
-                Some(error) => {
-                    return Err(Error::new(format!("could not construct new fileinfo packet: {}", error.text).as_str()));
-                }
-
-                None => {
-                    return Ok(Box::new(new_fileinfo_packet));
-                }
-            }
-        }
-
-        FILEDATA_PACKET_ID => {
-            let mut new_filedata_packet: FileDataPacket = FileDataPacket::empty();
-            let result = new_filedata_packet.from_bytes(packet_bytes);
-            match result {
-                Some(error) => {
-                    return Err(Error::new(format!("could not construct new filedata packet: {}", error.text).as_str()));
-                }
-
-                None => {
-                    return Ok(Box::new(new_filedata_packet));
-                }
-            }
-        }
-
-        _ => {
-            return Err(Error::new(format!("invalid packet type ID \"{}\"", packet_type_byte).as_str()));
-        }
-    }
 }

src/util/buf_read.rs

@@ -13,15 +13,7 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.
 */
 
-pub fn read_u128(buf: Vec<u8>) -> u128 {
-    let mut arr: [u8; 16] = [0; 16];
-    for i in 0..16 {
-        arr[i] = buf[i];
-    }
-    return u128::from_be_bytes(arr);
-}
-
-pub fn read_u128_slice(buf_16: &[u8]) -> u128 {
+pub fn read_u128_slice_be(buf_16: &[u8]) -> u128 {
     let mut arr: [u8; 16] = [0; 16];
     for i in 0..16 {
         arr[i] = buf_16[i];
@@ -29,10 +21,6 @@ pub fn read_u128_slice(buf_16: &[u8]) -> u128 {
     return u128::from_be_bytes(arr);
 }
 
-pub fn read_utf8_string(buf: Vec<u8>) -> String {
-    return String::from_utf8_lossy(&buf).into_owned();
-}
-
 pub fn read_utf8_string_slice(buf: &[u8]) -> String {
     return String::from_utf8_lossy(&buf).into_owned();
 }