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use std::fs::File;
use std::io::{Read, Seek, Write};
use std::net::{IpAddr, SocketAddr, UdpSocket};
use std::path::Path;
use std::time::Duration;
use super::config::ClientConfig;
use crate::tftp::core::{OptionType, Packet, TransferOption};
/// TFTP client
///
/// Supports file upload (PUT) and download (GET) operations
pub struct Client {
server_ip: IpAddr,
server_port: u16,
block_size: u16,
timeout: Duration,
window_size: u16,
mode: String,
}
impl Client {
/// Create a new TFTP client
pub fn new(config: ClientConfig) -> anyhow::Result<Self> {
let server_str = config
.server
.ok_or_else(|| anyhow::anyhow!("Server address not specified"))?;
let server_ip: IpAddr = server_str
.parse()
.map_err(|e| anyhow::anyhow!("Invalid server address '{}': {}", server_str, e))?;
Ok(Self {
server_ip,
server_port: config.port.unwrap_or(69),
block_size: config.block_size.unwrap_or(512),
timeout: config.timeout.unwrap_or(Duration::from_secs(5)),
window_size: config.window_size.unwrap_or(1),
mode: config.mode.unwrap_or_else(|| "octet".to_string()),
})
}
fn build_options(&self, transfer_size: u64) -> Vec<TransferOption> {
let mut options = Vec::new();
options.push(TransferOption {
option: OptionType::BlockSize,
value: self.block_size as u64,
});
options.push(TransferOption {
option: OptionType::Timeout,
value: self.timeout.as_secs(),
});
options.push(TransferOption {
option: OptionType::WindowSize,
value: self.window_size as u64,
});
if transfer_size > 0 {
options.push(TransferOption {
option: OptionType::TransferSize,
value: transfer_size,
});
}
options
}
/// Download a file from the server (RRQ - Read Request)
pub fn get(&self, remote_file: &str, local_file: &Path) -> anyhow::Result<()> {
log::info!("Downloading {} to {}", remote_file, local_file.display());
// Create local socket
let socket = UdpSocket::bind("0.0.0.0:0")?;
let mut server_addr = SocketAddr::new(self.server_ip, self.server_port);
let mut tid_set = false;
socket.set_read_timeout(Some(self.timeout))?;
socket.set_write_timeout(Some(self.timeout))?;
// Build options
let options = self.build_options(0);
// Send RRQ
let rrq = Packet::Rrq {
filename: remote_file.to_string(),
mode: self.mode.clone(),
options,
};
let bytes = rrq.serialize()?;
socket.send_to(&bytes, server_addr)?;
// Receive file
let mut file = File::create(local_file)?;
let mut block_num: u16 = 1;
let mut retries = 0;
let max_retries = 5;
loop {
let mut buf = vec![0; self.block_size as usize + 4];
match socket.recv_from(&mut buf) {
Ok((amt, src)) => {
if !tid_set {
if src.ip() == self.server_ip {
server_addr = src;
tid_set = true;
} else {
continue;
}
} else if src != server_addr {
continue;
}
let packet = Packet::deserialize(&buf[..amt])?;
match packet {
Packet::Data {
block_num: block,
data,
} => {
if block == block_num {
file.write_all(&data)?;
// Send ACK
let ack = Packet::Ack(block);
socket.send_to(&ack.serialize()?, server_addr)?;
block_num = block_num.wrapping_add(1);
retries = 0;
if data.len() < self.block_size as usize {
break; // End of file
}
}
}
Packet::Error { code, msg } => {
return Err(anyhow::anyhow!("TFTP Error {:?}: {}", code, msg));
}
Packet::Oack(_) => {
// Handle option negotiation
if block_num == 1 {
// Send ACK 0 to confirm options
let ack = Packet::Ack(0);
socket.send_to(&ack.serialize()?, server_addr)?;
}
}
_ => {}
}
}
Err(e)
if e.kind() == std::io::ErrorKind::WouldBlock
|| e.kind() == std::io::ErrorKind::TimedOut =>
{
if retries >= max_retries {
return Err(anyhow::anyhow!("Transfer timed out"));
}
retries += 1;
log::warn!("Timeout, retrying... ({}/{})", retries, max_retries);
// Resend last ACK
let ack = Packet::Ack(block_num.wrapping_sub(1));
socket.send_to(&ack.serialize()?, server_addr)?;
}
Err(e) => return Err(e.into()),
}
}
Ok(())
}
/// Upload a file to the server (WRQ - Write Request)
pub fn put(&self, local_file: &Path, remote_file: &str) -> anyhow::Result<()> {
log::info!("Uploading {} to {}", local_file.display(), remote_file);
let mut file = File::open(local_file)?;
let file_size = file.metadata()?.len();
// Create local socket
let socket = UdpSocket::bind("0.0.0.0:0")?;
let mut server_addr = SocketAddr::new(self.server_ip, self.server_port);
let mut tid_set = false;
socket.set_read_timeout(Some(self.timeout))?;
socket.set_write_timeout(Some(self.timeout))?;
// Build options
let options = self.build_options(file_size);
// Send WRQ
let wrq = Packet::Wrq {
filename: remote_file.to_string(),
mode: self.mode.clone(),
options,
};
let bytes = wrq.serialize()?;
socket.send_to(&bytes, server_addr)?;
let mut block_num: u16 = 0;
let mut retries = 0;
let max_retries = 5;
let mut finished = false;
loop {
let mut buf = vec![0; self.block_size as usize + 4];
match socket.recv_from(&mut buf) {
Ok((amt, src)) => {
if !tid_set {
if src.ip() == self.server_ip {
server_addr = src;
tid_set = true;
} else {
continue;
}
} else if src != server_addr {
continue;
}
let packet = Packet::deserialize(&buf[..amt])?;
match packet {
Packet::Ack(block) => {
if block == block_num {
if finished {
break;
}
block_num = block_num.wrapping_add(1);
// Read next block
let mut data = vec![0; self.block_size as usize];
let n = file.read(&mut data)?;
data.truncate(n);
if n < self.block_size as usize {
finished = true;
}
// Send Data
let data_packet = Packet::Data { block_num, data };
socket.send_to(&data_packet.serialize()?, server_addr)?;
retries = 0;
}
}
Packet::Oack(_) => {
if block_num == 0 {
// OACK received, start sending data (block 1)
block_num = 1;
let mut data = vec![0; self.block_size as usize];
let n = file.read(&mut data)?;
data.truncate(n);
if n < self.block_size as usize {
finished = true;
}
let data_packet = Packet::Data { block_num, data };
socket.send_to(&data_packet.serialize()?, server_addr)?;
retries = 0;
}
}
Packet::Error { code, msg } => {
return Err(anyhow::anyhow!("TFTP Error {:?}: {}", code, msg));
}
_ => {}
}
}
Err(e)
if e.kind() == std::io::ErrorKind::WouldBlock
|| e.kind() == std::io::ErrorKind::TimedOut =>
{
if retries >= max_retries {
return Err(anyhow::anyhow!("Transfer timed out"));
}
retries += 1;
log::warn!("Timeout, retrying... ({}/{})", retries, max_retries);
// Resend last packet (WRQ or Data)
if block_num == 0 {
// Resend WRQ
let wrq = Packet::Wrq {
filename: remote_file.to_string(),
mode: self.mode.clone(),
options: self.build_options(file_size),
};
socket.send_to(&wrq.serialize()?, server_addr)?;
} else {
// Resend Data
// We need to seek back in file?
// For simplicity in this refactor, we just error or warn.
// Proper retry for data requires caching the last data packet or seeking.
// Since we don't have the last data packet easily available here without restructuring,
// we will just log a warning that retry might fail if we don't resend data.
// Actually, we can seek back.
let offset = (block_num as u64 - 1) * (self.block_size as u64);
file.seek(std::io::SeekFrom::Start(offset))?;
let mut data = vec![0; self.block_size as usize];
let n = file.read(&mut data)?;
data.truncate(n);
let data_packet = Packet::Data { block_num, data };
socket.send_to(&data_packet.serialize()?, server_addr)?;
}
}
Err(e) => return Err(e.into()),
}
}
Ok(())
}
}