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|
use crate::{Config, PeerConfig, Serial};
use anyhow::{anyhow, bail};
use log::{debug, error, info, warn};
use serde::{Deserialize, Serialize};
use std::{
fs::{create_dir_all, read_to_string, remove_file, File},
io::{copy, BufRead, BufReader, BufWriter, Read, Write},
net::{SocketAddr, TcpListener, TcpStream},
os::unix::fs::MetadataExt,
sync::{Arc, Mutex},
thread::spawn,
time::SystemTime,
};
pub fn server(config: Arc<Config>) -> anyhow::Result<!> {
let listener = TcpListener::bind(&config.server.address)?;
info!("listening on {}", listener.local_addr()?);
loop {
let Ok((sock, addr)) = listener.accept() else {
error!("could not accept connection");
continue;
};
info!("connection from {addr}");
let config = config.clone();
spawn(
move || match handle_connection_wrapper(config, sock, addr) {
Ok(()) => {
info!("connection closed gracefully")
}
Err(err) => {
warn!("client error {addr}: {err:?}")
}
},
);
}
}
fn handle_connection_wrapper(
config: Arc<Config>,
sock: TcpStream,
addr: SocketAddr,
) -> anyhow::Result<()> {
let mut rsock = BufReader::new(sock.try_clone()?);
let mut wsock = BufWriter::new(sock);
match handle_connection(config, &mut rsock, &mut wsock, addr) {
Ok(()) => Ok(()),
Err(e) => {
writeln!(wsock, "error,{e}")?;
wsock.flush()?;
Err(e)
}
}
}
fn handle_connection(
config: Arc<Config>,
rsock: &mut BufReader<TcpStream>,
wsock: &mut BufWriter<TcpStream>,
addr: SocketAddr,
) -> anyhow::Result<()> {
let mut line = String::new();
rsock.by_ref().take(4096).read_line(&mut line)?;
let provided_secret = line.trim();
let Some(peer) = config
.peer
.iter()
.find(|p| p.shared_secret == provided_secret)
else {
bail!("invalid secret");
};
let peerdir = config.storage.root.join(&peer.name);
create_dir_all(&peerdir)?;
loop {
line.clear();
rsock.by_ref().take(4096).read_line(&mut line)?;
let mut toks = line.trim().split(",");
let command = toks.next().ok_or(anyhow!("command missing"))?;
debug!("command {command:?} issued");
match command {
"quit" => break Ok(()),
"list" => {
let mut dir = peerdir
.read_dir()?
.map(|e| {
let e = e?;
Ok::<_, anyhow::Error>((
e.metadata()?.mtime(),
e.metadata()?.size(),
e.file_name()
.to_str()
.unwrap()
.to_string()
.parse::<Serial>()?,
))
})
.try_collect::<Vec<_>>()?;
dir.sort_by_key(|(_, _, a)| *a);
for (m, s, p) in dir {
writeln!(wsock, "{m}:{s}:{p}")?;
}
writeln!(wsock)?;
wsock.flush()?;
}
"upload" => {
let size = toks.next().ok_or(anyhow!("size missing"))?.parse::<u64>()?;
if size > config.storage.size {
bail!("maximum size exceeded")
}
let serial = transact_user_state(&config, peer, |s| {
if s.last_upload.elapsed().unwrap().as_secs() > config.storage.upload_cooldown {
s.last_upload = SystemTime::now();
s.serial += 1;
Some(s.serial)
} else {
None
}
})?
.ok_or(anyhow!("upload cooldown"))?;
writeln!(wsock, "ready")?;
wsock.flush()?;
while peerdir.read_dir()?.fold(0, |a, _| a + 1) >= config.storage.versions {
let mut dir = peerdir
.read_dir()?
.map(|e| {
let e = e?;
Ok::<_, anyhow::Error>(
e.file_name()
.to_str()
.unwrap()
.to_string()
.parse::<Serial>()?,
)
})
.try_collect::<Vec<_>>()?;
dir.sort();
let rem = dir[0];
info!("removing serial={rem}");
remove_file(peerdir.join(rem.to_string()))?;
}
info!("upload from {addr} size={size} serial={serial}");
let mut upload = rsock.get_ref().take(size);
let mut target =
BufWriter::new(File::create_new(peerdir.join(serial.to_string()))?);
copy(&mut upload, &mut target)?; // TODO speed limit
info!("done {addr}");
writeln!(wsock, "done")?;
wsock.flush()?;
}
"download" => {
let serial = toks
.next()
.ok_or(anyhow!("serial missing"))?
.parse::<Serial>()?;
let ok = transact_user_state(&config, peer, |s| {
if s.last_download.elapsed().unwrap().as_secs()
> config.storage.download_cooldown
{
s.last_download = SystemTime::now();
true
} else {
false
}
})?;
if !ok {
bail!("download cooldown")
}
let source = File::open(peerdir.join(serial.to_string()))?;
let size = source.metadata()?.size();
let mut source = BufReader::new(source);
info!("download for {addr} size={size} serial={serial}");
writeln!(wsock, "ready,{size}")?;
wsock.flush()?;
copy(&mut source, wsock)?; // TODO speed limit
writeln!(wsock, "done")?;
wsock.flush()?;
}
_ => bail!("unknown command"),
}
}
}
#[derive(Serialize, Deserialize)]
struct PeerState {
last_upload: SystemTime,
last_download: SystemTime,
serial: Serial,
}
static USER_DB: Mutex<()> = Mutex::new(());
fn transact_user_state<T>(
config: &Config,
peer: &PeerConfig,
update: impl FnOnce(&mut PeerState) -> T,
) -> anyhow::Result<T> {
let _g = USER_DB
.lock()
.map_err(|_| anyhow!("user database locked"))?;
let conf_path = config.storage.root.join(&peer.name).with_extension("db");
let mut state = read_to_string(&conf_path)
.map(|s| toml::from_str(&s))
.unwrap_or_else(|_| {
Ok(PeerState {
last_download: SystemTime::UNIX_EPOCH,
last_upload: SystemTime::UNIX_EPOCH,
serial: 0,
})
})?;
let res = update(&mut state);
let ser_state = toml::to_string_pretty(&state)?;
File::create(conf_path)?.write_all(ser_state.as_bytes())?;
drop(_g);
Ok(res)
}
|
