ptth/src/server/file_server.rs

352 lines
8.0 KiB
Rust

// Static file server that can plug into the PTTH reverse server
use std::{
cmp::{min, max},
collections::*,
convert::{Infallible, TryInto},
error::Error,
io::SeekFrom,
path::{Path, PathBuf},
};
use handlebars::Handlebars;
use tokio::{
fs::{
File,
read_dir,
ReadDir,
},
io::AsyncReadExt,
sync::mpsc::{
channel,
},
};
use tracing::{
debug, error, info,
instrument,
};
use regex::Regex;
use crate::http_serde;
fn parse_range_header (range_str: &str) -> (Option <u64>, Option <u64>) {
use lazy_static::*;
lazy_static! {
static ref RE: Regex = Regex::new (r"^bytes=(\d*)-(\d*)$").expect ("Couldn't compile regex for Range header");
}
debug! ("{}", range_str);
let caps = match RE.captures (range_str) {
Some (x) => x,
_ => return (None, None),
};
let start = caps.get (1).map (|x| x.as_str ());
let end = caps.get (2).map (|x| x.as_str ());
let start = start.map (|x| u64::from_str_radix (x, 10).ok ()).flatten ();
let end = end.map (|x| u64::from_str_radix (x, 10).ok ()).flatten ();
(start, end)
}
use serde::Serialize;
use tokio::fs::DirEntry;
// This could probably be done with borrows, if I owned the
// tokio::fs::DirEntry instead of consuming it
#[derive (Serialize)]
struct TemplateDirEntry {
trailing_slash: &'static str,
file_name: String,
encoded_file_name: String,
error: bool,
}
async fn read_dir_entry (entry: DirEntry) -> TemplateDirEntry
{
let trailing_slash = match entry.file_type ().await {
Ok (t) => if t.is_dir () {
"/"
}
else {
""
},
Err (_) => "",
};
let file_name = match entry.file_name ().into_string () {
Ok (x) => x,
Err (_) => return TemplateDirEntry {
trailing_slash: "",
file_name: "".into (),
encoded_file_name: "".into (),
error: true,
},
};
use percent_encoding::*;
let encoded_file_name = utf8_percent_encode (&file_name, CONTROLS).to_string ();
TemplateDirEntry {
trailing_slash: &trailing_slash,
file_name,
encoded_file_name,
error: false,
}
}
use std::borrow::Cow;
#[instrument (level = "debug", skip (handlebars, dir))]
async fn serve_dir (
handlebars: &Handlebars <'static>,
path: Cow <'_, str>,
mut dir: ReadDir
) -> http_serde::Response
{
let mut entries = vec! [];
while let Ok (Some (entry)) = dir.next_entry ().await {
entries.push (read_dir_entry (entry).await);
}
entries.sort_unstable_by (|a, b| a.file_name.partial_cmp (&b.file_name).unwrap ());
#[derive (Serialize)]
struct TemplateDirPage <'a> {
path: Cow <'a, str>,
entries: Vec <TemplateDirEntry>,
}
let s = handlebars.render ("file_server_dir", &TemplateDirPage {
path,
entries,
}).unwrap ();
let body = s.into_bytes ();
let mut resp = http_serde::Response::default ();
resp.content_length = Some (body.len ().try_into ().unwrap ());
resp
.header ("content-type".to_string (), "text/html".to_string ().into_bytes ())
.header ("content-length".to_string (), body.len ().to_string ().into_bytes ())
.body_bytes (body)
;
resp
}
#[instrument (level = "debug", skip (f))]
async fn serve_file (
mut f: File,
should_send_body: bool,
range_start: Option <u64>,
range_end: Option <u64>
) -> http_serde::Response {
let (tx, rx) = channel (2);
let body = if should_send_body {
Some (rx)
}
else {
None
};
let file_md = f.metadata ().await.unwrap ();
let file_len = file_md.len ();
let start = range_start.unwrap_or (0);
let end = range_end.unwrap_or (file_len);
let start = max (0, min (start, file_len));
let end = max (0, min (end, file_len));
f.seek (SeekFrom::Start (start)).await.unwrap ();
info! ("Serving range {}-{}", start, end);
if should_send_body {
tokio::spawn (async move {
//println! ("Opening file {:?}", path);
let mut tx = tx;
let mut bytes_sent = 0;
let mut bytes_left = end - start;
loop {
let mut buffer = vec! [0u8; 65_536];
let bytes_read: u64 = f.read (&mut buffer).await.unwrap ().try_into ().unwrap ();
let bytes_read = min (bytes_left, bytes_read);
buffer.truncate (bytes_read.try_into ().unwrap ());
if bytes_read == 0 {
break;
}
if tx.send (Ok::<_, Infallible> (buffer)).await.is_err () {
error! ("Send failed while streaming file ({} bytes sent)", bytes_sent);
break;
}
bytes_left -= bytes_read;
if bytes_left == 0 {
info! ("Finished");
break;
}
bytes_sent += bytes_read;
debug! ("Sent {} bytes", bytes_sent);
//delay_for (Duration::from_millis (50)).await;
}
});
}
let mut response = http_serde::Response::default ();
response.header (String::from ("accept-ranges"), b"bytes".to_vec ());
if should_send_body {
if range_start.is_none () && range_end.is_none () {
response.status_code (http_serde::StatusCode::Ok);
response.header (String::from ("content-length"), end.to_string ().into_bytes ());
}
else {
response.status_code (http_serde::StatusCode::PartialContent);
response.header (String::from ("content-range"), format! ("bytes {}-{}/{}", start, end - 1, end).into_bytes ());
}
response.content_length = Some (end - start);
}
if let Some (body) = body {
response.body (body);
}
response
}
async fn serve_error (
status_code: http_serde::StatusCode,
msg: String
)
-> http_serde::Response
{
let mut resp = http_serde::Response::default ();
resp.status_code (status_code)
.body_bytes (msg.into_bytes ());
resp
}
#[instrument (level = "debug", skip (handlebars))]
pub async fn serve_all (
handlebars: &Handlebars <'static>,
root: &Path,
method: http_serde::Method,
uri: &str,
headers: &HashMap <String, Vec <u8>>,
)
-> http_serde::Response
{
info! ("Client requested {}", uri);
let mut range_start = None;
let mut range_end = None;
if let Some (v) = headers.get ("range") {
let v = std::str::from_utf8 (v).unwrap ();
let (start, end) = parse_range_header (v);
range_start = start;
range_end = end;
}
let should_send_body = match &method {
http_serde::Method::Get => true,
http_serde::Method::Head => false,
m => {
debug! ("Unsupported method {:?}", m);
return serve_error (http_serde::StatusCode::MethodNotAllowed, "Unsupported method".into ()).await;
}
};
use percent_encoding::*;
// TODO: There is totally a dir traversal attack in here somewhere
let encoded_path = &uri [1..];
let path_s = percent_decode (encoded_path.as_bytes ()).decode_utf8 ().unwrap ();
let path = Path::new (&*path_s);
let mut full_path = PathBuf::from (root);
full_path.push (path);
if let Ok (dir) = read_dir (&full_path).await {
serve_dir (
handlebars,
full_path.to_string_lossy (),
dir
).await
}
else if let Ok (file) = File::open (&full_path).await {
serve_file (
file,
should_send_body,
range_start,
range_end
).await
}
else {
serve_error (http_serde::StatusCode::NotFound, "404 Not Found".into ()).await
}
}
pub fn load_templates ()
-> Result <Handlebars <'static>, Box <dyn Error>>
{
let mut handlebars = Handlebars::new ();
handlebars.set_strict_mode (true);
for (k, v) in vec! [
("file_server_dir", "file_server_dir.html"),
].into_iter () {
handlebars.register_template_file (k, format! ("ptth_handlebars/{}", v))?;
}
Ok (handlebars)
}
#[cfg (test)]
mod tests {
#[test]
fn i_hate_paths () {
use std::{
ffi::OsStr,
path::{Component, Path}
};
let mut components = Path::new ("/home/user").components ();
assert_eq! (components.next (), Some (Component::RootDir));
assert_eq! (components.next (), Some (Component::Normal (OsStr::new ("home"))));
assert_eq! (components.next (), Some (Component::Normal (OsStr::new ("user"))));
assert_eq! (components.next (), None);
let mut components = Path::new ("./home/user").components ();
assert_eq! (components.next (), Some (Component::CurDir));
assert_eq! (components.next (), Some (Component::Normal (OsStr::new ("home"))));
assert_eq! (components.next (), Some (Component::Normal (OsStr::new ("user"))));
assert_eq! (components.next (), None);
let mut components = Path::new (".").components ();
assert_eq! (components.next (), Some (Component::CurDir));
assert_eq! (components.next (), None);
}
}