extern crate httparse;
extern crate netencode;
extern crate arglib_netencode;
extern crate ascii;
extern crate exec_helpers;
use std::os::unix::io::FromRawFd;
use std::io::Read;
use std::io::Write;
use exec_helpers::{die_user_error, die_expected_error, die_temporary};
use netencode::{U, T};
enum What {
Request,
Response
}
fn main() -> std::io::Result<()> {
let what : What = match arglib_netencode::arglib_netencode(None).unwrap() {
T::Record(rec) => match rec.get("what") {
Some(T::Text(t)) => match t.as_str() {
"request" => What::Request,
"response" => What::Response,
_ => die_user_error("read-http arglib", "`what` should be either t:request or t:response"),
},
Some(o) => die_user_error("read-http arglib", format!("expected a record of text, got {:#?}", o)),
None => {
eprintln!("read-http arglib: no `what` given, defaulting to Response");
What::Response
}
}
o => die_user_error("read-http arglib", format!("expected a record, got {:#?}", o))
};
fn read_stdin_to_complete<F>(mut parse: F) -> ()
where F: FnMut(&[u8]) -> httparse::Result<usize>
{
let mut res = httparse::Status::Partial;
loop {
if let httparse::Status::Complete(_) = res {
return;
}
let mut buf = [0; 2048];
match std::io::stdin().read(&mut buf[..]) {
Ok(size) => if size == 0 {
break;
},
Err(err) => die_temporary("read-http", format!("could not read from stdin, {:?}", err))
}
match parse(&buf) {
Ok(status) => {
res = status;
}
Err(err) => die_temporary("read-http", format!("httparse parsing failed: {:#?}", err))
}
}
}
fn normalize_headers<'a>(headers: &'a [httparse::Header]) -> Vec<(String, &'a str)> {
let mut res = vec![];
for httparse::Header { name, value } in headers {
let val = ascii::AsciiStr::from_ascii(*value)
.expect(&format!("read-http: we require header values to be ASCII, but the header {} was {:?}", name, value));
// lowercase the headers, since the standard doesn’t care
// and we want unique strings to match agains
res.push((name.to_lowercase(), val.as_str()))
}
res
}
// tries to read until the end of the http header (deliniated by two newlines "\r\n\r\n")
fn read_till_end_of_header<R: Read>(buf: &mut Vec<u8>, reader: R) -> Option<()> {
let mut chunker = Chunkyboi::new(reader, 4096);
loop {
match chunker.next() {
Some(Ok(chunk)) => {
buf.extend_from_slice(&chunk);
if chunk.windows(4).any(|c| c == b"\r\n\r\n" ) {
return Some(());
}
},
Some(Err(err)) => die_temporary("read-http", format!("error reading from stdin: {:?}", err)),
None => return None
}
}
}
// max header size chosen arbitrarily
let mut headers = [httparse::EMPTY_HEADER; 128];
let stdin = std::io::stdin();
match what {
Request => {
let mut req = httparse::Request::new(&mut headers);
let mut buf: Vec<u8> = vec![];
match read_till_end_of_header(&mut buf, stdin.lock()) {
Some(()) => match req.parse(&buf) {
Ok(httparse::Status::Complete(_body_start)) => {},
Ok(httparse::Status::Partial) => die_expected_error("read-http", "httparse should have gotten a full header"),
Err(err) => die_expected_error("read-http", format!("httparse response parsing failed: {:#?}", err))
},
None => die_expected_error("read-http", format!("httparse end of stdin reached before able to parse request headers"))
}
let method = req.method.expect("method must be filled on complete parse");
let path = req.path.expect("path must be filled on complete parse");
write_dict_req(method, path, &normalize_headers(req.headers))
},
Response => {
let mut resp = httparse::Response::new(&mut headers);
let mut buf: Vec<u8> = vec![];
match read_till_end_of_header(&mut buf, stdin.lock()) {
Some(()) => match resp.parse(&buf) {
Ok(httparse::Status::Complete(_body_start)) => {},
Ok(httparse::Status::Partial) => die_expected_error("read-http", "httparse should have gotten a full header"),
Err(err) => die_expected_error("read-http", format!("httparse response parsing failed: {:#?}", err))
},
None => die_expected_error("read-http", format!("httparse end of stdin reached before able to parse response headers"))
}
let code = resp.code.expect("code must be filled on complete parse");
let reason = resp.reason.expect("reason must be filled on complete parse");
write_dict_resp(code, reason, &normalize_headers(resp.headers))
}
}
}
fn write_dict_req<'buf>(method: &'buf str, path: &'buf str, headers: &[(String, &str)]) -> std::io::Result<()> {
let mut http = vec![
("method", U::Text(method.as_bytes())),
("path", U::Text(path.as_bytes())),
];
write_dict(http, headers)
}
fn write_dict_resp<'buf>(code: u16, reason: &'buf str, headers: &[(String, &str)]) -> std::io::Result<()> {
let mut http = vec![
("status", U::N6(code as u64)),
("status-text", U::Text(reason.as_bytes())),
];
write_dict(http, headers)
}
fn write_dict<'buf, 'a>(mut http: Vec<(&str, U<'a>)>, headers: &'a[(String, &str)]) -> std::io::Result<()> {
http.push(("headers", U::Record(
headers.iter().map(
|(name, value)|
(name.as_str(), U::Text(value.as_bytes()))
).collect::<Vec<_>>()
)));
netencode::encode(
&mut std::io::stdout(),
U::Record(http)
)?;
Ok(())
}
// iter helper
struct Chunkyboi<T> {
inner: T,
buf: Vec<u8>,
}
impl<R: Read> Chunkyboi<R> {
fn new(inner: R, chunksize: usize) -> Self {
let buf = vec![0; chunksize];
Chunkyboi {
inner,
buf
}
}
}
impl<R: Read> Iterator for Chunkyboi<R> {
type Item = std::io::Result<Vec<u8>>;
fn next(&mut self) -> Option<std::io::Result<Vec<u8>>> {
match self.inner.read(&mut self.buf) {
Ok(0) => None,
Ok(read) => {
// clone a new buffer so we can reuse the internal one
Some(Ok(self.buf[..read].to_owned()))
}
Err(err) => Some(Err(err))
}
}
}
