blob: b8e2cac7d5a9a73587e711afa79f02c135178ca8 [file] [log] [blame]
use std::error::Error as StdError;
use std::fmt;
use std::usize;
use std::io;
use futures::{Async, Poll};
use bytes::Bytes;
use super::io::MemRead;
use super::{DecodedLength};
use self::Kind::{Length, Chunked, Eof};
/// Decoders to handle different Transfer-Encodings.
///
/// If a message body does not include a Transfer-Encoding, it *should*
/// include a Content-Length header.
#[derive(Clone, PartialEq)]
pub struct Decoder {
kind: Kind,
}
#[derive(Debug, Clone, Copy, PartialEq)]
enum Kind {
/// A Reader used when a Content-Length header is passed with a positive integer.
Length(u64),
/// A Reader used when Transfer-Encoding is `chunked`.
Chunked(ChunkedState, u64),
/// A Reader used for responses that don't indicate a length or chunked.
///
/// The bool tracks when EOF is seen on the transport.
///
/// Note: This should only used for `Response`s. It is illegal for a
/// `Request` to be made with both `Content-Length` and
/// `Transfer-Encoding: chunked` missing, as explained from the spec:
///
/// > If a Transfer-Encoding header field is present in a response and
/// > the chunked transfer coding is not the final encoding, the
/// > message body length is determined by reading the connection until
/// > it is closed by the server. If a Transfer-Encoding header field
/// > is present in a request and the chunked transfer coding is not
/// > the final encoding, the message body length cannot be determined
/// > reliably; the server MUST respond with the 400 (Bad Request)
/// > status code and then close the connection.
Eof(bool),
}
#[derive(Debug, PartialEq, Clone, Copy)]
enum ChunkedState {
Size,
SizeLws,
Extension,
SizeLf,
Body,
BodyCr,
BodyLf,
EndCr,
EndLf,
End,
}
impl Decoder {
// constructors
pub fn length(x: u64) -> Decoder {
Decoder { kind: Kind::Length(x) }
}
pub fn chunked() -> Decoder {
Decoder { kind: Kind::Chunked(ChunkedState::Size, 0) }
}
pub fn eof() -> Decoder {
Decoder { kind: Kind::Eof(false) }
}
pub(super) fn new(len: DecodedLength) -> Self {
match len {
DecodedLength::CHUNKED => Decoder::chunked(),
DecodedLength::CLOSE_DELIMITED => Decoder::eof(),
length => Decoder::length(length.danger_len()),
}
}
// methods
pub fn is_eof(&self) -> bool {
match self.kind {
Length(0) |
Chunked(ChunkedState::End, _) |
Eof(true) => true,
_ => false,
}
}
pub fn decode<R: MemRead>(&mut self, body: &mut R) -> Poll<Bytes, io::Error> {
trace!("decode; state={:?}", self.kind);
match self.kind {
Length(ref mut remaining) => {
if *remaining == 0 {
Ok(Async::Ready(Bytes::new()))
} else {
let to_read = *remaining as usize;
let buf = try_ready!(body.read_mem(to_read));
let num = buf.as_ref().len() as u64;
if num > *remaining {
*remaining = 0;
} else if num == 0 {
return Err(io::Error::new(io::ErrorKind::UnexpectedEof, IncompleteBody));
} else {
*remaining -= num;
}
Ok(Async::Ready(buf))
}
}
Chunked(ref mut state, ref mut size) => {
loop {
let mut buf = None;
// advances the chunked state
*state = try_ready!(state.step(body, size, &mut buf));
if *state == ChunkedState::End {
trace!("end of chunked");
return Ok(Async::Ready(Bytes::new()));
}
if let Some(buf) = buf {
return Ok(Async::Ready(buf));
}
}
}
Eof(ref mut is_eof) => {
if *is_eof {
Ok(Async::Ready(Bytes::new()))
} else {
// 8192 chosen because its about 2 packets, there probably
// won't be that much available, so don't have MemReaders
// allocate buffers to big
let slice = try_ready!(body.read_mem(8192));
*is_eof = slice.is_empty();
Ok(Async::Ready(slice))
}
}
}
}
}
impl fmt::Debug for Decoder {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Debug::fmt(&self.kind, f)
}
}
macro_rules! byte (
($rdr:ident) => ({
let buf = try_ready!($rdr.read_mem(1));
if !buf.is_empty() {
buf[0]
} else {
return Err(io::Error::new(io::ErrorKind::UnexpectedEof,
"Unexpected eof during chunk size line"));
}
})
);
impl ChunkedState {
fn step<R: MemRead>(&self,
body: &mut R,
size: &mut u64,
buf: &mut Option<Bytes>)
-> Poll<ChunkedState, io::Error> {
use self::ChunkedState::*;
match *self {
Size => ChunkedState::read_size(body, size),
SizeLws => ChunkedState::read_size_lws(body),
Extension => ChunkedState::read_extension(body),
SizeLf => ChunkedState::read_size_lf(body, *size),
Body => ChunkedState::read_body(body, size, buf),
BodyCr => ChunkedState::read_body_cr(body),
BodyLf => ChunkedState::read_body_lf(body),
EndCr => ChunkedState::read_end_cr(body),
EndLf => ChunkedState::read_end_lf(body),
End => Ok(Async::Ready(ChunkedState::End)),
}
}
fn read_size<R: MemRead>(rdr: &mut R, size: &mut u64) -> Poll<ChunkedState, io::Error> {
trace!("Read chunk hex size");
let radix = 16;
match byte!(rdr) {
b @ b'0'...b'9' => {
*size *= radix;
*size += (b - b'0') as u64;
}
b @ b'a'...b'f' => {
*size *= radix;
*size += (b + 10 - b'a') as u64;
}
b @ b'A'...b'F' => {
*size *= radix;
*size += (b + 10 - b'A') as u64;
}
b'\t' | b' ' => return Ok(Async::Ready(ChunkedState::SizeLws)),
b';' => return Ok(Async::Ready(ChunkedState::Extension)),
b'\r' => return Ok(Async::Ready(ChunkedState::SizeLf)),
_ => {
return Err(io::Error::new(io::ErrorKind::InvalidInput,
"Invalid chunk size line: Invalid Size"));
}
}
Ok(Async::Ready(ChunkedState::Size))
}
fn read_size_lws<R: MemRead>(rdr: &mut R) -> Poll<ChunkedState, io::Error> {
trace!("read_size_lws");
match byte!(rdr) {
// LWS can follow the chunk size, but no more digits can come
b'\t' | b' ' => Ok(Async::Ready(ChunkedState::SizeLws)),
b';' => Ok(Async::Ready(ChunkedState::Extension)),
b'\r' => Ok(Async::Ready(ChunkedState::SizeLf)),
_ => {
Err(io::Error::new(io::ErrorKind::InvalidInput,
"Invalid chunk size linear white space"))
}
}
}
fn read_extension<R: MemRead>(rdr: &mut R) -> Poll<ChunkedState, io::Error> {
trace!("read_extension");
match byte!(rdr) {
b'\r' => Ok(Async::Ready(ChunkedState::SizeLf)),
_ => Ok(Async::Ready(ChunkedState::Extension)), // no supported extensions
}
}
fn read_size_lf<R: MemRead>(rdr: &mut R, size: u64) -> Poll<ChunkedState, io::Error> {
trace!("Chunk size is {:?}", size);
match byte!(rdr) {
b'\n' => {
if size == 0 {
Ok(Async::Ready(ChunkedState::EndCr))
} else {
debug!("incoming chunked header: {0:#X} ({0} bytes)", size);
Ok(Async::Ready(ChunkedState::Body))
}
},
_ => Err(io::Error::new(io::ErrorKind::InvalidInput, "Invalid chunk size LF")),
}
}
fn read_body<R: MemRead>(rdr: &mut R,
rem: &mut u64,
buf: &mut Option<Bytes>)
-> Poll<ChunkedState, io::Error> {
trace!("Chunked read, remaining={:?}", rem);
// cap remaining bytes at the max capacity of usize
let rem_cap = match *rem {
r if r > usize::MAX as u64 => usize::MAX,
r => r as usize,
};
let to_read = rem_cap;
let slice = try_ready!(rdr.read_mem(to_read));
let count = slice.len();
if count == 0 {
*rem = 0;
return Err(io::Error::new(io::ErrorKind::UnexpectedEof, IncompleteBody));
}
*buf = Some(slice);
*rem -= count as u64;
if *rem > 0 {
Ok(Async::Ready(ChunkedState::Body))
} else {
Ok(Async::Ready(ChunkedState::BodyCr))
}
}
fn read_body_cr<R: MemRead>(rdr: &mut R) -> Poll<ChunkedState, io::Error> {
match byte!(rdr) {
b'\r' => Ok(Async::Ready(ChunkedState::BodyLf)),
_ => Err(io::Error::new(io::ErrorKind::InvalidInput, "Invalid chunk body CR")),
}
}
fn read_body_lf<R: MemRead>(rdr: &mut R) -> Poll<ChunkedState, io::Error> {
match byte!(rdr) {
b'\n' => Ok(Async::Ready(ChunkedState::Size)),
_ => Err(io::Error::new(io::ErrorKind::InvalidInput, "Invalid chunk body LF")),
}
}
fn read_end_cr<R: MemRead>(rdr: &mut R) -> Poll<ChunkedState, io::Error> {
match byte!(rdr) {
b'\r' => Ok(Async::Ready(ChunkedState::EndLf)),
_ => Err(io::Error::new(io::ErrorKind::InvalidInput, "Invalid chunk end CR")),
}
}
fn read_end_lf<R: MemRead>(rdr: &mut R) -> Poll<ChunkedState, io::Error> {
match byte!(rdr) {
b'\n' => Ok(Async::Ready(ChunkedState::End)),
_ => Err(io::Error::new(io::ErrorKind::InvalidInput, "Invalid chunk end LF")),
}
}
}
#[derive(Debug)]
struct IncompleteBody;
impl fmt::Display for IncompleteBody {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str(self.description())
}
}
impl StdError for IncompleteBody {
fn description(&self) -> &str {
"end of file before message length reached"
}
}
#[cfg(test)]
mod tests {
use std::io;
use std::io::Write;
use super::Decoder;
use super::ChunkedState;
use super::super::io::MemRead;
use futures::{Async, Poll};
use bytes::{BytesMut, Bytes};
use mock::AsyncIo;
impl<'a> MemRead for &'a [u8] {
fn read_mem(&mut self, len: usize) -> Poll<Bytes, io::Error> {
let n = ::std::cmp::min(len, self.len());
if n > 0 {
let (a, b) = self.split_at(n);
let mut buf = BytesMut::from(a);
*self = b;
Ok(Async::Ready(buf.split_to(n).freeze()))
} else {
Ok(Async::Ready(Bytes::new()))
}
}
}
trait HelpUnwrap<T> {
fn unwrap(self) -> T;
}
impl HelpUnwrap<Bytes> for Async<Bytes> {
fn unwrap(self) -> Bytes {
match self {
Async::Ready(bytes) => bytes,
Async::NotReady => panic!(),
}
}
}
impl HelpUnwrap<ChunkedState> for Async<ChunkedState> {
fn unwrap(self) -> ChunkedState {
match self {
Async::Ready(state) => state,
Async::NotReady => panic!(),
}
}
}
#[test]
fn test_read_chunk_size() {
use std::io::ErrorKind::{UnexpectedEof, InvalidInput};
fn read(s: &str) -> u64 {
let mut state = ChunkedState::Size;
let rdr = &mut s.as_bytes();
let mut size = 0;
loop {
let result = state.step(rdr, &mut size, &mut None);
let desc = format!("read_size failed for {:?}", s);
state = result.expect(desc.as_str()).unwrap();
if state == ChunkedState::Body || state == ChunkedState::EndCr {
break;
}
}
size
}
fn read_err(s: &str, expected_err: io::ErrorKind) {
let mut state = ChunkedState::Size;
let rdr = &mut s.as_bytes();
let mut size = 0;
loop {
let result = state.step(rdr, &mut size, &mut None);
state = match result {
Ok(s) => s.unwrap(),
Err(e) => {
assert!(expected_err == e.kind(), "Reading {:?}, expected {:?}, but got {:?}",
s, expected_err, e.kind());
return;
}
};
if state == ChunkedState::Body || state == ChunkedState::End {
panic!(format!("Was Ok. Expected Err for {:?}", s));
}
}
}
assert_eq!(1, read("1\r\n"));
assert_eq!(1, read("01\r\n"));
assert_eq!(0, read("0\r\n"));
assert_eq!(0, read("00\r\n"));
assert_eq!(10, read("A\r\n"));
assert_eq!(10, read("a\r\n"));
assert_eq!(255, read("Ff\r\n"));
assert_eq!(255, read("Ff \r\n"));
// Missing LF or CRLF
read_err("F\rF", InvalidInput);
read_err("F", UnexpectedEof);
// Invalid hex digit
read_err("X\r\n", InvalidInput);
read_err("1X\r\n", InvalidInput);
read_err("-\r\n", InvalidInput);
read_err("-1\r\n", InvalidInput);
// Acceptable (if not fully valid) extensions do not influence the size
assert_eq!(1, read("1;extension\r\n"));
assert_eq!(10, read("a;ext name=value\r\n"));
assert_eq!(1, read("1;extension;extension2\r\n"));
assert_eq!(1, read("1;;; ;\r\n"));
assert_eq!(2, read("2; extension...\r\n"));
assert_eq!(3, read("3 ; extension=123\r\n"));
assert_eq!(3, read("3 ;\r\n"));
assert_eq!(3, read("3 ; \r\n"));
// Invalid extensions cause an error
read_err("1 invalid extension\r\n", InvalidInput);
read_err("1 A\r\n", InvalidInput);
read_err("1;no CRLF", UnexpectedEof);
}
#[test]
fn test_read_sized_early_eof() {
let mut bytes = &b"foo bar"[..];
let mut decoder = Decoder::length(10);
assert_eq!(decoder.decode(&mut bytes).unwrap().unwrap().len(), 7);
let e = decoder.decode(&mut bytes).unwrap_err();
assert_eq!(e.kind(), io::ErrorKind::UnexpectedEof);
}
#[test]
fn test_read_chunked_early_eof() {
let mut bytes = &b"\
9\r\n\
foo bar\
"[..];
let mut decoder = Decoder::chunked();
assert_eq!(decoder.decode(&mut bytes).unwrap().unwrap().len(), 7);
let e = decoder.decode(&mut bytes).unwrap_err();
assert_eq!(e.kind(), io::ErrorKind::UnexpectedEof);
}
#[test]
fn test_read_chunked_single_read() {
let mut mock_buf = &b"10\r\n1234567890abcdef\r\n0\r\n"[..];
let buf = Decoder::chunked().decode(&mut mock_buf).expect("decode").unwrap();
assert_eq!(16, buf.len());
let result = String::from_utf8(buf.as_ref().to_vec()).expect("decode String");
assert_eq!("1234567890abcdef", &result);
}
#[test]
fn test_read_chunked_after_eof() {
let mut mock_buf = &b"10\r\n1234567890abcdef\r\n0\r\n\r\n"[..];
let mut decoder = Decoder::chunked();
// normal read
let buf = decoder.decode(&mut mock_buf).expect("decode").unwrap();
assert_eq!(16, buf.len());
let result = String::from_utf8(buf.as_ref().to_vec()).expect("decode String");
assert_eq!("1234567890abcdef", &result);
// eof read
let buf = decoder.decode(&mut mock_buf).expect("decode").unwrap();
assert_eq!(0, buf.len());
// ensure read after eof also returns eof
let buf = decoder.decode(&mut mock_buf).expect("decode").unwrap();
assert_eq!(0, buf.len());
}
// perform an async read using a custom buffer size and causing a blocking
// read at the specified byte
fn read_async(mut decoder: Decoder,
content: &[u8],
block_at: usize)
-> String {
let content_len = content.len();
let mut ins = AsyncIo::new(content, block_at);
let mut outs = Vec::new();
loop {
match decoder.decode(&mut ins).expect("unexpected decode error: {}") {
Async::Ready(buf) => {
if buf.is_empty() {
break; // eof
}
outs.write(buf.as_ref()).expect("write buffer");
},
Async::NotReady => {
ins.block_in(content_len); // we only block once
}
};
}
String::from_utf8(outs).expect("decode String")
}
// iterate over the different ways that this async read could go.
// tests blocking a read at each byte along the content - The shotgun approach
fn all_async_cases(content: &str, expected: &str, decoder: Decoder) {
let content_len = content.len();
for block_at in 0..content_len {
let actual = read_async(decoder.clone(), content.as_bytes(), block_at);
assert_eq!(expected, &actual) //, "Failed async. Blocking at {}", block_at);
}
}
#[test]
fn test_read_length_async() {
let content = "foobar";
all_async_cases(content, content, Decoder::length(content.len() as u64));
}
#[test]
fn test_read_chunked_async() {
let content = "3\r\nfoo\r\n3\r\nbar\r\n0\r\n\r\n";
let expected = "foobar";
all_async_cases(content, expected, Decoder::chunked());
}
#[test]
fn test_read_eof_async() {
let content = "foobar";
all_async_cases(content, content, Decoder::eof());
}
}