Files
http_server/src/main.rs

478 lines
14 KiB
Rust

use signal_hook::{consts::*, iterator::Signals};
use std::{
collections::HashMap,
error::Error,
fs::{self},
io::{BufRead, BufReader, Write},
net::{TcpListener, TcpStream},
path::PathBuf,
process::exit,
thread,
};
#[derive(PartialEq, Eq, Debug, Copy, Clone)]
enum RequestMethods {
Null = -1, // This is only to initialise the struct
Get,
Head,
}
#[derive(Debug)]
struct StartLine {
method: RequestMethods,
target: String,
version: String,
}
impl StartLine {
pub fn new() -> Self {
Self {
method: RequestMethods::Null,
target: String::new(),
version: String::new(),
}
}
// https://datatracker.ietf.org/doc/html/rfc9110#name-methods
pub fn is_valid_method(method: &str) -> bool {
if method.trim().is_empty() {
return false;
}
// Only GET and HEAD are required, the rest is optional
["GET", "HEAD"].contains(&method.trim())
}
// TODO: make the checks less shit and actually correct
// https://datatracker.ietf.org/doc/html/rfc9112#name-request-target
pub fn is_valid_target(target: &str) -> bool {
if target.trim().is_empty() {
return false;
}
// origin-form
if target.starts_with("/") {
if target.contains("?") && target.split("?").count() != 2 {
return false;
}
return true;
}
// absolute-form
if target.starts_with("http://") {
return true;
}
// authority-form
if target.contains(":") && target.split(":").count() == 2 {
return true;
}
// asterisk-form
if target.trim() == "*" {
return true;
}
false
}
pub fn is_valid_version(version: &str) -> bool {
if version.trim().is_empty() {
return false;
}
let http_name = version.trim();
if http_name.starts_with("HTTP/") {
let version_numbers = http_name.trim_start_matches("HTTP/");
let version_numbers = version_numbers.split(".").collect::<Vec<&str>>();
if version_numbers.len() != 2 {
return false;
}
let major = match version_numbers[0].parse::<u8>() {
Ok(val) => val,
Err(_) => {
return false;
}
};
let minor = match version_numbers[1].parse::<u8>() {
Ok(val) => val,
Err(_) => {
return false;
}
};
return major <= 9 && minor <= 9;
}
false
}
}
fn parse_start_line(input: &str) -> Result<StartLine, Vec<u8>> {
let mut response_field_lines: HashMap<String, String> = HashMap::new();
let mut response_body: Vec<u8> = vec![];
let mut start_line = StartLine::new();
let vec = input.trim().split_ascii_whitespace().collect::<Vec<&str>>();
if vec.len() != 3 {
format!(
"The start-line has an incorrect amount of items. Got the value: {}",
vec.len()
)
.as_bytes()
.iter()
.for_each(|byte| response_body.push(*byte));
response_field_lines.insert(
String::from("Content-Length"),
response_body.len().to_string(),
);
response_field_lines.insert(String::from("Content-Type"), String::from("text/plain"));
return Err(response_builder(
RequestMethods::Get,
"HTTP/1.1 400 ",
Some(response_field_lines),
Some(response_body),
));
}
let method = vec[0];
let target = vec[1];
let version = vec[2];
if !StartLine::is_valid_method(method) {
return Err(response_builder(
RequestMethods::Head,
"HTTP/1.1 501 ",
None,
None,
));
}
// start_line.method will remain RequestMethods::NULL if it is not supported.
match method {
"GET" => start_line.method = RequestMethods::Get,
"HEAD" => start_line.method = RequestMethods::Head,
_ => start_line.method = RequestMethods::Null,
}
if !StartLine::is_valid_version(version) {
return Err(response_builder(
RequestMethods::Head,
"HTTP/1.1 400 ",
None,
None,
));
}
if version != "HTTP/1.1" && version != "HTTP/1.0" {
"Server only supports major version 1 of HTTP"
.as_bytes()
.iter()
.for_each(|byte| response_body.push(*byte));
response_field_lines.insert(
String::from("Content-Length"),
response_body.len().to_string(),
);
response_field_lines.insert(String::from("Content-Type"), String::from("text/plain"));
return Err(response_builder(
RequestMethods::Head,
"HTTP/1.1 505 ",
Some(response_field_lines),
Some(response_body),
));
}
start_line.version = version.to_string();
if !StartLine::is_valid_target(target) {
return Err(response_builder(
RequestMethods::Head,
"HTTP/1.1 400 ",
None,
None,
));
}
start_line.target = target.to_string();
Ok(start_line)
}
fn parse_field_lines(
reader: &mut BufReader<&mut TcpStream>,
) -> Result<HashMap<String, String>, Vec<u8>> {
let mut response_field_lines: HashMap<String, String> = HashMap::new();
let mut response_body: Vec<u8> = vec![];
let mut field_lines: HashMap<String, String> = HashMap::new();
// Read field-lines till I hit an empty line
loop {
let mut line = String::new();
reader.read_line(&mut line).unwrap();
if !line.ends_with("\r\n") {
"Lines need to end with a CRLF"
.as_bytes()
.iter()
.for_each(|byte| response_body.push(*byte));
response_field_lines.insert(
String::from("Content-Length"),
response_body.len().to_string(),
);
response_field_lines.insert(String::from("Content-Type"), String::from("text/plain"));
return Err(response_builder(
RequestMethods::Get,
"HTTP/1.1 400 ",
Some(response_field_lines),
Some(response_body),
));
}
if line.trim().is_empty() {
break;
}
let field_line = match line.split_once(":") {
Some(val) => val,
None => {
"Invalid field-line"
.as_bytes()
.iter()
.for_each(|byte| response_body.push(*byte));
response_field_lines.insert(
String::from("Content-Length"),
response_body.len().to_string(),
);
response_field_lines
.insert(String::from("Content-Type"), String::from("text/plain"));
return Err(response_builder(
RequestMethods::Get,
"HTTP/1.1 400 ",
Some(response_field_lines),
Some(response_body),
));
}
};
field_lines.insert(field_line.0.to_owned(), field_line.1.trim().to_owned());
}
if !field_lines.contains_key(&String::from("Host")) {
"field-line with key HOST is missing"
.as_bytes()
.iter()
.for_each(|byte| response_body.push(*byte));
response_field_lines.insert(
String::from("Content-Length"),
response_body.len().to_string(),
);
response_field_lines.insert(String::from("Content-Type"), String::from("text/plain"));
return Err(response_builder(
RequestMethods::Get,
"HTTP/1.1 400 ",
Some(response_field_lines),
Some(response_body),
));
}
Ok(field_lines)
}
fn response_builder(
method: RequestMethods,
status_line: &str,
field_lines: Option<HashMap<String, String>>,
body: Option<Vec<u8>>,
) -> Vec<u8> {
let mut response: Vec<u8> = vec![];
status_line
.as_bytes()
.iter()
.for_each(|byte| response.push(*byte));
response.push(b'\r');
response.push(b'\n');
if let Some(val) = field_lines {
for field_line in val.iter() {
field_line
.0
.as_bytes()
.iter()
.for_each(|byte| response.push(*byte));
response.push(b':');
response.push(b' ');
field_line
.1
.as_bytes()
.iter()
.for_each(|byte| response.push(*byte));
response.push(b'\r');
response.push(b'\n');
}
}
// Mandatory empty line between header and body
response.push(b'\r');
response.push(b'\n');
if method != RequestMethods::Head {
if let Some(val) = body {
val.iter().for_each(|byte| response.push(*byte));
response.push(b'\r');
response.push(b'\n');
}
}
response
}
fn try_get_file(start_line: &StartLine, _field_lines: &HashMap<String, String>) -> Vec<u8> {
let mut response_field_lines: HashMap<String, String> = HashMap::new();
let mut response_body: Vec<u8> = vec![];
let path: PathBuf = match start_line.target.as_str() {
"/" => PathBuf::from("/www/index.html"),
_ => PathBuf::from(format!("/www{}", start_line.target)),
};
// TODO: Check if wanted file is contained in the optional Accept field-line
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Accept for reference
// let mime_type = match MimeGuess::from_path(&path).first_raw() {
// Some(val) => val,
// _ => {
// return response_builder(RequestMethods::HEAD, "HTTP/1.1 500 ", None, None);
// }
// }
match fs::read(&path) {
Ok(val) => {
val.iter().for_each(|byte| response_body.push(*byte));
response_field_lines.insert(
String::from("Content-Length"),
response_body.len().to_string(),
);
let mime_type = mime_guess::from_path(&path)
.first_raw()
.expect("Could not guess mime-type from path");
response_field_lines.insert(String::from("Content-Type"), mime_type.to_string());
response_builder(
start_line.method,
"HTTP/1.1 200 ",
Some(response_field_lines),
Some(response_body),
)
}
Err(_) => response_builder(start_line.method, "HTTP/1.1 404 ", None, None),
}
}
fn handle_request(mut stream: TcpStream) -> Result<(), Box<dyn Error>> {
let mut line = String::new();
let mut reader = BufReader::new(&mut stream);
let mut response_field_lines: HashMap<String, String> = HashMap::new();
let mut response_body: Vec<u8> = vec![];
// Request can have one or many empty lines preceding the start-line and I will ignore these
loop {
if reader.read_line(&mut line)? > 2 && line != "\r\n" {
break;
}
}
if line.ends_with(" ") {
"There is whitespace between the start-line and the first field-line"
.as_bytes()
.iter()
.for_each(|byte| response_body.push(*byte));
response_field_lines.insert(
String::from("Content-Length"),
response_body.len().to_string(),
);
response_field_lines.insert(String::from("Content-Type"), String::from("text/plain"));
let response = response_builder(
RequestMethods::Get,
"HTTP/1.1 400 ",
Some(response_field_lines),
Some(response_body),
);
stream.write_all(&response)?;
return Ok(());
}
let start_line = match parse_start_line(&line) {
Ok(val) => val,
Err(response) => {
stream.write_all(&response)?;
return Ok(());
}
};
dbg!(&start_line);
let field_lines = match parse_field_lines(&mut reader) {
Ok(val) => val,
Err(response) => {
stream.write_all(&response)?;
return Ok(());
}
};
dbg!(&field_lines);
// let mut request_body: Vec<u8> = vec![];
// reader.read_to_end(&mut request_body)?;
let response = match start_line.target.as_str() {
// For docker healtcheck. If the server can properly respond, then it must be healthy.
"/server-health" => response_builder(RequestMethods::Head, "HTTP/1.1 200 ", None, None),
"/server-stats" => response_builder(start_line.method, "HTTP/1.1 404 ", None, None),
"/server-info" => response_builder(start_line.method, "HTTP/1.1 404 ", None, None),
_ => try_get_file(&start_line, &field_lines),
};
stream.write_all(&response)?;
Ok(())
}
fn main() -> Result<(), Box<dyn Error>> {
let mut signals = Signals::new([SIGINT, SIGTERM])?;
// TODO: Gracefully shutdown server
thread::spawn(move || {
if let Some(sig) = signals.forever().next() {
println!("Received signal {:?}", sig);
println!("Shutting down");
exit(1);
}
});
let listener = TcpListener::bind("0.0.0.0:8080")?;
println!("Server started");
for stream in listener.incoming() {
let stream = stream?;
handle_request(stream)?;
}
Ok(())
}