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extern crate iron;
#[macro_use] extern crate log;
use std::collections::HashSet;
use iron::{Request, Response, IronResult, AroundMiddleware, Handler};
use iron::method::Method;
use iron::status;
use iron::headers;
pub struct CorsMiddleware {
allowed_hosts: Option<HashSet<String>>,
}
impl CorsMiddleware {
pub fn with_whitelist(allowed_hosts: HashSet<String>) -> Self {
CorsMiddleware {
allowed_hosts: Some(allowed_hosts),
}
}
pub fn with_allow_any() -> Self {
CorsMiddleware {
allowed_hosts: None,
}
}
}
impl AroundMiddleware for CorsMiddleware {
fn around(self, handler: Box<Handler>) -> Box<Handler> {
match self.allowed_hosts {
Some(allowed_hosts) => Box::new(CorsHandlerWhitelist {
handler: handler,
allowed_hosts: allowed_hosts,
}),
None => Box::new(CorsHandlerAllowAny {
handler: handler,
}),
}
}
}
struct CorsHandlerWhitelist {
handler: Box<Handler>,
allowed_hosts: HashSet<String>,
}
struct CorsHandlerAllowAny {
handler: Box<Handler>,
}
impl CorsHandlerWhitelist {
fn add_cors_header(&self, headers: &mut headers::Headers, origin: &headers::Origin) {
let header = format_cors_origin(origin);
headers.set(headers::AccessControlAllowOrigin::Value(header));
}
fn add_cors_preflight_headers(&self,
headers: &mut headers::Headers,
origin: &headers::Origin,
acrm: &headers::AccessControlRequestMethod,
acrh: Option<&headers::AccessControlRequestHeaders>) {
self.add_cors_header(headers, origin);
headers.set(headers::AccessControlAllowMethods(vec!(acrm.0.clone())));
if let Some(acrh) = acrh {
headers.set(headers::AccessControlAllowHeaders(acrh.0.clone()));
}
}
fn process_possible_preflight(&self, req: &mut Request, origin: headers::Origin) -> IronResult<Response> {
let may_process = self.allowed_hosts.contains(&format_cors_origin(&origin));
if !may_process {
warn!("Got disallowed preflight CORS request from {}", &origin.host.hostname);
return Ok(Response::with((status::BadRequest, "Invalid CORS request: Origin not allowed")));
}
{
let acrm = req.headers.get::<headers::AccessControlRequestMethod>();
if let Some(acrm) = acrm {
let acrh = req.headers.get::<headers::AccessControlRequestHeaders>();
let mut response = Response::with((status::Ok, ""));
self.add_cors_preflight_headers(&mut response.headers, &origin, acrm, acrh);
return Ok(response);
}
}
return self.process_possible_cors_request(req, origin)
}
fn process_possible_cors_request(&self, req: &mut Request, origin: headers::Origin) -> IronResult<Response> {
let may_process = self.allowed_hosts.contains(&format_cors_origin(&origin));
if may_process {
self.handler.handle(req)
.map(|mut res| { self.add_cors_header(&mut res.headers, &origin); res })
.map_err(|mut err| { self.add_cors_header(&mut err.response.headers, &origin); err })
} else {
warn!("Got disallowed CORS request from {}", &origin.host.hostname);
Ok(Response::with((status::BadRequest, "Invalid CORS request: Origin not allowed")))
}
}
}
impl Handler for CorsHandlerWhitelist {
fn handle(&self, req: &mut Request) -> IronResult<Response> {
let origin = match req.headers.get::<headers::Origin>().cloned() {
Some(o) => o,
None => {
return self.handler.handle(req);
}
};
match req.method {
Method::Options => self.process_possible_preflight(req, origin),
_ => self.process_possible_cors_request(req, origin),
}
}
}
impl CorsHandlerAllowAny {
fn add_cors_header(&self, headers: &mut headers::Headers) {
headers.set(headers::AccessControlAllowOrigin::Any);
}
fn add_cors_preflight_headers(&self,
headers: &mut headers::Headers,
acrm: &headers::AccessControlRequestMethod,
acrh: Option<&headers::AccessControlRequestHeaders>) {
self.add_cors_header(headers);
headers.set(headers::AccessControlAllowMethods(vec!(acrm.0.clone())));
if let Some(acrh) = acrh {
headers.set(headers::AccessControlAllowHeaders(acrh.0.clone()));
}
}
fn process_possible_preflight(&self, req: &mut Request) -> IronResult<Response> {
{
let acrm = req.headers.get::<headers::AccessControlRequestMethod>();
if let Some(acrm) = acrm {
let acrh = req.headers.get::<headers::AccessControlRequestHeaders>();
let mut response = Response::with((status::Ok, ""));
self.add_cors_preflight_headers(&mut response.headers, acrm, acrh);
return Ok(response);
}
}
return self.process_possible_cors_request(req)
}
fn process_possible_cors_request(&self, req: &mut Request) -> IronResult<Response> {
self.handler.handle(req)
.map(|mut res| { self.add_cors_header(&mut res.headers); res })
.map_err(|mut err| { self.add_cors_header(&mut err.response.headers); err })
}
}
impl Handler for CorsHandlerAllowAny {
fn handle(&self, req: &mut Request) -> IronResult<Response> {
match req.headers.get::<headers::Origin>() {
None => {
self.handler.handle(req)
},
Some(_) => {
match req.method {
Method::Options => self.process_possible_preflight(req),
_ => self.process_possible_cors_request(req),
}
},
}
}
}
fn format_cors_origin(origin: &headers::Origin) -> String {
match origin.host.port {
Some(port) => format!("{}://{}:{}", &origin.scheme, &origin.host.hostname, &port),
None => format!("{}://{}", &origin.scheme, &origin.host.hostname),
}
}