micro_http: Import Firecracker HTTP 1.x implementation

Based on Firecracker commit 58edf03b.

We're going to use the micro_http crate to serve the cloud-hypervisor
HTTP API.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

micro_http/src/lib.rs

@@ -0,0 +1,85 @@
+// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+#![deny(missing_docs)]
+//! Minimal implementation of the [HTTP/1.0](https://tools.ietf.org/html/rfc1945)
+//! and [HTTP/1.1](https://www.ietf.org/rfc/rfc2616.txt) protocols.
+//!
+//! HTTP/1.1 has a mandatory header **Host**, but as this crate is only used
+//! for parsing MMDS requests, this header (if present) is ignored.
+//!
+//! This HTTP implementation is stateless thus it does not support chunking or
+//! compression.
+//!
+//! ## Supported Headers
+//! The **micro_http** crate has support for parsing the following **Request**
+//! headers:
+//! - Content-Length
+//! - Expect
+//! - Transfer-Encoding
+//!
+//! The **Response** does not have a public interface for adding headers, but whenever
+//! a write to the **Body** is made, the headers **ContentLength** and **MediaType**
+//! are automatically updated.
+//!
+//! ### Media Types
+//! The supported media types are:
+//! - text/plain
+//! - application/json
+//!
+//! ## Supported Methods
+//! The supported HTTP Methods are:
+//! - GET
+//! - PUT
+//! - PATCH
+//!
+//! ## Supported Status Codes
+//! The supported status codes are:
+//!
+//! - Continue - 100
+//! - OK - 200
+//! - No Content - 204
+//! - Bad Request - 400
+//! - Not Found - 404
+//! - Internal Server Error - 500
+//! - Not Implemented - 501
+//!
+//! ## Example for parsing an HTTP Request from a slice
+//! ```
+//! extern crate micro_http;
+//! use micro_http::{Request, Version};
+//!
+//! let http_request = Request::try_from(b"GET http://localhost/home HTTP/1.0\r\n\r\n").unwrap();
+//! assert_eq!(http_request.http_version(), Version::Http10);
+//! assert_eq!(http_request.uri().get_abs_path(), "/home");
+//! ```
+//!
+//! ## Example for creating an HTTP Response
+//! ```
+//! extern crate micro_http;
+//! use micro_http::{Body, Response, StatusCode, Version};
+//!
+//! let mut response = Response::new(Version::Http10, StatusCode::OK);
+//! let body = String::from("This is a test");
+//! response.set_body(Body::new(body.clone()));
+//!
+//! assert!(response.status() == StatusCode::OK);
+//! assert_eq!(response.body().unwrap(), Body::new(body));
+//! assert_eq!(response.http_version(), Version::Http10);
+//!
+//! let mut response_buf: [u8; 126] = [0; 126];
+//! assert!(response.write_all(&mut response_buf.as_mut()).is_ok());
+//! ```
+
+mod common;
+mod connection;
+mod request;
+mod response;
+use common::ascii;
+use common::headers;
+
+pub use connection::HttpConnection;
+pub use request::{Request, RequestError};
+pub use response::{Response, StatusCode};
+
+pub use common::headers::Headers;
+pub use common::{Body, Version};