fix buffer in PreambleRetriever

Renamed ServerMessage and ClientMessage to respectively ResponseMessage
and RequestMessage to make it more clear.

client.py

@@ -4,18 +4,20 @@ import logging
 import sys
 
 from client import command as cmd
+from httplib.exceptions import UnhandledHTTPCode
 
 
 def main():
     parser = argparse.ArgumentParser(description='HTTP Client')
     parser.add_argument("--verbose", "-v", action='count', default=0, help="Increase verbosity level of logging")
     parser.add_argument("--command", "-c", help="HEAD, GET, PUT or POST", default="GET")
-    parser.add_argument("--port", "-p", help="The port used to connect with the server", default=80)
+    parser.add_argument("--port", "-p", help="The port used to connect with the server", default=80, type=int)
     parser.add_argument("URI", help="The URI to connect to")
 
     arguments = parser.parse_args()
 
-    logging.basicConfig(level=logging.ERROR - (10 * arguments.verbose), format="[%(levelname)s] %(message)s")
+    # Setup logging
+    logging.basicConfig(level=logging.INFO - (10 * arguments.verbose), format="[%(levelname)s] %(message)s")
     logging.debug("Arguments: %s", arguments)
 
     command = cmd.create(arguments.command, arguments.URI, arguments.port)
@@ -24,7 +26,10 @@ def main():
 
 try:
     main()
+except UnhandledHTTPCode as e:
+    logging.info(f"[{e.status_code}] {e.cause}:\r\n{e.headers}")
+    sys.exit(2)
 except Exception as e:
-    print("[ABRT] Internal error: " + str(e), file=sys.stderr)
+    logging.info("[ABRT] Internal error: %s", e)
     logging.debug("Internal error", exc_info=e)
-    sys.exit(70)
+    sys.exit(1)

client/command.py

@@ -1,13 +1,12 @@
 import logging
 from abc import ABC, abstractmethod
-from typing import Dict, Tuple
-from urllib.parse import urlparse
+from typing import Dict
 
 from client.httpclient import HTTPClient
 from httplib import parser
-from httplib.exceptions import InvalidResponse, InvalidStatusLine, UnsupportedEncoding
+from httplib.exceptions import InvalidResponse, InvalidStatusLine, UnsupportedEncoding, UnsupportedProtocol
 from httplib.httpsocket import FORMAT
-from httplib.message import ClientMessage as Message
+from httplib.message import ResponseMessage as Message
 from httplib.retriever import PreambleRetriever
 
 sockets: Dict[str, HTTPClient] = {}
@@ -21,7 +20,7 @@ def create(method: str, url: str, port):
     @param port: The port for the command
     """
 
-    uri = parser.get_uri(url)
+    uri = parser.uri_from_url(url)
     if method == "GET":
         return GetCommand(uri, port)
     elif method == "HEAD":
@@ -38,17 +37,35 @@ class AbstractCommand(ABC):
     """
     A class representing the command for sending an HTTP request.
     """
-    uri: str
-    host: str
-    path: str
-    port: int
-    sub_request: bool
+    _uri: str
+    _host: str
+    _path: str
+    _port: int
 
     def __init__(self, uri: str, port):
         self.uri = uri
-        self.host, _, self.path = parser.parse_uri(uri)
-        self.port = int(port)
-        self.sub_request = False
+        self._port = int(port)
+
+    @property
+    def uri(self):
+        return self._uri
+
+    @uri.setter
+    def uri(self, value):
+        self._uri = value
+        self._host, self._port, self._path = parser.parse_uri(value)
+
+    @property
+    def host(self):
+        return self._host
+
+    @property
+    def path(self):
+        return self._path
+
+    @property
+    def port(self):
+        return self._port
 
     @property
     @abstractmethod
@@ -61,22 +78,24 @@ class AbstractCommand(ABC):
 
         @param sub_request: If this execution is in function of a prior command.
         """
-        self.sub_request = sub_request
-        (host, path) = self.parse_uri()
 
-        client = sockets.get(host)
+        client = sockets.get(self.host)
 
         if client and client.is_closed():
             sockets.pop(self.host)
             client = None
 
         if not client:
-            client = HTTPClient(host)
-            client.conn.connect((host, self.port))
-            sockets[host] = client
+            logging.info("Connecting to %s", self.host)
+            client = HTTPClient(self.host)
+            client.conn.connect((self.host, self.port))
+            logging.info("Connected.")
+            sockets[self.host] = client
+        else:
+            logging.info("Reusing socket for %s", self.host)
 
-        message = f"{self.method} {path} HTTP/1.1\r\n"
-        message += f"Host: {host}:{self.port}\r\n"
+        message = f"{self.method} {self.path} HTTP/1.1\r\n"
+        message += f"Host: {self.host}:{self.port}\r\n"
         message += "Accept: */*\r\n"
         message += "Accept-Encoding: identity\r\n"
         encoded_msg = self._build_message(message)
@@ -90,73 +109,51 @@ class AbstractCommand(ABC):
         try:
             self._await_response(client)
         except InvalidResponse as e:
-            logging.debug("Internal error: Response could not be parsed", exc_info=e)
-            return
+            logging.error("Response could not be parsed")
+            logging.debug("", exc_info=e)
         except InvalidStatusLine as e:
-            logging.debug("Internal error: Invalid status-line in response", exc_info=e)
-            return
+            logging.error("Invalid status-line in response")
+            logging.debug("", exc_info=e)
         except UnsupportedEncoding as e:
-            logging.debug("Internal error: Unsupported encoding in response", exc_info=e)
+            logging.error("Unsupported encoding in response")
+            logging.debug("", exc_info=e)
+        except UnsupportedProtocol as e:
+            logging.error("Unsupported protocol: %s", e.protocol)
+            logging.debug("", exc_info=e)
         finally:
             if not sub_request:
                 client.close()
 
+    def _get_preamble(self, client):
+        """
+        Returns the preamble (start-line and headers) of the response of this command.
+        @param client: the client object to retrieve from
+        @return: A Message object containing the HTTP-version, status code, status message, headers and buffer
+        """
+        retriever = PreambleRetriever(client)
+        lines = retriever.retrieve()
+        (version, status, msg) = parser.parse_status_line(next(lines))
+        headers = parser.parse_headers(lines)
+
+        buffer = retriever.buffer
+        logging.debug("---response begin---\r\n%s---response end---", "".join(buffer))
+
+        return Message(version, status, msg, headers, buffer)
+
     def _await_response(self, client):
         """
         Simple response method.
 
         Receives the response and prints to stdout.
         """
-        while True:
-            line = client.read_line()
-            print(line, end="")
-            if line in ("\r\n", "\n", ""):
-                break
+
+        msg = self._get_preamble(client)
+
+        print("".join(msg.raw))
 
     def _build_message(self, message: str) -> bytes:
         return (message + "\r\n").encode(FORMAT)
 
-    def parse_uri(self):
-        """
-        Parses the URI and returns the hostname and path.
-        @return: A tuple of the hostname and path.
-        """
-        parsed = urlparse(self.uri)
-
-        # If there is no netloc, the url is invalid, so prepend `//` and try again
-        if parsed.netloc == "":
-            parsed = urlparse("http://" + self.uri)
-
-        host = parsed.netloc
-        path = parsed.path
-        if len(path) == 0 or path[0] != '/':
-            path = "/" + path
-
-        port_pos = host.find(":")
-        if port_pos >= 0:
-            host = host[:port_pos]
-
-        return host, path
-
-
-class AbstractWithBodyCommand(AbstractCommand, ABC):
-    """
-    The building block for creating an HTTP message for an HTTP method with a body (POST and PUT).
-    """
-
-    def _build_message(self, message: str) -> bytes:
-        body = input(f"Enter {self.method} data: ").encode(FORMAT)
-        print()
-
-        message += "Content-Type: text/plain\r\n"
-        message += f"Content-Length: {len(body)}\r\n"
-        message += "\r\n"
-        message = message.encode(FORMAT)
-        message += body
-        message += b"\r\n"
-
-        return message
-
 
 class HeadCommand(AbstractCommand):
     """
@@ -183,30 +180,35 @@ class GetCommand(AbstractCommand):
     def method(self):
         return "GET"
 
-    def _get_preamble(self, client):
-        """
-        Returns the preamble (start-line and headers) of the response of this command.
-        @param client: the client object to retrieve from
-        @return: A Message object containing the HTTP-version, status code, status message, headers and buffer
-        """
-        retriever = PreambleRetriever(client)
-        lines = retriever.retrieve()
-        (version, status, msg) = parser.parse_status_line(next(lines))
-        headers = parser.parse_headers(lines)
-
-        buffer = retriever.buffer
-        logging.debug("---response begin---\r\n%s---response end---", "".join(buffer))
-
-        return Message(version, status, msg, headers, buffer)
-
     def _await_response(self, client):
         """
         Handles the response of this command.
         """
         msg = self._get_preamble(client)
 
-        from client import response_handler
-        self.filename = response_handler.handle(client, msg, self, self.dir)
+        from client import responsehandler
+        self.filename = responsehandler.handle(client, msg, self, self.dir)
+
+
+class AbstractWithBodyCommand(AbstractCommand, ABC):
+    """
+    The building block for creating an HTTP message for an HTTP method with a body (POST and PUT).
+    """
+
+    def _build_message(self, message: str) -> bytes:
+        input_line = input(f"Enter {self.method} data: ")
+        input_line += "\r\n"
+        body = input_line.encode(FORMAT)
+        print()
+
+        message += "Content-Type: text/plain\r\n"
+        message += f"Content-Length: {len(body)}\r\n"
+        message += "\r\n"
+        message = message.encode(FORMAT)
+        message += body
+        message += b"\r\n"
+
+        return message
 
 
 class PostCommand(AbstractWithBodyCommand):

client/htmlparser.py

@@ -1,6 +0,0 @@
-from bs4 import BeautifulSoup
-
-
-class HTMLParser:
-    def __init__(self, soup: BeautifulSoup):
-        pass

client/httpclient.py

@@ -4,12 +4,23 @@ from httplib.httpsocket import HTTPSocket, InvalidResponse
 
 
 class HTTPClient(HTTPSocket):
+    """
+    Wrapper class for a socket. Represents a client which connects to a server.
+    """
+
     host: str
 
     def __init__(self, host: str):
-        super().__init__(socket.socket(socket.AF_INET, socket.SOCK_STREAM), host)
+        super().__init__(socket.socket(socket.AF_INET, socket.SOCK_STREAM))
+        self.host = host
 
     def read_line(self):
+        """
+        Reads the next line decoded as `httpsocket.FORMAT`
+
+        @return: the decoded next line retrieved from the socket
+        @raise InvalidResponse: If the next line couldn't be decoded, but was expected to
+        """
         try:
             return super().read_line()
         except UnicodeDecodeError:

client/responsehandler.py

@@ -7,9 +7,9 @@ from urllib.parse import urlsplit, unquote
 from client.command import AbstractCommand, GetCommand
 from client.httpclient import HTTPClient
 from httplib import parser
-from httplib.exceptions import InvalidResponse
+from httplib.exceptions import InvalidResponse, UnhandledHTTPCode, UnsupportedProtocol
 from httplib.httpsocket import FORMAT
-from httplib.message import ClientMessage as Message
+from httplib.message import ResponseMessage as Message
 from httplib.retriever import Retriever
 
 BASE_REGEX = re.compile(r"<\s*base[^>]*\shref\s*=\s*['\"]([^\"']+)['\"][^>]*>", re.M | re.I)
@@ -17,6 +17,14 @@ IMG_REGEX = re.compile(r"<\s*img[^>]*\ssrc\s*=\s*['\"]([^\"']+)['\"][^>]*>", re.
 
 
 def handle(client: HTTPClient, msg: Message, command: AbstractCommand, directory=None):
+    """
+    Handle the response of the request message
+
+    @param client: the client which sent the request.
+    @param msg: the response message
+    @param command: the command of the sent request-message
+    @param directory: the directory to download the response to (if available)
+    """
     handler = BasicResponseHandler(client, msg, command)
     retriever = handler.handle()
 
@@ -33,6 +41,9 @@ def handle(client: HTTPClient, msg: Message, command: AbstractCommand, directory
 
 
 class ResponseHandler(ABC):
+    """
+    Helper class for handling response messages.
+    """
     client: HTTPClient
     retriever: Retriever
     msg: Message
@@ -46,12 +57,15 @@ class ResponseHandler(ABC):
 
     @abstractmethod
     def handle(self):
+        """
+        Handle the response.
+        """
         pass
 
 
 class BasicResponseHandler(ResponseHandler):
     """
-    Response handler which throws away the body and only shows the headers.
+    Response handler which will handle redirects and other HTTP status codes.
     In case of a redirect, it will process it and pass it to the appropriate response handler.
     """
 
@@ -67,7 +81,7 @@ class BasicResponseHandler(ResponseHandler):
         for line in self.retriever.retrieve():
             try:
                 logging.debug("%s", line.decode(FORMAT))
-            except Exception:
+            except UnicodeDecodeError:
                 logging.debug("%r", line)
 
         logging.debug("] done.")
@@ -77,8 +91,7 @@ class BasicResponseHandler(ResponseHandler):
 
         if self.msg.status == 101:
             # Switching protocols is not supported
-            print("".join(self.msg.raw), end="")
-            return
+            raise UnhandledHTTPCode(self.msg.status, "".join(self.msg.raw), "Switching protocols is not supported")
 
         if 200 <= self.msg.status < 300:
             return self.retriever
@@ -87,19 +100,17 @@ class BasicResponseHandler(ResponseHandler):
             # Redirect
             self._skip_body()
             return self._handle_redirect()
+
         if 400 <= self.msg.status < 600:
             self._skip_body()
             # Dump headers and exit with error
-            if not self.cmd.sub_request:
-                print("".join(self.msg.raw), end="")
-            return None
+            raise UnhandledHTTPCode(self.msg.status, "".join(self.msg.raw), self.msg.msg)
 
         return None
 
     def _handle_redirect(self):
         if self.msg.status == 304:
-            print("".join(self.msg.raw), end="")
-            return None
+            raise UnhandledHTTPCode(self.msg.status, "".join(self.msg.raw), self.msg.msg)
 
         location = self.msg.headers.get("location")
         if not location or len(location.strip()) == 0:
@@ -111,10 +122,9 @@ class BasicResponseHandler(ResponseHandler):
             raise InvalidResponse("Invalid location")
 
         if not parsed_location.scheme == "http":
-            raise InvalidResponse("Only http is supported")
+            raise UnsupportedProtocol(parsed_location.scheme)
 
         self.cmd.uri = location
-        self.cmd.host, self.cmd.port, self.cmd.path = parser.parse_uri(location)
 
         if self.msg.status == 301:
             logging.info("Status 301. Closing socket [%s]", self.cmd.host)
@@ -177,11 +187,11 @@ class DownloadHandler(ResponseHandler, ABC):
 
 class RawDownloadHandler(DownloadHandler):
 
-    def __init__(self, retriever: Retriever, client: HTTPClient, msg: Message, cmd: AbstractCommand, dir=None):
-        super().__init__(retriever, client, msg, cmd, dir)
+    def __init__(self, retriever: Retriever, client: HTTPClient, msg: Message, cmd: AbstractCommand, directory=None):
+        super().__init__(retriever, client, msg, cmd, directory)
 
     def handle(self) -> str:
-        logging.debug("Retrieving payload")
+        logging.info("Saving to '%s'", parser.get_relative_save_path(self.path))
         file = open(self.path, "wb")
 
         for buffer in self.retriever.retrieve():
@@ -211,20 +221,20 @@ class HTMLDownloadHandler(DownloadHandler):
         os.remove(tmp_path)
         return self.path
 
-    def _download_images(self, tmp_filename, target_filename, charset=FORMAT):
+    def _download_images(self, tmp_path, target_path, charset=FORMAT):
         """
-        Downloads images referenced in the html of `tmp_filename` and replaces the references in the html
+        Download images referenced in the html of `tmp_filename` and replaces the references in the html
         and writes it to `target_filename`.
-        @param tmp_filename: the path to the temporary html file
-        @param target_filename: the path for the final html fil
+        @param tmp_path: the path to the temporary html file
+        @param target_path: the path for the final html file
         @param charset: the charset to decode `tmp_filename`
         """
 
         try:
-            fp = open(tmp_filename, "r", encoding=charset)
+            fp = open(tmp_path, "r", encoding=charset)
             html = fp.read()
-        except UnicodeDecodeError:
-            fp = open(tmp_filename, "r", encoding=FORMAT, errors="replace")
+        except UnicodeDecodeError or LookupError:
+            fp = open(tmp_path, "r", encoding=FORMAT, errors="replace")
             html = fp.read()
 
         fp.close()
@@ -237,6 +247,7 @@ class HTMLDownloadHandler(DownloadHandler):
         processed = {}
         to_replace = []
 
+        # Find all <img> tags, and the urls from the corresponding `src` fields
         for m in IMG_REGEX.finditer(html):
             url_start = m.start(1)
             url_end = m.end(1)
@@ -245,14 +256,12 @@ class HTMLDownloadHandler(DownloadHandler):
             try:
                 if len(target) == 0:
                     continue
+
                 if target in processed:
+                    # url is already processed
                     new_url = processed.get(target)
                 else:
                     new_url = self.__download_image(target, base_url)
-                    if not new_url:
-                        # Image failed to download
-                        continue
-
                     processed[target] = new_url
 
                 if new_url:
@@ -260,13 +269,18 @@ class HTMLDownloadHandler(DownloadHandler):
                     to_replace.append((url_start, url_end, local_path))
 
             except Exception as e:
-                logging.error("Failed to download image: %s, skipping...", target, exc_info=e)
+                logging.error("Failed to download image: %s, skipping...", target)
+                logging.debug("", exc_info=e)
+                processed[target] = None
 
+        # reverse the list so urls at the bottom of the html file are processed first.
+        # Otherwise, our start and end positions won't be correct.
         to_replace.reverse()
         for (start, end, path) in to_replace:
             html = html[:start] + path + html[end:]
 
-        with open(target_filename, 'w', encoding=FORMAT) as file:
+        logging.info("Saving HTML to '%s'", parser.get_relative_save_path(target_path))
+        with open(target_path, 'w', encoding=FORMAT) as file:
             file.write(html)
 
     def __download_image(self, img_src, base_url):
@@ -280,6 +294,7 @@ class HTMLDownloadHandler(DownloadHandler):
         parsed = urlsplit(img_src)
         img_src = parser.urljoin(base_url, img_src)
 
+        # Check if the port of the image sh
         if parsed.hostname is None or parsed.hostname == self.cmd.host:
             port = self.cmd.port
         elif ":" in parsed.netloc:

httplib/exceptions.py

@@ -1,109 +1,163 @@
 class HTTPException(Exception):
-    """ Base class for HTTP exceptions """
+    """
+    Base class for HTTP exceptions
+    """
+
+
+class UnhandledHTTPCode(Exception):
+    """
+    Exception thrown if HTTP codes are not further processed.
+    """
+    status_code: str
+    headers: str
+    cause: str
+
+    def __init__(self, status, headers, cause):
+        self.status_code = status
+        self.headers = headers
+        self.cause = cause
 
 
 class InvalidResponse(HTTPException):
-    """ Response message cannot be parsed """
+    """
+    Response message cannot be parsed
+    """
 
-    def __init(self, message):
+    def __init__(self, message):
         self.message = message
 
 
 class InvalidStatusLine(HTTPException):
-    """ Response status line is invalid """
+    """
+    Response status line is invalid
+    """
 
-    def __init(self, line):
+    def __init__(self, line):
         self.line = line
 
 
 class UnsupportedEncoding(HTTPException):
-    """ Encoding not supported """
+    """
+    Encoding not supported
+    """
 
-    def __init(self, enc_type, encoding):
+    def __init__(self, enc_type, encoding):
         self.enc_type = enc_type
         self.encoding = encoding
 
 
+class UnsupportedProtocol(HTTPException):
+    """
+    Protocol is not supported
+    """
+
+    def __init__(self, protocol):
+        self.protocol = protocol
+
+
 class IncompleteResponse(HTTPException):
-    def __init(self, cause):
+    def __init__(self, cause):
         self.cause = cause
 
 
-class HTTPServerException(Exception):
-    """ Base class for HTTP Server exceptions """
+class HTTPServerException(HTTPException):
+    """
+    Base class for HTTP Server exceptions
+    """
     status_code: str
     message: str
-    body: str
     arg: str
 
-    def __init__(self, arg, body=""):
+    def __init__(self, arg):
         self.arg = arg
-        self.body = body
 
 
 class HTTPServerCloseException(HTTPServerException):
-    """ When thrown, the connection should be closed """
+    """
+    When raised, the connection should be closed
+    """
 
 
 class BadRequest(HTTPServerCloseException):
-    """ Malformed HTTP request"""
+    """
+    Malformed HTTP request
+    """
     status_code = 400
     message = "Bad Request"
 
 
 class Forbidden(HTTPServerException):
-    """ Request not allowed """
+    """
+    Request not allowed
+    """
     status_code = 403
     message = "Forbidden"
 
 
 class NotFound(HTTPServerException):
-    """ Resource not found """
+    """
+    Resource not found
+    """
     status_code = 404
     message = "Not Found"
 
 
 class MethodNotAllowed(HTTPServerException):
-    """ Method is not allowed """
+    """
+    Method is not allowed
+    """
     status_code = 405
     message = "Method Not Allowed"
 
-    def __init(self, allowed_methods):
+    def __init__(self, allowed_methods):
         self.allowed_methods = allowed_methods
 
 
 class InternalServerError(HTTPServerCloseException):
-    """ Internal Server Error """
+    """
+    Internal Server Error
+    """
     status_code = 500
     message = "Internal Server Error"
 
 
 class NotImplemented(HTTPServerException):
-    """ Functionality not implemented """
+    """
+    Functionality not implemented
+    """
     status_code = 501
     message = "Not Implemented"
 
 
 class HTTPVersionNotSupported(HTTPServerCloseException):
-    """ The server does not support the major version HTTP used in the request message """
+    """
+    The server does not support the major version HTTP used in the request message
+    """
     status_code = 505
     message = "HTTP Version Not Supported"
 
 
 class Conflict(HTTPServerException):
-    """ Conflict in the current state of the target resource """
+    """
+    Conflict in the current state of the target resource
+    """
     status_code = 409
     message = "Conflict"
 
 
 class NotModified(HTTPServerException):
-    """ Requested resource was not modified """
+    """
+    Requested resource was not modified
+    """
     status_code = 304
     message = "Not Modified"
 
 
 class InvalidRequestLine(BadRequest):
-    """ Request start-line is invalid """
+    """
+    Request start-line is invalid
+    """
 
-    def __init__(self, line):
+    def __init__(self, line, arg):
+        super().__init__(arg)
         self.request_line = line

httplib/httpsocket.py

@@ -1,10 +1,7 @@
-import logging
 import socket
 from io import BufferedReader
 from typing import Tuple
 
-from httplib.exceptions import BadRequest
-
 BUFSIZE = 4096
 TIMEOUT = 3
 FORMAT = "UTF-8"
@@ -12,13 +9,20 @@ MAXLINE = 4096
 
 
 class HTTPSocket:
-    host: str
+    """
+    Wrapper class for a socket. Represents an HTTP connection.
+
+    This class adds helper methods to read the underlying socket as a file.
+    """
     conn: socket.socket
-    file: Tuple[BufferedReader, None]
+    file: BufferedReader
 
-    def __init__(self, conn: socket.socket, host: str):
+    def __init__(self, conn: socket.socket):
+        """
+        Initialize an HTTPSocket with the given socket and host.
+        @param conn: the socket object
+        """
 
-        self.host = host
         self.conn = conn
         self.conn.settimeout(TIMEOUT)
         self.conn.setblocking(True)
@@ -78,11 +82,15 @@ class HTTPSocket:
 
 
 class HTTPException(Exception):
-    """ Base class for HTTP exceptions """
+    """
+    Base class for HTTP exceptions
+    """
 
 
 class InvalidResponse(HTTPException):
-    """ Response message cannot be parsed """
+    """
+    Response message cannot be parsed
+    """
 
     def __init(self, message):
         self.message = message

httplib/message.py

@@ -6,7 +6,7 @@ from urllib.parse import SplitResult
 class Message(ABC):
     version: str
     headers: Dict[str, str]
-    raw: str
+    raw: [str]
     body: bytes
 
     def __init__(self, version: str, headers: Dict[str, str], raw=None, body: bytes = None):
@@ -16,7 +16,7 @@ class Message(ABC):
         self.body = body
 
 
-class ClientMessage(Message):
+class ResponseMessage(Message):
     status: int
     msg: str
 
@@ -26,7 +26,7 @@ class ClientMessage(Message):
         self.msg = msg
 
 
-class ServerMessage(Message):
+class RequestMessage(Message):
     method: str
     target: SplitResult
 

httplib/parser.py

@@ -1,8 +1,13 @@
 import logging
+import os
+import pathlib
 import re
 import urllib
+from datetime import datetime
+from time import mktime
 from typing import Dict
 from urllib.parse import urlparse, urlsplit
+from wsgiref.handlers import format_date_time
 
 from httplib.exceptions import InvalidStatusLine, InvalidResponse, BadRequest, InvalidRequestLine
 from httplib.httpsocket import FORMAT
@@ -56,7 +61,7 @@ def parse_status_line(line: str):
 
 def parse_request_line(line: str):
     """
-    Parses the specified line as and HTTP request-line.
+    Parses the specified line as an HTTP request-line.
     Returns the method, target as ParseResult and HTTP version from the request-line.
 
     @param line: the request-line to be parsed
@@ -67,7 +72,7 @@ def parse_request_line(line: str):
 
     split = list(filter(None, line.rstrip().split(" ", 2)))
     if len(split) < 3:
-        raise InvalidRequestLine(line)
+        raise InvalidRequestLine(line, "missing argument in request-line")
 
     method, target, version = split
     if method not in ("CONNECT", "DELETE", "GET", "HEAD", "OPTIONS", "POST", "PUT", "TRACE"):
@@ -78,13 +83,19 @@ def parse_request_line(line: str):
         raise BadRequest(f"Invalid HTTP-version: {version}")
 
     if len(target) == "":
-        raise BadRequest()
+        raise BadRequest("request-target not specified")
     parsed_target = urlsplit(target)
 
     return method, parsed_target, version.split("/")[1]
 
 
 def parse_headers(lines):
+    """
+    Parses the lines from the `lines` iterator as headers.
+
+    @param lines: iterator to retrieve the lines from.
+    @return: A dictionary with header as key and value as value.
+    """
     headers = []
 
     try:
@@ -97,7 +108,7 @@ def parse_headers(lines):
                 break
 
         while True:
-            if line in ("\r\n", "\n", ""):
+            if line in ("\r\n", "\r", "\n", ""):
                 break
 
             if line[0].isspace():
@@ -127,17 +138,21 @@ def parse_headers(lines):
 def check_next_header(headers, next_header: str, next_value: str):
     if next_header == "content-length":
         if "content-length" in headers:
-            logging.error("Multiple content-length headers specified")
-            raise InvalidResponse()
+            raise InvalidResponse("Multiple content-length headers specified")
         if not next_value.isnumeric() or int(next_value) <= 0:
-            logging.error("Invalid content-length value: %r", next_value)
-            raise InvalidResponse()
+            raise InvalidResponse(f"Invalid content-length value: {next_value}")
 
 
 def parse_uri(uri: str):
+    """
+    Parse the specified URI into the host, port and path.
+    If the URI is invalid, this method will try to create one.
+    @param uri: the URI to be parsed
+    @return: A tuple with the host, port and path
+    """
     parsed = urlsplit(uri)
 
-    # If there is no netloc, the given string is not a valid URI, so split on /
+    # If there is no hostname, the given string is not a valid URI, so split on /
     if parsed.hostname:
         host = parsed.hostname
         path = parsed.path
@@ -159,13 +174,21 @@ def parse_uri(uri: str):
     return host, port, path
 
 
-def get_uri(url: str):
+def uri_from_url(url: str):
     """
     Returns a valid URI of the specified URL.
     """
     parsed = urlsplit(url)
 
-    result = f"http://{parsed.netloc}{parsed.path}"
+    if parsed.hostname is None:
+        url = f"http://{url}"
+        parsed = urlsplit(url)
+
+    path = parsed.path
+    if path == "":
+        path = "/"
+
+    result = f"http://{parsed.netloc}{path}"
     if parsed.query != "":
         result = f"{result}?{parsed.query}"
 
@@ -174,12 +197,18 @@ def get_uri(url: str):
 
 def urljoin(base, url):
     """
-    Join a base url and a URL to form a absolute url.
+    Join a base url, and a URL to form an absolute url.
     """
     return urllib.parse.urljoin(base, url)
 
 
 def get_charset(headers: Dict[str, str]):
+    """
+    Returns the charset of the content from the headers if found. Otherwise, returns `FORMAT`
+
+    @param headers: the headers to retrieve the charset from
+    @return: A charset
+    """
     if "content-type" in headers:
         content_type = headers["content-type"]
         match = re.search(r"charset\s*=\s*([a-z\-0-9]*)", content_type, re.I)
@@ -187,3 +216,26 @@ def get_charset(headers: Dict[str, str]):
             return match.group(1)
 
     return FORMAT
+
+
+def get_relative_save_path(path: str):
+    """
+    Returns the specified path relative to the working directory.
+
+    @param path: the path to compute
+    @return: the relative path
+    """
+
+    path_obj = pathlib.PurePath(path)
+    root = pathlib.PurePath(os.getcwd())
+    rel = path_obj.relative_to(root)
+    return str(rel)
+
+
+def get_date():
+    """
+    Returns a string representation of the current date according to RFC 1123.
+    """
+    now = datetime.now()
+    stamp = mktime(now.timetuple())
+    return format_date_time(stamp)

httplib/retriever.py

@@ -62,11 +62,18 @@ class PreambleRetriever(Retriever):
     """
     Retriever instance for retrieving the start-line and headers of an HTTP message.
     """
+
     client: HTTPSocket
     _buffer: []
 
     @property
     def buffer(self):
+        """
+        Returns a copy of the internal buffer.
+        Clears the internal buffer afterwards.
+
+        @return: A list of the buffered lines.
+        """
         tmp_buffer = self._buffer
         self._buffer = []
 
@@ -87,7 +94,7 @@ class PreambleRetriever(Retriever):
         while True:
             self._buffer.append(line)
 
-            if line in ("\r\n", "\n", ""):
+            if line in ("\r\n", "\r", "\n", ""):
                 return line
 
             yield line
@@ -140,8 +147,8 @@ class ContentLengthRetriever(Retriever):
 
 class RawRetriever(Retriever):
     """
-    Retriever instance for retrieve a message body without any length specifier or encoding.
-    This retriever will keep waiting until a timeout occurs or the connection is disconnected.
+    Retriever instance for retrieving a message body without any length specifier or encoding.
+    This retriever will keep waiting until a timeout occurs, or the connection is disconnected.
     """
 
     def retrieve(self):
@@ -161,6 +168,7 @@ class ChunkedRetriever(Retriever):
         """
         Returns an iterator of the received message bytes.
         The size of each iteration is not necessarily constant.
+
         @raise IncompleteResponse: if the connection is closed or timed out before receiving the complete payload.
         @raise InvalidResponse: if the length of a chunk could not be determined.
         """
@@ -184,6 +192,12 @@ class ChunkedRetriever(Retriever):
             raise IncompleteResponse("Connection closed before receiving the complete payload!")
 
     def __get_chunk_size(self):
+        """
+        Returns the next chunk size.
+
+        @return: The chunk size in bytes
+        @raise InvalidResponse: If an error occured when parsing the chunk size.
+        """
         line = self.client.read_line()
         sep_pos = line.find(";")
         if sep_pos >= 0:
@@ -192,4 +206,4 @@ class ChunkedRetriever(Retriever):
         try:
             return int(line, 16)
         except ValueError:
-            raise InvalidResponse()
+            raise InvalidResponse("Failed to parse chunk size")

requirements.txt

@@ -1 +0,0 @@
-lxml~=4.6.2

server.py

@@ -14,7 +14,7 @@ def main():
     parser.add_argument("--workers", "-w",
                         help="The amount of worker processes. This is by default based on the number of cpu threads.",
                         type=int)
-    parser.add_argument("--port", "-p", help="The port to listen on", default=8000)
+    parser.add_argument("--port", "-p", help="The port to listen on", default=5055)
     arguments = parser.parse_args()
 
     logging_level = logging.ERROR - (10 * arguments.verbose)

server/command.py

@@ -3,13 +3,11 @@ import os
 import sys
 from abc import ABC, abstractmethod
 from datetime import datetime
-from time import mktime
-from wsgiref.handlers import format_date_time
 
 from httplib import parser
-from httplib.exceptions import NotFound, Forbidden, NotModified
+from httplib.exceptions import NotFound, Forbidden, NotModified, BadRequest
 from httplib.httpsocket import FORMAT
-from httplib.message import ServerMessage as Message
+from httplib.message import RequestMessage as Message
 
 CONTENT_ROOT = os.path.join(os.path.dirname(sys.argv[0]), "public")
 
@@ -60,28 +58,36 @@ class AbstractCommand(ABC):
     @property
     @abstractmethod
     def _conditional_headers(self):
+        """
+        The conditional headers specific to this command instance.
+        """
         pass
 
-    def _get_date(self):
-        """
-        Returns a string representation of the current date according to RFC 1123.
-        """
-        now = datetime.now()
-        stamp = mktime(now.timetuple())
-        return format_date_time(stamp)
-
     @abstractmethod
     def execute(self):
+        """
+        Execute the command
+        """
         pass
 
     def _build_message(self, status: int, content_type: str, body: bytes, extra_headers=None):
+        """
+        Build the response message.
+
+        @param status: The response status code
+        @param content_type: The response content-type header
+        @param body: The response body, may be empty.
+        @param extra_headers: Extra headers needed in the response message
+        @return: The encoded response message
+        """
 
         if extra_headers is None:
             extra_headers = {}
+
         self._process_conditional_headers()
 
         message = f"HTTP/1.1 {status} {status_message[status]}\r\n"
-        message += f"Date: {self._get_date()}\r\n"
+        message += f"Date: {parser.get_date()}\r\n"
 
         content_length = len(body)
         message += f"Content-Length: {content_length}\r\n"
@@ -105,6 +111,13 @@ class AbstractCommand(ABC):
         return message
 
     def _get_path(self, check=True):
+        """
+        Returns the absolute file system path of the resource in the request.
+
+        @param check: If True, throws an error if the file doesn't exist
+        @raise NotFound: if `check` is True and the path doesn't exist
+        """
+
         norm_path = os.path.normpath(self.msg.target.path)
 
         if norm_path == "/":
@@ -118,6 +131,9 @@ class AbstractCommand(ABC):
         return path
 
     def _process_conditional_headers(self):
+        """
+        Processes the conditional headers for this command instance.
+        """
 
         for header in self._conditional_headers:
             tmp = self.msg.headers.get(header)
@@ -127,6 +143,13 @@ class AbstractCommand(ABC):
             self._conditional_headers[header]()
 
     def _if_modified_since(self):
+        """
+        Processes the if-modified-since header.
+        @return: True if the header is invalid, and thus shouldn't be taken into account, throws NotModified
+        if the content isn't modified since the given date.
+
+        @raise NotModified: If the date of if-modified-since greater than the modify-date of the resource.
+        """
         date_val = self.msg.headers.get("if-modified-since")
         if not date_val:
             return True
@@ -141,7 +164,14 @@ class AbstractCommand(ABC):
 
         return True
 
-    def get_mimetype(self, path):
+    @staticmethod
+    def get_mimetype(path):
+        """
+        Guess the type of file.
+        @param path: the path to the file to guess the type of
+        @return: The mimetype based on the extension, or if that fails, returns "text/plain" if the file is text,
+        otherwise returns "application/octet-stream"
+        """
         mime = mimetypes.guess_type(path)[0]
 
         if mime:
@@ -157,10 +187,16 @@ class AbstractCommand(ABC):
 
 
 class AbstractModifyCommand(AbstractCommand, ABC):
+    """
+    Base class for commands which modify a resource based on the request.
+    """
 
     @property
     @abstractmethod
     def _file_mode(self):
+        """
+        The mode to open the target resource with. (e.a. 'a' or 'w')
+        """
         pass
 
     @property
@@ -194,6 +230,10 @@ class AbstractModifyCommand(AbstractCommand, ABC):
 
 
 class HeadCommand(AbstractCommand):
+    """
+    A Command instance which represents an HEAD request
+    """
+
     @property
     def command(self):
         return "HEAD"
@@ -204,12 +244,16 @@ class HeadCommand(AbstractCommand):
 
     def execute(self):
         path = self._get_path()
-
         mime = self.get_mimetype(path)
+
         return self._build_message(200, mime, b"")
 
 
 class GetCommand(AbstractCommand):
+    """
+    A Command instance which represents a GET request
+    """
+
     @property
     def command(self):
         return "GET"
@@ -230,6 +274,10 @@ class GetCommand(AbstractCommand):
 
 
 class PostCommand(AbstractModifyCommand):
+    """
+    A Command instance which represents a POST request
+    """
+
     @property
     def command(self):
         return "POST"
@@ -240,6 +288,10 @@ class PostCommand(AbstractModifyCommand):
 
 
 class PutCommand(AbstractModifyCommand):
+    """
+    A Command instance which represents a PUT request
+    """
+
     @property
     def command(self):
         return "PUT"
@@ -247,3 +299,9 @@ class PutCommand(AbstractModifyCommand):
     @property
     def _file_mode(self):
         return "w"
+
+    def execute(self):
+        if "content-range" in self.msg.headers:
+            raise BadRequest("PUT request contains a Content-Range header")
+
+        super().execute()

server/httpserver.py

@@ -67,7 +67,7 @@ class HTTPServer:
         """
 
         self.server.listen()
-        logging.debug("Listening on %s:%d", self.address, self.port)
+        logging.info("Listening on %s:%d", self.address, self.port)
 
         while True:
             conn, addr = self.server.accept()
@@ -86,6 +86,8 @@ class HTTPServer:
         Notifies the worker processes to shut down and eventually closes the server socket
         """
 
+        logging.info("Shutting down server...")
+
         # Set stop event
         self._stop_event.set()
 
@@ -111,7 +113,7 @@ class HTTPServer:
         """
         Create worker processes up to `self.worker_count`.
 
-        A worker process is created with start method "spawn", target `worker.worker` and the `self.logging_level`
+        A worker process is created with start method "spawn", target `worker.worker`, and the `self.logging_level`
         is passed along with the `self.dispatch_queue` and `self._stop_event`
         """
         for i in range(self.worker_count):

server/requesthandler.py

@@ -1,18 +1,13 @@
 import logging
-import os
-import sys
-from datetime import datetime
 from socket import socket
-from time import mktime
 from typing import Union
 from urllib.parse import ParseResultBytes, ParseResult
-from wsgiref.handlers import format_date_time
 
 from httplib import parser
 from httplib.exceptions import MethodNotAllowed, BadRequest, UnsupportedEncoding, NotImplemented, NotFound, \
     HTTPVersionNotSupported
-from httplib.httpsocket import HTTPSocket, FORMAT
-from httplib.message import ServerMessage as Message
+from httplib.httpsocket import FORMAT
+from httplib.message import RequestMessage as Message
 from httplib.retriever import Retriever, PreambleRetriever
 from server import command
 from server.serversocket import ServerSocket
@@ -21,13 +16,24 @@ METHODS = ("GET", "HEAD", "PUT", "POST")
 
 
 class RequestHandler:
-    conn: HTTPSocket
-    root = os.path.join(os.path.dirname(sys.argv[0]), "public")
+    """
+    A RequestHandler instance processes incoming HTTP requests messages from a single client.
+
+    RequestHandler instances are created everytime a client connects. They will read the incoming
+    messages, parse, verify them and send a response.
+    """
+
+    conn: ServerSocket
+    host: str
 
     def __init__(self, conn: socket, host):
-        self.conn = ServerSocket(conn, host)
+        self.conn = ServerSocket(conn)
+        self.host = host
 
     def listen(self):
+        """
+        Listen to incoming messages and process them.
+        """
 
         retriever = PreambleRetriever(self.conn)
 
@@ -41,16 +47,27 @@ class RequestHandler:
             self._handle_message(retriever, line)
 
     def _handle_message(self, retriever, line):
+        """
+        Retrieves and processes the request message.
+
+        @param retriever: the retriever instance to retrieve the lines.
+        @param line: the first received line.
+        """
         lines = retriever.retrieve()
+
+        # Parse the request-line and headers
         (method, target, version) = parser.parse_request_line(line)
         headers = parser.parse_headers(lines)
 
+        # Create the response message object
         message = Message(version, method, target, headers, retriever.buffer)
 
         logging.debug("---request begin---\r\n%s---request end---", "".join(message.raw))
 
+        # validate if the request is valid
         self._validate_request(message)
 
+        # The body (if available) hasn't been retrieved up till now.
         body = b""
         if self._has_body(headers):
             try:
@@ -64,14 +81,26 @@ class RequestHandler:
 
         message.body = body
 
-        # completed message
-
+        # message completed
         cmd = command.create(message)
         msg = cmd.execute()
+
         logging.debug("---response begin---\r\n%s\r\n---response end---", msg.split(b"\r\n\r\n", 1)[0].decode(FORMAT))
+        # Send the response message
         self.conn.conn.sendall(msg)
 
     def _check_request_line(self, method: str, target: Union[ParseResultBytes, ParseResult], version):
+        """
+        Checks if the request-line is valid. Throws an appropriate exception if not.
+
+        @param method: HTTP request method
+        @param target: The request target
+        @param version: The HTTP version
+        @raise MethodNotAllowed: if the method is not any of the allowed methods in `METHODS`
+        @raise HTTPVersionNotSupported: If the HTTP version is not supported by this server
+        @raise BadRequest: If the scheme of the target is not supported
+        @raise NotFound: If the target is not found on this server
+        """
 
         if method not in METHODS:
             raise MethodNotAllowed(METHODS)
@@ -84,19 +113,33 @@ class RequestHandler:
             # Only http is supported...
             raise BadRequest(f"scheme={target.scheme}")
 
-        if target.netloc != "" and target.netloc != self.conn.host and target.netloc != self.conn.host.split(":")[0]:
+        if target.netloc != "" and target.netloc != self.host and target.netloc != self.host.split(":")[0]:
             raise NotFound(str(target))
 
         if target.path == "" or target.path[0] != "/":
             raise NotFound(str(target))
 
     def _validate_request(self, msg):
+        """
+        Validates the message request-line and headers. Throws an error if the message is invalid.
+
+        @see: _check_request_line for exceptions raised when validating the request-line.
+        @param msg: the message to validate
+        @raise BadRequest: if HTTP 1.1, and the Host header is missing
+        """
+
         if msg.version == "1.1" and "host" not in msg.headers:
             raise BadRequest("Missing host header")
 
         self._check_request_line(msg.method, msg.target, msg.version)
 
     def _has_body(self, headers):
+        """
+        Check if the headers notify the existing of a message body.
+
+        @param headers: the headers to check
+        @return: True if the message has a body. False otherwise.
+        """
 
         if "transfer-encoding" in headers:
             return True
@@ -106,16 +149,18 @@ class RequestHandler:
 
         return False
 
-    @staticmethod
-    def _get_date():
-        now = datetime.now()
-        stamp = mktime(now.timetuple())
-        return format_date_time(stamp)
-
     @staticmethod
     def send_error(client: socket, code, message):
+        """
+        Send and HTTP error response to the client
+
+        @param client: the client to send the response to
+        @param code: the HTTP status code
+        @param message: the status code message
+        """
+
         message = f"HTTP/1.1 {code} {message}\r\n"
-        message += RequestHandler._get_date() + "\r\n"
+        message += parser.get_date() + "\r\n"
         message += "Content-Length: 0\r\n"
         message += "\r\n"
 

server/serversocket.py

@@ -1,11 +1,18 @@
-import socket
-
 from httplib.exceptions import BadRequest
 from httplib.httpsocket import HTTPSocket
 
 
 class ServerSocket(HTTPSocket):
+    """
+    Wrapper class for a socket. Represents a client connected to this server.
+    """
 
+    """
+    Reads the next line decoded as `httpsocket.FORMAT`
+
+    @return: the decoded next line retrieved from the socket
+    @raise InvalidResponse: If the next line couldn't be decoded, but was expected to
+    """
     def read_line(self):
         try:
             return super().read_line()

server/worker.py

@@ -3,6 +3,7 @@ import multiprocessing as mp
 import socket
 import threading
 from concurrent.futures import ThreadPoolExecutor
+from typing import Dict
 
 from httplib.exceptions import HTTPServerException, InternalServerError, HTTPServerCloseException
 from server.requesthandler import RequestHandler
@@ -18,11 +19,19 @@ def worker(address, name, logging_level, queue: mp.Queue, stop_event: mp.Event):
     try:
         runner.run()
     except KeyboardInterrupt:
+        # Catch exit signals and close the threads appropriately.
         logging.debug("Ctrl+C pressed, terminating")
         runner.shutdown()
 
 
 class Worker:
+    """
+    A Worker instance represents a parallel execution process to handle incoming connections.
+
+    Worker instances are created when the HTTP server starts. They are used to handle many incoming connections
+    asynchronously.
+    """
+
     host: str
     name: str
     queue: mp.Queue
@@ -30,24 +39,40 @@ class Worker:
     stop_event: mp.Event
 
     finished_queue: mp.Queue
+    dispatched_sockets: Dict[int, socket.socket]
 
     def __init__(self, host, name, queue: mp.Queue, stop_event: mp.Event):
+        """
+        Create a new Worker instance
+
+        @param host: The hostname of the HTTP server
+        @param name: The name of this Worker instance
+        @param queue: The dispatch queue for incoming socket connections
+        @param stop_event: The Event that signals when to shut down this worker.
+        """
         self.host = host
         self.name = name
         self.queue = queue
         self.executor = ThreadPoolExecutor(THREAD_LIMIT)
         self.stop_event = stop_event
         self.finished_queue = mp.Queue()
+        self.dispatched_sockets = {}
 
         for i in range(THREAD_LIMIT):
             self.finished_queue.put(i)
 
     def run(self):
+        """
+        Run this worker.
+
+        The worker will start waiting for incoming clients being added to the queue and submit them to
+        the executor.
+        """
         while not self.stop_event.is_set():
 
-            # Blocks until thread is free
+            # Blocks until the thread is free
             self.finished_queue.get()
-            # Blocks until new client connects
+            # Blocks until a new client connects
             conn, addr = self.queue.get()
 
             if conn is None or addr is None:
@@ -55,12 +80,32 @@ class Worker:
 
             logging.debug("Processing new client: %s", addr)
 
-            # submit client to thread
+            # submit the client to the executor
             self.executor.submit(self._handle_client, conn, addr)
 
         self.shutdown()
 
     def _handle_client(self, conn: socket.socket, addr):
+        """
+        Target method for the worker threads.
+        Creates a RequestHandler and handles any exceptions which may occur.
+
+        @param conn: The client socket
+        @param addr: The address of the client.
+        """
+
+        self.dispatched_sockets[threading.get_ident()] = conn
+        try:
+            self.__do_handle_client(conn, addr)
+        except Exception:
+            if not self.stop_event:
+                logging.debug("Internal error in thread:", exc_info=True)
+
+        self.dispatched_sockets.pop(threading.get_ident())
+        # Finished, put back into queue
+        self.finished_queue.put(threading.get_ident())
+
+    def __do_handle_client(self, conn: socket.socket, addr):
 
         handler = RequestHandler(conn, self.host)
 
@@ -68,28 +113,50 @@ class Worker:
             try:
                 handler.listen()
             except HTTPServerCloseException as e:
+                # Exception raised after which the client should be disconnected.
                 logging.warning("[HTTP: %s] %s. Reason: %s", e.status_code, e.message, e.arg)
                 RequestHandler.send_error(conn, e.status_code, e.message)
+
                 break
             except HTTPServerException as e:
+                # Normal HTTP exception raised (e.a. 404) continue listening.
                 logging.debug("[HTTP: %s] %s. Reason: %s", e.status_code, e.message, e.arg)
                 RequestHandler.send_error(conn, e.status_code, e.message)
             except socket.timeout:
+                # socket timed out, disconnect.
                 logging.info("Socket for client %s timed out.", addr)
                 break
             except ConnectionAbortedError:
+                # Client aborted connection
                 logging.info("Socket for client %s disconnected.", addr)
                 break
             except Exception as e:
+                # Unexpected exception raised. Send 500 and disconnect.
                 logging.error("Internal error", exc_info=e)
                 RequestHandler.send_error(conn, InternalServerError.status_code, InternalServerError.message)
                 break
 
         conn.shutdown(socket.SHUT_RDWR)
         conn.close()
-        # Finished, put back into queue
-        self.finished_queue.put(threading.get_ident())
 
     def shutdown(self):
         logging.info("shutting down")
+        # shutdown executor, but do not wait
+        self.executor.shutdown(False)
+
+        logging.info("Closing sockets")
+
+        # Copy dictionary to prevent issues with concurrency
+        clients = self.dispatched_sockets.copy().values()
+
+        for client in clients:
+            client: socket.socket
+            try:
+                client.shutdown(socket.SHUT_RDWR)
+                client.close()
+            except OSError:
+                # Ignore exception due to already closed sockets
+                pass
+
+        # Call shutdown again and wait this time
         self.executor.shutdown()