X-Git-Url: https://code.grnet.gr/git/ganeti-local/blobdiff_plain/b18dd0195773aebcf3249bacfd6b9c4440c22960..2cc1da8b07305c1c322a5524a7e24ea07b071d72:/lib/http/__init__.py?ds=sidebyside diff --git a/lib/http/__init__.py b/lib/http/__init__.py index e8a355d..008cf9c 100644 --- a/lib/http/__init__.py +++ b/lib/http/__init__.py @@ -61,17 +61,23 @@ HTTP_CONTENT_TYPE = "Content-Type" HTTP_CONTENT_LENGTH = "Content-Length" HTTP_CONNECTION = "Connection" HTTP_KEEP_ALIVE = "Keep-Alive" +HTTP_WWW_AUTHENTICATE = "WWW-Authenticate" +HTTP_AUTHORIZATION = "Authorization" +HTTP_AUTHENTICATION_INFO = "Authentication-Info" +HTTP_ALLOW = "Allow" _SSL_UNEXPECTED_EOF = "Unexpected EOF" # Socket operations (SOCKOP_SEND, SOCKOP_RECV, - SOCKOP_SHUTDOWN) = range(3) + SOCKOP_SHUTDOWN, + SOCKOP_HANDSHAKE) = range(4) # send/receive quantum SOCK_BUF_SIZE = 32768 + class HttpError(Exception): """Internal exception for HTTP errors. @@ -80,8 +86,17 @@ class HttpError(Exception): """ -class _HttpClientError(Exception): - """Internal exception for HTTP client errors. +class HttpConnectionClosed(Exception): + """Internal exception for a closed connection. + + This should only be used for internal error reporting. Only use + it if there's no other way to report this condition. + + """ + + +class HttpSessionHandshakeUnexpectedEOF(HttpError): + """Internal exception for errors during SSL handshake. This should only be used for internal error reporting. @@ -100,45 +115,187 @@ class HttpException(Exception): code = None message = None - def __init__(self, message=None): + def __init__(self, message=None, headers=None): Exception.__init__(self) - if message is not None: - self.message = message + self.message = message + self.headers = headers class HttpBadRequest(HttpException): + """400 Bad Request + + RFC2616, 10.4.1: The request could not be understood by the server + due to malformed syntax. The client SHOULD NOT repeat the request + without modifications. + + """ code = 400 +class HttpUnauthorized(HttpException): + """401 Unauthorized + + RFC2616, section 10.4.2: The request requires user + authentication. The response MUST include a WWW-Authenticate header + field (section 14.47) containing a challenge applicable to the + requested resource. + + """ + code = 401 + + class HttpForbidden(HttpException): + """403 Forbidden + + RFC2616, 10.4.4: The server understood the request, but is refusing + to fulfill it. Authorization will not help and the request SHOULD + NOT be repeated. + + """ code = 403 class HttpNotFound(HttpException): + """404 Not Found + + RFC2616, 10.4.5: The server has not found anything matching the + Request-URI. No indication is given of whether the condition is + temporary or permanent. + + """ code = 404 +class HttpMethodNotAllowed(HttpException): + """405 Method Not Allowed + + RFC2616, 10.4.6: The method specified in the Request-Line is not + allowed for the resource identified by the Request-URI. The response + MUST include an Allow header containing a list of valid methods for + the requested resource. + + """ + code = 405 + + +class HttpRequestTimeout(HttpException): + """408 Request Timeout + + RFC2616, 10.4.9: The client did not produce a request within the + time that the server was prepared to wait. The client MAY repeat the + request without modifications at any later time. + + """ + code = 408 + + +class HttpConflict(HttpException): + """409 Conflict + + RFC2616, 10.4.10: The request could not be completed due to a + conflict with the current state of the resource. This code is only + allowed in situations where it is expected that the user might be + able to resolve the conflict and resubmit the request. + + """ + code = 409 + + class HttpGone(HttpException): + """410 Gone + + RFC2616, 10.4.11: The requested resource is no longer available at + the server and no forwarding address is known. This condition is + expected to be considered permanent. + + """ code = 410 class HttpLengthRequired(HttpException): + """411 Length Required + + RFC2616, 10.4.12: The server refuses to accept the request without a + defined Content-Length. The client MAY repeat the request if it adds + a valid Content-Length header field containing the length of the + message-body in the request message. + + """ code = 411 -class HttpInternalError(HttpException): +class HttpPreconditionFailed(HttpException): + """412 Precondition Failed + + RFC2616, 10.4.13: The precondition given in one or more of the + request-header fields evaluated to false when it was tested on the + server. + + """ + code = 412 + + +class HttpInternalServerError(HttpException): + """500 Internal Server Error + + RFC2616, 10.5.1: The server encountered an unexpected condition + which prevented it from fulfilling the request. + + """ code = 500 class HttpNotImplemented(HttpException): + """501 Not Implemented + + RFC2616, 10.5.2: The server does not support the functionality + required to fulfill the request. + + """ code = 501 +class HttpBadGateway(HttpException): + """502 Bad Gateway + + RFC2616, 10.5.3: The server, while acting as a gateway or proxy, + received an invalid response from the upstream server it accessed in + attempting to fulfill the request. + + """ + code = 502 + + class HttpServiceUnavailable(HttpException): + """503 Service Unavailable + + RFC2616, 10.5.4: The server is currently unable to handle the + request due to a temporary overloading or maintenance of the server. + + """ code = 503 +class HttpGatewayTimeout(HttpException): + """504 Gateway Timeout + + RFC2616, 10.5.5: The server, while acting as a gateway or proxy, did + not receive a timely response from the upstream server specified by + the URI (e.g. HTTP, FTP, LDAP) or some other auxiliary server + (e.g. DNS) it needed to access in attempting to complete the + request. + + """ + code = 504 + + class HttpVersionNotSupported(HttpException): + """505 HTTP Version Not Supported + + RFC2616, 10.5.6: The server does not support, or refuses to support, + the HTTP protocol version that was used in the request message. + + """ code = 505 @@ -152,13 +309,11 @@ class HttpJsonConverter: return serializer.LoadJson(data) -def WaitForSocketCondition(poller, sock, event, timeout): +def WaitForSocketCondition(sock, event, timeout): """Waits for a condition to occur on the socket. - @type poller: select.Poller - @param poller: Poller object as created by select.poll() @type sock: socket - @param socket: Wait for events on this socket + @param sock: Wait for events on this socket @type event: int @param event: ORed condition (see select module) @type timeout: float or None @@ -174,6 +329,7 @@ def WaitForSocketCondition(poller, sock, event, timeout): # Poller object expects milliseconds timeout *= 1000 + poller = select.poll() poller.register(sock, event) try: while True: @@ -191,26 +347,25 @@ def WaitForSocketCondition(poller, sock, event, timeout): poller.unregister(sock) -def SocketOperation(poller, sock, op, arg1, timeout): +def SocketOperation(sock, op, arg1, timeout): """Wrapper around socket functions. This function abstracts error handling for socket operations, especially for the complicated interaction with OpenSSL. - @type poller: select.Poller - @param poller: Poller object as created by select.poll() @type sock: socket - @param socket: Socket for the operation + @param sock: Socket for the operation @type op: int @param op: Operation to execute (SOCKOP_* constants) @type arg1: any @param arg1: Parameter for function (if needed) @type timeout: None or float @param timeout: Timeout in seconds or None + @return: Return value of socket function """ # TODO: event_poll/event_check/override - if op == SOCKOP_SEND: + if op in (SOCKOP_SEND, SOCKOP_HANDSHAKE): event_poll = select.POLLOUT event_check = select.POLLOUT @@ -229,18 +384,23 @@ def SocketOperation(poller, sock, op, arg1, timeout): else: raise AssertionError("Invalid socket operation") + # Handshake is only supported by SSL sockets + if (op == SOCKOP_HANDSHAKE and + not isinstance(sock, OpenSSL.SSL.ConnectionType)): + return + # No override by default event_override = 0 while True: # Poll only for certain operations and when asked for by an override - if event_override or op in (SOCKOP_SEND, SOCKOP_RECV): + if event_override or op in (SOCKOP_SEND, SOCKOP_RECV, SOCKOP_HANDSHAKE): if event_override: wait_for_event = event_override else: wait_for_event = event_poll - event = WaitForSocketCondition(poller, sock, wait_for_event, timeout) + event = WaitForSocketCondition(sock, wait_for_event, timeout) if event is None: raise HttpSocketTimeout() @@ -269,6 +429,9 @@ def SocketOperation(poller, sock, op, arg1, timeout): else: return sock.shutdown(arg1) + elif op == SOCKOP_HANDSHAKE: + return sock.do_handshake() + except OpenSSL.SSL.WantWriteError: # OpenSSL wants to write, poll for POLLOUT event_override = select.POLLOUT @@ -282,6 +445,21 @@ def SocketOperation(poller, sock, op, arg1, timeout): except OpenSSL.SSL.WantX509LookupError: continue + except OpenSSL.SSL.ZeroReturnError, err: + # SSL Connection has been closed. In SSL 3.0 and TLS 1.0, this only + # occurs if a closure alert has occurred in the protocol, i.e. the + # connection has been closed cleanly. Note that this does not + # necessarily mean that the transport layer (e.g. a socket) has been + # closed. + if op == SOCKOP_SEND: + # Can happen during a renegotiation + raise HttpConnectionClosed(err.args) + elif op == SOCKOP_RECV: + return "" + + # SSL_shutdown shouldn't return SSL_ERROR_ZERO_RETURN + raise socket.error(err.args) + except OpenSSL.SSL.SysCallError, err: if op == SOCKOP_SEND: # arg1 is the data when writing @@ -290,9 +468,13 @@ def SocketOperation(poller, sock, op, arg1, timeout): # and can be ignored return 0 - elif op == SOCKOP_RECV: - if err.args == (-1, _SSL_UNEXPECTED_EOF): + if err.args == (-1, _SSL_UNEXPECTED_EOF): + if op == SOCKOP_RECV: return "" + elif op == SOCKOP_HANDSHAKE: + # Can happen if peer disconnects directly after the connection is + # opened. + raise HttpSessionHandshakeUnexpectedEOF(err.args) raise socket.error(err.args) @@ -307,19 +489,30 @@ def SocketOperation(poller, sock, op, arg1, timeout): raise -def ShutdownConnection(poller, sock, close_timeout, write_timeout, msgreader, - force): +def ShutdownConnection(sock, close_timeout, write_timeout, msgreader, force): """Closes the connection. - """ - poller = select.poll() + @type sock: socket + @param sock: Socket to be shut down + @type close_timeout: float + @param close_timeout: How long to wait for the peer to close + the connection + @type write_timeout: float + @param write_timeout: Write timeout for shutdown + @type msgreader: http.HttpMessageReader + @param msgreader: Request message reader, used to determine whether + peer should close connection + @type force: bool + @param force: Whether to forcibly close the connection without + waiting for peer + """ #print msgreader.peer_will_close, force if msgreader and msgreader.peer_will_close and not force: # Wait for peer to close try: # Check whether it's actually closed - if not SocketOperation(poller, sock, SOCKOP_RECV, 1, close_timeout): + if not SocketOperation(sock, SOCKOP_RECV, 1, close_timeout): return except (socket.error, HttpError, HttpSocketTimeout): # Ignore errors at this stage @@ -327,12 +520,32 @@ def ShutdownConnection(poller, sock, close_timeout, write_timeout, msgreader, # Close the connection from our side try: - SocketOperation(poller, sock, SOCKOP_SHUTDOWN, socket.SHUT_RDWR, + # We don't care about the return value, see NOTES in SSL_shutdown(3). + SocketOperation(sock, SOCKOP_SHUTDOWN, socket.SHUT_RDWR, write_timeout) except HttpSocketTimeout: raise HttpError("Timeout while shutting down connection") except socket.error, err: - raise HttpError("Error while shutting down connection: %s" % err) + # Ignore ENOTCONN + if not (err.args and err.args[0] == errno.ENOTCONN): + raise HttpError("Error while shutting down connection: %s" % err) + + +def Handshake(sock, write_timeout): + """Shakes peer's hands. + + @type sock: socket + @param sock: Socket to be shut down + @type write_timeout: float + @param write_timeout: Write timeout for handshake + + """ + try: + return SocketOperation(sock, SOCKOP_HANDSHAKE, None, write_timeout) + except HttpSocketTimeout: + raise HttpError("Timeout during SSL handshake") + except socket.error, err: + raise HttpError("Error in SSL handshake: %s" % err) class HttpSslParams(object): @@ -345,7 +558,8 @@ class HttpSslParams(object): @type ssl_key_path: string @param ssl_key_path: Path to file containing SSL key in PEM format @type ssl_cert_path: string - @param ssl_cert_path: Path to file containing SSL certificate in PEM format + @param ssl_cert_path: Path to file containing SSL certificate + in PEM format """ self.ssl_key_pem = utils.ReadFile(ssl_key_path) @@ -360,12 +574,12 @@ class HttpSslParams(object): self.ssl_cert_pem) -class HttpSocketBase(object): +class HttpBase(object): """Base class for HTTP server and client. """ def __init__(self): - self._using_ssl = None + self.using_ssl = None self._ssl_params = None self._ssl_key = None self._ssl_cert = None @@ -376,8 +590,8 @@ class HttpSocketBase(object): @type ssl_params: HttpSslParams @param ssl_params: SSL key and certificate @type ssl_verify_peer: bool - @param ssl_verify_peer: Whether to require client certificate and compare - it with our certificate + @param ssl_verify_peer: Whether to require client certificate + and compare it with our certificate """ self._ssl_params = ssl_params @@ -385,9 +599,9 @@ class HttpSocketBase(object): sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # Should we enable SSL? - self._using_ssl = ssl_params is not None + self.using_ssl = ssl_params is not None - if not self._using_ssl: + if not self.using_ssl: return sock self._ssl_key = ssl_params.GetKey() @@ -462,22 +676,29 @@ class HttpMessageWriter(object): """ def __init__(self, sock, msg, write_timeout): + """Initializes this class and writes an HTTP message to a socket. + + @type sock: socket + @param sock: Socket to be written to + @type msg: http.HttpMessage + @param msg: HTTP message to be written + @type write_timeout: float + @param write_timeout: Write timeout for socket + + """ self._msg = msg self._PrepareMessage() buf = self._FormatMessage() - poller = select.poll() - pos = 0 end = len(buf) while pos < end: # Send only SOCK_BUF_SIZE bytes at a time - data = buf[pos:pos+SOCK_BUF_SIZE] + data = buf[pos:(pos + SOCK_BUF_SIZE)] - sent = SocketOperation(poller, sock, SOCKOP_SEND, data, - write_timeout) + sent = SocketOperation(sock, SOCKOP_SEND, data, write_timeout) # Remove sent bytes pos += sent @@ -544,10 +765,19 @@ class HttpMessageReader(object): PS_COMPLETE = "complete" def __init__(self, sock, msg, read_timeout): + """Reads an HTTP message from a socket. + + @type sock: socket + @param sock: Socket to be read from + @type msg: http.HttpMessage + @param msg: Object for the read message + @type read_timeout: float + @param read_timeout: Read timeout for socket + + """ self.sock = sock self.msg = msg - self.poller = select.poll() self.start_line_buffer = None self.header_buffer = StringIO() self.body_buffer = StringIO() @@ -558,8 +788,9 @@ class HttpMessageReader(object): buf = "" eof = False while self.parser_status != self.PS_COMPLETE: - data = SocketOperation(self.poller, sock, SOCKOP_RECV, SOCK_BUF_SIZE, - read_timeout) + # TODO: Don't read more than necessary (Content-Length), otherwise + # data might be lost and/or an error could occur + data = SocketOperation(sock, SOCKOP_RECV, SOCK_BUF_SIZE, read_timeout) if data: buf += data @@ -604,6 +835,7 @@ class HttpMessageReader(object): @return: Updated receive buffer """ + # TODO: Use offset instead of slicing when possible if self.parser_status == self.PS_START_LINE: # Expect start line while True: @@ -615,7 +847,7 @@ class HttpMessageReader(object): # beginning of a message and receives a CRLF first, it should ignore # the CRLF." if idx == 0: - # TODO: Limit number of CRLFs for safety? + # TODO: Limit number of CRLFs/empty lines for safety? buf = buf[:2] continue @@ -669,6 +901,8 @@ class HttpMessageReader(object): # [...] 5. By the server closing the connection. (Closing the connection # cannot be used to indicate the end of a request body, since that would # leave no possibility for the server to send back a response.)" + # + # TODO: Error when buffer length > Content-Length header if (eof or self.content_length is None or (self.content_length is not None and @@ -755,9 +989,9 @@ class HttpMessageReader(object): This function also adjusts internal variables based on header values. - RFC2616, section 4.3: "The presence of a message-body in a request is + RFC2616, section 4.3: The presence of a message-body in a request is signaled by the inclusion of a Content-Length or Transfer-Encoding header - field in the request's message-headers." + field in the request's message-headers. """ # Parse headers