X-Git-Url: https://code.grnet.gr/git/ganeti-local/blobdiff_plain/f4322a1e24cff4624e5ff7c922c1d4062e7a9d95..1a8337f2993bb426c7965e06d63178e4e7e4078a:/lib/http/__init__.py diff --git a/lib/http/__init__.py b/lib/http/__init__.py index 550bcc1..203e0d5 100644 --- a/lib/http/__init__.py +++ b/lib/http/__init__.py @@ -1,7 +1,7 @@ # # -# Copyright (C) 2007, 2008 Google Inc. +# Copyright (C) 2007, 2008, 2010 Google Inc. # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by @@ -32,7 +32,6 @@ import errno from cStringIO import StringIO from ganeti import constants -from ganeti import serializer from ganeti import utils @@ -61,13 +60,21 @@ 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" + +HTTP_APP_OCTET_STREAM = "application/octet-stream" +HTTP_APP_JSON = "application/json" _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 @@ -81,6 +88,23 @@ class HttpError(Exception): """ +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. + + """ + + class HttpSocketTimeout(Exception): """Internal exception for socket timeouts. @@ -93,105 +117,218 @@ 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 HttpNotAcceptable(HttpException): + """406 Not Acceptable + + RFC2616, 10.4.7: The resource identified by the request is only capable of + generating response entities which have content characteristics not + acceptable according to the accept headers sent in the request. + + """ + code = 406 + + +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 HttpUnsupportedMediaType(HttpException): + """415 Unsupported Media Type + + RFC2616, 10.4.16: The server is refusing to service the request because the + entity of the request is in a format not supported by the requested resource + for the requested method. + + """ + code = 415 + + +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): - code = 503 + """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. -class HttpVersionNotSupported(HttpException): - code = 505 + """ + code = 503 -class HttpJsonConverter: - CONTENT_TYPE = "application/json" +class HttpGatewayTimeout(HttpException): + """504 Gateway Timeout - def Encode(self, data): - return serializer.DumpJson(data) + 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. - def Decode(self, data): - return serializer.LoadJson(data) + """ + code = 504 -def WaitForSocketCondition(poller, sock, event, timeout): - """Waits for a condition to occur on the socket. +class HttpVersionNotSupported(HttpException): + """505 HTTP Version Not Supported - @type poller: select.Poller - @param poller: Poller object as created by select.poll() - @type sock: socket - @param sock: Wait for events on this socket - @type event: int - @param event: ORed condition (see select module) - @type timeout: float or None - @param timeout: Timeout in seconds - @rtype: int or None - @return: None for timeout, otherwise occured conditions + RFC2616, 10.5.6: The server does not support, or refuses to support, + the HTTP protocol version that was used in the request message. """ - check = (event | select.POLLPRI | - select.POLLNVAL | select.POLLHUP | select.POLLERR) + code = 505 - if timeout is not None: - # Poller object expects milliseconds - timeout *= 1000 - poller.register(sock, event) - try: - while True: - # TODO: If the main thread receives a signal and we have no timeout, we - # could wait forever. This should check a global "quit" flag or - # something every so often. - io_events = poller.poll(timeout) - if not io_events: - # Timeout - return None - for (evfd, evcond) in io_events: - if evcond & check: - return evcond - finally: - 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 sock: Socket for the operation @type op: int @@ -204,17 +341,14 @@ def SocketOperation(poller, sock, op, arg1, timeout): """ # 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 elif op == SOCKOP_RECV: event_poll = select.POLLIN - event_check = select.POLLIN | select.POLLPRI elif op == SOCKOP_SHUTDOWN: event_poll = None - event_check = None # The timeout is only used when OpenSSL requests polling for a condition. # It is not advisable to have no timeout for shutdown. @@ -223,24 +357,29 @@ 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 = utils.WaitForFdCondition(sock, wait_for_event, timeout) if event is None: raise HttpSocketTimeout() - if (op == SOCKOP_RECV and - event & (select.POLLNVAL | select.POLLHUP | select.POLLERR)): - return "" + if event & (select.POLLNVAL | select.POLLHUP | select.POLLERR): + # Let the socket functions handle these + break if not event & wait_for_event: continue @@ -263,6 +402,9 @@ 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 @@ -276,6 +418,21 @@ 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 @@ -284,9 +441,13 @@ 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) @@ -301,34 +462,30 @@ 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. - @type poller: select.Poller - @param poller: Poller object as created by 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 + @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 + @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 + @param force: Whether to forcibly close the connection without + waiting for peer """ - poller = select.poll() - #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 @@ -336,12 +493,45 @@ 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) + + +def InitSsl(): + """Initializes the SSL infrastructure. + + This function is idempotent. + + """ + if not OpenSSL.rand.status(): + raise EnvironmentError("OpenSSL could not collect enough entropy" + " for the PRNG") + + # TODO: Maybe add some additional seeding for OpenSSL's PRNG class HttpSslParams(object): @@ -354,7 +544,8 @@ 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) @@ -374,29 +565,32 @@ class HttpBase(object): """ def __init__(self): - self._using_ssl = None + self.using_ssl = None self._ssl_params = None self._ssl_key = None self._ssl_cert = None - def _CreateSocket(self, ssl_params, ssl_verify_peer): + def _CreateSocket(self, ssl_params, ssl_verify_peer, family): """Creates a TCP socket and initializes SSL if needed. @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 + @type family: int + @param family: socket.AF_INET | socket.AF_INET6 """ - self._ssl_params = ssl_params + assert family in (socket.AF_INET, socket.AF_INET6) - sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) + self._ssl_params = ssl_params + sock = socket.socket(family, 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() @@ -404,6 +598,7 @@ class HttpBase(object): ctx = OpenSSL.SSL.Context(OpenSSL.SSL.SSLv23_METHOD) ctx.set_options(OpenSSL.SSL.OP_NO_SSLv2) + ctx.set_cipher_list(constants.OPENSSL_CIPHERS) ctx.use_privatekey(self._ssl_key) ctx.use_certificate(self._ssl_cert) @@ -423,6 +618,8 @@ class HttpBase(object): we do on our side. """ + # some parameters are unused, but this is the API + # pylint: disable-msg=W0613 assert self._ssl_params, "SSL not initialized" return (self._ssl_cert.digest("sha1") == cert.digest("sha1") and @@ -437,7 +634,6 @@ class HttpMessage(object): self.start_line = None self.headers = None self.body = None - self.decoded_body = None class HttpClientToServerStartLine(object): @@ -487,16 +683,13 @@ class HttpMessageWriter(object): 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)] - sent = SocketOperation(poller, sock, SOCKOP_SEND, data, - write_timeout) + sent = SocketOperation(sock, SOCKOP_SEND, data, write_timeout) # Remove sent bytes pos += sent @@ -542,7 +735,7 @@ class HttpMessageWriter(object): def HasMessageBody(self): """Checks whether the HTTP message contains a body. - Can be overriden by subclasses. + Can be overridden by subclasses. """ return bool(self._msg.body) @@ -576,7 +769,6 @@ class HttpMessageReader(object): self.sock = sock self.msg = msg - self.poller = select.poll() self.start_line_buffer = None self.header_buffer = StringIO() self.body_buffer = StringIO() @@ -587,8 +779,9 @@ 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 @@ -599,7 +792,7 @@ class HttpMessageReader(object): buf = self._ContinueParsing(buf, eof) # Must be done only after the buffer has been evaluated - # TODO: Connection-length < len(data read) and connection closed + # TODO: Content-Length < len(data read) and connection closed if (eof and self.parser_status in (self.PS_START_LINE, self.PS_HEADERS)): @@ -611,17 +804,9 @@ class HttpMessageReader(object): assert self.parser_status == self.PS_COMPLETE assert not buf, "Parser didn't read full response" + # Body is complete msg.body = self.body_buffer.getvalue() - # TODO: Content-type, error handling - if msg.body: - msg.decoded_body = HttpJsonConverter().Decode(msg.body) - else: - msg.decoded_body = None - - if msg.decoded_body: - logging.debug("Message body: %s", msg.decoded_body) - def _ContinueParsing(self, buf, eof): """Main function for HTTP message state machine. @@ -633,6 +818,7 @@ 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: @@ -645,7 +831,7 @@ class HttpMessageReader(object): # the CRLF." if idx == 0: # TODO: Limit number of CRLFs/empty lines for safety? - buf = buf[:2] + buf = buf[2:] continue if idx > 0: @@ -698,6 +884,8 @@ 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 @@ -732,7 +920,7 @@ class HttpMessageReader(object): def ParseStartLine(self, start_line): """Parses the start line of a message. - Must be overriden by subclass. + Must be overridden by subclass. @type start_line: string @param start_line: Start line string @@ -784,9 +972,9 @@ 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 @@ -800,7 +988,7 @@ class HttpMessageReader(object): if hdr_content_length: try: self.content_length = int(hdr_content_length) - except ValueError: + except (TypeError, ValueError): self.content_length = None if self.content_length is not None and self.content_length < 0: self.content_length = None