root / lib / http / __init__.py @ dcd511c8
History | View | Annotate | Download (26.8 kB)
1 |
#
|
---|---|
2 |
#
|
3 |
|
4 |
# Copyright (C) 2007, 2008 Google Inc.
|
5 |
#
|
6 |
# This program is free software; you can redistribute it and/or modify
|
7 |
# it under the terms of the GNU General Public License as published by
|
8 |
# the Free Software Foundation; either version 2 of the License, or
|
9 |
# (at your option) any later version.
|
10 |
#
|
11 |
# This program is distributed in the hope that it will be useful, but
|
12 |
# WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
# General Public License for more details.
|
15 |
#
|
16 |
# You should have received a copy of the GNU General Public License
|
17 |
# along with this program; if not, write to the Free Software
|
18 |
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
19 |
# 02110-1301, USA.
|
20 |
|
21 |
"""HTTP module.
|
22 |
|
23 |
"""
|
24 |
|
25 |
import logging |
26 |
import mimetools |
27 |
import OpenSSL |
28 |
import select |
29 |
import socket |
30 |
import errno |
31 |
|
32 |
from cStringIO import StringIO |
33 |
|
34 |
from ganeti import constants |
35 |
from ganeti import serializer |
36 |
from ganeti import utils |
37 |
|
38 |
|
39 |
HTTP_GANETI_VERSION = "Ganeti %s" % constants.RELEASE_VERSION
|
40 |
|
41 |
HTTP_OK = 200
|
42 |
HTTP_NO_CONTENT = 204
|
43 |
HTTP_NOT_MODIFIED = 304
|
44 |
|
45 |
HTTP_0_9 = "HTTP/0.9"
|
46 |
HTTP_1_0 = "HTTP/1.0"
|
47 |
HTTP_1_1 = "HTTP/1.1"
|
48 |
|
49 |
HTTP_GET = "GET"
|
50 |
HTTP_HEAD = "HEAD"
|
51 |
HTTP_POST = "POST"
|
52 |
HTTP_PUT = "PUT"
|
53 |
HTTP_DELETE = "DELETE"
|
54 |
|
55 |
HTTP_ETAG = "ETag"
|
56 |
HTTP_HOST = "Host"
|
57 |
HTTP_SERVER = "Server"
|
58 |
HTTP_DATE = "Date"
|
59 |
HTTP_USER_AGENT = "User-Agent"
|
60 |
HTTP_CONTENT_TYPE = "Content-Type"
|
61 |
HTTP_CONTENT_LENGTH = "Content-Length"
|
62 |
HTTP_CONNECTION = "Connection"
|
63 |
HTTP_KEEP_ALIVE = "Keep-Alive"
|
64 |
HTTP_WWW_AUTHENTICATE = "WWW-Authenticate"
|
65 |
HTTP_AUTHORIZATION = "Authorization"
|
66 |
HTTP_AUTHENTICATION_INFO = "Authentication-Info"
|
67 |
HTTP_ALLOW = "Allow"
|
68 |
|
69 |
_SSL_UNEXPECTED_EOF = "Unexpected EOF"
|
70 |
|
71 |
# Socket operations
|
72 |
(SOCKOP_SEND, |
73 |
SOCKOP_RECV, |
74 |
SOCKOP_SHUTDOWN, |
75 |
SOCKOP_HANDSHAKE) = range(4) |
76 |
|
77 |
# send/receive quantum
|
78 |
SOCK_BUF_SIZE = 32768
|
79 |
|
80 |
|
81 |
class HttpError(Exception): |
82 |
"""Internal exception for HTTP errors.
|
83 |
|
84 |
This should only be used for internal error reporting.
|
85 |
|
86 |
"""
|
87 |
|
88 |
|
89 |
class HttpConnectionClosed(Exception): |
90 |
"""Internal exception for a closed connection.
|
91 |
|
92 |
This should only be used for internal error reporting. Only use
|
93 |
it if there's no other way to report this condition.
|
94 |
|
95 |
"""
|
96 |
|
97 |
|
98 |
class HttpSessionHandshakeUnexpectedEOF(HttpError): |
99 |
"""Internal exception for errors during SSL handshake.
|
100 |
|
101 |
This should only be used for internal error reporting.
|
102 |
|
103 |
"""
|
104 |
|
105 |
|
106 |
class HttpSocketTimeout(Exception): |
107 |
"""Internal exception for socket timeouts.
|
108 |
|
109 |
This should only be used for internal error reporting.
|
110 |
|
111 |
"""
|
112 |
|
113 |
|
114 |
class HttpException(Exception): |
115 |
code = None
|
116 |
message = None
|
117 |
|
118 |
def __init__(self, message=None, headers=None): |
119 |
Exception.__init__(self) |
120 |
self.message = message
|
121 |
self.headers = headers
|
122 |
|
123 |
|
124 |
class HttpBadRequest(HttpException): |
125 |
"""400 Bad Request
|
126 |
|
127 |
RFC2616, 10.4.1: The request could not be understood by the server
|
128 |
due to malformed syntax. The client SHOULD NOT repeat the request
|
129 |
without modifications.
|
130 |
|
131 |
"""
|
132 |
code = 400
|
133 |
|
134 |
|
135 |
class HttpUnauthorized(HttpException): |
136 |
"""401 Unauthorized
|
137 |
|
138 |
RFC2616, section 10.4.2: The request requires user
|
139 |
authentication. The response MUST include a WWW-Authenticate header
|
140 |
field (section 14.47) containing a challenge applicable to the
|
141 |
requested resource.
|
142 |
|
143 |
"""
|
144 |
code = 401
|
145 |
|
146 |
|
147 |
class HttpForbidden(HttpException): |
148 |
"""403 Forbidden
|
149 |
|
150 |
RFC2616, 10.4.4: The server understood the request, but is refusing
|
151 |
to fulfill it. Authorization will not help and the request SHOULD
|
152 |
NOT be repeated.
|
153 |
|
154 |
"""
|
155 |
code = 403
|
156 |
|
157 |
|
158 |
class HttpNotFound(HttpException): |
159 |
"""404 Not Found
|
160 |
|
161 |
RFC2616, 10.4.5: The server has not found anything matching the
|
162 |
Request-URI. No indication is given of whether the condition is
|
163 |
temporary or permanent.
|
164 |
|
165 |
"""
|
166 |
code = 404
|
167 |
|
168 |
|
169 |
class HttpMethodNotAllowed(HttpException): |
170 |
"""405 Method Not Allowed
|
171 |
|
172 |
RFC2616, 10.4.6: The method specified in the Request-Line is not
|
173 |
allowed for the resource identified by the Request-URI. The response
|
174 |
MUST include an Allow header containing a list of valid methods for
|
175 |
the requested resource.
|
176 |
|
177 |
"""
|
178 |
code = 405
|
179 |
|
180 |
|
181 |
class HttpRequestTimeout(HttpException): |
182 |
"""408 Request Timeout
|
183 |
|
184 |
RFC2616, 10.4.9: The client did not produce a request within the
|
185 |
time that the server was prepared to wait. The client MAY repeat the
|
186 |
request without modifications at any later time.
|
187 |
|
188 |
"""
|
189 |
code = 408
|
190 |
|
191 |
|
192 |
class HttpConflict(HttpException): |
193 |
"""409 Conflict
|
194 |
|
195 |
RFC2616, 10.4.10: The request could not be completed due to a
|
196 |
conflict with the current state of the resource. This code is only
|
197 |
allowed in situations where it is expected that the user might be
|
198 |
able to resolve the conflict and resubmit the request.
|
199 |
|
200 |
"""
|
201 |
code = 409
|
202 |
|
203 |
|
204 |
class HttpGone(HttpException): |
205 |
"""410 Gone
|
206 |
|
207 |
RFC2616, 10.4.11: The requested resource is no longer available at
|
208 |
the server and no forwarding address is known. This condition is
|
209 |
expected to be considered permanent.
|
210 |
|
211 |
"""
|
212 |
code = 410
|
213 |
|
214 |
|
215 |
class HttpLengthRequired(HttpException): |
216 |
"""411 Length Required
|
217 |
|
218 |
RFC2616, 10.4.12: The server refuses to accept the request without a
|
219 |
defined Content-Length. The client MAY repeat the request if it adds
|
220 |
a valid Content-Length header field containing the length of the
|
221 |
message-body in the request message.
|
222 |
|
223 |
"""
|
224 |
code = 411
|
225 |
|
226 |
|
227 |
class HttpPreconditionFailed(HttpException): |
228 |
"""412 Precondition Failed
|
229 |
|
230 |
RFC2616, 10.4.13: The precondition given in one or more of the
|
231 |
request-header fields evaluated to false when it was tested on the
|
232 |
server.
|
233 |
|
234 |
"""
|
235 |
code = 412
|
236 |
|
237 |
|
238 |
class HttpInternalServerError(HttpException): |
239 |
"""500 Internal Server Error
|
240 |
|
241 |
RFC2616, 10.5.1: The server encountered an unexpected condition
|
242 |
which prevented it from fulfilling the request.
|
243 |
|
244 |
"""
|
245 |
code = 500
|
246 |
|
247 |
|
248 |
class HttpNotImplemented(HttpException): |
249 |
"""501 Not Implemented
|
250 |
|
251 |
RFC2616, 10.5.2: The server does not support the functionality
|
252 |
required to fulfill the request.
|
253 |
|
254 |
"""
|
255 |
code = 501
|
256 |
|
257 |
|
258 |
class HttpBadGateway(HttpException): |
259 |
"""502 Bad Gateway
|
260 |
|
261 |
RFC2616, 10.5.3: The server, while acting as a gateway or proxy,
|
262 |
received an invalid response from the upstream server it accessed in
|
263 |
attempting to fulfill the request.
|
264 |
|
265 |
"""
|
266 |
code = 502
|
267 |
|
268 |
|
269 |
class HttpServiceUnavailable(HttpException): |
270 |
"""503 Service Unavailable
|
271 |
|
272 |
RFC2616, 10.5.4: The server is currently unable to handle the
|
273 |
request due to a temporary overloading or maintenance of the server.
|
274 |
|
275 |
"""
|
276 |
code = 503
|
277 |
|
278 |
|
279 |
class HttpGatewayTimeout(HttpException): |
280 |
"""504 Gateway Timeout
|
281 |
|
282 |
RFC2616, 10.5.5: The server, while acting as a gateway or proxy, did
|
283 |
not receive a timely response from the upstream server specified by
|
284 |
the URI (e.g. HTTP, FTP, LDAP) or some other auxiliary server
|
285 |
(e.g. DNS) it needed to access in attempting to complete the
|
286 |
request.
|
287 |
|
288 |
"""
|
289 |
code = 504
|
290 |
|
291 |
|
292 |
class HttpVersionNotSupported(HttpException): |
293 |
"""505 HTTP Version Not Supported
|
294 |
|
295 |
RFC2616, 10.5.6: The server does not support, or refuses to support,
|
296 |
the HTTP protocol version that was used in the request message.
|
297 |
|
298 |
"""
|
299 |
code = 505
|
300 |
|
301 |
|
302 |
class HttpJsonConverter: # pylint: disable-msg=W0232 |
303 |
CONTENT_TYPE = "application/json"
|
304 |
|
305 |
@staticmethod
|
306 |
def Encode(data): |
307 |
return serializer.DumpJson(data)
|
308 |
|
309 |
@staticmethod
|
310 |
def Decode(data): |
311 |
return serializer.LoadJson(data)
|
312 |
|
313 |
|
314 |
def SocketOperation(sock, op, arg1, timeout): |
315 |
"""Wrapper around socket functions.
|
316 |
|
317 |
This function abstracts error handling for socket operations, especially
|
318 |
for the complicated interaction with OpenSSL.
|
319 |
|
320 |
@type sock: socket
|
321 |
@param sock: Socket for the operation
|
322 |
@type op: int
|
323 |
@param op: Operation to execute (SOCKOP_* constants)
|
324 |
@type arg1: any
|
325 |
@param arg1: Parameter for function (if needed)
|
326 |
@type timeout: None or float
|
327 |
@param timeout: Timeout in seconds or None
|
328 |
@return: Return value of socket function
|
329 |
|
330 |
"""
|
331 |
# TODO: event_poll/event_check/override
|
332 |
if op in (SOCKOP_SEND, SOCKOP_HANDSHAKE): |
333 |
event_poll = select.POLLOUT |
334 |
|
335 |
elif op == SOCKOP_RECV:
|
336 |
event_poll = select.POLLIN |
337 |
|
338 |
elif op == SOCKOP_SHUTDOWN:
|
339 |
event_poll = None
|
340 |
|
341 |
# The timeout is only used when OpenSSL requests polling for a condition.
|
342 |
# It is not advisable to have no timeout for shutdown.
|
343 |
assert timeout
|
344 |
|
345 |
else:
|
346 |
raise AssertionError("Invalid socket operation") |
347 |
|
348 |
# Handshake is only supported by SSL sockets
|
349 |
if (op == SOCKOP_HANDSHAKE and |
350 |
not isinstance(sock, OpenSSL.SSL.ConnectionType)): |
351 |
return
|
352 |
|
353 |
# No override by default
|
354 |
event_override = 0
|
355 |
|
356 |
while True: |
357 |
# Poll only for certain operations and when asked for by an override
|
358 |
if event_override or op in (SOCKOP_SEND, SOCKOP_RECV, SOCKOP_HANDSHAKE): |
359 |
if event_override:
|
360 |
wait_for_event = event_override |
361 |
else:
|
362 |
wait_for_event = event_poll |
363 |
|
364 |
event = utils.WaitForSocketCondition(sock, wait_for_event, timeout) |
365 |
if event is None: |
366 |
raise HttpSocketTimeout()
|
367 |
|
368 |
if event & (select.POLLNVAL | select.POLLHUP | select.POLLERR):
|
369 |
# Let the socket functions handle these
|
370 |
break
|
371 |
|
372 |
if not event & wait_for_event: |
373 |
continue
|
374 |
|
375 |
# Reset override
|
376 |
event_override = 0
|
377 |
|
378 |
try:
|
379 |
try:
|
380 |
if op == SOCKOP_SEND:
|
381 |
return sock.send(arg1)
|
382 |
|
383 |
elif op == SOCKOP_RECV:
|
384 |
return sock.recv(arg1)
|
385 |
|
386 |
elif op == SOCKOP_SHUTDOWN:
|
387 |
if isinstance(sock, OpenSSL.SSL.ConnectionType): |
388 |
# PyOpenSSL's shutdown() doesn't take arguments
|
389 |
return sock.shutdown()
|
390 |
else:
|
391 |
return sock.shutdown(arg1)
|
392 |
|
393 |
elif op == SOCKOP_HANDSHAKE:
|
394 |
return sock.do_handshake()
|
395 |
|
396 |
except OpenSSL.SSL.WantWriteError:
|
397 |
# OpenSSL wants to write, poll for POLLOUT
|
398 |
event_override = select.POLLOUT |
399 |
continue
|
400 |
|
401 |
except OpenSSL.SSL.WantReadError:
|
402 |
# OpenSSL wants to read, poll for POLLIN
|
403 |
event_override = select.POLLIN | select.POLLPRI |
404 |
continue
|
405 |
|
406 |
except OpenSSL.SSL.WantX509LookupError:
|
407 |
continue
|
408 |
|
409 |
except OpenSSL.SSL.ZeroReturnError, err:
|
410 |
# SSL Connection has been closed. In SSL 3.0 and TLS 1.0, this only
|
411 |
# occurs if a closure alert has occurred in the protocol, i.e. the
|
412 |
# connection has been closed cleanly. Note that this does not
|
413 |
# necessarily mean that the transport layer (e.g. a socket) has been
|
414 |
# closed.
|
415 |
if op == SOCKOP_SEND:
|
416 |
# Can happen during a renegotiation
|
417 |
raise HttpConnectionClosed(err.args)
|
418 |
elif op == SOCKOP_RECV:
|
419 |
return "" |
420 |
|
421 |
# SSL_shutdown shouldn't return SSL_ERROR_ZERO_RETURN
|
422 |
raise socket.error(err.args)
|
423 |
|
424 |
except OpenSSL.SSL.SysCallError, err:
|
425 |
if op == SOCKOP_SEND:
|
426 |
# arg1 is the data when writing
|
427 |
if err.args and err.args[0] == -1 and arg1 == "": |
428 |
# errors when writing empty strings are expected
|
429 |
# and can be ignored
|
430 |
return 0 |
431 |
|
432 |
if err.args == (-1, _SSL_UNEXPECTED_EOF): |
433 |
if op == SOCKOP_RECV:
|
434 |
return "" |
435 |
elif op == SOCKOP_HANDSHAKE:
|
436 |
# Can happen if peer disconnects directly after the connection is
|
437 |
# opened.
|
438 |
raise HttpSessionHandshakeUnexpectedEOF(err.args)
|
439 |
|
440 |
raise socket.error(err.args)
|
441 |
|
442 |
except OpenSSL.SSL.Error, err:
|
443 |
raise socket.error(err.args)
|
444 |
|
445 |
except socket.error, err:
|
446 |
if err.args and err.args[0] == errno.EAGAIN: |
447 |
# Ignore EAGAIN
|
448 |
continue
|
449 |
|
450 |
raise
|
451 |
|
452 |
|
453 |
def ShutdownConnection(sock, close_timeout, write_timeout, msgreader, force): |
454 |
"""Closes the connection.
|
455 |
|
456 |
@type sock: socket
|
457 |
@param sock: Socket to be shut down
|
458 |
@type close_timeout: float
|
459 |
@param close_timeout: How long to wait for the peer to close
|
460 |
the connection
|
461 |
@type write_timeout: float
|
462 |
@param write_timeout: Write timeout for shutdown
|
463 |
@type msgreader: http.HttpMessageReader
|
464 |
@param msgreader: Request message reader, used to determine whether
|
465 |
peer should close connection
|
466 |
@type force: bool
|
467 |
@param force: Whether to forcibly close the connection without
|
468 |
waiting for peer
|
469 |
|
470 |
"""
|
471 |
#print msgreader.peer_will_close, force
|
472 |
if msgreader and msgreader.peer_will_close and not force: |
473 |
# Wait for peer to close
|
474 |
try:
|
475 |
# Check whether it's actually closed
|
476 |
if not SocketOperation(sock, SOCKOP_RECV, 1, close_timeout): |
477 |
return
|
478 |
except (socket.error, HttpError, HttpSocketTimeout):
|
479 |
# Ignore errors at this stage
|
480 |
pass
|
481 |
|
482 |
# Close the connection from our side
|
483 |
try:
|
484 |
# We don't care about the return value, see NOTES in SSL_shutdown(3).
|
485 |
SocketOperation(sock, SOCKOP_SHUTDOWN, socket.SHUT_RDWR, |
486 |
write_timeout) |
487 |
except HttpSocketTimeout:
|
488 |
raise HttpError("Timeout while shutting down connection") |
489 |
except socket.error, err:
|
490 |
# Ignore ENOTCONN
|
491 |
if not (err.args and err.args[0] == errno.ENOTCONN): |
492 |
raise HttpError("Error while shutting down connection: %s" % err) |
493 |
|
494 |
|
495 |
def Handshake(sock, write_timeout): |
496 |
"""Shakes peer's hands.
|
497 |
|
498 |
@type sock: socket
|
499 |
@param sock: Socket to be shut down
|
500 |
@type write_timeout: float
|
501 |
@param write_timeout: Write timeout for handshake
|
502 |
|
503 |
"""
|
504 |
try:
|
505 |
return SocketOperation(sock, SOCKOP_HANDSHAKE, None, write_timeout) |
506 |
except HttpSocketTimeout:
|
507 |
raise HttpError("Timeout during SSL handshake") |
508 |
except socket.error, err:
|
509 |
raise HttpError("Error in SSL handshake: %s" % err) |
510 |
|
511 |
|
512 |
def InitSsl(): |
513 |
"""Initializes the SSL infrastructure.
|
514 |
|
515 |
This function is idempotent.
|
516 |
|
517 |
"""
|
518 |
if not OpenSSL.rand.status(): |
519 |
raise EnvironmentError("OpenSSL could not collect enough entropy" |
520 |
" for the PRNG")
|
521 |
|
522 |
# TODO: Maybe add some additional seeding for OpenSSL's PRNG
|
523 |
|
524 |
|
525 |
class HttpSslParams(object): |
526 |
"""Data class for SSL key and certificate.
|
527 |
|
528 |
"""
|
529 |
def __init__(self, ssl_key_path, ssl_cert_path): |
530 |
"""Initializes this class.
|
531 |
|
532 |
@type ssl_key_path: string
|
533 |
@param ssl_key_path: Path to file containing SSL key in PEM format
|
534 |
@type ssl_cert_path: string
|
535 |
@param ssl_cert_path: Path to file containing SSL certificate
|
536 |
in PEM format
|
537 |
|
538 |
"""
|
539 |
self.ssl_key_pem = utils.ReadFile(ssl_key_path)
|
540 |
self.ssl_cert_pem = utils.ReadFile(ssl_cert_path)
|
541 |
|
542 |
def GetKey(self): |
543 |
return OpenSSL.crypto.load_privatekey(OpenSSL.crypto.FILETYPE_PEM,
|
544 |
self.ssl_key_pem)
|
545 |
|
546 |
def GetCertificate(self): |
547 |
return OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM,
|
548 |
self.ssl_cert_pem)
|
549 |
|
550 |
|
551 |
class HttpBase(object): |
552 |
"""Base class for HTTP server and client.
|
553 |
|
554 |
"""
|
555 |
def __init__(self): |
556 |
self.using_ssl = None |
557 |
self._ssl_params = None |
558 |
self._ssl_key = None |
559 |
self._ssl_cert = None |
560 |
|
561 |
def _CreateSocket(self, ssl_params, ssl_verify_peer): |
562 |
"""Creates a TCP socket and initializes SSL if needed.
|
563 |
|
564 |
@type ssl_params: HttpSslParams
|
565 |
@param ssl_params: SSL key and certificate
|
566 |
@type ssl_verify_peer: bool
|
567 |
@param ssl_verify_peer: Whether to require client certificate
|
568 |
and compare it with our certificate
|
569 |
|
570 |
"""
|
571 |
self._ssl_params = ssl_params
|
572 |
|
573 |
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) |
574 |
|
575 |
# Should we enable SSL?
|
576 |
self.using_ssl = ssl_params is not None |
577 |
|
578 |
if not self.using_ssl: |
579 |
return sock
|
580 |
|
581 |
self._ssl_key = ssl_params.GetKey()
|
582 |
self._ssl_cert = ssl_params.GetCertificate()
|
583 |
|
584 |
ctx = OpenSSL.SSL.Context(OpenSSL.SSL.SSLv23_METHOD) |
585 |
ctx.set_options(OpenSSL.SSL.OP_NO_SSLv2) |
586 |
|
587 |
ctx.use_privatekey(self._ssl_key)
|
588 |
ctx.use_certificate(self._ssl_cert)
|
589 |
ctx.check_privatekey() |
590 |
|
591 |
if ssl_verify_peer:
|
592 |
ctx.set_verify(OpenSSL.SSL.VERIFY_PEER | |
593 |
OpenSSL.SSL.VERIFY_FAIL_IF_NO_PEER_CERT, |
594 |
self._SSLVerifyCallback)
|
595 |
|
596 |
return OpenSSL.SSL.Connection(ctx, sock)
|
597 |
|
598 |
def _SSLVerifyCallback(self, conn, cert, errnum, errdepth, ok): |
599 |
"""Verify the certificate provided by the peer
|
600 |
|
601 |
We only compare fingerprints. The client must use the same certificate as
|
602 |
we do on our side.
|
603 |
|
604 |
"""
|
605 |
# some parameters are unused, but this is the API
|
606 |
# pylint: disable-msg=W0613
|
607 |
assert self._ssl_params, "SSL not initialized" |
608 |
|
609 |
return (self._ssl_cert.digest("sha1") == cert.digest("sha1") and |
610 |
self._ssl_cert.digest("md5") == cert.digest("md5")) |
611 |
|
612 |
|
613 |
class HttpMessage(object): |
614 |
"""Data structure for HTTP message.
|
615 |
|
616 |
"""
|
617 |
def __init__(self): |
618 |
self.start_line = None |
619 |
self.headers = None |
620 |
self.body = None |
621 |
self.decoded_body = None |
622 |
|
623 |
|
624 |
class HttpClientToServerStartLine(object): |
625 |
"""Data structure for HTTP request start line.
|
626 |
|
627 |
"""
|
628 |
def __init__(self, method, path, version): |
629 |
self.method = method
|
630 |
self.path = path
|
631 |
self.version = version
|
632 |
|
633 |
def __str__(self): |
634 |
return "%s %s %s" % (self.method, self.path, self.version) |
635 |
|
636 |
|
637 |
class HttpServerToClientStartLine(object): |
638 |
"""Data structure for HTTP response start line.
|
639 |
|
640 |
"""
|
641 |
def __init__(self, version, code, reason): |
642 |
self.version = version
|
643 |
self.code = code
|
644 |
self.reason = reason
|
645 |
|
646 |
def __str__(self): |
647 |
return "%s %s %s" % (self.version, self.code, self.reason) |
648 |
|
649 |
|
650 |
class HttpMessageWriter(object): |
651 |
"""Writes an HTTP message to a socket.
|
652 |
|
653 |
"""
|
654 |
def __init__(self, sock, msg, write_timeout): |
655 |
"""Initializes this class and writes an HTTP message to a socket.
|
656 |
|
657 |
@type sock: socket
|
658 |
@param sock: Socket to be written to
|
659 |
@type msg: http.HttpMessage
|
660 |
@param msg: HTTP message to be written
|
661 |
@type write_timeout: float
|
662 |
@param write_timeout: Write timeout for socket
|
663 |
|
664 |
"""
|
665 |
self._msg = msg
|
666 |
|
667 |
self._PrepareMessage()
|
668 |
|
669 |
buf = self._FormatMessage()
|
670 |
|
671 |
pos = 0
|
672 |
end = len(buf)
|
673 |
while pos < end:
|
674 |
# Send only SOCK_BUF_SIZE bytes at a time
|
675 |
data = buf[pos:(pos + SOCK_BUF_SIZE)] |
676 |
|
677 |
sent = SocketOperation(sock, SOCKOP_SEND, data, write_timeout) |
678 |
|
679 |
# Remove sent bytes
|
680 |
pos += sent |
681 |
|
682 |
assert pos == end, "Message wasn't sent completely" |
683 |
|
684 |
def _PrepareMessage(self): |
685 |
"""Prepares the HTTP message by setting mandatory headers.
|
686 |
|
687 |
"""
|
688 |
# RFC2616, section 4.3: "The presence of a message-body in a request is
|
689 |
# signaled by the inclusion of a Content-Length or Transfer-Encoding header
|
690 |
# field in the request's message-headers."
|
691 |
if self._msg.body: |
692 |
self._msg.headers[HTTP_CONTENT_LENGTH] = len(self._msg.body) |
693 |
|
694 |
def _FormatMessage(self): |
695 |
"""Serializes the HTTP message into a string.
|
696 |
|
697 |
"""
|
698 |
buf = StringIO() |
699 |
|
700 |
# Add start line
|
701 |
buf.write(str(self._msg.start_line)) |
702 |
buf.write("\r\n")
|
703 |
|
704 |
# Add headers
|
705 |
if self._msg.start_line.version != HTTP_0_9: |
706 |
for name, value in self._msg.headers.iteritems(): |
707 |
buf.write("%s: %s\r\n" % (name, value))
|
708 |
|
709 |
buf.write("\r\n")
|
710 |
|
711 |
# Add message body if needed
|
712 |
if self.HasMessageBody(): |
713 |
buf.write(self._msg.body)
|
714 |
|
715 |
elif self._msg.body: |
716 |
logging.warning("Ignoring message body")
|
717 |
|
718 |
return buf.getvalue()
|
719 |
|
720 |
def HasMessageBody(self): |
721 |
"""Checks whether the HTTP message contains a body.
|
722 |
|
723 |
Can be overridden by subclasses.
|
724 |
|
725 |
"""
|
726 |
return bool(self._msg.body) |
727 |
|
728 |
|
729 |
class HttpMessageReader(object): |
730 |
"""Reads HTTP message from socket.
|
731 |
|
732 |
"""
|
733 |
# Length limits
|
734 |
START_LINE_LENGTH_MAX = None
|
735 |
HEADER_LENGTH_MAX = None
|
736 |
|
737 |
# Parser state machine
|
738 |
PS_START_LINE = "start-line"
|
739 |
PS_HEADERS = "headers"
|
740 |
PS_BODY = "entity-body"
|
741 |
PS_COMPLETE = "complete"
|
742 |
|
743 |
def __init__(self, sock, msg, read_timeout): |
744 |
"""Reads an HTTP message from a socket.
|
745 |
|
746 |
@type sock: socket
|
747 |
@param sock: Socket to be read from
|
748 |
@type msg: http.HttpMessage
|
749 |
@param msg: Object for the read message
|
750 |
@type read_timeout: float
|
751 |
@param read_timeout: Read timeout for socket
|
752 |
|
753 |
"""
|
754 |
self.sock = sock
|
755 |
self.msg = msg
|
756 |
|
757 |
self.start_line_buffer = None |
758 |
self.header_buffer = StringIO()
|
759 |
self.body_buffer = StringIO()
|
760 |
self.parser_status = self.PS_START_LINE |
761 |
self.content_length = None |
762 |
self.peer_will_close = None |
763 |
|
764 |
buf = ""
|
765 |
eof = False
|
766 |
while self.parser_status != self.PS_COMPLETE: |
767 |
# TODO: Don't read more than necessary (Content-Length), otherwise
|
768 |
# data might be lost and/or an error could occur
|
769 |
data = SocketOperation(sock, SOCKOP_RECV, SOCK_BUF_SIZE, read_timeout) |
770 |
|
771 |
if data:
|
772 |
buf += data |
773 |
else:
|
774 |
eof = True
|
775 |
|
776 |
# Do some parsing and error checking while more data arrives
|
777 |
buf = self._ContinueParsing(buf, eof)
|
778 |
|
779 |
# Must be done only after the buffer has been evaluated
|
780 |
# TODO: Connection-length < len(data read) and connection closed
|
781 |
if (eof and |
782 |
self.parser_status in (self.PS_START_LINE, |
783 |
self.PS_HEADERS)):
|
784 |
raise HttpError("Connection closed prematurely") |
785 |
|
786 |
# Parse rest
|
787 |
buf = self._ContinueParsing(buf, True) |
788 |
|
789 |
assert self.parser_status == self.PS_COMPLETE |
790 |
assert not buf, "Parser didn't read full response" |
791 |
|
792 |
msg.body = self.body_buffer.getvalue()
|
793 |
|
794 |
# TODO: Content-type, error handling
|
795 |
if msg.body:
|
796 |
msg.decoded_body = HttpJsonConverter().Decode(msg.body) |
797 |
else:
|
798 |
msg.decoded_body = None
|
799 |
|
800 |
if msg.decoded_body:
|
801 |
logging.debug("Message body: %s", msg.decoded_body)
|
802 |
|
803 |
def _ContinueParsing(self, buf, eof): |
804 |
"""Main function for HTTP message state machine.
|
805 |
|
806 |
@type buf: string
|
807 |
@param buf: Receive buffer
|
808 |
@type eof: bool
|
809 |
@param eof: Whether we've reached EOF on the socket
|
810 |
@rtype: string
|
811 |
@return: Updated receive buffer
|
812 |
|
813 |
"""
|
814 |
# TODO: Use offset instead of slicing when possible
|
815 |
if self.parser_status == self.PS_START_LINE: |
816 |
# Expect start line
|
817 |
while True: |
818 |
idx = buf.find("\r\n")
|
819 |
|
820 |
# RFC2616, section 4.1: "In the interest of robustness, servers SHOULD
|
821 |
# ignore any empty line(s) received where a Request-Line is expected.
|
822 |
# In other words, if the server is reading the protocol stream at the
|
823 |
# beginning of a message and receives a CRLF first, it should ignore
|
824 |
# the CRLF."
|
825 |
if idx == 0: |
826 |
# TODO: Limit number of CRLFs/empty lines for safety?
|
827 |
buf = buf[2:]
|
828 |
continue
|
829 |
|
830 |
if idx > 0: |
831 |
self.start_line_buffer = buf[:idx]
|
832 |
|
833 |
self._CheckStartLineLength(len(self.start_line_buffer)) |
834 |
|
835 |
# Remove status line, including CRLF
|
836 |
buf = buf[idx + 2:]
|
837 |
|
838 |
self.msg.start_line = self.ParseStartLine(self.start_line_buffer) |
839 |
|
840 |
self.parser_status = self.PS_HEADERS |
841 |
else:
|
842 |
# Check whether incoming data is getting too large, otherwise we just
|
843 |
# fill our read buffer.
|
844 |
self._CheckStartLineLength(len(buf)) |
845 |
|
846 |
break
|
847 |
|
848 |
# TODO: Handle messages without headers
|
849 |
if self.parser_status == self.PS_HEADERS: |
850 |
# Wait for header end
|
851 |
idx = buf.find("\r\n\r\n")
|
852 |
if idx >= 0: |
853 |
self.header_buffer.write(buf[:idx + 2]) |
854 |
|
855 |
self._CheckHeaderLength(self.header_buffer.tell()) |
856 |
|
857 |
# Remove headers, including CRLF
|
858 |
buf = buf[idx + 4:]
|
859 |
|
860 |
self._ParseHeaders()
|
861 |
|
862 |
self.parser_status = self.PS_BODY |
863 |
else:
|
864 |
# Check whether incoming data is getting too large, otherwise we just
|
865 |
# fill our read buffer.
|
866 |
self._CheckHeaderLength(len(buf)) |
867 |
|
868 |
if self.parser_status == self.PS_BODY: |
869 |
# TODO: Implement max size for body_buffer
|
870 |
self.body_buffer.write(buf)
|
871 |
buf = ""
|
872 |
|
873 |
# Check whether we've read everything
|
874 |
#
|
875 |
# RFC2616, section 4.4: "When a message-body is included with a message,
|
876 |
# the transfer-length of that body is determined by one of the following
|
877 |
# [...] 5. By the server closing the connection. (Closing the connection
|
878 |
# cannot be used to indicate the end of a request body, since that would
|
879 |
# leave no possibility for the server to send back a response.)"
|
880 |
#
|
881 |
# TODO: Error when buffer length > Content-Length header
|
882 |
if (eof or |
883 |
self.content_length is None or |
884 |
(self.content_length is not None and |
885 |
self.body_buffer.tell() >= self.content_length)): |
886 |
self.parser_status = self.PS_COMPLETE |
887 |
|
888 |
return buf
|
889 |
|
890 |
def _CheckStartLineLength(self, length): |
891 |
"""Limits the start line buffer size.
|
892 |
|
893 |
@type length: int
|
894 |
@param length: Buffer size
|
895 |
|
896 |
"""
|
897 |
if (self.START_LINE_LENGTH_MAX is not None and |
898 |
length > self.START_LINE_LENGTH_MAX):
|
899 |
raise HttpError("Start line longer than %d chars" % |
900 |
self.START_LINE_LENGTH_MAX)
|
901 |
|
902 |
def _CheckHeaderLength(self, length): |
903 |
"""Limits the header buffer size.
|
904 |
|
905 |
@type length: int
|
906 |
@param length: Buffer size
|
907 |
|
908 |
"""
|
909 |
if (self.HEADER_LENGTH_MAX is not None and |
910 |
length > self.HEADER_LENGTH_MAX):
|
911 |
raise HttpError("Headers longer than %d chars" % self.HEADER_LENGTH_MAX) |
912 |
|
913 |
def ParseStartLine(self, start_line): |
914 |
"""Parses the start line of a message.
|
915 |
|
916 |
Must be overridden by subclass.
|
917 |
|
918 |
@type start_line: string
|
919 |
@param start_line: Start line string
|
920 |
|
921 |
"""
|
922 |
raise NotImplementedError() |
923 |
|
924 |
def _WillPeerCloseConnection(self): |
925 |
"""Evaluate whether peer will close the connection.
|
926 |
|
927 |
@rtype: bool
|
928 |
@return: Whether peer will close the connection
|
929 |
|
930 |
"""
|
931 |
# RFC2616, section 14.10: "HTTP/1.1 defines the "close" connection option
|
932 |
# for the sender to signal that the connection will be closed after
|
933 |
# completion of the response. For example,
|
934 |
#
|
935 |
# Connection: close
|
936 |
#
|
937 |
# in either the request or the response header fields indicates that the
|
938 |
# connection SHOULD NOT be considered `persistent' (section 8.1) after the
|
939 |
# current request/response is complete."
|
940 |
|
941 |
hdr_connection = self.msg.headers.get(HTTP_CONNECTION, None) |
942 |
if hdr_connection:
|
943 |
hdr_connection = hdr_connection.lower() |
944 |
|
945 |
# An HTTP/1.1 server is assumed to stay open unless explicitly closed.
|
946 |
if self.msg.start_line.version == HTTP_1_1: |
947 |
return (hdr_connection and "close" in hdr_connection) |
948 |
|
949 |
# Some HTTP/1.0 implementations have support for persistent connections,
|
950 |
# using rules different than HTTP/1.1.
|
951 |
|
952 |
# For older HTTP, Keep-Alive indicates persistent connection.
|
953 |
if self.msg.headers.get(HTTP_KEEP_ALIVE): |
954 |
return False |
955 |
|
956 |
# At least Akamai returns a "Connection: Keep-Alive" header, which was
|
957 |
# supposed to be sent by the client.
|
958 |
if hdr_connection and "keep-alive" in hdr_connection: |
959 |
return False |
960 |
|
961 |
return True |
962 |
|
963 |
def _ParseHeaders(self): |
964 |
"""Parses the headers.
|
965 |
|
966 |
This function also adjusts internal variables based on header values.
|
967 |
|
968 |
RFC2616, section 4.3: The presence of a message-body in a request is
|
969 |
signaled by the inclusion of a Content-Length or Transfer-Encoding header
|
970 |
field in the request's message-headers.
|
971 |
|
972 |
"""
|
973 |
# Parse headers
|
974 |
self.header_buffer.seek(0, 0) |
975 |
self.msg.headers = mimetools.Message(self.header_buffer, 0) |
976 |
|
977 |
self.peer_will_close = self._WillPeerCloseConnection() |
978 |
|
979 |
# Do we have a Content-Length header?
|
980 |
hdr_content_length = self.msg.headers.get(HTTP_CONTENT_LENGTH, None) |
981 |
if hdr_content_length:
|
982 |
try:
|
983 |
self.content_length = int(hdr_content_length) |
984 |
except (TypeError, ValueError): |
985 |
self.content_length = None |
986 |
if self.content_length is not None and self.content_length < 0: |
987 |
self.content_length = None |
988 |
|
989 |
# if the connection remains open and a content-length was not provided,
|
990 |
# then assume that the connection WILL close.
|
991 |
if self.content_length is None: |
992 |
self.peer_will_close = True |