source: trunk/essentials/dev-lang/python/Lib/BaseHTTPServer.py

Last change on this file was 3225, checked in by bird, 18 years ago

Python 2.5

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1"""HTTP server base class.
2
3Note: the class in this module doesn't implement any HTTP request; see
4SimpleHTTPServer for simple implementations of GET, HEAD and POST
5(including CGI scripts). It does, however, optionally implement HTTP/1.1
6persistent connections, as of version 0.3.
7
8Contents:
9
10- BaseHTTPRequestHandler: HTTP request handler base class
11- test: test function
12
13XXX To do:
14
15- log requests even later (to capture byte count)
16- log user-agent header and other interesting goodies
17- send error log to separate file
18"""
19
20
21# See also:
22#
23# HTTP Working Group T. Berners-Lee
24# INTERNET-DRAFT R. T. Fielding
25# <draft-ietf-http-v10-spec-00.txt> H. Frystyk Nielsen
26# Expires September 8, 1995 March 8, 1995
27#
28# URL: http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-v10-spec-00.txt
29#
30# and
31#
32# Network Working Group R. Fielding
33# Request for Comments: 2616 et al
34# Obsoletes: 2068 June 1999
35# Category: Standards Track
36#
37# URL: http://www.faqs.org/rfcs/rfc2616.html
38
39# Log files
40# ---------
41#
42# Here's a quote from the NCSA httpd docs about log file format.
43#
44# | The logfile format is as follows. Each line consists of:
45# |
46# | host rfc931 authuser [DD/Mon/YYYY:hh:mm:ss] "request" ddd bbbb
47# |
48# | host: Either the DNS name or the IP number of the remote client
49# | rfc931: Any information returned by identd for this person,
50# | - otherwise.
51# | authuser: If user sent a userid for authentication, the user name,
52# | - otherwise.
53# | DD: Day
54# | Mon: Month (calendar name)
55# | YYYY: Year
56# | hh: hour (24-hour format, the machine's timezone)
57# | mm: minutes
58# | ss: seconds
59# | request: The first line of the HTTP request as sent by the client.
60# | ddd: the status code returned by the server, - if not available.
61# | bbbb: the total number of bytes sent,
62# | *not including the HTTP/1.0 header*, - if not available
63# |
64# | You can determine the name of the file accessed through request.
65#
66# (Actually, the latter is only true if you know the server configuration
67# at the time the request was made!)
68
69__version__ = "0.3"
70
71__all__ = ["HTTPServer", "BaseHTTPRequestHandler"]
72
73import sys
74import time
75import socket # For gethostbyaddr()
76import mimetools
77import SocketServer
78
79# Default error message
80DEFAULT_ERROR_MESSAGE = """\
81<head>
82<title>Error response</title>
83</head>
84<body>
85<h1>Error response</h1>
86<p>Error code %(code)d.
87<p>Message: %(message)s.
88<p>Error code explanation: %(code)s = %(explain)s.
89</body>
90"""
91
92def _quote_html(html):
93 return html.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
94
95class HTTPServer(SocketServer.TCPServer):
96
97 allow_reuse_address = 1 # Seems to make sense in testing environment
98
99 def server_bind(self):
100 """Override server_bind to store the server name."""
101 SocketServer.TCPServer.server_bind(self)
102 host, port = self.socket.getsockname()[:2]
103 self.server_name = socket.getfqdn(host)
104 self.server_port = port
105
106
107class BaseHTTPRequestHandler(SocketServer.StreamRequestHandler):
108
109 """HTTP request handler base class.
110
111 The following explanation of HTTP serves to guide you through the
112 code as well as to expose any misunderstandings I may have about
113 HTTP (so you don't need to read the code to figure out I'm wrong
114 :-).
115
116 HTTP (HyperText Transfer Protocol) is an extensible protocol on
117 top of a reliable stream transport (e.g. TCP/IP). The protocol
118 recognizes three parts to a request:
119
120 1. One line identifying the request type and path
121 2. An optional set of RFC-822-style headers
122 3. An optional data part
123
124 The headers and data are separated by a blank line.
125
126 The first line of the request has the form
127
128 <command> <path> <version>
129
130 where <command> is a (case-sensitive) keyword such as GET or POST,
131 <path> is a string containing path information for the request,
132 and <version> should be the string "HTTP/1.0" or "HTTP/1.1".
133 <path> is encoded using the URL encoding scheme (using %xx to signify
134 the ASCII character with hex code xx).
135
136 The specification specifies that lines are separated by CRLF but
137 for compatibility with the widest range of clients recommends
138 servers also handle LF. Similarly, whitespace in the request line
139 is treated sensibly (allowing multiple spaces between components
140 and allowing trailing whitespace).
141
142 Similarly, for output, lines ought to be separated by CRLF pairs
143 but most clients grok LF characters just fine.
144
145 If the first line of the request has the form
146
147 <command> <path>
148
149 (i.e. <version> is left out) then this is assumed to be an HTTP
150 0.9 request; this form has no optional headers and data part and
151 the reply consists of just the data.
152
153 The reply form of the HTTP 1.x protocol again has three parts:
154
155 1. One line giving the response code
156 2. An optional set of RFC-822-style headers
157 3. The data
158
159 Again, the headers and data are separated by a blank line.
160
161 The response code line has the form
162
163 <version> <responsecode> <responsestring>
164
165 where <version> is the protocol version ("HTTP/1.0" or "HTTP/1.1"),
166 <responsecode> is a 3-digit response code indicating success or
167 failure of the request, and <responsestring> is an optional
168 human-readable string explaining what the response code means.
169
170 This server parses the request and the headers, and then calls a
171 function specific to the request type (<command>). Specifically,
172 a request SPAM will be handled by a method do_SPAM(). If no
173 such method exists the server sends an error response to the
174 client. If it exists, it is called with no arguments:
175
176 do_SPAM()
177
178 Note that the request name is case sensitive (i.e. SPAM and spam
179 are different requests).
180
181 The various request details are stored in instance variables:
182
183 - client_address is the client IP address in the form (host,
184 port);
185
186 - command, path and version are the broken-down request line;
187
188 - headers is an instance of mimetools.Message (or a derived
189 class) containing the header information;
190
191 - rfile is a file object open for reading positioned at the
192 start of the optional input data part;
193
194 - wfile is a file object open for writing.
195
196 IT IS IMPORTANT TO ADHERE TO THE PROTOCOL FOR WRITING!
197
198 The first thing to be written must be the response line. Then
199 follow 0 or more header lines, then a blank line, and then the
200 actual data (if any). The meaning of the header lines depends on
201 the command executed by the server; in most cases, when data is
202 returned, there should be at least one header line of the form
203
204 Content-type: <type>/<subtype>
205
206 where <type> and <subtype> should be registered MIME types,
207 e.g. "text/html" or "text/plain".
208
209 """
210
211 # The Python system version, truncated to its first component.
212 sys_version = "Python/" + sys.version.split()[0]
213
214 # The server software version. You may want to override this.
215 # The format is multiple whitespace-separated strings,
216 # where each string is of the form name[/version].
217 server_version = "BaseHTTP/" + __version__
218
219 def parse_request(self):
220 """Parse a request (internal).
221
222 The request should be stored in self.raw_requestline; the results
223 are in self.command, self.path, self.request_version and
224 self.headers.
225
226 Return True for success, False for failure; on failure, an
227 error is sent back.
228
229 """
230 self.command = None # set in case of error on the first line
231 self.request_version = version = "HTTP/0.9" # Default
232 self.close_connection = 1
233 requestline = self.raw_requestline
234 if requestline[-2:] == '\r\n':
235 requestline = requestline[:-2]
236 elif requestline[-1:] == '\n':
237 requestline = requestline[:-1]
238 self.requestline = requestline
239 words = requestline.split()
240 if len(words) == 3:
241 [command, path, version] = words
242 if version[:5] != 'HTTP/':
243 self.send_error(400, "Bad request version (%r)" % version)
244 return False
245 try:
246 base_version_number = version.split('/', 1)[1]
247 version_number = base_version_number.split(".")
248 # RFC 2145 section 3.1 says there can be only one "." and
249 # - major and minor numbers MUST be treated as
250 # separate integers;
251 # - HTTP/2.4 is a lower version than HTTP/2.13, which in
252 # turn is lower than HTTP/12.3;
253 # - Leading zeros MUST be ignored by recipients.
254 if len(version_number) != 2:
255 raise ValueError
256 version_number = int(version_number[0]), int(version_number[1])
257 except (ValueError, IndexError):
258 self.send_error(400, "Bad request version (%r)" % version)
259 return False
260 if version_number >= (1, 1) and self.protocol_version >= "HTTP/1.1":
261 self.close_connection = 0
262 if version_number >= (2, 0):
263 self.send_error(505,
264 "Invalid HTTP Version (%s)" % base_version_number)
265 return False
266 elif len(words) == 2:
267 [command, path] = words
268 self.close_connection = 1
269 if command != 'GET':
270 self.send_error(400,
271 "Bad HTTP/0.9 request type (%r)" % command)
272 return False
273 elif not words:
274 return False
275 else:
276 self.send_error(400, "Bad request syntax (%r)" % requestline)
277 return False
278 self.command, self.path, self.request_version = command, path, version
279
280 # Examine the headers and look for a Connection directive
281 self.headers = self.MessageClass(self.rfile, 0)
282
283 conntype = self.headers.get('Connection', "")
284 if conntype.lower() == 'close':
285 self.close_connection = 1
286 elif (conntype.lower() == 'keep-alive' and
287 self.protocol_version >= "HTTP/1.1"):
288 self.close_connection = 0
289 return True
290
291 def handle_one_request(self):
292 """Handle a single HTTP request.
293
294 You normally don't need to override this method; see the class
295 __doc__ string for information on how to handle specific HTTP
296 commands such as GET and POST.
297
298 """
299 self.raw_requestline = self.rfile.readline()
300 if not self.raw_requestline:
301 self.close_connection = 1
302 return
303 if not self.parse_request(): # An error code has been sent, just exit
304 return
305 mname = 'do_' + self.command
306 if not hasattr(self, mname):
307 self.send_error(501, "Unsupported method (%r)" % self.command)
308 return
309 method = getattr(self, mname)
310 method()
311
312 def handle(self):
313 """Handle multiple requests if necessary."""
314 self.close_connection = 1
315
316 self.handle_one_request()
317 while not self.close_connection:
318 self.handle_one_request()
319
320 def send_error(self, code, message=None):
321 """Send and log an error reply.
322
323 Arguments are the error code, and a detailed message.
324 The detailed message defaults to the short entry matching the
325 response code.
326
327 This sends an error response (so it must be called before any
328 output has been generated), logs the error, and finally sends
329 a piece of HTML explaining the error to the user.
330
331 """
332
333 try:
334 short, long = self.responses[code]
335 except KeyError:
336 short, long = '???', '???'
337 if message is None:
338 message = short
339 explain = long
340 self.log_error("code %d, message %s", code, message)
341 # using _quote_html to prevent Cross Site Scripting attacks (see bug #1100201)
342 content = (self.error_message_format %
343 {'code': code, 'message': _quote_html(message), 'explain': explain})
344 self.send_response(code, message)
345 self.send_header("Content-Type", "text/html")
346 self.send_header('Connection', 'close')
347 self.end_headers()
348 if self.command != 'HEAD' and code >= 200 and code not in (204, 304):
349 self.wfile.write(content)
350
351 error_message_format = DEFAULT_ERROR_MESSAGE
352
353 def send_response(self, code, message=None):
354 """Send the response header and log the response code.
355
356 Also send two standard headers with the server software
357 version and the current date.
358
359 """
360 self.log_request(code)
361 if message is None:
362 if code in self.responses:
363 message = self.responses[code][0]
364 else:
365 message = ''
366 if self.request_version != 'HTTP/0.9':
367 self.wfile.write("%s %d %s\r\n" %
368 (self.protocol_version, code, message))
369 # print (self.protocol_version, code, message)
370 self.send_header('Server', self.version_string())
371 self.send_header('Date', self.date_time_string())
372
373 def send_header(self, keyword, value):
374 """Send a MIME header."""
375 if self.request_version != 'HTTP/0.9':
376 self.wfile.write("%s: %s\r\n" % (keyword, value))
377
378 if keyword.lower() == 'connection':
379 if value.lower() == 'close':
380 self.close_connection = 1
381 elif value.lower() == 'keep-alive':
382 self.close_connection = 0
383
384 def end_headers(self):
385 """Send the blank line ending the MIME headers."""
386 if self.request_version != 'HTTP/0.9':
387 self.wfile.write("\r\n")
388
389 def log_request(self, code='-', size='-'):
390 """Log an accepted request.
391
392 This is called by send_response().
393
394 """
395
396 self.log_message('"%s" %s %s',
397 self.requestline, str(code), str(size))
398
399 def log_error(self, *args):
400 """Log an error.
401
402 This is called when a request cannot be fulfilled. By
403 default it passes the message on to log_message().
404
405 Arguments are the same as for log_message().
406
407 XXX This should go to the separate error log.
408
409 """
410
411 self.log_message(*args)
412
413 def log_message(self, format, *args):
414 """Log an arbitrary message.
415
416 This is used by all other logging functions. Override
417 it if you have specific logging wishes.
418
419 The first argument, FORMAT, is a format string for the
420 message to be logged. If the format string contains
421 any % escapes requiring parameters, they should be
422 specified as subsequent arguments (it's just like
423 printf!).
424
425 The client host and current date/time are prefixed to
426 every message.
427
428 """
429
430 sys.stderr.write("%s - - [%s] %s\n" %
431 (self.address_string(),
432 self.log_date_time_string(),
433 format%args))
434
435 def version_string(self):
436 """Return the server software version string."""
437 return self.server_version + ' ' + self.sys_version
438
439 def date_time_string(self, timestamp=None):
440 """Return the current date and time formatted for a message header."""
441 if timestamp is None:
442 timestamp = time.time()
443 year, month, day, hh, mm, ss, wd, y, z = time.gmtime(timestamp)
444 s = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
445 self.weekdayname[wd],
446 day, self.monthname[month], year,
447 hh, mm, ss)
448 return s
449
450 def log_date_time_string(self):
451 """Return the current time formatted for logging."""
452 now = time.time()
453 year, month, day, hh, mm, ss, x, y, z = time.localtime(now)
454 s = "%02d/%3s/%04d %02d:%02d:%02d" % (
455 day, self.monthname[month], year, hh, mm, ss)
456 return s
457
458 weekdayname = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
459
460 monthname = [None,
461 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
462 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
463
464 def address_string(self):
465 """Return the client address formatted for logging.
466
467 This version looks up the full hostname using gethostbyaddr(),
468 and tries to find a name that contains at least one dot.
469
470 """
471
472 host, port = self.client_address[:2]
473 return socket.getfqdn(host)
474
475 # Essentially static class variables
476
477 # The version of the HTTP protocol we support.
478 # Set this to HTTP/1.1 to enable automatic keepalive
479 protocol_version = "HTTP/1.0"
480
481 # The Message-like class used to parse headers
482 MessageClass = mimetools.Message
483
484 # Table mapping response codes to messages; entries have the
485 # form {code: (shortmessage, longmessage)}.
486 # See RFC 2616.
487 responses = {
488 100: ('Continue', 'Request received, please continue'),
489 101: ('Switching Protocols',
490 'Switching to new protocol; obey Upgrade header'),
491
492 200: ('OK', 'Request fulfilled, document follows'),
493 201: ('Created', 'Document created, URL follows'),
494 202: ('Accepted',
495 'Request accepted, processing continues off-line'),
496 203: ('Non-Authoritative Information', 'Request fulfilled from cache'),
497 204: ('No Content', 'Request fulfilled, nothing follows'),
498 205: ('Reset Content', 'Clear input form for further input.'),
499 206: ('Partial Content', 'Partial content follows.'),
500
501 300: ('Multiple Choices',
502 'Object has several resources -- see URI list'),
503 301: ('Moved Permanently', 'Object moved permanently -- see URI list'),
504 302: ('Found', 'Object moved temporarily -- see URI list'),
505 303: ('See Other', 'Object moved -- see Method and URL list'),
506 304: ('Not Modified',
507 'Document has not changed since given time'),
508 305: ('Use Proxy',
509 'You must use proxy specified in Location to access this '
510 'resource.'),
511 307: ('Temporary Redirect',
512 'Object moved temporarily -- see URI list'),
513
514 400: ('Bad Request',
515 'Bad request syntax or unsupported method'),
516 401: ('Unauthorized',
517 'No permission -- see authorization schemes'),
518 402: ('Payment Required',
519 'No payment -- see charging schemes'),
520 403: ('Forbidden',
521 'Request forbidden -- authorization will not help'),
522 404: ('Not Found', 'Nothing matches the given URI'),
523 405: ('Method Not Allowed',
524 'Specified method is invalid for this server.'),
525 406: ('Not Acceptable', 'URI not available in preferred format.'),
526 407: ('Proxy Authentication Required', 'You must authenticate with '
527 'this proxy before proceeding.'),
528 408: ('Request Timeout', 'Request timed out; try again later.'),
529 409: ('Conflict', 'Request conflict.'),
530 410: ('Gone',
531 'URI no longer exists and has been permanently removed.'),
532 411: ('Length Required', 'Client must specify Content-Length.'),
533 412: ('Precondition Failed', 'Precondition in headers is false.'),
534 413: ('Request Entity Too Large', 'Entity is too large.'),
535 414: ('Request-URI Too Long', 'URI is too long.'),
536 415: ('Unsupported Media Type', 'Entity body in unsupported format.'),
537 416: ('Requested Range Not Satisfiable',
538 'Cannot satisfy request range.'),
539 417: ('Expectation Failed',
540 'Expect condition could not be satisfied.'),
541
542 500: ('Internal Server Error', 'Server got itself in trouble'),
543 501: ('Not Implemented',
544 'Server does not support this operation'),
545 502: ('Bad Gateway', 'Invalid responses from another server/proxy.'),
546 503: ('Service Unavailable',
547 'The server cannot process the request due to a high load'),
548 504: ('Gateway Timeout',
549 'The gateway server did not receive a timely response'),
550 505: ('HTTP Version Not Supported', 'Cannot fulfill request.'),
551 }
552
553
554def test(HandlerClass = BaseHTTPRequestHandler,
555 ServerClass = HTTPServer, protocol="HTTP/1.0"):
556 """Test the HTTP request handler class.
557
558 This runs an HTTP server on port 8000 (or the first command line
559 argument).
560
561 """
562
563 if sys.argv[1:]:
564 port = int(sys.argv[1])
565 else:
566 port = 8000
567 server_address = ('', port)
568
569 HandlerClass.protocol_version = protocol
570 httpd = ServerClass(server_address, HandlerClass)
571
572 sa = httpd.socket.getsockname()
573 print "Serving HTTP on", sa[0], "port", sa[1], "..."
574 httpd.serve_forever()
575
576
577if __name__ == '__main__':
578 test()
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