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[python/dscho.git] / Lib / BaseHTTPServer.py
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1 """HTTP server base class.
3 Note: the class in this module doesn't implement any HTTP request; see
4 SimpleHTTPServer for simple implementations of GET, HEAD and POST
5 (including CGI scripts). It does, however, optionally implement HTTP/1.1
6 persistent connections, as of version 0.3.
8 Contents:
10 - BaseHTTPRequestHandler: HTTP request handler base class
11 - test: test function
13 XXX To do:
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 """
21 # See also:
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
28 # URL: http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-v10-spec-00.txt
30 # and
32 # Network Working Group R. Fielding
33 # Request for Comments: 2616 et al
34 # Obsoletes: 2068 June 1999
35 # Category: Standards Track
37 # URL: http://www.faqs.org/rfcs/rfc2616.html
39 # Log files
40 # ---------
42 # Here's a quote from the NCSA httpd docs about log file format.
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.
66 # (Actually, the latter is only true if you know the server configuration
67 # at the time the request was made!)
69 __version__ = "0.3"
71 __all__ = ["HTTPServer", "BaseHTTPRequestHandler"]
73 import sys
74 import time
75 import socket # For gethostbyaddr()
76 from warnings import filterwarnings, catch_warnings
77 with catch_warnings():
78 if sys.py3kwarning:
79 filterwarnings("ignore", ".*mimetools has been removed",
80 DeprecationWarning)
81 import mimetools
82 import SocketServer
84 # Default error message template
85 DEFAULT_ERROR_MESSAGE = """\
86 <head>
87 <title>Error response</title>
88 </head>
89 <body>
90 <h1>Error response</h1>
91 <p>Error code %(code)d.
92 <p>Message: %(message)s.
93 <p>Error code explanation: %(code)s = %(explain)s.
94 </body>
95 """
97 DEFAULT_ERROR_CONTENT_TYPE = "text/html"
99 def _quote_html(html):
100 return html.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
102 class HTTPServer(SocketServer.TCPServer):
104 allow_reuse_address = 1 # Seems to make sense in testing environment
106 def server_bind(self):
107 """Override server_bind to store the server name."""
108 SocketServer.TCPServer.server_bind(self)
109 host, port = self.socket.getsockname()[:2]
110 self.server_name = socket.getfqdn(host)
111 self.server_port = port
114 class BaseHTTPRequestHandler(SocketServer.StreamRequestHandler):
116 """HTTP request handler base class.
118 The following explanation of HTTP serves to guide you through the
119 code as well as to expose any misunderstandings I may have about
120 HTTP (so you don't need to read the code to figure out I'm wrong
121 :-).
123 HTTP (HyperText Transfer Protocol) is an extensible protocol on
124 top of a reliable stream transport (e.g. TCP/IP). The protocol
125 recognizes three parts to a request:
127 1. One line identifying the request type and path
128 2. An optional set of RFC-822-style headers
129 3. An optional data part
131 The headers and data are separated by a blank line.
133 The first line of the request has the form
135 <command> <path> <version>
137 where <command> is a (case-sensitive) keyword such as GET or POST,
138 <path> is a string containing path information for the request,
139 and <version> should be the string "HTTP/1.0" or "HTTP/1.1".
140 <path> is encoded using the URL encoding scheme (using %xx to signify
141 the ASCII character with hex code xx).
143 The specification specifies that lines are separated by CRLF but
144 for compatibility with the widest range of clients recommends
145 servers also handle LF. Similarly, whitespace in the request line
146 is treated sensibly (allowing multiple spaces between components
147 and allowing trailing whitespace).
149 Similarly, for output, lines ought to be separated by CRLF pairs
150 but most clients grok LF characters just fine.
152 If the first line of the request has the form
154 <command> <path>
156 (i.e. <version> is left out) then this is assumed to be an HTTP
157 0.9 request; this form has no optional headers and data part and
158 the reply consists of just the data.
160 The reply form of the HTTP 1.x protocol again has three parts:
162 1. One line giving the response code
163 2. An optional set of RFC-822-style headers
164 3. The data
166 Again, the headers and data are separated by a blank line.
168 The response code line has the form
170 <version> <responsecode> <responsestring>
172 where <version> is the protocol version ("HTTP/1.0" or "HTTP/1.1"),
173 <responsecode> is a 3-digit response code indicating success or
174 failure of the request, and <responsestring> is an optional
175 human-readable string explaining what the response code means.
177 This server parses the request and the headers, and then calls a
178 function specific to the request type (<command>). Specifically,
179 a request SPAM will be handled by a method do_SPAM(). If no
180 such method exists the server sends an error response to the
181 client. If it exists, it is called with no arguments:
183 do_SPAM()
185 Note that the request name is case sensitive (i.e. SPAM and spam
186 are different requests).
188 The various request details are stored in instance variables:
190 - client_address is the client IP address in the form (host,
191 port);
193 - command, path and version are the broken-down request line;
195 - headers is an instance of mimetools.Message (or a derived
196 class) containing the header information;
198 - rfile is a file object open for reading positioned at the
199 start of the optional input data part;
201 - wfile is a file object open for writing.
203 IT IS IMPORTANT TO ADHERE TO THE PROTOCOL FOR WRITING!
205 The first thing to be written must be the response line. Then
206 follow 0 or more header lines, then a blank line, and then the
207 actual data (if any). The meaning of the header lines depends on
208 the command executed by the server; in most cases, when data is
209 returned, there should be at least one header line of the form
211 Content-type: <type>/<subtype>
213 where <type> and <subtype> should be registered MIME types,
214 e.g. "text/html" or "text/plain".
218 # The Python system version, truncated to its first component.
219 sys_version = "Python/" + sys.version.split()[0]
221 # The server software version. You may want to override this.
222 # The format is multiple whitespace-separated strings,
223 # where each string is of the form name[/version].
224 server_version = "BaseHTTP/" + __version__
226 # The default request version. This only affects responses up until
227 # the point where the request line is parsed, so it mainly decides what
228 # the client gets back when sending a malformed request line.
229 # Most web servers default to HTTP 0.9, i.e. don't send a status line.
230 default_request_version = "HTTP/0.9"
232 def parse_request(self):
233 """Parse a request (internal).
235 The request should be stored in self.raw_requestline; the results
236 are in self.command, self.path, self.request_version and
237 self.headers.
239 Return True for success, False for failure; on failure, an
240 error is sent back.
243 self.command = None # set in case of error on the first line
244 self.request_version = version = self.default_request_version
245 self.close_connection = 1
246 requestline = self.raw_requestline
247 if requestline[-2:] == '\r\n':
248 requestline = requestline[:-2]
249 elif requestline[-1:] == '\n':
250 requestline = requestline[:-1]
251 self.requestline = requestline
252 words = requestline.split()
253 if len(words) == 3:
254 [command, path, version] = words
255 if version[:5] != 'HTTP/':
256 self.send_error(400, "Bad request version (%r)" % version)
257 return False
258 try:
259 base_version_number = version.split('/', 1)[1]
260 version_number = base_version_number.split(".")
261 # RFC 2145 section 3.1 says there can be only one "." and
262 # - major and minor numbers MUST be treated as
263 # separate integers;
264 # - HTTP/2.4 is a lower version than HTTP/2.13, which in
265 # turn is lower than HTTP/12.3;
266 # - Leading zeros MUST be ignored by recipients.
267 if len(version_number) != 2:
268 raise ValueError
269 version_number = int(version_number[0]), int(version_number[1])
270 except (ValueError, IndexError):
271 self.send_error(400, "Bad request version (%r)" % version)
272 return False
273 if version_number >= (1, 1) and self.protocol_version >= "HTTP/1.1":
274 self.close_connection = 0
275 if version_number >= (2, 0):
276 self.send_error(505,
277 "Invalid HTTP Version (%s)" % base_version_number)
278 return False
279 elif len(words) == 2:
280 [command, path] = words
281 self.close_connection = 1
282 if command != 'GET':
283 self.send_error(400,
284 "Bad HTTP/0.9 request type (%r)" % command)
285 return False
286 elif not words:
287 return False
288 else:
289 self.send_error(400, "Bad request syntax (%r)" % requestline)
290 return False
291 self.command, self.path, self.request_version = command, path, version
293 # Examine the headers and look for a Connection directive
294 self.headers = self.MessageClass(self.rfile, 0)
296 conntype = self.headers.get('Connection', "")
297 if conntype.lower() == 'close':
298 self.close_connection = 1
299 elif (conntype.lower() == 'keep-alive' and
300 self.protocol_version >= "HTTP/1.1"):
301 self.close_connection = 0
302 return True
304 def handle_one_request(self):
305 """Handle a single HTTP request.
307 You normally don't need to override this method; see the class
308 __doc__ string for information on how to handle specific HTTP
309 commands such as GET and POST.
312 try:
313 self.raw_requestline = self.rfile.readline()
314 if not self.raw_requestline:
315 self.close_connection = 1
316 return
317 if not self.parse_request():
318 # An error code has been sent, just exit
319 return
320 mname = 'do_' + self.command
321 if not hasattr(self, mname):
322 self.send_error(501, "Unsupported method (%r)" % self.command)
323 return
324 method = getattr(self, mname)
325 method()
326 self.wfile.flush() #actually send the response if not already done.
327 except socket.timeout, e:
328 #a read or a write timed out. Discard this connection
329 self.log_error("Request timed out: %r", e)
330 self.close_connection = 1
331 return
333 def handle(self):
334 """Handle multiple requests if necessary."""
335 self.close_connection = 1
337 self.handle_one_request()
338 while not self.close_connection:
339 self.handle_one_request()
341 def send_error(self, code, message=None):
342 """Send and log an error reply.
344 Arguments are the error code, and a detailed message.
345 The detailed message defaults to the short entry matching the
346 response code.
348 This sends an error response (so it must be called before any
349 output has been generated), logs the error, and finally sends
350 a piece of HTML explaining the error to the user.
354 try:
355 short, long = self.responses[code]
356 except KeyError:
357 short, long = '???', '???'
358 if message is None:
359 message = short
360 explain = long
361 self.log_error("code %d, message %s", code, message)
362 # using _quote_html to prevent Cross Site Scripting attacks (see bug #1100201)
363 content = (self.error_message_format %
364 {'code': code, 'message': _quote_html(message), 'explain': explain})
365 self.send_response(code, message)
366 self.send_header("Content-Type", self.error_content_type)
367 self.send_header('Connection', 'close')
368 self.end_headers()
369 if self.command != 'HEAD' and code >= 200 and code not in (204, 304):
370 self.wfile.write(content)
372 error_message_format = DEFAULT_ERROR_MESSAGE
373 error_content_type = DEFAULT_ERROR_CONTENT_TYPE
375 def send_response(self, code, message=None):
376 """Send the response header and log the response code.
378 Also send two standard headers with the server software
379 version and the current date.
382 self.log_request(code)
383 if message is None:
384 if code in self.responses:
385 message = self.responses[code][0]
386 else:
387 message = ''
388 if self.request_version != 'HTTP/0.9':
389 self.wfile.write("%s %d %s\r\n" %
390 (self.protocol_version, code, message))
391 # print (self.protocol_version, code, message)
392 self.send_header('Server', self.version_string())
393 self.send_header('Date', self.date_time_string())
395 def send_header(self, keyword, value):
396 """Send a MIME header."""
397 if self.request_version != 'HTTP/0.9':
398 self.wfile.write("%s: %s\r\n" % (keyword, value))
400 if keyword.lower() == 'connection':
401 if value.lower() == 'close':
402 self.close_connection = 1
403 elif value.lower() == 'keep-alive':
404 self.close_connection = 0
406 def end_headers(self):
407 """Send the blank line ending the MIME headers."""
408 if self.request_version != 'HTTP/0.9':
409 self.wfile.write("\r\n")
411 def log_request(self, code='-', size='-'):
412 """Log an accepted request.
414 This is called by send_response().
418 self.log_message('"%s" %s %s',
419 self.requestline, str(code), str(size))
421 def log_error(self, format, *args):
422 """Log an error.
424 This is called when a request cannot be fulfilled. By
425 default it passes the message on to log_message().
427 Arguments are the same as for log_message().
429 XXX This should go to the separate error log.
433 self.log_message(format, *args)
435 def log_message(self, format, *args):
436 """Log an arbitrary message.
438 This is used by all other logging functions. Override
439 it if you have specific logging wishes.
441 The first argument, FORMAT, is a format string for the
442 message to be logged. If the format string contains
443 any % escapes requiring parameters, they should be
444 specified as subsequent arguments (it's just like
445 printf!).
447 The client host and current date/time are prefixed to
448 every message.
452 sys.stderr.write("%s - - [%s] %s\n" %
453 (self.address_string(),
454 self.log_date_time_string(),
455 format%args))
457 def version_string(self):
458 """Return the server software version string."""
459 return self.server_version + ' ' + self.sys_version
461 def date_time_string(self, timestamp=None):
462 """Return the current date and time formatted for a message header."""
463 if timestamp is None:
464 timestamp = time.time()
465 year, month, day, hh, mm, ss, wd, y, z = time.gmtime(timestamp)
466 s = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
467 self.weekdayname[wd],
468 day, self.monthname[month], year,
469 hh, mm, ss)
470 return s
472 def log_date_time_string(self):
473 """Return the current time formatted for logging."""
474 now = time.time()
475 year, month, day, hh, mm, ss, x, y, z = time.localtime(now)
476 s = "%02d/%3s/%04d %02d:%02d:%02d" % (
477 day, self.monthname[month], year, hh, mm, ss)
478 return s
480 weekdayname = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
482 monthname = [None,
483 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
484 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
486 def address_string(self):
487 """Return the client address formatted for logging.
489 This version looks up the full hostname using gethostbyaddr(),
490 and tries to find a name that contains at least one dot.
494 host, port = self.client_address[:2]
495 return socket.getfqdn(host)
497 # Essentially static class variables
499 # The version of the HTTP protocol we support.
500 # Set this to HTTP/1.1 to enable automatic keepalive
501 protocol_version = "HTTP/1.0"
503 # The Message-like class used to parse headers
504 MessageClass = mimetools.Message
506 # Table mapping response codes to messages; entries have the
507 # form {code: (shortmessage, longmessage)}.
508 # See RFC 2616.
509 responses = {
510 100: ('Continue', 'Request received, please continue'),
511 101: ('Switching Protocols',
512 'Switching to new protocol; obey Upgrade header'),
514 200: ('OK', 'Request fulfilled, document follows'),
515 201: ('Created', 'Document created, URL follows'),
516 202: ('Accepted',
517 'Request accepted, processing continues off-line'),
518 203: ('Non-Authoritative Information', 'Request fulfilled from cache'),
519 204: ('No Content', 'Request fulfilled, nothing follows'),
520 205: ('Reset Content', 'Clear input form for further input.'),
521 206: ('Partial Content', 'Partial content follows.'),
523 300: ('Multiple Choices',
524 'Object has several resources -- see URI list'),
525 301: ('Moved Permanently', 'Object moved permanently -- see URI list'),
526 302: ('Found', 'Object moved temporarily -- see URI list'),
527 303: ('See Other', 'Object moved -- see Method and URL list'),
528 304: ('Not Modified',
529 'Document has not changed since given time'),
530 305: ('Use Proxy',
531 'You must use proxy specified in Location to access this '
532 'resource.'),
533 307: ('Temporary Redirect',
534 'Object moved temporarily -- see URI list'),
536 400: ('Bad Request',
537 'Bad request syntax or unsupported method'),
538 401: ('Unauthorized',
539 'No permission -- see authorization schemes'),
540 402: ('Payment Required',
541 'No payment -- see charging schemes'),
542 403: ('Forbidden',
543 'Request forbidden -- authorization will not help'),
544 404: ('Not Found', 'Nothing matches the given URI'),
545 405: ('Method Not Allowed',
546 'Specified method is invalid for this resource.'),
547 406: ('Not Acceptable', 'URI not available in preferred format.'),
548 407: ('Proxy Authentication Required', 'You must authenticate with '
549 'this proxy before proceeding.'),
550 408: ('Request Timeout', 'Request timed out; try again later.'),
551 409: ('Conflict', 'Request conflict.'),
552 410: ('Gone',
553 'URI no longer exists and has been permanently removed.'),
554 411: ('Length Required', 'Client must specify Content-Length.'),
555 412: ('Precondition Failed', 'Precondition in headers is false.'),
556 413: ('Request Entity Too Large', 'Entity is too large.'),
557 414: ('Request-URI Too Long', 'URI is too long.'),
558 415: ('Unsupported Media Type', 'Entity body in unsupported format.'),
559 416: ('Requested Range Not Satisfiable',
560 'Cannot satisfy request range.'),
561 417: ('Expectation Failed',
562 'Expect condition could not be satisfied.'),
564 500: ('Internal Server Error', 'Server got itself in trouble'),
565 501: ('Not Implemented',
566 'Server does not support this operation'),
567 502: ('Bad Gateway', 'Invalid responses from another server/proxy.'),
568 503: ('Service Unavailable',
569 'The server cannot process the request due to a high load'),
570 504: ('Gateway Timeout',
571 'The gateway server did not receive a timely response'),
572 505: ('HTTP Version Not Supported', 'Cannot fulfill request.'),
576 def test(HandlerClass = BaseHTTPRequestHandler,
577 ServerClass = HTTPServer, protocol="HTTP/1.0"):
578 """Test the HTTP request handler class.
580 This runs an HTTP server on port 8000 (or the first command line
581 argument).
585 if sys.argv[1:]:
586 port = int(sys.argv[1])
587 else:
588 port = 8000
589 server_address = ('', port)
591 HandlerClass.protocol_version = protocol
592 httpd = ServerClass(server_address, HandlerClass)
594 sa = httpd.socket.getsockname()
595 print "Serving HTTP on", sa[0], "port", sa[1], "..."
596 httpd.serve_forever()
599 if __name__ == '__main__':
600 test()