Guido van Rossum | e7e578f | 1995-08-04 04:00:20 +0000 | [diff] [blame] | 1 | """HTTP server base class. |
| 2 | |
| 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). |
| 6 | |
| 7 | Contents: |
| 8 | |
| 9 | - BaseHTTPRequestHandler: HTTP request handler base class |
| 10 | - test: test function |
| 11 | |
| 12 | XXX To do: |
| 13 | |
| 14 | - send server version |
| 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 | - are request names really case sensitive? |
| 19 | |
| 20 | """ |
| 21 | |
| 22 | |
| 23 | # See also: |
| 24 | # |
| 25 | # HTTP Working Group T. Berners-Lee |
| 26 | # INTERNET-DRAFT R. T. Fielding |
| 27 | # <draft-ietf-http-v10-spec-00.txt> H. Frystyk Nielsen |
| 28 | # Expires September 8, 1995 March 8, 1995 |
| 29 | # |
| 30 | # URL: http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-v10-spec-00.txt |
| 31 | |
| 32 | |
| 33 | # Log files |
| 34 | # --------- |
| 35 | # |
| 36 | # Here's a quote from the NCSA httpd docs about log file format. |
| 37 | # |
| 38 | # | The logfile format is as follows. Each line consists of: |
| 39 | # | |
| 40 | # | host rfc931 authuser [DD/Mon/YYYY:hh:mm:ss] "request" ddd bbbb |
| 41 | # | |
| 42 | # | host: Either the DNS name or the IP number of the remote client |
| 43 | # | rfc931: Any information returned by identd for this person, |
| 44 | # | - otherwise. |
| 45 | # | authuser: If user sent a userid for authentication, the user name, |
| 46 | # | - otherwise. |
| 47 | # | DD: Day |
| 48 | # | Mon: Month (calendar name) |
| 49 | # | YYYY: Year |
| 50 | # | hh: hour (24-hour format, the machine's timezone) |
| 51 | # | mm: minutes |
| 52 | # | ss: seconds |
| 53 | # | request: The first line of the HTTP request as sent by the client. |
| 54 | # | ddd: the status code returned by the server, - if not available. |
| 55 | # | bbbb: the total number of bytes sent, |
| 56 | # | *not including the HTTP/1.0 header*, - if not available |
| 57 | # | |
| 58 | # | You can determine the name of the file accessed through request. |
| 59 | # |
| 60 | # (Actually, the latter is only true if you know the server configuration |
| 61 | # at the time the request was made!) |
| 62 | |
| 63 | |
| 64 | __version__ = "0.2" |
| 65 | |
| 66 | |
| 67 | import sys |
| 68 | import time |
| 69 | import socket # For gethostbyaddr() |
| 70 | import string |
| 71 | import rfc822 |
| 72 | import mimetools |
| 73 | import SocketServer |
| 74 | |
| 75 | # Default error message |
| 76 | DEFAULT_ERROR_MESSAGE = """\ |
| 77 | <head> |
| 78 | <title>Error response</title> |
| 79 | </head> |
| 80 | <body> |
| 81 | <h1>Error response</h1> |
| 82 | <p>Error code %(code)d. |
| 83 | <p>Message: %(message)s. |
| 84 | <p>Error code explanation: %(code)s = %(explain)s. |
| 85 | </body> |
| 86 | """ |
| 87 | |
| 88 | |
| 89 | class HTTPServer(SocketServer.TCPServer): |
| 90 | |
| 91 | def server_bind(self): |
| 92 | """Override server_bind to store the server name.""" |
| 93 | SocketServer.TCPServer.server_bind(self) |
| 94 | host, port = self.socket.getsockname() |
| 95 | if not host or host == '0.0.0.0': |
| 96 | host = socket.gethostname() |
| 97 | hostname, hostnames, hostaddrs = socket.gethostbyaddr(host) |
| 98 | if '.' not in hostname: |
| 99 | for host in hostnames: |
| 100 | if '.' in host: |
| 101 | hostname = host |
| 102 | break |
| 103 | self.server_name = hostname |
| 104 | self.server_port = port |
| 105 | |
| 106 | |
| 107 | class 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". <path> is encoded |
| 133 | using the URL encoding scheme (using %xx to signify the ASCII |
| 134 | character with hex code xx). |
| 135 | |
| 136 | The protocol is vague about whether lines are separated by LF |
| 137 | characters or by CRLF pairs -- for compatibility with the widest |
| 138 | range of clients, both should be accepted. Similarly, whitespace |
| 139 | in the request line should be treated sensibly (allowing multiple |
| 140 | spaces between components 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 1.0 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 (always "HTTP/1.0"), |
| 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 handle_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/" + string.split(sys.version)[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 handle(self): |
| 220 | """Handle a single HTTP request. |
| 221 | |
| 222 | You normally don't need to override this method; see the class |
| 223 | __doc__ string for information on how to handle specific HTTP |
| 224 | commands such as GET and POST. |
| 225 | |
| 226 | """ |
| 227 | |
| 228 | self.raw_requestline = self.rfile.readline() |
Guido van Rossum | f69da22 | 1996-02-12 23:58:38 +0000 | [diff] [blame^] | 229 | self.request_version = version = "HTTP/0.9" # Default |
Guido van Rossum | e7e578f | 1995-08-04 04:00:20 +0000 | [diff] [blame] | 230 | requestline = self.raw_requestline |
| 231 | if requestline[-2:] == '\r\n': |
| 232 | requestline = requestline[:-2] |
| 233 | elif requestline[-1:] == '\n': |
| 234 | requestline = requestline[:-1] |
| 235 | self.requestline = requestline |
| 236 | words = string.split(requestline) |
| 237 | if len(words) == 3: |
| 238 | [command, path, version] = words |
| 239 | if version != self.protocol_version: |
| 240 | self.send_error(400, "Bad request version (%s)" % `version`) |
| 241 | return |
| 242 | elif len(words) == 2: |
| 243 | [command, path] = words |
| 244 | if command != 'GET': |
| 245 | self.send_error(400, |
| 246 | "Bad HTTP/0.9 request type (%s)" % `command`) |
| 247 | return |
Guido van Rossum | e7e578f | 1995-08-04 04:00:20 +0000 | [diff] [blame] | 248 | else: |
Guido van Rossum | f69da22 | 1996-02-12 23:58:38 +0000 | [diff] [blame^] | 249 | self.send_error(400, "Bad request syntax (%s)" % `requestline`) |
Guido van Rossum | e7e578f | 1995-08-04 04:00:20 +0000 | [diff] [blame] | 250 | return |
| 251 | self.command, self.path, self.request_version = command, path, version |
| 252 | self.headers = self.MessageClass(self.rfile, 0) |
| 253 | mname = 'do_' + command |
| 254 | if not hasattr(self, mname): |
Guido van Rossum | f69da22 | 1996-02-12 23:58:38 +0000 | [diff] [blame^] | 255 | self.send_error(501, "Unsupported method (%s)" % `mname`) |
Guido van Rossum | e7e578f | 1995-08-04 04:00:20 +0000 | [diff] [blame] | 256 | return |
| 257 | method = getattr(self, mname) |
| 258 | method() |
| 259 | |
| 260 | def send_error(self, code, message=None): |
| 261 | """Send and log an error reply. |
| 262 | |
| 263 | Arguments are the error code, and a detailed message. |
| 264 | The detailed message defaults to the short entry matching the |
| 265 | response code. |
| 266 | |
| 267 | This sends an error response (so it must be called before any |
| 268 | output has been generated), logs the error, and finally sends |
| 269 | a piece of HTML explaining the error to the user. |
| 270 | |
| 271 | """ |
| 272 | |
| 273 | try: |
| 274 | short, long = self.responses[code] |
| 275 | except KeyError: |
| 276 | short, long = '???', '???' |
| 277 | if not message: |
| 278 | message = short |
| 279 | explain = long |
| 280 | self.log_error("code %d, message %s", code, message) |
| 281 | self.send_response(code, message) |
| 282 | self.end_headers() |
| 283 | self.wfile.write(self.error_message_format % |
| 284 | {'code': code, |
| 285 | 'message': message, |
| 286 | 'explain': explain}) |
| 287 | |
| 288 | error_message_format = DEFAULT_ERROR_MESSAGE |
| 289 | |
| 290 | def send_response(self, code, message=None): |
| 291 | """Send the response header and log the response code. |
| 292 | |
| 293 | Also send two standard headers with the server software |
| 294 | version and the current date. |
| 295 | |
| 296 | """ |
| 297 | self.log_request(code) |
| 298 | if message is None: |
| 299 | if self.responses.has_key(code): |
| 300 | message = self.responses[code][1] |
| 301 | else: |
| 302 | message = '' |
| 303 | if self.request_version != 'HTTP/0.9': |
| 304 | self.wfile.write("%s %s %s\r\n" % |
| 305 | (self.protocol_version, str(code), message)) |
| 306 | self.send_header('Server', self.version_string()) |
| 307 | self.send_header('Date', self.date_time_string()) |
| 308 | |
| 309 | def send_header(self, keyword, value): |
| 310 | """Send a MIME header.""" |
| 311 | if self.request_version != 'HTTP/0.9': |
| 312 | self.wfile.write("%s: %s\r\n" % (keyword, value)) |
| 313 | |
| 314 | def end_headers(self): |
| 315 | """Send the blank line ending the MIME headers.""" |
| 316 | if self.request_version != 'HTTP/0.9': |
| 317 | self.wfile.write("\r\n") |
| 318 | |
| 319 | def log_request(self, code='-', size='-'): |
| 320 | """Log an accepted request. |
| 321 | |
| 322 | This is called by send_reponse(). |
| 323 | |
| 324 | """ |
| 325 | |
| 326 | self.log_message('"%s" %s %s', |
| 327 | self.requestline, str(code), str(size)) |
| 328 | |
| 329 | def log_error(self, *args): |
| 330 | """Log an error. |
| 331 | |
| 332 | This is called when a request cannot be fulfilled. By |
| 333 | default it passes the message on to log_message(). |
| 334 | |
| 335 | Arguments are the same as for log_message(). |
| 336 | |
| 337 | XXX This should go to the separate error log. |
| 338 | |
| 339 | """ |
| 340 | |
| 341 | apply(self.log_message, args) |
| 342 | |
| 343 | def log_message(self, format, *args): |
| 344 | """Log an arbitrary message. |
| 345 | |
| 346 | This is used by all other logging functions. Override |
| 347 | it if you have specific logging wishes. |
| 348 | |
| 349 | The first argument, FORMAT, is a format string for the |
| 350 | message to be logged. If the format string contains |
| 351 | any % escapes requiring parameters, they should be |
| 352 | specified as subsequent arguments (it's just like |
| 353 | printf!). |
| 354 | |
| 355 | The client host and current date/time are prefixed to |
| 356 | every message. |
| 357 | |
| 358 | """ |
| 359 | |
| 360 | sys.stderr.write("%s - - [%s] %s\n" % |
| 361 | (self.address_string(), |
| 362 | self.log_date_time_string(), |
| 363 | format%args)) |
| 364 | |
| 365 | def version_string(self): |
| 366 | """Return the server software version string.""" |
| 367 | return self.server_version + ' ' + self.sys_version |
| 368 | |
| 369 | def date_time_string(self): |
| 370 | """Return the current date and time formatted for a message header.""" |
| 371 | now = time.time() |
| 372 | year, month, day, hh, mm, ss, wd, y, z = time.gmtime(now) |
| 373 | s = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % ( |
| 374 | self.weekdayname[wd], |
| 375 | day, self.monthname[month], year, |
| 376 | hh, mm, ss) |
| 377 | return s |
| 378 | |
| 379 | def log_date_time_string(self): |
| 380 | """Return the current time formatted for logging.""" |
| 381 | now = time.time() |
| 382 | year, month, day, hh, mm, ss, x, y, z = time.localtime(now) |
| 383 | s = "%02d/%3s/%04d %02d:%02d:%02d" % ( |
| 384 | day, self.monthname[month], year, hh, mm, ss) |
| 385 | return s |
| 386 | |
| 387 | weekdayname = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'] |
| 388 | |
| 389 | monthname = [None, |
| 390 | 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', |
| 391 | 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'] |
| 392 | |
| 393 | def address_string(self): |
| 394 | """Return the client address formatted for logging. |
| 395 | |
| 396 | This version looks up the full hostname using gethostbyaddr(), |
| 397 | and tries to find a name that contains at least one dot. |
| 398 | |
| 399 | """ |
| 400 | |
| 401 | (host, port) = self.client_address |
| 402 | try: |
| 403 | name, names, addresses = socket.gethostbyaddr(host) |
| 404 | except socket.error, msg: |
| 405 | return host |
| 406 | names.insert(0, name) |
| 407 | for name in names: |
| 408 | if '.' in name: return name |
| 409 | return names[0] |
| 410 | |
| 411 | |
| 412 | # Essentially static class variables |
| 413 | |
| 414 | # The version of the HTTP protocol we support. |
| 415 | # Don't override unless you know what you're doing (hint: incoming |
| 416 | # requests are required to have exactly this version string). |
| 417 | protocol_version = "HTTP/1.0" |
| 418 | |
| 419 | # The Message-like class used to parse headers |
| 420 | MessageClass = mimetools.Message |
| 421 | |
| 422 | # Table mapping response codes to messages; entries have the |
| 423 | # form {code: (shortmessage, longmessage)}. |
| 424 | # See http://www.w3.org/hypertext/WWW/Protocols/HTTP/HTRESP.html |
| 425 | responses = { |
| 426 | 200: ('OK', 'Request fulfilled, document follows'), |
| 427 | 201: ('Created', 'Document created, URL follows'), |
| 428 | 202: ('Accepted', |
| 429 | 'Request accepted, processing continues off-line'), |
| 430 | 203: ('Partial information', 'Request fulfilled from cache'), |
| 431 | 204: ('No response', 'Request fulfilled, nothing follows'), |
| 432 | |
| 433 | 301: ('Moved', 'Object moved permanently -- see URI list'), |
| 434 | 302: ('Found', 'Object moved temporarily -- see URI list'), |
| 435 | 303: ('Method', 'Object moved -- see Method and URL list'), |
| 436 | 304: ('Not modified', |
| 437 | 'Document has not changed singe given time'), |
| 438 | |
| 439 | 400: ('Bad request', |
| 440 | 'Bad request syntax or unsupported method'), |
| 441 | 401: ('Unauthorized', |
| 442 | 'No permission -- see authorization schemes'), |
| 443 | 402: ('Payment required', |
| 444 | 'No payment -- see charging schemes'), |
| 445 | 403: ('Forbidden', |
| 446 | 'Request forbidden -- authorization will not help'), |
| 447 | 404: ('Not found', 'Nothing matches the given URI'), |
| 448 | |
| 449 | 500: ('Internal error', 'Server got itself in trouble'), |
| 450 | 501: ('Not implemented', |
| 451 | 'Server does not support this operation'), |
| 452 | 502: ('Service temporarily overloaded', |
| 453 | 'The server cannot process the request due to a high load'), |
| 454 | 503: ('Gateway timeout', |
| 455 | 'The gateway server did not receive a timely response'), |
| 456 | |
| 457 | } |
| 458 | |
| 459 | |
| 460 | def test(HandlerClass = BaseHTTPRequestHandler, |
| 461 | ServerClass = HTTPServer): |
| 462 | """Test the HTTP request handler class. |
| 463 | |
| 464 | This runs an HTTP server on port 8000 (or the first command line |
| 465 | argument). |
| 466 | |
| 467 | """ |
| 468 | |
| 469 | if sys.argv[1:]: |
| 470 | port = string.atoi(sys.argv[1]) |
| 471 | else: |
| 472 | port = 8000 |
| 473 | server_address = ('', port) |
| 474 | |
| 475 | httpd = ServerClass(server_address, HandlerClass) |
| 476 | |
| 477 | print "Serving HTTP on port", port, "..." |
| 478 | httpd.serve_forever() |
| 479 | |
| 480 | |
| 481 | if __name__ == '__main__': |
| 482 | test() |