Source

pypi / thfcgi.py

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
# -*- coding: iso-8859-1 -*-
"""
    thfcgi.py - FastCGI communication with thread support

    Copyright Peter Ĺstrand <astrand@lysator.liu.se> 2001

    Modified for MoinMoin by Oliver Graf <ograf@bitart.de> 2003

    Modified for PyPI by Martin v. Löwis <martin@v.loewis.de> 2007
    
    Added "external application" support, refactored code
        by Alexander Schremmer <alex AT alexanderweb DOT de>

    Cleanup, fixed typos, PEP-8, support for limiting creation of threads,
    limited number of requests lifetime, configurable backlog for socket
    .listen() by Thomas Waldmann <tw AT waldmann-edv DOT de>

    For code base see:
    http://cvs.lysator.liu.se/viewcvs/viewcvs.cgi/webkom/thfcgi.py?cvsroot=webkom

    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
    the Free Software Foundation; version 2 of the License. 

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
"""

# TODO: Compare compare the number of bytes received on FCGI_STDIN with
#       CONTENT_LENGTH and abort the update if the two numbers are not equal.

debug = False

import os
import sys
import select
import socket
import errno
import cgi
from cStringIO import StringIO
import struct
import syslog

try:
    import threading as _threading
except ImportError:
    import dummy_threading as _threading

# Maximum number of requests that can be handled
FCGI_MAX_REQS = 50
FCGI_MAX_CONNS = 50
FCGI_VERSION_1 = 1

# Can this application multiplex connections?
FCGI_MPXS_CONNS = 0

# Record types
FCGI_BEGIN_REQUEST = 1
FCGI_ABORT_REQUEST = 2
FCGI_END_REQUEST = 3
FCGI_PARAMS = 4
FCGI_STDIN = 5
FCGI_STDOUT = 6
FCGI_STDERR = 7
FCGI_DATA = 8
FCGI_GET_VALUES = 9
FCGI_GET_VALUES_RESULT = 10
FCGI_UNKNOWN_TYPE = 11
FCGI_MAXTYPE = FCGI_UNKNOWN_TYPE

# Types of management records
KNOWN_MANAGEMENT_TYPES = [FCGI_GET_VALUES]

FCGI_NULL_REQUEST_ID = 0

# Masks for flags component of FCGI_BEGIN_REQUEST
FCGI_KEEP_CONN = 1

# Values for role component of FCGI_BEGIN_REQUEST
FCGI_RESPONDER = 1
FCGI_AUTHORIZER = 2
FCGI_FILTER = 3

# Values for protocolStatus component of FCGI_END_REQUEST
FCGI_REQUEST_COMPLETE = 0     # Request completed ok
FCGI_CANT_MPX_CONN = 1        # This app cannot multiplex
FCGI_OVERLOADED = 2           # Too busy
FCGI_UNKNOWN_ROLE = 3         # Role value not known

# Struct format types
FCGI_BeginRequestBody = "!HB5x"
FCGI_Record_header = "!BBHHBx"
FCGI_UnknownTypeBody = "!B7x"
FCGI_EndRequestBody = "!IB3x"

LOGFILE = sys.stderr

def log(s):
    if debug:
        LOGFILE.write(s)
        LOGFILE.write('\n')

class SocketErrorOnWrite:
    """Is raised if a write fails in the socket code."""
    pass

class Record:
    """Class representing FastCGI records"""

    def __init__(self):
        """Initialize FastCGI record"""
        self.version = FCGI_VERSION_1
        self.rec_type = FCGI_UNKNOWN_TYPE
        self.req_id   = FCGI_NULL_REQUEST_ID
        self.content = ""

        # Only in FCGI_BEGIN_REQUEST
        self.role = None
        self.flags = None
        self.keep_conn = 0

        # Only in FCGI_UNKNOWN_TYPE
        self.unknownType = None

        # Only in FCGI_END_REQUEST
        self.appStatus = None
        self.protocolStatus = None

    def read_pair(self, data, pos):
        """Read a FastCGI key-value pair from the server."""
        namelen = struct.unpack("!B", data[pos])[0]
        if namelen & 128:
            # 4-byte name length
            namelen = struct.unpack("!I", data[pos:pos+4])[0] & 0x7fffffff
            pos += 4
        else:
            pos += 1

        valuelen = struct.unpack("!B", data[pos])[0]
        if valuelen & 128:
            # 4-byte value length
            valuelen = struct.unpack("!I", data[pos:pos+4])[0] & 0x7fffffff
            pos += 4
        else:
            pos += 1

        name = data[pos:pos+namelen]
        pos += namelen
        value = data[pos:pos+valuelen]
        pos += valuelen

        return name, value, pos

    def write_pair(self, name, value):
        """Write a FastCGI key-value pair to the server."""
        namelen = len(name)
        if namelen < 128:
            data = struct.pack("!B", namelen)
        else:
            # 4-byte name length
            data = struct.pack("!I", namelen | 0x80000000L)

        valuelen = len(value)
        if valuelen < 128:
            data += struct.pack("!B", value)
        else:
            # 4-byte value length
            data += struct.pack("!I", value | 0x80000000L)

        return data + name + value

    def readRecord(self, sock):
        """Read a FastCGI record from the server."""
        data = sock.recv(8)
        if not data:
            # No data received. This means EOF. 
            return None

        self.version, self.rec_type, self.req_id, contentLength, paddingLength = \
            struct.unpack(FCGI_Record_header, data)

        self.content = ""
        while len(self.content) < contentLength:
            data = sock.recv(contentLength - len(self.content))
            self.content = self.content + data
        if paddingLength != 0:
            sock.recv(paddingLength)

        # Parse the content information
        if self.rec_type == FCGI_BEGIN_REQUEST:
            self.role, self.flags = struct.unpack(FCGI_BeginRequestBody, self.content)
            self.keep_conn = self.flags & FCGI_KEEP_CONN

        elif self.rec_type == FCGI_UNKNOWN_TYPE:
            self.unknownType = struct.unpack(FCGI_UnknownTypeBody, self.content)

        elif self.rec_type == FCGI_GET_VALUES or self.rec_type == FCGI_PARAMS:
            self.values = {}
            pos = 0
            while pos < len(self.content):
                name, value, pos = self.read_pair(self.content, pos)
                self.values[name] = value

        elif self.rec_type == FCGI_END_REQUEST:
            self.appStatus, self.protocolStatus = struct.unpack(FCGI_EndRequestBody, self.content)

        return 1

    def writeRecord(self, sock):
        """Write a FastCGI record to the server."""
        content = self.content
        if self.rec_type == FCGI_BEGIN_REQUEST:
            content = struct.pack(FCGI_BeginRequestBody, self.role, self.flags)

        elif self.rec_type == FCGI_UNKNOWN_TYPE:
            content = struct.pack(FCGI_UnknownTypeBody, self.unknownType)

        elif self.rec_type == FCGI_GET_VALUES or self.rec_type == FCGI_PARAMS:
            content = ""
            for i in self.values:
                content = content + self.write_pair(i, self.values[i])

        elif self.rec_type == FCGI_END_REQUEST:
            content = struct.pack(FCGI_EndRequestBody, self.appStatus, self.protocolStatus)

        # Align to 8-byte boundary
        clen = len(content)
        padlen = ((clen + 7) & 0xfff8) - clen

        hdr = struct.pack(FCGI_Record_header, self.version, self.rec_type, self.req_id, clen, padlen)

        try:
            sock.sendall(hdr + content + padlen*"\x00")
        except socket.error, e:
            # Write error, probably broken pipe. Close connection
	    syslog.syslog(str(e))
	    sock.close()
            raise SocketErrorOnWrite


class Request:
    """A request, corresponding to an accept():ed connection and
    a FCGI request."""

    def __init__(self, conn, req_handler, inthread=False):
        """Initialize Request container."""
        self.conn = conn
        self.req_handler = req_handler
        self.inthread = inthread

        self.keep_conn = 0
        self.req_id = None

        # Input
        self.env = {}
        self.env_complete = 0
        self.stdin = StringIO()
        self.stdin_complete = 0
        self.data = StringIO()
        self.data_complete = 0

        # Output
        self.out = StringIO()
        self.err = StringIO()

        self.have_finished = 0

    def run(self):
        """Read records for this request and handle them through the
        request handler."""
        while 1:
            try:
                if self.conn.fileno() < 1:
                    # Connection lost
                    raise Exception("Connection lost")
            except:
                return

            select.select([self.conn], [], [])
            rec = Record()
            if rec.readRecord(self.conn):
                self._handle_record(rec)
            else:
                # EOF, connection closed. Break loop, end thread. 
                return

    def _flush(self, stream):
        """Flush a stream of this request."""
        stream.reset()

        rec = Record()
        rec.rec_type = FCGI_STDOUT
        rec.req_id = self.req_id
        data = stream.read()

        if not data:
            # Writing zero bytes would mean stream termination
            return

        while data:
            chunk, data = self.getNextChunk(data)
            rec.content = chunk
            rec.writeRecord(self.conn)
        # Truncate
        stream.reset()
        stream.truncate()

    def flush_out(self):
        """Flush Requests stdout stream."""
        self._flush(self.out)

    def flush_err(self):
        """Flush Requests stderr stream."""
        self._flush(self.err)

    def finish(self, status=0):
        """Finish this Request, flushing all output and
        possible exiting this thread."""
        if self.have_finished:
            return

        self.have_finished = 1

        # stderr
        if self.err.tell(): # just send err record if there is data on the err stream
            self.err.reset()
            rec = Record()
            rec.rec_type = FCGI_STDERR
            rec.req_id = self.req_id
            data = self.err.read()
            while data:
                chunk, data = self.getNextChunk(data)
                rec.content = chunk
                rec.writeRecord(self.conn)
            rec.content = ""
            rec.writeRecord(self.conn)      # Terminate stream

        # stdout
        self.out.reset()
        rec = Record()
        rec.rec_type = FCGI_STDOUT
        rec.req_id = self.req_id
        data = self.out.read()
        while data:
            chunk, data = self.getNextChunk(data)
            rec.content = chunk
            rec.writeRecord(self.conn)
        rec.content = ""
        rec.writeRecord(self.conn)      # Terminate stream

        # end request
        rec = Record()
        rec.rec_type = FCGI_END_REQUEST
        rec.req_id = self.req_id
        rec.appStatus = status
        rec.protocolStatus = FCGI_REQUEST_COMPLETE
        rec.writeRecord(self.conn)
        if not self.keep_conn:
            self.conn.close()
            if self.inthread:
	        syslog.syslog("Exiting: inthread and not keep_conn")
                raise SystemExit

    #
    # Record handlers
    #
    def _handle_record(self, rec):
        """Handle record."""
        if rec.req_id == FCGI_NULL_REQUEST_ID:
            # Management record            
            self._handle_man_record(rec)
        else:
            # Application record
            self._handle_app_record(rec)

    def _handle_man_record(self, rec):
        """Handle management record."""
        rec_type = rec.rec_type
        if rec_type in KNOWN_MANAGEMENT_TYPES:
            self._handle_known_man_types(rec)
        else:
            # It's a management record of an unknown type. Signal the error.
            rec = Record()
            rec.rec_type = FCGI_UNKNOWN_TYPE
            rec.unknownType = rec_type
            rec.writeRecord(self.conn)

    def _handle_known_man_types(self, rec):
        """Handle a known management record."""
        if rec.rec_type == FCGI_GET_VALUES:
            reply_rec = Record()
            reply_rec.rec_type = FCGI_GET_VALUES_RESULT

            params = {'FCGI_MAX_CONNS': FCGI_MAX_CONNS,
                      'FCGI_MAX_REQS': FCGI_MAX_REQS,
                      'FCGI_MPXS_CONNS': FCGI_MPXS_CONNS,
                     }

            for name in rec.values:
                if name in params:
                    # We known this value, include in reply
                    reply_rec.values[name] = params[name]

            rec.writeRecord(self.conn)

    def _handle_app_record(self, rec):
        """Handle an application record. This calls the specified
        request_handler, if environ and stdin is complete."""
        if rec.rec_type == FCGI_BEGIN_REQUEST:
            # Discrete
            self._handle_begin_request(rec)
            return
        elif rec.req_id != self.req_id:
            log("Received unknown request ID %r" % rec.req_id)
            # Ignore requests that aren't active
            return
        if rec.rec_type == FCGI_ABORT_REQUEST:
            # Discrete
            rec.rec_type = FCGI_END_REQUEST
            rec.protocolStatus = FCGI_REQUEST_COMPLETE
            rec.appStatus = 0
            rec.writeRecord(self.conn)
            return
        elif rec.rec_type == FCGI_PARAMS:
            # Stream
            self._handle_params(rec)
        elif rec.rec_type == FCGI_STDIN:
            # Stream
            self._handle_stdin(rec)
        elif rec.rec_type == FCGI_DATA:
            # Stream
            self._handle_data(rec)
        else:
            # Should never happen. 
            log("Received unknown FCGI record type %r" % rec.rec_type)
            pass

        if self.env_complete and self.stdin_complete:
            # Call application request handler. 
            # The arguments sent to the request handler is:
            # self: us. 
            # req: The request.
            # env: The request environment
            # form: FieldStorage.
            self.req_handler(self, self.env)

    def _handle_begin_request(self, rec):
        """Handle begin request."""
        if rec.role != FCGI_RESPONDER:
            # Unknown role, signal error.
            rec.rec_type = FCGI_END_REQUEST
            rec.appStatus = 0
            rec.protocolStatus = FCGI_UNKNOWN_ROLE
            rec.writeRecord(self.conn)
            return

        self.req_id = rec.req_id
        self.keep_conn = rec.keep_conn

    def _handle_params(self, rec):
        """Handle environment."""
        if self.env_complete:
            # Should not happen
            log("Received FCGI_PARAMS more than once")
            return

        if not rec.content:
            self.env_complete = 1

        # Add all vars to our environment
        self.env.update(rec.values)

    def _handle_stdin(self, rec):
        """Handle stdin."""
        if self.stdin_complete:
            # Should not happen
            log("Received FCGI_STDIN more than once")
            return

        if not rec.content:
            self.stdin_complete = 1
            self.stdin.reset()
            return

        self.stdin.write(rec.content)

    def _handle_data(self, rec):
        """Handle data."""
        if self.data_complete:
            # Should not happen
            log("Received FCGI_DATA more than once")
            return

        if not rec.content:
            self.data_complete = 1

        self.data.write(rec.content)

    def getNextChunk(self, data):
        """Helper function which returns chunks of data."""
        chunk = data[:8192]
        data = data[8192:]
        return chunk, data

class FCGI:
    """FCGI requests"""

    def __init__(self, req_handler, fd=sys.stdin, port=None, max_requests=-1, backlog=5, max_threads=5):
        """Initialize main loop and set request_handler."""
        self.req_handler = req_handler
        self.fd = fd
        self.__port = port
        self._make_socket()
        # how many requests we have left before terminating this process, -1 means infinite lifetime:
        self.requests_left = max_requests
        # for socket.listen(backlog):
        self.backlog = backlog
        # how many threads we have at maximum (including the main program = 1. thread)
        self.max_threads = max_threads

    def accept_handler(self, conn, addr, inthread=False):
        """Construct Request and run() it."""
        self._check_good_addrs(addr)
        try:
            req = Request(conn, self.req_handler, inthread)
            req.run()
        except SocketErrorOnWrite:
	    syslog.syslog("Exiting: SocketErrorOnWrite")
	    # this used to exit the FCGI server. Now just discard this
	    # connection, and go on accepting the next one
            #raise SystemExit

    def _make_socket(self):
        """Create socket and verify FCGI environment."""
        try:
            if self.__port:
                if isinstance(self.__port, str):
                    try:
                        os.unlink(self.__port)
                    except:
                        pass
                    s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
                    s.bind(self.__port)
                    # os.chmod(self.__port, 0660)
                else:
                    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
                    # bind to the localhost
                    s.bind(('127.0.0.1', self.__port))
                s.listen(1)
            else:
                if hasattr(socket, 'fromfd'):
                    s = socket.fromfd(self.fd.fileno(), socket.AF_INET, socket.SOCK_STREAM)
                    s.getpeername()
                else: # we do not run on posix, fire up an FCGI external process
                    raise ValueError("FastCGI port is not setup correctly")
        except socket.error, (err, errmsg):
            if err != errno.ENOTCONN:
                raise RuntimeError("No FastCGI environment: %s - %s" % (repr(err), errmsg))

        self.sock = s

    def _check_good_addrs(self, addr):
        """Check if request is done from the right server."""
        # Apaches mod_fastcgi seems not to use FCGI_WEB_SERVER_ADDRS. 
        if 'FCGI_WEB_SERVER_ADDRS' in os.environ:
            good_addrs = os.environ['FCGI_WEB_SERVER_ADDRS'].split(',')
            good_addrs = [addr.strip() for addr in good_addrs] # Remove whitespace
        else:
            good_addrs = None

        # Check if the connection is from a legal address
        if good_addrs is not None and addr not in good_addrs:
            raise RuntimeError("Connection from invalid server!")

    def run(self):
        """Wait & serve. Calls request_handler on every request."""
        self.sock.listen(self.backlog)
        log("Starting Process")
        running = True
        while running:
            if not self.requests_left:
                # self.sock.shutdown(RDWR) here does NOT help with backlog
                running = False
            elif self.requests_left > 0:
                self.requests_left -= 1
            if running:
                conn, addr = self.sock.accept()
                threadcount = _threading.activeCount()
                if threadcount < self.max_threads:
                    log("Accepted connection, starting thread...")
                    t = _threading.Thread(target=self.accept_handler, args=(conn, addr, True))
                    t.start()
                else:
                    log("Accepted connection, running in main-thread...")
                    self.accept_handler(conn, addr, False)
                log("Active Threads: %d" % _threading.activeCount())
        self.sock.close()
        log("Ending Process")
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.