summaryrefslogtreecommitdiffstats
path: root/library/http/http.tcl
blob: fbf94b899f827f928c2c8c36457a212051392bd3 (plain)
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
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
# http.tcl --
#
#	Client-side HTTP for GET, POST, and HEAD commands.
#	These routines can be used in untrusted code that uses 
#	the Safesock security policy.  These procedures use a 
#	callback interface to avoid using vwait, which is not 
#	defined in the safe base.
#
# See the file "license.terms" for information on usage and
# redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: http.tcl,v 1.30 2000/04/09 23:56:13 welch Exp $

# Rough version history:
# 1.0	Old http_get interface
# 2.0	http:: namespace and http::geturl
# 2.1	Added callbacks to handle arriving data, and timeouts
# 2.2	Added ability to fetch into a channel
# 2.3	Added SSL support, and ability to post from a channel

package provide http 2.3

namespace eval http {
    variable http
    array set http {
	-accept */*
	-proxyhost {}
	-proxyport {}
	-useragent {Tcl http client package 2.3}
	-proxyfilter http::ProxyRequired
    }

    variable formMap
    variable alphanumeric a-zA-Z0-9
    variable c
    variable i 0
    for {} {$i <= 256} {incr i} {
	set c [format %c $i]
	if {![string match \[$alphanumeric\] $c]} {
	    set formMap($c) %[format %.2x $i]
	}
    }
    # These are handled specially
    array set formMap {
	" " +   \n %0d%0a
    }

    variable urlTypes
    array set urlTypes {
	http	{80 ::socket}
    }

    namespace export geturl config reset wait formatQuery register unregister
    # Useful, but not exported: data size status code
}

# http::register --
#
#     See documentaion for details.
#
# Arguments:
#     proto           URL protocol prefix, e.g. https
#     port            Default port for protocol
#     command         Command to use to create socket
# Results:
#     list of port and command that was registered.

proc http::register {proto port command} {
    variable urlTypes
    set urlTypes($proto) [list $port $command]
}

# http::unregister --
#
#     Unregisters URL protocol handler
#
# Arguments:
#     proto           URL protocol prefix, e.g. https
# Results:
#     list of port and command that was unregistered.

proc http::unregister {proto} {
    variable urlTypes
    if {![info exists urlTypes($proto)]} {
	return -code error "unsupported url type \"$proto\""
    }
    set old $urlTypes($proto)
    unset urlTypes($proto)
    return $old
}

# http::config --
#
#	See documentaion for details.
#
# Arguments:
#	args		Options parsed by the procedure.
# Results:
#        TODO

proc http::config {args} {
    variable http
    set options [lsort [array names http -*]]
    set usage [join $options ", "]
    if {[llength $args] == 0} {
	set result {}
	foreach name $options {
	    lappend result $name $http($name)
	}
	return $result
    }
    regsub -all -- - $options {} options
    set pat ^-([join $options |])$
    if {[llength $args] == 1} {
	set flag [lindex $args 0]
	if {[regexp -- $pat $flag]} {
	    return $http($flag)
	} else {
	    return -code error "Unknown option $flag, must be: $usage"
	}
    } else {
	foreach {flag value} $args {
	    if {[regexp -- $pat $flag]} {
		set http($flag) $value
	    } else {
		return -code error "Unknown option $flag, must be: $usage"
	    }
	}
    }
}

# http::Finish --
#
#	Clean up the socket and eval close time callbacks
#
# Arguments:
#	token	Connection token.
#	errormsg	If set, forces status to error.
#
# Side Effects:
#        Closes the socket

 proc http::Finish { token {errormsg ""} } {
    variable $token
    upvar 0 $token state
    global errorInfo errorCode
    if {[string length $errormsg] != 0} {
	set state(error) [list $errormsg $errorInfo $errorCode]
	set state(status) error
    }
    catch {close $state(sock)}
    catch {after cancel $state(after)}
    if {[info exists state(-command)]} {
	if {[catch {eval $state(-command) {$token}} err]} {
	    if {[string length $errormsg] == 0} {
		set state(error) [list $err $errorInfo $errorCode]
		set state(status) error
	    }
	}
	if {[info exist state(-command)]} {
	    # Command callback may already have unset our state
	    unset state(-command)
	}
    }
}

# http::reset --
#
#	See documentaion for details.
#
# Arguments:
#	token	Connection token.
#	why	Status info.
#
# Side Effects:
#       See Finish

proc http::reset { token {why reset} } {
    variable $token
    upvar 0 $token state
    set state(status) $why
    catch {fileevent $state(sock) readable {}}
    catch {fileevent $state(sock) writable {}}
    Finish $token
    if {[info exists state(error)]} {
	set errorlist $state(error)
	unset state
	eval error $errorlist
    }
}

# http::geturl --
#
#	Establishes a connection to a remote url via http.
#
# Arguments:
#       url		The http URL to goget.
#       args		Option value pairs. Valid options include:
#				-blocksize, -validate, -headers, -timeout
# Results:
#	Returns a token for this connection.
#	This token is the name of an array that the caller should
#	unset to garbage collect the state.

proc http::geturl { url args } {
    variable http
    variable urlTypes

    # Initialize the state variable, an array.  We'll return the
    # name of this array as the token for the transaction.

    if {![info exists http(uid)]} {
	set http(uid) 0
    }
    set token [namespace current]::[incr http(uid)]
    variable $token
    upvar 0 $token state
    reset $token

    # Process command options.

    array set state {
	-blocksize 	8192
	-queryblocksize 8192
	-validate 	0
	-headers 	{}
	-timeout 	0
	-type           application/x-www-form-urlencoded
	-queryprogress	{}
	state		header
	meta		{}
	currentsize	0
	totalsize	0
	querylength	0
	queryoffset	0
        type            text/html
        body            {}
	status		""
	http            ""
    }
    set options {-blocksize -channel -command -handler -headers \
	    -progress -query -queryblocksize -querychannel -queryprogress\
	    -validate -timeout -type}
    set usage [join $options ", "]
    regsub -all -- - $options {} options
    set pat ^-([join $options |])$
    foreach {flag value} $args {
	if {[regexp $pat $flag]} {
	    # Validate numbers
	    if {[info exists state($flag)] && \
		    [string is integer -strict $state($flag)] && \
		    ![string is integer -strict $value]} {
		unset $token
		return -code error "Bad value for $flag ($value), must be integer"
	    }
	    set state($flag) $value
	} else {
	    unset $token
	    return -code error "Unknown option $flag, can be: $usage"
	}
    }

    # Make sure -query and -querychannel aren't both specified

    set isQueryChannel [info exists state(-querychannel)]
    set isQuery [info exists state(-query)]
    if {$isQuery && $isQueryChannel} {
	unset $token
	return -code error "Can't combine -query and -querychannel options!"
    }

    # Validate URL, determine the server host and port, and check proxy case

    if {![regexp -nocase {^(([^:]*)://)?([^/:]+)(:([0-9]+))?(/.*)?$} $url \
	    x prefix proto host y port srvurl]} {
	unset $token
	error "Unsupported URL: $url"
    }
    if {[string length $proto] == 0} {
	set proto http
	set url ${proto}://$url
    }
    if {![info exists urlTypes($proto)]} {
	unset $token
	return -code error "unsupported url type \"$proto\""
    }
    set defport [lindex $urlTypes($proto) 0]
    set defcmd [lindex $urlTypes($proto) 1]

    if {[string length $port] == 0} {
	set port $defport
    }
    if {[string length $srvurl] == 0} {
	set srvurl /
    }
    if {[string length $proto] == 0} {
	set url http://$url
    }
    set state(url) $url
    if {![catch {$http(-proxyfilter) $host} proxy]} {
	set phost [lindex $proxy 0]
	set pport [lindex $proxy 1]
    }

    # If a timeout is specified we set up the after event
    # and arrange for an asynchronous socket connection.

    if {$state(-timeout) > 0} {
	set state(after) [after $state(-timeout) \
		[list http::reset $token timeout]]
	set async -async
    } else {
	set async ""
    }

    # If we are using the proxy, we must pass in the full URL that
    # includes the server name.

    if {[info exists phost] && [string length $phost]} {
	set srvurl $url
	set conStat [catch {eval $defcmd $async {$phost $pport}} s]
    } else {
	set conStat [catch {eval $defcmd $async {$host $port}} s]
    }
    if {$conStat} {

	# something went wrong while trying to establish the connection

	Finish $token
	cleanup $token
	return -code error $s
    }
    set state(sock) $s

    # Wait for the connection to complete

    if {$state(-timeout) > 0} {
	fileevent $s writable [list http::Connect $token]
	http::wait $token
	if {$state(status) != "connect"} {
	    
	    # Likely to be connection timeout.  If there was a connection
	    # error, (e.g., bad port), then http::wait will have 
	    # raised an error already

	    return $token
	}
	set state(status) ""
    }

    # Send data in cr-lf format, but accept any line terminators

    fconfigure $s -translation {auto crlf} -buffersize $state(-blocksize)

    # The following is disallowed in safe interpreters, but the socket
    # is already in non-blocking mode in that case.

    catch {fconfigure $s -blocking off}
    set how GET
    if {$isQuery} {
	set state(querylength) [string length $state(-query)]
	if {$state(querylength) > 0} {
	    set how POST
	    set contDone 0
	} else {
	    # there's no query data
	    unset state(-query)
	    set isQuery 0
	}
    } elseif {$state(-validate)} {
	set how HEAD
    } elseif {$isQueryChannel} {
	set how POST
	# The query channel must be blocking for the async Write to
	# work properly.
	fconfigure $state(-querychannel) -blocking 1 -translation binary
	set contDone 0
    }

    if {[catch {
	puts $s "$how $srvurl HTTP/1.0"
	puts $s "Accept: $http(-accept)"
	puts $s "Host: $host"
	puts $s "User-Agent: $http(-useragent)"
	foreach {key value} $state(-headers) {
	    regsub -all \[\n\r\]  $value {} value
	    set key [string trim $key]
	    if {[string equal $key "Content-Length"]} {
		set contDone 1
		set state(querylength) $value
	    }
	    if {[string length $key]} {
		puts $s "$key: $value"
	    }
	}
	if {$isQueryChannel && $state(querylength) == 0} {
	    # Try to determine size of data in channel
	    # If we cannot seek, the surrounding catch will trap us

	    set start [tell $state(-querychannel)]
	    seek $state(-querychannel) 0 end
	    set state(querylength) \
		    [expr {[tell $state(-querychannel)] - $start}]
	    seek $state(-querychannel) $start
	}
		
	if {$isQuery || $isQueryChannel} {
	    puts $s "Content-Type: $state(-type)"
	    if {!$contDone} {
		puts $s "Content-Length: $state(querylength)"
	    }
	    puts $s ""
	    fconfigure $s -translation {auto binary}
	    fileevent $s writable [list http::Write $token]
	} else {
	    puts $s ""
	}
	# Set up the read file event here in either case.  This seems to
	# help in the case where the server replies but does not
	# read the query post data, and the server is on the same
	# machine so the loopback interface is being used.

	flush $s
	fileevent $s readable [list http::Event $token]

	if {! [info exists state(-command)]} {

	    # geturl does EVERYTHING asynchronously, so if the user
	    # calls it synchronously, we just do a wait here.

	    wait $token
	}
    } err]} {
	# The socket probably was never connected,
	# or the connection dropped later.

	Finish $token $err
	cleanup $token
	return -code error $err
    }

    return $token
}

# Data access functions:
# Data - the URL data
# Status - the transaction status: ok, reset, eof, timeout
# Code - the HTTP transaction code, e.g., 200
# Size - the size of the URL data

proc http::data {token} {
    variable $token
    upvar 0 $token state
    return $state(body)
}
proc http::status {token} {
    variable $token
    upvar 0 $token state
    return $state(status)
}
proc http::code {token} {
    variable $token
    upvar 0 $token state
    return $state(http)
}
proc http::ncode {token} {
    variable $token
    upvar 0 $token state
    if {[regexp {[0-9]+} $state(http) numeric_code]} {
	return $numeric_code
    } else {
	return $state(http)
    }
}
proc http::size {token} {
    variable $token
    upvar 0 $token state
    return $state(currentsize)
}

# http::cleanup
#
#	Garbage collect the state associated with a transaction
#
# Arguments
#	token	The token returned from http::geturl
#
# Side Effects
#	unsets the state array

proc http::cleanup {token} {
    variable $token
    upvar 0 $token state
    if {[info exist state]} {
	unset state
    }
}

# http::Connect
#
#	This callback is made when an asyncronous connection completes.
#
# Arguments
#	token	The token returned from http::geturl
#
# Side Effects
#	Sets the status of the connection, which unblocks
# 	the waiting geturl call

 proc http::Connect {token} {
    variable $token
    upvar 0 $token state
    global errorInfo errorCode
    if {[eof $state(sock)] ||
	    [string length [fconfigure $state(sock) -error]]} {
	set state(status) error
	set state(error) [list \
		"connect failed [fconfigure $state(sock) -error]" \
		$errorInfo $errorCode]
    } else {
	set state(status) connect
    }
    fileevent $state(sock) writable {}
 }

# http::Write
#
#	Write POST query data to the socket
#
# Arguments
#	token	The token for the connection
#
# Side Effects
#	Write the socket and handle callbacks.

proc http::Write {token} {
    variable $token
    upvar 0 $token state
    set s $state(sock)
    
    # Output a block.  Tcl will buffer this if the socket blocks
    
    if {[catch {
	
	# Catch I/O errors on dead sockets

	set done 0
	if {[info exists state(-query)]} {
	    
	    # Chop up large query strings so queryprogress callback
	    # can give smooth feedback

	    puts -nonewline $s \
		    [string range $state(-query) $state(queryoffset) \
		    [expr {$state(queryoffset) + $state(-queryblocksize) - 1}]]
	    incr state(queryoffset) $state(-queryblocksize)
	    if {$state(queryoffset) >= $state(querylength)} {
		set state(queryoffset) $state(querylength)
		flush $s
		fileevent $s writable {}
	    }
	} else {
	    
	    # Copy blocks from the query channel

	    set outStr [read $state(-querychannel) $state(-queryblocksize)]
	    puts -nonewline $s $outStr
	    incr state(queryoffset) [string length $outStr]
	    if {[eof $state(-querychannel)]} {
		flush $s
		fileevent $s writable {}
	    }
	}
    } err]} {
	# Do not call Finish here, but instead let the read half of
	# the socket process whatever server reply there is to get.
	# Simply turn off this write process

	set state(posterror) $err
	fileevent $s writable {}
    }

    # Callback to the client after we've completely handled everything

    if {[string length $state(-queryprogress)]} {
	eval $state(-queryprogress) [list $token $state(querylength)\
		$state(queryoffset)]
    }
}

# http::Event
#
#	Handle input on the socket
#
# Arguments
#	token	The token returned from http::geturl
#
# Side Effects
#	Read the socket and handle callbacks.

 proc http::Event {token} {
    variable $token
    upvar 0 $token state
    set s $state(sock)

     if {[eof $s]} {
	Eof $token
	return
    }
    if {[string equal $state(state) "header"]} {
	if {[catch {gets $s line} n]} {
	    Finish $token $n
	} elseif {$n == 0} {
	    set state(state) body
	    if {![regexp -nocase ^text $state(type)]} {
		# Turn off conversions for non-text data
		fconfigure $s -translation binary
		if {[info exists state(-channel)]} {
		    fconfigure $state(-channel) -translation binary
		}
	    }
	    if {[info exists state(-channel)] &&
		    ![info exists state(-handler)]} {
		# Initiate a sequence of background fcopies
		fileevent $s readable {}
		CopyStart $s $token
	    }
	} elseif {$n > 0} {
	    if {[regexp -nocase {^content-type:(.+)$} $line x type]} {
		set state(type) [string trim $type]
	    }
	    if {[regexp -nocase {^content-length:(.+)$} $line x length]} {
		set state(totalsize) [string trim $length]
	    }
	    if {[regexp -nocase {^([^:]+):(.+)$} $line x key value]} {
		lappend state(meta) $key [string trim $value]
	    } elseif {[regexp ^HTTP $line]} {
		set state(http) $line
	    }
	}
    } else {
	if {[catch {
	    if {[info exists state(-handler)]} {
		set n [eval $state(-handler) {$s $token}]
	    } else {
		set block [read $s $state(-blocksize)]
		set n [string length $block]
		if {$n >= 0} {
		    append state(body) $block
		}
	    }
	    if {$n >= 0} {
		incr state(currentsize) $n
	    }
	} err]} {
	    Finish $token $err
	} else {
	    if {[info exists state(-progress)]} {
		eval $state(-progress) {$token $state(totalsize) $state(currentsize)}
	    }
	}
    }
}

# http::CopyStart
#
#	Error handling wrapper around fcopy
#
# Arguments
#	s	The socket to copy from
#	token	The token returned from http::geturl
#
# Side Effects
#	This closes the connection upon error

 proc http::CopyStart {s token} {
    variable $token
    upvar 0 $token state
    if {[catch {
	fcopy $s $state(-channel) -size $state(-blocksize) -command \
	    [list http::CopyDone $token]
    } err]} {
	Finish $token $err
    }
}

# http::CopyDone
#
#	fcopy completion callback
#
# Arguments
#	token	The token returned from http::geturl
#	count	The amount transfered
#
# Side Effects
#	Invokes callbacks

 proc http::CopyDone {token count {error {}}} {
    variable $token
    upvar 0 $token state
    set s $state(sock)
    incr state(currentsize) $count
    if {[info exists state(-progress)]} {
	eval $state(-progress) {$token $state(totalsize) $state(currentsize)}
    }
    # At this point the token may have been reset
    if {[string length $error]} {
	Finish $token $error
    } elseif {[catch {eof $s} iseof] || $iseof} {
	Eof $token
    } else {
	CopyStart $s $token
    }
}

# http::Eof
#
#	Handle eof on the socket
#
# Arguments
#	token	The token returned from http::geturl
#
# Side Effects
#	Clean up the socket

 proc http::Eof {token} {
    variable $token
    upvar 0 $token state
    if {[string equal $state(state) "header"]} {
	# Premature eof
	set state(status) eof
    } else {
	set state(status) ok
    }
    set state(state) eof
    Finish $token
}

# http::wait --
#
#	See documentaion for details.
#
# Arguments:
#	token	Connection token.
#
# Results:
#        The status after the wait.

proc http::wait {token} {
    variable $token
    upvar 0 $token state

    if {![info exists state(status)] || [string length $state(status)] == 0} {
	# We must wait on the original variable name, not the upvar alias
	vwait $token\(status)
    }
    if {[info exists state(error)]} {
	set errorlist $state(error)
	unset state
	eval error $errorlist
    }
    return $state(status)
}

# http::formatQuery --
#
#	See documentaion for details.
#	Call http::formatQuery with an even number of arguments, where 
#	the first is a name, the second is a value, the third is another 
#	name, and so on.
#
# Arguments:
#	args	A list of name-value pairs.
#
# Results:
#        TODO

proc http::formatQuery {args} {
    set result ""
    set sep ""
    foreach i $args {
	append result $sep [mapReply $i]
	if {[string compare $sep "="]} {
	    set sep =
	} else {
	    set sep &
	}
    }
    return $result
}

# http::mapReply --
#
#	Do x-www-urlencoded character mapping
#
# Arguments:
#	string	The string the needs to be encoded
#
# Results:
#       The encoded string

 proc http::mapReply {string} {
    variable formMap

    # The spec says: "non-alphanumeric characters are replaced by '%HH'"
    # 1 leave alphanumerics characters alone
    # 2 Convert every other character to an array lookup
    # 3 Escape constructs that are "special" to the tcl parser
    # 4 "subst" the result, doing all the array substitutions

    set alphanumeric	a-zA-Z0-9
    regsub -all \[^$alphanumeric\] $string {$formMap(&)} string
    regsub -all \n $string {\\n} string
    regsub -all \t $string {\\t} string
    regsub -all {[][{})\\]\)} $string {\\&} string
    return [subst $string]
}

# http::ProxyRequired --
#	Default proxy filter. 
#
# Arguments:
#	host	The destination host
#
# Results:
#       The current proxy settings

 proc http::ProxyRequired {host} {
    variable http
    if {[info exists http(-proxyhost)] && [string length $http(-proxyhost)]} {
	if {![info exists http(-proxyport)] || ![string length $http(-proxyport)]} {
	    set http(-proxyport) 8080
	}
	return [list $http(-proxyhost) $http(-proxyport)]
    } else {
	return {}
    }
}