1# http.tcl
2# Client-side HTTP for GET, POST, and HEAD commands.
3# These routines can be used in untrusted code that uses the Safesock
4# security policy.
5# These procedures use a callback interface to avoid using vwait,
6# which is not defined in the safe base.
7#
8# RCS: @(#) $Id: http.tcl,v 1.4 2000/02/01 11:48:30 hobbs Exp $
9#
10# See the http.n man page for documentation
11
12package provide http 1.0
13
14array set http {
15    -accept */*
16    -proxyhost {}
17    -proxyport {}
18    -useragent {Tcl http client package 1.0}
19    -proxyfilter httpProxyRequired
20}
21proc http_config {args} {
22    global http
23    set options [lsort [array names http -*]]
24    set usage [join $options ", "]
25    if {[llength $args] == 0} {
26	set result {}
27	foreach name $options {
28	    lappend result $name $http($name)
29	}
30	return $result
31    }
32    regsub -all -- - $options {} options
33    set pat ^-([join $options |])$
34    if {[llength $args] == 1} {
35	set flag [lindex $args 0]
36	if {[regexp -- $pat $flag]} {
37	    return $http($flag)
38	} else {
39	    return -code error "Unknown option $flag, must be: $usage"
40	}
41    } else {
42	foreach {flag value} $args {
43	    if {[regexp -- $pat $flag]} {
44		set http($flag) $value
45	    } else {
46		return -code error "Unknown option $flag, must be: $usage"
47	    }
48	}
49    }
50}
51
52 proc httpFinish { token {errormsg ""} } {
53    upvar #0 $token state
54    global errorInfo errorCode
55    if {[string length $errormsg] != 0} {
56	set state(error) [list $errormsg $errorInfo $errorCode]
57	set state(status) error
58    }
59    catch {close $state(sock)}
60    catch {after cancel $state(after)}
61    if {[info exists state(-command)]} {
62	if {[catch {eval $state(-command) {$token}} err]} {
63	    if {[string length $errormsg] == 0} {
64		set state(error) [list $err $errorInfo $errorCode]
65		set state(status) error
66	    }
67	}
68	unset state(-command)
69    }
70}
71proc http_reset { token {why reset} } {
72    upvar #0 $token state
73    set state(status) $why
74    catch {fileevent $state(sock) readable {}}
75    httpFinish $token
76    if {[info exists state(error)]} {
77	set errorlist $state(error)
78	unset state(error)
79	eval error $errorlist
80    }
81}
82proc http_get { url args } {
83    global http
84    if {![info exists http(uid)]} {
85	set http(uid) 0
86    }
87    set token http#[incr http(uid)]
88    upvar #0 $token state
89    http_reset $token
90    array set state {
91	-blocksize 	8192
92	-validate 	0
93	-headers 	{}
94	-timeout 	0
95	state		header
96	meta		{}
97	currentsize	0
98	totalsize	0
99        type            text/html
100        body            {}
101	status		""
102    }
103    set options {-blocksize -channel -command -handler -headers \
104		-progress -query -validate -timeout}
105    set usage [join $options ", "]
106    regsub -all -- - $options {} options
107    set pat ^-([join $options |])$
108    foreach {flag value} $args {
109	if {[regexp $pat $flag]} {
110	    # Validate numbers
111	    if {[info exists state($flag)] && \
112		    [regexp {^[0-9]+$} $state($flag)] && \
113		    ![regexp {^[0-9]+$} $value]} {
114		return -code error "Bad value for $flag ($value), must be integer"
115	    }
116	    set state($flag) $value
117	} else {
118	    return -code error "Unknown option $flag, can be: $usage"
119	}
120    }
121    if {! [regexp -nocase {^(http://)?([^/:]+)(:([0-9]+))?(/.*)?$} $url \
122	    x proto host y port srvurl]} {
123	error "Unsupported URL: $url"
124    }
125    if {[string length $port] == 0} {
126	set port 80
127    }
128    if {[string length $srvurl] == 0} {
129	set srvurl /
130    }
131    if {[string length $proto] == 0} {
132	set url http://$url
133    }
134    set state(url) $url
135    if {![catch {$http(-proxyfilter) $host} proxy]} {
136	set phost [lindex $proxy 0]
137	set pport [lindex $proxy 1]
138    }
139    if {$state(-timeout) > 0} {
140	set state(after) [after $state(-timeout) [list http_reset $token timeout]]
141    }
142    if {[info exists phost] && [string length $phost]} {
143	set srvurl $url
144	set s [socket $phost $pport]
145    } else {
146	set s [socket $host $port]
147    }
148    set state(sock) $s
149
150    # Send data in cr-lf format, but accept any line terminators
151
152    fconfigure $s -translation {auto crlf} -buffersize $state(-blocksize)
153
154    # The following is disallowed in safe interpreters, but the socket
155    # is already in non-blocking mode in that case.
156
157    catch {fconfigure $s -blocking off}
158    set len 0
159    set how GET
160    if {[info exists state(-query)]} {
161	set len [string length $state(-query)]
162	if {$len > 0} {
163	    set how POST
164	}
165    } elseif {$state(-validate)} {
166	set how HEAD
167    }
168    puts $s "$how $srvurl HTTP/1.0"
169    puts $s "Accept: $http(-accept)"
170    puts $s "Host: $host"
171    puts $s "User-Agent: $http(-useragent)"
172    foreach {key value} $state(-headers) {
173	regsub -all \[\n\r\]  $value {} value
174	set key [string trim $key]
175	if {[string length $key]} {
176	    puts $s "$key: $value"
177	}
178    }
179    if {$len > 0} {
180	puts $s "Content-Length: $len"
181	puts $s "Content-Type: application/x-www-form-urlencoded"
182	puts $s ""
183	fconfigure $s -translation {auto binary}
184	puts -nonewline $s $state(-query)
185    } else {
186	puts $s ""
187    }
188    flush $s
189    fileevent $s readable [list httpEvent $token]
190    if {! [info exists state(-command)]} {
191	http_wait $token
192    }
193    return $token
194}
195proc http_data {token} {
196    upvar #0 $token state
197    return $state(body)
198}
199proc http_status {token} {
200    upvar #0 $token state
201    return $state(status)
202}
203proc http_code {token} {
204    upvar #0 $token state
205    return $state(http)
206}
207proc http_size {token} {
208    upvar #0 $token state
209    return $state(currentsize)
210}
211
212 proc httpEvent {token} {
213    upvar #0 $token state
214    set s $state(sock)
215
216     if {[eof $s]} {
217	httpEof $token
218	return
219    }
220    if {$state(state) == "header"} {
221	set n [gets $s line]
222	if {$n == 0} {
223	    set state(state) body
224	    if {![regexp -nocase ^text $state(type)]} {
225		# Turn off conversions for non-text data
226		fconfigure $s -translation binary
227		if {[info exists state(-channel)]} {
228		    fconfigure $state(-channel) -translation binary
229		}
230	    }
231	    if {[info exists state(-channel)] &&
232		    ![info exists state(-handler)]} {
233		# Initiate a sequence of background fcopies
234		fileevent $s readable {}
235		httpCopyStart $s $token
236	    }
237	} elseif {$n > 0} {
238	    if {[regexp -nocase {^content-type:(.+)$} $line x type]} {
239		set state(type) [string trim $type]
240	    }
241	    if {[regexp -nocase {^content-length:(.+)$} $line x length]} {
242		set state(totalsize) [string trim $length]
243	    }
244	    if {[regexp -nocase {^([^:]+):(.+)$} $line x key value]} {
245		lappend state(meta) $key $value
246	    } elseif {[regexp ^HTTP $line]} {
247		set state(http) $line
248	    }
249	}
250    } else {
251	if {[catch {
252	    if {[info exists state(-handler)]} {
253		set n [eval $state(-handler) {$s $token}]
254	    } else {
255		set block [read $s $state(-blocksize)]
256		set n [string length $block]
257		if {$n >= 0} {
258		    append state(body) $block
259		}
260	    }
261	    if {$n >= 0} {
262		incr state(currentsize) $n
263	    }
264	} err]} {
265	    httpFinish $token $err
266	} else {
267	    if {[info exists state(-progress)]} {
268		eval $state(-progress) {$token $state(totalsize) $state(currentsize)}
269	    }
270	}
271    }
272}
273 proc httpCopyStart {s token} {
274    upvar #0 $token state
275    if {[catch {
276	fcopy $s $state(-channel) -size $state(-blocksize) -command \
277	    [list httpCopyDone $token]
278    } err]} {
279	httpFinish $token $err
280    }
281}
282 proc httpCopyDone {token count {error {}}} {
283    upvar #0 $token state
284    set s $state(sock)
285    incr state(currentsize) $count
286    if {[info exists state(-progress)]} {
287	eval $state(-progress) {$token $state(totalsize) $state(currentsize)}
288    }
289    if {([string length $error] != 0)} {
290	httpFinish $token $error
291    } elseif {[eof $s]} {
292	httpEof $token
293    } else {
294	httpCopyStart $s $token
295    }
296}
297 proc httpEof {token} {
298    upvar #0 $token state
299    if {$state(state) == "header"} {
300	# Premature eof
301	set state(status) eof
302    } else {
303	set state(status) ok
304    }
305    set state(state) eof
306    httpFinish $token
307}
308proc http_wait {token} {
309    upvar #0 $token state
310    if {![info exists state(status)] || [string length $state(status)] == 0} {
311	vwait $token\(status)
312    }
313    if {[info exists state(error)]} {
314	set errorlist $state(error)
315	unset state(error)
316	eval error $errorlist
317    }
318    return $state(status)
319}
320
321# Call http_formatQuery with an even number of arguments, where the first is
322# a name, the second is a value, the third is another name, and so on.
323
324proc http_formatQuery {args} {
325    set result ""
326    set sep ""
327    foreach i $args {
328	append result  $sep [httpMapReply $i]
329	if {$sep != "="} {
330	    set sep =
331	} else {
332	    set sep &
333	}
334    }
335    return $result
336}
337
338# do x-www-urlencoded character mapping
339# The spec says: "non-alphanumeric characters are replaced by '%HH'"
340# 1 leave alphanumerics characters alone
341# 2 Convert every other character to an array lookup
342# 3 Escape constructs that are "special" to the tcl parser
343# 4 "subst" the result, doing all the array substitutions
344
345 proc httpMapReply {string} {
346    global httpFormMap
347    set alphanumeric	a-zA-Z0-9
348    if {![info exists httpFormMap]} {
349
350	for {set i 1} {$i <= 256} {incr i} {
351	    set c [format %c $i]
352	    if {![string match \[$alphanumeric\] $c]} {
353		set httpFormMap($c) %[format %.2x $i]
354	    }
355	}
356	# These are handled specially
357	array set httpFormMap {
358	    " " +   \n %0d%0a
359	}
360    }
361    regsub -all \[^$alphanumeric\] $string {$httpFormMap(&)} string
362    regsub -all \n $string {\\n} string
363    regsub -all \t $string {\\t} string
364    regsub -all {[][{})\\]\)} $string {\\&} string
365    return [subst $string]
366}
367
368# Default proxy filter.
369 proc httpProxyRequired {host} {
370    global http
371    if {[info exists http(-proxyhost)] && [string length $http(-proxyhost)]} {
372	if {![info exists http(-proxyport)] || ![string length $http(-proxyport)]} {
373	    set http(-proxyport) 8080
374	}
375	return [list $http(-proxyhost) $http(-proxyport)]
376    } else {
377	return {}
378    }
379}
380