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source: lib/http_client.c @ 6ba00ac

Last change on this file since 6ba00ac was 3f808ca, checked in by Wilmer van der Gaast <wilmer@…>, at 2011-12-11T16:38:02Z
Support HTTP/1.1 redirect status codes and use HTTPS for OAuth setup. This is required for identi.ca and really should be done for Twitter as well. Twitter OAuth is still broken though, it seems to disagree about signatures.
Property mode set to `100644`
File size: 12.3 KB

Line
1	/********************************************************************\
2	* BitlBee -- An IRC to other IM-networks gateway *
3	* *
4	* Copyright 2002-2011 Wilmer van der Gaast and others *
5	\********************************************************************/
6
7	/* HTTP(S) module */
8
9	/*
10	This program is free software; you can redistribute it and/or modify
11	it under the terms of the GNU General Public License as published by
12	the Free Software Foundation; either version 2 of the License, or
13	(at your option) any later version.
14
15	This program is distributed in the hope that it will be useful,
16	but WITHOUT ANY WARRANTY; without even the implied warranty of
17	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18	GNU General Public License for more details.
19
20	You should have received a copy of the GNU General Public License with
21	the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
22	if not, write to the Free Software Foundation, Inc., 59 Temple Place,
23	Suite 330, Boston, MA 02111-1307 USA
24	*/
25
26	#include <string.h>
27	#include <stdio.h>
28
29	#include "http_client.h"
30	#include "url.h"
31	#include "sock.h"
32
33
34	static gboolean http_connected( gpointer data, int source, b_input_condition cond );
35	static gboolean http_ssl_connected( gpointer data, void *source, b_input_condition cond );
36	static gboolean http_incoming_data( gpointer data, int source, b_input_condition cond );
37	static void http_free( struct http_request *req );
38
39
40	struct http_request http_dorequest( char host, int port, int ssl, char *request, http_input_function func, gpointer data )
41	{
42	struct http_request *req;
43	int error = 0;
44
45	req = g_new0( struct http_request, 1 );
46
47	if( ssl )
48	{
49	req->ssl = ssl_connect( host, port, http_ssl_connected, req );
50	if( req->ssl == NULL )
51	error = 1;
52	}
53	else
54	{
55	req->fd = proxy_connect( host, port, http_connected, req );
56	if( req->fd < 0 )
57	error = 1;
58	}
59
60	if( error )
61	{
62	http_free( req );
63	return NULL;
64	}
65
66	req->func = func;
67	req->data = data;
68	req->request = g_strdup( request );
69	req->request_length = strlen( request );
70	req->redir_ttl = 3;
71
72	if( getenv( "BITLBEE_DEBUG" ) )
73	printf( "About to send HTTP request:\n%s\n", req->request );
74
75	return( req );
76	}
77
78	struct http_request http_dorequest_url( char url_string, http_input_function func, gpointer data )
79	{
80	url_t *url = g_new0( url_t, 1 );
81	char *request;
82	void *ret;
83
84	if( !url_set( url, url_string ) )
85	{
86	g_free( url );
87	return NULL;
88	}
89
90	if( url->proto != PROTO_HTTP && url->proto != PROTO_HTTPS )
91	{
92	g_free( url );
93	return NULL;
94	}
95
96	request = g_strdup_printf( "GET %s HTTP/1.0\r\n"
97	"Host: %s\r\n"
98	"Connection: close\r\n"
99	"User-Agent: BitlBee " BITLBEE_VERSION " " ARCH "/" CPU "\r\n"
100	"\r\n", url->file, url->host );
101
102	ret = http_dorequest( url->host, url->port,
103	url->proto == PROTO_HTTPS, request, func, data );
104
105	g_free( url );
106	g_free( request );
107	return ret;
108	}
109
110	/* This one is actually pretty simple... Might get more calls if we can't write
111	the whole request at once. */
112	static gboolean http_connected( gpointer data, int source, b_input_condition cond )
113	{
114	struct http_request *req = data;
115	int st;
116
117	if( source < 0 )
118	goto error;
119
120	if( req->inpa > 0 )
121	b_event_remove( req->inpa );
122
123	sock_make_nonblocking( req->fd );
124
125	if( req->ssl )
126	{
127	st = ssl_write( req->ssl, req->request + req->bytes_written,
128	req->request_length - req->bytes_written );
129	if( st < 0 )
130	{
131	if( ssl_errno != SSL_AGAIN )
132	{
133	ssl_disconnect( req->ssl );
134	goto error;
135	}
136	}
137	}
138	else
139	{
140	st = write( source, req->request + req->bytes_written,
141	req->request_length - req->bytes_written );
142	if( st < 0 )
143	{
144	if( !sockerr_again() )
145	{
146	closesocket( req->fd );
147	goto error;
148	}
149	}
150	}
151
152	if( st > 0 )
153	req->bytes_written += st;
154
155	if( req->bytes_written < req->request_length )
156	req->inpa = b_input_add( source,
157	req->ssl ? ssl_getdirection( req->ssl ) : B_EV_IO_WRITE,
158	http_connected, req );
159	else
160	req->inpa = b_input_add( source, B_EV_IO_READ, http_incoming_data, req );
161
162	return FALSE;
163
164	error:
165	req->status_string = g_strdup( "Error while writing HTTP request" );
166
167	req->func( req );
168	http_free( req );
169	return FALSE;
170	}
171
172	static gboolean http_ssl_connected( gpointer data, void *source, b_input_condition cond )
173	{
174	struct http_request *req = data;
175
176	if( source == NULL )
177	return http_connected( data, -1, cond );
178
179	req->fd = ssl_getfd( source );
180
181	return http_connected( data, req->fd, cond );
182	}
183
184	static gboolean http_incoming_data( gpointer data, int source, b_input_condition cond )
185	{
186	struct http_request *req = data;
187	int evil_server = 0;
188	char buffer[2048];
189	char end1, end2;
190	int st;
191
192	if( req->inpa > 0 )
193	b_event_remove( req->inpa );
194
195	if( req->ssl )
196	{
197	st = ssl_read( req->ssl, buffer, sizeof( buffer ) );
198	if( st < 0 )
199	{
200	if( ssl_errno != SSL_AGAIN )
201	{
202	/* goto cleanup; */
203
204	/* YAY! We have to deal with crappy Microsoft
205	servers that LOVE to send invalid TLS
206	packets that abort connections! \o/ */
207
208	goto got_reply;
209	}
210	}
211	else if( st == 0 )
212	{
213	goto got_reply;
214	}
215	}
216	else
217	{
218	st = read( req->fd, buffer, sizeof( buffer ) );
219	if( st < 0 )
220	{
221	if( !sockerr_again() )
222	{
223	req->status_string = g_strdup( strerror( errno ) );
224	goto cleanup;
225	}
226	}
227	else if( st == 0 )
228	{
229	goto got_reply;
230	}
231	}
232
233	if( st > 0 )
234	{
235	req->reply_headers = g_realloc( req->reply_headers, req->bytes_read + st + 1 );
236	memcpy( req->reply_headers + req->bytes_read, buffer, st );
237	req->bytes_read += st;
238	}
239
240	/* There will be more! */
241	req->inpa = b_input_add( req->fd,
242	req->ssl ? ssl_getdirection( req->ssl ) : B_EV_IO_READ,
243	http_incoming_data, req );
244
245	if( ssl_pending( req->ssl ) )
246	return http_incoming_data( data, source, cond );
247	else
248	return FALSE;
249
250	got_reply:
251	/* Maybe if the webserver is overloaded, or when there's bad SSL
252	support... */
253	if( req->bytes_read == 0 )
254	{
255	req->status_string = g_strdup( "Empty HTTP reply" );
256	goto cleanup;
257	}
258
259	/* Zero termination is very convenient. */
260	req->reply_headers[req->bytes_read] = 0;
261
262	/* Find the separation between headers and body, and keep stupid
263	webservers in mind. */
264	end1 = strstr( req->reply_headers, "\r\n\r\n" );
265	end2 = strstr( req->reply_headers, "\n\n" );
266
267	if( end2 && end2 < end1 )
268	{
269	end1 = end2 + 1;
270	evil_server = 1;
271	}
272	else if( end1 )
273	{
274	end1 += 2;
275	}
276	else
277	{
278	req->status_string = g_strdup( "Malformed HTTP reply" );
279	goto cleanup;
280	}
281
282	*end1 = 0;
283
284	if( getenv( "BITLBEE_DEBUG" ) )
285	printf( "HTTP response headers:\n%s\n", req->reply_headers );
286
287	if( evil_server )
288	req->reply_body = end1 + 1;
289	else
290	req->reply_body = end1 + 2;
291
292	req->body_size = req->reply_headers + req->bytes_read - req->reply_body;
293
294	if( ( end1 = strchr( req->reply_headers, ' ' ) ) != NULL )
295	{
296	if( sscanf( end1 + 1, "%d", &req->status_code ) != 1 )
297	{
298	req->status_string = g_strdup( "Can't parse status code" );
299	req->status_code = -1;
300	}
301	else
302	{
303	char *eol;
304
305	if( evil_server )
306	eol = strchr( end1, '\n' );
307	else
308	eol = strchr( end1, '\r' );
309
310	req->status_string = g_strndup( end1 + 1, eol - end1 - 1 );
311
312	/* Just to be sure... */
313	if( ( eol = strchr( req->status_string, '\r' ) ) )
314	*eol = 0;
315	if( ( eol = strchr( req->status_string, '\n' ) ) )
316	*eol = 0;
317	}
318	}
319	else
320	{
321	req->status_string = g_strdup( "Can't locate status code" );
322	req->status_code = -1;
323	}
324
325	if( ( ( req->status_code >= 301 && req->status_code <= 303 ) \|\|
326	req->status_code == 307 ) && req->redir_ttl-- > 0 )
327	{
328	char loc, new_request, *new_host;
329	int error = 0, new_port, new_proto;
330
331	/* We might fill it again, so let's not leak any memory. */
332	g_free( req->status_string );
333	req->status_string = NULL;
334
335	loc = strstr( req->reply_headers, "\nLocation: " );
336	if( loc == NULL ) /* We can't handle this redirect... */
337	{
338	req->status_string = g_strdup( "Can't locate Location: header" );
339	goto cleanup;
340	}
341
342	loc += 11;
343	while( *loc == ' ' )
344	loc ++;
345
346	/* TODO/FIXME: Possibly have to handle relative redirections,
347	and rewrite Host: headers. Not necessary for now, it's
348	enough for passport authentication like this. */
349
350	if( *loc == '/' )
351	{
352	/* Just a different pathname... */
353
354	/* Since we don't cache the servername, and since we
355	don't need this yet anyway, I won't implement it. */
356
357	req->status_string = g_strdup( "Can't handle recursive redirects" );
358
359	goto cleanup;
360	}
361	else
362	{
363	/* A whole URL */
364	url_t *url;
365	char *s;
366	const char *new_method;
367
368	s = strstr( loc, "\r\n" );
369	if( s == NULL )
370	goto cleanup;
371
372	url = g_new0( url_t, 1 );
373	*s = 0;
374
375	if( !url_set( url, loc ) )
376	{
377	req->status_string = g_strdup( "Malformed redirect URL" );
378	g_free( url );
379	goto cleanup;
380	}
381
382	/* Find all headers and, if necessary, the POST request contents.
383	Skip the old Host: header though. This crappy code here means
384	anything using this http_client MUST put the Host: header at
385	the top. */
386	if( !( ( s = strstr( req->request, "\r\nHost: " ) ) &&
387	( s = strstr( s + strlen( "\r\nHost: " ), "\r\n" ) ) ) )
388	{
389	req->status_string = g_strdup( "Error while rebuilding request string" );
390	g_free( url );
391	goto cleanup;
392	}
393
394	/* More or less HTTP/1.0 compliant, from my reading of RFC 2616.
395	Always perform a GET request unless we received a 301. 303 was
396	meant for this but it's HTTP/1.1-only and we're specifically
397	speaking HTTP/1.0. ...
398
399	Well except someone at identi.ca's didn't bother reading any
400	RFCs and just return HTTP/1.1-specific status codes to HTTP/1.0
401	requests. Fuckers. So here we are, handle 301..303,307. */
402	if( strncmp( req->request, "GET", 3 ) == 0 )
403	/* GETs never become POSTs. */
404	new_method = "GET";
405	else if( req->status_code == 302 \|\| req->status_code == 303 )
406	/* 302 de-facto becomes GET, 303 as specified by RFC 2616#10.3.3 */
407	new_method = "GET";
408	else
409	/* 301 de-facto should stay POST, 307 specifally RFC 2616#10.3.8 */
410	new_method = "POST";
411
412	/* Okay, this isn't fun! We have to rebuild the request... :-( */
413	new_request = g_strdup_printf( "%s %s HTTP/1.0\r\nHost: %s%s",
414	new_method, url->file, url->host, s );
415
416	new_host = g_strdup( url->host );
417	new_port = url->port;
418	new_proto = url->proto;
419
420	/* If we went from POST to GET, truncate the request content. */
421	if( new_request[0] != req->request[0] && new_request[0] == 'G' &&
422	( s = strstr( new_request, "\r\n\r\n" ) ) )
423	s[4] = '\0';
424
425	g_free( url );
426	}
427
428	if( req->ssl )
429	ssl_disconnect( req->ssl );
430	else
431	closesocket( req->fd );
432
433	req->fd = -1;
434	req->ssl = NULL;
435
436	if( getenv( "BITLBEE_DEBUG" ) )
437	printf( "New headers for redirected HTTP request:\n%s\n", new_request );
438
439	if( new_proto == PROTO_HTTPS )
440	{
441	req->ssl = ssl_connect( new_host, new_port, http_ssl_connected, req );
442	if( req->ssl == NULL )
443	error = 1;
444	}
445	else
446	{
447	req->fd = proxy_connect( new_host, new_port, http_connected, req );
448	if( req->fd < 0 )
449	error = 1;
450	}
451	g_free( new_host );
452
453	if( error )
454	{
455	req->status_string = g_strdup( "Connection problem during redirect" );
456	g_free( new_request );
457	goto cleanup;
458	}
459
460	g_free( req->request );
461	g_free( req->reply_headers );
462	req->request = new_request;
463	req->request_length = strlen( new_request );
464	req->bytes_read = req->bytes_written = req->inpa = 0;
465	req->reply_headers = req->reply_body = NULL;
466
467	return FALSE;
468	}
469
470	/* Assume that a closed connection means we're finished, this indeed
471	breaks with keep-alive connections and faulty connections. */
472	req->finished = 1;
473
474	cleanup:
475	if( req->ssl )
476	ssl_disconnect( req->ssl );
477	else
478	closesocket( req->fd );
479
480	if( getenv( "BITLBEE_DEBUG" ) && req )
481	printf( "Finishing HTTP request with status: %s\n",
482	req->status_string ? req->status_string : "NULL" );
483
484	req->func( req );
485	http_free( req );
486	return FALSE;
487	}
488
489	static void http_free( struct http_request *req )
490	{
491	g_free( req->request );
492	g_free( req->reply_headers );
493	g_free( req->status_string );
494	g_free( req );
495	}
496

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