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source: lib/http_client.c @ a338faa

Last change on this file since a338faa was 792a93b, checked in by Wilmer van der Gaast <wilmer@…>, at 2011-12-23T12:44:08Z
Merging SSL certificate verification for GnuTLS, with help from AopicieR.
Property mode set to `100644`
File size: 12.7 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, int returncode, 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, TRUE, 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	if( req->status_string == NULL )
166	req->status_string = g_strdup( "Error while writing HTTP request" );
167
168	req->func( req );
169	http_free( req );
170	return FALSE;
171	}
172
173	static gboolean http_ssl_connected( gpointer data, int returncode, void *source, b_input_condition cond )
174	{
175	struct http_request *req = data;
176
177	if( source == NULL )
178	{
179	if( returncode != 0 )
180	{
181	char *err = ssl_verify_strerror( returncode );
182	req->status_string = g_strdup_printf(
183	"Certificate verification problem 0x%x: %s",
184	returncode, err ? err : "Unknown" );
185	g_free( err );
186	}
187	return http_connected( data, -1, cond );
188	}
189
190	req->fd = ssl_getfd( source );
191
192	return http_connected( data, req->fd, cond );
193	}
194
195	static gboolean http_incoming_data( gpointer data, int source, b_input_condition cond )
196	{
197	struct http_request *req = data;
198	int evil_server = 0;
199	char buffer[2048];
200	char end1, end2;
201	int st;
202
203	if( req->inpa > 0 )
204	b_event_remove( req->inpa );
205
206	if( req->ssl )
207	{
208	st = ssl_read( req->ssl, buffer, sizeof( buffer ) );
209	if( st < 0 )
210	{
211	if( ssl_errno != SSL_AGAIN )
212	{
213	/* goto cleanup; */
214
215	/* YAY! We have to deal with crappy Microsoft
216	servers that LOVE to send invalid TLS
217	packets that abort connections! \o/ */
218
219	goto got_reply;
220	}
221	}
222	else if( st == 0 )
223	{
224	goto got_reply;
225	}
226	}
227	else
228	{
229	st = read( req->fd, buffer, sizeof( buffer ) );
230	if( st < 0 )
231	{
232	if( !sockerr_again() )
233	{
234	req->status_string = g_strdup( strerror( errno ) );
235	goto cleanup;
236	}
237	}
238	else if( st == 0 )
239	{
240	goto got_reply;
241	}
242	}
243
244	if( st > 0 )
245	{
246	req->reply_headers = g_realloc( req->reply_headers, req->bytes_read + st + 1 );
247	memcpy( req->reply_headers + req->bytes_read, buffer, st );
248	req->bytes_read += st;
249	}
250
251	/* There will be more! */
252	req->inpa = b_input_add( req->fd,
253	req->ssl ? ssl_getdirection( req->ssl ) : B_EV_IO_READ,
254	http_incoming_data, req );
255
256	if( ssl_pending( req->ssl ) )
257	return http_incoming_data( data, source, cond );
258	else
259	return FALSE;
260
261	got_reply:
262	/* Maybe if the webserver is overloaded, or when there's bad SSL
263	support... */
264	if( req->bytes_read == 0 )
265	{
266	req->status_string = g_strdup( "Empty HTTP reply" );
267	goto cleanup;
268	}
269
270	/* Zero termination is very convenient. */
271	req->reply_headers[req->bytes_read] = 0;
272
273	/* Find the separation between headers and body, and keep stupid
274	webservers in mind. */
275	end1 = strstr( req->reply_headers, "\r\n\r\n" );
276	end2 = strstr( req->reply_headers, "\n\n" );
277
278	if( end2 && end2 < end1 )
279	{
280	end1 = end2 + 1;
281	evil_server = 1;
282	}
283	else if( end1 )
284	{
285	end1 += 2;
286	}
287	else
288	{
289	req->status_string = g_strdup( "Malformed HTTP reply" );
290	goto cleanup;
291	}
292
293	*end1 = 0;
294
295	if( getenv( "BITLBEE_DEBUG" ) )
296	printf( "HTTP response headers:\n%s\n", req->reply_headers );
297
298	if( evil_server )
299	req->reply_body = end1 + 1;
300	else
301	req->reply_body = end1 + 2;
302
303	req->body_size = req->reply_headers + req->bytes_read - req->reply_body;
304
305	if( ( end1 = strchr( req->reply_headers, ' ' ) ) != NULL )
306	{
307	if( sscanf( end1 + 1, "%d", &req->status_code ) != 1 )
308	{
309	req->status_string = g_strdup( "Can't parse status code" );
310	req->status_code = -1;
311	}
312	else
313	{
314	char *eol;
315
316	if( evil_server )
317	eol = strchr( end1, '\n' );
318	else
319	eol = strchr( end1, '\r' );
320
321	req->status_string = g_strndup( end1 + 1, eol - end1 - 1 );
322
323	/* Just to be sure... */
324	if( ( eol = strchr( req->status_string, '\r' ) ) )
325	*eol = 0;
326	if( ( eol = strchr( req->status_string, '\n' ) ) )
327	*eol = 0;
328	}
329	}
330	else
331	{
332	req->status_string = g_strdup( "Can't locate status code" );
333	req->status_code = -1;
334	}
335
336	if( ( ( req->status_code >= 301 && req->status_code <= 303 ) \|\|
337	req->status_code == 307 ) && req->redir_ttl-- > 0 )
338	{
339	char loc, new_request, *new_host;
340	int error = 0, new_port, new_proto;
341
342	/* We might fill it again, so let's not leak any memory. */
343	g_free( req->status_string );
344	req->status_string = NULL;
345
346	loc = strstr( req->reply_headers, "\nLocation: " );
347	if( loc == NULL ) /* We can't handle this redirect... */
348	{
349	req->status_string = g_strdup( "Can't locate Location: header" );
350	goto cleanup;
351	}
352
353	loc += 11;
354	while( *loc == ' ' )
355	loc ++;
356
357	/* TODO/FIXME: Possibly have to handle relative redirections,
358	and rewrite Host: headers. Not necessary for now, it's
359	enough for passport authentication like this. */
360
361	if( *loc == '/' )
362	{
363	/* Just a different pathname... */
364
365	/* Since we don't cache the servername, and since we
366	don't need this yet anyway, I won't implement it. */
367
368	req->status_string = g_strdup( "Can't handle recursive redirects" );
369
370	goto cleanup;
371	}
372	else
373	{
374	/* A whole URL */
375	url_t *url;
376	char *s;
377	const char *new_method;
378
379	s = strstr( loc, "\r\n" );
380	if( s == NULL )
381	goto cleanup;
382
383	url = g_new0( url_t, 1 );
384	*s = 0;
385
386	if( !url_set( url, loc ) )
387	{
388	req->status_string = g_strdup( "Malformed redirect URL" );
389	g_free( url );
390	goto cleanup;
391	}
392
393	/* Find all headers and, if necessary, the POST request contents.
394	Skip the old Host: header though. This crappy code here means
395	anything using this http_client MUST put the Host: header at
396	the top. */
397	if( !( ( s = strstr( req->request, "\r\nHost: " ) ) &&
398	( s = strstr( s + strlen( "\r\nHost: " ), "\r\n" ) ) ) )
399	{
400	req->status_string = g_strdup( "Error while rebuilding request string" );
401	g_free( url );
402	goto cleanup;
403	}
404
405	/* More or less HTTP/1.0 compliant, from my reading of RFC 2616.
406	Always perform a GET request unless we received a 301. 303 was
407	meant for this but it's HTTP/1.1-only and we're specifically
408	speaking HTTP/1.0. ...
409
410	Well except someone at identi.ca's didn't bother reading any
411	RFCs and just return HTTP/1.1-specific status codes to HTTP/1.0
412	requests. Fuckers. So here we are, handle 301..303,307. */
413	if( strncmp( req->request, "GET", 3 ) == 0 )
414	/* GETs never become POSTs. */
415	new_method = "GET";
416	else if( req->status_code == 302 \|\| req->status_code == 303 )
417	/* 302 de-facto becomes GET, 303 as specified by RFC 2616#10.3.3 */
418	new_method = "GET";
419	else
420	/* 301 de-facto should stay POST, 307 specifally RFC 2616#10.3.8 */
421	new_method = "POST";
422
423	/* Okay, this isn't fun! We have to rebuild the request... :-( */
424	new_request = g_strdup_printf( "%s %s HTTP/1.0\r\nHost: %s%s",
425	new_method, url->file, url->host, s );
426
427	new_host = g_strdup( url->host );
428	new_port = url->port;
429	new_proto = url->proto;
430
431	/* If we went from POST to GET, truncate the request content. */
432	if( new_request[0] != req->request[0] && new_request[0] == 'G' &&
433	( s = strstr( new_request, "\r\n\r\n" ) ) )
434	s[4] = '\0';
435
436	g_free( url );
437	}
438
439	if( req->ssl )
440	ssl_disconnect( req->ssl );
441	else
442	closesocket( req->fd );
443
444	req->fd = -1;
445	req->ssl = NULL;
446
447	if( getenv( "BITLBEE_DEBUG" ) )
448	printf( "New headers for redirected HTTP request:\n%s\n", new_request );
449
450	if( new_proto == PROTO_HTTPS )
451	{
452	req->ssl = ssl_connect( new_host, new_port, TRUE, http_ssl_connected, req );
453	if( req->ssl == NULL )
454	error = 1;
455	}
456	else
457	{
458	req->fd = proxy_connect( new_host, new_port, http_connected, req );
459	if( req->fd < 0 )
460	error = 1;
461	}
462	g_free( new_host );
463
464	if( error )
465	{
466	req->status_string = g_strdup( "Connection problem during redirect" );
467	g_free( new_request );
468	goto cleanup;
469	}
470
471	g_free( req->request );
472	g_free( req->reply_headers );
473	req->request = new_request;
474	req->request_length = strlen( new_request );
475	req->bytes_read = req->bytes_written = req->inpa = 0;
476	req->reply_headers = req->reply_body = NULL;
477
478	return FALSE;
479	}
480
481	/* Assume that a closed connection means we're finished, this indeed
482	breaks with keep-alive connections and faulty connections. */
483	req->finished = 1;
484
485	cleanup:
486	if( req->ssl )
487	ssl_disconnect( req->ssl );
488	else
489	closesocket( req->fd );
490
491	if( getenv( "BITLBEE_DEBUG" ) && req )
492	printf( "Finishing HTTP request with status: %s\n",
493	req->status_string ? req->status_string : "NULL" );
494
495	req->func( req );
496	http_free( req );
497	return FALSE;
498	}
499
500	static void http_free( struct http_request *req )
501	{
502	g_free( req->request );
503	g_free( req->reply_headers );
504	g_free( req->status_string );
505	g_free( req );
506	}
507

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