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source: protocols/jabber/s5bytestream.c @ 6cac643

Last change on this file since 6cac643 was 6cac643, checked in by ulim <a.sporto+bee@…>, at 2008-04-14T12:59:15Z
more verbose error logging
Property mode set to `100644`
File size: 31.2 KB

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1	/***************************************************************************\
2	* *
3	* BitlBee - An IRC to IM gateway *
4	* Jabber module - SOCKS5 Bytestreams ( XEP-0065 ) *
5	* *
6	* Copyright 2007 Uli Meis <a.sporto+bee@gmail.com> *
7	* *
8	* This program is free software; you can redistribute it and/or modify *
9	* it under the terms of the GNU General Public License as published by *
10	* the Free Software Foundation; either version 2 of the License, or *
11	* (at your option) any later version. *
12	* *
13	* This program is distributed in the hope that it will be useful, *
14	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16	* GNU General Public License for more details. *
17	* *
18	* You should have received a copy of the GNU General Public License along *
19	* with this program; if not, write to the Free Software Foundation, Inc., *
20	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
21	* *
22	\***************************************************************************/
23
24	#include "jabber.h"
25	#include "sha1.h"
26	#include <poll.h>
27
28	struct bs_transfer {
29
30	struct jabber_transfer *tf;
31
32	jabber_streamhost_t *sh;
33	GSList *streamhosts;
34
35	enum
36	{
37	BS_PHASE_CONNECT,
38	BS_PHASE_CONNECTED,
39	BS_PHASE_REQUEST,
40	BS_PHASE_REPLY
41	} phase;
42
43	/* SHA1( SID + Initiator JID + Target JID) */
44	char *pseudoadr;
45
46	gint connect_timeout;
47	};
48
49	struct socks5_message
50	{
51	unsigned char ver;
52	union
53	{
54	unsigned char cmd;
55	unsigned char rep;
56	} cmdrep;
57	unsigned char rsv;
58	unsigned char atyp;
59	unsigned char addrlen;
60	unsigned char address[40];
61	in_port_t port;
62	} __attribute__ ((packed));
63
64	/* connect() timeout in seconds. */
65	#define JABBER_BS_CONTIMEOUT 15
66	/* listen timeout */
67	#define JABBER_BS_LISTEN_TIMEOUT 90
68
69	/* very useful */
70	#define ASSERTSOCKOP(op, msg) \
71	if( (op) == -1 ) \
72	return jabber_bs_abort( bt , msg ": %s", strerror( errno ) );
73
74	gboolean jabber_bs_abort( struct bs_transfer bt, char format, ... );
75	void jabber_bs_canceled( file_transfer_t ft , char reason );
76	void jabber_bs_free_transfer( file_transfer_t *ft );
77	gboolean jabber_bs_connect_timeout( gpointer data, gint fd, b_input_condition cond );
78	gboolean jabber_bs_poll( struct bs_transfer bt, int fd, short revents );
79	gboolean jabber_bs_peek( struct bs_transfer bt, void buffer, int buflen );
80
81	void jabber_bs_recv_answer_request( struct bs_transfer *bt );
82	gboolean jabber_bs_recv_read( gpointer data, gint fd, b_input_condition cond );
83	gboolean jabber_bs_recv_write_request( file_transfer_t *ft );
84	gboolean jabber_bs_recv_handshake( gpointer data, gint fd, b_input_condition cond );
85	gboolean jabber_bs_recv_handshake_abort( struct bs_transfer bt, char error );
86	int jabber_bs_recv_request( struct im_connection ic, struct xt_node node, struct xt_node *qnode );
87
88	gboolean jabber_bs_send_handshake_abort( struct bs_transfer bt, char error );
89	gboolean jabber_bs_send_request( struct jabber_transfer tf, GSList streamhosts );
90	gboolean jabber_bs_send_handshake( gpointer data, gint fd, b_input_condition cond );
91	gboolean jabber_bs_send_listen( struct bs_transfer bt, struct sockaddr_storage saddr, char host, char port );
92	static xt_status jabber_bs_send_handle_activate( struct im_connection ic, struct xt_node node, struct xt_node *orig );
93	void jabber_bs_send_activate( struct bs_transfer *bt );
94
95	/*
96	* Frees a bs_transfer struct and calls the SI free function
97	*/
98	void jabber_bs_free_transfer( file_transfer_t *ft) {
99	struct jabber_transfer *tf = ft->data;
100	struct bs_transfer *bt = tf->streamhandle;
101	jabber_streamhost_t *sh;
102
103	if ( bt->connect_timeout )
104	{
105	b_event_remove( bt->connect_timeout );
106	bt->connect_timeout = 0;
107	}
108
109	if ( tf->watch_in )
110	b_event_remove( tf->watch_in );
111
112	if( tf->watch_out )
113	b_event_remove( tf->watch_out );
114
115	g_free( bt->pseudoadr );
116
117	while( bt->streamhosts )
118	{
119	sh = bt->streamhosts->data;
120	bt->streamhosts = g_slist_remove( bt->streamhosts, sh );
121	g_free( sh->jid );
122	g_free( sh->host );
123	g_free( sh );
124	}
125
126	g_free( bt );
127
128	jabber_si_free_transfer( ft );
129	}
130
131	/*
132	* Checks if buflen data is available on the socket and
133	* writes it to buffer if that's the case.
134	*/
135	gboolean jabber_bs_peek( struct bs_transfer bt, void buffer, int buflen )
136	{
137	int ret;
138	int fd = bt->tf->fd;
139
140	ASSERTSOCKOP( ret = recv( fd, buffer, buflen, MSG_PEEK ), "MSG_PEEK'ing" );
141
142	if( ret == 0 )
143	return jabber_bs_abort( bt, "Remote end closed connection" );
144
145	if( ret < buflen )
146	return ret;
147
148	ASSERTSOCKOP( ret = recv( fd, buffer, buflen, 0 ), "Dequeuing after MSG_PEEK" );
149
150	if( ret != buflen )
151	return jabber_bs_abort( bt, "recv returned less than previous recv with MSG_PEEK" );
152
153	return ret;
154	}
155
156
157	/*
158	* This function is scheduled in bs_handshake via b_timeout_add after a (non-blocking) connect().
159	*/
160	gboolean jabber_bs_connect_timeout( gpointer data, gint fd, b_input_condition cond )
161	{
162	struct bs_transfer *bt = data;
163
164	bt->connect_timeout = 0;
165
166	jabber_bs_abort( bt, "no connection after %d seconds", bt->tf->ft->sending ? JABBER_BS_LISTEN_TIMEOUT : JABBER_BS_CONTIMEOUT );
167
168	return FALSE;
169	}
170
171	/*
172	* Polls the socket, checks for errors and removes a connect timer
173	* if there is one.
174	*/
175	gboolean jabber_bs_poll( struct bs_transfer bt, int fd, short revents )
176	{
177	struct pollfd pfd = { .fd = fd, .events = POLLHUP\|POLLERR };
178
179	if ( bt->connect_timeout )
180	{
181	b_event_remove( bt->connect_timeout );
182	bt->connect_timeout = 0;
183	}
184
185	ASSERTSOCKOP( poll( &pfd, 1, 0 ), "poll()" )
186
187	if( pfd.revents & POLLERR )
188	{
189	int sockerror;
190	socklen_t errlen = sizeof( sockerror );
191
192	if ( getsockopt( fd, SOL_SOCKET, SO_ERROR, &sockerror, &errlen ) )
193	return jabber_bs_abort( bt, "getsockopt() failed, unknown socket error during SOCKS5 handshake (weird!)" );
194
195	if ( bt->phase == BS_PHASE_CONNECTED )
196	return jabber_bs_abort( bt, "connect failed: %s", strerror( sockerror ) );
197
198	return jabber_bs_abort( bt, "Socket error during SOCKS5 handshake(weird!): %s", strerror( sockerror ) );
199	}
200
201	if( pfd.revents & POLLHUP )
202	return jabber_bs_abort( bt, "Remote end closed connection" );
203
204	*revents = pfd.revents;
205
206	return TRUE;
207	}
208
209	/*
210	* Used for receive and send path.
211	*/
212	gboolean jabber_bs_abort( struct bs_transfer bt, char format, ... )
213	{
214	va_list params;
215	va_start( params, format );
216	char error[128];
217
218	if( vsnprintf( error, 128, format, params ) < 0 )
219	sprintf( error, "internal error parsing error string (BUG)" );
220	va_end( params );
221	if( bt->tf->ft->sending )
222	return jabber_bs_send_handshake_abort( bt, error );
223	else
224	return jabber_bs_recv_handshake_abort( bt, error );
225	}
226
227	/* Bad luck */
228	void jabber_bs_canceled( file_transfer_t ft , char reason )
229	{
230	struct jabber_transfer *tf = ft->data;
231
232	imcb_log( tf->ic, "File transfer aborted: %s", reason );
233	}
234
235	/*
236	* Parses an incoming bytestream request and calls jabber_bs_handshake on success.
237	*/
238	int jabber_bs_recv_request( struct im_connection ic, struct xt_node node, struct xt_node *qnode)
239	{
240	char sid, ini_jid, tgt_jid, mode, *iq_id;
241	struct jabber_data *jd = ic->proto_data;
242	struct jabber_transfer *tf = NULL;
243	GSList *tflist;
244	struct bs_transfer *bt;
245	GSList *shlist=NULL;
246	struct xt_node *shnode;
247
248	sha1_state_t sha;
249	char hash_hex[41];
250	unsigned char hash[20];
251	int i;
252
253	if( !(iq_id = xt_find_attr( node, "id" ) ) \|\|
254	!(ini_jid = xt_find_attr( node, "from" ) ) \|\|
255	!(tgt_jid = xt_find_attr( node, "to" ) ) \|\|
256	!(sid = xt_find_attr( qnode, "sid" ) ) )
257	{
258	imcb_log( ic, "WARNING: Received incomplete SI bytestream request");
259	return XT_HANDLED;
260	}
261
262	if( ( mode = xt_find_attr( qnode, "mode" ) ) &&
263	( strcmp( mode, "tcp" ) != 0 ) )
264	{
265	imcb_log( ic, "WARNING: Received SI Request for unsupported bytestream mode %s", xt_find_attr( qnode, "mode" ) );
266	return XT_HANDLED;
267	}
268
269	shnode = qnode->children;
270	while( ( shnode = xt_find_node( shnode, "streamhost" ) ) )
271	{
272	char jid, host;
273	int port;
274	if( ( jid = xt_find_attr( shnode, "jid" ) ) &&
275	( host = xt_find_attr( shnode, "host" ) ) &&
276	( ( port = atoi( xt_find_attr( shnode, "port" ) ) ) ) )
277	{
278	jabber_streamhost_t *sh = g_new0( jabber_streamhost_t, 1 );
279	sh->jid = g_strdup(jid);
280	sh->host = g_strdup(host);
281	sprintf( sh->port, "%u", port );
282	shlist = g_slist_append( shlist, sh );
283	}
284	shnode = shnode->next;
285	}
286
287	if( !shlist )
288	{
289	imcb_log( ic, "WARNING: Received incomplete SI bytestream request, no parseable streamhost entries");
290	return XT_HANDLED;
291	}
292
293	/* Let's see if we can find out what this bytestream should be for... */
294
295	for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) )
296	{
297	struct jabber_transfer *tft = tflist->data;
298	if( ( strcmp( tft->sid, sid ) == 0 ) &&
299	( strcmp( tft->ini_jid, ini_jid ) == 0 ) &&
300	( strcmp( tft->tgt_jid, tgt_jid ) == 0 ) )
301	{
302	tf = tft;
303	break;
304	}
305	}
306
307	if (!tf)
308	{
309	imcb_log( ic, "WARNING: Received bytestream request from %s that doesn't match an SI request", ini_jid );
310	return XT_HANDLED;
311	}
312
313	/* iq_id and canceled can be reused since SI is done */
314	g_free( tf->iq_id );
315	tf->iq_id = g_strdup( iq_id );
316
317	tf->ft->canceled = jabber_bs_canceled;
318
319	/* SHA1( SID + Initiator JID + Target JID ) is given to the streamhost which it will match against the initiator's value */
320	sha1_init( &sha );
321	sha1_append( &sha, (unsigned char*) sid, strlen( sid ) );
322	sha1_append( &sha, (unsigned char*) ini_jid, strlen( ini_jid ) );
323	sha1_append( &sha, (unsigned char*) tgt_jid, strlen( tgt_jid ) );
324	sha1_finish( &sha, hash );
325
326	for( i = 0; i < 20; i ++ )
327	sprintf( hash_hex + i * 2, "%02x", hash[i] );
328
329	bt = g_new0( struct bs_transfer, 1 );
330	bt->tf = tf;
331	bt->streamhosts = shlist;
332	bt->sh = shlist->data;
333	bt->phase = BS_PHASE_CONNECT;
334	bt->pseudoadr = g_strdup( hash_hex );
335	tf->streamhandle = bt;
336	tf->ft->free = jabber_bs_free_transfer;
337
338	jabber_bs_recv_handshake( bt, 0, 0 );
339
340	return XT_HANDLED;
341	}
342
343	/*
344	* This is what a protocol handshake can look like in cooperative multitasking :)
345	* Might be confusing at first because it's called from different places and is recursing.
346	* (places being the event thread, bs_request, bs_handshake_abort, and itself)
347	*
348	* All in all, it turned out quite nice :)
349	*/
350	gboolean jabber_bs_recv_handshake( gpointer data, gint fd, b_input_condition cond )
351	{
352
353	struct bs_transfer *bt = data;
354	short revents;
355	int gret;
356
357	if ( ( fd != 0 ) && !jabber_bs_poll( bt, fd, &revents ) )
358	return FALSE;
359
360	switch( bt->phase )
361	{
362	case BS_PHASE_CONNECT:
363	{
364	struct addrinfo hints, *rp;
365
366	memset( &hints, 0, sizeof( struct addrinfo ) );
367	hints.ai_socktype = SOCK_STREAM;
368
369	if ( ( gret = getaddrinfo( bt->sh->host, bt->sh->port, &hints, &rp ) ) != 0 )
370	return jabber_bs_abort( bt, "getaddrinfo() failed: %s", gai_strerror( gret ) );
371
372	ASSERTSOCKOP( bt->tf->fd = fd = socket( rp->ai_family, rp->ai_socktype, 0 ), "Opening socket" );
373
374	sock_make_nonblocking( fd );
375
376	imcb_log( bt->tf->ic, "File %s: Connecting to streamhost %s:%s", bt->tf->ft->file_name, bt->sh->host, bt->sh->port );
377
378	if( ( connect( fd, rp->ai_addr, rp->ai_addrlen ) == -1 ) &&
379	( errno != EINPROGRESS ) )
380	return jabber_bs_abort( bt , "connect() failed: %s", strerror( errno ) );
381
382	freeaddrinfo( rp );
383
384	bt->phase = BS_PHASE_CONNECTED;
385
386	bt->tf->watch_out = b_input_add( fd, GAIM_INPUT_WRITE, jabber_bs_recv_handshake, bt );
387
388	/* since it takes forever(3mins?) till connect() fails on itself we schedule a timeout */
389	bt->connect_timeout = b_timeout_add( JABBER_BS_CONTIMEOUT * 1000, jabber_bs_connect_timeout, bt );
390
391	bt->tf->watch_in = 0;
392	return FALSE;
393	}
394	case BS_PHASE_CONNECTED:
395	{
396	struct {
397	unsigned char ver;
398	unsigned char nmethods;
399	unsigned char method;
400	} socks5_hello = {
401	.ver = 5,
402	.nmethods = 1,
403	.method = 0x00 /* no auth */
404	/* one could also implement username/password. If you know
405	* a jabber client or proxy that actually does it, tell me.
406	*/
407	};
408
409	ASSERTSOCKOP( send( fd, &socks5_hello, sizeof( socks5_hello ) , 0 ), "Sending auth request" );
410
411	bt->phase = BS_PHASE_REQUEST;
412
413	bt->tf->watch_in = b_input_add( fd, GAIM_INPUT_READ, jabber_bs_recv_handshake, bt );
414
415	bt->tf->watch_out = 0;
416	return FALSE;
417	}
418	case BS_PHASE_REQUEST:
419	{
420	struct socks5_message socks5_connect =
421	{
422	.ver = 5,
423	.cmdrep.cmd = 0x01,
424	.rsv = 0,
425	.atyp = 0x03,
426	.addrlen = strlen( bt->pseudoadr ),
427	.port = 0
428	};
429	int ret;
430	char buf[2];
431
432	/* If someone's trying to be funny and sends only one byte at a time we'll fail :) */
433	ASSERTSOCKOP( ret = recv( fd, buf, 2, 0 ) , "Receiving auth reply" );
434
435	if( !( ret == 2 ) \|\|
436	!( buf[0] == 5 ) \|\|
437	!( buf[1] == 0 ) )
438	return jabber_bs_abort( bt, "Auth not accepted by streamhost (reply: len=%d, ver=%d, status=%d)",
439	ret, buf[0], buf[1] );
440
441	/* copy hash into connect message */
442	memcpy( socks5_connect.address, bt->pseudoadr, socks5_connect.addrlen );
443
444	ASSERTSOCKOP( send( fd, &socks5_connect, sizeof( struct socks5_message ), 0 ) , "Sending SOCKS5 Connect" );
445
446	bt->phase = BS_PHASE_REPLY;
447
448	return TRUE;
449	}
450	case BS_PHASE_REPLY:
451	{
452	struct socks5_message socks5_reply;
453	int ret;
454
455	if ( !( ret = jabber_bs_peek( bt, &socks5_reply, sizeof( struct socks5_message ) ) ) )
456	return FALSE;
457
458	if ( ret < sizeof( socks5_reply ) )
459	return TRUE;
460
461	if( !( socks5_reply.ver == 5 ) \|\|
462	!( socks5_reply.cmdrep.rep == 0 ) \|\|
463	!( socks5_reply.atyp == 3 ) \|\|
464	!( socks5_reply.addrlen == 40 ) )
465	return jabber_bs_abort( bt, "SOCKS5 CONNECT failed (reply: ver=%d, rep=%d, atyp=%d, addrlen=%d",
466	socks5_reply.ver,
467	socks5_reply.cmdrep.rep,
468	socks5_reply.atyp,
469	socks5_reply.addrlen);
470
471	if( bt->tf->ft->sending )
472	jabber_bs_send_activate( bt );
473	else
474	jabber_bs_recv_answer_request( bt );
475
476	return FALSE;
477	}
478	default:
479	/* BUG */
480	imcb_log( bt->tf->ic, "BUG in file transfer code: undefined handshake phase" );
481
482	bt->tf->watch_in = 0;
483	return FALSE;
484	}
485	}
486
487	/*
488	* If the handshake failed we can try the next streamhost, if there is one.
489	* An intelligent sender would probably specify himself as the first streamhost and
490	* a proxy as the second (Kopete and PSI are examples here). That way, a (potentially)
491	* slow proxy is only used if neccessary. This of course also means, that the timeout
492	* per streamhost should be kept short. If one or two firewalled adresses are specified,
493	* they have to timeout first before a proxy is tried.
494	*/
495	gboolean jabber_bs_recv_handshake_abort( struct bs_transfer bt, char error )
496	{
497	struct jabber_transfer *tf = bt->tf;
498	struct xt_node reply, iqnode;
499	GSList *shlist;
500
501	imcb_log( tf->ic, "Transferring file %s: connection to streamhost %s:%s failed (%s)",
502	tf->ft->file_name,
503	bt->sh->host,
504	bt->sh->port,
505	error );
506
507	/* Alright, this streamhost failed, let's try the next... */
508	bt->phase = BS_PHASE_CONNECT;
509	shlist = g_slist_find( bt->streamhosts, bt->sh );
510	if( shlist && shlist->next )
511	{
512	bt->sh = shlist->next->data;
513	return jabber_bs_recv_handshake( bt, 0, 0 );
514	}
515
516
517	/* out of stream hosts */
518
519	iqnode = jabber_make_packet( "iq", "result", tf->ini_jid, NULL );
520	reply = jabber_make_error_packet( iqnode, "item-not-found", "cancel" , "404" );
521	xt_free_node( iqnode );
522
523	xt_add_attr( reply, "id", tf->iq_id );
524
525	if( !jabber_write_packet( tf->ic, reply ) )
526	imcb_log( tf->ic, "WARNING: Error transmitting bytestream response" );
527	xt_free_node( reply );
528
529	imcb_file_canceled( tf->ft, "couldn't connect to any streamhosts" );
530
531	bt->tf->watch_in = 0;
532	return FALSE;
533	}
534
535	/*
536	* After the SOCKS5 handshake succeeds we need to inform the initiator which streamhost we chose.
537	* If he is the streamhost himself, he might already know that. However, if it's a proxy,
538	* the initiator will have to make a connection himself.
539	*/
540	void jabber_bs_recv_answer_request( struct bs_transfer *bt )
541	{
542	struct jabber_transfer *tf = bt->tf;
543	struct xt_node *reply;
544
545	imcb_log( tf->ic, "File %s: established SOCKS5 connection to %s:%s",
546	tf->ft->file_name,
547	bt->sh->host,
548	bt->sh->port );
549
550	tf->ft->data = tf;
551	tf->watch_in = b_input_add( tf->fd, GAIM_INPUT_READ, jabber_bs_recv_read, bt );
552	tf->ft->write_request = jabber_bs_recv_write_request;
553
554	reply = xt_new_node( "streamhost-used", NULL, NULL );
555	xt_add_attr( reply, "jid", bt->sh->jid );
556
557	reply = xt_new_node( "query", NULL, reply );
558	xt_add_attr( reply, "xmlns", XMLNS_BYTESTREAMS );
559
560	reply = jabber_make_packet( "iq", "result", tf->ini_jid, reply );
561
562	xt_add_attr( reply, "id", tf->iq_id );
563
564	if( !jabber_write_packet( tf->ic, reply ) )
565	imcb_file_canceled( tf->ft, "Error transmitting bytestream response" );
566	xt_free_node( reply );
567	}
568
569	/*
570	* This function is called from write_request directly. If no data is available, it will install itself
571	* as a watcher for input on fd and once that happens, deliver the data and unschedule itself again.
572	*/
573	gboolean jabber_bs_recv_read( gpointer data, gint fd, b_input_condition cond )
574	{
575	int ret;
576	struct bs_transfer *bt = data;
577	struct jabber_transfer *tf = bt->tf;
578
579	if( fd != 0 ) /* called via event thread */
580	{
581	tf->watch_in = 0;
582	ASSERTSOCKOP( ret = recv( fd, tf->ft->buffer, sizeof( tf->ft->buffer ), 0 ) , "Receiving" );
583	}
584	else
585	{
586	/* called directly. There might not be any data available. */
587	if( ( ( ret = recv( tf->fd, tf->ft->buffer, sizeof( tf->ft->buffer ), 0 ) ) == -1 ) &&
588	( errno != EAGAIN ) )
589	return jabber_bs_abort( bt, "Receiving: %s", strerror( errno ) );
590
591	if( ( ret == -1 ) && ( errno == EAGAIN ) )
592	{
593	tf->watch_in = b_input_add( tf->fd, GAIM_INPUT_READ, jabber_bs_recv_read, bt );
594	return FALSE;
595	}
596	}
597
598	/* shouldn't happen since we know the file size */
599	if( ret == 0 )
600	return jabber_bs_abort( bt, "Remote end closed connection" );
601
602	if( tf->bytesread == 0 )
603	tf->ft->started = time( NULL );
604
605	tf->bytesread += ret;
606
607	tf->ft->write( tf->ft, tf->ft->buffer, ret );
608
609	return FALSE;
610	}
611
612	/*
613	* imc callback that is invoked when it is ready to receive some data.
614	*/
615	gboolean jabber_bs_recv_write_request( file_transfer_t *ft )
616	{
617	struct jabber_transfer *tf = ft->data;
618
619	if( tf->watch_in )
620	{
621	imcb_file_canceled( ft, "BUG in jabber file transfer: write_request called when already watching for input" );
622	return FALSE;
623	}
624
625	jabber_bs_recv_read( tf->streamhandle, 0 , 0 );
626
627	return TRUE;
628	}
629
630	/*
631	* Issues a write_request to imc.
632	* */
633	gboolean jabber_bs_send_can_write( gpointer data, gint fd, b_input_condition cond )
634	{
635	struct bs_transfer *bt = data;
636
637	bt->tf->watch_out = 0;
638
639	bt->tf->ft->write_request( bt->tf->ft );
640
641	return FALSE;
642	}
643
644	/*
645	* This should only be called if we can write, so just do it.
646	* Add a write watch so we can write more during the next cycle (if possible).
647	*/
648	gboolean jabber_bs_send_write( file_transfer_t ft, char buffer, unsigned int len )
649	{
650	struct jabber_transfer *tf = ft->data;
651	struct bs_transfer *bt = tf->streamhandle;
652	int ret;
653
654	if( tf->watch_out )
655	return jabber_bs_abort( bt, "BUG: write() called while watching " );
656
657	/* TODO: catch broken pipe */
658	ASSERTSOCKOP( ret = send( tf->fd, buffer, len, 0 ), "Sending" );
659
660	if( tf->byteswritten == 0 )
661	tf->ft->started = time( NULL );
662
663	tf->byteswritten += ret;
664
665	/* TODO: this should really not be fatal */
666	if( ret < len )
667	return jabber_bs_abort( bt, "send() sent %d instead of %d (send buffer too big!)", ret, len );
668
669	bt->tf->watch_out = b_input_add( tf->fd, GAIM_INPUT_WRITE, jabber_bs_send_can_write, bt );
670
671	return TRUE;
672	}
673
674	/*
675	* Handles the reply by the receiver containing the used streamhost.
676	*/
677	static xt_status jabber_bs_send_handle_reply(struct im_connection ic, struct xt_node node, struct xt_node *orig ) {
678	struct jabber_transfer *tf = NULL;
679	struct jabber_data *jd = ic->proto_data;
680	struct bs_transfer *bt;
681	GSList *tflist;
682	struct xt_node *c;
683	char sid, jid;
684
685	if( !( c = xt_find_node( node->children, "query" ) ) \|\|
686	!( c = xt_find_node( c->children, "streamhost-used" ) ) \|\|
687	!( jid = xt_find_attr( c, "jid" ) ) )
688
689	{
690	imcb_log( ic, "WARNING: Received incomplete bytestream reply" );
691	return XT_HANDLED;
692	}
693
694	if( !( c = xt_find_node( orig->children, "query" ) ) \|\|
695	!( sid = xt_find_attr( c, "sid" ) ) )
696	{
697	imcb_log( ic, "WARNING: Error parsing request corresponding to the incoming bytestream reply" );
698	return XT_HANDLED;
699	}
700
701	/* Let's see if we can find out what this bytestream should be for... */
702
703	for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) )
704	{
705	struct jabber_transfer *tft = tflist->data;
706	if( ( strcmp( tft->sid, sid ) == 0 ) )
707	{
708	tf = tft;
709	break;
710	}
711	}
712
713	if( !tf )
714	{
715	imcb_log( ic, "WARNING: Received SOCKS5 bytestream reply to unknown request" );
716	return XT_HANDLED;
717	}
718
719	bt = tf->streamhandle;
720
721	tf->accepted = TRUE;
722
723	if( strcmp( jid, tf->ini_jid ) == 0 )
724	{
725	/* we're streamhost and target */
726	if( bt->phase == BS_PHASE_REPLY )
727	{
728	/* handshake went through, let's start transferring */
729	tf->ft->write_request( tf->ft );
730	}
731	} else
732	{
733	/* using a proxy, abort listen */
734
735	closesocket( tf->fd );
736	tf->fd = 0;
737
738	if ( bt->connect_timeout )
739	{
740	b_event_remove( bt->connect_timeout );
741	bt->connect_timeout = 0;
742	}
743
744	GSList *shlist;
745	for( shlist = jd->streamhosts ; shlist ; shlist = g_slist_next( shlist ) )
746	{
747	jabber_streamhost_t *sh = shlist->data;
748	if( strcmp( sh->jid, jid ) == 0 )
749	{
750	bt->sh = sh;
751	jabber_bs_recv_handshake( bt, 0, 0 );
752	return XT_HANDLED;
753	}
754	}
755
756	imcb_log( ic, "WARNING: Received SOCKS5 bytestream reply with unknown streamhost %s", jid );
757	}
758
759	return XT_HANDLED;
760	}
761
762	/*
763	* Tell the proxy to activate the stream. Looks like this:
764	*
765	* <iq type=set>
766	* <query xmlns=bs sid=sid>
767	* <activate>tgt_jid</activate>
768	* </query>
769	* </iq>
770	*/
771	void jabber_bs_send_activate( struct bs_transfer *bt )
772	{
773	struct xt_node *node;
774
775	node = xt_new_node( "activate", bt->tf->tgt_jid, NULL );
776	node = xt_new_node( "query", NULL, node );
777	xt_add_attr( node, "xmlns", XMLNS_BYTESTREAMS );
778	xt_add_attr( node, "sid", bt->tf->sid );
779	node = jabber_make_packet( "iq", "set", bt->sh->jid, node );
780
781	jabber_cache_add( bt->tf->ic, node, jabber_bs_send_handle_activate );
782
783	jabber_write_packet( bt->tf->ic, node );
784	}
785
786	/*
787	* The proxy has activated the bytestream.
788	* We can finally start pushing some data out.
789	*/
790	static xt_status jabber_bs_send_handle_activate( struct im_connection ic, struct xt_node node, struct xt_node *orig )
791	{
792	char *sid;
793	GSList *tflist;
794	struct jabber_transfer *tf;
795	struct xt_node *query;
796	struct jabber_data *jd = ic->proto_data;
797
798	query = xt_find_node( orig->children, "query" );
799	sid = xt_find_attr( query, "sid" );
800
801	for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) )
802	{
803	struct jabber_transfer *tft = tflist->data;
804	if( ( strcmp( tft->sid, sid ) == 0 ) )
805	{
806	tf = tft;
807	break;
808	}
809	}
810
811	if( !tf )
812	{
813	imcb_log( ic, "WARNING: Received SOCKS5 bytestream activation for unknown stream" );
814	return XT_HANDLED;
815	}
816
817	/* handshake went through, let's start transferring */
818	tf->ft->write_request( tf->ft );
819
820	return XT_HANDLED;
821	}
822
823	/*
824	* Starts a bytestream.
825	*/
826	gboolean jabber_bs_send_start( struct jabber_transfer *tf )
827	{
828	char host[INET6_ADDRSTRLEN];
829	struct bs_transfer *bt;
830	sha1_state_t sha;
831	char hash_hex[41];
832	unsigned char hash[20];
833	int i,ret;
834	struct jabber_data *jd = tf->ic->proto_data;
835	jabber_streamhost_t sh;
836	GSList *streamhosts = jd->streamhosts;
837
838	/* SHA1( SID + Initiator JID + Target JID ) is given to the streamhost which it will match against the initiator's value */
839	sha1_init( &sha );
840	sha1_append( &sha, (unsigned char*) tf->sid, strlen( tf->sid ) );
841	sha1_append( &sha, (unsigned char*) tf->ini_jid, strlen( tf->ini_jid ) );
842	sha1_append( &sha, (unsigned char*) tf->tgt_jid, strlen( tf->tgt_jid ) );
843	sha1_finish( &sha, hash );
844
845	for( i = 0; i < 20; i ++ )
846	sprintf( hash_hex + i * 2, "%02x", hash[i] );
847
848	bt = g_new0( struct bs_transfer, 1 );
849	bt->tf = tf;
850	bt->phase = BS_PHASE_CONNECT;
851	bt->pseudoadr = g_strdup( hash_hex );
852	tf->streamhandle = bt;
853	tf->ft->free = jabber_bs_free_transfer;
854	tf->ft->canceled = jabber_bs_canceled;
855
856	if ( !jabber_bs_send_listen( bt, &tf->saddr, sh.host = host, sh.port ) )
857	return FALSE;
858
859	bt->tf->watch_in = b_input_add( tf->fd, GAIM_INPUT_READ, jabber_bs_send_handshake, bt );
860	bt->connect_timeout = b_timeout_add( JABBER_BS_LISTEN_TIMEOUT * 1000, jabber_bs_connect_timeout, bt );
861
862	sh.jid = tf->ini_jid;
863
864	/* temporarily add listen address to streamhosts, send the request and remove it */
865	streamhosts = g_slist_prepend( streamhosts, &sh );
866	ret = jabber_bs_send_request( tf, streamhosts);
867	streamhosts = g_slist_remove( streamhosts, &sh );
868
869	return ret;
870	}
871
872	gboolean jabber_bs_send_request( struct jabber_transfer tf, GSList streamhosts )
873	{
874	struct xt_node shnode, query, *iq;
875
876	query = xt_new_node( "query", NULL, NULL );
877	xt_add_attr( query, "xmlns", XMLNS_BYTESTREAMS );
878	xt_add_attr( query, "sid", tf->sid );
879	xt_add_attr( query, "mode", "tcp" );
880
881	while( streamhosts ) {
882	jabber_streamhost_t *sh = streamhosts->data;
883	shnode = xt_new_node( "streamhost", NULL, NULL );
884	xt_add_attr( shnode, "jid", sh->jid );
885	xt_add_attr( shnode, "host", sh->host );
886	xt_add_attr( shnode, "port", sh->port );
887
888	xt_add_child( query, shnode );
889
890	streamhosts = g_slist_next( streamhosts );
891	}
892
893
894	iq = jabber_make_packet( "iq", "set", tf->tgt_jid, query );
895	xt_add_attr( iq, "from", tf->ini_jid );
896
897	jabber_cache_add( tf->ic, iq, jabber_bs_send_handle_reply );
898
899	if( !jabber_write_packet( tf->ic, iq ) )
900	imcb_file_canceled( tf->ft, "Error transmitting bytestream request" );
901	return TRUE;
902	}
903
904	gboolean jabber_bs_send_handshake_abort(struct bs_transfer bt, char error )
905	{
906	struct jabber_transfer *tf = bt->tf;
907	struct jabber_data *jd = tf->ic->proto_data;
908
909	/* TODO: did the receiver get here somehow??? */
910	imcb_log( tf->ic, "Transferring file %s: SOCKS5 handshake failed: %s",
911	tf->ft->file_name,
912	error );
913
914	if( jd->streamhosts==NULL ) /* we're done here unless we have a proxy to try */
915	imcb_file_canceled( tf->ft, error );
916
917	return FALSE;
918	}
919
920	/*
921	* Creates a listening socket and returns it in saddr_ptr.
922	*/
923	gboolean jabber_bs_send_listen( struct bs_transfer bt, struct sockaddr_storage saddr, char host, char port )
924	{
925	struct jabber_transfer *tf = bt->tf;
926	int fd,gret;
927	char hostname[ HOST_NAME_MAX + 1 ];
928	struct addrinfo hints, *rp;
929	socklen_t ssize = sizeof( struct sockaddr_storage );
930
931	/* won't be long till someone asks for this to be configurable :) */
932
933	ASSERTSOCKOP( gethostname( hostname, sizeof( hostname ) ), "gethostname()" );
934
935	memset( &hints, 0, sizeof( struct addrinfo ) );
936	hints.ai_socktype = SOCK_STREAM;
937	hints.ai_flags = AI_NUMERICSERV;
938
939	if ( ( gret = getaddrinfo( hostname, "0", &hints, &rp ) ) != 0 )
940	return jabber_bs_abort( bt, "getaddrinfo() failed: %s", gai_strerror( gret ) );
941
942	memcpy( saddr, rp->ai_addr, rp->ai_addrlen );
943
944	ASSERTSOCKOP( fd = tf->fd = socket( saddr->ss_family, SOCK_STREAM, 0 ), "Opening socket" );
945
946	ASSERTSOCKOP( bind( fd, ( struct sockaddr *)saddr, rp->ai_addrlen ), "Binding socket" );
947
948	freeaddrinfo( rp );
949
950	ASSERTSOCKOP( listen( fd, 1 ), "Making socket listen" );
951
952	if ( !inet_ntop( saddr->ss_family, saddr->ss_family == AF_INET ?
953	( void * )&( ( struct sockaddr_in * ) saddr )->sin_addr.s_addr : ( void * )&( ( struct sockaddr_in6 * ) saddr )->sin6_addr.s6_addr
954	, host, INET6_ADDRSTRLEN ) )
955	return jabber_bs_abort( bt, "inet_ntop failed on listening socket" );
956
957	ASSERTSOCKOP( getsockname( fd, ( struct sockaddr *)saddr, &ssize ), "Getting socket name" );
958
959	if( saddr->ss_family == AF_INET )
960	sprintf( port, "%d", ntohs( ( ( struct sockaddr_in *) saddr )->sin_port ) );
961	else
962	sprintf( port, "%d", ntohs( ( ( struct sockaddr_in6 *) saddr )->sin6_port ) );
963
964	return TRUE;
965	}
966
967	/*
968	* SOCKS5BYTESTREAM protocol for the sender
969	*/
970	gboolean jabber_bs_send_handshake( gpointer data, gint fd, b_input_condition cond )
971	{
972	struct bs_transfer *bt = data;
973	struct jabber_transfer *tf = bt->tf;
974	short revents;
975
976	if ( !jabber_bs_poll( bt, fd, &revents ) )
977	return FALSE;
978
979	switch( bt->phase )
980	{
981	case BS_PHASE_CONNECT:
982	{
983	struct sockaddr_storage clt_addr;
984	socklen_t ssize = sizeof( clt_addr );
985
986	/* Connect */
987
988	ASSERTSOCKOP( tf->fd = accept( fd, (struct sockaddr *) &clt_addr, &ssize ), "Accepting connection" );
989
990	closesocket( fd );
991	fd = tf->fd;
992	sock_make_nonblocking( fd );
993
994	bt->phase = BS_PHASE_CONNECTED;
995
996	bt->tf->watch_in = b_input_add( fd, GAIM_INPUT_READ, jabber_bs_send_handshake, bt );
997	return FALSE;
998	}
999	case BS_PHASE_CONNECTED:
1000	{
1001	int ret, have_noauth=FALSE;
1002	struct {
1003	unsigned char ver;
1004	unsigned char method;
1005	} socks5_auth_reply = { .ver = 5, .method = 0 };
1006	struct {
1007	unsigned char ver;
1008	unsigned char nmethods;
1009	unsigned char method;
1010	} socks5_hello;
1011
1012	if( !( ret = jabber_bs_peek( bt, &socks5_hello, sizeof( socks5_hello ) ) ) )
1013	return FALSE;
1014
1015	if( ret < sizeof( socks5_hello ) )
1016	return TRUE;
1017
1018	if( !( socks5_hello.ver == 5 ) \|\|
1019	!( socks5_hello.nmethods >= 1 ) \|\|
1020	!( socks5_hello.nmethods < 32 ) )
1021	return jabber_bs_abort( bt, "Invalid auth request ver=%d nmethods=%d method=%d", socks5_hello.ver, socks5_hello.nmethods, socks5_hello.method );
1022
1023	have_noauth = socks5_hello.method == 0;
1024
1025	if( socks5_hello.nmethods > 1 )
1026	{
1027	char mbuf[32];
1028	int i;
1029	ASSERTSOCKOP( ret = recv( fd, mbuf, socks5_hello.nmethods - 1, 0 ) , "Receiving auth methods" );
1030	if( ret < ( socks5_hello.nmethods - 1 ) )
1031	return jabber_bs_abort( bt, "Partial auth request");
1032	for( i = 0 ; !have_noauth && ( i < socks5_hello.nmethods - 1 ) ; i ++ )
1033	if( mbuf[i] == 0 )
1034	have_noauth = TRUE;
1035	}
1036
1037	if( !have_noauth )
1038	return jabber_bs_abort( bt, "Auth request didn't include no authentication" );
1039
1040	ASSERTSOCKOP( send( fd, &socks5_auth_reply, sizeof( socks5_auth_reply ) , 0 ), "Sending auth reply" );
1041
1042	bt->phase = BS_PHASE_REQUEST;
1043
1044	return TRUE;
1045	}
1046	case BS_PHASE_REQUEST:
1047	{
1048	struct socks5_message socks5_connect;
1049	int msgsize = sizeof( struct socks5_message );
1050
1051	if( !jabber_bs_peek( bt, &socks5_connect, msgsize ) )
1052	return FALSE;
1053
1054	if( !( socks5_connect.ver == 5) \|\|
1055	!( socks5_connect.cmdrep.cmd == 1 ) \|\|
1056	!( socks5_connect.atyp == 3 ) \|\|
1057	!(socks5_connect.addrlen == 40 ) )
1058	return jabber_bs_abort( bt, "Invalid SOCKS5 Connect message (addrlen=%d, ver=%d, cmd=%d, atyp=%d)", socks5_connect.addrlen, socks5_connect.ver, socks5_connect.cmdrep.cmd, socks5_connect.atyp );
1059	if( !( memcmp( socks5_connect.address, bt->pseudoadr, 40 ) == 0 ) )
1060	return jabber_bs_abort( bt, "SOCKS5 Connect message contained wrong digest");
1061
1062	socks5_connect.cmdrep.rep = 0;
1063
1064	ASSERTSOCKOP( send( fd, &socks5_connect, msgsize, 0 ), "Sending connect reply" );
1065
1066	bt->phase = BS_PHASE_REPLY;
1067
1068	imcb_log( tf->ic, "File %s: SOCKS5 handshake successful! Transfer about to start...", tf->ft->file_name );
1069
1070	if( tf->accepted )
1071	{
1072	/* streamhost-used message came already in(possible?), let's start sending */
1073	tf->ft->write_request( tf->ft );
1074	}
1075
1076	tf->watch_in = 0;
1077	return FALSE;
1078
1079	}
1080	default:
1081	/* BUG */
1082	imcb_log( bt->tf->ic, "BUG in file transfer code: undefined handshake phase" );
1083
1084	bt->tf->watch_in = 0;
1085	return FALSE;
1086	}
1087	}
1088	#undef ASSERTSOCKOP

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