Context Navigation

source: protocols/jabber/s5bytestream.c @ 4c225f0

Last change on this file since 4c225f0 was f1f7b5e, checked in by Wilmer van der Gaast <wilmer@…>, at 2010-07-24T22:50:23Z
Take the local address from the IM/IRC connection when setting up a listening socket for file transfers.
Property mode set to `100644`
File size: 32.9 KB

Line
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 "lib/ftutil.h"
27	#include <poll.h>
28
29	struct bs_transfer {
30
31	struct jabber_transfer *tf;
32
33	jabber_streamhost_t *sh;
34	GSList *streamhosts;
35
36	enum
37	{
38	BS_PHASE_CONNECT,
39	BS_PHASE_CONNECTED,
40	BS_PHASE_REQUEST,
41	BS_PHASE_REPLY
42	} phase;
43
44	/* SHA1( SID + Initiator JID + Target JID) */
45	char *pseudoadr;
46
47	gint connect_timeout;
48
49	char peek_buf[64];
50	int peek_buf_len;
51	};
52
53	struct socks5_message
54	{
55	unsigned char ver;
56	union
57	{
58	unsigned char cmd;
59	unsigned char rep;
60	} cmdrep;
61	unsigned char rsv;
62	unsigned char atyp;
63	unsigned char addrlen;
64	unsigned char address[40];
65	in_port_t port;
66	} __attribute__ ((packed));
67
68	char *socks5_reply_code[] = {
69	"succeeded",
70	"general SOCKS server failure",
71	"connection not allowed by ruleset",
72	"Network unreachable",
73	"Host unreachable",
74	"Connection refused",
75	"TTL expired",
76	"Command not supported",
77	"Address type not supported",
78	"unassigned"};
79
80	/* connect() timeout in seconds. */
81	#define JABBER_BS_CONTIMEOUT 15
82	/* listen timeout */
83	#define JABBER_BS_LISTEN_TIMEOUT 90
84
85	/* very useful */
86	#define ASSERTSOCKOP(op, msg) \
87	if( (op) == -1 ) \
88	return jabber_bs_abort( bt , msg ": %s", strerror( errno ) );
89
90	gboolean jabber_bs_abort( struct bs_transfer bt, char format, ... );
91	void jabber_bs_canceled( file_transfer_t ft , char reason );
92	void jabber_bs_free_transfer( file_transfer_t *ft );
93	gboolean jabber_bs_connect_timeout( gpointer data, gint fd, b_input_condition cond );
94	gboolean jabber_bs_poll( struct bs_transfer bt, int fd, short revents );
95	gboolean jabber_bs_peek( struct bs_transfer bt, void buffer, int buflen );
96
97	void jabber_bs_recv_answer_request( struct bs_transfer *bt );
98	gboolean jabber_bs_recv_read( gpointer data, gint fd, b_input_condition cond );
99	gboolean jabber_bs_recv_write_request( file_transfer_t *ft );
100	gboolean jabber_bs_recv_handshake( gpointer data, gint fd, b_input_condition cond );
101	gboolean jabber_bs_recv_handshake_abort( struct bs_transfer bt, char error );
102	int jabber_bs_recv_request( struct im_connection ic, struct xt_node node, struct xt_node *qnode );
103
104	gboolean jabber_bs_send_handshake_abort( struct bs_transfer bt, char error );
105	gboolean jabber_bs_send_request( struct jabber_transfer tf, GSList streamhosts );
106	gboolean jabber_bs_send_handshake( gpointer data, gint fd, b_input_condition cond );
107	static xt_status jabber_bs_send_handle_activate( struct im_connection ic, struct xt_node node, struct xt_node *orig );
108	void jabber_bs_send_activate( struct bs_transfer *bt );
109
110	/*
111	* Frees a bs_transfer struct and calls the SI free function
112	*/
113	void jabber_bs_free_transfer( file_transfer_t *ft) {
114	struct jabber_transfer *tf = ft->data;
115	struct bs_transfer *bt = tf->streamhandle;
116	jabber_streamhost_t *sh;
117
118	if ( bt->connect_timeout )
119	{
120	b_event_remove( bt->connect_timeout );
121	bt->connect_timeout = 0;
122	}
123
124	if ( tf->watch_in )
125	b_event_remove( tf->watch_in );
126
127	if( tf->watch_out )
128	b_event_remove( tf->watch_out );
129
130	g_free( bt->pseudoadr );
131
132	while( bt->streamhosts )
133	{
134	sh = bt->streamhosts->data;
135	bt->streamhosts = g_slist_remove( bt->streamhosts, sh );
136	g_free( sh->jid );
137	g_free( sh->host );
138	g_free( sh );
139	}
140
141	g_free( bt );
142
143	jabber_si_free_transfer( ft );
144	}
145
146	/*
147	* Checks if buflen data is available on the socket and
148	* writes it to buffer if that's the case.
149	*/
150	gboolean jabber_bs_peek( struct bs_transfer bt, void buffer, int buflen )
151	{
152	int ret;
153	int fd = bt->tf->fd;
154
155	if( buflen > sizeof( bt->peek_buf ) )
156	return jabber_bs_abort( bt, "BUG: %d > sizeof(peek_buf)", buflen );
157
158	ASSERTSOCKOP( ret = recv( fd, bt->peek_buf + bt->peek_buf_len,
159	buflen - bt->peek_buf_len, 0 ), "recv() on SOCKS5 connection" );
160
161	if( ret == 0 )
162	return jabber_bs_abort( bt, "Remote end closed connection" );
163
164	bt->peek_buf_len += ret;
165	memcpy( buffer, bt->peek_buf, bt->peek_buf_len );
166
167	if( bt->peek_buf_len == buflen )
168	{
169	/* If we have everything the caller wanted, reset the peek buffer. */
170	bt->peek_buf_len = 0;
171	return buflen;
172	}
173	else
174	return bt->peek_buf_len;
175	}
176
177
178	/*
179	* This function is scheduled in bs_handshake via b_timeout_add after a (non-blocking) connect().
180	*/
181	gboolean jabber_bs_connect_timeout( gpointer data, gint fd, b_input_condition cond )
182	{
183	struct bs_transfer *bt = data;
184
185	bt->connect_timeout = 0;
186
187	jabber_bs_abort( bt, "no connection after %d seconds", bt->tf->ft->sending ? JABBER_BS_LISTEN_TIMEOUT : JABBER_BS_CONTIMEOUT );
188
189	return FALSE;
190	}
191
192	/*
193	* Polls the socket, checks for errors and removes a connect timer
194	* if there is one.
195	*/
196	gboolean jabber_bs_poll( struct bs_transfer bt, int fd, short revents )
197	{
198	struct pollfd pfd = { .fd = fd, .events = POLLHUP\|POLLERR };
199
200	if ( bt->connect_timeout )
201	{
202	b_event_remove( bt->connect_timeout );
203	bt->connect_timeout = 0;
204	}
205
206	ASSERTSOCKOP( poll( &pfd, 1, 0 ), "poll()" )
207
208	if( pfd.revents & POLLERR )
209	{
210	int sockerror;
211	socklen_t errlen = sizeof( sockerror );
212
213	if ( getsockopt( fd, SOL_SOCKET, SO_ERROR, &sockerror, &errlen ) )
214	return jabber_bs_abort( bt, "getsockopt() failed, unknown socket error during SOCKS5 handshake (weird!)" );
215
216	if ( bt->phase == BS_PHASE_CONNECTED )
217	return jabber_bs_abort( bt, "connect failed: %s", strerror( sockerror ) );
218
219	return jabber_bs_abort( bt, "Socket error during SOCKS5 handshake(weird!): %s", strerror( sockerror ) );
220	}
221
222	if( pfd.revents & POLLHUP )
223	return jabber_bs_abort( bt, "Remote end closed connection" );
224
225	*revents = pfd.revents;
226
227	return TRUE;
228	}
229
230	/*
231	* Used for receive and send path.
232	*/
233	gboolean jabber_bs_abort( struct bs_transfer bt, char format, ... )
234	{
235	va_list params;
236	va_start( params, format );
237	char error[128];
238
239	if( vsnprintf( error, 128, format, params ) < 0 )
240	sprintf( error, "internal error parsing error string (BUG)" );
241	va_end( params );
242	if( bt->tf->ft->sending )
243	return jabber_bs_send_handshake_abort( bt, error );
244	else
245	return jabber_bs_recv_handshake_abort( bt, error );
246	}
247
248	/* Bad luck */
249	void jabber_bs_canceled( file_transfer_t ft , char reason )
250	{
251	struct jabber_transfer *tf = ft->data;
252
253	imcb_log( tf->ic, "File transfer aborted: %s", reason );
254	}
255
256	/*
257	* Parses an incoming bytestream request and calls jabber_bs_handshake on success.
258	*/
259	int jabber_bs_recv_request( struct im_connection ic, struct xt_node node, struct xt_node *qnode)
260	{
261	char sid, ini_jid, tgt_jid, mode, *iq_id;
262	struct jabber_data *jd = ic->proto_data;
263	struct jabber_transfer *tf = NULL;
264	GSList *tflist;
265	struct bs_transfer *bt;
266	GSList *shlist=NULL;
267	struct xt_node *shnode;
268
269	sha1_state_t sha;
270	char hash_hex[41];
271	unsigned char hash[20];
272	int i;
273
274	if( !(iq_id = xt_find_attr( node, "id" ) ) \|\|
275	!(ini_jid = xt_find_attr( node, "from" ) ) \|\|
276	!(tgt_jid = xt_find_attr( node, "to" ) ) \|\|
277	!(sid = xt_find_attr( qnode, "sid" ) ) )
278	{
279	imcb_log( ic, "WARNING: Received incomplete SI bytestream request");
280	return XT_HANDLED;
281	}
282
283	if( ( mode = xt_find_attr( qnode, "mode" ) ) &&
284	( strcmp( mode, "tcp" ) != 0 ) )
285	{
286	imcb_log( ic, "WARNING: Received SI Request for unsupported bytestream mode %s", xt_find_attr( qnode, "mode" ) );
287	return XT_HANDLED;
288	}
289
290	shnode = qnode->children;
291	while( ( shnode = xt_find_node( shnode, "streamhost" ) ) )
292	{
293	char jid, host, *port_s;
294	int port;
295	if( ( jid = xt_find_attr( shnode, "jid" ) ) &&
296	( host = xt_find_attr( shnode, "host" ) ) &&
297	( port_s = xt_find_attr( shnode, "port" ) ) &&
298	( sscanf( port_s, "%d", &port ) == 1 ) )
299	{
300	jabber_streamhost_t *sh = g_new0( jabber_streamhost_t, 1 );
301	sh->jid = g_strdup(jid);
302	sh->host = g_strdup(host);
303	sprintf( sh->port, "%u", port );
304	shlist = g_slist_append( shlist, sh );
305	}
306	shnode = shnode->next;
307	}
308
309	if( !shlist )
310	{
311	imcb_log( ic, "WARNING: Received incomplete SI bytestream request, no parseable streamhost entries");
312	return XT_HANDLED;
313	}
314
315	/* Let's see if we can find out what this bytestream should be for... */
316
317	for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) )
318	{
319	struct jabber_transfer *tft = tflist->data;
320	if( ( strcmp( tft->sid, sid ) == 0 ) &&
321	( strcmp( tft->ini_jid, ini_jid ) == 0 ) &&
322	( strcmp( tft->tgt_jid, tgt_jid ) == 0 ) )
323	{
324	tf = tft;
325	break;
326	}
327	}
328
329	if (!tf)
330	{
331	imcb_log( ic, "WARNING: Received bytestream request from %s that doesn't match an SI request", ini_jid );
332	return XT_HANDLED;
333	}
334
335	/* iq_id and canceled can be reused since SI is done */
336	g_free( tf->iq_id );
337	tf->iq_id = g_strdup( iq_id );
338
339	tf->ft->canceled = jabber_bs_canceled;
340
341	/* SHA1( SID + Initiator JID + Target JID ) is given to the streamhost which it will match against the initiator's value */
342	sha1_init( &sha );
343	sha1_append( &sha, (unsigned char*) sid, strlen( sid ) );
344	sha1_append( &sha, (unsigned char*) ini_jid, strlen( ini_jid ) );
345	sha1_append( &sha, (unsigned char*) tgt_jid, strlen( tgt_jid ) );
346	sha1_finish( &sha, hash );
347
348	for( i = 0; i < 20; i ++ )
349	sprintf( hash_hex + i * 2, "%02x", hash[i] );
350
351	bt = g_new0( struct bs_transfer, 1 );
352	bt->tf = tf;
353	bt->streamhosts = shlist;
354	bt->sh = shlist->data;
355	bt->phase = BS_PHASE_CONNECT;
356	bt->pseudoadr = g_strdup( hash_hex );
357	tf->streamhandle = bt;
358	tf->ft->free = jabber_bs_free_transfer;
359
360	jabber_bs_recv_handshake( bt, -1, 0 );
361
362	return XT_HANDLED;
363	}
364
365	/*
366	* This is what a protocol handshake can look like in cooperative multitasking :)
367	* Might be confusing at first because it's called from different places and is recursing.
368	* (places being the event thread, bs_request, bs_handshake_abort, and itself)
369	*
370	* All in all, it turned out quite nice :)
371	*/
372	gboolean jabber_bs_recv_handshake( gpointer data, gint fd, b_input_condition cond )
373	{
374
375	struct bs_transfer *bt = data;
376	short revents;
377	int gret;
378
379	if ( ( fd != -1 ) && !jabber_bs_poll( bt, fd, &revents ) )
380	return FALSE;
381
382	switch( bt->phase )
383	{
384	case BS_PHASE_CONNECT:
385	{
386	struct addrinfo hints, *rp;
387
388	memset( &hints, 0, sizeof( struct addrinfo ) );
389	hints.ai_socktype = SOCK_STREAM;
390
391	if ( ( gret = getaddrinfo( bt->sh->host, bt->sh->port, &hints, &rp ) ) != 0 )
392	return jabber_bs_abort( bt, "getaddrinfo() failed: %s", gai_strerror( gret ) );
393
394	ASSERTSOCKOP( bt->tf->fd = fd = socket( rp->ai_family, rp->ai_socktype, 0 ), "Opening socket" );
395
396	sock_make_nonblocking( fd );
397
398	imcb_log( bt->tf->ic, "File %s: Connecting to streamhost %s:%s", bt->tf->ft->file_name, bt->sh->host, bt->sh->port );
399
400	if( ( connect( fd, rp->ai_addr, rp->ai_addrlen ) == -1 ) &&
401	( errno != EINPROGRESS ) )
402	return jabber_bs_abort( bt , "connect() failed: %s", strerror( errno ) );
403
404	freeaddrinfo( rp );
405
406	bt->phase = BS_PHASE_CONNECTED;
407
408	bt->tf->watch_out = b_input_add( fd, B_EV_IO_WRITE, jabber_bs_recv_handshake, bt );
409
410	/* since it takes forever(3mins?) till connect() fails on itself we schedule a timeout */
411	bt->connect_timeout = b_timeout_add( JABBER_BS_CONTIMEOUT * 1000, jabber_bs_connect_timeout, bt );
412
413	bt->tf->watch_in = 0;
414	return FALSE;
415	}
416	case BS_PHASE_CONNECTED:
417	{
418	struct {
419	unsigned char ver;
420	unsigned char nmethods;
421	unsigned char method;
422	} socks5_hello = {
423	.ver = 5,
424	.nmethods = 1,
425	.method = 0x00 /* no auth */
426	/* one could also implement username/password. If you know
427	* a jabber client or proxy that actually does it, tell me.
428	*/
429	};
430
431	ASSERTSOCKOP( send( fd, &socks5_hello, sizeof( socks5_hello ) , 0 ), "Sending auth request" );
432
433	bt->phase = BS_PHASE_REQUEST;
434
435	bt->tf->watch_in = b_input_add( fd, B_EV_IO_READ, jabber_bs_recv_handshake, bt );
436
437	bt->tf->watch_out = 0;
438	return FALSE;
439	}
440	case BS_PHASE_REQUEST:
441	{
442	struct socks5_message socks5_connect =
443	{
444	.ver = 5,
445	.cmdrep.cmd = 0x01,
446	.rsv = 0,
447	.atyp = 0x03,
448	.addrlen = strlen( bt->pseudoadr ),
449	.port = 0
450	};
451	int ret;
452	char buf[2];
453
454	/* If someone's trying to be funny and sends only one byte at a time we'll fail :) */
455	ASSERTSOCKOP( ret = recv( fd, buf, 2, 0 ) , "Receiving auth reply" );
456
457	if( !( ret == 2 ) \|\|
458	!( buf[0] == 5 ) \|\|
459	!( buf[1] == 0 ) )
460	return jabber_bs_abort( bt, "Auth not accepted by streamhost (reply: len=%d, ver=%d, status=%d)",
461	ret, buf[0], buf[1] );
462
463	/* copy hash into connect message */
464	memcpy( socks5_connect.address, bt->pseudoadr, socks5_connect.addrlen );
465
466	ASSERTSOCKOP( send( fd, &socks5_connect, sizeof( struct socks5_message ), 0 ) , "Sending SOCKS5 Connect" );
467
468	bt->phase = BS_PHASE_REPLY;
469
470	return TRUE;
471	}
472	case BS_PHASE_REPLY:
473	{
474	struct socks5_message socks5_reply;
475	int ret;
476
477	if ( !( ret = jabber_bs_peek( bt, &socks5_reply, sizeof( struct socks5_message ) ) ) )
478	return FALSE;
479
480	if ( ret < 5 ) /* header up to address length */
481	return TRUE;
482	else if( ret < sizeof( struct socks5_message ) )
483	{
484	/* Either a buggy proxy or just one that doesnt regard
485	* the SHOULD in XEP-0065 saying the reply SHOULD
486	* contain the address. We'll take it, so make sure the
487	* next jabber_bs_peek starts with an empty buffer. */
488	bt->peek_buf_len = 0;
489	}
490
491	if( !( socks5_reply.ver == 5 ) \|\|
492	!( socks5_reply.cmdrep.rep == 0 ) ) {
493	char errstr[128] = "";
494	if( ( socks5_reply.ver == 5 ) && ( socks5_reply.cmdrep.rep <
495	( sizeof( socks5_reply_code ) / sizeof( socks5_reply_code[0] ) ) ) ) {
496	sprintf( errstr, "with \"%s\" ", socks5_reply_code[ socks5_reply.cmdrep.rep ] );
497	}
498	return jabber_bs_abort( bt, "SOCKS5 CONNECT failed %s(reply: ver=%d, rep=%d, atyp=%d, addrlen=%d)",
499	errstr,
500	socks5_reply.ver,
501	socks5_reply.cmdrep.rep,
502	socks5_reply.atyp,
503	socks5_reply.addrlen);
504	}
505
506	/* usually a proxy sends back the 40 bytes address but I encountered at least one (of jabber.cz)
507	* that sends atyp=0 addrlen=0 and only 6 bytes (one less than one would expect).
508	* Therefore I removed the wait for more bytes. Since we don't care about what else the proxy
509	* is sending, it shouldnt matter */
510
511	if( bt->tf->ft->sending )
512	jabber_bs_send_activate( bt );
513	else
514	jabber_bs_recv_answer_request( bt );
515
516	return FALSE;
517	}
518	default:
519	/* BUG */
520	imcb_log( bt->tf->ic, "BUG in file transfer code: undefined handshake phase" );
521
522	bt->tf->watch_in = 0;
523	return FALSE;
524	}
525	}
526
527	/*
528	* If the handshake failed we can try the next streamhost, if there is one.
529	* An intelligent sender would probably specify himself as the first streamhost and
530	* a proxy as the second (Kopete and PSI are examples here). That way, a (potentially)
531	* slow proxy is only used if neccessary. This of course also means, that the timeout
532	* per streamhost should be kept short. If one or two firewalled adresses are specified,
533	* they have to timeout first before a proxy is tried.
534	*/
535	gboolean jabber_bs_recv_handshake_abort( struct bs_transfer bt, char error )
536	{
537	struct jabber_transfer *tf = bt->tf;
538	struct xt_node reply, iqnode;
539	GSList *shlist;
540
541	imcb_log( tf->ic, "Transferring file %s: connection to streamhost %s:%s failed (%s)",
542	tf->ft->file_name,
543	bt->sh->host,
544	bt->sh->port,
545	error );
546
547	/* Alright, this streamhost failed, let's try the next... */
548	bt->phase = BS_PHASE_CONNECT;
549	shlist = g_slist_find( bt->streamhosts, bt->sh );
550	if( shlist && shlist->next )
551	{
552	bt->sh = shlist->next->data;
553	return jabber_bs_recv_handshake( bt, -1, 0 );
554	}
555
556
557	/* out of stream hosts */
558
559	iqnode = jabber_make_packet( "iq", "result", tf->ini_jid, NULL );
560	reply = jabber_make_error_packet( iqnode, "item-not-found", "cancel" , "404" );
561	xt_free_node( iqnode );
562
563	xt_add_attr( reply, "id", tf->iq_id );
564
565	if( !jabber_write_packet( tf->ic, reply ) )
566	imcb_log( tf->ic, "WARNING: Error transmitting bytestream response" );
567	xt_free_node( reply );
568
569	imcb_file_canceled( tf->ic, tf->ft, "couldn't connect to any streamhosts" );
570
571	/* MUST always return FALSE! */
572	return FALSE;
573	}
574
575	/*
576	* After the SOCKS5 handshake succeeds we need to inform the initiator which streamhost we chose.
577	* If he is the streamhost himself, he might already know that. However, if it's a proxy,
578	* the initiator will have to make a connection himself.
579	*/
580	void jabber_bs_recv_answer_request( struct bs_transfer *bt )
581	{
582	struct jabber_transfer *tf = bt->tf;
583	struct xt_node *reply;
584
585	imcb_log( tf->ic, "File %s: established SOCKS5 connection to %s:%s",
586	tf->ft->file_name,
587	bt->sh->host,
588	bt->sh->port );
589
590	tf->ft->data = tf;
591	tf->watch_in = b_input_add( tf->fd, B_EV_IO_READ, jabber_bs_recv_read, bt );
592	tf->ft->write_request = jabber_bs_recv_write_request;
593
594	reply = xt_new_node( "streamhost-used", NULL, NULL );
595	xt_add_attr( reply, "jid", bt->sh->jid );
596
597	reply = xt_new_node( "query", NULL, reply );
598	xt_add_attr( reply, "xmlns", XMLNS_BYTESTREAMS );
599
600	reply = jabber_make_packet( "iq", "result", tf->ini_jid, reply );
601
602	xt_add_attr( reply, "id", tf->iq_id );
603
604	if( !jabber_write_packet( tf->ic, reply ) )
605	imcb_file_canceled( tf->ic, tf->ft, "Error transmitting bytestream response" );
606	xt_free_node( reply );
607	}
608
609	/*
610	* This function is called from write_request directly. If no data is available, it will install itself
611	* as a watcher for input on fd and once that happens, deliver the data and unschedule itself again.
612	*/
613	gboolean jabber_bs_recv_read( gpointer data, gint fd, b_input_condition cond )
614	{
615	int ret;
616	struct bs_transfer *bt = data;
617	struct jabber_transfer *tf = bt->tf;
618
619	if( fd != -1 ) /* called via event thread */
620	{
621	tf->watch_in = 0;
622	ASSERTSOCKOP( ret = recv( fd, tf->ft->buffer, sizeof( tf->ft->buffer ), 0 ) , "Receiving" );
623	}
624	else
625	{
626	/* called directly. There might not be any data available. */
627	if( ( ( ret = recv( tf->fd, tf->ft->buffer, sizeof( tf->ft->buffer ), 0 ) ) == -1 ) &&
628	( errno != EAGAIN ) )
629	return jabber_bs_abort( bt, "Receiving: %s", strerror( errno ) );
630
631	if( ( ret == -1 ) && ( errno == EAGAIN ) )
632	{
633	tf->watch_in = b_input_add( tf->fd, B_EV_IO_READ, jabber_bs_recv_read, bt );
634	return FALSE;
635	}
636	}
637
638	/* shouldn't happen since we know the file size */
639	if( ret == 0 )
640	return jabber_bs_abort( bt, "Remote end closed connection" );
641
642	tf->bytesread += ret;
643
644	if( tf->bytesread >= tf->ft->file_size )
645	imcb_file_finished( tf->ic, tf->ft );
646
647	tf->ft->write( tf->ft, tf->ft->buffer, ret );
648
649	return FALSE;
650	}
651
652	/*
653	* imc callback that is invoked when it is ready to receive some data.
654	*/
655	gboolean jabber_bs_recv_write_request( file_transfer_t *ft )
656	{
657	struct jabber_transfer *tf = ft->data;
658
659	if( tf->watch_in )
660	{
661	imcb_file_canceled( tf->ic, ft, "BUG in jabber file transfer: write_request called when already watching for input" );
662	return FALSE;
663	}
664
665	jabber_bs_recv_read( tf->streamhandle, -1 , 0 );
666
667	return TRUE;
668	}
669
670	/*
671	* Issues a write_request to imc.
672	* */
673	gboolean jabber_bs_send_can_write( gpointer data, gint fd, b_input_condition cond )
674	{
675	struct bs_transfer *bt = data;
676
677	bt->tf->watch_out = 0;
678
679	bt->tf->ft->write_request( bt->tf->ft );
680
681	return FALSE;
682	}
683
684	/*
685	* This should only be called if we can write, so just do it.
686	* Add a write watch so we can write more during the next cycle (if possible).
687	*/
688	gboolean jabber_bs_send_write( file_transfer_t ft, char buffer, unsigned int len )
689	{
690	struct jabber_transfer *tf = ft->data;
691	struct bs_transfer *bt = tf->streamhandle;
692	int ret;
693
694	if( tf->watch_out )
695	return jabber_bs_abort( bt, "BUG: write() called while watching " );
696
697	/* TODO: catch broken pipe */
698	ASSERTSOCKOP( ret = send( tf->fd, buffer, len, 0 ), "Sending" );
699
700	tf->byteswritten += ret;
701
702	/* TODO: this should really not be fatal */
703	if( ret < len )
704	return jabber_bs_abort( bt, "send() sent %d instead of %d (send buffer too big!)", ret, len );
705
706	if( tf->byteswritten >= ft->file_size )
707	imcb_file_finished( tf->ic, ft );
708	else
709	bt->tf->watch_out = b_input_add( tf->fd, B_EV_IO_WRITE, jabber_bs_send_can_write, bt );
710
711	return TRUE;
712	}
713
714	/*
715	* Handles the reply by the receiver containing the used streamhost.
716	*/
717	static xt_status jabber_bs_send_handle_reply(struct im_connection ic, struct xt_node node, struct xt_node *orig ) {
718	struct jabber_transfer *tf = NULL;
719	struct jabber_data *jd = ic->proto_data;
720	struct bs_transfer *bt;
721	GSList *tflist;
722	struct xt_node *c;
723	char sid, jid;
724
725	if( !( c = xt_find_node( node->children, "query" ) ) \|\|
726	!( c = xt_find_node( c->children, "streamhost-used" ) ) \|\|
727	!( jid = xt_find_attr( c, "jid" ) ) )
728
729	{
730	imcb_log( ic, "WARNING: Received incomplete bytestream reply" );
731	return XT_HANDLED;
732	}
733
734	if( !( c = xt_find_node( orig->children, "query" ) ) \|\|
735	!( sid = xt_find_attr( c, "sid" ) ) )
736	{
737	imcb_log( ic, "WARNING: Error parsing request corresponding to the incoming bytestream reply" );
738	return XT_HANDLED;
739	}
740
741	/* Let's see if we can find out what this bytestream should be for... */
742
743	for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) )
744	{
745	struct jabber_transfer *tft = tflist->data;
746	if( ( strcmp( tft->sid, sid ) == 0 ) )
747	{
748	tf = tft;
749	break;
750	}
751	}
752
753	if( !tf )
754	{
755	imcb_log( ic, "WARNING: Received SOCKS5 bytestream reply to unknown request" );
756	return XT_HANDLED;
757	}
758
759	bt = tf->streamhandle;
760
761	tf->accepted = TRUE;
762
763	if( strcmp( jid, tf->ini_jid ) == 0 )
764	{
765	/* we're streamhost and target */
766	if( bt->phase == BS_PHASE_REPLY )
767	{
768	/* handshake went through, let's start transferring */
769	tf->ft->write_request( tf->ft );
770	}
771	} else
772	{
773	/* using a proxy, abort listen */
774
775	if( tf->watch_in )
776	{
777	b_event_remove( tf->watch_in );
778	tf->watch_in = 0;
779	}
780
781	if( tf->fd != -1 ) {
782	closesocket( tf->fd );
783	tf->fd = -1;
784	}
785
786	if ( bt->connect_timeout )
787	{
788	b_event_remove( bt->connect_timeout );
789	bt->connect_timeout = 0;
790	}
791
792	GSList *shlist;
793	for( shlist = jd->streamhosts ; shlist ; shlist = g_slist_next( shlist ) )
794	{
795	jabber_streamhost_t *sh = shlist->data;
796	if( strcmp( sh->jid, jid ) == 0 )
797	{
798	bt->sh = sh;
799	jabber_bs_recv_handshake( bt, -1, 0 );
800	return XT_HANDLED;
801	}
802	}
803
804	imcb_log( ic, "WARNING: Received SOCKS5 bytestream reply with unknown streamhost %s", jid );
805	}
806
807	return XT_HANDLED;
808	}
809
810	/*
811	* Tell the proxy to activate the stream. Looks like this:
812	*
813	* <iq type=set>
814	* <query xmlns=bs sid=sid>
815	* <activate>tgt_jid</activate>
816	* </query>
817	* </iq>
818	*/
819	void jabber_bs_send_activate( struct bs_transfer *bt )
820	{
821	struct xt_node *node;
822
823	node = xt_new_node( "activate", bt->tf->tgt_jid, NULL );
824	node = xt_new_node( "query", NULL, node );
825	xt_add_attr( node, "xmlns", XMLNS_BYTESTREAMS );
826	xt_add_attr( node, "sid", bt->tf->sid );
827	node = jabber_make_packet( "iq", "set", bt->sh->jid, node );
828
829	jabber_cache_add( bt->tf->ic, node, jabber_bs_send_handle_activate );
830
831	jabber_write_packet( bt->tf->ic, node );
832	}
833
834	/*
835	* The proxy has activated the bytestream.
836	* We can finally start pushing some data out.
837	*/
838	static xt_status jabber_bs_send_handle_activate( struct im_connection ic, struct xt_node node, struct xt_node *orig )
839	{
840	char *sid;
841	GSList *tflist;
842	struct jabber_transfer *tf = NULL;
843	struct xt_node *query;
844	struct jabber_data *jd = ic->proto_data;
845
846	query = xt_find_node( orig->children, "query" );
847	sid = xt_find_attr( query, "sid" );
848
849	for( tflist = jd->filetransfers ; tflist; tflist = g_slist_next(tflist) )
850	{
851	struct jabber_transfer *tft = tflist->data;
852	if( ( strcmp( tft->sid, sid ) == 0 ) )
853	{
854	tf = tft;
855	break;
856	}
857	}
858
859	if( !tf )
860	{
861	imcb_log( ic, "WARNING: Received SOCKS5 bytestream activation for unknown stream" );
862	return XT_HANDLED;
863	}
864
865	imcb_log( tf->ic, "File %s: SOCKS5 handshake and activation successful! Transfer about to start...", tf->ft->file_name );
866
867	/* handshake went through, let's start transferring */
868	tf->ft->write_request( tf->ft );
869
870	return XT_HANDLED;
871	}
872
873	jabber_streamhost_t jabber_si_parse_proxy( struct im_connection ic, char *proxy )
874	{
875	char host, port, *jid;
876	jabber_streamhost_t *sh;
877
878	if( ( ( host = strchr( proxy, ',' ) ) == 0 ) \|\|
879	( ( port = strchr( host+1, ',' ) ) == 0 ) ) {
880	imcb_log( ic, "Error parsing proxy setting: \"%s\" (ignored)", proxy );
881	return NULL;
882	}
883
884	jid = proxy;
885	*host++ = '\0';
886	*port++ = '\0';
887
888	sh = g_new0( jabber_streamhost_t, 1 );
889	sh->jid = g_strdup( jid );
890	sh->host = g_strdup( host );
891	strcpy( sh->port, port );
892
893	return sh;
894	}
895
896	void jabber_si_set_proxies( struct bs_transfer *bt )
897	{
898	struct jabber_transfer *tf = bt->tf;
899	struct jabber_data *jd = tf->ic->proto_data;
900	char *proxysetting = g_strdup ( set_getstr( &tf->ic->acc->set, "proxy" ) );
901	char proxy, next, *errmsg = NULL;
902	char port[6];
903	char host[HOST_NAME_MAX+1];
904	jabber_streamhost_t sh, sh2;
905	GSList *streamhosts = jd->streamhosts;
906
907	proxy = proxysetting;
908	while ( proxy && ( *proxy!='\0' ) ) {
909	if( ( next = strchr( proxy, ';' ) ) )
910	*next++ = '\0';
911
912	if( strcmp( proxy, "<local>" ) == 0 ) {
913	if( ( tf->fd = ft_listen( &tf->saddr, host, port, jd->fd, FALSE, &errmsg ) ) != -1 ) {
914	sh = g_new0( jabber_streamhost_t, 1 );
915	sh->jid = g_strdup( tf->ini_jid );
916	sh->host = g_strdup( host );
917	strcpy( sh->port, port );
918	bt->streamhosts = g_slist_append( bt->streamhosts, sh );
919
920	bt->tf->watch_in = b_input_add( tf->fd, B_EV_IO_READ, jabber_bs_send_handshake, bt );
921	bt->connect_timeout = b_timeout_add( JABBER_BS_LISTEN_TIMEOUT * 1000, jabber_bs_connect_timeout, bt );
922	} else {
923	imcb_log( tf->ic, "Transferring file %s: couldn't listen locally(non fatal, check your ft_listen setting in bitlbee.conf): %s",
924	tf->ft->file_name,
925	errmsg );
926	}
927	} else if( strcmp( proxy, "<auto>" ) == 0 ) {
928	while ( streamhosts ) {
929	sh = g_new0( jabber_streamhost_t, 1 );
930	sh2 = streamhosts->data;
931	sh->jid = g_strdup( sh2->jid );
932	sh->host = g_strdup( sh2->host );
933	strcpy( sh->port, sh2->port );
934	bt->streamhosts = g_slist_append( bt->streamhosts, sh );
935	streamhosts = g_slist_next( streamhosts );
936	}
937	} else if( ( sh = jabber_si_parse_proxy( tf->ic, proxy ) ) )
938	bt->streamhosts = g_slist_append( bt->streamhosts, sh );
939	proxy = next;
940	}
941	}
942
943	/*
944	* Starts a bytestream.
945	*/
946	gboolean jabber_bs_send_start( struct jabber_transfer *tf )
947	{
948	struct bs_transfer *bt;
949	sha1_state_t sha;
950	char hash_hex[41];
951	unsigned char hash[20];
952	int i,ret;
953
954	/* SHA1( SID + Initiator JID + Target JID ) is given to the streamhost which it will match against the initiator's value */
955	sha1_init( &sha );
956	sha1_append( &sha, (unsigned char*) tf->sid, strlen( tf->sid ) );
957	sha1_append( &sha, (unsigned char*) tf->ini_jid, strlen( tf->ini_jid ) );
958	sha1_append( &sha, (unsigned char*) tf->tgt_jid, strlen( tf->tgt_jid ) );
959	sha1_finish( &sha, hash );
960
961	for( i = 0; i < 20; i ++ )
962	sprintf( hash_hex + i * 2, "%02x", hash[i] );
963
964	bt = g_new0( struct bs_transfer, 1 );
965	bt->tf = tf;
966	bt->phase = BS_PHASE_CONNECT;
967	bt->pseudoadr = g_strdup( hash_hex );
968	tf->streamhandle = bt;
969	tf->ft->free = jabber_bs_free_transfer;
970	tf->ft->canceled = jabber_bs_canceled;
971
972	jabber_si_set_proxies( bt );
973
974	ret = jabber_bs_send_request( tf, bt->streamhosts);
975
976	return ret;
977	}
978
979	gboolean jabber_bs_send_request( struct jabber_transfer tf, GSList streamhosts )
980	{
981	struct xt_node shnode, query, *iq;
982
983	query = xt_new_node( "query", NULL, NULL );
984	xt_add_attr( query, "xmlns", XMLNS_BYTESTREAMS );
985	xt_add_attr( query, "sid", tf->sid );
986	xt_add_attr( query, "mode", "tcp" );
987
988	while( streamhosts ) {
989	jabber_streamhost_t *sh = streamhosts->data;
990	shnode = xt_new_node( "streamhost", NULL, NULL );
991	xt_add_attr( shnode, "jid", sh->jid );
992	xt_add_attr( shnode, "host", sh->host );
993	xt_add_attr( shnode, "port", sh->port );
994
995	xt_add_child( query, shnode );
996
997	streamhosts = g_slist_next( streamhosts );
998	}
999
1000
1001	iq = jabber_make_packet( "iq", "set", tf->tgt_jid, query );
1002	xt_add_attr( iq, "from", tf->ini_jid );
1003
1004	jabber_cache_add( tf->ic, iq, jabber_bs_send_handle_reply );
1005
1006	if( !jabber_write_packet( tf->ic, iq ) )
1007	imcb_file_canceled( tf->ic, tf->ft, "Error transmitting bytestream request" );
1008	return TRUE;
1009	}
1010
1011	gboolean jabber_bs_send_handshake_abort(struct bs_transfer bt, char error )
1012	{
1013	struct jabber_transfer *tf = bt->tf;
1014	struct jabber_data *jd = tf->ic->proto_data;
1015
1016	/* TODO: did the receiver get here somehow??? */
1017	imcb_log( tf->ic, "Transferring file %s: SOCKS5 handshake failed: %s",
1018	tf->ft->file_name,
1019	error );
1020
1021	if( jd->streamhosts==NULL ) /* we're done here unless we have a proxy to try */
1022	imcb_file_canceled( tf->ic, tf->ft, error );
1023
1024	/* MUST always return FALSE! */
1025	return FALSE;
1026	}
1027
1028	/*
1029	* SOCKS5BYTESTREAM protocol for the sender
1030	*/
1031	gboolean jabber_bs_send_handshake( gpointer data, gint fd, b_input_condition cond )
1032	{
1033	struct bs_transfer *bt = data;
1034	struct jabber_transfer *tf = bt->tf;
1035	short revents;
1036
1037	if ( !jabber_bs_poll( bt, fd, &revents ) )
1038	return FALSE;
1039
1040	switch( bt->phase )
1041	{
1042	case BS_PHASE_CONNECT:
1043	{
1044	struct sockaddr_storage clt_addr;
1045	socklen_t ssize = sizeof( clt_addr );
1046
1047	/* Connect */
1048
1049	ASSERTSOCKOP( tf->fd = accept( fd, (struct sockaddr *) &clt_addr, &ssize ), "Accepting connection" );
1050
1051	closesocket( fd );
1052	fd = tf->fd;
1053	sock_make_nonblocking( fd );
1054
1055	bt->phase = BS_PHASE_CONNECTED;
1056
1057	bt->tf->watch_in = b_input_add( fd, B_EV_IO_READ, jabber_bs_send_handshake, bt );
1058	return FALSE;
1059	}
1060	case BS_PHASE_CONNECTED:
1061	{
1062	int ret, have_noauth=FALSE;
1063	struct {
1064	unsigned char ver;
1065	unsigned char method;
1066	} socks5_auth_reply = { .ver = 5, .method = 0 };
1067	struct {
1068	unsigned char ver;
1069	unsigned char nmethods;
1070	unsigned char method;
1071	} socks5_hello;
1072
1073	if( !( ret = jabber_bs_peek( bt, &socks5_hello, sizeof( socks5_hello ) ) ) )
1074	return FALSE;
1075
1076	if( ret < sizeof( socks5_hello ) )
1077	return TRUE;
1078
1079	if( !( socks5_hello.ver == 5 ) \|\|
1080	!( socks5_hello.nmethods >= 1 ) \|\|
1081	!( socks5_hello.nmethods < 32 ) )
1082	return jabber_bs_abort( bt, "Invalid auth request ver=%d nmethods=%d method=%d", socks5_hello.ver, socks5_hello.nmethods, socks5_hello.method );
1083
1084	have_noauth = socks5_hello.method == 0;
1085
1086	if( socks5_hello.nmethods > 1 )
1087	{
1088	char mbuf[32];
1089	int i;
1090	ASSERTSOCKOP( ret = recv( fd, mbuf, socks5_hello.nmethods - 1, 0 ) , "Receiving auth methods" );
1091	if( ret < ( socks5_hello.nmethods - 1 ) )
1092	return jabber_bs_abort( bt, "Partial auth request");
1093	for( i = 0 ; !have_noauth && ( i < socks5_hello.nmethods - 1 ) ; i ++ )
1094	if( mbuf[i] == 0 )
1095	have_noauth = TRUE;
1096	}
1097
1098	if( !have_noauth )
1099	return jabber_bs_abort( bt, "Auth request didn't include no authentication" );
1100
1101	ASSERTSOCKOP( send( fd, &socks5_auth_reply, sizeof( socks5_auth_reply ) , 0 ), "Sending auth reply" );
1102
1103	bt->phase = BS_PHASE_REQUEST;
1104
1105	return TRUE;
1106	}
1107	case BS_PHASE_REQUEST:
1108	{
1109	struct socks5_message socks5_connect;
1110	int msgsize = sizeof( struct socks5_message );
1111	int ret;
1112
1113	if( !( ret = jabber_bs_peek( bt, &socks5_connect, msgsize ) ) )
1114	return FALSE;
1115
1116	if( ret < msgsize )
1117	return TRUE;
1118
1119	if( !( socks5_connect.ver == 5) \|\|
1120	!( socks5_connect.cmdrep.cmd == 1 ) \|\|
1121	!( socks5_connect.atyp == 3 ) \|\|
1122	!(socks5_connect.addrlen == 40 ) )
1123	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 );
1124	if( !( memcmp( socks5_connect.address, bt->pseudoadr, 40 ) == 0 ) )
1125	return jabber_bs_abort( bt, "SOCKS5 Connect message contained wrong digest");
1126
1127	socks5_connect.cmdrep.rep = 0;
1128
1129	ASSERTSOCKOP( send( fd, &socks5_connect, msgsize, 0 ), "Sending connect reply" );
1130
1131	bt->phase = BS_PHASE_REPLY;
1132
1133	imcb_log( tf->ic, "File %s: SOCKS5 handshake successful! Transfer about to start...", tf->ft->file_name );
1134
1135	if( tf->accepted )
1136	{
1137	/* streamhost-used message came already in(possible?), let's start sending */
1138	tf->ft->write_request( tf->ft );
1139	}
1140
1141	tf->watch_in = 0;
1142	return FALSE;
1143
1144	}
1145	default:
1146	/* BUG */
1147	imcb_log( bt->tf->ic, "BUG in file transfer code: undefined handshake phase" );
1148
1149	bt->tf->watch_in = 0;
1150	return FALSE;
1151	}
1152	}
1153	#undef ASSERTSOCKOP

Note: See TracBrowser for help on using the repository browser.

Download in other formats: