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io.c @ e61f9d1

Last change on this file since e61f9d1 was 0605498, checked in by dequis <dx@…>, at 2015-08-26T05:41:10Z

jabber/io: Split input buffer parsing to a jabber_feed_input() function

To simplify testing. Also allow passing a -1 as size to use strlen()

Minor behavior change: The jabber_init_iq_auth() branch can no longer
return immediately, which means it will continue through the
ssl_pending() check in jabber_read_callback().

Other than that, the size -1 change, and one indentation level less, the
function body is the same as before.

Property mode set to 100644

File size: 17.1 KB

Line
1	/***************************************************************************\
2	* *
3	* BitlBee - An IRC to IM gateway *
4	* Jabber module - I/O stuff (plain, SSL), queues, etc *
5	* *
6	* Copyright 2006-2012 Wilmer van der Gaast <wilmer@gaast.net> *
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 "ssl_client.h"
26
27	static gboolean jabber_write_callback(gpointer data, gint fd, b_input_condition cond);
28	static gboolean jabber_write_queue(struct im_connection *ic);
29
30	int jabber_write_packet(struct im_connection ic, struct xt_node node)
31	{
32	char *buf;
33	int st;
34
35	buf = xt_to_string(node);
36	st = jabber_write(ic, buf, strlen(buf));
37	g_free(buf);
38
39	return st;
40	}
41
42	int jabber_write(struct im_connection ic, char buf, int len)
43	{
44	struct jabber_data *jd = ic->proto_data;
45	gboolean ret;
46
47	if (jd->flags & JFLAG_XMLCONSOLE && !(ic->flags & OPT_LOGGING_OUT)) {
48	char msg, s;
49
50	msg = g_strdup_printf("TX: %s", buf);
51	/* Don't include auth info in XML logs. */
52	if (strncmp(msg, "TX: <auth ", 10) == 0 && (s = strchr(msg, '>'))) {
53	s++;
54	while (s && s != '<') {
55	(s++) = '';
56	}
57	}
58	imcb_buddy_msg(ic, JABBER_XMLCONSOLE_HANDLE, msg, 0, 0);
59	g_free(msg);
60	}
61
62	if (jd->tx_len == 0) {
63	/* If the queue is empty, allocate a new buffer. */
64	jd->tx_len = len;
65	jd->txq = g_memdup(buf, len);
66
67	/* Try if we can write it immediately so we don't have to do
68	it via the event handler. If not, add the handler. (In
69	most cases it probably won't be necessary.) */
70	if ((ret = jabber_write_queue(ic)) && jd->tx_len > 0) {
71	jd->w_inpa = b_input_add(jd->fd, B_EV_IO_WRITE, jabber_write_callback, ic);
72	}
73	} else {
74	/* Just add it to the buffer if it's already filled. The
75	event handler is already set. */
76	jd->txq = g_renew(char, jd->txq, jd->tx_len + len);
77	memcpy(jd->txq + jd->tx_len, buf, len);
78	jd->tx_len += len;
79
80	/* The return value for write() doesn't necessarily mean
81	that everything got sent, it mainly means that the
82	connection (officially) still exists and can still
83	be accessed without hitting SIGSEGV. IOW: */
84	ret = TRUE;
85	}
86
87	return ret;
88	}
89
90	/* Splitting up in two separate functions: One to use as a callback and one
91	to use in the function above to escape from having to wait for the event
92	handler to call us, if possible.
93
94	Two different functions are necessary because of the return values: The
95	callback should only return TRUE if the write was successful AND if the
96	buffer is not empty yet (ie. if the handler has to be called again when
97	the socket is ready for more data). */
98	static gboolean jabber_write_callback(gpointer data, gint fd, b_input_condition cond)
99	{
100	struct jabber_data jd = ((struct im_connection ) data)->proto_data;
101
102	return jd->fd != -1 &&
103	jabber_write_queue(data) &&
104	jd->tx_len > 0;
105	}
106
107	static gboolean jabber_write_queue(struct im_connection *ic)
108	{
109	struct jabber_data *jd = ic->proto_data;
110	int st;
111
112	if (jd->ssl) {
113	st = ssl_write(jd->ssl, jd->txq, jd->tx_len);
114	} else {
115	st = write(jd->fd, jd->txq, jd->tx_len);
116	}
117
118	if (st == jd->tx_len) {
119	/* We wrote everything, clear the buffer. */
120	g_free(jd->txq);
121	jd->txq = NULL;
122	jd->tx_len = 0;
123
124	return TRUE;
125	} else if (st == 0 \|\| (st < 0 && !ssl_sockerr_again(jd->ssl))) {
126	/* Set fd to -1 to make sure we won't write to it anymore. */
127	closesocket(jd->fd); /* Shouldn't be necessary after errors? */
128	jd->fd = -1;
129
130	imcb_error(ic, "Short write() to server");
131	imc_logout(ic, TRUE);
132	return FALSE;
133	} else if (st > 0) {
134	char *s;
135
136	s = g_memdup(jd->txq + st, jd->tx_len - st);
137	jd->tx_len -= st;
138	g_free(jd->txq);
139	jd->txq = s;
140
141	return TRUE;
142	} else {
143	/* Just in case we had EINPROGRESS/EAGAIN: */
144
145	return TRUE;
146	}
147	}
148
149	static gboolean jabber_feed_input(struct im_connection ic, char buf, int size)
150	{
151	struct jabber_data *jd = ic->proto_data;
152
153	/* Allow not passing a size for debugging purposes.
154	* This never happens when reading from the socket */
155	if (size == -1) {
156	size = strlen(buf);
157	}
158
159	/* Parse. */
160	if (xt_feed(jd->xt, buf, size) < 0) {
161	imcb_error(ic, "XML stream error");
162	imc_logout(ic, TRUE);
163	return FALSE;
164	}
165
166	/* Execute all handlers. */
167	if (!xt_handle(jd->xt, NULL, 1)) {
168	/* Don't do anything, the handlers should have
169	aborted the connection already. */
170	return FALSE;
171	}
172
173	if (jd->flags & JFLAG_STREAM_RESTART) {
174	jd->flags &= ~JFLAG_STREAM_RESTART;
175	jabber_start_stream(ic);
176	}
177
178	/* Garbage collection. */
179	xt_cleanup(jd->xt, NULL, 1);
180
181	/* This is a bit hackish, unfortunately. Although xmltree
182	has nifty event handler stuff, it only calls handlers
183	when nodes are complete. Since the server should only
184	send an opening <stream:stream> tag, we have to check
185	this by hand. :-( */
186	if (!(jd->flags & JFLAG_STREAM_STARTED) && jd->xt && jd->xt->root) {
187	if (g_strcasecmp(jd->xt->root->name, "stream:stream") == 0) {
188	jd->flags \|= JFLAG_STREAM_STARTED;
189
190	/* If there's no version attribute, assume
191	this is an old server that can't do SASL
192	authentication. */
193	if (!set_getbool(&ic->acc->set, "sasl") \|\| !sasl_supported(ic)) {
194	/* If there's no version= tag, we suppose
195	this server does NOT implement: XMPP 1.0,
196	SASL and TLS. */
197	if (set_getbool(&ic->acc->set, "tls")) {
198	imcb_error(ic, "TLS is turned on for this "
199	"account, but is not supported by this server");
200	imc_logout(ic, FALSE);
201	return FALSE;
202	} else {
203	if (!jabber_init_iq_auth(ic)) {
204	return FALSE;
205	}
206	}
207	}
208	} else {
209	imcb_error(ic, "XML stream error");
210	imc_logout(ic, TRUE);
211	return FALSE;
212	}
213	}
214
215	return TRUE;
216	}
217
218
219	static gboolean jabber_read_callback(gpointer data, gint fd, b_input_condition cond)
220	{
221	struct im_connection *ic = data;
222	struct jabber_data *jd = ic->proto_data;
223	char buf[512];
224	int st;
225
226	if (jd->fd == -1) {
227	return FALSE;
228	}
229
230	if (jd->ssl) {
231	st = ssl_read(jd->ssl, buf, sizeof(buf));
232	} else {
233	st = read(jd->fd, buf, sizeof(buf));
234	}
235
236	if (st > 0) {
237	if (!jabber_feed_input(ic, buf, st)) {
238	return FALSE;
239	}
240	} else if (st == 0 \|\| (st < 0 && !ssl_sockerr_again(jd->ssl))) {
241	closesocket(jd->fd);
242	jd->fd = -1;
243
244	imcb_error(ic, "Error while reading from server");
245	imc_logout(ic, TRUE);
246	return FALSE;
247	}
248
249	if (ssl_pending(jd->ssl)) {
250	/* OpenSSL empties the TCP buffers completely but may keep some
251	data in its internap buffers. select() won't see that, but
252	ssl_pending() does. */
253	return jabber_read_callback(data, fd, cond);
254	} else {
255	return TRUE;
256	}
257	}
258
259	gboolean jabber_connected_plain(gpointer data, gint source, b_input_condition cond)
260	{
261	struct im_connection *ic = data;
262
263	if (g_slist_find(jabber_connections, ic) == NULL) {
264	return FALSE;
265	}
266
267	if (source == -1) {
268	imcb_error(ic, "Could not connect to server");
269	imc_logout(ic, TRUE);
270	return FALSE;
271	}
272
273	imcb_log(ic, "Connected to server, logging in");
274
275	return jabber_start_stream(ic);
276	}
277
278	gboolean jabber_connected_ssl(gpointer data, int returncode, void *source, b_input_condition cond)
279	{
280	struct im_connection *ic = data;
281	struct jabber_data *jd;
282
283	if (g_slist_find(jabber_connections, ic) == NULL) {
284	return FALSE;
285	}
286
287	jd = ic->proto_data;
288
289	if (source == NULL) {
290	/* The SSL connection will be cleaned up by the SSL lib
291	already, set it to NULL here to prevent a double cleanup: */
292	jd->ssl = NULL;
293
294	if (returncode != 0) {
295	char *err = ssl_verify_strerror(returncode);
296	imcb_error(ic, "Certificate verification problem 0x%x: %s",
297	returncode, err ? err : "Unknown");
298	g_free(err);
299	imc_logout(ic, FALSE);
300	} else {
301	imcb_error(ic, "Could not connect to server");
302	imc_logout(ic, TRUE);
303	}
304
305	return FALSE;
306	}
307
308	imcb_log(ic, "Connected to server, logging in");
309
310	return jabber_start_stream(ic);
311	}
312
313	static xt_status jabber_end_of_stream(struct xt_node *node, gpointer data)
314	{
315	imc_logout(data, TRUE);
316	return XT_ABORT;
317	}
318
319	static xt_status jabber_pkt_features(struct xt_node *node, gpointer data)
320	{
321	struct im_connection *ic = data;
322	struct jabber_data *jd = ic->proto_data;
323	struct xt_node c, reply;
324	int trytls;
325
326	trytls = g_strcasecmp(set_getstr(&ic->acc->set, "tls"), "try") == 0;
327	c = xt_find_node(node->children, "starttls");
328	if (c && !jd->ssl) {
329	/* If the server advertises the STARTTLS feature and if we're
330	not in a secure connection already: */
331
332	c = xt_find_node(c->children, "required");
333
334	if (c && (!trytls && !set_getbool(&ic->acc->set, "tls"))) {
335	imcb_error(ic, "Server requires TLS connections, but TLS is turned off for this account");
336	imc_logout(ic, FALSE);
337
338	return XT_ABORT;
339	}
340
341	/* Only run this if the tls setting is set to true or try: */
342	if ((trytls \|\| set_getbool(&ic->acc->set, "tls"))) {
343	reply = xt_new_node("starttls", NULL, NULL);
344	xt_add_attr(reply, "xmlns", XMLNS_TLS);
345	if (!jabber_write_packet(ic, reply)) {
346	xt_free_node(reply);
347	return XT_ABORT;
348	}
349	xt_free_node(reply);
350
351	return XT_HANDLED;
352	}
353	} else if (!c && !jd->ssl) {
354	/* If the server does not advertise the STARTTLS feature and
355	we're not in a secure connection already: (Servers have a
356	habit of not advertising <starttls/> anymore when already
357	using SSL/TLS. */
358
359	if (!trytls && set_getbool(&ic->acc->set, "tls")) {
360	imcb_error(ic, "TLS is turned on for this account, but is not supported by this server");
361	imc_logout(ic, FALSE);
362
363	return XT_ABORT;
364	}
365	}
366
367	/* This one used to be in jabber_handlers[], but it has to be done
368	from here to make sure the TLS session will be initialized
369	properly before we attempt SASL authentication. */
370	if ((c = xt_find_node(node->children, "mechanisms"))) {
371	if (sasl_pkt_mechanisms(c, data) == XT_ABORT) {
372	return XT_ABORT;
373	}
374	}
375	/* If the server SEEMS to support SASL authentication but doesn't
376	support it after all, we should try to do authentication the
377	other way. jabber.com doesn't seem to do SASL while it pretends
378	to be XMPP 1.0 compliant! */
379	else if (!(jd->flags & JFLAG_AUTHENTICATED) && set_getbool(&ic->acc->set, "sasl") && sasl_supported(ic)) {
380	if (!jabber_init_iq_auth(ic)) {
381	return XT_ABORT;
382	}
383	}
384
385	if ((c = xt_find_node(node->children, "bind"))) {
386	jd->flags \|= JFLAG_WANT_BIND;
387	}
388
389	if ((c = xt_find_node(node->children, "session"))) {
390	jd->flags \|= JFLAG_WANT_SESSION;
391	}
392
393	if (jd->flags & JFLAG_AUTHENTICATED) {
394	return jabber_pkt_bind_sess(ic, NULL, NULL);
395	}
396
397	return XT_HANDLED;
398	}
399
400	static xt_status jabber_pkt_proceed_tls(struct xt_node *node, gpointer data)
401	{
402	struct im_connection *ic = data;
403	struct jabber_data *jd = ic->proto_data;
404	char xmlns, tlsname;
405
406	xmlns = xt_find_attr(node, "xmlns");
407
408	/* Just ignore it when it doesn't seem to be TLS-related (is that at
409	all possible??). */
410	if (!xmlns \|\| strcmp(xmlns, XMLNS_TLS) != 0) {
411	return XT_HANDLED;
412	}
413
414	/* We don't want event handlers to touch our TLS session while it's
415	still initializing! */
416	b_event_remove(jd->r_inpa);
417	if (jd->tx_len > 0) {
418	/* Actually the write queue should be empty here, but just
419	to be sure... */
420	b_event_remove(jd->w_inpa);
421	g_free(jd->txq);
422	jd->txq = NULL;
423	jd->tx_len = 0;
424	}
425	jd->w_inpa = jd->r_inpa = 0;
426
427	imcb_log(ic, "Converting stream to TLS");
428
429	jd->flags \|= JFLAG_STARTTLS_DONE;
430
431	/* If the user specified a server for the account, use this server as the
432	* hostname in the certificate verification. Else we use the domain from
433	* the username. */
434	if (ic->acc->server && *ic->acc->server) {
435	tlsname = ic->acc->server;
436	} else {
437	tlsname = jd->server;
438	}
439
440	jd->ssl = ssl_starttls(jd->fd, tlsname, set_getbool(&ic->acc->set, "tls_verify"),
441	jabber_connected_ssl, ic);
442
443	return XT_HANDLED;
444	}
445
446	static xt_status jabber_pkt_stream_error(struct xt_node *node, gpointer data)
447	{
448	struct im_connection *ic = data;
449	struct jabber_data *jd = ic->proto_data;
450	int allow_reconnect = TRUE;
451	struct jabber_error *err;
452	struct xt_node *host;
453
454	if (!(ic->flags & OPT_LOGGED_IN) &&
455	(host = xt_find_node(node->children, "see-other-host")) &&
456	host->text) {
457	char *s;
458	int port = set_getint(&ic->acc->set, "port");
459
460	/* Let's try to obey this request, if we're not logged
461	in yet (i.e. not have too much state yet). */
462	if (jd->ssl) {
463	ssl_disconnect(jd->ssl);
464	}
465	closesocket(jd->fd);
466	b_event_remove(jd->r_inpa);
467	b_event_remove(jd->w_inpa);
468
469	jd->ssl = NULL;
470	jd->r_inpa = jd->w_inpa = 0;
471	jd->flags &= JFLAG_XMLCONSOLE;
472
473	s = strchr(host->text, ':');
474	if (s != NULL) {
475	sscanf(s + 1, "%d", &port);
476	}
477
478	imcb_log(ic, "Redirected to %s", host->text);
479	jd->fd = proxy_connect(host->text, port, jabber_connected_plain, ic);
480
481	return XT_ABORT;
482	}
483
484	err = jabber_error_parse(node, XMLNS_STREAM_ERROR);
485
486	/* Tssk... */
487	if (err->code == NULL) {
488	imcb_error(ic, "Unknown stream error reported by server");
489	imc_logout(ic, allow_reconnect);
490	jabber_error_free(err);
491	return XT_ABORT;
492	}
493
494	/* We know that this is a fatal error. If it's a "conflict" error, we
495	should turn off auto-reconnect to make sure we won't get some nasty
496	infinite loop! */
497	if (strcmp(err->code, "conflict") == 0) {
498	imcb_error(ic, "Account and resource used from a different location");
499	allow_reconnect = FALSE;
500	} else if (strcmp(err->code, "not-authorized") == 0) {
501	imcb_error(ic, "Not authorized");
502	allow_reconnect = FALSE;
503	} else {
504	imcb_error(ic, "Stream error: %s%s%s", err->code, err->text ? ": " : "",
505	err->text ? err->text : "");
506	}
507
508	jabber_error_free(err);
509	imc_logout(ic, allow_reconnect);
510
511	return XT_ABORT;
512	}
513
514	static xt_status jabber_xmlconsole(struct xt_node *node, gpointer data)
515	{
516	struct im_connection *ic = data;
517	struct jabber_data *jd = ic->proto_data;
518
519	if (jd->flags & JFLAG_XMLCONSOLE) {
520	char msg, pkt;
521
522	pkt = xt_to_string(node);
523	msg = g_strdup_printf("RX: %s", pkt);
524	imcb_buddy_msg(ic, JABBER_XMLCONSOLE_HANDLE, msg, 0, 0);
525	g_free(msg);
526	g_free(pkt);
527	}
528
529	return XT_NEXT;
530	}
531
532	static const struct xt_handler_entry jabber_handlers[] = {
533	{ NULL, "stream:stream", jabber_xmlconsole },
534	{ "stream:stream", "<root>", jabber_end_of_stream },
535	{ "message", "stream:stream", jabber_pkt_message },
536	{ "presence", "stream:stream", jabber_pkt_presence },
537	{ "iq", "stream:stream", jabber_pkt_iq },
538	{ "stream:features", "stream:stream", jabber_pkt_features },
539	{ "stream:error", "stream:stream", jabber_pkt_stream_error },
540	{ "proceed", "stream:stream", jabber_pkt_proceed_tls },
541	{ "challenge", "stream:stream", sasl_pkt_challenge },
542	{ "success", "stream:stream", sasl_pkt_result },
543	{ "failure", "stream:stream", sasl_pkt_result },
544	{ NULL, NULL, NULL }
545	};
546
547	gboolean jabber_start_stream(struct im_connection *ic)
548	{
549	struct jabber_data *jd = ic->proto_data;
550	int st;
551	char *greet;
552
553	/* We'll start our stream now, so prepare everything to receive one
554	from the server too. */
555	xt_free(jd->xt); /* In case we're RE-starting. */
556	jd->xt = xt_new(jabber_handlers, ic);
557
558	if (jd->r_inpa <= 0) {
559	jd->r_inpa = b_input_add(jd->fd, B_EV_IO_READ, jabber_read_callback, ic);
560	}
561
562	greet = g_strdup_printf("%s<stream:stream to=\"%s\" xmlns=\"jabber:client\" "
563	"xmlns:stream=\"http://etherx.jabber.org/streams\" version=\"1.0\">",
564	(jd->flags & JFLAG_STARTTLS_DONE) ? "" : "<?xml version='1.0' ?>",
565	jd->server);
566
567	st = jabber_write(ic, greet, strlen(greet));
568
569	g_free(greet);
570
571	return st;
572	}
573
574	void jabber_end_stream(struct im_connection *ic)
575	{
576	struct jabber_data *jd = ic->proto_data;
577
578	/* Let's only do this if the queue is currently empty, otherwise it'd
579	take too long anyway. */
580	if (jd->tx_len == 0) {
581	char eos[] = "</stream:stream>";
582	struct xt_node *node;
583	int st = 1;
584
585	if (ic->flags & OPT_LOGGED_IN) {
586	node = jabber_make_packet("presence", "unavailable", NULL, NULL);
587	st = jabber_write_packet(ic, node);
588	xt_free_node(node);
589	}
590
591	if (st) {
592	jabber_write(ic, eos, strlen(eos));
593	}
594	}
595	}

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source: protocols/jabber/io.c @ e61f9d1

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