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source: mod_gnutls/src/gnutls_io.c @ fcb122d

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Last change on this file since fcb122d was fcb122d, checked in by Paul Querna <chip@…>, 18 years ago
checkpoint the work so far. The DBM cache needs a little more work.
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1	/**
2	* Copyright 2004-2005 Paul Querna
3	*
4	* Licensed under the Apache License, Version 2.0 (the "License");
5	* you may not use this file except in compliance with the License.
6	* You may obtain a copy of the License at
7	*
8	* http://www.apache.org/licenses/LICENSE-2.0
9	*
10	* Unless required by applicable law or agreed to in writing, software
11	* distributed under the License is distributed on an "AS IS" BASIS,
12	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13	* See the License for the specific language governing permissions and
14	* limitations under the License.
15	*
16	*/
17
18	#include "mod_gnutls.h"
19
20	/**
21	* Describe how the GnuTLS Filter system works here
22	* - Basicly the same as what mod_ssl does with OpenSSL.
23	*
24	*/
25
26	#define HTTP_ON_HTTPS_PORT \
27	"GET /" CRLF
28
29	#define HTTP_ON_HTTPS_PORT_BUCKET(alloc) \
30	apr_bucket_immortal_create(HTTP_ON_HTTPS_PORT, \
31	sizeof(HTTP_ON_HTTPS_PORT) - 1, \
32	alloc)
33
34	static apr_status_t gnutls_io_filter_error(ap_filter_t * f,
35	apr_bucket_brigade * bb,
36	apr_status_t status)
37	{
38	mod_gnutls_handle_t ctxt = (mod_gnutls_handle_t ) f->ctx;
39	apr_bucket *bucket;
40
41	switch (status) {
42	case HTTP_BAD_REQUEST:
43	/* log the situation */
44	ap_log_error(APLOG_MARK, APLOG_INFO, 0,
45	f->c->base_server,
46	"GnuTLS handshake failed: HTTP spoken on HTTPS port; "
47	"trying to send HTML error page");
48
49	ctxt->status = -1;
50
51	/* fake the request line */
52	bucket = HTTP_ON_HTTPS_PORT_BUCKET(f->c->bucket_alloc);
53	break;
54
55	default:
56	return status;
57	}
58
59	APR_BRIGADE_INSERT_TAIL(bb, bucket);
60	bucket = apr_bucket_eos_create(f->c->bucket_alloc);
61	APR_BRIGADE_INSERT_TAIL(bb, bucket);
62
63	return APR_SUCCESS;
64	}
65
66	static int char_buffer_read(mod_gnutls_char_buffer_t * buffer, char *in,
67	int inl)
68	{
69	if (!buffer->length) {
70	return 0;
71	}
72
73	if (buffer->length > inl) {
74	/* we have have enough to fill the caller's buffer */
75	memcpy(in, buffer->value, inl);
76	buffer->value += inl;
77	buffer->length -= inl;
78	}
79	else {
80	/* swallow remainder of the buffer */
81	memcpy(in, buffer->value, buffer->length);
82	inl = buffer->length;
83	buffer->value = NULL;
84	buffer->length = 0;
85	}
86
87	return inl;
88	}
89
90	static int char_buffer_write(mod_gnutls_char_buffer_t * buffer, char *in,
91	int inl)
92	{
93	buffer->value = in;
94	buffer->length = inl;
95	return inl;
96	}
97
98	/**
99	* From mod_ssl / ssl_engine_io.c
100	* This function will read from a brigade and discard the read buckets as it
101	* proceeds. It will read at most *len bytes.
102	*/
103	static apr_status_t brigade_consume(apr_bucket_brigade * bb,
104	apr_read_type_e block,
105	char c, apr_size_t len)
106	{
107	apr_size_t actual = 0;
108	apr_status_t status = APR_SUCCESS;
109
110	while (!APR_BRIGADE_EMPTY(bb)) {
111	apr_bucket *b = APR_BRIGADE_FIRST(bb);
112	const char *str;
113	apr_size_t str_len;
114	apr_size_t consume;
115
116	/* Justin points out this is an http-ism that might
117	* not fit if brigade_consume is added to APR. Perhaps
118	* apr_bucket_read(eos_bucket) should return APR_EOF?
119	* Then this becomes mainline instead of a one-off.
120	*/
121	if (APR_BUCKET_IS_EOS(b)) {
122	status = APR_EOF;
123	break;
124	}
125
126	/* The reason I'm not offering brigade_consume yet
127	* across to apr-util is that the following call
128	* illustrates how borked that API really is. For
129	* this sort of case (caller provided buffer) it
130	* would be much more trivial for apr_bucket_consume
131	* to do all the work that follows, based on the
132	* particular characteristics of the bucket we are
133	* consuming here.
134	*/
135	status = apr_bucket_read(b, &str, &str_len, block);
136
137	if (status != APR_SUCCESS) {
138	if (APR_STATUS_IS_EOF(status)) {
139	/* This stream bucket was consumed */
140	apr_bucket_delete(b);
141	continue;
142	}
143	break;
144	}
145
146	if (str_len > 0) {
147	/* Do not block once some data has been consumed */
148	block = APR_NONBLOCK_READ;
149
150	/* Assure we don't overflow. */
151	consume = (str_len + actual > len) ? len - actual : str_len;
152
153	memcpy(c, str, consume);
154
155	c += consume;
156	actual += consume;
157
158	if (consume >= b->length) {
159	/* This physical bucket was consumed */
160	apr_bucket_delete(b);
161	}
162	else {
163	/* Only part of this physical bucket was consumed */
164	b->start += consume;
165	b->length -= consume;
166	}
167	}
168	else if (b->length == 0) {
169	apr_bucket_delete(b);
170	}
171
172	/* This could probably be actual == *len, but be safe from stray
173	* photons. */
174	if (actual >= *len) {
175	break;
176	}
177	}
178
179	*len = actual;
180	return status;
181	}
182
183
184	static apr_status_t gnutls_io_input_read(mod_gnutls_handle_t * ctxt,
185	char buf, apr_size_t len)
186	{
187	apr_size_t wanted = *len;
188	apr_size_t bytes = 0;
189	int rc;
190
191	*len = 0;
192
193	/* If we have something leftover from last time, try that first. */
194	if ((bytes = char_buffer_read(&ctxt->input_cbuf, buf, wanted))) {
195	*len = bytes;
196	if (ctxt->input_mode == AP_MODE_SPECULATIVE) {
197	/* We want to rollback this read. */
198	if (ctxt->input_cbuf.length > 0) {
199	ctxt->input_cbuf.value -= bytes;
200	ctxt->input_cbuf.length += bytes;
201	}
202	else {
203	char_buffer_write(&ctxt->input_cbuf, buf, (int) bytes);
204	}
205	return APR_SUCCESS;
206	}
207	/* This could probably be *len == wanted, but be safe from stray
208	* photons.
209	*/
210	if (*len >= wanted) {
211	return APR_SUCCESS;
212	}
213	if (ctxt->input_mode == AP_MODE_GETLINE) {
214	if (memchr(buf, APR_ASCII_LF, *len)) {
215	return APR_SUCCESS;
216	}
217	}
218	else {
219	/* Down to a nonblock pattern as we have some data already
220	*/
221	ctxt->input_block = APR_NONBLOCK_READ;
222	}
223	}
224
225	while (1) {
226
227	rc = gnutls_record_recv(ctxt->session, buf + bytes, wanted - bytes);
228
229	if (rc > 0) {
230	*len += rc;
231	if (ctxt->input_mode == AP_MODE_SPECULATIVE) {
232	/* We want to rollback this read. */
233	char_buffer_write(&ctxt->input_cbuf, buf, rc);
234	}
235	return ctxt->input_rc;
236	}
237	else if (rc == 0) {
238	/* If EAGAIN, we will loop given a blocking read,
239	* otherwise consider ourselves at EOF.
240	*/
241	if (APR_STATUS_IS_EAGAIN(ctxt->input_rc)
242	\|\| APR_STATUS_IS_EINTR(ctxt->input_rc)) {
243	/* Already read something, return APR_SUCCESS instead.
244	* On win32 in particular, but perhaps on other kernels,
245	* a blocking call isn't 'always' blocking.
246	*/
247	if (*len > 0) {
248	ctxt->input_rc = APR_SUCCESS;
249	break;
250	}
251	if (ctxt->input_block == APR_NONBLOCK_READ) {
252	break;
253	}
254	}
255	else {
256	if (*len > 0) {
257	ctxt->input_rc = APR_SUCCESS;
258	}
259	else {
260	ctxt->input_rc = APR_EOF;
261	}
262	break;
263	}
264	}
265	else { /* (rc < 0) */
266
267	if (rc == GNUTLS_E_REHANDSHAKE) {
268	/* A client has asked for a new Hankshake. Currently, we don't do it */
269	ap_log_error(APLOG_MARK, APLOG_INFO, ctxt->input_rc,
270	ctxt->c->base_server,
271	"GnuTLS: Error reading data. Client Requested a New Handshake."
272	" (%d) '%s'", rc, gnutls_strerror(rc));
273	}
274	else {
275	/* Some Other Error. Report it. Die. */
276	if(gnutls_error_is_fatal(rc)) {
277	ap_log_error(APLOG_MARK, APLOG_INFO, ctxt->input_rc,
278	ctxt->c->base_server,
279	"GnuTLS: Error reading data. (%d) '%s'", rc,
280	gnutls_strerror(rc));
281	}
282	else if(*len > 0) {
283	ctxt->input_rc = APR_SUCCESS;
284	break;
285	}
286	}
287
288	if (ctxt->input_rc == APR_SUCCESS) {
289	ctxt->input_rc = APR_EGENERAL;
290	}
291	break;
292	}
293	}
294	return ctxt->input_rc;
295	}
296
297	static apr_status_t gnutls_io_input_getline(mod_gnutls_handle_t * ctxt,
298	char buf, apr_size_t len)
299	{
300	const char *pos = NULL;
301	apr_status_t status;
302	apr_size_t tmplen = len, buflen = len, offset = 0;
303
304	*len = 0;
305
306	while (tmplen > 0) {
307	status = gnutls_io_input_read(ctxt, buf + offset, &tmplen);
308
309	if (status != APR_SUCCESS) {
310	return status;
311	}
312
313	*len += tmplen;
314
315	if ((pos = memchr(buf, APR_ASCII_LF, *len))) {
316	break;
317	}
318
319	offset += tmplen;
320	tmplen = buflen - offset;
321	}
322
323	if (pos) {
324	char *value;
325	int length;
326	apr_size_t bytes = pos - buf;
327
328	bytes += 1;
329	value = buf + bytes;
330	length = *len - bytes;
331
332	char_buffer_write(&ctxt->input_cbuf, value, length);
333
334	*len = bytes;
335	}
336
337	return APR_SUCCESS;
338	}
339
340
341	static void gnutls_do_handshake(mod_gnutls_handle_t * ctxt)
342	{
343	int ret;
344
345	if (ctxt->status != 0) {
346	return;
347	}
348
349	tryagain:
350
351	ret = gnutls_handshake(ctxt->session);
352	if (ret < 0) {
353	if (ret == GNUTLS_E_WARNING_ALERT_RECEIVED
354	\|\| ret == GNUTLS_E_FATAL_ALERT_RECEIVED) {
355	ret = gnutls_alert_get(ctxt->session);
356	ap_log_error(APLOG_MARK, APLOG_ERR, 0, ctxt->c->base_server,
357	"GnuTLS: Hanshake Alert (%d) '%s'.\n", ret,
358	gnutls_alert_get_name(ret));
359	}
360
361	if (!gnutls_error_is_fatal(ret)) {
362	ap_log_error(APLOG_MARK, APLOG_INFO, 0, ctxt->c->base_server,
363	"GnuTLS: Non-Fatal Handshake Error: (%d) '%s'", ret,
364	gnutls_strerror(ret));
365	goto tryagain;
366	}
367
368	ap_log_error(APLOG_MARK, APLOG_ERR, 0, ctxt->c->base_server,
369	"GnuTLS: Handshake Failed (%d) '%s'", ret,
370	gnutls_strerror(ret));
371	ctxt->status = -1;
372	gnutls_alert_send(ctxt->session, GNUTLS_AL_FATAL,
373	gnutls_error_to_alert(ret, NULL));
374	gnutls_deinit(ctxt->session);
375	return;
376	}
377	else {
378	ctxt->status = 1;
379	return; /* all done with the handshake */
380	}
381	}
382
383
384	apr_status_t mod_gnutls_filter_input(ap_filter_t* f,
385	apr_bucket_brigade * bb,
386	ap_input_mode_t mode,
387	apr_read_type_e block,
388	apr_off_t readbytes)
389	{
390	apr_status_t status = APR_SUCCESS;
391	mod_gnutls_handle_t ctxt = (mod_gnutls_handle_t ) f->ctx;
392	apr_size_t len = sizeof(ctxt->input_buffer);
393
394	if (f->c->aborted) {
395	apr_bucket *bucket = apr_bucket_eos_create(f->c->bucket_alloc);
396	APR_BRIGADE_INSERT_TAIL(bb, bucket);
397	return APR_ECONNABORTED;
398	}
399
400	if (ctxt->status == 0) {
401	gnutls_do_handshake(ctxt);
402	}
403
404	if (ctxt->status < 0) {
405	return ap_get_brigade(f->next, bb, mode, block, readbytes);
406	}
407
408	/* XXX: we don't currently support anything other than these modes. */
409	if (mode != AP_MODE_READBYTES && mode != AP_MODE_GETLINE &&
410	mode != AP_MODE_SPECULATIVE && mode != AP_MODE_INIT) {
411	return APR_ENOTIMPL;
412	}
413
414	ctxt->input_mode = mode;
415	ctxt->input_block = block;
416
417	if (ctxt->input_mode == AP_MODE_READBYTES \|\|
418	ctxt->input_mode == AP_MODE_SPECULATIVE) {
419	/* Err. This is bad. readbytes can be a 64bit int! len.. is NOT */
420	if (readbytes < len) {
421	len = (apr_size_t) readbytes;
422	}
423	status = gnutls_io_input_read(ctxt, ctxt->input_buffer, &len);
424	}
425	else if (ctxt->input_mode == AP_MODE_GETLINE) {
426	status = gnutls_io_input_getline(ctxt, ctxt->input_buffer, &len);
427	}
428	else {
429	/* We have no idea what you are talking about, so return an error. */
430	return APR_ENOTIMPL;
431	}
432
433	if (status != APR_SUCCESS) {
434	return gnutls_io_filter_error(f, bb, status);
435	}
436
437	/* Create a transient bucket out of the decrypted data. */
438	if (len > 0) {
439	apr_bucket *bucket =
440	apr_bucket_transient_create(ctxt->input_buffer, len,
441	f->c->bucket_alloc);
442	APR_BRIGADE_INSERT_TAIL(bb, bucket);
443	}
444
445	return status;
446	}
447
448	apr_status_t mod_gnutls_filter_output(ap_filter_t * f,
449	apr_bucket_brigade * bb)
450	{
451	apr_size_t ret;
452	mod_gnutls_handle_t ctxt = (mod_gnutls_handle_t ) f->ctx;
453	apr_status_t status = APR_SUCCESS;
454	apr_read_type_e rblock = APR_NONBLOCK_READ;
455
456	if (f->c->aborted) {
457	apr_brigade_cleanup(bb);
458	return APR_ECONNABORTED;
459	}
460
461	if (ctxt->status == 0) {
462	gnutls_do_handshake(ctxt);
463	}
464
465	if (ctxt->status < 0) {
466	return ap_pass_brigade(f->next, bb);
467	}
468
469	while (!APR_BRIGADE_EMPTY(bb)) {
470	apr_bucket *bucket = APR_BRIGADE_FIRST(bb);
471	if (AP_BUCKET_IS_EOC(bucket)) {
472
473	gnutls_bye(ctxt->session, GNUTLS_SHUT_WR);
474	gnutls_deinit(ctxt->session);
475
476	if ((status = ap_pass_brigade(f->next, bb)) != APR_SUCCESS) {
477	return status;
478	}
479	break;
480
481	} else if (APR_BUCKET_IS_FLUSH(bucket) \|\| APR_BUCKET_IS_EOS(bucket)) {
482
483	if ((status = ap_pass_brigade(f->next, bb)) != APR_SUCCESS) {
484	return status;
485	}
486	break;
487	}
488	else {
489	/* filter output */
490	const char *data;
491	apr_size_t len;
492
493	status = apr_bucket_read(bucket, &data, &len, rblock);
494
495	if (APR_STATUS_IS_EAGAIN(status)) {
496	rblock = APR_BLOCK_READ;
497	continue; /* and try again with a blocking read. */
498	}
499
500	rblock = APR_NONBLOCK_READ;
501
502	if (!APR_STATUS_IS_EOF(status) && (status != APR_SUCCESS)) {
503	break;
504	}
505
506	do {
507	ret = gnutls_record_send(ctxt->session, data, len);
508	}
509	while(ret == GNUTLS_E_INTERRUPTED \|\| ret == GNUTLS_E_AGAIN);
510
511	if (ret < 0) {
512	/* error sending output */
513	ap_log_error(APLOG_MARK, APLOG_INFO, ctxt->output_rc,
514	ctxt->c->base_server,
515	"GnuTLS: Error writing data."
516	" (%d) '%s'", ret, gnutls_strerror(ret));
517	if (ctxt->output_rc == APR_SUCCESS) {
518	ctxt->output_rc = APR_EGENERAL;
519	}
520	}
521	else if (ret != len) {
522	/* Not able to send the entire bucket,
523	split it and send it again. */
524	apr_bucket_split(bucket, ret);
525	}
526
527	apr_bucket_delete(bucket);
528
529	if (ctxt->output_rc != APR_SUCCESS) {
530	break;
531	}
532	}
533	}
534
535	return status;
536	}
537
538	ssize_t mod_gnutls_transport_read(gnutls_transport_ptr_t ptr,
539	void *buffer, size_t len)
540	{
541	mod_gnutls_handle_t *ctxt = ptr;
542	apr_status_t rc;
543	apr_size_t in = len;
544	apr_read_type_e block = ctxt->input_block;
545
546	ctxt->input_rc = APR_SUCCESS;
547
548	/* If Len = 0, we don't do anything. */
549	if (!len)
550	return 0;
551
552	if (!ctxt->input_bb) {
553	ctxt->input_rc = APR_EOF;
554	return -1;
555	}
556
557	if (APR_BRIGADE_EMPTY(ctxt->input_bb)) {
558
559	rc = ap_get_brigade(ctxt->input_filter->next, ctxt->input_bb,
560	AP_MODE_READBYTES, ctxt->input_block, in);
561
562	/* Not a problem, there was simply no data ready yet.
563	*/
564	if (APR_STATUS_IS_EAGAIN(rc) \|\| APR_STATUS_IS_EINTR(rc)
565	\|\| (rc == APR_SUCCESS && APR_BRIGADE_EMPTY(ctxt->input_bb))) {
566	return 0;
567	}
568
569	if (rc != APR_SUCCESS) {
570	/* Unexpected errors discard the brigade */
571	apr_brigade_cleanup(ctxt->input_bb);
572	ctxt->input_bb = NULL;
573	return -1;
574	}
575	}
576
577	ctxt->input_rc = brigade_consume(ctxt->input_bb, block, buffer, &len);
578
579	if (ctxt->input_rc == APR_SUCCESS) {
580	return (ssize_t) len;
581	}
582
583	if (APR_STATUS_IS_EAGAIN(ctxt->input_rc)
584	\|\| APR_STATUS_IS_EINTR(ctxt->input_rc)) {
585	return (ssize_t) len;
586	}
587
588	/* Unexpected errors and APR_EOF clean out the brigade.
589	* Subsequent calls will return APR_EOF.
590	*/
591	apr_brigade_cleanup(ctxt->input_bb);
592	ctxt->input_bb = NULL;
593
594	if (APR_STATUS_IS_EOF(ctxt->input_rc) && len) {
595	/* Provide the results of this read pass,
596	* without resetting the BIO retry_read flag
597	*/
598	return (ssize_t) len;
599	}
600
601	return -1;
602	}
603
604
605	static ssize_t write_flush(mod_gnutls_handle_t * ctxt)
606	{
607	apr_bucket *e;
608
609	if (!(ctxt->output_blen \|\| ctxt->output_length)) {
610	ctxt->output_rc = APR_SUCCESS;
611	return 1;
612	}
613
614	if (ctxt->output_blen) {
615	e = apr_bucket_transient_create(ctxt->output_buffer,
616	ctxt->output_blen,
617	ctxt->output_bb->bucket_alloc);
618	/* we filled this buffer first so add it to the
619	* head of the brigade
620	*/
621	APR_BRIGADE_INSERT_HEAD(ctxt->output_bb, e);
622	ctxt->output_blen = 0;
623	}
624
625	ctxt->output_length = 0;
626	e = apr_bucket_flush_create(ctxt->output_bb->bucket_alloc);
627	APR_BRIGADE_INSERT_TAIL(ctxt->output_bb, e);
628
629	ctxt->output_rc = ap_pass_brigade(ctxt->output_filter->next,
630	ctxt->output_bb);
631	/* create new brigade ready for next time through */
632	ctxt->output_bb =
633	apr_brigade_create(ctxt->c->pool, ctxt->c->bucket_alloc);
634	return (ctxt->output_rc == APR_SUCCESS) ? 1 : -1;
635	}
636
637	ssize_t mod_gnutls_transport_write(gnutls_transport_ptr_t ptr,
638	const void *buffer, size_t len)
639	{
640	mod_gnutls_handle_t *ctxt = ptr;
641
642	/* pass along the encrypted data
643	* need to flush since we're using SSL's malloc-ed buffer
644	* which will be overwritten once we leave here
645	*/
646	apr_bucket *bucket = apr_bucket_transient_create(buffer, len,
647	ctxt->output_bb->
648	bucket_alloc);
649
650	ctxt->output_length += len;
651	APR_BRIGADE_INSERT_TAIL(ctxt->output_bb, bucket);
652
653	if (write_flush(ctxt) < 0) {
654	return -1;
655	}
656	return len;
657	}

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