3 * Copyright (C) 1999-2001 Erik Walthinsen <omega@cse.ogi.edu>
4 * Copyright (C) 2002 David A. Schleef <ds@schleef.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
35 #define MAP_ANONYMOUS MAP_ANON
37 /* assume we don't need it */
38 #define MAP_ANONYMOUS 0
42 GST_DEBUG_CATEGORY_STATIC (gst_efence_debug);
43 #define GST_CAT_DEFAULT gst_efence_debug
45 /* Filter signals and args */
58 static GstStaticPadTemplate gst_efence_sink_factory =
59 GST_STATIC_PAD_TEMPLATE ("sink",
64 static GstStaticPadTemplate gst_efence_src_factory =
65 GST_STATIC_PAD_TEMPLATE ("src",
70 static void gst_efence_base_init (gpointer g_class);
71 static void gst_efence_class_init (GstEFenceClass * klass);
72 static void gst_efence_init (GstEFence * filter);
74 static void gst_efence_set_property (GObject * object, guint prop_id,
75 const GValue * value, GParamSpec * pspec);
76 static void gst_efence_get_property (GObject * object, guint prop_id,
77 GValue * value, GParamSpec * pspec);
79 static GstFlowReturn gst_efence_chain (GstPad * pad, GstBuffer * buf);
80 static GstFlowReturn gst_efence_getrange (GstPad * pad, guint64 offset,
81 guint length, GstBuffer ** buffer);
82 static gboolean gst_efence_checkgetrange (GstPad * pad);
83 static gboolean gst_efence_activate_src_pull (GstPad * pad, gboolean active);
85 static GstElementClass *parent_class = NULL;
87 typedef struct _GstMetaFenced
95 static const GstMetaInfo *
96 gst_meta_fenced_get_info (void)
98 static const GstMetaInfo *meta_fenced_info = NULL;
100 if (meta_fenced_info == NULL) {
101 meta_fenced_info = gst_meta_register ("GstMetaFenced", "GstMetaFenced",
102 sizeof (GstMetaFenced),
103 (GstMetaInitFunction) NULL,
104 (GstMetaFreeFunction) NULL,
105 (GstMetaCopyFunction) NULL, (GstMetaTransformFunction) NULL);
107 return meta_fenced_info;
110 #define GST_META_FENCED_GET(buf) ((GstMetaFenced *)gst_buffer_get_meta(buf,gst_meta_fenced_get_info()))
111 #define GST_META_FENCED_ADD(buf) ((GstMetaFenced *)gst_buffer_add_meta(buf,gst_meta_fenced_get_info(),NULL))
113 static void gst_fenced_buffer_dispose (GstBuffer * buf);
114 static GstBuffer *gst_fenced_buffer_copy (const GstBuffer * buffer);
115 static void *gst_fenced_buffer_alloc (GstBuffer * buffer, unsigned int length,
118 static GstFlowReturn gst_efence_buffer_alloc (GstPad * pad, guint64 offset,
119 guint size, GstCaps * caps, GstBuffer ** buf);
123 gst_gst_efence_get_type (void)
125 static GType plugin_type = 0;
128 static const GTypeInfo plugin_info = {
129 sizeof (GstEFenceClass),
130 gst_efence_base_init,
132 (GClassInitFunc) gst_efence_class_init,
137 (GInstanceInitFunc) gst_efence_init,
140 plugin_type = g_type_register_static (GST_TYPE_ELEMENT,
141 "GstEFence", &plugin_info, 0);
147 gst_efence_base_init (gpointer g_class)
149 GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
151 gst_element_class_add_pad_template (element_class,
152 gst_static_pad_template_get (&gst_efence_sink_factory));
153 gst_element_class_add_pad_template (element_class,
154 gst_static_pad_template_get (&gst_efence_src_factory));
155 gst_element_class_set_details_simple (element_class, "Electric Fence",
157 "This element converts a stream of normal GStreamer buffers into a "
158 "stream of buffers that are allocated in such a way that out-of-bounds "
159 "access to data in the buffer is more likely to cause segmentation "
160 "faults. This allocation method is very similar to the debugging tool "
161 "\"Electric Fence\".", "David A. Schleef <ds@schleef.org>");
164 /* initialize the plugin's class */
166 gst_efence_class_init (GstEFenceClass * klass)
168 GObjectClass *gobject_class;
170 gobject_class = (GObjectClass *) klass;
172 parent_class = g_type_class_peek_parent (klass);
174 gobject_class->set_property = gst_efence_set_property;
175 gobject_class->get_property = gst_efence_get_property;
177 g_object_class_install_property (gobject_class, ARG_FENCE_TOP,
178 g_param_spec_boolean ("fence-top", "Fence Top",
179 "Align buffers with top of fenced region", TRUE,
180 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
183 /* initialize the new element
184 * instantiate pads and add them to element
186 * initialize structure
189 gst_efence_init (GstEFence * filter)
192 gst_pad_new_from_static_template (&gst_efence_sink_factory, "sink");
193 gst_pad_set_getcaps_function (filter->sinkpad,
194 GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
195 gst_pad_set_setcaps_function (filter->sinkpad,
196 GST_DEBUG_FUNCPTR (gst_pad_proxy_setcaps));
197 gst_pad_set_chain_function (filter->sinkpad,
198 GST_DEBUG_FUNCPTR (gst_efence_chain));
200 gst_pad_set_bufferalloc_function (filter->sinkpad,
201 GST_DEBUG_FUNCPTR (gst_efence_buffer_alloc));
203 gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
206 gst_pad_new_from_static_template (&gst_efence_src_factory, "src");
207 gst_pad_set_getcaps_function (filter->srcpad,
208 GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
209 gst_pad_set_setcaps_function (filter->srcpad,
210 GST_DEBUG_FUNCPTR (gst_pad_proxy_setcaps));
211 gst_pad_set_checkgetrange_function (filter->srcpad,
212 GST_DEBUG_FUNCPTR (gst_efence_checkgetrange));
213 gst_pad_set_getrange_function (filter->srcpad,
214 GST_DEBUG_FUNCPTR (gst_efence_getrange));
215 gst_pad_set_activatepull_function (filter->srcpad,
216 GST_DEBUG_FUNCPTR (gst_efence_activate_src_pull));
218 gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
220 filter->fence_top = TRUE;
224 * this function does the actual processing
228 gst_efence_chain (GstPad * pad, GstBuffer * buffer)
233 efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
234 g_return_val_if_fail (GST_IS_EFENCE (efence), GST_FLOW_ERROR);
237 if (GST_IS_FENCED_BUFFER (buffer)) {
238 GST_DEBUG_OBJECT (efence, "Passing on existing fenced buffer with caps %"
239 GST_PTR_FORMAT, GST_BUFFER_CAPS (buffer));
240 return gst_pad_push (efence->srcpad, buffer);
244 copy = (GstBuffer *) gst_fenced_buffer_copy (buffer);
246 GST_DEBUG_OBJECT (efence, "Pushing newly fenced buffer with caps %"
247 GST_PTR_FORMAT ", data=%p, size=%u", GST_BUFFER_CAPS (copy),
248 GST_BUFFER_DATA (copy), GST_BUFFER_SIZE (copy));
250 gst_buffer_unref (buffer);
252 return gst_pad_push (efence->srcpad, copy);
256 gst_efence_getrange (GstPad * pad, guint64 offset,
257 guint length, GstBuffer ** buffer)
264 efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
266 peer = gst_pad_get_peer (efence->sinkpad);
268 return GST_FLOW_NOT_LINKED;
270 if ((ret = gst_pad_get_range (peer, offset, length, buffer)) != GST_FLOW_OK)
273 ownbuf = (GstBuffer *) gst_fenced_buffer_copy (*buffer);
274 gst_buffer_unref ((GstBuffer *) * buffer);
278 gst_object_unref (peer);
283 gst_efence_checkgetrange (GstPad * pad)
285 GstEFence *efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
287 return gst_pad_check_pull_range (efence->sinkpad);
291 gst_efence_activate_src_pull (GstPad * pad, gboolean active)
293 GstEFence *efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
295 return gst_pad_activate_pull (efence->sinkpad, active);
300 gst_efence_buffer_alloc (GstPad * pad, guint64 offset,
301 guint size, GstCaps * caps, GstBuffer ** buf)
306 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
307 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
309 efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
311 buffer = (GstBuffer *) gst_mini_object_new (GST_TYPE_FENCED_BUFFER);
313 GST_BUFFER_DATA (buffer) = gst_fenced_buffer_alloc (buffer, size,
315 GST_BUFFER_SIZE (buffer) = size;
316 GST_BUFFER_OFFSET (buffer) = offset;
319 gst_buffer_set_caps (buffer, caps);
323 GST_DEBUG_OBJECT (efence, "Allocated buffer of size %u, caps: %"
324 GST_PTR_FORMAT, GST_BUFFER_SIZE (buffer), GST_BUFFER_CAPS (buffer));
331 gst_efence_set_property (GObject * object, guint prop_id,
332 const GValue * value, GParamSpec * pspec)
336 g_return_if_fail (GST_IS_EFENCE (object));
337 filter = GST_EFENCE (object);
341 filter->fence_top = g_value_get_boolean (value);
344 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
350 gst_efence_get_property (GObject * object, guint prop_id,
351 GValue * value, GParamSpec * pspec)
355 g_return_if_fail (GST_IS_EFENCE (object));
356 filter = GST_EFENCE (object);
360 g_value_set_boolean (value, filter->fence_top);
363 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
368 /* entry point to initialize the plug-in
369 * initialize the plug-in itself
370 * register the element factories and pad templates
371 * register the features
374 plugin_init (GstPlugin * plugin)
376 if (!gst_element_register (plugin, "efence", GST_RANK_NONE, GST_TYPE_EFENCE))
379 GST_DEBUG_CATEGORY_INIT (gst_efence_debug, "efence", 0,
380 "Debug output from the efence element");
382 /* plugin initialisation succeeded */
386 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
389 "This element converts a stream of normal GStreamer buffers into a "
390 "stream of buffers that are allocated in such a way that out-of-bounds "
391 "access to data in the buffer is more likely to cause segmentation "
392 "faults. This allocation method is very similar to the debugging tool "
393 "\"Electric Fence\".",
394 plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);
398 gst_fenced_buffer_dispose (GstBuffer * buffer)
402 meta = GST_META_FENCED_GET (buffer);
404 GST_DEBUG ("free buffer=%p", buffer);
407 if (GST_BUFFER_DATA (buffer)) {
408 GST_DEBUG ("free region %p %d", meta->region, meta->length);
409 munmap (meta->region, meta->length);
414 gst_fenced_buffer_copy (const GstBuffer * buffer)
420 g_return_val_if_fail (buffer != NULL, NULL);
422 /* create a fresh new buffer */
423 copy = gst_buffer_new ();
425 /* we simply copy everything from our parent */
426 ptr = gst_fenced_buffer_alloc (copy, GST_BUFFER_SIZE (buffer), TRUE);
427 memcpy (ptr, GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer));
429 /* copy relevant flags */
430 mask = GST_BUFFER_FLAG_PREROLL | GST_BUFFER_FLAG_IN_CAPS |
431 GST_BUFFER_FLAG_DELTA_UNIT;
432 GST_MINI_OBJECT (copy)->flags |= GST_MINI_OBJECT (buffer)->flags & mask;
434 GST_BUFFER_DATA (copy) = ptr;
435 GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
436 GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
437 GST_BUFFER_DURATION (copy) = GST_BUFFER_DURATION (buffer);
438 GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
439 GST_BUFFER_OFFSET_END (copy) = GST_BUFFER_OFFSET_END (buffer);
441 if (GST_BUFFER_CAPS (buffer))
442 GST_BUFFER_CAPS (copy) = gst_caps_ref (GST_BUFFER_CAPS (buffer));
444 GST_BUFFER_CAPS (copy) = NULL;
446 GST_DEBUG ("Copied buffer %p with ts %" GST_TIME_FORMAT
447 ", caps: %" GST_PTR_FORMAT, buffer,
448 GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (copy)), GST_BUFFER_CAPS (copy));
454 gst_fenced_buffer_alloc (GstBuffer * buffer, unsigned int length,
462 GST_DEBUG ("buffer=%p length=%d fence_top=%d", buffer, length, fence_top);
468 page_size = sysconf (_SC_PAGESIZE);
470 page_size = getpagesize ();
473 /* Allocate a complete page, and one on either side */
474 alloc_size = ((length - 1) & ~(page_size - 1)) + page_size;
475 alloc_size += 2 * page_size;
477 region = mmap (NULL, alloc_size, PROT_READ | PROT_WRITE,
478 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
479 if (region == MAP_FAILED) {
480 g_warning ("mmap failed");
484 GST_MINI_OBJECT_CAST (buffer)->dispose =
485 (GstMiniObjectDisposeFunction) gst_fenced_buffer_dispose;
486 GST_MINI_OBJECT_CAST (buffer)->copy =
487 (GstMiniObjectCopyFunction) gst_fenced_buffer_copy;
489 meta = GST_META_FENCED_ADD (buffer);
492 munmap (region, page_size);
493 munmap (region + alloc_size - page_size, page_size);
495 meta->region = region + page_size;
496 meta->length = alloc_size - page_size;
498 mprotect (region, page_size, PROT_NONE);
499 mprotect ((char *) region + alloc_size - page_size, page_size, PROT_NONE);
501 meta->region = region;
502 meta->length = alloc_size;
505 GST_DEBUG ("new region %p %d", meta->region, meta->length);
510 /* Align to top of region, but force alignment to 4 bytes */
511 offset = alloc_size - page_size - length;
513 return (void *) ((char *) region + offset);
515 return (void *) ((char *) region + page_size);