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 _GstFencedBuffer GstFencedBuffer;
88 struct _GstFencedBuffer
95 GType gst_fenced_buffer_get_type (void);
96 static void gst_fenced_buffer_finalize (GstFencedBuffer * buf);
97 static GstFencedBuffer *gst_fenced_buffer_copy (const GstBuffer * buffer);
98 static void *gst_fenced_buffer_alloc (GstBuffer * buffer, unsigned int length,
100 static GstFlowReturn gst_efence_buffer_alloc (GstPad * pad, guint64 offset,
101 guint size, GstCaps * caps, GstBuffer ** buf);
103 #define GST_TYPE_FENCED_BUFFER (gst_fenced_buffer_get_type())
105 #define GST_IS_FENCED_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_FENCED_BUFFER))
106 #define GST_FENCED_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_FENCED_BUFFER, GstFencedBuffer))
109 gst_gst_efence_get_type (void)
111 static GType plugin_type = 0;
114 static const GTypeInfo plugin_info = {
115 sizeof (GstEFenceClass),
116 gst_efence_base_init,
118 (GClassInitFunc) gst_efence_class_init,
123 (GInstanceInitFunc) gst_efence_init,
126 plugin_type = g_type_register_static (GST_TYPE_ELEMENT,
127 "GstEFence", &plugin_info, 0);
133 gst_efence_base_init (gpointer g_class)
135 GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
137 gst_element_class_add_pad_template (element_class,
138 gst_static_pad_template_get (&gst_efence_sink_factory));
139 gst_element_class_add_pad_template (element_class,
140 gst_static_pad_template_get (&gst_efence_src_factory));
141 gst_element_class_set_details_simple (element_class, "Electric Fence",
143 "This element converts a stream of normal GStreamer buffers into a "
144 "stream of buffers that are allocated in such a way that out-of-bounds "
145 "access to data in the buffer is more likely to cause segmentation "
146 "faults. This allocation method is very similar to the debugging tool "
147 "\"Electric Fence\".", "David A. Schleef <ds@schleef.org>");
150 /* initialize the plugin's class */
152 gst_efence_class_init (GstEFenceClass * klass)
154 GObjectClass *gobject_class;
156 gobject_class = (GObjectClass *) klass;
158 parent_class = g_type_class_peek_parent (klass);
160 gobject_class->set_property = gst_efence_set_property;
161 gobject_class->get_property = gst_efence_get_property;
163 g_object_class_install_property (gobject_class, ARG_FENCE_TOP,
164 g_param_spec_boolean ("fence-top", "Fence Top",
165 "Align buffers with top of fenced region", TRUE,
166 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
169 /* initialize the new element
170 * instantiate pads and add them to element
172 * initialize structure
175 gst_efence_init (GstEFence * filter)
178 gst_pad_new_from_static_template (&gst_efence_sink_factory, "sink");
179 gst_pad_set_getcaps_function (filter->sinkpad,
180 GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
181 gst_pad_set_setcaps_function (filter->sinkpad,
182 GST_DEBUG_FUNCPTR (gst_pad_proxy_setcaps));
183 gst_pad_set_chain_function (filter->sinkpad,
184 GST_DEBUG_FUNCPTR (gst_efence_chain));
185 gst_pad_set_bufferalloc_function (filter->sinkpad,
186 GST_DEBUG_FUNCPTR (gst_efence_buffer_alloc));
187 gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
190 gst_pad_new_from_static_template (&gst_efence_src_factory, "src");
191 gst_pad_set_getcaps_function (filter->srcpad,
192 GST_DEBUG_FUNCPTR (gst_pad_proxy_getcaps));
193 gst_pad_set_setcaps_function (filter->srcpad,
194 GST_DEBUG_FUNCPTR (gst_pad_proxy_setcaps));
195 gst_pad_set_checkgetrange_function (filter->srcpad,
196 GST_DEBUG_FUNCPTR (gst_efence_checkgetrange));
197 gst_pad_set_getrange_function (filter->srcpad,
198 GST_DEBUG_FUNCPTR (gst_efence_getrange));
199 gst_pad_set_activatepull_function (filter->srcpad,
200 GST_DEBUG_FUNCPTR (gst_efence_activate_src_pull));
202 gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
204 filter->fence_top = TRUE;
208 * this function does the actual processing
212 gst_efence_chain (GstPad * pad, GstBuffer * buffer)
217 efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
218 g_return_val_if_fail (GST_IS_EFENCE (efence), GST_FLOW_ERROR);
220 if (GST_IS_FENCED_BUFFER (buffer)) {
221 GST_DEBUG_OBJECT (efence, "Passing on existing fenced buffer with caps %"
222 GST_PTR_FORMAT, GST_BUFFER_CAPS (buffer));
223 return gst_pad_push (efence->srcpad, buffer);
226 copy = (GstBuffer *) gst_fenced_buffer_copy (buffer);
228 GST_DEBUG_OBJECT (efence, "Pushing newly fenced buffer with caps %"
229 GST_PTR_FORMAT ", data=%p, size=%u", GST_BUFFER_CAPS (copy),
230 GST_BUFFER_DATA (copy), GST_BUFFER_SIZE (copy));
232 gst_buffer_unref (buffer);
234 return gst_pad_push (efence->srcpad, copy);
238 gst_efence_getrange (GstPad * pad, guint64 offset,
239 guint length, GstBuffer ** buffer)
246 efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
248 peer = gst_pad_get_peer (efence->sinkpad);
250 return GST_FLOW_NOT_LINKED;
252 if ((ret = gst_pad_get_range (peer, offset, length, buffer)) != GST_FLOW_OK)
255 ownbuf = (GstBuffer *) gst_fenced_buffer_copy (*buffer);
256 gst_buffer_unref ((GstBuffer *) * buffer);
260 gst_object_unref (peer);
265 gst_efence_checkgetrange (GstPad * pad)
267 GstEFence *efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
269 return gst_pad_check_pull_range (efence->sinkpad);
273 gst_efence_activate_src_pull (GstPad * pad, gboolean active)
275 GstEFence *efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
277 return gst_pad_activate_pull (efence->sinkpad, active);
281 gst_efence_buffer_alloc (GstPad * pad, guint64 offset,
282 guint size, GstCaps * caps, GstBuffer ** buf)
287 g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
288 g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
290 efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
292 buffer = (GstBuffer *) gst_mini_object_new (GST_TYPE_FENCED_BUFFER);
294 GST_BUFFER_DATA (buffer) = gst_fenced_buffer_alloc (buffer, size,
296 GST_BUFFER_SIZE (buffer) = size;
297 GST_BUFFER_OFFSET (buffer) = offset;
300 gst_buffer_set_caps (buffer, caps);
304 GST_DEBUG_OBJECT (efence, "Allocated buffer of size %u, caps: %"
305 GST_PTR_FORMAT, GST_BUFFER_SIZE (buffer), GST_BUFFER_CAPS (buffer));
311 gst_efence_set_property (GObject * object, guint prop_id,
312 const GValue * value, GParamSpec * pspec)
316 g_return_if_fail (GST_IS_EFENCE (object));
317 filter = GST_EFENCE (object);
321 filter->fence_top = g_value_get_boolean (value);
324 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
330 gst_efence_get_property (GObject * object, guint prop_id,
331 GValue * value, GParamSpec * pspec)
335 g_return_if_fail (GST_IS_EFENCE (object));
336 filter = GST_EFENCE (object);
340 g_value_set_boolean (value, filter->fence_top);
343 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
348 /* entry point to initialize the plug-in
349 * initialize the plug-in itself
350 * register the element factories and pad templates
351 * register the features
354 plugin_init (GstPlugin * plugin)
356 if (!gst_element_register (plugin, "efence", GST_RANK_NONE, GST_TYPE_EFENCE))
359 GST_DEBUG_CATEGORY_INIT (gst_efence_debug, "efence", 0,
360 "Debug output from the efence element");
362 /* plugin initialisation succeeded */
366 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
369 "This element converts a stream of normal GStreamer buffers into a "
370 "stream of buffers that are allocated in such a way that out-of-bounds "
371 "access to data in the buffer is more likely to cause segmentation "
372 "faults. This allocation method is very similar to the debugging tool "
373 "\"Electric Fence\".",
374 plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);
377 static GstBufferClass *fenced_buffer_parent_class = NULL;
380 gst_fenced_buffer_finalize (GstFencedBuffer * buffer)
382 GstFencedBuffer *fenced_buffer;
384 GST_DEBUG ("free buffer=%p", buffer);
386 fenced_buffer = GST_FENCED_BUFFER (buffer);
389 if (GST_BUFFER_DATA (buffer)) {
390 GST_DEBUG ("free region %p %d", fenced_buffer->region,
391 fenced_buffer->length);
392 munmap (fenced_buffer->region, fenced_buffer->length);
395 GST_MINI_OBJECT_CLASS (fenced_buffer_parent_class)->finalize (GST_MINI_OBJECT
399 static GstFencedBuffer *
400 gst_fenced_buffer_copy (const GstBuffer * buffer)
406 g_return_val_if_fail (buffer != NULL, NULL);
408 /* create a fresh new buffer */
409 copy = (GstBuffer *) gst_mini_object_new (GST_TYPE_FENCED_BUFFER);
411 /* we simply copy everything from our parent */
412 ptr = gst_fenced_buffer_alloc (GST_BUFFER (copy),
413 GST_BUFFER_SIZE (buffer), TRUE);
414 memcpy (ptr, GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer));
416 /* copy relevant flags */
417 mask = GST_BUFFER_FLAG_PREROLL | GST_BUFFER_FLAG_IN_CAPS |
418 GST_BUFFER_FLAG_DELTA_UNIT;
419 GST_MINI_OBJECT (copy)->flags |= GST_MINI_OBJECT (buffer)->flags & mask;
421 GST_BUFFER_DATA (copy) = ptr;
422 GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
423 GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
424 GST_BUFFER_DURATION (copy) = GST_BUFFER_DURATION (buffer);
425 GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
426 GST_BUFFER_OFFSET_END (copy) = GST_BUFFER_OFFSET_END (buffer);
428 if (GST_BUFFER_CAPS (buffer))
429 GST_BUFFER_CAPS (copy) = gst_caps_ref (GST_BUFFER_CAPS (buffer));
431 GST_BUFFER_CAPS (copy) = NULL;
433 GST_DEBUG ("Copied buffer %p with ts %" GST_TIME_FORMAT
434 ", caps: %" GST_PTR_FORMAT, buffer,
435 GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (copy)), GST_BUFFER_CAPS (copy));
437 return GST_FENCED_BUFFER (copy);
441 gst_fenced_buffer_alloc (GstBuffer * buffer, unsigned int length,
446 GstFencedBuffer *fenced_buffer = (GstFencedBuffer *) buffer;
449 GST_DEBUG ("buffer=%p length=%d fence_top=%d", buffer, length, fence_top);
455 page_size = sysconf (_SC_PAGESIZE);
457 page_size = getpagesize ();
460 /* Allocate a complete page, and one on either side */
461 alloc_size = ((length - 1) & ~(page_size - 1)) + page_size;
462 alloc_size += 2 * page_size;
464 region = mmap (NULL, alloc_size, PROT_READ | PROT_WRITE,
465 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
466 if (region == MAP_FAILED) {
467 g_warning ("mmap failed");
471 munmap (region, page_size);
472 munmap (region + alloc_size - page_size, page_size);
474 fenced_buffer->region = region + page_size;
475 fenced_buffer->length = alloc_size - page_size;
477 mprotect (region, page_size, PROT_NONE);
478 mprotect ((char *) region + alloc_size - page_size, page_size, PROT_NONE);
480 fenced_buffer->region = region;
481 fenced_buffer->length = alloc_size;
484 GST_DEBUG ("new region %p %d", fenced_buffer->region, fenced_buffer->length);
489 /* Align to top of region, but force alignment to 4 bytes */
490 offset = alloc_size - page_size - length;
492 return (void *) ((char *) region + offset);
494 return (void *) ((char *) region + page_size);
499 gst_fenced_buffer_class_init (gpointer g_class, gpointer class_data)
501 GstMiniObjectClass *mini_object_class = GST_MINI_OBJECT_CLASS (g_class);
503 fenced_buffer_parent_class = g_type_class_peek_parent (g_class);
505 mini_object_class->finalize =
506 (GstMiniObjectFinalizeFunction) gst_fenced_buffer_finalize;
507 mini_object_class->copy = (GstMiniObjectCopyFunction) gst_fenced_buffer_copy;
511 gst_fenced_buffer_get_type (void)
513 static GType fenced_buf_type = 0;
515 if (G_UNLIKELY (!fenced_buf_type)) {
516 static const GTypeInfo fenced_buf_info = {
517 sizeof (GstBufferClass),
520 (GClassInitFunc) gst_fenced_buffer_class_init,
523 sizeof (GstFencedBuffer),
528 fenced_buf_type = g_type_register_static (GST_TYPE_BUFFER,
529 "GstFencedBuffer", &fenced_buf_info, 0);
531 return fenced_buf_type;