gstreamer/gst/debug/efence.c

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/*
* GStreamer
* Copyright (C) 1999-2001 Erik Walthinsen <omega@cse.ogi.edu>
* Copyright (C) 2002 David A. Schleef <ds@schleef.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include "efence.h"
#ifndef MAP_ANONYMOUS
#ifdef MAP_ANON
#define MAP_ANONYMOUS MAP_ANON
#else
/* assume we don't need it */
#define MAP_ANONYMOUS 0
#endif
#endif
static GstElementDetails plugin_details = {
"Electric Fence",
"Testing",
"This element converts a stream of normal GStreamer buffers into a "
"stream of buffers that are allocated in such a way that out-of-bounds "
"access to data in the buffer is more likely to cause segmentation "
"faults. This allocation method is very similar to the debugging tool "
"\"Electric Fence\".",
"David A. Schleef <ds@schleef.org>",
};
/* Filter signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
ARG_0,
ARG_FENCE_TOP
};
static GstStaticPadTemplate gst_efence_sink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static GstStaticPadTemplate gst_efence_src_factory =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS_ANY);
static void gst_efence_base_init (gpointer g_class);
static void gst_efence_class_init (GstEFenceClass * klass);
static void gst_efence_init (GstEFence * filter);
static void gst_efence_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_efence_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_efence_chain (GstPad * pad, GstData * _data);
static GstElementClass *parent_class = NULL;
typedef struct _GstFencedBuffer GstFencedBuffer;
struct _GstFencedBuffer
{
GstBuffer buffer;
void *region;
unsigned int length;
};
void gst_fenced_buffer_default_free (GstData * data);
GstData *gst_fenced_buffer_default_copy (const GstData * data);
void *gst_fenced_buffer_alloc (GstBuffer * buffer, unsigned int length,
gboolean fence_top);
static GstBuffer *gst_efence_buffer_alloc (GstPad * pad, guint64 offset,
guint size);
GstBuffer *gst_fenced_buffer_new (void);
GType
gst_gst_efence_get_type (void)
{
static GType plugin_type = 0;
if (!plugin_type) {
static const GTypeInfo plugin_info = {
sizeof (GstEFenceClass),
gst_efence_base_init,
NULL,
(GClassInitFunc) gst_efence_class_init,
NULL,
NULL,
sizeof (GstEFence),
0,
(GInstanceInitFunc) gst_efence_init,
};
plugin_type = g_type_register_static (GST_TYPE_ELEMENT,
"GstEFence", &plugin_info, 0);
}
return plugin_type;
}
static void
gst_efence_base_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_efence_sink_factory));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_efence_src_factory));
gst_element_class_set_details (element_class, &plugin_details);
}
/* initialize the plugin's class */
static void
gst_efence_class_init (GstEFenceClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
g_object_class_install_property (gobject_class, ARG_FENCE_TOP,
g_param_spec_boolean ("fence_top", "Fence Top",
"Align buffers with top of fenced region", TRUE, G_PARAM_READWRITE));
gobject_class->set_property = gst_efence_set_property;
gobject_class->get_property = gst_efence_get_property;
}
/* initialize the new element
* instantiate pads and add them to element
* set functions
* initialize structure
*/
static void
gst_efence_init (GstEFence * filter)
{
filter->sinkpad =
gst_pad_new_from_template (gst_static_pad_template_get
(&gst_efence_sink_factory), "sink");
gst_pad_set_getcaps_function (filter->sinkpad, gst_pad_proxy_getcaps);
gst_pad_set_link_function (filter->sinkpad, gst_pad_proxy_pad_link);
filter->srcpad =
gst_pad_new_from_template (gst_static_pad_template_get
(&gst_efence_src_factory), "src");
gst_pad_set_getcaps_function (filter->srcpad, gst_pad_proxy_getcaps);
gst_pad_set_link_function (filter->srcpad, gst_pad_proxy_pad_link);
gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad);
gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad);
gst_pad_set_chain_function (filter->sinkpad, gst_efence_chain);
gst_pad_set_bufferalloc_function (filter->sinkpad, gst_efence_buffer_alloc);
filter->fence_top = TRUE;
}
/* chain function
* this function does the actual processing
*/
static void
gst_efence_chain (GstPad * pad, GstData * _data)
{
GstBuffer *buffer = GST_BUFFER (_data);
GstEFence *efence;
GstBuffer *copy;
void *ptr;
GST_DEBUG ("gst_efence_chain");
g_return_if_fail (GST_IS_PAD (pad));
g_return_if_fail (buffer != NULL);
efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
g_return_if_fail (GST_IS_EFENCE (efence));
if (GST_DATA_FREE_FUNC (_data) == gst_fenced_buffer_default_free) {
gst_pad_push (efence->srcpad, _data);
return;
}
copy = gst_fenced_buffer_new ();
ptr = gst_fenced_buffer_alloc (copy, GST_BUFFER_SIZE (buffer),
efence->fence_top);
memcpy (ptr, GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer));
GST_BUFFER_DATA (copy) = ptr;
GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
GST_BUFFER_MAXSIZE (copy) = GST_BUFFER_SIZE (buffer);
GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
GST_BUFFER_DURATION (copy) = GST_BUFFER_DURATION (buffer);
GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
GST_BUFFER_FREE_DATA_FUNC (copy) = NULL;
GST_BUFFER_PRIVATE (copy) = NULL;
gst_buffer_unref (buffer);
gst_pad_push (efence->srcpad, GST_DATA (copy));
}
static GstBuffer *
gst_efence_buffer_alloc (GstPad * pad, guint64 offset, guint size)
{
GstBuffer *buffer;
GstEFence *efence;
efence = GST_EFENCE (GST_OBJECT_PARENT (pad));
buffer = gst_fenced_buffer_new ();
GST_BUFFER_DATA (buffer) = gst_fenced_buffer_alloc (buffer, size,
efence->fence_top);
GST_BUFFER_SIZE (buffer) = size;
return buffer;
}
static void
gst_efence_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstEFence *filter;
g_return_if_fail (GST_IS_EFENCE (object));
filter = GST_EFENCE (object);
switch (prop_id) {
case ARG_FENCE_TOP:
filter->fence_top = g_value_get_boolean (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_efence_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstEFence *filter;
g_return_if_fail (GST_IS_EFENCE (object));
filter = GST_EFENCE (object);
switch (prop_id) {
case ARG_FENCE_TOP:
g_value_set_boolean (value, filter->fence_top);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/* entry point to initialize the plug-in
* initialize the plug-in itself
* register the element factories and pad templates
* register the features
*/
static gboolean
plugin_init (GstPlugin * plugin)
{
if (!gst_element_register (plugin, "efence", GST_RANK_NONE, GST_TYPE_EFENCE))
return FALSE;
/* plugin initialisation succeeded */
return TRUE;
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"efence",
"This element converts a stream of normal GStreamer buffers into a "
"stream of buffers that are allocated in such a way that out-of-bounds "
"access to data in the buffer is more likely to cause segmentation "
"faults. This allocation method is very similar to the debugging tool "
"\"Electric Fence\".",
plugin_init, VERSION, "LGPL", GST_PACKAGE, GST_ORIGIN)
GstBuffer *gst_fenced_buffer_new (void)
{
GstBuffer *newbuf;
newbuf = (GstBuffer *) g_new0 (GstFencedBuffer, 1);
gst_data_init (GST_DATA (newbuf), _gst_buffer_type, 0,
gst_fenced_buffer_default_free, gst_fenced_buffer_default_copy);
GST_BUFFER_DATA (newbuf) = NULL;
GST_BUFFER_SIZE (newbuf) = 0;
GST_BUFFER_MAXSIZE (newbuf) = GST_BUFFER_MAXSIZE_NONE;
GST_BUFFER_TIMESTAMP (newbuf) = GST_CLOCK_TIME_NONE;
GST_BUFFER_DURATION (newbuf) = GST_CLOCK_TIME_NONE;
GST_BUFFER_OFFSET (newbuf) = GST_BUFFER_OFFSET_NONE;
GST_BUFFER_FREE_DATA_FUNC (newbuf) = NULL;
GST_BUFFER_PRIVATE (newbuf) = NULL;
GST_DEBUG ("new buffer=%p", newbuf);
return newbuf;
}
void
gst_fenced_buffer_default_free (GstData * data)
{
GstFencedBuffer *fenced_buffer;
GstBuffer *buffer = GST_BUFFER (data);
GST_DEBUG ("free buffer=%p", data);
g_return_if_fail (data != NULL);
fenced_buffer = (GstFencedBuffer *) data;
/* free our data */
if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE) &&
GST_BUFFER_DATA (buffer)) {
GST_DEBUG ("free region %p %d", fenced_buffer->region,
fenced_buffer->length);
munmap (fenced_buffer->region, fenced_buffer->length);
} else {
GST_DEBUG ("not freeing region %p %d %p", fenced_buffer->region,
GST_BUFFER_FLAGS (buffer), GST_BUFFER_DATA (buffer));
}
/* set to safe values */
GST_BUFFER_DATA (buffer) = NULL;
GST_BUFFER_SIZE (buffer) = 0;
g_free (buffer);
}
GstData *
gst_fenced_buffer_default_copy (const GstData * data)
{
GstBuffer *buffer = GST_BUFFER (data);
GstData *copy;
void *ptr;
g_return_val_if_fail (buffer != NULL, NULL);
/* create a fresh new buffer */
copy = (GstData *) g_new0 (GstFencedBuffer, 1);
gst_data_init (copy, _gst_buffer_type, 0,
gst_fenced_buffer_default_free, gst_fenced_buffer_default_copy);
/* we simply copy everything from our parent */
ptr = gst_fenced_buffer_alloc (GST_BUFFER (copy),
GST_BUFFER_SIZE (buffer), TRUE);
memcpy (ptr, GST_BUFFER_DATA (buffer), GST_BUFFER_SIZE (buffer));
GST_BUFFER_SIZE (copy) = GST_BUFFER_SIZE (buffer);
GST_BUFFER_MAXSIZE (copy) = GST_BUFFER_SIZE (buffer);
GST_BUFFER_TIMESTAMP (copy) = GST_BUFFER_TIMESTAMP (buffer);
GST_BUFFER_DURATION (copy) = GST_BUFFER_DURATION (buffer);
GST_BUFFER_OFFSET (copy) = GST_BUFFER_OFFSET (buffer);
GST_BUFFER_FREE_DATA_FUNC (copy) = NULL;
GST_BUFFER_PRIVATE (copy) = NULL;
return copy;
}
void *
gst_fenced_buffer_alloc (GstBuffer * buffer, unsigned int length,
gboolean fence_top)
{
int alloc_size;
void *region;
GstFencedBuffer *fenced_buffer = (GstFencedBuffer *) buffer;
int page_size;
GST_DEBUG ("buffer=%p length=%d fence_top=%d", buffer, length, fence_top);
if (length == 0)
return NULL;
#ifdef _SC_PAGESIZE
page_size = sysconf (_SC_PAGESIZE);
#else
page_size = getpagesize ();
#endif
alloc_size = ((length - 1) & ~(page_size - 1)) + page_size;
alloc_size += 2 * page_size;
region = mmap (NULL, alloc_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (region == MAP_FAILED) {
g_warning ("mmap failed");
return NULL;
}
munmap (region, page_size);
munmap (region + alloc_size - page_size, page_size);
fenced_buffer->region = region;
fenced_buffer->length = alloc_size;
GST_DEBUG ("new region %p %d", fenced_buffer->region, fenced_buffer->length);
if (fence_top) {
int offset;
/* Align to top of region, but force alignment to 4 bytes */
offset = alloc_size - page_size - length;
offset &= ~0x3;
return region + offset;
} else {
return region + page_size;
}
}