--- /dev/null
+/*
+ * 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.
+ */
+
+#include <gst/gst.h>
+
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+#include "efence.h"
+
+static GstElementDetails plugin_details = {
+ "Electric Fence",
+ "Testing/EFence",
+ "LGPL",
+ "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\".",
+ VERSION,
+ "David A. Schleef <ds@schleef.org>",
+ "(C) 2002, 2003"
+};
+
+/* Filter signals and args */
+enum {
+ /* FILL ME */
+ LAST_SIGNAL
+};
+
+enum {
+ ARG_0,
+ ARG_FENCE_TOP
+};
+
+GST_PAD_TEMPLATE_FACTORY (gst_efence_sink_factory,
+ "sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ NULL /* no caps */
+);
+
+GST_PAD_TEMPLATE_FACTORY (gst_efence_src_factory,
+ "src",
+ GST_PAD_SRC,
+ GST_PAD_ALWAYS,
+ NULL /* no caps */
+);
+
+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, GstBuffer *buf);
+
+static GstElementClass *parent_class = NULL;
+
+typedef struct _GstFencedBuffer GstFencedBuffer;
+struct _GstFencedBuffer {
+ GstBuffer buffer;
+ void *region;
+ unsigned int length;
+};
+
+void gst_fenced_buffer_default_free (GstBuffer *buffer);
+GstBuffer* gst_fenced_buffer_default_copy (GstBuffer *buffer);
+void *gst_fenced_buffer_alloc(GstBuffer *buffer, unsigned int length,
+ gboolean fence_top);
+
+GstBuffer *gst_fenced_buffer_new(void);
+
+static GstPadLinkReturn
+gst_efence_link (GstPad *pad, GstCaps *caps)
+{
+ GstEFence *filter;
+ GstPad *otherpad;
+
+ filter = GST_EFENCE (gst_pad_get_parent (pad));
+ g_return_val_if_fail (filter != NULL, GST_PAD_LINK_REFUSED);
+ g_return_val_if_fail (GST_IS_EFENCE (filter),
+ GST_PAD_LINK_REFUSED);
+ otherpad = (pad == filter->srcpad ? filter->sinkpad : filter->srcpad);
+
+ if (GST_CAPS_IS_FIXED (caps))
+ {
+ /* caps are not fixed, so try to link on the other side and see if
+ * that works */
+
+ if (!gst_pad_try_set_caps (otherpad, caps))
+ return GST_PAD_LINK_REFUSED;
+
+ /* caps on other side were accepted, so we're ok */
+ return GST_PAD_LINK_OK;
+ }
+ /* not enough information yet, delay negotation */
+ return GST_PAD_LINK_DELAYED;
+}
+
+GType
+gst_gst_efence_get_type (void)
+{
+ static GType plugin_type = 0;
+
+ if (!plugin_type)
+ {
+ static const GTypeInfo plugin_info =
+ {
+ sizeof (GstEFenceClass),
+ NULL,
+ 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;
+}
+
+/* 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_efence_sink_factory (),
+ "sink");
+ gst_pad_set_link_function (filter->sinkpad, gst_efence_link);
+ filter->srcpad = gst_pad_new_from_template (gst_efence_src_factory (),
+ "src");
+ gst_pad_set_link_function (filter->srcpad, gst_efence_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);
+
+ filter->fence_top = TRUE;
+}
+
+/* chain function
+ * this function does the actual processing
+ */
+
+static void
+gst_efence_chain (GstPad *pad, GstBuffer *buffer)
+{
+ GstEFence *efence;
+ GstBuffer *copy;
+ void *ptr;
+
+ GST_DEBUG(0, "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));
+
+ 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_BUFFERPOOL (copy) = NULL;
+ GST_BUFFER_POOL_PRIVATE (copy) = NULL;
+
+ gst_buffer_unref(buffer);
+ gst_pad_push (efence->srcpad, copy);
+}
+
+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 (GModule *module, GstPlugin *plugin)
+{
+ GstElementFactory *factory;
+
+ factory = gst_element_factory_new ("efence", GST_TYPE_EFENCE,
+ &plugin_details);
+ g_return_val_if_fail (factory != NULL, FALSE);
+
+ gst_element_factory_add_pad_template (factory,
+ gst_efence_src_factory ());
+ gst_element_factory_add_pad_template (factory,
+ gst_efence_sink_factory ());
+
+ gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
+
+ /* plugin initialisation succeeded */
+ return TRUE;
+}
+
+/* this is the structure that gst-register looks for
+ * so keep the name plugin_desc, or you cannot get your plug-in registered */
+GstPluginDesc plugin_desc = {
+ GST_VERSION_MAJOR,
+ GST_VERSION_MINOR,
+ "efence",
+ plugin_init
+};
+
+
+
+
+GstBuffer *gst_fenced_buffer_new(void)
+{
+ GstBuffer *newbuf;
+
+ newbuf = (GstBuffer *) g_new0(GstFencedBuffer,1);
+
+ gst_data_init (GST_DATA (newbuf), _gst_buffer_type, 0,
+ (GstDataFreeFunction) gst_fenced_buffer_default_free,
+ (GstDataCopyFunction) 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_BUFFERPOOL (newbuf) = NULL;
+ GST_BUFFER_POOL_PRIVATE (newbuf) = NULL;
+
+ GST_DEBUG(0, "new buffer=%p", newbuf);
+
+ return newbuf;
+}
+
+void gst_fenced_buffer_default_free (GstBuffer *buffer)
+{
+ GstFencedBuffer *fenced_buffer;
+
+ GST_DEBUG(0, "free buffer=%p", buffer);
+
+ g_return_if_fail (buffer != NULL);
+
+ fenced_buffer = (GstFencedBuffer *) buffer;
+
+ /* free our data */
+ if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_DONTFREE) &&
+ GST_BUFFER_DATA (buffer)) {
+ GST_DEBUG(0, "free region %p %d", fenced_buffer->region,
+ fenced_buffer->length);
+ munmap(fenced_buffer->region, fenced_buffer->length);
+ }else{
+ GST_DEBUG(0, "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);
+}
+
+GstBuffer* gst_fenced_buffer_default_copy (GstBuffer *buffer)
+{
+ GstBuffer *copy;
+ void *ptr;
+
+ g_return_val_if_fail (buffer != NULL, NULL);
+
+ /* create a fresh new buffer */
+ copy = (GstBuffer *) g_new0(GstFencedBuffer,1);
+
+ gst_data_init (GST_DATA (copy), _gst_buffer_type, 0,
+ (GstDataFreeFunction) gst_fenced_buffer_default_free,
+ (GstDataCopyFunction) gst_fenced_buffer_default_copy);
+
+ /* we simply copy everything from our parent */
+ ptr = gst_fenced_buffer_alloc(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_BUFFERPOOL (copy) = NULL;
+ GST_BUFFER_POOL_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(0, "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(0, "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;
+ }
+}
+
projects / platform / upstream / gst-plugins-good.git / commitdiff