[vlc-devel] [PATCH] demux/playlist: wpl: reimplement parsing
Filip Roséen
filip at atch.se
Wed Mar 15 10:07:28 CET 2017
The previous implementation suffered from a bunch of different issues,
mostly related to not properly checking errors and the current state
of the XML-parser.
This new implementation is somewhat more verbose, but manages things
in a correct manner:
- prevents infinite loops on unexpected data
- prevents memory corruption on unexpected data
- prevents memory-leaks on error
fixes: #18124
---
modules/demux/playlist/wpl.c | 249 ++++++++++++++++++++++++++++++++-----------
1 file changed, 186 insertions(+), 63 deletions(-)
diff --git a/modules/demux/playlist/wpl.c b/modules/demux/playlist/wpl.c
index b801eaef26..48d2c0a47f 100644
--- a/modules/demux/playlist/wpl.c
+++ b/modules/demux/playlist/wpl.c
@@ -36,53 +36,134 @@ struct demux_sys_t
char* psz_prefix;
};
+static int consume_tag( xml_reader_t* p_reader, char const* psz_tag )
+{
+ int i_type, i_depth = 0;
+ char const *psz_name;
+
+ if( xml_ReaderIsEmptyElement( p_reader ) == 1 )
+ return VLC_SUCCESS;
+
+ while( ( i_type = xml_ReaderNextNode( p_reader, &psz_name ) ) > 0 )
+ {
+ if( i_type == XML_READER_ENDELEM && !strcasecmp( psz_name, psz_tag ) )
+ {
+ if( --i_depth < 0 )
+ return VLC_SUCCESS;
+ }
+ else if( i_type == XML_READER_STARTELEM && !strcasecmp( psz_name, psz_tag ) )
+ ++i_depth;
+ }
+
+ return VLC_EGENERIC;
+}
+
+static int consume_volatile_tag( demux_t* p_demux, char const* psz_tag )
+{
+ char* psz_copy = strdup( psz_tag );
+ int ret = VLC_ENOMEM;
+
+ if( likely( psz_copy ) )
+ ret = consume_tag( p_demux->p_sys->p_reader, psz_copy );
+
+ free( psz_copy );
+ return ret;
+}
+
+static void parse_meta( demux_t* p_demux, input_item_t* p_input )
+{
+ xml_reader_t* p_reader = p_demux->p_sys->p_reader;
+ bool const b_empty = xml_ReaderIsEmptyElement( p_reader ) == 1;
+
+ char *psz_meta_name = NULL, *psz_meta_content = NULL;
+ char const *psz_attr, *psz_value;
+ while( ( psz_attr = xml_ReaderNextAttr( p_reader, &psz_value ) ) )
+ {
+ if( psz_value == NULL )
+ continue;
+
+ if( !strcasecmp( psz_attr, "name" ) && !psz_meta_name )
+ psz_meta_name = strdup( psz_value );
+ else
+ if( !strcasecmp( psz_attr, "content" ) && !psz_meta_content )
+ psz_meta_content = strdup( psz_value );
+
+ if( psz_meta_name && psz_meta_content )
+ break;
+ }
+
+ if( b_empty == false )
+ consume_tag( p_reader, "meta" );
+
+ if( !psz_meta_name || !psz_meta_content )
+ goto done;
+
+ if( !strcasecmp( psz_meta_name, "TotalDuration" ) )
+ input_item_SetDuration( p_input, atoll( psz_meta_content ) );
+ else
+ if( !strcasecmp( psz_meta_name, "Author" ) )
+ input_item_SetPublisher( p_input, psz_meta_content );
+ else
+ if( !strcasecmp( psz_meta_name, "Rating" ) )
+ input_item_SetRating( p_input, psz_meta_content );
+ else
+ if( !strcasecmp( psz_meta_name, "Genre" ) )
+ input_item_SetGenre( p_input, psz_meta_content );
+ else
+ msg_Warn( p_demux, "ignoring unknown meta-attribute %s", psz_meta_name );
+
+done:
+ free( psz_meta_name );
+ free( psz_meta_content );
+}
+
+static int parse_title_element( demux_t* p_demux, input_item_t* p_input )
+{
+ xml_reader_t* p_reader = p_demux->p_sys->p_reader;
+ char const* psz_title;
+
+ if( xml_ReaderIsEmptyElement( p_reader ) )
+ return VLC_SUCCESS;
+
+ if( xml_ReaderNextNode( p_reader, &psz_title ) != XML_READER_TEXT )
+ return VLC_EGENERIC;
+
+ input_item_SetTitle( p_input, psz_title );
+
+ consume_tag( p_reader, "title" );
+ return VLC_SUCCESS;
+}
+
static void read_head( demux_t* p_demux, input_item_t* p_input )
{
- demux_sys_t* p_sys = p_demux->p_sys;
- const char* psz_name;
+ xml_reader_t* p_reader = p_demux->p_sys->p_reader;
+ char const* psz_name;
int i_type;
- do
+ while( ( i_type = xml_ReaderNextNode( p_reader, &psz_name ) ) > 0 )
{
- i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_name );
- if ( !strcasecmp( psz_name, "meta" ) )
+ if( i_type == XML_READER_ENDELEM && !strcasecmp( psz_name, "head" ) )
+ break;
+
+ if( i_type == XML_READER_STARTELEM )
{
- char* psz_attribute_name = NULL;
- char* psz_attribute_value = NULL;
- while (!psz_attribute_name || !psz_attribute_value)
+ if( !strcasecmp( psz_name, "meta" ) )
{
- const char* psz_attr = NULL;
- const char* psz_val = NULL;
- psz_attr = xml_ReaderNextAttr( p_sys->p_reader, &psz_val );
- if ( !psz_attr || !psz_val )
- break;
- if ( !strcasecmp( psz_attr, "name" ) && !psz_attribute_name )
- psz_attribute_name = strdup( psz_val );
- else if ( !strcasecmp( psz_attr, "content" ) && !psz_attribute_value )
- psz_attribute_value = strdup( psz_val );
+ parse_meta( p_demux, p_input );
+ continue;
}
- if ( psz_attribute_name && psz_attribute_value )
+
+ if( !strcasecmp( psz_name, "title" ) )
{
- if ( !strcasecmp( psz_attribute_name, "TotalDuration" ) )
- input_item_SetDuration( p_input, atoll( psz_attribute_value ) );
- else if ( !strcasecmp( psz_attribute_name, "Author" ) )
- input_item_SetPublisher( p_input, psz_attribute_value );
- else if ( !strcasecmp( psz_attribute_name, "Rating" ) )
- input_item_SetRating( p_input, psz_attribute_value );
- else if ( !strcasecmp( psz_attribute_name, "Genre" ) )
- input_item_SetGenre( p_input, psz_attribute_value );
+ if( parse_title_element( p_demux, p_input ) )
+ break;
+ continue;
}
- free( psz_attribute_name );
- free( psz_attribute_value );
- }
- else if ( !strcasecmp( psz_name, "title" ) )
- {
- const char* psz_title;
- int i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_title );
- if ( i_type == XML_READER_TEXT && psz_title != NULL )
- input_item_SetTitle( p_input, psz_title );
+
+ msg_Warn( p_demux, "skipping unknown tag <%s> in <head>", psz_name );
+ consume_volatile_tag( p_demux, psz_name );
}
- } while ( i_type != XML_READER_ENDELEM || strcasecmp( psz_name, "head" ) );
+ }
}
static void read_body( demux_t* p_demux, input_item_node_t* p_node )
@@ -98,33 +179,50 @@ static void read_body( demux_t* p_demux, input_item_node_t* p_node )
return;
}
- do
+ if( xml_ReaderIsEmptyElement( p_sys->p_reader ) == 1 )
+ return;
+
+ while ( ( i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_name ) ) > 0 )
{
- i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_name );
- if ( !strcasecmp( psz_name, "media" ) )
+ if ( i_type == XML_READER_ENDELEM && !strcasecmp( psz_name, "seq" ) )
+ break;
+
+ if( i_type == XML_READER_STARTELEM )
{
- const char* psz_attr = NULL;
- const char* psz_val = NULL;
- while ((psz_attr = xml_ReaderNextAttr( p_sys->p_reader, &psz_val )))
+ if( !strcasecmp( psz_name, "media" ) )
{
- if ( !psz_val )
- continue;
- if (!strcasecmp( psz_attr, "src" ) )
+ const bool b_empty = xml_ReaderIsEmptyElement( p_sys->p_reader );
+
+ const char *psz_attr = NULL, *psz_val = NULL;
+ while ((psz_attr = xml_ReaderNextAttr( p_sys->p_reader, &psz_val )))
{
- char* mrl = ProcessMRL( psz_val, p_sys->psz_prefix );
- if ( unlikely( !mrl ) )
- return;
- input_item_t* p_item = input_item_New( mrl, NULL );
- if ( likely( p_item ) )
+ if ( !psz_val || *psz_val == '\0' )
+ continue;
+ if (!strcasecmp( psz_attr, "src" ) )
{
- input_item_node_AppendItem( p_node, p_item );
- input_item_Release( p_item );
+ char* mrl = ProcessMRL( psz_val, p_sys->psz_prefix );
+ if ( unlikely( !mrl ) )
+ return;
+ input_item_t* p_item = input_item_New( mrl, NULL );
+ if ( likely( p_item ) )
+ {
+ input_item_node_AppendItem( p_node, p_item );
+ input_item_Release( p_item );
+ }
+ free( mrl );
}
- free( mrl );
}
+
+ if( b_empty == false )
+ consume_tag( p_sys->p_reader, "media" );
+
+ continue;
}
+
+ msg_Warn( p_demux, "skipping unknown tag <%s> in <seq>", psz_name );
+ consume_volatile_tag( p_demux, psz_name );
}
- } while ( i_type != XML_READER_ENDELEM || strcasecmp( psz_name, "seq" ) );
+ }
i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_name );
if ( i_type != XML_READER_ENDELEM || strcasecmp( psz_name, "body" ) )
@@ -137,20 +235,45 @@ static int Demux( demux_t* p_demux )
int i_type;
demux_sys_t* p_sys = p_demux->p_sys;
- input_item_t* p_input = GetCurrentItem( p_demux );
- input_item_node_t* p_node = input_item_node_Create( p_input );
p_sys->psz_prefix = FindPrefix( p_demux );
if( unlikely(p_sys->psz_prefix == NULL) )
return VLC_DEMUXER_EOF;
- do
+ if( xml_ReaderNextNode( p_sys->p_reader, &psz_name ) != XML_READER_STARTELEM ||
+ strcasecmp( psz_name, "smil" ) || xml_ReaderIsEmptyElement( p_sys->p_reader ) == 1 )
{
- i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_name );
- if ( i_type == XML_READER_STARTELEM && !strcasecmp( psz_name, "head" ) )
- read_head( p_demux, p_input );
- else if ( i_type == XML_READER_STARTELEM && !strcasecmp( psz_name, "body" ) )
- read_body( p_demux, p_node );
- } while (i_type != XML_READER_ENDELEM || strcasecmp( psz_name, "smil" ) );
+ return VLC_DEMUXER_EOF;
+ }
+
+ input_item_t* p_input = GetCurrentItem( p_demux );
+ input_item_node_t* p_node = input_item_node_Create( p_input );
+
+ if( unlikely( !p_node ) )
+ return VLC_DEMUXER_EOF;
+
+ while( ( i_type = xml_ReaderNextNode( p_sys->p_reader, &psz_name ) ) > 0 )
+ {
+ if( i_type == XML_READER_ENDELEM && !strcasecmp( psz_name, "smil" ) )
+ break;
+
+ if( i_type == XML_READER_STARTELEM )
+ {
+ if( !strcasecmp( psz_name, "head" ) )
+ {
+ read_head( p_demux, p_input );
+ continue;
+ }
+
+ if( !strcasecmp( psz_name, "body" ) )
+ {
+ read_body( p_demux, p_node );
+ continue;
+ }
+
+ msg_Warn( p_demux, "skipping unknown tag <%s> in <smil>", psz_name );
+ consume_volatile_tag( p_demux, psz_name );
+ }
+ }
input_item_node_PostAndDelete( p_node );
input_item_Release( p_input );
--
2.12.0
More information about the vlc-devel
mailing list