--- a/libpurple/protocols/mxit/protocol.c Fri Jun 03 12:33:50 2016 -0500 +++ b/libpurple/protocols/mxit/protocol.c Fri Jun 03 12:39:32 2016 -0500 @@ -2076,21 +2076,6 @@ /*------------------------------------------------------------------------ - * Return the length of a multimedia chunk - * - * @return The actual chunk data length in bytes - */ -static int get_chunk_len( const char* chunkdata ) -{ - int* sizeptr; - - sizeptr = (int*) &chunkdata[1]; /* we skip the first byte (type field) */ - - return ntohl( *sizeptr ); -} - - -/*------------------------------------------------------------------------ * Process a received multimedia packet. * * @param session The MXit session object @@ -2099,22 +2084,33 @@ */ static void mxit_parse_cmd_media( struct MXitSession* session, struct record** records, int rcount ) { - char type; - int size; - - type = records[0]->fields[0]->data[0]; - size = get_chunk_len( records[0]->fields[0]->data ); - - purple_debug_info( MXIT_PLUGIN_ID, "mxit_parse_cmd_media (%i records) (%i bytes)\n", rcount, size ); + guint chunktype; + guint32 chunksize; + gchar* chunkdata; + + /* received packet is too short to even contain a chunk header */ + if ( records[0]->fields[0]->len < MXIT_CHUNK_HEADER_SIZE ) + return; + + /* decode the chunk header */ + chunktype = chunk_type( records[0]->fields[0]->data ); + chunksize = chunk_length( records[0]->fields[0]->data ); + chunkdata = chunk_data( records[0]->fields[0]->data ); + + /* check chunk size against length of received data */ + if ( MXIT_CHUNK_HEADER_SIZE + chunksize > records[0]->fields[0]->len ) + return; + + purple_debug_info( MXIT_PLUGIN_ID, "mxit_parse_cmd_media (%i records) (%i type) (%i bytes)\n", rcount, chunktype, chunksize ); /* supported chunked data types */ - switch ( type ) { + switch ( chunktype ) { case CP_CHUNK_CUSTOM : /* custom resource */ { struct cr_chunk chunk; /* decode the chunked data */ - if ( mxit_chunk_parse_cr( &records[0]->fields[0]->data[sizeof( char ) + sizeof( int )], records[0]->fields[0]->len, &chunk ) ) { + if ( mxit_chunk_parse_cr( chunkdata, chunksize, &chunk ) ) { purple_debug_info( MXIT_PLUGIN_ID, "chunk info id=%s handle=%s op=%i\n", chunk.id, chunk.handle, chunk.operation ); @@ -2142,7 +2138,7 @@ struct offerfile_chunk chunk; /* decode the chunked data */ - if ( mxit_chunk_parse_offer( &records[0]->fields[0]->data[sizeof( char ) + sizeof( int )], records[0]->fields[0]->len, &chunk ) ) { + if ( mxit_chunk_parse_offer( chunkdata, chunksize, &chunk ) ) { /* process the offer */ mxit_xfer_rx_offer( session, chunk.username, chunk.filename, chunk.filesize, chunk.fileid ); } @@ -2154,7 +2150,7 @@ struct getfile_chunk chunk; /* decode the chunked data */ - if ( mxit_chunk_parse_get( &records[0]->fields[0]->data[sizeof( char ) + sizeof( int )], records[0]->fields[0]->len, &chunk ) ) { + if ( mxit_chunk_parse_get( chunkdata, chunksize, &chunk ) ) { /* process the getfile */ mxit_xfer_rx_file( session, chunk.fileid, chunk.data, chunk.length ); } @@ -2167,7 +2163,7 @@ struct contact* contact = NULL; /* decode the chunked data */ - if ( mxit_chunk_parse_get_avatar( &records[0]->fields[0]->data[sizeof( char ) + sizeof( int )], records[0]->fields[0]->len, &chunk ) ) { + if ( mxit_chunk_parse_get_avatar( chunkdata, chunksize, &chunk ) ) { /* update avatar image */ purple_debug_info( MXIT_PLUGIN_ID, "updating avatar for contact '%s'\n", chunk.mxitid ); @@ -2190,12 +2186,16 @@ /* this is a reply packet to a set avatar request. no action is required */ break; + case CP_CHUNK_REJECT : + /* this is a reply packet to a reject file request. no action is required */ + break; + case CP_CHUNK_DIRECT_SND : /* this is a ack for a file send. */ { struct sendfile_chunk chunk; - if ( mxit_chunk_parse_sendfile( &records[0]->fields[0]->data[sizeof( char ) + sizeof( int )], records[0]->fields[0]->len, &chunk ) ) { + if ( mxit_chunk_parse_sendfile( chunkdata, chunksize, &chunk ) ) { purple_debug_info( MXIT_PLUGIN_ID, "file-send send to '%s' [status=%i message='%s']\n", chunk.username, chunk.status, chunk.statusmsg ); if ( chunk.status != 0 ) /* not success */ @@ -2209,7 +2209,7 @@ break; default : - purple_debug_error( MXIT_PLUGIN_ID, "Unsupported chunked data packet type received (%i)\n", type ); + purple_debug_error( MXIT_PLUGIN_ID, "Unsupported chunked data packet type received (%i)\n", chunktype ); break; } } @@ -2525,7 +2525,7 @@ for ( j = 0; j < r->fcount; j++ ) { f = r->fields[j]; - purple_debug_info( MXIT_PLUGIN_ID, "\tFIELD: (len=%i) '%s' \n", f->len, f->data ); + purple_debug_info( MXIT_PLUGIN_ID, "\tFIELD: (len=%zu) '%s' \n", f->len, f->data ); } } } @@ -2646,7 +2646,7 @@ field->data = &session->rx_dbuf[i + 1]; field->len = session->rx_i - i; /* now skip the binary data */ - res = get_chunk_len( field->data ); + res = chunk_length( field->data ); /* determine if we have more packets */ if ( res + 6 + i < session->rx_i ) { /* we have more than one packet in this stream */