sf_len
Length of socket filter extension structure; developers must initialize this to sizeof sflt_filter_ext structure. This field and all fields following it will only be valid if SFLT_EXTENDED flag is set in sf_flags field.
Length of socket filter extension structure; developers must initialize this to sizeof sflt_filter_ext structure. This field and all fields following it will only be valid if SFLT_EXTENDED flag is set in sf_flags field.