[vlc-devel] [PATCH] sftp: check symbolic links when readdir

[Rémi Denis-Courmont]

Le lauantaina 10. helmikuuta 2018, 15.44.40 EET Zhao Zhili a écrit :
> ---
>  modules/access/sftp.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/modules/access/sftp.c b/modules/access/sftp.c
> index 1219f573a1..f200a751b9 100644
> --- a/modules/access/sftp.c
> +++ b/modules/access/sftp.c
> @@ -649,7 +649,26 @@ static int DirRead (stream_t *p_access,
> input_item_node_t *p_current_node) }
>          free( psz_uri );
> 
> -        int i_type = LIBSSH2_SFTP_S_ISDIR( attrs.permissions ) ?
> ITEM_TYPE_DIRECTORY : ITEM_TYPE_FILE; +        int i_type;
> +        if( LIBSSH2_SFTP_S_ISDIR( attrs.permissions ) )
> +        {
> +            i_type = ITEM_TYPE_DIRECTORY;
> +        }
> +        else if( LIBSSH2_SFTP_S_ISLNK( attrs.permissions ) )
> +        {
> +            if( libssh2_sftp_stat( p_sys->sftp_session, psz_file, &attrs )
> ) +            {
> +                msg_Err( p_access, "Impossible to get information about
> symbolic link %s", psz_file ); +                free( psz_full_uri );
> +                break;
> +            }
> +            i_type = LIBSSH2_SFTP_S_ISDIR( attrs.permissions ) ?
> ITEM_TYPE_DIRECTORY : ITEM_TYPE_FILE; +        }
> +        else
> +        {
> +            i_type = ITEM_TYPE_FILE;
> +        }
> +
>          i_ret = vlc_readdir_helper_additem( &rdh, psz_full_uri, NULL,
> psz_file, i_type, ITEM_NET );
>          free( psz_full_uri );

If you want to resolve links, you should use the equivalent of stat() instead 
of lstat(). If there is no such thing, then that problem is not out of VLC 
scope.

Otherwise, you can also have links to links, and so on, and even circular 
links.

-- 
雷米‧德尼-库尔蒙
https://www.remlab.net/