[PATCH v4 6/7] samples/landlock: Add support for LANDLOCK_ACCESS_FS_IOCTL

[Mickaël Salaün]

On Fri, Nov 03, 2023 at 04:57:16PM +0100, Günther Noack wrote:
> Add ioctl support to the Landlock sample tool.
> 
> The ioctl right is grouped with the read-write rights in the sample
> tool, as some ioctl requests provide features that mutate state.
> 
> Signed-off-by: Günther Noack <gnoack at google.com>
> ---
>  samples/landlock/sandboxer.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
> index 08596c0ef070..a4b2bebaf203 100644
> --- a/samples/landlock/sandboxer.c
> +++ b/samples/landlock/sandboxer.c
> @@ -81,7 +81,8 @@ static int parse_path(char *env_path, const char ***const path_list)
>  	LANDLOCK_ACCESS_FS_EXECUTE | \
>  	LANDLOCK_ACCESS_FS_WRITE_FILE | \
>  	LANDLOCK_ACCESS_FS_READ_FILE | \
> -	LANDLOCK_ACCESS_FS_TRUNCATE)
> +	LANDLOCK_ACCESS_FS_TRUNCATE | \
> +	LANDLOCK_ACCESS_FS_IOCTL)
>  
>  /* clang-format on */
>  
> @@ -199,7 +200,8 @@ static int populate_ruleset_net(const char *const env_var, const int ruleset_fd,
>  	LANDLOCK_ACCESS_FS_MAKE_BLOCK | \
>  	LANDLOCK_ACCESS_FS_MAKE_SYM | \
>  	LANDLOCK_ACCESS_FS_REFER | \
> -	LANDLOCK_ACCESS_FS_TRUNCATE)
> +	LANDLOCK_ACCESS_FS_TRUNCATE | \
> +	LANDLOCK_ACCESS_FS_IOCTL)
>  
>  /* clang-format on */
>  

#define LANDLOCK_ABI_LAST 5

> @@ -317,6 +319,10 @@ int main(const int argc, char *const argv[], char *const *const envp)
>  		ruleset_attr.handled_access_net &=
>  			~(LANDLOCK_ACCESS_NET_BIND_TCP |
>  			  LANDLOCK_ACCESS_NET_CONNECT_TCP);

__attribute__((fallthrough));

> +	case 4:
> +		/* Removes LANDLOCK_ACCESS_FS_IOCTL for ABI < 5 */
> +		ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_IOCTL;
> +
>  		fprintf(stderr,
>  			"Hint: You should update the running kernel "
>  			"to leverage Landlock features "
> -- 
> 2.42.0.869.gea05f2083d-goog
>