Re: [PATCH 2/4] AppArmor: add initial "features" directory to securityfs

[John Johansen <john.johansen@canonical.com>]

On 01/26/2012 04:29 PM, Kees Cook wrote:
> From: Kees Cook <kees@outflux.net>
> 
> This adds the "features" subdirectory to the AppArmor securityfs
> to display boolean features flags and the known capability mask.
> 
> Signed-off-by: Kees Cook <kees@ubuntu.com>
Acked-by: John Johansen <john.johansen@canonical.com>

> ---
>  security/apparmor/apparmorfs.c         |   52 ++++++++++++++++++++++++++++++++
>  security/apparmor/include/apparmorfs.h |   14 ++++++++
>  2 files changed, 66 insertions(+), 0 deletions(-)
> 
> diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
> index 1e22bb3..36efe64 100644
> --- a/security/apparmor/apparmorfs.c
> +++ b/security/apparmor/apparmorfs.c
> @@ -18,6 +18,7 @@
>  #include <linux/seq_file.h>
>  #include <linux/uaccess.h>
>  #include <linux/namei.h>
> +#include <linux/capability.h>
>  
>  #include "include/apparmor.h"
>  #include "include/apparmorfs.h"
> @@ -142,12 +143,63 @@ static const struct file_operations aa_fs_profile_remove = {
>  	.llseek = default_llseek,
>  };
>  
> +static int aa_fs_seq_show(struct seq_file *seq, void *v)
> +{
> +	struct aa_fs_entry *fs_file = seq->private;
> +
> +	if (!fs_file)
> +		return 0;
> +
> +	switch (fs_file->v_type) {
> +	case AA_FS_TYPE_BOOLEAN:
> +		seq_printf(seq, "%s\n", fs_file->v.boolean ? "yes" : "no");
> +		break;
> +	case AA_FS_TYPE_U64:
> +		seq_printf(seq, "%#08lx\n", fs_file->v.u64);
> +		break;
> +	default:
> +		/* Ignore unpritable entry types. */
> +		break;
> +	}
> +
> +	return 0;
> +}
> +
> +static int aa_fs_seq_open(struct inode *inode, struct file *file)
> +{
> +	return single_open(file, aa_fs_seq_show, inode->i_private);
> +}
> +
> +const struct file_operations aa_fs_seq_file_ops = {
> +	.owner		= THIS_MODULE,
> +	.open		= aa_fs_seq_open,
> +	.read		= seq_read,
> +	.llseek		= seq_lseek,
> +	.release	= single_release,
> +};
> +
>  /** Base file system setup **/
>  
> +static struct aa_fs_entry aa_fs_entry_domain[] = {
> +	AA_FS_FILE_BOOLEAN("change_hat",	1),
> +	AA_FS_FILE_BOOLEAN("change_hatv",	1),
> +	AA_FS_FILE_BOOLEAN("change_onexec",	1),
> +	AA_FS_FILE_BOOLEAN("change_profile",	1),
> +	{ }
> +};
> +
> +static struct aa_fs_entry aa_fs_entry_features[] = {
> +	AA_FS_DIR("domain",			aa_fs_entry_domain),
> +	AA_FS_FILE_BOOLEAN("namespaces",	1),
> +	AA_FS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
> +	{ }
> +};
> +
>  static struct aa_fs_entry aa_fs_entry_apparmor[] = {
>  	AA_FS_FILE_FOPS(".load", 0640, &aa_fs_profile_load),
>  	AA_FS_FILE_FOPS(".replace", 0640, &aa_fs_profile_replace),
>  	AA_FS_FILE_FOPS(".remove", 0640, &aa_fs_profile_remove),
> +	AA_FS_DIR("features", aa_fs_entry_features),
>  	{ }
>  };
>  
> diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
> index 4fdf02f..16e6545 100644
> --- a/security/apparmor/include/apparmorfs.h
> +++ b/security/apparmor/include/apparmorfs.h
> @@ -16,6 +16,8 @@
>  #define __AA_APPARMORFS_H
>  
>  enum aa_fs_type {
> +	AA_FS_TYPE_BOOLEAN,
> +	AA_FS_TYPE_U64,
>  	AA_FS_TYPE_FOPS,
>  	AA_FS_TYPE_DIR,
>  };
> @@ -28,11 +30,23 @@ struct aa_fs_entry {
>  	umode_t mode;
>  	enum aa_fs_type v_type;
>  	union {
> +		bool boolean;
> +		unsigned long u64;
>  		struct aa_fs_entry *files;
>  	} v;
>  	const struct file_operations *file_ops;
>  };
>  
> +extern const struct file_operations aa_fs_seq_file_ops;
> +
> +#define AA_FS_FILE_BOOLEAN(_name, _value) \
> +	{ .name = (_name), .mode = 0444, \
> +	  .v_type = AA_FS_TYPE_BOOLEAN, .v.boolean = (_value), \
> +	  .file_ops = &aa_fs_seq_file_ops }
> +#define AA_FS_FILE_U64(_name, _value) \
> +	{ .name = (_name), .mode = 0444, \
> +	  .v_type = AA_FS_TYPE_U64, .v.u64 = (_value), \
> +	  .file_ops = &aa_fs_seq_file_ops }
>  #define AA_FS_FILE_FOPS(_name, _mode, _fops) \
>  	{ .name = (_name), .v_type = AA_FS_TYPE_FOPS, \
>  	  .mode = (_mode), .file_ops = (_fops) }