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SubjectRe: [PATCH 1/4] AppArmor: refactor securityfs to use structures
On 01/26/2012 04:29 PM, Kees Cook wrote:
> From: Kees Cook <kees@outflux.net>
>
> Use a file tree structure to represent the AppArmor securityfs.
>
> Signed-off-by: Kees Cook <kees@ubuntu.com>
Acked-by: John Johansen <john.johansen@canonical.com>

> ---
> security/apparmor/apparmorfs.c | 132 ++++++++++++++++++++++----------
> security/apparmor/include/apparmorfs.h | 24 ++++++
> 2 files changed, 114 insertions(+), 42 deletions(-)
>
> diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
> index e39df6d..1e22bb3 100644
> --- a/security/apparmor/apparmorfs.c
> +++ b/security/apparmor/apparmorfs.c
> @@ -144,36 +144,103 @@ static const struct file_operations aa_fs_profile_remove = {
>
> /** Base file system setup **/
>
> -static struct dentry *aa_fs_dentry __initdata;
> +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),
> + { }
> +};
>
> -static void __init aafs_remove(const char *name)
> -{
> - struct dentry *dentry;
> +static struct aa_fs_entry aa_fs_entry =
> + AA_FS_DIR("apparmor", aa_fs_entry_apparmor);
>
> - dentry = lookup_one_len(name, aa_fs_dentry, strlen(name));
> - if (!IS_ERR(dentry)) {
> - securityfs_remove(dentry);
> - dput(dentry);
> +/**
> + * aafs_create_file - create a file entry in the apparmor securityfs
> + * @fs_file: aa_fs_entry to build an entry for (NOT NULL)
> + * @parent: the parent dentry in the securityfs
> + *
> + * Use aafs_remove_file to remove entries created with this fn.
> + */
> +static int __init aafs_create_file(struct aa_fs_entry *fs_file,
> + struct dentry *parent)
> +{
> + int error = 0;
> +
> + fs_file->dentry = securityfs_create_file(fs_file->name,
> + S_IFREG | fs_file->mode,
> + parent, fs_file,
> + fs_file->file_ops);
> + if (IS_ERR(fs_file->dentry)) {
> + error = PTR_ERR(fs_file->dentry);
> + fs_file->dentry = NULL;
> }
> + return error;
> }
>
> /**
> - * aafs_create - create an entry in the apparmor filesystem
> - * @name: name of the entry (NOT NULL)
> - * @mask: file permission mask of the file
> - * @fops: file operations for the file (NOT NULL)
> + * aafs_create_dir - recursively create a directory entry in the securityfs
> + * @fs_dir: aa_fs_entry (and all child entries) to build (NOT NULL)
> + * @parent: the parent dentry in the securityfs
> *
> - * Used aafs_remove to remove entries created with this fn.
> + * Use aafs_remove_dir to remove entries created with this fn.
> */
> -static int __init aafs_create(const char *name, umode_t mask,
> - const struct file_operations *fops)
> +static int __init aafs_create_dir(struct aa_fs_entry *fs_dir,
> + struct dentry *parent)
> {
> - struct dentry *dentry;
> + int error;
> + struct aa_fs_entry *fs_file;
>
> - dentry = securityfs_create_file(name, S_IFREG | mask, aa_fs_dentry,
> - NULL, fops);
> + fs_dir->dentry = securityfs_create_dir(fs_dir->name, parent);
> + if (IS_ERR(fs_dir->dentry)) {
> + error = PTR_ERR(fs_dir->dentry);
> + fs_dir->dentry = NULL;
> + goto failed;
> + }
>
> - return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
> + for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
> + if (fs_file->v_type == AA_FS_TYPE_DIR)
> + error = aafs_create_dir(fs_file, fs_dir->dentry);
> + else
> + error = aafs_create_file(fs_file, fs_dir->dentry);
> + if (error)
> + goto failed;
> + }
> +
> + return 0;
> +
> +failed:
> + return error;
> +}
> +
> +/**
> + * aafs_remove_file - drop a single file entry in the apparmor securityfs
> + * @fs_file: aa_fs_entry to detach from the securityfs (NOT NULL)
> + */
> +static void __init aafs_remove_file(struct aa_fs_entry *fs_file)
> +{
> + if (!fs_file->dentry)
> + return;
> +
> + securityfs_remove(fs_file->dentry);
> + fs_file->dentry = NULL;
> +}
> +
> +/**
> + * aafs_remove_dir - recursively drop a directory entry from the securityfs
> + * @fs_dir: aa_fs_entry (and all child entries) to detach (NOT NULL)
> + */
> +static void __init aafs_remove_dir(struct aa_fs_entry *fs_dir)
> +{
> + struct aa_fs_entry *fs_file;
> +
> + for (fs_file = fs_dir->v.files; fs_file->name; ++fs_file) {
> + if (fs_file->v_type == AA_FS_TYPE_DIR)
> + aafs_remove_dir(fs_file);
> + else
> + aafs_remove_file(fs_file);
> + }
> +
> + aafs_remove_file(fs_dir);
> }
>
> /**
> @@ -183,14 +250,7 @@ static int __init aafs_create(const char *name, umode_t mask,
> */
> void __init aa_destroy_aafs(void)
> {
> - if (aa_fs_dentry) {
> - aafs_remove(".remove");
> - aafs_remove(".replace");
> - aafs_remove(".load");
> -
> - securityfs_remove(aa_fs_dentry);
> - aa_fs_dentry = NULL;
> - }
> + aafs_remove_dir(&aa_fs_entry);
> }
>
> /**
> @@ -207,25 +267,13 @@ static int __init aa_create_aafs(void)
> if (!apparmor_initialized)
> return 0;
>
> - if (aa_fs_dentry) {
> + if (aa_fs_entry.dentry) {
> AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
> return -EEXIST;
> }
>
> - aa_fs_dentry = securityfs_create_dir("apparmor", NULL);
> - if (IS_ERR(aa_fs_dentry)) {
> - error = PTR_ERR(aa_fs_dentry);
> - aa_fs_dentry = NULL;
> - goto error;
> - }
> -
> - error = aafs_create(".load", 0640, &aa_fs_profile_load);
> - if (error)
> - goto error;
> - error = aafs_create(".replace", 0640, &aa_fs_profile_replace);
> - if (error)
> - goto error;
> - error = aafs_create(".remove", 0640, &aa_fs_profile_remove);
> + /* Populate fs tree. */
> + error = aafs_create_dir(&aa_fs_entry, NULL);
> if (error)
> goto error;
>
> diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
> index cb1e93a..4fdf02f 100644
> --- a/security/apparmor/include/apparmorfs.h
> +++ b/security/apparmor/include/apparmorfs.h
> @@ -15,6 +15,30 @@
> #ifndef __AA_APPARMORFS_H
> #define __AA_APPARMORFS_H
>
> +enum aa_fs_type {
> + AA_FS_TYPE_FOPS,
> + AA_FS_TYPE_DIR,
> +};
> +
> +struct aa_fs_entry;
> +
> +struct aa_fs_entry {
> + const char *name;
> + struct dentry *dentry;
> + umode_t mode;
> + enum aa_fs_type v_type;
> + union {
> + struct aa_fs_entry *files;
> + } v;
> + const struct file_operations *file_ops;
> +};
> +
> +#define AA_FS_FILE_FOPS(_name, _mode, _fops) \
> + { .name = (_name), .v_type = AA_FS_TYPE_FOPS, \
> + .mode = (_mode), .file_ops = (_fops) }
> +#define AA_FS_DIR(_name, _value) \
> + { .name = (_name), .v_type = AA_FS_TYPE_DIR, .v.files = (_value) }
> +
> extern void __init aa_destroy_aafs(void);
>
> #endif /* __AA_APPARMORFS_H */



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