linux-imx

/*

 * fs/nfs_common/nfsacl.c

 *

 *  Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>

 */

​

/*

 * The Solaris nfsacl protocol represents some ACLs slightly differently

 * than POSIX 1003.1e draft 17 does (and we do):

 *

 *  - Minimal ACLs always have an ACL_MASK entry, so they have

 *    four instead of three entries.

 *  - The ACL_MASK entry in such minimal ACLs always has the same

 *    permissions as the ACL_GROUP_OBJ entry. (In extended ACLs

 *    the ACL_MASK and ACL_GROUP_OBJ entries may differ.)

 *  - The identifier fields of the ACL_USER_OBJ and ACL_GROUP_OBJ

 *    entries contain the identifiers of the owner and owning group.

 *    (In POSIX ACLs we always set them to ACL_UNDEFINED_ID).

 *  - ACL entries in the kernel are kept sorted in ascending order

 *    of (e_tag, e_id). Solaris ACLs are unsorted.

 */

​

#include <linux/module.h>

#include <linux/fs.h>

#include <linux/gfp.h>

#include <linux/sunrpc/xdr.h>

#include <linux/nfsacl.h>

#include <linux/nfs3.h>

#include <linux/sort.h>

​

MODULE_LICENSE("GPL");

​

struct nfsacl_encode_desc {

    struct xdr_array2_desc desc;

    unsigned int count;

    struct posix_acl *acl;

    int typeflag;

    kuid_t uid;

    kgid_t gid;

};

​

struct nfsacl_simple_acl {

    struct posix_acl acl;

    struct posix_acl_entry ace[4];

};

​

static int

xdr_nfsace_encode(struct xdr_array2_desc *desc, void *elem)

{

    struct nfsacl_encode_desc *nfsacl_desc =

        (struct nfsacl_encode_desc *) desc;

    __be32 *p = elem;

​

    struct posix_acl_entry *entry =

        &nfsacl_desc->acl->a_entries[nfsacl_desc->count++];

​

    *p++ = htonl(entry->e_tag | nfsacl_desc->typeflag);

    switch(entry->e_tag) {

        case ACL_USER_OBJ:

            *p++ = htonl(from_kuid(&init_user_ns, nfsacl_desc->uid));

            break;

        case ACL_GROUP_OBJ:

            *p++ = htonl(from_kgid(&init_user_ns, nfsacl_desc->gid));

            break;

        case ACL_USER:

            *p++ = htonl(from_kuid(&init_user_ns, entry->e_uid));

            break;

        case ACL_GROUP:

            *p++ = htonl(from_kgid(&init_user_ns, entry->e_gid));

            break;

        default:  /* Solaris depends on that! */

            *p++ = 0;

            break;

    }

    *p++ = htonl(entry->e_perm & S_IRWXO);

    return 0;

}

​

/**

 * nfsacl_encode - Encode an NFSv3 ACL

 *

 * @buf: destination xdr_buf to contain XDR encoded ACL

 * @base: byte offset in xdr_buf where XDR'd ACL begins

 * @inode: inode of file whose ACL this is

 * @acl: posix_acl to encode

 * @encode_entries: whether to encode ACEs as well

 * @typeflag: ACL type: NFS_ACL_DEFAULT or zero

 *

 * Returns size of encoded ACL in bytes or a negative errno value.

 */

int nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode,

          struct posix_acl *acl, int encode_entries, int typeflag)