forked from luck/tmp_suning_uos_patched
e782ef7109
The mount option access=client is overloaded as it assumes acl too. Adding posixacl option to enable POSIX ACLs makes it explicit and clear. Also it is convenient in the future to add other types of acls like richacls. Ideally, the access mode 'client' should be just like V9FS_ACCESS_USER except it underscores the location of access check. Traditional 9P protocol lets the server perform access checks but with this mode, all the access checks will be performed on the client itself. Server just follows the client's directive. Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
404 lines
9.2 KiB
C
404 lines
9.2 KiB
C
/*
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* Copyright IBM Corporation, 2010
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* Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of version 2.1 of the GNU Lesser General Public License
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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*
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <net/9p/9p.h>
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#include <net/9p/client.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/posix_acl_xattr.h>
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#include "xattr.h"
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#include "acl.h"
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#include "v9fs_vfs.h"
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#include "v9fs.h"
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static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
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{
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ssize_t size;
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void *value = NULL;
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struct posix_acl *acl = NULL;
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size = v9fs_fid_xattr_get(fid, name, NULL, 0);
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if (size > 0) {
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value = kzalloc(size, GFP_NOFS);
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if (!value)
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return ERR_PTR(-ENOMEM);
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size = v9fs_fid_xattr_get(fid, name, value, size);
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if (size > 0) {
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acl = posix_acl_from_xattr(value, size);
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if (IS_ERR(acl))
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goto err_out;
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}
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} else if (size == -ENODATA || size == 0 ||
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size == -ENOSYS || size == -EOPNOTSUPP) {
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acl = NULL;
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} else
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acl = ERR_PTR(-EIO);
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err_out:
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kfree(value);
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return acl;
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}
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int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
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{
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int retval = 0;
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struct posix_acl *pacl, *dacl;
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struct v9fs_session_info *v9ses;
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v9ses = v9fs_inode2v9ses(inode);
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if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
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((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
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set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
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set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
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return 0;
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}
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/* get the default/access acl values and cache them */
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dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
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pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);
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if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
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set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
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set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
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} else
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retval = -EIO;
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if (!IS_ERR(dacl))
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posix_acl_release(dacl);
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if (!IS_ERR(pacl))
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posix_acl_release(pacl);
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return retval;
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}
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static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
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{
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struct posix_acl *acl;
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/*
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* 9p Always cache the acl value when
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* instantiating the inode (v9fs_inode_from_fid)
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*/
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acl = get_cached_acl(inode, type);
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BUG_ON(acl == ACL_NOT_CACHED);
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return acl;
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}
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int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags)
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{
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struct posix_acl *acl;
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struct v9fs_session_info *v9ses;
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if (flags & IPERM_FLAG_RCU)
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return -ECHILD;
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v9ses = v9fs_inode2v9ses(inode);
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if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
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((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
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/*
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* On access = client and acl = on mode get the acl
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* values from the server
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*/
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return 0;
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}
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acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl) {
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int error = posix_acl_permission(inode, acl, mask);
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posix_acl_release(acl);
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return error;
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}
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return -EAGAIN;
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}
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static int v9fs_set_acl(struct dentry *dentry, int type, struct posix_acl *acl)
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{
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int retval;
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char *name;
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size_t size;
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void *buffer;
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struct inode *inode = dentry->d_inode;
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set_cached_acl(inode, type, acl);
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if (!acl)
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return 0;
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/* Set a setxattr request to server */
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size = posix_acl_xattr_size(acl->a_count);
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buffer = kmalloc(size, GFP_KERNEL);
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if (!buffer)
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return -ENOMEM;
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retval = posix_acl_to_xattr(acl, buffer, size);
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if (retval < 0)
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goto err_free_out;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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name = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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BUG();
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}
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retval = v9fs_xattr_set(dentry, name, buffer, size, 0);
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err_free_out:
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kfree(buffer);
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return retval;
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}
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int v9fs_acl_chmod(struct dentry *dentry)
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{
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int retval = 0;
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struct posix_acl *acl, *clone;
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struct inode *inode = dentry->d_inode;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
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if (acl) {
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clone = posix_acl_clone(acl, GFP_KERNEL);
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posix_acl_release(acl);
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if (!clone)
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return -ENOMEM;
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retval = posix_acl_chmod_masq(clone, inode->i_mode);
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if (!retval)
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retval = v9fs_set_acl(dentry, ACL_TYPE_ACCESS, clone);
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posix_acl_release(clone);
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}
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return retval;
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}
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int v9fs_set_create_acl(struct dentry *dentry,
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struct posix_acl *dpacl, struct posix_acl *pacl)
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{
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v9fs_set_acl(dentry, ACL_TYPE_DEFAULT, dpacl);
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v9fs_set_acl(dentry, ACL_TYPE_ACCESS, pacl);
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posix_acl_release(dpacl);
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posix_acl_release(pacl);
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return 0;
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}
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int v9fs_acl_mode(struct inode *dir, mode_t *modep,
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struct posix_acl **dpacl, struct posix_acl **pacl)
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{
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int retval = 0;
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mode_t mode = *modep;
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struct posix_acl *acl = NULL;
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if (!S_ISLNK(mode)) {
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acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (!acl)
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mode &= ~current_umask();
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}
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if (acl) {
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struct posix_acl *clone;
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if (S_ISDIR(mode))
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*dpacl = acl;
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clone = posix_acl_clone(acl, GFP_NOFS);
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retval = -ENOMEM;
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if (!clone)
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goto cleanup;
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retval = posix_acl_create_masq(clone, &mode);
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if (retval < 0) {
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posix_acl_release(clone);
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goto cleanup;
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}
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if (retval > 0)
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*pacl = clone;
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}
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*modep = mode;
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return 0;
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cleanup:
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posix_acl_release(acl);
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return retval;
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}
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static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
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void *buffer, size_t size, int type)
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{
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char *full_name;
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switch (type) {
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case ACL_TYPE_ACCESS:
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full_name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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full_name = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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BUG();
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}
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return v9fs_xattr_get(dentry, full_name, buffer, size);
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}
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static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
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void *buffer, size_t size, int type)
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{
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struct v9fs_session_info *v9ses;
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struct posix_acl *acl;
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int error;
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if (strcmp(name, "") != 0)
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return -EINVAL;
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v9ses = v9fs_inode2v9ses(dentry->d_inode);
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/*
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* We allow set/get/list of acl when access=client is not specified
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*/
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if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
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return v9fs_remote_get_acl(dentry, name, buffer, size, type);
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acl = v9fs_get_cached_acl(dentry->d_inode, type);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl == NULL)
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return -ENODATA;
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error = posix_acl_to_xattr(acl, buffer, size);
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posix_acl_release(acl);
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return error;
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}
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static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
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const void *value, size_t size,
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int flags, int type)
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{
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char *full_name;
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switch (type) {
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case ACL_TYPE_ACCESS:
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full_name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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full_name = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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BUG();
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}
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return v9fs_xattr_set(dentry, full_name, value, size, flags);
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}
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static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
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const void *value, size_t size,
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int flags, int type)
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{
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int retval;
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struct posix_acl *acl;
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struct v9fs_session_info *v9ses;
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struct inode *inode = dentry->d_inode;
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if (strcmp(name, "") != 0)
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return -EINVAL;
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v9ses = v9fs_inode2v9ses(dentry->d_inode);
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/*
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* set the attribute on the remote. Without even looking at the
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* xattr value. We leave it to the server to validate
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*/
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if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
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return v9fs_remote_set_acl(dentry, name,
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value, size, flags, type);
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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if (!is_owner_or_cap(inode))
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return -EPERM;
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if (value) {
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/* update the cached acl value */
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acl = posix_acl_from_xattr(value, size);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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else if (acl) {
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retval = posix_acl_valid(acl);
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if (retval)
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goto err_out;
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}
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} else
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acl = NULL;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name = POSIX_ACL_XATTR_ACCESS;
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if (acl) {
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mode_t mode = inode->i_mode;
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retval = posix_acl_equiv_mode(acl, &mode);
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if (retval < 0)
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goto err_out;
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else {
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struct iattr iattr;
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if (retval == 0) {
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/*
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* ACL can be represented
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* by the mode bits. So don't
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* update ACL.
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*/
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acl = NULL;
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value = NULL;
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size = 0;
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}
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/* Updte the mode bits */
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iattr.ia_mode = ((mode & S_IALLUGO) |
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(inode->i_mode & ~S_IALLUGO));
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iattr.ia_valid = ATTR_MODE;
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/* FIXME should we update ctime ?
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* What is the following setxattr update the
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* mode ?
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*/
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v9fs_vfs_setattr_dotl(dentry, &iattr);
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}
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}
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break;
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case ACL_TYPE_DEFAULT:
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name = POSIX_ACL_XATTR_DEFAULT;
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if (!S_ISDIR(inode->i_mode)) {
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retval = acl ? -EINVAL : 0;
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goto err_out;
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}
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break;
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default:
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BUG();
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}
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retval = v9fs_xattr_set(dentry, name, value, size, flags);
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if (!retval)
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set_cached_acl(inode, type, acl);
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err_out:
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posix_acl_release(acl);
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return retval;
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}
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const struct xattr_handler v9fs_xattr_acl_access_handler = {
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.prefix = POSIX_ACL_XATTR_ACCESS,
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.flags = ACL_TYPE_ACCESS,
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.get = v9fs_xattr_get_acl,
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.set = v9fs_xattr_set_acl,
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};
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const struct xattr_handler v9fs_xattr_acl_default_handler = {
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.prefix = POSIX_ACL_XATTR_DEFAULT,
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.flags = ACL_TYPE_DEFAULT,
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.get = v9fs_xattr_get_acl,
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.set = v9fs_xattr_set_acl,
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};
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