diff options
Diffstat (limited to 'fs/9p/acl.c')
| -rw-r--r-- | fs/9p/acl.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/fs/9p/acl.c b/fs/9p/acl.c new file mode 100644 index 0000000..02a2cf6 --- /dev/null +++ b/fs/9p/acl.c @@ -0,0 +1,395 @@ +/* + * Copyright IBM Corporation, 2010 + * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + */ + +#include <linux/module.h> +#include <linux/fs.h> +#include <net/9p/9p.h> +#include <net/9p/client.h> +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/posix_acl_xattr.h> +#include "xattr.h" +#include "acl.h" +#include "v9fs_vfs.h" +#include "v9fs.h" + +static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name) +{ + ssize_t size; + void *value = NULL; + struct posix_acl *acl = NULL; + + size = v9fs_fid_xattr_get(fid, name, NULL, 0); + if (size > 0) { + value = kzalloc(size, GFP_NOFS); + if (!value) + return ERR_PTR(-ENOMEM); + size = v9fs_fid_xattr_get(fid, name, value, size); + if (size > 0) { + acl = posix_acl_from_xattr(value, size); + if (IS_ERR(acl)) + goto err_out; + } + } else if (size == -ENODATA || size == 0 || + size == -ENOSYS || size == -EOPNOTSUPP) { + acl = NULL; + } else + acl = ERR_PTR(-EIO); + +err_out: + kfree(value); + return acl; +} + +int v9fs_get_acl(struct inode *inode, struct p9_fid *fid) +{ + int retval = 0; + struct posix_acl *pacl, *dacl; + struct v9fs_session_info *v9ses; + + v9ses = v9fs_inode2v9ses(inode); + if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) { + set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL); + set_cached_acl(inode, ACL_TYPE_ACCESS, NULL); + return 0; + } + /* get the default/access acl values and cache them */ + dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT); + pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS); + + if (!IS_ERR(dacl) && !IS_ERR(pacl)) { + set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); + set_cached_acl(inode, ACL_TYPE_ACCESS, pacl); + posix_acl_release(dacl); + posix_acl_release(pacl); + } else + retval = -EIO; + + return retval; +} + +static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) +{ + struct posix_acl *acl; + /* + * 9p Always cache the acl value when + * instantiating the inode (v9fs_inode_from_fid) + */ + acl = get_cached_acl(inode, type); + BUG_ON(acl == ACL_NOT_CACHED); + return acl; +} + +int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags) +{ + struct posix_acl *acl; + struct v9fs_session_info *v9ses; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + v9ses = v9fs_inode2v9ses(inode); + if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) { + /* + * On access = client mode get the acl + * values from the server + */ + return 0; + } + acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); + + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl) { + int error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + return error; + } + return -EAGAIN; +} + +static int v9fs_set_acl(struct dentry *dentry, int type, struct posix_acl *acl) +{ + int retval; + char *name; + size_t size; + void *buffer; + struct inode *inode = dentry->d_inode; + + set_cached_acl(inode, type, acl); + /* Set a setxattr request to server */ + size = posix_acl_xattr_size(acl->a_count); + buffer = kmalloc(size, GFP_KERNEL); + if (!buffer) + return -ENOMEM; + retval = posix_acl_to_xattr(acl, buffer, size); + if (retval < 0) + goto err_free_out; + switch (type) { + case ACL_TYPE_ACCESS: + name = POSIX_ACL_XATTR_ACCESS; + break; + case ACL_TYPE_DEFAULT: + name = POSIX_ACL_XATTR_DEFAULT; + break; + default: + BUG(); + } + retval = v9fs_xattr_set(dentry, name, buffer, size, 0); +err_free_out: + kfree(buffer); + return retval; +} + +int v9fs_acl_chmod(struct dentry *dentry) +{ + int retval = 0; + struct posix_acl *acl, *clone; + struct inode *inode = dentry->d_inode; + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); + if (acl) { + clone = posix_acl_clone(acl, GFP_KERNEL); + posix_acl_release(acl); + if (!clone) + return -ENOMEM; + retval = posix_acl_chmod_masq(clone, inode->i_mode); + if (!retval) + retval = v9fs_set_acl(dentry, ACL_TYPE_ACCESS, clone); + posix_acl_release(clone); + } + return retval; +} + +int v9fs_set_create_acl(struct dentry *dentry, + struct posix_acl *dpacl, struct posix_acl *pacl) +{ + if (dpacl) + v9fs_set_acl(dentry, ACL_TYPE_DEFAULT, dpacl); + if (pacl) + v9fs_set_acl(dentry, ACL_TYPE_ACCESS, pacl); + posix_acl_release(dpacl); + posix_acl_release(pacl); + return 0; +} + +int v9fs_acl_mode(struct inode *dir, mode_t *modep, + struct posix_acl **dpacl, struct posix_acl **pacl) +{ + int retval = 0; + mode_t mode = *modep; + struct posix_acl *acl = NULL; + + if (!S_ISLNK(mode)) { + acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (!acl) + mode &= ~current_umask(); + } + if (acl) { + struct posix_acl *clone; + + if (S_ISDIR(mode)) + *dpacl = acl; + clone = posix_acl_clone(acl, GFP_NOFS); + retval = -ENOMEM; + if (!clone) + goto cleanup; + + retval = posix_acl_create_masq(clone, &mode); + if (retval < 0) { + posix_acl_release(clone); + goto cleanup; + } + if (retval > 0) + *pacl = clone; + } + *modep = mode; + return 0; +cleanup: + posix_acl_release(acl); + return retval; + +} + +static int v9fs_remote_get_acl(struct dentry *dentry, const char *name, + void *buffer, size_t size, int type) +{ + char *full_name; + + switch (type) { + case ACL_TYPE_ACCESS: + full_name = POSIX_ACL_XATTR_ACCESS; + break; + case ACL_TYPE_DEFAULT: + full_name = POSIX_ACL_XATTR_DEFAULT; + break; + default: + BUG(); + } + return v9fs_xattr_get(dentry, full_name, buffer, size); +} + +static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name, + void *buffer, size_t size, int type) +{ + struct v9fs_session_info *v9ses; + struct posix_acl *acl; + int error; + + if (strcmp(name, "") != 0) + return -EINVAL; + + v9ses = v9fs_inode2v9ses(dentry->d_inode); + /* + * We allow set/get/list of acl when access=client is not specified + */ + if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) + return v9fs_remote_get_acl(dentry, name, buffer, size, type); + + acl = v9fs_get_cached_acl(dentry->d_inode, type); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl == NULL) + return -ENODATA; + error = posix_acl_to_xattr(acl, buffer, size); + posix_acl_release(acl); + + return error; +} + +static int v9fs_remote_set_acl(struct dentry *dentry, const char *name, + const void *value, size_t size, + int flags, int type) +{ + char *full_name; + + switch (type) { + case ACL_TYPE_ACCESS: + full_name = POSIX_ACL_XATTR_ACCESS; + break; + case ACL_TYPE_DEFAULT: + full_name = POSIX_ACL_XATTR_DEFAULT; + break; + default: + BUG(); + } + return v9fs_xattr_set(dentry, full_name, value, size, flags); +} + + +static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name, + const void *value, size_t size, + int flags, int type) +{ + int retval; + struct posix_acl *acl; + struct v9fs_session_info *v9ses; + struct inode *inode = dentry->d_inode; + + if (strcmp(name, "") != 0) + return -EINVAL; + + v9ses = v9fs_inode2v9ses(dentry->d_inode); + /* + * set the attribute on the remote. Without even looking at the + * xattr value. We leave it to the server to validate + */ + if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) + return v9fs_remote_set_acl(dentry, name, + value, size, flags, type); + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + if (!is_owner_or_cap(inode)) + return -EPERM; + if (value) { + /* update the cached acl value */ + acl = posix_acl_from_xattr(value, size); + if (IS_ERR(acl)) + return PTR_ERR(acl); + else if (acl) { + retval = posix_acl_valid(acl); + if (retval) + goto err_out; + } + } else + acl = NULL; + + switch (type) { + case ACL_TYPE_ACCESS: + name = POSIX_ACL_XATTR_ACCESS; + if (acl) { + mode_t mode = inode->i_mode; + retval = posix_acl_equiv_mode(acl, &mode); + if (retval < 0) + goto err_out; + else { + struct iattr iattr; + if (retval == 0) { + /* + * ACL can be represented + * by the mode bits. So don't + * update ACL. + */ + acl = NULL; + value = NULL; + size = 0; + } + /* Updte the mode bits */ + iattr.ia_mode = ((mode & S_IALLUGO) | + (inode->i_mode & ~S_IALLUGO)); + iattr.ia_valid = ATTR_MODE; + /* FIXME should we update ctime ? + * What is the following setxattr update the + * mode ? + */ + v9fs_vfs_setattr_dotl(dentry, &iattr); + } + } + break; + case ACL_TYPE_DEFAULT: + name = POSIX_ACL_XATTR_DEFAULT; + if (!S_ISDIR(inode->i_mode)) { + retval = acl ? -EINVAL : 0; + goto err_out; + } + break; + default: + BUG(); + } + retval = v9fs_xattr_set(dentry, name, value, size, flags); + if (!retval) + set_cached_acl(inode, type, acl); +err_out: + posix_acl_release(acl); + return retval; +} + +const struct xattr_handler v9fs_xattr_acl_access_handler = { + .prefix = POSIX_ACL_XATTR_ACCESS, + .flags = ACL_TYPE_ACCESS, + .get = v9fs_xattr_get_acl, + .set = v9fs_xattr_set_acl, +}; + +const struct xattr_handler v9fs_xattr_acl_default_handler = { + .prefix = POSIX_ACL_XATTR_DEFAULT, + .flags = ACL_TYPE_DEFAULT, + .get = v9fs_xattr_get_acl, + .set = v9fs_xattr_set_acl, +}; |