// SPDX-License-Identifier: GPL-2.0
/*
* (C) 2001 Clemson University and The University of Chicago
* Copyright 2018 Omnibond Systems, L.L.C.
*
* See COPYING in top-level directory.
*/
/*
* Linux VFS extended attribute operations.
*/
#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
#include <linux/hashtable.h>
#define SYSTEM_ORANGEFS_KEY "system.pvfs2."
#define SYSTEM_ORANGEFS_KEY_LEN 13
/*
* this function returns
* 0 if the key corresponding to name is not meant to be printed as part
* of a listxattr.
* 1 if the key corresponding to name is meant to be returned as part of
* a listxattr.
* The ones that start SYSTEM_ORANGEFS_KEY are the ones to avoid printing.
*/
static int is_reserved_key(const char *key, size_t size)
{
if (size < SYSTEM_ORANGEFS_KEY_LEN)
return 1;
return strncmp(key, SYSTEM_ORANGEFS_KEY, SYSTEM_ORANGEFS_KEY_LEN) ? 1 : 0;
}
static inline int convert_to_internal_xattr_flags(int setxattr_flags)
{
int internal_flag = 0;
if (setxattr_flags & XATTR_REPLACE) {
/* Attribute must exist! */
internal_flag = ORANGEFS_XATTR_REPLACE;
} else if (setxattr_flags & XATTR_CREATE) {
/* Attribute must not exist */
internal_flag = ORANGEFS_XATTR_CREATE;
}
return internal_flag;
}
static unsigned int xattr_key(const char *key)
{
unsigned int i = 0;
while (key)
i += *key++;
return i % 16;
}
static struct orangefs_cached_xattr *find_cached_xattr(struct inode *inode,
const char *key)
{
struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
struct orangefs_cached_xattr *cx;
struct hlist_head *h;
struct hlist_node *tmp;
h = &orangefs_inode->xattr_cache[xattr_key(key)];
if (hlist_empty(h))
return NULL;
hlist_for_each_entry_safe(cx, tmp, h, node) {
/* if (!time_before(jiffies, cx->timeout)) {
hlist_del(&cx->node);
kfree(cx);
continue;
}*/
if (!strcmp(cx->key, key))
return cx;
}
return NULL;
}
/*
* Tries to get a specified key's attributes of a given
* file into a user-specified buffer. Note that the getxattr
* interface allows for the users to probe the size of an
* extended attribute by passing in a value of 0 to size.
* Thus our return value is always the size of the attribute
* unless the key does not exist for the file and/or if
* there were errors in fetching the attribute value.
*/
ssize_t orangefs_inode_getxattr(struct inode *inode, const char *name,
void *buffer, size_t size)
{
struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
struct orangefs_kernel_op_s *new_op = NULL;
struct orangefs_cached_xattr *cx;
ssize_t ret = -ENOMEM;
ssize_t length = 0;
int fsuid;
int fsgid;
gossip_debug(GOSSIP_XATTR_DEBUG,
"%s: name %s, buffer_size %zd\n",
__func__, name, size);
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
return -EINVAL;
fsuid = from_kuid(&init_user_ns, current_fsuid());
fsgid = from_kgid(&init_user_ns, current_fsgid());
gossip_debug(GOSSIP_XATTR_DEBUG,
"getxattr on inode %pU, name %s "
"(uid %o, gid %o)\n",
get_khandle_from_ino(inode),
name,
fsuid,
fsgid);
down_read(&orangefs_inode->xattr_sem);
cx = find_cached_xattr(inode, name);
if (cx && time_before(jiffies, cx->timeout)) {
if (cx->length == -1) {
ret = -ENODATA;
goto out_unlock;
} else {
if (size == 0) {
ret = cx->length;
goto out_unlock;
}
if (cx->length > size) {
ret = -ERANGE;
goto out_unlock;
}
memcpy(buffer, cx->val, cx->length);
memset(buffer + cx->length, 0, size - cx->length);
ret = cx->length;
goto out_unlock;
}
}
new_op = op_alloc(ORANGEFS_VFS_OP_GETXATTR);
if (!new_op)
goto out_unlock;
new_op->upcall.req.getxattr.refn = orangefs_inode->refn;
strcpy(new_op->upcall.req.getxattr.key, name);
/*
* NOTE: Although keys are meant to be NULL terminated textual
* strings, I am going to explicitly pass the length just in case
* we change this later on...
*/
new_op->upcall.req.getxattr.key_sz = strlen(name) + 1;
ret = service_operation(new_op, "orangefs_inode_getxattr",
get_interruptible_flag(inode));
if (ret != 0) {
if (ret == -ENOENT) {
ret = -ENODATA;
gossip_debug(GOSSIP_XATTR_DEBUG,
"orangefs_inode_getxattr: inode %pU key %s"
" does not exist!\n",
get_khandle_from_ino(inode),
(char *)new_op->upcall.req.getxattr.key);
cx = kmalloc(sizeof *cx, GFP_KERNEL);
if (cx) {
strcpy(cx->key, name);
cx->length = -1;
cx->timeout = jiffies +
orangefs_getattr_timeout_msecs*HZ/1000;
hash_add(orangefs_inode->xattr_cache, &cx->node,
xattr_key(cx->key));
}
}
goto out_release_op;
}
/*
* Length returned includes null terminator.
*/
length = new_op->downcall.resp.getxattr.val_sz;
/*
* Just return the length of the queried attribute.
*/
if (size == 0) {
ret = length;
goto out_release_op;
}
/*
* Check to see if key length is > provided buffer size.
*/
if (length > size) {
ret = -ERANGE;
goto out_release_op;
}
memcpy(buffer, new_op->downcall.resp.getxattr.val, length);
memset(buffer + length, 0, size - length);
gossip_debug(GOSSIP_XATTR_DEBUG,
"orangefs_inode_getxattr: inode %pU "
"key %s key_sz %d, val_len %d\n",
get_khandle_from_ino(inode),
(char *)new_op->
upcall.req.getxattr.key,
(int)new_op->
upcall.req.getxattr.key_sz,
(int)ret);
ret = length;
if (cx) {
strcpy(cx->key, name);
memcpy(cx->val, buffer, length);
cx->length = length;
cx->timeout = jiffies + HZ;
} else {
cx = kmalloc(sizeof *cx, GFP_KERNEL);
if (cx) {
strcpy(cx->key, name);
memcpy(cx->val, buffer, length);
cx->length = length;
cx->timeout = jiffies + HZ;
hash_add(orangefs_inode->xattr_cache, &cx->node,
xattr_key(cx->key));
}
}
out_release_op:
op_release(new_op);
out_unlock:
up_read(&orangefs_inode->xattr_sem);
return ret;
}
static int orangefs_inode_removexattr(struct inode *inode, const char *name,
int flags)
{
struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
struct orangefs_kernel_op_s *new_op = NULL;
struct orangefs_cached_xattr *cx;
struct hlist_head *h;
struct hlist_node *tmp;
int ret = -ENOMEM;
if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
return -EINVAL;
down_write(&orangefs_inode->xattr_sem);
new_op = op_alloc(ORANGEFS_VFS_OP_REMOVEXATTR);
if (!new_op)
goto out_unlock;
new_op->upcall.req.removexattr.refn = orangefs_inode->refn;
/*
* NOTE: Although keys are meant to be NULL terminated
* textual strings, I am going to explicitly pass the
* length just in case we change this later on...
*/
strcpy(new_op->upcall.req.removexattr.key, name);
new_op->upcall.req.removexattr.key_sz = strlen(name) + 1;
gossip_debug(GOSSIP_XATTR_DEBUG,
"orangefs_inode_removexattr: key %s, key_sz %d\n",
(char *)new_op->upcall.req.removexattr.key,
(int)new_op->upcall.req.removexattr.key_sz);
ret = service_operation(new_op,
"orangefs_inode_removexattr",
get_interruptible_flag(inode));
if (ret == -ENOENT) {
/*
* Request to replace a non-existent attribute is an error.
*/
if (flags & XATTR_REPLACE)
ret = -ENODATA;
else
ret = 0;
}
gossip_debug(GOSSIP_XATTR_DEBUG,
"orangefs_inode_removexattr: returning %d\n", ret);
op_release(new_op);
h = &orangefs_inode->xattr_cache[xattr_key(name)];
hlist_for_each_entry_safe(cx, tmp, h, node) {
if (!strcmp(cx->key, name)) {
hlist_del(&cx->node);
kfree(cx);
break;
}
}
out_unlock:
up_write(&orangefs_inode->xattr_sem);
return ret;
}
/*
* Tries to set an attribute for a given key on a file.
*
* Returns a -ve number on error and 0 on success. Key is text, but value
* can be binary!
*/
int orangefs_inode_setxattr(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
struct orangefs_kernel_op_s *new_op;
int internal_flag = 0;
struct orangefs_cached_xattr *cx;
struct hlist_head *h;
struct hlist_node *tmp;
int ret = -ENOMEM;
gossip_debug(GOSSIP_XATTR_DEBUG,
"%s: name %s, buffer_size %zd\n",
__func__, name, size);
if (size > ORANGEFS_MAX_XATTR_VALUELEN)
return -EINVAL;
if (strlen(name) >= ORANGEFS_MAX_XATTR_NAMELEN)
return -EINVAL;
internal_flag = convert_to_internal_xattr_flags(flags);
/* This is equivalent to a removexattr */
if (size == 0 && !value) {
gossip_debug(GOSSIP_XATTR_DEBUG,
"removing xattr (%s)\n",
name);
return orangefs_inode_removexattr(inode, name, flags);
}
gossip_debug(GOSSIP_XATTR_DEBUG,
"setxattr on inode %pU, name %s\n",
get_khandle_from_ino(inode),
name);
down_write(&orangefs_inode->xattr_sem);
new_op = op_alloc(ORANGEFS_VFS_OP_SETXATTR);
if (!new_op)
goto out_unlock;
new_op->upcall.req.setxattr.refn = orangefs_inode->refn;
new_op->upcall.req.setxattr.flags = internal_flag;
/*
* NOTE: Although keys are meant to be NULL terminated textual
* strings, I am going to explicitly pass the length just in
* case we change this later on...
*/
strcpy(new_op->upcall.req.setxattr.keyval.key, name);
new_op->upcall.req.setxattr.keyval.key_sz = strlen(name) + 1;
memcpy(new_op->upcall.req.setxattr.keyval.val, value, size);
new_op->upcall.req.setxattr.keyval.val_sz = size;
gossip_debug(GOSSIP_XATTR_DEBUG,
"orangefs_inode_setxattr: key %s, key_sz %d "
" value size %zd\n",
(char *)new_op->upcall.req.setxattr.keyval.key,
(int)new_op->upcall.req.setxattr.keyval.key_sz,
size);
ret = service_operation(new_op,
"orangefs_inode_setxattr",
get_interruptible_flag(inode));
gossip_debug(GOSSIP_XATTR_DEBUG,
"orangefs_inode_setxattr: returning %d\n",
ret);
/* when request is serviced properly, free req op struct */
op_release(new_op);
h = &orangefs_inode->xattr_cache[xattr_key(name)];
hlist_for_each_entry_safe(cx, tmp, h, node) {
if (!strcmp(cx->key, name)) {
hlist_del(&cx->node);
kfree(cx);
break;
}
}
out_unlock:
up_write(&orangefs_inode->xattr_sem);
return ret;
}
/*
* Tries to get a specified object's keys into a user-specified buffer of a
* given size. Note that like the previous instances of xattr routines, this
* also allows you to pass in a NULL pointer and 0 size to probe the size for
* subsequent memory allocations. Thus our return value is always the size of
* all the keys unless there were errors in fetching the keys!
*/
ssize_t orangefs_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct inode *inode = dentry->d_inode;
struct orangefs_inode_s *orangefs_inode = ORANGEFS_I(inode);
struct orangefs_kernel_op_s *new_op;
__u64 token = ORANGEFS_ITERATE_START;
ssize_t ret = -ENOMEM;
ssize_t total = 0;
int count_keys = 0;
int key_size;
int i = 0;
int returned_count = 0;
if (size > 0 && !buffer) {
gossip_err("%s: bogus NULL pointers\n", __func__);
return -EINVAL;
}
down_read(&orangefs_inode->xattr_sem);
new_op = op_alloc(ORANGEFS_VFS_OP_LISTXATTR);
if (!new_op)
goto out_unlock;
if (buffer && size > 0)
memset(buffer, 0, size);
try_again:
key_size = 0;
new_op->upcall.req.listxattr.refn = orangefs_inode->refn;
new_op->upcall.req.listxattr.token = token;
new_op->upcall.req.listxattr.requested_count =
(size == 0) ? 0 : ORANGEFS_MAX_XATTR_LISTLEN;
ret = service_operation(new_op, __func__,
get_interruptible_flag(inode));
if (ret != 0)
goto done;
if (size == 0) {
/*
* This is a bit of a big upper limit, but I did not want to
* spend too much time getting this correct, since users end
* up allocating memory rather than us...
*/
total = new_op->downcall.resp.listxattr.returned_count *
ORANGEFS_MAX_XATTR_NAMELEN;
goto done;
}
returned_count = new_op->downcall.resp.listxattr.returned_count;
if (returned_count < 0 ||
returned_count > ORANGEFS_MAX_XATTR_LISTLEN) {
gossip_err("%s: impossible value for returned_count:%d:\n",
__func__,
returned_count);
ret = -EIO;
goto done;
}
/*
* Check to see how much can be fit in the buffer. Fit only whole keys.
*/
for (i = 0; i < returned_count; i++) {
if (new_op->downcall.resp.listxattr.lengths[i] < 0 ||
new_op->downcall.resp.listxattr.lengths[i] >
ORANGEFS_MAX_XATTR_NAMELEN) {
gossip_err("%s: impossible value for lengths[%d]\n",
__func__,
new_op->downcall.resp.listxattr.lengths[i]);
ret = -EIO;
goto done;
}
if (total + new_op->downcall.resp.listxattr.lengths[i] > size)
goto done;
/*
* Since many dumb programs try to setxattr() on our reserved
* xattrs this is a feeble attempt at defeating those by not
* listing them in the output of listxattr.. sigh
*/
if (is_reserved_key(new_op->downcall.resp.listxattr.key +
key_size,
new_op->downcall.resp.
listxattr.lengths[i])) {
gossip_debug(GOSSIP_XATTR_DEBUG, "Copying key %d -> %s\n",
i, new_op->downcall.resp.listxattr.key +
key_size);
memcpy(buffer + total,
new_op->downcall.resp.listxattr.key + key_size,
new_op->downcall.resp.listxattr.lengths[i]);
total += new_op->downcall.resp.listxattr.lengths[i];
count_keys++;
} else {
gossip_debug(GOSSIP_XATTR_DEBUG, "[RESERVED] key %d -> %s\n",
i, new_op->downcall.resp.listxattr.key +
key_size);
}
key_size += new_op->downcall.resp.listxattr.lengths[i];
}
/*
* Since the buffer was large enough, we might have to continue
* fetching more keys!
*/
token = new_op->downcall.resp.listxattr.token;
if (token != ORANGEFS_ITERATE_END)
goto try_again;
done:
gossip_debug(GOSSIP_XATTR_DEBUG, "%s: returning %d"
" [size of buffer %ld] (filled in %d keys)\n",
__func__,
ret ? (int)ret : (int)total,
(long)size,
count_keys);
op_release(new_op);
if (ret == 0)
ret = total;
out_unlock:
up_read(&orangefs_inode->xattr_sem);
return ret;
}
static int orangefs_xattr_set_default(const struct xattr_handler *handler,
struct mnt_idmap *idmap,
struct dentry *unused,
struct inode *inode,
const char *name,
const void *buffer,
size_t size,
int flags)
{
return orangefs_inode_setxattr(inode, name, buffer, size, flags);
}
static int orangefs_xattr_get_default(const struct xattr_handler *handler,
struct dentry *unused,
struct inode *inode,
const char *name,
void *buffer,
size_t size)
{
return orangefs_inode_getxattr(inode, name, buffer, size);
}
static const struct xattr_handler orangefs_xattr_default_handler = {
.prefix = "", /* match any name => handlers called with full name */
.get = orangefs_xattr_get_default,
.set = orangefs_xattr_set_default,
};
const struct xattr_handler * const orangefs_xattr_handlers[] = {
&orangefs_xattr_default_handler,
NULL
};
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