xemu/hw/9pfs/9p-xattr-user.c
Christian Schoenebeck 6f56908427 9pfs: add link to 9p developer docs
To lower the entry level for new developers, add a link to the 9p
developer docs (i.e. qemu wiki) to MAINTAINERS and to the beginning of
9p source files, that is to: https://wiki.qemu.org/Documentation/9p

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Acked-by: Greg Kurz <groug@kaod.org>
Message-Id: <E1leeDf-0008GZ-9q@lizzy.crudebyte.com>
2021-07-05 13:03:16 +02:00

115 lines
2.9 KiB
C

/*
* 9p user. xattr callback
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
/*
* Not so fast! You might want to read the 9p developer docs first:
* https://wiki.qemu.org/Documentation/9p
*/
#include "qemu/osdep.h"
#include "9p.h"
#include "fsdev/file-op-9p.h"
#include "9p-xattr.h"
static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
const char *name, void *value, size_t size)
{
if (strncmp(name, "user.virtfs.", 12) == 0) {
/*
* Don't allow fetch of user.virtfs namesapce
* in case of mapped security
*/
errno = ENOATTR;
return -1;
}
return local_getxattr_nofollow(ctx, path, name, value, size);
}
static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
char *name, void *value, size_t size)
{
int name_size = strlen(name) + 1;
if (strncmp(name, "user.virtfs.", 12) == 0) {
/* check if it is a mapped posix acl */
if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) {
/* adjust the name and size */
name += 12;
name_size -= 12;
} else {
/*
* Don't allow fetch of user.virtfs namesapce
* in case of mapped security
*/
return 0;
}
}
if (!value) {
return name_size;
}
if (size < name_size) {
errno = ERANGE;
return -1;
}
/* name_size includes the trailing NUL. */
memcpy(value, name, name_size);
return name_size;
}
static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
void *value, size_t size, int flags)
{
if (strncmp(name, "user.virtfs.", 12) == 0) {
/*
* Don't allow fetch of user.virtfs namesapce
* in case of mapped security
*/
errno = EACCES;
return -1;
}
return local_setxattr_nofollow(ctx, path, name, value, size, flags);
}
static int mp_user_removexattr(FsContext *ctx,
const char *path, const char *name)
{
if (strncmp(name, "user.virtfs.", 12) == 0) {
/*
* Don't allow fetch of user.virtfs namesapce
* in case of mapped security
*/
errno = EACCES;
return -1;
}
return local_removexattr_nofollow(ctx, path, name);
}
XattrOperations mapped_user_xattr = {
.name = "user.",
.getxattr = mp_user_getxattr,
.setxattr = mp_user_setxattr,
.listxattr = mp_user_listxattr,
.removexattr = mp_user_removexattr,
};
XattrOperations passthrough_user_xattr = {
.name = "user.",
.getxattr = pt_getxattr,
.setxattr = pt_setxattr,
.listxattr = pt_listxattr,
.removexattr = pt_removexattr,
};