diff options
Diffstat (limited to 'fs/xfs/xfs_xattr.c')
| -rw-r--r-- | fs/xfs/xfs_xattr.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c new file mode 100644 index 000000000..9a6301600 --- /dev/null +++ b/fs/xfs/xfs_xattr.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2008 Christoph Hellwig. + * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc. + */ + +#include "xfs.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_mount.h" +#include "xfs_da_format.h" +#include "xfs_inode.h" +#include "xfs_attr.h" +#include "xfs_attr_leaf.h" +#include "xfs_acl.h" + +#include <linux/posix_acl_xattr.h> +#include <linux/xattr.h> + + +static int +xfs_xattr_get(const struct xattr_handler *handler, struct dentry *unused, + struct inode *inode, const char *name, void *value, size_t size) +{ + int xflags = handler->flags; + struct xfs_inode *ip = XFS_I(inode); + int error, asize = size; + + /* Convert Linux syscall to XFS internal ATTR flags */ + if (!size) { + xflags |= ATTR_KERNOVAL; + value = NULL; + } + + error = xfs_attr_get(ip, (unsigned char *)name, value, &asize, xflags); + if (error) + return error; + return asize; +} + +void +xfs_forget_acl( + struct inode *inode, + const char *name, + int xflags) +{ + /* + * Invalidate any cached ACLs if the user has bypassed the ACL + * interface. We don't validate the content whatsoever so it is caller + * responsibility to provide data in valid format and ensure i_mode is + * consistent. + */ + if (xflags & ATTR_ROOT) { +#ifdef CONFIG_XFS_POSIX_ACL + if (!strcmp(name, SGI_ACL_FILE)) + forget_cached_acl(inode, ACL_TYPE_ACCESS); + else if (!strcmp(name, SGI_ACL_DEFAULT)) + forget_cached_acl(inode, ACL_TYPE_DEFAULT); +#endif + } +} + +static int +xfs_xattr_set(const struct xattr_handler *handler, struct dentry *unused, + struct inode *inode, const char *name, const void *value, + size_t size, int flags) +{ + int xflags = handler->flags; + struct xfs_inode *ip = XFS_I(inode); + int error; + + /* Convert Linux syscall to XFS internal ATTR flags */ + if (flags & XATTR_CREATE) + xflags |= ATTR_CREATE; + if (flags & XATTR_REPLACE) + xflags |= ATTR_REPLACE; + + if (!value) + return xfs_attr_remove(ip, (unsigned char *)name, xflags); + error = xfs_attr_set(ip, (unsigned char *)name, + (void *)value, size, xflags); + if (!error) + xfs_forget_acl(inode, name, xflags); + + return error; +} + +static const struct xattr_handler xfs_xattr_user_handler = { + .prefix = XATTR_USER_PREFIX, + .flags = 0, /* no flags implies user namespace */ + .get = xfs_xattr_get, + .set = xfs_xattr_set, +}; + +static const struct xattr_handler xfs_xattr_trusted_handler = { + .prefix = XATTR_TRUSTED_PREFIX, + .flags = ATTR_ROOT, + .get = xfs_xattr_get, + .set = xfs_xattr_set, +}; + +static const struct xattr_handler xfs_xattr_security_handler = { + .prefix = XATTR_SECURITY_PREFIX, + .flags = ATTR_SECURE, + .get = xfs_xattr_get, + .set = xfs_xattr_set, +}; + +const struct xattr_handler *xfs_xattr_handlers[] = { + &xfs_xattr_user_handler, + &xfs_xattr_trusted_handler, + &xfs_xattr_security_handler, +#ifdef CONFIG_XFS_POSIX_ACL + &posix_acl_access_xattr_handler, + &posix_acl_default_xattr_handler, +#endif + NULL +}; + +static void +__xfs_xattr_put_listent( + struct xfs_attr_list_context *context, + char *prefix, + int prefix_len, + unsigned char *name, + int namelen) +{ + char *offset; + int arraytop; + + if (context->count < 0 || context->seen_enough) + return; + + if (!context->alist) + goto compute_size; + + arraytop = context->count + prefix_len + namelen + 1; + if (arraytop > context->firstu) { + context->count = -1; /* insufficient space */ + context->seen_enough = 1; + return; + } + offset = (char *)context->alist + context->count; + strncpy(offset, prefix, prefix_len); + offset += prefix_len; + strncpy(offset, (char *)name, namelen); /* real name */ + offset += namelen; + *offset = '\0'; + +compute_size: + context->count += prefix_len + namelen + 1; + return; +} + +static void +xfs_xattr_put_listent( + struct xfs_attr_list_context *context, + int flags, + unsigned char *name, + int namelen, + int valuelen) +{ + char *prefix; + int prefix_len; + + ASSERT(context->count >= 0); + + if (flags & XFS_ATTR_ROOT) { +#ifdef CONFIG_XFS_POSIX_ACL + if (namelen == SGI_ACL_FILE_SIZE && + strncmp(name, SGI_ACL_FILE, + SGI_ACL_FILE_SIZE) == 0) { + __xfs_xattr_put_listent( + context, XATTR_SYSTEM_PREFIX, + XATTR_SYSTEM_PREFIX_LEN, + XATTR_POSIX_ACL_ACCESS, + strlen(XATTR_POSIX_ACL_ACCESS)); + } else if (namelen == SGI_ACL_DEFAULT_SIZE && + strncmp(name, SGI_ACL_DEFAULT, + SGI_ACL_DEFAULT_SIZE) == 0) { + __xfs_xattr_put_listent( + context, XATTR_SYSTEM_PREFIX, + XATTR_SYSTEM_PREFIX_LEN, + XATTR_POSIX_ACL_DEFAULT, + strlen(XATTR_POSIX_ACL_DEFAULT)); + } +#endif + + /* + * Only show root namespace entries if we are actually allowed to + * see them. + */ + if (!capable(CAP_SYS_ADMIN)) + return; + + prefix = XATTR_TRUSTED_PREFIX; + prefix_len = XATTR_TRUSTED_PREFIX_LEN; + } else if (flags & XFS_ATTR_SECURE) { + prefix = XATTR_SECURITY_PREFIX; + prefix_len = XATTR_SECURITY_PREFIX_LEN; + } else { + prefix = XATTR_USER_PREFIX; + prefix_len = XATTR_USER_PREFIX_LEN; + } + + __xfs_xattr_put_listent(context, prefix, prefix_len, name, + namelen); + return; +} + +ssize_t +xfs_vn_listxattr( + struct dentry *dentry, + char *data, + size_t size) +{ + struct xfs_attr_list_context context; + struct attrlist_cursor_kern cursor = { 0 }; + struct inode *inode = d_inode(dentry); + int error; + + /* + * First read the regular on-disk attributes. + */ + memset(&context, 0, sizeof(context)); + context.dp = XFS_I(inode); + context.cursor = &cursor; + context.resynch = 1; + context.alist = size ? data : NULL; + context.bufsize = size; + context.firstu = context.bufsize; + context.put_listent = xfs_xattr_put_listent; + + error = xfs_attr_list_int(&context); + if (error) + return error; + if (context.count < 0) + return -ERANGE; + + return context.count; +} |