diff options
Diffstat (limited to 'fs/xfs/xfs_xattr.c')
| -rw-r--r-- | fs/xfs/xfs_xattr.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c new file mode 100644 index 00000000000..87d3e03878c --- /dev/null +++ b/fs/xfs/xfs_xattr.c @@ -0,0 +1,241 @@ +/* + * Copyright (C) 2008 Christoph Hellwig. + * Portions Copyright (C) 2000-2008 Silicon Graphics, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU 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. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "xfs.h" +#include "xfs_da_btree.h" +#include "xfs_bmap_btree.h" +#include "xfs_inode.h" +#include "xfs_attr.h" +#include "xfs_attr_leaf.h" +#include "xfs_acl.h" +#include "xfs_vnodeops.h" + +#include <linux/posix_acl_xattr.h> +#include <linux/xattr.h> + + +static int +xfs_xattr_get(struct dentry *dentry, const char *name, + void *value, size_t size, int xflags) +{ + struct xfs_inode *ip = XFS_I(dentry->d_inode); + int error, asize = size; + + if (strcmp(name, "") == 0) + return -EINVAL; + + /* 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; +} + +static int +xfs_xattr_set(struct dentry *dentry, const char *name, const void *value, + size_t size, int flags, int xflags) +{ + struct xfs_inode *ip = XFS_I(dentry->d_inode); + + if (strcmp(name, "") == 0) + return -EINVAL; + + /* 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); + return -xfs_attr_set(ip, (unsigned char *)name, + (void *)value, size, xflags); +} + +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 + &xfs_xattr_acl_access_handler, + &xfs_xattr_acl_default_handler, +#endif + NULL +}; + +static unsigned int xfs_xattr_prefix_len(int flags) +{ + if (flags & XFS_ATTR_SECURE) + return sizeof("security"); + else if (flags & XFS_ATTR_ROOT) + return sizeof("trusted"); + else + return sizeof("user"); +} + +static const char *xfs_xattr_prefix(int flags) +{ + if (flags & XFS_ATTR_SECURE) + return xfs_xattr_security_handler.prefix; + else if (flags & XFS_ATTR_ROOT) + return xfs_xattr_trusted_handler.prefix; + else + return xfs_xattr_user_handler.prefix; +} + +static int +xfs_xattr_put_listent( + struct xfs_attr_list_context *context, + int flags, + unsigned char *name, + int namelen, + int valuelen, + unsigned char *value) +{ + unsigned int prefix_len = xfs_xattr_prefix_len(flags); + char *offset; + int arraytop; + + ASSERT(context->count >= 0); + + /* + * Only show root namespace entries if we are actually allowed to + * see them. + */ + if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN)) + return 0; + + arraytop = context->count + prefix_len + namelen + 1; + if (arraytop > context->firstu) { + context->count = -1; /* insufficient space */ + return 1; + } + offset = (char *)context->alist + context->count; + strncpy(offset, xfs_xattr_prefix(flags), prefix_len); + offset += prefix_len; + strncpy(offset, (char *)name, namelen); /* real name */ + offset += namelen; + *offset = '\0'; + context->count += prefix_len + namelen + 1; + return 0; +} + +static int +xfs_xattr_put_listent_sizes( + struct xfs_attr_list_context *context, + int flags, + unsigned char *name, + int namelen, + int valuelen, + unsigned char *value) +{ + context->count += xfs_xattr_prefix_len(flags) + namelen + 1; + return 0; +} + +static int +list_one_attr(const char *name, const size_t len, void *data, + size_t size, ssize_t *result) +{ + char *p = data + *result; + + *result += len; + if (!size) + return 0; + if (*result > size) + return -ERANGE; + + strcpy(p, name); + return 0; +} + +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 = dentry->d_inode; + 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 = data; + context.bufsize = size; + context.firstu = context.bufsize; + + if (size) + context.put_listent = xfs_xattr_put_listent; + else + context.put_listent = xfs_xattr_put_listent_sizes; + + xfs_attr_list_int(&context); + if (context.count < 0) + return -ERANGE; + + /* + * Then add the two synthetic ACL attributes. + */ + if (posix_acl_access_exists(inode)) { + error = list_one_attr(POSIX_ACL_XATTR_ACCESS, + strlen(POSIX_ACL_XATTR_ACCESS) + 1, + data, size, &context.count); + if (error) + return error; + } + + if (posix_acl_default_exists(inode)) { + error = list_one_attr(POSIX_ACL_XATTR_DEFAULT, + strlen(POSIX_ACL_XATTR_DEFAULT) + 1, + data, size, &context.count); + if (error) + return error; + } + + return context.count; +} |