1 files changed, 491 insertions, 0 deletions
diff --git a/fs/smb/client/xattr.c b/fs/smb/client/xattr.c
new file mode 100644
index 000000000000..4ad5531686d8
--- /dev/null
+++ b/fs/smb/client/xattr.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ *
+ *   Copyright (c) International Business Machines  Corp., 2003, 2007
+ *   Author(s): Steve French (sfrench@us.ibm.com)
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+#include "cifsfs.h"
+#include "cifspdu.h"
+#include "cifsglob.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+#include "cifs_fs_sb.h"
+#include "cifs_unicode.h"
+#include "cifs_ioctl.h"
+
+#define MAX_EA_VALUE_SIZE CIFSMaxBufSize
+#define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
+#define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
+#define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
+#define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
+#define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
+/*
+ * Although these three are just aliases for the above, need to move away from
+ * confusing users and using the 20+ year old term 'cifs' when it is no longer
+ * secure, replaced by SMB2 (then even more highly secure SMB3) many years ago
+ */
+#define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
+#define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
+#define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
+#define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
+#define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
+/* BB need to add server (Samba e.g) support for security and trusted prefix */
+
+enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
+	XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
+
+static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
+			   struct inode *inode, const char *full_path,
+			   const void *value, size_t size)
+{
+	ssize_t rc = -EOPNOTSUPP;
+	__u32 *pattrib = (__u32 *)value;
+	__u32 attrib;
+	FILE_BASIC_INFO info_buf;
+
+	if ((value == NULL) || (size != sizeof(__u32)))
+		return -ERANGE;
+
+	memset(&info_buf, 0, sizeof(info_buf));
+	attrib = *pattrib;
+	info_buf.Attributes = cpu_to_le32(attrib);
+	if (pTcon->ses->server->ops->set_file_info)
+		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
+				&info_buf, xid);
+	if (rc == 0)
+		CIFS_I(inode)->cifsAttrs = attrib;
+
+	return rc;
+}
+
+static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
+				  struct inode *inode, const char *full_path,
+				  const void *value, size_t size)
+{
+	ssize_t rc = -EOPNOTSUPP;
+	__u64 *pcreation_time = (__u64 *)value;
+	__u64 creation_time;
+	FILE_BASIC_INFO info_buf;
+
+	if ((value == NULL) || (size != sizeof(__u64)))
+		return -ERANGE;
+
+	memset(&info_buf, 0, sizeof(info_buf));
+	creation_time = *pcreation_time;
+	info_buf.CreationTime = cpu_to_le64(creation_time);
+	if (pTcon->ses->server->ops->set_file_info)
+		rc = pTcon->ses->server->ops->set_file_info(inode, full_path,
+				&info_buf, xid);
+	if (rc == 0)
+		CIFS_I(inode)->createtime = creation_time;
+
+	return rc;
+}
+
+static int cifs_xattr_set(const struct xattr_handler *handler,
+			  struct mnt_idmap *idmap,
+			  struct dentry *dentry, struct inode *inode,
+			  const char *name, const void *value,
+			  size_t size, int flags)
+{
+	int rc = -EOPNOTSUPP;
+	unsigned int xid;
+	struct super_block *sb = dentry->d_sb;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+	struct tcon_link *tlink;
+	struct cifs_tcon *pTcon;
+	const char *full_path;
+	void *page;
+
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	pTcon = tlink_tcon(tlink);
+
+	xid = get_xid();
+	page = alloc_dentry_path();
+
+	full_path = build_path_from_dentry(dentry, page);
+	if (IS_ERR(full_path)) {
+		rc = PTR_ERR(full_path);
+		goto out;
+	}
+	/* return dos attributes as pseudo xattr */
+	/* return alt name if available as pseudo attr */
+
+	/* if proc/fs/cifs/streamstoxattr is set then
+		search server for EAs or streams to
+		returns as xattrs */
+	if (size > MAX_EA_VALUE_SIZE) {
+		cifs_dbg(FYI, "size of EA value too large\n");
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+
+	switch (handler->flags) {
+	case XATTR_USER:
+		cifs_dbg(FYI, "%s:setting user xattr %s\n", __func__, name);
+		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
+		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
+			rc = cifs_attrib_set(xid, pTcon, inode, full_path,
+					value, size);
+			if (rc == 0) /* force revalidate of the inode */
+				CIFS_I(inode)->time = 0;
+			break;
+		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
+			   (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
+			rc = cifs_creation_time_set(xid, pTcon, inode,
+					full_path, value, size);
+			if (rc == 0) /* force revalidate of the inode */
+				CIFS_I(inode)->time = 0;
+			break;
+		}
+
+		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
+			goto out;
+
+		if (pTcon->ses->server->ops->set_EA)
+			rc = pTcon->ses->server->ops->set_EA(xid, pTcon,
+				full_path, name, value, (__u16)size,
+				cifs_sb->local_nls, cifs_sb);
+		break;
+
+	case XATTR_CIFS_ACL:
+	case XATTR_CIFS_NTSD:
+	case XATTR_CIFS_NTSD_FULL: {
+		struct cifs_ntsd *pacl;
+
+		if (!value)
+			goto out;
+		pacl = kmalloc(size, GFP_KERNEL);
+		if (!pacl) {
+			rc = -ENOMEM;
+		} else {
+			memcpy(pacl, value, size);
+			if (pTcon->ses->server->ops->set_acl) {
+				int aclflags = 0;
+				rc = 0;
+
+				switch (handler->flags) {
+				case XATTR_CIFS_NTSD_FULL:
+					aclflags = (CIFS_ACL_OWNER |
+						    CIFS_ACL_GROUP |
+						    CIFS_ACL_DACL |
+						    CIFS_ACL_SACL);
+					break;
+				case XATTR_CIFS_NTSD:
+					aclflags = (CIFS_ACL_OWNER |
+						    CIFS_ACL_GROUP |
+						    CIFS_ACL_DACL);
+					break;
+				case XATTR_CIFS_ACL:
+				default:
+					aclflags = CIFS_ACL_DACL;
+				}
+
+				rc = pTcon->ses->server->ops->set_acl(pacl,
+					size, inode, full_path, aclflags);
+			} else {
+				rc = -EOPNOTSUPP;
+			}
+			if (rc == 0) /* force revalidate of the inode */
+				CIFS_I(inode)->time = 0;
+			kfree(pacl);
+		}
+		break;
+	}
+	}
+
+out:
+	free_dentry_path(page);
+	free_xid(xid);
+	cifs_put_tlink(tlink);
+	return rc;
+}
+
+static int cifs_attrib_get(struct dentry *dentry,
+			   struct inode *inode, void *value,
+			   size_t size)
+{
+	ssize_t rc;
+	__u32 *pattribute;
+
+	rc = cifs_revalidate_dentry_attr(dentry);
+
+	if (rc)
+		return rc;
+
+	if ((value == NULL) || (size == 0))
+		return sizeof(__u32);
+	else if (size < sizeof(__u32))
+		return -ERANGE;
+
+	/* return dos attributes as pseudo xattr */
+	pattribute = (__u32 *)value;
+	*pattribute = CIFS_I(inode)->cifsAttrs;
+
+	return sizeof(__u32);
+}
+
+static int cifs_creation_time_get(struct dentry *dentry, struct inode *inode,
+				  void *value, size_t size)
+{
+	ssize_t rc;
+	__u64 *pcreatetime;
+
+	rc = cifs_revalidate_dentry_attr(dentry);
+	if (rc)
+		return rc;
+
+	if ((value == NULL) || (size == 0))
+		return sizeof(__u64);
+	else if (size < sizeof(__u64))
+		return -ERANGE;
+
+	/* return dos attributes as pseudo xattr */
+	pcreatetime = (__u64 *)value;
+	*pcreatetime = CIFS_I(inode)->createtime;
+	return sizeof(__u64);
+}
+
+
+static int cifs_xattr_get(const struct xattr_handler *handler,
+			  struct dentry *dentry, struct inode *inode,
+			  const char *name, void *value, size_t size)
+{
+	ssize_t rc = -EOPNOTSUPP;
+	unsigned int xid;
+	struct super_block *sb = dentry->d_sb;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+	struct tcon_link *tlink;
+	struct cifs_tcon *pTcon;
+	const char *full_path;
+	void *page;
+
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	pTcon = tlink_tcon(tlink);
+
+	xid = get_xid();
+	page = alloc_dentry_path();
+
+	full_path = build_path_from_dentry(dentry, page);
+	if (IS_ERR(full_path)) {
+		rc = PTR_ERR(full_path);
+		goto out;
+	}
+
+	/* return alt name if available as pseudo attr */
+	switch (handler->flags) {
+	case XATTR_USER:
+		cifs_dbg(FYI, "%s:querying user xattr %s\n", __func__, name);
+		if ((strcmp(name, CIFS_XATTR_ATTRIB) == 0) ||
+		    (strcmp(name, SMB3_XATTR_ATTRIB) == 0)) {
+			rc = cifs_attrib_get(dentry, inode, value, size);
+			break;
+		} else if ((strcmp(name, CIFS_XATTR_CREATETIME) == 0) ||
+		    (strcmp(name, SMB3_XATTR_CREATETIME) == 0)) {
+			rc = cifs_creation_time_get(dentry, inode, value, size);
+			break;
+		}
+
+		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
+			goto out;
+
+		if (pTcon->ses->server->ops->query_all_EAs)
+			rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
+				full_path, name, value, size, cifs_sb);
+		break;
+
+	case XATTR_CIFS_ACL:
+	case XATTR_CIFS_NTSD:
+	case XATTR_CIFS_NTSD_FULL: {
+		/*
+		 * fetch owner, DACL, and SACL if asked for full descriptor,
+		 * fetch owner and DACL otherwise
+		 */
+		u32 acllen, extra_info;
+		struct cifs_ntsd *pacl;
+
+		if (pTcon->ses->server->ops->get_acl == NULL)
+			goto out; /* rc already EOPNOTSUPP */
+
+		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
+			extra_info = SACL_SECINFO;
+		} else {
+			extra_info = 0;
+		}
+		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
+				inode, full_path, &acllen, extra_info);
+		if (IS_ERR(pacl)) {
+			rc = PTR_ERR(pacl);
+			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
+				 __func__, rc);
+		} else {
+			if (value) {
+				if (acllen > size)
+					acllen = -ERANGE;
+				else
+					memcpy(value, pacl, acllen);
+			}
+			rc = acllen;
+			kfree(pacl);
+		}
+		break;
+	}
+	}
+
+	/* We could add an additional check for streams ie
+	    if proc/fs/cifs/streamstoxattr is set then
+		search server for EAs or streams to
+		returns as xattrs */
+
+	if (rc == -EINVAL)
+		rc = -EOPNOTSUPP;
+
+out:
+	free_dentry_path(page);
+	free_xid(xid);
+	cifs_put_tlink(tlink);
+	return rc;
+}
+
+ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
+{
+	ssize_t rc = -EOPNOTSUPP;
+	unsigned int xid;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
+	struct tcon_link *tlink;
+	struct cifs_tcon *pTcon;
+	const char *full_path;
+	void *page;
+
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
+		return -EOPNOTSUPP;
+
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	pTcon = tlink_tcon(tlink);
+
+	xid = get_xid();
+	page = alloc_dentry_path();
+
+	full_path = build_path_from_dentry(direntry, page);
+	if (IS_ERR(full_path)) {
+		rc = PTR_ERR(full_path);
+		goto list_ea_exit;
+	}
+	/* return dos attributes as pseudo xattr */
+	/* return alt name if available as pseudo attr */
+
+	/* if proc/fs/cifs/streamstoxattr is set then
+		search server for EAs or streams to
+		returns as xattrs */
+
+	if (pTcon->ses->server->ops->query_all_EAs)
+		rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
+				full_path, NULL, data, buf_size, cifs_sb);
+list_ea_exit:
+	free_dentry_path(page);
+	free_xid(xid);
+	cifs_put_tlink(tlink);
+	return rc;
+}
+
+static const struct xattr_handler cifs_user_xattr_handler = {
+	.prefix = XATTR_USER_PREFIX,
+	.flags = XATTR_USER,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+/* os2.* attributes are treated like user.* attributes */
+static const struct xattr_handler cifs_os2_xattr_handler = {
+	.prefix = XATTR_OS2_PREFIX,
+	.flags = XATTR_USER,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+static const struct xattr_handler cifs_cifs_acl_xattr_handler = {
+	.name = CIFS_XATTR_CIFS_ACL,
+	.flags = XATTR_CIFS_ACL,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+/*
+ * Although this is just an alias for the above, need to move away from
+ * confusing users and using the 20 year old term 'cifs' when it is no
+ * longer secure and was replaced by SMB2/SMB3 a long time ago, and
+ * SMB3 and later are highly secure.
+ */
+static const struct xattr_handler smb3_acl_xattr_handler = {
+	.name = SMB3_XATTR_CIFS_ACL,
+	.flags = XATTR_CIFS_ACL,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+static const struct xattr_handler cifs_cifs_ntsd_xattr_handler = {
+	.name = CIFS_XATTR_CIFS_NTSD,
+	.flags = XATTR_CIFS_NTSD,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+/*
+ * Although this is just an alias for the above, need to move away from
+ * confusing users and using the 20 year old term 'cifs' when it is no
+ * longer secure and was replaced by SMB2/SMB3 a long time ago, and
+ * SMB3 and later are highly secure.
+ */
+static const struct xattr_handler smb3_ntsd_xattr_handler = {
+	.name = SMB3_XATTR_CIFS_NTSD,
+	.flags = XATTR_CIFS_NTSD,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
+	.name = CIFS_XATTR_CIFS_NTSD_FULL,
+	.flags = XATTR_CIFS_NTSD_FULL,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+/*
+ * Although this is just an alias for the above, need to move away from
+ * confusing users and using the 20 year old term 'cifs' when it is no
+ * longer secure and was replaced by SMB2/SMB3 a long time ago, and
+ * SMB3 and later are highly secure.
+ */
+static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
+	.name = SMB3_XATTR_CIFS_NTSD_FULL,
+	.flags = XATTR_CIFS_NTSD_FULL,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+const struct xattr_handler *cifs_xattr_handlers[] = {
+	&cifs_user_xattr_handler,
+	&cifs_os2_xattr_handler,
+	&cifs_cifs_acl_xattr_handler,
+	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
+	&cifs_cifs_ntsd_xattr_handler,
+	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
+	&cifs_cifs_ntsd_full_xattr_handler,
+	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
+	NULL
+};