smb: client: fix xattrxattr

WIP

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>

2 files changed, 55 insertions, 6 deletions

diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index 20dc31a07a56..82fba942bbcd 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -1022,10 +1022,9 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 		}
 		break;
 	case Opt_user_xattr:
-		if (result.negated)
-			ctx->no_xattr = 1;
-		else
-			ctx->no_xattr = 0;
+		ctx->no_xattr = result.negated;
+		if (!ctx->no_xattr)
+			pr_warn_once("CIFS: Extended Attributes names are limited to 127 characters\n");
 		break;
 	case Opt_forceuid:
 		if (result.negated)
diff --git a/fs/smb/client/xattr.c b/fs/smb/client/xattr.c
index 6780aa3e98a1..6242c3643b39 100644
--- a/fs/smb/client/xattr.c
+++ b/fs/smb/client/xattr.c
@@ -88,6 +88,42 @@ static int cifs_creation_time_set(unsigned int xid, struct cifs_tcon *pTcon,
 	return rc;
 }
 
+static char *xattr_encode_name(const char *name)
+{
+	const char forbidden[] = "\\/:*?\"<>|,+=[];";
+	char *new, *p;
+	size_t len = strlen(name);
+	int i, j;
+
+	if (len > 127)
+		return ERR_PTR(-EINVAL);
+
+	for (i = 0; i < sizeof(forbidden); i++)
+		for (j = 0; j < len; j++)
+			if (name[j] == forbidden[i])
+				return ERR_PTR(-EINVAL);
+
+	for (i = 0; i < 0x20; i++)
+		for (j = 0; j < len; j++)
+			if (name[j] == i)
+				return ERR_PTR(-EINVAL);
+
+	new = kzalloc(len * 2 + 1, GFP_KERNEL);
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+
+	p = new;
+	for (i = 0; i < len; i++)
+		p += snprintf(p, 3, "%02X", name[i]);
+
+	return new;
+}
+
+static char *xattr_decode_name(const char *name)
+{
+	num_to_str(&name[i]...);
+}
+
 static int cifs_xattr_set(const struct xattr_handler *handler,
 			  struct mnt_idmap *idmap,
 			  struct dentry *dentry, struct inode *inode,
@@ -101,8 +137,14 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
 	struct tcon_link *tlink;
 	struct cifs_tcon *pTcon;
 	const char *full_path;
+	char *new_name;
 	void *page;
 
+	pr_err("%s: name %s\n", __func__, name);
+	pr_err("%s: size %zu\n", __func__, size);
+	if (value)
+		print_hex_dump(KERN_ERR, "VALUE: ", DUMP_PREFIX_NONE, 16, 1, value, size, false);
+
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
@@ -116,8 +158,16 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
 		rc = PTR_ERR(full_path);
 		goto out;
 	}
-	/* return dos attributes as pseudo xattr */
-	/* return alt name if available as pseudo attr */
+
+	new_name = xattr_encode_name(name);
+	if (IS_ERR(new_name)) {
+		rc = PTR_ERR(new_name);
+		pr_err("%s: err %d\n", __func__, rc);
+		goto out;
+	}
+
+	pr_err("%s: old name %s, new name %s\n", __func__, name, new_name);
+	kfree(new_name);
 
 	/* if proc/fs/cifs/streamstoxattr is set then
 		search server for EAs or streams to