hfsplus: rework functionality of getting, setting and deleting of extended attributes

Rework functionality of getting, setting and deleting of extended attributes.

Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Reported-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 104 insertions, 0 deletions

diff --git a/fs/hfsplus/xattr_security.c b/fs/hfsplus/xattr_security.c
new file mode 100644
index 000000000000..83b842f113c5
--- /dev/null
+++ b/fs/hfsplus/xattr_security.c
@@ -0,0 +1,104 @@
+/*
+ * linux/fs/hfsplus/xattr_trusted.c
+ *
+ * Vyacheslav Dubeyko <slava@dubeyko.com>
+ *
+ * Handler for storing security labels as extended attributes.
+ */
+
+#include <linux/security.h>
+#include "hfsplus_fs.h"
+#include "xattr.h"
+
+static int hfsplus_security_getxattr(struct dentry *dentry, const char *name,
+                                        void *buffer, size_t size, int type)
+{
+        char xattr_name[HFSPLUS_ATTR_MAX_STRLEN + 1] = {0};
+        size_t len = strlen(name);
+
+        if (!strcmp(name, ""))
+                return -EINVAL;
+
+        if (len + XATTR_SECURITY_PREFIX_LEN > HFSPLUS_ATTR_MAX_STRLEN)
+                return -EOPNOTSUPP;
+
+        strcpy(xattr_name, XATTR_SECURITY_PREFIX);
+        strcpy(xattr_name + XATTR_SECURITY_PREFIX_LEN, name);
+
+        return hfsplus_getxattr(dentry, xattr_name, buffer, size);
+}
+
+static int hfsplus_security_setxattr(struct dentry *dentry, const char *name,
+                const void *buffer, size_t size, int flags, int type)
+{
+        char xattr_name[HFSPLUS_ATTR_MAX_STRLEN + 1] = {0};
+        size_t len = strlen(name);
+
+        if (!strcmp(name, ""))
+                return -EINVAL;
+
+        if (len + XATTR_SECURITY_PREFIX_LEN > HFSPLUS_ATTR_MAX_STRLEN)
+                return -EOPNOTSUPP;
+
+        strcpy(xattr_name, XATTR_SECURITY_PREFIX);
+        strcpy(xattr_name + XATTR_SECURITY_PREFIX_LEN, name);
+
+        return hfsplus_setxattr(dentry, xattr_name, buffer, size, flags);
+}
+
+static size_t hfsplus_security_listxattr(struct dentry *dentry, char *list,
+                size_t list_size, const char *name, size_t name_len, int type)
+{
+        /*
+         * This method is not used.
+         * It is used hfsplus_listxattr() instead of generic_listxattr().
+         */
+        return -EOPNOTSUPP;
+}
+
+static int hfsplus_initxattrs(struct inode *inode,
+                                const struct xattr *xattr_array,
+                                void *fs_info)
+{
+        const struct xattr *xattr;
+        char xattr_name[HFSPLUS_ATTR_MAX_STRLEN + 1] = {0};
+        size_t xattr_name_len;
+        int err = 0;
+
+        for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+                xattr_name_len = strlen(xattr->name);
+
+                if (xattr_name_len == 0)
+                        continue;
+
+                if (xattr_name_len + XATTR_SECURITY_PREFIX_LEN >
+                                HFSPLUS_ATTR_MAX_STRLEN)
+                        return -EOPNOTSUPP;
+
+                strcpy(xattr_name, XATTR_SECURITY_PREFIX);
+                strcpy(xattr_name +
+                        XATTR_SECURITY_PREFIX_LEN, xattr->name);
+                memset(xattr_name +
+                        XATTR_SECURITY_PREFIX_LEN + xattr_name_len, 0, 1);
+
+                err = __hfsplus_setxattr(inode, xattr_name,
+                                        xattr->value, xattr->value_len, 0);
+                if (err)
+                        break;
+        }
+        return err;
+}
+
+int hfsplus_init_security(struct inode *inode, struct inode *dir,
+                                const struct qstr *qstr)
+{
+        return security_inode_init_security(inode, dir, qstr,
+                                        &hfsplus_initxattrs, NULL);
+}
+
+const struct xattr_handler hfsplus_xattr_security_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .list   = hfsplus_security_listxattr,
+        .get    = hfsplus_security_getxattr,
+        .set    = hfsplus_security_setxattr,
+};