1 files changed, 98 insertions, 0 deletions
diff --git a/crypto/userspace/utils.h b/crypto/userspace/utils.h
new file mode 100644
index 00000000000..2802afa7758
--- /dev/null
+++ b/crypto/userspace/utils.h
@@ -0,0 +1,98 @@
+#ifndef NCR_UTILS_H
+#define  NCR_UTILS_H
+
+#include <linux/kernel.h>
+#include <linux/netlink.h>
+
+#define NCR_MAX_ATTR_SIZE 4096
+
+struct nlattr;
+
+struct ncr_out {
+	void *buf, *p;
+	size_t left;
+	void __user *arg;
+	size_t output_size_offset, fixed_size;
+	u32 orig_output_size;
+};
+
+#define __NCR_VERIFY_FIXED_SIZE(fixed)					\
+	(BUILD_BUG_ON(sizeof(*(fixed)) != NLA_ALIGN(sizeof(*(fixed)))))
+#define __NCR_VERIFY_TB(tb) (BUILD_BUG_ON(ARRAY_SIZE(tb) != NCR_ATTR_MAX + 1))
+
+extern u32 __ncr_u32_type_check;
+#define __OUT_SIZE_OFF(fixed)						\
+	((void)(&(fixed)->output_size == &__ncr_u32_type_check),	\
+	 (char *)&(fixed)->output_size - (char *)(fixed))
+
+
+/**
+ * Load *@fixed and a sequence of netlink-like attributes from @arg.  @fixed
+ * contains "input_size", which is an u32 filled with total input size,
+ * including the attributes, which are parsed into @tb.
+ */
+#define NCR_GET_INPUT_ARGS(fixed, tb, arg)			\
+	(__NCR_VERIFY_FIXED_SIZE(fixed),			\
+	 __NCR_VERIFY_TB(tb),					\
+	 __ncr_get_input_args(fixed, tb, sizeof(*(fixed)),	\
+			      &(fixed)->input_size, arg))
+void *__ncr_get_input_args(void *fixed, struct nlattr *tb[], size_t fixed_size,
+			   u32 *input_size_ptr, const void __user *arg);
+
+/**
+ * Load *@fixed and a sequence of netlink-like attributes from @arg.  @fixed
+ * contains "input_size", which is an u32 filled with total input size,
+ * including the attributes, which are parsed into @tb.  In addition, indicate
+ * to the user through u32 "output_size" that no output attributes will be
+ * returned.
+ */
+#define NCR_GET_INPUT_ARGS_NO_OUTPUT(fixed, tb, arg)			\
+	(__NCR_VERIFY_FIXED_SIZE(fixed),				\
+	 __NCR_VERIFY_TB(tb),						\
+	 __ncr_get_input_args_no_output(fixed, tb, sizeof(*(fixed)),	\
+					&(fixed)->input_size,		\
+					__OUT_SIZE_OFF(fixed), arg))
+void *__ncr_get_input_args_no_output(void *fixed, struct nlattr *tb[],
+				     size_t fixed_size, u32 *input_size_ptr,
+				     size_t output_size_offset,
+				     void __user *arg);
+
+/**
+ * Return a new output attribute context for attributes of *@fixed.  @fixed
+ * contains "output_size", an u32 containing total output size, including
+ * @fixed.  Store @arg for later ncr_out_finish().
+ */
+#define NCR_OUT_INIT(out, fixed, arg)				\
+	(__NCR_VERIFY_FIXED_SIZE(fixed),			\
+	 __ncr_out_init((out), (fixed), sizeof(*(fixed)),	\
+			__OUT_SIZE_OFF(fixed), (arg)))
+int __ncr_out_init(struct ncr_out *out, const void *fixed, size_t fixed_size,
+		   size_t output_size_offset, void __user *arg);
+
+/**
+ * Write attributes from @out to user space and update user-space output_size.
+ */
+int ncr_out_finish(struct ncr_out *out);
+
+void ncr_out_free(struct ncr_out *out);
+
+int ncr_out_put(struct ncr_out *out, int attrtype, int attrlen,
+		const void *data);
+
+static inline int ncr_out_put_u32(struct ncr_out *out, int attrtype, u32 value)
+{
+	return ncr_out_put(out, attrtype, sizeof(value), &value);
+}
+
+static inline int ncr_out_put_string(struct ncr_out *out, int attrtype,
+				     const char *value)
+{
+	return ncr_out_put(out, attrtype, strlen(value) + 1, value);
+}
+
+struct nlattr *ncr_out_reserve(struct ncr_out *out, int attrtype, int attrlen);
+
+struct nlattr *ncr_out_begin_buffer(struct ncr_out *out, int attrtype);
+void ncr_out_commit_buffer(struct ncr_out *out, int attrlen);
+
+#endif