implement dread

1 files changed, 47 insertions, 0 deletions

diff --git a/lib9p/9p.c b/lib9p/9p.c
index b1d4c32..832ae82 100644
--- a/lib9p/9p.c
+++ b/lib9p/9p.c
@@ -98,3 +98,50 @@ bool lib9p_marshal(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body,
 	struct _vtable_msg vtable = _lib9p_vtables[ctx->version].msgs[typ];
 	return vtable.marshal(&subctx, body);
 }
+
+bool lib9p_validate_stat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t *net_bytes,
+                         uint32_t *ret_net_size, ssize_t *ret_host_size) {
+	struct _validate_ctx subctx = {
+		.ctx        = ctx,
+		.net_size   = net_size,
+		.net_bytes  = net_bytes,
+
+		.net_offset = 0,
+		.host_extra = 0,
+	};
+	if (_lib9p_validate_stat(&subctx))
+		return true;
+	if (ret_net_size)
+		*ret_net_size = subctx.net_offset;
+	if (ret_host_size)
+		if (__builtin_add_overflow(sizeof(struct lib9p_stat), subctx.host_extra, ret_host_size))
+			return lib9p_error(ctx, LINUX_EMSGSIZE, "unmarshalled stat object overflows SSIZE_MAX");
+	return false;
+}
+
+uint32_t lib9p_unmarshal_stat(struct lib9p_ctx *ctx, uint8_t *net_bytes,
+                              struct lib9p_stat *ret_obj, void *ret_extra) {
+	struct _unmarshal_ctx subctx = {
+		.ctx = ctx,
+		.net_bytes = net_bytes,
+		.net_offset = 0,
+
+		.extra = ret_extra,
+	};
+	_lib9p_unmarshal_stat(&subctx, ret_obj);
+	return subctx.net_offset;
+}
+
+uint32_t lib9p_marshal_stat(struct lib9p_ctx *ctx, uint32_t max_net_size, struct lib9p_stat *obj,
+                            uint8_t *ret_bytes) {
+	struct lib9p_ctx _ctx = *ctx;
+	_ctx.max_msg_size = max_net_size;
+	struct _marshal_ctx subctx = {
+		.ctx        = &_ctx,
+		.net_bytes  = ret_bytes,
+		.net_offset = 0,
+	};
+	if (_lib9p_marshal_stat(&subctx, obj))
+		return 0;
+	return subctx.net_offset;
+}