1 files changed, 51 insertions, 0 deletions
diff --git a/control/controlclient/errors.go b/control/controlclient/errors.go
new file mode 100644
index 000000000..9b4dab844
--- /dev/null
+++ b/control/controlclient/errors.go
@@ -0,0 +1,51 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package controlclient
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+)
+
+// apiResponseError is an error type that can be returned by controlclient
+// api requests.
+//
+// It wraps an underlying error and a flag for clients to query if the
+// error is retryable via the Retryable() method.
+type apiResponseError struct {
+	err       error
+	retryable bool
+}
+
+// Error implements [error].
+func (e *apiResponseError) Error() string {
+	return e.err.Error()
+}
+
+// Retryable reports whether the error is retryable.
+func (e *apiResponseError) Retryable() bool {
+	return e.retryable
+}
+
+func (e *apiResponseError) Unwrap() error { return e.err }
+
+var (
+	errNoNodeKey       = &apiResponseError{errors.New("no node key"), true}
+	errNoNoiseClient   = &apiResponseError{errors.New("no noise client"), true}
+	errHTTPPostFailure = &apiResponseError{errors.New("http failure"), true}
+)
+
+func errBadHTTPResponse(code int, msg string) error {
+	retryable := false
+	switch code {
+	case http.StatusTooManyRequests,
+		http.StatusInternalServerError,
+		http.StatusBadGateway,
+		http.StatusServiceUnavailable,
+		http.StatusGatewayTimeout:
+		retryable = true
+	}
+	return &apiResponseError{fmt.Errorf("http error %d: %s", code, msg), retryable}
+}