From: Avery Pennarun <apenwarr@gmail.com>
Date: Sat, 12 Oct 2019 07:46:13 +0000 (-0700)
Subject: rwcancel: handle EINTR and EAGAIN in unixSelect()
X-Git-Tag: 0.0.20200121~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0abb6b668c708aa84daba4b036e536fd76a8b1c5;p=thirdparty%2Fwireguard-go.git

rwcancel: handle EINTR and EAGAIN in unixSelect()

On my Chromebook (Linux 4.19.44 in a VM) and on an AWS EC2
machine, select() was sometimes returning EINTR. This is
harmless and just means you should try again. So let's try
again.

This eliminates a problem where the tunnel fails to come up
correctly and the program needs to be restarted.

Signed-off-by: Avery Pennarun <apenwarr@gmail.com>
---

diff --git a/rwcancel/rwcancel.go b/rwcancel/rwcancel.go
index 62397c2..808e691 100644
--- a/rwcancel/rwcancel.go
+++ b/rwcancel/rwcancel.go
@@ -60,7 +60,13 @@ func (rw *RWCancel) ReadyRead() bool {
 	fdset := fdSet{}
 	fdset.set(rw.fd)
 	fdset.set(closeFd)
-	err := unixSelect(max(rw.fd, closeFd)+1, &fdset.FdSet, nil, nil, nil)
+	var err error
+	for {
+		err = unixSelect(max(rw.fd, closeFd)+1, &fdset.FdSet, nil, nil, nil)
+		if err == nil || !RetryAfterError(err) {
+			break
+		}
+	}
 	if err != nil {
 		return false
 	}
@@ -75,7 +81,13 @@ func (rw *RWCancel) ReadyWrite() bool {
 	fdset := fdSet{}
 	fdset.set(rw.fd)
 	fdset.set(closeFd)
-	err := unixSelect(max(rw.fd, closeFd)+1, nil, &fdset.FdSet, nil, nil)
+	var err error
+	for {
+		err = unixSelect(max(rw.fd, closeFd)+1, nil, &fdset.FdSet, nil, nil)
+		if err == nil || !RetryAfterError(err) {
+			break
+		}
+	}
 	if err != nil {
 		return false
 	}