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>
This commit is contained in:
Avery Pennarun 2019-10-12 00:46:13 -07:00 committed by Jason A. Donenfeld
parent 540d01e54a
commit 0abb6b668c

View file

@ -60,7 +60,13 @@ func (rw *RWCancel) ReadyRead() bool {
fdset := fdSet{} fdset := fdSet{}
fdset.set(rw.fd) fdset.set(rw.fd)
fdset.set(closeFd) 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 { if err != nil {
return false return false
} }
@ -75,7 +81,13 @@ func (rw *RWCancel) ReadyWrite() bool {
fdset := fdSet{} fdset := fdSet{}
fdset.set(rw.fd) fdset.set(rw.fd)
fdset.set(closeFd) 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 { if err != nil {
return false return false
} }