klibc - Jun 2023 - [klibc:master] ipconfig: Handle error events from poll

Commit-ID:  4ae6735c9f899815325a100a4019a7b385662bb4
Gitweb:    
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=4ae6735c9f899815325a100a4019a7b385662bb4
Author:     Ben Hutchings <ben at decadent.org.uk>
AuthorDate: Mon, 5 Jun 2023 00:16:26 +0200
Committer:  Ben Hutchings <ben at decadent.org.uk>
CommitDate: Mon, 5 Jun 2023 01:27:41 +0200

[klibc] ipconfig: Handle error events from poll

When poll returns events for a socket other than POLLRDNORM, such as
POLLERR, we do not read from the socket but keep polling on it.  This
results in busy-polling while the error state persists.

In case some other event is returned, put the device into DEVST_ERROR
state for 1 second.

Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

---
 usr/kinit/ipconfig/main.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/usr/kinit/ipconfig/main.c b/usr/kinit/ipconfig/main.c
index 32e3dd1f..d45be354 100644
--- a/usr/kinit/ipconfig/main.c
+++ b/usr/kinit/ipconfig/main.c
@@ -404,6 +404,12 @@ static void process_timeout_event(struct state *s, time_t
now)
 	}
 }
 
+static void process_error_event(struct state *s, time_t now)
+{
+	s->state = DEVST_ERROR;
+	s->expire = now + 1;
+}
+
 static struct state *slist;
 struct netdev *ifaces;
 
@@ -420,8 +426,11 @@ static int do_pkt_recv(int nr, struct pollfd *fds, time_t
now)
 	for (i = 0, s = slist; s && nr; s = s->next) {
 		if (s->dev->pkt_fd != fds[i].fd)
 			continue;
-		if (fds[i].revents & POLLRDNORM) {
-			ret |= process_receive_event(s, now);
+		if (fds[i].revents) {
+			if (fds[i].revents & POLLRDNORM)
+				ret |= process_receive_event(s, now);
+			else
+				process_error_event(s, now);
 			nr--;
 		}
 		i++;