From: Vincent Bernat <bernat@luffy.cx>
Date: Wed, 26 Sep 2012 22:21:45 +0000 (+0200)
Subject: interfaces: don't block when sending LLDP frames
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fheads%2Fbranch-0.5;p=thirdparty%2Flldpd.git

interfaces: don't block when sending LLDP frames

It seems that in some situations, sending on a network interface (a
virtual one for example) could block. We circumvent this by making the
interface non blocking before sending.
---

diff --git a/CHANGELOG b/CHANGELOG
index 6b40e267..efee53e2 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,7 @@
+lldpd (0.5.8)
+ * Fixes:
+    + Don't block when sending LLDP frames.
+
 lldpd (0.5.7)
  * Fixes:
     + Configure issue with NetSNMP and some linkers
diff --git a/src/interfaces.c b/src/interfaces.c
index c35bc840..57d25298 100644
--- a/src/interfaces.c
+++ b/src/interfaces.c
@@ -132,6 +132,14 @@ struct lldpd_ops bond_ops = {
 	.cleanup = iface_bond_close,
 };
 
+static void
+make_nonblock(int fd)
+{
+	int flags;
+	if ((flags = fcntl(fd, F_GETFL, NULL)) < 0) return;
+	fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+}
+
 static int
 old_iface_is_bridge(struct lldpd *cfg, const char *name)
 {
@@ -683,6 +691,7 @@ static int
 iface_eth_send(struct lldpd *cfg, struct lldpd_hardware *hardware,
     char *buffer, size_t size)
 {
+	make_nonblock(hardware->h_sendfd);
 	return write(hardware->h_sendfd,
 	    buffer, size);
 }
@@ -888,6 +897,7 @@ iface_bond_send(struct lldpd *cfg, struct lldpd_hardware *hardware,
 		}
 		memset(buffer + ETH_ALEN, 0, ETH_ALEN);
 	}
+	make_nonblock(hardware->h_sendfd);
 	return write(hardware->h_sendfd,
 	    buffer, size);
 }