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From: Eric Dumazet <eric.dumazet@gmail.com>
To: nicolas.dichtel@6wind.com
Cc: netdev <netdev@vger.kernel.org>, Octavian Purdila <opurdila@ixiacom.com>
Subject: Re: [PATCH] ipv4: remove all rt cache entries on UNREGISTER event
Date: Wed, 29 Sep 2010 11:18:49 +0200	[thread overview]
Message-ID: <1285751929.2615.30.camel@edumazet-laptop> (raw)
In-Reply-To: <1285749349.2615.27.camel@edumazet-laptop>

I found following patch was enough to avoid route being created if
device is down. This is still racy and needs more thinking.


diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index ac6559c..1ee0b1a 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2586,9 +2586,10 @@ static int ip_route_output_slow(struct net *net, struct rtable **rp,
 			goto out;
 
 		/* RACE: Check return value of inet_select_addr instead. */
-		if (__in_dev_get_rtnl(dev_out) == NULL) {
+		if (!(dev_out->flags & IFF_UP) || __in_dev_get_rtnl(dev_out) == NULL) {
 			dev_put(dev_out);
-			goto out;	/* Wrong error code */
+			err = -ENETUNREACH;
+			goto out;
 		}
 
 		if (ipv4_is_local_multicast(oldflp->fl4_dst) ||



  reply	other threads:[~2010-09-29  9:18 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-28 15:24 [PATCH] ipv4: remove all rt cache entries on UNREGISTER event Nicolas Dichtel
2010-09-28 16:33 ` Eric Dumazet
2010-09-28 16:45   ` Nicolas Dichtel
2010-09-28 16:56     ` Eric Dumazet
2010-09-29  7:49       ` Nicolas Dichtel
2010-09-29  8:35         ` Eric Dumazet
2010-09-29  9:18           ` Eric Dumazet [this message]
2010-09-30 11:49             ` Nicolas Dichtel
2010-12-22  8:32             ` Nicolas Dichtel
2010-12-22  9:55               ` Eric Dumazet
2010-12-22 10:07                 ` Eric Dumazet
2010-12-22 13:43                   ` Nicolas Dichtel
2010-12-22 14:39                     ` [PATCH] ipv4: dont create routes on down devices Eric Dumazet
2010-12-23  8:50                       ` Octavian Purdila
2010-12-26  4:05                         ` David Miller
2010-09-28 17:35   ` [PATCH] ipv4: remove all rt cache entries on UNREGISTER event Octavian Purdila

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