Re: ip route del bug?

Re: ip route del bug?

[Stephen Hemminger]

On Thu, 05 May 2005 07:53:36 -0700
Greg Varga <gvarga@skywaywest.com> wrote:

> Hey there,
> 
> I was working on one of our Linux routers yesterday, and when I issued a 
> "ip route del" command (no arg's) by mistake, it deleted the default route.
> 
> I was just wondering if this is indeed the way it was intended, or if 
> its a bug and in fact should have displayed an error message? I 
> personally would have preferred that it error'd with some sort of message.
> 
> I'm running Fedora Core 2 with iproute-2.4.7-14 rpm installed.
> 
> Thanks,
>    --Greg

It looks like an accidental behaviour (of the kernel) in response to
an ip route delete netlink message with no additional data.

Comments?

Re: ip route del bug?

[Patrick McHardy]

Stephen Hemminger wrote:
> It looks like an accidental behaviour (of the kernel) in response to
> an ip route delete netlink message with no additional data.

I don't believe it is accidental, it seems correct to me to delete
the default route when no more specific selector is given. To avoid
this, iproute could print an error when dst.bytelen == 0.

Regards
Patrick

Re: ip route del bug?

[Jamal Hadi Salim]

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On Thu, 2005-05-05 at 20:52 +0200, Patrick McHardy wrote:
> Stephen Hemminger wrote:
> > It looks like an accidental behaviour (of the kernel) in response to
> > an ip route delete netlink message with no additional data.
> 
> I don't believe it is accidental, it seems correct to me to delete
> the default route when no more specific selector is given. To avoid
> this, iproute could print an error when dst.bytelen == 0.

Agreed - basically the kernel does what its told.  
I think the check should be on missing dst (default will always give you
bytelen of 0 for example and is legit).
Patchlet attached.

cheers,
jamal

[-- Attachment #2: iprdl_p --]
[-- Type: text/plain, Size: 273 bytes --]

--- a/ip/iproute.c	2005/05/05 18:56:30	1.1
+++ b/ip/iproute.c	2005/05/05 19:10:49
@@ -857,6 +857,11 @@
 		argc--; argv++;
 	}
 
+	if (!dst_ok) {
+		fprintf(stderr,"route must specify destination address \n");
+		return -1;
+	}
+
 	if (rtnl_open(&rth, 0) < 0)
 		exit(1);