[PATCH] iproute: Ignore all output fields of ip route get for route add

[PATCH] iproute: Ignore all output fields of ip route get for route add

[Andi Kleen]

My vpnc-connect script broke in a kernel release because the new
kernel started returning the ipid in ip cache get. The script
would do ip route get, modify the route and then feed it back
to ip route add. But ip route add couldn't parse ipid ..

Make route add skip all status fields output by ip cache get

In theory they could be fed to the kernel too, but that's likely
not very useful (and I'm not fully sure if the kernel would
even use them)

Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/ip/iproute.c b/ip/iproute.c
index 2fef35b..8b7421e 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -936,6 +936,17 @@ int iproute_modify(int cmd, unsigned flags, int argc, char **argv)
 			   strcmp(*argv, "oif") == 0) {
 			NEXT_ARG();
 			d = *argv;
+		/* Ignore everything else printed by ip route get. */
+		} else if (strcmp(*argv, "ipid") == 0 ||
+			   strcmp(*argv, "ts") == 0 ||
+			   strcmp(*argv, "tsage") == 0 ||
+			   strcmp(*argv, "age") == 0 ||
+			   strcmp(*argv, "used") == 0 ||
+			   strcmp(*argv, "users") == 0 ||
+			   strcmp(*argv, "error") == 0 ||
+			   strcmp(*argv, "cache") == 0 ||
+			   strcmp(*argv, "expires") == 0) {
+			NEXT_ARG();
 		} else {
 			int type;
 			inet_prefix dst;
-- 
ak@linux.intel.com -- Speaking for myself only.

Re: [PATCH] iproute: Ignore all output fields of ip route get for route add

[David Miller]

From: Andi Kleen <andi@firstfloor.org>
Date: Fri, 3 Jun 2011 10:39:18 +0200

> My vpnc-connect script broke in a kernel release because the new
> kernel started returning the ipid in ip cache get. The script
> would do ip route get, modify the route and then feed it back
> to ip route add. But ip route add couldn't parse ipid ..
> 
> Make route add skip all status fields output by ip cache get
> 
> In theory they could be fed to the kernel too, but that's likely
> not very useful (and I'm not fully sure if the kernel would
> even use them)
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>

I think we've had this discussion before.

There are no guarentees that what the tool outputs for routes is
suitable for creating routes.

People have already put vpnc script fixes into Fedora and similar
already.

iproute2 is not where the hacks belong.

Re: [PATCH] iproute: Ignore all output fields of ip route get for route add

[Andi Kleen]

> There are no guarentees that what the tool outputs for routes is
> suitable for creating routes.
> 
> People have already put vpnc script fixes into Fedora and similar
> already.
> 
> iproute2 is not where the hacks belong.

Hmmm, so you expect every user to maintain the sed line from hell?
Does not sound very user friendly to me.

An alternative would be to add a option to ip route get that disables
printing any options that cannot be used for input.
Would that be more acceptable?

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only.