* [PATCH] IPv6: NLM_F_* flag support for route creation/changing when using netlink.
@ 2011-10-27 6:26 Vaittinen, Matti (EXT-Other - FI/Oulu)
2011-10-27 7:06 ` David Miller
0 siblings, 1 reply; 4+ messages in thread
From: Vaittinen, Matti (EXT-Other - FI/Oulu) @ 2011-10-27 6:26 UTC (permalink / raw)
To: davem; +Cc: netdev
Hi!
This patch enables checks for NLM_F_CREATE, NLM_F_REPLACE and NLM_F_EXCL
flags for IPv6 route creation. Checks are performed if netlink header in
info structure is non NULL. Patch is created against Linux 3.1.0-rc4
(Downloaded from kernel.org).
In a nutshell:
NLM_F_CREATE flag is required if new IPv6 route is being created.
If route with same key and metric exists, the route will be changed if
NLM_F_REPLACE flag is given. Else -EEXIST is returned.
Either NLM_F_CREATE or NLM_F_REPLACE must be specified in RTM_NEWROUTE
messages.
Thing to consider:
Will requiring NLM_F_CREATE break lots of existing userspace software?
Anyways, I believe this is justified. Especially in cases where user
wants to change route if it exists, but not create new one if no route
exists. And anyways, creating new routes when NLM_F_CREATE is not
specified is unexpected.
Signed-off-by: Matti Vaittinen <Mazziesaccount@gmail.com>
---
diff -uNr linux-3.1-rc4.orig/net/ipv6/ip6_fib.c
linux-3.1-rc4.new/net/ipv6/ip6_fib.c
--- linux-3.1-rc4.orig/net/ipv6/ip6_fib.c 2011-10-26
13:15:17.000000000 +0300
+++ linux-3.1-rc4.new/net/ipv6/ip6_fib.c 2011-10-26
14:03:25.000000000 +0300
@@ -39,6 +39,7 @@
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
+#define RT6_CANT_CREATE ((int)-1)
#define RT6_DEBUG 2
#if RT6_DEBUG >= 3
@@ -429,7 +430,7 @@
static struct fib6_node * fib6_add_1(struct fib6_node *root, void
*addr,
int addrlen, int plen,
- int offset)
+ int offset, int allow_create)
{
struct fib6_node *fn, *in, *ln;
struct fib6_node *pn = NULL;
@@ -451,8 +452,11 @@
* Prefix match
*/
if (plen < fn->fn_bit ||
- !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
+ !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
+ if (!allow_create)
+ return (struct fib6_node
*)RT6_CANT_CREATE;
goto insert_above;
+ }
/*
* Exact match ?
@@ -485,6 +489,8 @@
* We walked to the bottom of tree.
* Create new leaf node without children.
*/
+ if (!allow_create)
+ return (struct fib6_node *)RT6_CANT_CREATE;
ln = node_alloc();
@@ -618,6 +624,12 @@
{
struct rt6_info *iter = NULL;
struct rt6_info **ins;
+ int replace = (NULL != info &&
+ NULL != info->nlh &&
+ (info->nlh->nlmsg_flags&NLM_F_REPLACE));
+ int add = ((NULL == info || NULL == info->nlh) ||
+ (info->nlh->nlmsg_flags&NLM_F_CREATE));
+ int found = 0;
ins = &fn->leaf;
@@ -630,6 +642,13 @@
/*
* Same priority level
*/
+ if (NULL != info->nlh &&
+ (info->nlh->nlmsg_flags&NLM_F_EXCL))
+ return -EEXIST;
+ if (replace) {
+ found++;
+ break;
+ }
if (iter->rt6i_dev == rt->rt6i_dev &&
iter->rt6i_idev == rt->rt6i_idev &&
@@ -659,19 +678,37 @@
/*
* insert node
*/
+ if (!replace) {
+ if (!add)
+ return -EINVAL;
+ rt->dst.rt6_next = iter;
+ *ins = rt;
+ rt->rt6i_node = fn;
+ atomic_inc(&rt->rt6i_ref);
+ inet6_rt_notify(RTM_NEWROUTE, rt, info);
+ info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
+
+ if ((fn->fn_flags & RTN_RTINFO) == 0) {
+ info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
+ fn->fn_flags |= RTN_RTINFO;
+ }
- rt->dst.rt6_next = iter;
- *ins = rt;
- rt->rt6i_node = fn;
- atomic_inc(&rt->rt6i_ref);
- inet6_rt_notify(RTM_NEWROUTE, rt, info);
- info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
-
- if ((fn->fn_flags & RTN_RTINFO) == 0) {
- info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
- fn->fn_flags |= RTN_RTINFO;
+ } else {
+ if (!found)
+ return -ENOENT;
+ *ins = rt;
+ rt->rt6i_node = fn;
+ rt->dst.rt6_next = iter->dst.rt6_next;
+ atomic_inc(&rt->rt6i_ref);
+ inet6_rt_notify(RTM_NEWROUTE, rt, info);
+ rt6_release(iter);
+ if ((fn->fn_flags & RTN_RTINFO) == 0) {
+ info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
+ fn->fn_flags |= RTN_RTINFO;
+ }
}
+
return 0;
}
@@ -701,9 +738,31 @@
struct fib6_node *fn, *pn = NULL;
int err = -ENOMEM;
+ int allow_create = 1;
+ int allow_replace = 1;
+ if (NULL != info &&
+ NULL != info->nlh &&
+ !(info->nlh->nlmsg_flags&NLM_F_REPLACE)) {
+ allow_replace = 0;
+ }
+ if (NULL != info &&
+ NULL != info->nlh &&
+ !(info->nlh->nlmsg_flags&NLM_F_CREATE)) {
+ allow_create = 0;
+ }
+ if (!(allow_replace || allow_create)) {
+ err = -EINVAL;
+ fn = NULL;
+ goto out;
+ }
fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct
in6_addr),
- rt->rt6i_dst.plen, offsetof(struct rt6_info,
rt6i_dst));
+ rt->rt6i_dst.plen, offsetof(struct rt6_info,
rt6i_dst),
+ allow_create);
+ if (RT6_CANT_CREATE == (int)fn) {
+ err = -EINVAL;
+ fn = NULL;
+ }
if (fn == NULL)
goto out;
@@ -716,6 +775,11 @@
if (fn->subtree == NULL) {
struct fib6_node *sfn;
+ if (!allow_create) {
+ err = -EINVAL;
+ fn = NULL;
+ goto out;
+ }
/*
* Create subtree.
*
@@ -740,7 +804,7 @@
sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
sizeof(struct in6_addr),
rt->rt6i_src.plen,
- offsetof(struct rt6_info,
rt6i_src));
+ offsetof(struct rt6_info,
rt6i_src), 1);
if (sn == NULL) {
/* If it is failed, discard just
allocated
@@ -757,8 +821,13 @@
} else {
sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
sizeof(struct in6_addr),
rt->rt6i_src.plen,
- offsetof(struct rt6_info,
rt6i_src));
+ offsetof(struct rt6_info,
rt6i_src),
+ allow_create);
+ if (RT6_CANT_CREATE == (int)sn) {
+ err = -EINVAL;
+ sn = NULL;
+ }
if (sn == NULL)
goto st_failure;
}
diff -uNr linux-3.1-rc4.orig/net/ipv6/route.c
linux-3.1-rc4.new/net/ipv6/route.c
--- linux-3.1-rc4.orig/net/ipv6/route.c 2011-10-26 13:15:17.000000000
+0300
+++ linux-3.1-rc4.new/net/ipv6/route.c 2011-10-26 14:04:29.000000000
+0300
@@ -1223,9 +1223,15 @@
if (cfg->fc_metric == 0)
cfg->fc_metric = IP6_RT_PRIO_USER;
- table = fib6_new_table(net, cfg->fc_table);
+ if (NULL != cfg->fc_nlinfo.nlh &&
+ !(cfg->fc_nlinfo.nlh->nlmsg_flags&NLM_F_CREATE)) {
+ err = -EINVAL;
+ table = fib6_get_table(net, cfg->fc_table);
+ } else {
+ err = -ENOBUFS;
+ table = fib6_new_table(net, cfg->fc_table);
+ }
if (table == NULL) {
- err = -ENOBUFS;
goto out;
}
--
- Matti Vaittinen
Theory:
Theoretical approach means that everything is well known, but still
nothing works.
Practice:
Practical approach means that everything works but no one knows why.
Thank God we have theory and practice balanced here. Nothing works, and
no one knows why...
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] IPv6: NLM_F_* flag support for route creation/changing when using netlink.
2011-10-27 6:26 [PATCH] IPv6: NLM_F_* flag support for route creation/changing when using netlink Vaittinen, Matti (EXT-Other - FI/Oulu)
@ 2011-10-27 7:06 ` David Miller
2011-10-27 7:12 ` Stephen Hemminger
0 siblings, 1 reply; 4+ messages in thread
From: David Miller @ 2011-10-27 7:06 UTC (permalink / raw)
To: matti.vaittinen.ext; +Cc: netdev
From: "Vaittinen, Matti (EXT-Other - FI/Oulu)" <matti.vaittinen.ext@nsn.com>
Date: Thu, 27 Oct 2011 09:26:05 +0300
>
> Will requiring NLM_F_CREATE break lots of existing userspace software?
I can almost guarenetee that since we haven't been requiring this,
it will break almost everything.
> --- linux-3.1-rc4.orig/net/ipv6/ip6_fib.c 2011-10-26
> 13:15:17.000000000 +0300
Your patch is also severely mangled by your email client and is
thus unusable for us.
Please read Documentation/email-clients.txt before submitting any
more patches.
Thank you.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] IPv6: NLM_F_* flag support for route creation/changing when using netlink.
2011-10-27 7:06 ` David Miller
@ 2011-10-27 7:12 ` Stephen Hemminger
2011-10-27 7:20 ` Vaittinen, Matti (EXT-Other - FI/Oulu)
0 siblings, 1 reply; 4+ messages in thread
From: Stephen Hemminger @ 2011-10-27 7:12 UTC (permalink / raw)
To: David Miller; +Cc: netdev, matti vaittinen ext
> From: "Vaittinen, Matti (EXT-Other - FI/Oulu)"
> <matti.vaittinen.ext@nsn.com>
> Date: Thu, 27 Oct 2011 09:26:05 +0300
>
> >
> > Will requiring NLM_F_CREATE break lots of existing userspace
> > software?
>
> I can almost guarenetee that since we haven't been requiring this,
> it will break almost everything.
Why not just make it a kernel warning for several releases.
Just checked, and iproute and quagga will have no problem since
they both already pass the CREATE flag.
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH] IPv6: NLM_F_* flag support for route creation/changing when using netlink.
2011-10-27 7:12 ` Stephen Hemminger
@ 2011-10-27 7:20 ` Vaittinen, Matti (EXT-Other - FI/Oulu)
0 siblings, 0 replies; 4+ messages in thread
From: Vaittinen, Matti (EXT-Other - FI/Oulu) @ 2011-10-27 7:20 UTC (permalink / raw)
To: ext Stephen Hemminger, David Miller; +Cc: netdev
> -----Original Message-----
> From: ext Stephen Hemminger [mailto:stephen.hemminger@vyatta.com]
> Sent: Thursday, October 27, 2011 10:12 AM
> To: David Miller
> Cc: netdev@vger.kernel.org; Vaittinen, Matti (EXT-Other - FI/Oulu)
> Subject: Re: [PATCH] IPv6: NLM_F_* flag support for route
creation/changing when using netlink.
>
>
> > From: "Vaittinen, Matti (EXT-Other - FI/Oulu)"
> > <matti.vaittinen.ext@nsn.com>
> > Date: Thu, 27 Oct 2011 09:26:05 +0300
> >
> > >
> > > Will requiring NLM_F_CREATE break lots of existing userspace
> > > software?
> >
> > I can almost guarenetee that since we haven't been requiring this,
it
> > will break almost everything.
>
> Why not just make it a kernel warning for several releases.
>
> Just checked, and iproute and quagga will have no problem since they
both already pass the CREATE flag.
For me kernel warning sounds like a reasonable approach. I will change
the patch to not drop the request with error, but to issue a warning
instead. I'll also try using better email client next time.
Furthermore I believe that most tools used for both IPv4 and IPv6
routing (like iproute) do add the CREATE flag because IPv4 route
creation does require it.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-10-27 7:21 UTC | newest]
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2011-10-27 6:26 [PATCH] IPv6: NLM_F_* flag support for route creation/changing when using netlink Vaittinen, Matti (EXT-Other - FI/Oulu)
2011-10-27 7:06 ` David Miller
2011-10-27 7:12 ` Stephen Hemminger
2011-10-27 7:20 ` Vaittinen, Matti (EXT-Other - FI/Oulu)
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