Harald,
My (stoopid) ISP doesnt like your email address. In any case, attached
patch of what i was alluding to. Maybe be missing some things.
Compiles - not tested and extremely dangerous becdause of side effects
to arp and forwarding - so needs a lot of testing.
damn spent my tim hortons coffee on this patch and too cold to go out.
cheers,
jamal
On Sun, 2004-12-19 at 17:59, jamal wrote:
> I had something much simpler in mind.
> Basically, promote the next one in line. This would be cleanly backward
> compatible and would be an improvement over whats there (however
> medievial it is). Let me see if i can whip something that at least
> compiles. Unfortunately i wont have time to chase it to completion of
> testing until around xmas when i have time off from work.
>
> cheers,
> jamal
>
> On Sun, 2004-12-19 at 17:02, Thomas Graf wrote:
> > * Harald Welte <20041219214120.GX17302@xxxxxxxxxxxxxxxxxxxxxxx> 2004-12-19 22:41
> > > On Sun, Dec 19, 2004 at 03:18:37PM -0500, jamal wrote:
> > >
> > > > Having said the above, I think it would make sense to have a "promotion"
> > > > scheme so that in the case a primary address is deleted, one could
> > > > promote the next secondary address in line. But that should be optional.
> > >
> > > Oh yes, please. This would save a lot of headache. I'm much in favour
> > > of such a proposal.
> >
> > Agreed, would be nice to have.
> >
> > > > Now where is the fireman who wants to do this? I could help cheering
> > > > since i know the code.
> > >
> > > how would you think it fits best into the current netlink messages?
> >
> > 1) IFA_F_PROM_CAND flag and have inet_del_ifa* iterate over its
> > secondary addresses and elect the first with the flag set.
> >
> > 2) IFA_PROM_PRIO TLV of type u32 holding a priority where 0 means no
> > candiate. inet_del_ifa* iterates over its secondary addresses and
> > elects the one with the highest prio as new primary address or
> > deletes all addresses if none is found.
> >
> > * respectively the equivalent function of the other address families.
> >
> > Second variant requires more work but is more flexible so it's
> > definitely my favourite. I'm willing to put some effort into this,
> > I'm not familiar with all address families though.
> >
--- a/include/linux/bak.sysctl.h 2004-12-19 18:26:04.622675432 -0500
+++ b/include/linux/sysctl.h 2004-12-19 18:27:18.471448712 -0500
@@ -395,6 +395,7 @@
NET_IPV4_CONF_FORCE_IGMP_VERSION=17,
NET_IPV4_CONF_ARP_ANNOUNCE=18,
NET_IPV4_CONF_ARP_IGNORE=19,
+ NET_IPV4_CONF_PROMOTE_ALIASES=20,
};
/* /proc/sys/net/ipv4/netfilter */
--- a/net/ipv4/bak.devinet.c 2004-12-19 17:30:33.787039416 -0500
+++ b/net/ipv4/devinet.c 2004-12-19 18:11:46.931064376 -0500
@@ -230,11 +230,15 @@
static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
int destroy)
{
+ struct in_ifaddr *promote = NULL;
struct in_ifaddr *ifa1 = *ifap;
ASSERT_RTNL();
- /* 1. Deleting primary ifaddr forces deletion all secondaries */
+ /* 1. Deleting primary ifaddr forces deletion all secondaries
+ * unless sysctl aliaspromo not set
+ * ipv4_devconf.aliaspromo
+ **/
if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) {
struct in_ifaddr *ifa;
@@ -248,11 +252,16 @@
continue;
}
- *ifap1 = ifa->ifa_next;
+ if (!IN_DEV_PROMOTE_ALIASES(in_dev)) {
+ *ifap1 = ifa->ifa_next;
- rtmsg_ifa(RTM_DELADDR, ifa);
- notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa);
- inet_free_ifa(ifa);
+ rtmsg_ifa(RTM_DELADDR, ifa);
+ notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa);
+ inet_free_ifa(ifa);
+ } else {
+ promote = ifa;
+ break;
+ }
}
}
@@ -278,6 +287,13 @@
if (!in_dev->ifa_list)
inetdev_destroy(in_dev);
}
+
+ if (promote && IN_DEV_PROMOTE_ALIASES(in_dev)) {
+ /* not sure if we should send a delete notify first? */
+ promote->ifa_flags &= ~IFA_F_SECONDARY;
+ rtmsg_ifa(RTM_NEWADDR, promote);
+ notifier_call_chain(&inetaddr_chain, NETDEV_UP, promote);
+ }
}
static int inet_insert_ifa(struct in_ifaddr *ifa)
@@ -1374,6 +1390,15 @@
.proc_handler = &ipv4_doint_and_flush,
.strategy = &ipv4_doint_and_flush_strategy,
},
+ {
+ .ctl_name = NET_IPV4_CONF_PROMOTE_ALIASES,
+ .procname = "promote_aliases",
+ .data = &ipv4_devconf.promote_aliases,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &ipv4_doint_and_flush,
+ .strategy = &ipv4_doint_and_flush_strategy,
+ },
},
.devinet_dev = {
{
--- a/include/linux/bak.inetdevice.h 2004-12-19 17:54:26.610217184 -0500
+++ b/include/linux/inetdevice.h 2004-12-19 17:58:45.130916064 -0500
@@ -29,6 +29,7 @@
int no_xfrm;
int no_policy;
int force_igmp_version;
+ int promote_aliases;
void *sysctl;
};
@@ -71,6 +72,7 @@
#define IN_DEV_SEC_REDIRECTS(in_dev) (ipv4_devconf.secure_redirects || (in_dev)->cnf.secure_redirects)
#define IN_DEV_IDTAG(in_dev) ((in_dev)->cnf.tag)
#define IN_DEV_MEDIUM_ID(in_dev) ((in_dev)->cnf.medium_id)
+#define IN_DEV_PROMOTE_ALIASES(in_dev) (ipv4_devconf.promote_aliases || (in_dev)->cnf.promote_aliases)
#define IN_DEV_RX_REDIRECTS(in_dev) \
((IN_DEV_FORWARD(in_dev) && \
