ipv6: add knob to send unsolicited ND on link-layer address change
This patch introduces a new knob ndisc_notify. If enabled, the kernel
will transmit an unsolicited neighbour advertisement on link-layer address
change to update the neighbour tables of the corresponding hosts more quickly.
This is the equivalent to arp_notify in ipv4 world.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index bcba48a..5e11905 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -47,6 +47,7 @@
__s32 disable_ipv6;
__s32 accept_dad;
__s32 force_tllao;
+ __s32 ndisc_notify;
void *sysctl;
};
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index a6d7d1c..5a2991c 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -157,6 +157,7 @@
DEVCONF_DISABLE_IPV6,
DEVCONF_ACCEPT_DAD,
DEVCONF_FORCE_TLLAO,
+ DEVCONF_NDISC_NOTIFY,
DEVCONF_MAX
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index fab23db..cb803b7 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4037,6 +4037,7 @@
array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;
array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad;
array[DEVCONF_FORCE_TLLAO] = cnf->force_tllao;
+ array[DEVCONF_NDISC_NOTIFY] = cnf->ndisc_notify;
}
static inline size_t inet6_ifla6_size(void)
@@ -4705,6 +4706,13 @@
.proc_handler = proc_dointvec
},
{
+ .procname = "ndisc_notify",
+ .data = &ipv6_devconf.ndisc_notify,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec
+ },
+ {
/* sentinel */
}
},
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 6ba4b54..f41853b 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1572,11 +1572,18 @@
{
struct net_device *dev = ptr;
struct net *net = dev_net(dev);
+ struct inet6_dev *idev;
switch (event) {
case NETDEV_CHANGEADDR:
neigh_changeaddr(&nd_tbl, dev);
fib6_run_gc(~0UL, net);
+ idev = in6_dev_get(dev);
+ if (!idev)
+ break;
+ if (idev->cnf.ndisc_notify)
+ ndisc_send_unsol_na(dev);
+ in6_dev_put(idev);
break;
case NETDEV_DOWN:
neigh_ifdown(&nd_tbl, dev);