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-rw-r--r--Documentation/networking/ip-sysctl.rst9
-rw-r--r--include/linux/inetdevice.h2
-rw-r--r--include/uapi/linux/ip.h1
-rw-r--r--include/uapi/linux/sysctl.h1
-rw-r--r--net/ipv4/arp.c11
-rw-r--r--net/ipv4/devinet.c4
6 files changed, 27 insertions, 1 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 16b8bf72feaf..18fde4ed7a5e 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1611,6 +1611,15 @@ arp_accept - BOOLEAN
gratuitous arp frame, the arp table will be updated regardless
if this setting is on or off.
+arp_evict_nocarrier - BOOLEAN
+ Clears the ARP cache on NOCARRIER events. This option is important for
+ wireless devices where the ARP cache should not be cleared when roaming
+ between access points on the same network. In most cases this should
+ remain as the default (1).
+
+ - 1 - (default): Clear the ARP cache on NOCARRIER events
+ - 0 - Do not clear ARP cache on NOCARRIER events
+
mcast_solicit - INTEGER
The maximum number of multicast probes in INCOMPLETE state,
when the associated hardware address is unknown. Defaults
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index a038feb63f23..518b484a7f07 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -133,6 +133,8 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev)
#define IN_DEV_ARP_ANNOUNCE(in_dev) IN_DEV_MAXCONF((in_dev), ARP_ANNOUNCE)
#define IN_DEV_ARP_IGNORE(in_dev) IN_DEV_MAXCONF((in_dev), ARP_IGNORE)
#define IN_DEV_ARP_NOTIFY(in_dev) IN_DEV_MAXCONF((in_dev), ARP_NOTIFY)
+#define IN_DEV_ARP_EVICT_NOCARRIER(in_dev) IN_DEV_ANDCONF((in_dev), \
+ ARP_EVICT_NOCARRIER)
struct in_ifaddr {
struct hlist_node hash;
diff --git a/include/uapi/linux/ip.h b/include/uapi/linux/ip.h
index e42d13b55cf3..e00bbb9c47bb 100644
--- a/include/uapi/linux/ip.h
+++ b/include/uapi/linux/ip.h
@@ -169,6 +169,7 @@ enum
IPV4_DEVCONF_DROP_UNICAST_IN_L2_MULTICAST,
IPV4_DEVCONF_DROP_GRATUITOUS_ARP,
IPV4_DEVCONF_BC_FORWARDING,
+ IPV4_DEVCONF_ARP_EVICT_NOCARRIER,
__IPV4_DEVCONF_MAX
};
diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index 1e05d3caa712..6a3b194c50fe 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h
@@ -482,6 +482,7 @@ enum
NET_IPV4_CONF_PROMOTE_SECONDARIES=20,
NET_IPV4_CONF_ARP_ACCEPT=21,
NET_IPV4_CONF_ARP_NOTIFY=22,
+ NET_IPV4_CONF_ARP_EVICT_NOCARRIER=23,
};
/* /proc/sys/net/ipv4/netfilter */
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 922dd73e5740..857a144b1ea9 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -1247,6 +1247,8 @@ static int arp_netdev_event(struct notifier_block *this, unsigned long event,
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct netdev_notifier_change_info *change_info;
+ struct in_device *in_dev;
+ bool evict_nocarrier;
switch (event) {
case NETDEV_CHANGEADDR:
@@ -1257,7 +1259,14 @@ static int arp_netdev_event(struct notifier_block *this, unsigned long event,
change_info = ptr;
if (change_info->flags_changed & IFF_NOARP)
neigh_changeaddr(&arp_tbl, dev);
- if (!netif_carrier_ok(dev))
+
+ in_dev = __in_dev_get_rtnl(dev);
+ if (!in_dev)
+ evict_nocarrier = true;
+ else
+ evict_nocarrier = IN_DEV_ARP_EVICT_NOCARRIER(in_dev);
+
+ if (evict_nocarrier && !netif_carrier_ok(dev))
neigh_carrier_down(&arp_tbl, dev);
break;
default:
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index f4468980b675..ec73a0d52d3e 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -75,6 +75,7 @@ static struct ipv4_devconf ipv4_devconf = {
[IPV4_DEVCONF_SHARED_MEDIA - 1] = 1,
[IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL - 1] = 10000 /*ms*/,
[IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL - 1] = 1000 /*ms*/,
+ [IPV4_DEVCONF_ARP_EVICT_NOCARRIER - 1] = 1,
},
};
@@ -87,6 +88,7 @@ static struct ipv4_devconf ipv4_devconf_dflt = {
[IPV4_DEVCONF_ACCEPT_SOURCE_ROUTE - 1] = 1,
[IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL - 1] = 10000 /*ms*/,
[IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL - 1] = 1000 /*ms*/,
+ [IPV4_DEVCONF_ARP_EVICT_NOCARRIER - 1] = 1,
},
};
@@ -2532,6 +2534,8 @@ static struct devinet_sysctl_table {
DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"),
+ DEVINET_SYSCTL_RW_ENTRY(ARP_EVICT_NOCARRIER,
+ "arp_evict_nocarrier"),
DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP_PVLAN, "proxy_arp_pvlan"),
DEVINET_SYSCTL_RW_ENTRY(FORCE_IGMP_VERSION,
"force_igmp_version"),