From: Ido Schimmel <ido...@mellanox.com>
When a multipath route is hit the kernel doesn't consider nexthops that
are DEAD or LINKDOWN when IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN is set.
Devices that offload multipath routes need to be made aware of nexthop
status changes. Otherwise, the device will keep forwarding packets to
non-functional nexthops.
Add the FIB_EVENT_NH_{ADD,DEL} events to the fib notification chain,
which notify capable devices when they should add or delete a nexthop
from their tables.
Cc: Roopa Prabhu <ro...@cumulusnetworks.com>
Cc: David Ahern <d...@cumulusnetworks.com>
Cc: Andy Gospodarek <a...@greyhouse.net>
Signed-off-by: Ido Schimmel <ido...@mellanox.com>
Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
include/net/ip_fib.h | 7 +++++++
net/ipv4/fib_semantics.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 57c2a86..45a184e 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -214,11 +214,18 @@ struct fib_entry_notifier_info {
u32 nlflags;
};
+struct fib_nh_notifier_info {
+ struct fib_notifier_info info; /* must be first */
+ struct fib_nh *fib_nh;
+};
+
enum fib_event_type {
FIB_EVENT_ENTRY_ADD,
FIB_EVENT_ENTRY_DEL,
FIB_EVENT_RULE_ADD,
FIB_EVENT_RULE_DEL,
+ FIB_EVENT_NH_ADD,
+ FIB_EVENT_NH_DEL,
};
int register_fib_notifier(struct notifier_block *nb,
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 6306a67..317026a 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1355,6 +1355,36 @@ int fib_sync_down_addr(struct net_device *dev, __be32
local)
return ret;
}
+static int call_fib_nh_notifiers(struct fib_nh *fib_nh,
+ enum fib_event_type event_type)
+{
+ struct in_device *in_dev = __in_dev_get_rtnl(fib_nh->nh_dev);
+ struct fib_nh_notifier_info info = {
+ .fib_nh = fib_nh,
+ };
+
+ switch (event_type) {
+ case FIB_EVENT_NH_ADD:
+ if (fib_nh->nh_flags & RTNH_F_DEAD)
+ break;
+ if (IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
+ fib_nh->nh_flags & RTNH_F_LINKDOWN)
+ break;
+ return call_fib_notifiers(dev_net(fib_nh->nh_dev), event_type,
+ &info.info);
+ case FIB_EVENT_NH_DEL:
+ if ((IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) &&
+ fib_nh->nh_flags & RTNH_F_LINKDOWN) ||
+ (fib_nh->nh_flags & RTNH_F_DEAD))
+ return call_fib_notifiers(dev_net(fib_nh->nh_dev),
+ event_type, &info.info);
+ default:
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
/* Event force Flags Description
* NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host
* NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
@@ -1396,6 +1426,8 @@ int fib_sync_down_dev(struct net_device *dev, unsigned
long event, bool force)
nexthop_nh->nh_flags |= RTNH_F_LINKDOWN;
break;
}
+ call_fib_nh_notifiers(nexthop_nh,
+ FIB_EVENT_NH_DEL);
dead++;
}
#ifdef CONFIG_IP_ROUTE_MULTIPATH
@@ -1550,6 +1582,7 @@ int fib_sync_up(struct net_device *dev, unsigned int
nh_flags)
continue;
alive++;
nexthop_nh->nh_flags &= ~nh_flags;
+ call_fib_nh_notifiers(nexthop_nh, FIB_EVENT_NH_ADD);
} endfor_nexthops(fi)
if (alive > 0) {
--
2.7.4
